Merge branch 'blk-end-request' of git://git.kernel.dk/linux-2.6-block

* 'blk-end-request' of git://git.kernel.dk/linux-2.6-block: (30 commits)
blk_end_request: changing xsysace (take 4)
blk_end_request: changing ub (take 4)
blk_end_request: cleanup of request completion (take 4)
blk_end_request: cleanup 'uptodate' related code (take 4)
blk_end_request: remove/unexport end_that_request_* (take 4)
blk_end_request: changing scsi (take 4)
blk_end_request: add bidi completion interface (take 4)
blk_end_request: changing ide-cd (take 4)
blk_end_request: add callback feature (take 4)
blk_end_request: changing ide normal caller (take 4)
blk_end_request: changing cpqarray (take 4)
blk_end_request: changing cciss (take 4)
blk_end_request: changing ide-scsi (take 4)
blk_end_request: changing s390 (take 4)
blk_end_request: changing mmc (take 4)
blk_end_request: changing i2o_block (take 4)
blk_end_request: changing viocd (take 4)
blk_end_request: changing xen-blkfront (take 4)
blk_end_request: changing viodasd (take 4)
blk_end_request: changing sx8 (take 4)
...

arch/arm/plat-omap/mailbox.c

···
 		}
 
 		spin_lock(q->queue_lock);
-		blkdev_dequeue_request(rq);
-		end_that_request_last(rq, 0);
+		if (__blk_end_request(rq, 0, 0))
+			BUG();
 		spin_unlock(q->queue_lock);
 	}
 }
···
 
 		msg = (mbox_msg_t) rq->data;
 
-		spin_lock_irqsave(q->queue_lock, flags);
-		blkdev_dequeue_request(rq);
-		end_that_request_last(rq, 0);
-		spin_unlock_irqrestore(q->queue_lock, flags);
+		if (blk_end_request(rq, 0, 0))
+			BUG();
 
 		mbox->rxq->callback((void *)msg);
 	}
···
 
 		*p = (mbox_msg_t) rq->data;
 
-		spin_lock_irqsave(q->queue_lock, flags);
-		blkdev_dequeue_request(rq);
-		end_that_request_last(rq, 0);
-		spin_unlock_irqrestore(q->queue_lock, flags);
+		if (blk_end_request(rq, 0, 0))
+			BUG();
 
 		if (unlikely(mbox_seq_test(mbox, *p))) {
 			pr_info("mbox: Illegal seq bit!(%08x) ignored\n", *p);

arch/um/drivers/ubd_kern.c

···
 /* Only changed by ubd_init, which is an initcall. */
 int thread_fd = -1;
 
-static void ubd_end_request(struct request *req, int bytes, int uptodate)
+static void ubd_end_request(struct request *req, int bytes, int error)
 {
-	if (!end_that_request_first(req, uptodate, bytes >> 9)) {
-		struct ubd *dev = req->rq_disk->private_data;
-		unsigned long flags;
-
-		add_disk_randomness(req->rq_disk);
-		spin_lock_irqsave(&dev->lock, flags);
-		end_that_request_last(req, uptodate);
-		spin_unlock_irqrestore(&dev->lock, flags);
-	}
+	blk_end_request(req, error, bytes);
 }
 
 /* Callable only from interrupt context - otherwise you need to do
···
 static inline void ubd_finish(struct request *req, int bytes)
 {
 	if(bytes < 0){
-		ubd_end_request(req, 0, 0);
+		ubd_end_request(req, 0, -EIO);
 		return;
 	}
-	ubd_end_request(req, bytes, 1);
+	ubd_end_request(req, bytes, 0);
 }
 
 static LIST_HEAD(restart);

block/ll_rw_blk.c

···
 void blk_ordered_complete_seq(struct request_queue *q, unsigned seq, int error)
 {
 	struct request *rq;
-	int uptodate;
 
 	if (error && !q->orderr)
 		q->orderr = error;
···
 	/*
 	 * Okay, sequence complete.
 	 */
-	uptodate = 1;
-	if (q->orderr)
-		uptodate = q->orderr;
-
 	q->ordseq = 0;
 	rq = q->orig_bar_rq;
 
-	end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
-	end_that_request_last(rq, uptodate);
+	if (__blk_end_request(rq, q->orderr, blk_rq_bytes(rq)))
+		BUG();
 }
 
 static void pre_flush_end_io(struct request *rq, int error)
···
 			 * ORDERED_NONE while this request is on it.
 			 */
 			blkdev_dequeue_request(rq);
-			end_that_request_first(rq, -EOPNOTSUPP,
-					       rq->hard_nr_sectors);
-			end_that_request_last(rq, -EOPNOTSUPP);
+			if (__blk_end_request(rq, -EOPNOTSUPP,
+					      blk_rq_bytes(rq)))
+				BUG();
 			*rqp = NULL;
 			return 0;
 		}
···
 	}
 }
 
-static int __end_that_request_first(struct request *req, int uptodate,
+/**
+ * __end_that_request_first - end I/O on a request
+ * @req:      the request being processed
+ * @error:    0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @req, and sets it up
+ *     for the next range of segments (if any) in the cluster.
+ *
+ * Return:
+ *     0 - we are done with this request, call end_that_request_last()
+ *     1 - still buffers pending for this request
+ **/
+static int __end_that_request_first(struct request *req, int error,
 				    int nr_bytes)
 {
-	int total_bytes, bio_nbytes, error, next_idx = 0;
+	int total_bytes, bio_nbytes, next_idx = 0;
 	struct bio *bio;
 
 	blk_add_trace_rq(req->q, req, BLK_TA_COMPLETE);
-
-	/*
-	 * extend uptodate bool to allow < 0 value to be direct io error
-	 */
-	error = 0;
-	if (end_io_error(uptodate))
-		error = !uptodate ? -EIO : uptodate;
 
 	/*
 	 * for a REQ_BLOCK_PC request, we want to carry any eventual
···
 	if (!blk_pc_request(req))
 		req->errors = 0;
 
-	if (!uptodate) {
+	if (error) {
 		if (blk_fs_request(req) && !(req->cmd_flags & REQ_QUIET))
 			printk("end_request: I/O error, dev %s, sector %llu\n",
 				req->rq_disk ? req->rq_disk->disk_name : "?",
···
 	return 1;
 }
 
-/**
- * end_that_request_first - end I/O on a request
- * @req:      the request being processed
- * @uptodate: 1 for success, 0 for I/O error, < 0 for specific error
- * @nr_sectors: number of sectors to end I/O on
- *
- * Description:
- *     Ends I/O on a number of sectors attached to @req, and sets it up
- *     for the next range of segments (if any) in the cluster.
- *
- * Return:
- *     0 - we are done with this request, call end_that_request_last()
- *     1 - still buffers pending for this request
- **/
-int end_that_request_first(struct request *req, int uptodate, int nr_sectors)
-{
-	return __end_that_request_first(req, uptodate, nr_sectors << 9);
-}
-
-EXPORT_SYMBOL(end_that_request_first);
-
-/**
- * end_that_request_chunk - end I/O on a request
- * @req:      the request being processed
- * @uptodate: 1 for success, 0 for I/O error, < 0 for specific error
- * @nr_bytes: number of bytes to complete
- *
- * Description:
- *     Ends I/O on a number of bytes attached to @req, and sets it up
- *     for the next range of segments (if any). Like end_that_request_first(),
- *     but deals with bytes instead of sectors.
- *
- * Return:
- *     0 - we are done with this request, call end_that_request_last()
- *     1 - still buffers pending for this request
- **/
-int end_that_request_chunk(struct request *req, int uptodate, int nr_bytes)
-{
-	return __end_that_request_first(req, uptodate, nr_bytes);
-}
-
-EXPORT_SYMBOL(end_that_request_chunk);
-
 /*
  * splice the completion data to a local structure and hand off to
  * process_completion_queue() to complete the requests
···
 /*
  * queue lock must be held
  */
-void end_that_request_last(struct request *req, int uptodate)
+static void end_that_request_last(struct request *req, int error)
 {
 	struct gendisk *disk = req->rq_disk;
-	int error;
 
