From a78bb11d7acd525623c6a0c2ff4e213d527573fa Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Tue, 13 Mar 2012 15:43:04 -0400 Subject: jbd2: protect all log tail updates with j_checkpoint_mutex There are some log tail updates that are not protected by j_checkpoint_mutex. Some of these are harmless because they happen during startup or shutdown but updates in jbd2_journal_commit_transaction() and jbd2_journal_flush() can really race with other log tail updates (e.g. someone doing jbd2_journal_flush() with someone running jbd2_cleanup_journal_tail()). So protect all log tail updates with j_checkpoint_mutex. Signed-off-by: Jan Kara Signed-off-by: "Theodore Ts'o" --- fs/jbd2/commit.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/jbd2/commit.c') diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 19371a8a9015..6705717d9b7f 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -340,7 +340,9 @@ void jbd2_journal_commit_transaction(journal_t *journal) /* Do we need to erase the effects of a prior jbd2_journal_flush? */ if (journal->j_flags & JBD2_FLUSHED) { jbd_debug(3, "super block updated\n"); + mutex_lock(&journal->j_checkpoint_mutex); jbd2_journal_update_sb_log_tail(journal); + mutex_unlock(&journal->j_checkpoint_mutex); } else { jbd_debug(3, "superblock not updated\n"); } -- cgit v1.2.3