btrfs: concentrate all tree block parentness check parameters into one structure

There are several different tree block parentness check parameters used
across several helpers:

- level
  Mandatory

- transid
  Under most cases it's mandatory, but there are several backref cases
  which skips this check.

- owner_root
- first_key
  Utilized by most top-down tree search routine. Otherwise can be
  skipped.

Those four members are not always mandatory checks, and some of them are
the same u64, which means if some arguments got swapped compiler will
not catch it.

Furthermore if we're going to further expand the parentness check, we
need to modify quite some helpers just to add one more parameter.

This patch will concentrate all these members into a structure called
btrfs_tree_parent_check, and pass that structure for the following
helpers:

- btrfs_read_extent_buffer()
- read_tree_block()

Signed-off-by: Qu Wenruo <wqu@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>

1 files changed, 18 insertions, 7 deletions

diff --git a/fs/btrfs/tree-log.c b/fs/btrfs/tree-log.c
index f7b1bb9c63e4..4d9f6803bfbe 100644
--- a/fs/btrfs/tree-log.c
+++ b/fs/btrfs/tree-log.c
@@ -341,7 +341,12 @@ static int process_one_buffer(struct btrfs_root *log,
 	 * pin down any logged extents, so we have to read the block.
 	 */
 	if (btrfs_fs_incompat(fs_info, MIXED_GROUPS)) {
-		ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
+		struct btrfs_tree_parent_check check = {
+			.level = level,
+			.transid = gen
+		};
+
+		ret = btrfs_read_extent_buffer(eb, &check);
 		if (ret)
 			return ret;
 	}
@@ -2411,13 +2416,17 @@ static int replay_one_buffer(struct btrfs_root *log, struct extent_buffer *eb,
 			     struct walk_control *wc, u64 gen, int level)
 {
 	int nritems;
+	struct btrfs_tree_parent_check check = {
+		.transid = gen,
+		.level = level
+	};
 	struct btrfs_path *path;
 	struct btrfs_root *root = wc->replay_dest;
 	struct btrfs_key key;
 	int i;
 	int ret;
 
-	ret = btrfs_read_extent_buffer(eb, gen, level, NULL);
+	ret = btrfs_read_extent_buffer(eb, &check);
 	if (ret)
 		return ret;
 
@@ -2597,7 +2606,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 	int ret = 0;
 
 	while (*level > 0) {
-		struct btrfs_key first_key;
+		struct btrfs_tree_parent_check check = { 0 };
 
 		cur = path->nodes[*level];
 
@@ -2609,7 +2618,10 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
 		bytenr = btrfs_node_blockptr(cur, path->slots[*level]);
 		ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]);
-		btrfs_node_key_to_cpu(cur, &first_key, path->slots[*level]);
+		check.transid = ptr_gen;
+		check.level = *level - 1;
+		check.has_first_key = true;
+		btrfs_node_key_to_cpu(cur, &check.first_key, path->slots[*level]);
 		blocksize = fs_info->nodesize;
 
 		next = btrfs_find_create_tree_block(fs_info, bytenr,
@@ -2628,8 +2640,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 
 			path->slots[*level]++;
 			if (wc->free) {
-				ret = btrfs_read_extent_buffer(next, ptr_gen,
-							*level - 1, &first_key);
+				ret = btrfs_read_extent_buffer(next, &check);
 				if (ret) {
 					free_extent_buffer(next);
 					return ret;
@@ -2657,7 +2668,7 @@ static noinline int walk_down_log_tree(struct btrfs_trans_handle *trans,
 			free_extent_buffer(next);
 			continue;
 		}
-		ret = btrfs_read_extent_buffer(next, ptr_gen, *level - 1, &first_key);
+		ret = btrfs_read_extent_buffer(next, &check);
 		if (ret) {
 			free_extent_buffer(next);
 			return ret;