From: Hannes Reinecke <hare@suse.de>

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 a mechanism to switch off partition scanning and
creation via kpartx.

The new 'no_partitions' feature serves as a notifier to kpartx to _not_
create partitions on these multipath devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
---
drivers/md/dm-mpath.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 0fc6849..1039e7f 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -85,6 +85,7 @@ struct multipath {
unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */
unsigned saved_queue_if_no_path:1; /* Saved state during suspension */
unsigned use_default_hw_handler:1; /* Use attached device handler */
+ unsigned no_partitions:1; /* Avoid partition scanning */

unsigned pg_init_retries; /* Number of times to retry pg_init */
unsigned pg_init_count; /* Number of times pg_init called */
@@ -770,7 +771,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
const char *arg_name;

static struct dm_arg _args[] = {
- {0, 6, "invalid number of feature args"},
+ {0, 7, "invalid number of feature args"},
{1, 50, "pg_init_retries must be between 1 and 50"},
{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
};
@@ -796,6 +797,11 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
continue;
}

+ if (!strcasecmp(arg_name, "no_partitions")) {
+ m->no_partitions = 1;
+ continue;
+ }
+
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
@@ -1380,7 +1386,8 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
DMEMIT("%u ", m->queue_if_no_path +
(m->pg_init_retries > 0) * 2 +
(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
- m->use_default_hw_handler);
+ m->use_default_hw_handler +
+ m->no_partitions);
if (m->queue_if_no_path)
DMEMIT("queue_if_no_path ");
if (m->pg_init_retries)
@@ -1389,6 +1396,8 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
if (m->use_default_hw_handler)
DMEMIT("default_hw_handler ");
+ if (m->no_partitions)
+ DMEMIT("no_partitions ");
}

if (!m->hw_handler_name || type == STATUSTYPE_INFO)
--
1.7.4.4

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From: Hannes Reinecke <hare@suse.de>

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 a mechanism to switch off partition scanning and
creation via kpartx.

The new 'no_partitions' feature serves as a notifier to kpartx to _not_
create partitions on these multipath devices.

Signed-off-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Reviewed-by: Chandra Seetharaman <sekharan@us.ibm.com>
---
drivers/md/dm-mpath.c | 13 +++++++++++--
1 files changed, 11 insertions(+), 2 deletions(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index 4dd3f59..115ad9e 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -86,6 +86,7 @@ struct multipath {
unsigned queue_if_no_path:1; /* Queue I/O if last path fails? */
unsigned saved_queue_if_no_path:1; /* Saved state during suspension */
unsigned use_default_hw_handler:1; /* Use attached device handler */
+ unsigned no_partitions:1; /* Avoid partition scanning */

unsigned pg_init_retries; /* Number of times to retry pg_init */
unsigned pg_init_count; /* Number of times pg_init called */
@@ -772,7 +773,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
const char *arg_name;

static struct dm_arg _args[] = {
- {0, 6, "invalid number of feature args"},
+ {0, 7, "invalid number of feature args"},
{1, 50, "pg_init_retries must be between 1 and 50"},
{0, 60000, "pg_init_delay_msecs must be between 0 and 60000"},
};
@@ -798,6 +799,11 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m)
continue;
}

+ if (!strcasecmp(arg_name, "no_partitions")) {
+ m->no_partitions = 1;
+ continue;
+ }
+
if (!strcasecmp(arg_name, "pg_init_retries") &&
(argc >= 1)) {
r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error);
@@ -1382,7 +1388,8 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
DMEMIT("%u ", m->queue_if_no_path +
(m->pg_init_retries > 0) * 2 +
(m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 +
- m->use_default_hw_handler);
+ m->use_default_hw_handler +
+ m->no_partitions);
if (m->queue_if_no_path)
DMEMIT("queue_if_no_path ");
if (m->pg_init_retries)
@@ -1391,6 +1398,8 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs);
if (m->use_default_hw_handler)
DMEMIT("default_hw_handler ");
+ if (m->no_partitions)
+ DMEMIT("no_partitions ");
}

if (!m->hw_handler_name || type == STATUSTYPE_INFO)
--
1.7.4.4

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