From a490a07a67b7a37f588021410e06b721a752fc34 Mon Sep 17 00:00:00 2001 From: Mike Snitzer Date: Thu, 24 Mar 2011 13:54:33 +0000 Subject: [PATCH] dm mpath: allow table load with no priority groups This patch adjusts the multipath target to allow a table with both 0 priority groups and 0 for the initial priority group number. If any mpath device is held open when all paths in the last priority group have failed, userspace multipathd will attempt to reload the associated DM table to reflect the fact that the device no longer has any priority groups. But the reload attempt always failed because the multipath target did not allow 0 priority groups. All multipath target messages related to priority group (enable_group, disable_group, switch_group) will handle a priority group of 0 (will cause error). When reloading a multipath table with 0 priority groups, userspace multipathd must be updated to specify an initial priority group number of 0 (rather than 1). Signed-off-by: Mike Snitzer Cc: Babu Moger Acked-by: Hannes Reinecke Signed-off-by: Alasdair G Kergon --- drivers/md/dm-mpath.c | 13 ++++++++++--- 1 file changed, 10 insertions(+), 3 deletions(-) diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 52f0de3..a550a05 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -844,8 +844,8 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc, { /* target parameters */ static struct param _params[] = { - {1, 1024, "invalid number of priority groups"}, - {1, 1024, "invalid initial priority group number"}, + {0, 1024, "invalid number of priority groups"}, + {0, 1024, "invalid initial priority group number"}, }; int r; @@ -879,6 +879,13 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc, if (r) goto bad; + if ((!m->nr_priority_groups && next_pg_num) || + (m->nr_priority_groups && !next_pg_num)) { + ti->error = "invalid initial priority group"; + r = -EINVAL; + goto bad; + } + /* parse the priority groups */ while (as.argc) { struct priority_group *pg; @@ -1415,7 +1422,7 @@ static int multipath_status(struct dm_target *ti, status_type_t type, else if (m->current_pg) pg_num = m->current_pg->pg_num; else - pg_num = 1; + pg_num = (m->nr_priority_groups ? 1 : 0); DMEMIT("%u ", pg_num); -- 2.7.4