Commit Graph

6545 Commits

Author SHA1 Message Date
Aleksa Sarai 6c6b5a39c4 btrfs: resume qgroup rescan on rw remount
Several distributions mount the "proper root" as ro during initrd and
then remount it as rw before pivot_root(2). Thus, if a rescan had been
aborted by a previous shutdown, the rescan would never be resumed.

This issue would manifest itself as several btrfs ioctl(2)s causing the
entire machine to hang when btrfs_qgroup_wait_for_completion was hit
(due to the fs_info->qgroup_rescan_running flag being set but the rescan
itself not being resumed). Notably, Docker's btrfs storage driver makes
regular use of BTRFS_QUOTA_CTL_DISABLE and BTRFS_IOC_QUOTA_RESCAN_WAIT
(causing this problem to be manifested on boot for some machines).

Cc: <stable@vger.kernel.org> # v3.11+
Cc: Jeff Mahoney <jeffm@suse.com>
Fixes: b382a324b6 ("Btrfs: fix qgroup rescan resume on mount")
Signed-off-by: Aleksa Sarai <asarai@suse.de>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Tested-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Edmund Nadolski 01747e92a9 btrfs: clean up extraneous computations in add_delayed_refs
Repeating the same computation in multiple places is not
necessary.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Edmund Nadolski 3ec4d3238a btrfs: allow backref search checks for shared extents
When called with a struct share_check, find_parent_nodes()
will detect a shared extent and immediately return with
BACKREF_SHARED_FOUND.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Edmund Nadolski 9dd14fd696 btrfs: add cond_resched() calls when resolving backrefs
Since backref resolution is CPU-intensive, the cond_resched calls
should help alleviate soft lockup occurences.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Jeff Mahoney 00142756e1 btrfs: backref, add tracepoints for prelim_ref insertion and merging
This patch adds a tracepoint event for prelim_ref insertion and
merging.  For each, the ref being inserted or merged and the count
of tree nodes is issued.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Jeff Mahoney 6c336b212b btrfs: add a node counter to each of the rbtrees
This patch adds counters to each of the rbtrees so that we can tell
how large they are growing for a given workload.  These counters
will be exported by tracepoints in the next patch.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:12:01 +02:00
Edmund Nadolski 86d5f99442 btrfs: convert prelimary reference tracking to use rbtrees
It's been known for a while that the use of multiple lists
that are periodically merged was an algorithmic problem within
btrfs.  There are several workloads that don't complete in any
reasonable amount of time (e.g. btrfs/130) and others that cause
soft lockups.

The solution is to use a set of rbtrees that do insertion merging
for both indirect and direct refs, with the former converting
refs into the latter.  The result is a btrfs/130 workload that
used to take several hours now takes about half of that. This
runtime still isn't acceptable and a future patch will address that
by moving the rbtrees higher in the stack so the lookups can be
shared across multiple calls to find_parent_nodes.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 16:11:55 +02:00
Edmund Nadolski f6954245d9 btrfs: remove ref_tree implementation from backref.c
Commit afce772e87 ("btrfs: fix check_shared for fiemap ioctl") added
the ref_tree code in backref.c to reduce backref searching for
shared extents under the FIEMAP ioctl. This code will not be
compatible with the upcoming rbtree changes for improved backref
searching, so this patch removes the ref_tree code.  The rbtree
changes will provide the equivalent functionality for FIEMAP.

The above commit also introduced transaction semantics around calls to
btrfs_check_shared() in order to accurately account for delayed refs.
This functionality needs to be retained, so a complete revert of the
above commit is not desirable. This patch therefore removes the
ref_tree portion of the commit as above, however it does not remove
the transaction portion.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Edmund Nadolski bb739cf08e btrfs: btrfs_check_shared should manage its own transaction
Commit afce772e87 ("btrfs: fix check_shared for fiemap ioctl") added
transaction semantics around calls to btrfs_check_shared() in order to
provide accurate accounting of delayed refs. The transaction management
should be done inside btrfs_check_shared(), so that callers do not need
to manage transactions individually.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Jeff Mahoney e0c476b128 btrfs: backref, cleanup __ namespace abuse
We typically use __ to indicate a helper routine that shouldn't be
called directly without understanding the proper context required
to do so.  We use static functions to indicate that a function is
private to a particular C file.  The backref code uses static
function and __ prefixes on nearly everything, which makes the code
difficult to read and establishes a pattern for future code that
shouldn't be followed.  This patch drops all the unnecessary prefixes.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Jeff Mahoney 4dae077a83 btrfs: backref, add unode_aux_to_inode_list helper
Replacing the double cast and ternary conditional with a helper makes
the code easier on the eyes.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Jeff Mahoney 73980becae btrfs: backref, constify some arguments
This constifies a few buffers used in the backref code.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Jeff Mahoney 9a35b63728 btrfs: constify tracepoint arguments
Tracepoint arguments are all read-only.  If we mark the arguments
as const, we're able to keep or convert those arguments to const
where appropriate.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Jeff Mahoney 1cbb1f454e btrfs: struct-funcs, constify readers
We have reader helpers for most of the on-disk structures that use
an extent_buffer and pointer as offset into the buffer that are
read-only.  We should mark them as const and, in turn, allow consumers
of these interfaces to mark the buffers const as well.

No impact on code, but serves as documentation that a buffer is intended
not to be modified.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Nikolay Borisov 23d1f73788 btrfs: remove unused sectorsize member
The sectorsize member of btrfs_block_group_cache is unused. So remove it, this
reduces the number of holes in the struct.

With patch:
/* size: 856, cachelines: 14, members: 40 */
/* sum members: 837, holes: 4, sum holes: 19 */
/* bit holes: 1, sum bit holes: 29 bits */
/* last cacheline: 24 bytes */

Without patch:
/* size: 864, cachelines: 14, members: 41 */
/* sum members: 841, holes: 5, sum holes: 23 */
/* bit holes: 1, sum bit holes: 29 bits */
/* last cacheline: 32 bytes */

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:53 +02:00
Nikolay Borisov f148ef4d3a btrfs: Be explicit about usage of min()
__btrfs_alloc_chunk contains code which boils down to:

    ndevs = min(ndevs, devs_max)

It's conditional upon devs_max not being 0. However, it cannot really be 0
since it's always set to either BTRFS_MAX_DEVS_SYS_CHUNK or
BTRFS_MAX_DEVS(fs_info->chunk_root). So eliminate the condition check and use
min explicitly. This has no functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:52 +02:00
Nikolay Borisov e5600fd6fc btrfs: Use explicit round_down call rather than open-coding it
No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:52 +02:00
Nikolay Borisov ebcc9301ea btrfs: convert while loop to list_for_each_entry
No functional changes, just make the loop a bit more readable

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-08-16 14:19:52 +02:00
Nick Terrell 5c1aab1dd5 btrfs: Add zstd support
Add zstd compression and decompression support to BtrFS. zstd at its
fastest level compresses almost as well as zlib, while offering much
faster compression and decompression, approaching lzo speeds.

I benchmarked btrfs with zstd compression against no compression, lzo
compression, and zlib compression. I benchmarked two scenarios. Copying
a set of files to btrfs, and then reading the files. Copying a tarball
to btrfs, extracting it to btrfs, and then reading the extracted files.
After every operation, I call `sync` and include the sync time.
Between every pair of operations I unmount and remount the filesystem
to avoid caching. The benchmark files can be found in the upstream
zstd source repository under
`contrib/linux-kernel/{btrfs-benchmark.sh,btrfs-extract-benchmark.sh}`
[1] [2].

I ran the benchmarks on a Ubuntu 14.04 VM with 2 cores and 4 GiB of RAM.
The VM is running on a MacBook Pro with a 3.1 GHz Intel Core i7 processor,
16 GB of RAM, and a SSD.

The first compression benchmark is copying 10 copies of the unzipped
Silesia corpus [3] into a BtrFS filesystem mounted with
`-o compress-force=Method`. The decompression benchmark times how long
it takes to `tar` all 10 copies into `/dev/null`. The compression ratio is
measured by comparing the output of `df` and `du`. See the benchmark file
[1] for details. I benchmarked multiple zstd compression levels, although
the patch uses zstd level 1.

| Method  | Ratio | Compression MB/s | Decompression speed |
|---------|-------|------------------|---------------------|
| None    |  0.99 |              504 |                 686 |
| lzo     |  1.66 |              398 |                 442 |
| zlib    |  2.58 |               65 |                 241 |
| zstd 1  |  2.57 |              260 |                 383 |
| zstd 3  |  2.71 |              174 |                 408 |
| zstd 6  |  2.87 |               70 |                 398 |
| zstd 9  |  2.92 |               43 |                 406 |
| zstd 12 |  2.93 |               21 |                 408 |
| zstd 15 |  3.01 |               11 |                 354 |

The next benchmark first copies `linux-4.11.6.tar` [4] to btrfs. Then it
measures the compression ratio, extracts the tar, and deletes the tar.
Then it measures the compression ratio again, and `tar`s the extracted
files into `/dev/null`. See the benchmark file [2] for details.

| Method | Tar Ratio | Extract Ratio | Copy (s) | Extract (s)| Read (s) |
|--------|-----------|---------------|----------|------------|----------|
| None   |      0.97 |          0.78 |    0.981 |      5.501 |    8.807 |
| lzo    |      2.06 |          1.38 |    1.631 |      8.458 |    8.585 |
| zlib   |      3.40 |          1.86 |    7.750 |     21.544 |   11.744 |
| zstd 1 |      3.57 |          1.85 |    2.579 |     11.479 |    9.389 |

[1] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-benchmark.sh
[2] https://github.com/facebook/zstd/blob/dev/contrib/linux-kernel/btrfs-extract-benchmark.sh
[3] http://sun.aei.polsl.pl/~sdeor/index.php?page=silesia
[4] https://cdn.kernel.org/pub/linux/kernel/v4.x/linux-4.11.6.tar.xz

zstd source repository: https://github.com/facebook/zstd

Signed-off-by: Nick Terrell <terrelln@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-08-15 09:02:09 -07:00
Linus Torvalds 0a2a1330d2 Merge branch 'for-4.13-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
 "Fixes addressing problems reported by users, and there's one more
  regression fix"

* 'for-4.13-part3' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: round down size diff when shrinking/growing device
  Btrfs: fix early ENOSPC due to delalloc
  btrfs: fix lockup in find_free_extent with read-only block groups
  Btrfs: fix dir item validation when replaying xattr deletes
2017-07-28 12:26:59 -07:00
Nikolay Borisov 0e4324a4c3 btrfs: round down size diff when shrinking/growing device
Further testing showed that the fix introduced in 7dfb8be11b ("btrfs:
Round down values which are written for total_bytes_size") was
insufficient and it could still lead to discrepancies between the
total_bytes in the super block and the device total bytes. So this patch
also ensures that the difference between old/new sizes when
shrinking/growing is also rounded down. This ensure that we won't be
subtracting/adding a non-sectorsize multiples to the superblock/device
total sizees.

Fixes: 7dfb8be11b ("btrfs: Round down values which are written for total_bytes_size")
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-24 16:05:00 +02:00
Omar Sandoval 17024ad0a0 Btrfs: fix early ENOSPC due to delalloc
If a lot of metadata is reserved for outstanding delayed allocations, we
rely on shrink_delalloc() to reclaim metadata space in order to fulfill
reservation tickets. However, shrink_delalloc() has a shortcut where if
it determines that space can be overcommitted, it will stop early. This
made sense before the ticketed enospc system, but now it means that
shrink_delalloc() will often not reclaim enough space to fulfill any
tickets, leading to an early ENOSPC. (Reservation tickets don't care
about being able to overcommit, they need every byte accounted for.)

Fix it by getting rid of the shortcut so that shrink_delalloc() reclaims
all of the metadata it is supposed to. This fixes early ENOSPCs we were
seeing when doing a btrfs receive to populate a new filesystem, as well
as early ENOSPCs Christoph saw when doing a big cp -r onto Btrfs.

Fixes: 957780eb27 ("Btrfs: introduce ticketed enospc infrastructure")
Tested-by: Christoph Anton Mitterer <mail@christoph.anton.mitterer.name>
Cc: stable@vger.kernel.org
Reviewed-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-24 16:04:26 +02:00
Jeff Mahoney 144439376b btrfs: fix lockup in find_free_extent with read-only block groups
If we have a block group that is all of the following:
1) uncached in memory
2) is read-only
3) has a disk cache state that indicates we need to recreate the cache

AND the file system has enough free space fragmentation such that the
request for an extent of a given size can't be honored;

AND have a single CPU core;

AND it's the block group with the highest starting offset such that
there are no opportunities (like reading from disk) for the loop to
yield the CPU;

We can end up with a lockup.

The root cause is simple.  Once we're in the position that we've read in
all of the other block groups directly and none of those block groups
can honor the request, there are no more opportunities to sleep.  We end
up trying to start a caching thread which never gets run if we only have
one core.  This *should* present as a hung task waiting on the caching
thread to make some progress, but it doesn't.  Instead, it degrades into
a busy loop because of the placement of the read-only check.

During the first pass through the loop, block_group->cached will be set
to BTRFS_CACHE_STARTED and have_caching_bg will be set.  Then we hit the
read-only check and short circuit the loop.  We're not yet in
LOOP_CACHING_WAIT, so we skip that loop back before going through the
loop again for other raid groups.

Then we move to LOOP_CACHING_WAIT state.

During the this pass through the loop, ->cached will still be
BTRFS_CACHE_STARTED, which means it's not cached, so we'll enter
cache_block_group, do a lot of nothing, and return, and also set
have_caching_bg again.  Then we hit the read-only check and short circuit
the loop.  The same thing happens as before except now we DO trigger
the LOOP_CACHING_WAIT && have_caching_bg check and loop back up to the
top.  We do this forever.

There are two fixes in this patch since they address the same underlying
bug.

The first is to add a cond_resched to the end of the loop to ensure
that the caching thread always has an opportunity to run.  This will
fix the soft lockup issue, but find_free_extent will still loop doing
nothing until the thread has completed.

The second is to move the read-only check to the top of the loop.  We're
never going to return an allocation within a read-only block group so
we may as well skip it early.  The check for ->cached == BTRFS_CACHE_ERROR
would cause the same problem except that BTRFS_CACHE_ERROR is considered
a "done" state and we won't re-set have_caching_bg again.

Many thanks to Stephan Kulow <coolo@suse.de> for his excellent help in
the testing process.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-24 16:04:02 +02:00
Filipe Manana e33bf72361 Btrfs: fix dir item validation when replaying xattr deletes
We were passing an incorrect slot number to the function that validates
directory items when we are replaying xattr deletes from a log tree. The
correct slot is stored at variable 'i' and not at 'path->slots[0]', so
the call to the validation function was only correct for the first
iteration of the loop, when 'i == path->slots[0]'.
After this fix, the fstest generic/066 passes again.

Fixes: 8ee8c2d62d ("btrfs: Verify dir_item in replay_xattr_deletes")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-19 20:38:16 +02:00
David Howells bc98a42c1f VFS: Convert sb->s_flags & MS_RDONLY to sb_rdonly(sb)
Firstly by applying the following with coccinelle's spatch:

	@@ expression SB; @@
	-SB->s_flags & MS_RDONLY
	+sb_rdonly(SB)

to effect the conversion to sb_rdonly(sb), then by applying:

	@@ expression A, SB; @@
	(
	-(!sb_rdonly(SB)) && A
	+!sb_rdonly(SB) && A
	|
	-A != (sb_rdonly(SB))
	+A != sb_rdonly(SB)
	|
	-A == (sb_rdonly(SB))
	+A == sb_rdonly(SB)
	|
	-!(sb_rdonly(SB))
	+!sb_rdonly(SB)
	|
	-A && (sb_rdonly(SB))
	+A && sb_rdonly(SB)
	|
	-A || (sb_rdonly(SB))
	+A || sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) != A
	+sb_rdonly(SB) != A
	|
	-(sb_rdonly(SB)) == A
	+sb_rdonly(SB) == A
	|
	-(sb_rdonly(SB)) && A
	+sb_rdonly(SB) && A
	|
	-(sb_rdonly(SB)) || A
	+sb_rdonly(SB) || A
	)

	@@ expression A, B, SB; @@
	(
	-(sb_rdonly(SB)) ? 1 : 0
	+sb_rdonly(SB)
	|
	-(sb_rdonly(SB)) ? A : B
	+sb_rdonly(SB) ? A : B
	)

to remove left over excess bracketage and finally by applying:

	@@ expression A, SB; @@
	(
	-(A & MS_RDONLY) != sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) != sb_rdonly(SB)
	|
	-(A & MS_RDONLY) == sb_rdonly(SB)
	+(bool)(A & MS_RDONLY) == sb_rdonly(SB)
	)

to make comparisons against the result of sb_rdonly() (which is a bool)
work correctly.

Signed-off-by: David Howells <dhowells@redhat.com>
2017-07-17 08:45:34 +01:00
Linus Torvalds 78dcf73421 Merge branch 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull ->s_options removal from Al Viro:
 "Preparations for fsmount/fsopen stuff (coming next cycle). Everything
  gets moved to explicit ->show_options(), killing ->s_options off +
  some cosmetic bits around fs/namespace.c and friends. Basically, the
  stuff needed to work with fsmount series with minimum of conflicts
  with other work.

  It's not strictly required for this merge window, but it would reduce
  the PITA during the coming cycle, so it would be nice to have those
  bits and pieces out of the way"

* 'work.mount' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  isofs: Fix isofs_show_options()
  VFS: Kill off s_options and helpers
  orangefs: Implement show_options
  9p: Implement show_options
  isofs: Implement show_options
  afs: Implement show_options
  affs: Implement show_options
  befs: Implement show_options
  spufs: Implement show_options
  bpf: Implement show_options
  ramfs: Implement show_options
  pstore: Implement show_options
  omfs: Implement show_options
  hugetlbfs: Implement show_options
  VFS: Don't use save/replace_mount_options if not using generic_show_options
  VFS: Provide empty name qstr
  VFS: Make get_filesystem() return the affected filesystem
  VFS: Clean up whitespace in fs/namespace.c and fs/super.c
  Provide a function to create a NUL-terminated string from unterminated data
2017-07-15 12:00:42 -07:00
Linus Torvalds bc243704fb Merge branch 'for-4.13-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fixes from David Sterba:
 "We've identified and fixed a silent corruption (introduced by code in
  the first pull), a fixup after the blk_status_t merge and two fixes to
  incremental send that Filipe has been hunting for some time"

* 'for-4.13-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix unexpected return value of bio_readpage_error
  btrfs: btrfs_create_repair_bio never fails, skip error handling
  btrfs: cloned bios must not be iterated by bio_for_each_segment_all
  Btrfs: fix write corruption due to bio cloning on raid5/6
  Btrfs: incremental send, fix invalid memory access
  Btrfs: incremental send, fix invalid path for link commands
2017-07-14 22:55:52 -07:00
Liu Bo c3cfb65630 Btrfs: fix unexpected return value of bio_readpage_error
With blk_status_t conversion (that are now present in master),
bio_readpage_error() may return 1 as now ->submit_bio_hook() may not set
%ret if it runs without problems.

This fixes that unexpected return value by changing
btrfs_check_repairable() to return a bool instead of updating %ret, and
patch is applicable to both codebases with and without blk_status_t.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-14 20:42:37 +02:00
David Sterba e8f5b395d5 btrfs: btrfs_create_repair_bio never fails, skip error handling
As the function uses the non-failing bio allocation, we can remove error
handling from the callers as well.

Signed-off-by: David Sterba <dsterba@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-14 20:42:08 +02:00
David Sterba c09abff87f btrfs: cloned bios must not be iterated by bio_for_each_segment_all
We've started using cloned bios more in 4.13, there are some specifics
regarding the iteration.  Filipe found [1] that the raid56 iterated a
cloned bio using bio_for_each_segment_all, which is incorrect. The
cloned bios have wrong bi_vcnt and this could lead to silent
corruptions.  This patch adds assertions to all remaining
bio_for_each_segment_all cases.

[1] https://patchwork.kernel.org/patch/9838535/

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-14 20:39:31 +02:00
Filipe Manana 6592e58c6b Btrfs: fix write corruption due to bio cloning on raid5/6
The recent changes to make bio cloning faster (added in the 4.13 merge
window) by using the bio_clone_fast() API introduced a regression on
raid5/6 modes, because cloned bios have an invalid bi_vcnt field
(therefore it can not be used) and the raid5/6 code uses the
bio_for_each_segment_all() API to iterate the segments of a bio, and this
API uses a bio's bi_vcnt field.

The issue is very simple to trigger by doing for example a direct IO write
against a raid5 or raid6 filesystem and then attempting to read what we
wrote before:

  $ mkfs.btrfs -m raid5 -d raid5 -f /dev/sdc /dev/sdd /dev/sde /dev/sdf
  $ mount /dev/sdc /mnt
  $ xfs_io -f -d -c "pwrite -S 0xab 0 1M" /mnt/foobar
  $ od -t x1 /mnt/foobar
  od: /mnt/foobar: read error: Input/output error

For that example, the following is also reported in dmesg/syslog:

  [18274.985557] btrfs_print_data_csum_error: 18 callbacks suppressed
  [18274.995277] BTRFS warning (device sdf): csum failed root 5 ino 257 off 0 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18274.997205] BTRFS warning (device sdf): csum failed root 5 ino 257 off 4096 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.025221] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.047422] BTRFS warning (device sdf): csum failed root 5 ino 257 off 12288 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.054818] BTRFS warning (device sdf): csum failed root 5 ino 257 off 4096 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.054834] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.054943] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 2
  [18275.055207] BTRFS warning (device sdf): csum failed root 5 ino 257 off 8192 csum 0x98f94189 expected csum 0x94374193 mirror 3
  [18275.055571] BTRFS warning (device sdf): csum failed root 5 ino 257 off 0 csum 0x98f94189 expected csum 0x94374193 mirror 1
  [18275.062171] BTRFS warning (device sdf): csum failed root 5 ino 257 off 12288 csum 0x98f94189 expected csum 0x94374193 mirror 1

A scrub will also fail correcting bad copies, mentioning the following in
dmesg/syslog:

  [18276.128696] scrub_handle_errored_block: 498 callbacks suppressed
  [18276.129617] BTRFS warning (device sdf): checksum error at logical 2186346496 on dev /dev/sde, sector 2116608, root 5, inode 257, offset 65536, length 4096, links $
  [18276.149235] btrfs_dev_stat_print_on_error: 498 callbacks suppressed
  [18276.157897] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
  [18276.206059] BTRFS warning (device sdf): checksum error at logical 2186477568 on dev /dev/sdd, sector 2116736, root 5, inode 257, offset 196608, length 4096, links$
  [18276.206059] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
  [18276.306552] BTRFS warning (device sdf): checksum error at logical 2186543104 on dev /dev/sdd, sector 2116864, root 5, inode 257, offset 262144, length 4096, links$
  [18276.319152] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 2, gen 0
  [18276.394316] BTRFS warning (device sdf): checksum error at logical 2186739712 on dev /dev/sdf, sector 2116992, root 5, inode 257, offset 458752, length 4096, links$
  [18276.396348] BTRFS error (device sdf): bdev /dev/sdf errs: wr 0, rd 0, flush 0, corrupt 1, gen 0
  [18276.434127] BTRFS warning (device sdf): checksum error at logical 2186870784 on dev /dev/sde, sector 2117120, root 5, inode 257, offset 589824, length 4096, links$
  [18276.434127] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 2, gen 0
  [18276.500504] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186477568 on dev /dev/sdd
  [18276.538400] BTRFS warning (device sdf): checksum error at logical 2186481664 on dev /dev/sdd, sector 2116744, root 5, inode 257, offset 200704, length 4096, links$
  [18276.540452] BTRFS error (device sdf): bdev /dev/sdd errs: wr 0, rd 0, flush 0, corrupt 3, gen 0
  [18276.542012] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186481664 on dev /dev/sdd
  [18276.585030] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186346496 on dev /dev/sde
  [18276.598306] BTRFS warning (device sdf): checksum error at logical 2186412032 on dev /dev/sde, sector 2116736, root 5, inode 257, offset 131072, length 4096, links$
  [18276.598310] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 3, gen 0
  [18276.598582] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186350592 on dev /dev/sde
  [18276.603455] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 4, gen 0
  [18276.638362] BTRFS warning (device sdf): checksum error at logical 2186354688 on dev /dev/sde, sector 2116624, root 5, inode 257, offset 73728, length 4096, links $
  [18276.640445] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 5, gen 0
  [18276.645942] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186354688 on dev /dev/sde
  [18276.657204] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186412032 on dev /dev/sde
  [18276.660563] BTRFS warning (device sdf): checksum error at logical 2186416128 on dev /dev/sde, sector 2116744, root 5, inode 257, offset 135168, length 4096, links$
  [18276.664609] BTRFS error (device sdf): bdev /dev/sde errs: wr 0, rd 0, flush 0, corrupt 6, gen 0
  [18276.664609] BTRFS error (device sdf): unable to fixup (regular) error at logical 2186358784 on dev /dev/sde

So fix this by using the bio_for_each_segment() API and setting before
the bio's bi_iter field to the value of the corresponding btrfs bio
container's saved iterator if we are processing a cloned bio in the
raid5/6 code (the same code processes both cloned and non-cloned bios).

