ide-cd,atapi: use bio for internal commands

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 and atapi to use bio instead of rq->data
for request sense and internal pc commands.  With previous change to
unify sense request handling, this is relatively easily achieved by
adding blk_rq_map_kern() during sense_rq prep and PC issue.

If blk_rq_map_kern() fails for sense, the error is deferred till sense
issue and aborts the failed command which triggered the sense.  Note
that this is a slim possibility as sense prep is done on each command
issue, so for the above condition to actually trigger, all preps since
the last sense issue till the issue of the request which would require
a sense should fail.

* do_request functions might sleep now.  This should be okay as ide
  request_fn - do_ide_request() - is invoked only from make_request
  and plug work.  Make sure this is the case by adding might_sleep()
  to do_ide_request().

* Functions which access the read sense data before the sense request
  is complete now should access bio_data(sense_rq->bio) as the sense
  buffer might have been copied during blk_rq_map_kern().

* ide-tape updated to map sg.

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

* tp_ops->output/input_data path dropped from ide_pc_intr().

Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 14 insertions, 14 deletions

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 061d7bbcd34a..673628790f10 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -210,10 +210,12 @@ static void ide_cd_complete_failed_rq(ide_drive_t *drive, struct request *rq)
 {
 	/*
 	 * For REQ_TYPE_SENSE, "rq->special" points to the original
-	 * failed request
+	 * failed request.  Also, the sense data should be read
+	 * directly from rq which might be different from the original
+	 * sense buffer if it got copied during mapping.
 	 */
 	struct request *failed = (struct request *)rq->special;
-	struct request_sense *sense = &drive->sense_data;
+	void *sense = bio_data(rq->bio);
 
 	if (failed) {
 		if (failed->sense) {
@@ -398,7 +400,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 
 	/* if we got a CHECK_CONDITION status, queue a request sense command */
 	if (stat & ATA_ERR)
-		ide_queue_sense_rq(drive, NULL);
+		return ide_queue_sense_rq(drive, NULL) ? 2 : 1;
 	return 1;
 
 end_request:
@@ -412,8 +414,7 @@ end_request:
 
 		hwif->rq = NULL;
 
-		ide_queue_sense_rq(drive, rq);
-		return 1;
+		return ide_queue_sense_rq(drive, rq) ? 2 : 1;
 	} else
 		return 2;
 }
@@ -507,8 +508,12 @@ 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_NOIO);
+			if (error) {
+				blk_put_request(rq);
+				return error;
+			}
 		}
 
 		error = blk_execute_rq(drive->queue, info->disk, rq, 0);
@@ -802,15 +807,10 @@ 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);