kill req->errors V3

kill req->errors V3

[Christoph Hellwig]

Currently the request structure has an errors field that is used in
various different ways.  The oldest drivers use it as an error count,
blk-mq and the generic timeout code assume that it holds a Linux
errno for block completions, and various drivers use it for internal
status values, often overwriting them with Linux errnos later,
that is unless they are processing passthrough requests in which
case they'll leave their errors in it.

This series kills the ->errors field and replaced it with new fields
in the drivers (or an odd hack in a union in struct request for
two bitrotting old drivers).

Also available in the following git tree:

    git://git.infradead.org/users/hch/block.git request-errors

Gitweb:

    http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/request-errors

Changes since V2;
 - reorder one patch to be earlier in the series
 - fix the argument to a bsg dprintk
 - fix a kerneldoc comment

Changes since V1:
 - rebased on top the latest block for-next tree
 - fix error handling in nfsd blocklayout
 - dropped "scsi: fix fast-fail for non-passthrough requests"

kill req->errors V3

[Christoph Hellwig]

Currently the request structure has an errors field that is used in
various different ways.  The oldest drivers use it as an error count,
blk-mq and the generic timeout code assume that it holds a Linux
errno for block completions, and various drivers use it for internal
status values, often overwriting them with Linux errnos later,
that is unless they are processing passthrough requests in which
case they'll leave their errors in it.

This series kills the ->errors field and replaced it with new fields
in the drivers (or an odd hack in a union in struct request for
two bitrotting old drivers).

Also available in the following git tree:

    git://git.infradead.org/users/hch/block.git request-errors

Gitweb:

    http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/request-errors

Changes since V2;
 - reorder one patch to be earlier in the series
 - fix the argument to a bsg dprintk
 - fix a kerneldoc comment

Changes since V1:
 - rebased on top the latest block for-next tree
 - fix error handling in nfsd blocklayout
 - dropped "scsi: fix fast-fail for non-passthrough requests"

[PATCH 01/23] pd: don't check blk_execute_rq return value.

[Christoph Hellwig]

The driver never sets req->errors, so blk_execute_rq will always return 0.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/paride/pd.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index b05e151c9b38..7d2402f90978 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -739,18 +739,15 @@ static int pd_special_command(struct pd_unit *disk,
 		      enum action (*func)(struct pd_unit *disk))
 {
 	struct request *rq;
-	int err = 0;
 
 	rq = blk_get_request(disk->gd->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
 	rq->special = func;
-
-	err = blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
-
+	blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
 	blk_put_request(rq);
-	return err;
+	return 0;
 }
 
 /* kernel glue structures */
-- 
2.11.0

[PATCH 01/23] pd: don't check blk_execute_rq return value.

[Christoph Hellwig]

The driver never sets req->errors, so blk_execute_rq will always return 0.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/paride/pd.c | 7 ++-----
 1 file changed, 2 insertions(+), 5 deletions(-)

diff --git a/drivers/block/paride/pd.c b/drivers/block/paride/pd.c
index b05e151c9b38..7d2402f90978 100644
--- a/drivers/block/paride/pd.c
+++ b/drivers/block/paride/pd.c
@@ -739,18 +739,15 @@ static int pd_special_command(struct pd_unit *disk,
 		      enum action (*func)(struct pd_unit *disk))
 {
 	struct request *rq;
-	int err = 0;
 
 	rq = blk_get_request(disk->gd->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
 	if (IS_ERR(rq))
 		return PTR_ERR(rq);
 
 	rq->special = func;
-
-	err = blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
-
+	blk_execute_rq(disk->gd->queue, disk->gd, rq, 0);
 	blk_put_request(rq);
-	return err;
+	return 0;
 }
 
 /* kernel glue structures */
-- 
2.11.0

Re: [PATCH 01/23] pd: don't check blk_execute_rq return value.

[Bart Van Assche]

On Wed, 2017-04-19 at 21:26 +0200, Christoph Hellwig wrote:
> The driver never sets req->errors, so blk_execute_rq will always return 0=
.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>=

[PATCH 01/23] pd: don't check blk_execute_rq return value.

[Bart Van Assche]

On Wed, 2017-04-19@21:26 +0200, Christoph Hellwig wrote:
> The driver never sets req->errors, so blk_execute_rq will always return 0.

Reviewed-by: Bart Van Assche <Bart.VanAssche at sandisk.com>

Re: [PATCH 01/23] pd: don't check blk_execute_rq return value.

[Bart Van Assche]

On Wed, 2017-04-19 at 21:26 +0200, Christoph Hellwig wrote:
> The driver never sets req->errors, so blk_execute_rq will always return 0.

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>

[PATCH 02/23] block: remove the blk_execute_rq return value

[Christoph Hellwig]

The function only returns -EIO if rq->errors is non-zero, which is not
very useful and lets a large number of callers ignore the return value.

Just let the callers figure out their error themselves.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 block/blk-exec.c                 | 8 +-------
 block/scsi_ioctl.c               | 3 ++-
 drivers/block/virtio_blk.c       | 3 ++-
 drivers/cdrom/cdrom.c            | 3 ++-
 drivers/ide/ide-atapi.c          | 3 ++-
 drivers/ide/ide-cd.c             | 3 ++-
 drivers/ide/ide-cd_ioctl.c       | 3 ++-
 drivers/ide/ide-devsets.c        | 4 ++--
 drivers/ide/ide-disk.c           | 3 +--
 drivers/ide/ide-ioctls.c         | 7 ++++---
 drivers/ide/ide-park.c           | 3 ++-
 drivers/ide/ide-pm.c             | 3 ++-
 drivers/ide/ide-taskfile.c       | 4 ++--
 drivers/scsi/osd/osd_initiator.c | 5 ++++-
 fs/nfsd/blocklayout.c            | 5 +++--
 include/linux/blkdev.h           | 2 +-
 16 files changed, 34 insertions(+), 28 deletions(-)

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 8cd0e9bc8dc8..afa383248c7c 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -92,11 +92,10 @@ EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
  *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution and wait for completion.
  */
-int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
+void blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 		   struct request *rq, int at_head)
 {
 	DECLARE_COMPLETION_ONSTACK(wait);
-	int err = 0;
 	unsigned long hang_check;
 
 	rq->end_io_data = &wait;
@@ -108,10 +107,5 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 		while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
 	else
 		wait_for_completion_io(&wait);
-
-	if (rq->errors)
-		err = -EIO;
-
-	return err;
 }
 EXPORT_SYMBOL(blk_execute_rq);
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 82a43bb19967..b1352143f12f 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -547,7 +547,8 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	scsi_req(rq)->cmd[0] = cmd;
 	scsi_req(rq)->cmd[4] = data;
 	scsi_req(rq)->cmd_len = 6;
-	err = blk_execute_rq(q, bd_disk, rq, 0);
+	blk_execute_rq(q, bd_disk, rq, 0);
+	err = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 
 	return err;
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2d8290169271..eaf99022bdc6 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -310,7 +310,8 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
 	if (err)
 		goto out;
 
-	err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+	blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+	err = req->errors ? -EIO : 0;
 out:
 	blk_put_request(req);
 	return err;
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 87739649eac2..308501730ab3 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2218,7 +2218,8 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		rq->timeout = 60 * HZ;
 		bio = rq->bio;
 
-		if (blk_execute_rq(q, cdi->disk, rq, 0)) {
+		blk_execute_rq(q, cdi->disk, rq, 0);
+		if (rq->errors) {
 			struct request_sense *s = req->sense;
 			ret = -EIO;
 			cdi->last_sense = s->sense_key;
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index feb30061123b..1524797e1776 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -107,7 +107,8 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 	memcpy(scsi_req(rq)->cmd, pc->c, 12);
 	if (drive->media == ide_tape)
 		scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
-	error = blk_execute_rq(drive->queue, disk, rq, 0);
+	blk_execute_rq(drive->queue, disk, rq, 0);
+	error = rq->errors ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 74f1b7dc03f7..95c40afa9120 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -452,7 +452,8 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 			}
 		}
 
-		error = blk_execute_rq(drive->queue, info->disk, rq, 0);
+		blk_execute_rq(drive->queue, info->disk, rq, 0);
+		error = rq->errors ? -EIO : 0;
 
 		if (buffer)
 			*bufflen = scsi_req(rq)->resid_len;
diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c
index 9fcefbc8425e..f1ab726bd430 100644
--- a/drivers/ide/ide-cd_ioctl.c
+++ b/drivers/ide/ide-cd_ioctl.c
@@ -307,7 +307,8 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	scsi_req_init(rq);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->rq_flags = RQF_QUIET;
-	ret = blk_execute_rq(drive->queue, cd->disk, rq, 0);
+	blk_execute_rq(drive->queue, cd->disk, rq, 0);
+	ret = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 	/*
 	 * A reset will unlock the door. If it was previously locked,
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index a45dda5386e4..eea6a7cb80b5 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -173,8 +173,8 @@ int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 	*(int *)&scsi_req(rq)->cmd[1] = arg;
 	rq->special = setting->set;
 
-	if (blk_execute_rq(q, NULL, rq, 0))
-		ret = rq->errors;
+	blk_execute_rq(q, NULL, rq, 0);
+	ret = rq->errors;
 	blk_put_request(rq);
 
 	return ret;
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 186159715b71..7c06237f3479 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -470,7 +470,6 @@ ide_devset_get(multcount, mult_count);
 static int set_multcount(ide_drive_t *drive, int arg)
 {
 	struct request *rq;
-	int error;
 
 	if (arg < 0 || arg > (drive->id[ATA_ID_MAX_MULTSECT] & 0xff))
 		return -EINVAL;
@@ -484,7 +483,7 @@ static int set_multcount(ide_drive_t *drive, int arg)
 
 	drive->mult_req = arg;
 	drive->special_flags |= IDE_SFLAG_SET_MULTMODE;
-	error = blk_execute_rq(drive->queue, NULL, rq, 0);
+	blk_execute_rq(drive->queue, NULL, rq, 0);
 	blk_put_request(rq);
 
 	return (drive->mult_count == arg) ? 0 : -EIO;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 248a3e0ceb46..3e96e531b367 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -128,7 +128,8 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 		rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
 		scsi_req_init(rq);
 		ide_req(rq)->type = ATA_PRIV_TASKFILE;
-		err = blk_execute_rq(drive->queue, NULL, rq, 0);
+		blk_execute_rq(drive->queue, NULL, rq, 0);
+		err = rq->errors ? -EIO : 0;
 		blk_put_request(rq);
 
 		return err;
@@ -227,8 +228,8 @@ static int generic_drive_reset(ide_drive_t *drive)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	scsi_req(rq)->cmd_len = 1;
 	scsi_req(rq)->cmd[0] = REQ_DRIVE_RESET;
-	if (blk_execute_rq(drive->queue, NULL, rq, 1))
-		ret = rq->errors;
+	blk_execute_rq(drive->queue, NULL, rq, 1);
+	ret = rq->errors;
 	blk_put_request(rq);
 	return ret;
 }
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index 101aed9a61ca..b4f577016f5a 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -37,7 +37,8 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	scsi_req(rq)->cmd_len = 1;
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->special = &timeout;
-	rc = blk_execute_rq(q, NULL, rq, 1);
+	blk_execute_rq(q, NULL, rq, 1);
+	rc = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 	if (rc)
 		goto out;
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index ec951be4b0c8..bf513f886f3c 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -27,7 +27,8 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 		mesg.event = PM_EVENT_FREEZE;
 	rqpm.pm_state = mesg.event;
 
-	ret = blk_execute_rq(drive->queue, NULL, rq, 0);
+	blk_execute_rq(drive->queue, NULL, rq, 0);
+	ret = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 
 	if (ret == 0 && ide_port_acpi(hwif)) {
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 4c0007cb74e3..78924c7c9478 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -452,8 +452,8 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 	rq->special = cmd;
 	cmd->rq = rq;
 
-	error = blk_execute_rq(drive->queue, NULL, rq, 0);
-
+	blk_execute_rq(drive->queue, NULL, rq, 0);
+	error = rq->errors ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 9d0727b2bdec..44e03c3eb250 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -489,7 +489,10 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
 
 int osd_execute_request(struct osd_request *or)
 {
-	int error = blk_execute_rq(or->request->q, NULL, or->request, 0);
+	int error;
+
+	blk_execute_rq(or->request->q, NULL, or->request, 0);
+	error = or->request ? -EIO : 0;
 
 	_set_error_resid(or, or->request, error);
 	return error;
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 92b4b41d19d2..9f618b77ffee 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -242,10 +242,11 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 	req->cmd[4] = bufflen & 0xff;
 	req->cmd_len = COMMAND_SIZE(INQUIRY);
 
-	error = blk_execute_rq(rq->q, NULL, rq, 1);
-	if (error) {
+	blk_execute_rq(rq->q, NULL, rq, 1);
+	if (rq->errors) {
 		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
 			rq->errors);
+		error = -EIO;
 		goto out_put_request;
 	}
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index fe9c512cc6fa..d8bcd51b8a47 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -969,7 +969,7 @@ extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, uns
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 			       struct rq_map_data *, const struct iov_iter *,
 			       gfp_t);
-extern int blk_execute_rq(struct request_queue *, struct gendisk *,
+extern void blk_execute_rq(struct request_queue *, struct gendisk *,
 			  struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 				  struct request *, int, rq_end_io_fn *);
-- 
2.11.0

[PATCH 02/23] block: remove the blk_execute_rq return value

[Christoph Hellwig]

The function only returns -EIO if rq->errors is non-zero, which is not
very useful and lets a large number of callers ignore the return value.

Just let the callers figure out their error themselves.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
---
 block/blk-exec.c                 | 8 +-------
 block/scsi_ioctl.c               | 3 ++-
 drivers/block/virtio_blk.c       | 3 ++-
 drivers/cdrom/cdrom.c            | 3 ++-
 drivers/ide/ide-atapi.c          | 3 ++-
 drivers/ide/ide-cd.c             | 3 ++-
 drivers/ide/ide-cd_ioctl.c       | 3 ++-
 drivers/ide/ide-devsets.c        | 4 ++--
 drivers/ide/ide-disk.c           | 3 +--
 drivers/ide/ide-ioctls.c         | 7 ++++---
 drivers/ide/ide-park.c           | 3 ++-
 drivers/ide/ide-pm.c             | 3 ++-
 drivers/ide/ide-taskfile.c       | 4 ++--
 drivers/scsi/osd/osd_initiator.c | 5 ++++-
 fs/nfsd/blocklayout.c            | 5 +++--
 include/linux/blkdev.h           | 2 +-
 16 files changed, 34 insertions(+), 28 deletions(-)

diff --git a/block/blk-exec.c b/block/blk-exec.c
index 8cd0e9bc8dc8..afa383248c7c 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -92,11 +92,10 @@ EXPORT_SYMBOL_GPL(blk_execute_rq_nowait);
  *    Insert a fully prepared request at the back of the I/O scheduler queue
  *    for execution and wait for completion.
  */
-int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
+void blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 		   struct request *rq, int at_head)
 {
 	DECLARE_COMPLETION_ONSTACK(wait);
-	int err = 0;
 	unsigned long hang_check;
 
 	rq->end_io_data = &wait;
@@ -108,10 +107,5 @@ int blk_execute_rq(struct request_queue *q, struct gendisk *bd_disk,
 		while (!wait_for_completion_io_timeout(&wait, hang_check * (HZ/2)));
 	else
 		wait_for_completion_io(&wait);
-
-	if (rq->errors)
-		err = -EIO;
-
-	return err;
 }
 EXPORT_SYMBOL(blk_execute_rq);
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index 82a43bb19967..b1352143f12f 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -547,7 +547,8 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	scsi_req(rq)->cmd[0] = cmd;
 	scsi_req(rq)->cmd[4] = data;
 	scsi_req(rq)->cmd_len = 6;
-	err = blk_execute_rq(q, bd_disk, rq, 0);
+	blk_execute_rq(q, bd_disk, rq, 0);
+	err = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 
 	return err;
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 2d8290169271..eaf99022bdc6 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -310,7 +310,8 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
 	if (err)
 		goto out;
 
-	err = blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+	blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
+	err = req->errors ? -EIO : 0;
 out:
 	blk_put_request(req);
 	return err;
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 87739649eac2..308501730ab3 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2218,7 +2218,8 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		rq->timeout = 60 * HZ;
 		bio = rq->bio;
 
-		if (blk_execute_rq(q, cdi->disk, rq, 0)) {
+		blk_execute_rq(q, cdi->disk, rq, 0);
+		if (rq->errors) {
 			struct request_sense *s = req->sense;
 			ret = -EIO;
 			cdi->last_sense = s->sense_key;
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index feb30061123b..1524797e1776 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -107,7 +107,8 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 	memcpy(scsi_req(rq)->cmd, pc->c, 12);
 	if (drive->media == ide_tape)
 		scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
-	error = blk_execute_rq(drive->queue, disk, rq, 0);
+	blk_execute_rq(drive->queue, disk, rq, 0);
+	error = rq->errors ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 74f1b7dc03f7..95c40afa9120 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -452,7 +452,8 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 			}
 		}
 
-		error = blk_execute_rq(drive->queue, info->disk, rq, 0);
+		blk_execute_rq(drive->queue, info->disk, rq, 0);
+		error = rq->errors ? -EIO : 0;
 
 		if (buffer)
 			*bufflen = scsi_req(rq)->resid_len;
diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c
index 9fcefbc8425e..f1ab726bd430 100644
--- a/drivers/ide/ide-cd_ioctl.c
+++ b/drivers/ide/ide-cd_ioctl.c
@@ -307,7 +307,8 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	scsi_req_init(rq);
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->rq_flags = RQF_QUIET;
-	ret = blk_execute_rq(drive->queue, cd->disk, rq, 0);
+	blk_execute_rq(drive->queue, cd->disk, rq, 0);
+	ret = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 	/*
 	 * A reset will unlock the door. If it was previously locked,
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index a45dda5386e4..eea6a7cb80b5 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -173,8 +173,8 @@ int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 	*(int *)&scsi_req(rq)->cmd[1] = arg;
 	rq->special = setting->set;
 
-	if (blk_execute_rq(q, NULL, rq, 0))
-		ret = rq->errors;
+	blk_execute_rq(q, NULL, rq, 0);
+	ret = rq->errors;
 	blk_put_request(rq);
 
 	return ret;
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index 186159715b71..7c06237f3479 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -470,7 +470,6 @@ ide_devset_get(multcount, mult_count);
 static int set_multcount(ide_drive_t *drive, int arg)
 {
 	struct request *rq;
-	int error;
 
 	if (arg < 0 || arg > (drive->id[ATA_ID_MAX_MULTSECT] & 0xff))
 		return -EINVAL;
@@ -484,7 +483,7 @@ static int set_multcount(ide_drive_t *drive, int arg)
 
 	drive->mult_req = arg;
 	drive->special_flags |= IDE_SFLAG_SET_MULTMODE;
-	error = blk_execute_rq(drive->queue, NULL, rq, 0);
+	blk_execute_rq(drive->queue, NULL, rq, 0);
 	blk_put_request(rq);
 
 	return (drive->mult_count == arg) ? 0 : -EIO;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 248a3e0ceb46..3e96e531b367 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -128,7 +128,8 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 		rq = blk_get_request(drive->queue, REQ_OP_DRV_IN, __GFP_RECLAIM);
 		scsi_req_init(rq);
 		ide_req(rq)->type = ATA_PRIV_TASKFILE;
-		err = blk_execute_rq(drive->queue, NULL, rq, 0);
+		blk_execute_rq(drive->queue, NULL, rq, 0);
+		err = rq->errors ? -EIO : 0;
 		blk_put_request(rq);
 
 		return err;
@@ -227,8 +228,8 @@ static int generic_drive_reset(ide_drive_t *drive)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	scsi_req(rq)->cmd_len = 1;
 	scsi_req(rq)->cmd[0] = REQ_DRIVE_RESET;
-	if (blk_execute_rq(drive->queue, NULL, rq, 1))
-		ret = rq->errors;
+	blk_execute_rq(drive->queue, NULL, rq, 1);
+	ret = rq->errors;
 	blk_put_request(rq);
 	return ret;
 }
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index 101aed9a61ca..b4f577016f5a 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -37,7 +37,8 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	scsi_req(rq)->cmd_len = 1;
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->special = &timeout;
-	rc = blk_execute_rq(q, NULL, rq, 1);
+	blk_execute_rq(q, NULL, rq, 1);
+	rc = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 	if (rc)
 		goto out;
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index ec951be4b0c8..bf513f886f3c 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -27,7 +27,8 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 		mesg.event = PM_EVENT_FREEZE;
 	rqpm.pm_state = mesg.event;
 
-	ret = blk_execute_rq(drive->queue, NULL, rq, 0);
+	blk_execute_rq(drive->queue, NULL, rq, 0);
+	ret = rq->errors ? -EIO : 0;
 	blk_put_request(rq);
 
 	if (ret == 0 && ide_port_acpi(hwif)) {
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 4c0007cb74e3..78924c7c9478 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -452,8 +452,8 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 	rq->special = cmd;
 	cmd->rq = rq;
 
-	error = blk_execute_rq(drive->queue, NULL, rq, 0);
-
+	blk_execute_rq(drive->queue, NULL, rq, 0);
+	error = rq->errors ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 9d0727b2bdec..44e03c3eb250 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -489,7 +489,10 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
 
 int osd_execute_request(struct osd_request *or)
 {
-	int error = blk_execute_rq(or->request->q, NULL, or->request, 0);
+	int error;
+
+	blk_execute_rq(or->request->q, NULL, or->request, 0);
+	error = or->request ? -EIO : 0;
 
 	_set_error_resid(or, or->request, error);
 	return error;
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 92b4b41d19d2..9f618b77ffee 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -242,10 +242,11 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 	req->cmd[4] = bufflen & 0xff;
 	req->cmd_len = COMMAND_SIZE(INQUIRY);
 
-	error = blk_execute_rq(rq->q, NULL, rq, 1);
-	if (error) {
+	blk_execute_rq(rq->q, NULL, rq, 1);
+	if (rq->errors) {
 		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
 			rq->errors);
+		error = -EIO;
 		goto out_put_request;
 	}
 
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index fe9c512cc6fa..d8bcd51b8a47 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -969,7 +969,7 @@ extern int blk_rq_map_kern(struct request_queue *, struct request *, void *, uns
 extern int blk_rq_map_user_iov(struct request_queue *, struct request *,
 			       struct rq_map_data *, const struct iov_iter *,
 			       gfp_t);
-extern int blk_execute_rq(struct request_queue *, struct gendisk *,
+extern void blk_execute_rq(struct request_queue *, struct gendisk *,
 			  struct request *, int);
 extern void blk_execute_rq_nowait(struct request_queue *, struct gendisk *,
 				  struct request *, int, rq_end_io_fn *);
-- 
2.11.0

Re: [PATCH 02/23] block: remove the blk_execute_rq return value

[Bart Van Assche]

On Wed, 2017-04-19 at 21:26 +0200, Christoph Hellwig wrote:
> --- a/drivers/scsi/osd/osd_initiator.c
> +++ b/drivers/scsi/osd/osd_initiator.c
> @@ -489,7 +489,10 @@ static void _set_error_resid(struct osd_request *or,=
 struct request *req,
> =20
>  int osd_execute_request(struct osd_request *or)
>  {
> -	int error =3D blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	int error;
> +
> +	blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	error =3D or->request ? -EIO : 0;

Hello Christoph,

Did you perhaps intend or->request->errors instead of or->request?

Otherwise this patch looks fine to me.

Bart.=

[PATCH 02/23] block: remove the blk_execute_rq return value

[Bart Van Assche]

On Wed, 2017-04-19@21:26 +0200, Christoph Hellwig wrote:
> --- a/drivers/scsi/osd/osd_initiator.c
> +++ b/drivers/scsi/osd/osd_initiator.c
> @@ -489,7 +489,10 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
>  
>  int osd_execute_request(struct osd_request *or)
>  {
> -	int error = blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	int error;
> +
> +	blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	error = or->request ? -EIO : 0;

Hello Christoph,

Did you perhaps intend or->request->errors instead of or->request?

Otherwise this patch looks fine to me.

Bart.

Re: [PATCH 02/23] block: remove the blk_execute_rq return value

[Bart Van Assche]

On Wed, 2017-04-19 at 21:26 +0200, Christoph Hellwig wrote:
> --- a/drivers/scsi/osd/osd_initiator.c
> +++ b/drivers/scsi/osd/osd_initiator.c
> @@ -489,7 +489,10 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
>  
>  int osd_execute_request(struct osd_request *or)
>  {
> -	int error = blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	int error;
> +
> +	blk_execute_rq(or->request->q, NULL, or->request, 0);
> +	error = or->request ? -EIO : 0;

Hello Christoph,

Did you perhaps intend or->request->errors instead of or->request?

Otherwise this patch looks fine to me.

Bart.

Re: [PATCH 02/23] block: remove the blk_execute_rq return value

[hch]

On Wed, Apr 19, 2017 at 09:07:45PM +0000, Bart Van Assche wrote:
> > +	blk_execute_rq(or->request->q, NULL, or->request, 0);
> > +	error = or->request ? -EIO : 0;
> 
> Hello Christoph,
> 
> Did you perhaps intend or->request->errors instead of or->request?

Yes, thanks.

[PATCH 02/23] block: remove the blk_execute_rq return value

[hch]

On Wed, Apr 19, 2017@09:07:45PM +0000, Bart Van Assche wrote:
> > +	blk_execute_rq(or->request->q, NULL, or->request, 0);
> > +	error = or->request ? -EIO : 0;
> 
> Hello Christoph,
> 
> Did you perhaps intend or->request->errors instead of or->request?

Yes, thanks.

[PATCH 03/23] nvme-fc: fix status code handling in nvme_fc_fcpio_done

[Christoph Hellwig]

nvme_complete_async_event expects the little endian status code
including the phase bit, and a new completion handler I plan to
introduce will do so as well.

Change the status variable into the little endian format with the
phase bit used in the NVMe CQE to fix / enable this.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/nvme/host/fc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index fc42172c796a..aad7f9c0be32 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1147,7 +1147,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_fc_ctrl *ctrl = op->ctrl;
 	struct nvme_fc_queue *queue = op->queue;
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
-	u16 status = NVME_SC_SUCCESS;
+	__le16 status = cpu_to_le16(NVME_SC_SUCCESS << 1);
 
 	/*
 	 * WARNING:
@@ -1182,9 +1182,9 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 				sizeof(op->rsp_iu), DMA_FROM_DEVICE);
 
 	if (atomic_read(&op->state) == FCPOP_STATE_ABORTED)
-		status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+		status = cpu_to_le16((NVME_SC_ABORT_REQ | NVME_SC_DNR) << 1);
 	else if (freq->status)
-		status = NVME_SC_FC_TRANSPORT_ERROR;
+		status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 
 	/*
 	 * For the linux implementation, if we have an unsuccesful
@@ -1212,7 +1212,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 		 */
 		if (freq->transferred_length !=
 			be32_to_cpu(op->cmd_iu.data_len)) {
-			status = NVME_SC_FC_TRANSPORT_ERROR;
+			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
 		op->nreq.result.u64 = 0;
@@ -1229,15 +1229,15 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 					freq->transferred_length ||
 			     op->rsp_iu.status_code ||
 			     op->rqno != le16_to_cpu(cqe->command_id))) {
-			status = NVME_SC_FC_TRANSPORT_ERROR;
+			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
 		op->nreq.result = cqe->result;
-		status = le16_to_cpu(cqe->status) >> 1;
+		status = cqe->status;
 		break;
 
 	default:
-		status = NVME_SC_FC_TRANSPORT_ERROR;
+		status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 		goto done;
 	}
 
@@ -1249,7 +1249,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 		return;
 	}
 
-	blk_mq_complete_request(rq, status);
+	blk_mq_complete_request(rq, le16_to_cpu(status) >> 1);
 }
 
 static int
-- 
2.11.0

[PATCH 03/23] nvme-fc: fix status code handling in nvme_fc_fcpio_done

[Christoph Hellwig]

nvme_complete_async_event expects the little endian status code
including the phase bit, and a new completion handler I plan to
introduce will do so as well.

Change the status variable into the little endian format with the
phase bit used in the NVMe CQE to fix / enable this.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
---
 drivers/nvme/host/fc.c | 16 ++++++++--------
 1 file changed, 8 insertions(+), 8 deletions(-)

diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index fc42172c796a..aad7f9c0be32 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1147,7 +1147,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_fc_ctrl *ctrl = op->ctrl;
 	struct nvme_fc_queue *queue = op->queue;
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
-	u16 status = NVME_SC_SUCCESS;
+	__le16 status = cpu_to_le16(NVME_SC_SUCCESS << 1);
 
 	/*
 	 * WARNING:
@@ -1182,9 +1182,9 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 				sizeof(op->rsp_iu), DMA_FROM_DEVICE);
 
 	if (atomic_read(&op->state) == FCPOP_STATE_ABORTED)
-		status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+		status = cpu_to_le16((NVME_SC_ABORT_REQ | NVME_SC_DNR) << 1);
 	else if (freq->status)
-		status = NVME_SC_FC_TRANSPORT_ERROR;
+		status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 
 	/*
 	 * For the linux implementation, if we have an unsuccesful
@@ -1212,7 +1212,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 		 */
 		if (freq->transferred_length !=
 			be32_to_cpu(op->cmd_iu.data_len)) {
-			status = NVME_SC_FC_TRANSPORT_ERROR;
+			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
 		op->nreq.result.u64 = 0;
@@ -1229,15 +1229,15 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 					freq->transferred_length ||
 			     op->rsp_iu.status_code ||
 			     op->rqno != le16_to_cpu(cqe->command_id))) {
-			status = NVME_SC_FC_TRANSPORT_ERROR;
+			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
 		op->nreq.result = cqe->result;
-		status = le16_to_cpu(cqe->status) >> 1;
+		status = cqe->status;
 		break;
 
 	default:
-		status = NVME_SC_FC_TRANSPORT_ERROR;
+		status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 		goto done;
 	}
 
@@ -1249,7 +1249,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 		return;
 	}
 
-	blk_mq_complete_request(rq, status);
+	blk_mq_complete_request(rq, le16_to_cpu(status) >> 1);
 }
 
 static int
-- 
2.11.0

[PATCH 04/23] nvme: split nvme status from block req->errors

[Christoph Hellwig]

We want our own clearly defined error field for NVMe passthrough commands,
and the request errors field is going away in its current form.