This incorrect iteration of cloned bios was also causing some occasional
BUG_ONs when running fstest btrfs/064, which have a trace like the
following:

  [ 6674.416156] ------------[ cut here ]------------
  [ 6674.416157] kernel BUG at fs/btrfs/raid56.c:1897!
  [ 6674.416159] invalid opcode: 0000 [#1] PREEMPT SMP
  [ 6674.416160] Modules linked in: dm_flakey dm_mod dax ppdev tpm_tis parport_pc tpm_tis_core evdev tpm psmouse sg i2c_piix4 pcspkr parport i2c_core serio_raw button s
  [ 6674.416184] CPU: 3 PID: 19236 Comm: kworker/u32:10 Not tainted 4.12.0-rc6-btrfs-next-44+ #1
  [ 6674.416185] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
  [ 6674.416210] Workqueue: btrfs-endio btrfs_endio_helper [btrfs]
  [ 6674.416211] task: ffff880147f6c740 task.stack: ffffc90001fb8000
  [ 6674.416229] RIP: 0010:__raid_recover_end_io+0x1ac/0x370 [btrfs]
  [ 6674.416230] RSP: 0018:ffffc90001fbbb90 EFLAGS: 00010217
  [ 6674.416231] RAX: ffff8801ff4b4f00 RBX: 0000000000000002 RCX: 0000000000000001
  [ 6674.416232] RDX: ffff880099b045d8 RSI: ffffffff81a5f6e0 RDI: 0000000000000004
  [ 6674.416232] RBP: ffffc90001fbbbc8 R08: 0000000000000001 R09: 0000000000000001
  [ 6674.416233] R10: ffffc90001fbbac8 R11: 0000000000001000 R12: 0000000000000002
  [ 6674.416234] R13: ffff880099b045c0 R14: 0000000000000004 R15: ffff88012bff2000
  [ 6674.416235] FS:  0000000000000000(0000) GS:ffff88023f2c0000(0000) knlGS:0000000000000000
  [ 6674.416235] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 6674.416236] CR2: 00007f28cf282000 CR3: 00000001000c6000 CR4: 00000000000006e0
  [ 6674.416239] Call Trace:
  [ 6674.416259]  __raid56_parity_recover+0xfc/0x16e [btrfs]
  [ 6674.416276]  raid56_parity_recover+0x157/0x16b [btrfs]
  [ 6674.416293]  btrfs_map_bio+0xe0/0x259 [btrfs]
  [ 6674.416310]  btrfs_submit_bio_hook+0xbf/0x147 [btrfs]
  [ 6674.416327]  end_bio_extent_readpage+0x27b/0x4a0 [btrfs]
  [ 6674.416331]  bio_endio+0x17d/0x1b3
  [ 6674.416346]  end_workqueue_fn+0x3c/0x3f [btrfs]
  [ 6674.416362]  btrfs_scrubparity_helper+0x1aa/0x3b8 [btrfs]
  [ 6674.416379]  btrfs_endio_helper+0xe/0x10 [btrfs]
  [ 6674.416381]  process_one_work+0x276/0x4b6
  [ 6674.416384]  worker_thread+0x1ac/0x266
  [ 6674.416386]  ? rescuer_thread+0x278/0x278
  [ 6674.416387]  kthread+0x106/0x10e
  [ 6674.416389]  ? __list_del_entry+0x22/0x22
  [ 6674.416391]  ret_from_fork+0x27/0x40
  [ 6674.416395] Code: 44 89 e2 be 00 10 00 00 ff 15 b0 ab ef ff eb 72 4d 89 e8 89 d9 44 89 e2 be 00 10 00 00 ff 15 a3 ab ef ff eb 5d 41 83 fc ff 74 02 <0f> 0b 49 63 97
  [ 6674.416432] RIP: __raid_recover_end_io+0x1ac/0x370 [btrfs] RSP: ffffc90001fbbb90
  [ 6674.416434] ---[ end trace 74d56ebe7489dd6a ]---

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2017-07-13 19:26:01 +01:00
Linus Torvalds 6618a24ab2 Merge branch 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs fix from David Sterba:
 "This fixes a user-visible bug introduced by the nowait-aio patches
  merged in this cycle"

* 'nowait-aio-btrfs-fixup' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: nowait aio: Correct assignment of pos
2017-07-10 10:27:48 -07:00
Goldwyn Rodrigues ff0fa73247 btrfs: nowait aio: Correct assignment of pos
Assigning pos for usage early messes up in append mode, where the pos is
re-assigned in generic_write_checks(). Assign pos later to get the
correct position to write from iocb->ki_pos.

Since check_can_nocow also uses the value of pos, we shift
generic_write_checks() before check_can_nocow(). Checks with IOCB_DIRECT
are present in generic_write_checks(), so checking for IOCB_NOWAIT is
enough.

Also, put locking sequence in the fast path.

This fixes a user visible bug, as reported:

"apparently breaks several shell related features on my system.
In zsh history stopped working, because no new entries are added
anymore.
I fist noticed the issue when I tried to build mplayer. It uses a shell
script to generate a help_mp.h file:
[...]

Here is a simple testcase:

 % echo "foo" >> test
 % echo "foo" >> test
 % cat test
 foo
 %
"

Fixes: edf064e7c6 ("btrfs: nowait aio support")
CC: Jens Axboe <axboe@kernel.dk>
Reported-by: Markus Trippelsdorf <markus@trippelsdorf.de>
Link: https://lkml.kernel.org/r/20170704042306.GA274@x4
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-07-10 15:29:44 +02:00
Linus Torvalds 088737f44b Writeback error handling fixes (pile #2)
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Merge tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux

Pull Writeback error handling updates from Jeff Layton:
 "This pile represents the bulk of the writeback error handling fixes
  that I have for this cycle. Some of the earlier patches in this pile
  may look trivial but they are prerequisites for later patches in the
  series.

  The aim of this set is to improve how we track and report writeback
  errors to userland. Most applications that care about data integrity
  will periodically call fsync/fdatasync/msync to ensure that their
  writes have made it to the backing store.

  For a very long time, we have tracked writeback errors using two flags
  in the address_space: AS_EIO and AS_ENOSPC. Those flags are set when a
  writeback error occurs (via mapping_set_error) and are cleared as a
  side-effect of filemap_check_errors (as you noted yesterday). This
  model really sucks for userland.

  Only the first task to call fsync (or msync or fdatasync) will see the
  error. Any subsequent task calling fsync on a file will get back 0
  (unless another writeback error occurs in the interim). If I have
  several tasks writing to a file and calling fsync to ensure that their
  writes got stored, then I need to have them coordinate with one
  another. That's difficult enough, but in a world of containerized
  setups that coordination may even not be possible.

  But wait...it gets worse!

  The calls to filemap_check_errors can be buried pretty far down in the
  call stack, and there are internal callers of filemap_write_and_wait
  and the like that also end up clearing those errors. Many of those
  callers ignore the error return from that function or return it to
  userland at nonsensical times (e.g. truncate() or stat()). If I get
  back -EIO on a truncate, there is no reason to think that it was
  because some previous writeback failed, and a subsequent fsync() will
  (incorrectly) return 0.

  This pile aims to do three things:

   1) ensure that when a writeback error occurs that that error will be
      reported to userland on a subsequent fsync/fdatasync/msync call,
      regardless of what internal callers are doing

   2) report writeback errors on all file descriptions that were open at
      the time that the error occurred. This is a user-visible change,
      but I think most applications are written to assume this behavior
      anyway. Those that aren't are unlikely to be hurt by it.

   3) document what filesystems should do when there is a writeback
      error. Today, there is very little consistency between them, and a
      lot of cargo-cult copying. We need to make it very clear what
      filesystems should do in this situation.

  To achieve this, the set adds a new data type (errseq_t) and then
  builds new writeback error tracking infrastructure around that. Once
  all of that is in place, we change the filesystems to use the new
  infrastructure for reporting wb errors to userland.

  Note that this is just the initial foray into cleaning up this mess.
  There is a lot of work remaining here:

   1) convert the rest of the filesystems in a similar fashion. Once the
      initial set is in, then I think most other fs' will be fairly
      simple to convert. Hopefully most of those can in via individual
      filesystem trees.

   2) convert internal waiters on writeback to use errseq_t for
      detecting errors instead of relying on the AS_* flags. I have some
      draft patches for this for ext4, but they are not quite ready for
      prime time yet.

  This was a discussion topic this year at LSF/MM too. If you're
  interested in the gory details, LWN has some good articles about this:

      https://lwn.net/Articles/718734/
      https://lwn.net/Articles/724307/"

* tag 'for-linus-v4.13-2' of git://git.kernel.org/pub/scm/linux/kernel/git/jlayton/linux:
  btrfs: minimal conversion to errseq_t writeback error reporting on fsync
  xfs: minimal conversion to errseq_t writeback error reporting
  ext4: use errseq_t based error handling for reporting data writeback errors
  fs: convert __generic_file_fsync to use errseq_t based reporting
  block: convert to errseq_t based writeback error tracking
  dax: set errors in mapping when writeback fails
  Documentation: flesh out the section in vfs.txt on storing and reporting writeback errors
  mm: set both AS_EIO/AS_ENOSPC and errseq_t in mapping_set_error
  fs: new infrastructure for writeback error handling and reporting
  lib: add errseq_t type and infrastructure for handling it
  mm: don't TestClearPageError in __filemap_fdatawait_range
  mm: clear AS_EIO/AS_ENOSPC when writeback initiation fails
  jbd2: don't clear and reset errors after waiting on writeback
  buffer: set errors in mapping at the time that the error occurs
  fs: check for writeback errors after syncing out buffers in generic_file_fsync
  buffer: use mapping_set_error instead of setting the flag
  mm: fix mapping_set_error call in me_pagecache_dirty
2017-07-07 19:38:17 -07:00
Filipe Manana 24e52b11e0 Btrfs: incremental send, fix invalid memory access
When doing an incremental send, while processing an extent that changed
between the parent and send snapshots and that extent was an inline extent
in the parent snapshot, it's possible to access a memory region beyond
the end of leaf if the inline extent is very small and it is the first
item in a leaf.

An example scenario is described below.

The send snapshot has the following leaf:

 leaf 33865728 items 33 free space 773 generation 46 owner 5
 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
        (...)
        item 14 key (335 EXTENT_DATA 0) itemoff 3052 itemsize 53
                generation 36 type 1 (regular)
                extent data disk byte 12791808 nr 4096
                extent data offset 0 nr 4096 ram 4096
                extent compression 0 (none)
        item 15 key (335 EXTENT_DATA 8192) itemoff 2999 itemsize 53
                generation 36 type 1 (regular)
                extent data disk byte 138170368 nr 225280
                extent data offset 0 nr 225280 ram 225280
                extent compression 0 (none)
        (...)

And the parent snapshot has the following leaf:

 leaf 31272960 items 17 free space 17 generation 31 owner 5
 fs uuid ab7090d8-dafd-4fb9-9246-723b6d2e2fb7
 chunk uuid 2d16478c-c704-4ab9-b574-68bff2281b1f
        item 0 key (335 EXTENT_DATA 0) itemoff 3951 itemsize 44
                generation 31 type 0 (inline)
                inline extent data size 23 ram_bytes 613 compression 1 (zlib)
        (...)

When computing the send stream, it is detected that the extent of inode
335, at file offset 0, and at fs/btrfs/send.c:is_extent_unchanged() we
grab the leaf from the parent snapshot and access the inline extent item.
However, before jumping to the 'out' label, we access the 'offset' and
'disk_bytenr' fields of the extent item, which should not be done for
inline extents since the inlined data starts at the offset of the
'disk_bytenr' field and can be very small. For example accessing the
'offset' field of the file extent item results in the following trace:

[  599.705368] general protection fault: 0000 [#1] PREEMPT SMP
[  599.706296] Modules linked in: btrfs psmouse i2c_piix4 ppdev acpi_cpufreq serio_raw parport_pc i2c_core evdev tpm_tis tpm_tis_core sg pcspkr parport tpm button su$
[  599.709340] CPU: 7 PID: 5283 Comm: btrfs Not tainted 4.10.0-rc8-btrfs-next-46+ #1
[  599.709340] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  599.709340] task: ffff88023eedd040 task.stack: ffffc90006658000
[  599.709340] RIP: 0010:read_extent_buffer+0xdb/0xf4 [btrfs]
[  599.709340] RSP: 0018:ffffc9000665ba00 EFLAGS: 00010286
[  599.709340] RAX: db73880000000000 RBX: 0000000000000000 RCX: 0000000000000001
[  599.709340] RDX: ffffc9000665ba60 RSI: db73880000000000 RDI: ffffc9000665ba5f
[  599.709340] RBP: ffffc9000665ba30 R08: 0000000000000001 R09: ffff88020dc5e098
[  599.709340] R10: 0000000000001000 R11: 0000160000000000 R12: 6db6db6db6db6db7
[  599.709340] R13: ffff880000000000 R14: 0000000000000000 R15: ffff88020dc5e088
[  599.709340] FS:  00007f519555a8c0(0000) GS:ffff88023f3c0000(0000) knlGS:0000000000000000
[  599.709340] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  599.709340] CR2: 00007f1411afd000 CR3: 0000000235f8e000 CR4: 00000000000006e0
[  599.709340] Call Trace:
[  599.709340]  btrfs_get_token_64+0x93/0xce [btrfs]
[  599.709340]  ? printk+0x48/0x50
[  599.709340]  btrfs_get_64+0xb/0xd [btrfs]
[  599.709340]  process_extent+0x3a1/0x1106 [btrfs]
[  599.709340]  ? btree_read_extent_buffer_pages+0x5/0xef [btrfs]
[  599.709340]  changed_cb+0xb03/0xb3d [btrfs]
[  599.709340]  ? btrfs_get_token_32+0x7a/0xcc [btrfs]
[  599.709340]  btrfs_compare_trees+0x432/0x53d [btrfs]
[  599.709340]  ? process_extent+0x1106/0x1106 [btrfs]
[  599.709340]  btrfs_ioctl_send+0x960/0xe26 [btrfs]
[  599.709340]  btrfs_ioctl+0x181b/0x1fed [btrfs]
[  599.709340]  ? trace_hardirqs_on_caller+0x150/0x1ac
[  599.709340]  vfs_ioctl+0x21/0x38
[  599.709340]  ? vfs_ioctl+0x21/0x38
[  599.709340]  do_vfs_ioctl+0x611/0x645
[  599.709340]  ? rcu_read_unlock+0x5b/0x5d
[  599.709340]  ? __fget+0x6d/0x79
[  599.709340]  SyS_ioctl+0x57/0x7b
[  599.709340]  entry_SYSCALL_64_fastpath+0x18/0xad
[  599.709340] RIP: 0033:0x7f51945eec47
[  599.709340] RSP: 002b:00007ffc21c13e98 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[  599.709340] RAX: ffffffffffffffda RBX: ffffffff81096459 RCX: 00007f51945eec47
[  599.709340] RDX: 00007ffc21c13f20 RSI: 0000000040489426 RDI: 0000000000000004
[  599.709340] RBP: ffffc9000665bf98 R08: 00007f519450d700 R09: 00007f519450d700
[  599.709340] R10: 00007f519450d9d0 R11: 0000000000000202 R12: 0000000000000046
[  599.709340] R13: ffffc9000665bf78 R14: 0000000000000000 R15: 00007f5195574040
[  599.709340]  ? trace_hardirqs_off_caller+0x43/0xb1
[  599.709340] Code: 29 f0 49 39 d8 4c 0f 47 c3 49 03 81 58 01 00 00 44 89 c1 4c 01 c2 4c 29 c3 48 c1 f8 03 49 0f af c4 48 c1 e0 0c 4c 01 e8 48 01 c6 <f3> a4 31 f6 4$
[  599.709340] RIP: read_extent_buffer+0xdb/0xf4 [btrfs] RSP: ffffc9000665ba00
[  599.762057] ---[ end trace fe00d7af61b9f49e ]---

This is because the 'offset' field starts at an offset of 37 bytes
(offsetof(struct btrfs_file_extent_item, offset)), has a length of 8
bytes and therefore attemping to read it causes a 1 byte access beyond
the end of the leaf, as the first item's content in a leaf is located
at the tail of the leaf, the item size is 44 bytes and the offset of
that field plus its length (37 + 8 = 45) goes beyond the item's size
by 1 byte.

So fix this by accessing the 'offset' and 'disk_bytenr' fields after
jumping to the 'out' label if we are processing an inline extent. We
move the reading operation of the 'disk_bytenr' field too because we
have the same problem as for the 'offset' field explained above when
the inline data is less then 8 bytes. The access to the 'generation'
field is also moved but just for the sake of grouping access to all
the fields.

Fixes: e1cbfd7bf6 ("Btrfs: send, fix file hole not being preserved due to inline extent")
Cc: <stable@vger.kernel.org>  # v4.12+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-07-06 23:02:30 +01:00
Filipe Manana f59627810e Btrfs: incremental send, fix invalid path for link commands
In some scenarios an incremental send stream can contain link commands
with an invalid target path. Such scenarios happen after moving some
directory inode A, renaming a regular file inode B into the old name of
inode A and finally creating a new hard link for inode B at directory
inode A.

Consider the following example scenario where this issue happens.

Parent snapshot:

  .                                                      (ino 256)
  |
  |--- dir1/                                             (ino 257)
  |      |--- dir2/                                      (ino 258)
  |             |--- dir3/                               (ino 259)
  |                   |--- file1                         (ino 261)
  |                   |--- dir4/                         (ino 262)
  |
  |--- dir5/                                             (ino 260)

Send snapshot:

  .                                                      (ino 256)
  |
  |--- dir1/                                             (ino 257)
         |--- dir2/                                      (ino 258)
         |      |--- dir3/                               (ino 259)
         |            |--- dir4                          (ino 261)
         |
         |--- dir6/                                      (ino 263)
                |--- dir44/                              (ino 262)
                       |--- file11                       (ino 261)
                       |--- dir55/                       (ino 260)

When attempting to apply the corresponding incremental send stream, a
link command contains an invalid target path which makes the receiver
fail. The following is the verbose output of the btrfs receive command:

  receiving snapshot mysnap2 uuid=90076fe6-5ba6-e64a-9321-9279670ed16b (...)
  utimes
  utimes dir1
  utimes dir1/dir2/dir3
  utimes
  rename dir1/dir2/dir3/dir4 -> o262-7-0
  link dir1/dir2/dir3/dir4 -> dir1/dir2/dir3/file1
  link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1
  ERROR: link dir1/dir2/dir3/dir4/file11 -> dir1/dir2/dir3/file1 failed: Not a directory

The following steps happen during the computation of the incremental send
stream the lead to this issue:

1) When processing inode 261, we orphanize inode 262 due to a name/location
   collision with one of the new hard links for inode 261 (created in the
   second step below).

2) We create one of the 2 new hard links for inode 261, the one whose
   location is at "dir1/dir2/dir3/dir4".

3) We then attempt to create the other new hard link for inode 261, which
   has inode 262 as its parent directory. Because the path for this new
   hard link was computed before we started processing the new references
   (hard links), it reflects the old name/location of inode 262, that is,
   it does not account for the orphanization step that happened when
   we started processing the new references for inode 261, whence it is
   no longer valid, causing the receiver to fail.

So fix this issue by recomputing the full path of new references if we
ended up orphanizing other inodes which are directories.

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-07-06 23:02:18 +01:00
Linus Torvalds a4c20b9a57 Merge branch 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu
Pull percpu updates from Tejun Heo:
 "These are the percpu changes for the v4.13-rc1 merge window. There are
  a couple visibility related changes - tracepoints and allocator stats
  through debugfs, along with __ro_after_init markings and a cosmetic
  rename in percpu_counter.

  Please note that the simple O(#elements_in_the_chunk) area allocator
  used by percpu allocator is again showing scalability issues,
  primarily with bpf allocating and freeing large number of counters.
  Dennis is working on the replacement allocator and the percpu
  allocator will be seeing increased churns in the coming cycles"

* 'for-4.13' of git://git.kernel.org/pub/scm/linux/kernel/git/tj/percpu:
  percpu: fix static checker warnings in pcpu_destroy_chunk
  percpu: fix early calls for spinlock in pcpu_stats
  percpu: resolve err may not be initialized in pcpu_alloc
  percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch
  percpu: add tracepoint support for percpu memory
  percpu: expose statistics about percpu memory via debugfs
  percpu: migrate percpu data structures to internal header
  percpu: add missing lockdep_assert_held to func pcpu_free_area
  mark most percpu globals as __ro_after_init
2017-07-06 08:59:41 -07:00
Jeff Layton 333427a505 btrfs: minimal conversion to errseq_t writeback error reporting on fsync
Just check and advance the errseq_t in the file before returning, and
use an errseq_t based check for writeback errors.

Other internal callers of filemap_* functions are left as-is.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
2017-07-06 07:02:31 -04:00
David Howells c3d98ea082 VFS: Don't use save/replace_mount_options if not using generic_show_options
btrfs, debugfs, reiserfs and tracefs call save_mount_options() and reiserfs
calls replace_mount_options(), but they then implement their own
->show_options() methods and don't touch s_options, rendering the saved
options unnecessary.  I'm trying to eliminate s_options to make it easier
to implement a context-based mount where the mount options can be passed
individually over a file descriptor.

Remove the calls to save/replace_mount_options() call in these cases.

Signed-off-by: David Howells <dhowells@redhat.com>
cc: Chris Mason <clm@fb.com>
cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
cc: Steven Rostedt <rostedt@goodmis.org>
cc: linux-btrfs@vger.kernel.org
cc: reiserfs-devel@vger.kernel.org
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-07-06 03:31:46 -04:00
Linus Torvalds 8c27cb3566 Merge branch 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux
Pull btrfs updates from David Sterba:
 "The core updates improve error handling (mostly related to bios), with
  the usual incremental work on the GFP_NOFS (mis)use removal,
  refactoring or cleanups. Except the two top patches, all have been in
  for-next for an extensive amount of time.

  User visible changes:

   - statx support

   - quota override tunable

   - improved compression thresholds

   - obsoleted mount option alloc_start

  Core updates:

   - bio-related updates:
       - faster bio cloning
       - no allocation failures
       - preallocated flush bios

   - more kvzalloc use, memalloc_nofs protections, GFP_NOFS updates

   - prep work for btree_inode removal

   - dir-item validation

   - qgoup fixes and updates

   - cleanups:
       - removed unused struct members, unused code, refactoring
       - argument refactoring (fs_info/root, caller -> callee sink)
       - SEARCH_TREE ioctl docs"

* 'for-4.13-part1' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux: (115 commits)
  btrfs: Remove false alert when fiemap range is smaller than on-disk extent
  btrfs: Don't clear SGID when inheriting ACLs
  btrfs: fix integer overflow in calc_reclaim_items_nr
  btrfs: scrub: fix target device intialization while setting up scrub context
  btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges
  btrfs: qgroup: Introduce extent changeset for qgroup reserve functions
  btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled
  btrfs: qgroup: Return actually freed bytes for qgroup release or free data
  btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents function
  btrfs: qgroup: Add quick exit for non-fs extents
  Btrfs: rework delayed ref total_bytes_pinned accounting
  Btrfs: return old and new total ref mods when adding delayed refs
  Btrfs: always account pinned bytes when dropping a tree block ref
  Btrfs: update total_bytes_pinned when pinning down extents
  Btrfs: make BUG_ON() in add_pinned_bytes() an ASSERT()
  Btrfs: make add_pinned_bytes() take an s64 num_bytes instead of u64
  btrfs: fix validation of XATTR_ITEM dir items
  btrfs: Verify dir_item in iterate_object_props
  btrfs: Check name_len before in btrfs_del_root_ref
  btrfs: Check name_len before reading btrfs_get_name
  ...
2017-07-05 16:41:23 -07:00
Linus Torvalds c6b1e36c8f Merge branch 'for-4.13/block' of git://git.kernel.dk/linux-block
Pull core block/IO updates from Jens Axboe:
 "This is the main pull request for the block layer for 4.13. Not a huge
  round in terms of features, but there's a lot of churn related to some
  core cleanups.

  Note this depends on the UUID tree pull request, that Christoph
  already sent out.

  This pull request contains:

   - A series from Christoph, unifying the error/stats codes in the
     block layer. We now use blk_status_t everywhere, instead of using
     different schemes for different places.

   - Also from Christoph, some cleanups around request allocation and IO
     scheduler interactions in blk-mq.

   - And yet another series from Christoph, cleaning up how we handle
     and do bounce buffering in the block layer.

   - A blk-mq debugfs series from Bart, further improving on the support
     we have for exporting internal information to aid debugging IO
     hangs or stalls.

   - Also from Bart, a series that cleans up the request initialization
     differences across types of devices.

   - A series from Goldwyn Rodrigues, allowing the block layer to return
     failure if we will block and the user asked for non-blocking.

   - Patch from Hannes for supporting setting loop devices block size to
     that of the underlying device.

   - Two series of patches from Javier, fixing various issues with
     lightnvm, particular around pblk.

   - A series from me, adding support for write hints. This comes with
     NVMe support as well, so applications can help guide data placement
     on flash to improve performance, latencies, and write
     amplification.

   - A series from Ming, improving and hardening blk-mq support for
     stopping/starting and quiescing hardware queues.

   - Two pull requests for NVMe updates. Nothing major on the feature
     side, but lots of cleanups and bug fixes. From the usual crew.

   - A series from Neil Brown, greatly improving the bio rescue set
     support. Most notably, this kills the bio rescue work queues, if we
     don't really need them.

   - Lots of other little bug fixes that are all over the place"

* 'for-4.13/block' of git://git.kernel.dk/linux-block: (217 commits)
  lightnvm: pblk: set line bitmap check under debug
  lightnvm: pblk: verify that cache read is still valid
  lightnvm: pblk: add initialization check
  lightnvm: pblk: remove target using async. I/Os
  lightnvm: pblk: use vmalloc for GC data buffer
  lightnvm: pblk: use right metadata buffer for recovery
  lightnvm: pblk: schedule if data is not ready
  lightnvm: pblk: remove unused return variable
  lightnvm: pblk: fix double-free on pblk init
  lightnvm: pblk: fix bad le64 assignations
  nvme: Makefile: remove dead build rule
  blk-mq: map all HWQ also in hyperthreaded system
  nvmet-rdma: register ib_client to not deadlock in device removal
  nvme_fc: fix error recovery on link down.
  nvmet_fc: fix crashes on bad opcodes
  nvme_fc: Fix crash when nvme controller connection fails.
  nvme_fc: replace ioabort msleep loop with completion
  nvme_fc: fix double calls to nvme_cleanup_cmd()
  nvme-fabrics: verify that a controller returns the correct NQN
  nvme: simplify nvme_dev_attrs_are_visible
  ...
2017-07-03 10:34:51 -07:00
Qu Wenruo 848c23b78f btrfs: Remove false alert when fiemap range is smaller than on-disk extent
Commit 4751832da9 ("btrfs: fiemap: Cache and merge fiemap extent before
submit it to user") introduced a warning to catch unemitted cached
fiemap extent.

However such warning doesn't take the following case into consideration:

0			4K			8K
|<---- fiemap range --->|
|<----------- On-disk extent ------------------>|

In this case, the whole 0~8K is cached, and since it's larger than
fiemap range, it break the fiemap extent emit loop.
This leaves the fiemap extent cached but not emitted, and caught by the
final fiemap extent sanity check, causing kernel warning.

This patch removes the kernel warning and renames the sanity check to
emit_last_fiemap_cache() since it's possible and valid to have cached
fiemap extent.

Reported-by: David Sterba <dsterba@suse.cz>
Reported-by: Adam Borowski <kilobyte@angband.pl>
Fixes: 4751832da9 ("btrfs: fiemap: Cache and merge fiemap extent ...")
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:25:20 +02:00
Jan Kara b7f8a09f80 btrfs: Don't clear SGID when inheriting ACLs
When new directory 'DIR1' is created in a directory 'DIR0' with SGID bit
set, DIR1 is expected to have SGID bit set (and owning group equal to
the owning group of 'DIR0'). However when 'DIR0' also has some default
ACLs that 'DIR1' inherits, setting these ACLs will result in SGID bit on
'DIR1' to get cleared if user is not member of the owning group.

Fix the problem by moving posix_acl_update_mode() out of
__btrfs_set_acl() into btrfs_set_acl(). That way the function will not be
called when inheriting ACLs which is what we want as it prevents SGID
bit clearing and the mode has been properly set by posix_acl_create()
anyway.

Fixes: 073931017b
CC: stable@vger.kernel.org
CC: linux-btrfs@vger.kernel.org
CC: David Sterba <dsterba@suse.com>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:24:59 +02:00
Chris Mason 6374e57ad8 btrfs: fix integer overflow in calc_reclaim_items_nr
Dave Jones hit a WARN_ON(nr < 0) in btrfs_wait_ordered_roots() with
v4.12-rc6.  This was because commit 70e7af244 made it possible for
calc_reclaim_items_nr() to return a negative number.  It's not really a
bug in that commit, it just didn't go far enough down the stack to find
all the possible 64->32 bit overflows.

