[PATCH 14/14] ide-cd: use bio for request sense

[Tejun Heo <tj@kernel.org>]

Impact: unify request data buffer handling

rq->data is used mostly to pass kernel buffer through request queue
without using bio.  There are only a couple of places which still do
this in kernel and converting to bio isn't difficult.

This patch converts ide-cd to use bio instead of rq->data for request
sense and internal pc commands.  As request sense is issued from
atomic context, drive->request_sense_bio and ->request_sense_bvec[2]
are used via bio_map_kern_prealloc().  Internal pc commands use
blk_rq_map_kern().

cdrom_do_block_pc() now doesn't have to deal with REQ_TYPE_ATA_PC
special case.  Simplified.

Signed-off-by: Tejun Heo <tj@kernel.org>
Cc: Jens Axboe <axboe@kernel.dk>
---
 drivers/ide/ide-cd.c |   31 ++++++++++++++++++-------------
 1 files changed, 18 insertions(+), 13 deletions(-)

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index de6ce8d..22c95b9 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -209,8 +209,12 @@ static void cdrom_analyze_sense_data(ide_drive_t *drive,
 static void cdrom_queue_request_sense(ide_drive_t *drive, void *sense,
 				      struct request *failed_command)
 {
-	struct cdrom_info *info		= drive->driver_data;
-	struct request *rq		= &drive->request_sense_rq;
+	struct cdrom_info *info	= drive->driver_data;
+	struct request *rq	= &drive->request_sense_rq;
+	struct bio *bio		= &drive->request_sense_bio;
+	struct bio_vec *bvec	= drive->request_sense_bvec;
+	unsigned int bvec_len	= ARRAY_SIZE(drive->request_sense_bvec);
+	int error;
 
 	ide_debug_log(IDE_DBG_SENSE, "enter");
 
@@ -224,10 +228,12 @@ static void cdrom_queue_request_sense(ide_drive_t *drive, void *sense,
 	rq->cmd_type = REQ_TYPE_ATA_PC;
 	rq->rq_disk = info->disk;
 
-	rq->data = sense;
+	error = blk_rq_map_kern_prealloc(drive->queue, rq, bio, bvec, bvec_len,
+					 sense, 18, true);
+	BUG_ON(error);
+
 	rq->cmd[0] = GPCMD_REQUEST_SENSE;
 	rq->cmd[4] = 18;
-	rq->data_len = 18;
 
 	rq->cmd_type = REQ_TYPE_SENSE;
 	rq->cmd_flags |= REQ_PREEMPT;
@@ -556,8 +562,12 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 		rq->cmd_flags |= cmd_flags;
 		rq->timeout = timeout;
 		if (buffer) {
-			rq->data = buffer;
-			rq->data_len = *bufflen;
+			error = blk_rq_map_kern(drive->queue, rq, buffer,
+						*bufflen, __GFP_WAIT);
+			if (error) {
+				blk_put_request(rq);
+				return error;
+			}
 		}
 
 		error = blk_execute_rq(drive->queue, info->disk, rq, 0);
@@ -847,15 +857,10 @@ static void cdrom_do_block_pc(ide_drive_t *drive, struct request *rq)
 	drive->dma = 0;
 
 	/* sg request */
-	if (rq->bio || ((rq->cmd_type == REQ_TYPE_ATA_PC) && rq->data_len)) {
+	if (rq->bio) {
 		struct request_queue *q = drive->queue;
+		char *buf = bio_data(rq->bio);
 		unsigned int alignment;
-		char *buf;
-
-		if (rq->bio)
-			buf = bio_data(rq->bio);
-		else
-			buf = rq->data;
 
 		drive->dma = !!(drive->dev_flags & IDE_DFLAG_USING_DMA);
 
-- 
1.6.0.2