-	/*
-	 * extend uptodate bool to allow < 0 value to be direct io error
-	 */
-	error = 0;
-	if (end_io_error(uptodate))
-		error = !uptodate ? -EIO : uptodate;
+	if (blk_rq_tagged(req))
+		blk_queue_end_tag(req->q, req);
+
+	if (blk_queued_rq(req))
+		blkdev_dequeue_request(req);
 
 	if (unlikely(laptop_mode) && blk_fs_request(req))
 		laptop_io_completion();
···
 		disk_round_stats(disk);
 		disk->in_flight--;
 	}
+
 	if (req->end_io)
 		req->end_io(req, error);
-	else
+	else {
+		if (blk_bidi_rq(req))
+			__blk_put_request(req->next_rq->q, req->next_rq);
+
 		__blk_put_request(req->q, req);
-}
-
-EXPORT_SYMBOL(end_that_request_last);
-
-static inline void __end_request(struct request *rq, int uptodate,
-				 unsigned int nr_bytes, int dequeue)
-{
-	if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
-		if (dequeue)
-			blkdev_dequeue_request(rq);
-		add_disk_randomness(rq->rq_disk);
-		end_that_request_last(rq, uptodate);
 	}
 }
 
-static unsigned int rq_byte_size(struct request *rq)
+static inline void __end_request(struct request *rq, int uptodate,
+				 unsigned int nr_bytes)
+{
+	int error = 0;
+
+	if (uptodate <= 0)
+		error = uptodate ? uptodate : -EIO;
+
+	__blk_end_request(rq, error, nr_bytes);
+}
+
+/**
+ * blk_rq_bytes - Returns bytes left to complete in the entire request
+ **/
+unsigned int blk_rq_bytes(struct request *rq)
 {
 	if (blk_fs_request(rq))
 		return rq->hard_nr_sectors << 9;
 
 	return rq->data_len;
 }
+EXPORT_SYMBOL_GPL(blk_rq_bytes);
+
+/**
+ * blk_rq_cur_bytes - Returns bytes left to complete in the current segment
+ **/
+unsigned int blk_rq_cur_bytes(struct request *rq)
+{
+	if (blk_fs_request(rq))
+		return rq->current_nr_sectors << 9;
+
+	if (rq->bio)
+		return rq->bio->bi_size;
+
+	return rq->data_len;
+}
+EXPORT_SYMBOL_GPL(blk_rq_cur_bytes);
 
 /**
  * end_queued_request - end all I/O on a queued request
···
  **/
 void end_queued_request(struct request *rq, int uptodate)
 {
-	__end_request(rq, uptodate, rq_byte_size(rq), 1);
+	__end_request(rq, uptodate, blk_rq_bytes(rq));
 }
 EXPORT_SYMBOL(end_queued_request);
 
···
  **/
 void end_dequeued_request(struct request *rq, int uptodate)
 {
-	__end_request(rq, uptodate, rq_byte_size(rq), 0);
+	__end_request(rq, uptodate, blk_rq_bytes(rq));
 }
 EXPORT_SYMBOL(end_dequeued_request);
 
···
  **/
 void end_request(struct request *req, int uptodate)
 {
-	__end_request(req, uptodate, req->hard_cur_sectors << 9, 1);
+	__end_request(req, uptodate, req->hard_cur_sectors << 9);
 }
 EXPORT_SYMBOL(end_request);
+
+/**
+ * blk_end_io - Generic end_io function to complete a request.
+ * @rq:           the request being processed
+ * @error:        0 for success, < 0 for error
+ * @nr_bytes:     number of bytes to complete @rq
+ * @bidi_bytes:   number of bytes to complete @rq->next_rq
+ * @drv_callback: function called between completion of bios in the request
+ *                and completion of the request.
+ *                If the callback returns non 0, this helper returns without
+ *                completion of the request.
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ *     0 - we are done with this request
+ *     1 - this request is not freed yet, it still has pending buffers.
+ **/
+static int blk_end_io(struct request *rq, int error, int nr_bytes,
+		      int bidi_bytes, int (drv_callback)(struct request *))
+{
+	struct request_queue *q = rq->q;
+	unsigned long flags = 0UL;
+
+	if (blk_fs_request(rq) || blk_pc_request(rq)) {
+		if (__end_that_request_first(rq, error, nr_bytes))
+			return 1;
+
+		/* Bidi request must be completed as a whole */
+		if (blk_bidi_rq(rq) &&
+		    __end_that_request_first(rq->next_rq, error, bidi_bytes))
+			return 1;
+	}
+
+	/* Special feature for tricky drivers */
+	if (drv_callback && drv_callback(rq))
+		return 1;
+
+	add_disk_randomness(rq->rq_disk);
+
+	spin_lock_irqsave(q->queue_lock, flags);
+	end_that_request_last(rq, error);
+	spin_unlock_irqrestore(q->queue_lock, flags);
+
+	return 0;
+}
+
+/**
+ * blk_end_request - Helper function for drivers to complete the request.
+ * @rq:       the request being processed
+ * @error:    0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ * Return:
+ *     0 - we are done with this request
+ *     1 - still buffers pending for this request
+ **/
+int blk_end_request(struct request *rq, int error, int nr_bytes)
+{
+	return blk_end_io(rq, error, nr_bytes, 0, NULL);
+}
+EXPORT_SYMBOL_GPL(blk_end_request);
+
+/**
+ * __blk_end_request - Helper function for drivers to complete the request.
+ * @rq:       the request being processed
+ * @error:    0 for success, < 0 for error
+ * @nr_bytes: number of bytes to complete
+ *
+ * Description:
+ *     Must be called with queue lock held unlike blk_end_request().
+ *
+ * Return:
+ *     0 - we are done with this request
+ *     1 - still buffers pending for this request
+ **/
+int __blk_end_request(struct request *rq, int error, int nr_bytes)
+{
+	if (blk_fs_request(rq) || blk_pc_request(rq)) {
+		if (__end_that_request_first(rq, error, nr_bytes))
+			return 1;
+	}
+
+	add_disk_randomness(rq->rq_disk);
+
+	end_that_request_last(rq, error);
+
+	return 0;
+}
+EXPORT_SYMBOL_GPL(__blk_end_request);
+
+/**
+ * blk_end_bidi_request - Helper function for drivers to complete bidi request.
+ * @rq:         the bidi request being processed
+ * @error:      0 for success, < 0 for error
+ * @nr_bytes:   number of bytes to complete @rq
+ * @bidi_bytes: number of bytes to complete @rq->next_rq
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq and @rq->next_rq.
+ *
+ * Return:
+ *     0 - we are done with this request
+ *     1 - still buffers pending for this request
+ **/
+int blk_end_bidi_request(struct request *rq, int error, int nr_bytes,
+			 int bidi_bytes)
+{
+	return blk_end_io(rq, error, nr_bytes, bidi_bytes, NULL);
+}
+EXPORT_SYMBOL_GPL(blk_end_bidi_request);
+
+/**
+ * blk_end_request_callback - Special helper function for tricky drivers
+ * @rq:           the request being processed
+ * @error:        0 for success, < 0 for error
+ * @nr_bytes:     number of bytes to complete
+ * @drv_callback: function called between completion of bios in the request
+ *                and completion of the request.
+ *                If the callback returns non 0, this helper returns without
+ *                completion of the request.
+ *
+ * Description:
+ *     Ends I/O on a number of bytes attached to @rq.
+ *     If @rq has leftover, sets it up for the next range of segments.
+ *
+ *     This special helper function is used only for existing tricky drivers.
+ *     (e.g. cdrom_newpc_intr() of ide-cd)
+ *     This interface will be removed when such drivers are rewritten.
+ *     Don't use this interface in other places anymore.
+ *
+ * Return:
+ *     0 - we are done with this request
+ *     1 - this request is not freed yet.
+ *         this request still has pending buffers or
+ *         the driver doesn't want to finish this request yet.
+ **/
+int blk_end_request_callback(struct request *rq, int error, int nr_bytes,
+			     int (drv_callback)(struct request *))
+{
+	return blk_end_io(rq, error, nr_bytes, 0, drv_callback);
+}
+EXPORT_SYMBOL_GPL(blk_end_request_callback);
 