This switches calc_reclaim_items_nr() to return a u64 and changes everyone
that uses the results of that math to u64 as well.

Reported-by: Dave Jones <davej@codemonkey.org.uk>
Fixes: 70e7af2 ("Btrfs: fix delalloc accounting leak caused by u32 overflow")
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
David Sterba ded56184a5 btrfs: scrub: fix target device intialization while setting up scrub context
The commit "btrfs: scrub: inline helper scrub_setup_wr_ctx" inlined a
helper but wrongly sets up the target device. Incidentally there's a
local variable with the same name as a parameter in the previous
function, so this got caught during runtime as crash in test btrfs/027.

Reported-by: Chris Mason <clm@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo bc42bda223 btrfs: qgroup: Fix qgroup reserved space underflow by only freeing reserved ranges
[BUG]
For the following case, btrfs can underflow qgroup reserved space
at an error path:
(Page size 4K, function name without "btrfs_" prefix)

         Task A                  |             Task B
----------------------------------------------------------------------
Buffered_write [0, 2K)           |
|- check_data_free_space()       |
|  |- qgroup_reserve_data()      |
|     Range aligned to page      |
|     range [0, 4K)          <<< |
|     4K bytes reserved      <<< |
|- copy pages to page cache      |
                                 | Buffered_write [2K, 4K)
                                 | |- check_data_free_space()
                                 | |  |- qgroup_reserved_data()
                                 | |     Range alinged to page
                                 | |     range [0, 4K)
                                 | |     Already reserved by A <<<
                                 | |     0 bytes reserved      <<<
                                 | |- delalloc_reserve_metadata()
                                 | |  And it *FAILED* (Maybe EQUOTA)
                                 | |- free_reserved_data_space()
                                      |- qgroup_free_data()
                                         Range aligned to page range
                                         [0, 4K)
                                         Freeing 4K
(Special thanks to Chandan for the detailed report and analyse)

[CAUSE]
Above Task B is freeing reserved data range [0, 4K) which is actually
reserved by Task A.

And at writeback time, page dirty by Task A will go through writeback
routine, which will free 4K reserved data space at file extent insert
time, causing the qgroup underflow.

[FIX]
For btrfs_qgroup_free_data(), add @reserved parameter to only free
data ranges reserved by previous btrfs_qgroup_reserve_data().
So in above case, Task B will try to free 0 byte, so no underflow.

Reported-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Tested-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo 364ecf3651 btrfs: qgroup: Introduce extent changeset for qgroup reserve functions
Introduce a new parameter, struct extent_changeset for
btrfs_qgroup_reserved_data() and its callers.

Such extent_changeset was used in btrfs_qgroup_reserve_data() to record
which range it reserved in current reserve, so it can free it in error
paths.

The reason we need to export it to callers is, at buffered write error
path, without knowing what exactly which range we reserved in current
allocation, we can free space which is not reserved by us.

This will lead to qgroup reserved space underflow.

Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo a12b877b55 btrfs: qgroup: Fix qgroup reserved space underflow caused by buffered write and quotas being enabled
[BUG]
Under the following case, we can underflow qgroup reserved space.

            Task A                |            Task B
---------------------------------------------------------------
 Quota disabled                   |
 Buffered write                   |
 |- btrfs_check_data_free_space() |
 |  *NO* qgroup space is reserved |
 |  since quota is *DISABLED*     |
 |- All pages are copied to page  |
    cache                         |
                                  | Enable quota
                                  | Quota scan finished
                                  |
                                  | Sync_fs
                                  | |- run_delalloc_range
                                  | |- Write pages
                                  | |- btrfs_finish_ordered_io
                                  |    |- insert_reserved_file_extent
                                  |       |- btrfs_qgroup_release_data()
                                  |          Since no qgroup space is
                                             reserved in Task A, we
                                             underflow qgroup reserved
                                             space
This can be detected by fstest btrfs/104.

[CAUSE]
In insert_reserved_file_extent() we tell qgroup to release the @ram_bytes
size of qgroup reserved_space in all cases.
And btrfs_qgroup_release_data() will check if quotas are enabled.

However in the above case, the buffered write happens before quota is
enabled, so we don't have the reserved space for that range.

[FIX]
In insert_reserved_file_extent(), we tell qgroup to release the acctual
byte number it released.
In the above case, since we don't have the reserved space, we tell
qgroups to release 0 byte, so the problem can be fixed.

And thanks to the @reserved parameter introduced by the qgroup rework,
and previous patch to return released bytes, the fix can be as small as
10 lines.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ changelog updates ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo 7bc329c183 btrfs: qgroup: Return actually freed bytes for qgroup release or free data
btrfs_qgroup_release/free_data() only returns 0 or a negative error
number (ENOMEM is the only possible error).

This is normally good enough, but sometimes we need the exact byte
count it freed/released.

Change it to return actually released/freed bytenr number instead of 0
for success.
And slightly modify related extent_changeset structure, since in btrfs
one no-hole data extent won't be larger than 128M, so "unsigned int"
is large enough for the use case.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo d1b8b94a2b btrfs: qgroup: Cleanup btrfs_qgroup_prepare_account_extents function
Quite a lot of qgroup corruption happens due to wrong time of calling
btrfs_qgroup_prepare_account_extents().

Since the safest time is to call it just before
btrfs_qgroup_account_extents(), there is no need to separate these 2
functions.

Merging them will make code cleaner and less bug prone.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ changelog and comment adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Qu Wenruo 5edfd9fdc6 btrfs: qgroup: Add quick exit for non-fs extents
Modify btrfs_qgroup_account_extent() to exit quicker for non-fs extents.

The quick exit condition is:
1) The extent belongs to a non-fs tree
   Only fs-tree extents can affect qgroup numbers and is the only case
   where extent can be shared between different trees.

   Although strictly speaking extent in data-reloc or tree-reloc tree
   can be shared, data/tree-reloc root won't appear in the result of
   btrfs_find_all_roots(), so we can ignore such case.

   So we can check the first root in old_roots/new_roots ulist.
   - if we find the 1st root is a not a fs/subvol root, then we can skip
     the extent
   - if we find the 1st root is a fs/subvol root, then we must continue
     calculation

OR

2) both 'nr_old_roots' and 'nr_new_roots' are 0
   This means either such extent got allocated then freed in current
   transaction or it's a new reloc tree extent, whose nr_new_roots is 0.
   Either way it won't affect qgroup accounting and can be skipped
   safely.

Such quick exit can make trace output more quite and less confusing:
(example with fs uuid and time stamp removed)

Before:
------
add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0
btrfs_qgroup_account_extent: bytenr=29556736 num_bytes=16384 nr_old_roots=0 nr_new_roots=1
------
Extent tree block will trigger btrfs_qgroup_account_extent() trace point
while no qgroup number is changed, as extent tree won't affect qgroup
accounting.

After:
------
add_delayed_tree_ref: bytenr=29556736 num_bytes=16384 action=ADD_DELAYED_REF parent=0(-) ref_root=2(EXTENT_TREE) level=0 type=TREE_BLOCK_REF seq=0
------
Now such unrelated extent won't trigger btrfs_qgroup_account_extent()
trace point, making the trace less noisy.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
[ changelog and comment adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:02 +02:00
Omar Sandoval d7eae3403f Btrfs: rework delayed ref total_bytes_pinned accounting
The total_bytes_pinned counter is completely broken when accounting
delayed refs:

- If two drops for the same extent are merged, we will decrement
  total_bytes_pinned twice but only increment it once.
- If an add is merged into a drop or vice versa, we will decrement the
  total_bytes_pinned counter but never increment it.
- If multiple references to an extent are dropped, we will account it
  multiple times, potentially vastly over-estimating the number of bytes
  that will be freed by a commit and doing unnecessary work when we're
  close to ENOSPC.

The last issue is relatively minor, but the first two make the
total_bytes_pinned counter leak or underflow very often. These
accounting issues were introduced in b150a4f10d ("Btrfs: use a percpu
to keep track of possibly pinned bytes"), but they were papered over by
zeroing out the counter on every commit until d288db5dc0 ("Btrfs: fix
race of using total_bytes_pinned").

We need to make sure that an extent is accounted as pinned exactly once
if and only if we will drop references to it when when the transaction
is committed. Ideally we would only add to total_bytes_pinned when the
*last* reference is dropped, but this information isn't readily
available for data extents. Again, this over-estimation can lead to
extra commits when we're close to ENOSPC, but it's not as bad as before.

The fix implemented here is to increment total_bytes_pinned when the
total refmod count for an extent goes negative and decrement it if the
refmod count goes back to non-negative or after we've run all of the
delayed refs for that extent.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
Omar Sandoval 7be07912b3 Btrfs: return old and new total ref mods when adding delayed refs
We need this to decide when to account pinned bytes.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
Omar Sandoval 0a16c7d7ae Btrfs: always account pinned bytes when dropping a tree block ref
Currently, we only increment total_bytes_pinned in
btrfs_free_tree_block() when dropping the last reference on the block.
However, when the delayed ref is run later, we will decrement
total_bytes_pinned regardless of whether it was the last reference or
not. This causes the counter to underflow when the reference we dropped
was not the last reference. Fix it by incrementing the counter
unconditionally, which is what btrfs_free_extent() does. This makes
total_bytes_pinned an overestimate when references to shared extents are
dropped, but in the worst case this will just make us try to commit the
transaction to try to free up space and find we didn't free enough.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
Omar Sandoval 4da8b76d34 Btrfs: update total_bytes_pinned when pinning down extents
The extents marked in pin_down_extent() will be unpinned later in
unpin_extent_range(), which decrements total_bytes_pinned.
pin_down_extent() must increment the counter to avoid underflowing it.
Also adjust btrfs_free_tree_block() to avoid accounting for the same
extent twice.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
Omar Sandoval 55e8196a57 Btrfs: make BUG_ON() in add_pinned_bytes() an ASSERT()
The value of flags is one of DATA/METADATA/SYSTEM, they must exist at
when add_pinned_bytes is called.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ added changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
Omar Sandoval 0d9f824df3 Btrfs: make add_pinned_bytes() take an s64 num_bytes instead of u64
There are a few places where we pass in a negative num_bytes, so make it
signed for clarity. Also move it up in the file since later patches will
need it there.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Tested-by: Holger Hoffstätte <holger@applied-asynchrony.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:17:01 +02:00
David Sterba 1164a9fb9c btrfs: fix validation of XATTR_ITEM dir items
The XATTR_ITEM is a type of a directory item so we use the common
validator helper. Unlike other dir items, it can have data. The way the
name len validation is currently implemented does not reflect that. We'd
have to adjust by the data_len when comparing the read and item limits.

However, this will not work for multi-item xattr dir items.

Example from tree dump of generic/337:

        item 7 key (257 XATTR_ITEM 751495445) itemoff 15667 itemsize 147
                location key (0 UNKNOWN.0 0) type XATTR
                transid 8 data_len 3 name_len 11
                name: user.foobar
                data 123
                location key (0 UNKNOWN.0 0) type XATTR
                transid 8 data_len 6 name_len 13
                name: user.WvG1c1Td
                data qwerty
                location key (0 UNKNOWN.0 0) type XATTR
                transid 8 data_len 5 name_len 19
                name: user.J3__T_Km3dVsW_
                data hello

At the point of btrfs_is_name_len_valid call we don't have access to the
data_len value of the 2nd and 3rd sub-item. So simple btrfs_dir_data_len(leaf,
di) would always return 3, although we'd need to get 6 and 5 respectively to
get the claculations right. (read_end + name_len + data_len vs item_end)

We'd have to also pass data_len externally, which is not point of the
name validation. The last check is supposed to test if there's at least
one dir item space after the one we're processing. I don't think this is
particularly useful, validation of the next item would catch that too.
So the check is removed and we don't weaken the validation. Now tests
btrfs/048, btrfs/053, generic/273 and generic/337 pass.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-29 20:06:11 +02:00
Jens Axboe e6959b9350 btrfs: add support for passing in write hints for buffered writes
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Signed-off-by: Chris Mason <clm@fb.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-27 12:05:52 -06:00
Su Yue fbc326159a btrfs: Verify dir_item in iterate_object_props
Call verify_dir_item before memcmp_extent_buffer reading name from
dir_item.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 64c7b01446 btrfs: Check name_len before in btrfs_del_root_ref
btrfs_del_root_ref calls btrfs_search_slot and reads name from root_ref.
Call btrfs_is_name_len_valid before memcmp.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 488d7c4566 btrfs: Check name_len before reading btrfs_get_name
In btrfs_get_name, there's btrfs_search_slot and reads name from
inode_ref/root_ref.

Call btrfs_is_name_len_valid in btrfs_get_name.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 59b0a7f2c7 btrfs: Check name_len before read in iterate_dir_item
Since iterate_dir_item checks name_len in its own way,
so use btrfs_is_name_len_valid not 'verify_dir_item' to make more strict
name_len check.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ switched ENAMETOOLONG to EIO ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 3c1d418448 btrfs: Check name_len in btrfs_check_ref_name_override
In btrfs_log_inode, btrfs_search_forward gets the buffer and then
btrfs_check_ref_name_override will read name from ref/extref for the
first time.

Call btrfs_is_name_len_valid before reading name.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 8ee8c2d62d btrfs: Verify dir_item in replay_xattr_deletes
replay_xattr_deletes calls btrfs_search_slot to get buffer and reads
name.

Call verify_dir_item to check name_len in replay_xattr_deletes to avoid
reading out of boundary.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 26a836cec2 btrfs: Check name_len on add_inode_ref call path
replay_one_buffer first reads buffers and dispatches items accroding to
the item type.
In this patch, add_inode_ref handles inode_ref and inode_extref.
Then add_inode_ref calls ref_get_fields and extref_get_fields to read
ref/extref name for the first time.
So checking name_len before reading those two is fine.

add_inode_ref also calls inode_in_dir to match ref/extref in parent_dir.
The call graph includes btrfs_match_dir_item_name to read dir_item name
in the parent dir.
Checking first dir_item is not enough. Change it to verify every
dir_item while doing matches.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue e79a33270d btrfs: Check name_len with boundary in verify dir_item
Originally, verify_dir_item verifies name_len of dir_item with fixed
values but not item boundary.
If corrupted name_len was not bigger than the fixed value, for example
255, the function will think the dir_item is fine. And then reading
beyond boundary will cause crash.

Example:
	1. Corrupt one dir_item name_len to be 255.
        2. Run 'ls -lar /mnt/test/ > /dev/null'
dmesg:
[   48.451449] BTRFS info (device vdb1): disk space caching is enabled
[   48.451453] BTRFS info (device vdb1): has skinny extents
[   48.489420] general protection fault: 0000 [#1] SMP
[   48.489571] Modules linked in: ext4 jbd2 mbcache btrfs xor raid6_pq
[   48.489716] CPU: 1 PID: 2710 Comm: ls Not tainted 4.10.0-rc1 #5
[   48.489853] Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
[   48.490008] task: ffff880035df1bc0 task.stack: ffffc90004800000
[   48.490008] RIP: 0010:read_extent_buffer+0xd2/0x190 [btrfs]
[   48.490008] RSP: 0018:ffffc90004803d98 EFLAGS: 00010202
[   48.490008] RAX: 000000000000001b RBX: 000000000000001b RCX: 0000000000000000
[   48.490008] RDX: ffff880079dbf36c RSI: 0005080000000000 RDI: ffff880079dbf368
[   48.490008] RBP: ffffc90004803dc8 R08: ffff880078e8cc48 R09: ffff880000000000
[   48.490008] R10: 0000160000000000 R11: 0000000000001000 R12: ffff880079dbf288
[   48.490008] R13: ffff880078e8ca88 R14: 0000000000000003 R15: ffffc90004803e20
[   48.490008] FS:  00007fef50c60800(0000) GS:ffff88007d400000(0000) knlGS:0000000000000000
[   48.490008] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[   48.490008] CR2: 000055f335ac2ff8 CR3: 000000007356d000 CR4: 00000000001406e0
[   48.490008] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[   48.490008] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[   48.490008] Call Trace:
[   48.490008]  btrfs_real_readdir+0x3b7/0x4a0 [btrfs]
[   48.490008]  iterate_dir+0x181/0x1b0
[   48.490008]  SyS_getdents+0xa7/0x150
[   48.490008]  ? fillonedir+0x150/0x150
[   48.490008]  entry_SYSCALL_64_fastpath+0x18/0xad
[   48.490008] RIP: 0033:0x7fef5032546b
[   48.490008] RSP: 002b:00007ffeafcdb830 EFLAGS: 00000206 ORIG_RAX: 000000000000004e
[   48.490008] RAX: ffffffffffffffda RBX: 00007fef5061db38 RCX: 00007fef5032546b
[   48.490008] RDX: 0000000000008000 RSI: 000055f335abaff0 RDI: 0000000000000003
[   48.490008] RBP: 00007fef5061dae0 R08: 00007fef5061db48 R09: 0000000000000000
[   48.490008] R10: 000055f335abafc0 R11: 0000000000000206 R12: 00007fef5061db38
[   48.490008] R13: 0000000000008040 R14: 00007fef5061db38 R15: 000000000000270e
[   48.490008] RIP: read_extent_buffer+0xd2/0x190 [btrfs] RSP: ffffc90004803d98
[   48.499455] ---[ end trace 321920d8e8339505 ]---

Fix it by adding a parameter @slot and check name_len with item boundary
by calling btrfs_is_name_len_valid.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
rev
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
Su Yue 19c6dcbfa7 btrfs: Introduce btrfs_is_name_len_valid to avoid reading beyond boundary
Introduce function btrfs_is_name_len_valid.

The function compares parameter @name_len with item boundary then
returns true if name_len is valid.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ s/btrfs_leaf_data/BTRFS_LEAF_DATA_OFFSET/ ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:16:04 +02:00
David Sterba 66b4993e95 btrfs: move dev stats accounting out of wait_dev_flush
We should really just wait in wait_dev_flush and let the caller decide
what to do with the error value.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:03:39 +02:00
David Sterba 2980d5745f btrfs: account as waiting for IO, while waiting fot the flush bio completion
Similar to what submit_bio_wait does, we should account for IO while
waiting for a bio completion. This has marginal visible effects, flush
bio is short-lived.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:03:39 +02:00
David Sterba e0ae999414 btrfs: preallocate device flush bio
For devices that support flushing, we allocate a bio, submit, wait for
it and then free it. The bio allocation does not fail so ENOMEM is not a
problem but we still may unnecessarily stress the allocation subsystem.

Instead, we can allocate the bio at the same time we allocate the device
and reuse it each time we need to flush the barriers. The bio is reset
before each use. Reference counting is simplified to just device
allocation (get) and freeing (put).

The bio used to be submitted through the integrity checker which will
find out that bio has no data attached and call submit_bio.

Status of the bio in flight needs to be tracked separately in case the
device caches get switched off between write and wait.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 19:03:38 +02:00
Filipe Manana fdb1388994 Btrfs: incremental send, fix invalid path for unlink commands
An incremental send can contain unlink operations with an invalid target
path when we rename some directory inode A, then rename some file inode B
to the old name of inode A and directory inode A is an ancestor of inode B
in the parent snapshot (but not anymore in the send snapshot).

Consider the following example scenario where this issue happens.

Parent snapshot:

 .                                                      (ino 256)
 |
 |--- dir1/                                             (ino 257)
       |--- dir2/                                       (ino 258)
       |     |--- file1                                 (ino 259)
       |     |--- file3                                 (ino 261)
       |
       |--- dir3/                                       (ino 262)
             |--- file22                                (ino 260)
             |--- dir4/                                 (ino 263)

Send snapshot:

 .                                                      (ino 256)
 |
 |--- dir1/                                             (ino 257)
       |--- dir2/                                       (ino 258)
       |--- dir3                                        (ino 260)
       |--- file3/                                      (ino 262)
             |--- dir4/                                 (ino 263)
                   |--- file11                          (ino 269)
                   |--- file33                          (ino 261)

When attempting to apply the corresponding incremental send stream, an
unlink operation contains an invalid path which makes the receiver fail.
The following is verbose output of the btrfs receive command:

 receiving snapshot snap2 uuid=7d5450da-a573-e043-a451-ec85f4879f0f (...)
 utimes
 utimes dir1
 utimes dir1/dir2
 link dir1/dir3/dir4/file11 -> dir1/dir2/file1
 unlink dir1/dir2/file1
 utimes dir1/dir2
 truncate dir1/dir3/dir4/file11 size=0
 utimes dir1/dir3/dir4/file11
 rename dir1/dir3 -> o262-7-0
 link dir1/dir3 -> o262-7-0/file22
 unlink dir1/dir3/file22
 ERROR: unlink dir1/dir3/file22 failed. Not a directory

The following steps happen during the computation of the incremental send
stream the lead to this issue:

1) Before we start processing the new and deleted references for inode
   260, we compute the full path of the deleted reference
   ("dir1/dir3/file22") and cache it in the list of deleted references
   for our inode.

2) We then start processing the new references for inode 260, for which
   there is only one new, located at "dir1/dir3". When processing this
   new reference, we check that inode 262, which was not yet processed,
   collides with the new reference and because of that we orphanize
   inode 262 so its new full path becomes "o262-7-0".

3) After the orphanization of inode 262, we create the new reference for
   inode 260 by issuing a link command with a target path of "dir1/dir3"
   and a source path of "o262-7-0/file22".

4) We then start processing the deleted references for inode 260, for
   which there is only one with the base name of "file22", and issue
   an unlink operation containing the target path computed at step 1,
   which is wrong because that path no longer exists and should be
   replaced with "o262-7-0/file22".

So fix this issue by recomputing the full path of deleted references if
when we processed the new references for an inode we ended up orphanizing
any other inode that is an ancestor of our inode in the parent snapshot.

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
[ adjusted after prev patch removed fs_path::dir_path and dir_path_len ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 16:53:10 +02:00
Filipe Manana 72c3668fed Btrfs: send, fix invalid path after renaming and linking file
Currently an incremental snapshot can generate link operations which
contain an invalid target path. Such case happens when in the send
snapshot a file was renamed, a new hard link added for it and some
other inode (with a lower number) got renamed to the former name of
that file. Example:

Parent snapshot

 .                  (ino 256)
 |
 |--- f1            (ino 257)
 |--- f2            (ino 258)
 |--- f3            (ino 259)

Send snapshot

 .                  (ino 256)
 |
 |--- f2            (ino 257)
 |--- f3            (ino 258)
 |--- f4            (ino 259)
 |--- f5            (ino 258)

The following steps happen when computing the incremental send stream:

1) When processing inode 257, inode 258 is orphanized (renamed to
   "o258-7-0"), because its current reference has the same name as the
   new reference for inode 257;

2) When processing inode 258, we iterate over all its new references,
   which have the names "f3" and "f5". The first iteration sees name
   "f5" and renames the inode from its orphan name ("o258-7-0") to
   "f5", while the second iteration sees the name "f3" and, incorrectly,
   issues a link operation with a target name matching the orphan name,
   which no longer exists. The first iteration had reset the current
   valid path of the inode to "f5", but in the second iteration we lost
   it because we found another inode, with a higher number of 259, which
   has a reference named "f3" as well, so we orphanized inode 259 and
   recomputed the current valid path of inode 258 to its old orphan
   name because inode 259 could be an ancestor of inode 258 and therefore
   the current valid path could contain the pre-orphanization name of
   inode 259. However in this case inode 259 is not an ancestor of inode
   258 so the current valid path should not be recomputed.
   This makes the receiver fail with the following error:

   ERROR: link f3 -> o258-7-0 failed: No such file or directory

So fix this by not recomputing the current valid path for an inode
whenever we find a colliding reference from some not yet processed inode
(inode number higher then the one currently being processed), unless
that other inode is an ancestor of the one we are currently processing.

