linux-stable.git/fs/inode.c, branch v6.18

fs: add iput_not_last()

2025-11-12T09:47:42+00:00

Signed-off-by: Mateusz Guzik 
Link: https://patch.msgid.link/20251105212025.807549-1-mjguzik@gmail.com
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

Merge tag 'vfs-6.18-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs

2025-09-29T16:42:30+00:00

Pull vfs inode updates from Christian Brauner:
 "This contains a series I originally wrote and that Eric brought over
  the finish line. It moves out the i_crypt_info and i_verity_info
  pointers out of 'struct inode' and into the fs-specific part of the
  inode.

  So now the few filesytems that actually make use of this pay the price
  in their own private inode storage instead of forcing it upon every
  user of struct inode.

  The pointer for the crypt and verity info is simply found by storing
  an offset to its address in struct fsverity_operations and struct
  fscrypt_operations. This shrinks struct inode by 16 bytes.

  I hope to move a lot more out of it in the future so that struct inode
  becomes really just about very core stuff that we need, much like
  struct dentry and struct file, instead of the dumping ground it has
  become over the years.

  On top of this are a various changes associated with the ongoing inode
  lifetime handling rework that multiple people are pushing forward:

   - Stop accessing inode->i_count directly in f2fs and gfs2. They
     simply should use the __iget() and iput() helpers

   - Make the i_state flags an enum

   - Rework the iput() logic

     Currently, if we are the last iput, and we have the I_DIRTY_TIME
     bit set, we will grab a reference on the inode again and then mark
     it dirty and then redo the put. This is to make sure we delay the
     time update for as long as possible

     We can rework this logic to simply dec i_count if it is not 1, and
     if it is do the time update while still holding the i_count
     reference

     Then we can replace the atomic_dec_and_lock with locking the
     ->i_lock and doing atomic_dec_and_test, since we did the
     atomic_add_unless above

   - Add an icount_read() helper and convert everyone that accesses
     inode->i_count directly for this purpose to use the helper

   - Expand dump_inode() to dump more information about an inode helping
     in debugging

   - Add some might_sleep() annotations to iput() and associated
     helpers"

* tag 'vfs-6.18-rc1.inode' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  fs: add might_sleep() annotation to iput() and more
  fs: expand dump_inode()
  inode: fix whitespace issues
  fs: add an icount_read helper
  fs: rework iput logic
  fs: make the i_state flags an enum
  fs: stop accessing ->i_count directly in f2fs and gfs2
  fsverity: check IS_VERITY() in fsverity_cleanup_inode()
  fs: remove inode::i_verity_info
  btrfs: move verity info pointer to fs-specific part of inode
  f2fs: move verity info pointer to fs-specific part of inode
  ext4: move verity info pointer to fs-specific part of inode
  fsverity: add support for info in fs-specific part of inode
  fs: remove inode::i_crypt_info
  ceph: move crypt info pointer to fs-specific part of inode
  ubifs: move crypt info pointer to fs-specific part of inode
  f2fs: move crypt info pointer to fs-specific part of inode
  ext4: move crypt info pointer to fs-specific part of inode
  fscrypt: add support for info in fs-specific part of inode
  fscrypt: replace raw loads of info pointer with helper function

fs: add might_sleep() annotation to iput() and more

2025-09-19T12:14:55+00:00

When iput() drops the reference counter to zero, it may sleep via
inode_wait_for_writeback().  This happens rarely because it's usually
the dcache which evicts inodes, but really iput() should only ever be
called in contexts where sleeping is allowed.  This annotation allows
finding buggy callers.

Additionally, this patch annotates a few low-level functions that can
call iput() conditionally.

Cc: Mateusz Guzik 
Signed-off-by: Max Kellermann 
Link: https://lore.kernel.org/20250917153632.2228828-1-max.kellermann@ionos.com
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

fs: rename generic_delete_inode() and generic_drop_inode()

2025-09-15T14:09:42+00:00

generic_delete_inode() is rather misleading for what the routine is
doing. inode_just_drop() should be much clearer.

The new naming is inconsistent with generic_drop_inode(), so rename that
one as well with inode_ as the suffix.

No functional changes.

Signed-off-by: Mateusz Guzik 
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

fs: expand dump_inode()

2025-09-15T12:31:03+00:00

This adds fs name and few fields from struct inode: i_mode, i_opflags,
i_flags, i_state and i_count.

All values printed raw, no attempt to pretty-print anything.

Compile tested on i386 and runtime tested on amd64.

Sample output:
[   23.121281] VFS_WARN_ON_INODE("crap") encountered for inode ffff9a1a83ce3660
               fs pipefs mode 10600 opflags 0x4 flags 0x0 state 0x38 count 0

Signed-off-by: Mateusz Guzik

fs: use the switch statement in init_special_inode()

2025-09-15T12:28:37+00:00

Similar to may_open().

No functional changes.

Signed-off-by: Mateusz Guzik 
Reviewed-by: Jan Kara 
Signed-off-by: Christian Brauner

inode: fix whitespace issues

2025-09-01T10:41:09+00:00

Fix two minor whitespace issues.

Signed-off-by: Christian Brauner

fs: add an icount_read helper

2025-09-01T10:41:09+00:00

Instead of doing direct access to ->i_count, add a helper to handle
this. This will make it easier to convert i_count to a refcount later.

Signed-off-by: Josef Bacik 
Link: https://lore.kernel.org/9bc62a84c6b9d6337781203f60837bd98fbc4a96.1756222464.git.josef@toxicpanda.com
Signed-off-by: Christian Brauner

fs: rework iput logic

2025-09-01T10:38:04+00:00

Currently, if we are the last iput, and we have the I_DIRTY_TIME bit
set, we will grab a reference on the inode again and then mark it dirty
and then redo the put.  This is to make sure we delay the time update
for as long as possible.

We can rework this logic to simply dec i_count if it is not 1, and if it
is do the time update while still holding the i_count reference.

Then we can replace the atomic_dec_and_lock with locking the ->i_lock
and doing atomic_dec_and_test, since we did the atomic_add_unless above.

Co-developed-by: Mateusz Guzik 
Signed-off-by: Mateusz Guzik 
Signed-off-by: Josef Bacik 
Link: https://lore.kernel.org/be208b89bdb650202e712ce2bcfc407ac7044c7a.1756222464.git.josef@toxicpanda.com
Signed-off-by: Christian Brauner

vfs: show filesystem name at dump_inode()

2025-08-11T13:50:48+00:00

Commit 8b17e540969a ("vfs: add initial support for CONFIG_DEBUG_VFS") added
dump_inode(), but dump_inode() currently reports only raw pointer address.
Comment says that adding a proper inode dumping routine is a TODO.

However, syzkaller concurrently tests multiple filesystems, and several
filesystems started calling dump_inode() due to hitting VFS_BUG_ON_INODE()
added by commit af153bb63a33 ("vfs: catch invalid modes in may_open()")
before a proper inode dumping routine is implemented.

Show filesystem name at dump_inode() so that we can find which filesystem
has passed an invalid mode to may_open() from syzkaller's crash reports.

Link: https://syzkaller.appspot.com/bug?extid=895c23f6917da440ed0d
Signed-off-by: Tetsuo Handa 
Link: https://lore.kernel.org/ceaf4021-65cc-422e-9d0e-6afa18dd8276@I-love.SAKURA.ne.jp
Signed-off-by: Christian Brauner