[PATCH] update blk_execute_rq to take an at_head parameter

Original From: Mike Christie <michaelc@cs.wisc.edu> Modified to split out block changes (this patch) and SCSI pieces. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

[PATCH] update blk_execute_rq to take an at_head parameter
Original From: Mike Christie <michaelc@cs.wisc.edu> Modified to split out block changes (this patch) and SCSI pieces. Signed-off-by: Jens Axboe <axboe@suse.de> Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>
James Bottomley · Jens Axboe
1 parent f63eb21b4f
Showing 5 changed files with 11 additions and 10 deletions Side-by-side Diff
drivers/block/ll_rw_blk.c
drivers/block/scsi_ioctl.c
drivers/cdrom/cdrom.c
drivers/ide/ide-disk.c
include/linux/blkdev.h
@@ -2269,13 +2269,14 @@
  * @q:		queue to insert the request in
  * @bd_disk:	matching gendisk
  * @rq:		request to insert
+ * @at_head:    insert request at head or tail of queue
  *
  * Description:
  *    Insert a fully prepared request at the back of the io scheduler queue
  *    for execution.
  */
 int blk_execute_rq(request_queue_t *q, struct gendisk *bd_disk,
-		   struct request *rq)
+		   struct request *rq, int at_head)
 {
 	DECLARE_COMPLETION(wait);
 	char sense[SCSI_SENSE_BUFFERSIZE];
@@ -2294,7 +2295,7 @@
 	}
  
 	rq->waiting = &wait;
-	blk_execute_rq_nowait(q, bd_disk, rq, 0, blk_end_sync_rq);
+	blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
 	wait_for_completion(&wait);
 	rq->waiting = NULL;
  
@@ -2361,7 +2362,7 @@
 	rq->data_len = 0;
 	rq->timeout = 60 * HZ;
  
-	ret = blk_execute_rq(q, disk, rq);
+	ret = blk_execute_rq(q, disk, rq, 0);
  
 	if (ret && error_sector)
 		*error_sector = rq->sector;
@@ -308,7 +308,7 @@
 	 * (if he doesn't check that is his problem).
 	 * N.B. a non-zero SCSI status is _not_ necessarily an error.
 	 */
-	blk_execute_rq(q, bd_disk, rq);
+	blk_execute_rq(q, bd_disk, rq, 0);
  
 	/* write to all output members */
 	hdr->status = 0xff & rq->errors;
@@ -420,7 +420,7 @@
 	rq->data_len = bytes;
 	rq->flags |= REQ_BLOCK_PC;
  
-	blk_execute_rq(q, bd_disk, rq);
+	blk_execute_rq(q, bd_disk, rq, 0);
 	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
 	if (err) {
 		if (rq->sense_len && rq->sense) {
@@ -573,7 +573,7 @@
 			rq->cmd[0] = GPCMD_START_STOP_UNIT;
 			rq->cmd[4] = 0x02 + (close != 0);
 			rq->cmd_len = 6;
-			err = blk_execute_rq(q, bd_disk, rq);
+			err = blk_execute_rq(q, bd_disk, rq, 0);
 			blk_put_request(rq);
 			break;
 		default:
@@ -2136,7 +2136,7 @@
 		if (rq->bio)
 			blk_queue_bounce(q, &rq->bio);
  
-		if (blk_execute_rq(q, cdi->disk, rq)) {
+		if (blk_execute_rq(q, cdi->disk, rq, 0)) {
 			struct request_sense *s = rq->sense;
 			ret = -EIO;
 			cdi->last_sense = s->sense_key;
@@ -750,7 +750,7 @@
  
 	idedisk_prepare_flush(q, rq);
  
-	ret = blk_execute_rq(q, disk, rq);
+	ret = blk_execute_rq(q, disk, rq, 0);
  
