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Commit da32baea authored by Douglas Gilbert's avatar Douglas Gilbert Committed by Martin K. Petersen
Browse files

scsi: core: add scsi_io_completion_action helper 



Place scsi_io_completion()'s complex error processing associated with a
local enumeration into a static helper function. That enumeration's values
start with "ACTION_" so use the suffix "_action" in the helper function's
name.

Signed-off-by: default avatarDouglas Gilbert <dgilbert@interlog.com>
Reviewed-by: default avatarJohannes Thumshirn <jthumshirn@suse.de>
Reviewed-by: default avatarBart Van Assche <bart.vanassche@wdc.com>
Reviewed-by: default avatarHannes Reinecke <hare@suse.com>
Signed-off-by: default avatarMartin K. Petersen <martin.petersen@oracle.com>
parent ab831084

drivers/scsi/scsi_lib.c

+175 −154
Original line number Diff line number Diff line
@@ -761,6 +761,172 @@ static blk_status_t scsi_result_to_blk_status(struct scsi_cmnd *cmd, int result) 
	}

}



/* Helper for scsi_io_completion() when special action required. */

static void scsi_io_completion_action(struct scsi_cmnd *cmd, int result)

{

	struct request_queue *q = cmd->device->request_queue;

	struct request *req = cmd->request;

	int level = 0;

	enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,

	      ACTION_DELAYED_RETRY} action;

	unsigned long wait_for = (cmd->allowed + 1) * req->timeout;

	struct scsi_sense_hdr sshdr;

	bool sense_valid;

	bool sense_current = true;      /* false implies "deferred sense" */

	blk_status_t blk_stat;



	sense_valid = scsi_command_normalize_sense(cmd, &sshdr);

	if (sense_valid)

		sense_current = !scsi_sense_is_deferred(&sshdr);



	blk_stat = scsi_result_to_blk_status(cmd, result);



	if (host_byte(result) == DID_RESET) {

		/* Third party bus reset or reset for error recovery

		 * reasons.  Just retry the command and see what

		 * happens.

		 */

		action = ACTION_RETRY;

	} else if (sense_valid && sense_current) {

		switch (sshdr.sense_key) {

		case UNIT_ATTENTION:

			if (cmd->device->removable) {

				/* Detected disc change.  Set a bit

				 * and quietly refuse further access.

				 */

				cmd->device->changed = 1;

				action = ACTION_FAIL;

			} else {

				/* Must have been a power glitch, or a

				 * bus reset.  Could not have been a

				 * media change, so we just retry the

				 * command and see what happens.

				 */

				action = ACTION_RETRY;

			}

			break;

		case ILLEGAL_REQUEST:

			/* If we had an ILLEGAL REQUEST returned, then

			 * we may have performed an unsupported

			 * command.  The only thing this should be

			 * would be a ten byte read where only a six

			 * byte read was supported.  Also, on a system

			 * where READ CAPACITY failed, we may have

			 * read past the end of the disk.

			 */

			if ((cmd->device->use_10_for_rw &&

			    sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&

			    (cmd->cmnd[0] == READ_10 ||

			     cmd->cmnd[0] == WRITE_10)) {

				/* This will issue a new 6-byte command. */

				cmd->device->use_10_for_rw = 0;

				action = ACTION_REPREP;

			} else if (sshdr.asc == 0x10) /* DIX */ {

				action = ACTION_FAIL;

				blk_stat = BLK_STS_PROTECTION;

			/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */

			} else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {

				action = ACTION_FAIL;

				blk_stat = BLK_STS_TARGET;

			} else

				action = ACTION_FAIL;

			break;

		case ABORTED_COMMAND:

			action = ACTION_FAIL;

			if (sshdr.asc == 0x10) /* DIF */

				blk_stat = BLK_STS_PROTECTION;

			break;

		case NOT_READY:

			/* If the device is in the process of becoming

			 * ready, or has a temporary blockage, retry.

