Btrfs: fix a bug in parsing return value in logical resolve

In logical resolve, we parse extent_from_logical()'s 'ret' as a kind of flag.

It is possible to lose our errors because
(-EXXXX & BTRFS_EXTENT_FLAG_TREE_BLOCK) is true.

I'm not sure if it is on purpose, it just looks too hacky if it is.
I'd rather use a real flag and a 'ret' to catch errors.

Acked-by: Jan Schmidt <list.btrfs@jan-o-sch.net>
Signed-off-by: Liu Bo <liub.liubo@gmail.com>

1 files changed, 8 insertions, 6 deletions

diff --git a/fs/btrfs/scrub.c b/fs/btrfs/scrub.c
index 4e9eafe01c55..d3bb901ade42 100644
--- a/fs/btrfs/scrub.c
+++ b/fs/btrfs/scrub.c
@@ -352,13 +352,14 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 	struct extent_buffer *eb;
 	struct btrfs_extent_item *ei;
 	struct scrub_warning swarn;
-	u32 item_size;
-	int ret;
+	unsigned long ptr = 0;
+	u64 extent_item_pos;
+	u64 flags = 0;
 	u64 ref_root;
+	u32 item_size;
 	u8 ref_level;
-	unsigned long ptr = 0;
 	const int bufsize = 4096;
-	u64 extent_item_pos;
+	int ret;
 
 	path = btrfs_alloc_path();
 
@@ -375,7 +376,8 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 	if (!path || !swarn.scratch_buf || !swarn.msg_buf)
 		goto out;
 
-	ret = extent_from_logical(fs_info, swarn.logical, path, &found_key);
+	ret = extent_from_logical(fs_info, swarn.logical, path, &found_key,
+				  &flags);
 	if (ret < 0)
 		goto out;
 
@@ -387,7 +389,7 @@ static void scrub_print_warning(const char *errstr, struct scrub_block *sblock)
 	item_size = btrfs_item_size_nr(eb, path->slots[0]);
 	btrfs_release_path(path);
 
-	if (ret & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
+	if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) {
 		do {
 			ret = tree_backref_for_extent(&ptr, eb, ei, item_size,
 							&ref_root, &ref_level);