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>

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>
Tejun Heo · Jens Axboe
1 parent b243ddcbe9
Showing 15 changed files with 58 additions and 73 deletions Side-by-side Diff
arch/arm/plat-omap/mailbox.c
block/blk-barrier.c
block/blk-core.c
block/elevator.c
drivers/block/cpqarray.c
drivers/block/sx8.c
drivers/block/virtio_blk.c
drivers/block/xen-blkfront.c
drivers/cdrom/gdrom.c
drivers/cdrom/viocd.c
drivers/memstick/core/mspro_block.c
drivers/s390/block/dasd.c
drivers/s390/char/tape_block.c
drivers/scsi/scsi_lib.c
include/linux/blkdev.h
@@ -192,8 +192,7 @@
 		}
  
 		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 @@
 			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 @@
  
 		*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);
@@ -106,10 +106,7 @@
 	 */
 	q->ordseq = 0;
 	rq = q->orig_bar_rq;
-
-	if (__blk_end_request(rq, q->orderr, blk_rq_bytes(rq)))
-		BUG();
-
+	__blk_end_request_all(rq, q->orderr);
 	return true;
 }
  
@@ -252,9 +249,7 @@
 			 * with prejudice.
 			 */
 			elv_dequeue_request(q, rq);
-			if (__blk_end_request(rq, -EOPNOTSUPP,
-					      blk_rq_bytes(rq)))
-				BUG();
+			__blk_end_request_all(rq, -EOPNOTSUPP);
 			*rqp = NULL;
 			return false;
 		}
@@ -1780,7 +1780,7 @@
 			break;
 		} else if (ret == BLKPREP_KILL) {
 			rq->cmd_flags |= REQ_QUIET;
-			__blk_end_request(rq, -EIO, blk_rq_bytes(rq));
+			__blk_end_request_all(rq, -EIO);
 		} else {
 			printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
 			break;
@@ -810,7 +810,7 @@
 		rq = list_entry_rq(q->queue_head.next);
 		rq->cmd_flags |= REQ_QUIET;
 		trace_block_rq_abort(q, rq);
-		__blk_end_request(rq, -EIO, blk_rq_bytes(rq));
+		__blk_end_request_all(rq, -EIO);
 	}
 }
 EXPORT_SYMBOL(elv_abort_queue);
@@ -1024,8 +1024,7 @@
 				cmd->req.sg[i].size, ddir);
  
 	DBGPX(printk("Done with %p\n", rq););
-	if (__blk_end_request(rq, error, blk_rq_bytes(rq)))
-		BUG();
+	__blk_end_request_all(rq, error);
 }
  
 /*
@@ -749,8 +749,7 @@
 	struct request *req = crq->rq;
 	int rc;
  
-	rc = __blk_end_request(req, error, blk_rq_bytes(req));
-	assert(rc == 0);
+	__blk_end_request_all(req, error);
  
 	rc = carm_put_request(host, crq);
 	assert(rc == 0);
@@ -62,7 +62,7 @@
 			break;
 		}
  
-		__blk_end_request(vbr->req, error, blk_rq_bytes(vbr->req));
+		__blk_end_request_all(vbr->req, error);
 		list_del(&vbr->list);
 		mempool_free(vbr, vblk->pool);
 	}
@@ -551,7 +551,6 @@
  
 	for (i = info->ring.rsp_cons; i != rp; i++) {
 		unsigned long id;
-		int ret;
  
 		bret = RING_GET_RESPONSE(&info->ring, i);
 		id   = bret->id;
@@ -578,8 +577,7 @@
 				dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
 					"request: %x\n", bret->status);
  
-			ret = __blk_end_request(req, error, blk_rq_bytes(req));
-			BUG_ON(ret);
+			__blk_end_request_all(req, error);
 			break;
 		default:
 			BUG();
@@ -632,7 +632,7 @@
 		* before handling ending the request */
 		spin_lock(&gdrom_lock);
 		list_del_init(&req->queuelist);
-		__blk_end_request(req, err, blk_rq_bytes(req));
+		__blk_end_request_all(req, err);
 	}
 	spin_unlock(&gdrom_lock);
 	kfree(read_command);
@@ -291,23 +291,6 @@
 	return 0;
 }
  
