remove the legacy BLKPREP_* values

remove the legacy BLKPREP_* values

[Christoph Hellwig]

Hi Jens,

this series gets rid of the old BLKPREP_* values from the legacy block
layer in favor of always using a blk_status_t (or a bool in one case).

[PATCH 1/7] ide: cleanup ->prep_rq calling convention

[Christoph Hellwig]

The return value is just used as a binary yes/no decicsion, so switch
it to a bool instead of the old BLKPREP_* values returned as an int.

Also clean up a few related comments.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/ide/ide-cd.c   | 22 +++++++++++-----------
 drivers/ide/ide-disk.c |  8 ++++----
 drivers/ide/ide-io.c   |  4 ++--
 include/linux/ide.h    |  2 +-
 4 files changed, 18 insertions(+), 18 deletions(-)

diff --git a/drivers/ide/ide-cd.c b/drivers/ide/ide-cd.c
index 4ecaf2ace4cb..69c1aede5f93 100644
--- a/drivers/ide/ide-cd.c
+++ b/drivers/ide/ide-cd.c
@@ -527,8 +527,8 @@ static bool ide_cd_error_cmd(ide_drive_t *drive, struct ide_cmd *cmd)
 	return false;
 }
 
-/* standard prep_rq_fn that builds 10 byte cmds */
-static int ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
+/* standard prep_rq that builds 10 byte cmds */
+static bool ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
 {
 	int hard_sect = queue_logical_block_size(q);
 	long block = (long)blk_rq_pos(rq) / (hard_sect >> 9);
@@ -554,14 +554,14 @@ static int ide_cdrom_prep_fs(struct request_queue *q, struct request *rq)
 	req->cmd[7] = (blocks >> 8) & 0xff;
 	req->cmd[8] = blocks & 0xff;
 	req->cmd_len = 10;
-	return BLKPREP_OK;
+	return true;
 }
 
 /*
  * Most of the SCSI commands are supported directly by ATAPI devices.
  * This transform handles the few exceptions.
  */
-static int ide_cdrom_prep_pc(struct request *rq)
+static bool ide_cdrom_prep_pc(struct request *rq)
 {
 	u8 *c = scsi_req(rq)->cmd;
 
@@ -575,7 +575,7 @@ static int ide_cdrom_prep_pc(struct request *rq)
 		c[1] &= 0xe0;
 		c[0] += (READ_10 - READ_6);
 		scsi_req(rq)->cmd_len = 10;
-		return BLKPREP_OK;
+		return true;
 	}
 
 	/*
@@ -585,13 +585,13 @@ static int ide_cdrom_prep_pc(struct request *rq)
 	 */
 	if (c[0] == MODE_SENSE || c[0] == MODE_SELECT) {
 		scsi_req(rq)->result = ILLEGAL_REQUEST;
-		return BLKPREP_KILL;
+		return false;
 	}
 
-	return BLKPREP_OK;
+	return true;
 }
 
-static int ide_cdrom_prep_fn(ide_drive_t *drive, struct request *rq)
+static bool ide_cdrom_prep_rq(ide_drive_t *drive, struct request *rq)
 {
 	if (!blk_rq_is_passthrough(rq)) {
 		scsi_req_init(scsi_req(rq));
@@ -600,7 +600,7 @@ static int ide_cdrom_prep_fn(ide_drive_t *drive, struct request *rq)
 	} else if (blk_rq_is_scsi(rq))
 		return ide_cdrom_prep_pc(rq);
 
-	return 0;
+	return true;
 }
 
 static ide_startstop_t cdrom_newpc_intr(ide_drive_t *drive)
@@ -818,7 +818,7 @@ static ide_startstop_t cdrom_start_rw(ide_drive_t *drive, struct request *rq)
 		 * We may be retrying this request after an error.  Fix up any
 		 * weirdness which might be present in the request packet.
 		 */
-		ide_cdrom_prep_fn(drive, rq);
+		ide_cdrom_prep_rq(drive, rq);
 	}
 
 	/* fs requests *must* be hardware frame aligned */
@@ -1521,7 +1521,7 @@ static int ide_cdrom_setup(ide_drive_t *drive)
 
 	ide_debug_log(IDE_DBG_PROBE, "enter");
 
-	drive->prep_rq = ide_cdrom_prep_fn;
+	drive->prep_rq = ide_cdrom_prep_rq;
 	blk_queue_dma_alignment(q, 31);
 	blk_queue_update_dma_pad(q, 15);
 
diff --git a/drivers/ide/ide-disk.c b/drivers/ide/ide-disk.c
index f8567c8c9dd1..724db9af0d82 100644
--- a/drivers/ide/ide-disk.c
+++ b/drivers/ide/ide-disk.c
@@ -427,12 +427,12 @@ static void ide_disk_unlock_native_capacity(ide_drive_t *drive)
 		drive->dev_flags |= IDE_DFLAG_NOHPA; /* disable HPA on resume */
 }
 
-static int idedisk_prep_fn(ide_drive_t *drive, struct request *rq)
+static bool idedisk_prep_rq(ide_drive_t *drive, struct request *rq)
 {
 	struct ide_cmd *cmd;
 
 	if (req_op(rq) != REQ_OP_FLUSH)
-		return BLKPREP_OK;
+		return true;
 
 	if (rq->special) {
 		cmd = rq->special;
@@ -458,7 +458,7 @@ static int idedisk_prep_fn(ide_drive_t *drive, struct request *rq)
 	rq->special = cmd;
 	cmd->rq = rq;
 
-	return BLKPREP_OK;
+	return true;
 }
 
 ide_devset_get(multcount, mult_count);
@@ -547,7 +547,7 @@ static void update_flush(ide_drive_t *drive)
 
 		if (barrier) {
 			wc = true;
-			drive->prep_rq = idedisk_prep_fn;
+			drive->prep_rq = idedisk_prep_rq;
 		}
 	}
 
diff --git a/drivers/ide/ide-io.c b/drivers/ide/ide-io.c
index 5093c605c91c..64e72640acf8 100644
--- a/drivers/ide/ide-io.c
+++ b/drivers/ide/ide-io.c
@@ -326,7 +326,7 @@ static ide_startstop_t start_request (ide_drive_t *drive, struct request *rq)
 		goto kill_rq;
 	}
 
-	if (drive->prep_rq && drive->prep_rq(drive, rq))
+	if (drive->prep_rq && !drive->prep_rq(drive, rq))
 		return ide_stopped;
 
 	if (ata_pm_request(rq))
@@ -508,7 +508,7 @@ blk_status_t ide_queue_rq(struct blk_mq_hw_ctx *hctx,
 