Just store the status and result field in the nvme_request field from
hardirq completion context (using a new helper) and then generate a
Linux errno for the block layer only when we actually need it.

Because we can't overload the status value with a negative error code
for cancelled command we now have a flags filed in struct nvme_request
that contains a bit for this condition.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/nvme/host/core.c     | 50 +++++++++++++++++++++++++++-----------------
 drivers/nvme/host/fc.c       | 10 ++++-----
 drivers/nvme/host/lightnvm.c |  9 +++++---
 drivers/nvme/host/nvme.h     | 33 +++++++++++++----------------
 drivers/nvme/host/pci.c      | 11 +++++-----
 drivers/nvme/host/rdma.c     |  5 ++---
 drivers/nvme/target/loop.c   |  7 ++-----
 7 files changed, 65 insertions(+), 60 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d33f829c3ab7..c6f256d74b6b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -66,11 +66,24 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
+int nvme_error_status(struct request *req)
+{
+	switch (nvme_req(req)->status & 0x7ff) {
+	case NVME_SC_SUCCESS:
+		return 0;
+	case NVME_SC_CAP_EXCEEDED:
+		return -ENOSPC;
+	default:
+		return -EIO;
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_error_status);
+
 static inline bool nvme_req_needs_retry(struct request *req)
 {
 	if (blk_noretry_request(req))
 		return false;
-	if (req->errors & NVME_SC_DNR)
+	if (nvme_req(req)->status & NVME_SC_DNR)
 		return false;
 	if (jiffies - req->start_time >= req->timeout)
 		return false;
@@ -81,23 +94,13 @@ static inline bool nvme_req_needs_retry(struct request *req)
 
 void nvme_complete_rq(struct request *req)
 {
-	int error = 0;
-
-	if (unlikely(req->errors)) {
-		if (nvme_req_needs_retry(req)) {
-			nvme_req(req)->retries++;
-			blk_mq_requeue_request(req,
-					!blk_mq_queue_stopped(req->q));
-			return;
-		}
-
-		if (blk_rq_is_passthrough(req))
-			error = req->errors;
-		else
-			error = nvme_error_status(req->errors);
+	if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
+		nvme_req(req)->retries++;
+		blk_mq_requeue_request(req, !blk_mq_queue_stopped(req->q));
+		return;
 	}
 
-	blk_mq_end_request(req, error);
+	blk_mq_end_request(req, nvme_error_status(req));
 }
 EXPORT_SYMBOL_GPL(nvme_complete_rq);
 
@@ -114,7 +117,9 @@ void nvme_cancel_request(struct request *req, void *data, bool reserved)
 	status = NVME_SC_ABORT_REQ;
 	if (blk_queue_dying(req->q))
 		status |= NVME_SC_DNR;
-	blk_mq_complete_request(req, status);
+	nvme_req(req)->status = status;
+	blk_mq_complete_request(req, 0);
+
 }
 EXPORT_SYMBOL_GPL(nvme_cancel_request);
 
@@ -357,6 +362,7 @@ int nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
 		nvme_req(req)->retries = 0;
+		nvme_req(req)->flags = 0;
 		req->rq_flags |= RQF_DONTPREP;
 	}
 
@@ -413,7 +419,10 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 	blk_execute_rq(req->q, NULL, req, at_head);
 	if (result)
 		*result = nvme_req(req)->result;
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
  out:
 	blk_mq_free_request(req);
 	return ret;
@@ -498,7 +507,10 @@ int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 	}
  submit:
 	blk_execute_rq(req->q, disk, req, 0);
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
 	if (result)
 		*result = le32_to_cpu(nvme_req(req)->result.u32);
 	if (meta && !ret && !write) {
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index aad7f9c0be32..450733c8cd24 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1148,6 +1148,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_fc_queue *queue = op->queue;
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
 	__le16 status = cpu_to_le16(NVME_SC_SUCCESS << 1);
+	union nvme_result result;
 
 	/*
 	 * WARNING:
@@ -1215,7 +1216,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
-		op->nreq.result.u64 = 0;
+		result.u64 = 0;
 		break;
 
 	case sizeof(struct nvme_fc_ersp_iu):
@@ -1232,7 +1233,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
-		op->nreq.result = cqe->result;
+		result = cqe->result;
 		status = cqe->status;
 		break;
 
@@ -1243,13 +1244,12 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 
 done:
 	if (!queue->qnum && op->rqno >= AEN_CMDID_BASE) {
-		nvme_complete_async_event(&queue->ctrl->ctrl, status,
-					&op->nreq.result);
+		nvme_complete_async_event(&queue->ctrl->ctrl, status, &result);
 		nvme_fc_ctrl_put(ctrl);
 		return;
 	}
 
-	blk_mq_complete_request(rq, le16_to_cpu(status) >> 1);
+	nvme_end_request(rq, status, result);
 }
 
 static int
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 4b78090518e1..f85e6e57d641 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -484,7 +484,7 @@ static void nvme_nvm_end_io(struct request *rq, int error)
 	struct nvm_rq *rqd = rq->end_io_data;
 
 	rqd->ppa_status = nvme_req(rq)->result.u64;
-	rqd->error = error;
+	rqd->error = nvme_req(rq)->status;
 	nvm_end_io(rqd);
 
 	kfree(nvme_req(rq)->cmd);
@@ -669,9 +669,12 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 
 	wait_for_completion_io(&wait);
 
-	ret = nvme_error_status(rq->errors);
+	if (nvme_req(rq)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_error_status(rq);
 	if (result)
-		*result = rq->errors & 0x7ff;
+		*result = nvme_req(rq)->status & 0x7ff;
 	if (status)
 		*status = le64_to_cpu(nvme_req(rq)->result.u64);
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a317461c21d3..d7330f75632d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -21,16 +21,6 @@
 #include <linux/lightnvm.h>
 #include <linux/sed-opal.h>
 
-enum {
-	/*
-	 * Driver internal status code for commands that were cancelled due
-	 * to timeouts or controller shutdown.  The value is negative so
-	 * that it a) doesn't overlap with the unsigned hardware error codes,
-	 * and b) can easily be tested for.
-	 */
-	NVME_SC_CANCELLED		= -EINTR,
-};
-
 extern unsigned char nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)
 
@@ -91,6 +81,12 @@ struct nvme_request {
 	struct nvme_command	*cmd;
 	union nvme_result	result;
 	u8			retries;
+	u8			flags;
+	u16			status;
+};
+
+enum {
+	NVME_REQ_CANCELLED		= (1 << 0),
 };
 
 static inline struct nvme_request *nvme_req(struct request *req)
@@ -248,18 +244,17 @@ static inline void nvme_cleanup_cmd(struct request *req)
 	}
 }
 
-static inline int nvme_error_status(u16 status)
+static inline void nvme_end_request(struct request *req, __le16 status,
+		union nvme_result result)
 {
-	switch (status & 0x7ff) {
-	case NVME_SC_SUCCESS:
-		return 0;
-	case NVME_SC_CAP_EXCEEDED:
-		return -ENOSPC;
-	default:
-		return -EIO;
-	}
+	struct nvme_request *rq = nvme_req(req);
+
+	rq->status = le16_to_cpu(status) >> 1;
+	rq->result = result;
+	blk_mq_complete_request(req, 0);
 }
 
+int nvme_error_status(struct request *req);
 void nvme_complete_rq(struct request *req);
 void nvme_cancel_request(struct request *req, void *data, bool reserved);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f7a9f3fb5fdb..d9e2bd07ed56 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -679,8 +679,7 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 		}
 
 		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
-		nvme_req(req)->result = cqe.result;
-		blk_mq_complete_request(req, le16_to_cpu(cqe.status) >> 1);
+		nvme_end_request(req, cqe.status, cqe.result);
 	}
 
 	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
@@ -817,9 +816,9 @@ static void abort_endio(struct request *req, int error)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = iod->nvmeq;
-	u16 status = req->errors;
 
-	dev_warn(nvmeq->dev->ctrl.device, "Abort status: 0x%x", status);
+	dev_warn(nvmeq->dev->ctrl.device,
+		 "Abort status: 0x%x", nvme_req(req)->status);
 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
 	blk_mq_free_request(req);
 }
@@ -843,7 +842,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 			 "I/O %d QID %d timeout, disable controller\n",
 			 req->tag, nvmeq->qid);
 		nvme_dev_disable(dev, false);
-		req->errors = NVME_SC_CANCELLED;
+		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
 		return BLK_EH_HANDLED;
 	}
 
@@ -863,7 +862,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 		 * Mark the request as handled, since the inline shutdown
 		 * forces all outstanding requests to complete.
 		 */
-		req->errors = NVME_SC_CANCELLED;
+		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
 		return BLK_EH_HANDLED;
 	}
 
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 4aae363943e3..53b611f9ba5d 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1178,8 +1178,7 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
 	    wc->ex.invalidate_rkey == req->mr->rkey)
 		req->mr->need_inval = false;
 
-	req->req.result = cqe->result;
-	blk_mq_complete_request(rq, le16_to_cpu(cqe->status) >> 1);
+	nvme_end_request(rq, cqe->status, cqe->result);
 	return ret;
 }
 
@@ -1416,7 +1415,7 @@ nvme_rdma_timeout(struct request *rq, bool reserved)
 	nvme_rdma_error_recovery(req->queue->ctrl);
 
 	/* fail with DNR on cmd timeout */
-	rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+	nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 
 	return BLK_EH_HANDLED;
 }
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index 33b431e4eec3..8260ee1f8e48 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -124,7 +124,6 @@ static void nvme_loop_queue_response(struct nvmet_req *req)
 				&cqe->result);
 	} else {
 		struct request *rq;
-		struct nvme_loop_iod *iod;
 
 		rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 		if (!rq) {
@@ -134,9 +133,7 @@ static void nvme_loop_queue_response(struct nvmet_req *req)
 			return;
 		}
 
-		iod = blk_mq_rq_to_pdu(rq);
-		iod->nvme_req.result = cqe->result;
-		blk_mq_complete_request(rq, le16_to_cpu(cqe->status) >> 1);
+		nvme_end_request(rq, cqe->status, cqe->result);
 	}
 }
 
@@ -157,7 +154,7 @@ nvme_loop_timeout(struct request *rq, bool reserved)
 	schedule_work(&iod->queue->ctrl->reset_work);
 
 	/* fail with DNR on admin cmd timeout */
-	rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+	nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 
 	return BLK_EH_HANDLED;
 }
-- 
2.11.0

[PATCH 04/23] nvme: split nvme status from block req->errors

[Christoph Hellwig]

We want our own clearly defined error field for NVMe passthrough commands,
and the request errors field is going away in its current form.

Just store the status and result field in the nvme_request field from
hardirq completion context (using a new helper) and then generate a
Linux errno for the block layer only when we actually need it.

Because we can't overload the status value with a negative error code
for cancelled command we now have a flags filed in struct nvme_request
that contains a bit for this condition.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
---
 drivers/nvme/host/core.c     | 50 +++++++++++++++++++++++++++-----------------
 drivers/nvme/host/fc.c       | 10 ++++-----
 drivers/nvme/host/lightnvm.c |  9 +++++---
 drivers/nvme/host/nvme.h     | 33 +++++++++++++----------------
 drivers/nvme/host/pci.c      | 11 +++++-----
 drivers/nvme/host/rdma.c     |  5 ++---
 drivers/nvme/target/loop.c   |  7 ++-----
 7 files changed, 65 insertions(+), 60 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index d33f829c3ab7..c6f256d74b6b 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -66,11 +66,24 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
+int nvme_error_status(struct request *req)
+{
+	switch (nvme_req(req)->status & 0x7ff) {
+	case NVME_SC_SUCCESS:
+		return 0;
+	case NVME_SC_CAP_EXCEEDED:
+		return -ENOSPC;
+	default:
+		return -EIO;
+	}
+}
+EXPORT_SYMBOL_GPL(nvme_error_status);
+
 static inline bool nvme_req_needs_retry(struct request *req)
 {
 	if (blk_noretry_request(req))
 		return false;
-	if (req->errors & NVME_SC_DNR)
+	if (nvme_req(req)->status & NVME_SC_DNR)
 		return false;
 	if (jiffies - req->start_time >= req->timeout)
 		return false;
@@ -81,23 +94,13 @@ static inline bool nvme_req_needs_retry(struct request *req)
 
 void nvme_complete_rq(struct request *req)
 {
-	int error = 0;
-
-	if (unlikely(req->errors)) {
-		if (nvme_req_needs_retry(req)) {
-			nvme_req(req)->retries++;
-			blk_mq_requeue_request(req,
-					!blk_mq_queue_stopped(req->q));
-			return;
-		}
-
-		if (blk_rq_is_passthrough(req))
-			error = req->errors;
-		else
-			error = nvme_error_status(req->errors);
+	if (unlikely(nvme_req(req)->status && nvme_req_needs_retry(req))) {
+		nvme_req(req)->retries++;
+		blk_mq_requeue_request(req, !blk_mq_queue_stopped(req->q));
+		return;
 	}
 
-	blk_mq_end_request(req, error);
+	blk_mq_end_request(req, nvme_error_status(req));
 }
 EXPORT_SYMBOL_GPL(nvme_complete_rq);
 
@@ -114,7 +117,9 @@ void nvme_cancel_request(struct request *req, void *data, bool reserved)
 	status = NVME_SC_ABORT_REQ;
 	if (blk_queue_dying(req->q))
 		status |= NVME_SC_DNR;
-	blk_mq_complete_request(req, status);
+	nvme_req(req)->status = status;
+	blk_mq_complete_request(req, 0);
+
 }
 EXPORT_SYMBOL_GPL(nvme_cancel_request);
 
@@ -357,6 +362,7 @@ int nvme_setup_cmd(struct nvme_ns *ns, struct request *req,
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
 		nvme_req(req)->retries = 0;
+		nvme_req(req)->flags = 0;
 		req->rq_flags |= RQF_DONTPREP;
 	}
 
@@ -413,7 +419,10 @@ int __nvme_submit_sync_cmd(struct request_queue *q, struct nvme_command *cmd,
 	blk_execute_rq(req->q, NULL, req, at_head);
 	if (result)
 		*result = nvme_req(req)->result;
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
  out:
 	blk_mq_free_request(req);
 	return ret;
@@ -498,7 +507,10 @@ int __nvme_submit_user_cmd(struct request_queue *q, struct nvme_command *cmd,
 	}
  submit:
 	blk_execute_rq(req->q, disk, req, 0);
-	ret = req->errors;
+	if (nvme_req(req)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_req(req)->status;
 	if (result)
 		*result = le32_to_cpu(nvme_req(req)->result.u32);
 	if (meta && !ret && !write) {
diff --git a/drivers/nvme/host/fc.c b/drivers/nvme/host/fc.c
index aad7f9c0be32..450733c8cd24 100644
--- a/drivers/nvme/host/fc.c
+++ b/drivers/nvme/host/fc.c
@@ -1148,6 +1148,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 	struct nvme_fc_queue *queue = op->queue;
 	struct nvme_completion *cqe = &op->rsp_iu.cqe;
 	__le16 status = cpu_to_le16(NVME_SC_SUCCESS << 1);
+	union nvme_result result;
 
 	/*
 	 * WARNING:
@@ -1215,7 +1216,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
-		op->nreq.result.u64 = 0;
+		result.u64 = 0;
 		break;
 
 	case sizeof(struct nvme_fc_ersp_iu):
@@ -1232,7 +1233,7 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 			status = cpu_to_le16(NVME_SC_FC_TRANSPORT_ERROR << 1);
 			goto done;
 		}
-		op->nreq.result = cqe->result;
+		result = cqe->result;
 		status = cqe->status;
 		break;
 
@@ -1243,13 +1244,12 @@ nvme_fc_fcpio_done(struct nvmefc_fcp_req *req)
 
 done:
 	if (!queue->qnum && op->rqno >= AEN_CMDID_BASE) {
-		nvme_complete_async_event(&queue->ctrl->ctrl, status,
-					&op->nreq.result);
+		nvme_complete_async_event(&queue->ctrl->ctrl, status, &result);
 		nvme_fc_ctrl_put(ctrl);
 		return;
 	}
 
-	blk_mq_complete_request(rq, le16_to_cpu(status) >> 1);
+	nvme_end_request(rq, status, result);
 }
 
 static int
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index 4b78090518e1..f85e6e57d641 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -484,7 +484,7 @@ static void nvme_nvm_end_io(struct request *rq, int error)
 	struct nvm_rq *rqd = rq->end_io_data;
 
 	rqd->ppa_status = nvme_req(rq)->result.u64;
-	rqd->error = error;
+	rqd->error = nvme_req(rq)->status;
 	nvm_end_io(rqd);
 
 	kfree(nvme_req(rq)->cmd);
@@ -669,9 +669,12 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 
 	wait_for_completion_io(&wait);
 
-	ret = nvme_error_status(rq->errors);
+	if (nvme_req(rq)->flags & NVME_REQ_CANCELLED)
+		ret = -EINTR;
+	else
+		ret = nvme_error_status(rq);
 	if (result)
-		*result = rq->errors & 0x7ff;
+		*result = nvme_req(rq)->status & 0x7ff;
 	if (status)
 		*status = le64_to_cpu(nvme_req(rq)->result.u64);
 
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index a317461c21d3..d7330f75632d 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -21,16 +21,6 @@
 #include <linux/lightnvm.h>
 #include <linux/sed-opal.h>
 
-enum {
-	/*
-	 * Driver internal status code for commands that were cancelled due
-	 * to timeouts or controller shutdown.  The value is negative so
-	 * that it a) doesn't overlap with the unsigned hardware error codes,
-	 * and b) can easily be tested for.
-	 */
-	NVME_SC_CANCELLED		= -EINTR,
-};
-
 extern unsigned char nvme_io_timeout;
 #define NVME_IO_TIMEOUT	(nvme_io_timeout * HZ)
 
@@ -91,6 +81,12 @@ struct nvme_request {
 	struct nvme_command	*cmd;
 	union nvme_result	result;
 	u8			retries;
+	u8			flags;
+	u16			status;
+};
+
+enum {
+	NVME_REQ_CANCELLED		= (1 << 0),
 };
 
 static inline struct nvme_request *nvme_req(struct request *req)
@@ -248,18 +244,17 @@ static inline void nvme_cleanup_cmd(struct request *req)
 	}
 }
 
-static inline int nvme_error_status(u16 status)
+static inline void nvme_end_request(struct request *req, __le16 status,
+		union nvme_result result)
 {
-	switch (status & 0x7ff) {
-	case NVME_SC_SUCCESS:
-		return 0;
-	case NVME_SC_CAP_EXCEEDED:
-		return -ENOSPC;
-	default:
-		return -EIO;
-	}
+	struct nvme_request *rq = nvme_req(req);
+
+	rq->status = le16_to_cpu(status) >> 1;
+	rq->result = result;
+	blk_mq_complete_request(req, 0);
 }
 
+int nvme_error_status(struct request *req);
 void nvme_complete_rq(struct request *req);
 void nvme_cancel_request(struct request *req, void *data, bool reserved);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
diff --git a/drivers/nvme/host/pci.c b/drivers/nvme/host/pci.c
index f7a9f3fb5fdb..d9e2bd07ed56 100644
--- a/drivers/nvme/host/pci.c
+++ b/drivers/nvme/host/pci.c
@@ -679,8 +679,7 @@ static void __nvme_process_cq(struct nvme_queue *nvmeq, unsigned int *tag)
 		}
 
 		req = blk_mq_tag_to_rq(*nvmeq->tags, cqe.command_id);
-		nvme_req(req)->result = cqe.result;
-		blk_mq_complete_request(req, le16_to_cpu(cqe.status) >> 1);
+		nvme_end_request(req, cqe.status, cqe.result);
 	}
 
 	if (head == nvmeq->cq_head && phase == nvmeq->cq_phase)
@@ -817,9 +816,9 @@ static void abort_endio(struct request *req, int error)
 {
 	struct nvme_iod *iod = blk_mq_rq_to_pdu(req);
 	struct nvme_queue *nvmeq = iod->nvmeq;
-	u16 status = req->errors;
 
-	dev_warn(nvmeq->dev->ctrl.device, "Abort status: 0x%x", status);
+	dev_warn(nvmeq->dev->ctrl.device,
+		 "Abort status: 0x%x", nvme_req(req)->status);
 	atomic_inc(&nvmeq->dev->ctrl.abort_limit);
 	blk_mq_free_request(req);
 }
@@ -843,7 +842,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 			 "I/O %d QID %d timeout, disable controller\n",
 			 req->tag, nvmeq->qid);
 		nvme_dev_disable(dev, false);
-		req->errors = NVME_SC_CANCELLED;
+		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
 		return BLK_EH_HANDLED;
 	}
 
@@ -863,7 +862,7 @@ static enum blk_eh_timer_return nvme_timeout(struct request *req, bool reserved)
 		 * Mark the request as handled, since the inline shutdown
 		 * forces all outstanding requests to complete.
 		 */
-		req->errors = NVME_SC_CANCELLED;
+		nvme_req(req)->flags |= NVME_REQ_CANCELLED;
 		return BLK_EH_HANDLED;
 	}
 
diff --git a/drivers/nvme/host/rdma.c b/drivers/nvme/host/rdma.c
index 4aae363943e3..53b611f9ba5d 100644
--- a/drivers/nvme/host/rdma.c
+++ b/drivers/nvme/host/rdma.c
@@ -1178,8 +1178,7 @@ static int nvme_rdma_process_nvme_rsp(struct nvme_rdma_queue *queue,
 	    wc->ex.invalidate_rkey == req->mr->rkey)
 		req->mr->need_inval = false;
 
-	req->req.result = cqe->result;
-	blk_mq_complete_request(rq, le16_to_cpu(cqe->status) >> 1);
+	nvme_end_request(rq, cqe->status, cqe->result);
 	return ret;
 }
 
@@ -1416,7 +1415,7 @@ nvme_rdma_timeout(struct request *rq, bool reserved)
 	nvme_rdma_error_recovery(req->queue->ctrl);
 
 	/* fail with DNR on cmd timeout */
-	rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+	nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 
 	return BLK_EH_HANDLED;
 }
diff --git a/drivers/nvme/target/loop.c b/drivers/nvme/target/loop.c
index 33b431e4eec3..8260ee1f8e48 100644
--- a/drivers/nvme/target/loop.c
+++ b/drivers/nvme/target/loop.c
@@ -124,7 +124,6 @@ static void nvme_loop_queue_response(struct nvmet_req *req)
 				&cqe->result);
 	} else {
 		struct request *rq;
-		struct nvme_loop_iod *iod;
 
 		rq = blk_mq_tag_to_rq(nvme_loop_tagset(queue), cqe->command_id);
 		if (!rq) {
@@ -134,9 +133,7 @@ static void nvme_loop_queue_response(struct nvmet_req *req)
 			return;
 		}
 
-		iod = blk_mq_rq_to_pdu(rq);
-		iod->nvme_req.result = cqe->result;
-		blk_mq_complete_request(rq, le16_to_cpu(cqe->status) >> 1);
+		nvme_end_request(rq, cqe->status, cqe->result);
 	}
 }
 
@@ -157,7 +154,7 @@ nvme_loop_timeout(struct request *rq, bool reserved)
 	schedule_work(&iod->queue->ctrl->reset_work);
 
 	/* fail with DNR on admin cmd timeout */
-	rq->errors = NVME_SC_ABORT_REQ | NVME_SC_DNR;
+	nvme_req(rq)->status = NVME_SC_ABORT_REQ | NVME_SC_DNR;
 
 	return BLK_EH_HANDLED;
 }
-- 
2.11.0

[PATCH 05/23] nvme: make nvme_error_status private

[Christoph Hellwig]

Currently it's used by the lighnvm passthrough ioctl, but we'd like to make
it private in preparation of block layer specific error code.  Lighnvm already
returns the real NVMe status anyway, so I think we can just limit it to
returning -EIO for any status set.

This will need a careful audit from the lightnvm folks, though.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/nvme/host/core.c     | 3 +--
 drivers/nvme/host/lightnvm.c | 6 +++---
 drivers/nvme/host/nvme.h     | 1 -
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c6f256d74b6b..805f250315ec 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -66,7 +66,7 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
-int nvme_error_status(struct request *req)
+static int nvme_error_status(struct request *req)
 {
 	switch (nvme_req(req)->status & 0x7ff) {
 	case NVME_SC_SUCCESS:
@@ -77,7 +77,6 @@ int nvme_error_status(struct request *req)
 		return -EIO;
 	}
 }
-EXPORT_SYMBOL_GPL(nvme_error_status);
 
 static inline bool nvme_req_needs_retry(struct request *req)
 {
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index f85e6e57d641..7f407d5f0095 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -599,7 +599,7 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 	__le64 *metadata = NULL;
 	dma_addr_t metadata_dma;
 	DECLARE_COMPLETION_ONSTACK(wait);
-	int ret;
+	int ret = 0;
 
 	rq = nvme_alloc_request(q, (struct nvme_command *)vcmd, 0,
 			NVME_QID_ANY);
@@ -671,8 +671,8 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 
 	if (nvme_req(rq)->flags & NVME_REQ_CANCELLED)
 		ret = -EINTR;
-	else
-		ret = nvme_error_status(rq);
+	else if (nvme_req(rq)->status & 0x7ff)
+		ret = -EIO;
 	if (result)
 		*result = nvme_req(rq)->status & 0x7ff;
 	if (status)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index d7330f75632d..550037f5efea 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -254,7 +254,6 @@ static inline void nvme_end_request(struct request *req, __le16 status,
 	blk_mq_complete_request(req, 0);
 }
 
-int nvme_error_status(struct request *req);
 void nvme_complete_rq(struct request *req);
 void nvme_cancel_request(struct request *req, void *data, bool reserved);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
-- 
2.11.0

[PATCH 05/23] nvme: make nvme_error_status private

[Christoph Hellwig]

Currently it's used by the lighnvm passthrough ioctl, but we'd like to make
it private in preparation of block layer specific error code.  Lighnvm already
returns the real NVMe status anyway, so I think we can just limit it to
returning -EIO for any status set.