A test case for fstests will follow soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 16:53:03 +02:00
Filipe Manana 609805d809 Btrfs: fix invalid extent maps due to hole punching
While punching a hole in a range that is not aligned with the sector size
(currently the same as the page size) we can end up leaving an extent map
in memory with a length that is smaller then the sector size or with a
start offset that is not aligned to the sector size. Both cases are not
expected and can lead to problems. This issue is easily detected
after the patch from commit a7e3b975a0 ("Btrfs: fix reported number of
inode blocks"), introduced in kernel 4.12-rc1, in a scenario like the
following for example:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -c "pwrite -S 0xaa -b 100K 0 100K" /mnt/foo
  $ xfs_io -c "fpunch 60K 90K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xbb -b 100K 50K 100K" /mnt/foo
  $ xfs_io -c "pwrite -S 0xcc -b 50K 100K 50K" /mnt/foo
  $ umount /mnt

After the unmount operation we can see several warnings emmitted due to
underflows related to space reservation counters:

[ 2837.443299] ------------[ cut here ]------------
[ 2837.447395] WARNING: CPU: 8 PID: 2474 at fs/btrfs/inode.c:9444 btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.452108] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button se
rio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_gene
ric raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.458389] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.459754] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.462379] Call Trace:
[ 2837.462379]  dump_stack+0x68/0x92
[ 2837.462379]  __warn+0xc2/0xdd
[ 2837.462379]  warn_slowpath_null+0x1d/0x1f
[ 2837.462379]  btrfs_destroy_inode+0xe8/0x27e [btrfs]
[ 2837.462379]  destroy_inode+0x3d/0x55
[ 2837.462379]  evict+0x177/0x17e
[ 2837.462379]  dispose_list+0x50/0x71
[ 2837.462379]  evict_inodes+0x132/0x141
[ 2837.462379]  generic_shutdown_super+0x3f/0xeb
[ 2837.462379]  kill_anon_super+0x12/0x1c
[ 2837.462379]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.462379]  deactivate_locked_super+0x30/0x68
[ 2837.462379]  deactivate_super+0x36/0x39
[ 2837.462379]  cleanup_mnt+0x58/0x76
[ 2837.462379]  __cleanup_mnt+0x12/0x14
[ 2837.462379]  task_work_run+0x77/0x9b
[ 2837.462379]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.462379]  syscall_return_slowpath+0x196/0x1b9
[ 2837.462379]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.462379] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.462379] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.462379] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.462379] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.462379] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.462379] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.462379] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.519355] ---[ end trace e79345fe24b30b8d ]---
[ 2837.596256] ------------[ cut here ]------------
[ 2837.597625] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5699 btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.603547] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.659372] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.663359] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.663359] Call Trace:
[ 2837.663359]  dump_stack+0x68/0x92
[ 2837.663359]  __warn+0xc2/0xdd
[ 2837.663359]  warn_slowpath_null+0x1d/0x1f
[ 2837.663359]  btrfs_free_block_groups+0x246/0x3eb [btrfs]
[ 2837.663359]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.663359]  ? evict_inodes+0x132/0x141
[ 2837.663359]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.663359]  generic_shutdown_super+0x6a/0xeb
[ 2837.663359]  kill_anon_super+0x12/0x1c
[ 2837.663359]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.663359]  deactivate_locked_super+0x30/0x68
[ 2837.663359]  deactivate_super+0x36/0x39
[ 2837.663359]  cleanup_mnt+0x58/0x76
[ 2837.663359]  __cleanup_mnt+0x12/0x14
[ 2837.663359]  task_work_run+0x77/0x9b
[ 2837.663359]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.663359]  syscall_return_slowpath+0x196/0x1b9
[ 2837.663359]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.663359] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.663359] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.663359] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.663359] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.663359] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.663359] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.663359] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.739445] ---[ end trace e79345fe24b30b8e ]---
[ 2837.745595] ------------[ cut here ]------------
[ 2837.746412] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:5700 btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.747955] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.755395] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.756769] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.758526] Call Trace:
[ 2837.758925]  dump_stack+0x68/0x92
[ 2837.759383]  __warn+0xc2/0xdd
[ 2837.759383]  warn_slowpath_null+0x1d/0x1f
[ 2837.759383]  btrfs_free_block_groups+0x261/0x3eb [btrfs]
[ 2837.759383]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.759383]  ? evict_inodes+0x132/0x141
[ 2837.759383]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.759383]  generic_shutdown_super+0x6a/0xeb
[ 2837.759383]  kill_anon_super+0x12/0x1c
[ 2837.759383]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.759383]  deactivate_locked_super+0x30/0x68
[ 2837.759383]  deactivate_super+0x36/0x39
[ 2837.759383]  cleanup_mnt+0x58/0x76
[ 2837.759383]  __cleanup_mnt+0x12/0x14
[ 2837.759383]  task_work_run+0x77/0x9b
[ 2837.759383]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.759383]  syscall_return_slowpath+0x196/0x1b9
[ 2837.759383]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.759383] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.759383] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.759383] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.759383] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.759383] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.759383] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.759383] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.777063] ---[ end trace e79345fe24b30b8f ]---
[ 2837.778235] ------------[ cut here ]------------
[ 2837.778856] WARNING: CPU: 8 PID: 2474 at fs/btrfs/extent-tree.c:9825 btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.791385] Modules linked in: dm_flakey dm_mod ppdev parport_pc psmouse parport sg pcspkr acpi_cpufreq tpm_tis tpm_tis_core i2c_piix4 i2c_core evdev tpm button serio_raw sunrpc loop autofs4 ext4 crc16 jbd2 mbcache btrfs raid10 raid456 async_raid6_recov async_memcpy async_pq async_xor async_tx xor raid6_pq libcrc32c crc32c_generic raid1 raid0 multipath linear md_mod sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix libata virtio_pci virtio_ring virtio e1000 scsi_mod floppy
[ 2837.797711] CPU: 8 PID: 2474 Comm: umount Tainted: G        W       4.10.0-rc8-btrfs-next-43+ #1
[ 2837.798594] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[ 2837.800118] Call Trace:
[ 2837.800515]  dump_stack+0x68/0x92
[ 2837.801015]  __warn+0xc2/0xdd
[ 2837.801471]  warn_slowpath_null+0x1d/0x1f
[ 2837.801698]  btrfs_free_block_groups+0x348/0x3eb [btrfs]
[ 2837.801698]  close_ctree+0x1dd/0x2e1 [btrfs]
[ 2837.801698]  ? evict_inodes+0x132/0x141
[ 2837.801698]  btrfs_put_super+0x15/0x17 [btrfs]
[ 2837.801698]  generic_shutdown_super+0x6a/0xeb
[ 2837.801698]  kill_anon_super+0x12/0x1c
[ 2837.801698]  btrfs_kill_super+0x16/0x21 [btrfs]
[ 2837.801698]  deactivate_locked_super+0x30/0x68
[ 2837.801698]  deactivate_super+0x36/0x39
[ 2837.801698]  cleanup_mnt+0x58/0x76
[ 2837.801698]  __cleanup_mnt+0x12/0x14
[ 2837.801698]  task_work_run+0x77/0x9b
[ 2837.801698]  prepare_exit_to_usermode+0x9d/0xc5
[ 2837.801698]  syscall_return_slowpath+0x196/0x1b9
[ 2837.801698]  entry_SYSCALL_64_fastpath+0xab/0xad
[ 2837.801698] RIP: 0033:0x7f3ef3e6b9a7
[ 2837.801698] RSP: 002b:00007ffdd0d8de58 EFLAGS: 00000246 ORIG_RAX: 00000000000000a6
[ 2837.801698] RAX: 0000000000000000 RBX: 0000556f76a39060 RCX: 00007f3ef3e6b9a7
[ 2837.801698] RDX: 0000000000000001 RSI: 0000000000000000 RDI: 0000556f76a3f910
[ 2837.801698] RBP: 0000556f76a3f910 R08: 0000556f76a3e670 R09: 0000000000000015
[ 2837.801698] R10: 00000000000006b4 R11: 0000000000000246 R12: 00007f3ef436ce64
[ 2837.801698] R13: 0000000000000000 R14: 0000556f76a39240 R15: 00007ffdd0d8e0e0
[ 2837.818441] ---[ end trace e79345fe24b30b90 ]---
[ 2837.818991] BTRFS info (device sdc): space_info 1 has 7974912 free, is not full
[ 2837.819830] BTRFS info (device sdc): space_info total=8388608, used=417792, pinned=0, reserved=0, may_use=18446744073709547520, readonly=0

What happens in the above example is the following:

1) When punching the hole, at btrfs_punch_hole(), the variable tail_len
   is set to 2048 (as tail_start is 148Kb + 1 and offset + len is 150Kb).
   This results in the creation of an extent map with a length of 2Kb
   starting at file offset 148Kb, through find_first_non_hole() ->
   btrfs_get_extent().

2) The second write (first write after the hole punch operation), sets
   the range [50Kb, 152Kb[ to delalloc.

3) The third write, at btrfs_find_new_delalloc_bytes(), sees the extent
   map covering the range [148Kb, 150Kb[ and ends up calling
   set_extent_bit() for the same range, which results in splitting an
   existing extent state record, covering the range [148Kb, 152Kb[ into
   two 2Kb extent state records, covering the ranges [148Kb, 150Kb[ and
   [150Kb, 152Kb[.

4) Finally at lock_and_cleanup_extent_if_need(), immediately after calling
   btrfs_find_new_delalloc_bytes() we clear the delalloc bit from the
   range [100Kb, 152Kb[ which results in the btrfs_clear_bit_hook()
   callback being invoked against the two 2Kb extent state records that
   cover the ranges [148Kb, 150Kb[ and [150Kb, 152Kb[. When called against
   the first 2Kb extent state, it calls btrfs_delalloc_release_metadata()
   with a length argument of 2048 bytes. That function rounds up the length
   to a sector size aligned length, so it ends up considering a length of
   4096 bytes, and then calls calc_csum_metadata_size() which results in
   decrementing the inode's csum_bytes counter by 4096 bytes, so after
   it stays a value of 0 bytes. Then the same happens when
   btrfs_clear_bit_hook() is called against the second extent state that
   has a length of 2Kb, covering the range [150Kb, 152Kb[, the length is
   rounded up to 4096 and calc_csum_metadata_size() ends up being called
   to decrement 4096 bytes from the inode's csum_bytes counter, which
   at that time has a value of 0, leading to an underflow, which is
   exactly what triggers the first warning, at btrfs_destroy_inode().
   All the other warnings relate to several space accounting counters
   that underflow as well due to similar reasons.

A similar case but where the hole punching operation creates an extent map
with a start offset not aligned to the sector size is the following:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /mnt
  $ xfs_io -f -c "fpunch 695K 820K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xaa 1008K 307K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xbb -b 630K 1073K 630K" $SCRATCH_MNT/bar
  $ xfs_io -c "pwrite -S 0xcc -b 459K 1068K 459K" $SCRATCH_MNT/bar
  $ umount /mnt

During the unmount operation we get similar traces for the same reasons as
in the first example.

So fix the hole punching operation to make sure it never creates extent
maps with a length that is not aligned to the sector size nor with a start
offset that is not aligned to the sector size, as this breaks all
assumptions and it's a land mine.

Fixes: d77815461f ("btrfs: Avoid trucating page or punching hole in a already existed hole.")
Cc: <stable@vger.kernel.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 16:52:45 +02:00
Jeff Mahoney cddf3b2cb3 btrfs: add cond_resched to btrfs_qgroup_trace_leaf_items
On an uncontended system, we can end up hitting soft lockups while
doing replace_path.  At the core, and frequently called is
btrfs_qgroup_trace_leaf_items, so it makes sense to add a cond_resched
there.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-21 15:48:01 +02:00
Dan Carpenter 0e9350de2e btrfs: use new block error code
This function is supposed to return blk_status_t error codes now but
there was a stray -ENOMEM left behind.

Fixes: 4e4cbee93d ("block: switch bios to blk_status_t")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Acked-by: Christoph Hellwig <hch@lst.de>
Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-21 07:47:34 -06:00
Nikolay Borisov 104b4e5139 percpu_counter: Rename __percpu_counter_add to percpu_counter_add_batch
Currently, percpu_counter_add is a wrapper around __percpu_counter_add
which is preempt safe due to explicit calls to preempt_disable.  Given
how __ prefix is used in percpu related interfaces, the naming
unfortunately creates the false sense that __percpu_counter_add is
less safe than percpu_counter_add.  In terms of context-safety,
they're equivalent.  The only difference is that the __ version takes
a batch parameter.

Make this a bit more explicit by just renaming __percpu_counter_add to
percpu_counter_add_batch.

This patch doesn't cause any functional changes.

tj: Minor updates to patch description for clarity.  Cosmetic
    indentation updates.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <jbacik@fb.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Darrick J. Wong <darrick.wong@oracle.com>
Cc: Jan Kara <jack@suse.com>
Cc: Jens Axboe <axboe@fb.com>
Cc: linux-mm@kvack.org
Cc: "David S. Miller" <davem@davemloft.net>
2017-06-20 15:42:32 -04:00
Goldwyn Rodrigues edf064e7c6 btrfs: nowait aio support
Return EAGAIN if any of the following checks fail
 + i_rwsem is not lockable
 + NODATACOW or PREALLOC is not set
 + Cannot nocow at the desired location
 + Writing beyond end of file which is not allocated

Acked-by: David Sterba <dsterba@suse.com>
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-20 07:12:03 -06:00
Nikolay Borisov 7dfb8be11b btrfs: Round down values which are written for total_bytes_size
We got an internal report about a file system not wanting to mount
following 99e3ecfcb9 ("Btrfs: add more validation checks for
superblock").

BTRFS error (device sdb1): super_total_bytes 1000203816960 mismatch with
fs_devices total_rw_bytes 1000203820544

Subtracting the numbers we get a difference of less than a 4kb. Upon
closer inspection it became apparent that mkfs actually rounds down the
size of the device to a multiple of sector size. However, the same
cannot be said for various functions which modify the total size and are
called from btrfs_balance as well as when adding a new device. So this
patch ensures that values being saved into on-disk data structures are
always rounded down to a multiple of sectorsize.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20 14:22:48 +02:00
Nikolay Borisov eca152edf5 btrfs: Manually implement device_total_bytes getter/setter
The device->total_bytes member needs to always be rounded down to sectorsize
so that it corresponds to the value of super->total_bytes. However, there are
multiple places where the setter is fed a value which is not rounded which
can cause a fs to be unmountable due to the check introduced in
99e3ecfcb9 ("Btrfs: add more validation checks for superblock"). This patch
implements the getter/setter manually so that in a later patch I can add
necessary code to catch offenders.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20 14:22:48 +02:00
David Sterba 0d0c71b317 btrfs: obsolete and remove mount option alloc_start
The mount option alloc_start was used in the past for debugging and
stressing the chunk allocator. Not meant to be used by users, so we're
not breaking anybody's setup.

There was some added complexity handling changes of the value and when
it was not same as default. Such code has likely been untested and I
think it's better to remove it.

This patch kills all use of alloc_start, and by doing that also fixes
a bug when alloc_size is set, potentially called from statfs:

in btrfs_calc_avail_data_space, traversing the list in RCU, the RCU
protection is temporarily dropped so btrfs_account_dev_extents_size can
be called and then RCU is locked again! Doing that inside
list_for_each_entry_rcu is just asking for trouble, but unlikely to be
observed in practice.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20 14:22:48 +02:00
David Sterba fac03c8dae btrfs: move fs_info::fs_frozen to the flags
We can keep the state among the other fs_info flags, there's no reason
why fs_frozen would need to be separate.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20 14:22:42 +02:00
David Sterba 79b4f4c605 btrfs: cleanup duplicate return value in insert_inline_extent
The pattern when err is used for function exit and ret is used for
return values of callees is not used here.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-20 14:22:12 +02:00
David Sterba 6165572c11 btrfs: use GFP_KERNEL in btrfs_init_dev_replace_tgtdev
The function is called from ioctl context and we don't hold any locks
that take part in writeback. Right now it's only fs_info::volume_mutex.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
David Sterba 6a44517d79 btrfs: use GFP_KERNEL in btrfs_calc_avail_data_space
We don't hold any locks here. Inidirectly called from statfs.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
Nikolay Borisov 0eee8a494e btrfs: Use btrfs_space_info_used instead of opencoding it
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
Anand Jain 4fc6441aac btrfs: wait part of the write_dev_flush() can be separated out
Submit and wait parts of write_dev_flush() can be split into two
separate functions for better readability.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
Anand Jain cea7c8bf77 btrfs: remove redundant null bdev counting during flush submission
There is no extra benefit to count null bdev during the submit loop,
as these null devices will be anyway checked during command
completion device loop just after the submit loop. We are holding the
device_list_mutex, the device->bdev status won't change in between.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
Anand Jain 12b9bf0b94 btrfs: write_dev_flush does not return ENOMEM anymore
Since commit "btrfs: btrfs_io_bio_alloc never fails, skip error handling"
write_dev_flush will not return ENOMEM in the sending part. We do not
need to check for it in the callers.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ updated changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
Timofey Titovets 170607ebd9 Btrfs: compression must free at least one sector size
We already skip storing data where compression does not make the result
at least one byte less.  Let's make the logic better and check
that compression frees at least one sector size of bytes, otherwise it's
not that useful.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ changelog updated ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
David Sterba c5e4c3d750 btrfs: sink gfp parameter to btrfs_io_bio_alloc
We can hardcode GFP_NOFS to btrfs_io_bio_alloc, although it means we
change it back from GFP_KERNEL in scrub. I'd rather save a few stack
bytes from not passing the gfp flags in the remaining, more imporatant,
contexts and the bio allocating API now looks more consistent.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:04 +02:00
David Sterba 184f999e12 btrfs: add helper to initialize the non-bio part of btrfs_io_bio
We use btrfs_bioset for bios and ask to allocate the entire size of
btrfs_io_bio from btrfs bio_alloc_bioset. The member 'bio' is
initialized but the bytes from 0 to offset of 'bio' are left
uninitialized. Although we initialize some of the members in our
helpers, we should initialize the whole structures.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba fa1bcbe0a5 btrfs: document mandatory order of bio in btrfs_io_bio
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
Liu Bo ef7cdac101 Btrfs: skip checksum verification if IO error occurs
Currently dio read also goes to verify checksum if -EIO has been returned,
although it usually fails on checksum, it's not necessary at all, we could
directly check if there is another copy to read.

And with this, the behavior of dio read is now consistent with that of
buffered read.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ use bool for uptodate ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
Liu Bo e3d37faba2 Btrfs: tolerate errors if we have retried successfully
With raid1 profile, dio read isn't tolerating IO errors if read length is
less than the stripe length (64K).

Our bio didn't get split in btrfs_submit_direct_hook() if (dip->flags &
BTRFS_DIO_ORIG_BIO_SUBMITTED) is true and that happens when the read
length is less than 64k.  In this case, if the underlying device returns
error somehow, bio->bi_error has recorded that error.

If we could recover the correct data from another copy in profile raid1/10/5/6,
with btrfs_subio_endio_read() returning 0, bio would have the correct data in
its vector, but bio->bi_error is not updated accordingly so that the following
dio_end_io(dio_bio, bio->bi_error) makes directIO think this read has failed.

This fixes the problem by setting bio's error to 0 if a good copy has been
found.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba c821e7f3da btrfs: pass bytes to btrfs_bio_alloc
Most callers of btrfs_bio_alloc convert from bytes to sectors. Hide that
in the helper and simplify the logic in the callsers.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba 9886b17433 btrfs: opencode trivial compressed_bio_alloc, simplify error handling
compressed_bio_alloc is now a trivial wrapper around btrfs_bio_alloc, no
point keeping it. The error handling can be simplified, as we know
btrfs_bio_alloc will never fail.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba 9f2179a5e7 btrfs: remove redundant parameters from btrfs_bio_alloc
All callers pass gfp_flags=GFP_NOFS and nr_vecs=BIO_MAX_PAGES.

submit_extent_page adds __GFP_HIGH that does not make a difference in
our case as it allows access to memory reserves but otherwise does not
change the constraints.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba 8b6c1d56f2 btrfs: sink gfp parameter to btrfs_bio_clone
All callers pass GFP_NOFS.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:03 +02:00
David Sterba e4f5690386 btrfs: btrfs_io_bio_alloc never fails, skip error handling
Update direct callers of btrfs_io_bio_alloc that do error handling, that
we can now remove.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 3aa8e074ab btrfs: btrfs_bio_clone never fails, skip error handling
Update direct callers of btrfs_bio_clone that do error handling, that we
can now remove.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 0c4dd97c5e btrfs: btrfs_bio_alloc never fails, skip error handling
Update direct callers of btrfs_bio_alloc that do error handling, that we
can now remove.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 6e707bcd1f btrfs: bioset allocations will never fail, adapt our helpers
Christoph pointed out that bio allocations backed by a bioset will never
fail.  As we always use a bioset for all bio allocations, we can skip
the error handling.  This patch adjusts our low-level helpers, the
cascaded changes to all callers will come next.

CC: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 6acafd1eff btrfs: switch to kvmalloc and GFP_KERNEL in lzo/zlib alloc_workspace
The compression workspace buffers are larger than a page so we use
vmalloc, unconditionally. This is not always necessary as there might be
contiguous memory available.

Let's use the kvmalloc helpers that will try kmalloc first and fallback
to vmalloc. For that they require GFP_KERNEL flags. As we now have the
alloc_workspace calls protected by memalloc_nofs in the critical
contexts, we can safely use GFP_KERNEL.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 389a6cfc2a btrfs: switch kmallocs to GFP_KERNEL in lzo/zlib alloc_workspace
As alloc_workspace is now protected by memalloc_nofs where needed,
we can switch the kmalloc to use GFP_KERNEL.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba fe30853307 btrfs: add memalloc_nofs protections around alloc_workspace callback
The workspaces are preallocated at the beginning where we can safely use
GFP_KERNEL, but in some cases the find_workspace might reach the
allocation again, now in a more restricted context when the bios or
pages are being compressed.

To avoid potential lockup when alloc_workspace -> vmalloc would silently
use the GFP_KERNEL, add the memalloc_nofs helpers around the critical
call site.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba adf0212396 btrfs: adjust includes after vmalloc removal
As we don't use vmalloc/vzalloc/vfree directly in ctree.c, we can now
use the proper header that defines kvmalloc.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba f54de068dd btrfs: use GFP_KERNEL in init_ipath
Now that init_ipath is called either from a safe context or with
memalloc_nofs protection, we can switch to GFP_KERNEL allocations in
init_path and init_data_container.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba de2491fdef btrfs: scrub: add memalloc_nofs protection around init_ipath
init_ipath is called from a safe ioctl context and from scrub when
printing an error.  The protection is added for three reasons:

* init_data_container calls vmalloc and this does not work as expected
  in the GFP_NOFS context, so this silently does GFP_KERNEL and might
  deadlock in some cases
* keep the context constraint of GFP_NOFS, used by scrub
* we want to use GFP_KERNEL unconditionally inside init_ipath or its
  callees

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba f11f74416a btrfs: send: use kvmalloc in iterate_dir_item
We use a growing buffer for xattrs larger than a page size, at some
point vmalloc is unconditionally used for larger buffers. We can still
try to avoid it using the kvmalloc helper.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:02 +02:00
David Sterba 818e010bf9 btrfs: replace opencoded kvzalloc with the helper
The logic of kmalloc and vmalloc fallback is opencoded in
several places, we can now use the existing helper.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Timofey Titovets 1e9d7291e5 Btrfs: lzo: compressed data size must be less then input size
Logic already skips if compression makes data bigger, let's sync lzo
with zlib and also return error if compressed size is equal to
input size.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Guoqing Jiang 054ec2f626 btrfs: simplify code with bio_io_error
bio_io_error was introduced in the commit 4246a0b63b
("block: add a bi_error field to struct bio"), so use it to simplify
code.

Signed-off-by: Guoqing Jiang <gqjiang@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Omar Sandoval 25ff17e82f Btrfs: use memalloc_nofs and kvzalloc() for free space tree bitmaps
First, instead of open-coding the vmalloc() fallback, use the new
kvzalloc() helper. Second, use memalloc_nofs_{save,restore}() instead of
GFP_NOFS, as vmalloc() uses some GFP_KERNEL allocations internally which
could lead to deadlocks.

Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
David Sterba 4b5faeac46 btrfs: use generic slab for for btrfs_transaction
Observing the number of slab objects of btrfs_transaction, there's just
one active on an almost quiescent filesystem, and the number of objects
goes to about ten when sync is in progress. Then the nubmer goes down to
1.  This matches the expectations of the transaction lifetime.

For such use the separate slab cache is not justified, as we do not
reuse objects frequently. For the shortlived transaction, the generic
slab (size 512) should be ok. We can optimistically expect that the 512
slabs are not all used (fragmentation) and there are free slots to take
when we do the allocation, compared to potentially allocating a whole new
page for the separate slab.

We'll lose the stats about the object use, which could be added later if
we really need them.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
David Sterba 3fb99303c6 btrfs: scrub: embed scrub_wr_ctx into scrub context
The structure scrub_wr_ctx is not used anywhere just the scrub context,
we can move the members there. The tgtdev is renamed so it's more clear
that it belongs to the "wr" part.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
David Sterba 25cc1226c1 btrfs: scrub: use fs_info::sectorsize and drop it from scrub context
As we now have the node/block sizes in fs_info, we can use them and can
drop the local copies.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Yonghong Song 04a87e3472 Btrfs: add statx support
Return enhanced file attributes from the btrfs, including:
  (1). inode creation time as stx_btime, and
  (2). Certain BTRFS_INODE_xxx flags are mapped to stx_attributes flags.

Example output:
	[root@localhost ~]# cat t.sh
	touch t
	chattr +aic t
	~/linux/samples/statx/test-statx t
	chattr -aic t
	touch t
	echo "========================================"
	~/linux/samples/statx/test-statx t
	/bin/rm t
	[root@localhost ~]# ./t.sh
	statx(t) = 0
	results=fff
  	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:13.999856591-0700
	Modify: 2017-05-11 16:03:13.999856591-0700
	Change: 2017-05-11 16:03:14.000856663-0700
 	 Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000034 (........ ........ ........ ........ ........ ........ ........ .-ai.c..)
	========================================
	statx(t) = 0
	results=fff
	  Size: 0               Blocks: 0          IO Block: 4096    regular file
	Device: 00:1c           Inode: 63962       Links: 1
	Access: (0644/-rw-r--r--)  Uid:     0   Gid:     0
	Access: 2017-05-11 16:03:14.006857097-0700
	Modify: 2017-05-11 16:03:14.006857097-0700
	Change: 2017-05-11 16:03:14.006857097-0700
 	Birth: 2017-05-11 16:03:13.999856591-0700
	Attributes: 0000000000000000 (........ ........ ........ ........ ........ ........ ........ .---.-..)
	[root@localhost ~]#

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Yonghong Song <yhs@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Timofey Titovets 036b0217ad Btrfs: lzo: fix typo in error message after failed deflate
Fix copy paste typo in debug message for lzo.c, lzo is not deflate.

Signed-off-by: Timofey Titovets <nefelim4ag@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Jeff Layton 3189ff7786 btrfs: btrfs_wait_tree_block_writeback can be void return
Nothing checks its return value.

Is it safe to skip checking return value of btrfs_wait_tree_block_writeback?

Liu Bo: I think yes, it's used in walk_log_tree which is called in two
places, free_log_tree and log replay.  For free_log_tree, it waits for
any running writeback of the extent buffer under freeing to finish in
case we need to access the eb pointer from page->private, and it's OK to
not check the return value, while for log replay, it's doesn't wait
because wc->wait is not set. So neither cares about the writeback error.

Signed-off-by: Jeff Layton <jlayton@redhat.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
[ added more explanation to changelog, from Liu Bo ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Nikolay Borisov 118c701e20 btrfs: remove __BTRFS_LEAF_DATA_SIZE
__BTRFS_LAF_DATA_SIZE is used only by BTRFS_LEAF_DATA_SIZE. Make the
latter subsume the former.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:01 +02:00
Nikolay Borisov 3d9ec8c49a btrfs: rename btrfs_leaf_data to BTRFS_LEAF_DATA_OFFSET
Commit 5f39d397df ("Btrfs: Create extent_buffer interface
for large blocksizes") refactored btrfs_leaf_data function to take
extent_buffer rather than struct btrfs_leaf. However, as it turns out the
parameter being passed is never used. Furthermore this function no longer
returns the leaf data but rather the offset to it. So rename the function
to BTRFS_LEAF_DATA_OFFSET to make it consistent with other BTRFS_LEAF_*
helpers and turn it into a macro.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ removed () from the macro ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Anand Jain e1ddce71d6 btrfs: reduce arguments for decompress_bio ops
struct compressed_bio pointer can be used instead.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Anand Jain 8140dc30a4 btrfs: btrfs_decompress_bio() could accept compressed_bio instead
Instead of sending each argument of struct compressed_bio, send
the compressed_bio itself.

Also by having struct compressed_bio in btrfs_decompress_bio()
it would help tracing.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Nikolay Borisov d2006e6d28 btrfs: Refactor update_space_info
Following the factoring out of the creation code udpate_space_info can
only be called for already-existing space_info structs. As such it
cannot fail.  Remove superfluous error handling and make the function
return void.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Nikolay Borisov 2be12ef79f btrfs: Separate space_info create/update
Currently the struct space_info creation code is intermixed in the
udpate_space_info function. There are well-defined points at which the
we actually want to create brand-new space_info structs (e.g. during
mount of the filesystem as well as sometimes when adding/initialising
new chunks). In such cases update_space_info is called with 0 as the
bytes parameter. All of this makes for spaghetti code.

Fix it by factoring out the creation code in a separate
create_space_info structure. This also allows to simplify the internals.
Also remove BUG_ON from do_alloc_chunk since the callers handle errors.
Furthermore it will make the update_space_info function not fail,
allowing us to remove error handling in callers. This will come in a
follow up patch.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Liu Bo 555ba411aa Btrfs: let btrfs_print_leaf print more about block group
This adds chunk_objectid and flags, with flags we can recognize whether
the block group is about data or metadata.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Liu Bo 28785f70ef Btrfs: skip commit transaction if we don't have enough pinned bytes
We commit transaction in order to reclaim space from pinned bytes because
it could process delayed refs, and in may_commit_transaction(), we check
first if pinned bytes are enough for the required space, we then check if
that plus bytes reserved for delayed insert are enough for the required
space.

This changes the code to the above logic.

