[PATCH 15/18] z2ram: dequeue in-flight request

Tejun Heo
2009-05-08T03:04:04Z

z2ram processes requests one-by-one synchronously and can be easily
converted to dequeueing model. Convert it.

[ Impact: dequeue in-flight request ]

Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/z2ram.c | 19 +++++++++++++++----
1 files changed, 15 insertions(+), 4 deletions(-)

diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index 6a13838..c909c1a 100644
--- a/drivers/block/z2ram.c
+++ b/drivers/block/z2ram.c
@@ -70,15 +70,21 @@ static struct gendisk *z2ram_gendisk;
static void do_z2_request(struct request_queue *q)
{
struct request *req;
- while ((req = elv_next_request(q)) != NULL) {
+
+ req = elv_next_request(q);
+ if (req)
+ blkdev_dequeue_request(req);
+
+ while (req) {
unsigned long start = blk_rq_pos(req) << 9;
unsigned long len = blk_rq_cur_bytes(req);
+ int err = 0;

if (start + len > z2ram_size) {
printk( KERN_ERR DEVICE_NAME ": bad access: block=%lu, count=%u\n",
blk_rq_pos(req), blk_rq_cur_sectors(req));
- __blk_end_request_cur(req, -EIO);
- continue;
+ err = -EIO;
+ goto done;
}
while (len) {
unsigned long addr = start & Z2RAM_CHUNKMASK;
@@ -93,7 +99,12 @@ static void do_z2_request(struct request_queue *q)
start += size;
len -= size;
}
- __blk_end_request_cur(req, 0);
+ done:
+ if (!__blk_end_request_cur(req, err)) {
+ req = elv_next_request(q);
+ if (req)
+ blkdev_dequeue_request(req);
+ }
}
}

--
1.6.0.2