jbd2: Fix barrier fallback code to re-lock the buffer head
If the device doesn't support write barriers, the write is retried
without ordered mode. But the buffer head needs to be re-locked or
submit_bh will fail with on BUG(!buffer_locked(bh)).
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 4d99685..a2ed72f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -168,6 +168,7 @@
spin_unlock(&journal->j_state_lock);
/* And try again, without the barrier */
+ lock_buffer(bh);
set_buffer_uptodate(bh);
set_buffer_dirty(bh);
ret = submit_bh(WRITE, bh);
