From 1ce8486dcc00c1e095af8d155fa4451936b89013 Mon Sep 17 00:00:00 2001 From: Jan Kara Date: Sat, 7 Apr 2012 12:50:13 +0200 Subject: jbd: 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 journal_commit_transaction() and journal_flush() can really race with other log tail updates (e.g. someone doing journal_flush() with someone running cleanup_journal_tail()). So protect all log tail updates with j_checkpoint_mutex. Signed-off-by: Jan Kara --- fs/jbd/commit.c | 2 ++ 1 file changed, 2 insertions(+) (limited to 'fs/jbd/commit.c') diff --git a/fs/jbd/commit.c b/fs/jbd/commit.c index dba9cfd75f1a..1b27f46e6108 100644 --- a/fs/jbd/commit.c +++ b/fs/jbd/commit.c @@ -308,7 +308,9 @@ void journal_commit_transaction(journal_t *journal) /* Do we need to erase the effects of a prior journal_flush? */ if (journal->j_flags & JFS_FLUSHED) { jbd_debug(3, "super block updated\n"); + mutex_lock(&journal->j_checkpoint_mutex); journal_update_sb_log_tail(journal); + mutex_unlock(&journal->j_checkpoint_mutex); } else { jbd_debug(3, "superblock not updated\n"); } -- cgit v1.2.2