jbd2: minimize region locked by j_list_lock in journal_get_create_access()

It's not needed until we start trying to modifying fields in the
journal_head which are protected by j_list_lock.

Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 2 insertions, 1 deletions

diff --git a/fs/jbd2/transaction.c b/fs/jbd2/transaction.c
index 78900a1252b2..357f3dc5201f 100644
--- a/fs/jbd2/transaction.c
+++ b/fs/jbd2/transaction.c
@@ -1073,7 +1073,6 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
          * reused here.
          */
         jbd_lock_bh_state(bh);
-        spin_lock(&journal->j_list_lock);
         J_ASSERT_JH(jh, (jh->b_transaction == transaction ||
                 jh->b_transaction == NULL ||
                 (jh->b_transaction == journal->j_committing_transaction &&
@@ -1096,12 +1095,14 @@ int jbd2_journal_get_create_access(handle_t *handle, struct buffer_head *bh)
                 jh->b_modified = 0;
 
                 JBUFFER_TRACE(jh, "file as BJ_Reserved");
+                spin_lock(&journal->j_list_lock);
                 __jbd2_journal_file_buffer(jh, transaction, BJ_Reserved);
         } else if (jh->b_transaction == journal->j_committing_transaction) {
                 /* first access by this transaction */
                 jh->b_modified = 0;
 
                 JBUFFER_TRACE(jh, "set next transaction");
+                spin_lock(&journal->j_list_lock);
                 jh->b_next_transaction = transaction;
         }
         spin_unlock(&journal->j_list_lock);