btrfs: remove redundant extent_buffer_uptodate() checks after read_tree_block()

We have several places that call extent_buffer_uptodate() after reading a
tree block with read_tree_block(), but that is redundant since we already
call extent_buffer_uptodate() in the call chain of read_tree_block():

  read_tree_block()
     btrfs_read_extent_buffer()
        read_extent_buffer_pages()
           returns -EIO if extent_buffer_uptodate() returns false

So remove those redundant checks.

Reviewed-by: Boris Burkov <boris@bur.io>
Signed-off-by: Filipe Manana <fdmanana@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

fs/btrfs/backref.c

@@ -858,11 +858,6 @@ static int add_missing_keys(struct btrfs_fs_info *fs_info,
 			free_pref(ref);
 			return PTR_ERR(eb);
 		}
-		if (unlikely(!extent_buffer_uptodate(eb))) {
-			free_pref(ref);
-			free_extent_buffer(eb);
-			return -EIO;
-		}
 
 		if (lock)
 			btrfs_tree_read_lock(eb);
@@ -1620,11 +1615,6 @@ static int find_parent_nodes(struct btrfs_backref_walk_ctx *ctx,
 					ret = PTR_ERR(eb);
 					goto out;
 				}
-				if (unlikely(!extent_buffer_uptodate(eb))) {
-					free_extent_buffer(eb);
-					ret = -EIO;
-					goto out;
-				}
 
 				if (!path->skip_locking)
 					btrfs_tree_read_lock(eb);

fs/btrfs/ctree.c

@@ -822,7 +822,6 @@ struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
 {
 	int level = btrfs_header_level(parent);
 	struct btrfs_tree_parent_check check = { 0 };
-	struct extent_buffer *eb;
 
 	if (slot < 0 || slot >= btrfs_header_nritems(parent))
 		return ERR_PTR(-ENOENT);
@@ -835,16 +834,8 @@ struct extent_buffer *btrfs_read_node_slot(struct extent_buffer *parent,
 	check.has_first_key = true;
 	btrfs_node_key_to_cpu(parent, &check.first_key, slot);
 
-	eb = read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot),
-			     &check);
-	if (IS_ERR(eb))
-		return eb;
-	if (unlikely(!extent_buffer_uptodate(eb))) {
-		free_extent_buffer(eb);
-		return ERR_PTR(-EIO);
-	}
-
-	return eb;
+	return read_tree_block(parent->fs_info, btrfs_node_blockptr(parent, slot),
+			       &check);
 }
 
 /*

fs/btrfs/disk-io.c

@@ -2024,11 +2024,6 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 		btrfs_put_root(log_tree_root);
 		return ret;
 	}
-	if (unlikely(!extent_buffer_uptodate(log_tree_root->node))) {
-		btrfs_err(fs_info, "failed to read log tree");
-		btrfs_put_root(log_tree_root);
-		return -EIO;
-	}
 
 	/* returns with log_tree_root freed on success */
 	ret = btrfs_recover_log_trees(log_tree_root);
@@ -2628,11 +2623,6 @@ static int load_super_root(struct btrfs_root *root, u64 bytenr, u64 gen, int lev
 		root->node = NULL;
 		return ret;
 	}
-	if (unlikely(!extent_buffer_uptodate(root->node))) {
-		free_extent_buffer(root->node);
-		root->node = NULL;
-		return -EIO;
-	}
 
 	btrfs_set_root_node(&root->root_item, root->node);
 	root->commit_root = btrfs_root_node(root);

fs/btrfs/print-tree.c

@@ -626,10 +626,6 @@ void btrfs_print_tree(const struct extent_buffer *c, bool follow)
 		next = read_tree_block(fs_info, btrfs_node_blockptr(c, i), &check);
 		if (IS_ERR(next))
 			continue;
-		if (!extent_buffer_uptodate(next)) {
-			free_extent_buffer(next);
-			continue;
-		}
 
 		if (btrfs_is_leaf(next) &&
 		   level != 1)

fs/btrfs/qgroup.c

@@ -4883,10 +4883,6 @@ int btrfs_qgroup_trace_subtree_after_cow(struct btrfs_trans_handle *trans,
 		reloc_eb = NULL;
 		goto free_out;
 	}
-	if (unlikely(!extent_buffer_uptodate(reloc_eb))) {
-		ret = -EIO;
-		goto free_out;
-	}
 
 	ret = qgroup_trace_subtree_swap(trans, reloc_eb, subvol_eb,
 			block->last_snapshot, block->trace_leaf);

fs/btrfs/relocation.c

@@ -2440,10 +2440,7 @@ static int get_tree_block_key(struct btrfs_fs_info *fs_info,
 	eb = read_tree_block(fs_info, block->bytenr, &check);
 	if (IS_ERR(eb))
 		return PTR_ERR(eb);
-	if (unlikely(!extent_buffer_uptodate(eb))) {
-		free_extent_buffer(eb);
-		return -EIO;
-	}
+
 	if (block->level == 0)
 		btrfs_item_key_to_cpu(eb, &block->key, 0);
 	else

fs/btrfs/tree-mod-log.c

@@ -1042,12 +1042,10 @@ struct extent_buffer *btrfs_get_old_root(struct btrfs_root *root, u64 time_seq)
 		check.owner_root = btrfs_root_id(root);
 
 		old = read_tree_block(fs_info, logical, &check);
-		if (WARN_ON(IS_ERR(old) || !extent_buffer_uptodate(old))) {
-			if (!IS_ERR(old))
-				free_extent_buffer(old);
+		if (WARN_ON(IS_ERR(old))) {
 			btrfs_warn(fs_info,
-				   "failed to read tree block %llu from get_old_root",
-				   logical);
+				   "failed to read tree block %llu from get_old_root: %ld",
+				   logical, PTR_ERR(old));
 		} else {
 			struct tree_mod_elem *tm2;