Re: [PATCH 2/4] btrfs: tree-checker: Refactor inode key check into seperate function

[Qu WenRuo <wqu@suse.com>]

On 2019/12/10 下午10:42, Su Yue wrote:
> 
> 
> On 2019/12/9 6:54 PM, Qu Wenruo wrote:
>> Inode key check is not as easy as several lines, and it will be called
>> in more than one location (INODE_ITEM check and
>> DIR_ITEM/DIR_INDEX/XATTR_ITEM location key check).
>>
>> So here refactor such check into check_inode_key().
>>
>> And add extra checks for XATTR_ITEM.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>   fs/btrfs/tree-checker.c | 77 +++++++++++++++++++++++++++++++----------
>>   1 file changed, 59 insertions(+), 18 deletions(-)
>>
>> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
>> index 6cb49c75c5e1..68dad9ec38dd 100644
>> --- a/fs/btrfs/tree-checker.c
>> +++ b/fs/btrfs/tree-checker.c
>> @@ -359,6 +359,60 @@ static int check_csum_item(struct extent_buffer
>> *leaf, struct btrfs_key *key,
>>       return 0;
>>   }
>>
>> +/* Inode item error output has the same format as dir_item_err() */
>> +#define inode_item_err(eb, slot, fmt, ...)            \
>> +    dir_item_err(eb, slot, fmt, __VA_ARGS__)
>> +
>> +static int check_inode_key(struct extent_buffer *leaf, struct
>> btrfs_key *key,
>> +               int slot)
> 
> The function name is confusing to me. It checks xattr which is not
> inode related obviously.

If renamed to check_location_key() then the call site in
check_inode_item() will be very strange...

Thanks,
Qu

> 
> I saw the 4th patch. How about introduction of new function
> check_location_key(), then calls check_root_key() , check_inode_key()
> and checks xatrr case inside?
> 
> Others in the patchset seem fine to me.
> 
> 
> Thanks
>> +{
>> +    struct btrfs_key item_key;
>> +    bool is_inode_item;
>> +
>> +    btrfs_item_key_to_cpu(leaf, &item_key, slot);
>> +    is_inode_item = (item_key.type == BTRFS_INODE_ITEM_KEY);
>> +
>> +    /* For XATTR_ITEM, location key should be all 0 */
>> +    if (item_key.type == BTRFS_XATTR_ITEM_KEY) {
>> +        if (key->type != 0 || key->objectid != 0 || key->offset != 0)
>> +            return -EUCLEAN;
>> +        return 0;
>> +    }
>> +
>> +    if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
>> +         key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
>> +        key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
>> +        key->objectid != BTRFS_FREE_INO_OBJECTID) {
>> +        if (is_inode_item)
>> +            generic_err(leaf, slot,
>> +    "invalid key objectid: has %llu expect %llu or [%llu, %llu] or
>> %llu",
>> +                key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
>> +                BTRFS_FIRST_FREE_OBJECTID,
>> +                BTRFS_LAST_FREE_OBJECTID,
>> +                BTRFS_FREE_INO_OBJECTID);
>> +        else
>> +            dir_item_err(leaf, slot,
>> +"invalid location key objectid: has %llu expect %llu or [%llu, %llu]
>> or %llu",
>> +                key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
>> +                BTRFS_FIRST_FREE_OBJECTID,
>> +                BTRFS_LAST_FREE_OBJECTID,
>> +                BTRFS_FREE_INO_OBJECTID);
>> +        return -EUCLEAN;
>> +    }
>> +    if (key->offset != 0) {
>> +        if (is_inode_item)
>> +            inode_item_err(leaf, slot,
>> +                       "invalid key offset: has %llu expect 0",
>> +                       key->offset);
>> +        else
>> +            dir_item_err(leaf, slot,
>> +                "invalid location key offset:has %llu expect 0",
>> +                key->offset);
>> +        return -EUCLEAN;
>> +    }
>> +    return 0;
>> +}
>> +
>>   static int check_dir_item(struct extent_buffer *leaf,
>>                 struct btrfs_key *key, struct btrfs_key *prev_key,
>>                 int slot)
>> @@ -798,25 +852,12 @@ static int check_inode_item(struct extent_buffer
>> *leaf,
>>       u64 super_gen = btrfs_super_generation(fs_info->super_copy);
>>       u32 valid_mask = (S_IFMT | S_ISUID | S_ISGID | S_ISVTX | 0777);
>>       u32 mode;
>> +    int ret;
>> +
>> +    ret = check_inode_key(leaf, key, slot);
>> +    if (ret < 0)
>> +        return ret;
>>
>> -    if ((key->objectid < BTRFS_FIRST_FREE_OBJECTID ||
>> -         key->objectid > BTRFS_LAST_FREE_OBJECTID) &&
>> -        key->objectid != BTRFS_ROOT_TREE_DIR_OBJECTID &&
>> -        key->objectid != BTRFS_FREE_INO_OBJECTID) {
>> -        generic_err(leaf, slot,
>> -    "invalid key objectid: has %llu expect %llu or [%llu, %llu] or
>> %llu",
>> -                key->objectid, BTRFS_ROOT_TREE_DIR_OBJECTID,
>> -                BTRFS_FIRST_FREE_OBJECTID,
>> -                BTRFS_LAST_FREE_OBJECTID,
>> -                BTRFS_FREE_INO_OBJECTID);
>> -        return -EUCLEAN;
>> -    }
>> -    if (key->offset != 0) {
>> -        inode_item_err(leaf, slot,
>> -            "invalid key offset: has %llu expect 0",
>> -            key->offset);
>> -        return -EUCLEAN;
>> -    }
>>       iitem = btrfs_item_ptr(leaf, slot, struct btrfs_inode_item);
>>
>>       /* Here we use super block generation + 1 to handle log tree */
>>