btrfs: eliminate err variable from merge_reloc_root

In most cases when an error is returned from a function 'ret' is simply
assigned to 'err'. There is only one case where walk_up_reloc_tree can
return a positive value - in this case the code breaks from the loop and
ret is going to get its return value from btrfs_cow_block - either 0 or
negative. This retains the old logic of how 'err' used to be set at
this call site.

Signed-off-by: Nikolay Borisov <nborisov@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index c5774a8..8fc75db 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -1630,8 +1630,7 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
        int level;
        int max_level;
        int replaced = 0;
-       int ret;
-       int err = 0;
+       int ret = 0;
        u32 min_reserved;
 
        path = btrfs_alloc_path();
@@ -1682,13 +1681,11 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
        while (1) {
                ret = btrfs_block_rsv_refill(root, rc->block_rsv, min_reserved,
                                             BTRFS_RESERVE_FLUSH_LIMIT);
-               if (ret) {
-                       err = ret;
+               if (ret)
                        goto out;
-               }
                trans = btrfs_start_transaction(root, 0);
                if (IS_ERR(trans)) {
-                       err = PTR_ERR(trans);
+                       ret = PTR_ERR(trans);
                        trans = NULL;
                        goto out;
                }
@@ -1710,10 +1707,8 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
                max_level = level;
 
                ret = walk_down_reloc_tree(reloc_root, path, &level);
-               if (ret < 0) {
-                       err = ret;
+               if (ret < 0)
                        goto out;
-               }
                if (ret > 0)
                        break;
 
@@ -1724,11 +1719,8 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
                        ret = replace_path(trans, rc, root, reloc_root, path,
                                           &next_key, level, max_level);
                }
-               if (ret < 0) {
-                       err = ret;
+               if (ret < 0)
                        goto out;
-               }
-
                if (ret > 0) {
                        level = ret;
                        btrfs_node_key_to_cpu(path->nodes[level], &key,
@@ -1767,12 +1759,10 @@ static noinline_for_stack int merge_reloc_root(struct reloc_control *rc,
                              BTRFS_NESTING_COW);
        btrfs_tree_unlock(leaf);
        free_extent_buffer(leaf);
-       if (ret < 0)
-               err = ret;
 out:
        btrfs_free_path(path);
 
-       if (err == 0)
+       if (ret == 0)
                insert_dirty_subvol(trans, rc, root);
 
        if (trans)
@@ -1783,7 +1773,7 @@ out:
        if (replaced && rc->stage == UPDATE_DATA_PTRS)
                invalidate_extent_cache(root, &key, &next_key);
 
-       return err;
+       return ret;
 }
 
 static noinline_for_stack