Commit Graph

7560 Commits

Author SHA1 Message Date
Dan Williams
fd63612ae8 xfs: fix SB_BORN check in xfs_dax_notify_failure()
The SB_BORN flag is stored in the vfs superblock, not xfs_sb.

Link: https://lkml.kernel.org/r/166153428094.2758201.7936572520826540019.stgit@dwillia2-xfh.jf.intel.com
Fixes: 6f643c57d5 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 16:22:29 -07:00
Dan Williams
b14d067e85 xfs: quiet notify_failure EOPNOTSUPP cases
Patch series "mm, xfs, dax: Fixes for memory_failure() handling".

I failed to run the memory error injection section of the ndctl test suite
on linux-next prior to the merge window and as a result some bugs were
missed.  While the new enabling targeted reflink enabled XFS filesystems
the bugs cropped up in the surrounding cases of DAX error injection on
ext4-fsdax and device-dax.

One new assumption / clarification in this set is the notion that if a
filesystem's ->notify_failure() handler returns -EOPNOTSUPP, then it must
be the case that the fsdax usage of page->index and page->mapping are
valid.  I am fairly certain this is true for xfs_dax_notify_failure(), but
would appreciate another set of eyes.


This patch (of 4):

XFS always registers dax_holder_operations regardless of whether the
filesystem is capable of handling the notifications.  The expectation is
that if the notify_failure handler cannot run then there are no scenarios
where it needs to run.  In other words the expected semantic is that
page->index and page->mapping are valid for memory_failure() when the
conditions that cause -EOPNOTSUPP in xfs_dax_notify_failure() are present.

A fallback to the generic memory_failure() path is expected so do not warn
when that happens.

Link: https://lkml.kernel.org/r/166153426798.2758201.15108211981034512993.stgit@dwillia2-xfh.jf.intel.com
Link: https://lkml.kernel.org/r/166153427440.2758201.6709480562966161512.stgit@dwillia2-xfh.jf.intel.com
Fixes: 6f643c57d5 ("xfs: implement ->notify_failure() for XFS")
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Cc: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-09-11 16:22:29 -07:00
Linus Torvalds
9872e4a873 New code for 6.0:
- Return error codes from block device flushes to userspace.
  - Fix a deadlock between reclaim and mount time quotacheck.
  - Fix an unnecessary ENOSPC return when doing COW on a filesystem with
    severe free space fragmentation.
  - Fix a miscalculation in the transaction reservation computations for
    file removal operations.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-5.20-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull more xfs updates from Darrick Wong:
 "There's not a lot this time around, just the usual bug fixes and
  corrections for missing error returns.

   - Return error codes from block device flushes to userspace

   - Fix a deadlock between reclaim and mount time quotacheck

   - Fix an unnecessary ENOSPC return when doing COW on a filesystem
     with severe free space fragmentation

   - Fix a miscalculation in the transaction reservation computations
     for file removal operations"

* tag 'xfs-5.20-merge-8' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: fix inode reservation space for removing transaction
  xfs: Fix false ENOSPC when performing direct write on a delalloc extent in cow fork
  xfs: fix intermittent hang during quotacheck
  xfs: check return codes when flushing block devices
2022-08-13 13:50:11 -07:00
hexiaole
031d166f96 xfs: fix inode reservation space for removing transaction
In 'fs/xfs/libxfs/xfs_trans_resv.c', the comment for transaction of removing a
directory entry writes:

/* fs/xfs/libxfs/xfs_trans_resv.c begin */
/*
 * For removing a directory entry we can modify:
 *    the parent directory inode: inode size
 *    the removed inode: inode size
...
xfs_calc_remove_reservation(
        struct xfs_mount        *mp)
{
        return XFS_DQUOT_LOGRES(mp) +
                xfs_calc_iunlink_add_reservation(mp) +
                max((xfs_calc_inode_res(mp, 1) +
...
/* fs/xfs/libxfs/xfs_trans_resv.c end */

There has 2 inode size of space to be reserverd, but the actual code
for inode reservation space writes.

There only count for 1 inode size to be reserved in
'xfs_calc_inode_res(mp, 1)', rather than 2.

Signed-off-by: hexiaole <hexiaole@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: remove redundant code citations]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-08-10 17:43:49 -07:00
Chandan Babu R
d62113303d xfs: Fix false ENOSPC when performing direct write on a delalloc extent in cow fork
On a higly fragmented filesystem a Direct IO write can fail with -ENOSPC error
even though the filesystem has sufficient number of free blocks.

This occurs if the file offset range on which the write operation is being
performed has a delalloc extent in the cow fork and this delalloc extent
begins much before the Direct IO range.

In such a scenario, xfs_reflink_allocate_cow() invokes xfs_bmapi_write() to
allocate the blocks mapped by the delalloc extent. The extent thus allocated
may not cover the beginning of file offset range on which the Direct IO write
was issued. Hence xfs_reflink_allocate_cow() ends up returning -ENOSPC.

The following script reliably recreates the bug described above.

  #!/usr/bin/bash

  device=/dev/loop0
  shortdev=$(basename $device)

  mntpnt=/mnt/
  file1=${mntpnt}/file1
  file2=${mntpnt}/file2
  fragmentedfile=${mntpnt}/fragmentedfile
  punchprog=/root/repos/xfstests-dev/src/punch-alternating

  errortag=/sys/fs/xfs/${shortdev}/errortag/bmap_alloc_minlen_extent

  umount $device > /dev/null 2>&1

  echo "Create FS"
  mkfs.xfs -f -m reflink=1 $device > /dev/null 2>&1
  if [[ $? != 0 ]]; then
  	echo "mkfs failed."
  	exit 1
  fi

  echo "Mount FS"
  mount $device $mntpnt > /dev/null 2>&1
  if [[ $? != 0 ]]; then
  	echo "mount failed."
  	exit 1
  fi

  echo "Create source file"
  xfs_io -f -c "pwrite 0 32M" $file1 > /dev/null 2>&1

  sync

  echo "Create Reflinked file"
  xfs_io -f -c "reflink $file1" $file2 &>/dev/null

  echo "Set cowextsize"
  xfs_io -c "cowextsize 16M" $file1 > /dev/null 2>&1

  echo "Fragment FS"
  xfs_io -f -c "pwrite 0 64M" $fragmentedfile > /dev/null 2>&1
  sync
  $punchprog $fragmentedfile

  echo "Allocate block sized extent from now onwards"
  echo -n 1 > $errortag

  echo "Create 16MiB delalloc extent in CoW fork"
  xfs_io -c "pwrite 0 4k" $file1 > /dev/null 2>&1

  sync

  echo "Direct I/O write at offset 12k"
  xfs_io -d -c "pwrite 12k 8k" $file1

This commit fixes the bug by invoking xfs_bmapi_write() in a loop until disk
blocks are allocated for atleast the starting file offset of the Direct IO
write range.

Fixes: 3c68d44a2b ("xfs: allocate direct I/O COW blocks in iomap_begin")
Reported-and-Root-caused-by: Wengang Wang <wen.gang.wang@oracle.com>
Signed-off-by: Chandan Babu R <chandan.babu@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: slight editing to make the locking less grody, and fix some style things]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-08-05 17:00:36 -07:00
Darrick J. Wong
f0c2d7d2ab xfs: fix intermittent hang during quotacheck
Every now and then, I see the following hang during mount time
quotacheck when running fstests.  Turning on KASAN seems to make it
happen somewhat more frequently.  I've edited the backtrace for brevity.

XFS (sdd): Quotacheck needed: Please wait.
XFS: Assertion failed: bp->b_flags & _XBF_DELWRI_Q, file: fs/xfs/xfs_buf.c, line: 2411
------------[ cut here ]------------
WARNING: CPU: 0 PID: 1831409 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 0 PID: 1831409 Comm: mount Tainted: G        W         5.19.0-rc6-xfsx #rc6 09911566947b9f737b036b4af85e399e4b9aef64
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Code: a0 8f 41 a0 e8 45 fe ff ff 8a 1d 2c 36 10 00 80 fb 01 76 0f 0f b6 f3 48 c7 c7 c0 f0 4f a0 e8 10 f0 02 e1 80 e3 01 74 02 0f 0b <0f> 0b 5b c3 48 8d 45 10 48 89 e2 4c 89 e6 48 89 1c 24 48 89 44 24
RSP: 0018:ffffc900078c7b30 EFLAGS: 00010246
RAX: 0000000000000000 RBX: ffff8880099ac000 RCX: 000000007fffffff
RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffffffffa0418fa0
RBP: ffff8880197bc1c0 R08: 0000000000000000 R09: 000000000000000a
R10: 000000000000000a R11: f000000000000000 R12: ffffc900078c7d20
R13: 00000000fffffff5 R14: ffffc900078c7d20 R15: 0000000000000000
FS:  00007f0449903800(0000) GS:ffff88803ec00000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00005610ada631f0 CR3: 0000000014dd8002 CR4: 00000000001706f0
Call Trace:
 <TASK>
 xfs_buf_delwri_pushbuf+0x150/0x160 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_qm_flush_one+0xd6/0x130 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_qm_dquot_walk.isra.0+0x109/0x1e0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_qm_quotacheck+0x319/0x490 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_qm_mount_quotas+0x65/0x2c0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_mountfs+0x6b5/0xab0 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 xfs_fs_fill_super+0x781/0x990 [xfs 4561f5b32c9bfb874ec98d58d0719464e1f87368]
 get_tree_bdev+0x175/0x280
 vfs_get_tree+0x1a/0x80
 path_mount+0x6f5/0xaa0
 __x64_sys_mount+0x103/0x140
 do_syscall_64+0x2b/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

I /think/ this can happen if xfs_qm_flush_one is racing with
xfs_qm_dquot_isolate (i.e. dquot reclaim) when the second function has
taken the dquot flush lock but xfs_qm_dqflush hasn't yet locked the
dquot buffer, let alone queued it to the delwri list.  In this case,
flush_one will fail to get the dquot flush lock, but it can lock the
incore buffer, but xfs_buf_delwri_pushbuf will then trip over this
ASSERT, which checks that the buffer isn't on a delwri list.  The hang
results because the _delwri_submit_buffers ignores non DELWRI_Q buffers,
which means that xfs_buf_iowait waits forever for an IO that has not yet
been scheduled.

