705 Commits
Author SHA1 Message Date
Linus Torvalds a436a0b847 Merge tag 'ext4_for_linux-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4
Pull ext4 updates from Ted Ts'o:

 - Refactor code paths involved with partial block zero-out in
   prearation for converting ext4 to use iomap for buffered writes

 - Remove use of d_alloc() from ext4 in preparation for the deprecation
   of this interface

 - Replace some J_ASSERTS with a journal abort so we can avoid a kernel
   panic for a localized file system error

 - Simplify various code paths in mballoc, move_extent, and fast commit

 - Fix rare deadlock in jbd2_journal_cancel_revoke() that can be
   triggered by generic/013 when blocksize < pagesize

 - Fix memory leak when releasing an extended attribute when its value
   is stored in an ea_inode

 - Fix various potential kunit test bugs in fs/ext4/extents.c

 - Fix potential out-of-bounds access in check_xattr() with a corrupted
   file system

 - Make the jbd2_inode dirty range tracking safe for lockless reads

 - Avoid a WARN_ON when writeback files due to a corrupted file system;
   we already print an ext4 warning indicatign that data will be lost,
   so the WARN_ON is not necessary and doesn't add any new information

* tag 'ext4_for_linux-7.0-rc1' of git://git.kernel.org/pub/scm/linux/kernel/git/tytso/ext4: (37 commits)
  jbd2: fix deadlock in jbd2_journal_cancel_revoke()
  ext4: fix missing brelse() in ext4_xattr_inode_dec_ref_all()
  ext4: fix possible null-ptr-deref in mbt_kunit_exit()
  ext4: fix possible null-ptr-deref in extents_kunit_exit()
  ext4: fix the error handling process in extents_kunit_init).
  ext4: call deactivate_super() in extents_kunit_exit()
  ext4: fix miss unlock 'sb->s_umount' in extents_kunit_init()
  ext4: fix bounds check in check_xattrs() to prevent out-of-bounds access
  ext4: zero post-EOF partial block before appending write
  ext4: move pagecache_isize_extended() out of active handle
  ext4: remove ctime/mtime update from ext4_alloc_file_blocks()
  ext4: unify SYNC mode checks in fallocate paths
  ext4: ensure zeroed partial blocks are persisted in SYNC mode
  ext4: move zero partial block range functions out of active handle
  ext4: pass allocate range as loff_t to ext4_alloc_file_blocks()
  ext4: remove handle parameters from zero partial block functions
  ext4: move ordered data handling out of ext4_block_do_zero_range()
  ext4: rename ext4_block_zero_page_range() to ext4_block_zero_range()
  ext4: factor out journalled block zeroing range
  ext4: rename and extend ext4_block_truncate_page()
  ...
2026-04-17 17:08:31 -07:00
Linus Torvalds b7d74ea0fd Merge tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs
Pull vfs i_ino updates from Christian Brauner:
 "For historical reasons, the inode->i_ino field is an unsigned long,
  which means that it's 32 bits on 32 bit architectures. This has caused
  a number of filesystems to implement hacks to hash a 64-bit identifier
  into a 32-bit field, and deprives us of a universal identifier field
  for an inode.

  This changes the inode->i_ino field from an unsigned long to a u64.
  This shouldn't make any material difference on 64-bit hosts, but
  32-bit hosts will see struct inode grow by at least 4 bytes. This
  could have effects on slabcache sizes and field alignment.

  The bulk of the changes are to format strings and tracepoints, since
  the kernel itself doesn't care that much about the i_ino field. The
  first patch changes some vfs function arguments, so check that one out
  carefully.