This will need a careful audit from the lightnvm folks, though.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/nvme/host/core.c     | 3 +--
 drivers/nvme/host/lightnvm.c | 6 +++---
 drivers/nvme/host/nvme.h     | 1 -
 3 files changed, 4 insertions(+), 6 deletions(-)

diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index c6f256d74b6b..805f250315ec 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -66,7 +66,7 @@ static DEFINE_SPINLOCK(dev_list_lock);
 
 static struct class *nvme_class;
 
-int nvme_error_status(struct request *req)
+static int nvme_error_status(struct request *req)
 {
 	switch (nvme_req(req)->status & 0x7ff) {
 	case NVME_SC_SUCCESS:
@@ -77,7 +77,6 @@ int nvme_error_status(struct request *req)
 		return -EIO;
 	}
 }
-EXPORT_SYMBOL_GPL(nvme_error_status);
 
 static inline bool nvme_req_needs_retry(struct request *req)
 {
diff --git a/drivers/nvme/host/lightnvm.c b/drivers/nvme/host/lightnvm.c
index f85e6e57d641..7f407d5f0095 100644
--- a/drivers/nvme/host/lightnvm.c
+++ b/drivers/nvme/host/lightnvm.c
@@ -599,7 +599,7 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 	__le64 *metadata = NULL;
 	dma_addr_t metadata_dma;
 	DECLARE_COMPLETION_ONSTACK(wait);
-	int ret;
+	int ret = 0;
 
 	rq = nvme_alloc_request(q, (struct nvme_command *)vcmd, 0,
 			NVME_QID_ANY);
@@ -671,8 +671,8 @@ static int nvme_nvm_submit_user_cmd(struct request_queue *q,
 
 	if (nvme_req(rq)->flags & NVME_REQ_CANCELLED)
 		ret = -EINTR;
-	else
-		ret = nvme_error_status(rq);
+	else if (nvme_req(rq)->status & 0x7ff)
+		ret = -EIO;
 	if (result)
 		*result = nvme_req(rq)->status & 0x7ff;
 	if (status)
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index d7330f75632d..550037f5efea 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -254,7 +254,6 @@ static inline void nvme_end_request(struct request *req, __le16 status,
 	blk_mq_complete_request(req, 0);
 }
 
-int nvme_error_status(struct request *req);
 void nvme_complete_rq(struct request *req);
 void nvme_cancel_request(struct request *req, void *data, bool reserved);
 bool nvme_change_ctrl_state(struct nvme_ctrl *ctrl,
-- 
2.11.0

[PATCH 06/23] virtio: fix spelling of virtblk_scsi_request_done

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
---
 drivers/block/virtio_blk.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index eaf99022bdc6..dbc4e80680b1 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -111,7 +111,7 @@ static int virtblk_add_req_scsi(struct virtqueue *vq, struct virtblk_req *vbr,
 	return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
 }
 
-static inline void virtblk_scsi_reques_done(struct request *req)
+static inline void virtblk_scsi_request_done(struct request *req)
 {
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 	struct virtio_blk *vblk = req->q->queuedata;
@@ -144,7 +144,7 @@ static inline int virtblk_add_req_scsi(struct virtqueue *vq,
 {
 	return -EIO;
 }
-static inline void virtblk_scsi_reques_done(struct request *req)
+static inline void virtblk_scsi_request_done(struct request *req)
 {
 }
 #define virtblk_ioctl	NULL
@@ -180,7 +180,7 @@ static inline void virtblk_request_done(struct request *req)
 	switch (req_op(req)) {
 	case REQ_OP_SCSI_IN:
 	case REQ_OP_SCSI_OUT:
-		virtblk_scsi_reques_done(req);
+		virtblk_scsi_request_done(req);
 		break;
 	case REQ_OP_DRV_IN:
 		req->errors = (error != 0);
-- 
2.11.0

[PATCH 06/23] virtio: fix spelling of virtblk_scsi_request_done

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche at sandisk.com>
---
 drivers/block/virtio_blk.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index eaf99022bdc6..dbc4e80680b1 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -111,7 +111,7 @@ static int virtblk_add_req_scsi(struct virtqueue *vq, struct virtblk_req *vbr,
 	return virtqueue_add_sgs(vq, sgs, num_out, num_in, vbr, GFP_ATOMIC);
 }
 
-static inline void virtblk_scsi_reques_done(struct request *req)
+static inline void virtblk_scsi_request_done(struct request *req)
 {
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
 	struct virtio_blk *vblk = req->q->queuedata;
@@ -144,7 +144,7 @@ static inline int virtblk_add_req_scsi(struct virtqueue *vq,
 {
 	return -EIO;
 }
-static inline void virtblk_scsi_reques_done(struct request *req)
+static inline void virtblk_scsi_request_done(struct request *req)
 {
 }
 #define virtblk_ioctl	NULL
@@ -180,7 +180,7 @@ static inline void virtblk_request_done(struct request *req)
 	switch (req_op(req)) {
 	case REQ_OP_SCSI_IN:
 	case REQ_OP_SCSI_OUT:
-		virtblk_scsi_reques_done(req);
+		virtblk_scsi_request_done(req);
 		break;
 	case REQ_OP_DRV_IN:
 		req->errors = (error != 0);
-- 
2.11.0

[PATCH 07/23] virtio_blk: don't use req->errors

[Christoph Hellwig]

Remove passing req->errors (which at that point is always 0) to
blk_mq_complete_request, and rely on the virtio status code for the
serial number passthrough request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
---
 drivers/block/virtio_blk.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index dbc4e80680b1..8378ad480f77 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -175,19 +175,15 @@ static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
 static inline void virtblk_request_done(struct request *req)
 {
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
-	int error = virtblk_result(vbr);
 
 	switch (req_op(req)) {
 	case REQ_OP_SCSI_IN:
 	case REQ_OP_SCSI_OUT:
 		virtblk_scsi_request_done(req);
 		break;
-	case REQ_OP_DRV_IN:
-		req->errors = (error != 0);
-		break;
 	}
 
-	blk_mq_end_request(req, error);
+	blk_mq_end_request(req, virtblk_result(vbr));
 }
 
 static void virtblk_done(struct virtqueue *vq)
@@ -205,7 +201,7 @@ static void virtblk_done(struct virtqueue *vq)
 		while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
 			struct request *req = blk_mq_rq_from_pdu(vbr);
 
-			blk_mq_complete_request(req, req->errors);
+			blk_mq_complete_request(req, 0);
 			req_done = true;
 		}
 		if (unlikely(virtqueue_is_broken(vq)))
@@ -311,7 +307,7 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
 		goto out;
 
 	blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
-	err = req->errors ? -EIO : 0;
+	err = virtblk_result(blk_mq_rq_to_pdu(req));
 out:
 	blk_put_request(req);
 	return err;
-- 
2.11.0

[PATCH 07/23] virtio_blk: don't use req->errors

[Christoph Hellwig]

Remove passing req->errors (which at that point is always 0) to
blk_mq_complete_request, and rely on the virtio status code for the
serial number passthrough request.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
---
 drivers/block/virtio_blk.c | 10 +++-------
 1 file changed, 3 insertions(+), 7 deletions(-)

diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index dbc4e80680b1..8378ad480f77 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -175,19 +175,15 @@ static int virtblk_add_req(struct virtqueue *vq, struct virtblk_req *vbr,
 static inline void virtblk_request_done(struct request *req)
 {
 	struct virtblk_req *vbr = blk_mq_rq_to_pdu(req);
-	int error = virtblk_result(vbr);
 
 	switch (req_op(req)) {
 	case REQ_OP_SCSI_IN:
 	case REQ_OP_SCSI_OUT:
 		virtblk_scsi_request_done(req);
 		break;
-	case REQ_OP_DRV_IN:
-		req->errors = (error != 0);
-		break;
 	}
 
-	blk_mq_end_request(req, error);
+	blk_mq_end_request(req, virtblk_result(vbr));
 }
 
 static void virtblk_done(struct virtqueue *vq)
@@ -205,7 +201,7 @@ static void virtblk_done(struct virtqueue *vq)
 		while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
 			struct request *req = blk_mq_rq_from_pdu(vbr);
 
-			blk_mq_complete_request(req, req->errors);
+			blk_mq_complete_request(req, 0);
 			req_done = true;
 		}
 		if (unlikely(virtqueue_is_broken(vq)))
@@ -311,7 +307,7 @@ static int virtblk_get_id(struct gendisk *disk, char *id_str)
 		goto out;
 
 	blk_execute_rq(vblk->disk->queue, vblk->disk, req, false);
-	err = req->errors ? -EIO : 0;
+	err = virtblk_result(blk_mq_rq_to_pdu(req));
 out:
 	blk_put_request(req);
 	return err;
-- 
2.11.0

[PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Christoph Hellwig]

This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/bsg-lib.c                    |  8 ++++----
 block/bsg.c                        | 12 +++++------
 block/scsi_ioctl.c                 | 14 ++++++-------
 drivers/block/cciss.c              | 42 +++++++++++++++++++-------------------
 drivers/block/pktcdvd.c            |  2 +-
 drivers/block/virtio_blk.c         |  2 +-
 drivers/cdrom/cdrom.c              |  2 +-
 drivers/ide/ide-atapi.c            | 10 ++++-----
 drivers/ide/ide-cd.c               | 20 +++++++++---------
 drivers/ide/ide-cd_ioctl.c         |  2 +-
 drivers/ide/ide-devsets.c          |  4 ++--
 drivers/ide/ide-dma.c              |  2 +-
 drivers/ide/ide-eh.c               | 36 ++++++++++++++++----------------
 drivers/ide/ide-floppy.c           | 10 ++++-----
 drivers/ide/ide-io.c               | 10 ++++-----
 drivers/ide/ide-ioctls.c           |  4 ++--
 drivers/ide/ide-park.c             |  2 +-
 drivers/ide/ide-pm.c               |  8 ++++----
 drivers/ide/ide-tape.c             |  4 ++--
 drivers/ide/ide-taskfile.c         |  6 +++---
 drivers/scsi/osd/osd_initiator.c   |  2 +-
 drivers/scsi/osst.c                |  2 +-
 drivers/scsi/qla2xxx/qla_bsg.c     |  6 +++---
 drivers/scsi/scsi_lib.c            | 15 +++++++-------
 drivers/scsi/scsi_transport_sas.c  |  2 +-
 drivers/scsi/sg.c                  |  2 +-
 drivers/scsi/st.c                  |  6 +++---
 drivers/target/target_core_pscsi.c |  2 +-
 fs/nfsd/blocklayout.c              |  4 ++--
 include/linux/ide.h                |  2 +-
 include/scsi/scsi_request.h        |  1 +
 31 files changed, 122 insertions(+), 122 deletions(-)

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index cd15f9dbb147..0a23dbba2d30 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -37,7 +37,7 @@ static void bsg_destroy_job(struct kref *kref)
 	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
 	struct request *rq = job->req;
 
-	blk_end_request_all(rq, rq->errors);
+	blk_end_request_all(rq, scsi_req(rq)->result);
 
 	put_device(job->dev);	/* release reference for the request */
 
@@ -74,7 +74,7 @@ void bsg_job_done(struct bsg_job *job, int result,
 	struct scsi_request *rq = scsi_req(req);
 	int err;
 
-	err = job->req->errors = result;
+	err = scsi_req(job->req)->result = result;
 	if (err < 0)
 		/* we're only returning the result field in the reply */
 		rq->sense_len = sizeof(u32);
@@ -177,7 +177,7 @@ static int bsg_create_job(struct device *dev, struct request *req)
  * @q: request queue to manage
  *
  * On error the create_bsg_job function should return a -Exyz error value
- * that will be set to the req->errors.
+ * that will be set to ->result.
  *
  * Drivers/subsys should pass this to the queue init function.
  */
@@ -201,7 +201,7 @@ static void bsg_request_fn(struct request_queue *q)
 
 		ret = bsg_create_job(dev, req);
 		if (ret) {
-			req->errors = ret;
+			scsi_req(req)->result = ret;
 			blk_end_request_all(req, ret);
 			spin_lock_irq(q->queue_lock);
 			continue;
diff --git a/block/bsg.c b/block/bsg.c
index 74835dbf0c47..d9da1b613ced 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -391,13 +391,13 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	struct scsi_request *req = scsi_req(rq);
 	int ret = 0;
 
-	dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
+	dprintk("rq %p bio %p 0x%x\n", rq, bio, req->result);
 	/*
 	 * fill in all the output members
 	 */
-	hdr->device_status = rq->errors & 0xff;
-	hdr->transport_status = host_byte(rq->errors);
-	hdr->driver_status = driver_byte(rq->errors);
+	hdr->device_status = req->result & 0xff;
+	hdr->transport_status = host_byte(req->result);
+	hdr->driver_status = driver_byte(req->result);
 	hdr->info = 0;
 	if (hdr->device_status || hdr->transport_status || hdr->driver_status)
 		hdr->info |= SG_INFO_CHECK;
@@ -431,8 +431,8 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	 * just a protocol response (i.e. non negative), that gets
 	 * processed above.
 	 */
-	if (!ret && rq->errors < 0)
-		ret = rq->errors;
+	if (!ret && req->result < 0)
+		ret = req->result;
 
 	blk_rq_unmap_user(bio);
 	scsi_req_free_cmd(req);
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index b1352143f12f..4a294a5f7fab 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -262,11 +262,11 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
 	/*
 	 * fill in all the output members
 	 */
-	hdr->status = rq->errors & 0xff;
-	hdr->masked_status = status_byte(rq->errors);
-	hdr->msg_status = msg_byte(rq->errors);
-	hdr->host_status = host_byte(rq->errors);
-	hdr->driver_status = driver_byte(rq->errors);
+	hdr->status = req->result & 0xff;
+	hdr->masked_status = status_byte(req->result);
+	hdr->msg_status = msg_byte(req->result);
+	hdr->host_status = host_byte(req->result);
+	hdr->driver_status = driver_byte(req->result);
 	hdr->info = 0;
 	if (hdr->masked_status || hdr->host_status || hdr->driver_status)
 		hdr->info |= SG_INFO_CHECK;
@@ -509,7 +509,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 
 	blk_execute_rq(q, disk, rq, 0);
 
-	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
+	err = req->result & 0xff;	/* only 8 bit SCSI status */
 	if (err) {
 		if (req->sense_len && req->sense) {
 			bytes = (OMAX_SB_LEN > req->sense_len) ?
@@ -548,7 +548,7 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	scsi_req(rq)->cmd[4] = data;
 	scsi_req(rq)->cmd_len = 6;
 	blk_execute_rq(q, bd_disk, rq, 0);
-	err = rq->errors ? -EIO : 0;
+	err = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 
 	return err;
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 8e1a4554951c..cd375503f7b0 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1864,8 +1864,7 @@ static void cciss_softirq_done(struct request *rq)
 	/* set the residual count for pc requests */
 	if (blk_rq_is_passthrough(rq))
 		scsi_req(rq)->resid_len = c->err_info->ResidualCnt;
-
-	blk_end_request_all(rq, (rq->errors == 0) ? 0 : -EIO);
+	blk_end_request_all(rq, scsi_req(rq)->result ? -EIO : 0);
 
 	spin_lock_irqsave(&h->lock, flags);
 	cmd_free(h, c);
@@ -3140,18 +3139,19 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 {
 	int retry_cmd = 0;
 	struct request *rq = cmd->rq;
+	struct scsi_request *sreq = scsi_req(rq);
 
-	rq->errors = 0;
+	sreq->result = 0;
 
 	if (timeout)
-		rq->errors = make_status_bytes(0, 0, 0, DRIVER_TIMEOUT);
+		sreq->result = make_status_bytes(0, 0, 0, DRIVER_TIMEOUT);
 
 	if (cmd->err_info->CommandStatus == 0)	/* no error has occurred */
 		goto after_error_processing;
 
 	switch (cmd->err_info->CommandStatus) {
 	case CMD_TARGET_STATUS:
-		rq->errors = evaluate_target_status(h, cmd, &retry_cmd);
+		sreq->result = evaluate_target_status(h, cmd, &retry_cmd);
 		break;
 	case CMD_DATA_UNDERRUN:
 		if (!blk_rq_is_passthrough(cmd->rq)) {
@@ -3169,7 +3169,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_INVALID:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p is "
 		       "reported invalid\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3177,7 +3177,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_PROTOCOL_ERR:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p has "
 		       "protocol error\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3185,7 +3185,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_HARDWARE_ERR:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p had "
 		       " hardware error\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3193,7 +3193,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_CONNECTION_LOST:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p had "
 		       "connection lost\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3201,7 +3201,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_ABORTED:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p was "
 		       "aborted\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ABORT);
@@ -3209,7 +3209,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_ABORT_FAILED:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p reports "
 		       "abort failed\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3224,21 +3224,21 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 		} else
 			dev_warn(&h->pdev->dev,
 				"%p retried too many times\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ABORT);
 		break;
 	case CMD_TIMEOUT:
 		dev_warn(&h->pdev->dev, "cmd %p timedout\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
 		break;
 	case CMD_UNABORTABLE:
 		dev_warn(&h->pdev->dev, "cmd %p unabortable\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3247,7 +3247,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 		dev_warn(&h->pdev->dev, "cmd %p returned "
 		       "unknown status %x\n", cmd,
 		       cmd->err_info->CommandStatus);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3380,9 +3380,9 @@ static void do_cciss_request(struct request_queue *q)
 		if (dma_mapping_error(&h->pdev->dev, temp64.val)) {
 			dev_warn(&h->pdev->dev,
 				"%s: error mapping page for DMA\n", __func__);
-			creq->errors = make_status_bytes(SAM_STAT_GOOD,
-							0, DRIVER_OK,
-							DID_SOFT_ERROR);
+			scsi_req(creq)->result =
+				make_status_bytes(SAM_STAT_GOOD, 0, DRIVER_OK,
+						  DID_SOFT_ERROR);
 			cmd_free(h, c);
 			return;
 		}
@@ -3395,9 +3395,9 @@ static void do_cciss_request(struct request_queue *q)
 		if (cciss_map_sg_chain_block(h, c, h->cmd_sg_list[c->cmdindex],
 			(seg - (h->max_cmd_sgentries - 1)) *
 				sizeof(SGDescriptor_struct))) {
-			creq->errors = make_status_bytes(SAM_STAT_GOOD,
-							0, DRIVER_OK,
-							DID_SOFT_ERROR);
+			scsi_req(creq)->result =
+				make_status_bytes(SAM_STAT_GOOD, 0, DRIVER_OK,
+						  DID_SOFT_ERROR);
 			cmd_free(h, c);
 			return;
 		}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 66d846ba85a9..205b865ebeb9 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -724,7 +724,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 		rq->rq_flags |= RQF_QUIET;
 
 	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
-	if (rq->errors)
+	if (scsi_req(rq)->result)
 		ret = -EIO;
 out:
 	blk_put_request(rq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 8378ad480f77..dea2a58d6734 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -119,7 +119,7 @@ static inline void virtblk_scsi_request_done(struct request *req)
 
 	sreq->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
 	sreq->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
-	req->errors = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
+	sreq->result = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
 }
 
 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 308501730ab3..76c952fd9ab9 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2219,7 +2219,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		bio = rq->bio;
 
 		blk_execute_rq(q, cdi->disk, rq, 0);
-		if (rq->errors) {
+		if (scsi_req(rq)->result) {
 			struct request_sense *s = req->sense;
 			ret = -EIO;
 			cdi->last_sense = s->sense_key;
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 1524797e1776..5901937284e7 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -108,7 +108,7 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 	if (drive->media == ide_tape)
 		scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
 	blk_execute_rq(drive->queue, disk, rq, 0);
-	error = rq->errors ? -EIO : 0;
+	error = scsi_req(rq)->result ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
@@ -455,7 +455,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 			debug_log("%s: I/O error\n", drive->name);
 
 			if (drive->media != ide_tape)
-				pc->rq->errors++;
+				scsi_req(pc->rq)->result++;
 
 			if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
 				printk(KERN_ERR PFX "%s: I/O error in request "
@@ -489,13 +489,13 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 			drive->failed_pc = NULL;
 
 		if (ata_misc_request(rq)) {
-			rq->errors = 0;
+			scsi_req(rq)->result = 0;
 			error = 0;
 		} else {
 
 			if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
-				if (rq->errors == 0)
-					rq->errors = -EIO;
+				if (scsi_req(rq)->result == 0)
+					scsi_req(rq)->result = -EIO;
 			}
 
 			error = uptodate ? 0 : -EIO;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 95c40afa9120..07e5ff3a64c3 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -247,10 +247,10 @@ static int ide_cd_breathe(ide_drive_t *drive, struct request *rq)
 
 	struct cdrom_info *info = drive->driver_data;
 
-	if (!rq->errors)
+	if (!scsi_req(rq)->result)
 		info->write_timeout = jiffies +	ATAPI_WAIT_WRITE_BUSY;
 
-	rq->errors = 1;
+	scsi_req(rq)->result = 1;
 
 	if (time_after(jiffies, info->write_timeout))
 		return 0;
@@ -294,8 +294,8 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 	}
 
 	/* if we have an error, pass CHECK_CONDITION as the SCSI status byte */
-	if (blk_rq_is_scsi(rq) && !rq->errors)
-		rq->errors = SAM_STAT_CHECK_CONDITION;
+	if (blk_rq_is_scsi(rq) && !scsi_req(rq)->result)
+		scsi_req(rq)->result = SAM_STAT_CHECK_CONDITION;
 
 	if (blk_noretry_request(rq))
 		do_end_request = 1;
@@ -325,7 +325,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 		 * Arrange to retry the request but be sure to give up if we've
 		 * retried too many times.
 		 */
-		if (++rq->errors > ERROR_MAX)
+		if (++scsi_req(rq)->result > ERROR_MAX)
 			do_end_request = 1;
 		break;
 	case ILLEGAL_REQUEST:
@@ -372,7 +372,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 			/* go to the default handler for other errors */
 			ide_error(drive, "cdrom_decode_status", stat);
 			return 1;
-		} else if (++rq->errors > ERROR_MAX)
+		} else if (++scsi_req(rq)->result > ERROR_MAX)
 			/* we've racked up too many retries, abort */
 			do_end_request = 1;
 	}
@@ -453,7 +453,7 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 		}
 
 		blk_execute_rq(drive->queue, info->disk, rq, 0);
-		error = rq->errors ? -EIO : 0;
+		error = scsi_req(rq)->result ? -EIO : 0;
 
 		if (buffer)
 			*bufflen = scsi_req(rq)->resid_len;
@@ -684,8 +684,8 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
 			if (cmd->nleft == 0)
 				uptodate = 1;
 		} else {
-			if (uptodate <= 0 && rq->errors == 0)
-				rq->errors = -EIO;
+			if (uptodate <= 0 && scsi_req(rq)->result == 0)
+				scsi_req(rq)->result = -EIO;
 		}
 
 		if (uptodate == 0 && rq->bio)
@@ -1380,7 +1380,7 @@ static int ide_cdrom_prep_pc(struct request *rq)
 	 * appropriate action
 	 */
 	if (c[0] == MODE_SENSE || c[0] == MODE_SELECT) {
-		rq->errors = ILLEGAL_REQUEST;
+		scsi_req(rq)->result = ILLEGAL_REQUEST;
 		return BLKPREP_KILL;
 	}
 
diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c
index f1ab726bd430..55cd736c39c6 100644
--- a/drivers/ide/ide-cd_ioctl.c
+++ b/drivers/ide/ide-cd_ioctl.c
@@ -308,7 +308,7 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->rq_flags = RQF_QUIET;
 	blk_execute_rq(drive->queue, cd->disk, rq, 0);
-	ret = rq->errors ? -EIO : 0;
+	ret = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 	/*
 	 * A reset will unlock the door. If it was previously locked,
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index eea6a7cb80b5..b1223234037d 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -174,7 +174,7 @@ int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 	rq->special = setting->set;
 
 	blk_execute_rq(q, NULL, rq, 0);
-	ret = rq->errors;
+	ret = scsi_req(rq)->result;
 	blk_put_request(rq);
 
 	return ret;
@@ -186,7 +186,7 @@ ide_startstop_t ide_do_devset(ide_drive_t *drive, struct request *rq)
 
 	err = setfunc(drive, *(int *)&scsi_req(rq)->cmd[1]);
 	if (err)
-		rq->errors = err;
+		scsi_req(rq)->result = err;
 	ide_complete_rq(drive, err, blk_rq_bytes(rq));
 	return ide_stopped;
 }
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 17a65ac56491..51c81223e56d 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -490,7 +490,7 @@ ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
 	 * make sure request is sane
 	 */
 	if (hwif->rq)
-		hwif->rq->errors = 0;
+		scsi_req(hwif->rq)->result = 0;
 	return ret;
 }
 
diff --git a/drivers/ide/ide-eh.c b/drivers/ide/ide-eh.c
index cf3af6840368..4b7ffd7d158d 100644
--- a/drivers/ide/ide-eh.c
+++ b/drivers/ide/ide-eh.c
@@ -12,7 +12,7 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 	} else if (stat & ATA_ERR) {
 		/* err has different meaning on cdrom and tape */
 		if (err == ATA_ABORTED) {
@@ -25,10 +25,10 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 			drive->crc_count++;
 		} else if (err & (ATA_BBK | ATA_UNC)) {
 			/* retries won't help these */
-			rq->errors = ERROR_MAX;
+			scsi_req(rq)->result = ERROR_MAX;
 		} else if (err & ATA_TRK0NF) {
 			/* help it find track zero */
-			rq->errors |= ERROR_RECAL;
+			scsi_req(rq)->result |= ERROR_RECAL;
 		}
 	}
 
@@ -39,23 +39,23 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 		ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
 	}
 
-	if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
+	if (scsi_req(rq)->result >= ERROR_MAX || blk_noretry_request(rq)) {
 		ide_kill_rq(drive, rq);
 		return ide_stopped;
 	}
 
 	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 
-	if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
-		++rq->errors;
+	if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
+		++scsi_req(rq)->result;
 		return ide_do_reset(drive);
 	}
 
-	if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
+	if ((scsi_req(rq)->result & ERROR_RECAL) == ERROR_RECAL)
 		drive->special_flags |= IDE_SFLAG_RECALIBRATE;
 
-	++rq->errors;
+	++scsi_req(rq)->result;
 
 	return ide_stopped;
 }
@@ -68,7 +68,7 @@ static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 	} else {
 		/* add decoding error stuff */
 	}
@@ -77,14 +77,14 @@ static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
 		/* force an abort */
 		hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);
 
-	if (rq->errors >= ERROR_MAX) {
+	if (scsi_req(rq)->result >= ERROR_MAX) {
 		ide_kill_rq(drive, rq);
 	} else {
-		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
-			++rq->errors;
+		if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
+			++scsi_req(rq)->result;
 			return ide_do_reset(drive);
 		}
-		++rq->errors;
+		++scsi_req(rq)->result;
 	}
 
 	return ide_stopped;
@@ -130,11 +130,11 @@ ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
 			if (cmd)
 				ide_complete_cmd(drive, cmd, stat, err);
 		} else if (ata_pm_request(rq)) {
-			rq->errors = 1;
+			scsi_req(rq)->result = 1;
 			ide_complete_pm_rq(drive, rq);
 			return ide_stopped;
 		}
-		rq->errors = err;
+		scsi_req(rq)->result = err;
 		ide_complete_rq(drive, err ? -EIO : 0, blk_rq_bytes(rq));
 		return ide_stopped;
 	}
@@ -149,8 +149,8 @@ static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
 
 	if (rq && ata_misc_request(rq) &&
 	    scsi_req(rq)->cmd[0] == REQ_DRIVE_RESET) {
-		if (err <= 0 && rq->errors == 0)
-			rq->errors = -EIO;
+		if (err <= 0 && scsi_req(rq)->result == 0)
+			scsi_req(rq)->result = -EIO;
 		ide_complete_rq(drive, err ? err : 0, blk_rq_bytes(rq));
 	}
 }
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index a69e8013f1df..8ac6048cd2df 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -98,7 +98,7 @@ static int ide_floppy_callback(ide_drive_t *drive, int dsc)
 	}
 
 	if (ata_misc_request(rq))
-		rq->errors = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
+		scsi_req(rq)->result = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 
 	return uptodate;
 }
@@ -239,7 +239,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 					? rq->rq_disk->disk_name
 					: "dev?"));
 
-	if (rq->errors >= ERROR_MAX) {
+	if (scsi_req(rq)->result >= ERROR_MAX) {
 		if (drive->failed_pc) {
 			ide_floppy_report_error(floppy, drive->failed_pc);
 			drive->failed_pc = NULL;
@@ -247,7 +247,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 			printk(KERN_ERR PFX "%s: I/O error\n", drive->name);
 
 		if (ata_misc_request(rq)) {
-			rq->errors = 0;
+			scsi_req(rq)->result = 0;
 			ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 			return ide_stopped;
 		} else
@@ -301,8 +301,8 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 	return ide_floppy_issue_pc(drive, &cmd, pc);
 out_end:
 	drive->failed_pc = NULL;
-	if (blk_rq_is_passthrough(rq) && rq->errors == 0)
-		rq->errors = -EIO;
+	if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
+		scsi_req(rq)->result = -EIO;
 	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 	return ide_stopped;
 }
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 043b1fb963cb..45b3f41a43d4 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -141,12 +141,12 @@ void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 	drive->failed_pc = NULL;
 
 	if ((media == ide_floppy || media == ide_tape) && drv_req) {
-		rq->errors = 0;
+		scsi_req(rq)->result = 0;
 	} else {
 		if (media == ide_tape)
-			rq->errors = IDE_DRV_ERROR_GENERAL;
-		else if (blk_rq_is_passthrough(rq) && rq->errors == 0)
-			rq->errors = -EIO;
+			scsi_req(rq)->result = IDE_DRV_ERROR_GENERAL;
+		else if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
+			scsi_req(rq)->result = -EIO;
 	}
 
 	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
@@ -271,7 +271,7 @@ static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
 #ifdef DEBUG
  	printk("%s: DRIVE_CMD (null)\n", drive->name);
 #endif
-	rq->errors = 0;
+	scsi_req(rq)->result = 0;
 	ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 
  	return ide_stopped;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 3e96e531b367..8c0d17297a7a 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -129,7 +129,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 		scsi_req_init(rq);
 		ide_req(rq)->type = ATA_PRIV_TASKFILE;
 		blk_execute_rq(drive->queue, NULL, rq, 0);
-		err = rq->errors ? -EIO : 0;
+		err = scsi_req(rq)->result ? -EIO : 0;
 		blk_put_request(rq);
 
 		return err;
@@ -229,7 +229,7 @@ static int generic_drive_reset(ide_drive_t *drive)
 	scsi_req(rq)->cmd_len = 1;
 	scsi_req(rq)->cmd[0] = REQ_DRIVE_RESET;
 	blk_execute_rq(drive->queue, NULL, rq, 1);
-	ret = rq->errors;
+	ret = scsi_req(rq)->result;
 	blk_put_request(rq);
 	return ret;
 }
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index b4f577016f5a..94e3107f59b9 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -38,7 +38,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->special = &timeout;
 	blk_execute_rq(q, NULL, rq, 1);
-	rc = rq->errors ? -EIO : 0;
+	rc = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 	if (rc)
 		goto out;
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index bf513f886f3c..277c2bb7616f 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -28,7 +28,7 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 	rqpm.pm_state = mesg.event;
 
 	blk_execute_rq(drive->queue, NULL, rq, 0);
-	ret = rq->errors ? -EIO : 0;
+	ret = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 
 	if (ret == 0 && ide_port_acpi(hwif)) {
@@ -56,8 +56,8 @@ static int ide_pm_execute_rq(struct request *rq)
 	spin_lock_irq(q->queue_lock);
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		scsi_req(rq)->result = -ENXIO;
+		__blk_end_request_all(rq, scsi_req(rq)->result);
 		spin_unlock_irq(q->queue_lock);
 		return -ENXIO;
 	}
@@ -67,7 +67,7 @@ static int ide_pm_execute_rq(struct request *rq)
 
 	wait_for_completion_io(&wait);
 
-	return rq->errors ? -EIO : 0;
+	return scsi_req(rq)->result ? -EIO : 0;
 }
 
 int generic_ide_resume(struct device *dev)
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index d8a552b47718..a0651f948b76 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -366,7 +366,7 @@ static int ide_tape_callback(ide_drive_t *drive, int dsc)
 			err = pc->error;
 		}
 	}
-	rq->errors = err;
+	scsi_req(rq)->result = err;
 
 	return uptodate;
 }
@@ -879,7 +879,7 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 		tape->valid = 0;
 
 	ret = size;
-	if (rq->errors == IDE_DRV_ERROR_GENERAL)
+	if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 		ret = -EIO;
 out_put:
 	blk_put_request(rq);
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 78924c7c9478..d71199d23c9e 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -287,7 +287,7 @@ static void ide_pio_datablock(ide_drive_t *drive, struct ide_cmd *cmd,
 	u8 saved_io_32bit = drive->io_32bit;
 
 	if (cmd->tf_flags & IDE_TFLAG_FS)
-		cmd->rq->errors = 0;
+		scsi_req(cmd->rq)->result = 0;
 
 	if (cmd->tf_flags & IDE_TFLAG_IO_16BIT)
 		drive->io_32bit = 0;
@@ -329,7 +329,7 @@ void ide_finish_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat)
 	u8 set_xfer = !!(cmd->tf_flags & IDE_TFLAG_SET_XFER);
 
 	ide_complete_cmd(drive, cmd, stat, err);
-	rq->errors = err;
+	scsi_req(rq)->result = err;
 
 	if (err == 0 && set_xfer) {
 		ide_set_xfer_rate(drive, nsect);
@@ -453,7 +453,7 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 	cmd->rq = rq;
 
 	blk_execute_rq(drive->queue, NULL, rq, 0);
-	error = rq->errors ? -EIO : 0;
+	error = scsi_req(rq)->result ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 44e03c3eb250..8d6e2859d9f9 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -477,7 +477,7 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
 			     int error)
 {
 	or->async_error = error;
-	or->req_errors = req->errors ? : error;
+	or->req_errors = scsi_req(req)->result ? : error;
 	or->sense_len = scsi_req(req)->sense_len;
 	if (or->sense_len)
 		memcpy(or->sense, scsi_req(req)->sense, or->sense_len);
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 41bc1d64bf86..67cbed92f07d 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -327,7 +327,7 @@ static void osst_end_async(struct request *req, int update)
 	struct osst_tape *STp = SRpnt->stp;
 	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 #if DEBUG
 	STp->write_pending = 0;
 #endif
diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c
index 84c9098cc089..b6e40fd4c3c1 100644
--- a/drivers/scsi/qla2xxx/qla_bsg.c
+++ b/drivers/scsi/qla2xxx/qla_bsg.c
@@ -2553,13 +2553,13 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 						ql_log(ql_log_warn, vha, 0x7089,
 						    "mbx abort_command "
 						    "failed.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = -EIO;
 					} else {
 						ql_dbg(ql_dbg_user, vha, 0x708a,
 						    "mbx abort_command "
 						    "success.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = 0;
 					}
 					spin_lock_irqsave(&ha->hardware_lock, flags);
@@ -2570,7 +2570,7 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 	}
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 	ql_log(ql_log_info, vha, 0x708b, "SRB not found to abort.\n");
-	bsg_job->req->errors = bsg_reply->result = -ENXIO;
+	scsi_req(bsg_job->req)->result = bsg_reply->result = -ENXIO;
 	return 0;
 
 done:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7bc4513bf4e4..b9298a499e19 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -229,8 +229,8 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @rq_flags:	flags for ->rq_flags
  * @resid:	optional residual length
  *
- * returns the req->errors value which is the scsi_cmnd result
- * field.
+ * Returns the scsi_cmnd result field if a command was executed, or a negative
+ * Linux error code if we didn't get that far.
  */
 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		 int data_direction, void *buffer, unsigned bufflen,
@@ -281,7 +281,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 	if (sshdr)
 		scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
-	ret = req->errors;
+	ret = rq->result;
  out:
 	blk_put_request(req);
 