-static void viocd_end_request(struct request *req, int error)
-{
-	int nsectors = req->hard_nr_sectors;
-
-	/*
-	 * Make sure it's fully ended, and ensure that we process
-	 * at least one sector.
-	 */
-	if (blk_pc_request(req))
-		nsectors = (req->data_len + 511) >> 9;
-	if (!nsectors)
-		nsectors = 1;
-
-	if (__blk_end_request(req, error, nsectors << 9))
-		BUG();
-}
-
 static int rwreq;
  
 static void do_viocd_request(struct request_queue *q)
  
@@ -316,11 +299,11 @@
  
 	while ((rwreq == 0) && ((req = elv_next_request(q)) != NULL)) {
 		if (!blk_fs_request(req))
-			viocd_end_request(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 		else if (send_request(req) < 0) {
 			printk(VIOCD_KERN_WARNING
 					"unable to send message to OS/400!");
-			viocd_end_request(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 		} else
 			rwreq++;
 	}
  
@@ -531,9 +514,9 @@
 					"with rc %d:0x%04X: %s\n",
 					req, event->xRc,
 					bevent->sub_result, err->msg);
-			viocd_end_request(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 		} else
-			viocd_end_request(req, 0);
+			__blk_end_request_all(req, 0);
  
 		/* restart handling of incoming requests */
 		spin_unlock_irqrestore(&viocd_reqlock, flags);
@@ -826,7 +826,7 @@
  
 	if (msb->eject) {
 		while ((req = elv_next_request(q)) != NULL)
-			__blk_end_request(req, -ENODEV, blk_rq_bytes(req));
+			__blk_end_request_all(req, -ENODEV);
  
 		return;
 	}
@@ -1614,15 +1614,6 @@
 }
  
 /*
- * posts the buffer_cache about a finalized request
- */
-static inline void dasd_end_request(struct request *req, int error)
-{
-	if (__blk_end_request(req, error, blk_rq_bytes(req)))
-		BUG();
-}
-
-/*
  * Process finished error recovery ccw.
  */
 static inline void __dasd_block_process_erp(struct dasd_block *block,
@@ -1676,7 +1667,7 @@
 				      "Rejecting write request %p",
 				      req);
 			blkdev_dequeue_request(req);
-			dasd_end_request(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 			continue;
 		}
 		cqr = basedev->discipline->build_cp(basedev, block, req);
@@ -1705,7 +1696,7 @@
 				      "on request %p",
 				      PTR_ERR(cqr), req);
 			blkdev_dequeue_request(req);
-			dasd_end_request(req, -EIO);
+			__blk_end_request_all(req, -EIO);
 			continue;
 		}
 		/*
@@ -1731,7 +1722,7 @@
 	status = cqr->block->base->discipline->free_cp(cqr, req);
 	if (status <= 0)
 		error = status ? status : -EIO;
-	dasd_end_request(req, error);
+	__blk_end_request_all(req, error);
 }
  
 /*
@@ -2040,7 +2031,7 @@
 	spin_lock_irq(&block->request_queue_lock);
 	while ((req = elv_next_request(block->request_queue))) {
 		blkdev_dequeue_request(req);
-		dasd_end_request(req, -EIO);
+		__blk_end_request_all(req, -EIO);
 	}
 	spin_unlock_irq(&block->request_queue_lock);
 }
@@ -74,13 +74,6 @@
  * Post finished request.
  */
 static void
-tapeblock_end_request(struct request *req, int error)
-{
-	if (blk_end_request(req, error, blk_rq_bytes(req)))
-		BUG();
-}
-
-static void
 __tapeblock_end_request(struct tape_request *ccw_req, void *data)
 {
 	struct tape_device *device;
@@ -90,7 +83,7 @@
  
 	device = ccw_req->device;
 	req = (struct request *) data;
-	tapeblock_end_request(req, (ccw_req->rc == 0) ? 0 : -EIO);
+	blk_end_request_all(req, (ccw_req->rc == 0) ? 0 : -EIO);
 	if (ccw_req->rc == 0)
 		/* Update position. */
 		device->blk_data.block_position =
@@ -118,7 +111,7 @@
 	ccw_req = device->discipline->bread(device, req);
 	if (IS_ERR(ccw_req)) {
 		DBF_EVENT(1, "TBLOCK: bread failed\n");
-		tapeblock_end_request(req, -EIO);
+		blk_end_request_all(req, -EIO);
 		return PTR_ERR(ccw_req);
 	}
 	ccw_req->callback = __tapeblock_end_request;
@@ -131,7 +124,7 @@
 		 * Start/enqueueing failed. No retries in
 		 * this case.
 		 */
-		tapeblock_end_request(req, -EIO);
+		blk_end_request_all(req, -EIO);
 		device->discipline->free_bread(ccw_req);
 	}
  
