From: Mike Snitzer <snitzer@redhat.com>
To: Paolo Bonzini <pbonzini@redhat.com>
Cc: Hannes Reinecke <hare@suse.de>,
hch@lst.de,
Mauricio Faria de Oliveira <mauricfo@linux.vnet.ibm.com>,
dm-devel@redhat.com, linux-scsi@vger.kernel.org,
Peter Rajnoha <prajnoha@redhat.com>
Subject: Re: IBM request to allow unprivledged ioctls [Was: Revert "dm mpath: fix stalls when handling invalid ioctls"]
Date: Mon, 2 Nov 2015 10:49:43 -0500 [thread overview]
Message-ID: <20151102154942.GA23816@redhat.com> (raw)
In-Reply-To: <56378505.6080601@redhat.com>
On Mon, Nov 02 2015 at 10:45am -0500,
Paolo Bonzini <pbonzini@redhat.com> wrote:
>
>
> On 02/11/2015 16:05, Mike Snitzer wrote:
> > > In any case, if we don't start path activation we should return
> > > ENOTCONN, not ENOTTY.
> >
> > Currently, if we don't start path activation we're returning EIO.
> > ENOTCONN is used for when we do start path activation (and ENOTCONN is
> > the means for DM core to retry)
> >
> > We _could_ change the ENOTCONN to be EAGAIN and EIO to ENOTCONN...
>
> This makes sense... though of course testing the impact of this on
> userspace is going to be hard. :( Chances are that userspace is not
> expecting EAGAIN either.
>
> Even if they did, how would someone know that they can now retry the
> ioctl after getting EAGAIN? Should they just do it in a loop?
Turns out multipath (userspace) has a udev rule for this now (prajnoha
pointed this out):
http://git.opensvc.com/gitweb.cgi?p=multipath-tools/.git;a=blob;f=multipath/11-dm-mpath.rules
So now I'm wondering if we _need_ to do any retries in kernel (aside
from while activation is active)?
next prev parent reply other threads:[~2015-11-02 15:49 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
[not found] <1446121463-17828-1-git-send-email-mauricfo@linux.vnet.ibm.com>
2015-10-29 13:18 ` IBM request to allow unprivledged ioctls [Was: Revert "dm mpath: fix stalls when handling invalid ioctls"] Mike Snitzer
2015-10-29 14:47 ` [dm-devel] " Mauricio Faria de Oliveira
2015-10-31 15:33 ` Paolo Bonzini
2015-10-31 18:13 ` Mike Snitzer
2015-10-31 18:36 ` Mike Snitzer
2015-10-31 19:07 ` Paolo Bonzini
2015-10-31 22:47 ` Mike Snitzer
2015-11-02 7:28 ` Hannes Reinecke
2015-11-02 9:57 ` Paolo Bonzini
2015-11-02 13:31 ` Mike Snitzer
2015-11-02 13:56 ` Hannes Reinecke
2015-11-02 14:12 ` Mike Snitzer
2015-11-02 14:36 ` Hannes Reinecke
2015-11-02 15:14 ` Mike Snitzer
2015-11-02 15:29 ` Hannes Reinecke
2015-11-02 14:52 ` Paolo Bonzini
2015-11-02 15:05 ` Mike Snitzer
2015-11-02 15:45 ` Paolo Bonzini
2015-11-02 15:49 ` Mike Snitzer [this message]
2015-11-02 15:32 ` Hannes Reinecke
2015-11-02 9:55 ` Paolo Bonzini
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