linux.git/fs/xfs, branch v5.16

xfs: map unwritten blocks in XFS_IOC_{ALLOC,FREE}SP just like fallocate

2021-12-22T22:19:18+00:00

The old ALLOCSP/FREESP ioctls in XFS can be used to preallocate space at
the end of files, just like fallocate and RESVSP.  Make the behavior
consistent with the other ioctls.

Reported-by: Kirill Tkhai 
Signed-off-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Reviewed-by: Eric Sandeen

xfs: remove all COW fork extents when remounting readonly

2021-12-07T18:17:29+00:00

As part of multiple customer escalations due to file data corruption
after copy on write operations, I wrote some fstests that use fsstress
to hammer on COW to shake things loose.  Regrettably, I caught some
filesystem shutdowns due to incorrect rmap operations with the following
loop:

mount 				# (0)
fsstress  &		# (1)
while true; do
	fsstress 
	mount -o remount,ro			# (2)
	fsstress 
	mount -o remount,rw			# (3)
done

When (2) happens, notice that (1) is still running.  xfs_remount_ro will
call xfs_blockgc_stop to walk the inode cache to free all the COW
extents, but the blockgc mechanism races with (1)'s reader threads to
take IOLOCKs and loses, which means that it doesn't clean them all out.
Call such a file (A).

When (3) happens, xfs_remount_rw calls xfs_reflink_recover_cow, which
walks the ondisk refcount btree and frees any COW extent that it finds.
This function does not check the inode cache, which means that incore
COW forks of inode (A) is now inconsistent with the ondisk metadata.  If
one of those former COW extents are allocated and mapped into another
file (B) and someone triggers a COW to the stale reservation in (A), A's
dirty data will be written into (B) and once that's done, those blocks
will be transferred to (A)'s data fork without bumping the refcount.

The results are catastrophic -- file (B) and the refcount btree are now
corrupt.  Solve this race by forcing the xfs_blockgc_free_space to run
synchronously, which causes xfs_icwalk to return to inodes that were
skipped because the blockgc code couldn't take the IOLOCK.  This is safe
to do here because the VFS has already prohibited new writer threads.

Fixes: 10ddf64e420f ("xfs: remove leftover CoW reservations when remounting ro")
Signed-off-by: Darrick J. Wong 
Reviewed-by: Dave Chinner 
Reviewed-by: Chandan Babu R

xfs: remove incorrect ASSERT in xfs_rename

2021-12-02T01:27:48+00:00

This ASSERT in xfs_rename is a) incorrect, because
(RENAME_WHITEOUT|RENAME_NOREPLACE) is a valid combination, and
b) unnecessary, because actual invalid flag combinations are already
handled at the vfs level in do_renameat2() before we get called.
So, remove it.

Reported-by: Paolo Bonzini 
Signed-off-by: Eric Sandeen 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: remove xfs_inew_wait

2021-11-24T18:06:02+00:00

With the remove of xfs_dqrele_all_inodes, xfs_inew_wait and all the
infrastructure used to wake the XFS_INEW bit waitqueue is unused.

Reported-by: kernel test robot 
Fixes: 777eb1fa857e ("xfs: remove xfs_dqrele_all_inodes")
Signed-off-by: Christoph Hellwig 
Reviewed-by: Brian Foster 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: Fix the free logic of state in xfs_attr_node_hasname

2021-11-24T18:06:02+00:00

When testing xfstests xfs/126 on lastest upstream kernel, it will hang on some machine.
Adding a getxattr operation after xattr corrupted, I can reproduce it 100%.

