Btrfs: check return value of lookup_extent_mapping() correctly
This patch corrects error checking of lookup_extent_mapping().
Signed-off-by: Tsutomu Itoh <t-itoh@jp.fujitsu.com>
diff --git a/fs/btrfs/extent_io.c b/fs/btrfs/extent_io.c
index b05d35a..8d6f55f 100644
--- a/fs/btrfs/extent_io.c
+++ b/fs/btrfs/extent_io.c
@@ -3308,7 +3308,7 @@
len = end - start + 1;
write_lock(&map->lock);
em = lookup_extent_mapping(map, start, len);
- if (IS_ERR_OR_NULL(em)) {
+ if (!em) {
write_unlock(&map->lock);
break;
}