jbd2: don't read journal->j_commit_sequence without taking a lock

Take journal state lock before reading journal->j_commit_sequence.

Signed-off-by: Harshad Shirwadkar <harshadshirwadkar@gmail.com>
Link: https://lore.kernel.org/r/20201106035911.1942128-13-harshadshirwadkar@gmail.com
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Harshad Shirwadkar 2020-11-05 19:59:01 -08:00 committed by Theodore Ts'o
parent 0ee66ddcf3
commit 480f89d553

View File

@ -734,10 +734,12 @@ int jbd2_fc_begin_commit(journal_t *journal, tid_t tid)
if (!journal->j_stats.ts_tid)
return -EINVAL;
if (tid <= journal->j_commit_sequence)
return -EALREADY;
write_lock(&journal->j_state_lock);
if (tid <= journal->j_commit_sequence) {
write_unlock(&journal->j_state_lock);
return -EALREADY;
}
if (journal->j_flags & JBD2_FULL_COMMIT_ONGOING ||
(journal->j_flags & JBD2_FAST_COMMIT_ONGOING)) {
DEFINE_WAIT(wait);