Revert "scsi: core: Use scsi_cmd_to_rq() instead of scsi_cmnd.request"

This reverts commit df83ca8 which is
commit aa8e25e upstream.

As reported, a lot of scsi changes were made just to resolve a 2 line
patch, so let's revert them all and then manually fix up the 2 line
fixup so that things are simpler and potential abi changes are not an
issue.

Link: https://lore.kernel.org/r/ZZ042FejzwMM5vDW@duo.ucw.cz
Reported-by: Pavel Machek <pavel@ucw.cz>
Cc: "Martin K. Petersen" <martin.petersen@oracle.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Hannes Reinecke <hare@suse.de>
Cc: Ming Lei <ming.lei@redhat.com>
Cc: Bart Van Assche <bvanassche@acm.org>
Cc: Sasha Levin <sashal@kernel.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

drivers/scsi/scsi.c

@@ -197,7 +197,7 @@ void scsi_finish_command(struct scsi_cmnd *cmd)
 				"(result %x)\n", cmd->result));
 
 	good_bytes = scsi_bufflen(cmd);
-	if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) {
+	if (!blk_rq_is_passthrough(cmd->request)) {
 		int old_good_bytes = good_bytes;
 		drv = scsi_cmd_to_driver(cmd);
 		if (drv->done)

drivers/scsi/scsi_error.c

@@ -230,7 +230,7 @@ scsi_abort_command(struct scsi_cmnd *scmd)
  */
 static void scsi_eh_reset(struct scsi_cmnd *scmd)
 {
-	if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
+	if (!blk_rq_is_passthrough(scmd->request)) {
 		struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
 		if (sdrv->eh_reset)
 			sdrv->eh_reset(scmd);
@@ -1167,7 +1167,7 @@ static int scsi_request_sense(struct scsi_cmnd *scmd)
 
 static int scsi_eh_action(struct scsi_cmnd *scmd, int rtn)
 {
-	if (!blk_rq_is_passthrough(scsi_cmd_to_rq(scmd))) {
+	if (!blk_rq_is_passthrough(scmd->request)) {
 		struct scsi_driver *sdrv = scsi_cmd_to_driver(scmd);
 		if (sdrv->eh_action)
 			rtn = sdrv->eh_action(scmd, rtn);
@@ -1733,24 +1733,22 @@ static void scsi_eh_offline_sdevs(struct list_head *work_q,
  */
 int scsi_noretry_cmd(struct scsi_cmnd *scmd)
 {
-	struct request *req = scsi_cmd_to_rq(scmd);
-
 	switch (host_byte(scmd->result)) {
 	case DID_OK:
 		break;
 	case DID_TIME_OUT:
 		goto check_type;
 	case DID_BUS_BUSY:
-		return req->cmd_flags & REQ_FAILFAST_TRANSPORT;
+		return (scmd->request->cmd_flags & REQ_FAILFAST_TRANSPORT);
 	case DID_PARITY:
-		return req->cmd_flags & REQ_FAILFAST_DEV;
+		return (scmd->request->cmd_flags & REQ_FAILFAST_DEV);
 	case DID_ERROR:
 		if (msg_byte(scmd->result) == COMMAND_COMPLETE &&
 		    status_byte(scmd->result) == RESERVATION_CONFLICT)
 			return 0;
 		fallthrough;
 	case DID_SOFT_ERROR:
-		return req->cmd_flags & REQ_FAILFAST_DRIVER;
+		return (scmd->request->cmd_flags & REQ_FAILFAST_DRIVER);
 	}
 
 	if (status_byte(scmd->result) != CHECK_CONDITION)
@@ -1761,7 +1759,8 @@ int scsi_noretry_cmd(struct scsi_cmnd *scmd)
 	 * assume caller has checked sense and determined
 	 * the check condition was retryable.
 	 */
-	if (req->cmd_flags & REQ_FAILFAST_DEV || blk_rq_is_passthrough(req))
+	if (scmd->request->cmd_flags & REQ_FAILFAST_DEV ||
+	    blk_rq_is_passthrough(scmd->request))
 		return 1;
 
 	return 0;

drivers/scsi/scsi_lib.c

@@ -153,15 +153,13 @@ scsi_set_blocked(struct scsi_cmnd *cmd, int reason)
 
 static void scsi_mq_requeue_cmd(struct scsi_cmnd *cmd)
 {
-	struct request *rq = scsi_cmd_to_rq(cmd);
-
-	if (rq->rq_flags & RQF_DONTPREP) {
-		rq->rq_flags &= ~RQF_DONTPREP;
+	if (cmd->request->rq_flags & RQF_DONTPREP) {
+		cmd->request->rq_flags &= ~RQF_DONTPREP;
 		scsi_mq_uninit_cmd(cmd);
 	} else {
 		WARN_ON_ONCE(true);
 	}
-	blk_mq_requeue_request(rq, true);
+	blk_mq_requeue_request(cmd->request, true);
 }
 
