diff options
| -rw-r--r-- | drivers/md/dm-mpath.c | 41 |
1 files changed, 34 insertions, 7 deletions
diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c index e54ff372d711..9b16788118d2 100644 --- a/drivers/md/dm-mpath.c +++ b/drivers/md/dm-mpath.c @@ -63,6 +63,7 @@ struct multipath { spinlock_t lock; const char *hw_handler_name; + struct work_struct activate_path; unsigned nr_priority_groups; struct list_head priority_groups; unsigned pg_init_required; /* pg_init needs calling? */ @@ -107,10 +108,10 @@ typedef int (*action_fn) (struct pgpath *pgpath); static struct kmem_cache *_mpio_cache; -static struct workqueue_struct *kmultipathd; +static struct workqueue_struct *kmultipathd, *kmpath_handlerd; 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); +static void activate_path(struct work_struct *work); /*----------------------------------------------- @@ -180,6 +181,7 @@ 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_WORK(&m->activate_path, activate_path); m->mpio_pool = mempool_create_slab_pool(MIN_IOS, _mpio_cache); if (!m->mpio_pool) { kfree(m); @@ -432,11 +434,8 @@ static void process_queued_ios(struct work_struct *work) out: spin_unlock_irqrestore(&m->lock, flags); - 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 (init_required) + queue_work(kmpath_handlerd, &m->activate_path); if (!must_queue) dispatch_queued_ios(m); @@ -791,6 +790,7 @@ static void multipath_dtr(struct dm_target *ti) { struct multipath *m = (struct multipath *) ti->private; + flush_workqueue(kmpath_handlerd); flush_workqueue(kmultipathd); free_multipath(m); } @@ -1108,6 +1108,17 @@ static void pg_init_done(struct dm_path *path, int errors) spin_unlock_irqrestore(&m->lock, flags); } +static void activate_path(struct work_struct *work) +{ + int ret; + struct multipath *m = + container_of(work, struct multipath, activate_path); + struct dm_path *path = &m->current_pgpath->path; + + ret = scsi_dh_activate(bdev_get_queue(path->dev->bdev)); + pg_init_done(path, ret); +} + /* * end_io handling */ @@ -1451,6 +1462,21 @@ static int __init dm_multipath_init(void) return -ENOMEM; } + /* + * A separate workqueue is used to handle the device handlers + * to avoid overloading existing workqueue. Overloading the + * old workqueue would also create a bottleneck in the + * path of the storage hardware device activation. + */ + kmpath_handlerd = create_singlethread_workqueue("kmpath_handlerd"); + if (!kmpath_handlerd) { + DMERR("failed to create workqueue kmpath_handlerd"); + destroy_workqueue(kmultipathd); + dm_unregister_target(&multipath_target); + kmem_cache_destroy(_mpio_cache); + return -ENOMEM; + } + DMINFO("version %u.%u.%u loaded", multipath_target.version[0], multipath_target.version[1], multipath_target.version[2]); @@ -1462,6 +1488,7 @@ static void __exit dm_multipath_exit(void) { int r; + destroy_workqueue(kmpath_handlerd); destroy_workqueue(kmultipathd); r = dm_unregister_target(&multipath_target); |