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jbd: protect all log tail updates with j_checkpoint_mutex

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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 <jack@suse.cz>
This commit is contained in:
Jan Kara 2012-04-07 12:50:13 +02:00
parent 9754e39c7b
commit 1ce8486dcc
2 changed files with 17 additions and 1 deletions
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2
fs/jbd/commit.c
View file

@ -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");
}

16
fs/jbd/journal.c
View file

@ -936,8 +936,11 @@ static int journal_reset(journal_t *journal)
journal->j_errno);
journal->j_flags |= JFS_FLUSHED;
} else {
/* Lock here to make assertions happy... */
mutex_lock(&journal->j_checkpoint_mutex);
/* Add the dynamic fields and write it to disk. */
journal_update_sb_log_tail(journal);
mutex_unlock(&journal->j_checkpoint_mutex);
}
return journal_start_thread(journal);
}
@ -1061,6 +1064,7 @@ void journal_update_sb_log_tail(journal_t *journal)
{
journal_superblock_t *sb = journal->j_superblock;
BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
spin_lock(&journal->j_state_lock);
jbd_debug(1,"JBD: updating superblock (start %u, seq %d, errno %d)\n",
journal->j_tail, journal->j_tail_sequence, journal->j_errno);
@ -1089,6 +1093,7 @@ static void mark_journal_empty(journal_t *journal)
{
journal_superblock_t *sb = journal->j_superblock;
BUG_ON(!mutex_is_locked(&journal->j_checkpoint_mutex));
spin_lock(&journal->j_state_lock);
jbd_debug(1, "JBD: Marking journal as empty (seq %d)\n",
journal->j_tail_sequence);
@ -1293,6 +1298,8 @@ int journal_destroy(journal_t *journal)
/* Force any old transactions to disk */
/* We cannot race with anybody but must keep assertions happy */
mutex_lock(&journal->j_checkpoint_mutex);
/* Totally anal locking here... */
spin_lock(&journal->j_list_lock);
while (journal->j_checkpoint_transactions != NULL) {
@ -1315,6 +1322,7 @@ int journal_destroy(journal_t *journal)
err = -EIO;
brelse(journal->j_sb_buffer);
}
mutex_unlock(&journal->j_checkpoint_mutex);
if (journal->j_inode)
iput(journal->j_inode);
@ -1528,6 +1536,7 @@ int journal_flush(journal_t *journal)
if (is_journal_aborted(journal))
return -EIO;
mutex_lock(&journal->j_checkpoint_mutex);
cleanup_journal_tail(journal);
/* Finally, mark the journal as really needing no recovery.
@ -1536,6 +1545,7 @@ int journal_flush(journal_t *journal)
* commits of data to the journal will restore the current
* s_start value. */
mark_journal_empty(journal);
mutex_unlock(&journal->j_checkpoint_mutex);
spin_lock(&journal->j_state_lock);
J_ASSERT(!journal->j_running_transaction);
J_ASSERT(!journal->j_committing_transaction);
@ -1576,8 +1586,12 @@ int journal_wipe(journal_t *journal, int write)
write ? "Clearing" : "Ignoring");
err = journal_skip_recovery(journal);
if (write)
if (write) {
/* Lock to make assertions happy... */
mutex_lock(&journal->j_checkpoint_mutex);
mark_journal_empty(journal);
mutex_unlock(&journal->j_checkpoint_mutex);
}
no_recovery:
return err;