diff options
Diffstat (limited to 'fs/btrfs/backref.c')
| -rw-r--r-- | fs/btrfs/backref.c | 11 |
1 files changed, 10 insertions, 1 deletions
diff --git a/fs/btrfs/backref.c b/fs/btrfs/backref.c index e4054e533f6d..f94b2d8c744a 100644 --- a/fs/btrfs/backref.c +++ b/fs/btrfs/backref.c @@ -1264,7 +1264,16 @@ again: while (node) { ref = rb_entry(node, struct prelim_ref, rbnode); node = rb_next(&ref->rbnode); - WARN_ON(ref->count < 0); + /* + * ref->count < 0 can happen here if there are delayed + * refs with a node->action of BTRFS_DROP_DELAYED_REF. + * prelim_ref_insert() relies on this when merging + * identical refs to keep the overall count correct. + * prelim_ref_insert() will merge only those refs + * which compare identically. Any refs having + * e.g. different offsets would not be merged, + * and would retain their original ref->count < 0. + */ if (roots && ref->count && ref->root_id && ref->parent == 0) { if (sc && sc->root_objectid && ref->root_id != sc->root_objectid) { |