 static void blk_rq_bio_prep(struct request_queue *q, struct request *rq,
 			    struct bio *bio)

drivers/block/DAC960.c

···
 						 bool SuccessfulIO)
 {
 	struct request *Request = Command->Request;
-	int UpToDate;
-
-	UpToDate = 0;
-	if (SuccessfulIO)
-		UpToDate = 1;
+	int Error = SuccessfulIO ? 0 : -EIO;
 
 	pci_unmap_sg(Command->Controller->PCIDevice, Command->cmd_sglist,
 		Command->SegmentCount, Command->DmaDirection);
 
-	 if (!end_that_request_first(Request, UpToDate, Command->BlockCount)) {
-		add_disk_randomness(Request->rq_disk);
- 	 	end_that_request_last(Request, UpToDate);
-
+	 if (!__blk_end_request(Request, Error, Command->BlockCount << 9)) {
 		if (Command->Completion) {
 			complete(Command->Completion);
 			Command->Completion = NULL;

drivers/block/cciss.c

···
 	}
 }
 
-static inline void complete_buffers(struct bio *bio, int status)
-{
-	while (bio) {
-		struct bio *xbh = bio->bi_next;
-
-		bio->bi_next = NULL;
-		bio_endio(bio, status ? 0 : -EIO);
-		bio = xbh;
-	}
-}
-
 static void cciss_check_queues(ctlr_info_t *h)
 {
 	int start_queue = h->next_to_run;
···
 		pci_unmap_page(h->pdev, temp64.val, cmd->SG[i].Len, ddir);
 	}
 
-	complete_buffers(rq->bio, (rq->errors == 0));
-
-	if (blk_fs_request(rq)) {
-		const int rw = rq_data_dir(rq);
-
-		disk_stat_add(rq->rq_disk, sectors[rw], rq->nr_sectors);
-	}
-
 #ifdef CCISS_DEBUG
 	printk("Done with %p\n", rq);
 #endif				/* CCISS_DEBUG */
 
-	add_disk_randomness(rq->rq_disk);
+	if (blk_end_request(rq, (rq->errors == 0) ? 0 : -EIO, blk_rq_bytes(rq)))
+		BUG();
+
 	spin_lock_irqsave(&h->lock, flags);
-	end_that_request_last(rq, (rq->errors == 0));
 	cmd_free(h, cmd, 1);
 	cciss_check_queues(h);
 	spin_unlock_irqrestore(&h->lock, flags);
···
 	}
 	cmd->rq->data_len = 0;
 	cmd->rq->completion_data = cmd;
-	blk_add_trace_rq(cmd->rq->q, cmd->rq, BLK_TA_COMPLETE);
 	blk_complete_request(cmd->rq);
 }
 

drivers/block/cpqarray.c

···
 
 static inline void addQ(cmdlist_t **Qptr, cmdlist_t *c);
 static inline cmdlist_t *removeQ(cmdlist_t **Qptr, cmdlist_t *c);
-static inline void complete_buffers(struct bio *bio, int ok);
 static inline void complete_command(cmdlist_t *cmd, int timeout);
 
 static irqreturn_t do_ida_intr(int irq, void *dev_id);
···
 	}
 }
 
-static inline void complete_buffers(struct bio *bio, int ok)
-{
-	struct bio *xbh;
-
-	while (bio) {
-		xbh = bio->bi_next;
-		bio->bi_next = NULL;
-		
-		bio_endio(bio, ok ? 0 : -EIO);
-
-		bio = xbh;
-	}
-}
 /*
  * Mark all buffers that cmd was responsible for
  */
 static inline void complete_command(cmdlist_t *cmd, int timeout)
 {
 	struct request *rq = cmd->rq;
-	int ok=1;
+	int error = 0;
 	int i, ddir;
 
 	if (cmd->req.hdr.rcode & RCODE_NONFATAL &&
···
 	if (cmd->req.hdr.rcode & RCODE_FATAL) {
 		printk(KERN_WARNING "Fatal error on ida/c%dd%d\n",
 				cmd->ctlr, cmd->hdr.unit);
-		ok = 0;
+		error = -EIO;
 	}
 	if (cmd->req.hdr.rcode & RCODE_INVREQ) {
 				printk(KERN_WARNING "Invalid request on ida/c%dd%d = (cmd=%x sect=%d cnt=%d sg=%d ret=%x)\n",
 				cmd->ctlr, cmd->hdr.unit, cmd->req.hdr.cmd,
 				cmd->req.hdr.blk, cmd->req.hdr.blk_cnt,
 				cmd->req.hdr.sg_cnt, cmd->req.hdr.rcode);
-		ok = 0;	
+		error = -EIO;
 	}
-	if (timeout) ok = 0;
+	if (timeout)
+		error = -EIO;
 	/* unmap the DMA mapping for all the scatter gather elements */
 	if (cmd->req.hdr.cmd == IDA_READ)
 		ddir = PCI_DMA_FROMDEVICE;
···
                 pci_unmap_page(hba[cmd->ctlr]->pci_dev, cmd->req.sg[i].addr,
 				cmd->req.sg[i].size, ddir);
 
-	complete_buffers(rq->bio, ok);
-
-	if (blk_fs_request(rq)) {
-		const int rw = rq_data_dir(rq);
-
-		disk_stat_add(rq->rq_disk, sectors[rw], rq->nr_sectors);
-	}
-
-	add_disk_randomness(rq->rq_disk);
-
 	DBGPX(printk("Done with %p\n", rq););
-	end_that_request_last(rq, ok ? 1 : -EIO);
+	if (__blk_end_request(rq, error, blk_rq_bytes(rq)))
+		BUG();
 }
 
 /*

drivers/block/floppy.c

···
  * =============================
  */
 
-static void floppy_end_request(struct request *req, int uptodate)
+static void floppy_end_request(struct request *req, int error)
 {
 	unsigned int nr_sectors = current_count_sectors;
+	unsigned int drive = (unsigned long)req->rq_disk->private_data;
 
 	/* current_count_sectors can be zero if transfer failed */
-	if (!uptodate)
+	if (error)
 		nr_sectors = req->current_nr_sectors;
-	if (end_that_request_first(req, uptodate, nr_sectors))
+	if (__blk_end_request(req, error, nr_sectors << 9))
 		return;
-	add_disk_randomness(req->rq_disk);
-	floppy_off((long)req->rq_disk->private_data);
-	blkdev_dequeue_request(req);
-	end_that_request_last(req, uptodate);
 
 	/* We're done with the request */
+	floppy_off(drive);
 	current_req = NULL;
 }
 
···
 
 		/* unlock chained buffers */
 		spin_lock_irqsave(q->queue_lock, flags);
-		floppy_end_request(req, 1);
+		floppy_end_request(req, 0);
 		spin_unlock_irqrestore(q->queue_lock, flags);
 	} else {
 		if (rq_data_dir(req) == WRITE) {
···
 			DRWE->last_error_generation = DRS->generation;
 		}
 		spin_lock_irqsave(q->queue_lock, flags);
-		floppy_end_request(req, 0);
+		floppy_end_request(req, -EIO);
 		spin_unlock_irqrestore(q->queue_lock, flags);
 	}
 }

drivers/block/nbd.c

···
 
 static void nbd_end_request(struct request *req)
 {
-	int uptodate = (req->errors == 0) ? 1 : 0;
+	int error = req->errors ? -EIO : 0;
 	struct request_queue *q = req->q;
 	unsigned long flags;
 
 	dprintk(DBG_BLKDEV, "%s: request %p: %s\n", req->rq_disk->disk_name,
-			req, uptodate? "done": "failed");
+			req, error ? "failed" : "done");
 
 	spin_lock_irqsave(q->queue_lock, flags);
-	if (!end_that_request_first(req, uptodate, req->nr_sectors)) {
-		end_that_request_last(req, uptodate);
-	}
+	__blk_end_request(req, error, req->nr_sectors << 9);
 	spin_unlock_irqrestore(q->queue_lock, flags);
 }
 

drivers/block/ps3disk.c

···
 	struct ps3_storage_device *dev = data;
 	struct ps3disk_private *priv;
 	struct request *req;
-	int res, read, uptodate;
+	int res, read, error;
 	u64 tag, status;
 	unsigned long num_sectors;
 	const char *op;
···
 	if (status) {
 		dev_dbg(&dev->sbd.core, "%s:%u: %s failed 0x%lx\n", __func__,
 			__LINE__, op, status);
-		uptodate = 0;
+		error = -EIO;
 	} else {
 		dev_dbg(&dev->sbd.core, "%s:%u: %s completed\n", __func__,
 			__LINE__, op);
-		uptodate = 1;
+		error = 0;
 		if (read)
 			ps3disk_scatter_gather(dev, req, 0);
 	}
 
 	spin_lock(&priv->lock);
-	if (!end_that_request_first(req, uptodate, num_sectors)) {
-		add_disk_randomness(req->rq_disk);
-		blkdev_dequeue_request(req);
-		end_that_request_last(req, uptodate);
-	}
+	__blk_end_request(req, error, num_sectors << 9);
 	priv->req = NULL;
 	ps3disk_do_request(dev, priv->queue);
 	spin_unlock(&priv->lock);

drivers/block/sunvdc.c

···
 	vdc_finish(&port->vio, -err, WAITING_FOR_GEN_CMD);
 }
 
-static void vdc_end_request(struct request *req, int uptodate, int num_sectors)
+static void vdc_end_request(struct request *req, int error, int num_sectors)
 {
-	if (end_that_request_first(req, uptodate, num_sectors))
-		return;
-	add_disk_randomness(req->rq_disk);
-	end_that_request_last(req, uptodate);
+	__blk_end_request(req, error, num_sectors << 9);
 }
 
 static void vdc_end_one(struct vdc_port *port, struct vio_dring_state *dr,
···
 
 	rqe->req = NULL;
 
-	vdc_end_request(req, !desc->status, desc->size >> 9);
+	vdc_end_request(req, (desc->status ? -EIO : 0), desc->size >> 9);
 
 	if (blk_queue_stopped(port->disk->queue))
 		blk_start_queue(port->disk->queue);
···
 
 		blkdev_dequeue_request(req);
 		if (__send_request(req) < 0)
-			vdc_end_request(req, 0, req->hard_nr_sectors);
+			vdc_end_request(req, -EIO, req->hard_nr_sectors);
 	}
 }
 

drivers/block/sx8.c

···
 
 static inline void carm_end_request_queued(struct carm_host *host,
 					   struct carm_request *crq,
-					   int uptodate)
+					   int error)
 {
 	struct request *req = crq->rq;
 	int rc;
 
-	rc = end_that_request_first(req, uptodate, req->hard_nr_sectors);
+	rc = __blk_end_request(req, error, blk_rq_bytes(req));
 	assert(rc == 0);
-
-	end_that_request_last(req, uptodate);
 
 	rc = carm_put_request(host, crq);
 	assert(rc == 0);
···
 }
 
 static inline void carm_end_rq(struct carm_host *host, struct carm_request *crq,
-			int is_ok)
+			       int error)
 {
-	carm_end_request_queued(host, crq, is_ok);
+	carm_end_request_queued(host, crq, error);
 	if (max_queue == 1)
 		carm_round_robin(host);
 	else if ((host->n_msgs <= CARM_MSG_LOW_WATER) &&
···
 	sg = &crq->sg[0];
 	n_elem = blk_rq_map_sg(q, rq, sg);
 	if (n_elem <= 0) {
-		carm_end_rq(host, crq, 0);
+		carm_end_rq(host, crq, -EIO);
 		return;		/* request with no s/g entries? */
 	}
 
 	/* map scatterlist to PCI bus addresses */
 	n_elem = pci_map_sg(host->pdev, sg, n_elem, pci_dir);
 	if (n_elem <= 0) {
-		carm_end_rq(host, crq, 0);
+		carm_end_rq(host, crq, -EIO);
 		return;		/* request with no s/g entries? */
 	}
 	crq->n_elem = n_elem;
···
 
 static void carm_handle_array_info(struct carm_host *host,
 				   struct carm_request *crq, u8 *mem,
-				   int is_ok)
+				   int error)
 {
 	struct carm_port *port;
 	u8 *msg_data = mem + sizeof(struct carm_array_info);
···
 
 	DPRINTK("ENTER\n");
 
-	carm_end_rq(host, crq, is_ok);
+	carm_end_rq(host, crq, error);
 
-	if (!is_ok)
+	if (error)
 		goto out;
 	if (le32_to_cpu(desc->array_status) & ARRAY_NO_EXIST)
 		goto out;
···
 
 static void carm_handle_scan_chan(struct carm_host *host,
 				  struct carm_request *crq, u8 *mem,
-				  int is_ok)
+				  int error)
 {
 	u8 *msg_data = mem + IOC_SCAN_CHAN_OFFSET;
 	unsigned int i, dev_count = 0;
···
 
 	DPRINTK("ENTER\n");
 
-	carm_end_rq(host, crq, is_ok);
+	carm_end_rq(host, crq, error);
 