@@ -177,7 +170,7 @@
 			DBF_EVENT(1, "TBLOCK: Rejecting write request\n");
 			blkdev_dequeue_request(req);
 			spin_unlock_irq(&device->blk_data.request_queue_lock);
-			tapeblock_end_request(req, -EIO);
+			blk_end_request_all(req, -EIO);
 			spin_lock_irq(&device->blk_data.request_queue_lock);
 			continue;
 		}
@@ -922,7 +922,7 @@
 			if (driver_byte(result) & DRIVER_SENSE)
 				scsi_print_sense("", cmd);
 		}
-		blk_end_request(req, -EIO, blk_rq_bytes(req));
+		blk_end_request_all(req, -EIO);
 		scsi_next_command(cmd);
 		break;
 	case ACTION_REPREP:
@@ -883,6 +883,22 @@
 }
  
 /**
+ * blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ *     Completely finish @rq.
+ */
+static inline void blk_end_request_all(struct request *rq, int error)
+{
+	bool pending;
+
+	pending = blk_end_request(rq, error, blk_rq_bytes(rq));
+	BUG_ON(pending);
+}
+
+/**
  * __blk_end_request - Helper function for drivers to complete the request.
  * @rq:       the request being processed
  * @error:    %0 for success, < %0 for error
@@ -899,6 +915,22 @@
 				     unsigned int nr_bytes)
 {
 	return __blk_end_bidi_request(rq, error, nr_bytes, 0);
+}
+
+/**
+ * __blk_end_request_all - Helper function for drives to finish the request.
+ * @rq: the request to finish
+ * @err: %0 for success, < %0 for error
+ *
+ * Description:
+ *     Completely finish @rq.  Must be called with queue lock held.
+ */
+static inline void __blk_end_request_all(struct request *rq, int error)
+{
+	bool pending;
+
+	pending = __blk_end_request(rq, error, blk_rq_bytes(rq));
+	BUG_ON(pending);
 }
  