Fixes: b150a4f10d ("Btrfs: use a percpu to keep track of possibly pinned bytes")
Tested-by: Nikolay Borisov <nborisov@suse.com>
Reported-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba 4e2814ef04 btrfs: scrub: simplify cleanup of wr_ctx in scrub_free_ctx
We don't need to take the mutex and zero out wr_cur_bio, as this is
called after the scrub finished.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba e241ddeb9c btrfs: scrub: inline helper scrub_free_wr_ctx
The helper scrub_free_wr_ctx is used only once and fits into
scrub_free_ctx as it continues sctx shutdown, no need to keep it
separate.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
David Sterba 8fcdac3f20 btrfs: scrub: inline helper scrub_setup_wr_ctx
The helper scrub_setup_wr_ctx is used only once and fits into
scrub_setup_ctx as it continues intialization, no need to keep it
separate.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Jeff Mahoney c1c4919b11 btrfs: remove root usage from can_overcommit
can_overcommit using the root to determine the allocation profile
is the only use of a root in the call graph below reserve_metadata_bytes.

It turns out that we only need to know whether the allocation is for
the chunk root or not -- and we can pass that around as a bool instead.

This allows us to pull root usage out of the reservation path all the
way up to reserve_metadata_bytes itself, which uses it only to compare
against fs_info->chunk_root to set the bool.  In turn, this eliminates
a bunch of races where we use a particular root too early in the mount
process.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:26:00 +02:00
Jeff Mahoney 1b86826d12 btrfs: cleanup root usage by btrfs_get_alloc_profile
There are two places where we don't already know what kind of alloc
profile we need before calling btrfs_get_alloc_profile, but we need
access to a root everywhere we call it.

This patch adds helpers for btrfs_{data,metadata,system}_alloc_profile()
and relegates btrfs_system_alloc_profile to a static for use in those
two cases.  The next patch will eliminate one of those.

Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba e03733da5a btrfs: fix bool type in btrfs_page_exists_in_range
We use only a simple bool indicator, int is not a problem here.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba c9fed2bb61 btrfs: remove unused member list from btrfs_end_io_wq
The end io work queue items have been tracked by the work queues since
"Btrfs: Add async worker threads for pre and post IO checksumming"
(8b71284292) (2008).

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba ee4ea69852 btrfs: remove unused members dir_path from recorded_ref
The two members do not seem to be used since the initial commit.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba b297c9f68f btrfs: remove unused member list from async_submit_bio
The list used to track checksums in the early version (2.6.29), but I
was able not pinpoint the commit that stopped using it. Everything
apparently works without it for a long time.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
David Sterba 106204f191 btrfs: remove unused member err from reada_extent
Seems to be unused since the initial commit, we ignore readahead errors
anyway, the full read will handle that if necessary.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Sahil Kang 0bef71093d btrfs: Remove unnecessary branching in free-space-tree.c
Both btrfs_create_free_space_tree and btrfs_clear_free_space_tree
contain:

  if (ret)
          return ret;

  return 0;

The if statement is only false when ret equals zero, and since we return
zero in such cases, we can safely remove the branching.

Signed-off-by: Sahil Kang <sahil.kang@asilaycomputing.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo e477094f0d Btrfs: hardcode GFP_NOFS for btrfs_bio_clone_partial
We only pass GFP_NOFS to btrfs_bio_clone_partial, so lets hardcode it.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Arnd Bergmann 3c91ee6964 Btrfs: work around maybe-uninitialized warning
A rewrite of btrfs_submit_direct_hook appears to have introduced a warning:

fs/btrfs/inode.c: In function 'btrfs_submit_direct_hook':
fs/btrfs/inode.c:8467:14: error: 'bio' may be used uninitialized in this function [-Werror=maybe-uninitialized]

Where the 'bio' variable was previously initialized unconditionally, it
is now set in the "while (submit_len > 0)" loop that would never execute
if submit_len is zero.

Assuming this cannot happen in practice, we can avoid the warning
by simply replacing the while{} loop with a do{}while() loop so
the compiler knows that it will always be entered at least once.

Fixes changes introduced in "Btrfs: use bio_clone_bioset_partial to
simplify DIO submit".

Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo 3892ac9086 Btrfs: unify naming of btrfs_io_bio
All dio endio functions are using io_bio for struct btrfs_io_bio, this
makes btrfs_submit_direct to follow this convention.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo 11b5616516 Btrfs: check-integrity use bvec_iter
Some check-integrity code depends on bio->bi_vcnt, this changes it to use
bio segments because some bios passing here may not have a reliable
bi_vcnt.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo 629ebf4fad Btrfs: record error if one block has failed to retry
In the nocsum case of dio read endio, it returns immediately if an error
gets returned when repairing, which leaves the rest blocks unrepaired.  The
behavior is different from how buffered read endio works in the same case.
This changes it to record error only and go on repairing the rest blocks.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo 17347cec15 Btrfs: change how we iterate bios in endio
Since dio submit has used bio_clone_fast, the submitted bio may not have a
reliable bi_vcnt, for the bio vector iterations in checksum related
functions, bio->bi_iter is not modified yet and it's safe to use
bio_for_each_segment, while for those bio vector iterations in dio read's
endio, we now save a copy of bvec_iter in struct btrfs_io_bio when cloning
bios and use the helper __bio_for_each_segment with the saved bvec_iter to
access each bvec.

Also for dio reads which don't get split, we also need to save a copy of
bio iterator in btrfs_bio_clone to let __bio_for_each_segments to access
each bvec in dio read's endio.  Note that it doesn't affect other calls of
btrfs_bio_clone() because they don't need to use this iterator.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:59 +02:00
Liu Bo 725130bac5 Btrfs: use bio_clone_bioset_partial to simplify DIO submit
Currently when mapping bio to limit bio to a single stripe length, we
split bio by adding page to bio one by one, but later we don't modify
the vector of bio at all, thus we can use bio_clone_fast to use the
original bio vector directly.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Liu Bo 2f8e914042 Btrfs: new helper btrfs_bio_clone_partial
This adds a new helper btrfs_bio_clone_partial, it'll allocate a cloned
bio that only owns a part of the original bio's data.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Liu Bo 015c1bd9f1 Btrfs: use bio_clone_fast to clone our bio
For raid1 and raid10, we clone the original bio to the bios which are then
sent to different disks.

Right now we use bio_clone_bioset to create a clone bio with iterating
bi_io_vec to initialize it.  This changes it to use bio_clone_fast()
which creates a clone bio but only copies the bi_io_vec pointer
instead of iterating bi_io_vec.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik 7870d0822b Btrfs: don't pass the inode through clean_io_failure
Instead pass around the failure tree and the io tree.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik 6ec656bc0f btrfs: remove inode argument from repair_io_failure
Once we remove the btree_inode we won't have an inode to pass anymore,
just pass the fs_info directly and the inum since we use that to print
out the repair message.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Josef Bacik c6100a4b4e Btrfs: replace tree->mapping with tree->private_data
For extent_io tree's we have carried the address_mapping of the inode
around in the io tree in order to pull the inode back out for calling
into various tree ops hooks.  This works fine when everything that has
an extent_io_tree has an inode.  But we are going to remove the
btree_inode, so we need to change this.  Instead just have a generic
void * for private data that we can initialize with, and have all the
tree ops use that instead.  This had a lot of cascading changes but
should be relatively straightforward.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: Chandan Rajendra <chandan@linux.vnet.ibm.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor reordering of the callback prototypes ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Sargun Dhillon 2723480a0f btrfs: Add quota_override knob into sysfs
This patch adds the read-write attribute quota_override into sysfs.
Any process which has CAP_SYS_RESOURCE can set this flag to on, and
once it is set to true, processes with CAP_SYS_RESOURCE can exceed
the quota.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Sargun Dhillon f29efe2921 btrfs: add quota override flag to enable quota override for CAP_SYS_RESOURCE
This patch introduces the quota override flag to btrfs_fs_info, and a
change to quota limit checking code to temporarily allow for quota to be
overridden for processes with CAP_SYS_RESOURCE.

It's useful for administrative programs, such as log rotation, that may
need to temporarily use more disk space in order to free up a greater
amount of overall disk space without yielding more disk space to the
rest of userland.

Eventually, we may want to add the idea of an operator-specific quota,
operator reserved space, or something else to allow for administrative
override, but this is perhaps the simplest solution.

Signed-off-by: Sargun Dhillon <sargun@sargun.me>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor changelog edits ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Nikolay Borisov a5ed45f822 btrfs: Convert fs_info->free_chunk_space to atomic64_t
The ->free_chunk_space variable is used to track the unallocated space
and access to it is protected by a spinlock, which is not used for
anything else.  Make the code a bit self-explanatory by switching the
variable to an atomic64_t type and kill the spinlock.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ not a performance critical code, use of atomic type is ok ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Anand Jain 401b41e5a8 btrfs: add framework to handle device flush error as a volume
This adds comments to the flush error handling part of the code, and
hopes to maintain the same logic with a framework which can be used to
handle the errors at the volume level.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Daichou 6b349dfe80 Btrfs: remove obsolete FIXMEs in qgroup ioctls
These FIXMEs were already addressed in 2013. All functions check for
qgroup existence:

* btrfs_add_qgroup_relation
* btrfs_ioctl_qgroup_create
* btrfs_limit_qgroup
* btrfs_del_qgroup_relation

Signed-off-by: Daichou <tommy0705c@gmail.com>
[ enhance and reformat changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:58 +02:00
Dan Carpenter 97d038562a Btrfs: remove an unused variable
"item" is never used.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:57 +02:00
Fabian Frederick 977ec79271 btrfs: kmap() can't fail
Remove NULL test on kmap() as it will always return a valid pointer.

Signed-off-by: Fabian Frederick <fabf@skynet.be>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-19 18:25:57 +02:00
NeilBrown 011067b056 blk: replace bioset_create_nobvec() with a flags arg to bioset_create()
"flags" arguments are often seen as good API design as they allow
easy extensibility.
bioset_create_nobvec() is implemented internally as a variation in
flags passed to __bioset_create().

To support future extension, make the internal structure part of the
API.
i.e. add a 'flags' argument to bioset_create() and discard
bioset_create_nobvec().

Note that the bio_split allocations in drivers/md/raid* do not need
the bvec mempool - they should have used bioset_create_nobvec().

Suggested-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Christoph Hellwig <hch@infradead.org>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: NeilBrown <neilb@suse.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-18 12:40:59 -06:00
Linus Torvalds 54ed0f71f0 Merge branch 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6
Pull crypto fix from Herbert Xu:
 "This fixes a bug on sparc where we may dereference freed stack memory"

* 'linus' of git://git.kernel.org/pub/scm/linux/kernel/git/herbert/crypto-2.6:
  crypto: Work around deallocated stack frame reference gcc bug on sparc.
2017-06-15 17:54:51 +09:00
Jens Axboe 8f66439eec Linux 4.12-rc5
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Merge tag 'v4.12-rc5' into for-4.13/block

We've already got a few conflicts and upcoming work depends on some of the
changes that have gone into mainline as regression fixes for this series.

Pull in 4.12-rc5 to resolve these conflicts and make it easier on down stream
trees to continue working on 4.13 changes.

Signed-off-by: Jens Axboe <axboe@kernel.dk>
2017-06-12 08:30:13 -06:00
Linus Torvalds 66cea28a94 Merge branch 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Some fixes that Dave Sterba collected.

  We've been hitting an early enospc problem on production machines that
  Omar tracked down to an old int->u64 mistake. I waited a bit on this
  pull to make sure it was really the problem from production, but it's
  on ~2100 hosts now and I think we're good.

  Omar also noticed a commit in the queue would make new early ENOSPC
  problems. I pulled that out for now, which is why the top three
  commits are younger than the rest.

  Otherwise these are all fixes, some explaining very old bugs that
  we've been poking at for a while"

* 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix delalloc accounting leak caused by u32 overflow
  Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_io
  btrfs: tree-log.c: Wrong printk information about namelen
  btrfs: fix race with relocation recovery and fs_root setup
  btrfs: fix memory leak in update_space_info failure path
  btrfs: use correct types for page indices in btrfs_page_exists_in_range
  btrfs: fix incorrect error return ret being passed to mapping_set_error
  btrfs: Make flush bios explicitely sync
  btrfs: fiemap: Cache and merge fiemap extent before submit it to user
2017-06-10 11:06:05 -07:00
Omar Sandoval 70e7af244f Btrfs: fix delalloc accounting leak caused by u32 overflow
btrfs_calc_trans_metadata_size() does an unsigned 32-bit multiplication,
which can overflow if num_items >= 4 GB / (nodesize * BTRFS_MAX_LEVEL * 2).
For a nodesize of 16kB, this overflow happens at 16k items. Usually,
num_items is a small constant passed to btrfs_start_transaction(), but
we also use btrfs_calc_trans_metadata_size() for metadata reservations
for extent items in btrfs_delalloc_{reserve,release}_metadata().

In drop_outstanding_extents(), num_items is calculated as
inode->reserved_extents - inode->outstanding_extents. The difference
between these two counters is usually small, but if many delalloc
extents are reserved and then the outstanding extents are merged in
btrfs_merge_extent_hook(), the difference can become large enough to
overflow in btrfs_calc_trans_metadata_size().

The overflow manifests itself as a leak of a multiple of 4 GB in
delalloc_block_rsv and the metadata bytes_may_use counter. This in turn
can cause early ENOSPC errors. Additionally, these WARN_ONs in
extent-tree.c will be hit when unmounting:

    WARN_ON(fs_info->delalloc_block_rsv.size > 0);
    WARN_ON(fs_info->delalloc_block_rsv.reserved > 0);
    WARN_ON(space_info->bytes_pinned > 0 ||
            space_info->bytes_reserved > 0 ||
            space_info->bytes_may_use > 0);

Fix it by casting nodesize to a u64 so that
btrfs_calc_trans_metadata_size() does a full 64-bit multiplication.
While we're here, do the same in btrfs_calc_trunc_metadata_size(); this
can't overflow with any existing uses, but it's better to be safe here
than have another hard-to-debug problem later on.

Cc: stable@vger.kernel.org
Signed-off-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-06-09 12:48:36 -07:00
Liu Bo 452e62b71f Btrfs: clear EXTENT_DEFRAG bits in finish_ordered_io
Before this, we use 'filled' mode here, ie. if all range has been
filled with EXTENT_DEFRAG bits, get to clear it, but if the defrag
range joins the adjacent delalloc range, then we'll have EXTENT_DEFRAG
bits in extent_state until releasing this inode's pages, and that
prevents extent_data from being freed.

This clears the bit if any was found within the ordered extent.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-06-09 12:48:29 -07:00
Su Yue 286b92f43c btrfs: tree-log.c: Wrong printk information about namelen
In verify_dir_item, it wants to printk name_len of dir_item but
printk data_len acutally.

Fix it by calling btrfs_dir_name_len instead of btrfs_dir_data_len.

Signed-off-by: Su Yue <suy.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-06-09 12:48:07 -07:00
Christoph Hellwig 4e4cbee93d block: switch bios to blk_status_t
Replace bi_error with a new bi_status to allow for a clear conversion.
Note that device mapper overloaded bi_error with a private value, which
we'll have to keep arround at least for now and thus propagate to a
proper blk_status_t value.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
Christoph Hellwig 4055351cdb fs: remove the unused error argument to dio_end_io()
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-06-09 09:27:32 -06:00
David Miller d41519a69b crypto: Work around deallocated stack frame reference gcc bug on sparc.
On sparc, if we have an alloca() like situation, as is the case with
SHASH_DESC_ON_STACK(), we can end up referencing deallocated stack
memory.  The result can be that the value is clobbered if a trap
or interrupt arrives at just the right instruction.

It only occurs if the function ends returning a value from that
alloca() area and that value can be placed into the return value
register using a single instruction.

For example, in lib/libcrc32c.c:crc32c() we end up with a return
sequence like:

        return  %i7+8
         lduw   [%o5+16], %o0   ! MEM[(u32 *)__shash_desc.1_10 + 16B],

%o5 holds the base of the on-stack area allocated for the shash
descriptor.  But the return released the stack frame and the
register window.

So if an intererupt arrives between 'return' and 'lduw', then
the value read at %o5+16 can be corrupted.

Add a data compiler barrier to work around this problem.  This is
exactly what the gcc fix will end up doing as well, and it absolutely
should not change the code generated for other cpus (unless gcc
on them has the same bug :-)

With crucial insight from Eric Sandeen.

Cc: <stable@vger.kernel.org>
Reported-by: Anatoly Pugachev <matorola@gmail.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
2017-06-08 17:36:03 +08:00
Jeff Mahoney a9b3311ef3 btrfs: fix race with relocation recovery and fs_root setup
If we have to recover relocation during mount, we'll ultimately have to
evict the orphan inode.  That goes through the reservation dance, where
priority_reclaim_metadata_space and flush_space expect fs_info->fs_root
to be valid.  That's the next thing to be set up during mount, so we
crash, almost always in flush_space trying to join the transaction
but priority_reclaim_metadata_space is possible as well.  This call
path has been problematic in the past WRT whether ->fs_root is valid
yet.  Commit 957780eb27 (Btrfs: introduce ticketed enospc
infrastructure) added new users that are called in the direct path
instead of the async path that had already been worked around.

The thing is that we don't actually need the fs_root, specifically, for
anything.  We either use it to determine whether the root is the
chunk_root for use in choosing an allocation profile or as a root to pass
btrfs_join_transaction before immediately committing it.  Anything that
isn't the chunk root works in the former case and any root works in
the latter.

A simple fix is to use a root we know will always be there: the
extent_root.

Cc: <stable@vger.kernel.org> # v4.8+
Fixes: 957780eb27 (Btrfs: introduce ticketed enospc infrastructure)
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-01 16:56:55 +02:00
Jeff Mahoney 896533a7da btrfs: fix memory leak in update_space_info failure path
If we fail to add the space_info kobject, we'll leak the memory
for the percpu counter.

Fixes: 6ab0a2029c (btrfs: publish allocation data in sysfs)
Cc: <stable@vger.kernel.org> # v3.14+
Signed-off-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-01 16:56:31 +02:00
David Sterba cc2b702c52 btrfs: use correct types for page indices in btrfs_page_exists_in_range
Variables start_idx and end_idx are supposed to hold a page index
derived from the file offsets. The int type is not the right one though,
offsets larger than 1 << 44 will get silently trimmed off the high bits.
(1 << 44 is 16TiB)

What can go wrong, if start is below the boundary and end gets trimmed:
- if there's a page after start, we'll find it (radix_tree_gang_lookup_slot)
- the final check "if (page->index <= end_idx)" will unexpectedly fail

The function will return false, ie. "there's no page in the range",
although there is at least one.

btrfs_page_exists_in_range is used to prevent races in:

* in hole punching, where we make sure there are not pages in the
  truncated range, otherwise we'll wait for them to finish and redo
  truncation, but we're going to replace the pages with holes anyway so
  the only problem is the intermediate state

* lock_extent_direct: we want to make sure there are no pages before we
  lock and start DIO, to prevent stale data reads

For practical occurence of the bug, there are several constaints.  The
file must be quite large, the affected range must cross the 16TiB
boundary and the internal state of the file pages and pending operations
must match.  Also, we must not have started any ordered data in the
range, otherwise we don't even reach the buggy function check.

DIO locking tries hard in several places to avoid deadlocks with
buffered IO and avoids waiting for ranges. The worst consequence seems
to be stale data read.

CC: Liu Bo <bo.li.liu@oracle.com>
CC: stable@vger.kernel.org	# 3.16+
Fixes: fc4adbff82 ("btrfs: Drop EXTENT_UPTODATE check in hole punching and direct locking")
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-06-01 16:56:17 +02:00
Colin Ian King bff5baf8aa btrfs: fix incorrect error return ret being passed to mapping_set_error
The setting of return code ret should be based on the error code
passed into function end_extent_writepage and not on ret. Thanks
to Liu Bo for spotting this mistake in the original fix I submitted.

Detected by CoverityScan, CID#1414312 ("Logically dead code")

Fixes: 5dca6eea91 ("Btrfs: mark mapping with error flag to report errors to userspace")
Signed-off-by: Colin Ian King <colin.king@canonical.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-16 15:42:10 +02:00
Jan Kara 8d91012528 btrfs: Make flush bios explicitely sync
Commit b685d3d65a "block: treat REQ_FUA and REQ_PREFLUSH as
synchronous" removed REQ_SYNC flag from WRITE_{FUA|PREFLUSH|...}
definitions.  generic_make_request_checks() however strips REQ_FUA and
REQ_PREFLUSH flags from a bio when the storage doesn't report volatile
write cache and thus write effectively becomes asynchronous which can
lead to performance regressions

Fix the problem by making sure all bios which are synchronous are
properly marked with REQ_SYNC.

CC: David Sterba <dsterba@suse.com>
CC: linux-btrfs@vger.kernel.org
Fixes: b685d3d65a
Signed-off-by: Jan Kara <jack@suse.cz>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-16 15:42:01 +02:00
Qu Wenruo 4751832da9 btrfs: fiemap: Cache and merge fiemap extent before submit it to user
[BUG]
Cycle mount btrfs can cause fiemap to return different result.
Like:
 # mount /dev/vdb5 /mnt/btrfs
 # dd if=/dev/zero bs=16K count=4 oflag=dsync of=/mnt/btrfs/file
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        25088..25215       128   0x1
 # umount /mnt/btrfs
 # mount /dev/vdb5 /mnt/btrfs
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..31]:         25088..25119        32   0x0
   1: [32..63]:        25120..25151        32   0x0
   2: [64..95]:        25152..25183        32   0x0
   3: [96..127]:       25184..25215        32   0x1
But after above fiemap, we get correct merged result if we call fiemap
again.
 # xfs_io -c "fiemap -v" /mnt/btrfs/file
 /mnt/test/file:
 EXT: FILE-OFFSET      BLOCK-RANGE      TOTAL FLAGS
   0: [0..127]:        25088..25215       128   0x1

[REASON]
Btrfs will try to merge extent map when inserting new extent map.

btrfs_fiemap(start=0 len=(u64)-1)
|- extent_fiemap(start=0 len=(u64)-1)
   |- get_extent_skip_holes(start=0 len=64k)
   |  |- btrfs_get_extent_fiemap(start=0 len=64k)
   |     |- btrfs_get_extent(start=0 len=64k)
   |        |  Found on-disk (ino, EXTENT_DATA, 0)
   |        |- add_extent_mapping()
   |        |- Return (em->start=0, len=16k)
   |
   |- fiemap_fill_next_extent(logic=0 phys=X len=16k)
   |
   |- get_extent_skip_holes(start=0 len=64k)
   |  |- btrfs_get_extent_fiemap(start=0 len=64k)
   |     |- btrfs_get_extent(start=16k len=48k)
   |        |  Found on-disk (ino, EXTENT_DATA, 16k)
   |        |- add_extent_mapping()
   |        |  |- try_merge_map()
   |        |     Merge with previous em start=0 len=16k
   |        |     resulting em start=0 len=32k
   |        |- Return (em->start=0, len=32K)    << Merged result
   |- Stripe off the unrelated range (0~16K) of return em
   |- fiemap_fill_next_extent(logic=16K phys=X+16K len=16K)
      ^^^ Causing split fiemap extent.

And since in add_extent_mapping(), em is already merged, in next
fiemap() call, we will get merged result.

[FIX]
Here we introduce a new structure, fiemap_cache, which records previous
fiemap extent.

And will always try to merge current fiemap_cache result before calling
fiemap_fill_next_extent().
Only when we failed to merge current fiemap extent with cached one, we
will call fiemap_fill_next_extent() to submit cached one.

So by this method, we can merge all fiemap extents.

It can also be done in fs/ioctl.c, however the problem is if
fieinfo->fi_extents_max == 0, we have no space to cache previous fiemap
extent.
So I choose to merge it in btrfs.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-05-16 15:41:53 +02:00
Linus Torvalds 1176032cb1 Merge branch 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs updates from Chris Mason:
 "This has fixes and cleanups Dave Sterba collected for the merge
  window.

  The biggest functional fixes are between btrfs raid5/6 and scrub, and
  raid5/6 and device replacement. Some of our pending qgroup fixes are
  included as well while I bash on the rest in testing.

  We also have the usual set of cleanups, including one that makes
  __btrfs_map_block() much more maintainable, and conversions from
  atomic_t to refcount_t"

* 'for-linus-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (71 commits)
  btrfs: fix the gfp_mask for the reada_zones radix tree
  Btrfs: fix reported number of inode blocks
  Btrfs: send, fix file hole not being preserved due to inline extent
  Btrfs: fix extent map leak during fallocate error path
  Btrfs: fix incorrect space accounting after failure to insert inline extent
  Btrfs: fix invalid attempt to free reserved space on failure to cow range
  btrfs: Handle delalloc error correctly to avoid ordered extent hang
  btrfs: Fix metadata underflow caused by btrfs_reloc_clone_csum error
  btrfs: check if the device is flush capable
  btrfs: delete unused member nobarriers
  btrfs: scrub: Fix RAID56 recovery race condition
  btrfs: scrub: Introduce full stripe lock for RAID56
  btrfs: Use ktime_get_real_ts for root ctime
  Btrfs: handle only applicable errors returned by btrfs_get_extent
  btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount option
  btrfs: use q which is already obtained from bdev_get_queue
  Btrfs: switch to div64_u64 if with a u64 divisor
  Btrfs: update scrub_parity to use u64 stripe_len
  Btrfs: enable repair during read for raid56 profile
  btrfs: use clear_page where appropriate
  ...
2017-05-10 08:33:17 -07:00
Michal Hocko 19809c2da2 mm, vmalloc: use __GFP_HIGHMEM implicitly
__vmalloc* allows users to provide gfp flags for the underlying
allocation.  This API is quite popular

  $ git grep "=[[:space:]]__vmalloc\|return[[:space:]]*__vmalloc" | wc -l
  77

The only problem is that many people are not aware that they really want
to give __GFP_HIGHMEM along with other flags because there is really no
reason to consume precious lowmemory on CONFIG_HIGHMEM systems for pages
which are mapped to the kernel vmalloc space.  About half of users don't
use this flag, though.  This signals that we make the API unnecessarily
too complex.

This patch simply uses __GFP_HIGHMEM implicitly when allocating pages to
be mapped to the vmalloc space.  Current users which add __GFP_HIGHMEM
are simplified and drop the flag.

Link: http://lkml.kernel.org/r/20170307141020.29107-1-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Matthew Wilcox <mawilcox@microsoft.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Vlastimil Babka <vbabka@suse.cz>
Cc: David Rientjes <rientjes@google.com>
Cc: Cristopher Lameter <cl@linux.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:13 -07:00
Michal Hocko 752ade68cb treewide: use kv[mz]alloc* rather than opencoded variants
There are many code paths opencoding kvmalloc.  Let's use the helper
instead.  The main difference to kvmalloc is that those users are
usually not considering all the aspects of the memory allocator.  E.g.
allocation requests <= 32kB (with 4kB pages) are basically never failing
and invoke OOM killer to satisfy the allocation.  This sounds too
disruptive for something that has a reasonable fallback - the vmalloc.
On the other hand those requests might fallback to vmalloc even when the
memory allocator would succeed after several more reclaim/compaction
attempts previously.  There is no guarantee something like that happens
though.

This patch converts many of those places to kv[mz]alloc* helpers because
they are more conservative.

