For DIR_ITEM with mismatch hash, we could just remove the offending dir item.
Lowmem mode will handle the rest part (either re-create the correct dir_item or move the orphan inode to lost+found). This is especially important for old btrfs, since later kernel introduces restrict tree-checker, which could detect such hash mismatch and refuse to read the corrupted leaf. With this repair ability, user could repair with btrfs check --mode=lowmem --repair. Link: https://bugzilla.opensuse.org/show_bug.cgi?id=1111991 Signed-off-by: Qu Wenruo <w...@suse.com> --- check/mode-common.c | 51 +++++++++++++++++++++++++++++++++++++++++++++ check/mode-common.h | 5 ++++- check/mode-lowmem.c | 46 +++++++++++++++++++++++++++++++++++----- check/mode-lowmem.h | 1 + ctree.h | 3 +++ dir-item.c | 6 +----- 6 files changed, 101 insertions(+), 11 deletions(-) diff --git a/check/mode-common.c b/check/mode-common.c index 15e2bbd1f30f..8660f43f6b20 100644 --- a/check/mode-common.c +++ b/check/mode-common.c @@ -742,3 +742,54 @@ void cleanup_excluded_extents(struct btrfs_fs_info *fs_info) } fs_info->excluded_extents = NULL; } + +/* + * Delete one corrupted dir item whose hash doesn't match its name. + * + * Since its hash is incorrect, we can't use btrfs_name_hash() to calculate + * the search key, but relie on @di_key parameter to do the search. + */ +int delete_corrupted_dir_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_key *di_key, char *namebuf, + u32 namelen) +{ + struct btrfs_dir_item *di_item; + struct btrfs_path path; + int ret; + + btrfs_init_path(&path); + ret = btrfs_search_slot(trans, root, di_key, &path, 0, 1); + if (ret > 0) { + error("key (%llu %u %llu) doesn't exist in root %llu", + di_key->objectid, di_key->type, di_key->offset, + root->root_key.objectid); + ret = -ENOENT; + goto out; + } + if (ret < 0) { + error("failed to search root %llu: %d", + root->root_key.objectid, ret); + goto out; + } + + di_item = btrfs_match_dir_item_name(root, &path, namebuf, namelen); + if (!di_item) { + /* + * This is possible if the dir_item has incorrect namelen. + * But in that case, we shouldn't reach repair path here. + */ + error("no dir item named '%s' found with key (%llu %u %llu)", + namebuf, di_key->objectid, di_key->type, + di_key->offset); + ret = -ENOENT; + goto out; + } + ret = btrfs_delete_one_dir_name(trans, root, &path, di_item); + if (ret < 0) + error("failed to delete one dir name: %d", ret); + +out: + btrfs_release_path(&path); + return ret; +} diff --git a/check/mode-common.h b/check/mode-common.h index 6b05f8baf474..fda319267b04 100644 --- a/check/mode-common.h +++ b/check/mode-common.h @@ -121,5 +121,8 @@ void reset_cached_block_groups(struct btrfs_fs_info *fs_info); int pin_metadata_blocks(struct btrfs_fs_info *fs_info); int exclude_metadata_blocks(struct btrfs_fs_info *fs_info); void cleanup_excluded_extents(struct btrfs_fs_info *fs_info); - +int delete_corrupted_dir_item(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_key *di_key, char *namebuf, + u32 namelen); #endif diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c index 1bce44f5658a..fe3d5940faf0 100644 --- a/check/mode-lowmem.c +++ b/check/mode-lowmem.c @@ -1464,17 +1464,52 @@ out: return ret; } +/* + * A wrapper for delete_corrupted_dir_item(), with support part like + * start/commit transaction. + */ +static int lowmem_delete_corrupted_dir_item(struct btrfs_root *root, + struct btrfs_key *di_key, + char *namebuf, u32 name_len) +{ + struct btrfs_trans_handle *trans; + int