Bug#900442: linux-image-4.16.0-2-amd64: LVM2 COW snapshots fail as of 4.16

[Salvatore Bonaccorso <carnil@debian.org>]

Control: forwarded -1 https://www.spinics.net/lists/linux-block/msg29103.html
Control: tags -1 + upstream fixed-upstream confirmed
Control: clone -1 -2
Control: reassign -2 src:lvm2 2.02.176-4.1
Control: retitle -2 lvm2: Ensure COW device is writable even for read-only thick snapshots

Hi,

On Fri, Aug 03, 2018 at 12:44:23AM +0300, WGH wrote:
> This problem is being discussed in kernel mailing list right now:
> https://www.spinics.net/lists/linux-block/msg29103.html (its cause is
> more or less known now)

The upstream fix reverts partially "block: fail op_is_write() requests
to read-only partitions".

https://git.kernel.org/linus/a32e236eb93e62a0f692e79b7c3c9636689559b9

On the lvm2 side, the following commit can be applied:

https://sourceware.org/git/?p=lvm2.git;a=commit;h=a6fdb9d9d70f51c49ad11a87ab4243344e6701a3

(thus cloning the bug as well to src:lvm2 to include this commit or
update to 2.02.178 once released).

Regards,
Salvatore