[PATCH v3 1/2] block/xen-blkfront: Introduce blkif_ring_get_request

From: Julien Grall
Date: Wed Nov 18 2015 - 13:59:12 EST


The code to get a request is always the same. Therefore we can factorize
it in a single function.

Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
Acked-by: Roger Pau Monnà <roger.pau@xxxxxxxxxx>

---
Cc: Konrad Rzeszutek Wilk <konrad.wilk@xxxxxxxxxx>
Cc: Boris Ostrovsky <boris.ostrovsky@xxxxxxxxxx>
Cc: David Vrabel <david.vrabel@xxxxxxxxxx>
Cc: Bob Liu <bob.liu@xxxxxxxxxx>

Changes in v2:
- Add Royger's acked-by
---
drivers/block/xen-blkfront.c | 30 +++++++++++++++++++-----------
1 file changed, 19 insertions(+), 11 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 2fee2ee..2248a47 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -456,6 +456,23 @@ static int blkif_ioctl(struct block_device *bdev, fmode_t mode,
return 0;
}

+static unsigned long blkif_ring_get_request(struct blkfront_info *info,
+ struct request *req,
+ struct blkif_request **ring_req)
+{
+ unsigned long id;
+
+ *ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
+ info->ring.req_prod_pvt++;
+
+ id = get_id_from_freelist(info);
+ info->shadow[id].request = req;
+
+ (*ring_req)->u.rw.id = id;
+
+ return id;
+}
+
static int blkif_queue_discard_req(struct request *req)
{
struct blkfront_info *info = req->rq_disk->private_data;
@@ -463,9 +480,7 @@ static int blkif_queue_discard_req(struct request *req)
unsigned long id;

/* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
- id = get_id_from_freelist(info);
- info->shadow[id].request = req;
+ id = blkif_ring_get_request(info, req, &ring_req);

ring_req->operation = BLKIF_OP_DISCARD;
ring_req->u.discard.nr_sectors = blk_rq_sectors(req);
@@ -476,8 +491,6 @@ static int blkif_queue_discard_req(struct request *req)
else
ring_req->u.discard.flag = 0;

- info->ring.req_prod_pvt++;
-
/* Keep a private copy so we can reissue requests when recovering. */
info->shadow[id].req = *ring_req;

@@ -613,9 +626,7 @@ static int blkif_queue_rw_req(struct request *req)
new_persistent_gnts = 0;

/* Fill out a communications ring structure. */
- ring_req = RING_GET_REQUEST(&info->ring, info->ring.req_prod_pvt);
- id = get_id_from_freelist(info);
- info->shadow[id].request = req;
+ id = blkif_ring_get_request(info, req, &ring_req);

BUG_ON(info->max_indirect_segments == 0 &&
GREFS(req->nr_phys_segments) > BLKIF_MAX_SEGMENTS_PER_REQUEST);
@@ -628,7 +639,6 @@ static int blkif_queue_rw_req(struct request *req)
for_each_sg(info->shadow[id].sg, sg, num_sg, i)
num_grant += gnttab_count_grant(sg->offset, sg->length);

- ring_req->u.rw.id = id;
info->shadow[id].num_sg = num_sg;
if (num_grant > BLKIF_MAX_SEGMENTS_PER_REQUEST) {
/*
@@ -694,8 +704,6 @@ static int blkif_queue_rw_req(struct request *req)
if (setup.segments)
kunmap_atomic(setup.segments);

- info->ring.req_prod_pvt++;
-
/* Keep a private copy so we can reissue requests when recovering. */
info->shadow[id].req = *ring_req;

--
2.1.4

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