On 2018/9/17 下午3:28, Su Yue wrote:
> inode_extref is much similar with inode_ref, most codes are reused in
> check_inode_extref().
> Exceptions:
> There is no need to check root directory, so remove it.
As root directory should only have one INODE_REF "..", so it shouldn't
have any extref at all.
This part is pretty valid.
> Make check_inode_extref() verify hash value with key offset now.
>
> And lowmem check can detect errors about inode_extref and try to
> repair errors.
>
> Signed-off-by: Su Yue <suy.f...@cn.fujitsu.com>
Looks OK to me.
Reviewed-by: Qu Wenruo <w...@suse.com>
Thanks,
Qu
> ---
> check/mode-lowmem.c | 125 +++++++++++++++++++++++++++++++++++---------
> 1 file changed, 99 insertions(+), 26 deletions(-)
>
> diff --git a/check/mode-lowmem.c b/check/mode-lowmem.c
> index 612e5e28e45b..53e4fdccd740 100644
> --- a/check/mode-lowmem.c
> +++ b/check/mode-lowmem.c
> @@ -1182,37 +1182,86 @@ out:
> *
> * Return 0 if no error occurred.
> */
> -static int check_inode_extref(struct btrfs_root *root,
> - struct btrfs_key *ref_key,
> - struct extent_buffer *node, int slot, u64 *refs,
> - int mode)
> +static int check_inode_extref(struct btrfs_root *root, struct btrfs_key
> *ref_key,
> + struct btrfs_path *path, char *name_ret,
> + u32 *namelen_ret, u64 *refs_ret, int mode)
> {
> struct btrfs_key key;
> struct btrfs_key location;
> struct btrfs_inode_extref *extref;
> + struct extent_buffer *node;
> char namebuf[BTRFS_NAME_LEN] = {0};
> u32 total;
> - u32 cur = 0;
> + u32 cur;
> u32 len;
> u32 name_len;
> u64 index;
> u64 parent;
> + int err;
> + int tmp_err;
> int ret;
> - int err = 0;
> + int slot;
> + u64 refs;
> + bool search_again = false;
>
> location.objectid = ref_key->objectid;
> location.type = BTRFS_INODE_ITEM_KEY;
> location.offset = 0;
> +begin:
> + cur = 0;
> + err = 0;
> + refs = *refs_ret;
> + *namelen_ret = 0;
> +
> + /* since after repair, path and the dir item may be changed */
> + if (search_again) {
> + search_again = false;
> + btrfs_release_path(path);
> + ret = btrfs_search_slot(NULL, root, ref_key, path, 0, 0);
> + /*
> + * The item was deleted, let the path point to the last checked
> + * item.
> + */
> + if (ret > 0) {
> + if (path->slots[0] == 0) {
> + ret = btrfs_prev_leaf(root, path);
> + /*
> + * we are checking the inode item, there must
> + * be some items before, the case shall never
> + * happen.
> + */
> + if (ret > 0)
> + ret = -EIO;
> + if (ret)
> + error(
> + "failed to get item before INODE_REF[%llu, %llu] root %llu: %s",
> + ref_key->objectid,
> ref_key->offset,
> + root->objectid, strerror(-ret));
> + } else {
> + path->slots[0]--;
> + ret = 0;
> + }
> + goto out;
> + } else if (ret < 0) {
> + err |= FATAL_ERROR;
> + goto out;
> + }
> + }
> +
> + node = path->nodes[0];
> + slot = path->slots[0];
>
> extref = btrfs_item_ptr(node, slot, struct btrfs_inode_extref);
> total = btrfs_item_size_nr(node, slot);
>
> -next:
> - /* update inode ref count */
> - (*refs)++;
> - name_len = btrfs_inode_extref_name_len(node, extref);
> - index = btrfs_inode_extref_index(node, extref);
> +loop:
> + /* Update inode ref count */
> + refs++;
> + tmp_err = 0;
> parent = btrfs_inode_extref_parent(node, extref);
> + index = btrfs_inode_extref_index(node, extref);
> + name_len = btrfs_inode_extref_name_len(node, extref);
> +
> if (name_len <= BTRFS_NAME_LEN) {
> len = name_len;
> } else {
> @@ -1220,37 +1269,61 @@ next:
> warning("root %llu INODE_EXTREF[%llu %llu] name too long",
> root->objectid, ref_key->objectid, ref_key->offset);
> }
> +
> read_extent_buffer(node, namebuf, (unsigned long)(extref + 1), len);
>
> - /* Check root dir ref name */
> - if (index == 0 && strncmp(namebuf, "..", name_len)) {
> - error("root %llu INODE_EXTREF[%llu %llu] ROOT_DIR name
> shouldn't be %s",
> + /* verify hash value */
> + if (ref_key->offset != btrfs_extref_hash(parent, namebuf, len)) {
> + err |= FATAL_ERROR;
> + error("root %llu INODE_EXTREF[%llu %llu] name %s namelen %u
> mode %d mismatch with its hash, wanted %llu have %llu",
> root->objectid, ref_key->objectid, ref_key->offset,
> - namebuf);
> - err |= ROOT_DIR_ERROR;
> + namebuf, len, mode, ref_key->offset,
> + btrfs_extref_hash(parent, namebuf, len));
> + goto out;
> + }
> +
> + /* copy the first name found to name_ret */
> + if (refs == 1 && name_ret) {
> + memcpy(name_ret, namebuf, len);
> + *namelen_ret = len;
> }
>
> - /* find related dir_index */
> + /* Find related DIR_INDEX */
> key.objectid = parent;
> key.type = BTRFS_DIR_INDEX_KEY;
> key.offset = index;
> - ret = find_dir_item(root, &key, &location, namebuf, len, mode);
> - err |= ret;
> + tmp_err |= find_dir_item(root, &key, &location, namebuf, len,
> + imode_to_type(mode));
>
> - /* find related dir_item */
> + /* Find related dir_item */
> key.objectid = parent;
> key.type = BTRFS_DIR_ITEM_KEY;
> key.offset = btrfs_name_hash(namebuf, len);
> - ret = find_dir_item(root, &key, &location, namebuf, len, mode);
> - err |= ret;
> + tmp_err |= find_dir_item(root, &key, &location, namebuf, len,
> + imode_to_type(mode));
> +
> + if (tmp_err && repair) {
> + ret = repair_ternary_lowmem(root, parent, ref_key->objectid,
> + index, namebuf, name_len, imode_to_type(mode),
> + tmp_err);
> + if (!ret) {
> + search_again = true;
> + goto begin;
> + }
> + }
>
> + print_inode_ref_err(root, ref_key, index, namebuf, name_len,
> + imode_to_type(mode), tmp_err);
> +
> + err |= tmp_err;
> len = sizeof(*extref) + name_len;
> extref = (struct btrfs_inode_extref *)((char *)extref + len);
> cur += len;
>
> if (cur < total)
> - goto next;
> -
> + goto loop;
> +out:
> + *refs_ret = refs;
> return err;
> }
>
> @@ -2426,8 +2499,8 @@ static int check_inode_item(struct btrfs_root *root,
> struct btrfs_path *path)
> warning("root %llu EXTREF[%llu %llu] isn't
> supported",
> root->objectid, key.objectid,
> key.offset);
> - ret = check_inode_extref(root, &key, node, slot, &refs,
> - mode);
> + ret = check_inode_extref(root, &key, path, namebuf,
> + &name_len, &refs, mode);
> err |= ret;
> break;
> }
>