@@ -797,8 +797,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		/*
 		 * __scsi_error_from_host_byte may have reset the host_byte
 		 */
-		req->errors = cmd->result;
-
+		scsi_req(req)->result = cmd->result;
 		scsi_req(req)->resid_len = scsi_get_resid(cmd);
 
 		if (scsi_bidi_cmnd(cmd)) {
@@ -835,7 +834,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 	/*
 	 * Recovered errors need reporting, but they're always treated as
 	 * success, so fiddle the result code here.  For passthrough requests
-	 * we already took a copy of the original into rq->errors which
+	 * we already took a copy of the original into sreq->result which
 	 * is what gets returned to the user
 	 */
 	if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
@@ -1281,7 +1280,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 	switch (ret) {
 	case BLKPREP_KILL:
 	case BLKPREP_INVALID:
-		req->errors = DID_NO_CONNECT << 16;
+		scsi_req(req)->result = DID_NO_CONNECT << 16;
 		/* release the command and kill it */
 		if (req->special) {
 			struct scsi_cmnd *cmd = req->special;
@@ -1905,7 +1904,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, cmd->request->errors);
+	blk_mq_complete_request(cmd->request, 0);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index cdbb293aca08..a2b279737a4b 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -184,7 +184,7 @@ static void sas_smp_request(struct request_queue *q, struct Scsi_Host *shost,
 				blk_rq_bytes(req->next_rq);
 		handler = to_sas_internal(shost->transportt)->f->smp_handler;
 		ret = handler(shost, rphy, req);
-		req->errors = ret;
+		scsi_req(req)->result = ret;
 
 		blk_end_request_all(req, ret);
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c5aaceea8d77..504504beaa5e 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1300,7 +1300,7 @@ sg_rq_end_io(struct request *rq, int uptodate)
 		pr_info("%s: device detaching\n", __func__);
 
 	sense = req->sense;
-	result = rq->errors;
+	result = req->result;
 	resid = req->resid_len;
 
 	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 5408643431bb..1ea34d6f5437 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -480,7 +480,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->write_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_write_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->write_byte_cnt);
@@ -494,7 +494,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->read_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_read_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->read_byte_cnt);
@@ -518,7 +518,7 @@ static void st_scsi_execute_end(struct request *req, int uptodate)
 	struct scsi_tape *STp = SRpnt->stp;
 	struct bio *tmp;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 	STp->buffer->cmdstat.residual = rq->resid_len;
 
 	st_do_stats(STp, req);
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index c7fa372c527a..a93d94e68ab5 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1050,7 +1050,7 @@ static void pscsi_req_done(struct request *req, int uptodate)
 	struct se_cmd *cmd = req->end_io_data;
 	struct pscsi_plugin_task *pt = cmd->priv;
 
-	pt->pscsi_result = req->errors;
+	pt->pscsi_result = scsi_req(req)->result;
 	pt->pscsi_resid = scsi_req(req)->resid_len;
 
 	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 9f618b77ffee..fb5213afc854 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -243,9 +243,9 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 	req->cmd_len = COMMAND_SIZE(INQUIRY);
 
 	blk_execute_rq(rq->q, NULL, rq, 1);
-	if (rq->errors) {
+	if (req->result) {
 		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
-			rq->errors);
+			req->result);
 		error = -EIO;
 		goto out_put_request;
 	}
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 2f51c1724b5a..6980ca322074 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -88,7 +88,7 @@ static inline bool ata_pm_request(struct request *rq)
 		 ide_req(rq)->type == ATA_PRIV_PM_RESUME);
 }
 
-/* Error codes returned in rq->errors to the higher part of the driver. */
+/* Error codes returned in result to the higher part of the driver. */
 enum {
 	IDE_DRV_ERROR_GENERAL	= 101,
 	IDE_DRV_ERROR_FILEMARK	= 102,
diff --git a/include/scsi/scsi_request.h b/include/scsi/scsi_request.h
index 7c583a0f363a..f0c76f9dc285 100644
--- a/include/scsi/scsi_request.h
+++ b/include/scsi/scsi_request.h
@@ -9,6 +9,7 @@ struct scsi_request {
 	unsigned char	__cmd[BLK_MAX_CDB];
 	unsigned char	*cmd;
 	unsigned short	cmd_len;
+	int		result;
 	unsigned int	sense_len;
 	unsigned int	resid_len;	/* residual count */
 	int		retries;
-- 
2.11.0

[PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Christoph Hellwig]

This passes on the scsi_cmnd result field to users of passthrough
requests.  Currently we abuse req->errors for this purpose, but that
field will go away in its current form.

Note that the old IDE code abuses the errors field in very creative
ways and stores all kinds of different values in it.  I didn't dare
to touch this magic, so the abuses are brought forward 1:1.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 block/bsg-lib.c                    |  8 ++++----
 block/bsg.c                        | 12 +++++------
 block/scsi_ioctl.c                 | 14 ++++++-------
 drivers/block/cciss.c              | 42 +++++++++++++++++++-------------------
 drivers/block/pktcdvd.c            |  2 +-
 drivers/block/virtio_blk.c         |  2 +-
 drivers/cdrom/cdrom.c              |  2 +-
 drivers/ide/ide-atapi.c            | 10 ++++-----
 drivers/ide/ide-cd.c               | 20 +++++++++---------
 drivers/ide/ide-cd_ioctl.c         |  2 +-
 drivers/ide/ide-devsets.c          |  4 ++--
 drivers/ide/ide-dma.c              |  2 +-
 drivers/ide/ide-eh.c               | 36 ++++++++++++++++----------------
 drivers/ide/ide-floppy.c           | 10 ++++-----
 drivers/ide/ide-io.c               | 10 ++++-----
 drivers/ide/ide-ioctls.c           |  4 ++--
 drivers/ide/ide-park.c             |  2 +-
 drivers/ide/ide-pm.c               |  8 ++++----
 drivers/ide/ide-tape.c             |  4 ++--
 drivers/ide/ide-taskfile.c         |  6 +++---
 drivers/scsi/osd/osd_initiator.c   |  2 +-
 drivers/scsi/osst.c                |  2 +-
 drivers/scsi/qla2xxx/qla_bsg.c     |  6 +++---
 drivers/scsi/scsi_lib.c            | 15 +++++++-------
 drivers/scsi/scsi_transport_sas.c  |  2 +-
 drivers/scsi/sg.c                  |  2 +-
 drivers/scsi/st.c                  |  6 +++---
 drivers/target/target_core_pscsi.c |  2 +-
 fs/nfsd/blocklayout.c              |  4 ++--
 include/linux/ide.h                |  2 +-
 include/scsi/scsi_request.h        |  1 +
 31 files changed, 122 insertions(+), 122 deletions(-)

diff --git a/block/bsg-lib.c b/block/bsg-lib.c
index cd15f9dbb147..0a23dbba2d30 100644
--- a/block/bsg-lib.c
+++ b/block/bsg-lib.c
@@ -37,7 +37,7 @@ static void bsg_destroy_job(struct kref *kref)
 	struct bsg_job *job = container_of(kref, struct bsg_job, kref);
 	struct request *rq = job->req;
 
-	blk_end_request_all(rq, rq->errors);
+	blk_end_request_all(rq, scsi_req(rq)->result);
 
 	put_device(job->dev);	/* release reference for the request */
 
@@ -74,7 +74,7 @@ void bsg_job_done(struct bsg_job *job, int result,
 	struct scsi_request *rq = scsi_req(req);
 	int err;
 
-	err = job->req->errors = result;
+	err = scsi_req(job->req)->result = result;
 	if (err < 0)
 		/* we're only returning the result field in the reply */
 		rq->sense_len = sizeof(u32);
@@ -177,7 +177,7 @@ static int bsg_create_job(struct device *dev, struct request *req)
  * @q: request queue to manage
  *
  * On error the create_bsg_job function should return a -Exyz error value
- * that will be set to the req->errors.
+ * that will be set to ->result.
  *
  * Drivers/subsys should pass this to the queue init function.
  */
@@ -201,7 +201,7 @@ static void bsg_request_fn(struct request_queue *q)
 
 		ret = bsg_create_job(dev, req);
 		if (ret) {
-			req->errors = ret;
+			scsi_req(req)->result = ret;
 			blk_end_request_all(req, ret);
 			spin_lock_irq(q->queue_lock);
 			continue;
diff --git a/block/bsg.c b/block/bsg.c
index 74835dbf0c47..d9da1b613ced 100644
--- a/block/bsg.c
+++ b/block/bsg.c
@@ -391,13 +391,13 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	struct scsi_request *req = scsi_req(rq);
 	int ret = 0;
 
-	dprintk("rq %p bio %p 0x%x\n", rq, bio, rq->errors);
+	dprintk("rq %p bio %p 0x%x\n", rq, bio, req->result);
 	/*
 	 * fill in all the output members
 	 */
-	hdr->device_status = rq->errors & 0xff;
-	hdr->transport_status = host_byte(rq->errors);
-	hdr->driver_status = driver_byte(rq->errors);
+	hdr->device_status = req->result & 0xff;
+	hdr->transport_status = host_byte(req->result);
+	hdr->driver_status = driver_byte(req->result);
 	hdr->info = 0;
 	if (hdr->device_status || hdr->transport_status || hdr->driver_status)
 		hdr->info |= SG_INFO_CHECK;
@@ -431,8 +431,8 @@ static int blk_complete_sgv4_hdr_rq(struct request *rq, struct sg_io_v4 *hdr,
 	 * just a protocol response (i.e. non negative), that gets
 	 * processed above.
 	 */
-	if (!ret && rq->errors < 0)
-		ret = rq->errors;
+	if (!ret && req->result < 0)
+		ret = req->result;
 
 	blk_rq_unmap_user(bio);
 	scsi_req_free_cmd(req);
diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index b1352143f12f..4a294a5f7fab 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -262,11 +262,11 @@ static int blk_complete_sghdr_rq(struct request *rq, struct sg_io_hdr *hdr,
 	/*
 	 * fill in all the output members
 	 */
-	hdr->status = rq->errors & 0xff;
-	hdr->masked_status = status_byte(rq->errors);
-	hdr->msg_status = msg_byte(rq->errors);
-	hdr->host_status = host_byte(rq->errors);
-	hdr->driver_status = driver_byte(rq->errors);
+	hdr->status = req->result & 0xff;
+	hdr->masked_status = status_byte(req->result);
+	hdr->msg_status = msg_byte(req->result);
+	hdr->host_status = host_byte(req->result);
+	hdr->driver_status = driver_byte(req->result);
 	hdr->info = 0;
 	if (hdr->masked_status || hdr->host_status || hdr->driver_status)
 		hdr->info |= SG_INFO_CHECK;
@@ -509,7 +509,7 @@ int sg_scsi_ioctl(struct request_queue *q, struct gendisk *disk, fmode_t mode,
 
 	blk_execute_rq(q, disk, rq, 0);
 
-	err = rq->errors & 0xff;	/* only 8 bit SCSI status */
+	err = req->result & 0xff;	/* only 8 bit SCSI status */
 	if (err) {
 		if (req->sense_len && req->sense) {
 			bytes = (OMAX_SB_LEN > req->sense_len) ?
@@ -548,7 +548,7 @@ static int __blk_send_generic(struct request_queue *q, struct gendisk *bd_disk,
 	scsi_req(rq)->cmd[4] = data;
 	scsi_req(rq)->cmd_len = 6;
 	blk_execute_rq(q, bd_disk, rq, 0);
-	err = rq->errors ? -EIO : 0;
+	err = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 
 	return err;
diff --git a/drivers/block/cciss.c b/drivers/block/cciss.c
index 8e1a4554951c..cd375503f7b0 100644
--- a/drivers/block/cciss.c
+++ b/drivers/block/cciss.c
@@ -1864,8 +1864,7 @@ static void cciss_softirq_done(struct request *rq)
 	/* set the residual count for pc requests */
 	if (blk_rq_is_passthrough(rq))
 		scsi_req(rq)->resid_len = c->err_info->ResidualCnt;
-
-	blk_end_request_all(rq, (rq->errors == 0) ? 0 : -EIO);
+	blk_end_request_all(rq, scsi_req(rq)->result ? -EIO : 0);
 
 	spin_lock_irqsave(&h->lock, flags);
 	cmd_free(h, c);
@@ -3140,18 +3139,19 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 {
 	int retry_cmd = 0;
 	struct request *rq = cmd->rq;
+	struct scsi_request *sreq = scsi_req(rq);
 
-	rq->errors = 0;
+	sreq->result = 0;
 
 	if (timeout)
-		rq->errors = make_status_bytes(0, 0, 0, DRIVER_TIMEOUT);
+		sreq->result = make_status_bytes(0, 0, 0, DRIVER_TIMEOUT);
 
 	if (cmd->err_info->CommandStatus == 0)	/* no error has occurred */
 		goto after_error_processing;
 
 	switch (cmd->err_info->CommandStatus) {
 	case CMD_TARGET_STATUS:
-		rq->errors = evaluate_target_status(h, cmd, &retry_cmd);
+		sreq->result = evaluate_target_status(h, cmd, &retry_cmd);
 		break;
 	case CMD_DATA_UNDERRUN:
 		if (!blk_rq_is_passthrough(cmd->rq)) {
@@ -3169,7 +3169,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_INVALID:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p is "
 		       "reported invalid\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3177,7 +3177,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_PROTOCOL_ERR:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p has "
 		       "protocol error\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3185,7 +3185,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_HARDWARE_ERR:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p had "
 		       " hardware error\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3193,7 +3193,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_CONNECTION_LOST:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p had "
 		       "connection lost\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3201,7 +3201,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_ABORTED:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p was "
 		       "aborted\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ABORT);
@@ -3209,7 +3209,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 	case CMD_ABORT_FAILED:
 		dev_warn(&h->pdev->dev, "cciss: cmd %p reports "
 		       "abort failed\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3224,21 +3224,21 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 		} else
 			dev_warn(&h->pdev->dev,
 				"%p retried too many times\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ABORT);
 		break;
 	case CMD_TIMEOUT:
 		dev_warn(&h->pdev->dev, "cmd %p timedout\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
 		break;
 	case CMD_UNABORTABLE:
 		dev_warn(&h->pdev->dev, "cmd %p unabortable\n", cmd);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3247,7 +3247,7 @@ static inline void complete_command(ctlr_info_t *h, CommandList_struct *cmd,
 		dev_warn(&h->pdev->dev, "cmd %p returned "
 		       "unknown status %x\n", cmd,
 		       cmd->err_info->CommandStatus);
-		rq->errors = make_status_bytes(SAM_STAT_GOOD,
+		sreq->result = make_status_bytes(SAM_STAT_GOOD,
 			cmd->err_info->CommandStatus, DRIVER_OK,
 			blk_rq_is_passthrough(cmd->rq) ?
 				DID_PASSTHROUGH : DID_ERROR);
@@ -3380,9 +3380,9 @@ static void do_cciss_request(struct request_queue *q)
 		if (dma_mapping_error(&h->pdev->dev, temp64.val)) {
 			dev_warn(&h->pdev->dev,
 				"%s: error mapping page for DMA\n", __func__);
-			creq->errors = make_status_bytes(SAM_STAT_GOOD,
-							0, DRIVER_OK,
-							DID_SOFT_ERROR);
+			scsi_req(creq)->result =
+				make_status_bytes(SAM_STAT_GOOD, 0, DRIVER_OK,
+						  DID_SOFT_ERROR);
 			cmd_free(h, c);
 			return;
 		}
@@ -3395,9 +3395,9 @@ static void do_cciss_request(struct request_queue *q)
 		if (cciss_map_sg_chain_block(h, c, h->cmd_sg_list[c->cmdindex],
 			(seg - (h->max_cmd_sgentries - 1)) *
 				sizeof(SGDescriptor_struct))) {
-			creq->errors = make_status_bytes(SAM_STAT_GOOD,
-							0, DRIVER_OK,
-							DID_SOFT_ERROR);
+			scsi_req(creq)->result =
+				make_status_bytes(SAM_STAT_GOOD, 0, DRIVER_OK,
+						  DID_SOFT_ERROR);
 			cmd_free(h, c);
 			return;
 		}
diff --git a/drivers/block/pktcdvd.c b/drivers/block/pktcdvd.c
index 66d846ba85a9..205b865ebeb9 100644
--- a/drivers/block/pktcdvd.c
+++ b/drivers/block/pktcdvd.c
@@ -724,7 +724,7 @@ static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *
 		rq->rq_flags |= RQF_QUIET;
 
 	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
-	if (rq->errors)
+	if (scsi_req(rq)->result)
 		ret = -EIO;
 out:
 	blk_put_request(rq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index 8378ad480f77..dea2a58d6734 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -119,7 +119,7 @@ static inline void virtblk_scsi_request_done(struct request *req)
 
 	sreq->resid_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.residual);
 	sreq->sense_len = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.sense_len);
-	req->errors = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
+	sreq->result = virtio32_to_cpu(vblk->vdev, vbr->in_hdr.errors);
 }
 
 static int virtblk_ioctl(struct block_device *bdev, fmode_t mode,
diff --git a/drivers/cdrom/cdrom.c b/drivers/cdrom/cdrom.c
index 308501730ab3..76c952fd9ab9 100644
--- a/drivers/cdrom/cdrom.c
+++ b/drivers/cdrom/cdrom.c
@@ -2219,7 +2219,7 @@ static int cdrom_read_cdda_bpc(struct cdrom_device_info *cdi, __u8 __user *ubuf,
 		bio = rq->bio;
 
 		blk_execute_rq(q, cdi->disk, rq, 0);
-		if (rq->errors) {
+		if (scsi_req(rq)->result) {
 			struct request_sense *s = req->sense;
 			ret = -EIO;
 			cdi->last_sense = s->sense_key;
diff --git a/drivers/ide/ide-atapi.c b/drivers/ide/ide-atapi.c
index 1524797e1776..5901937284e7 100644
--- a/drivers/ide/ide-atapi.c
+++ b/drivers/ide/ide-atapi.c
@@ -108,7 +108,7 @@ int ide_queue_pc_tail(ide_drive_t *drive, struct gendisk *disk,
 	if (drive->media == ide_tape)
 		scsi_req(rq)->cmd[13] = REQ_IDETAPE_PC1;
 	blk_execute_rq(drive->queue, disk, rq, 0);
-	error = rq->errors ? -EIO : 0;
+	error = scsi_req(rq)->result ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
@@ -455,7 +455,7 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 			debug_log("%s: I/O error\n", drive->name);
 
 			if (drive->media != ide_tape)
-				pc->rq->errors++;
+				scsi_req(pc->rq)->result++;
 
 			if (scsi_req(rq)->cmd[0] == REQUEST_SENSE) {
 				printk(KERN_ERR PFX "%s: I/O error in request "
@@ -489,13 +489,13 @@ static ide_startstop_t ide_pc_intr(ide_drive_t *drive)
 			drive->failed_pc = NULL;
 
 		if (ata_misc_request(rq)) {
-			rq->errors = 0;
+			scsi_req(rq)->result = 0;
 			error = 0;
 		} else {
 
 			if (blk_rq_is_passthrough(rq) && uptodate <= 0) {
-				if (rq->errors == 0)
-					rq->errors = -EIO;
+				if (scsi_req(rq)->result == 0)
+					scsi_req(rq)->result = -EIO;
 			}
 
 			error = uptodate ? 0 : -EIO;
diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 95c40afa9120..07e5ff3a64c3 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -247,10 +247,10 @@ static int ide_cd_breathe(ide_drive_t *drive, struct request *rq)
 
 	struct cdrom_info *info = drive->driver_data;
 
-	if (!rq->errors)
+	if (!scsi_req(rq)->result)
 		info->write_timeout = jiffies +	ATAPI_WAIT_WRITE_BUSY;
 
-	rq->errors = 1;
+	scsi_req(rq)->result = 1;
 
 	if (time_after(jiffies, info->write_timeout))
 		return 0;
@@ -294,8 +294,8 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 	}
 
 	/* if we have an error, pass CHECK_CONDITION as the SCSI status byte */
-	if (blk_rq_is_scsi(rq) && !rq->errors)
-		rq->errors = SAM_STAT_CHECK_CONDITION;
+	if (blk_rq_is_scsi(rq) && !scsi_req(rq)->result)
+		scsi_req(rq)->result = SAM_STAT_CHECK_CONDITION;
 
 	if (blk_noretry_request(rq))
 		do_end_request = 1;
@@ -325,7 +325,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 		 * Arrange to retry the request but be sure to give up if we've
 		 * retried too many times.
 		 */
-		if (++rq->errors > ERROR_MAX)
+		if (++scsi_req(rq)->result > ERROR_MAX)
 			do_end_request = 1;
 		break;
 	case ILLEGAL_REQUEST:
@@ -372,7 +372,7 @@ static int cdrom_decode_status(ide_drive_t *drive, u8 stat)
 			/* go to the default handler for other errors */
 			ide_error(drive, "cdrom_decode_status", stat);
 			return 1;
-		} else if (++rq->errors > ERROR_MAX)
+		} else if (++scsi_req(rq)->result > ERROR_MAX)
 			/* we've racked up too many retries, abort */
 			do_end_request = 1;
 	}
@@ -453,7 +453,7 @@ int ide_cd_queue_pc(ide_drive_t *drive, const unsigned char *cmd,
 		}
 
 		blk_execute_rq(drive->queue, info->disk, rq, 0);
-		error = rq->errors ? -EIO : 0;
+		error = scsi_req(rq)->result ? -EIO : 0;
 
 		if (buffer)
 			*bufflen = scsi_req(rq)->resid_len;
@@ -684,8 +684,8 @@ static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
 			if (cmd->nleft == 0)
 				uptodate = 1;
 		} else {
-			if (uptodate <= 0 && rq->errors == 0)
-				rq->errors = -EIO;
+			if (uptodate <= 0 && scsi_req(rq)->result == 0)
+				scsi_req(rq)->result = -EIO;
 		}
 
 		if (uptodate == 0 && rq->bio)
@@ -1380,7 +1380,7 @@ static int ide_cdrom_prep_pc(struct request *rq)
 	 * appropriate action
 	 */
 	if (c[0] == MODE_SENSE || c[0] == MODE_SELECT) {
-		rq->errors = ILLEGAL_REQUEST;
+		scsi_req(rq)->result = ILLEGAL_REQUEST;
 		return BLKPREP_KILL;
 	}
 
diff --git a/drivers/ide/ide-cd_ioctl.c b/drivers/ide/ide-cd_ioctl.c
index f1ab726bd430..55cd736c39c6 100644
--- a/drivers/ide/ide-cd_ioctl.c
+++ b/drivers/ide/ide-cd_ioctl.c
@@ -308,7 +308,7 @@ int ide_cdrom_reset(struct cdrom_device_info *cdi)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->rq_flags = RQF_QUIET;
 	blk_execute_rq(drive->queue, cd->disk, rq, 0);
-	ret = rq->errors ? -EIO : 0;
+	ret = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 	/*
 	 * A reset will unlock the door. If it was previously locked,
diff --git a/drivers/ide/ide-devsets.c b/drivers/ide/ide-devsets.c
index eea6a7cb80b5..b1223234037d 100644
--- a/drivers/ide/ide-devsets.c
+++ b/drivers/ide/ide-devsets.c
@@ -174,7 +174,7 @@ int ide_devset_execute(ide_drive_t *drive, const struct ide_devset *setting,
 	rq->special = setting->set;
 
 	blk_execute_rq(q, NULL, rq, 0);
-	ret = rq->errors;
+	ret = scsi_req(rq)->result;
 	blk_put_request(rq);
 
 	return ret;
@@ -186,7 +186,7 @@ ide_startstop_t ide_do_devset(ide_drive_t *drive, struct request *rq)
 
 	err = setfunc(drive, *(int *)&scsi_req(rq)->cmd[1]);
 	if (err)
-		rq->errors = err;
+		scsi_req(rq)->result = err;
 	ide_complete_rq(drive, err, blk_rq_bytes(rq));
 	return ide_stopped;
 }
diff --git a/drivers/ide/ide-dma.c b/drivers/ide/ide-dma.c
index 17a65ac56491..51c81223e56d 100644
--- a/drivers/ide/ide-dma.c
+++ b/drivers/ide/ide-dma.c
@@ -490,7 +490,7 @@ ide_startstop_t ide_dma_timeout_retry(ide_drive_t *drive, int error)
 	 * make sure request is sane
 	 */
 	if (hwif->rq)
-		hwif->rq->errors = 0;
+		scsi_req(hwif->rq)->result = 0;
 	return ret;
 }
 
diff --git a/drivers/ide/ide-eh.c b/drivers/ide/ide-eh.c
index cf3af6840368..4b7ffd7d158d 100644
--- a/drivers/ide/ide-eh.c
+++ b/drivers/ide/ide-eh.c
@@ -12,7 +12,7 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 	} else if (stat & ATA_ERR) {
 		/* err has different meaning on cdrom and tape */
 		if (err == ATA_ABORTED) {
@@ -25,10 +25,10 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 			drive->crc_count++;
 		} else if (err & (ATA_BBK | ATA_UNC)) {
 			/* retries won't help these */
-			rq->errors = ERROR_MAX;
+			scsi_req(rq)->result = ERROR_MAX;
 		} else if (err & ATA_TRK0NF) {
 			/* help it find track zero */
-			rq->errors |= ERROR_RECAL;
+			scsi_req(rq)->result |= ERROR_RECAL;
 		}
 	}
 
@@ -39,23 +39,23 @@ static ide_startstop_t ide_ata_error(ide_drive_t *drive, struct request *rq,
 		ide_pad_transfer(drive, READ, nsect * SECTOR_SIZE);
 	}
 
-	if (rq->errors >= ERROR_MAX || blk_noretry_request(rq)) {
+	if (scsi_req(rq)->result >= ERROR_MAX || blk_noretry_request(rq)) {
 		ide_kill_rq(drive, rq);
 		return ide_stopped;
 	}
 
 	if (hwif->tp_ops->read_status(hwif) & (ATA_BUSY | ATA_DRQ))
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 
-	if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
-		++rq->errors;
+	if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
+		++scsi_req(rq)->result;
 		return ide_do_reset(drive);
 	}
 
-	if ((rq->errors & ERROR_RECAL) == ERROR_RECAL)
+	if ((scsi_req(rq)->result & ERROR_RECAL) == ERROR_RECAL)
 		drive->special_flags |= IDE_SFLAG_RECALIBRATE;
 
-	++rq->errors;
+	++scsi_req(rq)->result;
 
 	return ide_stopped;
 }
@@ -68,7 +68,7 @@ static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
 	if ((stat & ATA_BUSY) ||
 	    ((stat & ATA_DF) && (drive->dev_flags & IDE_DFLAG_NOWERR) == 0)) {
 		/* other bits are useless when BUSY */
-		rq->errors |= ERROR_RESET;
+		scsi_req(rq)->result |= ERROR_RESET;
 	} else {
 		/* add decoding error stuff */
 	}
@@ -77,14 +77,14 @@ static ide_startstop_t ide_atapi_error(ide_drive_t *drive, struct request *rq,
 		/* force an abort */
 		hwif->tp_ops->exec_command(hwif, ATA_CMD_IDLEIMMEDIATE);
 
-	if (rq->errors >= ERROR_MAX) {
+	if (scsi_req(rq)->result >= ERROR_MAX) {
 		ide_kill_rq(drive, rq);
 	} else {
-		if ((rq->errors & ERROR_RESET) == ERROR_RESET) {
-			++rq->errors;
+		if ((scsi_req(rq)->result & ERROR_RESET) == ERROR_RESET) {
+			++scsi_req(rq)->result;
 			return ide_do_reset(drive);
 		}
-		++rq->errors;
+		++scsi_req(rq)->result;
 	}
 
 	return ide_stopped;
@@ -130,11 +130,11 @@ ide_startstop_t ide_error(ide_drive_t *drive, const char *msg, u8 stat)
 			if (cmd)
 				ide_complete_cmd(drive, cmd, stat, err);
 		} else if (ata_pm_request(rq)) {
-			rq->errors = 1;
+			scsi_req(rq)->result = 1;
 			ide_complete_pm_rq(drive, rq);
 			return ide_stopped;
 		}
-		rq->errors = err;
+		scsi_req(rq)->result = err;
 		ide_complete_rq(drive, err ? -EIO : 0, blk_rq_bytes(rq));
 		return ide_stopped;
 	}
@@ -149,8 +149,8 @@ static inline void ide_complete_drive_reset(ide_drive_t *drive, int err)
 
 	if (rq && ata_misc_request(rq) &&
 	    scsi_req(rq)->cmd[0] == REQ_DRIVE_RESET) {
-		if (err <= 0 && rq->errors == 0)
-			rq->errors = -EIO;
+		if (err <= 0 && scsi_req(rq)->result == 0)
+			scsi_req(rq)->result = -EIO;
 		ide_complete_rq(drive, err ? err : 0, blk_rq_bytes(rq));
 	}
 }
diff --git a/drivers/ide/ide-floppy.c b/drivers/ide/ide-floppy.c
index a69e8013f1df..8ac6048cd2df 100644
--- a/drivers/ide/ide-floppy.c
+++ b/drivers/ide/ide-floppy.c
@@ -98,7 +98,7 @@ static int ide_floppy_callback(ide_drive_t *drive, int dsc)
 	}
 
 	if (ata_misc_request(rq))
-		rq->errors = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
+		scsi_req(rq)->result = uptodate ? 0 : IDE_DRV_ERROR_GENERAL;
 
 	return uptodate;
 }
@@ -239,7 +239,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 					? rq->rq_disk->disk_name
 					: "dev?"));
 