Link: http://lkml.kernel.org/r/20170306103327.2766-2-mhocko@kernel.org
Signed-off-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: Boris Ostrovsky <boris.ostrovsky@oracle.com> # Xen bits
Acked-by: Kees Cook <keescook@chromium.org>
Acked-by: Vlastimil Babka <vbabka@suse.cz>
Acked-by: Andreas Dilger <andreas.dilger@intel.com> # Lustre
Acked-by: Christian Borntraeger <borntraeger@de.ibm.com> # KVM/s390
Acked-by: Dan Williams <dan.j.williams@intel.com> # nvdim
Acked-by: David Sterba <dsterba@suse.com> # btrfs
Acked-by: Ilya Dryomov <idryomov@gmail.com> # Ceph
Acked-by: Tariq Toukan <tariqt@mellanox.com> # mlx4
Acked-by: Leon Romanovsky <leonro@mellanox.com> # mlx5
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Heiko Carstens <heiko.carstens@de.ibm.com>
Cc: Herbert Xu <herbert@gondor.apana.org.au>
Cc: Anton Vorontsov <anton@enomsg.org>
Cc: Colin Cross <ccross@android.com>
Cc: Tony Luck <tony.luck@intel.com>
Cc: "Rafael J. Wysocki" <rjw@rjwysocki.net>
Cc: Ben Skeggs <bskeggs@redhat.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Santosh Raspatur <santosh@chelsio.com>
Cc: Hariprasad S <hariprasad@chelsio.com>
Cc: Yishai Hadas <yishaih@mellanox.com>
Cc: Oleg Drokin <oleg.drokin@intel.com>
Cc: "Yan, Zheng" <zyan@redhat.com>
Cc: Alexander Viro <viro@zeniv.linux.org.uk>
Cc: Alexei Starovoitov <ast@kernel.org>
Cc: Eric Dumazet <eric.dumazet@gmail.com>
Cc: David Miller <davem@davemloft.net>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2017-05-08 17:15:13 -07:00
Chris Mason 9bcaaea741 btrfs: fix the gfp_mask for the reada_zones radix tree
Commits cc8385b59e and 7ef70b4d99 added preallocation for the
reada radix trees and also switched them over to GFP_KERNEL for the
default gfp mask.

Since we're doing radix tree insertions under spinlocks, we need
to make sure the mask doesn't allow sleeping.  This fix keeps
the radix preallocation but switches back to the original gfp_mask.

Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-05-04 16:56:11 -07:00
Linus Torvalds 694752922b Merge branch 'for-4.12/block' of git://git.kernel.dk/linux-block
Pull block layer updates from Jens Axboe:

 - Add BFQ IO scheduler under the new blk-mq scheduling framework. BFQ
   was initially a fork of CFQ, but subsequently changed to implement
   fairness based on B-WF2Q+, a modified variant of WF2Q. BFQ is meant
   to be used on desktop type single drives, providing good fairness.
   From Paolo.

 - Add Kyber IO scheduler. This is a full multiqueue aware scheduler,
   using a scalable token based algorithm that throttles IO based on
   live completion IO stats, similary to blk-wbt. From Omar.

 - A series from Jan, moving users to separately allocated backing
   devices. This continues the work of separating backing device life
   times, solving various problems with hot removal.

 - A series of updates for lightnvm, mostly from Javier. Includes a
   'pblk' target that exposes an open channel SSD as a physical block
   device.

 - A series of fixes and improvements for nbd from Josef.

 - A series from Omar, removing queue sharing between devices on mostly
   legacy drivers. This helps us clean up other bits, if we know that a
   queue only has a single device backing. This has been overdue for
   more than a decade.

 - Fixes for the blk-stats, and improvements to unify the stats and user
   windows. This both improves blk-wbt, and enables other users to
   register a need to receive IO stats for a device. From Omar.

 - blk-throttle improvements from Shaohua. This provides a scalable
   framework for implementing scalable priotization - particularly for
   blk-mq, but applicable to any type of block device. The interface is
   marked experimental for now.

 - Bucketized IO stats for IO polling from Stephen Bates. This improves
   efficiency of polled workloads in the presence of mixed block size
   IO.

 - A few fixes for opal, from Scott.

 - A few pulls for NVMe, including a lot of fixes for NVMe-over-fabrics.
   From a variety of folks, mostly Sagi and James Smart.

 - A series from Bart, improving our exposed info and capabilities from
   the blk-mq debugfs support.

 - A series from Christoph, cleaning up how handle WRITE_ZEROES.

 - A series from Christoph, cleaning up the block layer handling of how
   we track errors in a request. On top of being a nice cleanup, it also
   shrinks the size of struct request a bit.

 - Removal of mg_disk and hd (sorry Linus) by Christoph. The former was
   never used by platforms, and the latter has outlived it's usefulness.

 - Various little bug fixes and cleanups from a wide variety of folks.

* 'for-4.12/block' of git://git.kernel.dk/linux-block: (329 commits)
  block: hide badblocks attribute by default
  blk-mq: unify hctx delay_work and run_work
  block: add kblock_mod_delayed_work_on()
  blk-mq: unify hctx delayed_run_work and run_work
  nbd: fix use after free on module unload
  MAINTAINERS: bfq: Add Paolo as maintainer for the BFQ I/O scheduler
  blk-mq-sched: alloate reserved tags out of normal pool
  mtip32xx: use runtime tag to initialize command header
  scsi: Implement blk_mq_ops.show_rq()
  blk-mq: Add blk_mq_ops.show_rq()
  blk-mq: Show operation, cmd_flags and rq_flags names
  blk-mq: Make blk_flags_show() callers append a newline character
  blk-mq: Move the "state" debugfs attribute one level down
  blk-mq: Unregister debugfs attributes earlier
  blk-mq: Only unregister hctxs for which registration succeeded
  blk-mq-debugfs: Rename functions for registering and unregistering the mq directory
  blk-mq: Let blk_mq_debugfs_register() look up the queue name
  blk-mq: Register <dev>/queue/mq after having registered <dev>/queue
  ide-pm: always pass 0 error to ide_complete_rq in ide_do_devset
  ide-pm: always pass 0 error to __blk_end_request_all
  ..
2017-05-01 10:39:57 -07:00
Linus Torvalds 28b2013587 Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fix from Chris Mason:
 "We have one more fix for btrfs.

  This gets rid of a new WARN_ON from rc1 that ended up making more
  noise than we really want. The larger fix for the underflow got
  delayed a bit and it's better for now to put it under
  CONFIG_BTRFS_DEBUG"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: qgroup: move noisy underflow warning to debugging build
2017-04-28 10:13:17 -07:00
Chris Mason bce19f9d23 Merge branch 'for-chris-4.12' of git://git.kernel.org/pub/scm/linux/kernel/git/fdmanana/linux into for-linus-4.12 2017-04-27 14:13:09 -07:00
Filipe Manana a7e3b975a0 Btrfs: fix reported number of inode blocks
Currently when there are buffered writes that were not yet flushed and
they fall within allocated ranges of the file (that is, not in holes or
beyond eof assuming there are no prealloc extents beyond eof), btrfs
simply reports an incorrect number of used blocks through the stat(2)
system call (or any of its variants), regardless of mount options or
inode flags (compress, compress-force, nodatacow). This is because the
number of blocks used that is reported is based on the current number
of bytes in the vfs inode plus the number of dealloc bytes in the btrfs
inode. The later covers bytes that both fall within allocated regions
of the file and holes.

Example scenarios where the number of reported blocks is wrong while the
buffered writes are not flushed:

  $ mkfs.btrfs -f /dev/sdc
  $ mount /dev/sdc /mnt/sdc

  $ xfs_io -f -c "pwrite -S 0xaa 0 64K" /mnt/sdc/foo1
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (259.336 MiB/sec and 66390.0415 ops/sec)

  $ sync

  $ xfs_io -c "pwrite -S 0xbb 0 64K" /mnt/sdc/foo1
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (192.308 MiB/sec and 49230.7692 ops/sec)

  # The following should have reported 64K...
  $ du -h /mnt/sdc/foo1
  128K	/mnt/sdc/foo1

  $ sync

  # After flushing the buffered write, it now reports the correct value.
  $ du -h /mnt/sdc/foo1
  64K	/mnt/sdc/foo1

  $ xfs_io -f -c "falloc -k 0 128K" -c "pwrite -S 0xaa 0 64K" /mnt/sdc/foo2
  wrote 65536/65536 bytes at offset 0
  64 KiB, 16 ops; 0.0000 sec (520.833 MiB/sec and 133333.3333 ops/sec)

  $ sync

  $ xfs_io -c "pwrite -S 0xbb 64K 64K" /mnt/sdc/foo2
  wrote 65536/65536 bytes at offset 65536
  64 KiB, 16 ops; 0.0000 sec (260.417 MiB/sec and 66666.6667 ops/sec)

  # The following should have reported 128K...
  $ du -h /mnt/sdc/foo2
  192K	/mnt/sdc/foo2

  $ sync

  # After flushing the buffered write, it now reports the correct value.
  $ du -h /mnt/sdc/foo2
  128K	/mnt/sdc/foo2

So the number of used file blocks is simply incorrect, unlike in other
filesystems such as ext4 and xfs for example, but only while the buffered
writes are not flushed.

Fix this by tracking the number of delalloc bytes that fall within holes
and beyond eof of a file, and use instead this new counter when reporting
the number of used blocks for an inode.

Another different problem that exists is that the delalloc bytes counter
is reset when writeback starts (by clearing the EXTENT_DEALLOC flag from
the respective range in the inode's iotree) and the vfs inode's bytes
counter is only incremented when writeback finishes (through
insert_reserved_file_extent()). Therefore while writeback is ongoing we
simply report a wrong number of blocks used by an inode if the write
operation covers a range previously unallocated. While this change does
not fix this problem, it does minimizes it a lot by shortening that time
window, as the new dealloc bytes counter (new_delalloc_bytes) is only
decremented when writeback finishes right before updating the vfs inode's
bytes counter. Fully fixing this second problem is not trivial and will
be addressed later by a different patch.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-04-26 16:27:26 +01:00
Filipe Manana e1cbfd7bf6 Btrfs: send, fix file hole not being preserved due to inline extent
Normally we don't have inline extents followed by regular extents, but
there's currently at least one harmless case where this happens. For
example, when the page size is 4Kb and compression is enabled:

  $ mkfs.btrfs -f /dev/sdb
  $ mount -o compress /dev/sdb /mnt
  $ xfs_io -f -c "pwrite -S 0xaa 0 4K" -c "fsync" /mnt/foobar
  $ xfs_io -c "pwrite -S 0xbb 8K 4K" -c "fsync" /mnt/foobar

In this case we get a compressed inline extent, representing 4Kb of
data, followed by a hole extent and then a regular data extent. The
inline extent was not expanded/converted to a regular extent exactly
because it represents 4Kb of data. This does not cause any apparent
problem (such as the issue solved by commit e1699d2d7b
("btrfs: add missing memset while reading compressed inline extents"))
except trigger an unexpected case in the incremental send code path
that makes us issue an operation to write a hole when it's not needed,
resulting in more writes at the receiver and wasting space at the
receiver.

So teach the incremental send code to deal with this particular case.

The issue can be currently triggered by running fstests btrfs/137 with
compression enabled (MOUNT_OPTIONS="-o compress" ./check btrfs/137).

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2017-04-26 16:27:25 +01:00
Filipe Manana be2d253cc9 Btrfs: fix extent map leak during fallocate error path
If the call to btrfs_qgroup_reserve_data() failed, we were leaking an
extent map structure. The failure can happen either due to an -ENOMEM
condition or, when quotas are enabled, due to -EDQUOT for example.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
2017-04-26 16:27:24 +01:00
Filipe Manana 1c81ba237b Btrfs: fix incorrect space accounting after failure to insert inline extent
When using compression, if we fail to insert an inline extent we
incorrectly end up attempting to free the reserved data space twice,
once through extent_clear_unlock_delalloc(), because we pass it the
flag EXTENT_DO_ACCOUNTING, and once through a direct call to
btrfs_free_reserved_data_space_noquota(). This results in a trace
like the following:

[  834.576240] ------------[ cut here ]------------
[  834.576825] WARNING: CPU: 2 PID: 486 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  834.579501] Modules linked in: btrfs crc32c_generic xor raid6_pq ppdev i2c_piix4 acpi_cpufreq psmouse tpm_tis parport_pc pcspkr serio_raw tpm_tis_core sg parport evdev i2c_core tpm button loop autofs4 ext4 crc16 jbd2 mbcache sr_mod cdrom sd_mod ata_generic virtio_scsi ata_piix virtio_pci libata virtio_ring virtio scsi_mod e1000 floppy [last unloaded: btrfs]
[  834.592116] CPU: 2 PID: 486 Comm: kworker/u32:4 Not tainted 4.10.0-rc8-btrfs-next-37+ #2
[  834.593316] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  834.595273] Workqueue: btrfs-delalloc btrfs_delalloc_helper [btrfs]
[  834.596103] Call Trace:
[  834.596103]  dump_stack+0x67/0x90
[  834.596103]  __warn+0xc2/0xdd
[  834.596103]  warn_slowpath_null+0x1d/0x1f
[  834.596103]  btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  834.596103]  compress_file_range.constprop.42+0x2fa/0x3fc [btrfs]
[  834.596103]  ? submit_compressed_extents+0x3a7/0x3a7 [btrfs]
[  834.596103]  async_cow_start+0x32/0x4d [btrfs]
[  834.596103]  btrfs_scrubparity_helper+0x187/0x3e7 [btrfs]
[  834.596103]  btrfs_delalloc_helper+0xe/0x10 [btrfs]
[  834.596103]  process_one_work+0x273/0x4e4
[  834.596103]  worker_thread+0x1eb/0x2ca
[  834.596103]  ? rescuer_thread+0x2b6/0x2b6
[  834.596103]  kthread+0x100/0x108
[  834.596103]  ? __list_del_entry+0x22/0x22
[  834.596103]  ret_from_fork+0x2e/0x40
[  834.611656] ---[ end trace 719902fe6bdef08f ]---

So fix this by not calling directly btrfs_free_reserved_data_space_noquota()
if an error happened.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-04-26 16:27:23 +01:00
Filipe Manana a315e68f6e Btrfs: fix invalid attempt to free reserved space on failure to cow range
When attempting to COW a file range (we are starting writeback and doing
COW), if we manage to reserve an extent for the range we will write into
but fail after reserving it and before creating the respective ordered
extent, we end up in an error path where we attempt to decrement the
data space's bytes_may_use counter after we already did it while
reserving the extent, leading to a warning/trace like the following:

[  847.621524] ------------[ cut here ]------------
[  847.625441] WARNING: CPU: 5 PID: 4905 at fs/btrfs/extent-tree.c:4316 btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  847.633704] Modules linked in: btrfs crc32c_generic xor raid6_pq acpi_cpufreq i2c_piix4 ppdev psmouse tpm_tis serio_raw pcspkr parport_pc tpm_tis_core i2c_core sg
[  847.644616] CPU: 5 PID: 4905 Comm: xfs_io Not tainted 4.10.0-rc8-btrfs-next-37+ #2
[  847.648601] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.9.1-0-gb3ef39f-prebuilt.qemu-project.org 04/01/2014
[  847.648601] Call Trace:
[  847.648601]  dump_stack+0x67/0x90
[  847.648601]  __warn+0xc2/0xdd
[  847.648601]  warn_slowpath_null+0x1d/0x1f
[  847.648601]  btrfs_free_reserved_data_space_noquota+0x60/0x9f [btrfs]
[  847.648601]  btrfs_clear_bit_hook+0x140/0x258 [btrfs]
[  847.648601]  clear_state_bit+0x87/0x128 [btrfs]
[  847.648601]  __clear_extent_bit+0x222/0x2b7 [btrfs]
[  847.648601]  clear_extent_bit+0x17/0x19 [btrfs]
[  847.648601]  extent_clear_unlock_delalloc+0x3b/0x6b [btrfs]
[  847.648601]  cow_file_range.isra.39+0x387/0x39a [btrfs]
[  847.648601]  run_delalloc_nocow+0x4d7/0x70e [btrfs]
[  847.648601]  ? arch_local_irq_save+0x9/0xc
[  847.648601]  run_delalloc_range+0xa7/0x2b5 [btrfs]
[  847.648601]  writepage_delalloc.isra.31+0xb9/0x15c [btrfs]
[  847.648601]  __extent_writepage+0x249/0x2e8 [btrfs]
[  847.648601]  extent_write_cache_pages.constprop.33+0x28b/0x36c [btrfs]
[  847.648601]  ? arch_local_irq_save+0x9/0xc
[  847.648601]  ? mark_lock+0x24/0x201
[  847.648601]  extent_writepages+0x4b/0x5c [btrfs]
[  847.648601]  ? btrfs_writepage_start_hook+0xed/0xed [btrfs]
[  847.648601]  btrfs_writepages+0x28/0x2a [btrfs]
[  847.648601]  do_writepages+0x23/0x2c
[  847.648601]  __filemap_fdatawrite_range+0x5a/0x61
[  847.648601]  filemap_fdatawrite_range+0x13/0x15
[  847.648601]  btrfs_fdatawrite_range+0x20/0x46 [btrfs]
[  847.648601]  start_ordered_ops+0x19/0x23 [btrfs]
[  847.648601]  btrfs_sync_file+0x136/0x42c [btrfs]
[  847.648601]  vfs_fsync_range+0x8c/0x9e
[  847.648601]  vfs_fsync+0x1c/0x1e
[  847.648601]  do_fsync+0x31/0x4a
[  847.648601]  SyS_fsync+0x10/0x14
[  847.648601]  entry_SYSCALL_64_fastpath+0x18/0xad
[  847.648601] RIP: 0033:0x7f5b05200800
[  847.648601] RSP: 002b:00007ffe204f71c8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
[  847.648601] RAX: ffffffffffffffda RBX: ffffffff8109637b RCX: 00007f5b05200800
[  847.648601] RDX: 00000000008bd0a0 RSI: 00000000008bd2e0 RDI: 0000000000000003
[  847.648601] RBP: ffffc90001d67f98 R08: 000000000000ffff R09: 000000000000001f
[  847.648601] R10: 00000000000001f6 R11: 0000000000000246 R12: 0000000000000046
[  847.648601] R13: ffffc90001d67f78 R14: 00007f5b054be740 R15: 00007f5b054be740
[  847.648601]  ? trace_hardirqs_off_caller+0x3f/0xaa
[  847.685787] ---[ end trace 2a4a3e15382508e8 ]---

So fix this by not attempting to decrement the data space info's
bytes_may_use counter if we already reserved the extent and an error
happened before creating the ordered extent. We are already correctly
freeing the reserved extent if an error happens, so there's no additional
measure needed.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2017-04-26 16:27:22 +01:00
Qu Wenruo 524272607e btrfs: Handle delalloc error correctly to avoid ordered extent hang
[BUG]
If run_delalloc_range() returns error and there is already some ordered
extents created, btrfs will be hanged with the following backtrace:

Call Trace:
 __schedule+0x2d4/0xae0
 schedule+0x3d/0x90
 btrfs_start_ordered_extent+0x160/0x200 [btrfs]
 ? wake_atomic_t_function+0x60/0x60
 btrfs_run_ordered_extent_work+0x25/0x40 [btrfs]
 btrfs_scrubparity_helper+0x1c1/0x620 [btrfs]
 btrfs_flush_delalloc_helper+0xe/0x10 [btrfs]
 process_one_work+0x2af/0x720
 ? process_one_work+0x22b/0x720
 worker_thread+0x4b/0x4f0
 kthread+0x10f/0x150
 ? process_one_work+0x720/0x720
 ? kthread_create_on_node+0x40/0x40
 ret_from_fork+0x2e/0x40

[CAUSE]

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<>|                       |<---------- cleanup range --------->|
 ||
 \_=> First page handled by end_extent_writepage() in __extent_writepage()

The problem is caused by error handler of run_delalloc_range(), which
doesn't handle any created ordered extents, leaving them waiting on
btrfs_finish_ordered_io() to finish.

However after run_delalloc_range() returns error, __extent_writepage()
won't submit bio, so btrfs_writepage_end_io_hook() won't be triggered
except the first page, and btrfs_finish_ordered_io() won't be triggered
for created ordered extents either.

So OE 2~n will hang forever, and if OE 1 is larger than one page, it
will also hang.

[FIX]
Introduce btrfs_cleanup_ordered_extents() function to cleanup created
ordered extents and finish them manually.

The function is based on existing
btrfs_endio_direct_write_update_ordered() function, and modify it to
act just like btrfs_writepage_endio_hook() but handles specified range
other than one page.

After fix, delalloc error will be handled like:

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<>|<--------  ----------->|<------ old error handler --------->|
 ||          ||
 ||          \_=> Cleaned up by cleanup_ordered_extents()
 \_=> First page handled by end_extent_writepage() in __extent_writepage()

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
2017-04-26 16:27:21 +01:00
Qu Wenruo 4dbd80fb91 btrfs: Fix metadata underflow caused by btrfs_reloc_clone_csum error
[BUG]
When btrfs_reloc_clone_csum() reports error, it can underflow metadata
and leads to kernel assertion on outstanding extents in
run_delalloc_nocow() and cow_file_range().

 BTRFS info (device vdb5): relocating block group 12582912 flags data
 BTRFS info (device vdb5): found 1 extents
 assertion failed: inode->outstanding_extents >= num_extents, file: fs/btrfs//extent-tree.c, line: 5858

Currently, due to another bug blocking ordered extents, the bug is only
reproducible under certain block group layout and using error injection.

a) Create one data block group with one 4K extent in it.
   To avoid the bug that hangs btrfs due to ordered extent which never
   finishes
b) Make btrfs_reloc_clone_csum() always fail
c) Relocate that block group

[CAUSE]
run_delalloc_nocow() and cow_file_range() handles error from
btrfs_reloc_clone_csum() wrongly:

(The ascii chart shows a more generic case of this bug other than the
bug mentioned above)

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
                    |<----------- cleanup range --------------->|
|<-----------  ----------->|
             \/
 btrfs_finish_ordered_io() range

So error handler, which calls extent_clear_unlock_delalloc() with
EXTENT_DELALLOC and EXTENT_DO_ACCOUNT bits, and btrfs_finish_ordered_io()
will both cover OE n, and free its metadata, causing metadata under flow.

[Fix]
The fix is to ensure after calling btrfs_add_ordered_extent(), we only
call error handler after increasing the iteration offset, so that
cleanup range won't cover any created ordered extent.

|<------------------ delalloc range --------------------------->|
| OE 1 | OE 2 | ... | OE n |
|<-----------  ----------->|<---------- cleanup range --------->|
             \/
 btrfs_finish_ordered_io() range

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
2017-04-26 16:27:21 +01:00
Jan Kara 9e11ceee23 btrfs: Convert to separately allocated bdi
Allocate struct backing_dev_info separately instead of embedding it
inside superblock. This unifies handling of bdi among users.

CC: Chris Mason <clm@fb.com>
CC: Josef Bacik <jbacik@fb.com>
CC: David Sterba <dsterba@suse.com>
CC: linux-btrfs@vger.kernel.org
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jan Kara <jack@suse.cz>
Signed-off-by: Jens Axboe <axboe@fb.com>
2017-04-20 12:09:55 -06:00
David Sterba 338bd52f3c btrfs: qgroup: move noisy underflow warning to debugging build
The WARN_ON and warning from report_reserved_underflow can become very
noisy and is visible unconditionally although this is namely for
debugging. The patch "btrfs: Add WARN_ON for qgroup reserved underflow"
(18dc22c19b) went to 4.11-rc1 and the plan
was to get the fix as well, but this hasn't happened.

CC: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-19 12:40:49 +02:00
Anand Jain c2a9c7ab47 btrfs: check if the device is flush capable
The block layer call chain from submit_bio will check if the write cache
is enabled for the given queue before submitting the flush. This will
add a code to fail fast if its not.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ updated changelog to reflect current code stat, blkdev_issue_flush is
  not used yet ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 16:13:27 +02:00
Anand Jain 13e88e1560 btrfs: delete unused member nobarriers
The last consumer of nobarriers is removed by the commit [1] and sync
won't fail with EOPNOTSUPP anymore. Thus, now when write cache is write
through it just return success without actually transpiring such a
request to the block device/lun.

[1]
commit b25de9d6da
block: remove BIO_EOPNOTSUPP

And, as the device/lun write cache state may change dynamically saving
such as state won't help either. So deleting the member nobarriers.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 16:12:07 +02:00
Qu Wenruo 28d70e237d btrfs: scrub: Fix RAID56 recovery race condition
When scrubbing a RAID5 which has recoverable data corruption (only one
data stripe is corrupted), sometimes scrub will report more csum errors
than expected. Sometimes even unrecoverable error will be reported.

The problem can be easily reproduced by the following steps:
1) Create a btrfs with RAID5 data profile with 3 devs
2) Mount it with nospace_cache or space_cache=v2
   To avoid extra data space usage.
3) Create a 128K file and sync the fs, unmount it
   Now the 128K file lies at the beginning of the data chunk
4) Locate the physical bytenr of data chunk on dev3
   Dev3 is the 1st data stripe.
5) Corrupt the first 64K of the data chunk stripe on dev3
6) Mount the fs and scrub it

The correct csum error number should be 16 (assuming using x86_64).
Larger csum error number can be reported in a 1/3 chance.
And unrecoverable error can also be reported in a 1/10 chance.

The root cause of the problem is RAID5/6 recover code has race
condition, due to the fact that full scrub is initiated per device.

While for other mirror based profiles, each mirror is independent with
each other, so race won't cause any big problem.

For example:
        Corrupted       |       Correct          |      Correct        |
|   Scrub dev3 (D1)     |    Scrub dev2 (D2)     |    Scrub dev1(P)    |
------------------------------------------------------------------------
Read out D1             |Read out D2             |Read full stripe     |
Check csum              |Check csum              |Check parity         |
Csum mismatch           |Csum match, continue    |Parity mismatch      |
handle_errored_block    |                        |handle_errored_block |
 Read out full stripe   |                        | Read out full stripe|
 D1 csum error(err++)   |                        | D1 csum error(err++)|
 Recover D1             |                        | Recover D1          |

So D1's csum error is accounted twice, just because
handle_errored_block() doesn't have enough protection, and race can happen.

On even worse case, for example D1's recovery code is re-writing
D1/D2/P, and P's recovery code is just reading out full stripe, then we
can cause unrecoverable error.

This patch will use previously introduced lock_full_stripe() and
unlock_full_stripe() to protect the whole scrub_handle_errored_block()
function for RAID56 recovery.
So no extra csum error nor unrecoverable error.

Reported-by: Goffredo Baroncelli <kreijack@libero.it>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:27 +02:00
Qu Wenruo 0966a7b130 btrfs: scrub: Introduce full stripe lock for RAID56
Unlike mirror based profiles, RAID5/6 recovery needs to read out the
whole full stripe.

And if we don't do proper protection, it can easily cause race condition.

Introduce 2 new functions: lock_full_stripe() and unlock_full_stripe()
for RAID5/6.
Which store a rb_tree of mutexes for full stripes, so scrub callers can
use them to lock a full stripe to avoid race.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ minor comment adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:27 +02:00
Deepa Dinamani fa7aede2ab btrfs: Use ktime_get_real_ts for root ctime
btrfs_root_item maintains the ctime for root updates.  This is not part
of vfs_inode.

