From 57a0e67491914f6187b1847ee3b1a01a556b9238 Mon Sep 17 00:00:00 2001 From: Qu Wenruo Date: Mon, 9 Dec 2019 18:54:34 +0800 Subject: btrfs: tree-checker: Refactor root key check into separate function ROOT_ITEM key check itself is not as simple as single line check, and will be reused for both ROOT_ITEM and DIR_ITEM/DIR_INDEX location key check, so refactor such check into check_root_key(). Also since we are here, fix a comment error about ROOT_ITEM offset, which is transid of snapshot creation, not some "older kernel behavior". Reviewed-by: Nikolay Borisov Signed-off-by: Qu Wenruo Reviewed-by: David Sterba Signed-off-by: David Sterba --- fs/btrfs/tree-checker.c | 62 +++++++++++++++++++++++++++++++++++++------------ 1 file changed, 47 insertions(+), 15 deletions(-) (limited to 'fs/btrfs/tree-checker.c') diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c index 285c362b3121..9fc438be4bd9 100644 --- a/fs/btrfs/tree-checker.c +++ b/fs/btrfs/tree-checker.c @@ -428,6 +428,49 @@ static int check_inode_key(struct extent_buffer *leaf, struct btrfs_key *key, return 0; } +static int check_root_key(struct extent_buffer *leaf, struct btrfs_key *key, + int slot) +{ + struct btrfs_key item_key; + bool is_root_item; + + btrfs_item_key_to_cpu(leaf, &item_key, slot); + is_root_item = (item_key.type == BTRFS_ROOT_ITEM_KEY); + + /* No such tree id */ + if (key->objectid == 0) { + if (is_root_item) + generic_err(leaf, slot, "invalid root id 0"); + else + dir_item_err(leaf, slot, + "invalid location key root id 0"); + return -EUCLEAN; + } + + /* DIR_ITEM/INDEX/INODE_REF is not allowed to point to non-fs trees */ + if (!is_fstree(key->objectid) && !is_root_item) { + dir_item_err(leaf, slot, + "invalid location key objectid, have %llu expect [%llu, %llu]", + key->objectid, BTRFS_FIRST_FREE_OBJECTID, + BTRFS_LAST_FREE_OBJECTID); + return -EUCLEAN; + } + + /* + * ROOT_ITEM with non-zero offset means this is a snapshot, created at + * @offset transid. + * Furthermore, for location key in DIR_ITEM, its offset is always -1. + * + * So here we only check offset for reloc tree whose key->offset must + * be a valid tree. + */ + if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) { + generic_err(leaf, slot, "invalid root id 0 for reloc tree"); + return -EUCLEAN; + } + return 0; +} + static int check_dir_item(struct extent_buffer *leaf, struct btrfs_key *key, struct btrfs_key *prev_key, int slot) @@ -978,22 +1021,11 @@ static int check_root_item(struct extent_buffer *leaf, struct btrfs_key *key, struct btrfs_root_item ri; const u64 valid_root_flags = BTRFS_ROOT_SUBVOL_RDONLY | BTRFS_ROOT_SUBVOL_DEAD; + int ret; - /* No such tree id */ - if (key->objectid == 0) { - generic_err(leaf, slot, "invalid root id 0"); - return -EUCLEAN; - } - - /* - * Some older kernel may create ROOT_ITEM with non-zero offset, so here - * we only check offset for reloc tree whose key->offset must be a - * valid tree. - */ - if (key->objectid == BTRFS_TREE_RELOC_OBJECTID && key->offset == 0) { - generic_err(leaf, slot, "invalid root id 0 for reloc tree"); - return -EUCLEAN; - } + ret = check_root_key(leaf, key, slot); + if (ret < 0) + return ret; if (btrfs_item_size_nr(leaf, slot) != sizeof(ri)) { generic_err(leaf, slot, -- cgit v1.2.3-59-g8ed1b