 /**
...	...	@@ -192,8 +192,7 @@
192	192	}
193	193
194	194	spin_lock(q->queue_lock);
195		- if (__blk_end_request(rq, 0, 0))
196		- BUG();
	195	+ __blk_end_request_all(rq, 0);
197	196	spin_unlock(q->queue_lock);
198	197	}
199	198	}
...	...	@@ -224,10 +223,7 @@
224	223	break;
225	224
226	225	msg = (mbox_msg_t) rq->data;
227		-
228		- if (blk_end_request(rq, 0, 0))
229		- BUG();
230		-
	226	+ blk_end_request_all(rq, 0);
231	227	mbox->rxq->callback((void *)msg);
232	228	}
233	229	}
...	...	@@ -337,8 +333,7 @@
337	333
338	334	*p = (mbox_msg_t) rq->data;
339	335
340		- if (blk_end_request(rq, 0, 0))
341		- BUG();
	336	+ blk_end_request_all(rq, 0);
342	337
343	338	if (unlikely(mbox_seq_test(mbox, *p))) {
344	339	pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);
...	...	@@ -106,10 +106,7 @@
106	106	*/
107	107	q->ordseq = 0;
108	108	rq = q->orig_bar_rq;
109		-
110		- if (__blk_end_request(rq, q->orderr, blk_rq_bytes(rq)))
111		- BUG();
112		-
	109	+ __blk_end_request_all(rq, q->orderr);
113	110	return true;
114	111	}
115	112
...	...	@@ -252,9 +249,7 @@
252	249	* with prejudice.
253	250	*/
254	251	elv_dequeue_request(q, rq);
255		- if (__blk_end_request(rq, -EOPNOTSUPP,
256		- blk_rq_bytes(rq)))
257		- BUG();
	252	+ __blk_end_request_all(rq, -EOPNOTSUPP);
258	253	*rqp = NULL;
259	254	return false;
260	255	}
...	...	@@ -1780,7 +1780,7 @@
1780	1780	break;
1781	1781	} else if (ret == BLKPREP_KILL) {
1782	1782	rq->cmd_flags \|= REQ_QUIET;
1783		- __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
	1783	+ __blk_end_request_all(rq, -EIO);
1784	1784	} else {
1785	1785	printk(KERN_ERR "%s: bad return=%d\n", __func__, ret);
1786	1786	break;
...	...	@@ -810,7 +810,7 @@
810	810	rq = list_entry_rq(q->queue_head.next);
811	811	rq->cmd_flags \|= REQ_QUIET;
812	812	trace_block_rq_abort(q, rq);
813		- __blk_end_request(rq, -EIO, blk_rq_bytes(rq));
	813	+ __blk_end_request_all(rq, -EIO);
814	814	}
815	815	}
816	816	EXPORT_SYMBOL(elv_abort_queue);
...	...	@@ -1024,8 +1024,7 @@
1024	1024	cmd->req.sg[i].size, ddir);
1025	1025
1026	1026	DBGPX(printk("Done with %p\n", rq););
1027		- if (__blk_end_request(rq, error, blk_rq_bytes(rq)))
1028		- BUG();
	1027	+ __blk_end_request_all(rq, error);
1029	1028	}
1030	1029
1031	1030	/*
...	...	@@ -749,8 +749,7 @@
749	749	struct request *req = crq->rq;
750	750	int rc;
751	751
752		- rc = __blk_end_request(req, error, blk_rq_bytes(req));
753		- assert(rc == 0);
	752	+ __blk_end_request_all(req, error);
754	753
755	754	rc = carm_put_request(host, crq);
756	755	assert(rc == 0);
...	...	@@ -62,7 +62,7 @@
62	62	break;
63	63	}
64	64
65		- __blk_end_request(vbr->req, error, blk_rq_bytes(vbr->req));
	65	+ __blk_end_request_all(vbr->req, error);
66	66	list_del(&vbr->list);
67	67	mempool_free(vbr, vblk->pool);
68	68	}
...	...	@@ -551,7 +551,6 @@
551	551
552	552	for (i = info->ring.rsp_cons; i != rp; i++) {
553	553	unsigned long id;
554		- int ret;
555	554
556	555	bret = RING_GET_RESPONSE(&info->ring, i);
557	556	id = bret->id;
...	...	@@ -578,8 +577,7 @@
578	577	dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
579	578	"request: %x\n", bret->status);
580	579
581		- ret = __blk_end_request(req, error, blk_rq_bytes(req));
582		- BUG_ON(ret);
	580	+ __blk_end_request_all(req, error);
583	581	break;
584	582	default:
585	583	BUG();
...	...	@@ -632,7 +632,7 @@
632	632	* before handling ending the request */
633	633	spin_lock(&gdrom_lock);
634	634	list_del_init(&req->queuelist);
635		- __blk_end_request(req, err, blk_rq_bytes(req));
	635	+ __blk_end_request_all(req, err);
636	636	}
637	637	spin_unlock(&gdrom_lock);
638	638	kfree(read_command);
...	...	@@ -291,23 +291,6 @@
291	291	return 0;
292	292	}
293	293
294		-static void viocd_end_request(struct request *req, int error)
295		-{
296		- int nsectors = req->hard_nr_sectors;
297		-
298		- /*
299		- * Make sure it's fully ended, and ensure that we process
300		- * at least one sector.
301		- */
302		- if (blk_pc_request(req))
303		- nsectors = (req->data_len + 511) >> 9;
304		- if (!nsectors)
305		- nsectors = 1;
306		-
307		- if (__blk_end_request(req, error, nsectors << 9))
308		- BUG();
309		-}
310		-
311	294	static int rwreq;
312	295
313	296	static void do_viocd_request(struct request_queue *q)
314	297
...	...	@@ -316,11 +299,11 @@
316	299
317	300	while ((rwreq == 0) && ((req = elv_next_request(q)) != NULL)) {
318	301	if (!blk_fs_request(req))
319		- viocd_end_request(req, -EIO);
	302	+ __blk_end_request_all(req, -EIO);
320	303	else if (send_request(req) < 0) {
321	304	printk(VIOCD_KERN_WARNING
322	305	"unable to send message to OS/400!");
323		- viocd_end_request(req, -EIO);
	306	+ __blk_end_request_all(req, -EIO);
324	307	} else
325	308	rwreq++;
326	309	}
327	310
...	...	@@ -531,9 +514,9 @@
531	514	"with rc %d:0x%04X: %s\n",
532	515	req, event->xRc,
533	516	bevent->sub_result, err->msg);
534		- viocd_end_request(req, -EIO);
	517	+ __blk_end_request_all(req, -EIO);
535	518	} else
536		- viocd_end_request(req, 0);
	519	+ __blk_end_request_all(req, 0);
537	520
538	521	/* restart handling of incoming requests */
539	522	spin_unlock_irqrestore(&viocd_reqlock, flags);