AFAICT, a reasonable solution here is to detect a dquot buffer that is
not on a DELWRI list, drop it, and return -EAGAIN to try the flush
again.  It's not /that/ big of a deal if quotacheck writes the dquot
buffer repeatedly before we even set QUOTA_CHKD.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-08-05 17:00:36 -07:00
Darrick J. Wong
7d839e325a xfs: check return codes when flushing block devices
If a blkdev_issue_flush fails, fsync needs to report that to upper
levels.  Modify xfs_file_fsync to capture the errors, while trying to
flush as much data and log updates to disk as possible.

If log writes cannot flush the data device, we need to shut down the log
immediately because we've violated a log invariant.  Modify this code to
check the return value of blkdev_issue_flush as well.

This behavior seems to go back to about 2.6.15 or so, which makes this
fixes tag a bit misleading.

Link: https://elixir.bootlin.com/linux/v2.6.15/source/fs/xfs/xfs_vnodeops.c#L1187
Fixes: b5071ada51 ("xfs: remove xfs_blkdev_issue_flush")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-08-05 17:00:36 -07:00
Linus Torvalds
6614a3c316 - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
Lin, Yang Shi, Anshuman Khandual and Mike Rapoport
 
 - Some kmemleak fixes from Patrick Wang and Waiman Long
 
 - DAMON updates from SeongJae Park
 
 - memcg debug/visibility work from Roman Gushchin
 
 - vmalloc speedup from Uladzislau Rezki
 
 - more folio conversion work from Matthew Wilcox
 
 - enhancements for coherent device memory mapping from Alex Sierra
 
 - addition of shared pages tracking and CoW support for fsdax, from
   Shiyang Ruan
 
 - hugetlb optimizations from Mike Kravetz
 
 - Mel Gorman has contributed some pagealloc changes to improve latency
   and realtime behaviour.
 
 - mprotect soft-dirty checking has been improved by Peter Xu
 
 - Many other singleton patches all over the place
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Merge tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm

Pull MM updates from Andrew Morton:
 "Most of the MM queue. A few things are still pending.

  Liam's maple tree rework didn't make it. This has resulted in a few
  other minor patch series being held over for next time.

  Multi-gen LRU still isn't merged as we were waiting for mapletree to
  stabilize. The current plan is to merge MGLRU into -mm soon and to
  later reintroduce mapletree, with a view to hopefully getting both
  into 6.1-rc1.

  Summary:

   - The usual batches of cleanups from Baoquan He, Muchun Song, Miaohe
     Lin, Yang Shi, Anshuman Khandual and Mike Rapoport

   - Some kmemleak fixes from Patrick Wang and Waiman Long

   - DAMON updates from SeongJae Park

   - memcg debug/visibility work from Roman Gushchin

   - vmalloc speedup from Uladzislau Rezki

   - more folio conversion work from Matthew Wilcox

   - enhancements for coherent device memory mapping from Alex Sierra

   - addition of shared pages tracking and CoW support for fsdax, from
     Shiyang Ruan

   - hugetlb optimizations from Mike Kravetz

   - Mel Gorman has contributed some pagealloc changes to improve
     latency and realtime behaviour.

   - mprotect soft-dirty checking has been improved by Peter Xu

   - Many other singleton patches all over the place"

 [ XFS merge from hell as per Darrick Wong in

   https://lore.kernel.org/all/YshKnxb4VwXycPO8@magnolia/ ]

* tag 'mm-stable-2022-08-03' of git://git.kernel.org/pub/scm/linux/kernel/git/akpm/mm: (282 commits)
  tools/testing/selftests/vm/hmm-tests.c: fix build
  mm: Kconfig: fix typo
  mm: memory-failure: convert to pr_fmt()
  mm: use is_zone_movable_page() helper
  hugetlbfs: fix inaccurate comment in hugetlbfs_statfs()
  hugetlbfs: cleanup some comments in inode.c
  hugetlbfs: remove unneeded header file
  hugetlbfs: remove unneeded hugetlbfs_ops forward declaration
  hugetlbfs: use helper macro SZ_1{K,M}
  mm: cleanup is_highmem()
  mm/hmm: add a test for cross device private faults
  selftests: add soft-dirty into run_vmtests.sh
  selftests: soft-dirty: add test for mprotect
  mm/mprotect: fix soft-dirty check in can_change_pte_writable()
  mm: memcontrol: fix potential oom_lock recursion deadlock
  mm/gup.c: fix formatting in check_and_migrate_movable_page()
  xfs: fail dax mount if reflink is enabled on a partition
  mm/memcontrol.c: remove the redundant updating of stats_flush_threshold
  userfaultfd: don't fail on unrecognized features
  hugetlb_cgroup: fix wrong hugetlb cgroup numa stat
  ...
2022-08-05 16:32:45 -07:00
Linus Torvalds
b2a88c212e New code for 5.20:
- Improve scalability of the XFS log by removing spinlocks and global
   synchronization points.
 - Add security labels to whiteout inodes to match the other filesystems.
 - Clean up per-ag pointer passing to simplify call sites.
 - Reduce verifier overhead by precalculating more AG geometry.
 - Implement fast-path lockless lookups in the buffer cache to reduce
   spinlock hammering.
 - Make attr forks a permanent part of the inode structure to fix a UAF
   bug and because most files these days tend to have security labels and
   soon will have parent pointers too.
 - Clean up XFS_IFORK_Q usage and give it a better name.
 - Fix more UAF bugs in the xattr code.
 - SOB my tags.
 - Fix some typos in the timestamp range documentation.
 - Fix a few more memory leaks.
 - Code cleanups and typo fixes.
 - Fix an unlocked inode fork pointer access in getbmap.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

Pull xfs updates from Darrick Wong:
 "The biggest changes for this release are the log scalability
  improvements, lockless lookups for the buffer cache, and making the
  attr fork a permanent part of the incore inode in preparation for
  directory parent pointers.

  There's also a bunch of bug fixes that have accumulated since -rc5. I
  might send you a second pull request with some more bug fixes that I'm
  still working on.

  Once the merge window ends, I will hand maintainership back to Dave
  Chinner until the 6.1-rc1 release so that I can conduct the design
  review for the online fsck feature, and try to get it merged.

  Summary:

   - Improve scalability of the XFS log by removing spinlocks and global
     synchronization points.

   - Add security labels to whiteout inodes to match the other
     filesystems.

   - Clean up per-ag pointer passing to simplify call sites.

   - Reduce verifier overhead by precalculating more AG geometry.

   - Implement fast-path lockless lookups in the buffer cache to reduce
     spinlock hammering.

   - Make attr forks a permanent part of the inode structure to fix a
     UAF bug and because most files these days tend to have security
     labels and soon will have parent pointers too.

   - Clean up XFS_IFORK_Q usage and give it a better name.

   - Fix more UAF bugs in the xattr code.

   - SOB my tags.

   - Fix some typos in the timestamp range documentation.

   - Fix a few more memory leaks.

   - Code cleanups and typo fixes.

   - Fix an unlocked inode fork pointer access in getbmap"

* tag 'xfs-5.20-merge-6' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (61 commits)
  xfs: delete extra space and tab in blank line
  xfs: fix NULL pointer dereference in xfs_getbmap()
  xfs: Fix typo 'the the' in comment
  xfs: Fix comment typo
  xfs: don't leak memory when attr fork loading fails
  xfs: fix for variable set but not used warning
  xfs: xfs_buf cache destroy isn't RCU safe
  xfs: delete unnecessary NULL checks
  xfs: fix comment for start time value of inode with bigtime enabled
  xfs: fix use-after-free in xattr node block inactivation
  xfs: lockless buffer lookup
  xfs: remove a superflous hash lookup when inserting new buffers
  xfs: reduce the number of atomic when locking a buffer after lookup
  xfs: merge xfs_buf_find() and xfs_buf_get_map()
  xfs: break up xfs_buf_find() into individual pieces
  xfs: add in-memory iunlink log item
  xfs: add log item precommit operation
  xfs: combine iunlink inode update functions
  xfs: clean up xfs_iunlink_update_inode()
  xfs: double link the unlinked inode list
  ...
2022-08-04 20:19:16 -07:00
Linus Torvalds
f00654007f Folio changes for 6.0
- Fix an accounting bug that made NR_FILE_DIRTY grow without limit
    when running xfstests
 
  - Convert more of mpage to use folios
 
  - Remove add_to_page_cache() and add_to_page_cache_locked()
 
  - Convert find_get_pages_range() to filemap_get_folios()
 
  - Improvements to the read_cache_page() family of functions
 
  - Remove a few unnecessary checks of PageError
 
  - Some straightforward filesystem conversions to use folios
 
  - Split PageMovable users out from address_space_operations into their
    own movable_operations
 
  - Convert aops->migratepage to aops->migrate_folio
 
  - Remove nobh support (Christoph Hellwig)
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Merge tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache

Pull folio updates from Matthew Wilcox:

 - Fix an accounting bug that made NR_FILE_DIRTY grow without limit
   when running xfstests

 - Convert more of mpage to use folios

 - Remove add_to_page_cache() and add_to_page_cache_locked()

 - Convert find_get_pages_range() to filemap_get_folios()

 - Improvements to the read_cache_page() family of functions

 - Remove a few unnecessary checks of PageError

 - Some straightforward filesystem conversions to use folios

 - Split PageMovable users out from address_space_operations into
   their own movable_operations

 - Convert aops->migratepage to aops->migrate_folio

 - Remove nobh support (Christoph Hellwig)

* tag 'folio-6.0' of git://git.infradead.org/users/willy/pagecache: (78 commits)
  fs: remove the NULL get_block case in mpage_writepages
  fs: don't call ->writepage from __mpage_writepage
  fs: remove the nobh helpers
  jfs: stop using the nobh helper
  ext2: remove nobh support
  ntfs3: refactor ntfs_writepages
  mm/folio-compat: Remove migration compatibility functions
  fs: Remove aops->migratepage()
  secretmem: Convert to migrate_folio
  hugetlb: Convert to migrate_folio
  aio: Convert to migrate_folio
  f2fs: Convert to filemap_migrate_folio()
  ubifs: Convert to filemap_migrate_folio()
  btrfs: Convert btrfs_migratepage to migrate_folio
  mm/migrate: Add filemap_migrate_folio()
  mm/migrate: Convert migrate_page() to migrate_folio()
  nfs: Convert to migrate_folio
  btrfs: Convert btree_migratepage to migrate_folio
  mm/migrate: Convert expected_page_refs() to folio_expected_refs()
  mm/migrate: Convert buffer_migrate_page() to buffer_migrate_folio()
  ...
2022-08-03 10:35:43 -07:00
Linus Torvalds
c013d0af81 for-5.20/block-2022-07-29
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Merge tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block

Pull block updates from Jens Axboe:

 - Improve the type checking of request flags (Bart)

 - Ensure queue mapping for a single queues always picks the right queue
   (Bart)

 - Sanitize the io priority handling (Jan)

 - rq-qos race fix (Jinke)

 - Reserved tags handling improvements (John)

 - Separate memory alignment from file/disk offset aligment for O_DIRECT
   (Keith)

 - Add new ublk driver, userspace block driver using io_uring for
   communication with the userspace backend (Ming)

 - Use try_cmpxchg() to cleanup the code in various spots (Uros)

 - Finally remove bdevname() (Christoph)

 - Clean up the zoned device handling (Christoph)

 - Clean up independent access range support (Christoph)

 - Clean up and improve block sysfs handling (Christoph)

 - Clean up and improve teardown of block devices.

   This turns the usual two step process into something that is simpler
   to implement and handle in block drivers (Christoph)

 - Clean up chunk size handling (Christoph)

 - Misc cleanups and fixes (Bart, Bo, Dan, GuoYong, Jason, Keith, Liu,
   Ming, Sebastian, Yang, Ying)

* tag 'for-5.20/block-2022-07-29' of git://git.kernel.dk/linux-block: (178 commits)
  ublk_drv: fix double shift bug
  ublk_drv: make sure that correct flags(features) returned to userspace
  ublk_drv: fix error handling of ublk_add_dev
  ublk_drv: fix lockdep warning
  block: remove __blk_get_queue
  block: call blk_mq_exit_queue from disk_release for never added disks
  blk-mq: fix error handling in __blk_mq_alloc_disk
  ublk: defer disk allocation
  ublk: rewrite ublk_ctrl_get_queue_affinity to not rely on hctx->cpumask
  ublk: fold __ublk_create_dev into ublk_ctrl_add_dev
  ublk: cleanup ublk_ctrl_uring_cmd
  ublk: simplify ublk_ch_open and ublk_ch_release
  ublk: remove the empty open and release block device operations
  ublk: remove UBLK_IO_F_PREFLUSH
  ublk: add a MAINTAINERS entry
  block: don't allow the same type rq_qos add more than once
  mmc: fix disk/queue leak in case of adding disk failure
  ublk_drv: fix an IS_ERR() vs NULL check
  ublk: remove UBLK_IO_F_INTEGRITY
  ublk_drv: remove unneeded semicolon
  ...
2022-08-02 13:46:35 -07:00
Linus Torvalds
98e2474640 for-5.20/io_uring-buffered-writes-2022-07-29
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Merge tag 'for-5.20/io_uring-buffered-writes-2022-07-29' of git://git.kernel.dk/linux-block

Pull io_uring buffered writes support from Jens Axboe:
 "This contains support for buffered writes, specifically for XFS. btrfs
  is in progress, will be coming in the next release.

  io_uring does support buffered writes on any file type, but since the
  buffered write path just always -EAGAIN (or -EOPNOTSUPP) any attempt
  to do so if IOCB_NOWAIT is set, any buffered write will effectively be
  handled by io-wq offload. This isn't very efficient, and we even have
  specific code in io-wq to serialize buffered writes to the same inode
  to avoid further inefficiencies with thread offload.

  This is particularly sad since most buffered writes don't block, they
  simply copy data to a page and dirty it. With this pull request, we
  can handle buffered writes a lot more effiently.

  If balance_dirty_pages() needs to block, we back off on writes as
  indicated.

  This improves buffered write support by 2-3x.

  Jan Kara helped with the mm bits for this, and Stefan handled the
  fs/iomap/xfs/io_uring parts of it"

* tag 'for-5.20/io_uring-buffered-writes-2022-07-29' of git://git.kernel.dk/linux-block:
  mm: honor FGP_NOWAIT for page cache page allocation
  xfs: Add async buffered write support
  xfs: Specify lockmode when calling xfs_ilock_for_iomap()
  io_uring: Add tracepoint for short writes
  io_uring: fix issue with io_write() not always undoing sb_start_write()
  io_uring: Add support for async buffered writes
  fs: Add async write file modification handling.
  fs: Split off inode_needs_update_time and __file_update_time
  fs: add __remove_file_privs() with flags parameter
  fs: add a FMODE_BUF_WASYNC flags for f_mode
  iomap: Return -EAGAIN from iomap_write_iter()
  iomap: Add async buffered write support
  iomap: Add flags parameter to iomap_page_create()
  mm: Add balance_dirty_pages_ratelimited_flags() function
  mm: Move updates of dirty_exceeded into one place
  mm: Move starting of background writeback into the main balancing loop
2022-08-02 13:27:23 -07:00
Matthew Wilcox (Oracle)
2ec810d596 mm/migrate: Add filemap_migrate_folio()
There is nothing iomap-specific about iomap_migratepage(), and it fits
a pattern used by several other filesystems, so move it to mm/migrate.c,
convert it to be filemap_migrate_folio() and convert the iomap filesystems
to use it.

Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-08-02 12:34:04 -04:00
Linus Torvalds
bdfae5ce38 fs.idmapped.vfsuid.v5.20
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Merge tag 'fs.idmapped.vfsuid.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux

Pull fs idmapping updates from Christian Brauner:
 "This introduces the new vfs{g,u}id_t types we agreed on. Similar to
  k{g,u}id_t the new types are just simple wrapper structs around
  regular {g,u}id_t types.

  They allow to establish a type safety boundary in the VFS for idmapped
  mounts preventing confusion betwen {g,u}ids mapped into an idmapped
  mount and {g,u}ids mapped into the caller's or the filesystem's
  idmapping.

  An initial set of helpers is introduced that allows to operate on
  vfs{g,u}id_t types. We will remove all references to non-type safe
  idmapped mounts helpers in the very near future. The patches do
  already exist.

  This converts the core attribute changing codepaths which become
  significantly easier to reason about because of this change.

  Just a few highlights here as the patches give detailed overviews of
  what is happening in the commit messages:

   - The kernel internal struct iattr contains type safe vfs{g,u}id_t
     values clearly communicating that these values have to take a given
     mount's idmapping into account.

   - The ownership values placed in struct iattr to change ownership are
     identical for idmapped and non-idmapped mounts going forward. This
     also allows to simplify stacking filesystems such as overlayfs that
     change attributes In other words, they always represent the values.

   - Instead of open coding checks for whether ownership changes have
     been requested and an actual update of the inode is required we now
     have small static inline wrappers that abstract this logic away
     removing a lot of code duplication from individual filesystems that
     all open-coded the same checks"

* tag 'fs.idmapped.vfsuid.v5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/brauner/linux:
  mnt_idmapping: align kernel doc and parameter order
  mnt_idmapping: use new helpers in mapped_fs{g,u}id()
  fs: port HAS_UNMAPPED_ID() to vfs{g,u}id_t
  mnt_idmapping: return false when comparing two invalid ids
  attr: fix kernel doc
  attr: port attribute changes to new types
  security: pass down mount idmapping to setattr hook
  quota: port quota helpers mount ids
  fs: port to iattr ownership update helpers
  fs: introduce tiny iattr ownership update helpers
  fs: use mount types in iattr
  fs: add two type safe mapping helpers
  mnt_idmapping: add vfs{g,u}id_t
2022-08-01 08:56:55 -07:00
Xie Shaowen
5e9466a5d0 xfs: delete extra space and tab in blank line
delete extra space and tab in blank line, there is no functional change.