-	if (!is_ok) {
+	if (error) {
 		new_state = HST_ERROR;
 		goto out;
 	}
···
 }
 
 static void carm_handle_generic(struct carm_host *host,
-				struct carm_request *crq, int is_ok,
+				struct carm_request *crq, int error,
 				int cur_state, int next_state)
 {
 	DPRINTK("ENTER\n");
 
-	carm_end_rq(host, crq, is_ok);
+	carm_end_rq(host, crq, error);
 
 	assert(host->state == cur_state);
-	if (is_ok)
-		host->state = next_state;
-	else
+	if (error)
 		host->state = HST_ERROR;
+	else
+		host->state = next_state;
 	schedule_work(&host->fsm_task);
 }
 
 static inline void carm_handle_rw(struct carm_host *host,
-				  struct carm_request *crq, int is_ok)
+				  struct carm_request *crq, int error)
 {
 	int pci_dir;
 
···
 
 	pci_unmap_sg(host->pdev, &crq->sg[0], crq->n_elem, pci_dir);
 
-	carm_end_rq(host, crq, is_ok);
+	carm_end_rq(host, crq, error);
 }
 
 static inline void carm_handle_resp(struct carm_host *host,
···
 	u32 handle = le32_to_cpu(ret_handle_le);
 	unsigned int msg_idx;
 	struct carm_request *crq;
-	int is_ok = (status == RMSG_OK);
+	int error = (status == RMSG_OK) ? 0 : -EIO;
 	u8 *mem;
 
 	VPRINTK("ENTER, handle == 0x%x\n", handle);
···
 	/* fast path */
 	if (likely(crq->msg_type == CARM_MSG_READ ||
 		   crq->msg_type == CARM_MSG_WRITE)) {
-		carm_handle_rw(host, crq, is_ok);
+		carm_handle_rw(host, crq, error);
 		return;
 	}
 
···
 	case CARM_MSG_IOCTL: {
 		switch (crq->msg_subtype) {
 		case CARM_IOC_SCAN_CHAN:
-			carm_handle_scan_chan(host, crq, mem, is_ok);
+			carm_handle_scan_chan(host, crq, mem, error);
 			break;
 		default:
 			/* unknown / invalid response */
···
 	case CARM_MSG_MISC: {
 		switch (crq->msg_subtype) {
 		case MISC_ALLOC_MEM:
-			carm_handle_generic(host, crq, is_ok,
+			carm_handle_generic(host, crq, error,
 					    HST_ALLOC_BUF, HST_SYNC_TIME);
 			break;
 		case MISC_SET_TIME:
-			carm_handle_generic(host, crq, is_ok,
+			carm_handle_generic(host, crq, error,
 					    HST_SYNC_TIME, HST_GET_FW_VER);
 			break;
 		case MISC_GET_FW_VER: {
 			struct carm_fw_ver *ver = (struct carm_fw_ver *)
 				mem + sizeof(struct carm_msg_get_fw_ver);
-			if (is_ok) {
+			if (!error) {
 				host->fw_ver = le32_to_cpu(ver->version);
 				host->flags |= (ver->features & FL_FW_VER_MASK);
 			}
-			carm_handle_generic(host, crq, is_ok,
+			carm_handle_generic(host, crq, error,
 					    HST_GET_FW_VER, HST_PORT_SCAN);
 			break;
 		}
···
 	case CARM_MSG_ARRAY: {
 		switch (crq->msg_subtype) {
 		case CARM_ARRAY_INFO:
-			carm_handle_array_info(host, crq, mem, is_ok);
+			carm_handle_array_info(host, crq, mem, error);
 			break;
 		default:
 			/* unknown / invalid response */
···
 err_out:
 	printk(KERN_WARNING DRV_NAME "(%s): BUG: unhandled message type %d/%d\n",
 	       pci_name(host->pdev), crq->msg_type, crq->msg_subtype);
-	carm_end_rq(host, crq, 0);
+	carm_end_rq(host, crq, -EIO);
 }
 
 static inline void carm_handle_responses(struct carm_host *host)

drivers/block/ub.c

···
 
 static void ub_end_rq(struct request *rq, unsigned int scsi_status)
 {
-	int uptodate;
+	int error;
 
 	if (scsi_status == 0) {
-		uptodate = 1;
+		error = 0;
 	} else {
-		uptodate = 0;
+		error = -EIO;
 		rq->errors = scsi_status;
 	}
-	end_that_request_first(rq, uptodate, rq->hard_nr_sectors);
-	end_that_request_last(rq, uptodate);
+	if (__blk_end_request(rq, error, blk_rq_bytes(rq)))
+		BUG();
 }
 
 static int ub_rw_cmd_retry(struct ub_dev *sc, struct ub_lun *lun,

drivers/block/viodasd.c

···
 /*
  * End a request
  */
-static void viodasd_end_request(struct request *req, int uptodate,
+static void viodasd_end_request(struct request *req, int error,
 		int num_sectors)
 {
-	if (end_that_request_first(req, uptodate, num_sectors))
-		return;
-	add_disk_randomness(req->rq_disk);
-	end_that_request_last(req, uptodate);
+	__blk_end_request(req, error, num_sectors << 9);
 }
 
 /*
···
 		blkdev_dequeue_request(req);
 		/* check that request contains a valid command */
 		if (!blk_fs_request(req)) {
-			viodasd_end_request(req, 0, req->hard_nr_sectors);
+			viodasd_end_request(req, -EIO, req->hard_nr_sectors);
 			continue;
 		}
 		/* Try sending the request */
 		if (send_request(req) != 0)
-			viodasd_end_request(req, 0, req->hard_nr_sectors);
+			viodasd_end_request(req, -EIO, req->hard_nr_sectors);
 	}
 }
 
···
 	num_req_outstanding--;
 	spin_unlock_irqrestore(&viodasd_spinlock, irq_flags);
 
-	error = event->xRc != HvLpEvent_Rc_Good;
+	error = (event->xRc == HvLpEvent_Rc_Good) ? 0 : -EIO;
 	if (error) {
 		const struct vio_error_entry *err;
 		err = vio_lookup_rc(viodasd_err_table, bevent->sub_result);
···
 	}
 	qlock = req->q->queue_lock;
 	spin_lock_irqsave(qlock, irq_flags);
-	viodasd_end_request(req, !error, num_sect);
+	viodasd_end_request(req, error, num_sect);
 	spin_unlock_irqrestore(qlock, irq_flags);
 
 	/* Finally, try to get more requests off of this device's queue */

drivers/block/xen-blkfront.c

···
 	RING_IDX i, rp;
 	unsigned long flags;
 	struct blkfront_info *info = (struct blkfront_info *)dev_id;
-	int uptodate;
+	int error;
 
 	spin_lock_irqsave(&blkif_io_lock, flags);
 
···
 
 		add_id_to_freelist(info, id);
 
-		uptodate = (bret->status == BLKIF_RSP_OKAY);
+		error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
 		switch (bret->operation) {
 		case BLKIF_OP_WRITE_BARRIER:
 			if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
 				printk(KERN_WARNING "blkfront: %s: write barrier op failed\n",
 				       info->gd->disk_name);
-				uptodate = -EOPNOTSUPP;
+				error = -EOPNOTSUPP;
 				info->feature_barrier = 0;
 				xlvbd_barrier(info);
 			}
···
 				dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
 					"request: %x\n", bret->status);
 
