Unable to remove directory entry

Mike Gilbert
2019-12-08T19:19:24Z

Hello,

I have a directory entry that cannot be stat-ed or unlinked. This
issue persists across reboots, so it seems there is something wrong on
disk.

% ls -l /var/cache/ccache.bad/2/c
ls: cannot access
'/var/cache/ccache.bad/2/c/0390cb341d248c589c419007da68b2-7351.manifest':
No such
file or directory
total 0
-????????? ? ? ? ? ? 0390cb341d248c589c419007da68b2-7351.manifest

% uname -a
Linux naomi 4.19.67 #4 SMP Sun Aug 18 14:35:39 EDT 2019 x86_64 AMD
Phenom(tm) II X6 1055T Processor
AuthenticAMD GNU/Linux

% btrfs --version
btrfs-progs v5.4

I have tried running btrfs check, and I get differing results based on
the --mode switch:

# btrfs check --readonly /dev/sda3
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
[5/7] checking only csums items (without verifying data)
[6/7] checking root refs
[7/7] checking quota groups
Opening filesystem to check...
Checking filesystem on /dev/sda3
UUID: 5e9dcab6-036d-40f1-8b40-24ab4c062bf6
found 284337733632 bytes used, no error found
total csum bytes: 267182280
total tree bytes: 4498915328
total fs tree bytes: 3972464640
total extent tree bytes: 199819264
btree space waste bytes: 776711635
file data blocks allocated: 313928671232
referenced 279141621760

# btrfs check --readonly --mode=lowmem /dev/sda3
[1/7] checking root items
[2/7] checking extents
[3/7] checking free space cache
[4/7] checking fs roots
ERROR: root 5 INODE_ITEM[4065004] index 18446744073709551615 name
0390cb341d248c589c419007da68b2-7351.manifest filetype 1 missing
ERROR: root 5 DIR ITEM[486836 13905] name
0390cb341d248c589c419007da68b2-7351.manifest filetype 1 mismath
ERROR: root 5 DIR ITEM[486836 2543451757] mismatch name
0390cb341d248c589c419007da68b2-7351.manifest filetype 1
ERROR: errors found in fs roots
Opening filesystem to check...
Checking filesystem on /dev/sda3
UUID: 5e9dcab6-036d-40f1-8b40-24ab4c062bf6
found 284337733632 bytes used, error(s) found
total csum bytes: 267182280
total tree bytes: 4498915328
total fs tree bytes: 3972464640
total extent tree bytes: 199819264
btree space waste bytes: 776711635
file data blocks allocated: 313928671232
referenced 279141621760

Please advise on possible next steps to diagnose and fix this.