  With this change, we may be able to shrink some inode structures. For
  instance, struct nfs_inode has a fileid field that holds the 64-bit
  inode number. With this set of changes, that field could be
  eliminated. I'd rather leave that sort of cleanups for later just to
  keep this simple"

* tag 'vfs-7.1-rc1.kino' of git://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs:
  nilfs2: fix 64-bit division operations in nilfs_bmap_find_target_in_group()
  EVM: add comment describing why ino field is still unsigned long
  vfs: remove externs from fs.h on functions modified by i_ino widening
  treewide: fix missed i_ino format specifier conversions
  ext4: fix signed format specifier in ext4_load_inode trace event
  treewide: change inode->i_ino from unsigned long to u64
  nilfs2: widen trace event i_ino fields to u64
  f2fs: widen trace event i_ino fields to u64
  ext4: widen trace event i_ino fields to u64
  zonefs: widen trace event i_ino fields to u64
  hugetlbfs: widen trace event i_ino fields to u64
  ext2: widen trace event i_ino fields to u64
  cachefiles: widen trace event i_ino fields to u64
  vfs: widen trace event i_ino fields to u64
  net: change sock.sk_ino and sock_i_ino() to u64
  audit: widen ino fields to u64
  vfs: widen inode hash/lookup functions to u64
2026-04-13 12:19:01 -07:00
Zhang YiandTheodore Ts'o 981fcc5674 jbd2: fix deadlock in jbd2_journal_cancel_revoke()
Commit f76d4c28a4 ("fs/jbd2: use sleeping version of
__find_get_block()") changed jbd2_journal_cancel_revoke() to use
__find_get_block_nonatomic() which holds the folio lock instead of
i_private_lock. This breaks the lock ordering (folio -> buffer) and
causes an ABBA deadlock when the filesystem blocksize < pagesize:

     T1                                T2
ext4_mkdir()
 ext4_init_new_dir()
  ext4_append()
   ext4_getblk()
    lock_buffer()    <- A
                                   sync_blockdev()
                                    blkdev_writepages()
                                     writeback_iter()
                                      writeback_get_folio()
                                       folio_lock()   <- B
     ext4_journal_get_create_access()
      jbd2_journal_cancel_revoke()
       __find_get_block_nonatomic()
        folio_lock()  <- B
                                     block_write_full_folio()
                                      lock_buffer()   <- A

This can occasionally cause generic/013 to hang.

Fix by only calling __find_get_block_nonatomic() when the passed
buffer_head doesn't belong to the bdev, which is the only case that we
need to look up its bdev alias. Otherwise, the lookup is redundant since
the found buffer_head is equal to the one we passed in.

Fixes: f76d4c28a4 ("fs/jbd2: use sleeping version of __find_get_block()")
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20260409114204.917154-1-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2026-04-09 22:09:39 -04:00
Li ChenandTheodore Ts'o 4edafa81a1 jbd2: store jinode dirty range in PAGE_SIZE units
jbd2_inode fields are updated under journal->j_list_lock, but some paths
read them without holding the lock (e.g. fast commit helpers and ordered
truncate helpers).

READ_ONCE() alone is not sufficient for the dirty range fields when they
are stored as loff_t because 32-bit platforms can observe torn loads.
Store the dirty range in PAGE_SIZE units as pgoff_t instead.

Represent the dirty range end as an exclusive end page. This avoids a
special sentinel value and keeps MAX_LFS_FILESIZE on 32-bit representable.

Publish a new dirty range by updating end_page before start_page, and
treat start_page >= end_page as empty in the accessor for robustness.

Use READ_ONCE() on the read side and WRITE_ONCE() on the write side for the
dirty range and i_flags to match the existing lockless access pattern.

Suggested-by: Jan Kara <jack@suse.cz>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Li Chen <me@linux.beauty>
Link: https://patch.msgid.link/20260306085643.465275-5-me@linux.beauty
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09 10:52:35 -04:00
Milos NikicandTheodore Ts'o f7fc28b014 jbd2: gracefully abort on transaction state corruptions
Auditing the jbd2 codebase reveals several legacy J_ASSERT calls
that enforce internal state machine invariants (e.g., verifying
jh->b_transaction or jh->b_next_transaction pointers).

