Re: How to remove an unremovable file and directory?

["Henri Hyyryläinen" <henri.hyyrylainen@gmail.com>]

Thank you so much. After compiling that program and running it like 
that, I can now mount my filesystem.

It took a little bit to mount due to free space cache rebuild, but as 
far as I can tell from a quick look, everything is fine and all the used 
disk sizes are correct.

- Henri Hyyryläinen

Qu Wenruo kirjoitti 5.10.2025 klo 11.37:
>
>
> 在 2025/10/5 18:50, Henri Hyyryläinen 写道:
>> Hello,
>>
>> The check has completed and, probably thanks to the second repair, it 
>> did not find much. Here's the full output:
>>
>>> [1/8] checking log skipped (none written)
>>> [2/8] checking root items
>>> [3/8] checking extents
>>> Device extent[4, 19977638903808, 1073741824] didn't find the 
>>> relative chunk.
>
> Great news, we only need to delete that item.
>
>
> Try btrfs-corrupt-block (I know this sounds dangerous) command, which 
> may not be included by a lot of distros, thus recommended to build a 
> btrfs-progs and run it (without installing)
>
> # ./btrfs-corrupt-block -d 4,204,19977638903808 -r 4 <device>
>
> If it worked, there should be no message output. Otherwise something 
> went wrong.
>
> Normally even if the command failed, it shouldn't cause extra damages 
> since everything else in your fs is still fine.
>
> Thanks,
> Qu
>
>>> [4/8] checking free space cache
>>> [5/8] checking fs roots
>>> [6/8] checking only csums items (without verifying data)
>>> [7/8] checking root refs
>>> [8/8] checking quota groups skipped (not enabled on this FS)
>>> Opening filesystem to check...
>>> Checking filesystem on /dev/sdb
>>> UUID: 2b4ad16d-e456-4adf-960b-dca43560b98b
>>> found 49454062784512 bytes used, no error found
>>> total csum bytes: 48225005724
>>> total tree bytes: 72333164544
>>> total fs tree bytes: 19189743616
>>> total extent tree bytes: 3319316480
>>> btree space waste bytes: 5998261217
>>> file data blocks allocated: 119737771229184
>>>  referenced 72125752061952
>>
>>
>> - Henri Hyyryläinen
>>
>> Qu Wenruo kirjoitti 5.10.2025 klo 1.41:
>>>
>>>
>>> 在 2025/10/5 09:06, Henri Hyyryläinen 写道:
>>>> Thanks for the command.
>>>>
>>>> I tried reading through the data but I could not determine if there 
>>>> was any information related to scrub or balance status.
>>>
>>> It's fine. No persistent item for balance/dev-replace. So it's not 
>>> involved.
>>>
>>> Waiting for the readonly check result.
>>>
>>> And meanwhile, please prepare an environment to compile btrfs-progs.
>>>
>>> If there is only one stray dev extent, I'll create a simple dirty 
>>> fix so that you can mount the fs again.
>>>
>>> Thanks,
>>> Qu
>>>
>>>>
>>>> Here's the full output I got:
>>>>
>>>>> btrfs-progs v6.16.1
>>>>> root tree
>>>>> leaf 227587769614336 items 61 free space 3547 generation 2035509 
>>>>> owner ROOT_TREE
>>>>> leaf 227587769614336 flags 0x1(WRITTEN) backref revision 1
>>>>> fs uuid 2b4ad16d-e456-4adf-960b-dca43560b98b
>>>>> chunk uuid 0e317678-73cc-4485-ab6b-987285e19681
>>>>>     item 0 key (EXTENT_TREE ROOT_ITEM 0) itemoff 15844 itemsize 439
>>>>>         generation 2035509 root_dirid 0 bytenr 227587769630720 
>>>>> byte_limit 0 bytes_used 3319316480
>>>>>         last_snapshot 0 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2035509
>>>>>         uuid 00000000-0000-0000-0000-000000000000
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 0 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 0.0 (1970-01-01 02:00:00)
>>>>>         otime 0.0 (1970-01-01 02:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 1 key (DEV_TREE ROOT_ITEM 0) itemoff 15405 itemsize 439
>>>>>         generation 2025974 root_dirid 0 bytenr 227594196631552 
>>>>> byte_limit 0 bytes_used 21889024
>>>>>         last_snapshot 0 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 2 generation_v2 2025974
>>>>>         uuid 00000000-0000-0000-0000-000000000000
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 0 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 0.0 (1970-01-01 02:00:00)
>>>>>         otime 0.0 (1970-01-01 02:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 2 key (FS_TREE INODE_REF 6) itemoff 15388 itemsize 17
>>>>>         index 0 namelen 7 name: default
>>>>>     item 3 key (FS_TREE ROOT_ITEM 0) itemoff 14949 itemsize 439
>>>>>         generation 2025975 root_dirid 256 bytenr 227573939142656 
>>>>> byte_limit 0 bytes_used 6603997184
>>>>>         last_snapshot 2025951 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025975
>>>>>         uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025953 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 1759258850.523837328 (2025-09-30 22:00:50)
>>>>>         otime 1679586168.0 (2023-03-23 17:42:48)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 4 key (FS_TREE ROOT_REF 256) itemoff 14921 itemsize 28
>>>>>         root ref key dirid 256 sequence 6 name .snapshots
>>>>>     item 5 key (ROOT_TREE_DIR INODE_ITEM 0) itemoff 14761 itemsize 
>>>>> 160
>>>>>         generation 3 transid 0 size 0 nbytes 16384
>>>>>         block group 0 mode 40755 links 1 uid 0 gid 0 rdev 0
>>>>>         sequence 0 flags 0x0(none)
>>>>>         atime 1679586169.0 (2023-03-23 17:42:49)
>>>>>         ctime 1679586169.0 (2023-03-23 17:42:49)
>>>>>         mtime 1679586169.0 (2023-03-23 17:42:49)
>>>>>         otime 1679586169.0 (2023-03-23 17:42:49)
>>>>>     item 6 key (ROOT_TREE_DIR INODE_REF 6) itemoff 14749 itemsize 12
>>>>>         index 0 namelen 2 name: ..
