block: convert to dequeueing model (easy ones)

plat-omap/mailbox, floppy, viocd, mspro_block, i2o_block and
mmc/card/queue are already pretty close to dequeueing model and can be
converted with simple changes.  Convert them.

While at it,

* xen-blkfront: !fs check moved downwards to share dequeue call with
  normal path.

* mspro_block: __blk_end_request(..., blk_rq_cur_byte()) converted to
  __blk_end_request_cur()

* mmc/card/queue: loop of __blk_end_request() converted to
  __blk_end_request_all()

[ Impact: dequeue in-flight request ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: Markus Lidel <Markus.Lidel@shadowconnect.com>
Cc: Pierre Ossman <drzeus@drzeus.cx>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

2 files changed, 10 insertions, 7 deletions

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index 1e27ed9208b4..e2c70d2085ae 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -931,7 +931,7 @@ static inline void unlock_fdc(void)
         del_timer(&fd_timeout);
         cont = NULL;
         clear_bit(0, &fdc_busy);
-        if (elv_next_request(floppy_queue))
+        if (current_req || elv_next_request(floppy_queue))
                 do_fd_request(floppy_queue);
         spin_unlock_irqrestore(&floppy_lock, flags);
         wake_up(&fdc_wait);
@@ -2913,6 +2913,8 @@ static void redo_fd_request(void)
 
                         spin_lock_irq(floppy_queue->queue_lock);
                         req = elv_next_request(floppy_queue);
+                        if (req)
+                                blkdev_dequeue_request(req);
                         spin_unlock_irq(floppy_queue->queue_lock);
                         if (!req) {
                                 do_floppy = NULL;
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 91fc56597e9b..66f834571b88 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -301,22 +301,23 @@ static void do_blkif_request(struct request_queue *rq)
 
         while ((req = elv_next_request(rq)) != NULL) {
                 info = req->rq_disk->private_data;
-                if (!blk_fs_request(req)) {
-                        __blk_end_request_cur(req, -EIO);
-                        continue;
-                }
 
                 if (RING_FULL(&info->ring))
                         goto wait;
 
+                blkdev_dequeue_request(req);
+
+                if (!blk_fs_request(req)) {
+                        __blk_end_request_all(req, -EIO);
+                        continue;
+                }
+
                 pr_debug("do_blk_req %p: cmd %p, sec %lx, "
                          "(%u/%u) buffer:%p [%s]\n",
                          req, req->cmd, (unsigned long)blk_rq_pos(req),
                          blk_rq_cur_sectors(req), blk_rq_sectors(req),
                          req->buffer, rq_data_dir(req) ? "write" : "read");
 
-
-                blkdev_dequeue_request(req);
                 if (blkif_queue_request(req)) {
                         blk_requeue_request(rq, req);
 wait: