btrfs: reada: Jump into cleanup in direct way for __readahead_hook()

Current code set nritems to 0 to make for_loop useless to bypass it,
and set generation's value which is not necessary.
Jump into cleanup directly is better choise.

Signed-off-by: Zhao Lei <zhaolei@cn.fujitsu.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/reada.c b/fs/btrfs/reada.c
index 6d9069d..04d3e7c 100644 (file)
--- a/fs/btrfs/reada.c
+++ b/fs/btrfs/reada.c
@@ -130,26 +130,26 @@ static void __readahead_hook(struct btrfs_fs_info *fs_info,
        re->scheduled_for = NULL;
        spin_unlock(&re->lock);
 
-       if (err == 0) {
-               nritems = level ? btrfs_header_nritems(eb) : 0;
-               generation = btrfs_header_generation(eb);
-               /*
-                * FIXME: currently we just set nritems to 0 if this is a leaf,
-                * effectively ignoring the content. In a next step we could
-                * trigger more readahead depending from the content, e.g.
-                * fetch the checksums for the extents in the leaf.
-                */
-       } else {
-               /*
-                * this is the error case, the extent buffer has not been
-                * read correctly. We won't access anything from it and
-                * just cleanup our data structures. Effectively this will
-                * cut the branch below this node from read ahead.
-                */
-               nritems = 0;
-               generation = 0;
-       }
+       /*
+        * this is the error case, the extent buffer has not been
+        * read correctly. We won't access anything from it and
+        * just cleanup our data structures. Effectively this will
+        * cut the branch below this node from read ahead.
+        */
+       if (err)
+               goto cleanup;
 
+       /*
+        * FIXME: currently we just set nritems to 0 if this is a leaf,
+        * effectively ignoring the content. In a next step we could
+        * trigger more readahead depending from the content, e.g.
+        * fetch the checksums for the extents in the leaf.
+        */
+       if (!level)
+               goto cleanup;
+
+       nritems = btrfs_header_nritems(eb);
+       generation = btrfs_header_generation(eb);
        for (i = 0; i < nritems; i++) {
                struct reada_extctl *rec;
                u64 n_gen;
@@ -188,6 +188,8 @@ static void __readahead_hook(struct btrfs_fs_info *fs_info,
                                reada_add_block(rc, bytenr, &next_key, n_gen);
                }
        }
+
+cleanup:
        /*
         * free extctl records
         */