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  1. 03 9月, 2019 1 次提交
  3. 01 7月, 2019 1 次提交
  5. 29 6月, 2019 1 次提交
  7. 26 2月, 2019 2 次提交
  9. 21 2月, 2019 6 次提交
  11. 18 2月, 2019 4 次提交
  13. 12 2月, 2019 2 次提交
    • B
      xfs: use the latest extent at writeback delalloc conversion time · c2b31643
      由 Brian Foster 提交于 
      The writeback delalloc conversion code is racy with respect to
changes in the currently cached file mapping outside of the current
page. This is because the ilock is cycled between the time the
caller originally looked up the mapping and across each real
allocation of the provided file range. This code has collected
various hacks over the years to help combat the symptoms of these
races (i.e., truncate race detection, allocation into hole
detection, etc.), but none address the fundamental problem that the
imap may not be valid at allocation time.

Rather than continue to use race detection hacks, update writeback
delalloc conversion to a model that explicitly converts the delalloc
extent backing the current file offset being processed. The current
file offset is the only block we can trust to remain once the ilock
is dropped because any operation that can remove the block
(truncate, hole punch, etc.) must flush and discard pagecache pages
first.

Modify xfs_iomap_write_allocate() to use the xfs_bmapi_delalloc()
mechanism to request allocation of the entire delalloc extent
backing the current offset instead of assuming the extent passed by
the caller is unchanged. Record the range specified by the caller
and apply it to the resulting allocated extent so previous checks by
the caller for COW fork overlap are not lost. Finally, overload the
bmapi delalloc flag with the range reval flag behavior since this is
the only use case for both.

This ensures that writeback always picks up the correct
and current extent associated with the page, regardless of races
with other extent modifying operations. If operating on a data fork
and the COW overlap state has changed since the ilock was cycled,
the caller revalidates against the COW fork sequence number before
using the imap for the next block.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      c2b31643
    • B
      xfs: validate writeback mapping using data fork seq counter · d9252d52
      由 Brian Foster 提交于 
      The writeback code caches the current extent mapping across multiple
xfs_do_writepage() calls to avoid repeated lookups for sequential
pages backed by the same extent. This is known to be slightly racy
with extent fork changes in certain difficult to reproduce
scenarios. The cached extent is trimmed to within EOF to help avoid
the most common vector for this problem via speculative
preallocation management, but this is a band-aid that does not
address the fundamental problem.

Now that we have an xfs_ifork sequence counter mechanism used to
facilitate COW writeback, we can use the same mechanism to validate
consistency between the data fork and cached writeback mappings. On
its face, this is somewhat of a big hammer approach because any
change to the data fork invalidates any mapping currently cached by
a writeback in progress regardless of whether the data fork change
overlaps with the range under writeback. In practice, however, the
impact of this approach is minimal in most cases.

First, data fork changes (delayed allocations) caused by sustained
sequential buffered writes are amortized across speculative
preallocations. This means that a cached mapping won't be
invalidated by each buffered write of a common file copy workload,
but rather only on less frequent allocation events. Second, the
extent tree is always entirely in-core so an additional lookup of a
usable extent mostly costs a shared ilock cycle and in-memory tree
lookup. This means that a cached mapping reval is relatively cheap
compared to the I/O itself. Third, spurious invalidations don't
impact ioend construction. This means that even if the same extent
is revalidated multiple times across multiple writepage instances,
we still construct and submit the same size ioend (and bio) if the
blocks are physically contiguous.

Update struct xfs_writepage_ctx with a new field to hold the
sequence number of the data fork associated with the currently
cached mapping. Check the wpc seqno against the data fork when the
mapping is validated and reestablish the mapping whenever the fork
has changed since the mapping was cached. This ensures that
writeback always uses a valid extent mapping and thus prevents lost
writebacks and stale delalloc block problems.
Signed-off-by: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NAllison Henderson <allison.henderson@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      d9252d52
  15. 18 10月, 2018 3 次提交
  17. 08 8月, 2018 1 次提交
  19. 03 8月, 2018 2 次提交
    • B
      xfs: automatic dfops inode relogging · a8198666
      由 Brian Foster 提交于 
      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: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      a8198666
    • B
      xfs: add missing defer ijoins for held inodes · 488c919a
      由 Brian Foster 提交于 
      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: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      488c919a
  21. 01 8月, 2018 1 次提交
  23. 27 7月, 2018 1 次提交
    • B
      xfs: remove all boilerplate defer init/finish code · c8eac49e
      由 Brian Foster 提交于 
      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: NBrian Foster <bfoster@redhat.com>
Reviewed-by: NBill O'Donnell <billodo@redhat.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      c8eac49e
  25. 12 7月, 2018 10 次提交
  27. 25 6月, 2018 1 次提交
    • D
      xfs: recheck reflink state after grabbing ILOCK_SHARED for a write · 5bd88d15
      由 Darrick J. Wong 提交于 
      The reflink iflag could have changed since the earlier unlocked check,
so if we got ILOCK_SHARED for a write and but we're now a reflink inode
we have to switch to ILOCK_EXCL and relock.

