Re: I/O hangs after resuming from suspend-to-ram

[Ming Lei]

On Mon, Aug 28, 2017 at 03:10:35PM +0200, Martin Steigerwald wrote:
> Ming Lei - 28.08.17, 20:58:
> > On Sun, Aug 27, 2017 at 09:43:52AM +0200, Oleksandr Natalenko wrote:
> > > Hi.
> > > 
> > > Here is disk setup for QEMU VM:
> > > 
> > > ===
> > > [root@archmq ~]# smartctl -i /dev/sda
> > > â
> > > Device Model:     QEMU HARDDISK
> > > Serial Number:    QM00001
> > > Firmware Version: 2.5+
> > > User Capacity:    4,294,967,296 bytes [4.29 GB]
> > > Sector Size:      512 bytes logical/physical
> > > Device is:        Not in smartctl database [for details use: -P showall]
> > > ATA Version is:   ATA/ATAPI-7, ATA/ATAPI-5 published, ANSI NCITS 340-2000
> > > Local Time is:    Sun Aug 27 09:31:54 2017 CEST
> > > SMART support is: Available - device has SMART capability.
> > > SMART support is: Enabled
> > > 
> > > [root@archmq ~]# lsblk
> > > NAME                MAJ:MIN RM  SIZE RO TYPE   MOUNTPOINT
> > > sda                   8:0    0    4G  0 disk
> > > `-sda1                8:1    0    4G  0 part
> > > 
> > >   `-md0               9:0    0    4G  0 raid10
> > >   
> > >     `-system        253:0    0    4G  0 crypt
> > >     
> > >       |-system-boot 253:1    0  512M  0 lvm    /boot
> > >       |-system-swap 253:2    0  512M  0 lvm    [SWAP]
> > >       
> > >       `-system-root 253:3    0    3G  0 lvm    /
> > > 
> > > sdb                   8:16   0    4G  0 disk
> > > `-sdb1                8:17   0    4G  0 part
> > > 
> > >   `-md0               9:0    0    4G  0 raid10
> > >   
> > >     `-system        253:0    0    4G  0 crypt
> > >     
> > >       |-system-boot 253:1    0  512M  0 lvm    /boot
> > >       |-system-swap 253:2    0  512M  0 lvm    [SWAP]
> > >       
> > >       `-system-root 253:3    0    3G  0 lvm    /
> > > 
> > > sr0                  11:0    1 1024M  0 rom
> > > 
> > > [root@archmq ~]# mdadm --misc --detail /dev/md0
> > > 
> > > /dev/md0:
> > >         Version : 1.2
> > >   
> > >   Creation Time : Sat Jul 29 16:37:05 2017
> > >   
> > >      Raid Level : raid10
> > >      Array Size : 4191232 (4.00 GiB 4.29 GB)
> > >   
> > >   Used Dev Size : 4191232 (4.00 GiB 4.29 GB)
> > >   
> > >    Raid Devices : 2
> > >   
> > >   Total Devices : 2
> > >   
> > >     Persistence : Superblock is persistent
> > >     
> > >     Update Time : Sun Aug 27 09:30:33 2017
> > >     
> > >           State : clean
> > >  
> > >  Active Devices : 2
> > > 
> > > Working Devices : 2
> > > 
> > >  Failed Devices : 0
> > >  
> > >   Spare Devices : 0
> > >   
> > >          Layout : far=2
> > >      
> > >      Chunk Size : 512K
> > >      
> > >            Name : archiso:0
> > >            UUID : 43f4be59:c8d2fa0a:a94acdff:1c7f2f4e
> > >          
> > >          Events : 485
> > >     
> > >     Number   Major   Minor   RaidDevice State
> > >     
> > >        0       8        1        0      active sync   /dev/sda1
> > >        1       8       17        1      active sync   /dev/sdb1
> > > 
> > > ===
> > > 
> > > In words: 2 virtual disks, RAID10 setup with far-2 layout, LUKS on it,
> > > then
> > > LVM, then ext4 for boot, swap and btrfs for /.
> > > 
> > > I couldn't reproduce the issue with single disk without RAID.
> > 
> > Could you verify if the following patch fixes your issue?
> 
> Could this also apply to non MD RAID systems? I am using BTRFS RAID
> 1 with two SSDs. So far with CFQ it runs stable.

It is for fixing Oleksandr's issue wrt. blk-mq, and looks not for you.

-- 
Ming