Btrfs: do not allow logged extents to be merged or removed
We drop the extent map tree lock while we're logging extents, so somebody
could come in and merge another extent into this one and screw up our
logging, or they could even remove us from the list which would keep us from
logging the extent or freeing our ref on it, so we need to make sure to not
clear LOGGING until after the extent is logged, and then we can merge it to
adjacent extents. Thanks,
Signed-off-by: Josef Bacik <jbacik@fusionio.com>
diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index 83186c7..de8899b 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -3410,13 +3410,13 @@
em = list_entry(extents.next, struct extent_map, list);
list_del_init(&em->list);
- clear_bit(EXTENT_FLAG_LOGGING, &em->flags);
/*
* If we had an error we just need to delete everybody from our
* private list.
*/
if (ret) {
+ clear_em_logging(tree, em);
free_extent_map(em);
continue;
}
@@ -3424,8 +3424,9 @@
write_unlock(&tree->lock);
ret = log_one_extent(trans, inode, root, em, path);
- free_extent_map(em);
write_lock(&tree->lock);
+ clear_em_logging(tree, em);
+ free_extent_map(em);
}
WARN_ON(!list_empty(&extents));
write_unlock(&tree->lock);