ret; + + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + error("failed to start transaction: %d", ret); + return ret; + } + + ret = delete_corrupted_dir_item(trans, root, di_key, namebuf, name_len); + if (ret < 0) { + btrfs_abort_transaction(trans, ret); + } else { + ret = btrfs_commit_transaction(trans, root); + if (ret < 0) + error("failed to commit transaction: %d", ret); + } + return ret; +} /* * Call repair_inode_item_missing and repair_ternary_lowmem to repair * * Returns error after repair */ -static int repair_dir_item(struct btrfs_root *root, u64 dirid, u64 ino, - u64 index, u8 filetype, char *namebuf, u32 name_len, - int err) +static int repair_dir_item(struct btrfs_root *root, struct btrfs_key *di_key, + u64 ino, u64 index, u8 filetype, char *namebuf, + u32 name_len, int err) { + u64 dirid = di_key->objectid; int ret; + if (err & (DIR_ITEM_HASH_MISMATCH)) { + ret = lowmem_delete_corrupted_dir_item(root, di_key, namebuf, + name_len); + if (!ret) + err &= ~(DIR_ITEM_HASH_MISMATCH); + } if (err & INODE_ITEM_MISSING) { ret = repair_inode_item_missing(root, ino, filetype); if (!ret) @@ -1622,11 +1657,12 @@ begin: if (di_key->type == BTRFS_DIR_ITEM_KEY && di_key->offset != btrfs_name_hash(namebuf, len)) { - err |= -EIO; error("root %llu DIR_ITEM[%llu %llu] name %s namelen %u filetype %u mismatch with its hash, wanted %llu have %llu", root->objectid, di_key->objectid, di_key->offset, namebuf, len, filetype, di_key->offset, btrfs_name_hash(namebuf, len)); + tmp_err |= DIR_ITEM_HASH_MISMATCH; + goto next; } btrfs_dir_item_key_to_cpu(node, di, &location); @@ -1674,7 +1710,7 @@ begin: next: if (tmp_err && repair) { - ret = repair_dir_item(root, di_key->objectid, + ret = repair_dir_item(root, di_key, location.objectid, index, imode_to_type(mode), namebuf, name_len, tmp_err); diff --git a/check/mode-lowmem.h b/check/mode-lowmem.h index 91f7b6b1db53..afd376ad7d5d 100644 --- a/check/mode-lowmem.h +++ b/check/mode-lowmem.h @@ -45,6 +45,7 @@ #define BG_ACCOUNTING_ERROR (1<<21) /* Block group accounting error */ #define FATAL_ERROR (1<<22) /* Fatal bit for errno */ #define INODE_FLAGS_ERROR (1<<23) /* Invalid inode flags */ +#define DIR_ITEM_HASH_MISMATCH (1<<24) /* Dir item hash mismatch */ /* * Error bit for low memory mode check. diff --git a/ctree.h b/ctree.h index 4719962df67d..be0dacbe351d 100644 --- a/ctree.h +++ b/ctree.h @@ -2691,6 +2691,9 @@ int btrfs_insert_xattr_item(struct btrfs_trans_handle *trans, struct btrfs_root *root, const char *name, u16 name_len, const void *data, u16 data_len, u64 dir); +struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, + struct btrfs_path *path, + const char *name, int name_len); /* inode-map.c */ int btrfs_find_free_objectid(struct btrfs_trans_handle *trans, struct btrfs_root *fs_root, diff --git a/dir-item.c b/dir-item.c index d64f71e306e0..fa69dd1de185 100644 --- a/dir-item.c +++ b/dir-item.c @@ -22,10 +22,6 @@ #include "hash.h" #include "transaction.h" -static struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, - struct btrfs_path *path, - const char *name, int name_len); - static struct btrfs_dir_item *insert_with_overflow(struct btrfs_trans_handle *trans, struct btrfs_root *root, @@ -323,7 +319,7 @@ static int verify_dir_item(struct btrfs_root *root, return 0; } -static struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, +struct btrfs_dir_item *btrfs_match_dir_item_name(struct btrfs_root *root, struct btrfs_path *path, const char *name, int name_len) { -- 2.19.1