 		/*
 		 * we know that the queue isn't empty, but this can happen
-		 * if the q->prep_rq_fn() decides to kill a request
+		 * if ->prep_rq() decides to kill a request
 		 */
 		if (!rq) {
 			rq = bd->rq;
diff --git a/include/linux/ide.h b/include/linux/ide.h
index 079f8bc0b0f4..272704ff21ee 100644
--- a/include/linux/ide.h
+++ b/include/linux/ide.h
@@ -529,7 +529,7 @@ struct ide_drive_s {
 
 	struct request_queue	*queue;	/* request queue */
 
-	int (*prep_rq)(struct ide_drive_s *, struct request *);
+	bool (*prep_rq)(struct ide_drive_s *, struct request *);
 
 	struct blk_mq_tag_set	tag_set;
 
-- 
2.19.1

Re: [PATCH 1/7] ide: cleanup ->prep_rq calling convention

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> The return value is just used as a binary yes/no decicsion, so switch
> it to a bool instead of the old BLKPREP_* values returned as an int.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH 2/7] scsi: simplify scsi_prep_state_check

[Christoph Hellwig]

Return a blk_status_t directly, and make the code a little more compact
by handling the fast path in the caller.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_lib.c | 102 +++++++++++++++++++---------------------
 1 file changed, 48 insertions(+), 54 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index ed81b8e74cfe..5ecabb3e77b7 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1240,60 +1240,48 @@ static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
 		return scsi_setup_fs_cmnd(sdev, req);
 }
 
-static int
+static blk_status_t
 scsi_prep_state_check(struct scsi_device *sdev, struct request *req)
 {
-	int ret = BLKPREP_OK;
-
-	/*
-	 * If the device is not in running state we will reject some
-	 * or all commands.
-	 */
-	if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
-		switch (sdev->sdev_state) {
-		case SDEV_OFFLINE:
-		case SDEV_TRANSPORT_OFFLINE:
-			/*
-			 * If the device is offline we refuse to process any
-			 * commands.  The device must be brought online
-			 * before trying any recovery commands.
-			 */
-			sdev_printk(KERN_ERR, sdev,
-				    "rejecting I/O to offline device\n");
-			ret = BLKPREP_KILL;
-			break;
-		case SDEV_DEL:
-			/*
-			 * If the device is fully deleted, we refuse to
-			 * process any commands as well.
-			 */
-			sdev_printk(KERN_ERR, sdev,
-				    "rejecting I/O to dead device\n");
-			ret = BLKPREP_KILL;
-			break;
-		case SDEV_BLOCK:
-		case SDEV_CREATED_BLOCK:
-			ret = BLKPREP_DEFER;
-			break;
-		case SDEV_QUIESCE:
-			/*
-			 * If the devices is blocked we defer normal commands.
-			 */
-			if (req && !(req->rq_flags & RQF_PREEMPT))
-				ret = BLKPREP_DEFER;
-			break;
-		default:
-			/*
-			 * For any other not fully online state we only allow
-			 * special commands.  In particular any user initiated
-			 * command is not allowed.
-			 */
-			if (req && !(req->rq_flags & RQF_PREEMPT))
-				ret = BLKPREP_KILL;
-			break;
-		}
+	switch (sdev->sdev_state) {
+	case SDEV_OFFLINE:
+	case SDEV_TRANSPORT_OFFLINE:
+		/*
+		 * If the device is offline we refuse to process any
+		 * commands.  The device must be brought online
+		 * before trying any recovery commands.
+		 */
+		sdev_printk(KERN_ERR, sdev,
+			    "rejecting I/O to offline device\n");
+		return BLK_STS_IOERR;
+	case SDEV_DEL:
+		/*
+		 * If the device is fully deleted, we refuse to
+		 * process any commands as well.
+		 */
+		sdev_printk(KERN_ERR, sdev,
+			    "rejecting I/O to dead device\n");
+		return BLK_STS_IOERR;
+	case SDEV_BLOCK:
+	case SDEV_CREATED_BLOCK:
+		return BLK_STS_RESOURCE;
+	case SDEV_QUIESCE:
+		/*
+		 * If the devices is blocked we defer normal commands.
+		 */
+		if (req && !(req->rq_flags & RQF_PREEMPT))
+			return BLK_STS_RESOURCE;
+		return BLK_STS_OK;
+	default:
+		/*
+		 * For any other not fully online state we only allow
+		 * special commands.  In particular any user initiated
+		 * command is not allowed.
+		 */
+		if (req && !(req->rq_flags & RQF_PREEMPT))
+			return BLK_STS_IOERR;
+		return BLK_STS_OK;
 	}
-	return ret;
 }
 
 /*
@@ -1700,9 +1688,15 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 	blk_status_t ret;
 	int reason;
 
-	ret = prep_to_mq(scsi_prep_state_check(sdev, req));
-	if (ret != BLK_STS_OK)
-		goto out_put_budget;
+	/*
+	 * If the device is not in running state we will reject some or all
+	 * commands.
+	 */
+	if (unlikely(sdev->sdev_state != SDEV_RUNNING)) {
+		ret = scsi_prep_state_check(sdev, req);
+		if (ret != BLK_STS_OK)
+			goto out_put_budget;
+	}
 
 	ret = BLK_STS_RESOURCE;
 	if (!scsi_target_queue_ready(shost, sdev))
-- 
2.19.1

Re: [PATCH 2/7] scsi: simplify scsi_prep_state_check

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> Return a blk_status_t directly, and make the code a little more compact
> by handling the fast path in the caller.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH 3/7] scsi: push blk_status_t up into scsi_setup_{fs,scsi}_cmnd

[Christoph Hellwig]

This just moves the prep_to_mq calls up in preparation of further removal
of BLKPREP_* usage.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_lib.c | 45 ++++++++++++++++++++++-------------------
 1 file changed, 24 insertions(+), 21 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 5ecabb3e77b7..e665c25da144 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1177,7 +1177,20 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 	scsi_add_cmd_to_list(cmd);
 }
 
-static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
+static inline blk_status_t prep_to_mq(int ret)
+{
+	switch (ret) {
+	case BLKPREP_OK:
+		return BLK_STS_OK;
+	case BLKPREP_DEFER:
+		return BLK_STS_RESOURCE;
+	default:
+		return BLK_STS_IOERR;
+	}
+}
+
+static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
+		struct request *req)
 {
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 
@@ -1190,7 +1203,7 @@ static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
 	if (req->bio) {
 		int ret = scsi_init_io(cmd);
 		if (unlikely(ret))
-			return ret;
+			return prep_to_mq(ret);
 	} else {
 		BUG_ON(blk_rq_bytes(req));
 
