[PATCH 5.10 303/491] jbd2: gracefully abort on checkpointing state corruptions

Greg Kroah-Hartman
2026-04-13T16:55:42Z

From: Milos Nikic <nikic.milos@gmail.com>

commit bac3190a8e79beff6ed221975e0c9b1b5f2a21da upstream.

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
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
fs/jbd2/checkpoint.c | 15 +++++++++++++--
1 file changed, 13 insertions(+), 2 deletions(-)

--- a/fs/jbd2/checkpoint.c
+++ b/fs/jbd2/checkpoint.c
@@ -303,7 +303,15 @@ restart:
*/
BUFFER_TRACE(bh, "queue");
get_bh(bh);
- J_ASSERT_BH(bh, !buffer_jwrite(bh));
+ if (WARN_ON_ONCE(buffer_jwrite(bh))) {
+ put_bh(bh); /* drop the ref we just took */
+ spin_unlock(&journal->j_list_lock);
+ /* Clean up any previously batched buffers */
+ if (batch_count)
+ __flush_batch(journal, &batch_count);
+ jbd2_journal_abort(journal, -EFSCORRUPTED);
+ return -EFSCORRUPTED;
+ }
journal->j_chkpt_bhs[batch_count++] = bh;
transaction->t_chp_stats.cs_written++;
transaction->t_checkpoint_list = jh->b_cpnext;
@@ -361,7 +369,10 @@ int jbd2_cleanup_journal_tail(journal_t

if (!jbd2_journal_get_log_tail(journal, &first_tid, &blocknr))
return 1;
- J_ASSERT(blocknr != 0);
+ if (WARN_ON_ONCE(blocknr == 0)) {
+ jbd2_journal_abort(journal, -EFSCORRUPTED);
+ return -EFSCORRUPTED;
+ }

/*
* We need to make sure that any blocks that were recently written out