RE: [Regression] fstrim hangs on Hyper-V: caused by "block: improve handling of the magic discard payload"

[Dexuan Cui]

> From: Christoph Hellwig [mailto:hch@xxxxxx]
> Sent: Thursday, January 12, 2017 21:44
> To: Dexuan Cui <decui@xxxxxxxxxxxxx>
> Cc: Christoph Hellwig <hch@xxxxxx>; linux-block@xxxxxxxxxxxxxxx; Jens Axboe
> <axboe@xxxxxx>; Vitaly Kuznetsov <vkuznets@xxxxxxxxxx>; linux-
> kernel@xxxxxxxxxxxxxxx; KY Srinivasan <kys@xxxxxxxxxxxxx>; Chris Valean
> (Cloudbase Solutions SRL) <v-chvale@xxxxxxxxxxxxx>
> Subject: Re: [Regression] fstrim hangs on Hyper-V: caused by "block: improve
> handling of the magic discard payload"
> 
> Hi Dexuan,
> 
> sorry for dropping the ball on the previous private report, I hoped
> I could get my hands on a Hyper-V VM and reproduce it myself, but
> that has obviously not happened.
> 
> Can you send me the output of the provisioning_mode file for the
> scsi disk in question to get started?

Hi Christoph,
Thank you very much for the help! 

The file just shows "unmap":

root@decui-u1604:~# cd /sys/class/scsi_disk/2\:0\:0\:0
root@decui-u1604:/sys/class/scsi_disk/2:0:0:0# ls
allow_restart  cache_type      device  manage_start_stop           max_write_same_blocks  protection_mode  provisioning_mode  thin_provisioning
app_tag_own    deferred_probe  FUA     max_medium_access_timeouts  power                  protection_type  subsystem          uevent
root@decui-u1604:/sys/class/scsi_disk/2:0:0:0# cat provisioning_mode
unmap

I'm ready to provide any info you need. :-)

Thanks,
-- Dexuan