 	/*
 	 * if we failed and caller wants error offset, get it
@@ -562,8 +562,8 @@
 extern int blk_rq_unmap_user(struct bio *, unsigned int);
 extern int blk_rq_map_kern(request_queue_t *, struct request *, void *, unsigned int, unsigned int);
 extern int blk_rq_map_user_iov(request_queue_t *, struct request *, struct sg_iovec *, int);
-extern int blk_execute_rq(request_queue_t *, struct gendisk *, struct request *);
-
+extern int blk_execute_rq(request_queue_t *, struct gendisk *,
+			  struct request *, int);
 static inline request_queue_t *bdev_get_queue(struct block_device *bdev)
 {
 	return bdev->bd_disk->queue;
...	...	@@ -2269,13 +2269,14 @@
2269	2269	* @q: queue to insert the request in
2270	2270	* @bd_disk: matching gendisk
2271	2271	* @rq: request to insert
	2272	+ * @at_head: insert request at head or tail of queue
2272	2273	*
2273	2274	* Description:
2274	2275	* Insert a fully prepared request at the back of the io scheduler queue
2275	2276	* for execution.
2276	2277	*/
2277	2278	int blk_execute_rq(request_queue_t q, struct gendisk bd_disk,
2278		- struct request *rq)
	2279	+ struct request *rq, int at_head)
2279	2280	{
2280	2281	DECLARE_COMPLETION(wait);
2281	2282	char sense[SCSI_SENSE_BUFFERSIZE];
...	...	@@ -2294,7 +2295,7 @@
2294	2295	}
2295	2296
2296	2297	rq->waiting = &wait;
2297		- blk_execute_rq_nowait(q, bd_disk, rq, 0, blk_end_sync_rq);
	2298	+ blk_execute_rq_nowait(q, bd_disk, rq, at_head, blk_end_sync_rq);
2298	2299	wait_for_completion(&wait);
2299	2300	rq->waiting = NULL;
2300	2301
...	...	@@ -2361,7 +2362,7 @@
2361	2362	rq->data_len = 0;
2362	2363	rq->timeout = 60 * HZ;
2363	2364
2364		- ret = blk_execute_rq(q, disk, rq);
	2365	+ ret = blk_execute_rq(q, disk, rq, 0);
2365	2366
2366	2367	if (ret && error_sector)
2367	2368	*error_sector = rq->sector;
...	...	@@ -308,7 +308,7 @@
308	308	* (if he doesn't check that is his problem).
309	309	* N.B. a non-zero SCSI status is _not_ necessarily an error.
310	310	*/
311		- blk_execute_rq(q, bd_disk, rq);
	311	+ blk_execute_rq(q, bd_disk, rq, 0);
312	312
313	313	/* write to all output members */
314	314	hdr->status = 0xff & rq->errors;
...	...	@@ -420,7 +420,7 @@
420	420	rq->data_len = bytes;
421	421	rq->flags \|= REQ_BLOCK_PC;
422	422
423		- blk_execute_rq(q, bd_disk, rq);
	423	+ blk_execute_rq(q, bd_disk, rq, 0);
424	424	err = rq->errors & 0xff; /* only 8 bit SCSI status */
425	425	if (err) {
426	426	if (rq->sense_len && rq->sense) {
...	...	@@ -573,7 +573,7 @@
573	573	rq->cmd[0] = GPCMD_START_STOP_UNIT;
574	574	rq->cmd[4] = 0x02 + (close != 0);
575	575	rq->cmd_len = 6;
576		- err = blk_execute_rq(q, bd_disk, rq);
	576	+ err = blk_execute_rq(q, bd_disk, rq, 0);
577	577	blk_put_request(rq);
578	578	break;
579	579	default:
...	...	@@ -2136,7 +2136,7 @@
2136	2136	if (rq->bio)
2137	2137	blk_queue_bounce(q, &rq->bio);
2138	2138
2139		- if (blk_execute_rq(q, cdi->disk, rq)) {
	2139	+ if (blk_execute_rq(q, cdi->disk, rq, 0)) {
2140	2140	struct request_sense *s = rq->sense;
2141	2141	ret = -EIO;
2142	2142	cdi->last_sense = s->sense_key;
...	...	@@ -750,7 +750,7 @@
750	750
751	751	idedisk_prepare_flush(q, rq);
752	752
753		- ret = blk_execute_rq(q, disk, rq);
	753	+ ret = blk_execute_rq(q, disk, rq, 0);
754	754
755	755	/*
756	756	* if we failed and caller wants error offset, get it
...	...	@@ -562,8 +562,8 @@
562	562	extern int blk_rq_unmap_user(struct bio *, unsigned int);
563	563	extern int blk_rq_map_kern(request_queue_t , struct request , void *, unsigned int, unsigned int);
564	564	extern int blk_rq_map_user_iov(request_queue_t , struct request , struct sg_iovec *, int);
565		-extern int blk_execute_rq(request_queue_t , struct gendisk , struct request *);
566		-
	565	+extern int blk_execute_rq(request_queue_t , struct gendisk ,
	566	+ struct request *, int);
567	567	static inline request_queue_t bdev_get_queue(struct block_device bdev)
568	568	{
569	569	return bdev->bd_disk->queue;