When these invariants are broken, the journal is in a corrupted
state. However, triggering a fatal panic brings down the entire
system for a localized filesystem error.

This patch targets a specific class of these asserts: those
residing inside functions that natively return integer error codes,
booleans, or error pointers. It replaces the hard J_ASSERTs with
WARN_ON_ONCE to capture the offending stack trace, safely drops
any held locks, gracefully aborts the journal, and returns -EINVAL.

This prevents a catastrophic kernel panic while ensuring the
corrupted journal state is safely contained and upstream callers
(like ext4 or ocfs2) can gracefully handle the aborted handle.

Functions modified in fs/jbd2/transaction.c:
- jbd2__journal_start()
- do_get_write_access()
- jbd2_journal_dirty_metadata()
- jbd2_journal_forget()
- jbd2_journal_try_to_free_buffers()
- jbd2_journal_file_inode()

Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://patch.msgid.link/20260304172016.23525-3-nikic.milos@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09 10:46:36 -04:00
Milos NikicandTheodore Ts'o 64924362f8 jbd2: gracefully abort instead of panicking on unlocked buffer
In jbd2_journal_get_create_access(), if the caller passes an unlocked
buffer, the code currently triggers a fatal J_ASSERT.

While an unlocked buffer here is a clear API violation and a bug in the
caller, crashing the entire system is an overly severe response. It brings
down the whole machine for a localized filesystem inconsistency.

Replace the J_ASSERT with a WARN_ON_ONCE to capture the offending caller's
stack trace, and return an error (-EINVAL). This allows the journal to
gracefully abort the transaction, protecting data integrity without
causing a kernel panic.

Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Link: https://patch.msgid.link/20260304172016.23525-2-nikic.milos@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2026-04-09 10:46:36 -04:00
Milos NikicandTheodore Ts'o bac3190a8e jbd2: gracefully abort on checkpointing state corruptions
This patch targets two internal state machine invariants in checkpoint.c
residing inside functions that natively return integer error codes.

- In jbd2_cleanup_journal_tail(): A blocknr of 0 indicates a severely
corrupted journal superblock. Replaced the J_ASSERT with a WARN_ON_ONCE
and a graceful journal abort, returning -EFSCORRUPTED.

- In jbd2_log_do_checkpoint(): Replaced the J_ASSERT_BH checking for
an unexpected buffer_jwrite state. If the warning triggers, we
explicitly drop the just-taken get_bh() reference and call __flush_batch()
to safely clean up any previously queued buffers in the j_chkpt_bhs array,
preventing a memory leak before returning -EFSCORRUPTED.

Signed-off-by: Milos Nikic <nikic.milos@gmail.com>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Baokun Li <libaokun@linux.alibaba.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20260311041548.159424-1-nikic.milos@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2026-03-27 23:34:09 -04:00
Jeff LaytonandChristian Brauner 0b2600f81c treewide: change inode->i_ino from unsigned long to u64
On 32-bit architectures, unsigned long is only 32 bits wide, which
causes 64-bit inode numbers to be silently truncated. Several
filesystems (NFS, XFS, BTRFS, etc.) can generate inode numbers that
exceed 32 bits, and this truncation can lead to inode number collisions
and other subtle bugs on 32-bit systems.

Change the type of inode->i_ino from unsigned long to u64 to ensure that
inode numbers are always represented as 64-bit values regardless of
architecture. Update all format specifiers treewide from %lu/%lx to
%llu/%llx to match the new type, along with corresponding local variable
types.

This is the bulk treewide conversion. Earlier patches in this series
handled trace events separately to allow trace field reordering for
better struct packing on 32-bit.

Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20260304-iino-u64-v3-12-2257ad83d372@kernel.org
Acked-by: Damien Le Moal <dlemoal@kernel.org>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Christian Brauner <brauner@kernel.org>
2026-03-06 14:31:28 +01:00
Linus Torvalds 32a92f8c89 Convert more 'alloc_obj' cases to default GFP_KERNEL arguments
This converts some of the visually simpler cases that have been split
over multiple lines.  I only did the ones that are easy to verify the
resulting diff by having just that final GFP_KERNEL argument on the next
line.

Somebody should probably do a proper coccinelle script for this, but for
me the trivial script actually resulted in an assertion failure in the
middle of the script.  I probably had made it a bit _too_ trivial.

So after fighting that far a while I decided to just do some of the
syntactically simpler cases with variations of the previous 'sed'
scripts.

The more syntactically complex multi-line cases would mostly really want
whitespace cleanup anyway.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 20:03:00 -08:00
Linus Torvalds bf4afc53b7 Convert 'alloc_obj' family to use the new default GFP_KERNEL argument
This was done entirely with mindless brute force, using

    git grep -l '\<k[vmz]*alloc_objs*(.*, GFP_KERNEL)' |
        xargs sed -i 's/\(alloc_objs*(.*\), GFP_KERNEL)/\1)/'

to convert the new alloc_obj() users that had a simple GFP_KERNEL
argument to just drop that argument.

Note that due to the extreme simplicity of the scripting, any slightly
more complex cases spread over multiple lines would not be triggered:
they definitely exist, but this covers the vast bulk of the cases, and
the resulting diff is also then easier to check automatically.

For the same reason the 'flex' versions will be done as a separate
conversion.

Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
2026-02-21 17:09:51 -08:00
Kees Cook 69050f8d6d treewide: Replace kmalloc with kmalloc_obj for non-scalar types
This is the result of running the Coccinelle script from
scripts/coccinelle/api/kmalloc_objs.cocci. The script is designed to
avoid scalar types (which need careful case-by-case checking), and
instead replace kmalloc-family calls that allocate struct or union
object instances:

Single allocations:	kmalloc(sizeof(TYPE), ...)
are replaced with:	kmalloc_obj(TYPE, ...)

Array allocations:	kmalloc_array(COUNT, sizeof(TYPE), ...)
are replaced with:	kmalloc_objs(TYPE, COUNT, ...)

Flex array allocations:	kmalloc(struct_size(PTR, FAM, COUNT), ...)
are replaced with:	kmalloc_flex(*PTR, FAM, COUNT, ...)

(where TYPE may also be *VAR)

The resulting allocations no longer return "void *", instead returning
"TYPE *".

Signed-off-by: Kees Cook <kees@kernel.org>
2026-02-21 01:02:28 -08:00
Ye BinandTheodore Ts'o 6abfe10789 jbd2: fix the inconsistency between checksum and data in memory for journal sb
Copying the file system while it is mounted as read-only results in
a mount failure:
[~]# mkfs.ext4 -F /dev/sdc
[~]# mount /dev/sdc -o ro /mnt/test
[~]# dd if=/dev/sdc of=/dev/sda bs=1M
[~]# mount /dev/sda /mnt/test1
[ 1094.849826] JBD2: journal checksum error
[ 1094.850927] EXT4-fs (sda): Could not load journal inode
mount: mount /dev/sda on /mnt/test1 failed: Bad message

The process described above is just an abstracted way I came up with to
reproduce the issue. In the actual scenario, the file system was mounted
read-only and then copied while it was still mounted. It was found that
the mount operation failed. The user intended to verify the data or use
it as a backup, and this action was performed during a version upgrade.
Above issue may happen as follows:
ext4_fill_super
 set_journal_csum_feature_set(sb)
  if (ext4_has_metadata_csum(sb))
   incompat = JBD2_FEATURE_INCOMPAT_CSUM_V3;
  if (test_opt(sb, JOURNAL_CHECKSUM)
   jbd2_journal_set_features(sbi->s_journal, compat, 0, incompat);
    lock_buffer(journal->j_sb_buffer);
    sb->s_feature_incompat  |= cpu_to_be32(incompat);
    //The data in the journal sb was modified, but the checksum was not
      updated, so the data remaining in memory has a mismatch between the
      data and the checksum.
    unlock_buffer(journal->j_sb_buffer);

In this case, the journal sb copied over is in a state where the checksum
and data are inconsistent, so mounting fails.
To solve the above issue, update the checksum in memory after modifying
the journal sb.

