From 8295cda7ceceb7b25f9a12cd21bbfb6206e28a6d Mon Sep 17 00:00:00 2001 From: Alex Elder Date: Thu, 8 Nov 2012 08:01:39 -0600 Subject: [PATCH] rbd: encapsulate handling for a single request In rbd_rq_fn(), requests are fetched from the block layer and each request is processed, looping through the request's list of bio's until they've all been consumed. Separate the handling for a single request into its own function to make it a bit easier to see what's going on. Signed-off-by: Alex Elder Reviewed-by: Josh Durgin --- drivers/block/rbd.c | 119 +++++++++++++++++++++++++++------------------------- 1 file changed, 63 insertions(+), 56 deletions(-) diff --git a/drivers/block/rbd.c b/drivers/block/rbd.c index 8d93b6a649d8..738d1e4c0ab5 100644 --- a/drivers/block/rbd.c +++ b/drivers/block/rbd.c @@ -1583,6 +1583,64 @@ static struct rbd_req_coll *rbd_alloc_coll(int num_reqs) return coll; } +static int rbd_dev_do_request(struct request *rq, + struct rbd_device *rbd_dev, + struct ceph_snap_context *snapc, + u64 ofs, unsigned int size, + struct bio *bio_chain) +{ + int num_segs; + struct rbd_req_coll *coll; + unsigned int bio_offset; + int cur_seg = 0; + + dout("%s 0x%x bytes at 0x%llx\n", + rq_data_dir(rq) == WRITE ? "write" : "read", + size, (unsigned long long) blk_rq_pos(rq) * SECTOR_SIZE); + + num_segs = rbd_get_num_segments(&rbd_dev->header, ofs, size); + if (num_segs <= 0) + return num_segs; + + coll = rbd_alloc_coll(num_segs); + if (!coll) + return -ENOMEM; + + bio_offset = 0; + do { + u64 limit = rbd_segment_length(rbd_dev, ofs, size); + unsigned int clone_size; + struct bio *bio_clone; + + BUG_ON(limit > (u64)UINT_MAX); + clone_size = (unsigned int)limit; + dout("bio_chain->bi_vcnt=%hu\n", bio_chain->bi_vcnt); + + kref_get(&coll->kref); + + /* Pass a cloned bio chain via an osd request */ + + bio_clone = bio_chain_clone_range(&bio_chain, + &bio_offset, clone_size, + GFP_ATOMIC); + if (bio_clone) + (void)rbd_do_op(rq, rbd_dev, snapc, + ofs, clone_size, + bio_clone, coll, cur_seg); + else + rbd_coll_end_req_index(rq, coll, cur_seg, + (s32)-ENOMEM, + clone_size); + size -= clone_size; + ofs += clone_size; + + cur_seg++; + } while (size > 0); + kref_put(&coll->kref, rbd_coll_release); + + return 0; +} + /* * block device queue callback */ @@ -1596,10 +1654,8 @@ static void rbd_rq_fn(struct request_queue *q) bool do_write; unsigned int size; u64 ofs; - int num_segs, cur_seg = 0; - struct rbd_req_coll *coll; struct ceph_snap_context *snapc; - unsigned int bio_offset; + int result; dout("fetched request\n"); @@ -1637,60 +1693,11 @@ static void rbd_rq_fn(struct request_queue *q) ofs = blk_rq_pos(rq) * SECTOR_SIZE; bio = rq->bio; - dout("%s 0x%x bytes at 0x%llx\n", - do_write ? "write" : "read", - size, (unsigned long long) blk_rq_pos(rq) * SECTOR_SIZE); - - num_segs = rbd_get_num_segments(&rbd_dev->header, ofs, size); - if (num_segs <= 0) { - spin_lock_irq(q->queue_lock); - __blk_end_request_all(rq, num_segs); - ceph_put_snap_context(snapc); - continue; - } - coll = rbd_alloc_coll(num_segs); - if (!coll) { - spin_lock_irq(q->queue_lock); - __blk_end_request_all(rq, -ENOMEM); - ceph_put_snap_context(snapc); - continue; - } - - bio_offset = 0; - do { - u64 limit = rbd_segment_length(rbd_dev, ofs, size); - unsigned int chain_size; - struct bio *bio_chain; - - BUG_ON(limit > (u64) UINT_MAX); - chain_size = (unsigned int) limit; - dout("rq->bio->bi_vcnt=%hu\n", rq->bio->bi_vcnt); - - kref_get(&coll->kref); - - /* Pass a cloned bio chain via an osd request */ - - bio_chain = bio_chain_clone_range(&bio, - &bio_offset, chain_size, - GFP_ATOMIC); - if (bio_chain) - (void) rbd_do_op(rq, rbd_dev, snapc, - ofs, chain_size, - bio_chain, coll, cur_seg); - else - rbd_coll_end_req_index(rq, coll, cur_seg, - (s32)-ENOMEM, - chain_size); - size -= chain_size; - ofs += chain_size; - - cur_seg++; - } while (size > 0); - kref_put(&coll->kref, rbd_coll_release); - - spin_lock_irq(q->queue_lock); - + result = rbd_dev_do_request(rq, rbd_dev, snapc, ofs, size, bio); ceph_put_snap_context(snapc); + spin_lock_irq(q->queue_lock); + if (!size || result < 0) + __blk_end_request_all(rq, result); } } -- 2.11.0