diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 610af916891ec2328ef14e20bacf99d9475fefb9..5303af55d2c7502f9c44c5934860cc66798ba8c6 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -252,6 +252,7 @@ config DM_ZERO
config DM_MULTIPATH
tristate "Multipath target"
depends on BLK_DEV_DM
+ select SCSI_DH
---help---
Allow volume managers to support multipath hardware.
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e7ee59e655d58a66e53658794e5e0dc2b2042ed3..e54ff372d711b53e652220e8616ddf3d07995f5c 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -20,6 +20,7 @@
#include <linux/slab.h>
#include <linux/time.h>
#include <linux/workqueue.h>
+#include <scsi/scsi_dh.h>
#include <asm/atomic.h>
#define DM_MSG_PREFIX "multipath"
@@ -61,7 +62,7 @@ struct multipath {
spinlock_t lock;
- struct hw_handler hw_handler;
+ const char *hw_handler_name;
unsigned nr_priority_groups;
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
@@ -109,6 +110,7 @@ static struct kmem_cache *_mpio_cache;
static struct workqueue_struct *kmultipathd;
static void process_queued_ios(struct work_struct *work);
static void trigger_event(struct work_struct *work);
+static void pg_init_done(struct dm_path *, int);
/*-----------------------------------------------
@@ -193,18 +195,13 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
static void free_multipath(struct multipath *m)
{
struct priority_group *pg, *tmp;
- struct hw_handler *hwh = &m->hw_handler;
list_for_each_entry_safe(pg, tmp, &m->priority_groups, list) {
list_del(&pg->list);
free_priority_group(pg, m->ti);
}
- if (hwh->type) {
- hwh->type->destroy(hwh);
- dm_put_hw_handler(hwh->type);
- }
-
+ kfree(m->hw_handler_name);
mempool_destroy(m->mpio_pool);
kfree(m);
}
@@ -216,12 +213,10 @@ static void free_multipath(struct multipath *m)
static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
{
- struct hw_handler *hwh = &m->hw_handler;
-
m->current_pg = pgpath->pg;
/* Must we initialise the PG first, and queue I/O till it's ready? */
- if (hwh->type && hwh->type->pg_init) {
+ if (m->hw_handler_name) {
m->pg_init_required = 1;
m->queue_io = 1;
} else {
@@ -409,7 +404,6 @@ static void process_queued_ios(struct work_struct *work)
{
struct multipath *m =
container_of(work, struct multipath, process_queued_ios);
- struct hw_handler *hwh = &m->hw_handler;
struct pgpath *pgpath = NULL;
unsigned init_required = 0, must_queue = 1;
unsigned long flags;
@@ -438,8 +432,11 @@ static void process_queued_ios(struct work_struct *work)
out:
spin_unlock_irqrestore(&m->lock, flags);
- if (init_required)
- hwh->type->pg_init(hwh, pgpath->pg->bypassed, &pgpath->path);
+ if (init_required) {
+ struct dm_path *path = &pgpath->path;
+ int ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev));
+ pg_init_done(path, ret);
+ }
if (!must_queue)
dispatch_queued_ios(m);
@@ -652,8 +649,6 @@ static struct priority_group *parse_priority_group(struct arg_set *as,
static int parse_hw_handler(struct arg_set *as, struct multipath *m)
{
- int r;
- struct hw_handler_type *hwht;
unsigned hw_argc;
struct dm_target *ti = m->ti;
@@ -661,30 +656,18 @@ static int parse_hw_handler(struct arg_set *as, struct multipath *m)
{0, 1024, "invalid number of hardware handler args"},
};
- r = read_param(_params, shift(as), &hw_argc, &ti->error);
- if (r)
+ if (read_param(_params, shift(as), &hw_argc, &ti->error))
return -EINVAL;
if (!hw_argc)
return 0;
- hwht = dm_get_hw_handler(shift(as));
- if (!hwht) {
+ m->hw_handler_name = kstrdup(shift(as), GFP_KERNEL);
+ request_module("scsi_dh_%s", m->hw_handler_name);
+ if (scsi_dh_handler_exist(m->hw_handler_name) == 0) {
ti->error = "unknown hardware handler type";
return -EINVAL;
}
-
- m->hw_handler.md = dm_table_get_md(ti->table);
- dm_put(m->hw_handler.md);
-
- r = hwht->create(&m->hw_handler, hw_argc - 1, as->argv);
- if (r) {
- dm_put_hw_handler(hwht);
- ti->error = "hardware handler constructor failed";
- return r;
- }
-
- m->hw_handler.type = hwht;
consume(as, hw_argc - 1);
return 0;
@@ -1063,14 +1046,74 @@ void dm_pg_init_complete(struct dm_path *path, unsigned err_flags)
spin_unlock_irqrestore(&m->lock, flags);
}
+static void pg_init_done(struct dm_path *path, int errors)
+{
+ struct pgpath *pgpath = path_to_pgpath(path);
+ struct priority_group *pg = pgpath->pg;
+ struct multipath *m = pg->m;
+ unsigned long flags;
+
+ /* device or driver problems */
+ switch (errors) {
+ case SCSI_DH_OK:
+ break;
+ case SCSI_DH_NOSYS:
+ if (!m->hw_handler_name) {
+ errors = 0;
+ break;
+ }
+ DMERR("Cannot failover device because scsi_dh_%s was not "
+ "loaded.", m->hw_handler_name);
+ /*
+ * Fail path for now, so we do not ping pong
+ */
+ fail_path(pgpath);
+ break;
+ case SCSI_DH_DEV_TEMP_BUSY:
+ /*
+ * Probably doing something like FW upgrade on the
+ * controller so try the other pg.