-	if (rq->errors >= ERROR_MAX) {
+	if (scsi_req(rq)->result >= ERROR_MAX) {
 		if (drive->failed_pc) {
 			ide_floppy_report_error(floppy, drive->failed_pc);
 			drive->failed_pc = NULL;
@@ -247,7 +247,7 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 			printk(KERN_ERR PFX "%s: I/O error\n", drive->name);
 
 		if (ata_misc_request(rq)) {
-			rq->errors = 0;
+			scsi_req(rq)->result = 0;
 			ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 			return ide_stopped;
 		} else
@@ -301,8 +301,8 @@ static ide_startstop_t ide_floppy_do_request(ide_drive_t *drive,
 	return ide_floppy_issue_pc(drive, &cmd, pc);
 out_end:
 	drive->failed_pc = NULL;
-	if (blk_rq_is_passthrough(rq) && rq->errors == 0)
-		rq->errors = -EIO;
+	if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
+		scsi_req(rq)->result = -EIO;
 	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
 	return ide_stopped;
 }
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 043b1fb963cb..45b3f41a43d4 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -141,12 +141,12 @@ void ide_kill_rq(ide_drive_t *drive, struct request *rq)
 	drive->failed_pc = NULL;
 
 	if ((media == ide_floppy || media == ide_tape) && drv_req) {
-		rq->errors = 0;
+		scsi_req(rq)->result = 0;
 	} else {
 		if (media == ide_tape)
-			rq->errors = IDE_DRV_ERROR_GENERAL;
-		else if (blk_rq_is_passthrough(rq) && rq->errors == 0)
-			rq->errors = -EIO;
+			scsi_req(rq)->result = IDE_DRV_ERROR_GENERAL;
+		else if (blk_rq_is_passthrough(rq) && scsi_req(rq)->result == 0)
+			scsi_req(rq)->result = -EIO;
 	}
 
 	ide_complete_rq(drive, -EIO, blk_rq_bytes(rq));
@@ -271,7 +271,7 @@ static ide_startstop_t execute_drive_cmd (ide_drive_t *drive,
 #ifdef DEBUG
  	printk("%s: DRIVE_CMD (null)\n", drive->name);
 #endif
-	rq->errors = 0;
+	scsi_req(rq)->result = 0;
 	ide_complete_rq(drive, 0, blk_rq_bytes(rq));
 
  	return ide_stopped;
diff --git a/drivers/ide/ide-ioctls.c b/drivers/ide/ide-ioctls.c
index 3e96e531b367..8c0d17297a7a 100644
--- a/drivers/ide/ide-ioctls.c
+++ b/drivers/ide/ide-ioctls.c
@@ -129,7 +129,7 @@ static int ide_cmd_ioctl(ide_drive_t *drive, unsigned long arg)
 		scsi_req_init(rq);
 		ide_req(rq)->type = ATA_PRIV_TASKFILE;
 		blk_execute_rq(drive->queue, NULL, rq, 0);
-		err = rq->errors ? -EIO : 0;
+		err = scsi_req(rq)->result ? -EIO : 0;
 		blk_put_request(rq);
 
 		return err;
@@ -229,7 +229,7 @@ static int generic_drive_reset(ide_drive_t *drive)
 	scsi_req(rq)->cmd_len = 1;
 	scsi_req(rq)->cmd[0] = REQ_DRIVE_RESET;
 	blk_execute_rq(drive->queue, NULL, rq, 1);
-	ret = rq->errors;
+	ret = scsi_req(rq)->result;
 	blk_put_request(rq);
 	return ret;
 }
diff --git a/drivers/ide/ide-park.c b/drivers/ide/ide-park.c
index b4f577016f5a..94e3107f59b9 100644
--- a/drivers/ide/ide-park.c
+++ b/drivers/ide/ide-park.c
@@ -38,7 +38,7 @@ static void issue_park_cmd(ide_drive_t *drive, unsigned long timeout)
 	ide_req(rq)->type = ATA_PRIV_MISC;
 	rq->special = &timeout;
 	blk_execute_rq(q, NULL, rq, 1);
-	rc = rq->errors ? -EIO : 0;
+	rc = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 	if (rc)
 		goto out;
diff --git a/drivers/ide/ide-pm.c b/drivers/ide/ide-pm.c
index bf513f886f3c..277c2bb7616f 100644
--- a/drivers/ide/ide-pm.c
+++ b/drivers/ide/ide-pm.c
@@ -28,7 +28,7 @@ int generic_ide_suspend(struct device *dev, pm_message_t mesg)
 	rqpm.pm_state = mesg.event;
 
 	blk_execute_rq(drive->queue, NULL, rq, 0);
-	ret = rq->errors ? -EIO : 0;
+	ret = scsi_req(rq)->result ? -EIO : 0;
 	blk_put_request(rq);
 
 	if (ret == 0 && ide_port_acpi(hwif)) {
@@ -56,8 +56,8 @@ static int ide_pm_execute_rq(struct request *rq)
 	spin_lock_irq(q->queue_lock);
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		scsi_req(rq)->result = -ENXIO;
+		__blk_end_request_all(rq, scsi_req(rq)->result);
 		spin_unlock_irq(q->queue_lock);
 		return -ENXIO;
 	}
@@ -67,7 +67,7 @@ static int ide_pm_execute_rq(struct request *rq)
 
 	wait_for_completion_io(&wait);
 
-	return rq->errors ? -EIO : 0;
+	return scsi_req(rq)->result ? -EIO : 0;
 }
 
 int generic_ide_resume(struct device *dev)
diff --git a/drivers/ide/ide-tape.c b/drivers/ide/ide-tape.c
index d8a552b47718..a0651f948b76 100644
--- a/drivers/ide/ide-tape.c
+++ b/drivers/ide/ide-tape.c
@@ -366,7 +366,7 @@ static int ide_tape_callback(ide_drive_t *drive, int dsc)
 			err = pc->error;
 		}
 	}
-	rq->errors = err;
+	scsi_req(rq)->result = err;
 
 	return uptodate;
 }
@@ -879,7 +879,7 @@ static int idetape_queue_rw_tail(ide_drive_t *drive, int cmd, int size)
 		tape->valid = 0;
 
 	ret = size;
-	if (rq->errors == IDE_DRV_ERROR_GENERAL)
+	if (scsi_req(rq)->result == IDE_DRV_ERROR_GENERAL)
 		ret = -EIO;
 out_put:
 	blk_put_request(rq);
diff --git a/drivers/ide/ide-taskfile.c b/drivers/ide/ide-taskfile.c
index 78924c7c9478..d71199d23c9e 100644
--- a/drivers/ide/ide-taskfile.c
+++ b/drivers/ide/ide-taskfile.c
@@ -287,7 +287,7 @@ static void ide_pio_datablock(ide_drive_t *drive, struct ide_cmd *cmd,
 	u8 saved_io_32bit = drive->io_32bit;
 
 	if (cmd->tf_flags & IDE_TFLAG_FS)
-		cmd->rq->errors = 0;
+		scsi_req(cmd->rq)->result = 0;
 
 	if (cmd->tf_flags & IDE_TFLAG_IO_16BIT)
 		drive->io_32bit = 0;
@@ -329,7 +329,7 @@ void ide_finish_cmd(ide_drive_t *drive, struct ide_cmd *cmd, u8 stat)
 	u8 set_xfer = !!(cmd->tf_flags & IDE_TFLAG_SET_XFER);
 
 	ide_complete_cmd(drive, cmd, stat, err);
-	rq->errors = err;
+	scsi_req(rq)->result = err;
 
 	if (err == 0 && set_xfer) {
 		ide_set_xfer_rate(drive, nsect);
@@ -453,7 +453,7 @@ int ide_raw_taskfile(ide_drive_t *drive, struct ide_cmd *cmd, u8 *buf,
 	cmd->rq = rq;
 
 	blk_execute_rq(drive->queue, NULL, rq, 0);
-	error = rq->errors ? -EIO : 0;
+	error = scsi_req(rq)->result ? -EIO : 0;
 put_req:
 	blk_put_request(rq);
 	return error;
diff --git a/drivers/scsi/osd/osd_initiator.c b/drivers/scsi/osd/osd_initiator.c
index 44e03c3eb250..8d6e2859d9f9 100644
--- a/drivers/scsi/osd/osd_initiator.c
+++ b/drivers/scsi/osd/osd_initiator.c
@@ -477,7 +477,7 @@ static void _set_error_resid(struct osd_request *or, struct request *req,
 			     int error)
 {
 	or->async_error = error;
-	or->req_errors = req->errors ? : error;
+	or->req_errors = scsi_req(req)->result ? : error;
 	or->sense_len = scsi_req(req)->sense_len;
 	if (or->sense_len)
 		memcpy(or->sense, scsi_req(req)->sense, or->sense_len);
diff --git a/drivers/scsi/osst.c b/drivers/scsi/osst.c
index 41bc1d64bf86..67cbed92f07d 100644
--- a/drivers/scsi/osst.c
+++ b/drivers/scsi/osst.c
@@ -327,7 +327,7 @@ static void osst_end_async(struct request *req, int update)
 	struct osst_tape *STp = SRpnt->stp;
 	struct rq_map_data *mdata = &SRpnt->stp->buffer->map_data;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 #if DEBUG
 	STp->write_pending = 0;
 #endif
diff --git a/drivers/scsi/qla2xxx/qla_bsg.c b/drivers/scsi/qla2xxx/qla_bsg.c
index 84c9098cc089..b6e40fd4c3c1 100644
--- a/drivers/scsi/qla2xxx/qla_bsg.c
+++ b/drivers/scsi/qla2xxx/qla_bsg.c
@@ -2553,13 +2553,13 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 						ql_log(ql_log_warn, vha, 0x7089,
 						    "mbx abort_command "
 						    "failed.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = -EIO;
 					} else {
 						ql_dbg(ql_dbg_user, vha, 0x708a,
 						    "mbx abort_command "
 						    "success.\n");
-						bsg_job->req->errors =
+						scsi_req(bsg_job->req)->result =
 						bsg_reply->result = 0;
 					}
 					spin_lock_irqsave(&ha->hardware_lock, flags);
@@ -2570,7 +2570,7 @@ qla24xx_bsg_timeout(struct bsg_job *bsg_job)
 	}
 	spin_unlock_irqrestore(&ha->hardware_lock, flags);
 	ql_log(ql_log_info, vha, 0x708b, "SRB not found to abort.\n");
-	bsg_job->req->errors = bsg_reply->result = -ENXIO;
+	scsi_req(bsg_job->req)->result = bsg_reply->result = -ENXIO;
 	return 0;
 
 done:
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 7bc4513bf4e4..b9298a499e19 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -229,8 +229,8 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @rq_flags:	flags for ->rq_flags
  * @resid:	optional residual length
  *
- * returns the req->errors value which is the scsi_cmnd result
- * field.
+ * Returns the scsi_cmnd result field if a command was executed, or a negative
+ * Linux error code if we didn't get that far.
  */
 int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		 int data_direction, void *buffer, unsigned bufflen,
@@ -281,7 +281,7 @@ int scsi_execute(struct scsi_device *sdev, const unsigned char *cmd,
 		memcpy(sense, rq->sense, SCSI_SENSE_BUFFERSIZE);
 	if (sshdr)
 		scsi_normalize_sense(rq->sense, rq->sense_len, sshdr);
-	ret = req->errors;
+	ret = rq->result;
  out:
 	blk_put_request(req);
 
@@ -797,8 +797,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		/*
 		 * __scsi_error_from_host_byte may have reset the host_byte
 		 */
-		req->errors = cmd->result;
-
+		scsi_req(req)->result = cmd->result;
 		scsi_req(req)->resid_len = scsi_get_resid(cmd);
 
 		if (scsi_bidi_cmnd(cmd)) {
@@ -835,7 +834,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 	/*
 	 * Recovered errors need reporting, but they're always treated as
 	 * success, so fiddle the result code here.  For passthrough requests
-	 * we already took a copy of the original into rq->errors which
+	 * we already took a copy of the original into sreq->result which
 	 * is what gets returned to the user
 	 */
 	if (sense_valid && (sshdr.sense_key == RECOVERED_ERROR)) {
@@ -1281,7 +1280,7 @@ scsi_prep_return(struct request_queue *q, struct request *req, int ret)
 	switch (ret) {
 	case BLKPREP_KILL:
 	case BLKPREP_INVALID:
-		req->errors = DID_NO_CONNECT << 16;
+		scsi_req(req)->result = DID_NO_CONNECT << 16;
 		/* release the command and kill it */
 		if (req->special) {
 			struct scsi_cmnd *cmd = req->special;
@@ -1905,7 +1904,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, cmd->request->errors);
+	blk_mq_complete_request(cmd->request, 0);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/drivers/scsi/scsi_transport_sas.c b/drivers/scsi/scsi_transport_sas.c
index cdbb293aca08..a2b279737a4b 100644
--- a/drivers/scsi/scsi_transport_sas.c
+++ b/drivers/scsi/scsi_transport_sas.c
@@ -184,7 +184,7 @@ static void sas_smp_request(struct request_queue *q, struct Scsi_Host *shost,
 				blk_rq_bytes(req->next_rq);
 		handler = to_sas_internal(shost->transportt)->f->smp_handler;
 		ret = handler(shost, rphy, req);
-		req->errors = ret;
+		scsi_req(req)->result = ret;
 
 		blk_end_request_all(req, ret);
 
diff --git a/drivers/scsi/sg.c b/drivers/scsi/sg.c
index c5aaceea8d77..504504beaa5e 100644
--- a/drivers/scsi/sg.c
+++ b/drivers/scsi/sg.c
@@ -1300,7 +1300,7 @@ sg_rq_end_io(struct request *rq, int uptodate)
 		pr_info("%s: device detaching\n", __func__);
 
 	sense = req->sense;
-	result = rq->errors;
+	result = req->result;
 	resid = req->resid_len;
 
 	SCSI_LOG_TIMEOUT(4, sg_printk(KERN_INFO, sdp,
diff --git a/drivers/scsi/st.c b/drivers/scsi/st.c
index 5408643431bb..1ea34d6f5437 100644
--- a/drivers/scsi/st.c
+++ b/drivers/scsi/st.c
@@ -480,7 +480,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_write_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->write_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_write_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->write_byte_cnt);
@@ -494,7 +494,7 @@ static void st_do_stats(struct scsi_tape *STp, struct request *req)
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_read_time);
 		atomic64_add(ktime_to_ns(now), &STp->stats->tot_io_time);
 		atomic64_inc(&STp->stats->read_cnt);
-		if (req->errors) {
+		if (scsi_req(req)->result) {
 			atomic64_add(atomic_read(&STp->stats->last_read_size)
 				- STp->buffer->cmdstat.residual,
 				&STp->stats->read_byte_cnt);
@@ -518,7 +518,7 @@ static void st_scsi_execute_end(struct request *req, int uptodate)
 	struct scsi_tape *STp = SRpnt->stp;
 	struct bio *tmp;
 
-	STp->buffer->cmdstat.midlevel_result = SRpnt->result = req->errors;
+	STp->buffer->cmdstat.midlevel_result = SRpnt->result = rq->result;
 	STp->buffer->cmdstat.residual = rq->resid_len;
 
 	st_do_stats(STp, req);
diff --git a/drivers/target/target_core_pscsi.c b/drivers/target/target_core_pscsi.c
index c7fa372c527a..a93d94e68ab5 100644
--- a/drivers/target/target_core_pscsi.c
+++ b/drivers/target/target_core_pscsi.c
@@ -1050,7 +1050,7 @@ static void pscsi_req_done(struct request *req, int uptodate)
 	struct se_cmd *cmd = req->end_io_data;
 	struct pscsi_plugin_task *pt = cmd->priv;
 
-	pt->pscsi_result = req->errors;
+	pt->pscsi_result = scsi_req(req)->result;
 	pt->pscsi_resid = scsi_req(req)->resid_len;
 
 	cmd->scsi_status = status_byte(pt->pscsi_result) << 1;
diff --git a/fs/nfsd/blocklayout.c b/fs/nfsd/blocklayout.c
index 9f618b77ffee..fb5213afc854 100644
--- a/fs/nfsd/blocklayout.c
+++ b/fs/nfsd/blocklayout.c
@@ -243,9 +243,9 @@ static int nfsd4_scsi_identify_device(struct block_device *bdev,
 	req->cmd_len = COMMAND_SIZE(INQUIRY);
 
 	blk_execute_rq(rq->q, NULL, rq, 1);
-	if (rq->errors) {
+	if (req->result) {
 		pr_err("pNFS: INQUIRY 0x83 failed with: %x\n",
-			rq->errors);
+			req->result);
 		error = -EIO;
 		goto out_put_request;
 	}
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 2f51c1724b5a..6980ca322074 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -88,7 +88,7 @@ static inline bool ata_pm_request(struct request *rq)
 		 ide_req(rq)->type == ATA_PRIV_PM_RESUME);
 }
 
-/* Error codes returned in rq->errors to the higher part of the driver. */
+/* Error codes returned in result to the higher part of the driver. */
 enum {
 	IDE_DRV_ERROR_GENERAL	= 101,
 	IDE_DRV_ERROR_FILEMARK	= 102,
diff --git a/include/scsi/scsi_request.h b/include/scsi/scsi_request.h
index 7c583a0f363a..f0c76f9dc285 100644
--- a/include/scsi/scsi_request.h
+++ b/include/scsi/scsi_request.h
@@ -9,6 +9,7 @@ struct scsi_request {
 	unsigned char	__cmd[BLK_MAX_CDB];
 	unsigned char	*cmd;
 	unsigned short	cmd_len;
+	int		result;
 	unsigned int	sense_len;
 	unsigned int	resid_len;	/* residual count */
 	int		retries;
-- 
2.11.0

Re: [PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Martin K. Petersen]

Christoph Hellwig <hch@lst.de> writes:

> This passes on the scsi_cmnd result field to users of passthrough
> requests.  Currently we abuse req->errors for this purpose, but that
> field will go away in its current form.

Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>

> Note that the old IDE code abuses the errors field in very creative
> ways and stores all kinds of different values in it.  I didn't dare
> to touch this magic, so the abuses are brought forward 1:1.

Really wish we could just obliterate drivers/ide.

-- 
Martin K. Petersen	Oracle Linux Engineering

[PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Martin K. Petersen]

Christoph Hellwig <hch at lst.de> writes:

> This passes on the scsi_cmnd result field to users of passthrough
> requests.  Currently we abuse req->errors for this purpose, but that
> field will go away in its current form.

Reviewed-by: Martin K. Petersen <martin.petersen at oracle.com>

> Note that the old IDE code abuses the errors field in very creative
> ways and stores all kinds of different values in it.  I didn't dare
> to touch this magic, so the abuses are brought forward 1:1.

Really wish we could just obliterate drivers/ide.

-- 
Martin K. Petersen	Oracle Linux Engineering

Re: [PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Christoph Hellwig]

On Wed, Apr 19, 2017 at 09:43:00PM -0400, Martin K. Petersen wrote:
> Really wish we could just obliterate drivers/ide.

Same here.  It's been _the_ major pain point for doing block layer
heavy lifting for the last 1 or two years.

[PATCH 08/23] scsi: introduce a result field in struct scsi_request

[Christoph Hellwig]

On Wed, Apr 19, 2017@09:43:00PM -0400, Martin K. Petersen wrote:
> Really wish we could just obliterate drivers/ide.

Same here.  It's been _the_ major pain point for doing block layer
heavy lifting for the last 1 or two years.

[PATCH 09/23] loop: zero-fill bio on the submitting cpu

[Christoph Hellwig]

In thruth I've just audited which blk-mq drivers don't currently have a
complete callback, but I think this change is at least borderline useful.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Ming Lei <ming.lei@redhat.com>
---
 drivers/block/loop.c | 30 ++++++++++++++----------------
 drivers/block/loop.h |  1 +
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3081d83d2ea3..86351b3f7350 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -445,32 +445,27 @@ static int lo_req_flush(struct loop_device *lo, struct request *rq)
 	return ret;
 }
 
-static inline void handle_partial_read(struct loop_cmd *cmd, long bytes)
+static void lo_complete_rq(struct request *rq)
 {
-	if (bytes < 0 || op_is_write(req_op(cmd->rq)))
-		return;
+	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
-	if (unlikely(bytes < blk_rq_bytes(cmd->rq))) {
+	if (unlikely(req_op(cmd->rq) == REQ_OP_READ && cmd->use_aio &&
+		     cmd->ret >= 0 && cmd->ret < blk_rq_bytes(cmd->rq))) {
 		struct bio *bio = cmd->rq->bio;
 
-		bio_advance(bio, bytes);
+		bio_advance(bio, cmd->ret);
 		zero_fill_bio(bio);
 	}
+
+	blk_mq_end_request(rq, cmd->ret < 0 ? -EIO : 0);
 }
 
 static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 {
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
-	struct request *rq = cmd->rq;
-
-	handle_partial_read(cmd, ret);
 
-	if (ret > 0)
-		ret = 0;
-	else if (ret < 0)
-		ret = -EIO;
-
-	blk_mq_complete_request(rq, ret);
+	cmd->ret = ret;
+	blk_mq_complete_request(cmd->rq, 0);
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
@@ -1688,8 +1683,10 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	ret = do_req_filebacked(lo, cmd->rq);
  failed:
 	/* complete non-aio request */
-	if (!cmd->use_aio || ret)
-		blk_mq_complete_request(cmd->rq, ret ? -EIO : 0);
+	if (!cmd->use_aio || ret) {
+		cmd->ret = ret ? -EIO : 0;
+		blk_mq_complete_request(cmd->rq, 0);
+	}
 }
 
 static void loop_queue_work(struct kthread_work *work)
@@ -1715,6 +1712,7 @@ static int loop_init_request(void *data, struct request *rq,
 static const struct blk_mq_ops loop_mq_ops = {
 	.queue_rq       = loop_queue_rq,
 	.init_request	= loop_init_request,
+	.complete	= lo_complete_rq,
 };
 
 static int loop_add(struct loop_device **l, int i)
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index fb2237c73e61..fecd3f97ef8c 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -70,6 +70,7 @@ struct loop_cmd {
 	struct request *rq;
 	struct list_head list;
 	bool use_aio;           /* use AIO interface to handle I/O */
+	long ret;
 	struct kiocb iocb;
 };
 
-- 
2.11.0

[PATCH 09/23] loop: zero-fill bio on the submitting cpu

[Christoph Hellwig]

In thruth I've just audited which blk-mq drivers don't currently have a
complete callback, but I think this change is at least borderline useful.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Ming Lei <ming.lei at redhat.com>
---
 drivers/block/loop.c | 30 ++++++++++++++----------------
 drivers/block/loop.h |  1 +
 2 files changed, 15 insertions(+), 16 deletions(-)

diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 3081d83d2ea3..86351b3f7350 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -445,32 +445,27 @@ static int lo_req_flush(struct loop_device *lo, struct request *rq)
 	return ret;
 }
 
-static inline void handle_partial_read(struct loop_cmd *cmd, long bytes)
+static void lo_complete_rq(struct request *rq)
 {
-	if (bytes < 0 || op_is_write(req_op(cmd->rq)))
-		return;
+	struct loop_cmd *cmd = blk_mq_rq_to_pdu(rq);
 
-	if (unlikely(bytes < blk_rq_bytes(cmd->rq))) {
+	if (unlikely(req_op(cmd->rq) == REQ_OP_READ && cmd->use_aio &&
+		     cmd->ret >= 0 && cmd->ret < blk_rq_bytes(cmd->rq))) {
 		struct bio *bio = cmd->rq->bio;
 
-		bio_advance(bio, bytes);
+		bio_advance(bio, cmd->ret);
 		zero_fill_bio(bio);
 	}
+
+	blk_mq_end_request(rq, cmd->ret < 0 ? -EIO : 0);
 }
 
 static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 {
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
-	struct request *rq = cmd->rq;
-
-	handle_partial_read(cmd, ret);
 
-	if (ret > 0)
-		ret = 0;
-	else if (ret < 0)
-		ret = -EIO;
-
-	blk_mq_complete_request(rq, ret);
+	cmd->ret = ret;
+	blk_mq_complete_request(cmd->rq, 0);
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
@@ -1688,8 +1683,10 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	ret = do_req_filebacked(lo, cmd->rq);
  failed:
 	/* complete non-aio request */
-	if (!cmd->use_aio || ret)
-		blk_mq_complete_request(cmd->rq, ret ? -EIO : 0);
+	if (!cmd->use_aio || ret) {
+		cmd->ret = ret ? -EIO : 0;
+		blk_mq_complete_request(cmd->rq, 0);
+	}
 }
 
 static void loop_queue_work(struct kthread_work *work)
@@ -1715,6 +1712,7 @@ static int loop_init_request(void *data, struct request *rq,
 static const struct blk_mq_ops loop_mq_ops = {
 	.queue_rq       = loop_queue_rq,
 	.init_request	= loop_init_request,
+	.complete	= lo_complete_rq,
 };
 
 static int loop_add(struct loop_device **l, int i)
diff --git a/drivers/block/loop.h b/drivers/block/loop.h
index fb2237c73e61..fecd3f97ef8c 100644
--- a/drivers/block/loop.h
+++ b/drivers/block/loop.h
@@ -70,6 +70,7 @@ struct loop_cmd {
 	struct request *rq;
 	struct list_head list;
 	bool use_aio;           /* use AIO interface to handle I/O */
+	long ret;
 	struct kiocb iocb;
 };
 
-- 
2.11.0

[PATCH 10/23] null_blk: don't pass always-0 req->errors to blk_mq_complete_request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/null_blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index f93906ff31e8..24ca85a70fd8 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -281,7 +281,7 @@ static inline void null_handle_cmd(struct nullb_cmd *cmd)
 	case NULL_IRQ_SOFTIRQ:
 		switch (queue_mode)  {
 		case NULL_Q_MQ:
-			blk_mq_complete_request(cmd->rq, cmd->rq->errors);
+			blk_mq_complete_request(cmd->rq, 0);
 			break;
 		case NULL_Q_RQ:
 			blk_complete_request(cmd->rq);
-- 
2.11.0

[PATCH 10/23] null_blk: don't pass always-0 req->errors to blk_mq_complete_request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/null_blk.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index f93906ff31e8..24ca85a70fd8 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -281,7 +281,7 @@ static inline void null_handle_cmd(struct nullb_cmd *cmd)
 	case NULL_IRQ_SOFTIRQ:
 		switch (queue_mode)  {
 		case NULL_Q_MQ:
-			blk_mq_complete_request(cmd->rq, cmd->rq->errors);
+			blk_mq_complete_request(cmd->rq, 0);
 			break;
 		case NULL_Q_RQ:
 			blk_complete_request(cmd->rq);
-- 
2.11.0

[PATCH 11/23] dm rq: don't pass irrelevant error code to blk_mq_complete_request

[Christoph Hellwig]

dm never uses rq->errors, so there is no need to pass an error argument
to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/dm-rq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index e60f1b6845be..1173be21f6f6 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -363,7 +363,7 @@ static void dm_complete_request(struct request *rq, int error)
 	if (!rq->q->mq_ops)
 		blk_complete_request(rq);
 	else
-		blk_mq_complete_request(rq, error);
+		blk_mq_complete_request(rq, 0);
 }
 
 /*
-- 
2.11.0

[PATCH 11/23] dm rq: don't pass irrelevant error code to blk_mq_complete_request

[Christoph Hellwig]

dm never uses rq->errors, so there is no need to pass an error argument
to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/md/dm-rq.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index e60f1b6845be..1173be21f6f6 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -363,7 +363,7 @@ static void dm_complete_request(struct request *rq, int error)
 	if (!rq->q->mq_ops)
 		blk_complete_request(rq);
 	else
-		blk_mq_complete_request(rq, error);
+		blk_mq_complete_request(rq, 0);
 }
 
 /*
-- 
2.11.0

[PATCH 12/23] dm mpath: don't check for req->errors

[Christoph Hellwig]

We'll get all proper errors reported through ->end_io and ->errors will
go away soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/md/dm-mpath.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index ab55955ed704..2950b145443d 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1492,7 +1492,7 @@ static int do_end_io(struct multipath *m, struct request *clone,
 	 */
 	int r = DM_ENDIO_REQUEUE;
 
-	if (!error && !clone->errors)
+	if (!error)
 		return 0;	/* I/O complete */
 
 	if (noretry_error(error))
-- 
2.11.0

[PATCH 12/23] dm mpath: don't check for req->errors

[Christoph Hellwig]

We'll get all proper errors reported through ->end_io and ->errors will
go away soon.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/md/dm-mpath.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/dm-mpath.c b/drivers/md/dm-mpath.c
index ab55955ed704..2950b145443d 100644
--- a/drivers/md/dm-mpath.c
+++ b/drivers/md/dm-mpath.c
@@ -1492,7 +1492,7 @@ static int do_end_io(struct multipath *m, struct request *clone,
 	 */
 	int r = DM_ENDIO_REQUEUE;
 
-	if (!error && !clone->errors)
+	if (!error)
 		return 0;	/* I/O complete */
 
 	if (noretry_error(error))
-- 
2.11.0

[PATCH 13/23] nbd: don't use req->errors

[Christoph Hellwig]