>>>>>     item 7 key (ROOT_TREE_DIR DIR_ITEM 2378154706) itemoff 14712 
>>>>> itemsize 37
>>>>>         location key (FS_TREE ROOT_ITEM 18446744073709551615) type 
>>>>> DIR
>>>>>         transid 0 data_len 0 name_len 7
>>>>>         name: default
>>>>>     item 8 key (CSUM_TREE ROOT_ITEM 0) itemoff 14273 itemsize 439
>>>>>         generation 2025954 root_dirid 0 bytenr 227588044062720 
>>>>> byte_limit 0 bytes_used 49791238144
>>>>>         last_snapshot 0 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025954
>>>>>         uuid 00000000-0000-0000-0000-000000000000
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 0 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 0.0 (1970-01-01 02:00:00)
>>>>>         otime 0.0 (1970-01-01 02:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 9 key (UUID_TREE ROOT_ITEM 0) itemoff 13834 itemsize 439
>>>>>         generation 2025954 root_dirid 0 bytenr 227587802447872 
>>>>> byte_limit 0 bytes_used 16384
>>>>>         last_snapshot 0 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 0 generation_v2 2025954
>>>>>         uuid 00000000-0000-0000-0000-000000000000
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 0 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 0.0 (1970-01-01 02:00:00)
>>>>>         otime 0.0 (1970-01-01 02:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 10 key (256 ROOT_ITEM 0) itemoff 13395 itemsize 439
>>>>>         generation 2025954 root_dirid 256 bytenr 227587802316800 
>>>>> byte_limit 0 bytes_used 49152
>>>>>         last_snapshot 2015386 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 1 generation_v2 2025954
>>>>>         uuid 56f85f76-1eb8-1245-a35b-8a9307d5c68f
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025954 otransid 31 stransid 0 rtransid 0
>>>>>         ctime 1759260258.238143629 (2025-09-30 22:24:18)
>>>>>         otime 1679588253.995834574 (2023-03-23 18:17:33)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 11 key (256 ROOT_BACKREF 5) itemoff 13367 itemsize 28
>>>>>         root backref key dirid 256 sequence 6 name .snapshots
>>>>>     item 12 key (256 ROOT_REF 14428) itemoff 13341 itemsize 26
>>>>>         root ref key dirid 28589 sequence 2 name snapshot
>>>>>     item 13 key (256 ROOT_REF 14451) itemoff 13315 itemsize 26
>>>>>         root ref key dirid 28635 sequence 2 name snapshot
>>>>>     item 14 key (256 ROOT_REF 14475) itemoff 13289 itemsize 26
>>>>>         root ref key dirid 28683 sequence 2 name snapshot
>>>>>     item 15 key (256 ROOT_REF 14499) itemoff 13263 itemsize 26
>>>>>         root ref key dirid 28731 sequence 2 name snapshot
>>>>>     item 16 key (256 ROOT_REF 14523) itemoff 13237 itemsize 26
>>>>>         root ref key dirid 28779 sequence 2 name snapshot
>>>>>     item 17 key (256 ROOT_REF 14547) itemoff 13211 itemsize 26
>>>>>         root ref key dirid 28827 sequence 2 name snapshot
>>>>>     item 18 key (256 ROOT_REF 14559) itemoff 13185 itemsize 26
>>>>>         root ref key dirid 28851 sequence 2 name snapshot
>>>>>     item 19 key (256 ROOT_REF 14583) itemoff 13159 itemsize 26
>>>>>         root ref key dirid 28899 sequence 2 name snapshot
>>>>>     item 20 key (256 ROOT_REF 14607) itemoff 13133 itemsize 26
>>>>>         root ref key dirid 28947 sequence 2 name snapshot
>>>>>     item 21 key (256 ROOT_REF 14631) itemoff 13107 itemsize 26
>>>>>         root ref key dirid 28995 sequence 2 name snapshot
>>>>>     item 22 key (256 ROOT_REF 14640) itemoff 13081 itemsize 26
>>>>>         root ref key dirid 29013 sequence 2 name snapshot
>>>>>     item 23 key (256 ROOT_REF 14641) itemoff 13055 itemsize 26
>>>>>         root ref key dirid 29015 sequence 2 name snapshot
>>>>>     item 24 key (256 ROOT_REF 14642) itemoff 13029 itemsize 26
>>>>>         root ref key dirid 29017 sequence 2 name snapshot
>>>>>     item 25 key (256 ROOT_REF 14643) itemoff 13003 itemsize 26
>>>>>         root ref key dirid 29019 sequence 2 name snapshot
>>>>>     item 26 key (256 ROOT_REF 14644) itemoff 12977 itemsize 26
>>>>>         root ref key dirid 29021 sequence 2 name snapshot
>>>>>     item 27 key (256 ROOT_REF 14645) itemoff 12951 itemsize 26
>>>>>         root ref key dirid 29023 sequence 2 name snapshot
