Btrfs: make sure we wait on logged extents when fsycning two subvols

If we have two fsync()'s race on different subvols one will do all of its work
to get into the log_tree, wait on it's outstanding IO, and then allow the
log_tree to finish it's commit.  The problem is we were just free'ing that
subvols logged extents instead of waiting on them, so whoever lost the race
wouldn't really have their data on disk.  Fix this by waiting properly instead
of freeing the logged extents.  Thanks,

cc: stable@vger.kernel.org
Signed-off-by: Josef Bacik <jbacik@fb.com>
Signed-off-by: Chris Mason <clm@fb.com>
This commit is contained in:
Josef Bacik 2014-11-06 10:19:54 -05:00 committed by Chris Mason
parent 0d95c1bec9
commit 9dba8cf128

View file

@ -2600,9 +2600,9 @@ int btrfs_sync_log(struct btrfs_trans_handle *trans,
if (atomic_read(&log_root_tree->log_commit[index2])) { if (atomic_read(&log_root_tree->log_commit[index2])) {
blk_finish_plug(&plug); blk_finish_plug(&plug);
btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark); btrfs_wait_marked_extents(log, &log->dirty_log_pages, mark);
btrfs_wait_logged_extents(log, log_transid);
wait_log_commit(trans, log_root_tree, wait_log_commit(trans, log_root_tree,
root_log_ctx.log_transid); root_log_ctx.log_transid);
btrfs_free_logged_extents(log, log_transid);
mutex_unlock(&log_root_tree->log_mutex); mutex_unlock(&log_root_tree->log_mutex);
ret = root_log_ctx.log_ret; ret = root_log_ctx.log_ret;
goto out; goto out;