The deadlock as below:
[983.923403] task:setfattr        state:D stack:    0 pid:17639 ppid: 14687 flags:0x00000080
[  983.923405] Call Trace:
[  983.923410]  __schedule+0x2c4/0x700
[  983.923412]  schedule+0x37/0xa0
[  983.923414]  schedule_timeout+0x274/0x300
[  983.923416]  __down+0x9b/0xf0
[  983.923451]  ? xfs_buf_find.isra.29+0x3c8/0x5f0 [xfs]
[  983.923453]  down+0x3b/0x50
[  983.923471]  xfs_buf_lock+0x33/0xf0 [xfs]
[  983.923490]  xfs_buf_find.isra.29+0x3c8/0x5f0 [xfs]
[  983.923508]  xfs_buf_get_map+0x4c/0x320 [xfs]
[  983.923525]  xfs_buf_read_map+0x53/0x310 [xfs]
[  983.923541]  ? xfs_da_read_buf+0xcf/0x120 [xfs]
[  983.923560]  xfs_trans_read_buf_map+0x1cf/0x360 [xfs]
[  983.923575]  ? xfs_da_read_buf+0xcf/0x120 [xfs]
[  983.923590]  xfs_da_read_buf+0xcf/0x120 [xfs]
[  983.923606]  xfs_da3_node_read+0x1f/0x40 [xfs]
[  983.923621]  xfs_da3_node_lookup_int+0x69/0x4a0 [xfs]
[  983.923624]  ? kmem_cache_alloc+0x12e/0x270
[  983.923637]  xfs_attr_node_hasname+0x6e/0xa0 [xfs]
[  983.923651]  xfs_has_attr+0x6e/0xd0 [xfs]
[  983.923664]  xfs_attr_set+0x273/0x320 [xfs]
[  983.923683]  xfs_xattr_set+0x87/0xd0 [xfs]
[  983.923686]  __vfs_removexattr+0x4d/0x60
[  983.923688]  __vfs_removexattr_locked+0xac/0x130
[  983.923689]  vfs_removexattr+0x4e/0xf0
[  983.923690]  removexattr+0x4d/0x80
[  983.923693]  ? __check_object_size+0xa8/0x16b
[  983.923695]  ? strncpy_from_user+0x47/0x1a0
[  983.923696]  ? getname_flags+0x6a/0x1e0
[  983.923697]  ? _cond_resched+0x15/0x30
[  983.923699]  ? __sb_start_write+0x1e/0x70
[  983.923700]  ? mnt_want_write+0x28/0x50
[  983.923701]  path_removexattr+0x9b/0xb0
[  983.923702]  __x64_sys_removexattr+0x17/0x20
[  983.923704]  do_syscall_64+0x5b/0x1a0
[  983.923705]  entry_SYSCALL_64_after_hwframe+0x65/0xca
[  983.923707] RIP: 0033:0x7f080f10ee1b

When getxattr calls xfs_attr_node_get function, xfs_da3_node_lookup_int fails with EFSCORRUPTED in
xfs_attr_node_hasname because we have use blocktrash to random it in xfs/126. So it
free state in internal and xfs_attr_node_get doesn't do xfs_buf_trans release job.

Then subsequent removexattr will hang because of it.

This bug was introduced by kernel commit 07120f1abdff ("xfs: Add xfs_has_attr and subroutines").
It adds xfs_attr_node_hasname helper and said caller will be responsible for freeing the state
in this case. But xfs_attr_node_hasname will free state itself instead of caller if
xfs_da3_node_lookup_int fails.

Fix this bug by moving the step of free state into caller.

Also, use "goto error/out" instead of returning error directly in xfs_attr_node_addname_find_attr and
xfs_attr_node_removename_setup function because we should free state ourselves.

Fixes: 07120f1abdff ("xfs: Add xfs_has_attr and subroutines")
Signed-off-by: Yang Xu 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

Merge tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2021-11-14T20:18:22+00:00

Pull xfs cleanups from Darrick Wong:
 "The most 'exciting' aspect of this branch is that the xfsprogs
  maintainer and I have worked through the last of the code
  discrepancies between kernel and userspace libxfs such that there are
  no code differences between the two except for #includes.

  IOWs, diff suffices to demonstrate that the userspace tools behave the
  same as the kernel, and kernel-only bits are clearly marked in the
  /kernel/ source code instead of just the userspace source.

  Summary:

   - Clean up open-coded swap() calls.

   - A little bit of #ifdef golf to complete the reunification of the
     kernel and userspace libxfs source code"

* tag 'xfs-5.16-merge-5' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux:
  xfs: sync xfs_btree_split macros with userspace libxfs
  xfs: #ifdef out perag code for userspace
  xfs: use swap() to make dabtree code cleaner

xfs: sync xfs_btree_split macros with userspace libxfs

2021-11-11T17:13:39+00:00

Sync this one last bit of discrepancy between kernel and userspace
libxfs.

