On 2019-11-05 09:52, Qu Wenruo wrote:

>> Now let's try to unmount and see what "btrfs rescue fix-device-size"
>> shows again - I'd expect "No device size related problem found", 
>> correct?
>> 
>> 
>> # umount /home
>> 
>> # btrfs rescue fix-device-size /dev/sda4
>> parent transid verify failed on 265344253952 wanted 42646 found 46119
>> parent transid verify failed on 265344253952 wanted 42646 found 46119
>> parent transid verify failed on 265344253952 wanted 42646 found 46119
> 
> This is not correct. What happened during your /home mount and unmount?
> 
> The fs looks already screwed up.

Nothing happened - it normally mounts/unmounts without errors.

Also scrub works without issues (a few days ago):

# btrfs scrub status /home
UUID:             c94ea4a9-6d10-4e78-9b4a-ffe664386af2
Scrub started:    Sat Nov  2 01:14:17 2019
Status:           finished
Duration:         0:55:23
Total to scrub:   1.17TiB
Rate:             368.41MiB/s
Error summary:    no errors found


It also no longer shows "parent transid verify failed" after a few more 
cycles like this:

# umount /home

# btrfs rescue fix-device-size /dev/sda4
parent transid verify failed on 265344253952 wanted 42646 found 46119
parent transid verify failed on 265344253952 wanted 42646 found 46119
parent transid verify failed on 265344253952 wanted 42646 found 46119
Ignoring transid failure
Fixed super total bytes, old size: 7901711842304 new size: 7901711835136
Fixed unaligned/mismatched total_bytes for super block and device items

# btrfs rescue fix-device-size /dev/sda4
No device size related problem found

# mount /home ; sync ; umount /home

# btrfs rescue fix-device-size /dev/sda4
parent transid verify failed on 265344253952 wanted 42646 found 46119
parent transid verify failed on 265344253952 wanted 42646 found 46119
parent transid verify failed on 265344253952 wanted 42646 found 46119
Ignoring transid failure
Fixed super total bytes, old size: 7901711842304 new size: 7901711835136
Fixed unaligned/mismatched total_bytes for super block and device items

# mount /home ; sync ; umount /home

# btrfs rescue fix-device-size /dev/sda4
No device size related problem found

# btrfs rescue fix-device-size /dev/sda4
No device size related problem found

# mount /home ; sync ; umount /home

# btrfs rescue fix-device-size /dev/sda4
No device size related problem found

# btrfs rescue fix-device-size /dev/sdb4
No device size related problem found

# mount /home

# date > /home/date.txt

# umount /home

# btrfs rescue fix-device-size /dev/sdb4
No device size related problem found



Tomasz Chmielewski
https://lxadm.com