Fixes: 4fd5ea43bc ("jbd2: checksum journal superblock")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Reviewed-by: Darrick J. Wong <djwong@kernel.org>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20251103010123.3753631-1-yebin@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2025-11-26 17:05:47 -05:00
Wengang WangandTheodore Ts'o 80d05f640a jbd2: store more accurate errno in superblock when possible
When jbd2_journal_abort() is called, the provided error code is stored
in the journal superblock. Some existing calls hard-code -EIO even when
the actual failure is not I/O related.

This patch updates those calls to pass more accurate error codes,
allowing the superblock to record the true cause of failure. This helps
improve diagnostics and debugging clarity when analyzing journal aborts.

Signed-off-by: Wengang Wang <wen.gang.wang@oracle.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Message-ID: <20251031210501.7337-1-wen.gang.wang@oracle.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-26 17:05:39 -05:00
Ye BinandTheodore Ts'o 986835bf4d jbd2: avoid bug_on in jbd2_journal_get_create_access() when file system corrupted
There's issue when file system corrupted:
------------[ cut here ]------------
kernel BUG at fs/jbd2/transaction.c:1289!
Oops: invalid opcode: 0000 [#1] SMP KASAN PTI
CPU: 5 UID: 0 PID: 2031 Comm: mkdir Not tainted 6.18.0-rc1-next
RIP: 0010:jbd2_journal_get_create_access+0x3b6/0x4d0
RSP: 0018:ffff888117aafa30 EFLAGS: 00010202
RAX: 0000000000000000 RBX: ffff88811a86b000 RCX: ffffffff89a63534
RDX: 1ffff110200ec602 RSI: 0000000000000004 RDI: ffff888100763010
RBP: ffff888100763000 R08: 0000000000000001 R09: ffff888100763028
R10: 0000000000000003 R11: 0000000000000000 R12: 0000000000000000
R13: ffff88812c432000 R14: ffff88812c608000 R15: ffff888120bfc000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007f91d6970c99 CR3: 00000001159c4000 CR4: 00000000000006f0
Call Trace:
 <TASK>
 __ext4_journal_get_create_access+0x42/0x170
 ext4_getblk+0x319/0x6f0
 ext4_bread+0x11/0x100
 ext4_append+0x1e6/0x4a0
 ext4_init_new_dir+0x145/0x1d0
 ext4_mkdir+0x326/0x920
 vfs_mkdir+0x45c/0x740
 do_mkdirat+0x234/0x2f0
 __x64_sys_mkdir+0xd6/0x120
 do_syscall_64+0x5f/0xfa0
 entry_SYSCALL_64_after_hwframe+0x76/0x7e

The above issue occurs with us in errors=continue mode when accompanied by
storage failures. There have been many inconsistencies in the file system
data.
In the case of file system data inconsistency, for example, if the block
bitmap of a referenced block is not set, it can lead to the situation where
a block being committed is allocated and used again. As a result, the
following condition will not be satisfied then trigger BUG_ON. Of course,
it is entirely possible to construct a problematic image that can trigger
this BUG_ON through specific operations. In fact, I have constructed such
an image and easily reproduced this issue.
Therefore, J_ASSERT() holds true only under ideal conditions, but it may
not necessarily be satisfied in exceptional scenarios. Using J_ASSERT()
directly in abnormal situations would cause the system to crash, which is
clearly not what we want. So here we directly trigger a JBD abort instead
of immediately invoking BUG_ON.