This helps us avoid blowing lock assertions in things like generic/166:

XFS: Assertion failed: xfs_isilocked(ip, XFS_ILOCK_EXCL), file: fs/xfs/xfs_reflink.c, line: 383
WARNING: CPU: 1 PID: 24707 at fs/xfs/xfs_message.c:104 assfail+0x25/0x30 [xfs]
Modules linked in: deadline_iosched dm_snapshot dm_bufio ext4 mbcache jbd2 dm_flakey xfs libcrc32c dax_pmem device_dax nd_pmem sch_fq_codel af_packet [last unloaded: scsi_debug]
CPU: 1 PID: 24707 Comm: xfs_io Not tainted 4.18.0-rc1-djw #1
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.10.2-1ubuntu1 04/01/2014
RIP: 0010:assfail+0x25/0x30 [xfs]
Code: ff 0f 0b c3 90 66 66 66 66 90 48 89 f1 41 89 d0 48 c7 c6 e8 ef 1b a0 48 89 fa 31 ff e8 54 f9 ff ff 80 3d fd ba 0f 00 00 75 03 <0f> 0b c3 0f 0b 66 0f 1f 44 00 00 66 66 66 66 90 48 63 f6 49 89 f9
RSP: 0018:ffffc90006423ad8 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff880030b65e80 RCX: 0000000000000000
RDX: 00000000ffffffc0 RSI: 000000000000000a RDI: ffffffffa01b0447
RBP: ffffc90006423c10 R08: 0000000000000000 R09: 0000000000000000
R10: ffff88003d43fc30 R11: f000000000000000 R12: ffff880077cda000
R13: 0000000000000000 R14: ffffc90006423c30 R15: ffffc90006423bf9
FS:  00007feba8986800(0000) GS:ffff88003ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 000000000138ab58 CR3: 000000003d40a000 CR4: 00000000000006a0
Call Trace:
 xfs_reflink_allocate_cow+0x24c/0x3d0 [xfs]
 xfs_file_iomap_begin+0x6d2/0xeb0 [xfs]
 ? iomap_to_fiemap+0x80/0x80
 iomap_apply+0x5e/0x130
 iomap_dio_rw+0x2e0/0x400
 ? iomap_to_fiemap+0x80/0x80
 ? xfs_file_dio_aio_write+0x133/0x4a0 [xfs]
 xfs_file_dio_aio_write+0x133/0x4a0 [xfs]
 xfs_file_write_iter+0x7b/0xb0 [xfs]
 __vfs_write+0x16f/0x1f0
 vfs_write+0xc8/0x1c0
 ksys_pwrite64+0x74/0x90
 do_syscall_64+0x56/0x180
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: NChristoph Hellwig <hch@lst.de>
      5bd88d15
  29. 21 6月, 2018 1 次提交
  31. 09 6月, 2018 1 次提交
  33. 07 6月, 2018 1 次提交
    • D
      xfs: convert to SPDX license tags · 0b61f8a4
      由 Dave Chinner 提交于 
      Remove the verbose license text from XFS files and replace them
with SPDX tags. This does not change the license of any of the code,
merely refers to the common, up-to-date license files in LICENSES/

This change was mostly scripted. fs/xfs/Makefile and
fs/xfs/libxfs/xfs_fs.h were modified by hand, the rest were detected
and modified by the following command:

for f in `git grep -l "GNU General" fs/xfs/` ; do
	echo $f
	cat $f | awk -f hdr.awk > $f.new
	mv -f $f.new $f
done

And the hdr.awk script that did the modification (including
detecting the difference between GPL-2.0 and GPL-2.0+ licenses)
is as follows:

$ cat hdr.awk
BEGIN {
	hdr = 1.0
	tag = "GPL-2.0"
	str = ""
}

/^ \* This program is free software/ {
	hdr = 2.0;
	next
}

/any later version./ {
	tag = "GPL-2.0+"
	next
}

/^ \*\// {
	if (hdr > 0.0) {
		print "// SPDX-License-Identifier: " tag
		print str
		print $0
		str=""
		hdr = 0.0
		next
	}
	print $0
	next
}

/^ \* / {
	if (hdr > 1.0)
		next
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
	next
}

/^ \*/ {
	if (hdr > 0.0)
		next
	print $0
	next
}

// {
	if (hdr > 0.0) {
		if (str != "")
			str = str "\n"
		str = str $0
		next
	}
	print $0
}

END { }
$
Signed-off-by: NDave Chinner <dchinner@redhat.com>
Reviewed-by: NDarrick J. Wong <darrick.wong@oracle.com>
Signed-off-by: NDarrick J. Wong <darrick.wong@oracle.com>
      0b61f8a4
  35. 10 5月, 2018 1 次提交