Commit Graph

209 Commits

Author SHA1 Message Date
Brian Foster d0c2204135 xfs: stabilize insert range start boundary to avoid COW writeback race
generic/522 (fsx) occasionally fails with a file corruption due to
an insert range operation. The primary characteristic of the
corruption is a misplaced insert range operation that differs from
the requested target offset. The reason for this behavior is a race
between the extent shift sequence of an insert range and a COW
writeback completion that causes a front merge with the first extent
in the shift.

The shift preparation function flushes and unmaps from the target
offset of the operation to the end of the file to ensure no
modifications can be made and page cache is invalidated before file
data is shifted. An insert range operation then splits the extent at
the target offset, if necessary, and begins to shift the start
offset of each extent starting from the end of the file to the start
offset. The shift sequence operates at extent level and so depends
on the preparation sequence to guarantee no changes can be made to
the target range during the shift. If the block immediately prior to
the target offset was dirty and shared, however, it can undergo
writeback and move from the COW fork to the data fork at any point
during the shift. If the block is contiguous with the block at the
start offset of the insert range, it can front merge and alter the
start offset of the extent. Once the shift sequence reaches the
target offset, it shifts based on the latest start offset and
silently changes the target offset of the operation and corrupts the
file.

To address this problem, update the shift preparation code to
stabilize the start boundary along with the full range of the
insert. Also update the existing corruption check to fail if any
extent is shifted with a start offset behind the target offset of
the insert range. This prevents insert from racing with COW
writeback completion and fails loudly in the event of an unexpected
extent shift.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-12-11 13:18:42 -08:00
Darrick J. Wong 2713fefa5d xfs: attach dquots before performing xfs_swap_extents
Make sure we attach dquots to both inodes before swapping their extents.
This was found via manual code inspection by looking for places where we
could call xfs_trans_mod_dquot without dquots attached to inodes, and
confirmed by instrumenting the kernel and running xfs/328.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-11-11 12:42:52 -08:00
Christoph Hellwig fd638f1de1 xfs: move extent zeroing to xfs_bmapi_allocate
Move the extent zeroing case there for the XFS_BMAPI_ZERO flag outside
the low-level allocator and into xfs_bmapi_allocate, where is still
is in transaction context, but outside the very lowlevel code where
it doesn't belong.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-03 10:22:30 -08:00
Christoph Hellwig ae7e403fa5 xfs: simplify xfs_iomap_eof_align_last_fsb
By open coding xfs_bmap_last_extent instead of calling it through a
double indirection we don't need to handle an error return that
can't happen given that we are guaranteed to have the extent list in
memory already.  Also simplify the calling conventions a little and
move the extent list assert from the only caller into the function.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-11-03 10:22:30 -08:00
Dave Chinner 249bd9087a xfs: properly serialise fallocate against AIO+DIO
AIO+DIO can extend the file size on IO completion, and it holds
no inode locks while the IO is in flight. Therefore, a race
condition exists in file size updates if we do something like this:

aio-thread			fallocate-thread

lock inode
submit IO beyond inode->i_size
unlock inode
.....
				lock inode
				break layouts
				if (off + len > inode->i_size)
					new_size = off + len
				.....
				inode_dio_wait()
				<blocks>
.....
completes
inode->i_size updated
inode_dio_done()
....
				<wakes>
				<does stuff no long beyond EOF>
				if (new_size)
					xfs_vn_setattr(inode, new_size)


Yup, that attempt to extend the file size in the fallocate code
turns into a truncate - it removes the whatever the aio write
allocated and put to disk, and reduced the inode size back down to
where the fallocate operation ends.

Fundamentally, xfs_file_fallocate()  not compatible with racing
AIO+DIO completions, so we need to move the inode_dio_wait() call
up to where the lock the inode and break the layouts.

Secondly, storing the inode size and then using it unchecked without
holding the ILOCK is not safe; we can only do such a thing if we've
locked out and drained all IO and other modification operations,
which we don't do initially in xfs_file_fallocate.

