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path: root/drivers/md/dm-mpath.c
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Diffstat (limited to 'drivers/md/dm-mpath.c')
-rw-r--r--drivers/md/dm-mpath.c111
1 files changed, 72 insertions, 39 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index e81345a1d08..826bce7343b 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -69,6 +69,7 @@ struct multipath {
struct list_head priority_groups;
unsigned pg_init_required; /* pg_init needs calling? */
unsigned pg_init_in_progress; /* Only one pg_init allowed at once */
+ wait_queue_head_t pg_init_wait; /* Wait for pg_init completion */
unsigned nr_valid_paths; /* Total number of usable paths */
struct pgpath *current_pgpath;
@@ -95,8 +96,6 @@ struct multipath {
mempool_t *mpio_pool;
struct mutex work_mutex;
-
- unsigned suspended; /* Don't create new I/O internally when set. */
};
/*
@@ -202,6 +201,7 @@ static struct multipath *alloc_multipath(struct dm_target *ti)
m->queue_io = 1;
INIT_WORK(&m->process_queued_ios, process_queued_ios);
INIT_WORK(&m->trigger_event, trigger_event);
+ init_waitqueue_head(&m->pg_init_wait);
mutex_init(&m->work_mutex);
m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache);
if (!m->mpio_pool) {
@@ -235,6 +235,21 @@ static void free_multipath(struct multipath *m)
* Path selection
*-----------------------------------------------*/
+static void __pg_init_all_paths(struct multipath *m)
+{
+ struct pgpath *pgpath;
+
+ m->pg_init_count++;
+ m->pg_init_required = 0;
+ list_for_each_entry(pgpath, &m->current_pg->pgpaths, list) {
+ /* Skip failed paths */
+ if (!pgpath->is_active)
+ continue;
+ if (queue_work(kmpath_handlerd, &pgpath->activate_path))
+ m->pg_init_in_progress++;
+ }
+}
+
static void __switch_pg(struct multipath *m, struct pgpath *pgpath)
{
m->current_pg = pgpath->pg;
@@ -439,7 +454,7 @@ static void process_queued_ios(struct work_struct *work)
{
struct multipath *m =
container_of(work, struct multipath, process_queued_ios);
- struct pgpath *pgpath = NULL, *tmp;
+ struct pgpath *pgpath = NULL;
unsigned must_queue = 1;
unsigned long flags;
@@ -457,14 +472,9 @@ static void process_queued_ios(struct work_struct *work)
(!pgpath && !m->queue_if_no_path))
must_queue = 0;
- if (m->pg_init_required && !m->pg_init_in_progress && pgpath) {
- m->pg_init_count++;
- m->pg_init_required = 0;
- list_for_each_entry(tmp, &pgpath->pg->pgpaths, list) {
- if (queue_work(kmpath_handlerd, &tmp->activate_path))
- m->pg_init_in_progress++;
- }
- }
+ if (m->pg_init_required && !m->pg_init_in_progress && pgpath)
+ __pg_init_all_paths(m);
+
out:
spin_unlock_irqrestore(&m->lock, flags);
if (!must_queue)
@@ -597,8 +607,8 @@ static struct pgpath *parse_path(struct arg_set *as, struct path_selector *ps,
if (!p)
return ERR_PTR(-ENOMEM);
- r = dm_get_device(ti, shift(as), ti->begin, ti->len,
- dm_table_get_mode(ti->table), &p->path.dev);
+ r = dm_get_device(ti, shift(as), dm_table_get_mode(ti->table),
+ &p->path.dev);
if (r) {
ti->error = "error getting device";
goto bad;
@@ -890,9 +900,34 @@ static int multipath_ctr(struct dm_target *ti, unsigned int argc,
return r;
}
-static void flush_multipath_work(void)
+static void multipath_wait_for_pg_init_completion(struct multipath *m)
+{
+ DECLARE_WAITQUEUE(wait, current);
+ unsigned long flags;
+
+ add_wait_queue(&m->pg_init_wait, &wait);
+
+ while (1) {
+ set_current_state(TASK_UNINTERRUPTIBLE);
