Btrfs: fix a out-of-bound access of raid_map
We add the number of stripes on target devices into bbio->num_stripes
if we are under device replacement, and we just sort the raid_map of
those stripes that not on the target devices, so if when we need
real raid_map, we need skip the stripes on the target devices.
Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: Miao Xie <miaox@cn.fujitsu.com>
Signed-off-by: Chris Mason <clm@fb.com>
diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 53575a4..673e32b 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -1299,7 +1299,9 @@
static inline int scrub_nr_raid_mirrors(struct btrfs_bio *bbio, u64 *raid_map)
{
if (raid_map) {
- if (raid_map[bbio->num_stripes - 1] == RAID6_Q_STRIPE)
+ int real_stripes = bbio->num_stripes - bbio->num_tgtdevs;
+
+ if (raid_map[real_stripes - 1] == RAID6_Q_STRIPE)
return 3;
else
return 2;
@@ -1420,7 +1422,8 @@
scrub_stripe_index_and_offset(logical, raid_map,
mapped_length,
- bbio->num_stripes,
+ bbio->num_stripes -
+ bbio->num_tgtdevs,
mirror_index,
&stripe_index,
&stripe_offset);