1 files changed, 20 insertions, 7 deletions

diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c
index 689d25ac6a68..82b912a293ab 100644
--- a/fs/btrfs/extent-tree.c
+++ b/fs/btrfs/extent-tree.c
@@ -2835,6 +2835,7 @@ int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans,
 
 struct async_delayed_refs {
         struct btrfs_root *root;
+        u64 transid;
         int count;
         int error;
         int sync;
@@ -2850,6 +2851,10 @@ static void delayed_ref_async_start(struct btrfs_work *work)
 
         async = container_of(work, struct async_delayed_refs, work);
 
+        /* if the commit is already started, we don't need to wait here */
+        if (btrfs_transaction_blocked(async->root->fs_info))
+                goto done;
+
         trans = btrfs_join_transaction(async->root);
         if (IS_ERR(trans)) {
                 async->error = PTR_ERR(trans);
@@ -2861,10 +2866,15 @@ static void delayed_ref_async_start(struct btrfs_work *work)
          * wait on delayed refs
          */
         trans->sync = true;
+
+        /* Don't bother flushing if we got into a different transaction */
+        if (trans->transid > async->transid)
+                goto end;
+
         ret = btrfs_run_delayed_refs(trans, async->root, async->count);
         if (ret)
                 async->error = ret;
-
+end:
         ret = btrfs_end_transaction(trans, async->root);
         if (ret && !async->error)
                 async->error = ret;
@@ -2876,7 +2886,7 @@ done:
 }
 
 int btrfs_async_run_delayed_refs(struct btrfs_root *root,
-                                 unsigned long count, int wait)
+                                 unsigned long count, u64 transid, int wait)
 {
         struct async_delayed_refs *async;
         int ret;
@@ -2888,6 +2898,7 @@ int btrfs_async_run_delayed_refs(struct btrfs_root *root,
         async->root = root->fs_info->tree_root;
         async->count = count;
         async->error = 0;
+        async->transid = transid;
         if (wait)
                 async->sync = 1;
         else
@@ -8016,8 +8027,9 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
         struct extent_buffer *buf;
 
         buf = btrfs_find_create_tree_block(root, bytenr);
-        if (!buf)
-                return ERR_PTR(-ENOMEM);
+        if (IS_ERR(buf))
+                return buf;
+
         btrfs_set_header_generation(buf, trans->transid);
         btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level);
         btrfs_tree_lock(buf);
@@ -8044,7 +8056,7 @@ btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root,
                 set_extent_dirty(&trans->transaction->dirty_pages, buf->start,
                          buf->start + buf->len - 1, GFP_NOFS);
         }
-        trans->blocks_used++;
+        trans->dirty = true;
         /* this returns a buffer locked for blocking */
         return buf;
 }
@@ -8659,8 +8671,9 @@ static noinline int do_walk_down(struct btrfs_trans_handle *trans,
         next = btrfs_find_tree_block(root->fs_info, bytenr);
         if (!next) {
                 next = btrfs_find_create_tree_block(root, bytenr);
-                if (!next)
-                        return -ENOMEM;
+                if (IS_ERR(next))
+                        return PTR_ERR(next);
+
                 btrfs_set_buffer_lockdep_class(root->root_key.objectid, next,
                                                level - 1);
                 reada = 1;