Add a nbd-specific field instead.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Josef Bacik <jbacik@fb.com>
---
 drivers/block/nbd.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 6e592c2ba8fd..09a74a66beb1 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -115,6 +115,7 @@ struct nbd_cmd {
 	int index;
 	int cookie;
 	struct completion send_complete;
+	int status;
 };
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
@@ -244,16 +245,14 @@ static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
 	nbd_size_update(nbd);
 }
 
-static void nbd_end_request(struct nbd_cmd *cmd)
+static void nbd_complete_rq(struct request *req)
 {
-	struct nbd_device *nbd = cmd->nbd;
-	struct request *req = blk_mq_rq_from_pdu(cmd);
-	int error = req->errors ? -EIO : 0;
+	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
 
-	dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd,
-		error ? "failed" : "done");
+	dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", cmd,
+		cmd->status ? "failed" : "done");
 
-	blk_mq_complete_request(req, error);
+	blk_mq_end_request(req, cmd->status);
 }
 
 /*
@@ -286,7 +285,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 	struct nbd_config *config;
 
 	if (!refcount_inc_not_zero(&nbd->config_refs)) {
-		req->errors = -EIO;
+		cmd->status = -EIO;
 		return BLK_EH_HANDLED;
 	}
 
@@ -331,7 +330,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 				    "Connection timed out\n");
 	}
 	set_bit(NBD_TIMEDOUT, &config->runtime_flags);
-	req->errors = -EIO;
+	cmd->status = -EIO;
 	sock_shutdown(nbd);
 	nbd_config_put(nbd);
 
@@ -574,7 +573,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 	if (ntohl(reply.error)) {
 		dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
 			ntohl(reply.error));
-		req->errors = -EIO;
+		cmd->status = -EIO;
 		return cmd;
 	}
 
@@ -599,7 +598,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 				 */
 				if (nbd_disconnected(config) ||
 				    config->num_connections <= 1) {
-					req->errors = -EIO;
+					cmd->status = -EIO;
 					return cmd;
 				}
 				return ERR_PTR(-EIO);
@@ -636,7 +635,7 @@ static void recv_work(struct work_struct *work)
 			break;
 		}
 
-		nbd_end_request(cmd);
+		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd), 0);
 	}
 	atomic_dec(&config->recv_threads);
 	wake_up(&config->recv_wq);
@@ -651,8 +650,8 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
 	if (!blk_mq_request_started(req))
 		return;
 	cmd = blk_mq_rq_to_pdu(req);
-	req->errors = -EIO;
-	nbd_end_request(cmd);
+	cmd->status = -EIO;
+	blk_mq_complete_request(req, 0);
 }
 
 static void nbd_clear_que(struct nbd_device *nbd)
@@ -740,7 +739,7 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 		nbd_config_put(nbd);
 		return -EINVAL;
 	}
-	req->errors = 0;
+	cmd->status = 0;
 again:
 	nsock = config->socks[index];
 	mutex_lock(&nsock->tx_lock);
@@ -1408,6 +1407,7 @@ static int nbd_init_request(void *data, struct request *rq,
 
 static const struct blk_mq_ops nbd_mq_ops = {
 	.queue_rq	= nbd_queue_rq,
+	.complete	= nbd_complete_rq,
 	.init_request	= nbd_init_request,
 	.timeout	= nbd_xmit_timeout,
 };
-- 
2.11.0

[PATCH 13/23] nbd: don't use req->errors

[Christoph Hellwig]

Add a nbd-specific field instead.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Josef Bacik <jbacik at fb.com>
---
 drivers/block/nbd.c | 30 +++++++++++++++---------------
 1 file changed, 15 insertions(+), 15 deletions(-)

diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 6e592c2ba8fd..09a74a66beb1 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -115,6 +115,7 @@ struct nbd_cmd {
 	int index;
 	int cookie;
 	struct completion send_complete;
+	int status;
 };
 
 #if IS_ENABLED(CONFIG_DEBUG_FS)
@@ -244,16 +245,14 @@ static void nbd_size_set(struct nbd_device *nbd, loff_t blocksize,
 	nbd_size_update(nbd);
 }
 
-static void nbd_end_request(struct nbd_cmd *cmd)
+static void nbd_complete_rq(struct request *req)
 {
-	struct nbd_device *nbd = cmd->nbd;
-	struct request *req = blk_mq_rq_from_pdu(cmd);
-	int error = req->errors ? -EIO : 0;
+	struct nbd_cmd *cmd = blk_mq_rq_to_pdu(req);
 
-	dev_dbg(nbd_to_dev(nbd), "request %p: %s\n", cmd,
-		error ? "failed" : "done");
+	dev_dbg(nbd_to_dev(cmd->nbd), "request %p: %s\n", cmd,
+		cmd->status ? "failed" : "done");
 
-	blk_mq_complete_request(req, error);
+	blk_mq_end_request(req, cmd->status);
 }
 
 /*
@@ -286,7 +285,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 	struct nbd_config *config;
 
 	if (!refcount_inc_not_zero(&nbd->config_refs)) {
-		req->errors = -EIO;
+		cmd->status = -EIO;
 		return BLK_EH_HANDLED;
 	}
 
@@ -331,7 +330,7 @@ static enum blk_eh_timer_return nbd_xmit_timeout(struct request *req,
 				    "Connection timed out\n");
 	}
 	set_bit(NBD_TIMEDOUT, &config->runtime_flags);
-	req->errors = -EIO;
+	cmd->status = -EIO;
 	sock_shutdown(nbd);
 	nbd_config_put(nbd);
 
@@ -574,7 +573,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 	if (ntohl(reply.error)) {
 		dev_err(disk_to_dev(nbd->disk), "Other side returned error (%d)\n",
 			ntohl(reply.error));
-		req->errors = -EIO;
+		cmd->status = -EIO;
 		return cmd;
 	}
 
@@ -599,7 +598,7 @@ static struct nbd_cmd *nbd_read_stat(struct nbd_device *nbd, int index)
 				 */
 				if (nbd_disconnected(config) ||
 				    config->num_connections <= 1) {
-					req->errors = -EIO;
+					cmd->status = -EIO;
 					return cmd;
 				}
 				return ERR_PTR(-EIO);
@@ -636,7 +635,7 @@ static void recv_work(struct work_struct *work)
 			break;
 		}
 
-		nbd_end_request(cmd);
+		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd), 0);
 	}
 	atomic_dec(&config->recv_threads);
 	wake_up(&config->recv_wq);
@@ -651,8 +650,8 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
 	if (!blk_mq_request_started(req))
 		return;
 	cmd = blk_mq_rq_to_pdu(req);
-	req->errors = -EIO;
-	nbd_end_request(cmd);
+	cmd->status = -EIO;
+	blk_mq_complete_request(req, 0);
 }
 
 static void nbd_clear_que(struct nbd_device *nbd)
@@ -740,7 +739,7 @@ static int nbd_handle_cmd(struct nbd_cmd *cmd, int index)
 		nbd_config_put(nbd);
 		return -EINVAL;
 	}
-	req->errors = 0;
+	cmd->status = 0;
 again:
 	nsock = config->socks[index];
 	mutex_lock(&nsock->tx_lock);
@@ -1408,6 +1407,7 @@ static int nbd_init_request(void *data, struct request *rq,
 
 static const struct blk_mq_ops nbd_mq_ops = {
 	.queue_rq	= nbd_queue_rq,
+	.complete	= nbd_complete_rq,
 	.init_request	= nbd_init_request,
 	.timeout	= nbd_xmit_timeout,
 };
-- 
2.11.0

[PATCH 14/23] mtip32xx: add a status field to struct mtip_cmd

[Christoph Hellwig]

Instead of using req->errors, which will go away.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/mtip32xx/mtip32xx.c | 16 +++++++++-------
 drivers/block/mtip32xx/mtip32xx.h |  1 +
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 05e3e664ea1b..7406de29db58 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -241,7 +241,8 @@ static void mtip_async_complete(struct mtip_port *port,
 
 	rq = mtip_rq_from_tag(dd, tag);
 
-	blk_mq_complete_request(rq, status);
+	cmd->status = status;
+	blk_mq_complete_request(rq, 0);
 }
 
 /*
@@ -2910,18 +2911,19 @@ static void mtip_softirq_done_fn(struct request *rq)
 	if (unlikely(cmd->unaligned))
 		up(&dd->port->cmd_slot_unal);
 
-	blk_mq_end_request(rq, rq->errors);
+	blk_mq_end_request(rq, cmd->status);
 }
 
 static void mtip_abort_cmd(struct request *req, void *data,
 							bool reserved)
 {
+	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
 	struct driver_data *dd = data;
 
 	dbg_printk(MTIP_DRV_NAME " Aborting request, tag = %d\n", req->tag);
 
 	clear_bit(req->tag, dd->port->cmds_to_issue);
-	req->errors = -EIO;
+	cmd->status = -EIO;
 	mtip_softirq_done_fn(req);
 }
 
@@ -3816,7 +3818,6 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (likely(!ret))
 		return BLK_MQ_RQ_QUEUE_OK;
 
-	rq->errors = ret;
 	return BLK_MQ_RQ_QUEUE_ERROR;
 }
 
@@ -4106,9 +4107,10 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 	struct driver_data *dd = (struct driver_data *)data;
 	struct mtip_cmd *cmd;
 
-	if (likely(!reserv))
-		blk_mq_complete_request(rq, -ENODEV);
-	else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
+	if (likely(!reserv)) {
+		cmd->status = -ENODEV;
+		blk_mq_complete_request(rq, 0);
+	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
 		if (cmd->comp_func)
diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h
index 7617888f7944..57b41528a824 100644
--- a/drivers/block/mtip32xx/mtip32xx.h
+++ b/drivers/block/mtip32xx/mtip32xx.h
@@ -352,6 +352,7 @@ struct mtip_cmd {
 	int retries; /* The number of retries left for this command. */
 
 	int direction; /* Data transfer direction */
+	int status;
 };
 
 /* Structure used to describe a port. */
-- 
2.11.0

[PATCH 14/23] mtip32xx: add a status field to struct mtip_cmd

[Christoph Hellwig]

Instead of using req->errors, which will go away.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/mtip32xx/mtip32xx.c | 16 +++++++++-------
 drivers/block/mtip32xx/mtip32xx.h |  1 +
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 05e3e664ea1b..7406de29db58 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -241,7 +241,8 @@ static void mtip_async_complete(struct mtip_port *port,
 
 	rq = mtip_rq_from_tag(dd, tag);
 
-	blk_mq_complete_request(rq, status);
+	cmd->status = status;
+	blk_mq_complete_request(rq, 0);
 }
 
 /*
@@ -2910,18 +2911,19 @@ static void mtip_softirq_done_fn(struct request *rq)
 	if (unlikely(cmd->unaligned))
 		up(&dd->port->cmd_slot_unal);
 
-	blk_mq_end_request(rq, rq->errors);
+	blk_mq_end_request(rq, cmd->status);
 }
 
 static void mtip_abort_cmd(struct request *req, void *data,
 							bool reserved)
 {
+	struct mtip_cmd *cmd = blk_mq_rq_to_pdu(req);
 	struct driver_data *dd = data;
 
 	dbg_printk(MTIP_DRV_NAME " Aborting request, tag = %d\n", req->tag);
 
 	clear_bit(req->tag, dd->port->cmds_to_issue);
-	req->errors = -EIO;
+	cmd->status = -EIO;
 	mtip_softirq_done_fn(req);
 }
 
@@ -3816,7 +3818,6 @@ static int mtip_queue_rq(struct blk_mq_hw_ctx *hctx,
 	if (likely(!ret))
 		return BLK_MQ_RQ_QUEUE_OK;
 
-	rq->errors = ret;
 	return BLK_MQ_RQ_QUEUE_ERROR;
 }
 
@@ -4106,9 +4107,10 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 	struct driver_data *dd = (struct driver_data *)data;
 	struct mtip_cmd *cmd;
 
-	if (likely(!reserv))
-		blk_mq_complete_request(rq, -ENODEV);
-	else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
+	if (likely(!reserv)) {
+		cmd->status = -ENODEV;
+		blk_mq_complete_request(rq, 0);
+	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
 		if (cmd->comp_func)
diff --git a/drivers/block/mtip32xx/mtip32xx.h b/drivers/block/mtip32xx/mtip32xx.h
index 7617888f7944..57b41528a824 100644
--- a/drivers/block/mtip32xx/mtip32xx.h
+++ b/drivers/block/mtip32xx/mtip32xx.h
@@ -352,6 +352,7 @@ struct mtip_cmd {
 	int retries; /* The number of retries left for this command. */
 
 	int direction; /* Data transfer direction */
+	int status;
 };
 
 /* Structure used to describe a port. */
-- 
2.11.0

[PATCH 15/23] xen-blkfront: don't use req->errors

[Christoph Hellwig]

xen-blkfron is the last users using rq->errros for passing back error to
blk-mq, and I'd like to get rid of that.  In the longer run the driver
should be moving more of the completion processing into .complete, but
this is the minimal change to move forward for now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 drivers/block/xen-blkfront.c | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index abed296ce605..57866355c060 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -115,6 +115,15 @@ struct split_bio {
 	atomic_t pending;
 };
 
+struct blkif_req {
+	int	error;
+};
+
+static inline struct blkif_req *blkif_req(struct request *rq)
+{
+	return blk_mq_rq_to_pdu(rq);
+}
+
 static DEFINE_MUTEX(blkfront_mutex);
 static const struct block_device_operations xlvbd_block_fops;
 
@@ -907,8 +916,14 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return BLK_MQ_RQ_QUEUE_BUSY;
 }
 
+static void blkif_complete_rq(struct request *rq)
+{
+	blk_mq_end_request(rq, blkif_req(rq)->error);
+}
+
 static const struct blk_mq_ops blkfront_mq_ops = {
 	.queue_rq = blkif_queue_rq,
+	.complete = blkif_complete_rq,
 };
 
 static void blkif_set_queue_limits(struct blkfront_info *info)
@@ -969,7 +984,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
 		info->tag_set.queue_depth = BLK_RING_SIZE(info);
 	info->tag_set.numa_node = NUMA_NO_NODE;
 	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
-	info->tag_set.cmd_size = 0;
+	info->tag_set.cmd_size = sizeof(struct blkif_req);
 	info->tag_set.driver_data = info;
 
 	if (blk_mq_alloc_tag_set(&info->tag_set))
@@ -1543,7 +1558,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 	struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
 	struct blkfront_info *info = rinfo->dev_info;
-	int error;
 
 	if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
 		return IRQ_HANDLED;
@@ -1587,37 +1601,36 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 			continue;
 		}
 
-		error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
+		blkif_req(req)->error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
 		switch (bret->operation) {
 		case BLKIF_OP_DISCARD:
 			if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
 				struct request_queue *rq = info->rq;
 				printk(KERN_WARNING "blkfront: %s: %s op failed\n",
 					   info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 				info->feature_discard = 0;
 				info->feature_secdiscard = 0;
 				queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
 				queue_flag_clear(QUEUE_FLAG_SECERASE, rq);
 			}
-			blk_mq_complete_request(req, error);
 			break;
 		case BLKIF_OP_FLUSH_DISKCACHE:
 		case BLKIF_OP_WRITE_BARRIER:
 			if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
 				printk(KERN_WARNING "blkfront: %s: %s op failed\n",
 				       info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 			}
 			if (unlikely(bret->status == BLKIF_RSP_ERROR &&
 				     rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
 				printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
 				       info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 			}
-			if (unlikely(error)) {
-				if (error == -EOPNOTSUPP)
-					error = 0;
+			if (unlikely(blkif_req(req)->error)) {
+				if (blkif_req(req)->error == -EOPNOTSUPP)
+					blkif_req(req)->error = 0;
 				info->feature_fua = 0;
 				info->feature_flush = 0;
 				xlvbd_flush(info);
@@ -1629,11 +1642,12 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 				dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
 					"request: %x\n", bret->status);
 
-			blk_mq_complete_request(req, error);
 			break;
 		default:
 			BUG();
 		}
+
+		blk_mq_complete_request(req, 0);
 	}
 
 	rinfo->ring.rsp_cons = i;
-- 
2.11.0

[PATCH 15/23] xen-blkfront: don't use req->errors

[Christoph Hellwig]

xen-blkfron is the last users using rq->errros for passing back error to
blk-mq, and I'd like to get rid of that.  In the longer run the driver
should be moving more of the completion processing into .complete, but
this is the minimal change to move forward for now.

Signed-off-by: Christoph Hellwig <hch at lst.de>
Acked-by: Roger Pau Monn? <roger.pau at citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 drivers/block/xen-blkfront.c | 36 +++++++++++++++++++++++++-----------
 1 file changed, 25 insertions(+), 11 deletions(-)

diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index abed296ce605..57866355c060 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -115,6 +115,15 @@ struct split_bio {
 	atomic_t pending;
 };
 
+struct blkif_req {
+	int	error;
+};
+
+static inline struct blkif_req *blkif_req(struct request *rq)
+{
+	return blk_mq_rq_to_pdu(rq);
+}
+
 static DEFINE_MUTEX(blkfront_mutex);
 static const struct block_device_operations xlvbd_block_fops;
 
@@ -907,8 +916,14 @@ static int blkif_queue_rq(struct blk_mq_hw_ctx *hctx,
 	return BLK_MQ_RQ_QUEUE_BUSY;
 }
 
+static void blkif_complete_rq(struct request *rq)
+{
+	blk_mq_end_request(rq, blkif_req(rq)->error);
+}
+
 static const struct blk_mq_ops blkfront_mq_ops = {
 	.queue_rq = blkif_queue_rq,
+	.complete = blkif_complete_rq,
 };
 
 static void blkif_set_queue_limits(struct blkfront_info *info)
@@ -969,7 +984,7 @@ static int xlvbd_init_blk_queue(struct gendisk *gd, u16 sector_size,
 		info->tag_set.queue_depth = BLK_RING_SIZE(info);
 	info->tag_set.numa_node = NUMA_NO_NODE;
 	info->tag_set.flags = BLK_MQ_F_SHOULD_MERGE | BLK_MQ_F_SG_MERGE;
-	info->tag_set.cmd_size = 0;
+	info->tag_set.cmd_size = sizeof(struct blkif_req);
 	info->tag_set.driver_data = info;
 
 	if (blk_mq_alloc_tag_set(&info->tag_set))
@@ -1543,7 +1558,6 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 	unsigned long flags;
 	struct blkfront_ring_info *rinfo = (struct blkfront_ring_info *)dev_id;
 	struct blkfront_info *info = rinfo->dev_info;
-	int error;
 
 	if (unlikely(info->connected != BLKIF_STATE_CONNECTED))
 		return IRQ_HANDLED;
@@ -1587,37 +1601,36 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 			continue;
 		}
 
-		error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
+		blkif_req(req)->error = (bret->status == BLKIF_RSP_OKAY) ? 0 : -EIO;
 		switch (bret->operation) {
 		case BLKIF_OP_DISCARD:
 			if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
 				struct request_queue *rq = info->rq;
 				printk(KERN_WARNING "blkfront: %s: %s op failed\n",
 					   info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 				info->feature_discard = 0;
 				info->feature_secdiscard = 0;
 				queue_flag_clear(QUEUE_FLAG_DISCARD, rq);
 				queue_flag_clear(QUEUE_FLAG_SECERASE, rq);
 			}
-			blk_mq_complete_request(req, error);
 			break;
 		case BLKIF_OP_FLUSH_DISKCACHE:
 		case BLKIF_OP_WRITE_BARRIER:
 			if (unlikely(bret->status == BLKIF_RSP_EOPNOTSUPP)) {
 				printk(KERN_WARNING "blkfront: %s: %s op failed\n",
 				       info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 			}
 			if (unlikely(bret->status == BLKIF_RSP_ERROR &&
 				     rinfo->shadow[id].req.u.rw.nr_segments == 0)) {
 				printk(KERN_WARNING "blkfront: %s: empty %s op failed\n",
 				       info->gd->disk_name, op_name(bret->operation));
-				error = -EOPNOTSUPP;
+				blkif_req(req)->error = -EOPNOTSUPP;
 			}
-			if (unlikely(error)) {
-				if (error == -EOPNOTSUPP)
-					error = 0;
+			if (unlikely(blkif_req(req)->error)) {
+				if (blkif_req(req)->error == -EOPNOTSUPP)
+					blkif_req(req)->error = 0;
 				info->feature_fua = 0;
 				info->feature_flush = 0;
 				xlvbd_flush(info);
@@ -1629,11 +1642,12 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 				dev_dbg(&info->xbdev->dev, "Bad return from blkdev data "
 					"request: %x\n", bret->status);
 
-			blk_mq_complete_request(req, error);
 			break;
 		default:
 			BUG();
 		}
+
+		blk_mq_complete_request(req, 0);
 	}
 
 	rinfo->ring.rsp_cons = i;
-- 
2.11.0

[PATCH 16/23] blk-mq: remove the error argument to blk_mq_complete_request

[Christoph Hellwig]

Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq.c                    | 15 +++------------
 drivers/block/loop.c              |  4 ++--
 drivers/block/mtip32xx/mtip32xx.c |  4 ++--
 drivers/block/nbd.c               |  4 ++--
 drivers/block/null_blk.c          |  2 +-
 drivers/block/virtio_blk.c        |  2 +-
 drivers/block/xen-blkfront.c      |  2 +-
 drivers/md/dm-rq.c                |  2 +-
 drivers/nvme/host/core.c          |  2 +-
 drivers/nvme/host/nvme.h          |  2 +-
 drivers/scsi/scsi_lib.c           |  2 +-
 include/linux/blk-mq.h            |  2 +-
 12 files changed, 17 insertions(+), 26 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e2ef7b460924..0c19df66f5a0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -442,17 +442,10 @@ static void blk_mq_stat_add(struct request *rq)
 
 static void __blk_mq_complete_request(struct request *rq)
 {
-	struct request_queue *q = rq->q;
-
 	if (rq->internal_tag != -1)
 		blk_mq_sched_completed_request(rq);
-
 	blk_mq_stat_add(rq);
-
-	if (!q->softirq_done_fn)
-		blk_mq_end_request(rq, rq->errors);
-	else
-		blk_mq_ipi_complete_request(rq);
+	blk_mq_ipi_complete_request(rq);
 }
 
 /**
@@ -463,16 +456,14 @@ static void __blk_mq_complete_request(struct request *rq)
  *	Ends all I/O on a request. It does not handle partial completions.
  *	The actual completion happens out-of-order, through a IPI handler.
  **/
-void blk_mq_complete_request(struct request *rq, int error)
+void blk_mq_complete_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 
 	if (unlikely(blk_should_fake_timeout(q)))
 		return;
-	if (!blk_mark_rq_complete(rq)) {
-		rq->errors = error;
+	if (!blk_mark_rq_complete(rq))
 		__blk_mq_complete_request(rq);
-	}
 }
 EXPORT_SYMBOL(blk_mq_complete_request);
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 86351b3f7350..994403efee19 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -465,7 +465,7 @@ static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
 
 	cmd->ret = ret;
-	blk_mq_complete_request(cmd->rq, 0);
+	blk_mq_complete_request(cmd->rq);
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
@@ -1685,7 +1685,7 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	/* complete non-aio request */
 	if (!cmd->use_aio || ret) {
 		cmd->ret = ret ? -EIO : 0;
-		blk_mq_complete_request(cmd->rq, 0);
+		blk_mq_complete_request(cmd->rq);
 	}
 }
 
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 7406de29db58..66a6bd83faae 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -242,7 +242,7 @@ static void mtip_async_complete(struct mtip_port *port,
 	rq = mtip_rq_from_tag(dd, tag);
 
 	cmd->status = status;
-	blk_mq_complete_request(rq, 0);
+	blk_mq_complete_request(rq);
 }
 
 /*
@@ -4109,7 +4109,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 
 	if (likely(!reserv)) {
 		cmd->status = -ENODEV;
-		blk_mq_complete_request(rq, 0);
+		blk_mq_complete_request(rq);
 	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 09a74a66beb1..d387bef07fcc 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -635,7 +635,7 @@ static void recv_work(struct work_struct *work)
 			break;
 		}
 
-		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd), 0);
+		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
 	}
 	atomic_dec(&config->recv_threads);
 	wake_up(&config->recv_wq);
@@ -651,7 +651,7 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
 		return;
 	cmd = blk_mq_rq_to_pdu(req);
 	cmd->status = -EIO;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 }
 
 static void nbd_clear_que(struct nbd_device *nbd)
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 24ca85a70fd8..c27cccec368b 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -281,7 +281,7 @@ static inline void null_handle_cmd(struct nullb_cmd *cmd)
 	case NULL_IRQ_SOFTIRQ:
 		switch (queue_mode)  {
 		case NULL_Q_MQ:
-			blk_mq_complete_request(cmd->rq, 0);
+			blk_mq_complete_request(cmd->rq);
 			break;
 		case NULL_Q_RQ:
 			blk_complete_request(cmd->rq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index dea2a58d6734..f94614257462 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -201,7 +201,7 @@ static void virtblk_done(struct virtqueue *vq)
 		while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
 			struct request *req = blk_mq_rq_from_pdu(vbr);
 
-			blk_mq_complete_request(req, 0);
+			blk_mq_complete_request(req);
 			req_done = true;
 		}
 		if (unlikely(virtqueue_is_broken(vq)))
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 57866355c060..39459631667c 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1647,7 +1647,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 			BUG();
 		}
 
-		blk_mq_complete_request(req, 0);
+		blk_mq_complete_request(req);
 	}
 
 	rinfo->ring.rsp_cons = i;
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1173be21f6f6..bff7e3bdb4ed 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -363,7 +363,7 @@ static void dm_complete_request(struct request *rq, int error)
 	if (!rq->q->mq_ops)
 		blk_complete_request(rq);
 	else
-		blk_mq_complete_request(rq, 0);
+		blk_mq_complete_request(rq);
 }
 
 /*
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 805f250315ec..8dc664798293 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -117,7 +117,7 @@ void nvme_cancel_request(struct request *req, void *data, bool reserved)
 	if (blk_queue_dying(req->q))
 		status |= NVME_SC_DNR;
 	nvme_req(req)->status = status;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 
 }
 EXPORT_SYMBOL_GPL(nvme_cancel_request);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 550037f5efea..c6ef6c30e2f0 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -251,7 +251,7 @@ static inline void nvme_end_request(struct request *req, __le16 status,
 
 	rq->status = le16_to_cpu(status) >> 1;
 	rq->result = result;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 }
 
 void nvme_complete_rq(struct request *req);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b9298a499e19..4a20e6098f7c 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1904,7 +1904,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, 0);
+	blk_mq_complete_request(cmd->request);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index d75de612845d..0c4dadb85f62 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -228,7 +228,7 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
 void blk_mq_kick_requeue_list(struct request_queue *q);
 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 void blk_mq_abort_requeue_list(struct request_queue *q);
-void blk_mq_complete_request(struct request *rq, int error);
+void blk_mq_complete_request(struct request *rq);
 
 bool blk_mq_queue_stopped(struct request_queue *q);
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
-- 
2.11.0

[PATCH 16/23] blk-mq: remove the error argument to blk_mq_complete_request

[Christoph Hellwig]

Now that all drivers that call blk_mq_complete_requests have a
->complete callback we can remove the direct call to blk_mq_end_request,
as well as the error argument to blk_mq_complete_request.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 block/blk-mq.c                    | 15 +++------------
 drivers/block/loop.c              |  4 ++--
 drivers/block/mtip32xx/mtip32xx.c |  4 ++--
 drivers/block/nbd.c               |  4 ++--
 drivers/block/null_blk.c          |  2 +-
 drivers/block/virtio_blk.c        |  2 +-
 drivers/block/xen-blkfront.c      |  2 +-
 drivers/md/dm-rq.c                |  2 +-
 drivers/nvme/host/core.c          |  2 +-
 drivers/nvme/host/nvme.h          |  2 +-
 drivers/scsi/scsi_lib.c           |  2 +-
 include/linux/blk-mq.h            |  2 +-
 12 files changed, 17 insertions(+), 26 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index e2ef7b460924..0c19df66f5a0 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -442,17 +442,10 @@ static void blk_mq_stat_add(struct request *rq)
 
 static void __blk_mq_complete_request(struct request *rq)
 {
-	struct request_queue *q = rq->q;
-
 	if (rq->internal_tag != -1)
 		blk_mq_sched_completed_request(rq);
-
 	blk_mq_stat_add(rq);
-
-	if (!q->softirq_done_fn)
-		blk_mq_end_request(rq, rq->errors);
-	else
-		blk_mq_ipi_complete_request(rq);
+	blk_mq_ipi_complete_request(rq);
 }
 
 /**
@@ -463,16 +456,14 @@ static void __blk_mq_complete_request(struct request *rq)
  *	Ends all I/O on a request. It does not handle partial completions.
  *	The actual completion happens out-of-order, through a IPI handler.
  **/
-void blk_mq_complete_request(struct request *rq, int error)
+void blk_mq_complete_request(struct request *rq)
 {
 	struct request_queue *q = rq->q;
 
 	if (unlikely(blk_should_fake_timeout(q)))
 		return;
-	if (!blk_mark_rq_complete(rq)) {
-		rq->errors = error;
+	if (!blk_mark_rq_complete(rq))
 		__blk_mq_complete_request(rq);
-	}
 }
 EXPORT_SYMBOL(blk_mq_complete_request);
 
diff --git a/drivers/block/loop.c b/drivers/block/loop.c
index 86351b3f7350..994403efee19 100644
--- a/drivers/block/loop.c
+++ b/drivers/block/loop.c
@@ -465,7 +465,7 @@ static void lo_rw_aio_complete(struct kiocb *iocb, long ret, long ret2)
 	struct loop_cmd *cmd = container_of(iocb, struct loop_cmd, iocb);
 
 	cmd->ret = ret;
-	blk_mq_complete_request(cmd->rq, 0);
+	blk_mq_complete_request(cmd->rq);
 }
 
 static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
@@ -1685,7 +1685,7 @@ static void loop_handle_cmd(struct loop_cmd *cmd)
 	/* complete non-aio request */
 	if (!cmd->use_aio || ret) {
 		cmd->ret = ret ? -EIO : 0;
-		blk_mq_complete_request(cmd->rq, 0);
+		blk_mq_complete_request(cmd->rq);
 	}
 }
 
diff --git a/drivers/block/mtip32xx/mtip32xx.c b/drivers/block/mtip32xx/mtip32xx.c
index 7406de29db58..66a6bd83faae 100644
--- a/drivers/block/mtip32xx/mtip32xx.c
+++ b/drivers/block/mtip32xx/mtip32xx.c
@@ -242,7 +242,7 @@ static void mtip_async_complete(struct mtip_port *port,
 	rq = mtip_rq_from_tag(dd, tag);
 
 	cmd->status = status;
-	blk_mq_complete_request(rq, 0);
+	blk_mq_complete_request(rq);
 }
 
