[PATCH v3 0/2] jbd2: audit and convert legacy J_ASSERT usage
From: Milos Nikic
Date: Mon Mar 02 2026 - 19:55:23 EST
Hello Jan and the ext4 team,
This patch series follows up on the previous discussion regarding
converting hard J_ASSERT panics into graceful journal aborts.
In v1, we addressed a specific panic on unlock. Per Jan's suggestion,
I have audited fs/jbd2/transaction.c for other low-hanging fruit
where state machine invariants are enforced by J_ASSERT inside
functions that natively support error returns.
Changes in v3:
Patch 2: Added pr_err() statements inside the ambiguous WARN_ON_ONCE()
blocks (where multiple conditions are checked via logical OR/AND) to
explicitly dump the b_transaction, b_next_transaction, and
j_committing_transaction pointers. This provides necessary context for
debugging state machine corruptions from the dmesg stack trace.
Changes in v2:
Patch 1: Unmodified from v1. Collected Reviewed-by tags.
Patch 2: New patch resulting from the broader audit. Systematically
replaces J_ASSERTs with WARN_ON_ONCE and graceful -EINVAL returns
across 6 core transaction lifecycle functions. Careful attention was
paid to ensuring spinlocks are safely dropped before triggering
jbd2_journal_abort(), and no memory is leaked on the error paths.
Milos Nikic (2):
jbd2: gracefully abort instead of panicking on unlocked buffer
jbd2: gracefully abort on transaction state corruptions
fs/jbd2/transaction.c | 115 +++++++++++++++++++++++++++++++++---------
1 file changed, 91 insertions(+), 24 deletions(-)
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2.53.0