Signed-off-by: Darrick J. Wong 
Reviewed-by: Eric Sandeen

xfs: #ifdef out perag code for userspace

2021-11-10T17:37:38+00:00

The xfs_perag structure and initialization is unused in userspace,
so #ifdef it out with __KERNEL__ to facilitate the xfsprogs sync
and build.

Signed-off-by: Eric Sandeen 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

xfs: use swap() to make dabtree code cleaner

2021-11-08T19:23:25+00:00

Use the macro 'swap()' defined in 'include/linux/minmax.h' to avoid
opencoding it.

Reported-by: Zeal Robot 
Signed-off-by: Yang Guang 
Reviewed-by: Darrick J. Wong 
Signed-off-by: Darrick J. Wong

Merge tag 'xfs-5.16-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux

2021-11-02T19:42:56+00:00

Pull xfs updates from Darrick Wong:
 "This cycle we've worked on fixing bugs and improving XFS' memory
  footprint.

  The most notable fixes include: fixing a corruption warning (and free
  space accounting skew) if copy on write fails; fixing slab cache
  misuse if SLOB is enabled, which apparently was broken for years
  without anybody noticing; and fixing a potential race with online
  shrinkfs.

  Otherwise, the bulk of the changes here involve setting up separate
  slab caches for frequently used items such as btree cursors and log
  intent items, and compacting the structures to reduce memory usage of
  those items substantially. This also sets us up to support larger
  btrees in future kernels. We also switch parts of online fsck to
  allocate scrub context information from the heap instead of using
  stack space.

  Summary:

   - Bug fixes and cleanups for kernel memory allocation usage, this
     time without touching the mm code.

   - Refactor the log recovery mechanism that preserves held resources
     across a transaction roll so that it uses the exact same mechanism
     that we use for that during regular runtime.

   - Fix bugs and tighten checking around btree heights.

   - Remove more old typedefs.

   - Fix perag reference leaks when racing with growfs.

   - Remove unused fields from xfs_btree_cur.

   - Allocate various scrub structures on the heap to reduce stack
     usage.

   - Pack xfs_btree_cur fields and rearrange to support arbitrary
     heights.

   - Compute maximum possible heights for each btree height, and use
     that to set up slab caches for each btree type.

   - Finally remove kmem_zone_t, since these have always been struct
     kmem_cache on Linux.

   - Compact the structures used to coordinate work intent items.

   - Set up slab caches for each work intent item type.

   - Rename the "bmap_add_free" function to "free_extent_later", which
     more accurately describes what it does.

   - Fix corruption warning on unmount when a CoW preallocation covers a
     data fork delalloc reservation but then the CoW fails.

   - Add some more minor code improvements"

* tag 'xfs-5.16-merge-4' of git://git.kernel.org/pub/scm/fs/xfs/xfs-linux: (45 commits)
  xfs: use swap() to make code cleaner
  xfs: Remove duplicated include in xfs_super
  xfs: punch out data fork delalloc blocks on COW writeback failure
  xfs: remove unused parameter from refcount code
  xfs: reduce the size of struct xfs_extent_free_item
  xfs: rename xfs_bmap_add_free to xfs_free_extent_later
  xfs: create slab caches for frequently-used deferred items
  xfs: compact deferred intent item structures
  xfs: rename _zone variables to _cache
  xfs: remove kmem_zone typedef
  xfs: use separate btree cursor cache for each btree type
  xfs: compute absolute maximum nlevels for each btree type
  xfs: kill XFS_BTREE_MAXLEVELS
  xfs: compute the maximum height of the rmap btree when reflink enabled
  xfs: clean up xfs_btree_{calc_size,compute_maxlevels}
  xfs: compute maximum AG btree height for critical reservation calculation
  xfs: rename m_ag_maxlevels to m_allocbt_maxlevels
  xfs: dynamically allocate cursors based on maxlevels
  xfs: encode the max btree height in the cursor
  xfs: refactor btree cursor allocation function
  ...