Reported-by: Hacash Robot <hacashRobot@santino.com>
Signed-off-by: Xie Shaowen <studentxswpy@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-31 09:21:27 -07:00
ChenXiaoSong
001c179c4e xfs: fix NULL pointer dereference in xfs_getbmap()
Reproducer:
 1. fallocate -l 100M image
 2. mkfs.xfs -f image
 3. mount image /mnt
 4. setxattr("/mnt", "trusted.overlay.upper", NULL, 0, XATTR_CREATE)
 5. char arg[32] = "\x01\xff\x00\x00\x00\x00\x03\x00\x00\x00\x00\x00\x00"
                   "\x00\x00\x00\x00\x00\x08\x00\x00\x00\xc6\x2a\xf7";
    fd = open("/mnt", O_RDONLY|O_DIRECTORY);
    ioctl(fd, _IOC(_IOC_READ|_IOC_WRITE, 0x58, 0x2c, 0x20), arg);

NULL pointer dereference will occur when race happens between xfs_getbmap()
and xfs_bmap_set_attrforkoff():

         ioctl               |       setxattr
 ----------------------------|---------------------------
 xfs_getbmap                 |
   xfs_ifork_ptr             |
     xfs_inode_has_attr_fork |
       ip->i_forkoff == 0    |
     return NULL             |
   ifp == NULL               |
                             | xfs_bmap_set_attrforkoff
                             |   ip->i_forkoff > 0
   xfs_inode_has_attr_fork   |
     ip->i_forkoff > 0       |
   ifp == NULL               |
   ifp->if_format            |

Fix this by locking i_lock before xfs_ifork_ptr().

Fixes: abbf9e8a45 ("xfs: rewrite getbmap using the xfs_iext_* helpers")
Signed-off-by: ChenXiaoSong <chenxiaosong2@huawei.com>
Signed-off-by: Guo Xuenan <guoxuenan@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
[djwong: added fixes tag]
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-31 09:21:27 -07:00
Shiyang Ruan
35fcd75af3 xfs: fail dax mount if reflink is enabled on a partition
Failure notification is not supported on partitions.  So, when we mount a
reflink enabled xfs on a partition with dax option, let it fail with
-EINVAL code.

Link: https://lkml.kernel.org/r/20220609143435.393724-1-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-29 18:07:17 -07:00
Stefan Roesch
1aa91d9c99 xfs: Add async buffered write support
This adds the async buffered write support to XFS. For async buffered
write requests, the request will return -EAGAIN if the ilock cannot be
obtained immediately.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-15-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:32 -06:00
Stefan Roesch
9641506b2d xfs: Specify lockmode when calling xfs_ilock_for_iomap()
This patch changes the helper function xfs_ilock_for_iomap such that the
lock mode must be passed in.

Signed-off-by: Stefan Roesch <shr@fb.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Link: https://lore.kernel.org/r/20220623175157.1715274-14-shr@fb.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-24 18:39:32 -06:00
Slark Xiao
4869b6e84a xfs: Fix typo 'the the' in comment
Replace 'the the' with 'the' in the comment.

Signed-off-by: Slark Xiao <slark_xiao@163.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-22 10:58:39 -07:00
Xin Gao
29d286d0ce xfs: Fix comment typo
The double `the' is duplicated in line 552, remove one.

Signed-off-by: Xin Gao <gaoxin@cdjrlc.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-22 10:58:39 -07:00
Darrick J. Wong
c78c2d0903 xfs: don't leak memory when attr fork loading fails
I observed the following evidence of a memory leak while running xfs/399
from the xfs fsck test suite (edited for brevity):

XFS (sde): Metadata corruption detected at xfs_attr_shortform_verify_struct.part.0+0x7b/0xb0 [xfs], inode 0x1172 attr fork
XFS: Assertion failed: ip->i_af.if_u1.if_data == NULL, file: fs/xfs/libxfs/xfs_inode_fork.c, line: 315
------------[ cut here ]------------
WARNING: CPU: 2 PID: 91635 at fs/xfs/xfs_message.c:104 assfail+0x46/0x4a [xfs]
CPU: 2 PID: 91635 Comm: xfs_scrub Tainted: G        W         5.19.0-rc7-xfsx #rc7 6e6475eb29fd9dda3181f81b7ca7ff961d277a40
Hardware name: QEMU Standard PC (Q35 + ICH9, 2009), BIOS 1.15.0-1 04/01/2014
RIP: 0010:assfail+0x46/0x4a [xfs]
Call Trace:
 <TASK>
 xfs_ifork_zap_attr+0x7c/0xb0
 xfs_iformat_attr_fork+0x86/0x110
 xfs_inode_from_disk+0x41d/0x480
 xfs_iget+0x389/0xd70
 xfs_bulkstat_one_int+0x5b/0x540
 xfs_bulkstat_iwalk+0x1e/0x30
 xfs_iwalk_ag_recs+0xd1/0x160
 xfs_iwalk_run_callbacks+0xb9/0x180
 xfs_iwalk_ag+0x1d8/0x2e0
 xfs_iwalk+0x141/0x220
 xfs_bulkstat+0x105/0x180
 xfs_ioc_bulkstat.constprop.0.isra.0+0xc5/0x130
 xfs_file_ioctl+0xa5f/0xef0
 __x64_sys_ioctl+0x82/0xa0
 do_syscall_64+0x2b/0x80
 entry_SYSCALL_64_after_hwframe+0x46/0xb0

This newly-added assertion checks that there aren't any incore data
structures hanging off the incore fork when we're trying to reset its
contents.  From the call trace, it is evident that iget was trying to
construct an incore inode from the ondisk inode, but the attr fork
verifier failed and we were trying to undo all the memory allocations
that we had done earlier.

The three assertions in xfs_ifork_zap_attr check that the caller has
already called xfs_idestroy_fork, which clearly has not been done here.
As the zap function then zeroes the pointers, we've effectively leaked
the memory.

The shortest change would have been to insert an extra call to
xfs_idestroy_fork, but it makes more sense to bundle the _idestroy_fork
call into _zap_attr, since all other callsites call _idestroy_fork
immediately prior to calling _zap_attr.  IOWs, it eliminates one way to
fail.

Note: This change only applies cleanly to 2ed5b09b3e, since we just
reworked the attr fork lifetime.  However, I think this memory leak has
existed since 0f45a1b20c, since the chain xfs_iformat_attr_fork ->
xfs_iformat_local -> xfs_init_local_fork will allocate
ifp->if_u1.if_data, but if xfs_ifork_verify_local_attr fails,
xfs_iformat_attr_fork will free i_afp without freeing any of the stuff
hanging off i_afp.  The solution for older kernels I think is to add the
missing call to xfs_idestroy_fork just prior to calling kmem_cache_free.

Found by fuzzing a.sfattr.hdr.totsize = lastbit in xfs/399.

Fixes: 2ed5b09b3e ("xfs: make inode attribute forks a permanent part of struct xfs_inode")
Probably-Fixes: 0f45a1b20c ("xfs: improve local fork verification")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
2022-07-20 16:40:39 -07:00
sunliming
1a53d3d426 xfs: fix for variable set but not used warning
Fix below kernel warning:

fs/xfs/scrub/repair.c:539:19: warning: variable 'agno' set but not used [-Wunused-but-set-variable]

Reported-by: kernel test robot <lkp@intel.com>
Signed-off-by: sunliming <sunliming@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-20 16:40:39 -07:00
Dave Chinner
231f91ab50 xfs: xfs_buf cache destroy isn't RCU safe
Darrick and Sachin Sant reported that xfs/435 and xfs/436 would
report an non-empty xfs_buf slab on module remove. This isn't easily
to reproduce, but is clearly a side effect of converting the buffer
caceh to RUC freeing and lockless lookups. Sachin bisected and
Darrick hit it when testing the patchset directly.

Turns out that the xfs_buf slab is not destroyed when all the other
XFS slab caches are destroyed. Instead, it's got it's own little
wrapper function that gets called separately, and so it doesn't have
an rcu_barrier() call in it that is needed to drain all the rcu
callbacks before the slab is destroyed.

Fix it by removing the xfs_buf_init/terminate wrappers that just
allocate and destroy the xfs_buf slab, and move them to the same
place that all the other slab caches are set up and destroyed.

Reported-and-tested-by: Sachin Sant <sachinp@linux.ibm.com>
Fixes: 298f342245 ("xfs: lockless buffer lookup")
Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-20 16:40:39 -07:00
Dan Carpenter
3f52e016af xfs: delete unnecessary NULL checks
These NULL check are no long needed after commit 2ed5b09b3e ("xfs:
make inode attribute forks a permanent part of struct xfs_inode").