It should be noted that some of the fallocate operations are
compound operations - they are made up of multiple manipulations
that may zero data, and so we may need to flush and invalidate the
file multiple times during an operation. However, we only need to
lock out IO and other space manipulation operations once, as that
lockout is maintained until the entire fallocate operation has been
completed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-31 09:17:55 -07:00
Darrick J. Wong fec40e220f xfs: refactor xfs_bmap_count_blocks using newer btree helpers
Currently, this function open-codes walking a bmbt to count the extents
and blocks in use by a particular inode fork.  Since we now have a
function to tally extent records from the incore extent tree and a btree
helper to count every block in a btree, replace all that with calls to
the helpers.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2019-10-29 09:50:11 -07:00
Christoph Hellwig 360c09c01c xfs: consolidate preallocation in xfs_file_fallocate
Remove xfs_zero_file_space and reorganize xfs_file_fallocate so that a
single call to xfs_alloc_file_space covers all modes that preallocate
blocks.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-28 16:08:17 -07:00
Christoph Hellwig 30fa529e3b xfs: add a xfs_inode_buftarg helper
Add a new xfs_inode_buftarg helper that gets the data I/O buftarg for a
given inode.  Replace the existing xfs_find_bdev_for_inode and
xfs_find_daxdev_for_inode helpers with this new general one and cleanup
some of the callers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-28 08:37:54 -07:00
Brian Foster da781e64b2 xfs: don't set bmapi total block req where minleft is
xfs_bmapi_write() takes a total block requirement parameter that is
passed down to the block allocation code and is used to specify the
total block requirement of the associated transaction. This is used
to try and select an AG that can not only satisfy the requested
extent allocation, but can also accommodate subsequent allocations
that might be required to complete the transaction. For example,
additional bmbt block allocations may be required on insertion of
the resulting extent to an inode data fork.

While it's important for callers to calculate and reserve such extra
blocks in the transaction, it is not necessary to pass the total
value to xfs_bmapi_write() in all cases. The latter automatically
sets minleft to ensure that sufficient free blocks remain after the
allocation attempt to expand the format of the associated inode
(i.e., such as extent to btree conversion, btree splits, etc).
Therefore, any callers that pass a total block requirement of the
bmap mapping length plus worst case bmbt expansion essentially
specify the additional reservation requirement twice. These callers
can pass a total of zero to rely on the bmapi minleft policy.

Beyond being superfluous, the primary motivation for this change is
that the total reservation logic in the bmbt code is dubious in
scenarios where minlen < maxlen and a maxlen extent cannot be
allocated (which is more common for data extent allocations where
contiguity is not required). The total value is based on maxlen in
the xfs_bmapi_write() caller. If the bmbt code falls back to an
allocation between minlen and maxlen, that allocation will not
succeed until total is reset to minlen, which essentially throws
away any additional reservation included in total by the caller. In
addition, the total value is not reset until after alignment is
dropped, which means that such callers drop alignment far too
aggressively than necessary.

Update all callers of xfs_bmapi_write() that pass a total block
value of the mapping length plus bmbt reservation to instead pass
zero and rely on xfs_bmapi_minleft() to enforce the bmbt reservation
requirement. This trades off slightly less conservative AG selection
for the ability to preserve alignment in more scenarios.
xfs_bmapi_write() callers that incorporate unrelated or additional
reservations in total beyond what is already included in minleft
must continue to use the former.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-23 17:01:08 -07:00
Christoph Hellwig f150b42343 xfs: split the iomap ops for buffered vs direct writes
Instead of lots of magic conditionals in the main write_begin
handler this make the intent very clear.  Thing will become even
better once we support delayed allocations for extent size hints
and realtime allocations.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-21 09:04:58 -07:00
Max Reitz e093c4be76 xfs: Fix tail rounding in xfs_alloc_file_space()
To ensure that all blocks touched by the range [offset, offset + count)
are allocated, we need to calculate the block count from the difference
of the range end (rounded up) and the range start (rounded down).

Before this patch, we just round up the byte count, which may lead to
unaligned ranges not being fully allocated:

$ touch test_file
$ block_size=$(stat -fc '%S' test_file)
$ fallocate -o $((block_size / 2)) -l $block_size test_file
$ xfs_bmap test_file
test_file:
        0: [0..7]: 1396264..1396271
        1: [8..15]: hole

There should not be a hole there.  Instead, the first two blocks should
be fully allocated.