Since current_time() uses struct inode* as an argument as Linus
suggested, this cannot be used to update root times unless, we modify
the signature to use inode.

Since btrfs uses nanosecond time granularity, it can also use
ktime_get_real_ts directly to obtain timestamp for the root. It is
necessary to use the timespec time api here because the same
btrfs_set_stack_timespec_*() apis are used for vfs inode times as well.
These can be transitioned to using timespec64 when btrfs internally
changes to use timespec64 as well.

Signed-off-by: Deepa Dinamani <deepa.kernel@gmail.com>
Acked-by: David Sterba <dsterba@suse.com>
Reviewed-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:27 +02:00
Dan Carpenter 9986277e0e Btrfs: handle only applicable errors returned by btrfs_get_extent
btrfs_get_extent() never returns NULL pointers, so this code introduces
a static checker warning.

The btrfs_get_extent() is a bit complex, but trust me that it doesn't
return NULLs and also if it did we would trigger the BUG_ON(!em) before
the last return statement.

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
[ updated subject ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:27 +02:00
Qu Wenruo 82bafb38c2 btrfs: qgroup: Fix qgroup corruption caused by inode_cache mount option
[BUG]
The easist way to reproduce the bug is:
------
 # mkfs.btrfs -f $dev -n 16K
 # mount $dev $mnt -o inode_cache
 # btrfs quota enable $mnt
 # btrfs quota rescan -w $mnt
 # btrfs qgroup show $mnt
qgroupid         rfer         excl
--------         ----         ----
0/5          32.00KiB     32.00KiB
             ^^ Twice the correct value
------

And fstests/btrfs qgroup test group can easily detect them with
inode_cache mount option.
Although some of them are false alerts since old test cases are using
fixed golden output.
While new test cases will use "btrfs check" to detect qgroup mismatch.

[CAUSE]
Inode_cache mount option will make commit_fs_roots() to call
btrfs_save_ino_cache() to update fs/subvol trees, and generate new
delayed refs.

However we call btrfs_qgroup_prepare_account_extents() too early, before
commit_fs_roots().
This makes the "old_roots" for newly generated extents are always NULL.
For freeing extent case, this makes both new_roots and old_roots to be
empty, while correct old_roots should not be empty.
This causing qgroup numbers not decreased correctly.

[FIX]
Modify the timing of calling btrfs_qgroup_prepare_account_extents() to
just before btrfs_qgroup_account_extents(), and add needed delayed_refs
handler.
So qgroup can handle inode_map mount options correctly.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Anand Jain e884f4f06e btrfs: use q which is already obtained from bdev_get_queue
We have already assigned q from bdev_get_queue() so use it.
And rearrange the code for better view.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Liu Bo 42c61ab676 Btrfs: switch to div64_u64 if with a u64 divisor
This is fixing code pieces where we use div_u64 when passing a u64 divisor.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Liu Bo 972d721939 Btrfs: update scrub_parity to use u64 stripe_len
Commit 3d8da67817 ("Btrfs: fix divide error upon chunk's stripe_len")
changed stripe_len in struct map_lookup to u64, but didn't update
stripe_len in struct scrub_parity.

This updates the type and switches to div64_u64_rem to match u64 divisor.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Liu Bo c725328c55 Btrfs: enable repair during read for raid56 profile
Now that scrub can fix data errors with the help of parity for raid56
profile, repair during read is able to as well.

Although the mirror num in raid56 scenario has different meanings, i.e.
0 or 1: read data directly
> 1:    do recover with parity,
it could be fit into how we repair bad block during read.

The trick is to use BTRFS_MAP_READ instead of BTRFS_MAP_WRITE to get the
device and position on it.

Cc: David Sterba <dsterba@suse.cz>
Tested-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
David Sterba 619a974292 btrfs: use clear_page where appropriate
There's a helper to clear whole page, with a arch-specific optimized
code. The replaced cases do not seem to be in performace critical code,
but we still might get some percent gain.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Qu Wenruo e501bfe323 btrfs: Prevent scrub recheck from racing with dev replace
scrub_setup_recheck_block() calls btrfs_map_sblock() and then accesses
bbio without protection of bio_counter.

This can lead to use-after-free if racing with dev replace cancel.

Fix it by increasing bio_counter before calling btrfs_map_sblock() and
decreasing the bio_counter when corresponding recover is finished.

Cc: Liu Bo <bo.li.liu@oracle.com>
Reported-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Qu Wenruo ae6529c35b btrfs: Wait for in-flight bios before freeing target device for raid56
When raid56 dev-replace is cancelled by running scrub, we will free
target device without waiting for in-flight bios, causing the following
NULL pointer deference or general protection failure.

 BUG: unable to handle kernel NULL pointer dereference at 00000000000005e0
 IP: generic_make_request_checks+0x4d/0x610
 CPU: 1 PID: 11676 Comm: kworker/u4:14 Tainted: G  O    4.11.0-rc2 #72
 Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-20170228_101828-anatol 04/01/2014
 Workqueue: btrfs-endio-raid56 btrfs_endio_raid56_helper [btrfs]
 task: ffff88002875b4c0 task.stack: ffffc90001334000
 RIP: 0010:generic_make_request_checks+0x4d/0x610
 Call Trace:
  ? generic_make_request+0xc7/0x360
  generic_make_request+0x24/0x360
  ? generic_make_request+0xc7/0x360
  submit_bio+0x64/0x120
  ? page_in_rbio+0x4d/0x80 [btrfs]
  ? rbio_orig_end_io+0x80/0x80 [btrfs]
  finish_rmw+0x3f4/0x540 [btrfs]
  validate_rbio_for_rmw+0x36/0x40 [btrfs]
  raid_rmw_end_io+0x7a/0x90 [btrfs]
  bio_endio+0x56/0x60
  end_workqueue_fn+0x3c/0x40 [btrfs]
  btrfs_scrubparity_helper+0xef/0x620 [btrfs]
  btrfs_endio_raid56_helper+0xe/0x10 [btrfs]
  process_one_work+0x2af/0x720
  ? process_one_work+0x22b/0x720
  worker_thread+0x4b/0x4f0
  kthread+0x10f/0x150
  ? process_one_work+0x720/0x720
  ? kthread_create_on_node+0x40/0x40
  ret_from_fork+0x2e/0x40
 RIP: generic_make_request_checks+0x4d/0x610 RSP: ffffc90001337bb8

In btrfs_dev_replace_finishing(), we will call
btrfs_rm_dev_replace_blocked() to wait bios before destroying the target
device when scrub is finished normally.

However when dev-replace is aborted, either due to error or cancelled by
scrub, we didn't wait for bios, this can lead to use-after-free if there
are bios holding the target device.

Furthermore, for raid56 scrub, at least 2 places are calling
btrfs_map_sblock() without protection of bio_counter, leading to the
problem.

This patch fixes the problem:
1) Wait for bio_counter before freeing target device when canceling
   replace
2) When calling btrfs_map_sblock() for raid56, use bio_counter to
   protect the call.

Cc: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Qu Wenruo 9a33944bdf btrfs: scrub: Don't append on-disk pages for raid56 scrub
In the following situation, scrub will calculate wrong parity to
overwrite the correct one:

RAID5 full stripe:

Before
|     Dev 1      |     Dev  2     |     Dev 3     |
| Data stripe 1  | Data stripe 2  | Parity Stripe |
--------------------------------------------------- 0
| 0x0000 (Bad)   |     0xcdcd     |     0x0000    |
--------------------------------------------------- 4K
|     0xcdcd     |     0xcdcd     |     0x0000    |
...
|     0xcdcd     |     0xcdcd     |     0x0000    |
--------------------------------------------------- 64K

After scrubbing dev3 only:

|     Dev 1      |     Dev  2     |     Dev 3     |
| Data stripe 1  | Data stripe 2  | Parity Stripe |
--------------------------------------------------- 0
| 0xcdcd (Good)  |     0xcdcd     | 0xcdcd (Bad)  |
--------------------------------------------------- 4K
|     0xcdcd     |     0xcdcd     |     0x0000    |
...
|     0xcdcd     |     0xcdcd     |     0x0000    |
--------------------------------------------------- 64K

The reason is that after raid56 read rebuild rbio->stripe_pages are all
correctly recovered (0xcd for data stripes).

However when we check and repair parity in
scrub_parity_check_and_repair(), we will append pages in sparity->spages
list to rbio->bio_pages[], which contains old on-disk data.

And when we submit parity data to disk, we calculate parity using
rbio->bio_pages[] first, if rbio->bio_pages[] not found, then fallback
to rbio->stripe_pages[].

The patch fix it by not appending pages from sparity->spages.
So finish_parity_scrub() will use rbio->stripe_pages[] which is correct.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Qu Wenruo d51ea5dd22 btrfs: qgroup: Re-arrange tracepoint timing to co-operate with reserved space tracepoint
Newly introduced qgroup reserved space trace points are normally nested
into several common qgroup operations.

While some other trace points are not well placed to co-operate with
them, causing confusing output.

This patch re-arrange trace_btrfs_qgroup_release_data() and
trace_btrfs_qgroup_free_delayed_ref() trace points so they are triggered
before reserved space ones.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Qu Wenruo 3159fe7bae btrfs: qgroup: Add trace point for qgroup reserved space
Introduce the following trace points:
qgroup_update_reserve
qgroup_meta_reserve

These trace points are handy to trace qgroup reserve space related
problems.

Also export btrfs_qgroup structure, as now we directly pass btrfs_qgroup
structure to trace points, so that structure needs to be exported.

Signed-off-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
David Sterba 825ad4c964 btrfs: drop redundant parameters from btrfs_map_sblock
All callers pass 0 for mirror_num and 1 for need_raid_map.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
David Sterba bcc8e07f9e btrfs: sink GFP flags parameter to tree_mod_log_insert_root
All (1) callers pass the same value.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
David Sterba 176ef8f5e6 btrfs: sink GFP flags parameter to tree_mod_log_insert_move
All (1) callers pass the same value.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Liu Bo abad60c601 Btrfs: fix wrong failed mirror_num of read-repair on raid56
In raid56 scenario, after trying parity recovery, we didn't set
mirror_num for btrfs_bio with failed mirror_num, hence
end_bio_extent_readpage() will report a random mirror_num in dmesg
log.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
Liu Bo 1bcd7aa17f Btrfs: set scrub page's io_error if failing to submit io
Scrub repairs data by the unit called scrub_block, which may contain
several pages.  Scrub always tries to look up a good copy of a whole
block, but if there's no such copy, it tries to do repair page by page.

If we don't set page's io_error when checking this bad copy, in the last
step, we may skip this page when repairing bad copy from good copy.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:26 +02:00
David Sterba 171938e528 btrfs: track exclusive filesystem operation in flags
There are several operations, usually started from ioctls, that cannot
run concurrently. The status is tracked in
mutually_exclusive_operation_running as an atomic_t. We can easily track
the status as one of the per-filesystem flag bits with same
synchronization guarantees.

The conversion replaces:

* atomic_xchg(..., 1)    ->   test_and_set_bit(FLAG, ...)
* atomic_set(..., 0)     ->   clear_bit(FLAG, ...)

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Goldwyn Rodrigues 48a89bc4f2 btrfs: qgroups: Retry after commit on getting EDQUOT
We are facing the same problem with EDQUOT which was experienced with
ENOSPC. Not sure if we require a full ticketing system such as ENOSPC, but
here is a quick fix, which may be too big a hammer.

Quotas are reserved during the start of an operation, incrementing
qg->reserved. However, it is written to disk in a commit_transaction
which could take as long as commit_interval. In the meantime there
could be deletions which are not accounted for because deletions are
accounted for only while committed (free_refroot). So, when we get
a EDQUOT flush the data to disk and try again.

This fixes fstests btrfs/139.

Here is a sample script which shows this issue.

DEVICE=/dev/vdb
MOUNTPOINT=/mnt
TESTVOL=$MOUNTPOINT/tmp
QUOTA=5
PROG=btrfs
DD_BS="4k"
DD_COUNT="256"
RUN_TIMES=5000

mkfs.btrfs -f $DEVICE
mount -o commit=240 $DEVICE $MOUNTPOINT
$PROG subvolume create $TESTVOL
$PROG quota enable $TESTVOL
$PROG qgroup limit ${QUOTA}G $TESTVOL

typeset -i DD_RUN_GOOD
typeset -i QUOTA

function _check_cmd() {
        if [[ ${?} > 0 ]]; then
                echo -n "$(date) E: Running previous command"
                echo ${*}
                echo "Without sync"
                $PROG qgroup show -pcreFf ${TESTVOL}
                echo "With sync"
                $PROG qgroup show -pcreFf --sync ${TESTVOL}
                exit 1
        fi
}

while true; do
  DD_RUN_GOOD=$RUN_TIMES

  while (( ${DD_RUN_GOOD} != 0 )); do
        dd if=/dev/zero of=${TESTVOL}/quotatest${DD_RUN_GOOD} bs=${DD_BS} count=${DD_COUNT}
        _check_cmd "dd if=/dev/zero of=${TESTVOL}/quotatest${DD_RUN_GOOD} bs=${DD_BS} count=${DD_COUNT}"
        DD_RUN_GOOD=(${DD_RUN_GOOD}-1)
  done

  $PROG qgroup show -pcref $TESTVOL
  echo "----------- Cleanup ---------- "
  rm $TESTVOL/quotatest*

done

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Edmund Nadolski de47c9d3ff btrfs: replace hardcoded value with SEQ_LAST macro
Define the SEQ_LAST macro to replace (u64)-1 in places where said
value triggers a special-case ref search behavior.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Edmund Nadolski f58d88b336 btrfs: provide enumeration for __merge_refs mode argument
Replace hardcoded numeric values for __merge_refs 'mode' argument
with descriptive constants.

Signed-off-by: Edmund Nadolski <enadolski@suse.com>
Reviewed-by: Jeff Mahoney <jeffm@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba f486135eba btrfs: remove unused qgroup members from btrfs_trans_handle
The members have been effectively unused since "Btrfs: rework qgroup
accounting" (fcebe4562d), there's no substitute for
assert_qgroups_uptodate so it's removed as well.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba 994a5d2bc7 btrfs: remove local blocksize variable in reada_find_extent
The name is misleading and the local variable serves no purpose.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba 5721b8ad26 btrfs: remove redundant parameter from reada_start_machine_dev
We can read fs_info from dev.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba 0ceaf28213 btrfs: remove redundant parameter from reada_find_zone
We can read fs_info from dev.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba d48d71aa99 btrfs: remove redundant parameter from btree_readahead_hook
We can read fs_info from eb.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba 7ef70b4d99 btrfs: preallocate radix tree node for global readahead tree
We can preallocate the node so insertion does not have to do that under
the lock. The GFP flags for the global radix tree are initialized to
 GFP_NOFS & ~__GFP_DIRECT_RECLAIM
but we can use GFP_KERNEL, because readahead is optional and not on any
critical writeout path.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
David Sterba cc8385b59e btrfs: preallocate radix tree node for readahead
We can preallocate the node so insertion does not have to do that under
the lock. The GFP flags for the per-device radix tree are initialized to
 GFP_NOFS & ~__GFP_DIRECT_RECLAIM
but we can use GFP_KERNEL, same as an allocation above anyway, but also
because readahead is optional and not on any critical writeout path.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Goldwyn Rodrigues 4d339d0106 btrfs: No need to check !(flags & MS_RDONLY) twice
Code cleanup.
The code block is for !(*flags & MS_RDONLY). We don't need
to check it again.

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Liu Bo 1a79c1f246 Btrfs: update comments in cache_save_setup
We also don't bother to flush free space cache while with free space
tree.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Liu Bo 539b50d2f6 Btrfs: convert BUG_ON to WARN_ON
These two BUG_ON()s would never be true, ensured by callers' logic.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Liu Bo 2b19a1fef7 Btrfs: helper for ops that requires full stripe
This adds a helper to show directly whether ops require full stripe.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Liu Bo 6fad823f49 Btrfs: do not add extra mirror when dev_replace target dev is not available
With this, we can avoid allocating memory for dev replace copies if the
target dev is not available.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:25 +02:00
Liu Bo 73c0f22825 Btrfs: handle operations for device replace separately
Since this part is mostly independent, this moves it to a separate
function.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Liu Bo 5ab56090b8 Btrfs: introduce a function to get extra mirror from replace
As the part of getting extra mirror in __btrfs_map_block is
independent, this puts it into a separate function.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Liu Bo 0b3d4cd371 Btrfs: separate DISCARD from __btrfs_map_block
Since DISCARD is not as important as an operation like write, we don't
copy it to target device during replace, and it makes __btrfs_map_block
less complex.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Liu Bo 592d92eeab Btrfs: create a helper for getting chunk map
We have similar code here and there, this merges them into a helper.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Liu Bo 09ed2f165c Btrfs: add file item tracepoints
While debugging truncate problems, I found that these tracepoints could
help us quickly know what went wrong.

Two sets of tracepoints are created to track regular/prealloc file item
and inline file item respectively, I put inline as a separate one since
what inline file items cares about are way less than the regular one.

This adds four tracepoints:
- btrfs_get_extent_show_fi_regular
- btrfs_get_extent_show_fi_inline
- btrfs_truncate_show_fi_regular
- btrfs_truncate_show_fi_inline

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ formatting adjustments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova dec95574f4 btrfs: convert btrfs_raid_bio.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova 99f4cdb16f btrfs: convert scrub_ctx.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova 78a764504d btrfs: convert scrub_parity.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova 186debd6ed btrfs: convert scrub_block.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova 6f615018b3 btrfs: convert scrub_recover.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova a50299ae7c btrfs: convert compressed_bio.pending_bios from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:24 +02:00
Elena Reshetova b7ac31b7b2 btrfs: convert extent_state.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 0700cea7c8 btrfs: convert btrfs_root.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 089e77e10d btrfs: convert btrfs_delayed_item.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 6de5f18e7b btrfs: convert btrfs_delayed_node.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 6df8cdf5bd btrfs: convert btrfs_delayed_ref_node.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 1e4f4714d5 btrfs: convert btrfs_caching_control.count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova e76edab7f0 btrfs: convert btrfs_ordered_extent.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 490b54d6fb btrfs: convert extent_map.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 9b64f57ddf btrfs: convert btrfs_transaction.use_count from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Elena Reshetova 140475ae4a btrfs: convert btrfs_bio.refs from atomic_t to refcount_t
refcount_t type and corresponding API should be
used instead of atomic_t when the variable is used as
a reference counter. This allows to avoid accidental
refcounter overflows that might lead to use-after-free
situations.

Signed-off-by: Elena Reshetova <elena.reshetova@intel.com>
Signed-off-by: Hans Liljestrand <ishkamiel@gmail.com>
Signed-off-by: Kees Cook <keescook@chromium.org>
Signed-off-by: David Windsor <dwindsor@gmail.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Liu Bo f95fda8751 Btrfs: remove ASSERT in btrfs_truncate_inode_items
After 76b42abbf7 ("Btrfs: fix data loss after truncate when using the
no-holes feature"),

For either NO_HOLES or inline extents, we've set last_size to newsize to
avoid data loss after remount or inode got evicted and read again, thus,
we don't need this check anymore.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Adam Borowski 1450612797 btrfs: fix a bogus warning when converting only data or metadata
If your filesystem has, eg, data:raid0 metadata:raid1, and you run "btrfs
balance -dconvert=raid1", the meta.target field will be uninitialized.
That's otherwise ok, as it's unused except for this warning.

Thus, let's use the existing set of raid levels for the comparison.

As a side effect, non-convert balances will now nag about data>metadata.

Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-18 14:07:23 +02:00
Linus Torvalds 4b31ac485d Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Dave Sterba collected a few more fixes for the last rc.

  These aren't marked for stable, but I'm putting them in with a batch
  were testing/sending by hand for this release"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix potential use-after-free for cloned bio
  Btrfs: fix segmentation fault when doing dio read
  Btrfs: fix invalid dereference in btrfs_retry_endio
  btrfs: drop the nossd flag when remounting with -o ssd
2017-04-14 16:53:45 -07:00
Liu Bo a967efb30b Btrfs: fix potential use-after-free for cloned bio
KASAN reports that there is a use-after-free case of bio in btrfs_map_bio.

If we need to submit IOs to several disks at a time, the original bio
would get cloned and mapped to the destination disk, but we really should
use the original bio instead of a cloned bio to do the sanity check
because cloned bios are likely to be freed by its endio.

Reported-by: Diego <diegocg@gmail.com>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11 18:49:56 +02:00
Liu Bo 97bf5a5589 Btrfs: fix segmentation fault when doing dio read
Commit 2dabb32484 ("Btrfs: Direct I/O read: Work on sectorsized blocks")
introduced this bug during iterating bio pages in dio read's endio hook,
and it could end up with segment fault of the dio reading task.

So the reason is 'if (nr_sectors--)', and it makes the code assume that
there is one more block in the same page, so page offset is increased and
the bio which is created to repair the bad block then has an incorrect
bvec.bv_offset, and a later access of the page content would throw a
segmentation fault.

This also adds ASSERT to check page offset against page size.

Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11 18:49:29 +02:00
Liu Bo 2e949b0a55 Btrfs: fix invalid dereference in btrfs_retry_endio
When doing directIO repair, we have this oops:

[ 1458.532816] general protection fault: 0000 [#1] SMP
...
[ 1458.536291] Workqueue: btrfs-endio-repair btrfs_endio_repair_helper [btrfs]
[ 1458.536893] task: ffff88082a42d100 task.stack: ffffc90002b3c000
[ 1458.537499] RIP: 0010:btrfs_retry_endio+0x7e/0x1a0 [btrfs]
...
[ 1458.543261] Call Trace:
[ 1458.543958]  ? rcu_read_lock_sched_held+0xc4/0xd0
[ 1458.544374]  bio_endio+0xed/0x100
[ 1458.544750]  end_workqueue_fn+0x3c/0x40 [btrfs]
[ 1458.545257]  normal_work_helper+0x9f/0x900 [btrfs]
[ 1458.545762]  btrfs_endio_repair_helper+0x12/0x20 [btrfs]
[ 1458.546224]  process_one_work+0x34d/0xb70
[ 1458.546570]  ? process_one_work+0x29e/0xb70
[ 1458.546938]  worker_thread+0x1cf/0x960
[ 1458.547263]  ? process_one_work+0xb70/0xb70
[ 1458.547624]  kthread+0x17d/0x180
[ 1458.547909]  ? kthread_create_on_node+0x70/0x70
[ 1458.548300]  ret_from_fork+0x31/0x40

It turns out that btrfs_retry_endio is trying to get inode from a directIO
page.

This fixes the problem by using the saved inode pointer, done->inode.
btrfs_retry_endio_nocsum has the same problem, and it's fixed as well.

Also cleanup unused @start (which is too trivial for a separate patch).

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11 18:49:08 +02:00
Adam Borowski 951e796639 btrfs: drop the nossd flag when remounting with -o ssd
The opposite case was already handled right in the very next switch entry.
And also when turning on nossd, drop ssd_spread.

Reported-by: Hans van Kranenburg <hans.van.kranenburg@mendix.com>
Signed-off-by: Adam Borowski <kilobyte@angband.pl>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-04-11 18:48:59 +02:00
Linus Torvalds fe8e12b503 Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "We have three small fixes queued up in my for-linus-4.11 branch"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  Btrfs: fix an integer overflow check
  btrfs: Change qgroup_meta_rsv to 64bit
  Btrfs: bring back repair during read
2017-03-31 17:58:48 -07:00
Dan Carpenter 457ae7268b Btrfs: fix an integer overflow check
This isn't super serious because you need CAP_ADMIN to run this code.

I added this integer overflow check last year but apparently I am
rubbish at writing integer overflow checks...  There are two issues.
First, access_ok() works on unsigned long type and not u64 so on 32 bit
systems the access_ok() could be checking a truncated size.  The other
issue is that we should be using a stricter limit so we don't overflow
the kzalloc() setting ctx->clone_roots later in the function after the
access_ok():

	alloc_size = sizeof(struct clone_root) * (arg->clone_sources_count + 1);
	sctx->clone_roots = kzalloc(alloc_size, GFP_KERNEL | __GFP_NOWARN);

Fixes: f5ecec3ce2 ("btrfs: send: silence an integer overflow warning")
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ added comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-29 14:29:08 +02:00
Goldwyn Rodrigues ce0dcee626 btrfs: Change qgroup_meta_rsv to 64bit
Using an int value is causing qg->reserved to become negative and
exclusive -EDQUOT to be reached prematurely.

This affects exclusive qgroups only.

TEST CASE:

DEVICE=/dev/vdb
MOUNTPOINT=/mnt
SUBVOL=$MOUNTPOINT/tmp

umount $SUBVOL
umount $MOUNTPOINT

mkfs.btrfs -f $DEVICE
mount /dev/vdb $MOUNTPOINT
btrfs quota enable $MOUNTPOINT
btrfs subvol create $SUBVOL
umount $MOUNTPOINT
mount /dev/vdb $MOUNTPOINT
mount -o subvol=tmp $DEVICE $SUBVOL
btrfs qgroup limit -e 3G $SUBVOL

btrfs quota rescan /mnt -w

for i in `seq 1 44000`; do
  dd if=/dev/zero of=/mnt/tmp/test_$i bs=10k count=1
  if [[ $? > 0 ]]; then
     btrfs qgroup show -pcref $SUBVOL
     exit 1
  fi
done

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
[ add reproducer to changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-29 14:29:08 +02:00
Liu Bo 9d0d1c8b1c Btrfs: bring back repair during read
Commit 20a7db8ab3 ("btrfs: add dummy callback for readpage_io_failed
and drop checks") made a cleanup around readpage_io_failed_hook, and
it was supposed to keep the original sematics, but it also
unexpectedly disabled repair during read for dup, raid1 and raid10.

This fixes the problem by letting data's inode call the generic
readpage_io_failed callback by returning -EAGAIN from its
readpage_io_failed_hook in order to notify end_bio_extent_readpage to
do the rest.  We don't call it directly because the generic one takes
an offset from end_bio_extent_readpage() to calculate the index in the
checksum array and inode's readpage_io_failed_hook doesn't offer that
offset.

Cc: David Sterba <dsterba@suse.cz>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ keep the const function attribute ]
Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-29 14:29:07 +02:00
Linus Torvalds 131fbf4f9c Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull btrfs fixes from Chris Mason:
 "Zygo tracked down a very old bug with inline compressed extents.

  I didn't tag this one for stable because I want to do individual
  tested backports. It's a little tricky and I'd rather do some extra
  testing on it along the way"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs:
  btrfs: add missing memset while reading compressed inline extents
  Btrfs: fix regression in lock_delalloc_pages
  btrfs: remove btrfs_err_str function from uapi/linux/btrfs.h
2017-03-23 11:39:33 -07:00
Zygo Blaxell e1699d2d7b btrfs: add missing memset while reading compressed inline extents
This is a story about 4 distinct (and very old) btrfs bugs.

Commit c8b978188c ("Btrfs: Add zlib compression support") added
three data corruption bugs for inline extents (bugs #1-3).

