Commit Graph

7920 Commits

Author SHA1 Message Date
Nathan Chancellor e8baf7abcf btrfs: Turn an 'else if' into an 'else' in btrfs_uuid_tree_add
When building with -Wsometimes-uninitialized, Clang warns:

fs/btrfs/uuid-tree.c:129:13: warning: variable 'eb' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]
fs/btrfs/uuid-tree.c:129:13: warning: variable 'offset' is used uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized]

Clang can't tell that all cases are covered with this final else if.
Just turn it into an else so that it is clear.

Link: https://github.com/ClangBuiltLinux/linux/issues/385
Suggested-by: Nick Desaulniers <ndesaulniers@google.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Anand Jain 262c96a3c3 btrfs: refactor btrfs_set_prop and add btrfs_set_prop_trans
btrfs_set_prop() takes transaction pointer as the first argument,
however in ioctl.c for the purpose of setting the compression property,
we call btrfs_set_prop() with NULL transaction pointer. Down in
the call chain  btrfs_setxattr() starts transaction to update the
attribute and also to update the inode.

So for clarity, create btrfs_set_prop_trans() with no transaction
pointer as argument, in preparation to start transaction here instead of
doing it down the call chain at btrfs_setxattr().

Also now the btrfs_set_prop() is a static function.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Anand Jain 419a6f30fd btrfs: rename fs_info argument to fs_private
fs_info is commonly used to represent struct fs_info *, rename
to fs_private to avoid confusion.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Anand Jain 3dcf96c7b9 btrfs: drop redundant forward declaration in props.c
Drop forward declaration of the functions:

- prop_compression_validate
- prop_compression_apply
- prop_compression_extract

No functional changes.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Anand Jain 7715da84f7 btrfs: merge _btrfs_set_prop helpers
btrfs_set_prop() is a redirect to __btrfs_set_prop() with the
transaction handle equal to NULL.  __btrfs_set_prop() in turn passes
this to do_setxattr() which then transaction is actually created.

Instead merge  __btrfs_set_prop() to btrfs_set_prop(), and update the
caller with NULL argument.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Johannes Thumshirn 443c8e2a83 btrfs: reduce kmap_atomic time for checksumming
Since commit c40a3d38af ("Btrfs: Compute and look up csums based on
sectorsized blocks") we do a kmap_atomic() on the contents of a bvec.
The code before c40a3d38af had the kmap region just around the
checksumming too.

kmap_atomic() in turn does a preempt_disable() and pagefault_disable(),
so we shouldn't map the data for too long. Reduce the time the bvec's
page is mapped to when we actually need it.

Performance wise it doesn't seem to make a huge difference with a 2 vcpu VM
on a /dev/zram device:

       vanilla      patched      delta
write  17.4MiB/s    17.8MiB/s	+0.4MiB/s (+2%)
read   40.6MiB/s    41.5MiB/s   +0.9MiB/s (+2%)

The following fio job profile was used in the comparision:

[global]
ioengine=libaio
direct=1
sync=1
norandommap
time_based
runtime=10m
size=100m
group_reporting
numjobs=2

[test]
filename=/mnt/test/fio
rw=randrw
rwmixread=70

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Qu Wenruo a1d198478e btrfs: tracepoints: Add trace events for extent_io_tree
Although btrfs heavily relies on extent_io_tree, we don't really have
any good trace events for them.

This patch will add the folowing trace events:
- trace_btrfs_set_extent_bit()
- trace_btrfs_clear_extent_bit()
- trace_btrfs_convert_extent_bit()

Since selftests could create temporary extent_io_tree without fs_info,
modify TP_fast_assign_fsid() to accept NULL as fs_info.  NULL fs_info
will lead to all zero fsid.

The output would be:
  btrfs_set_extent_bit: <FDID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22040576 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22044672 len=4096 set_bits=LOCKED
  btrfs_set_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22048768 len=4096 set_bits=LOCKED
  btrfs_clear_extent_bit: <FSID>: io_tree=INODE_IO ino=1 root=1 start=22036480 len=16384 clear_bits=LOCKED
  ^^^ Extent buffer 22036480 read from disk, the locking progress

  btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30425088 len=16384 set_bits=DIRTY
  btrfs_set_extent_bit: <FSID>: io_tree=TRANS_DIRTY_PAGES ino=1 root=1 start=30441472 len=16384 set_bits=DIRTY
  ^^^ 2 new tree blocks allocated in one transaction

  btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30523392 len=16384 set_bits=DIRTY
  btrfs_set_extent_bit: <FSID>: io_tree=FREED_EXTENTS0 ino=0 root=0 start=30556160 len=16384 set_bits=DIRTY
  ^^^ 2 old tree blocks get pinned down

There is one point which need attention:
1) Those trace events can be pretty heavy:
   The following workload would generate over 400 trace events.

	mkfs.btrfs -f $dev
	start_trace
	mount $dev $mnt -o enospc_debug
	sync
	touch $mnt/file1
	touch $mnt/file2
	touch $mnt/file3
	xfs_io -f -c "pwrite 0 16k" $mnt/file4
	umount $mnt
	end_trace

   It's not recommended to use them in real world environment.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ rename enums ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:19 +02:00
Qu Wenruo 43eb5f2975 btrfs: Introduce extent_io_tree::owner to distinguish different io_trees
Btrfs has the following different extent_io_trees used:

- fs_info::free_extents[2]
- btrfs_inode::io_tree - for both normal inodes and the btree inode
- btrfs_inode::io_failure_tree
- btrfs_transaction::dirty_pages
- btrfs_root::dirty_log_pages

If we want to trace changes in those trees, it will be pretty hard to
distinguish them.

Instead of using hard-to-read pointer address, this patch will introduce
a new member extent_io_tree::owner to track the owner.

This modification needs all the callers of extent_io_tree_init() to
accept a new parameter @owner.

This patch provides the basis for later trace events.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:18 +02:00
David Sterba 7b4397386f btrfs: switch extent_io_tree::track_uptodate to bool
This patch is split from the following one "btrfs: Introduce
extent_io_tree::owner to distinguish different io_trees" from Qu, so the
different changes are not mixed together.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:18 +02:00
Qu Wenruo c258d6e364 btrfs: Introduce fs_info to extent_io_tree
This patch will add a new member fs_info to extent_io_tree.

This provides the basis for later trace events to distinguish the output
between different btrfs filesystems. While this increases the size of
the structure, we want to know the source of the trace events and
passing the fs_info as an argument to all contexts is not possible.

The selftests are now allowed to set it to NULL as they don't use the
tracepoints.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:18 +02:00
Filipe Manana 3b1da515c6 Btrfs: remove no longer used 'sync' member from transaction handle
Commit db2462a6ad ("btrfs: don't run delayed refs in the end transaction
logic") removed its last use, so now it does absolutely nothing, therefore
remove it.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:18 +02:00
Dennis Zhou b2423496a6 btrfs: zstd: remove indirect calls for local functions
While calling functions inside zstd, we don't need to use the
indirection provided by the workspace_manager. Forward declarations are
added to maintain the function order of btrfs_compress_op.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:18 +02:00
David Sterba 6c3abeda77 btrfs: scrub: return EAGAIN when fs is closing
The error code used here is wrong as it's not invalid to try to start
scrub when umount has begun.  Returning EAGAIN is more user friendly as
it's recoverable.

Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:17 +02:00
Goldwyn Rodrigues 8de60fe942 btrfs: Initialize inode::i_mapping once in btrfs_symlink
inode->i_op is initialized multiple times. Perform it once. This was
left by 4779cc0424 ("Btrfs: get rid of btrfs_symlink_aops").

Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:17 +02:00
Qu Wenruo 7ac1e464c4 btrfs: Don't panic when we can't find a root key
When we failed to find a root key in btrfs_update_root(), we just panic.

That's definitely not cool, fix it by outputting an unique error
message, aborting current transaction and return -EUCLEAN. This should
not normally happen as the root has been used by the callers in some
way.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:17 +02:00
Johannes Thumshirn c53839fc32 btrfs: warn if extent buffer mapping crosses a page boundary in csum_tree_block
Since commit d2e174d5d3 ("btrfs: document extent mapping assumptions in
checksum") we have a comment in place why map_private_extent_buffer()
can't return 1 in the csum_tree_block() case.

Make this a bit more explicit and WARN_ON() in case this this assumption
breaks.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:17 +02:00
Johannes Thumshirn 2996e1f8bc btrfs: factor our read/write stage off csum_tree_block into its callers
Currently csum_tree_block() does two things, first it as it's name
suggests it calculates the checksum for a tree-block. But it also writes
this checksum to disk or reads an extent_buffer from disk and compares the
checksum with the calculated checksum, depending on the verify argument.

Furthermore one of the two callers passes in '1' for the verify argument,
the other one passes in '0'.

For clarity and less layering violations, factor out the second stage in
csum_tree_block()'s callers.

Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-29 19:02:17 +02:00
Linus Torvalds d0473f978e for-5.1-rc6-tag
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Merge tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fix from David Sterba:
 "One patch to fix a crash in io submission path, due to memory
  allocation errors.

  In short, the multipage bio work that landed in 5.1 caused larger bios
  that in turn require larger temporary memory for checksums. The patch
  is a workaround, we're going to rework the allocation so it does not
  require the vmalloc fallback.

  It took a while to identify that it's caused by patches in 5.1 and not
  a patchset that did some changes in error handling in the code. I've
  tested it on various memory/cpu combinations, it could hit OOM but
  does not crash.

  The timestamp of the patch is less than a day due to updates in the
  changelog, tests were running meanwhile"

* tag 'for-5.1-rc6-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Switch memory allocations in async csum calculation path to kvmalloc
2019-04-26 09:46:46 -07:00
Nikolay Borisov a3d46aea46 btrfs: Switch memory allocations in async csum calculation path to kvmalloc
Recent multi-page biovec rework allowed creation of bios that can span
large regions - up to 128 megabytes in the case of btrfs. OTOH btrfs'
submission path currently allocates a contiguous array to store the
checksums for every bio submitted. This means we can request up to
(128mb / BTRFS_SECTOR_SIZE) * 4 bytes + 32bytes of memory from kmalloc.
On busy systems with possibly fragmented memory said kmalloc can fail
which will trigger BUG_ON due to improper error handling IO submission
context in btrfs.

Until error handling is improved or bios in btrfs limited to a more
manageable size (e.g. 1m) let's use kvmalloc to fallback to vmalloc for
such large allocations. There is no hard requirement that the memory
allocated for checksums during IO submission has to be contiguous, but
this is a simple fix that does not require several non-contiguous
allocations.

For small writes this is unlikely to have any visible effect since
kmalloc will still satisfy allocation requests as usual. For larger
requests the code will just fallback to vmalloc.

We've performed evaluation on several workload types and there was no
significant difference kmalloc vs kvmalloc.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-25 14:17:38 +02:00
Linus Torvalds 2d06b23581 for-5.1-rc4-tag
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Merge tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - fix parsing of compression algorithm when set as a inode property,
   this could end up with eg. 'zst' or 'zli' in the value

 - don't allow trim on a filesystem with unreplayed log, this could
   cause data loss if there are pending updates to the block groups that
   would not be subject to trim after replay

* tag 'for-5.1-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: prop: fix vanished compression property after failed set
  btrfs: prop: fix zstd compression parameter validation
  Btrfs: do not allow trimming when a fs is mounted with the nologreplay option
2019-04-11 14:19:02 -07:00
Anand Jain 272e5326c7 btrfs: prop: fix vanished compression property after failed set
The compression property resets to NULL, instead of the old value if we
fail to set the new compression parameter.

  $ btrfs prop get /btrfs compression
    compression=lzo
  $ btrfs prop set /btrfs compression zli
    ERROR: failed to set compression for /btrfs: Invalid argument
  $ btrfs prop get /btrfs compression

This is because the compression property ->validate() is successful for
'zli' as the strncmp() used the length passed from the userspace.

Fix it by using the expected string length in strncmp().

Fixes: 63541927c8 ("Btrfs: add support for inode properties")
Fixes: 5c1aab1dd5 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-04 17:57:53 +02:00
Anand Jain 50398fde99 btrfs: prop: fix zstd compression parameter validation
We let pass zstd compression parameter even if it is not fully valid.
For example:

  $ btrfs prop set /btrfs compression zst
  $ btrfs prop get /btrfs compression
     compression=zst

zlib and lzo are fine.

Fix it by checking the correct prefix length.

Fixes: 5c1aab1dd5 ("btrfs: Add zstd support")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-04-04 17:56:12 +02:00
Filipe Manana f35f06c355 Btrfs: do not allow trimming when a fs is mounted with the nologreplay option
Whan a filesystem is mounted with the nologreplay mount option, which
requires it to be mounted in RO mode as well, we can not allow discard on
free space inside block groups, because log trees refer to extents that
are not pinned in a block group's free space cache (pinning the extents is
precisely the first phase of replaying a log tree).

So do not allow the fitrim ioctl to do anything when the filesystem is
mounted with the nologreplay option, because later it can be mounted RW
without that option, which causes log replay to happen and result in
either a failure to replay the log trees (leading to a mount failure), a
crash or some silent corruption.

Reported-by: Darrick J. Wong <darrick.wong@oracle.com>
Fixes: 96da09192c ("btrfs: Introduce new mount option to disable tree log replay")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-28 18:10:27 +01:00
Linus Torvalds 65ae689329 for-5.1-rc2-tag
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Merge tag 'for-5.1-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - fsync fixes: i_size for truncate vs fsync, dio vs buffered during
   snapshotting, remove complicated but incomplete assertion

 - removed excessive warnigs, misreported device stats updates

 - fix raid56 page mapping for 32bit arch

 - fixes reported by static analyzer

* tag 'for-5.1-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  Btrfs: fix assertion failure on fsync with NO_HOLES enabled
  btrfs: Avoid possible qgroup_rsv_size overflow in btrfs_calculate_inode_block_rsv_size
  btrfs: Fix bound checking in qgroup_trace_new_subtree_blocks
  btrfs: raid56: properly unmap parity page in finish_parity_scrub()
  btrfs: don't report readahead errors and don't update statistics
  Btrfs: fix file corruption after snapshotting due to mix of buffered/DIO writes
  btrfs: remove WARN_ON in log_dir_items
  Btrfs: fix incorrect file size after shrinking truncate and fsync
2019-03-26 10:32:13 -07:00
Filipe Manana 0ccc3876e4 Btrfs: fix assertion failure on fsync with NO_HOLES enabled
Back in commit a89ca6f24f ("Btrfs: fix fsync after truncate when
no_holes feature is enabled") I added an assertion that is triggered when
an inline extent is found to assert that the length of the (uncompressed)
data the extent represents is the same as the i_size of the inode, since
that is true most of the time I couldn't find or didn't remembered about
any exception at that time. Later on the assertion was expanded twice to
deal with a case of a compressed inline extent representing a range that
matches the sector size followed by an expanding truncate, and another
case where fallocate can update the i_size of the inode without adding
or updating existing extents (if the fallocate range falls entirely within
the first block of the file). These two expansion/fixes of the assertion
were done by commit 7ed586d0a8 ("Btrfs: fix assertion on fsync of
regular file when using no-holes feature") and commit 6399fb5a0b
("Btrfs: fix assertion failure during fsync in no-holes mode").
These however missed the case where an falloc expands the i_size of an
inode to exactly the sector size and inline extent exists, for example:

 $ mkfs.btrfs -f -O no-holes /dev/sdc
 $ mount /dev/sdc /mnt

 $ xfs_io -f -c "pwrite -S 0xab 0 1096" /mnt/foobar
 wrote 1096/1096 bytes at offset 0
 1 KiB, 1 ops; 0.0002 sec (4.448 MiB/sec and 4255.3191 ops/sec)

 $ xfs_io -c "falloc 1096 3000" /mnt/foobar
 $ xfs_io -c "fsync" /mnt/foobar
 Segmentation fault

 $ dmesg
 [701253.602385] assertion failed: len == i_size || (len == fs_info->sectorsize && btrfs_file_extent_compression(leaf, extent) != BTRFS_COMPRESS_NONE) || (len < i_size && i_size < fs_info->sectorsize), file: fs/btrfs/tree-log.c, line: 4727
 [701253.602962] ------------[ cut here ]------------
 [701253.603224] kernel BUG at fs/btrfs/ctree.h:3533!
 [701253.603503] invalid opcode: 0000 [#1] SMP DEBUG_PAGEALLOC PTI
 [701253.603774] CPU: 2 PID: 7192 Comm: xfs_io Tainted: G        W         5.0.0-rc8-btrfs-next-45 #1
 [701253.604054] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
 [701253.604650] RIP: 0010:assfail.constprop.23+0x18/0x1a [btrfs]
 (...)
 [701253.605591] RSP: 0018:ffffbb48c186bc48 EFLAGS: 00010286
 [701253.605914] RAX: 00000000000000de RBX: ffff921d0a7afc08 RCX: 0000000000000000
 [701253.606244] RDX: 0000000000000000 RSI: ffff921d36b16868 RDI: ffff921d36b16868
 [701253.606580] RBP: ffffbb48c186bcf0 R08: 0000000000000000 R09: 0000000000000000
 [701253.606913] R10: 0000000000000003 R11: 0000000000000000 R12: ffff921d05d2de18
 [701253.607247] R13: ffff921d03b54000 R14: 0000000000000448 R15: ffff921d059ecf80
 [701253.607769] FS:  00007f14da906700(0000) GS:ffff921d36b00000(0000) knlGS:0000000000000000
 [701253.608163] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [701253.608516] CR2: 000056087ea9f278 CR3: 00000002268e8001 CR4: 00000000003606e0
 [701253.608880] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
 [701253.609250] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
 [701253.609608] Call Trace:
 [701253.609994]  btrfs_log_inode+0xdfb/0xe40 [btrfs]
 [701253.610383]  btrfs_log_inode_parent+0x2be/0xa60 [btrfs]
 [701253.610770]  ? do_raw_spin_unlock+0x49/0xc0
 [701253.611150]  btrfs_log_dentry_safe+0x4a/0x70 [btrfs]
 [701253.611537]  btrfs_sync_file+0x3b2/0x440 [btrfs]
 [701253.612010]  ? do_sysinfo+0xb0/0xf0
 [701253.612552]  do_fsync+0x38/0x60
 [701253.612988]  __x64_sys_fsync+0x10/0x20
 [701253.613360]  do_syscall_64+0x60/0x1b0
 [701253.613733]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [701253.614103] RIP: 0033:0x7f14da4e66d0
 (...)
 [701253.615250] RSP: 002b:00007fffa670fdb8 EFLAGS: 00000246 ORIG_RAX: 000000000000004a
 [701253.615647] RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007f14da4e66d0
 [701253.616047] RDX: 000056087ea9c260 RSI: 000056087ea9c260 RDI: 0000000000000003
 [701253.616450] RBP: 0000000000000001 R08: 0000000000000020 R09: 0000000000000010
 [701253.616854] R10: 000000000000009b R11: 0000000000000246 R12: 000056087ea9c260
 [701253.617257] R13: 000056087ea9c240 R14: 0000000000000000 R15: 000056087ea9dd10
 (...)
 [701253.619941] ---[ end trace e088d74f132b6da5 ]---

Updating the assertion again to allow for this particular case would result
in a meaningless assertion, plus there is currently no risk of logging
content that would result in any corruption after a log replay if the size
of the data encoded in an inline extent is greater than the inode's i_size
(which is not currently possibe either with or without compression),
therefore just remove the assertion.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-20 19:53:39 +01:00
Nikolay Borisov 139a56170d btrfs: Avoid possible qgroup_rsv_size overflow in btrfs_calculate_inode_block_rsv_size
qgroup_rsv_size is calculated as the product of
outstanding_extent * fs_info->nodesize. The product is calculated with
32 bit precision since both variables are defined as u32. Yet
qgroup_rsv_size expects a 64 bit result.

Avoid possible multiplication overflow by casting outstanding_extent to
u64. Such overflow would in the worst case (64K nodesize) require more
than 65536 extents, which is quite large and i'ts not likely that it
would happen in practice.

Fixes-coverity-id: 1435101
Fixes: ff6bc37eb7 ("btrfs: qgroup: Use independent and accurate per inode qgroup rsv")
CC: stable@vger.kernel.org # 4.19+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-19 14:12:36 +01:00
Nikolay Borisov 7ff2c2a1a7 btrfs: Fix bound checking in qgroup_trace_new_subtree_blocks
If 'cur_level' is 7  then the bound checking at the top of the function
will actually pass. Later on, it's possible to dereference
ds_path->nodes[cur_level+1] which will be an out of bounds.

The correct check will be cur_level >= BTRFS_MAX_LEVEL - 1 .

Fixes-coverty-id: 1440918
Fixes-coverty-id: 1440911
Fixes: ea49f3e73c ("btrfs: qgroup: Introduce function to find all new tree blocks of reloc tree")
CC: stable@vger.kernel.org # 4.20+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-19 14:12:31 +01:00
Andrea Righi 3897b6f0a8 btrfs: raid56: properly unmap parity page in finish_parity_scrub()
Parity page is incorrectly unmapped in finish_parity_scrub(), triggering
a reference counter bug on i386, i.e.:

 [ 157.662401] kernel BUG at mm/highmem.c:349!
 [ 157.666725] invalid opcode: 0000 [#1] SMP PTI

The reason is that kunmap(p_page) was completely left out, so we never
did an unmap for the p_page and the loop unmapping the rbio page was
iterating over the wrong number of stripes: unmapping should be done
with nr_data instead of rbio->real_stripes.

Test case to reproduce the bug:

 - create a raid5 btrfs filesystem:
   # mkfs.btrfs -m raid5 -d raid5 /dev/sdb /dev/sdc /dev/sdd /dev/sde

 - mount it:
   # mount /dev/sdb /mnt

 - run btrfs scrub in a loop:
   # while :; do btrfs scrub start -BR /mnt; done

BugLink: https://bugs.launchpad.net/bugs/1812845
Fixes: 5a6ac9eacb ("Btrfs, raid56: support parity scrub on raid56")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Andrea Righi <andrea.righi@canonical.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-18 19:47:36 +01:00
David Sterba 0cc068e6ee btrfs: don't report readahead errors and don't update statistics
As readahead is an optimization, all errors are usually filtered out,
but still properly handled when the real read call is done. The commit
5e9d398240 ("btrfs: readpages() should submit IO as read-ahead") added
REQ_RAHEAD to readpages() because that's only used for readahead
(despite what one would expect from the callback name).

This causes a flood of messages and inflated read error stats, so skip
reporting in case it's readahead.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202403
Reported-by: LimeTech <tomm@lime-technology.com>
Fixes: 5e9d398240 ("btrfs: readpages() should submit IO as read-ahead")
CC: stable@vger.kernel.org # 4.19+
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-13 17:14:27 +01:00
Filipe Manana 609e804d77 Btrfs: fix file corruption after snapshotting due to mix of buffered/DIO writes
When we are mixing buffered writes with direct IO writes against the same
file and snapshotting is happening concurrently, we can end up with a
corrupt file content in the snapshot. Example:

1) Inode/file is empty.

2) Snapshotting starts.

2) Buffered write at offset 0 length 256Kb. This updates the i_size of the
   inode to 256Kb, disk_i_size remains zero. This happens after the task
   doing the snapshot flushes all existing delalloc.

3) DIO write at offset 256Kb length 768Kb. Once the ordered extent
   completes it sets the inode's disk_i_size to 1Mb (256Kb + 768Kb) and
   updates the inode item in the fs tree with a size of 1Mb (which is
   the value of disk_i_size).

4) The dealloc for the range [0, 256Kb[ did not start yet.