Signed-off-by: Dan Carpenter <dan.carpenter@oracle.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-20 16:40:38 -07:00
Xiaole He
fdbae121b4 xfs: fix comment for start time value of inode with bigtime enabled
The 'ctime', 'mtime', and 'atime' for inode is the type of
'xfs_timestamp_t', which is a 64-bit type:

/* fs/xfs/libxfs/xfs_format.h begin */
typedef __be64 xfs_timestamp_t;
/* fs/xfs/libxfs/xfs_format.h end */

When the 'bigtime' feature is disabled, this 64-bit type is splitted
into two parts of 32-bit, one part is encoded for seconds since
1970-01-01 00:00:00 UTC, the other part is encoded for nanoseconds
above the seconds, this two parts are the type of
'xfs_legacy_timestamp' and the min and max time value of this type are
defined as macros 'XFS_LEGACY_TIME_MIN' and 'XFS_LEGACY_TIME_MAX':

/* fs/xfs/libxfs/xfs_format.h begin */
struct xfs_legacy_timestamp {
        __be32          t_sec;          /* timestamp seconds */
        __be32          t_nsec;         /* timestamp nanoseconds */
};
 #define XFS_LEGACY_TIME_MIN     ((int64_t)S32_MIN)
 #define XFS_LEGACY_TIME_MAX     ((int64_t)S32_MAX)
/* fs/xfs/libxfs/xfs_format.h end */
/* include/linux/limits.h begin */
 #define U32_MAX         ((u32)~0U)
 #define S32_MAX         ((s32)(U32_MAX >> 1))
 #define S32_MIN         ((s32)(-S32_MAX - 1))
/* include/linux/limits.h end */

'XFS_LEGACY_TIME_MIN' is the min time value of the
'xfs_legacy_timestamp', that is -(2^31) seconds relative to the
1970-01-01 00:00:00 UTC, it can be converted to human-friendly time
value by 'date' command:

/* command begin */
[root@~]# date --utc -d '@0' +'%Y-%m-%d %H:%M:%S'
1970-01-01 00:00:00
[root@~]# date --utc -d "@`echo '-(2^31)'|bc`" +'%Y-%m-%d %H:%M:%S'
1901-12-13 20:45:52
[root@~]#
/* command end */

When 'bigtime' feature is enabled, this 64-bit type becomes a 64-bit
nanoseconds counter, with the start time value is the min time value of
'xfs_legacy_timestamp'(start time means the value of 64-bit nanoseconds
counter is 0). We have already caculated the min time value of
'xfs_legacy_timestamp', that is 1901-12-13 20:45:52 UTC, but the comment
for the start time value of inode with 'bigtime' feature enabled writes
the value is 1901-12-31 20:45:52 UTC:

/* fs/xfs/libxfs/xfs_format.h begin */
/*
 * XFS Timestamps
 * ==============
 * When the bigtime feature is enabled, ondisk inode timestamps become an
 * unsigned 64-bit nanoseconds counter.  This means that the bigtime inode
 * timestamp epoch is the start of the classic timestamp range, which is
 * Dec 31 20:45:52 UTC 1901. ...
 ...
 */
/* fs/xfs/libxfs/xfs_format.h end */

That is a typo, and this patch corrects the typo, from 'Dec 31' to
'Dec 13'.

Suggested-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Xiaole He <hexiaole@kylinos.cn>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
2022-07-20 16:40:38 -07:00
Shiyang Ruan
13f9e267fd xfs: add dax dedupe support
Introduce xfs_mmaplock_two_inodes_and_break_dax_layout() for dax files who
are going to be deduped.  After that, call compare range function only
when files are both DAX or not.

Link: https://lkml.kernel.org/r/20220603053738.1218681-15-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:32 -07:00
Shiyang Ruan
ea6c49b784 xfs: support CoW in fsdax mode
In fsdax mode, WRITE and ZERO on a shared extent need CoW performed. 
After that, new allocated extents needs to be remapped to the file.  So,
add a CoW identification in ->iomap_begin(), and implement ->iomap_end()
to do the remapping work.

[akpm@linux-foundation.org: make xfs_dax_fault() static]
Link: https://lkml.kernel.org/r/20220603053738.1218681-14-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:32 -07:00
Shiyang Ruan
6f7db3894a fsdax: dedup file range to use a compare function
With dax we cannot deal with readpage() etc.  So, we create a dax
comparison function which is similar with vfs_dedupe_file_range_compare().
And introduce dax_remap_file_range_prep() for filesystem use.

Link: https://lkml.kernel.org/r/20220603053738.1218681-13-ruansy.fnst@fujitsu.com
Signed-off-by: Goldwyn Rodrigues <rgoldwyn@suse.com>
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:32 -07:00
Shiyang Ruan
6f643c57d5 xfs: implement ->notify_failure() for XFS
Introduce xfs_notify_failure.c to handle failure related works, such as
implement ->notify_failure(), register/unregister dax holder in xfs, and
so on.

If the rmap feature of XFS enabled, we can query it to find files and
metadata which are associated with the corrupt data.  For now all we do is
kill processes with that file mapped into their address spaces, but future
patches could actually do something about corrupt metadata.

After that, the memory failure needs to notify the processes who are using
those files.

Link: https://lkml.kernel.org/r/20220603053738.1218681-7-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Dan Williams <dan.j.wiliams@intel.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:30 -07:00
Shiyang Ruan
8012b86608 dax: introduce holder for dax_device
Patch series "v14 fsdax-rmap + v11 fsdax-reflink", v2.

The patchset fsdax-rmap is aimed to support shared pages tracking for
fsdax.

It moves owner tracking from dax_assocaite_entry() to pmem device driver,
by introducing an interface ->memory_failure() for struct pagemap.  This
interface is called by memory_failure() in mm, and implemented by pmem
device.

Then call holder operations to find the filesystem which the corrupted
data located in, and call filesystem handler to track files or metadata
associated with this page.

Finally we are able to try to fix the corrupted data in filesystem and do
other necessary processing, such as killing processes who are using the
files affected.

The call trace is like this:
memory_failure()
|* fsdax case
|------------
|pgmap->ops->memory_failure()      => pmem_pgmap_memory_failure()
| dax_holder_notify_failure()      =>
|  dax_device->holder_ops->notify_failure() =>
|                                     - xfs_dax_notify_failure()
|  |* xfs_dax_notify_failure()
|  |--------------------------
|  |   xfs_rmap_query_range()
|  |    xfs_dax_failure_fn()
|  |    * corrupted on metadata
|  |       try to recover data, call xfs_force_shutdown()
|  |    * corrupted on file data
|  |       try to recover data, call mf_dax_kill_procs()
|* normal case
|-------------
|mf_generic_kill_procs()


The patchset fsdax-reflink attempts to add CoW support for fsdax, and
takes XFS, which has both reflink and fsdax features, as an example.

One of the key mechanisms needed to be implemented in fsdax is CoW.  Copy
the data from srcmap before we actually write data to the destination
iomap.  And we just copy range in which data won't be changed.

Another mechanism is range comparison.  In page cache case, readpage() is
used to load data on disk to page cache in order to be able to compare
data.  In fsdax case, readpage() does not work.  So, we need another
compare data with direct access support.

With the two mechanisms implemented in fsdax, we are able to make reflink
and fsdax work together in XFS.


This patch (of 14):

To easily track filesystem from a pmem device, we introduce a holder for
dax_device structure, and also its operation.  This holder is used to
remember who is using this dax_device:

 - When it is the backend of a filesystem, the holder will be the
   instance of this filesystem.
 - When this pmem device is one of the targets in a mapped device, the
   holder will be this mapped device.  In this case, the mapped device
   has its own dax_device and it will follow the first rule.  So that we
   can finally track to the filesystem we needed.

The holder and holder_ops will be set when filesystem is being mounted,
or an target device is being activated.

Link: https://lkml.kernel.org/r/20220603053738.1218681-1-ruansy.fnst@fujitsu.com
Link: https://lkml.kernel.org/r/20220603053738.1218681-2-ruansy.fnst@fujitsu.com
Signed-off-by: Shiyang Ruan <ruansy.fnst@fujitsu.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dan Williams <dan.j.wiliams@intel.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Dave Chinner <david@fromorbit.com>
Cc: Jane Chu <jane.chu@oracle.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.de>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Cc: Matthew Wilcox <willy@infradead.org>
Cc: Naoya Horiguchi <naoya.horiguchi@nec.com>
Cc: Miaohe Lin <linmiaohe@huawei.com>
Cc: Dan Williams <dan.j.williams@intel.com>
Cc: Goldwyn Rodrigues <rgoldwyn@suse.com>
Cc: Ritesh Harjani <riteshh@linux.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
2022-07-17 17:14:30 -07:00
Bart Van Assche
d03025aef8 fs/xfs: Use the enum req_op and blk_opf_t types
Improve static type checking by using the enum req_op type for variables
that represent a request operation and the new blk_opf_t type for the
combination of a request operation with request flags.

Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Cc: Christoph Hellwig <hch@lst.de>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
Link: https://lore.kernel.org/r/20220714180729.1065367-63-bvanassche@acm.org
Signed-off-by: Jens Axboe <axboe@kernel.dk>
2022-07-14 12:14:33 -06:00
Darrick J. Wong
95ff0363f3 xfs: fix use-after-free in xattr node block inactivation
The kernel build robot reported a UAF error while running xfs/433
(edited somewhat for brevity):

 BUG: KASAN: use-after-free in xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:214) xfs
 Read of size 4 at addr ffff88820ac2bd44 by task kworker/0:2/139

 CPU: 0 PID: 139 Comm: kworker/0:2 Tainted: G S                5.19.0-rc2-00004-g7cf2b0f9611b #1
 Hardware name: Hewlett-Packard p6-1451cx/2ADA, BIOS 8.15 02/05/2013
 Workqueue: xfs-inodegc/sdb4 xfs_inodegc_worker [xfs]
 Call Trace:
  <TASK>
 dump_stack_lvl (lib/dump_stack.c:107 (discriminator 1))
 print_address_description+0x1f/0x200
 print_report.cold (mm/kasan/report.c:430)
 kasan_report (mm/kasan/report.c:162 mm/kasan/report.c:493)
 xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:214) xfs
 xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:296) xfs
 xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
 process_one_work
 worker_thread
 kthread
 ret_from_fork
  </TASK>

 Allocated by task 139:
 kasan_save_stack (mm/kasan/common.c:39)
 __kasan_slab_alloc (mm/kasan/common.c:45 mm/kasan/common.c:436 mm/kasan/common.c:469)
 kmem_cache_alloc (mm/slab.h:750 mm/slub.c:3214 mm/slub.c:3222 mm/slub.c:3229 mm/slub.c:3239)
 _xfs_buf_alloc (include/linux/instrumented.h:86 include/linux/atomic/atomic-instrumented.h:41 fs/xfs/xfs_buf.c:232) xfs
 xfs_buf_get_map (fs/xfs/xfs_buf.c:660) xfs
 xfs_buf_read_map (fs/xfs/xfs_buf.c:777) xfs
 xfs_trans_read_buf_map (fs/xfs/xfs_trans_buf.c:289) xfs
 xfs_da_read_buf (fs/xfs/libxfs/xfs_da_btree.c:2652) xfs
 xfs_da3_node_read (fs/xfs/libxfs/xfs_da_btree.c:392) xfs
 xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:272) xfs
 xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
 process_one_work
 worker_thread
 kthread
 ret_from_fork