+ */
+ bypass_pg(m, pg, 1);
+ break;
+ /* TODO: For SCSI_DH_RETRY we should wait a couple seconds */
+ case SCSI_DH_RETRY:
+ case SCSI_DH_IMM_RETRY:
+ case SCSI_DH_RES_TEMP_UNAVAIL:
+ if (pg_init_limit_reached(m, pgpath))
+ fail_path(pgpath);
+ errors = 0;
+ break;
+ default:
+ /*
+ * We probably do not want to fail the path for a device
+ * error, but this is what the old dm did. In future
+ * patches we can do more advanced handling.
+ */
+ fail_path(pgpath);
+ }
+
+ spin_lock_irqsave(&m->lock, flags);
+ if (errors) {
+ DMERR("Could not failover device. Error %d.", errors);
+ m->current_pgpath = NULL;
+ m->current_pg = NULL;
+ } else if (!m->pg_init_required) {
+ m->queue_io = 0;
+ pg->bypassed = 0;
+ }
+
+ m->pg_init_in_progress = 0;
+ queue_work(kmultipathd, &m->process_queued_ios);
+ spin_unlock_irqrestore(&m->lock, flags);
+}
+
/*
* end_io handling
*/
static int do_end_io(struct multipath *m, struct bio *bio,
int error, struct dm_mpath_io *mpio)
{
- struct hw_handler *hwh = &m->hw_handler;
- unsigned err_flags = MP_FAIL_PATH; /* Default behavior */
unsigned long flags;
if (!error)
@@ -1097,19 +1140,8 @@ static int do_end_io(struct multipath *m, struct bio *bio,
}
spin_unlock_irqrestore(&m->lock, flags);
- if (hwh->type && hwh->type->error)
- err_flags = hwh->type->error(hwh, bio);
-
- if (mpio->pgpath) {
- if (err_flags & MP_FAIL_PATH)
- fail_path(mpio->pgpath);
-
- if (err_flags & MP_BYPASS_PG)
- bypass_pg(m, mpio->pgpath->pg, 1);
- }
-
- if (err_flags & MP_ERROR_IO)
- return -EIO;
+ if (mpio->pgpath)
+ fail_path(mpio->pgpath);
requeue:
dm_bio_restore(&mpio->details, bio);
@@ -1194,7 +1226,6 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
int sz = 0;
unsigned long flags;
struct multipath *m = (struct multipath *) ti->private;
- struct hw_handler *hwh = &m->hw_handler;
struct priority_group *pg;
struct pgpath *p;
unsigned pg_num;
@@ -1214,12 +1245,10 @@ static int multipath_status(struct dm_target *ti, status_type_t type,
DMEMIT("pg_init_retries %u ", m->pg_init_retries);
}
- if (hwh->type && hwh->type->status)
- sz += hwh->type->status(hwh, type, result + sz, maxlen - sz);
- else if (!hwh->type || type == STATUSTYPE_INFO)
+ if (!m->hw_handler_name || type == STATUSTYPE_INFO)
DMEMIT("0 ");
else
- DMEMIT("1 %s ", hwh->type->name);
+ DMEMIT("1 %s ", m->hw_handler_name);
DMEMIT("%u ", m->nr_priority_groups);