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>

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 3fa3b24947dac893431d29ec2bc5aee4f4e1d290..126ed21e6b177d816733aab12f55eb5f6d2d26c8 100644 (file)
--- 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);
 }