From: Hannes Reinecke <hare@suse.de>
Subject: Disable partitions scan for multipathed devices
References: bnc#402922,bnc#514767
Patch-mainline: not yet, <hare: reworked by mwilck, will update, Oct 4, 2017>
When multipath devices are being used as disks for VM Guests
any partition scanning / setup should be done within the VM Guest,
not from host. So we need to switch off partitions scanning via
kpartx there.
For this I've implemented a new feature 'no_partitions' which
just serves as a notifier to kpartx to _not_ create partitions
on these devices.
Patch ported to SLES11.
[Update jeffm: Upstream commit 518257b13276 switched to using a flags
field for multipath state, so we can use that now.]
Signed-off-by: Hannes Reinecke <hare@suse.de>
---
drivers/md/dm-mpath.c | 8 ++++++++
1 file changed, 8 insertions(+)
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -127,6 +127,7 @@ static void queue_if_no_path_timeout_wor
#define MPATHF_PG_INIT_DISABLED 4 /* pg_init is not currently allowed */
#define MPATHF_PG_INIT_REQUIRED 5 /* pg_init needs calling? */
#define MPATHF_PG_INIT_DELAY_RETRY 6 /* Delay pg_init retry? */
+#define MPATHF_NO_PARTITIONS 31 /* Don't scan partition table */
static bool mpath_double_check_test_bit(int MPATHF_bit, struct multipath *m)
{
@@ -1133,6 +1134,10 @@ static int parse_features(struct dm_arg_
continue;
}
+ if (!strcasecmp(arg_name, "no_partitions")) {
+ set_bit(MPATHF_NO_PARTITIONS, &m->flags);
+ continue;
+ }
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
@@ -1802,6 +1807,7 @@ static void multipath_status(struct dm_t
DMEMIT("%u ", test_bit(MPATHF_QUEUE_IF_NO_PATH, &m->flags) +
(m->pg_init_retries > 0) * 2 +
(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
+ test_bit(MPATHF_NO_PARTITIONS, &m->flags) +
test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags) +
(m->queue_mode != DM_TYPE_REQUEST_BASED) * 2);
@@ -1809,6 +1815,8 @@ static void multipath_status(struct dm_t
DMEMIT("queue_if_no_path ");
if (m->pg_init_retries)
DMEMIT("pg_init_retries %u ", m->pg_init_retries);
+ if (test_bit(MPATHF_NO_PARTITIONS, &m->flags))
+ DMEMIT("no_partitions ");
if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT)
DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
if (test_bit(MPATHF_RETAIN_ATTACHED_HW_HANDLER, &m->flags))