[PATCH 3.16 126/306] jbd2: fix incorrect unlock on j_list_lock

Ben Hutchings
2017-02-15T23:15:29Z

From: Taesoo Kim <tsgatesv@gmail.com>

commit 559cce698eaf4ccecb2213b2519ea3a0413e5155 upstream.

When 'jh->b_transaction == transaction' (asserted by below)

J_ASSERT_JH(jh, (jh->b_transaction == transaction || ...

'journal->j_list_lock' will be incorrectly unlocked, since
the the lock is aquired only at the end of if / else-if
statements (missing the else case).

Signed-off-by: Taesoo Kim <tsgatesv@gmail.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Andreas Dilger <adilger@dilger.ca>
Fixes: 6e4862a5bb9d12be87e4ea5d9a60836ebed71d28
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
fs/jbd2/transaction.c | 3 ++-
1 file changed, 2 insertions(+), 1 deletion(-)

--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1093,6 +1093,7 @@ int jbd2_journal_get_create_access(handl
JBUFFER_TRACE(jh, "file as BJ_Reserved");
spin_lock(&journal->j_list_lock);
__jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
+ spin_unlock(&journal->j_list_lock);
} else if (jh->b_transaction == journal->j_committing_transaction) {
/* first access by this transaction */
jh->b_modified = 0;
@@ -1100,8 +1101,8 @@ int jbd2_journal_get_create_access(handl
JBUFFER_TRACE(jh, "set next transaction");
spin_lock(&journal->j_list_lock);
jh->b_next_transaction = transaction;
+ spin_unlock(&journal->j_list_lock);
}
- spin_unlock(&journal->j_list_lock);
jbd_unlock_bh_state(bh);

/*