5) The transaction used in the DIO ordered extent completion, which updated
   the inode item, is committed by the snapshotting task.

6) Snapshot creation completes.

7) Dealloc for the range [0, 256Kb[ is flushed.

After that when reading the file from the snapshot we always get zeroes for
the range [0, 256Kb[, the file has a size of 1Mb and the data written by
the direct IO write is found. From an application's point of view this is
a corruption, since in the source subvolume it could never read a version
of the file that included the data from the direct IO write without the
data from the buffered write included as well. In the snapshot's tree,
file extent items are missing for the range [0, 256Kb[.

The issue, obviously, does not happen when using the -o flushoncommit
mount option.

Fix this by flushing delalloc for all the roots that are about to be
snapshotted when committing a transaction. This guarantees total ordering
when updating the disk_i_size of an inode since the flush for dealloc is
done when a transaction is in the TRANS_STATE_COMMIT_START state and wait
is done once no more external writers exist. This is similar to what we
do when using the flushoncommit mount option, but we do it only if the
transaction has snapshots to create and only for the roots of the
subvolumes to be snapshotted. The bulk of the dealloc is flushed in the
snapshot creation ioctl, so the flush work we do inside the transaction
is minimized.

This issue, involving buffered and direct IO writes with snapshotting, is
often triggered by fstest btrfs/078, and got reported by fsck when not
using the NO_HOLES features, for example:

  $ cat results/btrfs/078.full
  (...)
  _check_btrfs_filesystem: filesystem on /dev/sdc is inconsistent
  *** fsck.btrfs output ***
  [1/7] checking root items
  [2/7] checking extents
  [3/7] checking free space cache
  [4/7] checking fs roots
  root 258 inode 264 errors 100, file extent discount
  Found file extent holes:
        start: 524288, len: 65536
  ERROR: errors found in fs roots

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-13 17:13:48 +01:00
Josef Bacik 2cc8334270 btrfs: remove WARN_ON in log_dir_items
When Filipe added the recursive directory logging stuff in
2f2ff0ee5e ("Btrfs: fix metadata inconsistencies after directory
fsync") he specifically didn't take the directory i_mutex for the
children directories that we need to log because of lockdep.  This is
generally fine, but can lead to this WARN_ON() tripping if we happen to
run delayed deletion's in between our first search and our second search
of dir_item/dir_indexes for this directory.  We expect this to happen,
so the WARN_ON() isn't necessary.  Drop the WARN_ON() and add a comment
so we know why this case can happen.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-13 17:13:32 +01:00
Filipe Manana bf504110bc Btrfs: fix incorrect file size after shrinking truncate and fsync
If we do a shrinking truncate against an inode which is already present
in the respective log tree and then rename it, as part of logging the new
name we end up logging an inode item that reflects the old size of the
file (the one which we previously logged) and not the new smaller size.
The decision to preserve the size previously logged was added by commit
1a4bcf470c ("Btrfs: fix fsync data loss after adding hard link to
inode") in order to avoid data loss after replaying the log. However that
decision is only needed for the case the logged inode size is smaller then
the current size of the inode, as explained in that commit's change log.
If the current size of the inode is smaller then the previously logged
size, we know a shrinking truncate happened and therefore need to use
that smaller size.

Example to trigger the problem:

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

  $ xfs_io -f -c "pwrite -S 0xab 0 8000" /mnt/foo
  $ xfs_io -c "fsync" /mnt/foo
  $ xfs_io -c "truncate 3000" /mnt/foo

  $ mv /mnt/foo /mnt/bar
  $ xfs_io -c "fsync" /mnt/bar

  <power failure>

  $ mount /dev/sdb /mnt
  $ od -t x1 -A d /mnt/bar
  0000000 ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab ab
  *
  0008000

Once we rename the file, we log its name (and inode item), and because
the inode was already logged before in the current transaction, we log it
with a size of 8000 bytes because that is the size we previously logged
(with the first fsync). As part of the rename, besides logging the inode,
we do also sync the log, which is done since commit d4682ba03e
("Btrfs: sync log after logging new name"), so the next fsync against our
inode is effectively a no-op, since no new changes happened since the
rename operation. Even if did not sync the log during the rename
operation, the same problem (fize size of 8000 bytes instead of 3000
bytes) would be visible after replaying the log if the log ended up
getting synced to disk through some other means, such as for example by
fsyncing some other modified file. In the example above the fsync after
the rename operation is there just because not every filesystem may
guarantee logging/journalling the inode (and syncing the log/journal)
during the rename operation, for example it is needed for f2fs, but not
for ext4 and xfs.

Fix this scenario by, when logging a new name (which is triggered by
rename and link operations), using the current size of the inode instead
of the previously logged inode size.

A test case for fstests follows soon.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202695
CC: stable@vger.kernel.org # 4.4+
Reported-by: Seulbae Kim <seulbae@gatech.edu>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-03-13 17:13:23 +01:00
Linus Torvalds 92825b0298 for-5.1-part2-tag
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Merge tag 'for-5.1-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "Correctness and a deadlock fixes"

* tag 'for-5.1-part2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: zstd: ensure reclaim timer is properly cleaned up
  btrfs: move ulist allocation out of transaction in quota enable
  btrfs: save drop_progress if we drop refs at all
  btrfs: check for refs on snapshot delete resume
  Btrfs: fix deadlock between clone/dedupe and rename
  Btrfs: fix corruption reading shared and compressed extents after hole punching
2019-03-12 14:53:57 -07:00
Nikolay Borisov b5420237ec mm: refactor readahead defines in mm.h
All users of VM_MAX_READAHEAD actually convert it to kbytes and then to
pages. Define the macro explicitly as (SZ_128K / PAGE_SIZE). This
simplifies the expression in every filesystem. Also rename the macro to
VM_READAHEAD_PAGES to properly convey its meaning. Finally remove unused
VM_MIN_READAHEAD

[akpm@linux-foundation.org: fix fs/io_uring.c, per Stephen]
Link: http://lkml.kernel.org/r/20181221144053.24318-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Matthew Wilcox <willy@infradead.org>
Reviewed-by: David Hildenbrand <david@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Cc: Eric Van Hensbergen <ericvh@gmail.com>
Cc: Latchesar Ionkov <lucho@ionkov.net>
Cc: Dominique Martinet <asmadeus@codewreck.org>
Cc: David Howells <dhowells@redhat.com>
Cc: Chris Mason <clm@fb.com>
Cc: Josef Bacik <josef@toxicpanda.com>
Cc: David Sterba <dsterba@suse.com>
Cc: Miklos Szeredi <miklos@szeredi.hu>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-12 10:04:01 -07:00
Linus Torvalds 80201fe175 for-5.1/block-20190302
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Merge tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block

Pull block layer updates from Jens Axboe:
 "Not a huge amount of changes in this round, the biggest one is that we
  finally have Mings multi-page bvec support merged. Apart from that,
  this pull request contains:

   - Small series that avoids quiescing the queue for sysfs changes that
     match what we currently have (Aleksei)

   - Series of bcache fixes (via Coly)

   - Series of lightnvm fixes (via Mathias)

   - NVMe pull request from Christoph. Nothing major, just SPDX/license
     cleanups, RR mp policy (Hannes), and little fixes (Bart,
     Chaitanya).

   - BFQ series (Paolo)

   - Save blk-mq cpu -> hw queue mapping, removing a pointer indirection
     for the fast path (Jianchao)

   - fops->iopoll() added for async IO polling, this is a feature that
     the upcoming io_uring interface will use (Christoph, me)

   - Partition scan loop fixes (Dongli)

   - mtip32xx conversion from managed resource API (Christoph)

   - cdrom registration race fix (Guenter)

   - MD pull from Song, two minor fixes.

   - Various documentation fixes (Marcos)

   - Multi-page bvec feature. This brings a lot of nice improvements
     with it, like more efficient splitting, larger IOs can be supported
     without growing the bvec table size, and so on. (Ming)

   - Various little fixes to core and drivers"

* tag 'for-5.1/block-20190302' of git://git.kernel.dk/linux-block: (117 commits)
  block: fix updating bio's front segment size
  block: Replace function name in string with __func__
  nbd: propagate genlmsg_reply return code
  floppy: remove set but not used variable 'q'
  null_blk: fix checking for REQ_FUA
  block: fix NULL pointer dereference in register_disk
  fs: fix guard_bio_eod to check for real EOD errors
  blk-mq: use HCTX_TYPE_DEFAULT but not 0 to index blk_mq_tag_set->map
  block: optimize bvec iteration in bvec_iter_advance
  block: introduce mp_bvec_for_each_page() for iterating over page
  block: optimize blk_bio_segment_split for single-page bvec
  block: optimize __blk_segment_map_sg() for single-page bvec
  block: introduce bvec_nth_page()
  iomap: wire up the iopoll method
  block: add bio_set_polled() helper
  block: wire up block device iopoll method
  fs: add an iopoll method to struct file_operations
  loop: set GENHD_FL_NO_PART_SCAN after blkdev_reread_part()
  loop: do not print warn message if partition scan is successful
  block: bounce: make sure that bvec table is updated
  ...
2019-03-08 14:12:17 -08:00
Linus Torvalds b5dd0c658c Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - some of the rest of MM

 - various misc things

 - dynamic-debug updates

 - checkpatch

 - some epoll speedups

 - autofs

 - rapidio

 - lib/, lib/lzo/ updates

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (83 commits)
  samples/mic/mpssd/mpssd.h: remove duplicate header
  kernel/fork.c: remove duplicated include
  include/linux/relay.h: fix percpu annotation in struct rchan
  arch/nios2/mm/fault.c: remove duplicate include
  unicore32: stop printing the virtual memory layout
  MAINTAINERS: fix GTA02 entry and mark as orphan
  mm: create the new vm_fault_t type
  arm, s390, unicore32: remove oneliner wrappers for memblock_alloc()
  arch: simplify several early memory allocations
  openrisc: simplify pte_alloc_one_kernel()
  sh: prefer memblock APIs returning virtual address
  microblaze: prefer memblock API returning virtual address
  powerpc: prefer memblock APIs returning virtual address
  lib/lzo: separate lzo-rle from lzo
  lib/lzo: implement run-length encoding
  lib/lzo: fast 8-byte copy on arm64
  lib/lzo: 64-bit CTZ on arm64
  lib/lzo: tidy-up ifdefs
  ipc/sem.c: replace kvmalloc/memset with kvzalloc and use struct_size
  ipc: annotate implicit fall through
  ...
2019-03-07 19:25:37 -08:00
Rasmus Villemoes afe1a715e8 btrfs: implement btrfs_debug* in terms of helper macro
First, the btrfs_debug macros open-code (one possible definition of)
DYNAMIC_DEBUG_BRANCH, so they don't benefit from the CONFIG_JUMP_LABEL
optimization.

Second, a planned change of struct _ddebug (to reduce its size on 64 bit
machines) requires that all descriptors in a translation unit use
distinct identifiers.

Using the new _dynamic_func_call_no_desc helper macro from
dynamic_debug.h takes care of both of these.  No functional change.

Link: http://lkml.kernel.org/r/20190212214150.4807-12-linux@rasmusvillemoes.dk
Signed-off-by: Rasmus Villemoes <linux@rasmusvillemoes.dk>
Acked-by: David Sterba <dsterba@suse.com>
Acked-by: Jason Baron <jbaron@akamai.com>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Ingo Molnar <mingo@kernel.org>
Cc: Petr Mladek <pmladek@suse.com>
Cc: "Rafael J . Wysocki" <rafael.j.wysocki@intel.com>
Cc: Steven Rostedt <rostedt@goodmis.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-03-07 18:32:00 -08:00
Dennis Zhou d3865159ac btrfs: zstd: ensure reclaim timer is properly cleaned up
The timer function, zstd_reclaim_timer_fn(), reschedules itself under
certain conditions. When cleaning up, take the lock and remove all
workspaces. This prevents the timer from rearming itself. Lastly, switch
to del_timer_sync() to ensure that the timer function can't trigger as
we're unloading.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 17:45:04 +01:00
David Sterba 7503b83d80 btrfs: move ulist allocation out of transaction in quota enable
The allocation happens with GFP_KERNEL after a transaction has been
started, this can potentially cause deadlock if reclaim tries to get the
memory by flushing filesystem data.

The fs_info::qgroup_ulist is not used during transaction start when
quotas are not enabled. The status bit BTRFS_FS_QUOTA_ENABLED is set
later in btrfs_quota_enable so it's safe to move it before the
transaction start.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 14:10:25 +01:00
Josef Bacik aea6f028d0 btrfs: save drop_progress if we drop refs at all
Previously we only updated the drop_progress key if we were in the
DROP_REFERENCE stage of snapshot deletion.  This is because the
UPDATE_BACKREF stage checks the flags of the blocks it's converting to
FULL_BACKREF, so if we go over a block we processed before it doesn't
matter, we just don't do anything.

The problem is in do_walk_down() we will go ahead and drop the roots
reference to any blocks that we know we won't need to walk into.

Given subvolume A and snapshot B.  The root of B points to all of the
nodes that belong to A, so all of those nodes have a refcnt > 1.  If B
did not modify those blocks it'll hit this condition in do_walk_down

if (!wc->update_ref ||
    generation <= root->root_key.offset)
	goto skip;

and in "goto skip" we simply do a btrfs_free_extent() for that bytenr
that we point at.

Now assume we modified some data in B, and then took a snapshot of B and
call it C.  C points to all the nodes in B, making every node the root
of B points to have a refcnt > 1.  This assumes the root level is 2 or
higher.

We delete snapshot B, which does the above work in do_walk_down,
free'ing our ref for nodes we share with A that we didn't modify.  Now
we hit a node we _did_ modify, thus we own.  We need to walk down into
this node and we set wc->stage == UPDATE_BACKREF.  We walk down to level
0 which we also own because we modified data.  We can't walk any further
down and thus now need to walk up and start the next part of the
deletion.  Now walk_up_proc is supposed to put us back into
DROP_REFERENCE, but there's an exception to this

if (level < wc->shared_level)
	goto out;

we are at level == 0, and our shared_level == 1.  We skip out of this
one and go up to level 1.  Since path->slots[1] < nritems we
path->slots[1]++ and break out of walk_up_tree to stop our transaction
and loop back around.  Now in btrfs_drop_snapshot we have this snippet

if (wc->stage == DROP_REFERENCE) {
	level = wc->level;
	btrfs_node_key(path->nodes[level],
		       &root_item->drop_progress,
		       path->slots[level]);
	root_item->drop_level = level;
}

our stage == UPDATE_BACKREF still, so we don't update the drop_progress
key.  This is a problem because we would have done btrfs_free_extent()
for the nodes leading up to our current position.  If we crash or
unmount here and go to remount we'll start over where we were before and
try to free our ref for blocks we've already freed, and thus abort()
out.

Fix this by keeping track of the last place we dropped a reference for
our block in do_walk_down.  Then if wc->stage == UPDATE_BACKREF we know
we'll start over from a place we meant to, and otherwise things continue
to work as they did before.

I have a complicated reproducer for this problem, without this patch
we'll fail to fsck the fs when replaying the log writes log.  With this
patch we can replay the whole log without any fsck or mount failures.

The steps to reproduce this easily are sort of tricky, I had to add a
couple of debug patches to the kernel in order to make it easy,
basically I just needed to make sure we did actually commit the
transaction every time we finished a walk_down_tree/walk_up_tree combo.

The reproducer:

1) Creates a base subvolume.
2) Creates 100k files in the subvolume.
3) Snapshots the base subvolume (snap1).
4) Touches files 5000-6000 in snap1.
5) Snapshots snap1 (snap2).
6) Deletes snap1.

I do this with dm-log-writes, and then replay to every FUA in the log
and fsck the fs.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ copy reproducer steps ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 14:08:47 +01:00
Josef Bacik 78c52d9eb6 btrfs: check for refs on snapshot delete resume
There's a bug in snapshot deletion where we won't update the
drop_progress key if we're in the UPDATE_BACKREF stage.  This is a
problem because we could drop refs for blocks we know don't belong to
ours.  If we crash or umount at the right time we could experience
messages such as the following when snapshot deletion resumes

 BTRFS error (device dm-3): unable to find ref byte nr 66797568 parent 0 root 258  owner 1 offset 0
 ------------[ cut here ]------------
 WARNING: CPU: 3 PID: 16052 at fs/btrfs/extent-tree.c:7108 __btrfs_free_extent.isra.78+0x62c/0xb30 [btrfs]
 CPU: 3 PID: 16052 Comm: umount Tainted: G        W  OE     5.0.0-rc4+ #147
 Hardware name: To Be Filled By O.E.M. To Be Filled By O.E.M./890FX Deluxe5, BIOS P1.40 05/03/2011
 RIP: 0010:__btrfs_free_extent.isra.78+0x62c/0xb30 [btrfs]
 RSP: 0018:ffffc90005cd7b18 EFLAGS: 00010286
 RAX: 0000000000000000 RBX: 0000000000000001 RCX: 0000000000000000
 RDX: ffff88842fade680 RSI: ffff88842fad6b18 RDI: ffff88842fad6b18
 RBP: ffffc90005cd7bc8 R08: 0000000000000000 R09: 0000000000000001
 R10: 0000000000000001 R11: ffffffff822696b8 R12: 0000000003fb4000
 R13: 0000000000000001 R14: 0000000000000102 R15: ffff88819c9d67e0
 FS:  00007f08bb138fc0(0000) GS:ffff88842fac0000(0000) knlGS:0000000000000000
 CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 CR2: 00007f8f5d861ea0 CR3: 00000003e99fe000 CR4: 00000000000006e0
 Call Trace:
 ? _raw_spin_unlock+0x27/0x40
 ? btrfs_merge_delayed_refs+0x356/0x3e0 [btrfs]
 __btrfs_run_delayed_refs+0x75a/0x13c0 [btrfs]
 ? join_transaction+0x2b/0x460 [btrfs]
 btrfs_run_delayed_refs+0xf3/0x1c0 [btrfs]
 btrfs_commit_transaction+0x52/0xa50 [btrfs]
 ? start_transaction+0xa6/0x510 [btrfs]
 btrfs_sync_fs+0x79/0x1c0 [btrfs]
 sync_filesystem+0x70/0x90
 generic_shutdown_super+0x27/0x120
 kill_anon_super+0x12/0x30
 btrfs_kill_super+0x16/0xa0 [btrfs]
 deactivate_locked_super+0x43/0x70
 deactivate_super+0x40/0x60
 cleanup_mnt+0x3f/0x80
 __cleanup_mnt+0x12/0x20
 task_work_run+0x8b/0xc0
 exit_to_usermode_loop+0xce/0xd0
 do_syscall_64+0x20b/0x210
 entry_SYSCALL_64_after_hwframe+0x49/0xbe

To fix this simply mark dead roots we read from disk as DEAD and then
set the walk_control->restarted flag so we know we have a restarted
deletion.  From here whenever we try to drop refs for blocks we check to
verify our ref is set on them, and if it is not we skip it.  Once we
find a ref that is set we unset walk_control->restarted since the tree
should be in a normal state from then on, and any problems we run into
from there are different issues.  I tested this with an existing broken
fs and my reproducer that creates a broken fs and it fixed both file
systems.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 14:08:47 +01:00
Filipe Manana 4ea748e1d2 Btrfs: fix deadlock between clone/dedupe and rename
Reflinking (clone/dedupe) and rename are operations that operate on two
inodes and therefore need to lock them in the same order to avoid ABBA
deadlocks. It happens that Btrfs' reflink implementation always locked
them in a different order from VFS's lock_two_nondirectories() helper,
which is used by the rename code in VFS, resulting in ABBA type deadlocks.

Btrfs' locking order:

  static void btrfs_double_inode_lock(struct inode *inode1, struct inode *inode2)
  {
         if (inode1 < inode2)
                swap(inode1, inode2);

         inode_lock_nested(inode1, I_MUTEX_PARENT);
         inode_lock_nested(inode2, I_MUTEX_CHILD);
  }

VFS's locking order:

  void lock_two_nondirectories(struct inode *inode1, struct inode *inode2)
  {
        if (inode1 > inode2)
                swap(inode1, inode2);

        if (inode1 && !S_ISDIR(inode1->i_mode))
                inode_lock(inode1);
        if (inode2 && !S_ISDIR(inode2->i_mode) && inode2 != inode1)
                inode_lock_nested(inode2, I_MUTEX_NONDIR2);
}

Fix this by killing the btrfs helper function that does the double inode
locking and replace it with VFS's helper lock_two_nondirectories().

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Fixes: 416161db9b ("btrfs: offline dedupe")
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 12:24:16 +01:00
Filipe Manana 8e92821878 Btrfs: fix corruption reading shared and compressed extents after hole punching
In the past we had data corruption when reading compressed extents that
are shared within the same file and they are consecutive, this got fixed
by commit 005efedf2c ("Btrfs: fix read corruption of compressed and
shared extents") and by commit 808f80b467 ("Btrfs: update fix for read
corruption of compressed and shared extents"). However there was a case
that was missing in those fixes, which is when the shared and compressed
extents are referenced with a non-zero offset. The following shell script
creates a reproducer for this issue:

  #!/bin/bash

  mkfs.btrfs -f /dev/sdc &> /dev/null
  mount -o compress /dev/sdc /mnt/sdc

  # Create a file with 3 consecutive compressed extents, each has an
  # uncompressed size of 128Kb and a compressed size of 4Kb.
  for ((i = 1; i <= 3; i++)); do
      head -c 4096 /dev/zero
      for ((j = 1; j <= 31; j++)); do
          head -c 4096 /dev/zero | tr '\0' "\377"
      done
  done > /mnt/sdc/foobar
  sync

  echo "Digest after file creation:   $(md5sum /mnt/sdc/foobar)"

  # Clone the first extent into offsets 128K and 256K.
  xfs_io -c "reflink /mnt/sdc/foobar 0 128K 128K" /mnt/sdc/foobar
  xfs_io -c "reflink /mnt/sdc/foobar 0 256K 128K" /mnt/sdc/foobar
  sync

  echo "Digest after cloning:         $(md5sum /mnt/sdc/foobar)"

  # Punch holes into the regions that are already full of zeroes.
  xfs_io -c "fpunch 0 4K" /mnt/sdc/foobar
  xfs_io -c "fpunch 128K 4K" /mnt/sdc/foobar
  xfs_io -c "fpunch 256K 4K" /mnt/sdc/foobar
  sync

  echo "Digest after hole punching:   $(md5sum /mnt/sdc/foobar)"

  echo "Dropping page cache..."
  sysctl -q vm.drop_caches=1
  echo "Digest after hole punching:   $(md5sum /mnt/sdc/foobar)"

  umount /dev/sdc

When running the script we get the following output:

  Digest after file creation:   5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  linked 131072/131072 bytes at offset 131072
  128 KiB, 1 ops; 0.0033 sec (36.960 MiB/sec and 295.6830 ops/sec)
  linked 131072/131072 bytes at offset 262144
  128 KiB, 1 ops; 0.0015 sec (78.567 MiB/sec and 628.5355 ops/sec)
  Digest after cloning:         5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  Digest after hole punching:   5a0888d80d7ab1fd31c229f83a3bbcc8  /mnt/sdc/foobar
  Dropping page cache...
  Digest after hole punching:   fba694ae8664ed0c2e9ff8937e7f1484  /mnt/sdc/foobar

This happens because after reading all the pages of the extent in the
range from 128K to 256K for example, we read the hole at offset 256K
and then when reading the page at offset 260K we don't submit the
existing bio, which is responsible for filling all the page in the
range 128K to 256K only, therefore adding the pages from range 260K
to 384K to the existing bio and submitting it after iterating over the
entire range. Once the bio completes, the uncompressed data fills only
the pages in the range 128K to 256K because there's no more data read
from disk, leaving the pages in the range 260K to 384K unfilled. It is
just a slightly different variant of what was solved by commit
005efedf2c ("Btrfs: fix read corruption of compressed and shared
extents").