 /**
@@ -200,7 +198,7 @@ static void __scsi_queue_insert(struct scsi_cmnd *cmd, int reason, bool unbusy)
 	 */
 	cmd->result = 0;
 
-	blk_mq_requeue_request(scsi_cmd_to_rq(cmd), true);
+	blk_mq_requeue_request(cmd->request, true);
 }
 
 /**
@@ -510,7 +508,7 @@ void scsi_run_host_queues(struct Scsi_Host *shost)
 
 static void scsi_uninit_cmd(struct scsi_cmnd *cmd)
 {
-	if (!blk_rq_is_passthrough(scsi_cmd_to_rq(cmd))) {
+	if (!blk_rq_is_passthrough(cmd->request)) {
 		struct scsi_driver *drv = scsi_cmd_to_driver(cmd);
 
 		if (drv->uninit_command)
@@ -660,7 +658,7 @@ static void scsi_io_completion_reprep(struct scsi_cmnd *cmd,
 
 static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd)
 {
-	struct request *req = scsi_cmd_to_rq(cmd);
+	struct request *req = cmd->request;
 	unsigned long wait_for;
 
 	if (cmd->allowed == SCSI_CMD_RETRIES_NO_LIMIT)
@@ -679,7 +677,7 @@ static bool scsi_cmd_runtime_exceeced(struct scsi_cmnd *cmd)
 static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)
 {
 	struct request_queue *q = cmd->device->request_queue;
-	struct request *req = scsi_cmd_to_rq(cmd);
+	struct request *req = cmd->request;
 	int level = 0;
 	enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,
 	      ACTION_DELAYED_RETRY} action;
@@ -851,7 +849,7 @@ static int scsi_io_completion_nz_result(struct scsi_cmnd *cmd, int result,
 {
 	bool sense_valid;
 	bool sense_current = true;	/* false implies "deferred sense" */
-	struct request *req = scsi_cmd_to_rq(cmd);
+	struct request *req = cmd->request;
 	struct scsi_sense_hdr sshdr;
 
 	sense_valid = scsi_command_normalize_sense(cmd, &sshdr);
@@ -940,7 +938,7 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes)
 {
 	int result = cmd->result;
 	struct request_queue *q = cmd->device->request_queue;
-	struct request *req = scsi_cmd_to_rq(cmd);
+	struct request *req = cmd->request;
 	blk_status_t blk_stat = BLK_STS_OK;
 
 	if (unlikely(result))	/* a nz result may or may not be an error */
@@ -1008,7 +1006,7 @@ static inline bool scsi_cmd_needs_dma_drain(struct scsi_device *sdev,
 blk_status_t scsi_alloc_sgtables(struct scsi_cmnd *cmd)
 {
 	struct scsi_device *sdev = cmd->device;
-	struct request *rq = scsi_cmd_to_rq(cmd);
+	struct request *rq = cmd->request;
 	unsigned short nr_segs = blk_rq_nr_phys_segments(rq);
 	struct scatterlist *last_sg = NULL;
 	blk_status_t ret;
@@ -1137,7 +1135,7 @@ void scsi_init_command(struct scsi_device *dev, struct scsi_cmnd *cmd)
 {
 	void *buf = cmd->sense_buffer;
 	void *prot = cmd->prot_sdb;
-	struct request *rq = scsi_cmd_to_rq(cmd);
+	struct request *rq = blk_mq_rq_from_pdu(cmd);
 	unsigned int flags = cmd->flags & SCMD_PRESERVED_FLAGS;
 	unsigned long jiffies_at_alloc;
 	int retries, to_clear;
@@ -1596,12 +1594,12 @@ static blk_status_t scsi_prepare_cmd(struct request *req)
 
 static void scsi_mq_done(struct scsi_cmnd *cmd)
 {
-	if (unlikely(blk_should_fake_timeout(scsi_cmd_to_rq(cmd)->q)))
+	if (unlikely(blk_should_fake_timeout(cmd->request->q)))
 		return;
 	if (unlikely(test_and_set_bit(SCMD_STATE_COMPLETE, &cmd->state)))
 		return;
 	trace_scsi_dispatch_cmd_done(cmd);
-	blk_mq_complete_request(scsi_cmd_to_rq(cmd));
+	blk_mq_complete_request(cmd->request);
 }
 
 static void scsi_mq_put_budget(struct request_queue *q)

drivers/scsi/scsi_logging.c

@@ -28,9 +28,8 @@ static void scsi_log_release_buffer(char *bufptr)
 
 static inline const char *scmd_name(const struct scsi_cmnd *scmd)
 {
-	struct request *rq = scsi_cmd_to_rq((struct scsi_cmnd *)scmd);
-
-	return rq->rq_disk ? rq->rq_disk->disk_name : NULL;
+	return scmd->request->rq_disk ?
+		scmd->request->rq_disk->disk_name : NULL;
 }
 
