From b395e8b5b8f06399e3fe3ee016c9cf41ff665efc Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 8 Nov 2012 08:01:39 -0600 Subject: [PATCH] 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: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 50 ++++++++++++++++++++++++-------------------------- 1 file changed, 24 insertions(+), 26 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 21468d0..9d49e5b 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -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) -- 2.7.4