@@ -1201,29 +1214,31 @@ static int scsi_setup_scsi_cmnd(struct scsi_device *sdev, struct request *req)
 	cmd->cmnd = scsi_req(req)->cmd;
 	cmd->transfersize = blk_rq_bytes(req);
 	cmd->allowed = scsi_req(req)->retries;
-	return BLKPREP_OK;
+	return BLK_STS_OK;
 }
 
 /*
  * Setup a normal block command.  These are simple request from filesystems
  * that still need to be translated to SCSI CDBs from the ULD.
  */
-static int scsi_setup_fs_cmnd(struct scsi_device *sdev, struct request *req)
+static blk_status_t scsi_setup_fs_cmnd(struct scsi_device *sdev,
+		struct request *req)
 {
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 
 	if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
 		int ret = sdev->handler->prep_fn(sdev, req);
 		if (ret != BLKPREP_OK)
-			return ret;
+			return prep_to_mq(ret);
 	}
 
 	cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
 	memset(cmd->cmnd, 0, BLK_MAX_CDB);
-	return scsi_cmd_to_driver(cmd)->init_command(cmd);
+	return prep_to_mq(scsi_cmd_to_driver(cmd)->init_command(cmd));
 }
 
-static int scsi_setup_cmnd(struct scsi_device *sdev, struct request *req)
+static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev,
+		struct request *req)
 {
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 
@@ -1581,18 +1596,6 @@ static int scsi_dispatch_cmd(struct scsi_cmnd *cmd)
 	return 0;
 }
 
-static inline blk_status_t prep_to_mq(int ret)
-{
-	switch (ret) {
-	case BLKPREP_OK:
-		return BLK_STS_OK;
-	case BLKPREP_DEFER:
-		return BLK_STS_RESOURCE;
-	default:
-		return BLK_STS_IOERR;
-	}
-}
-
 /* Size in bytes of the sg-list stored in the scsi-mq command-private data. */
 static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost)
 {
@@ -1600,7 +1603,7 @@ static unsigned int scsi_mq_sgl_size(struct Scsi_Host *shost)
 		sizeof(struct scatterlist);
 }
 
-static int scsi_mq_prep_fn(struct request *req)
+static blk_status_t scsi_mq_prep_fn(struct request *req)
 {
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 	struct scsi_device *sdev = req->q->queuedata;
@@ -1705,7 +1708,7 @@ static blk_status_t scsi_queue_rq(struct blk_mq_hw_ctx *hctx,
 		goto out_dec_target_busy;
 
 	if (!(req->rq_flags & RQF_DONTPREP)) {
-		ret = prep_to_mq(scsi_mq_prep_fn(req));
+		ret = scsi_mq_prep_fn(req);
 		if (ret != BLK_STS_OK)
 			goto out_dec_host_busy;
 		req->rq_flags |= RQF_DONTPREP;
-- 
2.19.1

Re: [PATCH 3/7] scsi: push blk_status_t up into scsi_setup_{fs,scsi}_cmnd

[Johannes Thumshirn]

Look good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
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

Re: [PATCH 3/7] scsi: push blk_status_t up into scsi_setup_{fs,scsi}_cmnd

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> This just moves the prep_to_mq calls up in preparation of further removal
> of BLKPREP_* usage.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH 4/7] scsi: clean up error handling in scsi_init_io

[Christoph Hellwig]

There is no need to call scsi_mq_free_sgtables until we have actually
allocated sgtables.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_lib.c | 15 +++++++--------
 1 file changed, 7 insertions(+), 8 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index e665c25da144..1f84e2cec57b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1044,31 +1044,30 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 	int error = BLKPREP_KILL;
 
 	if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
-		goto err_exit;
+		return BLKPREP_KILL;
 
 	error = scsi_init_sgtable(rq, &cmd->sdb);
 	if (error)
-		goto err_exit;
+		return error;
 
 	if (blk_bidi_rq(rq)) {
 		error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
 		if (error)
-			goto err_exit;
+			goto out_free_sgtables;
 	}
 
 	if (blk_integrity_rq(rq)) {
 		struct scsi_data_buffer *prot_sdb = cmd->prot_sdb;
 		int ivecs, count;
 
-		if (prot_sdb == NULL) {
+		if (WARN_ON_ONCE(!prot_sdb)) {
 			/*
 			 * This can happen if someone (e.g. multipath)
 			 * queues a command to a device on an adapter
 			 * that does not support DIX.
 			 */
-			WARN_ON_ONCE(1);
 			error = BLKPREP_KILL;
-			goto err_exit;
+			goto out_free_sgtables;
 		}
 
 		ivecs = blk_rq_count_integrity_sg(rq->q, rq->bio);
@@ -1076,7 +1075,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 		if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
 				prot_sdb->table.sgl)) {
 			error = BLKPREP_DEFER;
-			goto err_exit;
+			goto out_free_sgtables;
 		}
 
 		count = blk_rq_map_integrity_sg(rq->q, rq->bio,
@@ -1089,7 +1088,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 	}
 
 	return BLKPREP_OK;
-err_exit:
+out_free_sgtables:
 	scsi_mq_free_sgtables(cmd);
 	return error;
 }
-- 
2.19.1

Re: [PATCH 4/7] scsi: clean up error handling in scsi_init_io

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
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

Re: [PATCH 4/7] scsi: clean up error handling in scsi_init_io

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> There is no need to call scsi_mq_free_sgtables until we have actually
> allocated sgtables.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH 5/7] scsi: return blk_status_t from scsi_init_io and ->init_command

[Christoph Hellwig]

Replace the old BLKRREP_* values with the BLK_STS_ ones that they are
converted to later anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/scsi_lib.c    | 45 ++++++++++----------
 drivers/scsi/sd.c          | 85 +++++++++++++++++---------------------
 drivers/scsi/sd.h          |  6 +--
 drivers/scsi/sd_zbc.c      | 10 ++---
 drivers/scsi/sr.c          | 12 +++---
 include/scsi/scsi_cmnd.h   |  2 +-
 include/scsi/scsi_driver.h |  3 +-
 7 files changed, 78 insertions(+), 85 deletions(-)

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1f84e2cec57b..3e3bdeee8f14 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1005,7 +1005,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 		scsi_io_completion_action(cmd, result);
 }
 