			 */

			if (sshdr.asc == 0x04) {

				switch (sshdr.ascq) {

				case 0x01: /* becoming ready */

				case 0x04: /* format in progress */

				case 0x05: /* rebuild in progress */

				case 0x06: /* recalculation in progress */

				case 0x07: /* operation in progress */

				case 0x08: /* Long write in progress */

				case 0x09: /* self test in progress */

				case 0x14: /* space allocation in progress */

				case 0x1a: /* start stop unit in progress */

				case 0x1b: /* sanitize in progress */

				case 0x1d: /* configuration in progress */

				case 0x24: /* depopulation in progress */

					action = ACTION_DELAYED_RETRY;

					break;

				default:

					action = ACTION_FAIL;

					break;

				}

			} else

				action = ACTION_FAIL;

			break;

		case VOLUME_OVERFLOW:

			/* See SSC3rXX or current. */

			action = ACTION_FAIL;

			break;

		default:

			action = ACTION_FAIL;

			break;

		}

	} else

		action = ACTION_FAIL;



	if (action != ACTION_FAIL &&

	    time_before(cmd->jiffies_at_alloc + wait_for, jiffies))

		action = ACTION_FAIL;



	switch (action) {

	case ACTION_FAIL:

		/* Give up and fail the remainder of the request */

		if (!(req->rq_flags & RQF_QUIET)) {

			static DEFINE_RATELIMIT_STATE(_rs,

					DEFAULT_RATELIMIT_INTERVAL,

					DEFAULT_RATELIMIT_BURST);



			if (unlikely(scsi_logging_level))

				level =

				     SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,

						    SCSI_LOG_MLCOMPLETE_BITS);



			/*

			 * if logging is enabled the failure will be printed

			 * in scsi_log_completion(), so avoid duplicate messages

			 */

			if (!level && __ratelimit(&_rs)) {

				scsi_print_result(cmd, NULL, FAILED);

				if (driver_byte(result) & DRIVER_SENSE)

					scsi_print_sense(cmd);

				scsi_print_command(cmd);

			}

		}

		if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req), 0))

			return;

		/*FALLTHRU*/

	case ACTION_REPREP:

		/* Unprep the request and put it back at the head of the queue.

		 * A new command will be prepared and issued.

		 */

		if (q->mq_ops) {

			scsi_mq_requeue_cmd(cmd);

		} else {

			scsi_release_buffers(cmd);

			scsi_requeue_command(q, cmd);

		}

		break;

	case ACTION_RETRY:

		/* Retry the same command immediately */

		__scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);

		break;

	case ACTION_DELAYED_RETRY:

		/* Retry the same command after a delay */

		__scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);

		break;

	}

}



/*

 * Helper for scsi_io_completion() when cmd->result is non-zero. Returns a

 * new result that may suppress further error checking. Also modifies
@@ -869,20 +1035,9 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 
	struct request_queue *q = cmd->device->request_queue;

	struct request *req = cmd->request;

	blk_status_t blk_stat = BLK_STS_OK;

	struct scsi_sense_hdr sshdr;

	bool sense_valid = false;

	bool sense_current = true;	/* false implies "deferred sense" */

	int level = 0;

	enum {ACTION_FAIL, ACTION_REPREP, ACTION_RETRY,

	      ACTION_DELAYED_RETRY} action;

	unsigned long wait_for = (cmd->allowed + 1) * req->timeout;



	if (result) {	/* does not necessarily mean there is an error */

		sense_valid = scsi_command_normalize_sense(cmd, &sshdr);

		if (sense_valid)

			sense_current = !scsi_sense_is_deferred(&sshdr);

	if (result)	/* does not necessarily mean there is an error */

		result = scsi_io_completion_nz_result(cmd, result, &blk_stat);

	}



	if (blk_rq_is_passthrough(req)) {

		/*
@@ -936,138 +1091,12 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 
	 * If there had been no error, but we have leftover bytes in the

	 * requeues just queue the command up again.

	 */

	if (result == 0)

		goto requeue;



	blk_stat = scsi_result_to_blk_status(cmd, result);



	if (host_byte(result) == DID_RESET) {

		/* Third party bus reset or reset for error recovery

		 * reasons.  Just retry the command and see what

		 * happens.

		 */

		action = ACTION_RETRY;

	} else if (sense_valid && sense_current) {

		switch (sshdr.sense_key) {

		case UNIT_ATTENTION:

			if (cmd->device->removable) {

				/* Detected disc change.  Set a bit

				 * and quietly refuse further access.

				 */

				cmd->device->changed = 1;

				action = ACTION_FAIL;

			} else {

				/* Must have been a power glitch, or a

				 * bus reset.  Could not have been a

				 * media change, so we just retry the

				 * command and see what happens.

				 */

				action = ACTION_RETRY;

			}

			break;

		case ILLEGAL_REQUEST:

			/* If we had an ILLEGAL REQUEST returned, then

			 * we may have performed an unsupported

			 * command.  The only thing this should be

			 * would be a ten byte read where only a six

			 * byte read was supported.  Also, on a system

			 * where READ CAPACITY failed, we may have

			 * read past the end of the disk.