Fixes: 470decc613 ("[PATCH] jbd2: initial copy of files from jbd")
Signed-off-by: Ye Bin <yebin10@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20251025072657.307851-1-yebin@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2025-11-26 17:05:02 -05:00
Byungchul ParkandTheodore Ts'o 40a71b53d5 jbd2: use a weaker annotation in journal handling
jbd2 journal handling code doesn't want jbd2_might_wait_for_commit()
to be placed between start_this_handle() and stop_this_handle().  So it
marks the region with rwsem_acquire_read() and rwsem_release().

However, the annotation is too strong for that purpose.  We don't have
to use more than try lock annotation for that.

rwsem_acquire_read() implies:

   1. might be a waiter on contention of the lock.
   2. enter to the critical section of the lock.

All we need in here is to act 2, not 1.  So trylock version of
annotation is sufficient for that purpose.  Now that dept partially
relies on lockdep annotaions, dept interpets rwsem_acquire_read() as a
potential wait and might report a deadlock by the wait.

Replace it with trylock version of annotation.

Signed-off-by: Byungchul Park <byungchul@sk.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@kernel.org
Message-ID: <20251024073940.1063-1-byungchul@sk.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-11-13 08:43:44 -05:00
Tetsuo HandaandTheodore Ts'o 524c385383 jbd2: use a per-journal lock_class_key for jbd2_trans_commit_key
syzbot is reporting possibility of deadlock due to sharing lock_class_key
for jbd2_handle across ext4 and ocfs2. But this is a false positive, for
one disk partition can't have two filesystems at the same time.

Reported-by: syzbot+6e493c165d26d6fcbf72@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=6e493c165d26d6fcbf72
Signed-off-by: Tetsuo Handa <penguin-kernel@I-love.SAKURA.ne.jp>
Tested-by: syzbot+6e493c165d26d6fcbf72@syzkaller.appspotmail.com
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <987110fc-5470-457a-a218-d286a09dd82f@I-love.SAKURA.ne.jp>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2025-11-13 08:34:39 -05:00
Zhang YiandTheodore Ts'o 3c652c3a71 jbd2: ensure that all ongoing I/O complete before freeing blocks
When releasing file system metadata blocks in jbd2_journal_forget(), if
this buffer has not yet been checkpointed, it may have already been
written back, currently be in the process of being written back, or has
not yet written back.  jbd2_journal_forget() calls
jbd2_journal_try_remove_checkpoint() to check the buffer's status and
add it to the current transaction if it has not been written back. This
buffer can only be reallocated after the transaction is committed.

jbd2_journal_try_remove_checkpoint() attempts to lock the buffer and
check its dirty status while holding the buffer lock. If the buffer has
already been written back, everything proceeds normally. However, there
are two issues. First, the function returns immediately if the buffer is
locked by the write-back process. It does not wait for the write-back to
complete. Consequently, until the current transaction is committed and
the block is reallocated, there is no guarantee that the I/O will
complete. This means that ongoing I/O could write stale metadata to the
newly allocated block, potentially corrupting data. Second, the function
unlocks the buffer as soon as it detects that the buffer is still dirty.
If a concurrent write-back occurs immediately after this unlocking and
before clear_buffer_dirty() is called in jbd2_journal_forget(), data
corruption can theoretically still occur.

Although these two issues are unlikely to occur in practice since the
undergoing metadata writeback I/O does not take this long to complete,
it's better to explicitly ensure that all ongoing I/O operations are
completed.