 /*
@@ -4109,7 +4109,7 @@ static void mtip_no_dev_cleanup(struct request *rq, void *data, bool reserv)
 
 	if (likely(!reserv)) {
 		cmd->status = -ENODEV;
-		blk_mq_complete_request(rq, 0);
+		blk_mq_complete_request(rq);
 	} else if (test_bit(MTIP_PF_IC_ACTIVE_BIT, &dd->port->flags)) {
 
 		cmd = mtip_cmd_from_tag(dd, MTIP_TAG_INTERNAL);
diff --git a/drivers/block/nbd.c b/drivers/block/nbd.c
index 09a74a66beb1..d387bef07fcc 100644
--- a/drivers/block/nbd.c
+++ b/drivers/block/nbd.c
@@ -635,7 +635,7 @@ static void recv_work(struct work_struct *work)
 			break;
 		}
 
-		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd), 0);
+		blk_mq_complete_request(blk_mq_rq_from_pdu(cmd));
 	}
 	atomic_dec(&config->recv_threads);
 	wake_up(&config->recv_wq);
@@ -651,7 +651,7 @@ static void nbd_clear_req(struct request *req, void *data, bool reserved)
 		return;
 	cmd = blk_mq_rq_to_pdu(req);
 	cmd->status = -EIO;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 }
 
 static void nbd_clear_que(struct nbd_device *nbd)
diff --git a/drivers/block/null_blk.c b/drivers/block/null_blk.c
index 24ca85a70fd8..c27cccec368b 100644
--- a/drivers/block/null_blk.c
+++ b/drivers/block/null_blk.c
@@ -281,7 +281,7 @@ static inline void null_handle_cmd(struct nullb_cmd *cmd)
 	case NULL_IRQ_SOFTIRQ:
 		switch (queue_mode)  {
 		case NULL_Q_MQ:
-			blk_mq_complete_request(cmd->rq, 0);
+			blk_mq_complete_request(cmd->rq);
 			break;
 		case NULL_Q_RQ:
 			blk_complete_request(cmd->rq);
diff --git a/drivers/block/virtio_blk.c b/drivers/block/virtio_blk.c
index dea2a58d6734..f94614257462 100644
--- a/drivers/block/virtio_blk.c
+++ b/drivers/block/virtio_blk.c
@@ -201,7 +201,7 @@ static void virtblk_done(struct virtqueue *vq)
 		while ((vbr = virtqueue_get_buf(vblk->vqs[qid].vq, &len)) != NULL) {
 			struct request *req = blk_mq_rq_from_pdu(vbr);
 
-			blk_mq_complete_request(req, 0);
+			blk_mq_complete_request(req);
 			req_done = true;
 		}
 		if (unlikely(virtqueue_is_broken(vq)))
diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c
index 57866355c060..39459631667c 100644
--- a/drivers/block/xen-blkfront.c
+++ b/drivers/block/xen-blkfront.c
@@ -1647,7 +1647,7 @@ static irqreturn_t blkif_interrupt(int irq, void *dev_id)
 			BUG();
 		}
 
-		blk_mq_complete_request(req, 0);
+		blk_mq_complete_request(req);
 	}
 
 	rinfo->ring.rsp_cons = i;
diff --git a/drivers/md/dm-rq.c b/drivers/md/dm-rq.c
index 1173be21f6f6..bff7e3bdb4ed 100644
--- a/drivers/md/dm-rq.c
+++ b/drivers/md/dm-rq.c
@@ -363,7 +363,7 @@ static void dm_complete_request(struct request *rq, int error)
 	if (!rq->q->mq_ops)
 		blk_complete_request(rq);
 	else
-		blk_mq_complete_request(rq, 0);
+		blk_mq_complete_request(rq);
 }
 
 /*
diff --git a/drivers/nvme/host/core.c b/drivers/nvme/host/core.c
index 805f250315ec..8dc664798293 100644
--- a/drivers/nvme/host/core.c
+++ b/drivers/nvme/host/core.c
@@ -117,7 +117,7 @@ void nvme_cancel_request(struct request *req, void *data, bool reserved)
 	if (blk_queue_dying(req->q))
 		status |= NVME_SC_DNR;
 	nvme_req(req)->status = status;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 
 }
 EXPORT_SYMBOL_GPL(nvme_cancel_request);
diff --git a/drivers/nvme/host/nvme.h b/drivers/nvme/host/nvme.h
index 550037f5efea..c6ef6c30e2f0 100644
--- a/drivers/nvme/host/nvme.h
+++ b/drivers/nvme/host/nvme.h
@@ -251,7 +251,7 @@ static inline void nvme_end_request(struct request *req, __le16 status,
 
 	rq->status = le16_to_cpu(status) >> 1;
 	rq->result = result;
-	blk_mq_complete_request(req, 0);
+	blk_mq_complete_request(req);
 }
 
 void nvme_complete_rq(struct request *req);
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index b9298a499e19..4a20e6098f7c 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1904,7 +1904,7 @@ static int scsi_mq_prep_fn(struct request *req)
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(cmd->request, 0);
+	blk_mq_complete_request(cmd->request);
 }
 
 static int scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
diff --git a/include/linux/blk-mq.h b/include/linux/blk-mq.h
index d75de612845d..0c4dadb85f62 100644
--- a/include/linux/blk-mq.h
+++ b/include/linux/blk-mq.h
@@ -228,7 +228,7 @@ void blk_mq_add_to_requeue_list(struct request *rq, bool at_head,
 void blk_mq_kick_requeue_list(struct request_queue *q);
 void blk_mq_delay_kick_requeue_list(struct request_queue *q, unsigned long msecs);
 void blk_mq_abort_requeue_list(struct request_queue *q);
-void blk_mq_complete_request(struct request *rq, int error);
+void blk_mq_complete_request(struct request *rq);
 
 bool blk_mq_queue_stopped(struct request_queue *q);
 void blk_mq_stop_hw_queue(struct blk_mq_hw_ctx *hctx);
-- 
2.11.0

[PATCH 17/23] blk-mq: simplify __blk_mq_complete_request

[Christoph Hellwig]

Merge blk_mq_ipi_complete_request and blk_mq_stat_add into their only
caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 block/blk-mq.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0c19df66f5a0..1f98db082da3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -406,12 +406,19 @@ static void __blk_mq_complete_request_remote(void *data)
 	rq->q->softirq_done_fn(rq);
 }
 
-static void blk_mq_ipi_complete_request(struct request *rq)
+static void __blk_mq_complete_request(struct request *rq)
 {
 	struct blk_mq_ctx *ctx = rq->mq_ctx;
 	bool shared = false;
 	int cpu;
 
+	if (rq->internal_tag != -1)
+		blk_mq_sched_completed_request(rq);
+	if (rq->rq_flags & RQF_STATS) {
+		blk_mq_poll_stats_start(rq->q);
+		blk_stat_add(rq);
+	}
+
 	if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
 		rq->q->softirq_done_fn(rq);
 		return;
@@ -432,22 +439,6 @@ static void blk_mq_ipi_complete_request(struct request *rq)
 	put_cpu();
 }
 
-static void blk_mq_stat_add(struct request *rq)
-{
-	if (rq->rq_flags & RQF_STATS) {
-		blk_mq_poll_stats_start(rq->q);
-		blk_stat_add(rq);
-	}
-}
-
-static void __blk_mq_complete_request(struct request *rq)
-{
-	if (rq->internal_tag != -1)
-		blk_mq_sched_completed_request(rq);
-	blk_mq_stat_add(rq);
-	blk_mq_ipi_complete_request(rq);
-}
-
 /**
  * blk_mq_complete_request - end I/O on a request
  * @rq:		the request being processed
-- 
2.11.0

[PATCH 17/23] blk-mq: simplify __blk_mq_complete_request

[Christoph Hellwig]

Merge blk_mq_ipi_complete_request and blk_mq_stat_add into their only
caller.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 block/blk-mq.c | 25 ++++++++-----------------
 1 file changed, 8 insertions(+), 17 deletions(-)

diff --git a/block/blk-mq.c b/block/blk-mq.c
index 0c19df66f5a0..1f98db082da3 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -406,12 +406,19 @@ static void __blk_mq_complete_request_remote(void *data)
 	rq->q->softirq_done_fn(rq);
 }
 
-static void blk_mq_ipi_complete_request(struct request *rq)
+static void __blk_mq_complete_request(struct request *rq)
 {
 	struct blk_mq_ctx *ctx = rq->mq_ctx;
 	bool shared = false;
 	int cpu;
 
+	if (rq->internal_tag != -1)
+		blk_mq_sched_completed_request(rq);
+	if (rq->rq_flags & RQF_STATS) {
+		blk_mq_poll_stats_start(rq->q);
+		blk_stat_add(rq);
+	}
+
 	if (!test_bit(QUEUE_FLAG_SAME_COMP, &rq->q->queue_flags)) {
 		rq->q->softirq_done_fn(rq);
 		return;
@@ -432,22 +439,6 @@ static void blk_mq_ipi_complete_request(struct request *rq)
 	put_cpu();
 }
 
-static void blk_mq_stat_add(struct request *rq)
-{
-	if (rq->rq_flags & RQF_STATS) {
-		blk_mq_poll_stats_start(rq->q);
-		blk_stat_add(rq);
-	}
-}
-
-static void __blk_mq_complete_request(struct request *rq)
-{
-	if (rq->internal_tag != -1)
-		blk_mq_sched_completed_request(rq);
-	blk_mq_stat_add(rq);
-	blk_mq_ipi_complete_request(rq);
-}
-
 /**
  * blk_mq_complete_request - end I/O on a request
  * @rq:		the request being processed
-- 
2.11.0

[PATCH 18/23] block: add a error_count field to struct request

[Christoph Hellwig]

This is for the legacy floppy and ataflop drivers that currently abuse
->errors for this purpose.  It's stashed away in a union to not grow
the struct size, the other fields are either used by modern drivers
for different purposes or the I/O scheduler before queing the I/O
to drivers.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/blkdev.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d8bcd51b8a47..e8006abce8b6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -175,6 +175,7 @@ struct request {
 		struct rb_node rb_node;	/* sort/lookup */
 		struct bio_vec special_vec;
 		void *completion_data;
+		int error_count; /* for legacy drivers, don't use */
 	};
 
 	/*
-- 
2.11.0

[PATCH 18/23] block: add a error_count field to struct request

[Christoph Hellwig]

This is for the legacy floppy and ataflop drivers that currently abuse
->errors for this purpose.  It's stashed away in a union to not grow
the struct size, the other fields are either used by modern drivers
for different purposes or the I/O scheduler before queing the I/O
to drivers.

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 include/linux/blkdev.h | 1 +
 1 file changed, 1 insertion(+)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index d8bcd51b8a47..e8006abce8b6 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -175,6 +175,7 @@ struct request {
 		struct rb_node rb_node;	/* sort/lookup */
 		struct bio_vec special_vec;
 		void *completion_data;
+		int error_count; /* for legacy drivers, don't use */
 	};
 
 	/*
-- 
2.11.0

[PATCH 19/23] floppy: switch from req->errors to req->error_count

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/floppy.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index ce102ec47ef2..60d4c7653178 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2805,8 +2805,10 @@ static int set_next_request(void)
 			fdc_queue = 0;
 		if (q) {
 			current_req = blk_fetch_request(q);
-			if (current_req)
+			if (current_req) {
+				current_req->error_count = 0;
 				break;
+			}
 		}
 	} while (fdc_queue != old_pos);
 
@@ -2866,7 +2868,7 @@ static void redo_fd_request(void)
 		_floppy = floppy_type + DP->autodetect[DRS->probed_format];
 	} else
 		probing = 0;
-	errors = &(current_req->errors);
+	errors = &(current_req->error_count);
 	tmp = make_raw_rw_request();
 	if (tmp < 2) {
 		request_done(tmp);
-- 
2.11.0

[PATCH 19/23] floppy: switch from req->errors to req->error_count

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/floppy.c | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/block/floppy.c b/drivers/block/floppy.c
index ce102ec47ef2..60d4c7653178 100644
--- a/drivers/block/floppy.c
+++ b/drivers/block/floppy.c
@@ -2805,8 +2805,10 @@ static int set_next_request(void)
 			fdc_queue = 0;
 		if (q) {
 			current_req = blk_fetch_request(q);
-			if (current_req)
+			if (current_req) {
+				current_req->error_count = 0;
 				break;
+			}
 		}
 	} while (fdc_queue != old_pos);
 
@@ -2866,7 +2868,7 @@ static void redo_fd_request(void)
 		_floppy = floppy_type + DP->autodetect[DRS->probed_format];
 	} else
 		probing = 0;
-	errors = &(current_req->errors);
+	errors = &(current_req->error_count);
 	tmp = make_raw_rw_request();
 	if (tmp < 2) {
 		request_done(tmp);
-- 
2.11.0

[PATCH 20/23] ataflop: switch from req->errors to req->error_count

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/ataflop.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 2104b1b4ccda..fa69ecd52cb5 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -617,12 +617,12 @@ static void fd_error( void )
 	if (!fd_request)
 		return;
 
-	fd_request->errors++;
-	if (fd_request->errors >= MAX_ERRORS) {
+	fd_request->error_count++;
+	if (fd_request->error_count >= MAX_ERRORS) {
 		printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
 		fd_end_request_cur(-EIO);
 	}
-	else if (fd_request->errors == RECALIBRATE_ERRORS) {
+	else if (fd_request->error_count == RECALIBRATE_ERRORS) {
 		printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive );
 		if (SelectedDrive != -1)
 			SUD.track = -1;
@@ -1386,7 +1386,7 @@ static void setup_req_params( int drive )
 	ReqData = ReqBuffer + 512 * ReqCnt;
 
 	if (UseTrackbuffer)
-		read_track = (ReqCmd == READ && fd_request->errors == 0);
+		read_track = (ReqCmd == READ && fd_request->error_count == 0);
 	else
 		read_track = 0;
 
@@ -1409,8 +1409,10 @@ static struct request *set_next_request(void)
 			fdc_queue = 0;
 		if (q) {
 			rq = blk_fetch_request(q);
-			if (rq)
+			if (rq) {
+				rq->error_count = 0;
 				break;
+			}
 		}
 	} while (fdc_queue != old_pos);
 
-- 
2.11.0

[PATCH 20/23] ataflop: switch from req->errors to req->error_count

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/ataflop.c | 12 +++++++-----
 1 file changed, 7 insertions(+), 5 deletions(-)

diff --git a/drivers/block/ataflop.c b/drivers/block/ataflop.c
index 2104b1b4ccda..fa69ecd52cb5 100644
--- a/drivers/block/ataflop.c
+++ b/drivers/block/ataflop.c
@@ -617,12 +617,12 @@ static void fd_error( void )
 	if (!fd_request)
 		return;
 
-	fd_request->errors++;
-	if (fd_request->errors >= MAX_ERRORS) {
+	fd_request->error_count++;
+	if (fd_request->error_count >= MAX_ERRORS) {
 		printk(KERN_ERR "fd%d: too many errors.\n", SelectedDrive );
 		fd_end_request_cur(-EIO);
 	}
-	else if (fd_request->errors == RECALIBRATE_ERRORS) {
+	else if (fd_request->error_count == RECALIBRATE_ERRORS) {
 		printk(KERN_WARNING "fd%d: recalibrating\n", SelectedDrive );
 		if (SelectedDrive != -1)
 			SUD.track = -1;
@@ -1386,7 +1386,7 @@ static void setup_req_params( int drive )
 	ReqData = ReqBuffer + 512 * ReqCnt;
 
 	if (UseTrackbuffer)
-		read_track = (ReqCmd == READ && fd_request->errors == 0);
+		read_track = (ReqCmd == READ && fd_request->error_count == 0);
 	else
 		read_track = 0;
 
@@ -1409,8 +1409,10 @@ static struct request *set_next_request(void)
 			fdc_queue = 0;
 		if (q) {
 			rq = blk_fetch_request(q);
-			if (rq)
+			if (rq) {
+				rq->error_count = 0;
 				break;
+			}
 		}
 	} while (fdc_queue != old_pos);
 
-- 
2.11.0

[PATCH 21/23] swim3: remove (commented out) printing of req->errors

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/block/swim3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 61b3ffa4f458..ba4809c9bdba 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -343,8 +343,8 @@ static void start_request(struct floppy_state *fs)
 			  req->rq_disk->disk_name, req->cmd,
 			  (long)blk_rq_pos(req), blk_rq_sectors(req),
 			  bio_data(req->bio));
-		swim3_dbg("           errors=%d current_nr_sectors=%u\n",
-			  req->errors, blk_rq_cur_sectors(req));
+		swim3_dbg("           current_nr_sectors=%u\n",
+			  blk_rq_cur_sectors(req));
 #endif
 
 		if (blk_rq_pos(req) >= fs->total_secs) {
-- 
2.11.0

[PATCH 21/23] swim3: remove (commented out) printing of req->errors

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 drivers/block/swim3.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/block/swim3.c b/drivers/block/swim3.c
index 61b3ffa4f458..ba4809c9bdba 100644
--- a/drivers/block/swim3.c
+++ b/drivers/block/swim3.c
@@ -343,8 +343,8 @@ static void start_request(struct floppy_state *fs)
 			  req->rq_disk->disk_name, req->cmd,
 			  (long)blk_rq_pos(req), blk_rq_sectors(req),
 			  bio_data(req->bio));
-		swim3_dbg("           errors=%d current_nr_sectors=%u\n",
-			  req->errors, blk_rq_cur_sectors(req));
+		swim3_dbg("           current_nr_sectors=%u\n",
+			  blk_rq_cur_sectors(req));
 #endif
 
 		if (blk_rq_pos(req) >= fs->total_secs) {
-- 
2.11.0

[PATCH 22/23] blktrace: remove the unused block_rq_abort tracepoint

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/trace/events/block.h | 44 ++++++++++----------------------------------
 kernel/trace/blktrace.c      |  9 ---------
 2 files changed, 10 insertions(+), 43 deletions(-)

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index a88ed13446ff..99ed69fad041 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -61,7 +61,16 @@ DEFINE_EVENT(block_buffer, block_dirty_buffer,
 	TP_ARGS(bh)
 );
 
-DECLARE_EVENT_CLASS(block_rq_with_error,
+/**
+ * block_rq_requeue - place block IO request back on a queue
+ * @q: queue holding operation
+ * @rq: block IO operation request
+ *
+ * The block operation request @rq is being placed back into queue
+ * @q.  For some reason the request was not completed and needs to be
+ * put back in the queue.
+ */
+TRACE_EVENT(block_rq_requeue,
 
 	TP_PROTO(struct request_queue *q, struct request *rq),
 
@@ -94,39 +103,6 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
 );
 
 /**
- * block_rq_abort - abort block operation request
- * @q: queue containing the block operation request
- * @rq: block IO operation request
- *
- * Called immediately after pending block IO operation request @rq in
- * queue @q is aborted. The fields in the operation request @rq
- * can be examined to determine which device and sectors the pending
- * operation would access.
- */
-DEFINE_EVENT(block_rq_with_error, block_rq_abort,
-
-	TP_PROTO(struct request_queue *q, struct request *rq),
-
-	TP_ARGS(q, rq)
-);
-
-/**
- * block_rq_requeue - place block IO request back on a queue
- * @q: queue holding operation
- * @rq: block IO operation request
- *
- * The block operation request @rq is being placed back into queue
- * @q.  For some reason the request was not completed and needs to be
- * put back in the queue.
- */
-DEFINE_EVENT(block_rq_with_error, block_rq_requeue,
-
-	TP_PROTO(struct request_queue *q, struct request *rq),
-
-	TP_ARGS(q, rq)
-);
-
-/**
  * block_rq_complete - block IO operation completed by device driver
  * @q: queue containing the block operation request
  * @rq: block operations request
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index b2058a7f94bd..9f3624dadb09 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -716,12 +716,6 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 			rq->cmd_flags, what, rq->errors, 0, NULL);
 }
 
-static void blk_add_trace_rq_abort(void *ignore,
-				   struct request_queue *q, struct request *rq)
-{
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ABORT);
-}
-
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
@@ -974,8 +968,6 @@ static void blk_register_tracepoints(void)
 {
 	int ret;
 
-	ret = register_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
-	WARN_ON(ret);
 	ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
 	WARN_ON(ret);
 	ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
@@ -1028,7 +1020,6 @@ static void blk_unregister_tracepoints(void)
 	unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
 	unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
 	unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
-	unregister_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
 
 	tracepoint_synchronize_unregister();
 }
-- 
2.11.0

[PATCH 22/23] blktrace: remove the unused block_rq_abort tracepoint

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
---
 include/trace/events/block.h | 44 ++++++++++----------------------------------
 kernel/trace/blktrace.c      |  9 ---------
 2 files changed, 10 insertions(+), 43 deletions(-)

diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index a88ed13446ff..99ed69fad041 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -61,7 +61,16 @@ DEFINE_EVENT(block_buffer, block_dirty_buffer,
 	TP_ARGS(bh)
 );
 
-DECLARE_EVENT_CLASS(block_rq_with_error,
+/**
+ * block_rq_requeue - place block IO request back on a queue
+ * @q: queue holding operation
+ * @rq: block IO operation request
+ *
+ * The block operation request @rq is being placed back into queue
+ * @q.  For some reason the request was not completed and needs to be
+ * put back in the queue.
+ */
+TRACE_EVENT(block_rq_requeue,
 
 	TP_PROTO(struct request_queue *q, struct request *rq),
 
@@ -94,39 +103,6 @@ DECLARE_EVENT_CLASS(block_rq_with_error,
 );
 
 /**
- * block_rq_abort - abort block operation request
- * @q: queue containing the block operation request
- * @rq: block IO operation request
- *
- * Called immediately after pending block IO operation request @rq in
- * queue @q is aborted. The fields in the operation request @rq
- * can be examined to determine which device and sectors the pending
- * operation would access.
- */
-DEFINE_EVENT(block_rq_with_error, block_rq_abort,
-
-	TP_PROTO(struct request_queue *q, struct request *rq),
-
-	TP_ARGS(q, rq)
-);
-
-/**
- * block_rq_requeue - place block IO request back on a queue
- * @q: queue holding operation
- * @rq: block IO operation request
- *
- * The block operation request @rq is being placed back into queue
- * @q.  For some reason the request was not completed and needs to be
- * put back in the queue.
- */
-DEFINE_EVENT(block_rq_with_error, block_rq_requeue,
-
-	TP_PROTO(struct request_queue *q, struct request *rq),
-
-	TP_ARGS(q, rq)
-);
-
-/**
  * block_rq_complete - block IO operation completed by device driver
  * @q: queue containing the block operation request
  * @rq: block operations request
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index b2058a7f94bd..9f3624dadb09 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -716,12 +716,6 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 			rq->cmd_flags, what, rq->errors, 0, NULL);
 }
 
-static void blk_add_trace_rq_abort(void *ignore,
-				   struct request_queue *q, struct request *rq)
-{
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ABORT);
-}
-
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
@@ -974,8 +968,6 @@ static void blk_register_tracepoints(void)
 {
 	int ret;
 
-	ret = register_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
-	WARN_ON(ret);
 	ret = register_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
 	WARN_ON(ret);
 	ret = register_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
@@ -1028,7 +1020,6 @@ static void blk_unregister_tracepoints(void)
 	unregister_trace_block_rq_requeue(blk_add_trace_rq_requeue, NULL);
 	unregister_trace_block_rq_issue(blk_add_trace_rq_issue, NULL);
 	unregister_trace_block_rq_insert(blk_add_trace_rq_insert, NULL);
-	unregister_trace_block_rq_abort(blk_add_trace_rq_abort, NULL);
 
 	tracepoint_synchronize_unregister();
 }
-- 
2.11.0

[PATCH 23/23] block: remove the errors field from struct request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 block/blk-core.c             | 14 +-------------
 block/blk-exec.c             |  3 +--
 block/blk-mq.c               | 10 +++-------
 block/blk-timeout.c          |  1 -
 include/linux/blkdev.h       |  2 --
 include/trace/events/block.h | 17 +++++++----------
 kernel/trace/blktrace.c      | 26 ++++++++++++--------------
 7 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 8654aa0cef6d..48f522a02f54 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1633,7 +1633,6 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 	if (bio->bi_opf & REQ_RAHEAD)
 		req->cmd_flags |= REQ_FAILFAST_MASK;
 
-	req->errors = 0;
 	req->__sector = bio->bi_iter.bi_sector;
 	blk_rq_set_prio(req, rq_ioc(bio));
 	if (ioprio_valid(bio_prio(bio)))
@@ -2567,22 +2566,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 {
 	int total_bytes;
 
-	trace_block_rq_complete(req->q, req, nr_bytes);
+	trace_block_rq_complete(req, error, nr_bytes);
 
 	if (!req->bio)
 		return false;
 
-	/*
-	 * For fs requests, rq is just carrier of independent bio's
-	 * and each partial completion should be handled separately.
-	 * Reset per-request error on each partial completion.
-	 *
-	 * TODO: tj: This is too subtle.  It would be better to let
-	 * low level drivers do what they see fit.
-	 */
-	if (!blk_rq_is_passthrough(req))
-		req->errors = 0;
-
 	if (error && !blk_rq_is_passthrough(req) &&
 	    !(req->rq_flags & RQF_QUIET)) {
 		char *error_type;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index afa383248c7c..a9451e3b8587 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -69,8 +69,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		__blk_end_request_all(rq, -ENXIO);
 		spin_unlock_irq(q->queue_lock);
 		return;
 	}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1f98db082da3..f5e3cf153ad7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -213,7 +213,6 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 #endif
 	rq->special = NULL;
 	/* tag was already set */
-	rq->errors = 0;
 	rq->extra_len = 0;
 
 	INIT_LIST_HEAD(&rq->timeout_list);
@@ -624,8 +623,7 @@ void blk_mq_abort_requeue_list(struct request_queue *q)
 
 		rq = list_first_entry(&rq_list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 	}
 }
 EXPORT_SYMBOL(blk_mq_abort_requeue_list);
@@ -1032,8 +1030,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
 			pr_err("blk-mq: bad return on queue: %d\n", ret);
 		case BLK_MQ_RQ_QUEUE_ERROR:
 			errors++;
-			rq->errors = -EIO;
-			blk_mq_end_request(rq, rq->errors);
+			blk_mq_end_request(rq, -EIO);
 			break;
 		}
 
@@ -1484,8 +1481,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,
 
 	if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
 		*cookie = BLK_QC_T_NONE;
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 		return;
 	}
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a30441a200c0..cbff183f3d9f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -89,7 +89,6 @@ static void blk_rq_timed_out(struct request *req)
 		ret = q->rq_timed_out_fn(req);
 	switch (ret) {
 	case BLK_EH_HANDLED:
-		/* Can we use req->errors here? */
 		__blk_complete_request(req);
 		break;
 	case BLK_EH_RESET_TIMER:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e8006abce8b6..b9b958a3bd08 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -220,8 +220,6 @@ struct request {
 
 	void *special;		/* opaque pointer available for LLD use */
 
-	int errors;
-
 	unsigned int extra_len;	/* length of alignment and padding */
 
 	unsigned long deadline;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 99ed69fad041..d0dbe60d8a6d 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -80,7 +80,6 @@ TRACE_EVENT(block_rq_requeue,
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -89,7 +88,6 @@ TRACE_EVENT(block_rq_requeue,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
-		__entry->errors    = rq->errors;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		__get_str(cmd)[0] = '\0';
@@ -99,13 +97,13 @@ TRACE_EVENT(block_rq_requeue,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, 0)
 );
 
 /**
  * block_rq_complete - block IO operation completed by device driver
- * @q: queue containing the block operation request
  * @rq: block operations request
+ * @error: status code
  * @nr_bytes: number of completed bytes
  *
  * The block_rq_complete tracepoint event indicates that some portion
@@ -116,16 +114,15 @@ TRACE_EVENT(block_rq_requeue,
  */
 TRACE_EVENT(block_rq_complete,
 
-	TP_PROTO(struct request_queue *q, struct request *rq,
-		 unsigned int nr_bytes),
+	TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),
 
-	TP_ARGS(q, rq, nr_bytes),
+	TP_ARGS(rq, error, nr_bytes),
 
 	TP_STRUCT__entry(
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
+		__field(  int,		error			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -134,7 +131,7 @@ TRACE_EVENT(block_rq_complete,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_pos(rq);
 		__entry->nr_sector = nr_bytes >> 9;
-		__entry->errors    = rq->errors;
+		__entry->error     = error;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
 		__get_str(cmd)[0] = '\0';
@@ -144,7 +141,7 @@ TRACE_EVENT(block_rq_complete,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, __entry->error)
 );
 
 DECLARE_EVENT_CLASS(block_rq,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9f3624dadb09..bd8ae8d5ae9c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -690,8 +690,8 @@ void blk_trace_shutdown(struct request_queue *q)
 
 /**
  * blk_add_trace_rq - Add a trace for a request oriented action
- * @q:		queue the io is for
  * @rq:		the source request
+ * @error:	return status to log
  * @nr_bytes:	number of completed bytes
  * @what:	the action
  *
@@ -699,10 +699,10 @@ void blk_trace_shutdown(struct request_queue *q)
  *     Records an action against a request. Will log the bio offset + size.
  *
  **/
-static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+static void blk_add_trace_rq(struct request *rq, int error,
 			     unsigned int nr_bytes, u32 what)
 {
-	struct blk_trace *bt = q->blk_trace;
+	struct blk_trace *bt = rq->q->blk_trace;
 
 	if (likely(!bt))
 		return;
@@ -713,34 +713,32 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 		what |= BLK_TC_ACT(BLK_TC_FS);
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
-			rq->cmd_flags, what, rq->errors, 0, NULL);
+			rq->cmd_flags, what, error, 0, NULL);
 }
 