With this patch applied, the result is something like this:

$ touch test_file
$ block_size=$(stat -fc '%S' test_file)
$ fallocate -o $((block_size / 2)) -l $block_size test_file
$ xfs_bmap test_file
test_file:
        0: [0..15]: 11024..11039

Signed-off-by: Max Reitz <mreitz@redhat.com>
Reviewed-by: Carlos Maiolino <cmaiolino@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-10-06 15:39:05 -07:00
Christoph Hellwig ecfc28a41c xfs: cleanup xfs_fsb_to_db
This function isn't a macro anymore, so remove various superflous braces,
and explicit cast that is done implicitly due to the return value, use
a normal if statement instead of trying to squeeze everything together.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-08-30 22:43:58 -07:00
Darrick J. Wong 3e08f42ae7 xfs: remove unnecessary int returns from deferred bmap functions
Remove the return value from the functions that schedule deferred bmap
operations since they never fail and do not return status.

Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-08-28 08:31:02 -07:00
Eric Sandeen 250d4b4c40 xfs: remove unused header files
There are many, many xfs header files which are included but
unneeded (or included twice) in the xfs code, so remove them.

nb: xfs_linux.h includes about 9 headers for everyone, so those
explicit includes get removed by this.  I'm not sure what the
preference is, but if we wanted explicit includes everywhere,
a followup patch could remove those xfs_*.h includes from
xfs_linux.h and move them into the files that need them.
Or it could be left as-is.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-28 19:30:43 -07:00
Eric Sandeen f5b999c03f xfs: remove unused flag arguments
There are several functions which take a flag argument that is
only ever passed as "0," so remove these arguments.

Signed-off-by: Eric Sandeen <sandeen@redhat.com>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-06-12 09:00:00 -07:00
Brian Foster 1749d1ea89 xfs: add missing error check in xfs_prepare_shift()
xfs_prepare_shift() fails to check the error return from
xfs_flush_unmap_range(). If the latter fails, that could lead to an
insert/collapse range operation over a delalloc range, which is not
supported.

Add an error check and return appropriately. This is reproduced
rarely by generic/475.

Fixes: 7f9f71be84 ("xfs: extent shifting doesn't fully invalidate page cache")
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Allison Collins <allison.henderson@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2019-04-26 12:28:56 -07:00
Christoph Hellwig 66ae56a53f xfs: introduce an always_cow mode
Add a mode where XFS never overwrites existing blocks in place.  This
is to aid debugging our COW code, and also put infatructure in place
for things like possible future support for zoned block devices, which
can't support overwrites.

This mode is enabled globally by doing a:

    echo 1 > /sys/fs/xfs/debug/always_cow

Note that the parameter is global to allow running all tests in xfstests
easily in this mode, which would not easily be possible with a per-fs
sysfs file.

In always_cow mode persistent preallocations are disabled, and fallocate
will fail when called with a 0 mode (with our without
FALLOC_FL_KEEP_SIZE), and not create unwritten extent for zeroed space
when called with FALLOC_FL_ZERO_RANGE or FALLOC_FL_UNSHARE_RANGE.

There are a few interesting xfstests failures when run in always_cow
mode:

 - generic/392 fails because the bytes used in the file used to test
   hole punch recovery are less after the log replay.  This is
   because the blocks written and then punched out are only freed
   with a delay due to the logging mechanism.
 - xfs/170 will fail as the already fragile file streams mechanism
   doesn't seem to interact well with the COW allocator
 - xfs/180 xfs/182 xfs/192 xfs/198 xfs/204 and xfs/208 will claim
   the file system is badly fragmented, but there is not much we
   can do to avoid that when always writing out of place
 - xfs/205 fails because overwriting a file in always_cow mode
   will require new space allocation and the assumption in the
   test thus don't work anymore.
 - xfs/326 fails to modify the file at all in always_cow mode after
   injecting the refcount error, leading to an unexpected md5sum
   after the remount, but that again is expected

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2019-02-21 07:55:07 -08:00
Darrick J. Wong a579121f94 xfs: fix PAGE_MASK usage in xfs_free_file_space
In commit e53c4b598, I *tried* to teach xfs to force writeback when we
fzero/fpunch right up to EOF so that if EOF is in the middle of a page,
the post-EOF part of the page gets zeroed before we return to userspace.
Unfortunately, I missed the part where PAGE_MASK is ~(PAGE_SIZE - 1),
which means that we totally fail to zero if we're fpunching and EOF is
within the first page.  Worse yet, the same PAGE_MASK thinko plagues the
filemap_write_and_wait_range call, so we'd initiate writeback of the
entire file, which (mostly) masked the thinko.