 static size_t sdev_format_header(char *logbuf, size_t logbuf_len,
@@ -92,7 +91,7 @@ void scmd_printk(const char *level, const struct scsi_cmnd *scmd,
 	if (!logbuf)
 		return;
 	off = sdev_format_header(logbuf, logbuf_len, scmd_name(scmd),
-				 scsi_cmd_to_rq((struct scsi_cmnd *)scmd)->tag);
+				 scmd->request->tag);
 	if (off < logbuf_len) {
 		va_start(args, fmt);
 		off += vscnprintf(logbuf + off, logbuf_len - off, fmt, args);
@@ -189,7 +188,7 @@ void scsi_print_command(struct scsi_cmnd *cmd)
 		return;
 
 	off = sdev_format_header(logbuf, logbuf_len,
-				 scmd_name(cmd), scsi_cmd_to_rq(cmd)->tag);
+				 scmd_name(cmd), cmd->request->tag);
 	if (off >= logbuf_len)
 		goto out_printk;
 	off += scnprintf(logbuf + off, logbuf_len - off, "CDB: ");
@@ -211,7 +210,7 @@ void scsi_print_command(struct scsi_cmnd *cmd)
 
 			off = sdev_format_header(logbuf, logbuf_len,
 						 scmd_name(cmd),
-						 scsi_cmd_to_rq(cmd)->tag);
+						 cmd->request->tag);
 			if (!WARN_ON(off > logbuf_len - 58)) {
 				off += scnprintf(logbuf + off, logbuf_len - off,
 						 "CDB[%02x]: ", k);
@@ -374,8 +373,7 @@ EXPORT_SYMBOL(__scsi_print_sense);
 /* Normalize and print sense buffer in SCSI command */
 void scsi_print_sense(const struct scsi_cmnd *cmd)
 {
-	scsi_log_print_sense(cmd->device, scmd_name(cmd),
-			     scsi_cmd_to_rq((struct scsi_cmnd *)cmd)->tag,
+	scsi_log_print_sense(cmd->device, scmd_name(cmd), cmd->request->tag,
 			     cmd->sense_buffer, SCSI_SENSE_BUFFERSIZE);
 }
 EXPORT_SYMBOL(scsi_print_sense);
@@ -394,8 +392,8 @@ void scsi_print_result(const struct scsi_cmnd *cmd, const char *msg,
 	if (!logbuf)
 		return;
 
-	off = sdev_format_header(logbuf, logbuf_len, scmd_name(cmd),
-				 scsi_cmd_to_rq((struct scsi_cmnd *)cmd)->tag);
+	off = sdev_format_header(logbuf, logbuf_len,
+				 scmd_name(cmd), cmd->request->tag);
 
 	if (off >= logbuf_len)
 		goto out_printk;

include/scsi/scsi_cmnd.h

@@ -162,9 +162,7 @@ static inline void *scsi_cmd_priv(struct scsi_cmnd *cmd)
 /* make sure not to use it with passthrough commands */
 static inline struct scsi_driver *scsi_cmd_to_driver(struct scsi_cmnd *cmd)
 {
-	struct request *rq = scsi_cmd_to_rq(cmd);
-
-	return *(struct scsi_driver **)rq->rq_disk->private_data;
+	return *(struct scsi_driver **)cmd->request->rq_disk->private_data;
 }
 
 extern void scsi_finish_command(struct scsi_cmnd *cmd);
@@ -228,14 +226,14 @@ static inline int scsi_sg_copy_to_buffer(struct scsi_cmnd *cmd,
 
 static inline sector_t scsi_get_sector(struct scsi_cmnd *scmd)
 {
-	return blk_rq_pos(scsi_cmd_to_rq(scmd));
+	return blk_rq_pos(scmd->request);
 }
 
 static inline sector_t scsi_get_lba(struct scsi_cmnd *scmd)
 {
 	unsigned int shift = ilog2(scmd->device->sector_size) - SECTOR_SHIFT;
 
-	return blk_rq_pos(scsi_cmd_to_rq(scmd)) >> shift;
+	return blk_rq_pos(scmd->request) >> shift;
 }
 
 /*

include/scsi/scsi_device.h

@@ -264,15 +264,13 @@ sdev_prefix_printk(const char *, const struct scsi_device *, const char *,
 __printf(3, 4) void
 scmd_printk(const char *, const struct scsi_cmnd *, const char *, ...);
 
-#define scmd_dbg(scmd, fmt, a...)					\
-	do {								\
-		struct request *__rq = scsi_cmd_to_rq((scmd));		\
-									\
-		if (__rq->rq_disk)					\
-			sdev_dbg((scmd)->device, "[%s] " fmt,		\
-				 __rq->rq_disk->disk_name, ##a);	\
-		else							\
-			sdev_dbg((scmd)->device, fmt, ##a);		\
+#define scmd_dbg(scmd, fmt, a...)					   \
+	do {								   \
+		if ((scmd)->request->rq_disk)				   \
+			sdev_dbg((scmd)->device, "[%s] " fmt,		   \
+				 (scmd)->request->rq_disk->disk_name, ##a);\
+		else							   \
+			sdev_dbg((scmd)->device, fmt, ##a);		   \
 	} while (0)
 
 enum scsi_target_state {