dm crypt: use per device singlethread workqueues

Use a separate single-threaded workqueue for each crypt device
instead of one global workqueue.

Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 14 insertions, 18 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3fa3b24947da..126ed21e6b17 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -80,6 +80,7 @@ struct crypt_config {
         mempool_t *page_pool;
         struct bio_set *bs;
 
+        struct workqueue_struct *queue;
         /*
          * crypto related data
          */
@@ -480,13 +481,14 @@ static void dec_pending(struct dm_crypt_io *io, int error)
  * Needed because it would be very unwise to do decryption in an
  * interrupt context.
  */
-static struct workqueue_struct *_kcryptd_workqueue;
 static void kcryptd_do_work(struct work_struct *work);
 
 static void kcryptd_queue_io(struct dm_crypt_io *io)
 {
+        struct crypt_config *cc = io->target->private;
+
         INIT_WORK(&io->work, kcryptd_do_work);
-        queue_work(_kcryptd_workqueue, &io->work);
+        queue_work(cc->queue, &io->work);
 }
 
 static void crypt_endio(struct bio *clone, int error)
@@ -868,9 +870,17 @@ static int crypt_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         } else
                 cc->iv_mode = NULL;
 
+        cc->queue = create_singlethread_workqueue("kcryptd");
+        if (!cc->queue) {
+                ti->error = "Couldn't create kcryptd queue";
+                goto bad_queue;
+        }
+
         ti->private = cc;
         return 0;
 
+bad_queue:
+        kfree(cc->iv_mode);
 bad_iv_mode:
         dm_put_device(ti, cc->dev);
 bad5:
@@ -895,7 +905,7 @@ static void crypt_dtr(struct dm_target *ti)
 {
         struct crypt_config *cc = (struct crypt_config *) ti->private;
 
-        flush_workqueue(_kcryptd_workqueue);
+        destroy_workqueue(cc->queue);
 
         bioset_free(cc->bs);
         mempool_destroy(cc->page_pool);
@@ -1040,25 +1050,12 @@ static int __init dm_crypt_init(void)
         if (!_crypt_io_pool)
                 return -ENOMEM;
 
-        _kcryptd_workqueue = create_workqueue("kcryptd");
-        if (!_kcryptd_workqueue) {
-                r = -ENOMEM;
-                DMERR("couldn't create kcryptd");
-                goto bad1;
-        }
-
         r = dm_register_target(&crypt_target);
         if (r < 0) {
                 DMERR("register failed %d", r);
-                goto bad2;
+                kmem_cache_destroy(_crypt_io_pool);
         }
 
-        return 0;
-
-bad2:
-        destroy_workqueue(_kcryptd_workqueue);
-bad1:
-        kmem_cache_destroy(_crypt_io_pool);
         return r;
 }
 
@@ -1069,7 +1066,6 @@ static void __exit dm_crypt_exit(void)
         if (r < 0)
                 DMERR("unregister failed %d", r);
 
-        destroy_workqueue(_kcryptd_workqueue);
         kmem_cache_destroy(_crypt_io_pool);
 }