Drop the tricky PAGE_MASK and replace it with correct usage of PAGE_SIZE
and the proper rounding macros.

Fixes: e53c4b598 ("xfs: ensure post-EOF zeroing happens after zeroing part of a file")
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2018-12-04 08:50:49 -08:00
Dave Chinner 2c307174ab xfs: flush removing page cache in xfs_reflink_remap_prep
On a sub-page block size filesystem, fsx is failing with a data
corruption after a series of operations involving copying a file
with the destination offset beyond EOF of the destination of the file:

8093(157 mod 256): TRUNCATE DOWN        from 0x7a120 to 0x50000 ******WWWW
8094(158 mod 256): INSERT 0x25000 thru 0x25fff  (0x1000 bytes)
8095(159 mod 256): COPY 0x18000 thru 0x1afff    (0x3000 bytes) to 0x2f400
8096(160 mod 256): WRITE    0x5da00 thru 0x651ff        (0x7800 bytes) HOLE
8097(161 mod 256): COPY 0x2000 thru 0x5fff      (0x4000 bytes) to 0x6fc00

The second copy here is beyond EOF, and it is to sub-page (4k) but
block aligned (1k) offset. The clone runs the EOF zeroing, landing
in a pre-existing post-eof delalloc extent. This zeroes the post-eof
extents in the page cache just fine, dirtying the pages correctly.

The problem is that xfs_reflink_remap_prep() now truncates the page
cache over the range that it is copying it to, and rounds that down
to cover the entire start page. This removes the dirty page over the
delalloc extent from the page cache without having written it back.
Hence later, when the page cache is flushed, the page at offset
0x6f000 has not been written back and hence exposes stale data,
which fsx trips over less than 10 operations later.

Fix this by changing xfs_reflink_remap_prep() to use
xfs_flush_unmap_range().

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-21 10:10:53 -08:00
Dave Chinner 7f9f71be84 xfs: extent shifting doesn't fully invalidate page cache
The extent shifting code uses a flush and invalidate mechainsm prior
to shifting extents around. This is similar to what
xfs_free_file_space() does, but it doesn't take into account things
like page cache vs block size differences, and it will fail if there
is a page that it currently busy.

xfs_flush_unmap_range() handles all of these cases, so just convert
xfs_prepare_shift() to us that mechanism rather than having it's own
special sauce.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-11-20 10:36:19 -08:00
Christoph Hellwig 96987eea53 xfs: cancel COW blocks before swapext
We need to make sure we have no outstanding COW blocks before we swap
extents, as there is nothing preventing us from having preallocated COW
delalloc on either inode that swapext is called on.  That case can
easily be reproduced by running generic/324 in always_cow mode:

[  620.760572] XFS: Assertion failed: tip->i_delayed_blks == 0, file: fs/xfs/xfs_bmap_util.c, line: 1669
[  620.761608] ------------[ cut here ]------------
[  620.762171] kernel BUG at fs/xfs/xfs_message.c:102!
[  620.762732] invalid opcode: 0000 [#1] SMP PTI
[  620.763272] CPU: 0 PID: 24153 Comm: xfs_fsr Tainted: G        W         4.19.0-rc1+ #4182
[  620.764203] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS 1.11.1-1 04/01/2014
[  620.765202] RIP: 0010:assfail+0x20/0x28
[  620.765646] Code: 31 ff e8 83 fc ff ff 0f 0b c3 48 89 f1 41 89 d0 48 c7 c6 48 ca 8d 82 48 89 fa 38
[  620.767758] RSP: 0018:ffffc9000898bc10 EFLAGS: 00010202
[  620.768359] RAX: 0000000000000000 RBX: ffff88012f14ba40 RCX: 0000000000000000
[  620.769174] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828560d9
[  620.769982] RBP: ffff88012f14b300 R08: 0000000000000000 R09: 0000000000000000
[  620.770788] R10: 000000000000000a R11: f000000000000000 R12: ffffc9000898bc98
[  620.771638] R13: ffffc9000898bc9c R14: ffff880130b5e2b8 R15: ffff88012a1fa2a8
[  620.772504] FS:  00007fdc36e0fbc0(0000) GS:ffff88013ba00000(0000) knlGS:0000000000000000
[  620.773475] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  620.774168] CR2: 00007fdc3604d000 CR3: 0000000132afc000 CR4: 00000000000006f0
[  620.774978] Call Trace:
[  620.775274]  xfs_swap_extent_forks+0x2a0/0x2e0
[  620.775792]  xfs_swap_extents+0x38b/0xab0
[  620.776256]  xfs_ioc_swapext+0x121/0x140
[  620.776709]  xfs_file_ioctl+0x328/0xc90
[  620.777154]  ? rcu_read_lock_sched_held+0x50/0x60
[  620.777694]  ? xfs_iunlock+0x233/0x260
[  620.778127]  ? xfs_setattr_nonsize+0x3be/0x6a0
[  620.778647]  do_vfs_ioctl+0x9d/0x680
[  620.779071]  ? ksys_fchown+0x47/0x80
[  620.779552]  ksys_ioctl+0x35/0x70
[  620.780040]  __x64_sys_ioctl+0x11/0x20
[  620.780530]  do_syscall_64+0x4b/0x190
[  620.780927]  entry_SYSCALL_64_after_hwframe+0x49/0xbe
[  620.781467] RIP: 0033:0x7fdc364d0f07
[  620.781900] Code: b3 66 90 48 8b 05 81 5f 2c 00 64 c7 00 26 00 00 00 48 c7 c0 ff ff ff ff c3 66 28
[  620.784044] RSP: 002b:00007ffe2a766038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010
[  620.784896] RAX: ffffffffffffffda RBX: 0000000000000025 RCX: 00007fdc364d0f07
[  620.785667] RDX: 0000560296ca2fc0 RSI: 00000000c0c0586d RDI: 0000000000000005
[  620.786398] RBP: 0000000000000025 R08: 0000000000001200 R09: 0000000000000000
[  620.787283] R10: 0000000000000432 R11: 0000000000000246 R12: 0000000000000005
[  620.788051] R13: 0000000000000000 R14: 0000000000001000 R15: 0000000000000006
[  620.788927] Modules linked in:
[  620.789340] ---[ end trace 9503b7417ffdbdb0 ]---
[  620.790065] RIP: 0010:assfail+0x20/0x28
[  620.790642] Code: 31 ff e8 83 fc ff ff 0f 0b c3 48 89 f1 41 89 d0 48 c7 c6 48 ca 8d 82 48 89 fa 38
[  620.793038] RSP: 0018:ffffc9000898bc10 EFLAGS: 00010202
[  620.793609] RAX: 0000000000000000 RBX: ffff88012f14ba40 RCX: 0000000000000000
[  620.794317] RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffff828560d9
[  620.795025] RBP: ffff88012f14b300 R08: 0000000000000000 R09: 0000000000000000
[  620.795778] R10: 000000000000000a R11: f000000000000000 R12: ffffc9000898bc98
[  620.796675] R13: ffffc9000898bc9c R14: ffff880130b5e2b8 R15: ffff88012a1fa2a8
[  620.797782] FS:  00007fdc36e0fbc0(0000) GS:ffff88013ba00000(0000) knlGS:0000000000000000
[  620.798908] CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
[  620.799594] CR2: 00007fdc3604d000 CR3: 0000000132afc000 CR4: 00000000000006f0
[  620.800424] Kernel panic - not syncing: Fatal exception
[  620.801191] Kernel Offset: disabled
[  620.801597] ---[ end Kernel panic - not syncing: Fatal exception ]---

