When we do backref walking, we search firstly in queued delayed refs and then the on-disk backrefs, but we parse differently for shared references, for delayed refs we also add 'ref->root' while for on-disk backrefs we don't, this can prevent us from merging refs indexed by the same bytenr and cause find_parent_nodes() to throw a warning at 'WARN_ON(ref->count < 0)', for example, when we have a shared data extent with 'ref_cnt=1' and a delayed shared data with a BTRFS_DROP_DELAYED_REF, that happens. For shared references, no matter if it's delayed or on-disk, ref->root is not at all used, instead it's ref->parent that really matters, so this has delayed refs handled as the same way as on-disk refs. Signed-off-by: Liu Bo <bo.li.liu@xxxxxxxxxx> --- fs/btrfs/backref.c | 5 ++--- 1 file changed, 2 insertions(+), 3 deletions(-) diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index 802fabb..2485b868 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -632,7 +632,7 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, struct btrfs_delayed_tree_ref *ref; ref = btrfs_delayed_node_to_tree_ref(node); - ret = __add_prelim_ref(prefs, ref->root, NULL, + ret = __add_prelim_ref(prefs, 0, NULL, ref->level + 1, ref->parent, node->bytenr, node->ref_mod * sgn, GFP_ATOMIC); @@ -665,10 +665,9 @@ static int __add_delayed_refs(struct btrfs_delayed_ref_head *head, u64 seq, ref = btrfs_delayed_node_to_data_ref(node); - key.objectid = ref->objectid; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = ref->offset; - ret = __add_prelim_ref(prefs, ref->root, &key, 0, + ret = __add_prelim_ref(prefs, 0, NULL, 0, ref->parent, node->bytenr, node->ref_mod * sgn, GFP_ATOMIC); break; -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