-			ret = end_that_request_first(req, uptodate,
-				req->hard_nr_sectors);
+			ret = __blk_end_request(req, error, blk_rq_bytes(req));
 			BUG_ON(ret);
-			end_that_request_last(req, uptodate);
 			break;
 		default:
 			BUG();

drivers/block/xsysace.c

···
 
 		/* bio finished; is there another one? */
 		i = ace->req->current_nr_sectors;
-		if (end_that_request_first(ace->req, 1, i)) {
+		if (__blk_end_request(ace->req, 0, i)) {
 			/* dev_dbg(ace->dev, "next block; h=%li c=%i\n",
 			 *      ace->req->hard_nr_sectors,
 			 *      ace->req->current_nr_sectors);
···
 		break;
 
 	case ACE_FSM_STATE_REQ_COMPLETE:
-		/* Complete the block request */
-		blkdev_dequeue_request(ace->req);
-		end_that_request_last(ace->req, 1);
 		ace->req = NULL;
 
 		/* Finished request; go to idle state */

drivers/cdrom/viocd.c

···
 	return 0;
 }
 
-static void viocd_end_request(struct request *req, int uptodate)
+static void viocd_end_request(struct request *req, int error)
 {
 	int nsectors = req->hard_nr_sectors;
 
···
 	if (!nsectors)
 		nsectors = 1;
 
-	if (end_that_request_first(req, uptodate, nsectors))
+	if (__blk_end_request(req, error, nsectors << 9))
 		BUG();
-	add_disk_randomness(req->rq_disk);
-	blkdev_dequeue_request(req);
-	end_that_request_last(req, uptodate);
 }
 
 static int rwreq;
···
 
 	while ((rwreq == 0) && ((req = elv_next_request(q)) != NULL)) {
 		if (!blk_fs_request(req))
-			viocd_end_request(req, 0);
+			viocd_end_request(req, -EIO);
 		else if (send_request(req) < 0) {
 			printk(VIOCD_KERN_WARNING
 					"unable to send message to OS/400!");
-			viocd_end_request(req, 0);
+			viocd_end_request(req, -EIO);
 		} else
 			rwreq++;
 	}
···
 					"with rc %d:0x%04X: %s\n",
 					req, event->xRc,
 					bevent->sub_result, err->msg);
-			viocd_end_request(req, 0);
+			viocd_end_request(req, -EIO);
 		} else
-			viocd_end_request(req, 1);
+			viocd_end_request(req, 0);
 
 		/* restart handling of incoming requests */
 		spin_unlock_irqrestore(&viocd_reqlock, flags);

drivers/ide/ide-cd.c

···
 					BUG();
 			} else {
 				spin_lock_irqsave(&ide_lock, flags);
-				end_that_request_chunk(failed, 0,
-							failed->data_len);
-				end_that_request_last(failed, 0);
+				if (__blk_end_request(failed, -EIO,
+						      failed->data_len))
+					BUG();
 				spin_unlock_irqrestore(&ide_lock, flags);
 			}
 		} else
···
 	return 1;
 }
 
+/*
+ * Called from blk_end_request_callback() after the data of the request
+ * is completed and before the request is completed.
+ * By returning value '1', blk_end_request_callback() returns immediately
+ * without completing the request.
+ */
+static int cdrom_newpc_intr_dummy_cb(struct request *rq)
+{
+	return 1;
+}
+
 typedef void (xfer_func_t)(ide_drive_t *, void *, u32);
 
 /*
···
 			return ide_error(drive, "dma error", stat);
 		}
 
-		end_that_request_chunk(rq, 1, rq->data_len);
-		rq->data_len = 0;
-		goto end_request;
+		spin_lock_irqsave(&ide_lock, flags);
+		if (__blk_end_request(rq, 0, rq->data_len))
+			BUG();
+		HWGROUP(drive)->rq = NULL;
+		spin_unlock_irqrestore(&ide_lock, flags);
+
+		return ide_stopped;
 	}
 
 	/*
···
 	/*
 	 * If DRQ is clear, the command has completed.
 	 */
-	if ((stat & DRQ_STAT) == 0)
-		goto end_request;
+	if ((stat & DRQ_STAT) == 0) {
+		spin_lock_irqsave(&ide_lock, flags);
+		if (__blk_end_request(rq, 0, 0))
+			BUG();
+		HWGROUP(drive)->rq = NULL;
+		spin_unlock_irqrestore(&ide_lock, flags);
+
+		return ide_stopped;
+	}
 
 	/*
 	 * check which way to transfer data
···
 		rq->data_len -= blen;
 
 		if (rq->bio)
-			end_that_request_chunk(rq, 1, blen);
+			/*
+			 * The request can't be completed until DRQ is cleared.
+			 * So complete the data, but don't complete the request
+			 * using the dummy function for the callback feature
+			 * of blk_end_request_callback().
+			 */
+			blk_end_request_callback(rq, 0, blen,
+						 cdrom_newpc_intr_dummy_cb);
 		else
 			rq->data += blen;
 	}
···
 
 	ide_set_handler(drive, cdrom_newpc_intr, rq->timeout, NULL);
 	return ide_started;
-
-end_request:
-	spin_lock_irqsave(&ide_lock, flags);
-	blkdev_dequeue_request(rq);
-	end_that_request_last(rq, 1);
-	HWGROUP(drive)->rq = NULL;
-	spin_unlock_irqrestore(&ide_lock, flags);
-	return ide_stopped;
 }
 
 static ide_startstop_t cdrom_write_intr(ide_drive_t *drive)

drivers/ide/ide-io.c

···
 			     int uptodate, unsigned int nr_bytes, int dequeue)
 {
 	int ret = 1;
+	int error = 0;
+
+	if (uptodate <= 0)
+		error = uptodate ? uptodate : -EIO;
 
 	/*
 	 * if failfast is set on a request, override number of sectors and
 	 * complete the whole request right now
 	 */
-	if (blk_noretry_request(rq) && end_io_error(uptodate))
+	if (blk_noretry_request(rq) && error)
 		nr_bytes = rq->hard_nr_sectors << 9;
 
-	if (!blk_fs_request(rq) && end_io_error(uptodate) && !rq->errors)
+	if (!blk_fs_request(rq) && error && !rq->errors)
 		rq->errors = -EIO;
 
 	/*
···
 		ide_dma_on(drive);
 	}
 
-	if (!end_that_request_chunk(rq, uptodate, nr_bytes)) {
-		add_disk_randomness(rq->rq_disk);
-		if (dequeue) {
-			if (!list_empty(&rq->queuelist))
-				blkdev_dequeue_request(rq);
+	if (!__blk_end_request(rq, error, nr_bytes)) {
+		if (dequeue)
 			HWGROUP(drive)->rq = NULL;
-		}
-		end_that_request_last(rq, uptodate);
 		ret = 0;
 	}
 
···
 		drive->blocked = 0;
 		blk_start_queue(drive->queue);
 	}
-	blkdev_dequeue_request(rq);
 	HWGROUP(drive)->rq = NULL;
-	end_that_request_last(rq, 1);
+	if (__blk_end_request(rq, 0, 0))
+		BUG();
 	spin_unlock_irqrestore(&ide_lock, flags);
 }
 