>>>>>     item 28 key (14428 ROOT_ITEM 1849346) itemoff 12512 itemsize 439
>>>>>         generation 2025978 root_dirid 256 bytenr 71398781173760 
>>>>> byte_limit 0 bytes_used 8815476736
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025978
>>>>>         uuid 97cd122d-c519-8746-bdfe-13479bfefb9d
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 1849346 otransid 1849346 stransid 0 rtransid 0
>>>>>         ctime 1758406304.841464812 (2025-09-21 01:11:44)
>>>>>         otime 1758406304.840394467 (2025-09-21 01:11:44)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 29 key (14428 ROOT_BACKREF 256) itemoff 12486 itemsize 26
>>>>>         root backref key dirid 28589 sequence 2 name snapshot
>>>>>     item 30 key (14451 ROOT_ITEM 1899154) itemoff 12047 itemsize 439
>>>>>         generation 2025981 root_dirid 256 bytenr 71398809468928 
>>>>> byte_limit 0 bytes_used 6747799552
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025981
>>>>>         uuid c5e2ba38-c982-8a4f-99e5-bb9ff8c5f7cd
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 1897416 otransid 1899154 stransid 0 rtransid 0
>>>>>         ctime 1758484800.817458724 (2025-09-21 23:00:00)
>>>>>         otime 1758488400.101635440 (2025-09-22 00:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 31 key (14451 ROOT_BACKREF 256) itemoff 12021 itemsize 26
>>>>>         root backref key dirid 28635 sequence 2 name snapshot
>>>>>     item 32 key (14475 ROOT_ITEM 1942246) itemoff 11582 itemsize 439
>>>>>         generation 2025984 root_dirid 256 bytenr 71398831259648 
>>>>> byte_limit 0 bytes_used 6755549184
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025984
>>>>>         uuid 38b9ea09-54ef-5140-bddc-83dc884c31b3
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 1940067 otransid 1942246 stransid 0 rtransid 0
>>>>>         ctime 1758570000.151997903 (2025-09-22 22:40:00)
>>>>>         otime 1758574800.777676964 (2025-09-23 00:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 33 key (14475 ROOT_BACKREF 256) itemoff 11556 itemsize 26
>>>>>         root backref key dirid 28683 sequence 2 name snapshot
>>>>>     item 34 key (14499 ROOT_ITEM 1977241) itemoff 11117 itemsize 439
>>>>>         generation 2025986 root_dirid 256 bytenr 71398873153536 
>>>>> byte_limit 0 bytes_used 6538182656
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025986
>>>>>         uuid 703f0298-831b-1e4d-b1f1-fc37ff582770
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 1977241 otransid 1977241 stransid 0 rtransid 0
>>>>>         ctime 1758661201.518446292 (2025-09-24 00:00:01)
>>>>>         otime 1758661204.161207119 (2025-09-24 00:00:04)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 35 key (14499 ROOT_BACKREF 256) itemoff 11091 itemsize 26
>>>>>         root backref key dirid 28731 sequence 2 name snapshot
>>>>>     item 36 key (14523 ROOT_ITEM 2001507) itemoff 10652 itemsize 439
>>>>>         generation 2025988 root_dirid 256 bytenr 71398873497600 
>>>>> byte_limit 0 bytes_used 6561398784
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025988
>>>>>         uuid 9672abd0-7e7b-ab4f-9e0f-7183e58bb6c4
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2001507 otransid 2001507 stransid 0 rtransid 0
>>>>>         ctime 1758747600.712874426 (2025-09-25 00:00:00)
>>>>>         otime 1758747600.840460363 (2025-09-25 00:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 37 key (14523 ROOT_BACKREF 256) itemoff 10626 itemsize 26
>>>>>         root backref key dirid 28779 sequence 2 name snapshot
>>>>>     item 38 key (14547 ROOT_ITEM 2017206) itemoff 10187 itemsize 439
>>>>>         generation 2025990 root_dirid 256 bytenr 71398872924160 
>>>>> byte_limit 0 bytes_used 6570868736
>>>>>         last_snapshot 2018745 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025990
>>>>>         uuid 671b4b4f-fd99-e140-8535-fce0a16babfb
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2017206 otransid 2017206 stransid 0 rtransid 0
>>>>>         ctime 1758834001.88320469 (2025-09-26 00:00:01)
>>>>>         otime 1758834001.271433540 (2025-09-26 00:00:01)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 39 key (14547 ROOT_BACKREF 256) itemoff 10161 itemsize 26
>>>>>         root backref key dirid 28827 sequence 2 name snapshot
