1 files changed, 40 insertions, 1 deletions

diff --git a/drivers/md/dm-crypt.c b/drivers/md/dm-crypt.c
index ad98ded3008..046ee516074 100644
--- a/drivers/md/dm-crypt.c
+++ b/drivers/md/dm-crypt.c
@@ -56,6 +56,7 @@ struct dm_crypt_io {
 	atomic_t pending;
 	int error;
 	sector_t sector;
+	struct dm_crypt_io *base_io;
 };
 
 struct dm_crypt_request {
@@ -534,6 +535,7 @@ static struct dm_crypt_io *crypt_io_alloc(struct dm_target *ti,
 	io->base_bio = bio;
 	io->sector = sector;
 	io->error = 0;
+	io->base_io = NULL;
 	atomic_set(&io->pending, 0);
 
 	return io;
@@ -547,6 +549,7 @@ static void crypt_inc_pending(struct dm_crypt_io *io)
 /*
  * One of the bios was finished. Check for completion of
  * the whole request and correctly clean up the buffer.
+ * If base_io is set, wait for the last fragment to complete.
  */
 static void crypt_dec_pending(struct dm_crypt_io *io)
 {
@@ -555,7 +558,14 @@ static void crypt_dec_pending(struct dm_crypt_io *io)
 	if (!atomic_dec_and_test(&io->pending))
 		return;
 
-	bio_endio(io->base_bio, io->error);
+	if (likely(!io->base_io))
+		bio_endio(io->base_bio, io->error);
+	else {
+		if (io->error && !io->base_io->error)
+			io->base_io->error = io->error;
+		crypt_dec_pending(io->base_io);
+	}
+
 	mempool_free(io, cc->io_pool);
 }
 
@@ -699,6 +709,7 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 {
 	struct crypt_config *cc = io->target->private;
 	struct bio *clone;
+	struct dm_crypt_io *new_io;
 	int crypt_finished;
 	unsigned out_of_pages = 0;
 	unsigned remaining = io->base_bio->bi_size;
@@ -753,6 +764,34 @@ static void kcryptd_crypt_write_convert(struct dm_crypt_io *io)
 		if (unlikely(out_of_pages))
 			congestion_wait(WRITE, HZ/100);
 
+		/*
+		 * With async crypto it is unsafe to share the crypto context
+		 * between fragments, so switch to a new dm_crypt_io structure.
+		 */
+		if (unlikely(!crypt_finished && remaining)) {
+			new_io = crypt_io_alloc(io->target, io->base_bio,
+						sector);
+			crypt_inc_pending(new_io);
+			crypt_convert_init(cc, &new_io->ctx, NULL,
+					   io->base_bio, sector);
+			new_io->ctx.idx_in = io->ctx.idx_in;
+			new_io->ctx.offset_in = io->ctx.offset_in;
+
+			/*
+			 * Fragments after the first use the base_io
+			 * pending count.
+			 */
+			if (!io->base_io)
+				new_io->base_io = io;
+			else {
+				new_io->base_io = io->base_io;
+				crypt_inc_pending(io->base_io);
+				crypt_dec_pending(io);
+			}
+
+			io = new_io;
+		}
+
 		if (unlikely(remaining))
 			wait_event(cc->writeq, !atomic_read(&io->ctx.pending));
 	}