On 2019/1/25 下午3:39, Stefan K wrote:
> Hello,
> 
> if I run 'bonnie++ -c4' the system is unusable and hangs, I got also some CallTraces in my syslog. Is that a normal behavior? 
> 
> My system is:
> uname -a 
> Linux tani 4.19.0-0.bpo.1-amd64 #1 SMP Debian 4.19.12-1~bpo9+1 (2018-12-30) x86_64 GNU/Linux
> 
> btrfs fi sh
> Label: none  uuid: 24be286b-ece6-4481-aa48-af255e96e5bd
>         Total devices 2 FS bytes used 128.89GiB
>         devid    1 size 219.84GiB used 131.03GiB path /dev/sdb2
>         devid    2 size 219.84GiB used 131.03GiB path /dev/sde2
> 
> both are new SSDs:
> smartctl -i /dev/sdb
> smartctl 6.6 2016-05-31 r4324 [x86_64-linux-4.19.0-0.bpo.1-amd64] (local build)
> Copyright (C) 2002-16, Bruce Allen, Christian Franke, www.smartmontools.org
> 
> === START OF INFORMATION SECTION ===
> Device Model:     SAMSUNG MZ7LM240HMHQ-00005
> Serial Number:    S2TWNX0KA02412
> LU WWN Device Id: 5 002538 c40b988bf
> Firmware Version: GXT5404Q
> User Capacity:    240,057,409,536 bytes [240 GB]
> Sector Size:      512 bytes logical/physical
> Rotation Rate:    Solid State Device
> Form Factor:      2.5 inches
> Device is:        Not in smartctl database [for details use: -P showall]
> ATA Version is:   ACS-2, ATA8-ACS T13/1699-D revision 4c
> SATA Version is:  SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
> Local Time is:    Fri Jan 25 08:37:49 2019 CET
> SMART support is: Available - device has SMART capability.
> SMART support is: Enabled
> 
> 
> if I run this I got this output in my /var/log/syslog:
> 
> Jan 25 08:19:20 tani kernel: [  480.733545] WARNING: CPU: 8 PID: 8564 at /build/linux-Ut6wTa/linux-4.19.12/fs/btrfs/ctree.h:1588 btrfs_update_device+0x1b2/0x1c0 [btrfs]

This is a known bug for older created btrfs with unaligned device size.

You could resize the fs by -4K and it should make the warning disappear.

Or you can use offline tool, "btrfs rescue fix-device-size" to fix it
offline.

Thanks,
Qu