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT);
 }
 
 static void blk_add_trace_rq_issue(void *ignore,
 				   struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE);
 }
 
 static void blk_add_trace_rq_requeue(void *ignore,
 				     struct request_queue *q,
 				     struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE);
 }
 
-static void blk_add_trace_rq_complete(void *ignore,
-				      struct request_queue *q,
-				      struct request *rq,
-				      unsigned int nr_bytes)
+static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
+			int error, unsigned int nr_bytes)
 {
-	blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
+	blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE);
 }
 
 /**
@@ -935,7 +933,7 @@ static void blk_add_trace_rq_remap(void *ignore,
 	r.sector_from = cpu_to_be64(from);
 
 	__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
-			rq_data_dir(rq), 0, BLK_TA_REMAP, !!rq->errors,
+			rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
 			sizeof(r), &r);
 }
 
@@ -960,7 +958,7 @@ void blk_add_driver_data(struct request_queue *q,
 		return;
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
-				BLK_TA_DRV_DATA, rq->errors, len, data);
+				BLK_TA_DRV_DATA, 0, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);
 
-- 
2.11.0

[PATCH 23/23] block: remove the errors field from struct request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
Acked-by: Roger Pau Monn? <roger.pau at citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 block/blk-core.c             | 14 +-------------
 block/blk-exec.c             |  3 +--
 block/blk-mq.c               | 10 +++-------
 block/blk-timeout.c          |  1 -
 include/linux/blkdev.h       |  2 --
 include/trace/events/block.h | 17 +++++++----------
 kernel/trace/blktrace.c      | 26 ++++++++++++--------------
 7 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 8654aa0cef6d..48f522a02f54 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1633,7 +1633,6 @@ void init_request_from_bio(struct request *req, struct bio *bio)
 	if (bio->bi_opf & REQ_RAHEAD)
 		req->cmd_flags |= REQ_FAILFAST_MASK;
 
-	req->errors = 0;
 	req->__sector = bio->bi_iter.bi_sector;
 	blk_rq_set_prio(req, rq_ioc(bio));
 	if (ioprio_valid(bio_prio(bio)))
@@ -2567,22 +2566,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 {
 	int total_bytes;
 
-	trace_block_rq_complete(req->q, req, nr_bytes);
+	trace_block_rq_complete(req, error, nr_bytes);
 
 	if (!req->bio)
 		return false;
 
-	/*
-	 * For fs requests, rq is just carrier of independent bio's
-	 * and each partial completion should be handled separately.
-	 * Reset per-request error on each partial completion.
-	 *
-	 * TODO: tj: This is too subtle.  It would be better to let
-	 * low level drivers do what they see fit.
-	 */
-	if (!blk_rq_is_passthrough(req))
-		req->errors = 0;
-
 	if (error && !blk_rq_is_passthrough(req) &&
 	    !(req->rq_flags & RQF_QUIET)) {
 		char *error_type;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index afa383248c7c..a9451e3b8587 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -69,8 +69,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		__blk_end_request_all(rq, -ENXIO);
 		spin_unlock_irq(q->queue_lock);
 		return;
 	}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 1f98db082da3..f5e3cf153ad7 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -213,7 +213,6 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 #endif
 	rq->special = NULL;
 	/* tag was already set */
-	rq->errors = 0;
 	rq->extra_len = 0;
 
 	INIT_LIST_HEAD(&rq->timeout_list);
@@ -624,8 +623,7 @@ void blk_mq_abort_requeue_list(struct request_queue *q)
 
 		rq = list_first_entry(&rq_list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 	}
 }
 EXPORT_SYMBOL(blk_mq_abort_requeue_list);
@@ -1032,8 +1030,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
 			pr_err("blk-mq: bad return on queue: %d\n", ret);
 		case BLK_MQ_RQ_QUEUE_ERROR:
 			errors++;
-			rq->errors = -EIO;
-			blk_mq_end_request(rq, rq->errors);
+			blk_mq_end_request(rq, -EIO);
 			break;
 		}
 
@@ -1484,8 +1481,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,
 
 	if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
 		*cookie = BLK_QC_T_NONE;
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 		return;
 	}
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a30441a200c0..cbff183f3d9f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -89,7 +89,6 @@ static void blk_rq_timed_out(struct request *req)
 		ret = q->rq_timed_out_fn(req);
 	switch (ret) {
 	case BLK_EH_HANDLED:
-		/* Can we use req->errors here? */
 		__blk_complete_request(req);
 		break;
 	case BLK_EH_RESET_TIMER:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index e8006abce8b6..b9b958a3bd08 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -220,8 +220,6 @@ struct request {
 
 	void *special;		/* opaque pointer available for LLD use */
 
-	int errors;
-
 	unsigned int extra_len;	/* length of alignment and padding */
 
 	unsigned long deadline;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 99ed69fad041..d0dbe60d8a6d 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -80,7 +80,6 @@ TRACE_EVENT(block_rq_requeue,
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -89,7 +88,6 @@ TRACE_EVENT(block_rq_requeue,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
-		__entry->errors    = rq->errors;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		__get_str(cmd)[0] = '\0';
@@ -99,13 +97,13 @@ TRACE_EVENT(block_rq_requeue,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, 0)
 );
 
 /**
  * block_rq_complete - block IO operation completed by device driver
- * @q: queue containing the block operation request
  * @rq: block operations request
+ * @error: status code
  * @nr_bytes: number of completed bytes
  *
  * The block_rq_complete tracepoint event indicates that some portion
@@ -116,16 +114,15 @@ TRACE_EVENT(block_rq_requeue,
  */
 TRACE_EVENT(block_rq_complete,
 
-	TP_PROTO(struct request_queue *q, struct request *rq,
-		 unsigned int nr_bytes),
+	TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),
 
-	TP_ARGS(q, rq, nr_bytes),
+	TP_ARGS(rq, error, nr_bytes),
 
 	TP_STRUCT__entry(
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
+		__field(  int,		error			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -134,7 +131,7 @@ TRACE_EVENT(block_rq_complete,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_pos(rq);
 		__entry->nr_sector = nr_bytes >> 9;
-		__entry->errors    = rq->errors;
+		__entry->error     = error;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
 		__get_str(cmd)[0] = '\0';
@@ -144,7 +141,7 @@ TRACE_EVENT(block_rq_complete,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, __entry->error)
 );
 
 DECLARE_EVENT_CLASS(block_rq,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9f3624dadb09..bd8ae8d5ae9c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -690,8 +690,8 @@ void blk_trace_shutdown(struct request_queue *q)
 
 /**
  * blk_add_trace_rq - Add a trace for a request oriented action
- * @q:		queue the io is for
  * @rq:		the source request
+ * @error:	return status to log
  * @nr_bytes:	number of completed bytes
  * @what:	the action
  *
@@ -699,10 +699,10 @@ void blk_trace_shutdown(struct request_queue *q)
  *     Records an action against a request. Will log the bio offset + size.
  *
  **/
-static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+static void blk_add_trace_rq(struct request *rq, int error,
 			     unsigned int nr_bytes, u32 what)
 {
-	struct blk_trace *bt = q->blk_trace;
+	struct blk_trace *bt = rq->q->blk_trace;
 
 	if (likely(!bt))
 		return;
@@ -713,34 +713,32 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 		what |= BLK_TC_ACT(BLK_TC_FS);
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
-			rq->cmd_flags, what, rq->errors, 0, NULL);
+			rq->cmd_flags, what, error, 0, NULL);
 }
 
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT);
 }
 
 static void blk_add_trace_rq_issue(void *ignore,
 				   struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE);
 }
 
 static void blk_add_trace_rq_requeue(void *ignore,
 				     struct request_queue *q,
 				     struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE);
 }
 
-static void blk_add_trace_rq_complete(void *ignore,
-				      struct request_queue *q,
-				      struct request *rq,
-				      unsigned int nr_bytes)
+static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
+			int error, unsigned int nr_bytes)
 {
-	blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
+	blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE);
 }
 
 /**
@@ -935,7 +933,7 @@ static void blk_add_trace_rq_remap(void *ignore,
 	r.sector_from = cpu_to_be64(from);
 
 	__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
-			rq_data_dir(rq), 0, BLK_TA_REMAP, !!rq->errors,
+			rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
 			sizeof(r), &r);
 }
 
@@ -960,7 +958,7 @@ void blk_add_driver_data(struct request_queue *q,
 		return;
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
-				BLK_TA_DRV_DATA, rq->errors, len, data);
+				BLK_TA_DRV_DATA, 0, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);
 
-- 
2.11.0

Re: [PATCH 23/23] block: remove the errors field from struct request

[Bart Van Assche]

On Wed, 2017-04-19 at 21:27 +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Roger Pau Monn=E9 <roger.pau@citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>=

[PATCH 23/23] block: remove the errors field from struct request

[Bart Van Assche]

On Wed, 2017-04-19@21:27 +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Acked-by: Roger Pau Monn? <roger.pau at citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>

Reviewed-by: Bart Van Assche <Bart.VanAssche at sandisk.com>

Re: [PATCH 23/23] block: remove the errors field from struct request

[Bart Van Assche]

On Wed, 2017-04-19 at 21:27 +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Acked-by: Roger Pau Monné <roger.pau@citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>

Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>

kill req->errors V4

[Christoph Hellwig]

Currently the request structure has an errors field that is used in
various different ways.  The oldest drivers use it as an error count,
blk-mq and the generic timeout code assume that it holds a Linux
errno for block completions, and various drivers use it for internal
status values, often overwriting them with Linux errnos later,
that is unless they are processing passthrough requests in which
case they'll leave their errors in it.

This series kills the ->errors field and replaced it with new fields
in the drivers (or an odd hack in a union in struct request for
two bitrotting old drivers).

Also available in the following git tree:

    git://git.infradead.org/users/hch/block.git request-errors

Gitweb:

    http://git.infradead.org/users/hch/block.git/shortlog/refs/heads/request-errors

Changes since V3:
 - SCSI OSD fix
 - Various Reviewed-by: tags

Changes since V2;
 - reorder one patch to be earlier in the series
 - fix the argument to a bsg dprintk
 - fix a kerneldoc comment

Changes since V1:
 - rebased on top the latest block for-next tree
 - fix error handling in nfsd blocklayout
 - dropped "scsi: fix fast-fail for non-passthrough requests"

[PATCH 23/23] block: remove the errors field from struct request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
Acked-by: Roger Pau Monné <roger.pau@citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
---
 block/blk-core.c             | 14 +-------------
 block/blk-exec.c             |  3 +--
 block/blk-mq.c               | 10 +++-------
 block/blk-timeout.c          |  1 -
 include/linux/blkdev.h       |  2 --
 include/trace/events/block.h | 17 +++++++----------
 kernel/trace/blktrace.c      | 26 ++++++++++++--------------
 7 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 25aea293ee98..a49b0830aaaf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1635,7 +1635,6 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio)
 	if (bio->bi_opf & REQ_RAHEAD)
 		req->cmd_flags |= REQ_FAILFAST_MASK;
 
-	req->errors = 0;
 	req->__sector = bio->bi_iter.bi_sector;
 	if (ioprio_valid(bio_prio(bio)))
 		req->ioprio = bio_prio(bio);
@@ -2573,22 +2572,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 {
 	int total_bytes;
 
-	trace_block_rq_complete(req->q, req, nr_bytes);
+	trace_block_rq_complete(req, error, nr_bytes);
 
 	if (!req->bio)
 		return false;
 
-	/*
-	 * For fs requests, rq is just carrier of independent bio's
-	 * and each partial completion should be handled separately.
-	 * Reset per-request error on each partial completion.
-	 *
-	 * TODO: tj: This is too subtle.  It would be better to let
-	 * low level drivers do what they see fit.
-	 */
-	if (!blk_rq_is_passthrough(req))
-		req->errors = 0;
-
 	if (error && !blk_rq_is_passthrough(req) &&
 	    !(req->rq_flags & RQF_QUIET)) {
 		char *error_type;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index afa383248c7c..a9451e3b8587 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -69,8 +69,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		__blk_end_request_all(rq, -ENXIO);
 		spin_unlock_irq(q->queue_lock);
 		return;
 	}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3a21948c867a..f2f6c59c5b05 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -213,7 +213,6 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 #endif
 	rq->special = NULL;
 	/* tag was already set */
-	rq->errors = 0;
 	rq->extra_len = 0;
 
 	INIT_LIST_HEAD(&rq->timeout_list);
@@ -624,8 +623,7 @@ void blk_mq_abort_requeue_list(struct request_queue *q)
 
 		rq = list_first_entry(&rq_list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 	}
 }
 EXPORT_SYMBOL(blk_mq_abort_requeue_list);
@@ -1032,8 +1030,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
 			pr_err("blk-mq: bad return on queue: %d\n", ret);
 		case BLK_MQ_RQ_QUEUE_ERROR:
 			errors++;
-			rq->errors = -EIO;
-			blk_mq_end_request(rq, rq->errors);
+			blk_mq_end_request(rq, -EIO);
 			break;
 		}
 
@@ -1484,8 +1481,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,
 
 	if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
 		*cookie = BLK_QC_T_NONE;
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 		return;
 	}
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a30441a200c0..cbff183f3d9f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -89,7 +89,6 @@ static void blk_rq_timed_out(struct request *req)
 		ret = q->rq_timed_out_fn(req);
 	switch (ret) {
 	case BLK_EH_HANDLED:
-		/* Can we use req->errors here? */
 		__blk_complete_request(req);
 		break;
 	case BLK_EH_RESET_TIMER:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a3dcee624de3..6c4ab0d4a160 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -220,8 +220,6 @@ struct request {
 
 	void *special;		/* opaque pointer available for LLD use */
 
-	int errors;
-
 	unsigned int extra_len;	/* length of alignment and padding */
 
 	unsigned long deadline;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 99ed69fad041..d0dbe60d8a6d 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -80,7 +80,6 @@ TRACE_EVENT(block_rq_requeue,
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -89,7 +88,6 @@ TRACE_EVENT(block_rq_requeue,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
-		__entry->errors    = rq->errors;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		__get_str(cmd)[0] = '\0';
@@ -99,13 +97,13 @@ TRACE_EVENT(block_rq_requeue,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, 0)
 );
 
 /**
  * block_rq_complete - block IO operation completed by device driver
- * @q: queue containing the block operation request
  * @rq: block operations request
+ * @error: status code
  * @nr_bytes: number of completed bytes
  *
  * The block_rq_complete tracepoint event indicates that some portion
@@ -116,16 +114,15 @@ TRACE_EVENT(block_rq_requeue,
  */
 TRACE_EVENT(block_rq_complete,
 
-	TP_PROTO(struct request_queue *q, struct request *rq,
-		 unsigned int nr_bytes),
+	TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),
 
-	TP_ARGS(q, rq, nr_bytes),
+	TP_ARGS(rq, error, nr_bytes),
 
 	TP_STRUCT__entry(
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
+		__field(  int,		error			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -134,7 +131,7 @@ TRACE_EVENT(block_rq_complete,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_pos(rq);
 		__entry->nr_sector = nr_bytes >> 9;
-		__entry->errors    = rq->errors;
+		__entry->error     = error;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
 		__get_str(cmd)[0] = '\0';
@@ -144,7 +141,7 @@ TRACE_EVENT(block_rq_complete,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, __entry->error)
 );
 
 DECLARE_EVENT_CLASS(block_rq,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9f3624dadb09..bd8ae8d5ae9c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -690,8 +690,8 @@ void blk_trace_shutdown(struct request_queue *q)
 
 /**
  * blk_add_trace_rq - Add a trace for a request oriented action
- * @q:		queue the io is for
  * @rq:		the source request
+ * @error:	return status to log
  * @nr_bytes:	number of completed bytes
  * @what:	the action
  *
@@ -699,10 +699,10 @@ void blk_trace_shutdown(struct request_queue *q)
  *     Records an action against a request. Will log the bio offset + size.
  *
  **/
-static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+static void blk_add_trace_rq(struct request *rq, int error,
 			     unsigned int nr_bytes, u32 what)
 {
-	struct blk_trace *bt = q->blk_trace;
+	struct blk_trace *bt = rq->q->blk_trace;
 
 	if (likely(!bt))
 		return;
@@ -713,34 +713,32 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 		what |= BLK_TC_ACT(BLK_TC_FS);
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
-			rq->cmd_flags, what, rq->errors, 0, NULL);
+			rq->cmd_flags, what, error, 0, NULL);
 }
 
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT);
 }
 
 static void blk_add_trace_rq_issue(void *ignore,
 				   struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE);
 }
 
 static void blk_add_trace_rq_requeue(void *ignore,
 				     struct request_queue *q,
 				     struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE);
 }
 
-static void blk_add_trace_rq_complete(void *ignore,
-				      struct request_queue *q,
-				      struct request *rq,
-				      unsigned int nr_bytes)
+static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
+			int error, unsigned int nr_bytes)
 {
-	blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
+	blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE);
 }
 
 /**
@@ -935,7 +933,7 @@ static void blk_add_trace_rq_remap(void *ignore,
 	r.sector_from = cpu_to_be64(from);
 
 	__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
-			rq_data_dir(rq), 0, BLK_TA_REMAP, !!rq->errors,
+			rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
 			sizeof(r), &r);
 }
 
@@ -960,7 +958,7 @@ void blk_add_driver_data(struct request_queue *q,
 		return;
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
-				BLK_TA_DRV_DATA, rq->errors, len, data);
+				BLK_TA_DRV_DATA, 0, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);
 
-- 
2.11.0

[PATCH 23/23] block: remove the errors field from struct request

[Christoph Hellwig]

Signed-off-by: Christoph Hellwig <hch at lst.de>
Reviewed-by: Bart Van Assche <Bart.VanAssche at sandisk.com>
Acked-by: Roger Pau Monn? <roger.pau at citrix.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
---
 block/blk-core.c             | 14 +-------------
 block/blk-exec.c             |  3 +--
 block/blk-mq.c               | 10 +++-------
 block/blk-timeout.c          |  1 -
 include/linux/blkdev.h       |  2 --
 include/trace/events/block.h | 17 +++++++----------
 kernel/trace/blktrace.c      | 26 ++++++++++++--------------
 7 files changed, 24 insertions(+), 49 deletions(-)

diff --git a/block/blk-core.c b/block/blk-core.c
index 25aea293ee98..a49b0830aaaf 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1635,7 +1635,6 @@ void blk_init_request_from_bio(struct request *req, struct bio *bio)
 	if (bio->bi_opf & REQ_RAHEAD)
 		req->cmd_flags |= REQ_FAILFAST_MASK;
 
-	req->errors = 0;
 	req->__sector = bio->bi_iter.bi_sector;
 	if (ioprio_valid(bio_prio(bio)))
 		req->ioprio = bio_prio(bio);
@@ -2573,22 +2572,11 @@ bool blk_update_request(struct request *req, int error, unsigned int nr_bytes)
 {
 	int total_bytes;
 
-	trace_block_rq_complete(req->q, req, nr_bytes);
+	trace_block_rq_complete(req, error, nr_bytes);
 
 	if (!req->bio)
 		return false;
 
-	/*
-	 * For fs requests, rq is just carrier of independent bio's
-	 * and each partial completion should be handled separately.
-	 * Reset per-request error on each partial completion.
-	 *
-	 * TODO: tj: This is too subtle.  It would be better to let
-	 * low level drivers do what they see fit.
-	 */
-	if (!blk_rq_is_passthrough(req))
-		req->errors = 0;
-
 	if (error && !blk_rq_is_passthrough(req) &&
 	    !(req->rq_flags & RQF_QUIET)) {
 		char *error_type;
diff --git a/block/blk-exec.c b/block/blk-exec.c
index afa383248c7c..a9451e3b8587 100644
--- a/block/blk-exec.c
+++ b/block/blk-exec.c
@@ -69,8 +69,7 @@ void blk_execute_rq_nowait(struct request_queue *q, struct gendisk *bd_disk,
 
 	if (unlikely(blk_queue_dying(q))) {
 		rq->rq_flags |= RQF_QUIET;
-		rq->errors = -ENXIO;
-		__blk_end_request_all(rq, rq->errors);
+		__blk_end_request_all(rq, -ENXIO);
 		spin_unlock_irq(q->queue_lock);
 		return;
 	}
diff --git a/block/blk-mq.c b/block/blk-mq.c
index 3a21948c867a..f2f6c59c5b05 100644
--- a/block/blk-mq.c
+++ b/block/blk-mq.c
@@ -213,7 +213,6 @@ void blk_mq_rq_ctx_init(struct request_queue *q, struct blk_mq_ctx *ctx,
 #endif
 	rq->special = NULL;
 	/* tag was already set */
-	rq->errors = 0;
 	rq->extra_len = 0;
 
 	INIT_LIST_HEAD(&rq->timeout_list);
@@ -624,8 +623,7 @@ void blk_mq_abort_requeue_list(struct request_queue *q)
 
 		rq = list_first_entry(&rq_list, struct request, queuelist);
 		list_del_init(&rq->queuelist);
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 	}
 }
 EXPORT_SYMBOL(blk_mq_abort_requeue_list);
@@ -1032,8 +1030,7 @@ bool blk_mq_dispatch_rq_list(struct request_queue *q, struct list_head *list)
 			pr_err("blk-mq: bad return on queue: %d\n", ret);
 		case BLK_MQ_RQ_QUEUE_ERROR:
 			errors++;
-			rq->errors = -EIO;
-			blk_mq_end_request(rq, rq->errors);
+			blk_mq_end_request(rq, -EIO);
 			break;
 		}
 
@@ -1484,8 +1481,7 @@ static void __blk_mq_try_issue_directly(struct request *rq, blk_qc_t *cookie,
 
 	if (ret == BLK_MQ_RQ_QUEUE_ERROR) {
 		*cookie = BLK_QC_T_NONE;
-		rq->errors = -EIO;
-		blk_mq_end_request(rq, rq->errors);
+		blk_mq_end_request(rq, -EIO);
 		return;
 	}
 
diff --git a/block/blk-timeout.c b/block/blk-timeout.c
index a30441a200c0..cbff183f3d9f 100644
--- a/block/blk-timeout.c
+++ b/block/blk-timeout.c
@@ -89,7 +89,6 @@ static void blk_rq_timed_out(struct request *req)
 		ret = q->rq_timed_out_fn(req);
 	switch (ret) {
 	case BLK_EH_HANDLED:
-		/* Can we use req->errors here? */
 		__blk_complete_request(req);
 		break;
 	case BLK_EH_RESET_TIMER:
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index a3dcee624de3..6c4ab0d4a160 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -220,8 +220,6 @@ struct request {
 
 	void *special;		/* opaque pointer available for LLD use */
 
-	int errors;
-
 	unsigned int extra_len;	/* length of alignment and padding */
 
 	unsigned long deadline;
diff --git a/include/trace/events/block.h b/include/trace/events/block.h
index 99ed69fad041..d0dbe60d8a6d 100644
--- a/include/trace/events/block.h
+++ b/include/trace/events/block.h
@@ -80,7 +80,6 @@ TRACE_EVENT(block_rq_requeue,
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -89,7 +88,6 @@ TRACE_EVENT(block_rq_requeue,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_trace_sector(rq);
 		__entry->nr_sector = blk_rq_trace_nr_sectors(rq);
-		__entry->errors    = rq->errors;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, blk_rq_bytes(rq));
 		__get_str(cmd)[0] = '\0';
@@ -99,13 +97,13 @@ TRACE_EVENT(block_rq_requeue,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, 0)
 );
 
 /**
  * block_rq_complete - block IO operation completed by device driver
- * @q: queue containing the block operation request
  * @rq: block operations request
+ * @error: status code
  * @nr_bytes: number of completed bytes
  *
  * The block_rq_complete tracepoint event indicates that some portion
@@ -116,16 +114,15 @@ TRACE_EVENT(block_rq_requeue,
  */
 TRACE_EVENT(block_rq_complete,
 
-	TP_PROTO(struct request_queue *q, struct request *rq,
-		 unsigned int nr_bytes),
+	TP_PROTO(struct request *rq, int error, unsigned int nr_bytes),
 
-	TP_ARGS(q, rq, nr_bytes),
+	TP_ARGS(rq, error, nr_bytes),
 
 	TP_STRUCT__entry(
 		__field(  dev_t,	dev			)
 		__field(  sector_t,	sector			)
 		__field(  unsigned int,	nr_sector		)
-		__field(  int,		errors			)
+		__field(  int,		error			)
 		__array(  char,		rwbs,	RWBS_LEN	)
 		__dynamic_array( char,	cmd,	1		)
 	),
@@ -134,7 +131,7 @@ TRACE_EVENT(block_rq_complete,
 		__entry->dev	   = rq->rq_disk ? disk_devt(rq->rq_disk) : 0;
 		__entry->sector    = blk_rq_pos(rq);
 		__entry->nr_sector = nr_bytes >> 9;
-		__entry->errors    = rq->errors;
+		__entry->error     = error;
 
 		blk_fill_rwbs(__entry->rwbs, rq->cmd_flags, nr_bytes);
 		__get_str(cmd)[0] = '\0';
@@ -144,7 +141,7 @@ TRACE_EVENT(block_rq_complete,
 		  MAJOR(__entry->dev), MINOR(__entry->dev),
 		  __entry->rwbs, __get_str(cmd),
 		  (unsigned long long)__entry->sector,
-		  __entry->nr_sector, __entry->errors)
+		  __entry->nr_sector, __entry->error)
 );
 
 DECLARE_EVENT_CLASS(block_rq,
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 9f3624dadb09..bd8ae8d5ae9c 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -690,8 +690,8 @@ void blk_trace_shutdown(struct request_queue *q)
 
 /**
  * blk_add_trace_rq - Add a trace for a request oriented action
- * @q:		queue the io is for
  * @rq:		the source request
+ * @error:	return status to log
  * @nr_bytes:	number of completed bytes
  * @what:	the action
  *
@@ -699,10 +699,10 @@ void blk_trace_shutdown(struct request_queue *q)
  *     Records an action against a request. Will log the bio offset + size.
  *
  **/
-static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
+static void blk_add_trace_rq(struct request *rq, int error,
 			     unsigned int nr_bytes, u32 what)
 {
-	struct blk_trace *bt = q->blk_trace;
+	struct blk_trace *bt = rq->q->blk_trace;
 
 	if (likely(!bt))
 		return;
@@ -713,34 +713,32 @@ static void blk_add_trace_rq(struct request_queue *q, struct request *rq,
 		what |= BLK_TC_ACT(BLK_TC_FS);
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), nr_bytes, req_op(rq),
-			rq->cmd_flags, what, rq->errors, 0, NULL);
+			rq->cmd_flags, what, error, 0, NULL);
 }
 
 static void blk_add_trace_rq_insert(void *ignore,
 				    struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_INSERT);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_INSERT);
 }
 
 static void blk_add_trace_rq_issue(void *ignore,
 				   struct request_queue *q, struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_ISSUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_ISSUE);
 }
 
 static void blk_add_trace_rq_requeue(void *ignore,
 				     struct request_queue *q,
 				     struct request *rq)
 {
-	blk_add_trace_rq(q, rq, blk_rq_bytes(rq), BLK_TA_REQUEUE);
+	blk_add_trace_rq(rq, 0, blk_rq_bytes(rq), BLK_TA_REQUEUE);
 }
 
-static void blk_add_trace_rq_complete(void *ignore,
-				      struct request_queue *q,
-				      struct request *rq,
-				      unsigned int nr_bytes)
+static void blk_add_trace_rq_complete(void *ignore, struct request *rq,
+			int error, unsigned int nr_bytes)
 {
-	blk_add_trace_rq(q, rq, nr_bytes, BLK_TA_COMPLETE);
+	blk_add_trace_rq(rq, error, nr_bytes, BLK_TA_COMPLETE);
 }
 
 /**
@@ -935,7 +933,7 @@ static void blk_add_trace_rq_remap(void *ignore,
 	r.sector_from = cpu_to_be64(from);
 
 	__blk_add_trace(bt, blk_rq_pos(rq), blk_rq_bytes(rq),
-			rq_data_dir(rq), 0, BLK_TA_REMAP, !!rq->errors,
+			rq_data_dir(rq), 0, BLK_TA_REMAP, 0,
 			sizeof(r), &r);
 }
 
@@ -960,7 +958,7 @@ void blk_add_driver_data(struct request_queue *q,
 		return;
 
 	__blk_add_trace(bt, blk_rq_trace_sector(rq), blk_rq_bytes(rq), 0, 0,
-				BLK_TA_DRV_DATA, rq->errors, len, data);
+				BLK_TA_DRV_DATA, 0, len, data);
 }
 EXPORT_SYMBOL_GPL(blk_add_driver_data);
 
-- 
2.11.0

Re: [PATCH 23/23] block: remove the errors field from struct request

[Johannes Thumshirn]

On Thu, Apr 20, 2017 at 04:03:16PM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
> Acked-by: Roger Pau Monn� <roger.pau@citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N�rnberg
GF: Felix Imend�rffer, Jane Smithard, Graham Norton
HRB 21284 (AG N�rnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

[PATCH 23/23] block: remove the errors field from struct request

[Johannes Thumshirn]

On Thu, Apr 20, 2017@04:03:16PM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch at lst.de>
> Reviewed-by: Bart Van Assche <Bart.VanAssche at sandisk.com>
> Acked-by: Roger Pau Monn? <roger.pau at citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk at oracle.com>
> ---

Reviewed-by: Johannes Thumshirn <jthumshirn at suse.de>
-- 
Johannes Thumshirn                                          Storage
jthumshirn at suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 N?rnberg
GF: Felix Imend?rffer, Jane Smithard, Graham Norton
HRB 21284 (AG N?rnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850

Re: [PATCH 23/23] block: remove the errors field from struct request

[Johannes Thumshirn]

On Thu, Apr 20, 2017 at 04:03:16PM +0200, Christoph Hellwig wrote:
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> Reviewed-by: Bart Van Assche <Bart.VanAssche@sandisk.com>
> Acked-by: Roger Pau Monné <roger.pau@citrix.com>
> Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
> ---

Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                          Storage
jthumshirn@suse.de                                +49 911 74053 689
SUSE LINUX GmbH, Maxfeldstr. 5, 90409 Nürnberg
GF: Felix Imendörffer, Jane Smithard, Graham Norton
HRB 21284 (AG Nürnberg)
Key fingerprint = EC38 9CAB C2C4 F25D 8600 D0D0 0393 969D 2D76 0850