[PATCH 12/18] xd: dequeue in-flight request

Tejun Heo
2009-05-08T03:04:55Z

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

While at it, use rq_cur_bytes instead of rq_bytes when checking for
sector overflow. This is for for consistency and better behavior for
merged requests.

[ Impact: dequeue in-flight request ]

Signed-off-by: Tejun Heo <tj@kernel.org>
---
drivers/block/xd.c | 29 +++++++++++++++++------------
1 files changed, 17 insertions(+), 12 deletions(-)

diff --git a/drivers/block/xd.c b/drivers/block/xd.c
index 4ef8801..d4c4352 100644
--- a/drivers/block/xd.c
+++ b/drivers/block/xd.c
@@ -305,26 +305,31 @@ static void do_xd_request (struct request_queue * q)
if (xdc_busy)
return;

- while ((req = elv_next_request(q)) != NULL) {
+ req = elv_next_request(q);
+ if (req)
+ blkdev_dequeue_request(req);
+
+ while (req) {
unsigned block = blk_rq_pos(req);
- unsigned count = blk_rq_sectors(req);
+ unsigned count = blk_rq_cur_sectors(req);
XD_INFO *disk = req->rq_disk->private_data;
- int res = 0;
+ int res = -EIO;
int retry;

- if (!blk_fs_request(req)) {
- __blk_end_request_cur(req, -EIO);
- continue;
- }
- if (block + count > get_capacity(req->rq_disk)) {
- __blk_end_request_cur(req, -EIO);
- continue;
- }
+ if (!blk_fs_request(req))
+ goto done;
+ if (block + count > get_capacity(req->rq_disk))
+ goto done;
for (retry = 0; (retry < XD_RETRIES) && !res; retry++)
res = xd_readwrite(rq_data_dir(req), disk, req->buffer,
block, count);
+ done:
/* wrap up, 0 = success, -errno = fail */
- __blk_end_request_cur(req, res);
+ if (!__blk_end_request_cur(req, res)) {
+ req = elv_next_request(q);
+ if (req)
+ blkdev_dequeue_request(req);
+ }
}
}

--
1.6.0.2