From 2f94517bc45058e14c9b41e624bb7bb846dffb53 Mon Sep 17 00:00:00 2001 From: Lu Fengqi Date: Tue, 26 Jul 2016 13:12:11 +0800 Subject: btrfs-progs: check: introduce function to check root ref Introduce a new function check_root_ref() to check root_ref/root_backref. Signed-off-by: Lu Fengqi Signed-off-by: Qu Wenruo Signed-off-by: David Sterba --- cmds-check.c | 93 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 93 insertions(+) (limited to 'cmds-check.c') diff --git a/cmds-check.c b/cmds-check.c index b965f2e4..ede612d5 100644 --- a/cmds-check.c +++ b/cmds-check.c @@ -3842,6 +3842,8 @@ out: #define ORPHAN_ITEM (1<<13) /* INODE_ITEM no reference */ #define NO_INODE_ITEM (1<<14) /* no inode_item */ #define LAST_ITEM (1<<15) /* Complete this tree traversal */ +#define ROOT_REF_MISSING (1<<16) /* ROOT_REF not found */ +#define ROOT_REF_MISMATCH (1<<17) /* ROOT_REF found but not match */ /* * Find DIR_ITEM/DIR_INDEX for the given key and check it with the specified @@ -4734,6 +4736,97 @@ out: return ret; } +/* + * Find the relative ref for root_ref and root_backref. + * + * @root: the root of the root tree. + * @ref_key: the key of the root ref. + * + * Return 0 if no error occurred. + */ +static int check_root_ref(struct btrfs_root *root, struct btrfs_key *ref_key, + struct extent_buffer *node, int slot) +{ + struct btrfs_path *path; + struct btrfs_key key; + struct btrfs_root_ref *ref; + struct btrfs_root_ref *backref; + char ref_name[BTRFS_NAME_LEN]; + char backref_name[BTRFS_NAME_LEN]; + u64 ref_dirid; + u64 ref_seq; + u32 ref_namelen; + u64 backref_dirid; + u64 backref_seq; + u32 backref_namelen; + u32 len; + int ret; + int err = 0; + + ref = btrfs_item_ptr(node, slot, struct btrfs_root_ref); + ref_dirid = btrfs_root_ref_dirid(node, ref); + ref_seq = btrfs_root_ref_sequence(node, ref); + ref_namelen = btrfs_root_ref_name_len(node, ref); + + if (ref_namelen <= BTRFS_NAME_LEN) { + len = ref_namelen; + } else { + len = BTRFS_NAME_LEN; + warning("%s[%llu %llu] ref_name too long", + ref_key->type == BTRFS_ROOT_REF_KEY ? + "ROOT_REF" : "ROOT_BACKREF", ref_key->objectid, + ref_key->offset); + } + read_extent_buffer(node, ref_name, (unsigned long)(ref + 1), len); + + /* Find relative root_ref */ + key.objectid = ref_key->offset; + key.type = BTRFS_ROOT_BACKREF_KEY + BTRFS_ROOT_REF_KEY - ref_key->type; + key.offset = ref_key->objectid; + + path = btrfs_alloc_path(); + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + if (ret) { + err |= ROOT_REF_MISSING; + error("%s[%llu %llu] couldn't find relative ref", + ref_key->type == BTRFS_ROOT_REF_KEY ? + "ROOT_REF" : "ROOT_BACKREF", + ref_key->objectid, ref_key->offset); + goto out; + } + + backref = btrfs_item_ptr(path->nodes[0], path->slots[0], + struct btrfs_root_ref); + backref_dirid = btrfs_root_ref_dirid(path->nodes[0], backref); + backref_seq = btrfs_root_ref_sequence(path->nodes[0], backref); + backref_namelen = btrfs_root_ref_name_len(path->nodes[0], backref); + + if (backref_namelen <= BTRFS_NAME_LEN) { + len = backref_namelen; + } else { + len = BTRFS_NAME_LEN; + warning("%s[%llu %llu] ref_name too long", + key.type == BTRFS_ROOT_REF_KEY ? + "ROOT_REF" : "ROOT_BACKREF", + key.objectid, key.offset); + } + read_extent_buffer(path->nodes[0], backref_name, + (unsigned long)(backref + 1), len); + + if (ref_dirid != backref_dirid || ref_seq != backref_seq || + ref_namelen != backref_namelen || + strncmp(ref_name, backref_name, len)) { + err |= ROOT_REF_MISMATCH; + error("%s[%llu %llu] mismatch relative ref", + ref_key->type == BTRFS_ROOT_REF_KEY ? + "ROOT_REF" : "ROOT_BACKREF", + ref_key->objectid, ref_key->offset); + } +out: + btrfs_free_path(path); + return err; +} + static int all_backpointers_checked(struct extent_record *rec, int print_errs) { struct list_head *cur = rec->backrefs.next; -- cgit v1.2.3