jbd2: check jh->b_transaction without taking j_list_lock

jh->b_transaction is adequately protected for reading by the
jbd_lock_bh_state(bh), so we don't need to take j_list_lock in
__journal_try_to_free_buffer().

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2014-03-09 00:07:19 -05:00
parent d4e839d4a9
commit d2eb0b9989

View File

@ -1821,11 +1821,11 @@ __journal_try_to_free_buffer(journal_t *journal, struct buffer_head *bh)
if (buffer_locked(bh) || buffer_dirty(bh))
goto out;
if (jh->b_next_transaction != NULL)
if (jh->b_next_transaction != NULL || jh->b_transaction != NULL)
goto out;
spin_lock(&journal->j_list_lock);
if (jh->b_cp_transaction != NULL && jh->b_transaction == NULL) {
if (jh->b_cp_transaction != NULL) {
/* written-back checkpointed metadata buffer */
JBUFFER_TRACE(jh, "remove from checkpoint list");
__jbd2_journal_remove_checkpoint(jh);