-static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
+static blk_status_t scsi_init_sgtable(struct request *req,
+		struct scsi_data_buffer *sdb)
 {
 	int count;
 
@@ -1014,7 +1015,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
 	 */
 	if (unlikely(sg_alloc_table_chained(&sdb->table,
 			blk_rq_nr_phys_segments(req), sdb->table.sgl)))
-		return BLKPREP_DEFER;
+		return BLK_STS_RESOURCE;
 
 	/* 
 	 * Next, walk the list, and fill in the addresses and sizes of
@@ -1024,7 +1025,7 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
 	BUG_ON(count > sdb->table.nents);
 	sdb->table.nents = count;
 	sdb->length = blk_rq_payload_bytes(req);
-	return BLKPREP_OK;
+	return BLK_STS_OK;
 }
 
 /*
@@ -1034,25 +1035,25 @@ static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)
  *
  * Arguments:   cmd   - Command descriptor we wish to initialize
  *
- * Returns:     0 on success
- *		BLKPREP_DEFER if the failure is retryable
- *		BLKPREP_KILL if the failure is fatal
+ * Returns:     BLK_STS_OK on success
+ *		BLK_STS_RESOURCE if the failure is retryable
+ *		BLK_STS_IOERR if the failure is fatal
  */
-int scsi_init_io(struct scsi_cmnd *cmd)
+blk_status_t scsi_init_io(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
-	int error = BLKPREP_KILL;
+	blk_status_t ret;
 
 	if (WARN_ON_ONCE(!blk_rq_nr_phys_segments(rq)))
-		return BLKPREP_KILL;
+		return BLK_STS_IOERR;
 
-	error = scsi_init_sgtable(rq, &cmd->sdb);
-	if (error)
-		return error;
+	ret = scsi_init_sgtable(rq, &cmd->sdb);
+	if (ret)
+		return ret;
 
 	if (blk_bidi_rq(rq)) {
-		error = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
-		if (error)
+		ret = scsi_init_sgtable(rq->next_rq, rq->next_rq->special);
+		if (ret)
 			goto out_free_sgtables;
 	}
 
@@ -1066,7 +1067,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 			 * queues a command to a device on an adapter
 			 * that does not support DIX.
 			 */
-			error = BLKPREP_KILL;
+			ret = BLK_STS_IOERR;
 			goto out_free_sgtables;
 		}
 
@@ -1074,7 +1075,7 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 
 		if (sg_alloc_table_chained(&prot_sdb->table, ivecs,
 				prot_sdb->table.sgl)) {
-			error = BLKPREP_DEFER;
+			ret = BLK_STS_RESOURCE;
 			goto out_free_sgtables;
 		}
 
@@ -1087,10 +1088,10 @@ int scsi_init_io(struct scsi_cmnd *cmd)
 		cmd->prot_sdb->table.nents = count;
 	}
 
-	return BLKPREP_OK;
+	return BLK_STS_OK;
 out_free_sgtables:
 	scsi_mq_free_sgtables(cmd);
-	return error;
+	return ret;
 }
 EXPORT_SYMBOL(scsi_init_io);
 
@@ -1200,9 +1201,9 @@ static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
 	 * submit a request without an attached bio.
 	 */
 	if (req->bio) {
-		int ret = scsi_init_io(cmd);
-		if (unlikely(ret))
-			return prep_to_mq(ret);
+		blk_status_t ret = scsi_init_io(cmd);
+		if (unlikely(ret != BLK_STS_OK))
+			return ret;
 	} else {
 		BUG_ON(blk_rq_bytes(req));
 
@@ -1233,7 +1234,7 @@ static blk_status_t scsi_setup_fs_cmnd(struct scsi_device *sdev,
 
 	cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
 	memset(cmd->cmnd, 0, BLK_MAX_CDB);
-	return prep_to_mq(scsi_cmd_to_driver(cmd)->init_command(cmd));
+	return scsi_cmd_to_driver(cmd)->init_command(cmd);
 }
 
 static blk_status_t scsi_setup_cmnd(struct scsi_device *sdev,
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 3bb2b3351e35..4a6ed2fc8c71 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -114,7 +114,7 @@ static int sd_suspend_system(struct device *);
 static int sd_suspend_runtime(struct device *);
 static int sd_resume(struct device *);
 static void sd_rescan(struct device *);
-static int sd_init_command(struct scsi_cmnd *SCpnt);
+static blk_status_t sd_init_command(struct scsi_cmnd *SCpnt);
 static void sd_uninit_command(struct scsi_cmnd *SCpnt);
 static int sd_done(struct scsi_cmnd *);
 static void sd_eh_reset(struct scsi_cmnd *);
@@ -750,7 +750,7 @@ static void sd_config_discard(struct scsi_disk *sdkp, unsigned int mode)
 	blk_queue_flag_set(QUEUE_FLAG_DISCARD, q);
 }
 
-static int sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
+static blk_status_t sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
 {
 	struct scsi_device *sdp = cmd->device;
 	struct request *rq = cmd->request;
@@ -761,7 +761,7 @@ static int sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
 
 	rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
 	if (!rq->special_vec.bv_page)
-		return BLKPREP_DEFER;
+		return BLK_STS_RESOURCE;
 	rq->special_vec.bv_offset = 0;
 	rq->special_vec.bv_len = data_len;
 	rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@@ -784,7 +784,8 @@ static int sd_setup_unmap_cmnd(struct scsi_cmnd *cmd)
 	return scsi_init_io(cmd);
 }
 
-static int sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd, bool unmap)
+static blk_status_t sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd,
+		bool unmap)
 {
 	struct scsi_device *sdp = cmd->device;
 	struct request *rq = cmd->request;
@@ -794,7 +795,7 @@ static int sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd, bool unmap)
 
 	rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
 	if (!rq->special_vec.bv_page)
-		return BLKPREP_DEFER;
+		return BLK_STS_RESOURCE;
 	rq->special_vec.bv_offset = 0;
 	rq->special_vec.bv_len = data_len;
 	rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@@ -814,7 +815,8 @@ static int sd_setup_write_same16_cmnd(struct scsi_cmnd *cmd, bool unmap)
 	return scsi_init_io(cmd);
 }
 
