Re: [PATCH v2] xen-blkfront: allow discard-* nodes to be optional

[Arthur Borsboom <arthurborsboom@xxxxxxxxx>]

This time the patch applied cleanly.

The trim command seems to work as well, meaning no error messages and
a certain amount of blocks (5GB) is trimmed.
The trimming did consume a bit of time (10-20 seconds), assuming it is
actually discarding the blocks at the host.

First run:

[arthur@test-arch ~]$ sudo fstrim -v /
/: 5.7 GiB (6074368000 bytes) trimmed

Second run:

[arthur@test-arch ~]$ sudo fstrim -v /
/: 0 B (0 bytes) trimmed

No errors were reported in the dmesg of the VM; no errors in Dom0 and
no errors in dmesg of Xen (xl dmesg).

Based on this single test, it seems to work.
You can add me as Tested-By.

On Wed, 20 Jan 2021 at 15:35, Roger Pau Monné <roger.pau@xxxxxxxxxx> wrote:
>
> On Wed, Jan 20, 2021 at 03:23:30PM +0100, Arthur Borsboom wrote:
> > Hi Roger,
> >
> > I have set up a test environment based on Linux 5.11.0-rc4.
> > The patch did not apply clean, so I copied/pasted the patch manually.
> >
> > Without the patch the call trace (as reported) is visible in dmesg.
> > With the patch the call trace in dmesg is gone, but ... (there is always a
> > but) ...
> >
> > Now the discard action returns the following.
> >
> > [arthur@test-arch ~]$ sudo fstrim -v /
> > fstrim: /: the discard operation is not supported
> >
> > It might be correct, but of course I was hoping the Xen VM guest would pass
> > on the discard request to the block device in the Xen VM host, which is a
> > disk partition.
> > Any suggestions?
>
> Hm, that's not what I did see on my testing, the operation worked OK,
> and that's what I would expect to happen in your case also, since I
> know the xenstore keys.
>
> I think it's possible your email client has mangled the patch, I'm
> attaching the same patch to this email, could you try to apply it
> again and report back? (this time it should apply cleanly)
>
> Thanks, Roger.



-- 
Arthur Borsboom