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path: root/drivers/md/dm-crypt.c
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Diffstat (limited to 'drivers/md/dm-crypt.c')
-rw-r--r--drivers/md/dm-crypt.c67
1 files changed, 51 insertions, 16 deletions
diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index 126ed21..357387f 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -36,7 +36,6 @@ struct dm_crypt_io {
struct work_struct work;
atomic_t pending;
int error;
- int post_process;
};
/*
@@ -80,7 +79,8 @@ struct crypt_config {
mempool_t *page_pool;
struct bio_set *bs;
- struct workqueue_struct *queue;
+ struct workqueue_struct *io_queue;
+ struct workqueue_struct *crypt_queue;
/*
* crypto related data
*/
@@ -476,19 +476,36 @@ static void dec_pending(struct dm_crypt_io *io, int error)
}
/*
- * kcryptd:
+ * kcryptd/kcryptd_io:
*
* Needed because it would be very unwise to do decryption in an
* interrupt context.
+ *
+ * kcryptd performs the actual encryption or decryption.
+ *
+ * kcryptd_io performs the IO submission.
+ *
+ * They must be separated as otherwise the final stages could be
+ * starved by new requests which can block in the first stages due
+ * to memory allocation.
*/
static void kcryptd_do_work(struct work_struct *work);
+static void kcryptd_do_crypt(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(cc->queue, &io->work);
+ queue_work(cc->io_queue, &io->work);
+}
+
+static void kcryptd_queue_crypt(struct dm_crypt_io *io)
+{
+ struct crypt_config *cc = io->target->private;
+
+ INIT_WORK(&io->work, kcryptd_do_crypt);
+ queue_work(cc->crypt_queue, &io->work);
}
static void crypt_endio(struct bio *clone, int error)
@@ -511,8 +528,7 @@ static void crypt_endio(struct bio *clone, int error)
}
bio_put(clone);
- io->post_process = 1;
- kcryptd_queue_io(io);
+ kcryptd_queue_crypt(io);
return;
out:
@@ -634,10 +650,16 @@ static void kcryptd_do_work(struct work_struct *work)
{
struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
- if (io->post_process)
- process_read_endio(io);
- else if (bio_data_dir(io->base_bio) == READ)
+ if (bio_data_dir(io->base_bio) == READ)
process_read(io);
+}
+
+static void kcryptd_do_crypt(struct work_struct *work)
+{
+ struct dm_crypt_io *io = container_of(work, struct dm_crypt_io, work);
+
+ if (bio_data_dir(io->base_bio) == READ)
+ process_read_endio(io);
else
process_write(io);
}
@@ -870,16 +892,24 @@ 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) {
+ cc->io_queue = create_singlethread_workqueue("kcryptd_io");
+ if (!cc->io_queue) {
+ ti->error = "Couldn't create kcryptd io queue";
+ goto bad_io_queue;
+ }
+
+ cc->crypt_queue = create_singlethread_workqueue("kcryptd");
+ if (!cc->crypt_queue) {
ti->error = "Couldn't create kcryptd queue";
- goto bad_queue;
+ goto bad_crypt_queue;
}
ti->private = cc;
return 0;
-bad_queue:
+bad_crypt_queue:
+ destroy_workqueue(cc->io_queue);
+bad_io_queue:
kfree(cc->iv_mode);
bad_iv_mode:
dm_put_device(ti, cc->dev);
@@ -905,7 +935,8 @@ static void crypt_dtr(struct dm_target *ti)
{
struct crypt_config *cc = (struct crypt_config *) ti->private;
- destroy_workqueue(cc->queue);
+ destroy_workqueue(cc->io_queue);
+ destroy_workqueue(cc->crypt_queue);
bioset_free(cc->bs);
mempool_destroy(cc->page_pool);
@@ -931,9 +962,13 @@ static int crypt_map(struct dm_target *ti, struct bio *bio,
io = mempool_alloc(cc->io_pool, GFP_NOIO);
io->target = ti;
io->base_bio = bio;
- io->error = io->post_process = 0;
+ io->error = 0;
atomic_set(&io->pending, 0);
- kcryptd_queue_io(io);
+
+ if (bio_data_dir(io->base_bio) == READ)
+ kcryptd_queue_io(io);
+ else
+ kcryptd_queue_crypt(io);
return DM_MAPIO_SUBMITTED;
}