Fixes: 597599268e ("jbd2: discard dirty data when forgetting an un-journalled buffer")
Cc: stable@kernel.org
Suggested-by: Jan Kara <jack@suse.cz>
Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Message-ID: <20250916093337.3161016-2-yi.zhang@huaweicloud.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-10-10 13:10:06 -04:00
Julian SunandTheodore Ts'o 0f3b05c121 jbd2: increase IO priority of checkpoint
In commit 6a3afb6ac6 ("jbd2: increase the journal IO's priority"),
the priority of IOs initiated by jbd2 has been raised, exempting them
from WBT throttling.
Checkpoint is also a crucial operation of jbd2. While no serious issues
have been observed so far, it should still be reasonable to exempt
checkpoint from WBT throttling.

Signed-off-by: Julian Sun <sunjunchao@bytedance.com>
Reviewed-by: Zhang Yi <yi.zhang@huawei.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-09-25 14:37:07 -04:00
Baokun LiandTheodore Ts'o 9d98cf4632 jbd2: prevent softlockup in jbd2_log_do_checkpoint()
Both jbd2_log_do_checkpoint() and jbd2_journal_shrink_checkpoint_list()
periodically release j_list_lock after processing a batch of buffers to
avoid long hold times on the j_list_lock. However, since both functions
contend for j_list_lock, the combined time spent waiting and processing
can be significant.

jbd2_journal_shrink_checkpoint_list() explicitly calls cond_resched() when
need_resched() is true to avoid softlockups during prolonged operations.
But jbd2_log_do_checkpoint() only exits its loop when need_resched() is
true, relying on potentially sleeping functions like __flush_batch() or
wait_on_buffer() to trigger rescheduling. If those functions do not sleep,
the kernel may hit a softlockup.

watchdog: BUG: soft lockup - CPU#3 stuck for 156s! [kworker/u129:2:373]
CPU: 3 PID: 373 Comm: kworker/u129:2 Kdump: loaded Not tainted 6.6.0+ #10
Hardware name: Huawei TaiShan 2280 /BC11SPCD, BIOS 1.27 06/13/2017
Workqueue: writeback wb_workfn (flush-7:2)
pstate: 20000005 (nzCv daif -PAN -UAO -TCO -DIT -SSBS BTYPE=--)
pc : native_queued_spin_lock_slowpath+0x358/0x418
lr : jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]
Call trace:
 native_queued_spin_lock_slowpath+0x358/0x418
 jbd2_log_do_checkpoint+0x31c/0x438 [jbd2]
 __jbd2_log_wait_for_space+0xfc/0x2f8 [jbd2]
 add_transaction_credits+0x3bc/0x418 [jbd2]
 start_this_handle+0xf8/0x560 [jbd2]
 jbd2__journal_start+0x118/0x228 [jbd2]
 __ext4_journal_start_sb+0x110/0x188 [ext4]
 ext4_do_writepages+0x3dc/0x740 [ext4]
 ext4_writepages+0xa4/0x190 [ext4]
 do_writepages+0x94/0x228
 __writeback_single_inode+0x48/0x318
 writeback_sb_inodes+0x204/0x590
 __writeback_inodes_wb+0x54/0xf8
 wb_writeback+0x2cc/0x3d8
 wb_do_writeback+0x2e0/0x2f8
 wb_workfn+0x80/0x2a8
 process_one_work+0x178/0x3e8
 worker_thread+0x234/0x3b8
 kthread+0xf0/0x108
 ret_from_fork+0x10/0x20

So explicitly call cond_resched() in jbd2_log_do_checkpoint() to avoid
softlockup.

Cc: stable@kernel.org
Signed-off-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250812063752.912130-1-libaokun@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-08-13 14:24:14 -04:00
Ingo MolnarandThomas Gleixner 41cb08555c treewide, timers: Rename from_timer() to timer_container_of()
Move this API to the canonical timer_*() namespace.

