diff options
| -rw-r--r-- | drivers/md/dm-mpath.c | 47 |
1 files changed, 41 insertions, 6 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index 638dae048b4f..8a3b2d53f81b 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -85,6 +85,7 @@ struct multipath { unsigned queue_io:1; /* Must we queue all I/O? */ 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 retain_attached_hw_handler:1; /* If there's already a hw_handler present, don't change it. */ unsigned pg_init_retries; /* Number of times to retry pg_init */ unsigned pg_init_count; /* Number of times pg_init called */ @@ -568,6 +569,8 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps int r; struct pgpath *p; struct multipath *m = ti->private; + struct request_queue *q = NULL; + const char *attached_handler_name; /* we need at least a path arg */ if (as->argc < 1) { @@ -586,13 +589,37 @@ static struct pgpath *parse_path(struct dm_arg_set *as, struct path_selector *ps goto bad; } - if (m->hw_handler_name) { - struct request_queue *q = bdev_get_queue(p->path.dev->bdev); + if (m->retain_attached_hw_handler || m->hw_handler_name) + q = bdev_get_queue(p->path.dev->bdev); + + if (m->retain_attached_hw_handler) { + attached_handler_name = scsi_dh_attached_handler_name(q, GFP_KERNEL); + if (attached_handler_name) { + /* + * Reset hw_handler_name to match the attached handler + * and clear any hw_handler_params associated with the + * ignored handler. + * + * NB. This modifies the table line to show the actual + * handler instead of the original table passed in. + */ + kfree(m->hw_handler_name); + m->hw_handler_name = attached_handler_name; + + kfree(m->hw_handler_params); + m->hw_handler_params = NULL; + } + } + if (m->hw_handler_name) { + /* + * Increments scsi_dh reference, even when using an + * already-attached handler. + */ r = scsi_dh_attach(q, m->hw_handler_name); if (r == -EBUSY) { /* - * Already attached to different hw_handler, + * Already attached to different hw_handler: * try to reattach with correct one. */ scsi_dh_detach(q); @@ -760,7 +787,7 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) const char *arg_name; static struct dm_arg _args[] = { - {0, 5, "invalid number of feature args"}, + {0, 6, "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"}, }; @@ -781,6 +808,11 @@ static int parse_features(struct dm_arg_set *as, struct multipath *m) continue; } + if (!strcasecmp(arg_name, "retain_attached_hw_handler")) { + m->retain_attached_hw_handler = 1; + continue; + } + if (!strcasecmp(arg_name, "pg_init_retries") && (argc >= 1)) { r = dm_read_arg(_args + 1, as, &m->pg_init_retries, &ti->error); @@ -1364,13 +1396,16 @@ static int multipath_status(struct dm_target *ti, status_type_t type, else { 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->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) * 2 + + m->retain_attached_hw_handler); if (m->queue_if_no_path) DMEMIT("queue_if_no_path "); if (m->pg_init_retries) DMEMIT("pg_init_retries %u ", m->pg_init_retries); if (m->pg_init_delay_msecs != DM_PG_INIT_DELAY_DEFAULT) DMEMIT("pg_init_delay_msecs %u ", m->pg_init_delay_msecs); + if (m->retain_attached_hw_handler) + DMEMIT("retain_attached_hw_handler "); } if (!m->hw_handler_name || type == STATUSTYPE_INFO) @@ -1656,7 +1691,7 @@ out: *---------------------------------------------------------------*/ static struct target_type multipath_target = { .name = "multipath", - .version = {1, 4, 0}, + .version = {1, 5, 0}, .module = THIS_MODULE, .ctr = multipath_ctr, .dtr = multipath_dtr, |