[PATCH RFC 1/7] btrfs-progs: check/lowmem: Lookup block group item in a seperate function

Qu Wenruo
2019-11-04T12:04:18Z

In check_chunk_item() we search extent tree for block group item.

Refactor this part into a separate function, find_block_group_item(),
so that later skinny-bg-tree feature can reuse it.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
check/mode-lowmem.c | 74 ++++++++++++++++++++++++++++-----------------
1 file changed, 47 insertions(+), 27 deletions(-)

diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
index f53a0c39e86e..7ecf95ed0170 100644
--- a/check/mode-lowmem.c
+++ b/check/mode-lowmem.c
@@ -4472,6 +4472,50 @@ next:
return 0;
}

+/*
+ * Find the block group item with @bytenr, @len and @type
+ *
+ * Return 0 if found.
+ * Return -ENOENT if not found.
+ * Return <0 for fatal error.
+ */
+static int find_block_group_item(struct btrfs_fs_info *fs_info,
+ struct btrfs_path *path, u64 bytenr, u64 len,
+ u64 type)
+{
+ struct btrfs_block_group_item bgi;
+ struct btrfs_key key;
+ int ret;
+
+ key.objectid = bytenr;
+ key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
+ key.offset = len;
+
+ ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0);
+ if (ret < 0)
+ return ret;
+ if (ret > 0) {
+ ret = -ENOENT;
+ error("chunk [%llu %llu) doesn't have related block group item",
+ bytenr, bytenr + len);
+ goto out;
+ }
+ read_extent_buffer(path->nodes[0], &bgi,
+ btrfs_item_ptr_offset(path->nodes[0], path->slots[0]),
+ sizeof(bgi));
+ if (btrfs_block_group_flags(&bgi) != type) {
+ error(
+"chunk [%llu %llu) type mismatch with block group, block group has 0x%llx chunk has %llx",
+ bytenr, bytenr + len, btrfs_block_group_flags(&bgi),
+ type);
+ ret = -EUCLEAN;
+ }
+
+out:
+ btrfs_release_path(path);
+ return ret;
+}
+
/*
* Check a chunk item.
* Including checking all referred dev_extents and block group
@@ -4479,16 +4523,12 @@ next:
static int check_chunk_item(struct btrfs_fs_info *fs_info,
struct extent_buffer *eb, int slot)
{
- struct btrfs_root *extent_root = fs_info->extent_root;
struct btrfs_root *dev_root = fs_info->dev_root;
struct btrfs_path path;
struct btrfs_key chunk_key;
- struct btrfs_key bg_key;
struct btrfs_key devext_key;
struct btrfs_chunk *chunk;
struct extent_buffer *leaf;
- struct btrfs_block_group_item *bi;
- struct btrfs_block_group_item bg_item;
struct btrfs_dev_extent *ptr;
u64 length;
u64 chunk_end;
@@ -4515,31 +4555,11 @@ static int check_chunk_item(struct btrfs_fs_info *fs_info,
}
type = btrfs_chunk_type(eb, chunk);

- bg_key.objectid = chunk_key.offset;
- bg_key.type = BTRFS_BLOCK_GROUP_ITEM_KEY;
- bg_key.offset = length;
-
btrfs_init_path(&path);
- ret = btrfs_search_slot(NULL, extent_root, &bg_key, &path, 0, 0);
- if (ret) {
- error(
- "chunk[%llu %llu) did not find the related block group item",
- chunk_key.offset, chunk_end);
+ ret = find_block_group_item(fs_info, &path, chunk_key.offset, length,
+ type);
+ if (ret < 0)
err |= REFERENCER_MISSING;
- } else{
- leaf = path.nodes[0];
- bi = btrfs_item_ptr(leaf, path.slots[0],
- struct btrfs_block_group_item);
- read_extent_buffer(leaf, &bg_item, (unsigned long)bi,
- sizeof(bg_item));
- if (btrfs_block_group_flags(&bg_item) != type) {
- error(
-"chunk[%llu %llu) related block group item flags mismatch, wanted: %llu, have: %llu",
- chunk_key.offset, chunk_end, type,
- btrfs_block_group_flags(&bg_item));
- err |= REFERENCER_MISSING;
- }
- }

num_stripes = btrfs_chunk_num_stripes(eb, chunk);
stripe_len = btrfs_stripe_length(fs_info, eb, chunk);
--
2.23.0