-static int sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd, bool unmap)
+static blk_status_t sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd,
+		bool unmap)
 {
 	struct scsi_device *sdp = cmd->device;
 	struct request *rq = cmd->request;
@@ -824,7 +826,7 @@ static int sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd, bool unmap)
 
 	rq->special_vec.bv_page = alloc_page(GFP_ATOMIC | __GFP_ZERO);
 	if (!rq->special_vec.bv_page)
-		return BLKPREP_DEFER;
+		return BLK_STS_RESOURCE;
 	rq->special_vec.bv_offset = 0;
 	rq->special_vec.bv_len = data_len;
 	rq->rq_flags |= RQF_SPECIAL_PAYLOAD;
@@ -844,7 +846,7 @@ static int sd_setup_write_same10_cmnd(struct scsi_cmnd *cmd, bool unmap)
 	return scsi_init_io(cmd);
 }
 
-static int sd_setup_write_zeroes_cmnd(struct scsi_cmnd *cmd)
+static blk_status_t sd_setup_write_zeroes_cmnd(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
 	struct scsi_device *sdp = cmd->device;
@@ -862,7 +864,7 @@ static int sd_setup_write_zeroes_cmnd(struct scsi_cmnd *cmd)
 	}
 
 	if (sdp->no_write_same)
-		return BLKPREP_INVALID;
+		return BLK_STS_TARGET;
 
 	if (sdkp->ws16 || sector > 0xffffffff || nr_sectors > 0xffff)
 		return sd_setup_write_same16_cmnd(cmd, false);
@@ -939,7 +941,7 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
  * Will set up either WRITE SAME(10) or WRITE SAME(16) depending on
  * the preference indicated by the target device.
  **/
-static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
+static blk_status_t sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
 	struct scsi_device *sdp = cmd->device;
@@ -948,10 +950,10 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 	sector_t sector = blk_rq_pos(rq);
 	unsigned int nr_sectors = blk_rq_sectors(rq);
 	unsigned int nr_bytes = blk_rq_bytes(rq);
-	int ret;
+	blk_status_t ret;
 
 	if (sdkp->device->no_write_same)
-		return BLKPREP_INVALID;
+		return BLK_STS_TARGET;
 
 	BUG_ON(bio_offset(bio) || bio_iovec(bio).bv_len != sdp->sector_size);
 
@@ -992,7 +994,7 @@ static int sd_setup_write_same_cmnd(struct scsi_cmnd *cmd)
 	return ret;
 }
 
-static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
+static blk_status_t sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
 
@@ -1005,10 +1007,10 @@ static int sd_setup_flush_cmnd(struct scsi_cmnd *cmd)
 	cmd->allowed = SD_MAX_RETRIES;
 
 	rq->timeout = rq->q->rq_timeout * SD_FLUSH_TIMEOUT_MULTIPLIER;
-	return BLKPREP_OK;
+	return BLK_STS_OK;
 }
 
-static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
+static blk_status_t sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 {
 	struct request *rq = SCpnt->request;
 	struct scsi_device *sdp = SCpnt->device;
@@ -1018,18 +1020,14 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 	sector_t threshold;
 	unsigned int this_count = blk_rq_sectors(rq);
 	unsigned int dif, dix;
-	int ret;
 	unsigned char protect;
+	blk_status_t ret;
 
 	ret = scsi_init_io(SCpnt);
-	if (ret != BLKPREP_OK)
+	if (ret != BLK_STS_OK)
 		return ret;
 	WARN_ON_ONCE(SCpnt != rq->special);
 
-	/* from here on until we're complete, any goto out
-	 * is used for a killable error condition */
-	ret = BLKPREP_KILL;
-
 	SCSI_LOG_HLQUEUE(1,
 		scmd_printk(KERN_INFO, SCpnt,
 			"%s: block=%llu, count=%d\n",
@@ -1042,7 +1040,7 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 						blk_rq_sectors(rq)));
 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 						"Retry with 0x%p\n", SCpnt));
-		goto out;
+		return BLK_STS_IOERR;
 	}
 
 	if (sdp->changed) {
@@ -1051,7 +1049,7 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 		 * the changed bit has been reset
 		 */
 		/* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
-		goto out;
+		return BLK_STS_IOERR;
 	}
 
 	/*
@@ -1089,31 +1087,28 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 		if ((block & 1) || (blk_rq_sectors(rq) & 1)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
-			goto out;
-		} else {
-			block = block >> 1;
-			this_count = this_count >> 1;
+			return BLK_STS_IOERR;
 		}
+		block = block >> 1;
+		this_count = this_count >> 1;
 	}
 	if (sdp->sector_size == 2048) {
 		if ((block & 3) || (blk_rq_sectors(rq) & 3)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
-			goto out;
-		} else {
-			block = block >> 2;
-			this_count = this_count >> 2;
+			return BLK_STS_IOERR;
 		}
+		block = block >> 2;
+		this_count = this_count >> 2;
 	}
 	if (sdp->sector_size == 4096) {
 		if ((block & 7) || (blk_rq_sectors(rq) & 7)) {
 			scmd_printk(KERN_ERR, SCpnt,
 				    "Bad block number requested\n");
-			goto out;
-		} else {
-			block = block >> 3;
-			this_count = this_count >> 3;
+			return BLK_STS_IOERR;
 		}
+		block = block >> 3;
+		this_count = this_count >> 3;
 	}
 	if (rq_data_dir(rq) == WRITE) {
 		SCpnt->cmnd[0] = WRITE_6;
@@ -1125,7 +1120,7 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 		SCpnt->cmnd[0] = READ_6;
 	} else {
 		scmd_printk(KERN_ERR, SCpnt, "Unknown command %d\n", req_op(rq));
-		goto out;
+		return BLK_STS_IOERR;
 	}
 
 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
@@ -1145,10 +1140,8 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 	if (protect && sdkp->protection_type == T10_PI_TYPE2_PROTECTION) {
 		SCpnt->cmnd = mempool_alloc(sd_cdb_pool, GFP_ATOMIC);
 
-		if (unlikely(SCpnt->cmnd == NULL)) {
-			ret = BLKPREP_DEFER;
-			goto out;
-		}
+		if (unlikely(!SCpnt->cmnd))
+			return BLK_STS_RESOURCE;
 
 		SCpnt->cmd_len = SD_EXT_CDB_SIZE;
 		memset(SCpnt->cmnd, 0, SCpnt->cmd_len);
@@ -1216,7 +1209,7 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 			 */
 			scmd_printk(KERN_ERR, SCpnt,
 				    "FUA write on READ/WRITE(6) drive\n");
-			goto out;
+			return BLK_STS_IOERR;
 		}
 
 		SCpnt->cmnd[1] |= (unsigned char) ((block >> 16) & 0x1f);
@@ -1240,12 +1233,10 @@ static int sd_setup_read_write_cmnd(struct scsi_cmnd *SCpnt)
 	 * This indicates that the command is ready from our end to be
 	 * queued.
 	 */
-	ret = BLKPREP_OK;
- out:
-	return ret;
+	return BLK_STS_OK;
 }
 