[ tglx: Redone against pre rc1 ]

Signed-off-by: Ingo Molnar <mingo@kernel.org>
Signed-off-by: Thomas Gleixner <tglx@linutronix.de>
Link: https://lore.kernel.org/all/aB2X0jCKQO56WdMt@gmail.com
2025-06-08 09:07:37 +02:00
Eric BiggersandTheodore Ts'o fff6f35b9b jbd2: remove journal_t argument from jbd2_superblock_csum()
Since jbd2_superblock_csum() no longer uses its journal_t argument,
remove it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250513053809.699974-5-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20 10:31:12 -04:00
Eric BiggersandTheodore Ts'o 76005718cf jbd2: remove journal_t argument from jbd2_chksum()
Since jbd2_chksum() no longer uses its journal_t argument, remove it.

Signed-off-by: Eric Biggers <ebiggers@google.com>
Reviewed-by: Baokun Li <libaokun1@huawei.com>
Link: https://patch.msgid.link/20250513053809.699974-4-ebiggers@kernel.org
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20 10:31:12 -04:00
Zhang YiandTheodore Ts'o d6bf294773 ext4/jbd2: convert jbd2_journal_blocks_per_page() to support large folio
jbd2_journal_blocks_per_page() returns the number of blocks in a single
page. Rename it to jbd2_journal_blocks_per_folio() and make it returns
the number of blocks in the largest folio, preparing for the calculation
of journal credits blocks when allocating blocks within a large folio in
the writeback path.

Signed-off-by: Zhang Yi <yi.zhang@huawei.com>
Link: https://patch.msgid.link/20250512063319.3539411-5-yi.zhang@huaweicloud.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-20 10:31:12 -04:00
Jeongjun ParkandTheodore Ts'o af98b0157a jbd2: fix data-race and null-ptr-deref in jbd2_journal_dirty_metadata()
Since handle->h_transaction may be a NULL pointer, so we should change it
to call is_handle_aborted(handle) first before dereferencing it.

And the following data-race was reported in my fuzzer:

==================================================================
BUG: KCSAN: data-race in jbd2_journal_dirty_metadata / jbd2_journal_dirty_metadata

write to 0xffff888011024104 of 4 bytes by task 10881 on cpu 1:
 jbd2_journal_dirty_metadata+0x2a5/0x770 fs/jbd2/transaction.c:1556
 __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
 ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
 ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
 __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
 ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....

read to 0xffff888011024104 of 4 bytes by task 10880 on cpu 0:
 jbd2_journal_dirty_metadata+0xf2/0x770 fs/jbd2/transaction.c:1512
 __ext4_handle_dirty_metadata+0xe7/0x4b0 fs/ext4/ext4_jbd2.c:358
 ext4_do_update_inode fs/ext4/inode.c:5220 [inline]
 ext4_mark_iloc_dirty+0x32c/0xd50 fs/ext4/inode.c:5869
 __ext4_mark_inode_dirty+0xe1/0x450 fs/ext4/inode.c:6074
 ext4_dirty_inode+0x98/0xc0 fs/ext4/inode.c:6103
....

value changed: 0x00000000 -> 0x00000001
==================================================================

This issue is caused by missing data-race annotation for jh->b_modified.
Therefore, the missing annotation needs to be added.

Reported-by: syzbot+de24c3fe3c4091051710@syzkaller.appspotmail.com
Closes: https://syzkaller.appspot.com/bug?extid=de24c3fe3c4091051710
Fixes: 6e06ae88ed ("jbd2: speedup jbd2_journal_dirty_metadata()")
Signed-off-by: Jeongjun Park <aha310510@gmail.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Link: https://patch.msgid.link/20250514130855.99010-1-aha310510@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Cc: stable@kernel.org
2025-05-20 10:30:37 -04:00
Harshad ShirwadkarandTheodore Ts'o 857d32f261 ext4: rework fast commit commit path
This patch reworks fast commit's commit path to remove locking the
journal for the entire duration of a fast commit. Instead, we only lock
the journal while marking all the eligible inodes as "committing". This
allows handles to make progress in parallel with the fast commit.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://patch.msgid.link/20250508175908.1004880-5-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
2025-05-08 21:56:17 -04:00