Fix this by forcing a bio submit, during readpages(), whenever we find a
compressed extent map for a page that is different from the extent map
for the previous page or has a different starting offset (in case it's
the same compressed extent), instead of the extent map's original start
offset.

A test case for fstests follows soon.

Reported-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Fixes: 808f80b467 ("Btrfs: update fix for read corruption of compressed and shared extents")
Fixes: 005efedf2c ("Btrfs: fix read corruption of compressed and shared extents")
Cc: stable@vger.kernel.org # 4.3+
Tested-by: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-27 12:24:07 +01:00
YueHaibing f65e25e343 btrfs: Remove unnecessary casts in btrfs_read_root_item
There is a messy cast here:
	min_t(int, len, (int)sizeof(*item)));

min_t() should normally cast to unsigned.  It's not possible for "len"
to be negative, but if it were then we definitely wouldn't want to pass
negatives to read_extent_buffer().  Also there is an extra cast.

This patch shouldn't affect runtime, it's just a clean up.

Reviewed-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:19:23 +01:00
Filipe Manana 253002f2e3 Btrfs: remove assertion when searching for a key in a node/leaf
At ctree.c:key_search(), the assertion that verifies the first key on a
child extent buffer corresponds to the key at a specific slot in the
parent has a disadvantage: we effectively hit a BUG_ON() which requires
rebooting the machine later. It also does not tell any information about
which extent buffer is affected, from which root, the expected and found
keys, etc.

However as of commit 581c176041 ("btrfs: Validate child tree block's
level and first key"), that assertion is not needed since at the time we
read an extent buffer from disk we validate that its first key matches the
key, at the respective slot, in the parent extent buffer. Therefore just
remove the assertion at key_search().

Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:19:23 +01:00
Filipe Manana cbca7d59fe Btrfs: add missing error handling after doing leaf/node binary search
The function map_private_extent_buffer() can return an -EINVAL error, and
it is called by generic_bin_search() which will return back the error. The
btrfs_bin_search() function in turn calls generic_bin_search() and the
key_search() function calls btrfs_bin_search(), so both can return the
-EINVAL error coming from the map_private_extent_buffer() function. Some
callers of these functions were ignoring that these functions can return
an error, so fix them to deal with error return values.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:19:23 +01:00
Dan Carpenter 669e859b5e btrfs: drop the lock on error in btrfs_dev_replace_cancel
We should drop the lock on this error path.  This has been found by a
static tool.

The lock needs to be released, it's there to protect access to the
dev_replace members and is not supposed to be left locked. The value of
state that's being switched would need to be artifically changed to an
invalid value so the default: branch is taken.

Fixes: d189dd70e2 ("btrfs: fix use-after-free due to race between replace start and cancel")
CC: stable@vger.kernel.org # 5.0+
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:41 +01:00
Johannes Thumshirn 349ae63f40 btrfs: ensure that a DUP or RAID1 block group has exactly two stripes
We recently had a customer issue with a corrupted filesystem. When
trying to mount this image btrfs panicked with a division by zero in
calc_stripe_length().

The corrupt chunk had a 'num_stripes' value of 1. calc_stripe_length()
takes this value and divides it by the number of copies the RAID profile
is expected to have to calculate the amount of data stripes. As a DUP
profile is expected to have 2 copies this division resulted in 1/2 = 0.
Later then the 'data_stripes' variable is used as a divisor in the
stripe length calculation which results in a division by 0 and thus a
kernel panic.

When encountering a filesystem with a DUP block group and a
'num_stripes' value unequal to 2, refuse mounting as the image is
corrupted and will lead to unexpected behaviour.

Code inspection showed a RAID1 block group has the same issues.

Fixes: e06cd3dd7c ("Btrfs: add validadtion checks for chunk loading")
CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:41 +01:00
Dan Robertson e49be14b8d btrfs: init csum_list before possible free
The scrub_ctx csum_list member must be initialized before scrub_free_ctx
is called. If the csum_list is not initialized beforehand, the
list_empty call in scrub_free_csums will result in a null deref if the
allocation fails in the for loop.

Fixes: a2de733c78 ("btrfs: scrub")
CC: stable@vger.kernel.org # 3.0+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Dan Robertson <dan@dlrobertson.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:41 +01:00
Filipe Manana 57a50e2506 Btrfs: remove no longer needed range length checks for deduplication
Comparing the content of the pages in the range to deduplicate is now
done in generic_remap_checks called by the generic helper
generic_remap_file_range_prep(), which takes care of ensuring we do not
compare/deduplicate undefined data beyond a file's EOF (range from EOF
to the next block boundary). So remove these checks which are now
redundant.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:40 +01:00
Filipe Manana a3baaf0d78 Btrfs: fix fsync after succession of renames and unlink/rmdir
After a succession of renames operations of different files and unlinking
one of them, if we fsync one of the renamed files we can end up with a
log that will either fail to replay at mount time or result in a filesystem
that is in an inconsistent state. One example scenario:

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

  $ mkdir /mnt/testdir
  $ touch /mnt/testdir/fname1
  $ touch /mnt/testdir/fname2

  $ sync

  $ mv /mnt/testdir/fname1 /mnt/testdir/fname3
  $ rm -f /mnt/testdir/fname2
  $ ln /mnt/testdir/fname3 /mnt/testdir/fname2

  $ touch /mnt/testdir/fname1
  $ xfs_io -c "fsync" /mnt/testdir/fname1

  <power failure>

  $ mount /dev/sdb /mnt
  $ umount /mnt
  $ btrfs check /dev/sdb
  [1/7] checking root items
  [2/7] checking extents
  [3/7] checking free space cache
  [4/7] checking fs roots
  root 5 inode 259 errors 2, no orphan item
  ERROR: errors found in fs roots
  Opening filesystem to check...
  Checking filesystem on /dev/sdc
  UUID: 20e4abb8-5a19-4492-8bb4-6084125c2d0d
  found 393216 bytes used, error(s) found
  total csum bytes: 0
  total tree bytes: 131072
  total fs tree bytes: 32768
  total extent tree bytes: 16384
  btree space waste bytes: 122986
  file data blocks allocated: 262144
   referenced 262144

On a kernel without the first patch in this series, titled
"[PATCH] Btrfs: fix fsync after succession of renames of different files",
we get instead an error when mounting the filesystem due to failure of
replaying the log:

  $ mount /dev/sdb /mnt
  mount: mount /dev/sdb on /mnt failed: File exists

Fix this by logging the parent directory of an inode whenever we find an
inode that no longer exists (was unlinked in the current transaction),
during the procedure which finds inodes that have old names that collide
with new names of other inodes.

A test case for fstests follows soon.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:40 +01:00
Filipe Manana 6b5fc433a7 Btrfs: fix fsync after succession of renames of different files
After a succession of rename operations of different files and fsyncing
one of them, such that each file gets a new name that corresponds to an
old name of another file, we can end up with a log that will cause a
failure when attempted to replay at mount time (an EEXIST error).
We currently have correct behaviour when such succession of renames
involves only two files, but if there are more files involved, we end up
not logging all the inodes that are needed, therefore resulting in a
failure when attempting to replay the log.

Example:

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

  $ mkdir /mnt/testdir
  $ touch /mnt/testdir/fname1
  $ touch /mnt/testdir/fname2

  $ sync

  $ mv /mnt/testdir/fname1 /mnt/testdir/fname3
  $ mv /mnt/testdir/fname2 /mnt/testdir/fname4
  $ ln /mnt/testdir/fname3 /mnt/testdir/fname2

  $ touch /mnt/testdir/fname1
  $ xfs_io -c "fsync" /mnt/testdir/fname1

  <power failure>

  $ mount /dev/sdb /mnt
  mount: mount /dev/sdb on /mnt failed: File exists

So fix this by checking all inode dependencies when logging an inode. That
is, if one logged inode A has a new name that matches the old name of some
other inode B, check if inode B has a new name that matches the old name
of some other inode C, and so on. This fix is implemented not by doing any
recursive function calls but by using an iterative method using a linked
list that is used in a first-in-first-out fashion.

A test case for fstests follows soon.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:40 +01:00
Josef Bacik 38e3eebff6 btrfs: honor path->skip_locking in backref code
Qgroups will do the old roots lookup at delayed ref time, which could be
while walking down the extent root while running a delayed ref.  This
should be fine, except we specifically lock eb's in the backref walking
code irrespective of path->skip_locking, which deadlocks the system.
Fix up the backref code to honor path->skip_locking, nobody will be
modifying the commit_root when we're searching so it's completely safe
to do.

This happens since fb235dc06f ("btrfs: qgroup: Move half of the qgroup
accounting time out of commit trans"), kernel may lockup with quota
enabled.

There is one backref trace triggered by snapshot dropping along with
write operation in the source subvolume.  The example can be reliably
reproduced:

  btrfs-cleaner   D    0  4062      2 0x80000000
  Call Trace:
   schedule+0x32/0x90
   btrfs_tree_read_lock+0x93/0x130 [btrfs]
   find_parent_nodes+0x29b/0x1170 [btrfs]
   btrfs_find_all_roots_safe+0xa8/0x120 [btrfs]
   btrfs_find_all_roots+0x57/0x70 [btrfs]
   btrfs_qgroup_trace_extent_post+0x37/0x70 [btrfs]
   btrfs_qgroup_trace_leaf_items+0x10b/0x140 [btrfs]
   btrfs_qgroup_trace_subtree+0xc8/0xe0 [btrfs]
   do_walk_down+0x541/0x5e3 [btrfs]
   walk_down_tree+0xab/0xe7 [btrfs]
   btrfs_drop_snapshot+0x356/0x71a [btrfs]
   btrfs_clean_one_deleted_snapshot+0xb8/0xf0 [btrfs]
   cleaner_kthread+0x12b/0x160 [btrfs]
   kthread+0x112/0x130
   ret_from_fork+0x27/0x50

When dropping snapshots with qgroup enabled, we will trigger backref
walk.

However such backref walk at that timing is pretty dangerous, as if one
of the parent nodes get WRITE locked by other thread, we could cause a
dead lock.

For example:

           FS 260     FS 261 (Dropped)
            node A        node B
           /      \      /      \
       node C      node D      node E
      /   \         /  \        /     \
  leaf F|leaf G|leaf H|leaf I|leaf J|leaf K

The lock sequence would be:

      Thread A (cleaner)             |       Thread B (other writer)
-----------------------------------------------------------------------
write_lock(B)                        |
write_lock(D)                        |
^^^ called by walk_down_tree()       |
                                     |       write_lock(A)
                                     |       write_lock(D) << Stall
read_lock(H) << for backref walk     |
read_lock(D) << lock owner is        |
                the same thread A    |
                so read lock is OK   |
read_lock(A) << Stall                |

So thread A hold write lock D, and needs read lock A to unlock.
While thread B holds write lock A, while needs lock D to unlock.

This will cause a deadlock.

This is not only limited to snapshot dropping case.  As the backref
walk, even only happens on commit trees, is breaking the normal top-down
locking order, makes it deadlock prone.

Fixes: fb235dc06f ("btrfs: qgroup: Move half of the qgroup accounting time out of commit trans")
CC: stable@vger.kernel.org # 4.14+
Reported-and-tested-by: David Sterba <dsterba@suse.com>
Reported-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Filipe Manana <fdmanana@suse.com>
[ rebase to latest branch and fix lock assert bug in btrfs/007 ]
Signed-off-by: Qu Wenruo <wqu@suse.com>
[ copy logs and deadlock analysis from Qu's patch ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:39 +01:00
Qu Wenruo f5fef45936 btrfs: qgroup: Make qgroup async transaction commit more aggressive
[BUG]
Btrfs qgroup will still hit EDQUOT under the following case:

  $ dev=/dev/test/test
  $ mnt=/mnt/btrfs
  $ umount $mnt &> /dev/null
  $ umount $dev &> /dev/null

  $ mkfs.btrfs -f $dev
  $ mount $dev $mnt -o nospace_cache

  $ btrfs subv create $mnt/subv
  $ btrfs quota enable $mnt
  $ btrfs quota rescan -w $mnt
  $ btrfs qgroup limit -e 1G $mnt/subv

  $ fallocate -l 900M $mnt/subv/padding
  $ sync

  $ rm $mnt/subv/padding

  # Hit EDQUOT
  $ xfs_io -f -c "pwrite 0 512M" $mnt/subv/real_file

[CAUSE]
Since commit a514d63882 ("btrfs: qgroup: Commit transaction in advance
to reduce early EDQUOT"), btrfs is not forced to commit transaction to
reclaim more quota space.

Instead, we just check pertrans metadata reservation against some
threshold and try to do asynchronously transaction commit.

However in above case, the pertrans metadata reservation is pretty small
thus it will never trigger asynchronous transaction commit.

[FIX]
Instead of only accounting pertrans metadata reservation, we calculate
how much free space we have, and if there isn't much free space left,
commit transaction asynchronously to try to free some space.

This may slow down the fs when we have less than 32M free qgroup space,
but should reduce a lot of false EDQUOT, so the cost should be
acceptable.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:39 +01:00
Qu Wenruo 1418bae1c2 btrfs: qgroup: Move reserved data accounting from btrfs_delayed_ref_head to btrfs_qgroup_extent_record
[BUG]
Btrfs/139 will fail with a high probability if the testing machine (VM)
has only 2G RAM.

Resulting the final write success while it should fail due to EDQUOT,
and the fs will have quota exceeding the limit by 16K.

The simplified reproducer will be: (needs a 2G ram VM)

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

  $ btrfs subv create $mnt/subv
  $ btrfs quota enable $mnt
  $ btrfs quota rescan -w $mnt
  $ btrfs qgroup limit -e 1G $mnt/subv

  $ for i in $(seq -w  1 8); do
  	xfs_io -f -c "pwrite 0 128M" $mnt/subv/file_$i > /dev/null
  	echo "file $i written" > /dev/kmsg
    done
  $ sync
  $ btrfs qgroup show -pcre --raw $mnt

The last pwrite will not trigger EDQUOT and final 'qgroup show' will
show something like:

  qgroupid         rfer         excl     max_rfer     max_excl parent  child
  --------         ----         ----     --------     -------- ------  -----
  0/5             16384        16384         none         none ---     ---
  0/256      1073758208   1073758208         none   1073741824 ---     ---

And 1073758208 is larger than
  > 1073741824.

[CAUSE]
It's a bug in btrfs qgroup data reserved space management.

For quota limit, we must ensure that:
  reserved (data + metadata) + rfer/excl <= limit

Since rfer/excl is only updated at transaction commmit time, reserved
space needs to be taken special care.

One important part of reserved space is data, and for a new data extent
written to disk, we still need to take the reserved space until
rfer/excl numbers get updated.

Originally when an ordered extent finishes, we migrate the reserved
qgroup data space from extent_io tree to delayed ref head of the data
extent, expecting delayed ref will only be cleaned up at commit
transaction time.

However for small RAM machine, due to memory pressure dirty pages can be
flushed back to disk without committing a transaction.

The related events will be something like:

  file 1 written
  btrfs_finish_ordered_io: ino=258 ordered offset=0 len=54947840
  btrfs_finish_ordered_io: ino=258 ordered offset=54947840 len=5636096
  btrfs_finish_ordered_io: ino=258 ordered offset=61153280 len=57344
  btrfs_finish_ordered_io: ino=258 ordered offset=61210624 len=8192
  btrfs_finish_ordered_io: ino=258 ordered offset=60583936 len=569344
  cleanup_ref_head: num_bytes=54947840
  cleanup_ref_head: num_bytes=5636096
  cleanup_ref_head: num_bytes=569344
  cleanup_ref_head: num_bytes=57344
  cleanup_ref_head: num_bytes=8192
  ^^^^^^^^^^^^^^^^ This will free qgroup data reserved space
  file 2 written
  ...
  file 8 written
  cleanup_ref_head: num_bytes=8192
  ...
  btrfs_commit_transaction  <<< the only transaction committed during
				the test

When file 2 is written, we have already freed 128M reserved qgroup data
space for ino 258. Thus later write won't trigger EDQUOT.

This allows us to write more data beyond qgroup limit.

In my 2G ram VM, it could reach about 1.2G before hitting EDQUOT.

[FIX]
By moving reserved qgroup data space from btrfs_delayed_ref_head to
btrfs_qgroup_extent_record, we can ensure that reserved qgroup data
space won't be freed half way before commit transaction, thus fix the
problem.

Fixes: f64d5ca868 ("btrfs: delayed_ref: Add new function to record reserved space into delayed ref")
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:39 +01:00
David Sterba 0ea8207626 btrfs: scrub: remove unused nocow worker pointer
The member btrfs_fs_info::scrub_nocow_workers is unused since the nocow
optimization was removed from scrub in 9bebe665c3 ("btrfs: scrub:
Remove unused copy_nocow_pages and its callchain").

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
David Sterba c835294274 btrfs: scrub: add assertions for worker pointers
The scrub worker pointers are not NULL iff the scrub is running, so
reset them back once the last reference is dropped. Add assertions to
the initial phase of scrub to verify that.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
Anand Jain ff09c4ca59 btrfs: scrub: convert scrub_workers_refcnt to refcount_t
Use the refcount_t for fs_info::scrub_workers_refcnt instead of int so
we get the extra checks. All reference changes are still done under
scrub_lock.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:38 +01:00
Anand Jain eb4318e59a btrfs: scrub: add scrub_lock lockdep check in scrub_workers_get
scrub_workers_refcnt is protected by scrub_lock, add lockdep_assert_held()
in scrub_workers_get().

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Suggested-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:37 +01:00
Anand Jain 1cec3f2716 btrfs: scrub: fix circular locking dependency warning
This fixes a longstanding lockdep warning triggered by
fstests/btrfs/011.

Circular locking dependency check reports warning[1], that's because the
btrfs_scrub_dev() calls the stack #0 below with, the fs_info::scrub_lock
held. The test case leading to this warning:

  $ mkfs.btrfs -f /dev/sdb
  $ mount /dev/sdb /btrfs
  $ btrfs scrub start -B /btrfs

In fact we have fs_info::scrub_workers_refcnt to track if the init and destroy
of the scrub workers are needed. So once we have incremented and decremented
the fs_info::scrub_workers_refcnt value in the thread, its ok to drop the
scrub_lock, and then actually do the btrfs_destroy_workqueue() part. So this
patch drops the scrub_lock before calling btrfs_destroy_workqueue().

  [359.258534] ======================================================
  [359.260305] WARNING: possible circular locking dependency detected
  [359.261938] 5.0.0-rc6-default #461 Not tainted
  [359.263135] ------------------------------------------------------
  [359.264672] btrfs/20975 is trying to acquire lock:
  [359.265927] 00000000d4d32bea ((wq_completion)"%s-%s""btrfs", name){+.+.}, at: flush_workqueue+0x87/0x540
  [359.268416]
  [359.268416] but task is already holding lock:
  [359.270061] 0000000053ea26a6 (&fs_info->scrub_lock){+.+.}, at: btrfs_scrub_dev+0x322/0x590 [btrfs]
  [359.272418]
  [359.272418] which lock already depends on the new lock.
  [359.272418]
  [359.274692]
  [359.274692] the existing dependency chain (in reverse order) is:
  [359.276671]
  [359.276671] -> #3 (&fs_info->scrub_lock){+.+.}:
  [359.278187]        __mutex_lock+0x86/0x9c0
  [359.279086]        btrfs_scrub_pause+0x31/0x100 [btrfs]
  [359.280421]        btrfs_commit_transaction+0x1e4/0x9e0 [btrfs]
  [359.281931]        close_ctree+0x30b/0x350 [btrfs]
  [359.283208]        generic_shutdown_super+0x64/0x100
  [359.284516]        kill_anon_super+0x14/0x30
  [359.285658]        btrfs_kill_super+0x12/0xa0 [btrfs]
  [359.286964]        deactivate_locked_super+0x29/0x60
  [359.288242]        cleanup_mnt+0x3b/0x70
  [359.289310]        task_work_run+0x98/0xc0
  [359.290428]        exit_to_usermode_loop+0x83/0x90
  [359.291445]        do_syscall_64+0x15b/0x180
  [359.292598]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [359.294011]
  [359.294011] -> #2 (sb_internal#2){.+.+}:
  [359.295432]        __sb_start_write+0x113/0x1d0
  [359.296394]        start_transaction+0x369/0x500 [btrfs]
  [359.297471]        btrfs_finish_ordered_io+0x2aa/0x7c0 [btrfs]
  [359.298629]        normal_work_helper+0xcd/0x530 [btrfs]
  [359.299698]        process_one_work+0x246/0x610
  [359.300898]        worker_thread+0x3c/0x390
  [359.302020]        kthread+0x116/0x130
  [359.303053]        ret_from_fork+0x24/0x30
  [359.304152]
  [359.304152] -> #1 ((work_completion)(&work->normal_work)){+.+.}:
  [359.306100]        process_one_work+0x21f/0x610
  [359.307302]        worker_thread+0x3c/0x390
  [359.308465]        kthread+0x116/0x130
  [359.309357]        ret_from_fork+0x24/0x30
  [359.310229]
  [359.310229] -> #0 ((wq_completion)"%s-%s""btrfs", name){+.+.}:
  [359.311812]        lock_acquire+0x90/0x180
  [359.312929]        flush_workqueue+0xaa/0x540
  [359.313845]        drain_workqueue+0xa1/0x180
  [359.314761]        destroy_workqueue+0x17/0x240
  [359.315754]        btrfs_destroy_workqueue+0x57/0x200 [btrfs]
  [359.317245]        scrub_workers_put+0x2c/0x60 [btrfs]
  [359.318585]        btrfs_scrub_dev+0x336/0x590 [btrfs]
  [359.319944]        btrfs_dev_replace_by_ioctl.cold.19+0x179/0x1bb [btrfs]
  [359.321622]        btrfs_ioctl+0x28a4/0x2e40 [btrfs]
  [359.322908]        do_vfs_ioctl+0xa2/0x6d0
  [359.324021]        ksys_ioctl+0x3a/0x70
  [359.325066]        __x64_sys_ioctl+0x16/0x20
  [359.326236]        do_syscall_64+0x54/0x180
  [359.327379]        entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [359.328772]
  [359.328772] other info that might help us debug this:
  [359.328772]
  [359.330990] Chain exists of:
  [359.330990]   (wq_completion)"%s-%s""btrfs", name --> sb_internal#2 --> &fs_info->scrub_lock
  [359.330990]
  [359.334376]  Possible unsafe locking scenario:
  [359.334376]
  [359.336020]        CPU0                    CPU1
  [359.337070]        ----                    ----
  [359.337821]   lock(&fs_info->scrub_lock);
  [359.338506]                                lock(sb_internal#2);
  [359.339506]                                lock(&fs_info->scrub_lock);
  [359.341461]   lock((wq_completion)"%s-%s""btrfs", name);
  [359.342437]
  [359.342437]  *** DEADLOCK ***
  [359.342437]
  [359.343745] 1 lock held by btrfs/20975:
  [359.344788]  #0: 0000000053ea26a6 (&fs_info->scrub_lock){+.+.}, at: btrfs_scrub_dev+0x322/0x590 [btrfs]
  [359.346778]
  [359.346778] stack backtrace:
  [359.347897] CPU: 0 PID: 20975 Comm: btrfs Not tainted 5.0.0-rc6-default #461
  [359.348983] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
  [359.350501] Call Trace:
  [359.350931]  dump_stack+0x67/0x90
  [359.351676]  print_circular_bug.isra.37.cold.56+0x15c/0x195
  [359.353569]  check_prev_add.constprop.44+0x4f9/0x750
  [359.354849]  ? check_prev_add.constprop.44+0x286/0x750
  [359.356505]  __lock_acquire+0xb84/0xf10
  [359.357505]  lock_acquire+0x90/0x180
  [359.358271]  ? flush_workqueue+0x87/0x540
  [359.359098]  flush_workqueue+0xaa/0x540
  [359.359912]  ? flush_workqueue+0x87/0x540
  [359.360740]  ? drain_workqueue+0x1e/0x180
  [359.361565]  ? drain_workqueue+0xa1/0x180
  [359.362391]  drain_workqueue+0xa1/0x180
  [359.363193]  destroy_workqueue+0x17/0x240
  [359.364539]  btrfs_destroy_workqueue+0x57/0x200 [btrfs]
  [359.365673]  scrub_workers_put+0x2c/0x60 [btrfs]
  [359.366618]  btrfs_scrub_dev+0x336/0x590 [btrfs]
  [359.367594]  ? start_transaction+0xa1/0x500 [btrfs]
  [359.368679]  btrfs_dev_replace_by_ioctl.cold.19+0x179/0x1bb [btrfs]
  [359.369545]  btrfs_ioctl+0x28a4/0x2e40 [btrfs]
  [359.370186]  ? __lock_acquire+0x263/0xf10
  [359.370777]  ? kvm_clock_read+0x14/0x30
  [359.371392]  ? kvm_sched_clock_read+0x5/0x10
  [359.372248]  ? sched_clock+0x5/0x10
  [359.372786]  ? sched_clock_cpu+0xc/0xc0
  [359.373662]  ? do_vfs_ioctl+0xa2/0x6d0
  [359.374552]  do_vfs_ioctl+0xa2/0x6d0
  [359.375378]  ? do_sigaction+0xff/0x250
  [359.376233]  ksys_ioctl+0x3a/0x70
  [359.376954]  __x64_sys_ioctl+0x16/0x20
  [359.377772]  do_syscall_64+0x54/0x180
  [359.378841]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
  [359.380422] RIP: 0033:0x7f5429296a97

Backporting to older kernels: scrub_nocow_workers must be freed the same
way as the others.

CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Anand Jain <anand.jain@oracle.com>
[ update changelog ]
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:37 +01:00
Anand Jain 7faad6e25c btrfs: fix comment its device list mutex not volume lock
We have killed volume mutex (commit: dccdb07bc9
btrfs: kill btrfs_fs_info::volume_mutex). This a trival one seems to have
escaped.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:37 +01:00
Qu Wenruo bb58eb9e16 btrfs: extent_io: Kill the forward declaration of flush_write_bio
There is no need to forward declare flush_write_bio(), as it only
depends on submit_one_bio().  Both of them are pretty small, just move
them to kill the forward declaration.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:37 +01:00
Nikolay Borisov 352646c7bf btrfs: Fix grossly misleading argument names in extent io search
The variables and function parameters of __etree_search which pertain to
prev/next are grossly misnamed. Namely, prev_ret holds the next state
and not the previous. Similarly, next_ret actually holds the previous
extent state relating to the offset we are interested in. Fix this by
renaming the variables as well as switching the arguments order. 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>
2019-02-25 14:13:36 +01:00
Nikolay Borisov ba8f5206a4 btrfs: Remove EXTENT_FIRST_DELALLOC bit
With the refactoring introduced in 8b62f87bad ("Btrfs: reworki
outstanding_extents") this flag became unused. Remove it and renumber
the following flags accordingly. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:36 +01:00
Nikolay Borisov 9a0ec83d57 btrfs: use WARN_ON in a canonical form btrfs_remove_block_group
There is no point in using a construct like 'if (!condition)
WARN_ON(1)'. Use WARN_ON(!condition) directly. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:36 +01:00
Josef Bacik 260e77025f btrfs: reserve extra space during evict
We could generate a lot of delayed refs in evict but never have any left
over space from our block rsv to make up for that fact.  So reserve some
extra space and give it to the transaction so it can be used to refill
the delayed refs rsv every loop through the truncate path.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:35 +01:00
Josef Bacik 8a1bbe1d5c btrfs: be more explicit about allowed flush states
For FLUSH_LIMIT flushers we really can only allocate chunks and flush
delayed inode items, everything else is problematic.  I added a bunch of
new states and it lead to weirdness in the FLUSH_LIMIT case because I
forgot about how it worked.  So instead explicitly declare the states
that are ok for flushing with FLUSH_LIMIT and use that for our state
machine.  Then as we add new things that are safe we can just add them
to this list.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:35 +01:00
Josef Bacik 5df1136363 btrfs: loop in inode_rsv_refill
With severe fragmentation we can end up with our inode rsv size being
huge during writeout, which would cause us to need to make very large
metadata reservations.

However we may not actually need that much once writeout is complete,
because of the over-reservation for the worst case.

So instead try to make our reservation, and if we couldn't make it
re-calculate our new reservation size and try again.  If our reservation
size doesn't change between tries then we know we are actually out of
space and can error. Flushing that could have been running in parallel
did not make any space.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ rename to calc_refill_bytes, update comment and changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:35 +01:00
Josef Bacik f91587e415 btrfs: don't enospc all tickets on flush failure
With the introduction of the per-inode block_rsv it became possible to
have really really large reservation requests made because of data
fragmentation.  Since the ticket stuff assumed that we'd always have
relatively small reservation requests it just killed all tickets if we
were unable to satisfy the current request.

However, this is generally not the case anymore.  So fix this logic to
instead see if we had a ticket that we were able to give some
reservation to, and if we were continue the flushing loop again.

Likewise we make the tickets use the space_info_add_old_bytes() method
of returning what reservation they did receive in hopes that it could
satisfy reservations down the line.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik 450114fc0d btrfs: don't use global reserve for chunk allocation
We've done this forever because of the voodoo around knowing how much
space we have.  However, we have better ways of doing this now, and on
normal file systems we'll easily have a global reserve of 512MiB, and
since metadata chunks are usually 1GiB that means we'll allocate
metadata chunks more readily.  Instead use the actual used amount when
determining if we need to allocate a chunk or not.

This has a side effect for mixed block group fs'es where we are no
longer allocating enough chunks for the data/metadata requirements.  To
deal with this add a ALLOC_CHUNK_FORCE step to the flushing state
machine.  This will only get used if we've already made a full loop
through the flushing machinery and tried committing the transaction.

If we have then we can try and force a chunk allocation since we likely
need it to make progress.  This resolves issues I was seeing with
the mixed bg tests in xfstests without the new flushing state.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ merged with patch "add ALLOC_CHUNK_FORCE to the flushing code" ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik b78e5616af btrfs: dump block_rsv details when dumping space info
For enospc_debug having the block rsvs is super helpful to see if we've
done something wrong.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:34 +01:00
Josef Bacik d89dbefb8c btrfs: check if there are free block groups for commit
may_commit_transaction will skip committing the transaction if we don't
have enough pinned space or if we're trying to find space for a SYSTEM
chunk.  However, if we have pending free block groups in this transaction
we still want to commit as we may be able to allocate a chunk to make
our reservation.  So instead of just returning ENOSPC, check if we have
free block groups pending, and if so commit the transaction to allow us
to use that free space.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou 3f93aef535 btrfs: add zstd compression level support
Zstd compression requires different amounts of memory for each level of
compression. The prior patches implemented indirection to allow for each
compression type to manage their workspaces independently. This patch
uses this indirection to implement compression level support for zstd.

To manage the additional memory require, each compression level has its
own queue of workspaces. A global LRU is used to help with reclaim.
Reclaim is done via a timer which provides a mechanism to decrease
memory utilization by keeping only workspaces around that are sized
appropriately. Forward progress is guaranteed by a preallocated max
workspace hidden from the LRU.

When getting a workspace, it uses a bitmap to identify the levels that
are populated and scans up. If it finds a workspace that is greater than
it, it uses it, but does not update the last_used time and the
corresponding place in the LRU. If we hit memory pressure, we sleep on
the max level workspace. We continue to rescan in case we can use a
smaller workspace, but eventually should be able to obtain the max level
workspace or allocate one again should memory pressure subside.

The memory requirement for decompression is the same as level 1, and
therefore can use any of available workspace.

The number of workspaces is bound by an upper limit of the workqueue's
limit which currently is 2 (percpu limit). The reclaim timer is used to
free inactive/improperly sized workspaces and is set to 307s to avoid
colliding with transaction commit (every 30s).

Repeating the experiment from v2 [1], the Silesia corpus was copied to a
btrfs filesystem 10 times and then read back after dropping the caches.
The btrfs filesystem was on an SSD.

Level   Ratio   Compression (MB/s)  Decompression (MB/s)  Memory (KB)
1       2.658        438.47                910.51            780
2       2.744        364.86                886.55           1004
3       2.801        336.33                828.41           1260
4       2.858        286.71                886.55           1260
5       2.916        212.77                556.84           1388
6       2.363        119.82                990.85           1516
7       3.000        154.06                849.30           1516
8       3.011        159.54                875.03           1772
9       3.025        100.51                940.15           1772
10      3.033        118.97                616.26           1772
11      3.036         94.19                802.11           1772
12      3.037         73.45                931.49           1772
13      3.041         55.17                835.26           2284
14      3.087         44.70                716.78           2547
15      3.126         37.30                878.84           2547

[1] https://lore.kernel.org/linux-btrfs/20181031181108.289340-1-terrelln@fb.com/

Cc: Nick Terrell <terrelln@fb.com>
Cc: Omar Sandoval <osandov@osandov.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou d3c6ab752c btrfs: make zstd memory requirements monotonic
It is possible based on the level configurations that a higher level
workspace uses less memory than a lower level workspace. In order to
reuse workspaces, this must be made a monotonic relationship. This
precomputes the required memory for each level and enforces the
monotonicity between level and memory required. This is also done
in upstream zstd in [1].

[1] a68b76afef

Cc: Nick Terrell <terrelln@fb.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou e0dc87afcd btrfs: zstd use the passed through level instead of default
Zstd currently only supports the default level of compression. This
patch switches to using the level passed in for btrfs zstd
configuration.

Zstd workspaces now keep track of the requested level as this can differ
from the size of the workspace.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:33 +01:00
Dennis Zhou d0ab62ce2d btrfs: change set_level() to bound the level passed in
Currently, the only user of set_level() is zlib which sets an internal
workspace parameter. As level is now plumbed into get_workspace(), this
can be handled there rather than separately.

This repurposes set_level() to bound the level passed in so it can be
used when setting the mounts compression level and as well as verifying
the level before getting a workspace. The other benefit is this divides
the meaning of compress(0) and get_workspace(0). The former means we
want to use the default compression level of the compression type. The
latter means we can use any workspace available.

Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou 7bf4994304 btrfs: plumb level through the compression interface
Zlib compression supports multiple levels, but doesn't require changing
in how a workspace itself is created and managed. Zstd introduces a
different memory requirement such that higher levels of compression
require more memory.

This requires changes in how the alloc()/get() methods work for zstd.
This pach plumbs compression level through the interface as a parameter
in preparation for zstd compression levels.  This gives the compression
types opportunity to create/manage based on the compression level.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou 92ee553036 btrfs: move to function pointers for get/put workspaces
The previous patch added generic helpers for get_workspace() and
put_workspace(). Now, we can migrate ownership of the workspace_manager
to be in the compression type code as the compression code itself
doesn't care beyond being able to get a workspace. The init/cleanup and
get/put methods are abstracted so each compression algorithm can decide
how they want to manage their workspaces.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:32 +01:00
Dennis Zhou 929f4baf93 btrfs: add compression interface in (get/put)_workspace
There are two levels of workspace management. First, alloc()/free()
which are responsible for actually creating and destroy workspaces.
Second, at a higher level, get()/put() which is the compression code
asking for a workspace from a workspace_manager.

The compression code shouldn't really care how it gets a workspace, but
that it got a workspace. This adds get_workspace() and put_workspace()
to be the higher level interface which is responsible for indexing into
the appropriate compression type. It also introduces
btrfs_put_workspace() and btrfs_get_workspace() to be the generic
implementations of the higher interface.

Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou 1666edabc8 btrfs: add helper methods for workspace manager init and cleanup
Workspace manager init and cleanup code is open coded inside a for loop
over the compression types. This forces each compression type to rely on
the same workspace manager implementation. This patch creates helper
methods that will be the generic implementation for btrfs workspace
management.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou 10b94a51ca btrfs: unify compression ops with workspace_manager
Make the workspace_manager own the interface operations rather than
managing index-paired arrays for the workspace_manager and compression
operations.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou ca4ac360af btrfs: manage heuristic workspace as index 0
While the heuristic workspaces aren't really compression workspaces,
they use the same interface for managing them. So rather than branching,
let's just handle them once again as the index 0 compression type.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:31 +01:00
Dennis Zhou acce85de12 btrfs: rename workspaces_list to workspace_manager
This is in preparation for zstd compression levels. As each level will
require different size of workspace, workspaces_list is no longer a
really fitting name.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Dennis Zhou 1972708a89 btrfs: add helpers for compression type and level
It is very easy to miss places that rely on a certain bitshifting for
decoding the type_level overloading. Add helpers to do this instead.

Cc: Omar Sandoval <osandov@osandov.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Dennis Zhou <dennis@kernel.org>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Anand Jain 228a73abde btrfs: introduce new ioctl to unregister a btrfs device
Support for a new command that can be used eg. as a command

  $ btrfs device scan --forget [dev]'
(the final name may change though)

to undo the effects of 'btrfs device scan [dev]'. For this purpose
this patch proposes to use ioctl #5 as it was empty and is next to the
SCAN ioctl.

The new ioctl BTRFS_IOC_FORGET_DEV works only on the control device
(/dev/btrfs-control) to unregister one or all devices, devices that are
not mounted.

The argument is struct btrfs_ioctl_vol_args, ::name specifies the device
path. To unregister all device, the path is an empty string.

Again, the devices are removed only if they aren't part of a mounte
filesystem.

This new ioctl provides:

- release of unwanted btrfs_fs_devices and btrfs_devices structures
  from memory if the device is not going to be mounted

- ability to mount filesystem in degraded mode, when one devices is
  corrupted like in split brain raid1

- running test cases which would require reloading the kernel module
  but this is not possible eg. due to mounted filesystem or built-in

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:30 +01:00
Josef Bacik 034f784d7c btrfs: replace cleaner_delayed_iput_mutex with a waitqueue
The throttle path doesn't take cleaner_delayed_iput_mutex, which means
we could think we're done flushing iputs in the data space reservation
path when we could have a throttler doing an iput.  There's no real
reason to serialize the delayed iput flushing, so instead of taking the
cleaner_delayed_iput_mutex whenever we flush the delayed iputs just
replace it with an atomic counter and a waitqueue.  This removes the
short (or long depending on how big the inode is) window where we think
there are no more pending iputs when there really are some.

The waiting is killable as it could be indirectly called from user
operations like fallocate or zero-range. Such call sites should handle
the error but otherwise it's not necessary. Eg. flush_space just needs
to attempt to make space by waiting on iputs.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add killable comment and changelog parts ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:29 +01:00
Qu Wenruo 3ece54e504 btrfs: Output ENOSPC debug info in inc_block_group_ro
Since inc_block_group_ro() would return -ENOSPC, outputting debug info
for enospc_debug mount option would be helpful to debug some balance
false ENOSPC report.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:29 +01:00
Qu Wenruo c8f72b98b6 btrfs: qgroup: Remove duplicated trace points for qgroup_rsv_add/release
Inside qgroup_rsv_add/release(), we have trace events
trace_qgroup_update_reserve() to catch reserved space update.

However we still have two manual trace_qgroup_update_reserve() calls
just outside these functions.  Remove these duplicated calls.

Fixes: 64ee4e751a ("btrfs: qgroup: Update trace events to use new separate rsv types")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
Anders Roxell 2eec5f0042 btrfs: let the assertion expression compile in all configs
A compiler warning (in a patch in development) pointed to a variable
that was used only inside and ASSERT:

  u64 root_objectid = root->root_key.objectid;
  ASSERT(root_objectid == ...);

  fs/btrfs/relocation.c: In function ‘insert_dirty_subv’:
  fs/btrfs/relocation.c:2138:6: warning: unused variable ‘root_objectid’ [-Wunused-variable]
    u64 root_objectid = root->root_key.objectid;
	^~~~~~~~~~~~~

When CONFIG_BRTFS_ASSERT isn't enabled, variable root_objectid isn't used.

Rework the assertion helper by adding a runtime check instead of the
'#ifdef CONFIG_BTRFS_ASSERT #else ...", so the compiler sees the
condition being passed into an inline function after preprocessing.

Signed-off-by: Anders Roxell <anders.roxell@linaro.org>
Reviewed-by: David Sterba <dsterba@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba 766ece54f4 btrfs: merge btrfs_set_lock_blocking_rw with it's caller
The last caller that does not have a fixed value of lock is
btrfs_set_path_blocking, that actually does the same conditional swtich
by the lock type so we can merge the branches together and remove the
helper.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba 970e74d961 btrfs: simplify waiting loop in btrfs_tree_lock
Currently, the number of readers and writers is checked and in case
there are any, wait and redo the locks. There's some duplication
before the branches go back to again label, eg. calling wait_event on
blocking_readers twice.

The sequence is transformed

loop:
* wait for readers
* wait for writers
* write_lock
* check readers, unlock and wait for readers, loop
* check writers, unlock and wait for writers, loop

The new sequence is not exactly the same due to the simplification, for
readers it's slightly faster. For the writers, original code does

* wait for writers
* (loop) wait for readers
*        wait for writers -- again

while the new goes directly to the reader check. This should behave the
same on a contended lock with multiple writers and readers, but can
reduce number of times we're waiting on something.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:28 +01:00
David Sterba 8bead25820 btrfs: open code now trivial btrfs_set_lock_blocking
btrfs_set_lock_blocking is now only a simple wrapper around
btrfs_set_lock_blocking_write. The name does not bring any semantic
value that could not be inferred from the new function so there's no
point keeping it.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba 300aa896e1 btrfs: replace btrfs_set_lock_blocking_rw with appropriate helpers
We can use the right helper where the lock type is a fixed parameter.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba aa12c02778 btrfs: split btrfs_clear_lock_blocking_rw to read and write helpers
There are many callers that hardcode the desired lock type so we can
avoid the switch and call them directly. Split the current function to
two. There are no remaining users of btrfs_clear_lock_blocking_rw so
it's removed.  The call sites will be converted in followup patches.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
David Sterba b95be2d9fb btrfs: split btrfs_set_lock_blocking_rw to read and write helpers
There are many callers that hardcode the desired lock type so we can
avoid the switch and call them directly. Split the current function to
two but leave a helper that still takes the variable lock type to make
current code compile.  The call sites will be converted in followup
patches.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:27 +01:00
Qu Wenruo 9627736b75 btrfs: qgroup: Cleanup old subtree swap code
Since it's replaced by new delayed subtree swap code, remove the
original code.

The cleanup is small since most of its core function is still used by
delayed subtree swap trace.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo f616f5cd9d btrfs: qgroup: Use delayed subtree rescan for balance
Before this patch, qgroup code traces the whole subtree of subvolume and
reloc trees unconditionally.

This makes qgroup numbers consistent, but it could cause tons of
unnecessary extent tracing, which causes a lot of overhead.

However for subtree swap of balance, just swap both subtrees because
they contain the same contents and tree structure, so qgroup numbers
won't change.

It's the race window between subtree swap and transaction commit could
cause qgroup number change.

This patch will delay the qgroup subtree scan until COW happens for the
subtree root.

So if there is no other operations for the fs, balance won't cause extra
qgroup overhead. (best case scenario)
Depending on the workload, most of the subtree scan can still be
avoided.

Only for worst case scenario, it will fall back to old subtree swap
overhead. (scan all swapped subtrees)

[[Benchmark]]
Hardware:
	VM 4G vRAM, 8 vCPUs,
	disk is using 'unsafe' cache mode,
	backing device is SAMSUNG 850 evo SSD.
	Host has 16G ram.

Mkfs parameter:
	--nodesize 4K (To bump up tree size)

Initial subvolume contents:
	4G data copied from /usr and /lib.
	(With enough regular small files)

Snapshots:
	16 snapshots of the original subvolume.
	each snapshot has 3 random files modified.

balance parameter:
	-m

So the content should be pretty similar to a real world root fs layout.

And after file system population, there is no other activity, so it
should be the best case scenario.

                     | v4.20-rc1            | w/ patchset    | diff
-----------------------------------------------------------------------
relocated extents    | 22615                | 22457          | -0.1%
qgroup dirty extents | 163457               | 121606         | -25.6%
time (sys)           | 22.884s              | 18.842s        | -17.6%
time (real)          | 27.724s              | 22.884s        | -17.5%

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo 370a11b811 btrfs: qgroup: Introduce per-root swapped blocks infrastructure
To allow delayed subtree swap rescan, btrfs needs to record per-root
information about which tree blocks get swapped.  This patch introduces
the required infrastructure.

The designed workflow will be:

1) Record the subtree root block that gets swapped.

   During subtree swap:
   O = Old tree blocks
   N = New tree blocks
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         NA     OB                          OA      OB
       /  |     |  \                      /  |      |  \
     NC  ND     OE  OF                   OC  OD     OE  OF

  In this case, NA and OA are going to be swapped, record (NA, OA) into
  subvolume tree X.

2) After subtree swap.
         reloc tree                         subvolume tree X
            Root                               Root
           /    \                             /    \
         OA     OB                          NA      OB
       /  |     |  \                      /  |      |  \
     OC  OD     OE  OF                   NC  ND     OE  OF

3a) COW happens for OB
    If we are going to COW tree block OB, we check OB's bytenr against
    tree X's swapped_blocks structure.
    If it doesn't fit any, nothing will happen.

3b) COW happens for NA
    Check NA's bytenr against tree X's swapped_blocks, and get a hit.
    Then we do subtree scan on both subtrees OA and NA.
    Resulting 6 tree blocks to be scanned (OA, OC, OD, NA, NC, ND).

    Then no matter what we do to subvolume tree X, qgroup numbers will
    still be correct.
    Then NA's record gets removed from X's swapped_blocks.

4)  Transaction commit
    Any record in X's swapped_blocks gets removed, since there is no
    modification to swapped subtrees, no need to trigger heavy qgroup
    subtree rescan for them.

This will introduce 128 bytes overhead for each btrfs_root even qgroup
is not enabled. This is to reduce memory allocations and potential
failures.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo 5aea1a4fcf btrfs: qgroup: Refactor btrfs_qgroup_trace_subtree_swap
Refactor btrfs_qgroup_trace_subtree_swap() into
qgroup_trace_subtree_swap(), which only needs two extent buffer and some
other bool to control the behavior.

This provides the basis for later delayed subtree scan work.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:26 +01:00
Qu Wenruo d2311e6985 btrfs: relocation: Delay reloc tree deletion after merge_reloc_roots
Relocation code will drop btrfs_root::reloc_root as soon as
merge_reloc_root() finishes.

However later qgroup code will need to access btrfs_root::reloc_root
after merge_reloc_root() for delayed subtree rescan.

So alter the timming of resetting btrfs_root:::reloc_root, make it
happens after transaction commit.

With this patch, we will introduce a new btrfs_root::state,
BTRFS_ROOT_DEAD_RELOC_TREE, to info part of btrfs_root::reloc_tree user
that although btrfs_root::reloc_tree is still non-NULL, but still it's
not used any more.