-static int sd_init_command(struct scsi_cmnd *cmd)
+static blk_status_t sd_init_command(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
 
@@ -1261,7 +1252,7 @@ static int sd_init_command(struct scsi_cmnd *cmd)
 		case SD_LBP_ZERO:
 			return sd_setup_write_same10_cmnd(cmd, false);
 		default:
-			return BLKPREP_INVALID;
+			return BLK_STS_TARGET;
 		}
 	case REQ_OP_WRITE_ZEROES:
 		return sd_setup_write_zeroes_cmnd(cmd);
@@ -1276,7 +1267,7 @@ static int sd_init_command(struct scsi_cmnd *cmd)
 		return sd_zbc_setup_reset_cmnd(cmd);
 	default:
 		WARN_ON_ONCE(1);
-		return BLKPREP_KILL;
+		return BLK_STS_NOTSUPP;
 	}
 }
 
diff --git a/drivers/scsi/sd.h b/drivers/scsi/sd.h
index 1d63f3a23ffb..7f43e6839bce 100644
--- a/drivers/scsi/sd.h
+++ b/drivers/scsi/sd.h
@@ -271,7 +271,7 @@ static inline int sd_is_zoned(struct scsi_disk *sdkp)
 
 extern int sd_zbc_read_zones(struct scsi_disk *sdkp, unsigned char *buffer);
 extern void sd_zbc_print_zones(struct scsi_disk *sdkp);
-extern int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd);
+extern blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd);
 extern void sd_zbc_complete(struct scsi_cmnd *cmd, unsigned int good_bytes,
 			    struct scsi_sense_hdr *sshdr);
 extern int sd_zbc_report_zones(struct gendisk *disk, sector_t sector,
@@ -288,9 +288,9 @@ static inline int sd_zbc_read_zones(struct scsi_disk *sdkp,
 
 static inline void sd_zbc_print_zones(struct scsi_disk *sdkp) {}
 
-static inline int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
+static inline blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
 {
-	return BLKPREP_INVALID;
+	return BLK_STS_TARGET;
 }
 
 static inline void sd_zbc_complete(struct scsi_cmnd *cmd,
diff --git a/drivers/scsi/sd_zbc.c b/drivers/scsi/sd_zbc.c
index e06c48c866e4..83365b29a4d8 100644
--- a/drivers/scsi/sd_zbc.c
+++ b/drivers/scsi/sd_zbc.c
@@ -185,7 +185,7 @@ static inline sector_t sd_zbc_zone_sectors(struct scsi_disk *sdkp)
  *
  * Called from sd_init_command() for a REQ_OP_ZONE_RESET request.
  */
-int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
+blk_status_t sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
 {
 	struct request *rq = cmd->request;
 	struct scsi_disk *sdkp = scsi_disk(rq->rq_disk);
@@ -194,14 +194,14 @@ int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
 
 	if (!sd_is_zoned(sdkp))
 		/* Not a zoned device */
-		return BLKPREP_KILL;
+		return BLK_STS_IOERR;
 
 	if (sdkp->device->changed)
-		return BLKPREP_KILL;
+		return BLK_STS_IOERR;
 
 	if (sector & (sd_zbc_zone_sectors(sdkp) - 1))
 		/* Unaligned request */
-		return BLKPREP_KILL;
+		return BLK_STS_IOERR;
 
 	cmd->cmd_len = 16;
 	memset(cmd->cmnd, 0, cmd->cmd_len);
@@ -214,7 +214,7 @@ int sd_zbc_setup_reset_cmnd(struct scsi_cmnd *cmd)
 	cmd->transfersize = 0;
 	cmd->allowed = 0;
 
-	return BLKPREP_OK;
+	return BLK_STS_OK;
 }
 
 /**
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 54dd70ae9731..38ddbbfe5f3c 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -80,7 +80,7 @@ MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
 static DEFINE_MUTEX(sr_mutex);
 static int sr_probe(struct device *);
 static int sr_remove(struct device *);
-static int sr_init_command(struct scsi_cmnd *SCpnt);
+static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
 static int sr_done(struct scsi_cmnd *);
 static int sr_runtime_suspend(struct device *dev);
 
@@ -384,22 +384,22 @@ static int sr_done(struct scsi_cmnd *SCpnt)
 	return good_bytes;
 }
 
-static int sr_init_command(struct scsi_cmnd *SCpnt)
+static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
 {
 	int block = 0, this_count, s_size;
 	struct scsi_cd *cd;
 	struct request *rq = SCpnt->request;
-	int ret;
+	blk_status_t ret;
 
 	ret = scsi_init_io(SCpnt);
-	if (ret != BLKPREP_OK)
+	if (ret != BLK_STS_OK)
 		goto out;
 	WARN_ON_ONCE(SCpnt != rq->special);
 	cd = scsi_cd(rq->rq_disk);
 
 	/* from here on until we're complete, any goto out
 	 * is used for a killable error condition */
-	ret = BLKPREP_KILL;
+	ret = BLK_STS_IOERR;
 
 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
 		"Doing sr request, block = %d\n", block));
@@ -516,7 +516,7 @@ static int sr_init_command(struct scsi_cmnd *SCpnt)
 	 * This indicates that the command is ready from our end to be
 	 * queued.
 	 */
-	ret = BLKPREP_OK;
+	ret = BLK_STS_OK;
  out:
 	return ret;
 }
diff --git a/include/scsi/scsi_cmnd.h b/include/scsi/scsi_cmnd.h
index c891ada3c5c2..d6fd2aba0380 100644
--- a/include/scsi/scsi_cmnd.h
+++ b/include/scsi/scsi_cmnd.h
@@ -171,7 +171,7 @@ extern void *scsi_kmap_atomic_sg(struct scatterlist *sg, int sg_count,
 				 size_t *offset, size_t *len);
 extern void scsi_kunmap_atomic_sg(void *virt);
 
-extern int scsi_init_io(struct scsi_cmnd *cmd);
+extern blk_status_t scsi_init_io(struct scsi_cmnd *cmd);
 
 #ifdef CONFIG_SCSI_DMA
 extern int scsi_dma_map(struct scsi_cmnd *cmd);
diff --git a/include/scsi/scsi_driver.h b/include/scsi/scsi_driver.h
index fae8b465233e..6dffa8555a39 100644
--- a/include/scsi/scsi_driver.h
+++ b/include/scsi/scsi_driver.h
@@ -2,6 +2,7 @@
 #ifndef _SCSI_SCSI_DRIVER_H
 #define _SCSI_SCSI_DRIVER_H
 
