Commit b395e8b5 authored by Alex Elder's avatar Alex Elder Committed by Alex Elder
Browse files

rbd: a little more cleanup of rbd_rq_fn() 



Now that a big hunk in the middle of rbd_rq_fn() has been moved
into its own routine we can simplify it a little more.

Signed-off-by: default avatarAlex Elder <elder@inktank.com>
Reviewed-by: default avatarJosh Durgin <josh.durgin@inktank.com>
parent cd323ac0

drivers/block/rbd.c

+24 −26
Original line number Diff line number Diff line
@@ -1644,53 +1644,51 @@ static int rbd_dev_do_request(struct request *rq, 
static void rbd_rq_fn(struct request_queue *q)

{

	struct rbd_device *rbd_dev = q->queuedata;

	bool read_only = rbd_dev->mapping.read_only;

	struct request *rq;



	while ((rq = blk_fetch_request(q))) {

		struct bio *bio;

		bool do_write;

		unsigned int size;

		u64 ofs;

		struct ceph_snap_context *snapc;

		struct ceph_snap_context *snapc = NULL;

		unsigned int size = 0;

		int result;



		dout("fetched request\n");



		/* filter out block requests we don't understand */

		/* Filter out block requests we don't understand */



		if ((rq->cmd_type != REQ_TYPE_FS)) {

			__blk_end_request_all(rq, 0);

			continue;

		}

		spin_unlock_irq(q->queue_lock);



		/* deduce our operation (read, write) */

		do_write = (rq_data_dir(rq) == WRITE);

		if (do_write && rbd_dev->mapping.read_only) {

			__blk_end_request_all(rq, -EROFS);

			continue;

		}

		/* Stop writes to a read-only device */



		spin_unlock_irq(q->queue_lock);

		result = -EROFS;

		if (read_only && rq_data_dir(rq) == WRITE)

			goto out_end_request;



		/* Grab a reference to the snapshot context */



		down_read(&rbd_dev->header_rwsem);

		if (rbd_dev->exists) {

			snapc = ceph_get_snap_context(rbd_dev->header.snapc);

			rbd_assert(snapc != NULL);

		}

		up_read(&rbd_dev->header_rwsem);



		if (!rbd_dev->exists) {

		if (!snapc) {

			rbd_assert(rbd_dev->spec->snap_id != CEPH_NOSNAP);

			up_read(&rbd_dev->header_rwsem);

			dout("request for non-existent snapshot");

			spin_lock_irq(q->queue_lock);

			__blk_end_request_all(rq, -ENXIO);

			continue;

			result = -ENXIO;

			goto out_end_request;

		}



		snapc = ceph_get_snap_context(rbd_dev->header.snapc);



		up_read(&rbd_dev->header_rwsem);



		size = blk_rq_bytes(rq);

		ofs = blk_rq_pos(rq) * SECTOR_SIZE;

		bio = rq->bio;



		result = rbd_dev_do_request(rq, rbd_dev, snapc, ofs, size, bio);

		result = rbd_dev_do_request(rq, rbd_dev, snapc,

				blk_rq_pos(rq) * SECTOR_SIZE,

				size, rq->bio);

out_end_request:

		ceph_put_snap_context(snapc);

		spin_lock_irq(q->queue_lock);

		if (!size || result < 0)