dm io: remove code duplication between sync_io and aysnc_io

The only difference between the code to setup and dispatch the io in
sync_io() and async_io() is the sync argument to dispatch_io(), which
is used to update the opf argument.

Update the opf argument direcly in sync_io(), and remove the sync
argument from dispatch_io(). Then, make sync_io() call async_io()
instead of duplicting all of its code.

Signed-off-by: Benjamin Marzinski <[e-mail]>
Signed-off-by: Mikulas Patocka <[e-mail]>

drivers/md/dm-io.c

···
 
 static void dispatch_io(blk_opf_t opf, unsigned int num_regions,
 			struct dm_io_region *where, struct dpages *dp,
-			struct io *io, int sync, unsigned short ioprio)
+			struct io *io, unsigned short ioprio)
 {
 	int i;
 	struct dpages old_pages = *dp;
 
 	BUG_ON(num_regions > DM_IO_MAX_REGIONS);
-
-	if (sync)
-		opf |= REQ_SYNC;
 
 	/*
 	 * For multiple regions we need to be careful to rewind
···
 	 * the io being completed too early.
 	 */
 	dec_count(io, 0, 0);
-}
-
-struct sync_io {
-	unsigned long error_bits;
-	struct completion wait;
-};
-
-static void sync_io_complete(unsigned long error, void *context)
-{
-	struct sync_io *sio = context;
-
-	sio->error_bits = error;
-	complete(&sio->wait);
-}
-
-static int sync_io(struct dm_io_client *client, unsigned int num_regions,
-		   struct dm_io_region *where, blk_opf_t opf, struct dpages *dp,
-		   unsigned long *error_bits, unsigned short ioprio)
-{
-	struct io *io;
-	struct sync_io sio;
-
-	init_completion(&sio.wait);
-
-	io = mempool_alloc(&client->pool, GFP_NOIO);
-	io->error_bits = 0;
-	atomic_set(&io->count, 1); /* see dispatch_io() */
-	io->client = client;
-	io->callback = sync_io_complete;
-	io->context = &sio;
-
-	io->vma_invalidate_address = dp->vma_invalidate_address;
-	io->vma_invalidate_size = dp->vma_invalidate_size;
-
-	dispatch_io(opf, num_regions, where, dp, io, 1, ioprio);
-
-	wait_for_completion_io(&sio.wait);
-
-	if (error_bits)
-		*error_bits = sio.error_bits;
-
-	return sio.error_bits ? -EIO : 0;
 }
 
 static void async_io(struct dm_io_client *client, unsigned int num_regions,
···
 	io->vma_invalidate_address = dp->vma_invalidate_address;
 	io->vma_invalidate_size = dp->vma_invalidate_size;
 
-	dispatch_io(opf, num_regions, where, dp, io, 0, ioprio);
+	dispatch_io(opf, num_regions, where, dp, io, ioprio);
+}
+
+struct sync_io {
+	unsigned long error_bits;
+	struct completion wait;
+};
+
+static void sync_io_complete(unsigned long error, void *context)
+{
+	struct sync_io *sio = context;
+
+	sio->error_bits = error;
+	complete(&sio->wait);
+}
+
+static int sync_io(struct dm_io_client *client, unsigned int num_regions,
+		   struct dm_io_region *where, blk_opf_t opf, struct dpages *dp,
+		   unsigned long *error_bits, unsigned short ioprio)
+{
+	struct sync_io sio;
+
+	init_completion(&sio.wait);
+
+	async_io(client, num_regions, where, opf | REQ_SYNC, dp,
+		 sync_io_complete, &sio, ioprio);
+
+	wait_for_completion_io(&sio.wait);
+
+	if (error_bits)
+		*error_bits = sio.error_bits;
+
+	return sio.error_bits ? -EIO : 0;
 }
 
 static int dp_init(struct dm_io_request *io_req, struct dpages *dp,