+#include <linux/blk_types.h>
 #include <linux/device.h>
 
 struct module;
@@ -13,7 +14,7 @@ struct scsi_driver {
 	struct device_driver	gendrv;
 
 	void (*rescan)(struct device *);
-	int (*init_command)(struct scsi_cmnd *);
+	blk_status_t (*init_command)(struct scsi_cmnd *);
 	void (*uninit_command)(struct scsi_cmnd *);
 	int (*done)(struct scsi_cmnd *);
 	int (*eh_action)(struct scsi_cmnd *, int);
-- 
2.19.1

Re: [PATCH 5/7] scsi: return blk_status_t from scsi_init_io and ->init_command

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
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

Re: [PATCH 5/7] scsi: return blk_status_t from scsi_init_io and ->init_command

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> Replace the old BLKRREP_* values with the BLK_STS_ ones that they are
> converted to later anyway.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: [PATCH 5/7] scsi: return blk_status_t from scsi_init_io and ->init_command

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> Replace the old BLKRREP_* values with the BLK_STS_ ones that they are
> converted to later anyway.

Just noticed a typo: I think BLKRREP_ should be changed into BLKPREP_.

[PATCH 6/7] scsi: return blk_status_t from device handler ->prep_fn

[Christoph Hellwig]

Remove the last use of the old BLKPREP_* values, which get converted
to BLK_STS_* later anyway.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 drivers/scsi/device_handler/scsi_dh_alua.c  | 21 +++++++++++----------
 drivers/scsi/device_handler/scsi_dh_emc.c   |  8 ++++----
 drivers/scsi/device_handler/scsi_dh_hp_sw.c |  7 +++----
 drivers/scsi/device_handler/scsi_dh_rdac.c  |  7 +++----
 drivers/scsi/scsi_lib.c                     | 18 +++---------------
 include/scsi/scsi_dh.h                      |  2 +-
 6 files changed, 25 insertions(+), 38 deletions(-)

diff --git a/drivers/scsi/device_handler/scsi_dh_alua.c b/drivers/scsi/device_handler/scsi_dh_alua.c
index 12dc7100bb4c..d7ac498ba35a 100644
--- a/drivers/scsi/device_handler/scsi_dh_alua.c
+++ b/drivers/scsi/device_handler/scsi_dh_alua.c
@@ -1071,28 +1071,29 @@ static void alua_check(struct scsi_device *sdev, bool force)
  * Fail I/O to all paths not in state
  * active/optimized or active/non-optimized.
  */
-static int alua_prep_fn(struct scsi_device *sdev, struct request *req)
+static blk_status_t alua_prep_fn(struct scsi_device *sdev, struct request *req)
 {
 	struct alua_dh_data *h = sdev->handler_data;
 	struct alua_port_group *pg;
 	unsigned char state = SCSI_ACCESS_STATE_OPTIMAL;
-	int ret = BLKPREP_OK;
 
 	rcu_read_lock();
 	pg = rcu_dereference(h->pg);
 	if (pg)
 		state = pg->state;
 	rcu_read_unlock();
-	if (state == SCSI_ACCESS_STATE_TRANSITIONING)
-		ret = BLKPREP_DEFER;
-	else if (state != SCSI_ACCESS_STATE_OPTIMAL &&
-		 state != SCSI_ACCESS_STATE_ACTIVE &&
-		 state != SCSI_ACCESS_STATE_LBA) {
-		ret = BLKPREP_KILL;
+
+	switch (state) {
+	case SCSI_ACCESS_STATE_OPTIMAL:
+	case SCSI_ACCESS_STATE_ACTIVE:
+	case SCSI_ACCESS_STATE_LBA:
+		return BLK_STS_OK;
+	case SCSI_ACCESS_STATE_TRANSITIONING:
+		return BLK_STS_RESOURCE;
+	default:
 		req->rq_flags |= RQF_QUIET;
+		return BLK_STS_IOERR;
 	}
-	return ret;
-
 }
 
 static void alua_rescan(struct scsi_device *sdev)
diff --git a/drivers/scsi/device_handler/scsi_dh_emc.c b/drivers/scsi/device_handler/scsi_dh_emc.c
index 95c47909a58f..bea8e13febb6 100644
--- a/drivers/scsi/device_handler/scsi_dh_emc.c
+++ b/drivers/scsi/device_handler/scsi_dh_emc.c
@@ -341,17 +341,17 @@ static int clariion_check_sense(struct scsi_device *sdev,
 	return SCSI_RETURN_NOT_HANDLED;
 }
 
-static int clariion_prep_fn(struct scsi_device *sdev, struct request *req)
+static blk_status_t clariion_prep_fn(struct scsi_device *sdev,
+		struct request *req)
 {
 	struct clariion_dh_data *h = sdev->handler_data;
-	int ret = BLKPREP_OK;
 
 	if (h->lun_state != CLARIION_LUN_OWNED) {
-		ret = BLKPREP_KILL;
 		req->rq_flags |= RQF_QUIET;
+		return BLK_STS_IOERR;
 	}
-	return ret;
 
+	return BLK_STS_OK;
 }
 
 static int clariion_std_inquiry(struct scsi_device *sdev,
diff --git a/drivers/scsi/device_handler/scsi_dh_hp_sw.c b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
index e65a0ebb4b54..80129b033855 100644
--- a/drivers/scsi/device_handler/scsi_dh_hp_sw.c
+++ b/drivers/scsi/device_handler/scsi_dh_hp_sw.c
@@ -172,17 +172,16 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
 	return rc;
 }
 
-static int hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
+static blk_status_t hp_sw_prep_fn(struct scsi_device *sdev, struct request *req)
 {
 	struct hp_sw_dh_data *h = sdev->handler_data;
-	int ret = BLKPREP_OK;
 
 	if (h->path_state != HP_SW_PATH_ACTIVE) {
-		ret = BLKPREP_KILL;
 		req->rq_flags |= RQF_QUIET;
+		return BLK_STS_IOERR;
 	}
-	return ret;
 
+	return BLK_STS_OK;
 }
 
 /*
diff --git a/drivers/scsi/device_handler/scsi_dh_rdac.c b/drivers/scsi/device_handler/scsi_dh_rdac.c
index d27fabae8ddd..65f1fe343c64 100644
--- a/drivers/scsi/device_handler/scsi_dh_rdac.c
+++ b/drivers/scsi/device_handler/scsi_dh_rdac.c
@@ -642,17 +642,16 @@ static int rdac_activate(struct scsi_device *sdev,
 	return 0;
 }
 