>>>>>     item 40 key (14559 ROOT_ITEM 2019735) itemoff 9722 itemsize 439
>>>>>         generation 2025992 root_dirid 256 bytenr 75423231606784 
>>>>> byte_limit 0 bytes_used 6576078848
>>>>>         last_snapshot 2019735 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025992
>>>>>         uuid 3ff52125-57ee-6140-87a5-4fb848ec4638
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2019711 otransid 2019735 stransid 0 rtransid 0
>>>>>         ctime 1758919659.690576855 (2025-09-26 23:47:39)
>>>>>         otime 1758920400.700930626 (2025-09-27 00:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 41 key (14559 ROOT_BACKREF 256) itemoff 9696 itemsize 26
>>>>>         root backref key dirid 28851 sequence 2 name snapshot
>>>>>     item 42 key (14583 ROOT_ITEM 2022097) itemoff 9257 itemsize 439
>>>>>         generation 2025994 root_dirid 256 bytenr 65812067024896 
>>>>> byte_limit 0 bytes_used 6557646848
>>>>>         last_snapshot 2022097 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025994
>>>>>         uuid 860f0635-f296-a04b-9fc5-bd85d480799c
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2022097 otransid 2022097 stransid 0 rtransid 0
>>>>>         ctime 1759006819.37527411 (2025-09-28 00:00:19)
>>>>>         otime 1759006820.861182212 (2025-09-28 00:00:20)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 43 key (14583 ROOT_BACKREF 256) itemoff 9231 itemsize 26
>>>>>         root backref key dirid 28899 sequence 2 name snapshot
>>>>>     item 44 key (14607 ROOT_ITEM 2024585) itemoff 8792 itemsize 439
>>>>>         generation 2025996 root_dirid 256 bytenr 227573944696832 
>>>>> byte_limit 0 bytes_used 6583533568
>>>>>         last_snapshot 2024585 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025996
>>>>>         uuid af3524d0-8a9a-894c-b5b7-705b10114326
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2024474 otransid 2024585 stransid 0 rtransid 0
>>>>>         ctime 1759089642.387498362 (2025-09-28 23:00:42)
>>>>>         otime 1759093200.412309185 (2025-09-29 00:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 45 key (14607 ROOT_BACKREF 256) itemoff 8766 itemsize 26
>>>>>         root backref key dirid 28947 sequence 2 name snapshot
>>>>>     item 46 key (14631 ROOT_ITEM 2025813) itemoff 8327 itemsize 439
>>>>>         generation 2025998 root_dirid 256 bytenr 178141351657472 
>>>>> byte_limit 0 bytes_used 6602981376
>>>>>         last_snapshot 2025813 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2025998
>>>>>         uuid 6f085114-93b0-d146-8997-9a41ff62f8db
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025812 otransid 2025813 stransid 0 rtransid 0
>>>>>         ctime 1759177902.175859896 (2025-09-29 23:31:42)
>>>>>         otime 1759210423.120386595 (2025-09-30 08:33:43)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 47 key (14631 ROOT_BACKREF 256) itemoff 8301 itemsize 26
>>>>>         root backref key dirid 28995 sequence 2 name snapshot
>>>>>     item 48 key (14640 ROOT_ITEM 2025865) itemoff 7862 itemsize 439
>>>>>         generation 2026000 root_dirid 256 bytenr 194611771719680 
>>>>> byte_limit 0 bytes_used 6603735040
>>>>>         last_snapshot 2025865 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026000
>>>>>         uuid a48f03d9-4847-654a-af1d-5e0eaf6ecd0c
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025863 otransid 2025865 stransid 0 rtransid 0
>>>>>         ctime 1759237252.139079795 (2025-09-30 16:00:52)
>>>>>         otime 1759240800.56609287 (2025-09-30 17:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 49 key (14640 ROOT_BACKREF 256) itemoff 7836 itemsize 26
>>>>>         root backref key dirid 29013 sequence 2 name snapshot
>>>>>     item 50 key (14641 ROOT_ITEM 2025870) itemoff 7397 itemsize 439
>>>>>         generation 2026002 root_dirid 256 bytenr 65801342844928 
>>>>> byte_limit 0 bytes_used 6603292672
>>>>>         last_snapshot 2025870 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026002
>>>>>         uuid 56e7aa4e-e166-504d-9a55-8c8b074c0fd9
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025868 otransid 2025870 stransid 0 rtransid 0
>>>>>         ctime 1759241717.101400473 (2025-09-30 17:15:17)
