Don''t dereference em if it''s NULL or an error pointer.
Signed-off-by: Roel Kluin <roel.kluin@gmail.com>
---
I just noticed this by code analysis. It wasn''t tested in any way.
fs/btrfs/inode.c | 3 ++-
1 files changed, 2 insertions(+), 1 deletions(-)
diff --git a/fs/btrfs/inode.c b/fs/btrfs/inode.c
index c038644..d4a37f8 100644
--- a/fs/btrfs/inode.c
+++ b/fs/btrfs/inode.c
@@ -1787,7 +1787,8 @@ static int btrfs_io_failed_hook(struct bio *failed_bio,
read_lock(&em_tree->lock);
em = lookup_extent_mapping(em_tree, start, failrec->len);
- if (em->start > start || em->start + em->len < start) {
+ if (em && !IS_ERR(em) && (em->start > start ||
+ em->start + em->len < start)) {
free_extent_map(em);
em = NULL;
}