-static int rdac_prep_fn(struct scsi_device *sdev, struct request *req)
+static blk_status_t rdac_prep_fn(struct scsi_device *sdev, struct request *req)
 {
 	struct rdac_dh_data *h = sdev->handler_data;
-	int ret = BLKPREP_OK;
 
 	if (h->state != RDAC_STATE_ACTIVE) {
-		ret = BLKPREP_KILL;
 		req->rq_flags |= RQF_QUIET;
+		return BLK_STS_IOERR;
 	}
-	return ret;
 
+	return BLK_STS_OK;
 }
 
 static int rdac_check_sense(struct scsi_device *sdev,
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 3e3bdeee8f14..5d83a162d03b 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1177,18 +1177,6 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 	scsi_add_cmd_to_list(cmd);
 }
 
-static inline blk_status_t prep_to_mq(int ret)
-{
-	switch (ret) {
-	case BLKPREP_OK:
-		return BLK_STS_OK;
-	case BLKPREP_DEFER:
-		return BLK_STS_RESOURCE;
-	default:
-		return BLK_STS_IOERR;
-	}
-}
-
 static blk_status_t scsi_setup_scsi_cmnd(struct scsi_device *sdev,
 		struct request *req)
 {
@@ -1227,9 +1215,9 @@ static blk_status_t scsi_setup_fs_cmnd(struct scsi_device *sdev,
 	struct scsi_cmnd *cmd = blk_mq_rq_to_pdu(req);
 
 	if (unlikely(sdev->handler && sdev->handler->prep_fn)) {
-		int ret = sdev->handler->prep_fn(sdev, req);
-		if (ret != BLKPREP_OK)
-			return prep_to_mq(ret);
+		blk_status_t ret = sdev->handler->prep_fn(sdev, req);
+		if (ret != BLK_STS_OK)
+			return ret;
 	}
 
 	cmd->cmnd = scsi_req(req)->cmd = scsi_req(req)->__cmd;
diff --git a/include/scsi/scsi_dh.h b/include/scsi/scsi_dh.h
index c7bba2b24849..a862dc23c68d 100644
--- a/include/scsi/scsi_dh.h
+++ b/include/scsi/scsi_dh.h
@@ -69,7 +69,7 @@ struct scsi_device_handler {
 	int (*attach)(struct scsi_device *);
 	void (*detach)(struct scsi_device *);
 	int (*activate)(struct scsi_device *, activate_complete, void *);
-	int (*prep_fn)(struct scsi_device *, struct request *);
+	blk_status_t (*prep_fn)(struct scsi_device *, struct request *);
 	int (*set_params)(struct scsi_device *, const char *);
 	void (*rescan)(struct scsi_device *);
 };
-- 
2.19.1

Re: [PATCH 6/7] scsi: return blk_status_t from device handler ->prep_fn

[Johannes Thumshirn]

Looks good,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
-- 
Johannes Thumshirn                                        SUSE Labs
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

Re: [PATCH 6/7] scsi: return blk_status_t from device handler ->prep_fn

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> Remove the last use of the old BLKPREP_* values, which get converted
> to BLK_STS_* later anyway.

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

[PATCH 7/7] block: remove the BLKPREP_* values.

[Christoph Hellwig]

Unused now.

Signed-off-by: Christoph Hellwig <hch@lst.de>
---
 include/linux/blkdev.h | 10 ----------
 1 file changed, 10 deletions(-)

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 9b1f470cc784..55597948868b 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -778,16 +778,6 @@ static inline unsigned int blk_queue_depth(struct request_queue *q)
 	return q->nr_requests;
 }
 
-/*
- * q->prep_rq_fn return values
- */
-enum {
-	BLKPREP_OK,		/* serve it */
-	BLKPREP_KILL,		/* fatal error, kill, return -EIO */
-	BLKPREP_DEFER,		/* leave on queue */
-	BLKPREP_INVALID,	/* invalid command, kill, return -EREMOTEIO */
-};
-
 extern unsigned long blk_max_low_pfn, blk_max_pfn;
 
 /*
-- 
2.19.1

Re: [PATCH 7/7] block: remove the BLKPREP_* values.

[Johannes Thumshirn]

So long and thanks for all the fish,
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>

-- 
Johannes Thumshirn                                        SUSE Labs
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

Re: [PATCH 7/7] block: remove the BLKPREP_* values.

[Bart Van Assche]

On Fri, 2018-11-09 at 14:42 +0100, Christoph Hellwig wrote:
> Unused now.
> 
> Signed-off-by: Christoph Hellwig <hch@lst.de>
> ---
>  include/linux/blkdev.h | 10 ----------
>  1 file changed, 10 deletions(-)
> 
> diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
> index 9b1f470cc784..55597948868b 100644
> --- a/include/linux/blkdev.h
> +++ b/include/linux/blkdev.h
> @@ -778,16 +778,6 @@ static inline unsigned int blk_queue_depth(struct request_queue *q)
>  	return q->nr_requests;
>  }
>  
> -/*
> - * q->prep_rq_fn return values
> - */
> -enum {
> -	BLKPREP_OK,		/* serve it */
> -	BLKPREP_KILL,		/* fatal error, kill, return -EIO */
> -	BLKPREP_DEFER,		/* leave on queue */
> -	BLKPREP_INVALID,	/* invalid command, kill, return -EREMOTEIO */
> -};
> -
>  extern unsigned long blk_max_low_pfn, blk_max_pfn;
>  
>  /*

Reviewed-by: Bart Van Assche <bvanassche@acm.org>

Re: remove the legacy BLKPREP_* values

[Jens Axboe]

On 11/9/18 6:42 AM, Christoph Hellwig wrote:
> Hi Jens,
> 
> this series gets rid of the old BLKPREP_* values from the legacy block
> layer in favor of always using a blk_status_t (or a bool in one case).

Series looks good to me, tested the IDE bits too. I'm assuming we'll
take this through the block tree with the dependencies, I'll wait
a bit to let folks take a closer look.

-- 
Jens Axboe

Re: remove the legacy BLKPREP_* values

[Jens Axboe]

On 11/9/18 6:42 AM, Christoph Hellwig wrote:
> Hi Jens,
> 
> this series gets rid of the old BLKPREP_* values from the legacy block
> layer in favor of always using a blk_status_t (or a bool in one case).

Applied

-- 
Jens Axboe