block: implement and use [__]blk_end_request_all()

There are many [__]blk_end_request() call sites which call it with
full request length and expect full completion.  Many of them ensure
that the request actually completes by doing BUG_ON() the return
value, which is awkward and error-prone.

This patch adds [__]blk_end_request_all() which takes @rq and @error
and fully completes the request.  BUG_ON() is added to to ensure that
this actually happens.

Most conversions are simple but there are a few noteworthy ones.

* cdrom/viocd: viocd_end_request() replaced with direct calls to
  __blk_end_request_all().

* s390/block/dasd: dasd_end_request() replaced with direct calls to
  __blk_end_request_all().

* s390/char/tape_block: tapeblock_end_request() replaced with direct
  calls to blk_end_request_all().

[ Impact: cleanup ]

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Russell King <rmk@arm.linux.org.uk>
Cc: Stephen Rothwell <sfr@canb.auug.org.au>
Cc: Mike Miller <mike.miller@hp.com>
Cc: Martin Schwidefsky <schwidefsky@de.ibm.com>
Cc: Jeff Garzik <jgarzik@pobox.com>
Cc: Rusty Russell <rusty@rustcorp.com.au>
Cc: Jeremy Fitzhardinge <jeremy@xensource.com>
Cc: Alex Dubov <oakad@yahoo.com>
Cc: James Bottomley <James.Bottomley@HansenPartnership.com>

1 files changed, 3 insertions, 8 deletions

diff --git a/arch/arm/plat-omap/mailbox.c b/arch/arm/plat-omap/mailbox.c
index 0abfbaa59871..cf81bad8aec2 100644
--- a/arch/arm/plat-omap/mailbox.c
+++ b/arch/arm/plat-omap/mailbox.c
@@ -192,8 +192,7 @@ static void mbox_tx_work(struct work_struct *work)
                 }
 
                 spin_lock(q->queue_lock);
-                if (__blk_end_request(rq, 0, 0))
-                        BUG();
+                __blk_end_request_all(rq, 0);
                 spin_unlock(q->queue_lock);
         }
 }
@@ -224,10 +223,7 @@ static void mbox_rx_work(struct work_struct *work)
                         break;
 
                 msg = (mbox_msg_t) rq->data;
-
-                if (blk_end_request(rq, 0, 0))
-                        BUG();
-
+                blk_end_request_all(rq, 0);
                 mbox->rxq->callback((void *)msg);
         }
 }
@@ -337,8 +333,7 @@ omap_mbox_read(struct device *dev, struct device_attribute *attr, char *buf)
 
                 *p = (mbox_msg_t) rq->data;
 
-                if (blk_end_request(rq, 0, 0))
-                        BUG();
+                blk_end_request_all(rq, 0);
 
                 if (unlikely(mbox_seq_test(mbox, *p))) {
                         pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);