[PATCH 3/3] btrfs-progs: backport btrfs_check_node() from kernel

Qu Wenruo
2021-09-02T13:08:53Z

The btrfs_check_node() has far less meaningful error message compared to
kernel counterpart, and it even lacks certain checks like level check.

Backport btrfs_check_node() to btrfs-progs to not only unify the code
but greatly improve the readability of the error messages.

Extra modification includes:

- No fs_info needed
As we don't need to output fsid.

- Remove unlikely() macro

- Extra BTRFS_TREE_BLOCK_* error type

- Btrfs-progs specific error handling
To record the corrupted tree blocks.

Signed-off-by: Qu Wenruo <wqu@suse.com>
---
kernel-shared/ctree.c | 70 ++++++++++++++++++++++++++++++-------------
kernel-shared/ctree.h | 1 +
2 files changed, 51 insertions(+), 20 deletions(-)

diff --git a/kernel-shared/ctree.c b/kernel-shared/ctree.c
index b53107d5a84e..84b57c8fba3d 100644
--- a/kernel-shared/ctree.c
+++ b/kernel-shared/ctree.c
@@ -582,41 +582,71 @@ static void generic_err(const struct extent_buffer *buf, int slot,

enum btrfs_tree_block_status
btrfs_check_node(struct btrfs_fs_info *fs_info,
- struct btrfs_key *parent_key, struct extent_buffer *buf)
+ struct btrfs_key *parent_key, struct extent_buffer *node)
{
- int i;
- struct btrfs_key key;
- u32 nritems = btrfs_header_nritems(buf);
+ unsigned long nr = btrfs_header_nritems(node);
+ struct btrfs_key key, next_key;
+ int slot;
+ int level = btrfs_header_level(node);
+ u64 bytenr;
enum btrfs_tree_block_status ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;

- if (nritems == 0 || nritems > BTRFS_NODEPTRS_PER_BLOCK(fs_info))
+ if (level <= 0 || level >= BTRFS_MAX_LEVEL) {
+ generic_err(node, 0,
+ "invalid level for node, have %d expect [1, %d]",
+ level, BTRFS_MAX_LEVEL - 1);
+ ret = BTRFS_TREE_BLOCK_INVALID_LEVEL;
goto fail;
+ }
+ if (nr == 0 || nr > BTRFS_NODEPTRS_PER_BLOCK(fs_info)) {
+ generic_err(node, 0,
+"corrupt node: root=%llu block=%llu, nritems too %s, have %lu expect range [1,%u]",
+ btrfs_header_owner(node), node->start,
+ nr == 0 ? "small" : "large", nr,
+ BTRFS_NODEPTRS_PER_BLOCK(fs_info));
+ ret = BTRFS_TREE_BLOCK_INVALID_NRITEMS;
+ goto fail;
+ }

- ret = BTRFS_TREE_BLOCK_INVALID_PARENT_KEY;
- if (parent_key && parent_key->type) {
- btrfs_node_key_to_cpu(buf, &key, 0);
- if (memcmp(parent_key, &key, sizeof(key)))
+ for (slot = 0; slot < nr - 1; slot++) {
+ bytenr = btrfs_node_blockptr(node, slot);
+ btrfs_node_key_to_cpu(node, &key, slot);
+ btrfs_node_key_to_cpu(node, &next_key, slot + 1);
+
+ if (!bytenr) {
+ generic_err(node, slot,
+ "invalid NULL node pointer");
+ ret = BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
goto fail;
- }
- ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
- for (i = 0; nritems > 1 && i < nritems - 2; i++) {
- struct btrfs_key next_key;
+ }
+ if (!IS_ALIGNED(bytenr, fs_info->sectorsize)) {
+ generic_err(node, slot,
+ "unaligned pointer, have %llu should be aligned to %u",
+ bytenr, fs_info->sectorsize);
+ ret = BTRFS_TREE_BLOCK_INVALID_BLOCKPTR;
+ goto fail;
+ }

- btrfs_node_key_to_cpu(buf, &key, i);
- btrfs_node_key_to_cpu(buf, &next_key, i + 1);
- if (btrfs_comp_cpu_keys(&key, &next_key) >= 0)
+ if (btrfs_comp_cpu_keys(&key, &next_key) >= 0) {
+ generic_err(node, slot,
+ "bad key order, current (%llu %u %llu) next (%llu %u %llu)",
+ key.objectid, key.type, key.offset,
+ next_key.objectid, next_key.type,
+ next_key.offset);
+ ret = BTRFS_TREE_BLOCK_BAD_KEY_ORDER;
goto fail;
+ }
}
return BTRFS_TREE_BLOCK_CLEAN;
fail:
- if (btrfs_header_owner(buf) == BTRFS_EXTENT_TREE_OBJECTID) {
+ if (btrfs_header_owner(node) == BTRFS_EXTENT_TREE_OBJECTID) {
if (parent_key)
memcpy(&key, parent_key, sizeof(struct btrfs_key));
else
- btrfs_node_key_to_cpu(buf, &key, 0);
+ btrfs_node_key_to_cpu(node, &key, 0);
btrfs_add_corrupt_extent_record(fs_info, &key,
- buf->start, buf->len,
- btrfs_header_level(buf));
+ node->start, node->len,
+ btrfs_header_level(node));
}
return ret;
}
diff --git a/kernel-shared/ctree.h b/kernel-shared/ctree.h
index 5ed8e3e373fa..529f8bce2f50 100644
--- a/kernel-shared/ctree.h
+++ b/kernel-shared/ctree.h
@@ -697,6 +697,7 @@ enum btrfs_tree_block_status {
BTRFS_TREE_BLOCK_INVALID_LEVEL,
BTRFS_TREE_BLOCK_INVALID_FREE_SPACE,
BTRFS_TREE_BLOCK_INVALID_OFFSETS,
+ BTRFS_TREE_BLOCK_INVALID_BLOCKPTR,
};

struct btrfs_inode_item {
--
2.33.0