z2ram: dequeue in-flight request

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>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

diff --git a/drivers/block/z2ram.c b/drivers/block/z2ram.c
index 6a1383834ecff3aaaa8c769e5fe89f6ce9f95441..c909c1a3f6507cf0817ef6f63a44d972bc8b3e2a 100644 (file)
--- 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);
+               }
        }
 }