diff options
| author | Jan Kara <jack@suse.cz> | 2012-03-13 15:43:04 -0400 |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-03-13 15:43:04 -0400 |
| commit | a78bb11d7acd525623c6a0c2ff4e213d527573fa (patch) | |
| tree | 6e2e228cc51a2138046b499d6d9002f35f6d56d0 /fs/jbd2 | |
| parent | 24bcc89c7e7c64982e6192b4952a0a92379fc341 (diff) | |
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')
| -rw-r--r-- | fs/jbd2/commit.c | 2 | ||||
| -rw-r--r-- | fs/jbd2/journal.c | 19 |
2 files changed, 18 insertions, 3 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 19371a8a901..6705717d9b7 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"); } diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 6e75fbd75ba..fc5f2acc9f1 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -1123,8 +1123,11 @@ static int journal_reset(journal_t *journal) journal->j_errno); journal->j_flags |= JBD2_FLUSHED; } else { + /* Lock here to make assertions happy... */ + mutex_lock(&journal->j_checkpoint_mutex); /* Add the dynamic fields and write it to disk. */ jbd2_journal_update_sb_log_tail(journal); + mutex_unlock(&journal->j_checkpoint_mutex); } return jbd2_journal_start_thread(journal); } @@ -1173,6 +1176,7 @@ void jbd2_journal_update_sb_log_tail(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; + BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); read_lock(&journal->j_state_lock); jbd_debug(1, "JBD2: updating superblock (start %ld, seq %d)\n", journal->j_tail, journal->j_tail_sequence); @@ -1201,6 +1205,7 @@ static void jbd2_mark_journal_empty(journal_t *journal) { journal_superblock_t *sb = journal->j_superblock; + BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex)); read_lock(&journal->j_state_lock); jbd_debug(1, "JBD2: Marking journal as empty (seq %d)\n", journal->j_tail_sequence); @@ -1434,9 +1439,11 @@ int jbd2_journal_destroy(journal_t *journal) spin_unlock(&journal->j_list_lock); if (journal->j_sb_buffer) { - if (!is_journal_aborted(journal)) + if (!is_journal_aborted(journal)) { + mutex_lock(&journal->j_checkpoint_mutex); jbd2_mark_journal_empty(journal); - else + mutex_unlock(&journal->j_checkpoint_mutex); + } else err = -EIO; brelse(journal->j_sb_buffer); } @@ -1630,6 +1637,7 @@ int jbd2_journal_flush(journal_t *journal) if (is_journal_aborted(journal)) return -EIO; + mutex_lock(&journal->j_checkpoint_mutex); jbd2_cleanup_journal_tail(journal); /* Finally, mark the journal as really needing no recovery. @@ -1638,6 +1646,7 @@ int jbd2_journal_flush(journal_t *journal) * commits of data to the journal will restore the current * s_start value. */ jbd2_mark_journal_empty(journal); + mutex_unlock(&journal->j_checkpoint_mutex); write_lock(&journal->j_state_lock); J_ASSERT(!journal->j_running_transaction); J_ASSERT(!journal->j_committing_transaction); @@ -1678,8 +1687,12 @@ int jbd2_journal_wipe(journal_t *journal, int write) write ? "Clearing" : "Ignoring"); err = jbd2_journal_skip_recovery(journal); - if (write) + if (write) { + /* Lock to make assertions happy... */ + mutex_lock(&journal->j_checkpoint_mutex); jbd2_mark_journal_empty(journal); + mutex_unlock(&journal->j_checkpoint_mutex); + } no_recovery: return err; |