The lifespan of btrfs_root::reloc tree will become:
          Old behavior            |              New
------------------------------------------------------------------------
btrfs_init_reloc_root()      ---  | btrfs_init_reloc_root()      ---
  set reloc_root              |   |   set reloc_root              |
                              |   |                               |
                              |   |                               |
merge_reloc_root()            |   | merge_reloc_root()            |
|- btrfs_update_reloc_root() ---  | |- btrfs_update_reloc_root() -+-
     clear btrfs_root::reloc_root |      set ROOT_DEAD_RELOC_TREE |
                                  |      record root into dirty   |
                                  |      roots rbtree             |
                                  |                               |
                                  | reloc_block_group() Or        |
                                  | btrfs_recover_relocation()    |
                                  | | After transaction commit    |
                                  | |- clean_dirty_subvols()     ---
                                  |     clear btrfs_root::reloc_root

During ROOT_DEAD_RELOC_TREE set lifespan, the only user of
btrfs_root::reloc_tree should be qgroup.

Since reloc root needs a longer life-span, this patch will also delay
btrfs_drop_snapshot() call.
Now btrfs_drop_snapshot() is called in clean_dirty_subvols().

This patch will increase the size of btrfs_root by 16 bytes.

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Josef Bacik 119e80df7d btrfs: call btrfs_create_pending_block_groups unconditionally
The first thing we do is loop through the list, this

if (!list_empty())
	btrfs_create_pending_block_groups();

thing is just wasted space.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Josef Bacik fa781cea3d btrfs: make btrfs_destroy_delayed_refs use btrfs_delete_ref_head
Instead of open coding this stuff use the helper instead.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Josef Bacik 3069bd2669 btrfs: make btrfs_destroy_delayed_refs use btrfs_delayed_ref_lock
We have this open coded in btrfs_destroy_delayed_refs, use the helper
instead.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:25 +01:00
Anand Jain d1e1442065 btrfs: scrub: print messages when started or finished
The kernel log messages help debugging and audit, add them for scrub

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
David Sterba ce3ded1061 btrfs: simplify workqueue name when allocating
The workqueue name is constructed from a format string but the prefix
does not need to be set by %s.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
Anand Jain 09ba3bc9dd btrfs: merge btrfs_find_device and find_device
Both btrfs_find_device() and find_device() does the same thing except
that the latter does not take the seed device onto account in the device
scanning context. We can merge them.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:24 +01:00
Anand Jain 70bc7088aa btrfs: refactor btrfs_free_stale_devices() to get return value
Preparatory patch to add ioctl that allows to forget a device (ie.
reverse of scan).

Refactors btrfs_free_stale_devices() to obtain return status. As this
function can fail if it can't find the given path (returns -ENOENT) or
trying to delete a mounted device (returns -EBUSY).

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain e4319cd9ca btrfs: refactor btrfs_find_device() take fs_devices as argument
btrfs_find_device() accepts fs_info as an argument and retrieves
fs_devices from fs_info.

Instead use fs_devices, so that this function can be used in non-mount
(during device scanning) context as well.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain 6e927cebe2 btrfs: cleanup btrfs_find_device_by_devspec()
btrfs_find_device_by_devspec() finds the device by @devid or by
@device_path. This patch makes code flow easy to read by open coding the
else part and renames devpath to device_path.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:23 +01:00
Anand Jain d95a830c78 btrfs: merge btrfs_find_device_missing_or_by_path() into parent
btrfs_find_device_missing_or_by_path() is relatively small function, and
its only parent btrfs_find_device_by_devspec() is small as well. Besides
there are a number of find_device functions. Merge
btrfs_find_device_missing_or_by_path() into its parent.

Signed-off-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov 02a033df7a btrfs: Remove not_found_em label from btrfs_get_extent
In order to avoid duplicating init code for em there is an additional
label, not_found_em, which is used to only set ->block_start. The only
case when it will be used is if the extent we are adding overlaps with
an existing extent. Make that case more obvious by:

 1. Adding a comment hinting at what's going on
 2. Assigning EXTENT_MAP_HOLE and directly going to insert.

 No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov b8eeab7fce btrfs: Consolidate retval checking of core btree functions
Core btree functions in btrfs generally return 0 when an item is found,
1 in case the sought item cannot be found and <0 when an error happens.
Consolidate the checks for those conditions in one 'if () {} else if ()
{}' construct rather than 2 separate 'if () {}' statements. This
emphasizes that the handling code pertains to a single function. No
functional changes.

Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Nikolay Borisov 694c12ed9d btrfs: Rename found_type to extent_type in btrfs_get_extent
found_type really holds the type of extent and is guaranteed to to have
a value between [0, 2]. The only time it can contain anything different
is if btrfs_lookup_file_extent returned a positive value and the
previous item is different than an extent. Avoid this situation by
simply checking found_key.type rather than assigning the item type to
found_type intermittently. Also make the variable an u8 to reduce stack
usage. No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:22 +01:00
Filipe Manana 500710d3b8 Btrfs: move duplicated nodatasum check into common reflink/dedupe helper
Move the check that verifies if both inodes have checksums disabled or
both have them enabled, from the clone and deduplication functions into
the new common helper btrfs_remap_file_range_prep().

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:21 +01:00
Nikolay Borisov 951e05a904 btrfs: Remove impossible condition from mergable_maps
We can never have extents marked as EXTENT_MAP_DELALLOC since this
value is only ever used by btrfs_get_extent_fiemap. In this case the
extent map is created by btrfs_get_extent_fiemap and is never really
published, this flag is used to return the corresponding userspace one.
Considering this, it's pointless having a check for EXTENT_MAP_DELALLOC
in mergable_maps. Just remove it.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:21 +01:00
Filipe Manana d00c2d9c76 Btrfs: do not overwrite error return value in the balance ioctl
If the call to btrfs_balance() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_balance()
returned success or was canceled.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:21 +01:00
Filipe Manana d3a53286c1 Btrfs: do not overwrite error return value in the device replace ioctl
If the call to btrfs_dev_replace_by_ioctl() failed we would overwrite the
error returned to user space with -EFAULT if the call to copy_to_user()
failed as well. Fix that by calling copy_to_user() only if no error
happened before or a device replace operation was canceled.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:20 +01:00
Filipe Manana 0f39b60563 Btrfs: remove redundant check for swapfiles when reflinking
Checking if either of the inodes corresponds to a swapfile is already
performed by generic_remap_file_range_prep(), so we do not need to do
it in the btrfs clone and deduplication functions.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:20 +01:00
Nikolay Borisov 420829d8ea btrfs: Refactor shrink_delalloc
Add a couple of comments regarding the logic flow in shrink_delalloc.
Then, cease using max_reclaim as a temporary variable when calculating
nr_pages. Finally give max_reclaim a more becoming name, which
uneqivocally shows at what this variable really holds. 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>
2019-02-25 14:13:20 +01:00
Nikolay Borisov 4546d17874 btrfs: Document logic regarding inode in async_cow_submit
Add a comment explaining when ->inode could be NULL and why we always
perform the ->async_delalloc_pages modification.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:20 +01:00
Nikolay Borisov a1d64ba609 btrfs: Remove WARN_ON in btrfs_alloc_delalloc_work
It can never trigger since before calling alloc_delalloc_work we have
called igrab in start_delalloc_inodes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:19 +01:00
Nikolay Borisov bd4691a0e8 btrfs: Use ihold instead of igrab in cow_file_range_async
ihold is supposed to be used when the caller already has a reference to
the inode. In the case of cow_file_range_async this invariants holds,
since the 3 call chains leading to this function all take a reference:

btrfs_writepage  <--- does igrab
 extent_write_full_page
  __extent_writepage
   writepage_delalloc
     btrfs_run_delalloc_range
      cow_file_range_async

extent_write_cache_pages <--- does igrab
 __extent_writepage (same callchain as above)

and

submit_compressed_extents <-- already called from async CoW submit path,
			      which would have done ihold.
 extent_write_locked_range
  __extent_writepage

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:19 +01:00
Nikolay Borisov 62b3762271 btrfs: Remove isize local variable in compress_file_range
It's used only once so just inline the call to i_size_read. The
semantics regarding the inode size are not changed, the pages in the
range are locked and i_size cannot change between the time it was set
and used.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:19 +01:00
Nikolay Borisov 532425ff9e btrfs: Remove inode argument from async_cow_submit
We already pass the async_cow struct that holds a reference to the
inode. Exploit this fact and remove the extra inode argument. No
functional changes.

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
YueHaibing aa704d4e75 btrfs: remove set but not used variable 'num_pages'
Fixes gcc '-Wunused-but-set-variable' warning:

fs/btrfs/ioctl.c: In function 'btrfs_extent_same':
fs/btrfs/ioctl.c:3260:6: warning:
 variable 'num_pages' set but not used [-Wunused-but-set-variable]

It not used any more since commit 9ee8234e6220 ("Btrfs: use
generic_remap_file_range_prep() for cloning and deduplication")

Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
Nikolay Borisov 02950af4e3 btrfs: Remove redundant assignment in btrfs_get_extent_fiemap
hole_len is only used if the hole falls within the requested range. Make
that explicitly clear by only assigning in the corresponding branch.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
Nikolay Borisov f3714ef479 btrfs: Refactor btrfs_get_extent_fiemap
Make btrfs_get_extent_fiemap a bit more friendly. First step is to
rename the closely related, yet arbitrary named
range_start/found_end/found variables. They define the delalloc range
that is found in case a real extent wasn't found. Subsequently remove
an unnecessary check for hole_em since it's guaranteed to be set i.e the
check is always true. Top it off by giving all comments a refresh.

No functional changes.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ reformatted a few more comments ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:18 +01:00
Nikolay Borisov 4ab47a8d9c btrfs: Remove unused arguments from btrfs_get_extent_fiemap
This function is a simple wrapper over btrfs_get_extent that returns
either:

a) A real extent in the passed range or
b) Adjusted extent based on whether delalloc bytes are found backing up
   a hole.

To support these semantics it doesn't need the page/pg_offset/create
arguments which are passed to btrfs_get_extent in case an extent is to
be created. So simplify the function by removing the unused arguments.
No functional changes.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:17 +01:00
Filipe Manana a087349066 Btrfs: setup a nofs context for memory allocation at __btrfs_set_acl
We are holding a transaction handle when setting an acl, therefore we can
not allocate the xattr value buffer using GFP_KERNEL, as we could deadlock
if reclaim is triggered by the allocation, therefore setup a nofs context.

Fixes: 39a27ec100 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:17 +01:00
Filipe Manana b89f6d1fcb Btrfs: setup a nofs context for memory allocation at btrfs_create_tree()
We are holding a transaction handle when creating a tree, therefore we can
not allocate the root using GFP_KERNEL, as we could deadlock if reclaim is
triggered by the allocation, therefore setup a nofs context.

Fixes: 74e4d82757 ("btrfs: let callers of btrfs_alloc_root pass gfp flags")
CC: stable@vger.kernel.org # 4.9+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:16 +01:00
Filipe Manana eee9957754 Btrfs: do not overwrite error return value in the get device stats ioctl
If the call to btrfs_get_dev_stats() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_get_dev_stats()
returned success.

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:16 +01:00
Filipe Manana 4fa99b008f Btrfs: do not overwrite error return value in scrub progress ioctl
If the call to btrfs_scrub_progress() failed we would overwrite the error
returned to user space with -EFAULT if the call to copy_to_user() failed
as well. Fix that by calling copy_to_user() only if btrfs_scrub_progress()
returned success.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:16 +01:00
Filipe Manana 06fe39ab15 Btrfs: do not overwrite scrub error with fault error in scrub ioctl
If scrub returned an error and then the copy_to_user() call did not
succeed, we would overwrite the error returned by scrub with -EFAULT.
Fix that by calling copy_to_user() only if btrfs_scrub_dev() returned
success.

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:15 +01:00
Nikolay Borisov bc9a8bf79c btrfs: Make first argument of btrfs_run_delalloc_range directly an inode
Since this function is no longer a callback there is no need to have
its first argument obfuscated with a void *. Change it directly to a
pointer to an inode. 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>
2019-02-25 14:13:15 +01:00
Julia Lawall 9cf10cc195 Btrfs: drop useless LIST_HEAD in merge_reloc_root
Drop LIST_HEAD where the variable it declares is never used.

The uses were removed in 3fd0a5585e ("Btrfs: Metadata ENOSPC
handling for balance"), but not the declaration.

The semantic patch that fixes this problem is as follows:
(http://coccinelle.lip6.fr/)

// <smpl>
@@
identifier x;
@@
- LIST_HEAD(x);
  ... when != x
// </smpl>

Signed-off-by: Julia Lawall <Julia.Lawall@lip6.fr>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-02-25 14:13:15 +01:00
Jens Axboe 6fb845f0e7 Linux 5.0-rc6
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Merge tag 'v5.0-rc6' into for-5.1/block

Pull in 5.0-rc6 to avoid a dumb merge conflict with fs/iomap.c.
This is needed since io_uring is now based on the block branch,
to avoid a conflict between the multi-page bvecs and the bits
of io_uring that touch the core block parts.

* tag 'v5.0-rc6': (525 commits)
  Linux 5.0-rc6
  x86/mm: Make set_pmd_at() paravirt aware
  MAINTAINERS: Update the ocores i2c bus driver maintainer, etc
  blk-mq: remove duplicated definition of blk_mq_freeze_queue
  Blk-iolatency: warn on negative inflight IO counter
  blk-iolatency: fix IO hang due to negative inflight counter
  MAINTAINERS: unify reference to xen-devel list
  x86/mm/cpa: Fix set_mce_nospec()
  futex: Handle early deadlock return correctly
  futex: Fix barrier comment
  net: dsa: b53: Fix for failure when irq is not defined in dt
  blktrace: Show requests without sector
  mips: cm: reprime error cause
  mips: loongson64: remove unreachable(), fix loongson_poweroff().
  sit: check if IPv6 enabled before calling ip6_err_gen_icmpv6_unreach()
  geneve: should not call rt6_lookup() when ipv6 was disabled
  KVM: nVMX: unconditionally cancel preemption timer in free_nested (CVE-2019-7221)
  KVM: x86: work around leak of uninitialized stack contents (CVE-2019-7222)
  kvm: fix kvm_ioctl_create_device() reference counting (CVE-2019-6974)
  signal: Better detection of synchronous signals
  ...
2019-02-15 08:43:59 -07:00
Ming Lei 6dc4f100c1 block: allow bio_for_each_segment_all() to iterate over multi-page bvec
This patch introduces one extra iterator variable to bio_for_each_segment_all(),
then we can allow bio_for_each_segment_all() to iterate over multi-page bvec.

Given it is just one mechannical & simple change on all bio_for_each_segment_all()
users, this patch does tree-wide change in one single patch, so that we can
avoid to use a temporary helper for this conversion.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:11 -07:00
Ming Lei c3a7ce7380 btrfs: use mp_bvec_last_segment to get bio's last page
Preparing for supporting multi-page bvec.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:11 -07:00
Christoph Hellwig 8a2ee44a37 btrfs: look at bi_size for repair decisions
bio_readpage_error currently uses bi_vcnt to decide if it is worth
retrying an I/O.  But the vector count is mostly an implementation
artifact - it really should figure out if there is more than a
single sector worth retrying.  Use bi_size for that and shift by
PAGE_SHIFT.  This really should be blocks/sectors, but given that
btrfs doesn't support a sector size different from the PAGE_SIZE
using the page size keeps the changes to a minimum.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2019-02-15 08:40:10 -07:00
Linus Torvalds 312b3a93dd for-5.0-rc4-tag
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Merge tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - regression fix: transaction commit can run away due to delayed ref
   waiting heuristic, this is not necessary now because of the proper
   reservation mechanism introduced in 5.0

 - regression fix: potential crash due to use-before-check of an ERR_PTR
   return value

 - fix for transaction abort during transaction commit that needs to
   properly clean up pending block groups

 - fix deadlock during b-tree node/leaf splitting, when this happens on
   some of the fundamental trees, we must prevent new tree block
   allocation to re-enter indirectly via the block group flushing path

 - potential memory leak after errors during mount

* tag 'for-5.0-rc4-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: On error always free subvol_name in btrfs_mount
  btrfs: clean up pending block groups when transaction commit aborts
  btrfs: fix potential oops in device_list_add
  btrfs: don't end the transaction for delayed refs in throttle
  Btrfs: fix deadlock when allocating tree block during leaf/node split
2019-02-03 08:48:33 -08:00
Eric W. Biederman 532b618bdf btrfs: On error always free subvol_name in btrfs_mount
The subvol_name is allocated in btrfs_parse_subvol_options and is
consumed and freed in mount_subvol.  Add a free to the error paths that
don't call mount_subvol so that it is guaranteed that subvol_name is
freed when an error happens.

Fixes: 312c89fbca ("btrfs: cleanup btrfs_mount() using btrfs_mount_root()")
Cc: stable@vger.kernel.org # v4.19+
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: "Eric W. Biederman" <ebiederm@xmission.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:47 +01:00
David Sterba c7cc64a985 btrfs: clean up pending block groups when transaction commit aborts
The fstests generic/475 stresses transaction aborts and can reveal
space accounting or use-after-free bugs regarding block goups.

In this case the pending block groups that remain linked to the
structures after transaction commit aborts in the middle.

The corrupted slabs lead to failures in following tests, eg. generic/476

  [ 8172.752887] BUG: unable to handle kernel NULL pointer dereference at 0000000000000058
  [ 8172.755799] #PF error: [normal kernel read fault]
  [ 8172.757571] PGD 661ae067 P4D 661ae067 PUD 3db8e067 PMD 0
  [ 8172.759000] Oops: 0000 [#1] PREEMPT SMP
  [ 8172.760209] CPU: 0 PID: 39 Comm: kswapd0 Tainted: G        W         5.0.0-rc2-default #408
  [ 8172.762495] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
  [ 8172.765772] RIP: 0010:shrink_page_list+0x2f9/0xe90
  [ 8172.770453] RSP: 0018:ffff967f00663b18 EFLAGS: 00010287
  [ 8172.771184] RAX: 0000000000000000 RBX: ffff967f00663c20 RCX: 0000000000000000
  [ 8172.772850] RDX: 0000000000000000 RSI: 0000000000000001 RDI: ffff8c0620ab20e0
  [ 8172.774629] RBP: ffff967f00663dd8 R08: 0000000000000000 R09: 0000000000000000
  [ 8172.776094] R10: ffff8c0620ab22f8 R11: ffff8c063f772688 R12: ffff967f00663b78
  [ 8172.777533] R13: ffff8c063f625600 R14: ffff8c063f625608 R15: dead000000000200
  [ 8172.778886] FS:  0000000000000000(0000) GS:ffff8c063d400000(0000) knlGS:0000000000000000
  [ 8172.780545] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8172.781787] CR2: 0000000000000058 CR3: 000000004e962000 CR4: 00000000000006f0
  [ 8172.783547] Call Trace:
  [ 8172.784112]  shrink_inactive_list+0x194/0x410
  [ 8172.784747]  shrink_node_memcg.constprop.85+0x3a5/0x6a0
  [ 8172.785472]  shrink_node+0x62/0x1e0
  [ 8172.786011]  balance_pgdat+0x216/0x460
  [ 8172.786577]  kswapd+0xe3/0x4a0
  [ 8172.787085]  ? finish_wait+0x80/0x80
  [ 8172.787795]  ? balance_pgdat+0x460/0x460
  [ 8172.788799]  kthread+0x116/0x130
  [ 8172.789640]  ? kthread_create_on_node+0x60/0x60
  [ 8172.790323]  ret_from_fork+0x24/0x30
  [ 8172.794253] CR2: 0000000000000058

or accounting errors at umount time:

  [ 8159.537251] WARNING: CPU: 2 PID: 19031 at fs/btrfs/extent-tree.c:5987 btrfs_free_block_groups+0x3d5/0x410 [btrfs]
  [ 8159.543325] CPU: 2 PID: 19031 Comm: umount Tainted: G        W         5.0.0-rc2-default #408
  [ 8159.545472] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
  [ 8159.548155] RIP: 0010:btrfs_free_block_groups+0x3d5/0x410 [btrfs]
  [ 8159.554030] RSP: 0018:ffff967f079cbde8 EFLAGS: 00010206
  [ 8159.555144] RAX: 0000000001000000 RBX: ffff8c06366cf800 RCX: 0000000000000000
  [ 8159.556730] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff8c06255ad800
  [ 8159.558279] RBP: ffff8c0637ac0000 R08: 0000000000000001 R09: 0000000000000000
  [ 8159.559797] R10: 0000000000000000 R11: 0000000000000001 R12: ffff8c0637ac0108
  [ 8159.561296] R13: ffff8c0637ac0158 R14: 0000000000000000 R15: dead000000000100
  [ 8159.562852] FS:  00007f7f693b9fc0(0000) GS:ffff8c063d800000(0000) knlGS:0000000000000000
  [ 8159.564839] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8159.566160] CR2: 00007f7f68fab7b0 CR3: 000000000aec7000 CR4: 00000000000006e0
  [ 8159.567898] Call Trace:
  [ 8159.568597]  close_ctree+0x17f/0x350 [btrfs]
  [ 8159.569628]  generic_shutdown_super+0x64/0x100
  [ 8159.570808]  kill_anon_super+0x14/0x30
  [ 8159.571857]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [ 8159.573063]  deactivate_locked_super+0x29/0x60
  [ 8159.574234]  cleanup_mnt+0x3b/0x70
  [ 8159.575176]  task_work_run+0x98/0xc0
  [ 8159.576177]  exit_to_usermode_loop+0x83/0x90
  [ 8159.577315]  do_syscall_64+0x15b/0x180
  [ 8159.578339]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

This fix is based on 2 Josef's patches that used sideefects of
btrfs_create_pending_block_groups, this fix introduces the helper that
does what we need.

CC: stable@vger.kernel.org # 4.4+
CC: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:47 +01:00
Al Viro 92900e5160 btrfs: fix potential oops in device_list_add
alloc_fs_devices() can return ERR_PTR(-ENOMEM), so dereferencing its
result before the check for IS_ERR() is a bad idea.

Fixes: d1a6300282 ("btrfs: add members to fs_devices to track fsid changes")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Anand Jain <anand.jain@oracle.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-30 18:16:40 +01:00
Josef Bacik 302167c50b btrfs: don't end the transaction for delayed refs in throttle
Previously callers to btrfs_end_transaction_throttle() would commit the
transaction if there wasn't enough delayed refs space.  This happens in
relocation, and if the fs is relatively empty we'll run out of delayed
refs space basically immediately, so we'll just be stuck in this loop of
committing the transaction over and over again.

This code existed because we didn't have a good feedback mechanism for
running delayed refs, but with the delayed refs rsv we do now.  Delete
this throttling code and let the btrfs_start_transaction() in relocation
deal with putting pressure on the delayed refs infrastructure.  With
this patch we no longer take 5 minutes to balance a metadata only fs.

Qu has submitted a fstest to catch slow balance or excessive transaction
commits. Steps to reproduce:

* create subvolume
* create many (eg. 16000) inlined files, of size 2KiB
* iteratively snapshot and touch several files to trigger metadata
  updates
* start balance -m

Reported-by: Qu Wenruo <wqu@suse.com>
Fixes: 64403612b7 ("btrfs: rework btrfs_check_space_for_delayed_refs")
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add tags and steps to reproduce ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-28 15:41:11 +01:00
Filipe Manana a627947076 Btrfs: fix deadlock when allocating tree block during leaf/node split
When splitting a leaf or node from one of the trees that are modified when
flushing pending block groups (extent, chunk, device and free space trees),
we need to allocate a new tree block, which in turn can result in the need
to allocate a new block group. After allocating the new block group we may
need to flush new block groups that were previously allocated during the
course of the current transaction, which is what may cause a deadlock due
to attempts to write lock twice the same leaf or node, as when splitting
a leaf or node we are holding a write lock on it and its parent node.