>>>>>         otime 1759244400.232224532 (2025-09-30 18:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 51 key (14641 ROOT_BACKREF 256) itemoff 7371 itemsize 26
>>>>>         root backref key dirid 29015 sequence 2 name snapshot
>>>>>     item 52 key (14642 ROOT_ITEM 2025874) itemoff 6932 itemsize 439
>>>>>         generation 2026004 root_dirid 256 bytenr 187252895498240 
>>>>> byte_limit 0 bytes_used 6603341824
>>>>>         last_snapshot 2025874 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026004
>>>>>         uuid f1761dfd-ec60-724a-9af0-dea952cc6771
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025872 otransid 2025874 stransid 0 rtransid 0
>>>>>         ctime 1759244441.841998010 (2025-09-30 18:00:41)
>>>>>         otime 1759248000.122051877 (2025-09-30 19:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 53 key (14642 ROOT_BACKREF 256) itemoff 6906 itemsize 26
>>>>>         root backref key dirid 29017 sequence 2 name snapshot
>>>>>     item 54 key (14643 ROOT_ITEM 2025904) itemoff 6467 itemsize 439
>>>>>         generation 2026006 root_dirid 256 bytenr 227587769647104 
>>>>> byte_limit 0 bytes_used 6603587584
>>>>>         last_snapshot 2025904 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026006
>>>>>         uuid 68fd5037-6c8a-c74e-b08f-cff4cdccf752
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025904 otransid 2025904 stransid 0 rtransid 0
>>>>>         ctime 1759251597.815452999 (2025-09-30 19:59:57)
>>>>>         otime 1759251600.884521740 (2025-09-30 20:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 55 key (14643 ROOT_BACKREF 256) itemoff 6441 itemsize 26
>>>>>         root backref key dirid 29019 sequence 2 name snapshot
>>>>>     item 56 key (14644 ROOT_ITEM 2025922) itemoff 6002 itemsize 439
>>>>>         generation 2026008 root_dirid 256 bytenr 227594191208448 
>>>>> byte_limit 0 bytes_used 6603653120
>>>>>         last_snapshot 2025922 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026008
>>>>>         uuid 07ccd2ae-f51d-2c46-82df-05e16964b2e5
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025921 otransid 2025922 stransid 0 rtransid 0
>>>>>         ctime 1759254975.20573006 (2025-09-30 20:56:15)
>>>>>         otime 1759255200.196692319 (2025-09-30 21:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 57 key (14644 ROOT_BACKREF 256) itemoff 5976 itemsize 26
>>>>>         root backref key dirid 29021 sequence 2 name snapshot
>>>>>     item 58 key (14645 ROOT_ITEM 2025951) itemoff 5537 itemsize 439
>>>>>         generation 2026010 root_dirid 256 bytenr 193309358817280 
>>>>> byte_limit 0 bytes_used 6603964416
>>>>>         last_snapshot 2025951 flags 0x1(RDONLY) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 3 generation_v2 2026010
>>>>>         uuid b46ce558-2c39-3944-91d4-b2b229f04a16
>>>>>         parent_uuid eea49a45-adcf-4bff-a203-0f600f2db6a8
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 2025950 otransid 2025951 stransid 0 rtransid 0
>>>>>         ctime 1759257514.988583086 (2025-09-30 21:38:34)
>>>>>         otime 1759258800.482340435 (2025-09-30 22:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>>     item 59 key (14645 ROOT_BACKREF 256) itemoff 5511 itemsize 26
>>>>>         root backref key dirid 29023 sequence 2 name snapshot
>>>>>     item 60 key (DATA_RELOC_TREE ROOT_ITEM 0) itemoff 5072 
>>>>> itemsize 439
>>>>>         generation 2018764 root_dirid 256 bytenr 71399055278080 
>>>>> byte_limit 0 bytes_used 16384
>>>>>         last_snapshot 0 flags 0x0(none) refs 1
>>>>>         drop_progress key (0 UNKNOWN.0 0) drop_level 0
>>>>>         level 0 generation_v2 2018764
>>>>>         uuid 00000000-0000-0000-0000-000000000000
>>>>>         parent_uuid 00000000-0000-0000-0000-000000000000
>>>>>         received_uuid 00000000-0000-0000-0000-000000000000
>>>>>         ctransid 0 otransid 0 stransid 0 rtransid 0
>>>>>         ctime 0.0 (1970-01-01 02:00:00)
>>>>>         otime 0.0 (1970-01-01 02:00:00)
>>>>>         stime 0.0 (1970-01-01 02:00:00)
>>>>>         rtime 0.0 (1970-01-01 02:00:00)
>>>>
>>>> Qu Wenruo kirjoitti 5.10.2025 klo 1.07:
>>>>>
>>>>>
>>>>> 在 2025/10/5 08:23, Henri Hyyryläinen 写道:
>>>>>>> One extra thing, at the time of the initial "btrfs check -- 
>>>>>>> repair", there is no running dev-replace/balance or whatever 
>>>>>>> running?