···
 	}
 
 	spin_lock_irqsave(&ide_lock, flags);
-	blkdev_dequeue_request(rq);
 	HWGROUP(drive)->rq = NULL;
 	rq->errors = err;
-	end_that_request_last(rq, !rq->errors);
+	if (__blk_end_request(rq, (rq->errors ? -EIO : 0), 0))
+		BUG();
 	spin_unlock_irqrestore(&ide_lock, flags);
 }
 

drivers/message/i2o/i2o_block.c

···
 /**
  *	i2o_block_end_request - Post-processing of completed commands
  *	@req: request which should be completed
- *	@uptodate: 1 for success, 0 for I/O error, < 0 for specific error
+ *	@error: 0 for success, < 0 for error
  *	@nr_bytes: number of bytes to complete
  *
  *	Mark the request as complete. The lock must not be held when entering.
  *
  */
-static void i2o_block_end_request(struct request *req, int uptodate,
+static void i2o_block_end_request(struct request *req, int error,
 				  int nr_bytes)
 {
 	struct i2o_block_request *ireq = req->special;
···
 	struct request_queue *q = req->q;
 	unsigned long flags;
 
-	if (end_that_request_chunk(req, uptodate, nr_bytes)) {
+	if (blk_end_request(req, error, nr_bytes)) {
 		int leftover = (req->hard_nr_sectors << KERNEL_SECTOR_SHIFT);
 
 		if (blk_pc_request(req))
 			leftover = req->data_len;
 
-		if (end_io_error(uptodate))
-			end_that_request_chunk(req, 0, leftover);
+		if (error)
+			blk_end_request(req, -EIO, leftover);
 	}
 
-	add_disk_randomness(req->rq_disk);
-
 	spin_lock_irqsave(q->queue_lock, flags);
-
-	end_that_request_last(req, uptodate);
 
 	if (likely(dev)) {
 		dev->open_queue_depth--;
···
 			   struct i2o_message *msg)
 {
 	struct request *req;
-	int uptodate = 1;
+	int error = 0;
 
 	req = i2o_cntxt_list_get(c, le32_to_cpu(msg->u.s.tcntxt));
 	if (unlikely(!req)) {
···
 
 		req->errors++;
 
-		uptodate = 0;
+		error = -EIO;
 	}
 
-	i2o_block_end_request(req, uptodate, le32_to_cpu(msg->body[1]));
+	i2o_block_end_request(req, error, le32_to_cpu(msg->body[1]));
 
 	return 1;
 };

drivers/mmc/card/block.c

···
 		 * A block was successfully transferred.
 		 */
 		spin_lock_irq(&md->lock);
-		ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
-		if (!ret) {
-			/*
-			 * The whole request completed successfully.
-			 */
-			add_disk_randomness(req->rq_disk);
-			blkdev_dequeue_request(req);
-			end_that_request_last(req, 1);
-		}
+		ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 		spin_unlock_irq(&md->lock);
 	} while (ret);
 
···
 			else
 				bytes = blocks << 9;
 			spin_lock_irq(&md->lock);
-			ret = end_that_request_chunk(req, 1, bytes);
+			ret = __blk_end_request(req, 0, bytes);
 			spin_unlock_irq(&md->lock);
 		}
 	} else if (rq_data_dir(req) != READ &&
 		   (card->host->caps & MMC_CAP_MULTIWRITE)) {
 		spin_lock_irq(&md->lock);
-		ret = end_that_request_chunk(req, 1, brq.data.bytes_xfered);
+		ret = __blk_end_request(req, 0, brq.data.bytes_xfered);
 		spin_unlock_irq(&md->lock);
 	}
 
 	mmc_release_host(card->host);
 
 	spin_lock_irq(&md->lock);
-	while (ret) {
-		ret = end_that_request_chunk(req, 0,
-				req->current_nr_sectors << 9);
-	}
-
-	add_disk_randomness(req->rq_disk);
-	blkdev_dequeue_request(req);
-	end_that_request_last(req, 0);
+	while (ret)
+		ret = __blk_end_request(req, -EIO, blk_rq_cur_bytes(req));
 	spin_unlock_irq(&md->lock);
 
 	return 0;

drivers/mmc/card/queue.c

···
 		printk(KERN_ERR "MMC: killing requests for dead queue\n");
 		while ((req = elv_next_request(q)) != NULL) {
 			do {
-				ret = end_that_request_chunk(req, 0,
-					req->current_nr_sectors << 9);
+				ret = __blk_end_request(req, -EIO,
+							blk_rq_cur_bytes(req));
 			} while (ret);
 		}
 		return;

drivers/s390/block/dasd.c

···
 /*
  * posts the buffer_cache about a finalized request
  */
-static inline void dasd_end_request(struct request *req, int uptodate)
+static inline void dasd_end_request(struct request *req, int error)
 {
-	if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
+	if (__blk_end_request(req, error, blk_rq_bytes(req)))
 		BUG();
-	add_disk_randomness(req->rq_disk);
-	end_that_request_last(req, uptodate);
 }
 
 /*
···
 				      "Rejecting write request %p",
 				      req);
 			blkdev_dequeue_request(req);
-			dasd_end_request(req, 0);
+			dasd_end_request(req, -EIO);
 			continue;
 		}
 		cqr = basedev->discipline->build_cp(basedev, block, req);
···
 				      "on request %p",
 				      PTR_ERR(cqr), req);
 			blkdev_dequeue_request(req);
-			dasd_end_request(req, 0);
+			dasd_end_request(req, -EIO);
 			continue;
 		}
 		/*
···
 {
 	struct request *req;
 	int status;
+	int error = 0;
 
 	req = (struct request *) cqr->callback_data;
 	dasd_profile_end(cqr->block, cqr, req);
 	status = cqr->memdev->discipline->free_cp(cqr, req);
-	dasd_end_request(req, status);
+	if (status <= 0)
+		error = status ? status : -EIO;
+	dasd_end_request(req, error);
 }
 
 /*
···
 	spin_lock_irq(&block->request_queue_lock);
 	while ((req = elv_next_request(block->request_queue))) {
 		blkdev_dequeue_request(req);
-		dasd_end_request(req, 0);
+		dasd_end_request(req, -EIO);
 	}
 	spin_unlock_irq(&block->request_queue_lock);
 }

drivers/s390/char/tape_block.c

···
  * Post finished request.
  */
 static void
-tapeblock_end_request(struct request *req, int uptodate)
+tapeblock_end_request(struct request *req, int error)
 {
-	if (end_that_request_first(req, uptodate, req->hard_nr_sectors))
+	if (__blk_end_request(req, error, blk_rq_bytes(req)))
 		BUG();
-	end_that_request_last(req, uptodate);
 }
 
 static void
···
 
 	device = ccw_req->device;
 	req = (struct request *) data;
-	tapeblock_end_request(req, ccw_req->rc == 0);
+	tapeblock_end_request(req, (ccw_req->rc == 0) ? 0 : -EIO);
 	if (ccw_req->rc == 0)
 		/* Update position. */
 		device->blk_data.block_position =
···
 	ccw_req = device->discipline->bread(device, req);
 	if (IS_ERR(ccw_req)) {
 		DBF_EVENT(1, "TBLOCK: bread failed\n");
-		tapeblock_end_request(req, 0);
+		tapeblock_end_request(req, -EIO);
 		return PTR_ERR(ccw_req);
 	}
 	ccw_req->callback = __tapeblock_end_request;
···
 		 * Start/enqueueing failed. No retries in
 		 * this case.
 		 */
-		tapeblock_end_request(req, 0);
+		tapeblock_end_request(req, -EIO);
 		device->discipline->free_bread(ccw_req);
 	}
 