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:21:55 +11:00
Christoph Hellwig d392bc81bb xfs: remove the unused trimmed argument from xfs_reflink_trim_around_shared
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:19:48 +11:00
Christoph Hellwig daa79baefc xfs: remove suport for filesystems without unwritten extent flag
The option to enable unwritten extents was made default in 2003,
removed from mkfs in 2007, and cannot be disabled in v5.  We also
rely on it for a lot of common functionality, so filesystems without
it will run a completely untested and buggy code path.  Enabling the
support also is a simple bit flip using xfs_db, so legacy file
systems can still be brought forward.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-10-18 17:18:58 +11:00
Christoph Hellwig 0065b54119 xfs: don't bring in extents in xfs_bmap_punch_delalloc_range
This function is only used to punch out delayed allocations on I/O
failure, which means we need to have read the extents earlier.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:47:46 +10:00
Brian Foster d5a2e2893d xfs: remove last of unnecessary xfs_defer_cancel() callers
Now that deferred operations are completely managed via
transactions, it's no longer necessary to cancel the dfops in error
paths that already cancel the associated transaction. There are a
few such calls lingering throughout the codebase.

Remove all remaining unnecessary calls to xfs_defer_cancel(). This
leaves xfs_defer_cancel() calls in two places. The first is the call
in the transaction cancel path itself, which facilitates this patch.
The second is made via the xfs_defer_finish() error path to provide
consistent error semantics with transaction commit. For example,
xfs_trans_commit() expects an xfs_defer_finish() failure to clean up
the dfops structure before it returns.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>
2018-09-29 13:41:58 +10:00
Brian Foster 0f37d1780c xfs: pass transaction to xfs_defer_add()
The majority of remaining references to struct xfs_defer_ops in XFS
are associated with xfs_defer_add(). At this point, there are no
more external xfs_defer_ops users left. All instances of
xfs_defer_ops are embedded in the transaction, which means we can
safely pass the transaction down to the dfops add interface.

Update xfs_defer_add() to receive the transaction as a parameter.
Various subsystems implement wrappers to allocate and construct the
context specific data structures for the associated deferred
operation type. Update these to also carry the transaction down as
needed and clean up unused dfops parameters along the way.

This removes most of the remaining references to struct
xfs_defer_ops throughout the code and facilitates removal of the
structure.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
[darrick: fix unused variable warnings with ftrace disabled]
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 23:05:14 -07:00
Brian Foster 9b1f4e9831 xfs: cancel dfops on xfs_defer_finish() error
The current semantics of xfs_defer_finish() require the caller to
call xfs_defer_cancel() on error. This is slightly inconsistent with
transaction commit error handling where a failed commit cleans up
the transaction before returning.

More significantly, the only requirement for exposure of
->dop_pending outside of xfs_defer_finish() is so that
xfs_defer_cancel() can drain it on error. Since the only recourse of
xfs_defer_finish() errors is cancellation, mirror the transaction
logic and cancel remaining dfops before returning from
xfs_defer_finish() with an error.

Beside simplifying xfs_defer_finish() semantics, this ensures that
xfs_defer_finish() always returns with an empty ->dop_pending and
thus facilitates removal of the list from xfs_defer_ops.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 23:05:14 -07:00
Brian Foster a8198666fb xfs: automatic dfops inode relogging
Inodes that are held across deferred operations are explicitly
joined to the dfops structure to ensure appropriate relogging.
While inodes are currently joined explicitly, we can detect the
conditions that require relogging at dfops finish time by inspecting
the transaction item list for inodes with ili_lock_flags == 0.

Replace the xfs_defer_ijoin() infrastructure with such detection and
automatic relogging of held inodes. This eliminates the need for the
per-dfops inode list, replaced by an on-stack variant in
xfs_defer_trans_roll().

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 23:05:14 -07:00
Brian Foster 488c919a5b xfs: add missing defer ijoins for held inodes
Log items that require relogging during deferred operations
processing are explicitly joined to the associated dfops via the
xfs_defer_*join() helpers. These calls imply that the associated
object is "held" by the transaction such that when rolled, the item
can be immediately joined to a follow up transaction. For buffers,
this means the buffer remains locked and held after each roll. For
inodes, this means that the inode remains locked.

Failure to join a held item to the dfops structure means the
associated object pins the tail of the log while dfops processing
completes, because the item never relogs and is not unlocked or
released until deferred processing completes.