The same type of deadlock can also happen when increasing the tree's
height, since we are holding a lock on the existing root while allocating
the tree block to use as the new root node.

An example trace when the deadlock happens during the leaf split path is:

  [27175.293054] CPU: 0 PID: 3005 Comm: kworker/u17:6 Tainted: G        W         4.19.16 #1
  [27175.293942] Hardware name: Penguin Computing Relion 1900/MD90-FS0-ZB-XX, BIOS R15 06/25/2018
  [27175.294846] Workqueue: btrfs-extent-refs btrfs_extent_refs_helper [btrfs]
  (...)
  [27175.298384] RSP: 0018:ffffab2087107758 EFLAGS: 00010246
  [27175.299269] RAX: 0000000000000bbd RBX: ffff9fadc7141c48 RCX: 0000000000000001
  [27175.300155] RDX: 0000000000000001 RSI: 0000000000000002 RDI: ffff9fadc7141c48
  [27175.301023] RBP: 0000000000000001 R08: ffff9faeb6ac1040 R09: ffff9fa9c0000000
  [27175.301887] R10: 0000000000000000 R11: 0000000000000040 R12: ffff9fb21aac8000
  [27175.302743] R13: ffff9fb1a64d6a20 R14: 0000000000000001 R15: ffff9fb1a64d6a18
  [27175.303601] FS:  0000000000000000(0000) GS:ffff9fb21fa00000(0000) knlGS:0000000000000000
  [27175.304468] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [27175.305339] CR2: 00007fdc8743ead8 CR3: 0000000763e0a006 CR4: 00000000003606f0
  [27175.306220] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
  [27175.307087] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
  [27175.307940] Call Trace:
  [27175.308802]  btrfs_search_slot+0x779/0x9a0 [btrfs]
  [27175.309669]  ? update_space_info+0xba/0xe0 [btrfs]
  [27175.310534]  btrfs_insert_empty_items+0x67/0xc0 [btrfs]
  [27175.311397]  btrfs_insert_item+0x60/0xd0 [btrfs]
  [27175.312253]  btrfs_create_pending_block_groups+0xee/0x210 [btrfs]
  [27175.313116]  do_chunk_alloc+0x25f/0x300 [btrfs]
  [27175.313984]  find_free_extent+0x706/0x10d0 [btrfs]
  [27175.314855]  btrfs_reserve_extent+0x9b/0x1d0 [btrfs]
  [27175.315707]  btrfs_alloc_tree_block+0x100/0x5b0 [btrfs]
  [27175.316548]  split_leaf+0x130/0x610 [btrfs]
  [27175.317390]  btrfs_search_slot+0x94d/0x9a0 [btrfs]
  [27175.318235]  btrfs_insert_empty_items+0x67/0xc0 [btrfs]
  [27175.319087]  alloc_reserved_file_extent+0x84/0x2c0 [btrfs]
  [27175.319938]  __btrfs_run_delayed_refs+0x596/0x1150 [btrfs]
  [27175.320792]  btrfs_run_delayed_refs+0xed/0x1b0 [btrfs]
  [27175.321643]  delayed_ref_async_start+0x81/0x90 [btrfs]
  [27175.322491]  normal_work_helper+0xd0/0x320 [btrfs]
  [27175.323328]  ? move_linked_works+0x6e/0xa0
  [27175.324160]  process_one_work+0x191/0x370
  [27175.324976]  worker_thread+0x4f/0x3b0
  [27175.325763]  kthread+0xf8/0x130
  [27175.326531]  ? rescuer_thread+0x320/0x320
  [27175.327284]  ? kthread_create_worker_on_cpu+0x50/0x50
  [27175.328027]  ret_from_fork+0x35/0x40
  [27175.328741] ---[ end trace 300a1b9f0ac30e26 ]---

Fix this by preventing the flushing of new blocks groups when splitting a
leaf/node and when inserting a new root node for one of the trees modified
by the flushing operation, similar to what is done when COWing a node/leaf
from on of these trees.

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202383
Reported-by: Eli V <eliventer@gmail.com>
CC: stable@vger.kernel.org # 4.4+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-28 15:04:58 +01:00
Linus Torvalds 1be969f468 for-5.0-rc2-tag
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Merge tag 'for-5.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:
 "A handful of fixes (some of them in testing for a long time):

   - fix some test failures regarding cleanup after transaction abort

   - revert of a patch that could cause a deadlock

   - delayed iput fixes, that can help in ENOSPC situation when there's
     low space and a lot data to write"

* tag 'for-5.0-rc2-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: wakeup cleaner thread when adding delayed iput
  btrfs: run delayed iputs before committing
  btrfs: wait on ordered extents on abort cleanup
  btrfs: handle delayed ref head accounting cleanup in abort
  Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"
2019-01-21 07:35:26 +13:00
Josef Bacik fd340d0f68 btrfs: wakeup cleaner thread when adding delayed iput
The cleaner thread usually takes care of delayed iputs, with the
exception of the btrfs_end_transaction_throttle path.  Delaying iputs
means we are potentially delaying the eviction of an inode and it's
respective space.  The cleaner thread only gets woken up every 30
seconds, or when we require space.  If there are a lot of inodes that
need to be deleted we could induce a serious amount of latency while we
wait for these inodes to be evicted.  So instead wakeup the cleaner if
it's not already awake to process any new delayed iputs we add to the
list.  If we suddenly need space we will less likely be backed up
behind a bunch of inodes that are waiting to be deleted, and we could
possibly free space before we need to get into the flushing logic which
will save us some latency.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18 17:27:23 +01:00
Josef Bacik 3ec9a4c81c btrfs: run delayed iputs before committing
Delayed iputs means we can have final iputs of deleted inodes in the
queue, which could potentially generate a lot of pinned space that could
be free'd.  So before we decide to commit the transaction for ENOPSC
reasons, run the delayed iputs so that any potential space is free'd up.
If there is and we freed enough we can then commit the transaction and
potentially be able to make our reservation.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18 17:27:21 +01:00
Josef Bacik 74d5d229b1 btrfs: wait on ordered extents on abort cleanup
If we flip read-only before we initiate writeback on all dirty pages for
ordered extents we've created then we'll have ordered extents left over
on umount, which results in all sorts of bad things happening.  Fix this
by making sure we wait on ordered extents if we have to do the aborted
transaction cleanup stuff.

generic/475 can produce this warning:

 [ 8531.177332] WARNING: CPU: 2 PID: 11997 at fs/btrfs/disk-io.c:3856 btrfs_free_fs_root+0x95/0xa0 [btrfs]
 [ 8531.183282] CPU: 2 PID: 11997 Comm: umount Tainted: G        W 5.0.0-rc1-default+ #394
 [ 8531.185164] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996),BIOS rel-1.11.2-0-gf9626cc-prebuilt.qemu-project.org 04/01/2014
 [ 8531.187851] RIP: 0010:btrfs_free_fs_root+0x95/0xa0 [btrfs]
 [ 8531.193082] RSP: 0018:ffffb1ab86163d98 EFLAGS: 00010286
 [ 8531.194198] RAX: ffff9f3449494d18 RBX: ffff9f34a2695000 RCX:0000000000000000
 [ 8531.195629] RDX: 0000000000000002 RSI: 0000000000000001 RDI:0000000000000000
 [ 8531.197315] RBP: ffff9f344e930000 R08: 0000000000000001 R09:0000000000000000
 [ 8531.199095] R10: 0000000000000000 R11: ffff9f34494d4ff8 R12:ffffb1ab86163dc0
 [ 8531.200870] R13: ffff9f344e9300b0 R14: ffffb1ab86163db8 R15:0000000000000000
 [ 8531.202707] FS:  00007fc68e949fc0(0000) GS:ffff9f34bd800000(0000)knlGS:0000000000000000
 [ 8531.204851] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
 [ 8531.205942] CR2: 00007ffde8114dd8 CR3: 000000002dfbd000 CR4:00000000000006e0
 [ 8531.207516] Call Trace:
 [ 8531.208175]  btrfs_free_fs_roots+0xdb/0x170 [btrfs]
 [ 8531.210209]  ? wait_for_completion+0x5b/0x190
 [ 8531.211303]  close_ctree+0x157/0x350 [btrfs]
 [ 8531.212412]  generic_shutdown_super+0x64/0x100
 [ 8531.213485]  kill_anon_super+0x14/0x30
 [ 8531.214430]  btrfs_kill_super+0x12/0xa0 [btrfs]
 [ 8531.215539]  deactivate_locked_super+0x29/0x60
 [ 8531.216633]  cleanup_mnt+0x3b/0x70
 [ 8531.217497]  task_work_run+0x98/0xc0
 [ 8531.218397]  exit_to_usermode_loop+0x83/0x90
 [ 8531.219324]  do_syscall_64+0x15b/0x180
 [ 8531.220192]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
 [ 8531.221286] RIP: 0033:0x7fc68e5e4d07
 [ 8531.225621] RSP: 002b:00007ffde8116608 EFLAGS: 00000246 ORIG_RAX:00000000000000a6
 [ 8531.227512] RAX: 0000000000000000 RBX: 00005580c2175970 RCX:00007fc68e5e4d07
 [ 8531.229098] RDX: 0000000000000001 RSI: 0000000000000000 RDI:00005580c2175b80
 [ 8531.230730] RBP: 0000000000000000 R08: 00005580c2175ba0 R09:00007ffde8114e80
 [ 8531.232269] R10: 0000000000000000 R11: 0000000000000246 R12:00005580c2175b80
 [ 8531.233839] R13: 00007fc68eac61c4 R14: 00005580c2175a68 R15:0000000000000000

Leaving a tree in the rb-tree:

3853 void btrfs_free_fs_root(struct btrfs_root *root)
3854 {
3855         iput(root->ino_cache_inode);
3856         WARN_ON(!RB_EMPTY_ROOT(&root->inode_tree));

CC: stable@vger.kernel.org
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add stacktrace ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18 17:24:19 +01:00
Josef Bacik 31890da0bf btrfs: handle delayed ref head accounting cleanup in abort
We weren't doing any of the accounting cleanup when we aborted
transactions.  Fix this by making cleanup_ref_head_accounting global and
calling it from the abort code, this fixes the issue where our
accounting was all wrong after the fs aborts.

The test generic/475 on a 2G VM can trigger the problems eg.:

  [ 8502.136957] WARNING: CPU: 0 PID: 11064 at fs/btrfs/extent-tree.c:5986 btrfs_free_block_grou +ps+0x3dc/0x410 [btrfs]
  [ 8502.148372] CPU: 0 PID: 11064 Comm: umount Not tainted 5.0.0-rc1-default+ #394
  [ 8502.150807] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626 +cc-prebuilt.qemu-project.org 04/01/2014
  [ 8502.154317] RIP: 0010:btrfs_free_block_groups+0x3dc/0x410 [btrfs]
  [ 8502.160623] RSP: 0018:ffffb1ab84b93de8 EFLAGS: 00010206
  [ 8502.161906] RAX: 0000000001000000 RBX: ffff9f34b1756400 RCX: 0000000000000000
  [ 8502.163448] RDX: 0000000000000002 RSI: 0000000000000001 RDI: ffff9f34b1755400
  [ 8502.164906] RBP: ffff9f34b7e8c000 R08: 0000000000000001 R09: 0000000000000000
  [ 8502.166716] R10: 0000000000000000 R11: 0000000000000001 R12: ffff9f34b7e8c108
  [ 8502.168498] R13: ffff9f34b7e8c158 R14: 0000000000000000 R15: dead000000000100
  [ 8502.170296] FS:  00007fb1cf15ffc0(0000) GS:ffff9f34bd400000(0000) knlGS:0000000000000000
  [ 8502.172439] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
  [ 8502.173669] CR2: 00007fb1ced507b0 CR3: 000000002f7a6000 CR4: 00000000000006f0
  [ 8502.175094] Call Trace:
  [ 8502.175759]  close_ctree+0x17f/0x350 [btrfs]
  [ 8502.176721]  generic_shutdown_super+0x64/0x100
  [ 8502.177702]  kill_anon_super+0x14/0x30
  [ 8502.178607]  btrfs_kill_super+0x12/0xa0 [btrfs]
  [ 8502.179602]  deactivate_locked_super+0x29/0x60
  [ 8502.180595]  cleanup_mnt+0x3b/0x70
  [ 8502.181406]  task_work_run+0x98/0xc0
  [ 8502.182255]  exit_to_usermode_loop+0x83/0x90
  [ 8502.183113]  do_syscall_64+0x15b/0x180
  [ 8502.183919]  entry_SYSCALL_64_after_hwframe+0x49/0xbe

Corresponding to

  release_global_block_rsv() {
  ...
  WARN_ON(fs_info->delayed_refs_rsv.reserved > 0);

CC: stable@vger.kernel.org
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
[ add log dump ]
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18 17:10:04 +01:00
David Sterba 77b7aad195 Revert "btrfs: balance dirty metadata pages in btrfs_finish_ordered_io"
This reverts commit e73e81b6d0.

This patch causes a few problems:

- adds latency to btrfs_finish_ordered_io
- as btrfs_finish_ordered_io is used for free space cache, generating
  more work from btrfs_btree_balance_dirty_nodelay could end up in the
  same workque, effectively deadlocking

12260 kworker/u96:16+btrfs-freespace-write D
[<0>] balance_dirty_pages+0x6e6/0x7ad
[<0>] balance_dirty_pages_ratelimited+0x6bb/0xa90
[<0>] btrfs_finish_ordered_io+0x3da/0x770
[<0>] normal_work_helper+0x1c5/0x5a0
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x46/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Transaction commit will wait on the freespace cache:

838 btrfs-transacti D
[<0>] btrfs_start_ordered_extent+0x154/0x1e0
[<0>] btrfs_wait_ordered_range+0xbd/0x110
[<0>] __btrfs_wait_cache_io+0x49/0x1a0
[<0>] btrfs_write_dirty_block_groups+0x10b/0x3b0
[<0>] commit_cowonly_roots+0x215/0x2b0
[<0>] btrfs_commit_transaction+0x37e/0x910
[<0>] transaction_kthread+0x14d/0x180
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

And then writepages ends up waiting on transaction commit:

9520 kworker/u96:13+flush-btrfs-1 D
[<0>] wait_current_trans+0xac/0xe0
[<0>] start_transaction+0x21b/0x4b0
[<0>] cow_file_range_inline+0x10b/0x6b0
[<0>] cow_file_range.isra.69+0x329/0x4a0
[<0>] run_delalloc_range+0x105/0x3c0
[<0>] writepage_delalloc+0x119/0x180
[<0>] __extent_writepage+0x10c/0x390
[<0>] extent_write_cache_pages+0x26f/0x3d0
[<0>] extent_writepages+0x4f/0x80
[<0>] do_writepages+0x17/0x60
[<0>] __writeback_single_inode+0x59/0x690
[<0>] writeback_sb_inodes+0x291/0x4e0
[<0>] __writeback_inodes_wb+0x87/0xb0
[<0>] wb_writeback+0x3bb/0x500
[<0>] wb_workfn+0x40d/0x610
[<0>] process_one_work+0x1ee/0x5a0
[<0>] worker_thread+0x1e0/0x3d0
[<0>] kthread+0xf5/0x130
[<0>] ret_from_fork+0x24/0x30
[<0>] 0xffffffffffffffff

Eventually, we have every process in the system waiting on
balance_dirty_pages(), and nobody is able to make progress on page
writeback.

The original patch tried to fix an OOM condition, that happened on 4.4 but no
success reproducing that on later kernels (4.19 and 4.20). This is more likely
a problem in OOM itself.

Link: https://lore.kernel.org/linux-btrfs/20180528054821.9092-1-ethanlien@synology.com/
Reported-by: Chris Mason <clm@fb.com>
CC: stable@vger.kernel.org # 4.18+
CC: ethanlien <ethanlien@synology.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-18 17:09:55 +01:00
Linus Torvalds 6b529fb0a3 for-5.0-rc1-tag
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Merge tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux

Pull btrfs fixes from David Sterba:

 - two regression fixes in clone/dedupe ioctls, the generic check
   callback needs to lock extents properly and wait for io to avoid
   problems with writeback and relocation

 - fix deadlock when using free space tree due to block group creation

 - a recently added check refuses a valid fileystem with seeding device,
   make that work again with a quickfix, proper solution needs more
   intrusive changes

* tag 'for-5.0-rc1-tag' of git://git.kernel.org/pub/scm/linux/kernel/git/kdave/linux:
  btrfs: Use real device structure to verify dev extent
  Btrfs: fix deadlock when using free space tree due to block group creation
  Btrfs: fix race between reflink/dedupe and relocation
  Btrfs: fix race between cloning range ending at eof and writeback
2019-01-14 05:55:51 +12:00
Qu Wenruo 1b3922a8bc btrfs: Use real device structure to verify dev extent
[BUG]
Linux v5.0-rc1 will fail fstests/btrfs/163 with the following kernel
message:

  BTRFS error (device dm-6): dev extent devid 1 physical offset 13631488 len 8388608 is beyond device boundary 0
  BTRFS error (device dm-6): failed to verify dev extents against chunks: -117
  BTRFS error (device dm-6): open_ctree failed

[CAUSE]
Commit cf90d884b3 ("btrfs: Introduce mount time chunk <-> dev extent
mapping check") introduced strict check on dev extents.

We use btrfs_find_device() with dev uuid and fs uuid set to NULL, and
only dependent on @devid to find the real device.

For seed devices, we call clone_fs_devices() in open_seed_devices() to
allow us search seed devices directly.

However clone_fs_devices() just populates devices with devid and dev
uuid, without populating other essential members, like disk_total_bytes.

This makes any device returned by btrfs_find_device(fs_info, devid,
NULL, NULL) is just a dummy, with 0 disk_total_bytes, and any dev
extents on the seed device will not pass the device boundary check.

[FIX]
This patch will try to verify the device returned by btrfs_find_device()
and if it's a dummy then re-search in seed devices.

Fixes: cf90d884b3 ("btrfs: Introduce mount time chunk <-> dev extent mapping check")
CC: stable@vger.kernel.org # 4.19+
Reported-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-10 17:13:00 +01:00
Filipe Manana a6d8654d88 Btrfs: fix deadlock when using free space tree due to block group creation
When modifying the free space tree we can end up COWing one of its extent
buffers which in turn might result in allocating a new chunk, which in
turn can result in flushing (finish creation) of pending block groups. If
that happens we can deadlock because creating a pending block group needs
to update the free space tree, and if any of the updates tries to modify
the same extent buffer that we are COWing, we end up in a deadlock since
we try to write lock twice the same extent buffer.

So fix this by skipping pending block group creation if we are COWing an
extent buffer from the free space tree. This is a case missed by commit
5ce555578e ("Btrfs: fix deadlock when writing out free space caches").

Bugzilla: https://bugzilla.kernel.org/show_bug.cgi?id=202173
Fixes: 5ce555578e ("Btrfs: fix deadlock when writing out free space caches")
CC: stable@vger.kernel.org # 4.18+
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09 14:52:36 +01:00
Filipe Manana d8b5524242 Btrfs: fix race between reflink/dedupe and relocation
The recent rework that makes btrfs' remap_file_range operation use the
generic helper generic_remap_file_range_prep() introduced a race between
relocation and reflinking (for both cloning and deduplication) the file
extents between the source and destination inodes.

This happens because we no longer lock the source range anymore, and we do
not lock it anymore because we wait for direct IO writes and writeback to
complete early on the code path right after locking the inodes, which
guarantees no other file operations interfere with the reflinking. However
there is one exception which is relocation, since it replaces the byte
number of file extents items in the fs tree after locking the range the
file extent items represent. This is a problem because after finding each
file extent to clone in the fs tree, the reflink process copies the file
extent item into a local buffer, releases the search path, inserts new
file extent items in the destination range and then increments the
reference count for the extent mentioned in the file extent item that it
previously copied to the buffer. If right after copying the file extent
item into the buffer and releasing the path the relocation process
updates the file extent item to point to the new extent, the reflink
process ends up creating a delayed reference to increment the reference
count of the old extent, for which the relocation process already created
a delayed reference to drop it. This results in failure to run delayed
references because we will attempt to increment the count of a reference
that was already dropped. This is illustrated by the following diagram:

        CPU 1                                       CPU 2

                                        relocation is running

  btrfs_clone_files()

    btrfs_clone()
      --> finds extent item
          in source range
          point to extent
          at bytenr X
      --> copies it into a
          local buffer
      --> releases path

                                        replace_file_extents()
                                          --> successfully locks the
                                              range represented by
                                              the file extent item
                                          --> replaces disk_bytenr
                                              field in the file
                                              extent item with some
                                              other value Y
                                          --> creates delayed reference
                                              to increment reference
                                              count for extent at
                                              bytenr Y
                                          --> creates delayed reference
                                              to drop the extent at
                                              bytenr X

      --> starts transaction
      --> creates delayed
          reference to
          increment extent
          at bytenr X

                    <delayed references are run, due to a transaction
                     commit for example, and the transaction is aborted
                     with -EIO because we attempt to increment reference
                     count for the extent at bytenr X after we freed it>

When this race is hit the running transaction ends up getting aborted with
an -EIO error and a trace like the following is produced:

[ 4382.553858] WARNING: CPU: 2 PID: 3648 at fs/btrfs/extent-tree.c:1552 lookup_inline_extent_backref+0x4f4/0x650 [btrfs]
(...)
[ 4382.556293] CPU: 2 PID: 3648 Comm: btrfs Tainted: G        W         4.20.0-rc6-btrfs-next-41 #1
[ 4382.556294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[ 4382.556308] RIP: 0010:lookup_inline_extent_backref+0x4f4/0x650 [btrfs]
(...)
[ 4382.556310] RSP: 0018:ffffac784408f738 EFLAGS: 00010202
[ 4382.556311] RAX: 0000000000000001 RBX: ffff8980673c3a48 RCX: 0000000000000001
[ 4382.556312] RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000
[ 4382.556312] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
[ 4382.556313] R10: 0000000000000001 R11: ffff897f40000000 R12: 0000000000001000
[ 4382.556313] R13: 00000000c224f000 R14: ffff89805de9bd40 R15: ffff8980453f4548
[ 4382.556315] FS:  00007f5e759178c0(0000) GS:ffff89807b300000(0000) knlGS:0000000000000000
[ 4382.563130] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4382.563562] CR2: 00007f2e9789fcbc CR3: 0000000120512001 CR4: 00000000003606e0
[ 4382.564005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4382.564451] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 4382.564887] Call Trace:
[ 4382.565343]  insert_inline_extent_backref+0x55/0xe0 [btrfs]
[ 4382.565796]  __btrfs_inc_extent_ref.isra.60+0x88/0x260 [btrfs]
[ 4382.566249]  ? __btrfs_run_delayed_refs+0x93/0x1650 [btrfs]
[ 4382.566702]  __btrfs_run_delayed_refs+0xa22/0x1650 [btrfs]
[ 4382.567162]  btrfs_run_delayed_refs+0x7e/0x1d0 [btrfs]
[ 4382.567623]  btrfs_commit_transaction+0x50/0x9c0 [btrfs]
[ 4382.568112]  ? _raw_spin_unlock+0x24/0x30
[ 4382.568557]  ? block_rsv_release_bytes+0x14e/0x410 [btrfs]
[ 4382.569006]  create_subvol+0x3c8/0x830 [btrfs]
[ 4382.569461]  ? btrfs_mksubvol+0x317/0x600 [btrfs]
[ 4382.569906]  btrfs_mksubvol+0x317/0x600 [btrfs]
[ 4382.570383]  ? rcu_sync_lockdep_assert+0xe/0x60
[ 4382.570822]  ? __sb_start_write+0xd4/0x1c0
[ 4382.571262]  ? mnt_want_write_file+0x24/0x50
[ 4382.571712]  btrfs_ioctl_snap_create_transid+0x117/0x1a0 [btrfs]
[ 4382.572155]  ? _copy_from_user+0x66/0x90
[ 4382.572602]  btrfs_ioctl_snap_create+0x66/0x80 [btrfs]
[ 4382.573052]  btrfs_ioctl+0x7c1/0x30e0 [btrfs]
[ 4382.573502]  ? mem_cgroup_commit_charge+0x8b/0x570
[ 4382.573946]  ? do_raw_spin_unlock+0x49/0xc0
[ 4382.574379]  ? _raw_spin_unlock+0x24/0x30
[ 4382.574803]  ? __handle_mm_fault+0xf29/0x12d0
[ 4382.575215]  ? do_vfs_ioctl+0xa2/0x6f0
[ 4382.575622]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[ 4382.576020]  do_vfs_ioctl+0xa2/0x6f0
[ 4382.576405]  ksys_ioctl+0x70/0x80
[ 4382.576776]  __x64_sys_ioctl+0x16/0x20
[ 4382.577137]  do_syscall_64+0x60/0x1b0
[ 4382.577488]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
(...)
[ 4382.578837] RSP: 002b:00007ffe04bf64c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[ 4382.579174] RAX: ffffffffffffffda RBX: 00005564136f3050 RCX: 00007f5e74724dd7
[ 4382.579505] RDX: 00007ffe04bf64d0 RSI: 000000005000940e RDI: 0000000000000003
[ 4382.579848] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000044
[ 4382.580164] R10: 0000000000000541 R11: 0000000000000202 R12: 00005564136f3010
[ 4382.580477] R13: 0000000000000003 R14: 00005564136f3035 R15: 00005564136f3050
[ 4382.580792] irq event stamp: 0
[ 4382.581106] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
[ 4382.581441] hardirqs last disabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320
[ 4382.581772] softirqs last  enabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320
[ 4382.582095] softirqs last disabled at (0): [<0000000000000000>]           (null)
[ 4382.582413] ---[ end trace d3c188e3e9367382 ]---
[ 4382.623855] BTRFS: error (device sdc) in btrfs_run_delayed_refs:2981: errno=-5 IO failure
[ 4382.624295] BTRFS info (device sdc): forced readonly

Fix this by locking the source range before searching for the file extent
items in the fs tree, since the relocation process will try to lock the
range a file extent item represents before updating it with the new extent
location.

