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authorJan Kara2012-03-13 20:43:04 +0100
committerTheodore Ts'o2012-03-13 20:43:04 +0100
commita78bb11d7acd525623c6a0c2ff4e213d527573fa (patch)
tree6e2e228cc51a2138046b499d6d9002f35f6d56d0 /fs/jbd2/commit.c
parentjbd2: split updating of journal superblock and marking journal empty (diff)
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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 <jack@suse.cz> Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/commit.c')
-rw-r--r--fs/jbd2/commit.c2
1 files changed, 2 insertions, 0 deletions
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");
}