Reviewed-by: Chandra Seetharaman <sekharan@xxxxxxxxxx>
On Tue, 2012-05-08 at 17:56 -0400, Mike Snitzer wrote:
> From: Hannes Reinecke <hare@xxxxxxx>
>
> 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@xxxxxxx>
> Signed-off-by: Mike Snitzer <snitzer@xxxxxxxxxx>
> ---
> 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)
--
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