 Freed by task 139:
 kasan_save_stack (mm/kasan/common.c:39)
 kasan_set_track (mm/kasan/common.c:45)
 kasan_set_free_info (mm/kasan/generic.c:372)
 __kasan_slab_free (mm/kasan/common.c:368 mm/kasan/common.c:328 mm/kasan/common.c:374)
 kmem_cache_free (mm/slub.c:1753 mm/slub.c:3507 mm/slub.c:3524)
 xfs_buf_rele (fs/xfs/xfs_buf.c:1040) xfs
 xfs_attr3_node_inactive (fs/xfs/xfs_attr_inactive.c:210) xfs
 xfs_attr3_root_inactive (fs/xfs/xfs_attr_inactive.c:296) xfs
 xfs_attr_inactive (fs/xfs/xfs_attr_inactive.c:371) xfs
 xfs_inactive (fs/xfs/xfs_inode.c:1781) xfs
 xfs_inodegc_worker (fs/xfs/xfs_icache.c:1837 fs/xfs/xfs_icache.c:1860) xfs
 process_one_work
 worker_thread
 kthread
 ret_from_fork

I reproduced this for my own satisfaction, and got the same report,
along with an extra morsel:

 The buggy address belongs to the object at ffff88802103a800
  which belongs to the cache xfs_buf of size 432
 The buggy address is located 396 bytes inside of
  432-byte region [ffff88802103a800, ffff88802103a9b0)

I tracked this code down to:

	error = xfs_trans_get_buf(*trans, mp->m_ddev_targp,
			child_blkno,
			XFS_FSB_TO_BB(mp, mp->m_attr_geo->fsbcount), 0,
			&child_bp);
	if (error)
		return error;
	error = bp->b_error;

That doesn't look right -- I think this should be dereferencing
child_bp, not bp.  Looking through the codebase history, I think this
was added by commit 2911edb653 ("xfs: remove the mappedbno argument to
xfs_da_get_buf"), which replaced a call to xfs_da_get_buf with the
current call to xfs_trans_get_buf.  Not sure why we trans_brelse'd @bp
earlier in the function, but I'm guessing it's to avoid pinning too many
buffers in memory while we inactivate the bottom of the attr tree.
Hence we now have to get the buffer back.

I /think/ this was supposed to check child_bp->b_error and fail the rest
of the invalidation if child_bp had experienced any kind of IO or
corruption error.  I bet the xfs_da3_node_read earlier in the loop will
catch most cases of incoming on-disk corruption which makes this check
mostly moot unless someone corrupts the buffer and the AIL pushes it out
to disk while the buffer's unlocked.

In the first case we'll never get to the bad check, and in the second
case the AIL will shut down the log, at which point there's no reason to
check b_error.  Remove the check, and null out @bp to avoid this problem
in the future.

Cc: hch@lst.de
Reported-by: kernel test robot <oliver.sang@intel.com>
Fixes: 2911edb653 ("xfs: remove the mappedbno argument to xfs_da_get_buf")
Signed-off-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 09:47:43 -07:00
Darrick J. Wong
6d200bdc01 xfs: make attr forks permanent
This series fixes a use-after-free bug that syzbot uncovered.  The UAF
 itself is a result of a race condition between getxattr and removexattr
 because callers to getxattr do not necessarily take any sort of locks
 before calling into the filesystem.
 
 Although the race condition itself can be fixed through clever use of a
 memory barrier, further consideration of the use cases of extended
 attributes shows that most files always have at least one attribute, so
 we might as well make them permanent.
 
 v2: Minor tweaks suggested by Dave, and convert some more macros to
 helper functions.
 
 Signed-off-by: Darrick J. Wong <djwong@kernel.org>
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Merge tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux into xfs-5.20-mergeB

xfs: make attr forks permanent

This series fixes a use-after-free bug that syzbot uncovered.  The UAF
itself is a result of a race condition between getxattr and removexattr
because callers to getxattr do not necessarily take any sort of locks
before calling into the filesystem.

Although the race condition itself can be fixed through clever use of a
memory barrier, further consideration of the use cases of extended
attributes shows that most files always have at least one attribute, so
we might as well make them permanent.

v2: Minor tweaks suggested by Dave, and convert some more macros to
helper functions.

Signed-off-by: Darrick J. Wong <djwong@kernel.org>

* tag 'make-attr-fork-permanent-5.20_2022-07-14' of git://git.kernel.org/pub/scm/linux/kernel/git/djwong/xfs-linux:
  xfs: replace inode fork size macros with functions
  xfs: replace XFS_IFORK_Q with a proper predicate function
  xfs: use XFS_IFORK_Q to determine the presence of an xattr fork
  xfs: make inode attribute forks a permanent part of struct xfs_inode
  xfs: convert XFS_IFORK_PTR to a static inline helper
2022-07-14 09:46:37 -07:00
Darrick J. Wong
35c5a09f53 xfs: lockless buffer cache lookups
Current work to merge the XFS inode life cycle with the VFS inode
 life cycle is finding some interesting issues. If we have a path
 that hits buffer trylocks fairly hard (e.g. a non-blocking
 background inode freeing function), we end up hitting massive
 contention on the buffer cache hash locks:
 
 -   92.71%     0.05%  [kernel]                  [k] xfs_inodegc_worker
    - 92.67% xfs_inodegc_worker
       - 92.13% xfs_inode_unlink
          - 91.52% xfs_inactive_ifree
             - 85.63% xfs_read_agi
                - 85.61% xfs_trans_read_buf_map
                   - 85.59% xfs_buf_read_map
                      - xfs_buf_get_map
                         - 85.55% xfs_buf_find
                            - 72.87% _raw_spin_lock
                               - do_raw_spin_lock
                                    71.86% __pv_queued_spin_lock_slowpath
                            - 8.74% xfs_buf_rele
                               - 7.88% _raw_spin_lock
                                  - 7.88% do_raw_spin_lock
                                       7.63% __pv_queued_spin_lock_slowpath
                            - 1.70% xfs_buf_trylock
                               - 1.68% down_trylock
                                  - 1.41% _raw_spin_lock_irqsave
                                     - 1.39% do_raw_spin_lock
                                          __pv_queued_spin_lock_slowpath
                            - 0.76% _raw_spin_unlock
                                 0.75% do_raw_spin_unlock
 
 This is basically hammering the pag->pag_buf_lock from lots of CPUs
 doing trylocks at the same time. Most of the buffer trylock
 operations ultimately fail after we've done the lookup, so we're
 really hammering the buf hash lock whilst making no progress.
 
 We can also see significant spinlock traffic on the same lock just
 under normal operation when lots of tasks are accessing metadata
 from the same AG, so let's avoid all this by creating a lookup fast
 path which leverages the rhashtable's ability to do RCU protected
 lookups.
 
 Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Merge tag 'xfs-buf-lockless-lookup-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.20-mergeB

xfs: lockless buffer cache lookups

Current work to merge the XFS inode life cycle with the VFS inode
life cycle is finding some interesting issues. If we have a path
that hits buffer trylocks fairly hard (e.g. a non-blocking
background inode freeing function), we end up hitting massive
contention on the buffer cache hash locks:

-   92.71%     0.05%  [kernel]                  [k] xfs_inodegc_worker
   - 92.67% xfs_inodegc_worker
      - 92.13% xfs_inode_unlink
         - 91.52% xfs_inactive_ifree
            - 85.63% xfs_read_agi
               - 85.61% xfs_trans_read_buf_map
                  - 85.59% xfs_buf_read_map
                     - xfs_buf_get_map
                        - 85.55% xfs_buf_find
                           - 72.87% _raw_spin_lock
                              - do_raw_spin_lock
                                   71.86% __pv_queued_spin_lock_slowpath
                           - 8.74% xfs_buf_rele
                              - 7.88% _raw_spin_lock
                                 - 7.88% do_raw_spin_lock
                                      7.63% __pv_queued_spin_lock_slowpath
                           - 1.70% xfs_buf_trylock
                              - 1.68% down_trylock
                                 - 1.41% _raw_spin_lock_irqsave
                                    - 1.39% do_raw_spin_lock
                                         __pv_queued_spin_lock_slowpath
                           - 0.76% _raw_spin_unlock
                                0.75% do_raw_spin_unlock

This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.

We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by creating a lookup fast
path which leverages the rhashtable's ability to do RCU protected
lookups.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

* tag 'xfs-buf-lockless-lookup-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: lockless buffer lookup
  xfs: remove a superflous hash lookup when inserting new buffers
  xfs: reduce the number of atomic when locking a buffer after lookup
  xfs: merge xfs_buf_find() and xfs_buf_get_map()
  xfs: break up xfs_buf_find() into individual pieces
  xfs: rework xfs_buf_incore() API
2022-07-14 09:22:14 -07:00
Darrick J. Wong
4613b17cc4 xfs: introduce in-memory inode unlink log items
To facilitate future improvements in inode logging and improving
 inode cluster buffer locking order consistency, we need a new
 mechanism for defering inode cluster buffer modifications during
 unlinked list modifications.
 