>>>>>>>
>>>>>>> Although those operations will be automatically paused by unmount,
>>>>>>> btrfs check is not going to be able to handle some of those 
>>>>>>> paused operations. 
>>>>>>
>>>>>> Is there a way for me to check that without mounting the 
>>>>>> filesystem? As far as I could find, none of the balance / scrub 
>>>>>> commands allow working on an unmounted filesystem. So I couldn't 
>>>>>> find out if I had any in canceled state.
>>>>>
>>>>> # btrfs ins dump-tree -t root <device>
>>>>>>
>>>>>> Though, I'm pretty sure I let the last scrub and balance 
>>>>>> operation I tried to fully complete before starting using the 
>>>>>> check and repair commands. But I'm not absolutely certain that I 
>>>>>> didn't try one of those a last time and didn't let it fully 
>>>>>> complete.
>>>>>>
>>>>>> I'll start that "btrfs check --readonly" command now. And I'll 
>>>>>> report back once it is done (hopefully by the morning in my 
>>>>>> timezone).
>>>>>>
>>>>>> - Henri Hyyryläinen
>>>>>>
>>>>>> Qu Wenruo kirjoitti 4.10.2025 klo 23.55:
>>>>>>>
>>>>>>>
>>>>>>> 在 2025/10/5 07:14, Qu Wenruo 写道:
>>>>>>>>
>>>>>>>>
>>>>>>>> 在 2025/10/5 04:13, Henri Hyyryläinen 写道:
>>>>>>>>> Hello again.
>>>>>>>>>
>>>>>>>>> It took over 3 days, but the btrfs check --repair has now 
>>>>>>>>> completed seemingly successfully. I mostly saw output about 
>>>>>>>>> the file being placed in lost+found and and directory size 
>>>>>>>>> being corrected. However, there were some messages about 
>>>>>>>>> mismatch of used bytes.
>>>>>>>>>
>>>>>>>>> Unfortunately it seems like the situation has gotten worse 
>>>>>>>>> since the repair, because now I cannot mount the filesystem at 
>>>>>>>>> all. Instead I get an error like this:
>>>>>>>>>
>>>>>>>>>> BTRFS error (device sdc): dev extent physical offset 
>>>>>>>>>> 19977638903808 on devid 4 doesn't have corresponding chunk
>>>>>>>>>> BTRFS error (device sdc): failed to verify dev extents 
>>>>>>>>>> against chunks: -117
>>>>>>>>>> BTRFS error (device sdc): open_ctree failed: -117
>>>>>>>>> Even if I remove that one problematic device physically from 
>>>>>>>>> my computer, the filesystem still refuses to mount with the 
>>>>>>>>> same error. Maybe the problems with the device replace are 
>>>>>>>>> again showing up with the actual size of the hard drive not 
>>>>>>>>> being used correctly? I cannot try to remove the device slack 
>>>>>>>>> as I cannot mount the filesystem.
>>>>>>>>
>>>>>>>> Nope, this is a different problem, and not related to dev replace.
>>>>>>>>
>>>>>>>> Unfortunately btrfs check has not implemented any repair for that.
>>>>>>>>
>>>>>>>> Overall if the dev extent is found but not corresponding chunk, 
>>>>>>>> it should still be fine but some space unavailable.
>>>>>>>>
>>>>>>>> But the kernel is overly cautious on chunk tree, as it's a very 
>>>>>>>> important and basic functionality.
>>>>>>>>
>>>>>>>> Please provide the full "btrfs check --readonly" output so that 
>>>>>>>> we can evaluate and add the missing repair functionality.
>>>>>>>
>>>>>>> One extra thing, at the time of the initial "btrfs check -- 
>>>>>>> repair", there is no running dev-replace/balance or whatever 
>>>>>>> running?
>>>>>>>
>>>>>>> Although those operations will be automatically paused by unmount,
>>>>>>> btrfs check is not going to be able to handle some of those 
>>>>>>> paused operations.
>>>>>>>>
>>>>>>>> Thanks,
>>>>>>>> Qu
>>>>>>>>
>>>>>>>>>
>>>>>>>>> I did try to run a repair again, and this time I got a bunch 
>>>>>>>>> of messages like:
>>>>>>>>>
>>>>>>>>>> repair deleting extent record: key [65795546775552,169,0]
>>>>>>>>>> adding new tree backref on start 65795546775552 len 16384 
>>>>>>>>>> parent 65811674234880 root 65811674234880
>>>>>>>>>> adding new tree backref on start 65795546775552 len 16384 
>>>>>>>>>> parent 0 root 14499
>>>>>>>>>> adding new tree backref on start 65795546775552 len 16384 
>>>>>>>>>> parent 65791012274176 root 65791012274176
>>>>>>>>>> adding new tree backref on start 65795546775552 len 16384 
>>>>>>>>>> parent 65806385807360 root 65806385807360
>>>>>>>>>> Repaired extent references for 65795546775552
>>>>>>>>>> ref mismatch on [65795548233728 16384] extent item 5, found 4
>>>>>>>>
>>>>>>>> That's fixing some backref mismatch, which you can ignore 
>>>>>>>> unless "btrfs check --reaonly" later reports new problems.
