@@ -427,7 +427,7 @@ int __log_space_left(journal_t *journal)
}
/*
- * Called under j_state_lock. Returns true if a transaction was started.
+ * Called under j_state_lock. Returns true if a transaction commit was started.
*/
int __log_start_commit(journal_t *journal, tid_t target)
{
@@ -495,7 +495,8 @@ int journal_force_commit_nested(journal_
/*
* Start a commit of the current running transaction (if any). Returns true
- * if a transaction was started, and fills its tid in at *ptid
+ * if a transaction is going to be committed (or is currently already
+ * committing), and fills its tid in at *ptid
*/
int journal_start_commit(journal_t *journal, tid_t *ptid)
{
@@ -505,15 +506,19 @@ int journal_start_commit(journal_t *jour
if (journal->j_running_transaction) {
tid_t tid = journal->j_running_transaction->t_tid;
- ret = __log_start_commit(journal, tid);
- if (ret && ptid)
+ __log_start_commit(journal, tid);
+ /* There's a running transaction and we've just made sure
+ * it's commit has been scheduled. */
+ if (ptid)
*ptid = tid;
- } else if (journal->j_committing_transaction && ptid) {
+ ret = 1;
+ } else if (journal->j_committing_transaction) {
/*
* If ext3_write_super() recently started a commit, then we
* have to wait for completion of that transaction
*/
- *ptid = journal->j_committing_transaction->t_tid;
+ if (ptid)
+ *ptid = journal->j_committing_transaction->t_tid;
ret = 1;
}
spin_unlock(&journal->j_state_lock);
The patch titled jbd: fix return value of journal_start_commit() has been removed from the -mm tree. Its filename was jbd-fix-return-value-of-journal_start_commit.patch This patch was dropped because it was merged into mainline or a subsystem tree The current -mm tree may be found at http://userweb.kernel.org/~akpm/mmotm/ ------------------------------------------------------ Subject: jbd: fix return value of journal_start_commit() From: Jan Kara <jack@suse.cz> journal_start_commit() returns 1 if either a transaction is committing or the function has queued a transaction commit. But it returns 0 if we raced with somebody queueing the transaction commit as well. This resulted in ext3_sync_fs() not functioning correctly (description from Arthur Jones): In the case of a data=ordered umount with pending long symlinks which are delayed due to a long list of other I/O on the backing block device, this causes the buffer associated with the long symlinks to not be moved to the inode dirty list in the second phase of fsync_super. Then, before they can be dirtied again, kjournald exits, seeing the UMOUNT flag and the dirty pages are never written to the backing block device, causing long symlink corruption and exposing new or previously freed block data to userspace. This can be reproduced with a script created by Eric Sandeen <sandeen@redhat.com>: #!/bin/bash umount /mnt/test2 mount /dev/sdb4 /mnt/test2 rm -f /mnt/test2/* dd if=/dev/zero of=/mnt/test2/bigfile bs=1M count=512 touch /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename ln -s /mnt/test2/thisisveryveryveryveryveryveryveryveryveryveryveryveryveryveryveryverylongfilename /mnt/test2/link umount /mnt/test2 mount /dev/sdb4 /mnt/test2 ls /mnt/test2/ This patch fixes journal_start_commit() to always return 1 when there's a transaction committing or queued for commit. Cc: Eric Sandeen <sandeen@redhat.com> Cc: Mike Snitzer <snitzer@gmail.com> Cc: <linux-ext4@vger.kernel.org> Signed-off-by: Jan Kara <jack@suse.cz> Signed-off-by: Andrew Morton <akpm@linux-foundation.org> --- fs/jbd/journal.c | 17 +++++++++++------ 1 file changed, 11 insertions(+), 6 deletions(-)