 The unlinked inode list buffer locking is complex. The unlinked
 list is unordered - we add to the tail, remove from where-ever the
 inode is in the list. Hence we might need to lock two inode buffers
 here (previous inode in list and the one being removed). While we
 can order the locking of these buffers correctly within the confines
 of the unlinked list, there may be other inodes that need buffer
 locking in the same transaction. e.g. O_TMPFILE being linked into a
 directory also modifies the directory inode.
 
 Hence we need a mechanism for defering unlinked inode list updates
 until a point where we know that all modifications have been made
 and all that remains is to lock and modify the cluster buffers.
 
 We can do this by first observing that we serialise unlinked list
 modifications by holding the AGI buffer lock. IOWs, the AGI is going
 to be locked until the transaction commits any time we modify the
 unlinked list. Hence it doesn't matter when in the unlink
 transactions that we actually load, lock and modify the inode
 cluster buffer.
 
 We add an in-memory unlinked inode log item to defer the inode
 cluster buffer update to transaction commit time where it can be
 ordered with all the other inode cluster operations that need to be
 done. Essentially all we need to do is record the inodes that need
 to have their unlinked list pointer updated in a new log item that
 we attached to the transaction.
 
 This log item exists purely for the purpose of delaying the update
 of the unlinked list pointer until the inode cluster buffer can be
 locked in the correct order around the other inode cluster buffers.
 It plays no part in the actual commit, and there's no change to
 anything that is written to the log. i.e. the inode cluster buffers
 still have to be fully logged here (not just ordered) as log
 recovery depedends on this to replay mods to the unlinked inode
 list.
 
 Hence if we add a "precommit" hook into xfs_trans_commit()
 to run a "precommit" operation on these iunlink log items, we can
 delay the locking, modification and logging of the inode cluster
 buffer until after all other modifications have been made. The
 precommit hook reuires us to sort the items that are going to be run
 so that we can lock precommit items in the correct order as we
 perform the modifications they describe.
 
 To make this unlinked inode list processing simpler and easier to
 implement as a log item, we need to change the way we track the
 unlinked list in memory. Starting from the observation that an inode
 on the unlinked list is pinned in memory by the VFS, we can use the
 xfs_inode itself to track the unlinked list. To do this efficiently,
 we want the unlinked list to be a double linked list. The problem
 here is that we need a list per AGI unlinked list, and there are 64
 of these per AGI. The approach taken in this patchset is to shadow
 the AGI unlinked list heads in the perag, and link inodes by agino,
 hence requiring only 8 extra bytes per inode to track this state.
 
 We can then use the agino pointers for lockless inode cache lookups
 to retreive the inode. The aginos in the inode are modified only
 under the AGI lock, just like the cluster buffer pointers, so we
 don't need any extra locking here.  The i_next_unlinked field tracks
 the on-disk value of the unlinked list, and the i_prev_unlinked is a
 purely in-memory pointer that enables us to efficiently remove
 inodes from the middle of the list.
 
 This results in moving a lot of the unlink modification work into
 the precommit operations on the unlink log item. Tracking all the
 unlinked inodes in the inodes themselves also gets rid of the
 unlinked list reference hash table that is used to track this back
 pointer relationship. This greatly simplifies the the unlinked list
 modification code, and removes memory allocations in this hot path
 to track back pointers. This, overall, slightly reduces the CPU
 overhead of the unlink path.
 
 The result of this log item means that we move all the actual
 manipulation of objects to be logged out of the iunlink path and
 into the iunlink item. This allows for future optimisation of this
 mechanism without needing changes to high level unlink path, as
 well as making the unlink lock ordering predictable and synchronised
 with other operations that may require inode cluster locking.
 
 Signed-off-by: Dave Chinner <dchinner@redhat.com>
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Merge tag 'xfs-iunlink-item-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs into xfs-5.20-mergeB

xfs: introduce in-memory inode unlink log items

To facilitate future improvements in inode logging and improving
inode cluster buffer locking order consistency, we need a new
mechanism for defering inode cluster buffer modifications during
unlinked list modifications.

The unlinked inode list buffer locking is complex. The unlinked
list is unordered - we add to the tail, remove from where-ever the
inode is in the list. Hence we might need to lock two inode buffers
here (previous inode in list and the one being removed). While we
can order the locking of these buffers correctly within the confines
of the unlinked list, there may be other inodes that need buffer
locking in the same transaction. e.g. O_TMPFILE being linked into a
directory also modifies the directory inode.

Hence we need a mechanism for defering unlinked inode list updates
until a point where we know that all modifications have been made
and all that remains is to lock and modify the cluster buffers.

We can do this by first observing that we serialise unlinked list
modifications by holding the AGI buffer lock. IOWs, the AGI is going
to be locked until the transaction commits any time we modify the
unlinked list. Hence it doesn't matter when in the unlink
transactions that we actually load, lock and modify the inode
cluster buffer.

We add an in-memory unlinked inode log item to defer the inode
cluster buffer update to transaction commit time where it can be
ordered with all the other inode cluster operations that need to be
done. Essentially all we need to do is record the inodes that need
to have their unlinked list pointer updated in a new log item that
we attached to the transaction.

This log item exists purely for the purpose of delaying the update
of the unlinked list pointer until the inode cluster buffer can be
locked in the correct order around the other inode cluster buffers.
It plays no part in the actual commit, and there's no change to
anything that is written to the log. i.e. the inode cluster buffers
still have to be fully logged here (not just ordered) as log
recovery depedends on this to replay mods to the unlinked inode
list.

Hence if we add a "precommit" hook into xfs_trans_commit()
to run a "precommit" operation on these iunlink log items, we can
delay the locking, modification and logging of the inode cluster
buffer until after all other modifications have been made. The
precommit hook reuires us to sort the items that are going to be run
so that we can lock precommit items in the correct order as we
perform the modifications they describe.

To make this unlinked inode list processing simpler and easier to
implement as a log item, we need to change the way we track the
unlinked list in memory. Starting from the observation that an inode
on the unlinked list is pinned in memory by the VFS, we can use the
xfs_inode itself to track the unlinked list. To do this efficiently,
we want the unlinked list to be a double linked list. The problem
here is that we need a list per AGI unlinked list, and there are 64
of these per AGI. The approach taken in this patchset is to shadow
the AGI unlinked list heads in the perag, and link inodes by agino,
hence requiring only 8 extra bytes per inode to track this state.

We can then use the agino pointers for lockless inode cache lookups
to retreive the inode. The aginos in the inode are modified only
under the AGI lock, just like the cluster buffer pointers, so we
don't need any extra locking here.  The i_next_unlinked field tracks
the on-disk value of the unlinked list, and the i_prev_unlinked is a
purely in-memory pointer that enables us to efficiently remove
inodes from the middle of the list.

This results in moving a lot of the unlink modification work into
the precommit operations on the unlink log item. Tracking all the
unlinked inodes in the inodes themselves also gets rid of the
unlinked list reference hash table that is used to track this back
pointer relationship. This greatly simplifies the the unlinked list
modification code, and removes memory allocations in this hot path
to track back pointers. This, overall, slightly reduces the CPU
overhead of the unlink path.

The result of this log item means that we move all the actual
manipulation of objects to be logged out of the iunlink path and
into the iunlink item. This allows for future optimisation of this
mechanism without needing changes to high level unlink path, as
well as making the unlink lock ordering predictable and synchronised
with other operations that may require inode cluster locking.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Darrick J. Wong <djwong@kernel.org>

* tag 'xfs-iunlink-item-5.20' of git://git.kernel.org/pub/scm/linux/kernel/git/dgc/linux-xfs:
  xfs: add in-memory iunlink log item
  xfs: add log item precommit operation
  xfs: combine iunlink inode update functions
  xfs: clean up xfs_iunlink_update_inode()
  xfs: double link the unlinked inode list
  xfs: introduce xfs_iunlink_lookup
  xfs: refactor xlog_recover_process_iunlinks()
  xfs: track the iunlink list pointer in the xfs_inode
  xfs: factor the xfs_iunlink functions
  xfs: flush inode gc workqueue before clearing agi bucket
2022-07-14 09:21:42 -07:00
Dave Chinner
298f342245 xfs: lockless buffer lookup
Now that we have a standalone fast path for buffer lookup, we can
easily convert it to use rcu lookups. When we continually hammer the
buffer cache with trylock lookups, we end up with a huge amount of
lock contention on the per-ag buffer hash locks:

-   92.71%     0.05%  [kernel]                  [k] xfs_inodegc_worker
   - 92.67% xfs_inodegc_worker
      - 92.13% xfs_inode_unlink
         - 91.52% xfs_inactive_ifree
            - 85.63% xfs_read_agi
               - 85.61% xfs_trans_read_buf_map
                  - 85.59% xfs_buf_read_map
                     - xfs_buf_get_map
                        - 85.55% xfs_buf_find
                           - 72.87% _raw_spin_lock
                              - do_raw_spin_lock
                                   71.86% __pv_queued_spin_lock_slowpath
                           - 8.74% xfs_buf_rele
                              - 7.88% _raw_spin_lock
                                 - 7.88% do_raw_spin_lock
                                      7.63% __pv_queued_spin_lock_slowpath
                           - 1.70% xfs_buf_trylock
                              - 1.68% down_trylock
                                 - 1.41% _raw_spin_lock_irqsave
                                    - 1.39% do_raw_spin_lock
                                         __pv_queued_spin_lock_slowpath
                           - 0.76% _raw_spin_unlock
                                0.75% do_raw_spin_unlock

This is basically hammering the pag->pag_buf_lock from lots of CPUs
doing trylocks at the same time. Most of the buffer trylock
operations ultimately fail after we've done the lookup, so we're
really hammering the buf hash lock whilst making no progress.

