Re: [PATCH 2/2] btrfs: tree-checker: Add check for INODE_REF

[Qu Wenruo <quwenruo.btrfs@gmx.com>]

On 2019/8/26 下午7:45, Nikolay Borisov wrote:
>
>
> On 26.08.19 г. 10:40 ч., Qu Wenruo wrote:
>> For INODE_REF we will check:
>> - Objectid (ino) against previous key
>>   To detect missing INODE_ITEM.
>>
>> - No overflow/padding in the data payload
>>   Much like DIR_ITEM, but with less members to check.
>>
>> Signed-off-by: Qu Wenruo <wqu@suse.com>
>> ---
>>  fs/btrfs/tree-checker.c | 53 +++++++++++++++++++++++++++++++++++++++++
>>  1 file changed, 53 insertions(+)
>>
>> diff --git a/fs/btrfs/tree-checker.c b/fs/btrfs/tree-checker.c
>> index 636ce1b4566e..3ce447eb591c 100644
>> --- a/fs/btrfs/tree-checker.c
>> +++ b/fs/btrfs/tree-checker.c
>> @@ -842,6 +842,56 @@ static int check_inode_item(struct extent_buffer *leaf,
>>  	return 0;
>>  }
>>
>> +#define inode_ref_err(fs_info, eb, slot, fmt, ...)		\
>> +	inode_item_err(fs_info, eb, slot, fmt, __VA_ARGS__)
>
> This define doesn't bring anything, just opencode the call to
> inode_item_err directly.

I could argue we that in an inode ref context, using a inode_item_err()
doesn't look right.

And since it's doesn't do any hurt, I prefer to make the error message
parse to match the context.

Thanks,
Qu
>
>> +static int check_inode_ref(struct extent_buffer *leaf,
>> +			   struct btrfs_key *key, struct btrfs_key *prev_key,
>> +			   int slot)
>> +{
>> +	struct btrfs_inode_ref *iref;
>> +	unsigned long ptr;
>> +	unsigned long end;
>> +
>> +	/* namelen can't be 0, so item_size == sizeof() is also invalid */
>> +	if (btrfs_item_size_nr(leaf, slot) <= sizeof(*iref)) {
>> +		inode_ref_err(fs_info, leaf, slot,
>> +		"invalid item size, have %u expect (%zu, %u)",
>> +			btrfs_item_size_nr(leaf, slot),
>> +			sizeof(*iref), BTRFS_LEAF_DATA_SIZE(leaf->fs_info));
>> +		return -EUCLEAN;
>> +	}
>> +
>> +	ptr = btrfs_item_ptr_offset(leaf, slot);
>> +	end = ptr + btrfs_item_size_nr(leaf, slot);
>> +	while (ptr < end) {
>> +		u16 namelen;
>> +
>> +		if (ptr + sizeof(iref) > end) {
>> +			inode_ref_err(fs_info, leaf, slot,
>> +		"inode ref overflow, ptr %lu end %lu inode_ref_size %zu",
>> +				ptr, end, sizeof(iref));
>> +			return -EUCLEAN;
>> +		}
>> +
>> +		iref = (struct btrfs_inode_ref *)ptr;
>> +		namelen = btrfs_inode_ref_name_len(leaf, iref);
>> +		if (ptr + sizeof(*iref) + namelen > end) {
>> +			inode_ref_err(fs_info, leaf, slot,
>> +		"inode ref overflow, ptr %lu end %lu namelen %u",
>> +				ptr, end, namelen);
>> +			return -EUCLEAN;
>> +		}
>> +
>> +		/*
>> +		 * NOTE: In theory we should record all found index number
>> +		 * to find any duplicated index. But that will be too time
>> +		 * consuming for inodes with too many hard links.
>> +		 */
>> +		ptr += sizeof(*iref) + namelen;
>> +	}
>> +	return 0;
>> +}
>> +
>>  /*
>>   * Common point to switch the item-specific validation.
>>   */
>> @@ -864,6 +914,9 @@ static int check_leaf_item(struct extent_buffer *leaf,
>>  	case BTRFS_XATTR_ITEM_KEY:
>>  		ret = check_dir_item(leaf, key, prev_key, slot);
>>  		break;
>> +	case BTRFS_INODE_REF_KEY:
>> +		ret = check_inode_ref(leaf, key, prev_key, slot);
>> +		break;
>>  	case BTRFS_BLOCK_GROUP_ITEM_KEY:
>>  		ret = check_block_group_item(leaf, key, slot);
>>  		break;
>>