+
+ spin_lock_irqsave(&m->lock, flags);
+ if (!m->pg_init_in_progress) {
+ spin_unlock_irqrestore(&m->lock, flags);
+ break;
+ }
+ spin_unlock_irqrestore(&m->lock, flags);
+
+ io_schedule();
+ }
+ set_current_state(TASK_RUNNING);
+
+ remove_wait_queue(&m->pg_init_wait, &wait);
+}
+
+static void flush_multipath_work(struct multipath *m)
{
flush_workqueue(kmpath_handlerd);
+ multipath_wait_for_pg_init_completion(m);
flush_workqueue(kmultipathd);
flush_scheduled_work();
}
@@ -901,7 +936,7 @@ static void multipath_dtr(struct dm_target *ti)
{
struct multipath *m = ti->private;
- flush_multipath_work();
+ flush_multipath_work(m);
free_multipath(m);
}
@@ -1128,8 +1163,7 @@ static int pg_init_limit_reached(struct multipath *m, struct pgpath *pgpath)
static void pg_init_done(void *data, int errors)
{
- struct dm_path *path = data;
- struct pgpath *pgpath = path_to_pgpath(path);
+ struct pgpath *pgpath = data;
struct priority_group *pg = pgpath->pg;
struct multipath *m = pg->m;
unsigned long flags;
@@ -1143,8 +1177,8 @@ static void pg_init_done(void *data, int errors)
errors = 0;
break;
}
- DMERR("Cannot failover device because scsi_dh_%s was not "
- "loaded.", m->hw_handler_name);
+ DMERR("Could not failover the device: Handler scsi_dh_%s "
+ "Error %d.", m->hw_handler_name, errors);
/*
* Fail path for now, so we do not ping pong
*/
@@ -1181,14 +1215,24 @@ static void pg_init_done(void *data, int errors)
m->current_pgpath = NULL;
m->current_pg = NULL;
}
- } else if (!m->pg_init_required) {
- m->queue_io = 0;
+ } else if (!m->pg_init_required)
pg->bypassed = 0;
- }
- m->pg_init_in_progress--;
- if (!m->pg_init_in_progress)
- queue_work(kmultipathd, &m->process_queued_ios);
+ if (--m->pg_init_in_progress)
+ /* Activations of other paths are still on going */
+ goto out;
+
+ if (!m->pg_init_required)
+ m->queue_io = 0;
+
+ queue_work(kmultipathd, &m->process_queued_ios);
+
+ /*
+ * Wake up any thread waiting to suspend.
+ */
+ wake_up(&m->pg_init_wait);
+
+out:
spin_unlock_irqrestore(&m->lock, flags);
}
@@ -1198,7 +1242,7 @@ static void activate_path(struct work_struct *work)
container_of(work, struct pgpath, activate_path);
scsi_dh_activate(bdev_get_queue(pgpath->path.dev->bdev),
- pg_init_done, &pgpath->path);
+ pg_init_done, pgpath);
}
/*
@@ -1276,8 +1320,7 @@ static void multipath_postsuspend(struct dm_target *ti)
struct multipath *m = ti->private;
mutex_lock(&m->work_mutex);
- m->suspended = 1;
- flush_multipath_work();
+ flush_multipath_work(m);
mutex_unlock(&m->work_mutex);
}
@@ -1289,10 +1332,6 @@ static void multipath_resume(struct dm_target *ti)
struct multipath *m = (struct multipath *) ti->private;
unsigned long flags;
- mutex_lock(&m->work_mutex);
- m->suspended = 0;
- mutex_unlock(&m->work_mutex);
-
spin_lock_irqsave(&m->lock, flags);
m->queue_if_no_path = m->saved_queue_if_no_path;
spin_unlock_irqrestore(&m->lock, flags);
@@ -1428,11 +1467,6 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
mutex_lock(&m->work_mutex);
- if (m->suspended) {
- r = -EBUSY;
- goto out;
- }
-
if (dm_suspended(ti)) {
r = -EBUSY;
goto out;
@@ -1471,8 +1505,7 @@ static int multipath_message(struct dm_target *ti, unsigned argc, char **argv)
goto out;
}
- r = dm_get_device(ti, argv[1], ti->begin, ti->len,
- dm_table_get_mode(ti->table), &dev);
+ r = dm_get_device(ti, argv[1], dm_table_get_mode(ti->table), &dev);
if (r) {
DMWARN("message: error getting device %s",
argv[1]);