We can also see significant spinlock traffic on the same lock just
under normal operation when lots of tasks are accessing metadata
from the same AG, so let's avoid all this by converting the lookup
fast path to leverages the rhashtable's ability to do rcu protected
lookups.

We avoid races with the buffer release path by using
atomic_inc_not_zero() on the buffer hold count. Any buffer that is
in the LRU will have a non-zero count, thereby allowing the lockless
fast path to be taken in most cache hit situations. If the buffer
hold count is zero, then it is likely going through the release path
so in that case we fall back to the existing lookup miss slow path.

The slow path will then do an atomic lookup and insert under the
buffer hash lock and hence serialise correctly against buffer
release freeing the buffer.

The use of rcu protected lookups means that buffer handles now need
to be freed by RCU callbacks (same as inodes). We still free the
buffer pages before the RCU callback - we won't be trying to access
them at all on a buffer that has zero references - but we need the
buffer handle itself to be present for the entire rcu protected read
side to detect a zero hold count correctly.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:05:07 +10:00
Dave Chinner
32dd4f9c50 xfs: remove a superflous hash lookup when inserting new buffers
Currently on the slow path insert we repeat the initial hash table
lookup before we attempt the insert, resulting in a two traversals
of the hash table to ensure the insert is valid. The rhashtable API
provides a method for an atomic lookup and insert operation, so we
can avoid one of the hash table traversals by using this method.

Adapted from a large patch containing this optimisation by Christoph
Hellwig.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:43 +10:00
Dave Chinner
d8d9bbb0ee xfs: reduce the number of atomic when locking a buffer after lookup
Avoid an extra atomic operation in the non-trylock case by only
doing a trylock if the XBF_TRYLOCK flag is set. This follows the
pattern in the IO path with NOWAIT semantics where the
"trylock-fail-lock" path showed 5-10% reduced throughput compared to
just using single lock call when not under NOWAIT conditions. So
make that same change here, too.

See commit 942491c9e6 ("xfs: fix AIM7 regression") for details.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
[hch: split from a larger patch]
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:38 +10:00
Dave Chinner
348000804a xfs: merge xfs_buf_find() and xfs_buf_get_map()
Now that we factored xfs_buf_find(), we can start separating into
distinct fast and slow paths from xfs_buf_get_map(). We start by
moving the lookup map and perag setup to _get_map(), and then move
all the specifics of the fast path lookup into xfs_buf_lookup()
and call it directly from _get_map(). We the move all the slow path
code to xfs_buf_find_insert(), which is now also called directly
from _get_map(). As such, xfs_buf_find() now goes away.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:04:31 +10:00
Dave Chinner
de67dc5754 xfs: break up xfs_buf_find() into individual pieces
xfs_buf_find() is made up of three main parts: lookup, insert and
locking. The interactions with xfs_buf_get_map() require it to be
called twice - once for a pure lookup, and again on lookup failure
so the insert path can be run. We want to simplify this down a lot,
so split it into a fast path lookup, a slow path insert and a "lock
the found buffer" helper. This will then let us integrate these
operations more effectively into xfs_buf_get_map() in future
patches.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 12:02:46 +10:00
Dave Chinner
784eb7d8dd xfs: add in-memory iunlink log item
Now that we have a clean operation to update the di_next_unlinked
field of inode cluster buffers, we can easily defer this operation
to transaction commit time so we can order the inode cluster buffer
locking consistently.

To do this, we introduce a new in-memory log item to track the
unlinked list item modification that we are going to make. This
follows the same observations as the in-memory double linked list
used to track unlinked inodes in that the inodes on the list are
pinned in memory and cannot go away, and hence we can simply
reference them for the duration of the transaction without needing
to take active references or pin them or look them up.

This allows us to pass the xfs_inode to the transaction commit code
along with the modification to be made, and then order the logged
modifications via the ->iop_sort and ->iop_precommit operations
for the new log item type. As this is an in-memory log item, it
doesn't have formatting, CIL or AIL operational hooks - it exists
purely to run the inode unlink modifications and is then removed
from the transaction item list and freed once the precommit
operation has run.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:47:42 +10:00
Dave Chinner
fad743d7cd xfs: add log item precommit operation
For inodes that are dirty, we have an attached cluster buffer that
we want to use to track the dirty inode through the AIL.
Unfortunately, locking the cluster buffer and adding it to the
transaction when the inode is first logged in a transaction leads to
buffer lock ordering inversions.

The specific problem is ordering against the AGI buffer. When
modifying unlinked lists, the buffer lock order is AGI -> inode
cluster buffer as the AGI buffer lock serialises all access to the
unlinked lists. Unfortunately, functionality like xfs_droplink()
logs the inode before calling xfs_iunlink(), as do various directory
manipulation functions. The inode can be logged way down in the
stack as far as the bmapi routines and hence, without a major
rewrite of lots of APIs there's no way we can avoid the inode being
logged by something until after the AGI has been logged.

As we are going to be using ordered buffers for inode AIL tracking,
there isn't a need to actually lock that buffer against modification
as all the modifications are captured by logging the inode item
itself. Hence we don't actually need to join the cluster buffer into
the transaction until just before it is committed. This means we do
not perturb any of the existing buffer lock orders in transactions,
and the inode cluster buffer is always locked last in a transaction
that doesn't otherwise touch inode cluster buffers.

We do this by introducing a precommit log item method.  This commit
just introduces the mechanism; the inode item implementation is in
followup commits.

The precommit items need to be sorted into consistent order as we
may be locking multiple items here. Hence if we have two dirty
inodes in cluster buffers A and B, and some other transaction has
two separate dirty inodes in the same cluster buffers, locking them
in different orders opens us up to ABBA deadlocks. Hence we sort the
items on the transaction based on the presence of a sort log item
method.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:47:26 +10:00
Dave Chinner
062efdb080 xfs: combine iunlink inode update functions
Combine the logging of the inode unlink list update into the
calling function that looks up the buffer we end up logging. These
do not need to be separate functions as they are both short, simple
operations and there's only a single call path through them. This
new function will end up being the core of the iunlink log item
processing...

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 11:46:59 +10:00
Dave Chinner
5301f87013 xfs: clean up xfs_iunlink_update_inode()
We no longer need to have this function return the previous next
agino value from the on-disk inode as we have it in the in-core
inode now.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 11:46:46 +10:00
Dave Chinner
2fd26cc07e xfs: double link the unlinked inode list
Now we have forwards traversal via the incore inode in place, we now
need to add back pointers to the incore inode to entirely replace
the back reference cache. We use the same lookup semantics and
constraints as for the forwards pointer lookups during unlinks, and
so we can look up any inode in the unlinked list directly and update
the list pointers, forwards or backwards, at any time.

The only wrinkle in converting the unlinked list manipulations to
use in-core previous pointers is that log recovery doesn't have the
incore inode state built up so it can't just read in an inode and
release it to finish off the unlink. Hence we need to modify the
traversal in recovery to read one inode ahead before we
release the inode at the head of the list. This populates the
next->prev relationship sufficient to be able to replay the unlinked
list and hence greatly simplify the runtime code.

This recovery algorithm also requires that we actually remove inodes
from the unlinked list one at a time as background inode
inactivation will result in unlinked list removal racing with the
building of the in-memory unlinked list state. We could serialise
this by holding the AGI buffer lock when constructing the in memory
state, but all that does is lockstep background processing with list
building. It is much simpler to flush the inodegc immediately after
releasing the inode so that it is unlinked immediately and there is
no races present at all.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:46:43 +10:00
Dave Chinner
a83d5a8b1d xfs: introduce xfs_iunlink_lookup
When an inode is on an unlinked list during normal operation, it is
guaranteed to be pinned in memory as it is either referenced by the
current unlink operation or it has a open file descriptor that
references it and has it pinned in memory. Hence to look up an inode
on the unlinked list, we can do a direct inode cache lookup and
always expect the lookup to succeed.

Add a function to do this lookup based on the agino that we use to
link the chain of unlinked inodes together so we can begin the
conversion the unlinked list manipulations to use in-memory inodes
rather than inode cluster buffers and remove the backref cache.

Use this lookup function to replace the on-disk inode buffer walk
when removing inodes from the unlinked list with an in-core inode
unlinked list walk.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 11:43:09 +10:00
Dave Chinner
04755d2e58 xfs: refactor xlog_recover_process_iunlinks()
For upcoming changes to the way inode unlinked list processing is
done, the structure of recovery needs to change slightly. We also
really need to untangle the messy error handling in list recovery
so that actions like emptying the bucket on inode lookup failure
are associated with the bucket list walk failing, not failing
to look up the inode.

Refactor the recovery code now to keep the re-organisation seperate
to the algorithm changes.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 11:42:39 +10:00
Dave Chinner
4fcc94d653 xfs: track the iunlink list pointer in the xfs_inode
Having direct access to the i_next_unlinked pointer in unlinked
inodes greatly simplifies the processing of inodes on the unlinked
list. We no longer need to look up the inode buffer just to find
next inode in the list if the xfs_inode is in memory. These
improvements will be realised over upcoming patches as other
dependencies on the inode buffer for unlinked list processing are
removed.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
2022-07-14 11:38:54 +10:00
Dave Chinner
a4454cd69c xfs: factor the xfs_iunlink functions
Prep work that separates the locking that protects the unlinked list
from the actual operations being performed. This also helps document
the fact they are performing list insert  and remove operations. No
functional code change.

Signed-off-by: Dave Chinner <dchinner@redhat.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
2022-07-14 11:36:40 +10:00