Currently, all buffers that are held in transactions (XFS_BLI_HOLD)
with deferred operations are explicitly joined to the dfops. This is
not the case for inodes, however, as various contexts defer
operations to transactions with held inodes without explicit joins
to the associated dfops (and thus not relogging).

While this is not a catastrophic problem, it is not ideal. Given
that we want to eventually relog such items automatically during
dfops processing, start by explicitly adding these missing
xfs_defer_ijoin() calls. A call is added everywhere an inode is
joined to a transaction without transferring lock ownership and
said transaction runs deferred operations.

All xfs_defer_ijoin() calls will eventually be replaced by automatic
dfops inode relogging. This patch essentially implements the
behavior change that would otherwise occur due to automatic inode
dfops relogging.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-08-02 23:05:13 -07:00
Christoph Hellwig 51d6269030 xfs: introduce a new xfs_inode_has_cow_data helper
We have a few places that already check if an inode has actual data in
the COW fork to avoid work on reflink inodes that do not actually have
outstanding COW blocks.  There are a few more places that can avoid
working if doing the same check, so add a documented helper for this
condition and use it in all places where it makes sense.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-30 07:57:48 -07:00
Brian Foster 9e28a242be xfs: drop unnecessary xfs_defer_finish() dfops parameter
Every caller of xfs_defer_finish() now passes the transaction and
its associated ->t_dfops. The xfs_defer_ops parameter is therefore
no longer necessary and can be removed.

Since most xfs_defer_finish() callers also have to consider
xfs_defer_cancel() on error, update the latter to also receive the
transaction for consistency. The log recovery code contains an
outlier case that cancels a dfops directly without an available
transaction. Retain an internal wrapper to support this outlier case
for the time being.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26 10:15:16 -07:00
Brian Foster c8eac49ef7 xfs: remove all boilerplate defer init/finish code
At this point, the transaction subsystem completely manages deferred
items internally such that the common and boilerplate
xfs_trans_alloc() -> xfs_defer_init() -> xfs_defer_finish() ->
xfs_trans_commit() sequence can be replaced with a simple
transaction allocation and commit.

Remove all such boilerplate deferred ops code. In doing so, we
change each case over to use the dfops in the transaction and
specifically eliminate:

- The on-stack dfops and associated xfs_defer_init() call, as the
  internal dfops is initialized on transaction allocation.
- xfs_bmap_finish() calls that precede a final xfs_trans_commit() of
  a transaction.
- xfs_defer_cancel() calls in error handlers that precede a
  transaction cancel.

The only deferred ops calls that remain are those that are
non-deterministic with respect to the final commit of the associated
transaction or are open-coded due to special handling.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26 10:15:15 -07:00
Brian Foster 02dff7bf81 xfs: pull up dfops from xfs_itruncate_extents()
xfs_itruncate_extents[_flags]() uses a local dfops with a
transaction provided by the caller. It uses hacky ->t_dfops
replacement logic to avoid stomping over an already populated
->t_dfops.

The latter never occurs for current callers and the logic itself is
not really appropriate. Clean this up by updating all callers to
initialize a dfops and to use that down in xfs_itruncate_extents().
This more closely resembles the upcoming logic where dfops will be
embedded within the transaction. We can also replace the
xfs_defer_init() in the xfs_itruncate_extents_flags() loop with an
assert. Both dfops and firstblock should be in a valid state
after xfs_defer_finish() and the inode joined to the dfops is fixed
throughout the loop.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bill O'Donnell <billodo@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-26 10:15:12 -07:00
Gustavo A. R. Silva 897992b7e3 xfs_bmap_util: use swap macro
Make use of the swap macro and remove some unnecessary variables.
This makes the code easier to read and maintain. Also, reduces the
stack usage.

This code was detected with the help of Coccinelle.

Signed-off-by: Gustavo A. R. Silva <gustavo@embeddedor.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-17 14:25:57 -07:00
Brian Foster 5fdd97944e xfs: remove xfs_defer_init() firstblock param
All but one caller of xfs_defer_init() passes in the ->t_firstblock
of the associated transaction. The one outlier is
xlog_recover_process_intents(), which simply passes a dummy value
because a valid pointer is required. This firstblock variable can
simply be removed.