Fixes: 34a28e3d77 ("Btrfs: use generic_remap_file_range_prep() for cloning and deduplication")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09 14:52:25 +01:00
Filipe Manana f7fa1107f3 Btrfs: fix race between cloning range ending at eof and writeback
The recent rework that makes btrfs' remap_file_range operation use the
generic helper generic_remap_file_range_prep() introduced a race between
writeback and cloning a range that covers the eof extent of the source
file into a destination offset that is greater then the same file's size.

This happens because we now wait for writeback to complete before doing
the truncation of the eof block, while previously we did the truncation
and then waited for writeback to complete. This leads to a race between
writeback of the truncated block and cloning the file extents in the
source range, because we copy each file extent item we find in the fs
root into a buffer, then release the path and then increment the reference
count for the extent referred in that file extent item we copied, which
can no longer exist if writeback of the truncated eof block completes
after we copied the file extent item into the buffer and before we
incremented the reference count. This is illustrated by the following
diagram:

        CPU 1                                       CPU 2

  btrfs_clone_files()
    btrfs_cont_expand()
      btrfs_truncate_block()
         --> zeroes part of the
             page containg eof,
             marking it for
            delalloc

    btrfs_clone()
      --> finds extent item
          covering eof,
          points to extent
          at bytenr X
      --> copies it into a
          local buffer
      --> releases path

                                        writeback starts

                                        btrfs_finish_ordered_io()
                                          insert_reserved_file_extent()
                                            __btrfs_drop_extents()
                                              --> creates delayed
                                                  reference to drop
                                                  the extent at
                                                  bytenr X

      --> starts transaction
      --> creates delayed
          reference to
          increment extent
          at bytenr X

                    <delayed references are run, due to a transaction
                     commit for example, and the transaction is aborted
                     with -EIO because we attempt to increment reference
                     count for the extent at bytenr X after we freed it>

When this race is hit the running transaction ends up getting aborted with
an -EIO error and a trace like the following is produced:

[ 4382.553858] WARNING: CPU: 2 PID: 3648 at fs/btrfs/extent-tree.c:1552 lookup_inline_extent_backref+0x4f4/0x650 [btrfs]
(...)
[ 4382.556293] CPU: 2 PID: 3648 Comm: btrfs Tainted: G        W         4.20.0-rc6-btrfs-next-41 #1
[ 4382.556294] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS rel-1.11.2-0-gf9626ccb91-prebuilt.qemu-project.org 04/01/2014
[ 4382.556308] RIP: 0010:lookup_inline_extent_backref+0x4f4/0x650 [btrfs]
(...)
[ 4382.556310] RSP: 0018:ffffac784408f738 EFLAGS: 00010202
[ 4382.556311] RAX: 0000000000000001 RBX: ffff8980673c3a48 RCX: 0000000000000001
[ 4382.556312] RDX: 0000000000000008 RSI: 0000000000000000 RDI: 0000000000000000
[ 4382.556312] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000001
[ 4382.556313] R10: 0000000000000001 R11: ffff897f40000000 R12: 0000000000001000
[ 4382.556313] R13: 00000000c224f000 R14: ffff89805de9bd40 R15: ffff8980453f4548
[ 4382.556315] FS:  00007f5e759178c0(0000) GS:ffff89807b300000(0000) knlGS:0000000000000000
[ 4382.563130] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[ 4382.563562] CR2: 00007f2e9789fcbc CR3: 0000000120512001 CR4: 00000000003606e0
[ 4382.564005] DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000
[ 4382.564451] DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400
[ 4382.564887] Call Trace:
[ 4382.565343]  insert_inline_extent_backref+0x55/0xe0 [btrfs]
[ 4382.565796]  __btrfs_inc_extent_ref.isra.60+0x88/0x260 [btrfs]
[ 4382.566249]  ? __btrfs_run_delayed_refs+0x93/0x1650 [btrfs]
[ 4382.566702]  __btrfs_run_delayed_refs+0xa22/0x1650 [btrfs]
[ 4382.567162]  btrfs_run_delayed_refs+0x7e/0x1d0 [btrfs]
[ 4382.567623]  btrfs_commit_transaction+0x50/0x9c0 [btrfs]
[ 4382.568112]  ? _raw_spin_unlock+0x24/0x30
[ 4382.568557]  ? block_rsv_release_bytes+0x14e/0x410 [btrfs]
[ 4382.569006]  create_subvol+0x3c8/0x830 [btrfs]
[ 4382.569461]  ? btrfs_mksubvol+0x317/0x600 [btrfs]
[ 4382.569906]  btrfs_mksubvol+0x317/0x600 [btrfs]
[ 4382.570383]  ? rcu_sync_lockdep_assert+0xe/0x60
[ 4382.570822]  ? __sb_start_write+0xd4/0x1c0
[ 4382.571262]  ? mnt_want_write_file+0x24/0x50
[ 4382.571712]  btrfs_ioctl_snap_create_transid+0x117/0x1a0 [btrfs]
[ 4382.572155]  ? _copy_from_user+0x66/0x90
[ 4382.572602]  btrfs_ioctl_snap_create+0x66/0x80 [btrfs]
[ 4382.573052]  btrfs_ioctl+0x7c1/0x30e0 [btrfs]
[ 4382.573502]  ? mem_cgroup_commit_charge+0x8b/0x570
[ 4382.573946]  ? do_raw_spin_unlock+0x49/0xc0
[ 4382.574379]  ? _raw_spin_unlock+0x24/0x30
[ 4382.574803]  ? __handle_mm_fault+0xf29/0x12d0
[ 4382.575215]  ? do_vfs_ioctl+0xa2/0x6f0
[ 4382.575622]  ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
[ 4382.576020]  do_vfs_ioctl+0xa2/0x6f0
[ 4382.576405]  ksys_ioctl+0x70/0x80
[ 4382.576776]  __x64_sys_ioctl+0x16/0x20
[ 4382.577137]  do_syscall_64+0x60/0x1b0
[ 4382.577488]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
(...)
[ 4382.578837] RSP: 002b:00007ffe04bf64c8 EFLAGS: 00000202 ORIG_RAX: 0000000000000010
[ 4382.579174] RAX: ffffffffffffffda RBX: 00005564136f3050 RCX: 00007f5e74724dd7
[ 4382.579505] RDX: 00007ffe04bf64d0 RSI: 000000005000940e RDI: 0000000000000003
[ 4382.579848] RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000044
[ 4382.580164] R10: 0000000000000541 R11: 0000000000000202 R12: 00005564136f3010
[ 4382.580477] R13: 0000000000000003 R14: 00005564136f3035 R15: 00005564136f3050
[ 4382.580792] irq event stamp: 0
[ 4382.581106] hardirqs last  enabled at (0): [<0000000000000000>]           (null)
[ 4382.581441] hardirqs last disabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320
[ 4382.581772] softirqs last  enabled at (0): [<ffffffff8d085842>] copy_process.part.32+0x6e2/0x2320
[ 4382.582095] softirqs last disabled at (0): [<0000000000000000>]           (null)
[ 4382.582413] ---[ end trace d3c188e3e9367382 ]---
[ 4382.623855] BTRFS: error (device sdc) in btrfs_run_delayed_refs:2981: errno=-5 IO failure
[ 4382.624295] BTRFS info (device sdc): forced readonly

Fix this by waiting for writeback to complete after truncating the eof
block.

Fixes: 34a28e3d77 ("Btrfs: use generic_remap_file_range_prep() for cloning and deduplication")
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2019-01-09 14:52:22 +01:00
Linus Torvalds 505b050fdf Merge branch 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs
Pull vfs mount API prep from Al Viro:
 "Mount API prereqs.

  Mostly that's LSM mount options cleanups. There are several minor
  fixes in there, but nothing earth-shattering (leaks on failure exits,
  mostly)"

* 'mount.part1' of git://git.kernel.org/pub/scm/linux/kernel/git/viro/vfs: (27 commits)
  mount_fs: suppress MAC on MS_SUBMOUNT as well as MS_KERNMOUNT
  smack: rewrite smack_sb_eat_lsm_opts()
  smack: get rid of match_token()
  smack: take the guts of smack_parse_opts_str() into a new helper
  LSM: new method: ->sb_add_mnt_opt()
  selinux: rewrite selinux_sb_eat_lsm_opts()
  selinux: regularize Opt_... names a bit
  selinux: switch away from match_token()
  selinux: new helper - selinux_add_opt()
  LSM: bury struct security_mnt_opts
  smack: switch to private smack_mnt_opts
  selinux: switch to private struct selinux_mnt_opts
  LSM: hide struct security_mnt_opts from any generic code
  selinux: kill selinux_sb_get_mnt_opts()
  LSM: turn sb_eat_lsm_opts() into a method
  nfs_remount(): don't leak, don't ignore LSM options quietly
  btrfs: sanitize security_mnt_opts use
  selinux; don't open-code a loop in sb_finish_set_opts()
  LSM: split ->sb_set_mnt_opts() out of ->sb_kern_mount()
  new helper: security_sb_eat_lsm_opts()
  ...
2019-01-05 13:25:58 -08:00
Linus Torvalds a65981109f Merge branch 'akpm' (patches from Andrew)
Merge more updates from Andrew Morton:

 - procfs updates

 - various misc bits

 - lib/ updates

 - epoll updates

 - autofs

 - fatfs

 - a few more MM bits

* emailed patches from Andrew Morton <akpm@linux-foundation.org>: (58 commits)
  mm/page_io.c: fix polled swap page in
  checkpatch: add Co-developed-by to signature tags
  docs: fix Co-Developed-by docs
  drivers/base/platform.c: kmemleak ignore a known leak
  fs: don't open code lru_to_page()
  fs/: remove caller signal_pending branch predictions
  mm/: remove caller signal_pending branch predictions
  arch/arc/mm/fault.c: remove caller signal_pending_branch predictions
  kernel/sched/: remove caller signal_pending branch predictions
  kernel/locking/mutex.c: remove caller signal_pending branch predictions
  mm: select HAVE_MOVE_PMD on x86 for faster mremap
  mm: speed up mremap by 20x on large regions
  mm: treewide: remove unused address argument from pte_alloc functions
  initramfs: cleanup incomplete rootfs
  scripts/gdb: fix lx-version string output
  kernel/kcov.c: mark write_comp_data() as notrace
  kernel/sysctl: add panic_print into sysctl
  panic: add options to print system info when panic happens
  bfs: extra sanity checking and static inode bitmap
  exec: separate MM_ANONPAGES and RLIMIT_STACK accounting
  ...
2019-01-05 09:16:18 -08:00
Nikolay Borisov f86196ea87 fs: don't open code lru_to_page()
Multiple filesystems open code lru_to_page().  Rectify this by moving
the macro from mm_inline (which is specific to lru stuff) to the more
generic mm.h header and start using the macro where appropriate.

No functional changes.

Link: http://lkml.kernel.org/r/20181129104810.23361-1-nborisov@suse.com
Link: https://lkml.kernel.org/r/20181129075301.29087-1-nborisov@suse.com
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Acked-by: Michal Hocko <mhocko@suse.com>
Reviewed-by: David Hildenbrand <david@redhat.com>
Reviewed-by: Mike Rapoport <rppt@linux.ibm.com>
Acked-by: Pankaj gupta <pagupta@redhat.com>
Acked-by: "Yan, Zheng" <zyan@redhat.com>		[ceph]
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-04 13:13:48 -08:00
Linus Torvalds 96d4f267e4 Remove 'type' argument from access_ok() function
Nobody has actually used the type (VERIFY_READ vs VERIFY_WRITE) argument
of the user address range verification function since we got rid of the
old racy i386-only code to walk page tables by hand.

It existed because the original 80386 would not honor the write protect
bit when in kernel mode, so you had to do COW by hand before doing any
user access.  But we haven't supported that in a long time, and these
days the 'type' argument is a purely historical artifact.

A discussion about extending 'user_access_begin()' to do the range
checking resulted this patch, because there is no way we're going to
move the old VERIFY_xyz interface to that model.  And it's best done at
the end of the merge window when I've done most of my merges, so let's
just get this done once and for all.

This patch was mostly done with a sed-script, with manual fix-ups for
the cases that weren't of the trivial 'access_ok(VERIFY_xyz' form.

There were a couple of notable cases:

 - csky still had the old "verify_area()" name as an alias.

 - the iter_iov code had magical hardcoded knowledge of the actual
   values of VERIFY_{READ,WRITE} (not that they mattered, since nothing
   really used it)

 - microblaze used the type argument for a debug printout

but other than those oddities this should be a total no-op patch.

I tried to fix up all architectures, did fairly extensive grepping for
access_ok() uses, and the changes are trivial, but I may have missed
something.  Any missed conversion should be trivially fixable, though.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2019-01-03 18:57:57 -08:00
Al Viro 204cc0ccf1 LSM: hide struct security_mnt_opts from any generic code
Keep void * instead, allocate on demand (in parse_str_opts, at the
moment).  Eventually both selinux and smack will be better off
with private structures with several strings in those, rather than
this "counter and two pointers to dynamically allocated arrays"
ugliness.  This commit allows to do that at leisure, without
disrupting anything outside of given module.

Changes:
	* instead of struct security_mnt_opt use an opaque pointer
initialized to NULL.
	* security_sb_eat_lsm_opts(), security_sb_parse_opts_str() and
security_free_mnt_opts() take it as var argument (i.e. as void **);
call sites are unchanged.
	* security_sb_set_mnt_opts() and security_sb_remount() take
it by value (i.e. as void *).
	* new method: ->sb_free_mnt_opts().  Takes void *, does
whatever freeing that needs to be done.
	* ->sb_set_mnt_opts() and ->sb_remount() might get NULL as
mnt_opts argument, meaning "empty".

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:48:34 -05:00
Al Viro a65001e8a4 btrfs: sanitize security_mnt_opts use
1) keeping a copy in btrfs_fs_info is completely pointless - we never
use it for anything.  Getting rid of that allows for simpler calling
conventions for setup_security_options() (caller is responsible for
freeing mnt_opts in all cases).

2) on remount we want to use ->sb_remount(), not ->sb_set_mnt_opts(),
same as we would if not for FS_BINARY_MOUNTDATA.  Behaviours *are*
close (in fact, selinux sb_set_mnt_opts() ought to punt to
sb_remount() in "already initialized" case), but let's handle
that uniformly.  And the only reason why the original btrfs changes
didn't go for security_sb_remount() in btrfs_remount() case is that
it hadn't been exported.  Let's export it for a while - it'll be
going away soon anyway.

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:47:08 -05:00
Al Viro f5c0c26d90 new helper: security_sb_eat_lsm_opts()
combination of alloc_secdata(), security_sb_copy_data(),
security_sb_parse_opt_str() and free_secdata().

Reviewed-by: David Howells <dhowells@redhat.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
2018-12-21 11:46:00 -05:00
Andrea Gelmini 52042d8e82 btrfs: Fix typos in comments and strings
The typos accumulate over time so once in a while time they get fixed in
a large patch.

Signed-off-by: Andrea Gelmini <andrea.gelmini@gelma.net>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:50 +01:00
Johannes Thumshirn 1690dd41e0 btrfs: improve error handling of btrfs_add_link
In the error handling block, err holds the return value of either
btrfs_del_root_ref() or btrfs_del_inode_ref() but it hasn't been checked
since it's introduction with commit fe66a05a06 (Btrfs: improve error
handling for btrfs_insert_dir_item callers) in 2012.

If the error handling in the error handling fails, there's not much left
to do and the abort either happened earlier in the callees or is
necessary here.

So if one of btrfs_del_root_ref() or btrfs_del_inode_ref() failed, abort
the transaction, but still return the original code of the failure
stored in 'ret' as this will be reported to the user.

Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:50 +01:00
Filipe Manana 34a28e3d77 Btrfs: use generic_remap_file_range_prep() for cloning and deduplication
Since cloning and deduplication are no longer Btrfs specific operations, we
now have generic code to handle parameter validation, compare file ranges
used for deduplication, clear capabilities when cloning, etc. This change
makes Btrfs use it, eliminating a lot of code in Btrfs and also fixing a
few bugs, such as:

1) When cloning, the destination file's capabilities were not dropped
   (the fstest generic/513 tests this);

2) We were not checking if the destination file is immutable;

3) Not checking if either the source or destination files are swap
   files (swap file support is coming soon for Btrfs);

4) System limits were not checked (resource limits and O_LARGEFILE).

Note that the generic helper generic_remap_file_range_prep() does start
and waits for writeback by calling filemap_write_and_wait_range(), however
that is not enough for Btrfs for two reasons:

1) With compression, we need to start writeback twice in order to get the
   pages marked for writeback and ordered extents created;

2) filemap_write_and_wait_range() (and all its other variants) only waits
   for the IO to complete, but we need to wait for the ordered extents to
   finish, so that when we do the actual reflinking operations the file
   extent items are in the fs tree. This is also important due to the fact
   that the generic helper, for the deduplication case, compares the
   contents of the pages in the requested range, which might require
   reading extents from disk in the very unlikely case that pages get
   invalidated after writeback finishes (so the file extent items must be
   up to date in the fs tree).

Since these reasons are specific to Btrfs we have to do it in the Btrfs
code before calling generic_remap_file_range_prep(). This also results
in a simpler way of dealing with existing delalloc in the source/target
ranges, specially for the deduplication case where we used to lock all
the pages first and then if we found any dealloc for the range, or
ordered extent, we would unlock the pages trigger writeback and wait for
ordered extents to complete, then lock all the pages again and check if
deduplication can be done. So now we get a simpler approach: lock the
inodes, then trigger writeback and then wait for ordered extents to
complete.

So make btrfs use generic_remap_file_range_prep() (XFS and OCFS2 use it)
to eliminate duplicated code, fix a few bugs and benefit from future bug
fixes done there - for example the recent clone and dedupe bugs involving
reflinking a partial EOF block got a counterpart fix in the generic
helper, since it affected all filesystems supporting these operations,
so we no longer need special checks in Btrfs for them.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:50 +01:00
Nikolay Borisov 61ed3a144a btrfs: Refactor main loop in extent_readpages
extent_readpages processes all pages in the readlist in batches of 16,
this is implemented by a single for loop but thanks to an if condition
the loop does 2 things based on whether we've filled the batch or not.
Additionally due to the structure of the code there is an additional
check which deals with partial batches.

Streamline all of this by explicitly using two loops. The outter one is
used to process all pages while the inner one just fills in the batch
of 16 (currently). Due to this new structure the code guarantees that
all pages are processed in the loop hence the code to deal with any
leftovers is eliminated.

This also enable the compiler to inline __extent_readpages:

	./scripts/bloat-o-meter fs/btrfs/extent_io.o extent_io.for

	add/remove: 0/1 grow/shrink: 1/0 up/down: 660/-820 (-160)
	Function                                     old     new   delta
	extent_readpages                             476    1136    +660
	__extent_readpages                           820       -    -820
	Total: Before=44315, After=44155, chg -0.36%

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:49 +01:00
Nikolay Borisov 15c8276302 btrfs: Remove 1st shrink/grow phase from balance
The first step of the rebalance process ensures there is 1MiB free on
each device. This number seems rather small. And in fact when talking to
the original authors their opinions were:

"man that's a little bonkers"
"i don't think we even need that code anymore"
"I think it was there to make sure we had room for the blank 1M at the
beginning. I bet it goes all the way back to v0"
"we just don't need any of that tho, i say we just delete it"

Clearly, this piece of code has lost its original intent throughout the
years. It doesn't really bring any real practical benefits to the
relocation process.

Additionally, this patch makes the balance process more lightweight by
removing a pair of shrink/grow operations which are rather expensive for
heavily populated filesystems. This is mainly due to shrink requiring
relocating block groups, involving heavy use of the btree.

The intermediate shrink/grow can fail and leave the filesystem in a
middle state that would need to be changed back by the user.

Suggested-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
[ update changelog ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:49 +01:00
Filipe Manana be6821f82c Btrfs: send, fix race with transaction commits that create snapshots
If we create a snapshot of a snapshot currently being used by a send
operation, we can end up with send failing unexpectedly (returning
-ENOENT error to user space for example). The following diagram shows
how this happens.