>>>>>>>>
>>>>>>>>> But the filesystem still refuses to mount with the exact same 
>>>>>>>>> error. I did not let the repair run entirely as it would have 
>>>>>>>>> likely taken another 3 days. What should I do? This time I'm 
>>>>>>>>> not finding any good information on what to do. For now, I've 
>>>>>>>>> started the repair again, but it doesn't exactly sound like it 
>>>>>>>>> is even fixing anything now. Still, I'll let it continue. The 
>>>>>>>>> output so far is:
>>>>>>>>>
>>>>>>>>>> [1/8] checking log skipped (none written)
>>>>>>>>>> [2/8] checking root items
>>>>>>>>>> Fixed 0 roots.
>>>>>>>>>> [3/8] checking extents
>>>>>>>>>> Device extent[4, 19977638903808, 1073741824] didn't find the 
>>>>>>>>>> relative chunk.
>>>>>>>>>> super bytes used 49454738989056 mismatches actual used 
>>>>>>>>>> 49454738923520
>>>>>>>>>> Device extent[4, 19977638903808, 1073741824] didn't find the 
>>>>>>>>>> relative chunk.
>>>>>>>>>> super bytes used 49454739005440 mismatches actual used 
>>>>>>>>>> 49454738956288
>>>>>>>>>> Device extent[4, 19977638903808, 1073741824] didn't find the 
>>>>>>>>>> relative chunk.
>>>>>>>>>> super bytes used 49454739021824 mismatches actual used 
>>>>>>>>>> 49454738972672
>>>>>>>>>> Device extent[4, 19977638903808, 1073741824] didn't find the 
>>>>>>>>>> relative chunk.
>>>>>>>>>> super bytes used 49454739005440 mismatches actual used 
>>>>>>>>>> 49454738972672
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> If I was able to somehow remove that one logically corrupt 
>>>>>>>>> devid from the filesystem, or somehow correct the size, that 
>>>>>>>>> would hopefully allow me to rebuild from the raid10 data then, 
>>>>>>>>> but I can't do those with the unmountable filesystem.
>>>>>>>>>
>>>>>>>>>
>>>>>>>>> - Henri Hyyryläinen
>>>>>>>>>
>>>>>>>>> Qu Wenruo kirjoitti 30.9.2025 klo 0.52:
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> ��� 2025/9/30 02:41, Henri Hyyryläinen 写道:
>>>>>>>>>>> Hello,
>>>>>>>>>>>
>>>>>>>>>>> I hope this is the right place to ask about a filesystem 
>>>>>>>>>>> problem. Really shortly put, I have a file that both exists 
>>>>>>>>>>> and doesn't and prevents the containing directory from being 
>>>>>>>>>>> deleted. No matter what variant of rm and inode based 
>>>>>>>>>>> deletion I try I get an error about the file not existing, 
>>>>>>>>>>> and I also cannot try to read the file, but if I try to 
>>>>>>>>>>> delete the directory I get an error that it is not empty (so 
>>>>>>>>>>> the file kind of exists). Trying to ls the directory also 
>>>>>>>>>>> gives a file doesn't exist error.
>>>>>>>>>>>
>>>>>>>>>>> Here's what btrfs check found, which I hope does better in 
>>>>>>>>>>> illustrating the problem:
>>>>>>>>>>>
>>>>>>>>>>>> root 5 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 5 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>
>>>>>>>>>>> I've tried everything I've found suggested including a full 
>>>>>>>>>>> scrub, balance with -dusage=75 -musage=75, resetting file 
>>>>>>>>>>> attributes, deleting through the find command, and even some 
>>>>>>>>>>> repair mount flags that don't seem to exist for btrfs.
>>>>>>>>>>
>>>>>>>>>> The fs is corrupted, thus none of those will help.
>>>>>>>>>> I'm more interested in how the corruption happened.
>>>>>>>>>>
>>>>>>>>>> Did you use some tools other than btrfs kernel module and 
>>>>>>>>>> btrfs- progs?
>>>>>>>>>> Like ntfs2btrfs or winbtrfs?
>>>>>>>>>>
>>>>>>>>>> IIRC certain versions have some bugs related to extent tree, 
>>>>>>>>>> but should not cause this problem.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> The other possibility is hardware memory bitflip, which is 
>>>>>>>>>> more common than you thought (almostly one report per month)
>>>>>>>>>>
>>>>>>>>>> In that case, a full memtest is always recommended, or you 
>>>>>>>>>> will hit all kinds of weird corruptions in the future anyway.
