Re: invalid files names, btrfs check can't repair it

[Lu Fengqi <lufq.fnst@cn.fujitsu.com>]

On Mon, Jan 15, 2018 at 09:26:27AM +0800, Qu Wenruo wrote:
>
>
>On 2018年01月15日 00:38, Sebastian Andrzej Siewior wrote:
>> On 2018-01-14 08:36:41 [+0800], Qu Wenruo wrote:
>>> Still needs more. (and maybe even more depending on the output)
>>>
>>> The original mode doesn't report error clear enough, so it would help if
>>> --mode=lowmem can be used.
>>>
>>> # btrfs check --mode=lowmem /dev/sdb4
>> 
>> ~# btrfs check --mode=lowmem /dev/sdb4
>> Checking filesystem on /dev/sdb4
>> UUID: b3bfb56e-d445-4335-93f0-c1fb2d1f6df1
>> checking extents
>> checking free space cache
>> Wanted bytes 4096, found 8192 for off 159178047488
>> Wanted bytes 1073725440, found 8192 for off 159178047488
>> cache appears valid but isn't 159178031104
>> ERROR: errors found in free space cache
>
>A new bug is exposed for lowmem mode.
>It doesn't check fs tree if space cache has any problem.
>

Just a reminder, the problem is not only for lowmem mode.

        ret = check_space_cache(root);
        err |= !!ret;
        if (ret) {
                if (btrfs_fs_compat_ro(info, FREE_SPACE_TREE))
                        error("errors found in free space tree");
                else
                        error("errors found in free space cache");
                goto out;
                ^^^
        }

        /*
         * We used to have to have these hole extents in between our real
         * extents so if we don't have this flag set we need to make sure there
         * are no gaps in the file extents for inodes, otherwise we can just
         * ignore it when this happens.
         */
        no_holes = btrfs_fs_incompat(root->fs_info, NO_HOLES);
        ret = do_check_fs_roots(info, &root_cache);
              ^^^
        err |= !!ret;
        if (ret) {
                error("errors found in fs roots");
                goto out;
        }

-- 
Thanks,
Lu

>> found 63691210752 bytes used, error(s) found
>> total csum bytes: 61339388
>> total tree bytes: 860540928
>> total fs tree bytes: 688816128
>> total extent tree bytes: 84549632
>> btree space waste bytes: 224428280
>> file data blocks allocated: 62890483712
>>  referenced 62828957696
>>