            CPU 1                                   CPU2                                CPU3

 btrfs_ioctl_send()
  (...)
                                     create_snapshot()
                                      -> creates snapshot of a
                                         root used by the send
                                         task
                                      btrfs_commit_transaction()
                                       create_pending_snapshot()
  __get_inode_info()
   btrfs_search_slot()
    btrfs_search_slot_get_root()
     down_read commit_root_sem

     get reference on eb of the
     commit root
      -> eb with bytenr == X

     up_read commit_root_sem

                                        btrfs_cow_block(root node)
                                         btrfs_free_tree_block()
                                          -> creates delayed ref to
                                             free the extent

                                       btrfs_run_delayed_refs()
                                        -> runs the delayed ref,
                                           adds extent to
                                           fs_info->pinned_extents

                                       btrfs_finish_extent_commit()
                                        unpin_extent_range()
                                         -> marks extent as free
                                            in the free space cache

                                      transaction commit finishes

                                                                       btrfs_start_transaction()
                                                                        (...)
                                                                        btrfs_cow_block()
                                                                         btrfs_alloc_tree_block()
                                                                          btrfs_reserve_extent()
                                                                           -> allocates extent at
                                                                              bytenr == X
                                                                          btrfs_init_new_buffer(bytenr X)
                                                                           btrfs_find_create_tree_block()
                                                                            alloc_extent_buffer(bytenr X)
                                                                             find_extent_buffer(bytenr X)
                                                                              -> returns existing eb,
                                                                                 which the send task got

                                                                        (...)
                                                                         -> modifies content of the
                                                                            eb with bytenr == X

    -> uses an eb that now
       belongs to some other
       tree and no more matches
       the commit root of the
       snapshot, resuts will be
       unpredictable

The consequences of this race can be various, and can lead to searches in
the commit root performed by the send task failing unexpectedly (unable to
find inode items, returning -ENOENT to user space, for example) or not
failing because an inode item with the same number was added to the tree
that reused the metadata extent, in which case send can behave incorrectly
in the worst case or just fail later for some reason.

Fix this by performing a copy of the commit root's extent buffer when doing
a search in the context of a send operation.

CC: stable@vger.kernel.org # 4.4.x: 1fc28d8e2e9: Btrfs: move get root out of btrfs_search_slot to a helper
CC: stable@vger.kernel.org # 4.4.x: f9ddfd0592a: Btrfs: remove unused check of skip_locking
CC: stable@vger.kernel.org # 4.4.x
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:49 +01:00
Filipe Manana 827aa18e7b Btrfs: use nofs context when initializing security xattrs to avoid deadlock
When initializing the security xattrs, we are holding a transaction handle
therefore we need to use a GFP_NOFS context in order to avoid a deadlock
with reclaim in case it's triggered.

Fixes: 39a27ec100 ("btrfs: use GFP_KERNEL for xattr and acl allocations")
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:49 +01:00
Josef Bacik 0568e82dbe btrfs: run delayed items before dropping the snapshot
With my delayed refs patches in place we started seeing a large amount
of aborts in __btrfs_free_extent:

 BTRFS error (device sdb1): unable to find ref byte nr 91947008 parent 0 root 35964  owner 1 offset 0
 Call Trace:
  ? btrfs_merge_delayed_refs+0xaf/0x340
  __btrfs_run_delayed_refs+0x6ea/0xfc0
  ? btrfs_set_path_blocking+0x31/0x60
  btrfs_run_delayed_refs+0xeb/0x180
  btrfs_commit_transaction+0x179/0x7f0
  ? btrfs_check_space_for_delayed_refs+0x30/0x50
  ? should_end_transaction.isra.19+0xe/0x40
  btrfs_drop_snapshot+0x41c/0x7c0
  btrfs_clean_one_deleted_snapshot+0xb5/0xd0
  cleaner_kthread+0xf6/0x120
  kthread+0xf8/0x130
  ? btree_invalidatepage+0x90/0x90
  ? kthread_bind+0x10/0x10
  ret_from_fork+0x35/0x40

This was because btrfs_drop_snapshot depends on the root not being
modified while it's dropping the snapshot.  It will unlock the root node
(and really every node) as it walks down the tree, only to re-lock it
when it needs to do something.  This is a problem because if we modify
the tree we could cow a block in our path, which frees our reference to
that block.  Then once we get back to that shared block we'll free our
reference to it again, and get ENOENT when trying to lookup our extent
reference to that block in __btrfs_free_extent.

This is ultimately happening because we have delayed items left to be
processed for our deleted snapshot _after_ all of the inodes are closed
for the snapshot.  We only run the delayed inode item if we're deleting
the inode, and even then we do not run the delayed insertions or delayed
removals.  These can be run at any point after our final inode does its
last iput, which is what triggers the snapshot deletion.  We can end up
with the snapshot deletion happening and then have the delayed items run
on that file system, resulting in the above problem.

This problem has existed forever, however my patches made it much easier
to hit as I wake up the cleaner much more often to deal with delayed
iputs, which made us more likely to start the snapshot dropping work
before the transaction commits, which is when the delayed items would
generally be run.  Before, generally speaking, we would run the delayed
items, commit the transaction, and wakeup the cleaner thread to start
deleting snapshots, which means we were less likely to hit this problem.
You could still hit it if you had multiple snapshots to be deleted and
ended up with lots of delayed items, but it was definitely harder.

Fix for now by simply running all the delayed items before starting to
drop the snapshot.  We could make this smarter in the future by making
the delayed items per-root, and then simply drop any delayed items for
roots that we are going to delete.  But for now just a quick and easy
solution is the safest.

CC: stable@vger.kernel.org # 4.4+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:49 +01:00
Josef Bacik 83354f0772 btrfs: catch cow on deleting snapshots
When debugging some weird extent reference bug I suspected that we were
changing a snapshot while we were deleting it, which could explain my
bug.  This was indeed what was happening, and this patch helped me
verify my theory.  It is never correct to modify the snapshot once it's
being deleted, so mark the root when we are deleting it and make sure we
complain about it when it happens.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:48 +01:00
Qu Wenruo 01e0da4885 btrfs: extent-tree: cleanup one-shot usage of @blocksize in do_walk_down
@blocksize variable in do_walk_down() is only used once, really no need
to declare it.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:48 +01:00
Filipe Manana 7c3c7cb99c Btrfs: scrub, move setup of nofs contexts higher in the stack
Since scrub workers only do memory allocation with GFP_KERNEL when they
need to perform repair, we can move the recent setup of the nofs context
up to scrub_handle_errored_block() instead of setting it up down the call
chain at insert_full_stripe_lock() and scrub_add_page_to_wr_bio(),
removing some duplicate code and comment. So the only paths for which a
scrub worker can do memory allocations using GFP_KERNEL are the following:

 scrub_bio_end_io_worker()
   scrub_block_complete()
     scrub_handle_errored_block()
       lock_full_stripe()
         insert_full_stripe_lock()
           -> kmalloc with GFP_KERNEL

  scrub_bio_end_io_worker()
    scrub_block_complete()
      scrub_handle_errored_block()
        scrub_write_page_to_dev_replace()
          scrub_add_page_to_wr_bio()
            -> kzalloc with GFP_KERNEL

Signed-off-by: Filipe Manana <fdmanana@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:48 +01:00
David Sterba 0e94c4f45d btrfs: scrub: move scrub_setup_ctx allocation out of device_list_mutex
The scrub context is allocated with GFP_KERNEL and called from
btrfs_scrub_dev under the fs_info::device_list_mutex. This is not safe
regarding reclaim that could try to flush filesystem data in order to
get the memory. And the device_list_mutex is held during superblock
commit, so this would cause a lockup.

Move the alocation and initialization before any changes that require
the mutex.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:48 +01:00
David Sterba 92f7ba434f btrfs: scrub: pass fs_info to scrub_setup_ctx
We can pass fs_info directly as this is the only member of btrfs_device
that's bing used inside scrub_setup_ctx.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:48 +01:00
Josef Bacik 28bad21257 btrfs: fix truncate throttling
We have a bunch of magic to make sure we're throttling delayed refs when
truncating a file.  Now that we have a delayed refs rsv and a mechanism
for refilling that reserve simply use that instead of all of this magic.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:47 +01:00
Josef Bacik db2462a6ad btrfs: don't run delayed refs in the end transaction logic
Over the years we have built up a lot of infrastructure to keep delayed
refs in check, mostly by running them at btrfs_end_transaction() time.
We have a lot of different maths we do to figure out how much, if we
should do it inline or async, etc.  This existed because we had no
feedback mechanism to force the flushing of delayed refs when they
became a problem.  However with the enospc flushing infrastructure in
place for flushing delayed refs when they put too much pressure on the
enospc system we have this problem solved.  Rip out all of this code as
it is no longer needed.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:47 +01:00
Josef Bacik 64403612b7 btrfs: rework btrfs_check_space_for_delayed_refs
Now with the delayed_refs_rsv we can now know exactly how much pending
delayed refs space we need.  This means we can drastically simplify
btrfs_check_space_for_delayed_refs by simply checking how much space we
have reserved for the global rsv (which acts as a spill over buffer) and
the delayed refs rsv.  If our total size is beyond that amount then we
know it's time to commit the transaction and stop any more delayed refs
from being generated.

With the introduction of dealyed_refs_rsv infrastructure, namely
btrfs_update_delayed_refs_rsv we now know exactly how much pending
delayed refs space is required.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:47 +01:00
Josef Bacik 413df7252d btrfs: add new flushing states for the delayed refs rsv
A nice thing we gain with the delayed refs rsv is the ability to flush
the delayed refs on demand to deal with enospc pressure.  Add states to
flush delayed refs on demand, and this will allow us to remove a lot of
ad-hoc work around checking to see if we should commit the transaction
to run our delayed refs.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:47 +01:00
Josef Bacik 4c8edbc75c btrfs: update may_commit_transaction to use the delayed refs rsv
Any space used in the delayed_refs_rsv will be freed up by a transaction
commit, so instead of just counting the pinned space we also need to
account for any space in the delayed_refs_rsv when deciding if it will
make a different to commit the transaction to satisfy our space
reservation.  If we have enough bytes to satisfy our reservation ticket
then we are good to go, otherwise subtract out what space we would gain
back by committing the transaction and compare that against the pinned
space to make our decision.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:47 +01:00
Josef Bacik ba2c4d4e3b btrfs: introduce delayed_refs_rsv
Traditionally we've had voodoo in btrfs to account for the space that
delayed refs may take up by having a global_block_rsv.  This works most
of the time, except when it doesn't.  We've had issues reported and seen
in production where sometimes the global reserve is exhausted during
transaction commit before we can run all of our delayed refs, resulting
in an aborted transaction.  Because of this voodoo we have equally
dubious flushing semantics around throttling delayed refs which we often
get wrong.

So instead give them their own block_rsv.  This way we can always know
exactly how much outstanding space we need for delayed refs.  This
allows us to make sure we are constantly filling that reservation up
with space, and allows us to put more precise pressure on the enospc
system.  Instead of doing math to see if its a good time to throttle,
the normal enospc code will be invoked if we have a lot of delayed refs
pending, and they will be run via the normal flushing mechanism.

For now the delayed_refs_rsv will hold the reservations for the delayed
refs, the block group updates, and deleting csums.  We could have a
separate rsv for the block group updates, but the csum deletion stuff is
still handled via the delayed_refs so that will stay there.

Historical background:

The global reserve has grown to cover everything we don't reserve space
explicitly for, and we've grown a lot of weird ad-hoc heuristics to know
if we're running short on space and when it's time to force a commit.  A
failure rate of 20-40 file systems when we run hundreds of thousands of
them isn't super high, but cleaning up this code will make things less
ugly and more predictible.

Thus the delayed refs rsv.  We always know how many delayed refs we have
outstanding, and although running them generates more we can use the
global reserve for that spill over, which fits better into it's desired
use than a full blown reservation.  This first approach is to simply
take how many times we're reserving space for and multiply that by 2 in
order to save enough space for the delayed refs that could be generated.
This is a niave approach and will probably evolve, but for now it works.

Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com> # high-level review
[ added background notes from the cover letter ]
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:46 +01:00
Josef Bacik 158ffa364b btrfs: only track ref_heads in delayed_ref_updates
We use this number to figure out how many delayed refs to run, but
__btrfs_run_delayed_refs really only checks every time we need a new
delayed ref head, so we always run at least one ref head completely no
matter what the number of items on it.  Fix the accounting to only be
adjusted when we add/remove a ref head.

In addition to using this number to limit the number of delayed refs
run, a future patch is also going to use it to calculate the amount of
space required for delayed refs space reservation.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:46 +01:00
Josef Bacik bedc661760 btrfs: cleanup extent_op handling
The cleanup_extent_op function actually would run the extent_op if it
needed running, which made the name sort of a misnomer.  Change it to
run_and_cleanup_extent_op, and move the actual cleanup work to
cleanup_extent_op so it can be used by check_ref_cleanup() in order to
unify the extent op handling.

Reviewed-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:46 +01:00
Josef Bacik 07c47775f4 btrfs: add cleanup_ref_head_accounting helper
We were missing some quota cleanups in check_ref_cleanup, so break the
ref head accounting cleanup into a helper and call that from both
check_ref_cleanup and cleanup_ref_head.  This will hopefully ensure that
we don't screw up accounting in the future for other things that we add.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Liu Bo <bo.liu@linux.alibaba.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:46 +01:00
Josef Bacik d7baffdaf9 btrfs: add btrfs_delete_ref_head helper
We do this dance in cleanup_ref_head and check_ref_cleanup, unify it
into a helper and cleanup the calling functions.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Josef Bacik <jbacik@fb.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:46 +01:00
Johannes Thumshirn fdb1e12180 btrfs: use PAGE_ALIGNED instead of open-coding it
When using a 'var & (PAGE_SIZE - 1)' construct one is checking for a page
alignment and thus should use the PAGE_ALIGNED() macro instead of
open-coding it.

Convert all open-coded occurrences of PAGE_ALIGNED().

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:45 +01:00
Johannes Thumshirn 7073017aeb btrfs: use offset_in_page instead of open-coding it
Constructs like 'var & (PAGE_SIZE - 1)' or 'var & ~PAGE_MASK' can denote an
offset into a page.

So replace them by the offset_in_page() macro instead of open-coding it if
they're not used as an alignment check.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:45 +01:00
David Sterba cb5583dd52 btrfs: dev-replace: open code trivial locking helpers
The dev-replace locking functions are now trivial wrappers around rw
semaphore that can be used directly everywhere. No functional change.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:45 +01:00
David Sterba 53176dde0a btrfs: dev-replace: remove custom read/write blocking scheme
After the rw semaphore has been added, the custom blocking using
::blocking_readers and ::read_lock_wq is redundant.

The blocking logic in __btrfs_map_block is replaced by extending the
time the semaphore is held, that has the same blocking effect on writes
as the previous custom scheme that waited until ::blocking_readers was
zero.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:45 +01:00
David Sterba 129827e300 btrfs: dev-replace: swich locking to rw semaphore
This is the first part of removing the custom locking and waiting scheme
used for device replace. It was probably copied from extent buffer
locking, but there's nothing that would require more than is provided by
the common locking primitives.

The rw spinlock protects waiting tasks counter in case of incompatible
locks and the waitqueue. Same as rw semaphore.

This patch only switches the locking primitive, for better
bisectability.  There should be no functional change other than the
overhead of the locking and potential sleeping instead of spinning when
the lock is contended.

Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:44 +01:00
David Sterba ceb21a8db4 btrfs: reada: reorder dev-replace locks before radix tree preload
The device-replace read lock is going to use rw semaphore in followup
commits. The semaphore might sleep which is not possible in the radix
tree preload section. The lock nesting is now:

* device replace
  * radix tree preload
    * readahead spinlock

Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:44 +01:00
Nikolay Borisov d1051d6ebf btrfs: Fix error handling in btrfs_cleanup_ordered_extents
Running btrfs/124 in a loop hung up on me sporadically with the
following call trace:

	btrfs           D    0  5760   5324 0x00000000
	Call Trace:
	 ? __schedule+0x243/0x800
	 schedule+0x33/0x90
	 btrfs_start_ordered_extent+0x10c/0x1b0 [btrfs]
	 ? wait_woken+0xa0/0xa0
	 btrfs_wait_ordered_range+0xbb/0x100 [btrfs]
	 btrfs_relocate_block_group+0x1ff/0x230 [btrfs]
	 btrfs_relocate_chunk+0x49/0x100 [btrfs]
	 btrfs_balance+0xbeb/0x1740 [btrfs]
	 btrfs_ioctl_balance+0x2ee/0x380 [btrfs]
	 btrfs_ioctl+0x1691/0x3110 [btrfs]
	 ? lockdep_hardirqs_on+0xed/0x180
	 ? __handle_mm_fault+0x8e7/0xfb0
	 ? _raw_spin_unlock+0x24/0x30
	 ? __handle_mm_fault+0x8e7/0xfb0
	 ? do_vfs_ioctl+0xa5/0x6e0
	 ? btrfs_ioctl_get_supported_features+0x30/0x30 [btrfs]
	 do_vfs_ioctl+0xa5/0x6e0
	 ? entry_SYSCALL_64_after_hwframe+0x3e/0xbe
	 ksys_ioctl+0x3a/0x70
	 __x64_sys_ioctl+0x16/0x20
	 do_syscall_64+0x60/0x1b0
	 entry_SYSCALL_64_after_hwframe+0x49/0xbe

This happens because during page writeback it's valid for
writepage_delalloc to instantiate a delalloc range which doesn't belong
to the page currently being written back.

The reason this case is valid is due to find_lock_delalloc_range
returning any available range after the passed delalloc_start and
ignoring whether the page under writeback is within that range.

In turn ordered extents (OE) are always created for the returned range
from find_lock_delalloc_range. If, however, a failure occurs while OE
are being created then the clean up code in btrfs_cleanup_ordered_extents
will be called.

Unfortunately the code in btrfs_cleanup_ordered_extents doesn't consider
the case of such 'foreign' range being processed and instead it always
assumes that the range OE are created for belongs to the page. This
leads to the first page of such foregin range to not be cleaned up since
it's deliberately missed and skipped by the current cleaning up code.

Fix this by correctly checking whether the current page belongs to the
range being instantiated and if so adjsut the range parameters passed
for cleaning up. If it doesn't, then just clean the whole OE range
directly.

Fixes: 524272607e ("btrfs: Handle delalloc error correctly to avoid ordered extent hang")
CC: stable@vger.kernel.org # 4.14+
Reviewed-by: Josef Bacik <josef@toxicpanda.com>
Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:44 +01:00
Lu Fengqi 3522e90301 btrfs: remove always true if branch in find_delalloc_range
The @found is always false when it comes to the if branch. Besides, the
bool type is more suitable for @found. Change the return value of the
function and its caller to bool as well.

Reviewed-by: Nikolay Borisov <nborisov@suse.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:44 +01:00
Lu Fengqi 27a7ff554e btrfs: skip file_extent generation check for free_space_inode in run_delalloc_nocow
The test case btrfs/001 with inode_cache mount option will encounter the
following warning:

  WARNING: CPU: 1 PID: 23700 at fs/btrfs/inode.c:956 cow_file_range.isra.19+0x32b/0x430 [btrfs]
  CPU: 1 PID: 23700 Comm: btrfs Kdump: loaded Tainted: G        W  O      4.20.0-rc4-custom+ #30
  Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 0.0.0 02/06/2015
  RIP: 0010:cow_file_range.isra.19+0x32b/0x430 [btrfs]
  Call Trace:
   ? free_extent_buffer+0x46/0x90 [btrfs]
   run_delalloc_nocow+0x455/0x900 [btrfs]
   btrfs_run_delalloc_range+0x1a7/0x360 [btrfs]
   writepage_delalloc+0xf9/0x150 [btrfs]
   __extent_writepage+0x125/0x3e0 [btrfs]
   extent_write_cache_pages+0x1b6/0x3e0 [btrfs]
   ? __wake_up_common_lock+0x63/0xc0
   extent_writepages+0x50/0x80 [btrfs]
   do_writepages+0x41/0xd0
   ? __filemap_fdatawrite_range+0x9e/0xf0
   __filemap_fdatawrite_range+0xbe/0xf0
   btrfs_fdatawrite_range+0x1b/0x50 [btrfs]
   __btrfs_write_out_cache+0x42c/0x480 [btrfs]
   btrfs_write_out_ino_cache+0x84/0xd0 [btrfs]
   btrfs_save_ino_cache+0x551/0x660 [btrfs]
   commit_fs_roots+0xc5/0x190 [btrfs]
   btrfs_commit_transaction+0x2bf/0x8d0 [btrfs]
   btrfs_mksubvol+0x48d/0x4d0 [btrfs]
   btrfs_ioctl_snap_create_transid+0x170/0x180 [btrfs]
   btrfs_ioctl_snap_create_v2+0x124/0x180 [btrfs]
   btrfs_ioctl+0x123f/0x3030 [btrfs]

The file extent generation of the free space inode is equal to the last
snapshot of the file root, so the inode will be passed to cow_file_rage.
But the inode was created and its extents were preallocated in
btrfs_save_ino_cache, there are no cow copies on disk.

The preallocated extent is not yet in the extent tree, and
btrfs_cross_ref_exist will ignore the -ENOENT returned by
check_committed_ref, so we can directly write the inode to the disk.

Fixes: 78d4295b1e ("btrfs: lift some btrfs_cross_ref_exist checks in nocow path")
CC: stable@vger.kernel.org # 4.18+
Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Lu Fengqi <lufq.fnst@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:44 +01:00
Filipe Manana 41bd606769 Btrfs: fix fsync of files with multiple hard links in new directories
The log tree has a long standing problem that when a file is fsync'ed we
only check for new ancestors, created in the current transaction, by
following only the hard link for which the fsync was issued. We follow the
ancestors using the VFS' dget_parent() API. This means that if we create a
new link for a file in a directory that is new (or in an any other new
ancestor directory) and then fsync the file using an old hard link, we end
up not logging the new ancestor, and on log replay that new hard link and
ancestor do not exist. In some cases, involving renames, the file will not
exist at all.

Example:

  mkfs.btrfs -f /dev/sdb
  mount /dev/sdb /mnt

  mkdir /mnt/A
  touch /mnt/foo
  ln /mnt/foo /mnt/A/bar
  xfs_io -c fsync /mnt/foo

  <power failure>

In this example after log replay only the hard link named 'foo' exists
and directory A does not exist, which is unexpected. In other major linux
filesystems, such as ext4, xfs and f2fs for example, both hard links exist
and so does directory A after mounting again the filesystem.

Checking if any new ancestors are new and need to be logged was added in
2009 by commit 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes"),
however only for the ancestors of the hard link (dentry) for which the
fsync was issued, instead of checking for all ancestors for all of the
inode's hard links.

So fix this by tracking the id of the last transaction where a hard link
was created for an inode and then on fsync fallback to a full transaction
commit when an inode has more than one hard link and at least one new hard
link was created in the current transaction. This is the simplest solution
since this is not a common use case (adding frequently hard links for
which there's an ancestor created in the current transaction and then
fsync the file). In case it ever becomes a common use case, a solution
that consists of iterating the fs/subvol btree for each hard link and
check if any ancestor is new, could be implemented.

This solves many unexpected scenarios reported by Jayashree Mohan and
Vijay Chidambaram, and for which there is a new test case for fstests
under review.

Fixes: 12fcfd22fe ("Btrfs: tree logging unlink/rename fixes")
CC: stable@vger.kernel.org # 4.4+
Reported-by: Vijay Chidambaram <vvijay03@gmail.com>
Reported-by: Jayashree Mohan <jayashree2912@gmail.com>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:43 +01:00
David Sterba bbe339cc32 btrfs: drop extra enum initialization where using defaults
The first auto-assigned value to enum is 0, we can use that and not
initialize all members where the auto-increment does the same. This is
used for values that are not part of on-disk format.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:43 +01:00
David Sterba 5b840301ac btrfs: switch BTRFS_ORDERED_* to enums
We can use simple enum for values that are not part of on-disk format:
ordered extent flags.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:43 +01:00
David Sterba 50b5b6020f btrfs: switch EXTENT_FLAG_* to enums
We can use simple enum for values that are not part of on-disk format:
extent map flags.

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:43 +01:00
David Sterba 80cb38362d btrfs: switch EXTENT_BUFFER_* to enums
We can use simple enum for values that are not part of on-disk format:
extent buffer flags;

Reviewed-by: Omar Sandoval <osandov@fb.com>
Reviewed-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: David Sterba <dsterba@suse.com>
2018-12-17 14:51:43 +01:00