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>> With a full memtest proving the memory hardware is fine, then 
>>>>>>>>>> "btrfs check --repair" should be able to fix it.
>>>>>>>>>>
>>>>>>>>>> Thanks,
>>>>>>>>>> Qu
>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>>>> What I haven't tried is a full rebalance with no filters, 
>>>>>>>>>>> but I did not try that yet as it would take quite a long 
>>>>>>>>>>> time and if it only moves data blocks around without 
>>>>>>>>>>> recomputing directory items, it doesn't seem like the right 
>>>>>>>>>>> tool to fix my problem. So I'm pretty much stuck and to me 
>>>>>>>>>>> it seems like my only option is to run btrfs check with the 
>>>>>>>>>>> repair flag, but as that has big warnings on it I thought I 
>>>>>>>>>>> would try asking here first (sorry if this is not the right 
>>>>>>>>>>> experts group to ask). So is there still something I can try 
>>>>>>>>>>> or am I finally "allowed" to use the repair command? Here's 
>>>>>>>>>>> the full output I got from btrfs check:
>>>>>>>>>>>
>>>>>>>>>>>> Opening filesystem to check...
>>>>>>>>>>>> Checking filesystem on /dev/sdc
>>>>>>>>>>>> UUID: 2b4ad16d-e456-4adf-960b-dca43560b98b
>>>>>>>>>>>> [1/8] checking log skipped (none written)
>>>>>>>>>>>> [2/8] checking root items
>>>>>>>>>>>> [3/8] checking extents
>>>>>>>>>>>> [4/8] checking free space tree
>>>>>>>>>>>> We have a space info key for a block group that doesn't exist
>>>>>>>>>>>> [5/8] checking fs roots
>>>>>>>>>>>> root 5 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 5 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14428 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14428 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14451 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14451 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14475 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14475 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14499 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14499 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14523 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14523 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14544 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14544 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14545 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14545 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14546 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14546 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14547 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14547 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14548 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14548 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14549 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14549 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> root 14550 inode 25953213 errors 200, dir isize wrong
>>>>>>>>>>>> root 14550 inode 27166085 errors 2000, link count wrong
>>>>>>>>>>>>         unresolved ref dir 25953213 index 7 namelen 33 name 
>>>>>>>>>>>> Microsoft.AspNetCore.Metadata.dll filetype 1 errors 1, no 
>>>>>>>>>>>> dir item
>>>>>>>>>>>> ERROR: errors found in fs roots
>>>>>>>>>>>> found 49400296812544 bytes used, error(s) found
>>>>>>>>>>>> total csum bytes: 48179330432
>>>>>>>>>>>> total tree bytes: 65067483136
>>>>>>>>>>>> total fs tree bytes: 12107431936
>>>>>>>>>>>> total extent tree bytes: 3194437632
>>>>>>>>>>>> btree space waste bytes: 4558984171
>>>>>>>>>>>> file data blocks allocated: 76487982252032
>>>>>>>>>>>>  referenced 60030799097856
>>>>>>>>>>>
>>>>>>>>>>> So hopefully if I'm reading things right, running a repair 
>>>>>>>>>>> would delete just that one file and directory (which itself 
>>>>>>>>>>> is a backup so I will not miss that file at all)?
>>>>>>>>>>>
>>>>>>>>>>> I do not have enough disk space to copy off the entire 
>>>>>>>>>>> filesystem and rebuild from scratch, without doing something 
>>>>>>>>>>> like rebalancing all data from raid10 to single and then 
>>>>>>>>>>> removing half the disks, but I assume that would take at 
>>>>>>>>>>> least 4 weeks to process (as I just replaced a disk which 
>>>>>>>>>>> took like a week).
>>>>>>>>>>>
>>>>>>>>>>> As to what originally caused the corruption, I think it was 
>>>>>>>>>>> probably faulty RAM, because up to to like 3 weeks ago I had 
>>>>>>>>>>> one really bad RAM stick in my computer where a certain 
>>>>>>>>>>> memory region always had incorrectly reading bytes. I had 
>>>>>>>>>>> seen intermittent quite high csum errors in monthly scrubs 
>>>>>>>>>>> pretty randomly, which thankfully could almost always be 
>>>>>>>>>>> corrected so I didn't have any major problems even though I 
>>>>>>>>>>> had like totally broken RAM in my computer for who knows how 
>>>>>>>>>>> long. So btrfs was able to protect my data quite 
>>>>>>>>>>> impressively from bad RAM.
>>>>>>>>>>>
>>>>>>>>>>> Sorry for getting a bit sidetracked there, but what should I 
>>>>>>>>>>> do in this situation?
>>>>>>>>>>>
>>>>>>>>>>> - Henri Hyyryläinen
>>>>>>>>>>>
>>>>>>>>>>>
>>>>>>>>>>
>>>>>>>>
>>>>>>>>
>>>>>>>
>>>>>
>>>>
>>>
>