kernel/linux.git/fs/jbd2, branch v7.0-rc7

jbd2: gracefully abort on checkpointing state corruptions

2026-03-28T03:34:09+00:00

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 Reviewed-by: Andreas Dilger Reviewed-by: Zhang Yi Reviewed-by: Baokun Li Reviewed-by: Jan Kara Link: https://patch.msgid.link/20260311041548.159424-1-nikic.milos@gmail.com Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

Convert more 'alloc_obj' cases to default GFP_KERNEL arguments

2026-02-22T04:03:00+00:00

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

Convert 'alloc_obj' family to use the new default GFP_KERNEL argument

2026-02-22T01:09:51+00:00

This was done entirely with mindless brute force, using git grep -l '\

treewide: Replace kmalloc with kmalloc_obj for non-scalar types

2026-02-21T09:02:28+00:00

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

jbd2: fix the inconsistency between checksum and data in memory for journal sb

2025-11-26T22:05:47+00:00

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: 4fd5ea43bc11 ("jbd2: checksum journal superblock") Signed-off-by: Ye Bin Reviewed-by: Baokun Li Reviewed-by: Darrick J. Wong Reviewed-by: Jan Kara Message-ID: <20251103010123.3753631-1-yebin@huaweicloud.com> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

jbd2: store more accurate errno in superblock when possible

2025-11-26T22:05:39+00:00

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 Reviewed-by: Zhang Yi Message-ID: <20251031210501.7337-1-wen.gang.wang@oracle.com> Signed-off-by: Theodore Ts'o

jbd2: avoid bug_on in jbd2_journal_get_create_access() when file system corrupted

2025-11-26T22:05:02+00:00

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: __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: 470decc613ab ("[PATCH] jbd2: initial copy of files from jbd") Signed-off-by: Ye Bin Reviewed-by: Jan Kara Message-ID: <20251025072657.307851-1-yebin@huaweicloud.com> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

jbd2: use a weaker annotation in journal handling

2025-11-13T13:43:44+00:00

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 Reviewed-by: Jan Kara Cc: stable@kernel.org Message-ID: <20251024073940.1063-1-byungchul@sk.com> Signed-off-by: Theodore Ts'o

jbd2: use a per-journal lock_class_key for jbd2_trans_commit_key

2025-11-13T13:34:39+00:00

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 Tested-by: syzbot+6e493c165d26d6fcbf72@syzkaller.appspotmail.com Reviewed-by: Jan Kara Message-ID: <987110fc-5470-457a-a218-d286a09dd82f@I-love.SAKURA.ne.jp> Signed-off-by: Theodore Ts'o Cc: stable@kernel.org

jbd2: ensure that all ongoing I/O complete before freeing blocks

2025-10-10T17:10:06+00:00

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: 597599268e3b ("jbd2: discard dirty data when forgetting an un-journalled buffer") Cc: stable@kernel.org Suggested-by: Jan Kara Signed-off-by: Zhang Yi Reviewed-by: Jan Kara Message-ID: <20250916093337.3161016-2-yi.zhang@huaweicloud.com> Signed-off-by: Theodore Ts'o