At this point we could remove the xfs_defer_init() firstblock
parameter and initialize ->t_firstblock directly. Even that is not
necessary, however, because ->t_firstblock is automatically
reinitialized in the new transaction on a transaction roll. Since
xfs_defer_init() should never occur more than once on a particular
transaction (since the corresponding finish will roll it), replace
the reinit from xfs_defer_init() with an assert that verifies the
transaction has a NULLFSBLOCK firstblock.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:33 -07:00
Brian Foster f537538921 xfs: use ->t_firstblock in extent swap
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:32 -07:00
Brian Foster 333f950c89 xfs: remove bmap insert/collapse firstblock param
The only callers pass ->t_firstblock.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:27 -07:00
Brian Foster 2af5284253 xfs: remove xfs_bunmapi() firstblock param
All callers pass ->t_firstblock from the current transaction.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:25 -07:00
Brian Foster a7beabeae2 xfs: remove xfs_bmapi_write() firstblock param
All callers pass ->t_firstblock from the current transaction.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:25 -07:00
Brian Foster d0a9d79572 xfs: use ->t_firstblock in insert/collapse range
Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:24 -07:00
Brian Foster 372837978d xfs: use ->t_firstblock for all xfs_bunmapi() callers
Convert all xfs_bunmapi() callers to ->t_firstblock.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:23 -07:00
Brian Foster 650919f131 xfs: use ->t_firstblock for all xfs_bmapi_write() callers
Convert all xfs_bmapi_write() users to ->t_firstblock.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:23 -07:00
Brian Foster bcd2c9f335 xfs: refactor dfops init to attach to transaction
Most callers of xfs_defer_init() immediately attach the dfops
structure to a transaction. Add a transaction parameter to eliminate
much of this boilerplate code. This also helps self-document the
fact that many codepaths now expect a dfops pointer implicitly via
xfs_trans->t_dfops.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:19 -07:00
Brian Foster 7a7943c7e0 xfs: use ->t_dfops for rmap extent swap operations
xfs_swap_extent_rmap() uses a local dfops instance with a
transaction from the caller. Since there is only one caller, pull
the dfops structure into the caller and attach it to the
transaction. This avoids the need to clear ->t_dfops to prevent
invalid stack memory access.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:17 -07:00
Brian Foster f4a9cf97fa xfs: use ->t_dfops for collapse/insert range operations
Use ->t_dfops for the collapse and insert range transactions. These
are the only callers of the respective bmap helpers, so replace the
unnecessary dfops parameters with direct accesses to ->t_dfops.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:15 -07:00
Brian Foster ccd9d91148 xfs: remove xfs_bunmapi() dfops param
Now that all xfs_bunmapi() callers use ->t_dfops, remove the
unnecessary parameter and access ->t_dfops directly. This patch does
not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:13 -07:00
Brian Foster 4bcfa613a0 xfs: use ->t_dfops for all xfs_bunmapi() callers
Use ->t_dfops for all remaining xfs_bunmapi() callers. This prepares
the latter to no longer require a dfops parameter.

Note that xfs_itruncate_extents_flags() associates a local dfops
with a transaction provided from the caller. Since there are
multiple callers, set and reset ->t_dfops before the function
returns to avoid exposure of stack memory to the caller.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:13 -07:00
Brian Foster 6e702a5dcb xfs: remove xfs_bmapi_write() dfops param
Now that all callers use ->t_dfops, the xfs_bmapi_write() dfops
parameter is no longer necessary. Remove it and access ->t_dfops
directly. This patch does not change behavior.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:12 -07:00
Brian Foster 175d1a013e xfs: use ->t_dfops for all xfs_bmapi_write() callers
Attach ->t_dfops for all remaining callers of xfs_bmapi_write().
This prepares the latter to no longer require a separate dfops
parameter.

Note that xfs_symlink() already uses ->t_dfops. Fix up the local
references for consistency.

Signed-off-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:26:12 -07:00
Christoph Hellwig d438017757 xfs: move locking into xfs_bmap_punch_delalloc_range
Both callers want the same looking, so do it only once.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Brian Foster <bfoster@redhat.com>
Reviewed-by: Darrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
2018-07-11 22:25:57 -07:00