			 */

			if ((cmd->device->use_10_for_rw &&

			    sshdr.asc == 0x20 && sshdr.ascq == 0x00) &&

			    (cmd->cmnd[0] == READ_10 ||

			     cmd->cmnd[0] == WRITE_10)) {

				/* This will issue a new 6-byte command. */

				cmd->device->use_10_for_rw = 0;

				action = ACTION_REPREP;

			} else if (sshdr.asc == 0x10) /* DIX */ {

				action = ACTION_FAIL;

				blk_stat = BLK_STS_PROTECTION;

			/* INVALID COMMAND OPCODE or INVALID FIELD IN CDB */

			} else if (sshdr.asc == 0x20 || sshdr.asc == 0x24) {

				action = ACTION_FAIL;

				blk_stat = BLK_STS_TARGET;

			} else

				action = ACTION_FAIL;

			break;

		case ABORTED_COMMAND:

			action = ACTION_FAIL;

			if (sshdr.asc == 0x10) /* DIF */

				blk_stat = BLK_STS_PROTECTION;

			break;

		case NOT_READY:

			/* If the device is in the process of becoming

			 * ready, or has a temporary blockage, retry.

			 */

			if (sshdr.asc == 0x04) {

				switch (sshdr.ascq) {

				case 0x01: /* becoming ready */

				case 0x04: /* format in progress */

				case 0x05: /* rebuild in progress */

				case 0x06: /* recalculation in progress */

				case 0x07: /* operation in progress */

				case 0x08: /* Long write in progress */

				case 0x09: /* self test in progress */

				case 0x14: /* space allocation in progress */

				case 0x1a: /* start stop unit in progress */

				case 0x1b: /* sanitize in progress */

				case 0x1d: /* configuration in progress */

				case 0x24: /* depopulation in progress */

					action = ACTION_DELAYED_RETRY;

					break;

				default:

					action = ACTION_FAIL;

					break;

				}

			} else

				action = ACTION_FAIL;

			break;

		case VOLUME_OVERFLOW:

			/* See SSC3rXX or current. */

			action = ACTION_FAIL;

			break;

		default:

			action = ACTION_FAIL;

			break;

		}

	} else

		action = ACTION_FAIL;



	if (action != ACTION_FAIL &&

	    time_before(cmd->jiffies_at_alloc + wait_for, jiffies))

		action = ACTION_FAIL;



	switch (action) {

	case ACTION_FAIL:

		/* Give up and fail the remainder of the request */

		if (!(req->rq_flags & RQF_QUIET)) {

			static DEFINE_RATELIMIT_STATE(_rs,

					DEFAULT_RATELIMIT_INTERVAL,

					DEFAULT_RATELIMIT_BURST);



			if (unlikely(scsi_logging_level))

				level = SCSI_LOG_LEVEL(SCSI_LOG_MLCOMPLETE_SHIFT,

						       SCSI_LOG_MLCOMPLETE_BITS);



	if (result == 0) {

		/*

			 * if logging is enabled the failure will be printed

			 * in scsi_log_completion(), so avoid duplicate messages

			 */

			if (!level && __ratelimit(&_rs)) {

				scsi_print_result(cmd, NULL, FAILED);

				if (driver_byte(result) & DRIVER_SENSE)

					scsi_print_sense(cmd);

				scsi_print_command(cmd);

			}

		}

		if (!scsi_end_request(req, blk_stat, blk_rq_err_bytes(req), 0))

			return;

		/*FALLTHRU*/

	case ACTION_REPREP:

	requeue:

		/* Unprep the request and put it back at the head of the queue.

		 * A new command will be prepared and issued.

		 * Unprep the request and put it back at the head of the

		 * queue. A new command will be prepared and issued.

		 * This block is the same as case ACTION_REPREP in

		 * scsi_io_completion_action() above.

		 */

		if (q->mq_ops) {

			scsi_mq_requeue_cmd(cmd);
@@ -1075,16 +1104,8 @@ void scsi_io_completion(struct scsi_cmnd *cmd, unsigned int good_bytes) 
			scsi_release_buffers(cmd);

			scsi_requeue_command(q, cmd);

		}

		break;

	case ACTION_RETRY:

		/* Retry the same command immediately */

		__scsi_queue_insert(cmd, SCSI_MLQUEUE_EH_RETRY, false);

		break;

	case ACTION_DELAYED_RETRY:

		/* Retry the same command after a delay */

		__scsi_queue_insert(cmd, SCSI_MLQUEUE_DEVICE_BUSY, false);

		break;

	}

	} else

		scsi_io_completion_action(cmd, result);

}



static int scsi_init_sgtable(struct request *req, struct scsi_data_buffer *sdb)