···
 		if (rq_data_dir(req) == WRITE) {
 			DBF_EVENT(1, "TBLOCK: Rejecting write request\n");
 			blkdev_dequeue_request(req);
-			tapeblock_end_request(req, 0);
+			tapeblock_end_request(req, -EIO);
 			continue;
 		}
 		spin_unlock_irq(&device->blk_data.request_queue_lock);

drivers/scsi/ide-scsi.c

···
 	}
 
 	/* kill current request */
-	blkdev_dequeue_request(req);
-	end_that_request_last(req, 0);
+	if (__blk_end_request(req, -EIO, 0))
+		BUG();
 	if (blk_sense_request(req))
 		kfree(scsi->pc->buffer);
 	kfree(scsi->pc);
···
 
 	/* now nuke the drive queue */
 	while ((req = elv_next_request(drive->queue))) {
-		blkdev_dequeue_request(req);
-		end_that_request_last(req, 0);
+		if (__blk_end_request(req, -EIO, 0))
+			BUG();
 	}
 
 	HWGROUP(drive)->rq = NULL;

drivers/scsi/scsi_lib.c

···
  *		of upper level post-processing and scsi_io_completion).
  *
  * Arguments:   cmd	 - command that is complete.
- *              uptodate - 1 if I/O indicates success, <= 0 for I/O error.
+ *              error    - 0 if I/O indicates success, < 0 for I/O error.
  *              bytes    - number of bytes of completed I/O
  *		requeue  - indicates whether we should requeue leftovers.
  *
···
  *		at some point during this call.
  * Notes:	If cmd was requeued, upon return it will be a stale pointer.
  */
-static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int uptodate,
+static struct scsi_cmnd *scsi_end_request(struct scsi_cmnd *cmd, int error,
 					  int bytes, int requeue)
 {
 	struct request_queue *q = cmd->device->request_queue;
 	struct request *req = cmd->request;
-	unsigned long flags;
 
 	/*
 	 * If there are blocks left over at the end, set up the command
 	 * to queue the remainder of them.
 	 */
-	if (end_that_request_chunk(req, uptodate, bytes)) {
+	if (blk_end_request(req, error, bytes)) {
 		int leftover = (req->hard_nr_sectors << 9);
 
 		if (blk_pc_request(req))
 			leftover = req->data_len;
 
 		/* kill remainder if no retrys */
-		if (!uptodate && blk_noretry_request(req))
-			end_that_request_chunk(req, 0, leftover);
+		if (error && blk_noretry_request(req))
+			blk_end_request(req, error, leftover);
 		else {
 			if (requeue) {
 				/*
···
 			return cmd;
 		}
 	}
-
-	add_disk_randomness(req->rq_disk);
-
-	spin_lock_irqsave(q->queue_lock, flags);
-	if (blk_rq_tagged(req))
-		blk_queue_end_tag(q, req);
-	end_that_request_last(req, uptodate);
-	spin_unlock_irqrestore(q->queue_lock, flags);
 
 	/*
 	 * This will goose the queue request function at the end, so we don't
···
 	 * are leftovers and there is some kind of error
 	 * (result != 0), retry the rest.
 	 */
-	if (scsi_end_request(cmd, 1, good_bytes, result == 0) == NULL)
+	if (scsi_end_request(cmd, 0, good_bytes, result == 0) == NULL)
 		return;
 
 	/* good_bytes = 0, or (inclusive) there were leftovers and
···
 				 * and quietly refuse further access.
 				 */
 				cmd->device->changed = 1;
-				scsi_end_request(cmd, 0, this_count, 1);
+				scsi_end_request(cmd, -EIO, this_count, 1);
 				return;
 			} else {
 				/* Must have been a power glitch, or a
···
 				scsi_requeue_command(q, cmd);
 				return;
 			} else {
-				scsi_end_request(cmd, 0, this_count, 1);
+				scsi_end_request(cmd, -EIO, this_count, 1);
 				return;
 			}
 			break;
···
 							 "Device not ready",
 							 &sshdr);
 
-			scsi_end_request(cmd, 0, this_count, 1);
+			scsi_end_request(cmd, -EIO, this_count, 1);
 			return;
 		case VOLUME_OVERFLOW:
 			if (!(req->cmd_flags & REQ_QUIET)) {
···
 				scsi_print_sense("", cmd);
 			}
 			/* See SSC3rXX or current. */
-			scsi_end_request(cmd, 0, this_count, 1);
+			scsi_end_request(cmd, -EIO, this_count, 1);
 			return;
 		default:
 			break;
···
 				scsi_print_sense("", cmd);
 		}
 	}
-	scsi_end_request(cmd, 0, this_count, !result);
+	scsi_end_request(cmd, -EIO, this_count, !result);
 }
 
 /*

include/linux/blkdev.h

···
 #define blk_fua_rq(rq)		((rq)->cmd_flags & REQ_FUA)
 #define blk_bidi_rq(rq)		((rq)->next_rq != NULL)
 #define blk_empty_barrier(rq)	(blk_barrier_rq(rq) && blk_fs_request(rq) && !(rq)->hard_nr_sectors)
+/* rq->queuelist of dequeued request must be list_empty() */
+#define blk_queued_rq(rq)	(!list_empty(&(rq)->queuelist))
 
 #define list_entry_rq(ptr)	list_entry((ptr), struct request, queuelist)
 
···
 }
 
 /*
- * end_request() and friends. Must be called with the request queue spinlock
- * acquired. All functions called within end_request() _must_be_ atomic.
+ * blk_end_request() and friends.
+ * __blk_end_request() and end_request() must be called with
+ * the request queue spinlock acquired.
  *
  * Several drivers define their own end_request and call
- * end_that_request_first() and end_that_request_last()
- * for parts of the original function. This prevents
- * code duplication in drivers.
+ * blk_end_request() for parts of the original function.
+ * This prevents code duplication in drivers.
  */
-extern int end_that_request_first(struct request *, int, int);
-extern int end_that_request_chunk(struct request *, int, int);
-extern void end_that_request_last(struct request *, int);
+extern int blk_end_request(struct request *rq, int error, int nr_bytes);
+extern int __blk_end_request(struct request *rq, int error, int nr_bytes);
+extern int blk_end_bidi_request(struct request *rq, int error, int nr_bytes,
+				int bidi_bytes);
 extern void end_request(struct request *, int);
 extern void end_queued_request(struct request *, int);
 extern void end_dequeued_request(struct request *, int);
+extern int blk_end_request_callback(struct request *rq, int error, int nr_bytes,
+				    int (drv_callback)(struct request *));
 extern void blk_complete_request(struct request *);
 
 /*
- * end_that_request_first/chunk() takes an uptodate argument. we account
- * any value <= as an io error. 0 means -EIO for compatability reasons,
- * any other < 0 value is the direct error type. An uptodate value of
- * 1 indicates successful io completion
+ * blk_end_request() takes bytes instead of sectors as a complete size.
+ * blk_rq_bytes() returns bytes left to complete in the entire request.
+ * blk_rq_cur_bytes() returns bytes left to complete in the current segment.
  */
-#define end_io_error(uptodate)	(unlikely((uptodate) <= 0))
+extern unsigned int blk_rq_bytes(struct request *rq);
+extern unsigned int blk_rq_cur_bytes(struct request *rq);
 
 static inline void blkdev_dequeue_request(struct request *req)
 {