1 files changed, 6 insertions, 0 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index a400951e8678..689d25ac6a68 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2042,6 +2042,11 @@ int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
         struct btrfs_bio *bbio = NULL;
 
 
+        /*
+         * Avoid races with device replace and make sure our bbio has devices
+         * associated to its stripes that don't go away while we are discarding.
+         */
+        btrfs_bio_counter_inc_blocked(root->fs_info);
         /* Tell the block device(s) that the sectors can be discarded */
         ret = btrfs_map_block(root->fs_info, REQ_DISCARD,
                               bytenr, &num_bytes, &bbio, 0);
@@ -2074,6 +2079,7 @@ int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr,
                 }
                 btrfs_put_bbio(bbio);
         }
+        btrfs_bio_counter_dec(root->fs_info);
 
         if (actual_bytes)
                 *actual_bytes = discarded_bytes;