Commit b0042ba7 authored by Benjamin Marzinski's avatar Benjamin Marzinski Committed by Mikulas Patocka
Browse files

dm io: don't call the async_io notify.fn on invalid num_regions 



If dm_io() returned an error, callers that set a notify.fn and wanted it
called on an error need to check the return value and call notify.fn
themselves if it was -EINVAL but not if it was -EIO. None of them do
this (granted, all the existing async_io users of dm_io call it in a way
that is guaranteed to not return an error).

Simplify the interface by never calling the notify.fn if dm_io returns
an error. This works with the existing dm_io callers which check for an
error and handle it using the same methods as the notify.fn.

This also allows us to move the now equivalent num_regions checks out of
sync_io() and async_io() and into dm_io() itself. Additionally, change
async_io() into a void function, since it can no longer fail.

Signed-off-by: default avatarBenjamin Marzinski <bmarzins@redhat.com>
Signed-off-by: default avatarMikulas Patocka <mpatocka@redhat.com>
parent 06a0b333

drivers/md/dm-io.c

+12 −19
Original line number Diff line number Diff line
@@ -431,11 +431,6 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, 
	struct io *io;

	struct sync_io sio;



	if (num_regions > 1 && !op_is_write(opf)) {

		WARN_ON(1);

		return -EIO;

	}



	init_completion(&sio.wait);



	io = mempool_alloc(&client->pool, GFP_NOIO);
@@ -458,19 +453,13 @@ static int sync_io(struct dm_io_client *client, unsigned int num_regions, 
	return sio.error_bits ? -EIO : 0;

}



static int async_io(struct dm_io_client *client, unsigned int num_regions,

static void async_io(struct dm_io_client *client, unsigned int num_regions,

		     struct dm_io_region *where, blk_opf_t opf,

		     struct dpages *dp, io_notify_fn fn, void *context,

		     unsigned short ioprio)

{

	struct io *io;



	if (num_regions > 1 && !op_is_write(opf)) {

		WARN_ON(1);

		fn(1, context);

		return -EIO;

	}



	io = mempool_alloc(&client->pool, GFP_NOIO);

	io->error_bits = 0;

	atomic_set(&io->count, 1); /* see dispatch_io() */
@@ -482,7 +471,6 @@ static int async_io(struct dm_io_client *client, unsigned int num_regions, 
	io->vma_invalidate_size = dp->vma_invalidate_size;



	dispatch_io(opf, num_regions, where, dp, io, 0, ioprio);

	return 0;

}



static int dp_init(struct dm_io_request *io_req, struct dpages *dp,
@@ -529,6 +517,11 @@ int dm_io(struct dm_io_request *io_req, unsigned int num_regions, 
	int r;

	struct dpages dp;



	if (num_regions > 1 && !op_is_write(io_req->bi_opf)) {

		WARN_ON(1);

		return -EIO;

	}



	r = dp_init(io_req, &dp, (unsigned long)where->count << SECTOR_SHIFT);

	if (r)

		return r;
@@ -537,9 +530,9 @@ int dm_io(struct dm_io_request *io_req, unsigned int num_regions, 
		return sync_io(io_req->client, num_regions, where,

			       io_req->bi_opf, &dp, sync_error_bits, ioprio);



	return async_io(io_req->client, num_regions, where,

			io_req->bi_opf, &dp, io_req->notify.fn,

			io_req->notify.context, ioprio);

	async_io(io_req->client, num_regions, where, io_req->bi_opf, &dp,

		 io_req->notify.fn, io_req->notify.context, ioprio);

	return 0;

}

EXPORT_SYMBOL(dm_io);