[PATCH] btrfs: Annotate structs with __counted_by()

[Thorsten Blum]

Add the __counted_by compiler attribute to the flexible array member
stripes to improve access bounds-checking via CONFIG_UBSAN_BOUNDS and
CONFIG_FORTIFY_SOURCE.

Signed-off-by: Thorsten Blum <thorsten.b...@toblux.com>
---
 fs/btrfs/volumes.h | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/fs/btrfs/volumes.h b/fs/btrfs/volumes.h
index 37a09ebb34dd..f28fa318036b 100644
--- a/fs/btrfs/volumes.h
+++ b/fs/btrfs/volumes.h
@@ -551,7 +551,7 @@ struct btrfs_io_context {
         * stripes[data_stripes + 1]:   The Q stripe (only for RAID6).
         */
        u64 full_stripe_logical;
-       struct btrfs_io_stripe stripes[];
+       struct btrfs_io_stripe stripes[] __counted_by(num_stripes);
 };
 
 struct btrfs_device_info {
@@ -591,7 +591,7 @@ struct btrfs_chunk_map {
        int io_width;
        int num_stripes;
        int sub_stripes;
-       struct btrfs_io_stripe stripes[];
+       struct btrfs_io_stripe stripes[] __counted_by(num_stripes);
 };
 
 #define btrfs_chunk_map_size(n) (sizeof(struct btrfs_chunk_map) + \
-- 
2.46.0