btrfs: use btrfs_read_node_slot in do_relocation

We're open coding btrfs_read_node_slot in do_relocation, replace this
with the proper helper.

Reviewed-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: Josef Bacik <josef@toxicpanda.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 91ed88e..57efb90 100644 (file)
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -2191,7 +2191,6 @@ static int do_relocation(struct btrfs_trans_handle *trans,
                         struct btrfs_key *key,
                         struct btrfs_path *path, int lowest)
 {
-       struct btrfs_fs_info *fs_info = rc->extent_root->fs_info;
        struct btrfs_backref_node *upper;
        struct btrfs_backref_edge *edge;
        struct btrfs_backref_edge *edges[BTRFS_MAX_LEVEL - 1];
@@ -2199,7 +2198,6 @@ static int do_relocation(struct btrfs_trans_handle *trans,
        struct extent_buffer *eb;
        u32 blocksize;
        u64 bytenr;
-       u64 generation;
        int slot;
        int ret;
        int err = 0;
@@ -2209,7 +2207,6 @@ static int do_relocation(struct btrfs_trans_handle *trans,
        path->lowest_level = node->level + 1;
        rc->backref_cache.path[node->level] = node;
        list_for_each_entry(edge, &node->upper, list[LOWER]) {
-               struct btrfs_key first_key;
                struct btrfs_ref ref = { 0 };
 
                cond_resched();
@@ -2282,17 +2279,10 @@ static int do_relocation(struct btrfs_trans_handle *trans,
                }
 
                blocksize = root->fs_info->nodesize;
-               generation = btrfs_node_ptr_generation(upper->eb, slot);
-               btrfs_node_key_to_cpu(upper->eb, &first_key, slot);
-               eb = read_tree_block(fs_info, bytenr, generation,
-                                    upper->level - 1, &first_key);
+               eb = btrfs_read_node_slot(upper->eb, slot);
                if (IS_ERR(eb)) {
                        err = PTR_ERR(eb);
                        goto next;
-               } else if (!extent_buffer_uptodate(eb)) {
-                       free_extent_buffer(eb);
-                       err = -EIO;
-                       goto next;
                }
                btrfs_tree_lock(eb);