1 files changed, 8 insertions, 3 deletions

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index 45bc3132b054..45b4f7285275 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -460,6 +460,13 @@ int btrfs_wq_submit_bio(struct btrfs_fs_info *fs_info, struct inode *inode,
         async->submit_bio_hook = submit_bio_hook;
         async->work.func = run_one_async_submit;
         async->work.flags = 0;
+
+        while(atomic_read(&fs_info->async_submit_draining) &&
+              atomic_read(&fs_info->nr_async_submits)) {
+                wait_event(fs_info->async_submit_wait,
+                           (atomic_read(&fs_info->nr_async_submits) == 0));
+        }
+
         atomic_inc(&fs_info->nr_async_submits);
         btrfs_queue_worker(&fs_info->workers, &async->work);
 
@@ -495,11 +502,8 @@ static int __btree_submit_bio_hook(struct inode *inode, int rw, struct bio *bio,
                                  int mirror_num)
 {
         struct btrfs_root *root = BTRFS_I(inode)->root;
-        u64 offset;
         int ret;
 
-        offset = bio->bi_sector << 9;
-
         /*
          * when we're called for a write, we're already in the async
          * submission context.  Just jump into btrfs_map_bio
@@ -1360,6 +1364,7 @@ struct btrfs_root *open_ctree(struct super_block *sb,
         INIT_LIST_HEAD(&fs_info->space_info);
         btrfs_mapping_init(&fs_info->mapping_tree);
         atomic_set(&fs_info->nr_async_submits, 0);
+        atomic_set(&fs_info->async_submit_draining, 0);
         atomic_set(&fs_info->nr_async_bios, 0);
         atomic_set(&fs_info->throttles, 0);
         atomic_set(&fs_info->throttle_gen, 0);