Commit 93c82d5750 ("Btrfs: zero page past end of inline file items")
fixed bug #1:  uncompressed inline extents followed by a hole and more
extents could get non-zero data in the hole as they were read.  The fix
was to add a memset in btrfs_get_extent to zero out the hole.

Commit 166ae5a418 ("btrfs: fix inline compressed read err corruption")
fixed bug #2:  compressed inline extents which contained non-zero bytes
might be replaced with zero bytes in some cases.  This patch removed an
unhelpful memset from uncompress_inline, but the case where memset is
required was missed.

There is also a memset in the decompression code, but this only covers
decompressed data that is shorter than the ram_bytes from the extent
ref record.  This memset doesn't cover the region between the end of the
decompressed data and the end of the page.  It has also moved around a
few times over the years, so there's no single patch to refer to.

This patch fixes bug #3:  compressed inline extents followed by a hole
and more extents could get non-zero data in the hole as they were read
(i.e. bug #3 is the same as bug #1, but s/uncompressed/compressed/).
The fix is the same:  zero out the hole in the compressed case too,
by putting a memset back in uncompress_inline, but this time with
correct parameters.

The last and oldest bug, bug #0, is the cause of the offending inline
extent/hole/extent pattern.  Bug #0 is a subtle and mostly-harmless quirk
of behavior somewhere in the btrfs write code.  In a few special cases,
an inline extent and hole are allowed to persist where they normally
would be combined with later extents in the file.

A fast reproducer for bug #0 is presented below.  A few offending extents
are also created in the wild during large rsync transfers with the -S
flag.  A Linux kernel build (git checkout; make allyesconfig; make -j8)
will produce a handful of offending files as well.  Once an offending
file is created, it can present different content to userspace each
time it is read.

Bug #0 is at least 4 and possibly 8 years old.  I verified every vX.Y
kernel back to v3.5 has this behavior.  There are fossil records of this
bug's effects in commits all the way back to v2.6.32.  I have no reason
to believe bug #0 wasn't present at the beginning of btrfs compression
support in v2.6.29, but I can't easily test kernels that old to be sure.

It is not clear whether bug #0 is worth fixing.  A fix would likely
require injecting extra reads into currently write-only paths, and most
of the exceptional cases caused by bug #0 are already handled now.

Whether we like them or not, bug #0's inline extents followed by holes
are part of the btrfs de-facto disk format now, and we need to be able
to read them without data corruption or an infoleak.  So enough about
bug #0, let's get back to bug #3 (this patch).

An example of on-disk structure leading to data corruption found in
the wild:

        item 61 key (606890 INODE_ITEM 0) itemoff 9662 itemsize 160
                inode generation 50 transid 50 size 47424 nbytes 49141
                block group 0 mode 100644 links 1 uid 0 gid 0
                rdev 0 flags 0x0(none)
        item 62 key (606890 INODE_REF 603050) itemoff 9642 itemsize 20
                inode ref index 3 namelen 10 name: DB_File.so
        item 63 key (606890 EXTENT_DATA 0) itemoff 8280 itemsize 1362
                inline extent data size 1341 ram 4085 compress(zlib)
        item 64 key (606890 EXTENT_DATA 4096) itemoff 8227 itemsize 53
                extent data disk byte 5367308288 nr 20480
                extent data offset 0 nr 45056 ram 45056
                extent compression(zlib)

Different data appears in userspace during each read of the 11 bytes
between 4085 and 4096.  The extent in item 63 is not long enough to
fill the first page of the file, so a memset is required to fill the
space between item 63 (ending at 4085) and item 64 (beginning at 4096)
with zero.

Here is a reproducer from Liu Bo, which demonstrates another method
of creating the same inline extent and hole pattern:

Using 'page_poison=on' kernel command line (or enable
CONFIG_PAGE_POISONING) run the following:

	# touch foo
	# chattr +c foo
	# xfs_io -f -c "pwrite -W 0 1000" foo
	# xfs_io -f -c "falloc 4 8188" foo
	# od -x foo
	# echo 3 >/proc/sys/vm/drop_caches
	# od -x foo

This produce the following on my box:

Correct output:  file contains 1000 data bytes followed
by zeros:

	0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
	*
	0001740 cdcd cdcd cdcd cdcd 0000 0000 0000 0000
	0001760 0000 0000 0000 0000 0000 0000 0000 0000
	*
	0020000

Actual output:  the data after the first 1000 bytes
will be different each run:

	0000000 cdcd cdcd cdcd cdcd cdcd cdcd cdcd cdcd
	*
	0001740 cdcd cdcd cdcd cdcd 6c63 7400 635f 006d
	0001760 5f74 6f43 7400 435f 0053 5f74 7363 7400
	0002000 435f 0056 5f74 6164 7400 645f 0062 5f74
	(...)

Signed-off-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Reviewed-by: Chris Mason <clm@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
2017-03-17 13:47:10 -07:00
Liu Bo 49d4a33472 Btrfs: fix regression in lock_delalloc_pages
The bug is a regression after commit
(da2c7009f6 "btrfs: teach __process_pages_contig about PAGE_LOCK operation")
and commit
(76c0021db8 "Btrfs: use helper to simplify lock/unlock pages").

So if the dirty pages which are under writeback got truncated partially
before we lock the dirty pages, we couldn't find all pages mapping to the
delalloc range, and the bug didn't return an error so it kept going on and
found that the delalloc range got truncated and got to unlock the dirty
pages, and then the ASSERT could caught the error, and showed

-----------------------------------------------------------------------------
assertion failed: page_ops & PAGE_LOCK, file: fs/btrfs/extent_io.c, line: 1716
-----------------------------------------------------------------------------

This fixes the bug by returning the proper -EAGAIN.

Cc: David Sterba <dsterba@suse.com>
Reported-by: Dave Jones <davej@codemonkey.org.uk>
Signed-off-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-03-17 13:47:09 -07:00
Linus Torvalds 590dce2d49 Merge branch 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs 'statx()' update from Al Viro.

This adds the new extended stat() interface that internally subsumes our
previous stat interfaces, and allows user mode to specify in more detail
what kind of information it wants.

It also allows for some explicit synchronization information to be
passed to the filesystem, which can be relevant for network filesystems:
is the cached value ok, or do you need open/close consistency, or what?

From David Howells.

Andreas Dilger points out that the first version of the extended statx
interface was posted June 29, 2010:

    https://www.spinics.net/lists/linux-fsdevel/msg33831.html

* 'rebased-statx' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs:
  statx: Add a system call to make enhanced file info available
2017-03-03 11:38:56 -08:00
Linus Torvalds 1827adb11a Merge branch 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip
Pull sched.h split-up from Ingo Molnar:
 "The point of these changes is to significantly reduce the
  <linux/sched.h> header footprint, to speed up the kernel build and to
  have a cleaner header structure.

  After these changes the new <linux/sched.h>'s typical preprocessed
  size goes down from a previous ~0.68 MB (~22K lines) to ~0.45 MB (~15K
  lines), which is around 40% faster to build on typical configs.

  Not much changed from the last version (-v2) posted three weeks ago: I
  eliminated quirks, backmerged fixes plus I rebased it to an upstream
  SHA1 from yesterday that includes most changes queued up in -next plus
  all sched.h changes that were pending from Andrew.

  I've re-tested the series both on x86 and on cross-arch defconfigs,
  and did a bisectability test at a number of random points.

  I tried to test as many build configurations as possible, but some
  build breakage is probably still left - but it should be mostly
  limited to architectures that have no cross-compiler binaries
  available on kernel.org, and non-default configurations"

* 'WIP.sched-core-for-linus' of git://git.kernel.org/pub/scm/linux/kernel/git/tip/tip: (146 commits)
  sched/headers: Clean up <linux/sched.h>
  sched/headers: Remove #ifdefs from <linux/sched.h>
  sched/headers: Remove the <linux/topology.h> include from <linux/sched.h>
  sched/headers, hrtimer: Remove the <linux/wait.h> include from <linux/hrtimer.h>
  sched/headers, x86/apic: Remove the <linux/pm.h> header inclusion from <asm/apic.h>
  sched/headers, timers: Remove the <linux/sysctl.h> include from <linux/timer.h>
  sched/headers: Remove <linux/magic.h> from <linux/sched/task_stack.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/init.h>
  sched/core: Remove unused prefetch_stack()
  sched/headers: Remove <linux/rculist.h> from <linux/sched.h>
  sched/headers: Remove the 'init_pid_ns' prototype from <linux/sched.h>
  sched/headers: Remove <linux/signal.h> from <linux/sched.h>
  sched/headers: Remove <linux/rwsem.h> from <linux/sched.h>
  sched/headers: Remove the runqueue_is_locked() prototype
  sched/headers: Remove <linux/sched.h> from <linux/sched/hotplug.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/debug.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/nohz.h>
  sched/headers: Remove <linux/sched.h> from <linux/sched/stat.h>
  sched/headers: Remove the <linux/gfp.h> include from <linux/sched.h>
  sched/headers: Remove <linux/rtmutex.h> from <linux/sched.h>
  ...
2017-03-03 10:16:38 -08:00
David Howells a528d35e8b statx: Add a system call to make enhanced file info available
Add a system call to make extended file information available, including
file creation and some attribute flags where available through the
underlying filesystem.

The getattr inode operation is altered to take two additional arguments: a
u32 request_mask and an unsigned int flags that indicate the
synchronisation mode.  This change is propagated to the vfs_getattr*()
function.

Functions like vfs_stat() are now inline wrappers around new functions
vfs_statx() and vfs_statx_fd() to reduce stack usage.

========
OVERVIEW
========

The idea was initially proposed as a set of xattrs that could be retrieved
with getxattr(), but the general preference proved to be for a new syscall
with an extended stat structure.

A number of requests were gathered for features to be included.  The
following have been included:

 (1) Make the fields a consistent size on all arches and make them large.

 (2) Spare space, request flags and information flags are provided for
     future expansion.

 (3) Better support for the y2038 problem [Arnd Bergmann] (tv_sec is an
     __s64).

 (4) Creation time: The SMB protocol carries the creation time, which could
     be exported by Samba, which will in turn help CIFS make use of
     FS-Cache as that can be used for coherency data (stx_btime).

     This is also specified in NFSv4 as a recommended attribute and could
     be exported by NFSD [Steve French].

 (5) Lightweight stat: Ask for just those details of interest, and allow a
     netfs (such as NFS) to approximate anything not of interest, possibly
     without going to the server [Trond Myklebust, Ulrich Drepper, Andreas
     Dilger] (AT_STATX_DONT_SYNC).

 (6) Heavyweight stat: Force a netfs to go to the server, even if it thinks
     its cached attributes are up to date [Trond Myklebust]
     (AT_STATX_FORCE_SYNC).

And the following have been left out for future extension:

 (7) Data version number: Could be used by userspace NFS servers [Aneesh
     Kumar].

     Can also be used to modify fill_post_wcc() in NFSD which retrieves
     i_version directly, but has just called vfs_getattr().  It could get
     it from the kstat struct if it used vfs_xgetattr() instead.

     (There's disagreement on the exact semantics of a single field, since
     not all filesystems do this the same way).

 (8) BSD stat compatibility: Including more fields from the BSD stat such
     as creation time (st_btime) and inode generation number (st_gen)
     [Jeremy Allison, Bernd Schubert].

 (9) Inode generation number: Useful for FUSE and userspace NFS servers
     [Bernd Schubert].

     (This was asked for but later deemed unnecessary with the
     open-by-handle capability available and caused disagreement as to
     whether it's a security hole or not).

(10) Extra coherency data may be useful in making backups [Andreas Dilger].

     (No particular data were offered, but things like last backup
     timestamp, the data version number and the DOS archive bit would come
     into this category).

(11) Allow the filesystem to indicate what it can/cannot provide: A
     filesystem can now say it doesn't support a standard stat feature if
     that isn't available, so if, for instance, inode numbers or UIDs don't
     exist or are fabricated locally...

     (This requires a separate system call - I have an fsinfo() call idea
     for this).

(12) Store a 16-byte volume ID in the superblock that can be returned in
     struct xstat [Steve French].

     (Deferred to fsinfo).

(13) Include granularity fields in the time data to indicate the
     granularity of each of the times (NFSv4 time_delta) [Steve French].

     (Deferred to fsinfo).

(14) FS_IOC_GETFLAGS value.  These could be translated to BSD's st_flags.
     Note that the Linux IOC flags are a mess and filesystems such as Ext4
     define flags that aren't in linux/fs.h, so translation in the kernel
     may be a necessity (or, possibly, we provide the filesystem type too).

     (Some attributes are made available in stx_attributes, but the general
     feeling was that the IOC flags were to ext[234]-specific and shouldn't
     be exposed through statx this way).

(15) Mask of features available on file (eg: ACLs, seclabel) [Brad Boyer,
     Michael Kerrisk].

     (Deferred, probably to fsinfo.  Finding out if there's an ACL or
     seclabal might require extra filesystem operations).

(16) Femtosecond-resolution timestamps [Dave Chinner].

     (A __reserved field has been left in the statx_timestamp struct for
     this - if there proves to be a need).

(17) A set multiple attributes syscall to go with this.

===============
NEW SYSTEM CALL
===============

The new system call is:

	int ret = statx(int dfd,
			const char *filename,
			unsigned int flags,
			unsigned int mask,
			struct statx *buffer);

The dfd, filename and flags parameters indicate the file to query, in a
similar way to fstatat().  There is no equivalent of lstat() as that can be
emulated with statx() by passing AT_SYMLINK_NOFOLLOW in flags.  There is
also no equivalent of fstat() as that can be emulated by passing a NULL
filename to statx() with the fd of interest in dfd.

Whether or not statx() synchronises the attributes with the backing store
can be controlled by OR'ing a value into the flags argument (this typically
only affects network filesystems):

 (1) AT_STATX_SYNC_AS_STAT tells statx() to behave as stat() does in this
     respect.

 (2) AT_STATX_FORCE_SYNC will require a network filesystem to synchronise
     its attributes with the server - which might require data writeback to
     occur to get the timestamps correct.

 (3) AT_STATX_DONT_SYNC will suppress synchronisation with the server in a
     network filesystem.  The resulting values should be considered
     approximate.

mask is a bitmask indicating the fields in struct statx that are of
interest to the caller.  The user should set this to STATX_BASIC_STATS to
get the basic set returned by stat().  It should be noted that asking for
more information may entail extra I/O operations.

buffer points to the destination for the data.  This must be 256 bytes in
size.

======================
MAIN ATTRIBUTES RECORD
======================

The following structures are defined in which to return the main attribute
set:

	struct statx_timestamp {
		__s64	tv_sec;
		__s32	tv_nsec;
		__s32	__reserved;
	};

	struct statx {
		__u32	stx_mask;
		__u32	stx_blksize;
		__u64	stx_attributes;
		__u32	stx_nlink;
		__u32	stx_uid;
		__u32	stx_gid;
		__u16	stx_mode;
		__u16	__spare0[1];
		__u64	stx_ino;
		__u64	stx_size;
		__u64	stx_blocks;
		__u64	__spare1[1];
		struct statx_timestamp	stx_atime;
		struct statx_timestamp	stx_btime;
		struct statx_timestamp	stx_ctime;
		struct statx_timestamp	stx_mtime;
		__u32	stx_rdev_major;
		__u32	stx_rdev_minor;
		__u32	stx_dev_major;
		__u32	stx_dev_minor;
		__u64	__spare2[14];
	};

The defined bits in request_mask and stx_mask are:

	STATX_TYPE		Want/got stx_mode & S_IFMT
	STATX_MODE		Want/got stx_mode & ~S_IFMT
	STATX_NLINK		Want/got stx_nlink
	STATX_UID		Want/got stx_uid
	STATX_GID		Want/got stx_gid
	STATX_ATIME		Want/got stx_atime{,_ns}
	STATX_MTIME		Want/got stx_mtime{,_ns}
	STATX_CTIME		Want/got stx_ctime{,_ns}
	STATX_INO		Want/got stx_ino
	STATX_SIZE		Want/got stx_size
	STATX_BLOCKS		Want/got stx_blocks
	STATX_BASIC_STATS	[The stuff in the normal stat struct]
	STATX_BTIME		Want/got stx_btime{,_ns}
	STATX_ALL		[All currently available stuff]

stx_btime is the file creation time, stx_mask is a bitmask indicating the
data provided and __spares*[] are where as-yet undefined fields can be
placed.

Time fields are structures with separate seconds and nanoseconds fields
plus a reserved field in case we want to add even finer resolution.  Note
that times will be negative if before 1970; in such a case, the nanosecond
fields will also be negative if not zero.

The bits defined in the stx_attributes field convey information about a
file, how it is accessed, where it is and what it does.  The following
attributes map to FS_*_FL flags and are the same numerical value:

	STATX_ATTR_COMPRESSED		File is compressed by the fs
	STATX_ATTR_IMMUTABLE		File is marked immutable
	STATX_ATTR_APPEND		File is append-only
	STATX_ATTR_NODUMP		File is not to be dumped
	STATX_ATTR_ENCRYPTED		File requires key to decrypt in fs

Within the kernel, the supported flags are listed by:

	KSTAT_ATTR_FS_IOC_FLAGS

[Are any other IOC flags of sufficient general interest to be exposed
through this interface?]

New flags include:

	STATX_ATTR_AUTOMOUNT		Object is an automount trigger

These are for the use of GUI tools that might want to mark files specially,
depending on what they are.

Fields in struct statx come in a number of classes:

 (0) stx_dev_*, stx_blksize.

     These are local system information and are always available.

 (1) stx_mode, stx_nlinks, stx_uid, stx_gid, stx_[amc]time, stx_ino,
     stx_size, stx_blocks.

     These will be returned whether the caller asks for them or not.  The
     corresponding bits in stx_mask will be set to indicate whether they
     actually have valid values.

     If the caller didn't ask for them, then they may be approximated.  For
     example, NFS won't waste any time updating them from the server,
     unless as a byproduct of updating something requested.

     If the values don't actually exist for the underlying object (such as
     UID or GID on a DOS file), then the bit won't be set in the stx_mask,
     even if the caller asked for the value.  In such a case, the returned
     value will be a fabrication.

     Note that there are instances where the type might not be valid, for
     instance Windows reparse points.

 (2) stx_rdev_*.

     This will be set only if stx_mode indicates we're looking at a
     blockdev or a chardev, otherwise will be 0.

 (3) stx_btime.

     Similar to (1), except this will be set to 0 if it doesn't exist.

=======
TESTING
=======

The following test program can be used to test the statx system call:

	samples/statx/test-statx.c

Just compile and run, passing it paths to the files you want to examine.
The file is built automatically if CONFIG_SAMPLES is enabled.

Here's some example output.  Firstly, an NFS directory that crosses to
another FSID.  Note that the AUTOMOUNT attribute is set because transiting
this directory will cause d_automount to be invoked by the VFS.

	[root@andromeda ~]# /tmp/test-statx -A /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:26           Inode: 1703937     Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000
	Attributes: 0000000000001000 (-------- -------- -------- -------- -------- -------- ---m---- --------)

Secondly, the result of automounting on that directory.

	[root@andromeda ~]# /tmp/test-statx /warthog/data
	statx(/warthog/data) = 0
	results=7ff
	  Size: 4096            Blocks: 8          IO Block: 1048576  directory
	Device: 00:27           Inode: 2           Links: 125
	Access: (3777/drwxrwxrwx)  Uid:     0   Gid:  4041
	Access: 2016-11-24 09:02:12.219699527+0000
	Modify: 2016-11-17 10:44:36.225653653+0000
	Change: 2016-11-17 10:44:36.225653653+0000

Signed-off-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2017-03-02 20:51:15 -05:00
Linus Torvalds bbe08c0a43 Merge branch 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs
Pull more btrfs updates from Chris Mason:
 "Btrfs round two.

  These are mostly a continuation of Dave Sterba's collection of
  cleanups, but Filipe also has some bug fixes and performance
  improvements"

* 'for-linus-4.11' of git://git.kernel.org/pub/scm/linux/kernel/git/mason/linux-btrfs: (69 commits)
  btrfs: add dummy callback for readpage_io_failed and drop checks
  btrfs: drop checks for mandatory extent_io_ops callbacks
  btrfs: document existence of extent_io ops callbacks
  btrfs: let writepage_end_io_hook return void
  btrfs: do proper error handling in btrfs_insert_xattr_item
  btrfs: handle allocation error in update_dev_stat_item
  btrfs: remove BUG_ON from __tree_mod_log_insert
  btrfs: derive maximum output size in the compression implementation
  btrfs: use predefined limits for calculating maximum number of pages for compression
  btrfs: export compression buffer limits in a header
  btrfs: merge nr_pages input and output parameter in compress_pages
  btrfs: merge length input and output parameter in compress_pages
  btrfs: constify name of subvolume in creation helpers
  btrfs: constify buffers used by compression helpers
  btrfs: constify input buffer of btrfs_csum_data
  btrfs: constify device path passed to relevant helpers
  btrfs: make btrfs_inode_resume_unlocked_dio take btrfs_inode
  btrfs: make btrfs_inode_block_unlocked_dio take btrfs_inode
  btrfs: Make btrfs_add_nondir take btrfs_inode
  btrfs: Make btrfs_add_link take btrfs_inode
  ...
2017-03-02 16:03:00 -08:00
Ingo Molnar f361bf4a66 sched/headers: Prepare for the reduction of <linux/sched.h>'s signal API dependency
Instead of including the full <linux/signal.h>, we are going to include the
types-only <linux/signal_types.h> header in <linux/sched.h>, to further
decouple the scheduler header from the signal headers.

This means that various files which relied on the full <linux/signal.h> need
to be updated to gain an explicit dependency on it.

Update the code that relies on sched.h's inclusion of the <linux/signal.h> header.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:37 +01:00
Ingo Molnar 174cd4b1e5 sched/headers: Prepare to move signal wakeup & sigpending methods from <linux/sched.h> into <linux/sched/signal.h>
Fix up affected files that include this signal functionality via sched.h.

Acked-by: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Mike Galbraith <efault@gmx.de>
Cc: Peter Zijlstra <peterz@infradead.org>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: linux-kernel@vger.kernel.org
Signed-off-by: Ingo Molnar <mingo@kernel.org>
2017-03-02 08:42:32 +01:00
Chris Mason e9f467d028 Merge branch 'for-chris-4.11-part2' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux into for-linus-4.11 2017-02-28 14:35:09 -08:00
David Sterba 20a7db8ab3 btrfs: add dummy callback for readpage_io_failed and drop checks
Make extent_io_ops::readpage_io_failed_hook callback mandatory and
define a dummy function for btrfs_extent_io_ops. As the failed IO
callback is not performance critical, the branch vs extra trade off does
not hurt.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:29:24 +01:00
David Sterba 20c9801d39 btrfs: drop checks for mandatory extent_io_ops callbacks
We know that eadpage_end_io_hook, submit_bio_hook and merge_bio_hook are
always defined so we can drop the checks before we call them.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:29:24 +01:00
David Sterba 4d53dddbec btrfs: document existence of extent_io ops callbacks
Some of the callbacks defined in btree_extent_io_ops and
btrfs_extent_io_ops do always exist so we don't need to check the
existence before each call. This patch just reorders the definition and
documents which are mandatory/optional.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:29:24 +01:00
David Sterba c3988d630a btrfs: let writepage_end_io_hook return void
There's no error path in any of the instances, always return 0.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:29:24 +01:00
David Sterba b9d04c607c btrfs: do proper error handling in btrfs_insert_xattr_item
The space check in btrfs_insert_xattr_item is duplicated in it's caller
(do_setxattr) so we won't hit the BUG_ON. Continuing without any check
could be disasterous so turn it to a proper error handling.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:27:11 +01:00
David Sterba fa2529923d btrfs: handle allocation error in update_dev_stat_item
Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:27:11 +01:00
David Sterba 047e5e17c1 btrfs: remove BUG_ON from __tree_mod_log_insert
All callers dereference the 'tm' parameter before it gets to this
function, the NULL check does not make much sense here.

Reviewed-by: Liu Bo <bo.li.liu@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:27:11 +01:00
David Sterba e5d7490236 btrfs: derive maximum output size in the compression implementation
The value of max_out can be calculated from the parameters passed to the
compressors, which is number of pages and the page size, and we don't
have to needlessly pass it around.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:36 +01:00
David Sterba 069eac7850 btrfs: use predefined limits for calculating maximum number of pages for compression
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:35 +01:00
David Sterba ff7638665c btrfs: export compression buffer limits in a header
Move the buffer limit definitions out of compress_file_range.

Reviewed-by: Qu Wenruo <quwenruo@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:35 +01:00
David Sterba 4d3a800ebb btrfs: merge nr_pages input and output parameter in compress_pages
The parameter saying how many pages can be allocated at maximum can be
merged with the output page counter, to save some stack space.  The
compression implementation will sink the parameter to a local variable
so everything works as before.

The nr_pages variables can also be simply merged in compress_file_range
into one.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:35 +01:00
David Sterba 38c3146408 btrfs: merge length input and output parameter in compress_pages
The length parameter is basically duplicated for input and output in the
top level caller of the compress_pages chain. We can simply use one
variable for that and reduce stack consumption. The compression
implementation will sink the parameter to a local variable so everything
works as before.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:35 +01:00
David Sterba 52f75f4fe7 btrfs: constify name of subvolume in creation helpers
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:08 +01:00
David Sterba 14a3357b40 btrfs: constify buffers used by compression helpers
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:07 +01:00
David Sterba 9ed573674a btrfs: constify input buffer of btrfs_csum_data
The function does not modify the input buffer, also update a typecast in
one caller.

Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:07 +01:00
David Sterba da353f6b30 btrfs: constify device path passed to relevant helpers
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 14:26:07 +01:00
Nikolay Borisov 0b581701d9 btrfs: make btrfs_inode_resume_unlocked_dio take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:12 +01:00
Nikolay Borisov abcefb1eee btrfs: make btrfs_inode_block_unlocked_dio take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:12 +01:00
Nikolay Borisov cef415af20 btrfs: Make btrfs_add_nondir take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:12 +01:00
Nikolay Borisov db0a669fb0 btrfs: Make btrfs_add_link take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov 9e3e97f45c btrfs: Make btrfs_del_delalloc_inode take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov fc4f21b1d8 btrfs: Make get_extent_t take btrfs_inode
In addition to changing the signature, this patch also switches
all the functions which are used as an argument to also take btrfs_inode.
Namely those are: btrfs_get_extent and btrfs_get_extent_filemap.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov 1c8c9c5216 btrfs: Make check_extent_to_block take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov a2f392e401 btrfs: Make clone_update_extent_map take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov 6fc0ef6870 btrfs: Make btrfs_clear_bit_hook take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov 9cdc512410 btrfs: Make btrfs_extent_item_to_extent_map take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:11 +01:00
Nikolay Borisov 19df27a9e4 btrfs: make btrfs_log_inode_parent take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:10 +01:00
Nikolay Borisov aefa6115c0 btrfs: Make check_parent_dirs_for_sync take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:10 +01:00
Nikolay Borisov 73f2e545b6 btrfs: Make btrfs_orphan_add take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:10 +01:00
Nikolay Borisov 3d6ae7bb6a btrfs: make btrfs_orphan_del take btrfs_inode
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2017-02-28 11:30:10 +01:00