[dm-devel] [PATCH] multipath-tools: update mpp->force_readonly in ev_add_path

[Martin Wilck]

On Wed, 2022-03-23 at 18:10 -0500, Benjamin Marzinski wrote:
> On Wed, Mar 09, 2022 at 01:03:26PM -0700, Uday Shankar wrote:
> > When NVMe disks are added to the system, no uevent containing the
> > DISK_RO property is generated. As a result, dm-* nodes backed by
> > readonly NVMe disks will not have their RO state set properly. The
> > result looks like this:
> > 
> > $ multipath -l
> > eui.00c92c091fd6564424a9376600011bd1 dm-3 NVME,Pure Storage
> > FlashArray
> > size=1.0T features='0' hwhandler='0' wp=rw
> > > -+- policy='service-time 0' prio=0 status=active
> > > `- 0:2:2:72657 nvme0n2 259:4 active undef running
> > `-+- policy='service-time 0' prio=0 status=enabled
> >   `- 1:0:2:72657 nvme1n2 259:1 active undef running
> > $ cat /sys/block/dm-3/ro
> > 0
> > $ cat /sys/block/nvme*n2/ro
> > 1
> > 1
> > 
> > This is not a problem for SCSI disks, since the kernel will emit
> > change
> > uevents containing the DISK_RO property when the disk is added to
> > the
> > system. See the following thread for my initial attempt to fix this
> > issue at the kernel level:
> > https://lore.kernel.org/linux-block/Yib8GqCA5e3SQYty@infradead.org/T/#t
> > 
> > Fix the issue by picking up the path ro state from sysfs in
> > ev_add_path,
> > setting the mpp->force_readonly accordingly, and changing
> > dm_addmap_create to be aware of mpp->force_readonly.
> > 
> > Signed-off-by: Uday Shankar <ushankar at purestorage.com>
> 
> Reviewed-by: Benjamin Marzinski <bmarzins at redhat.com>

Thanks, applied to
https://github.com/openSUSE/multipath-tools/tree/queue

Martin

(Please set me on CC next time to speed up review).