Merge patch series "scsi: Allow scsi_execute users to request retries"

Mike Christie <michael.christie@oracle.com> says:

The following patches were made over Linus's tree which contains a fix
for sd which was not in Martin's branches.

The patches allow scsi_execute_cmd users to have scsi-ml retry the cmd
for it instead of the caller having to parse the error and loop
itself.

Link: https://lore.kernel.org/r/20240123002220.129141-1-michael.christie@oracle.comSigned-off-by: Martin K. Petersen <martin.petersen@oracle.com>

drivers/scsi/Kconfig

@@ -67,6 +67,15 @@ config SCSI_PROC_FS
 
 	  If unsure say Y.
 
+config SCSI_LIB_KUNIT_TEST
+	tristate "KUnit tests for SCSI Mid Layer's scsi_lib" if !KUNIT_ALL_TESTS
+	depends on KUNIT
+	default KUNIT_ALL_TESTS
+	help
+	  Run SCSI Mid Layer's KUnit tests for scsi_lib.
+
+	  If unsure say N.
+
 comment "SCSI support type (disk, tape, CD-ROM)"
 	depends on SCSI
 

drivers/scsi/ch.c

@@ -113,7 +113,6 @@ typedef struct {
 	struct scsi_device  **dt;        /* ptrs to data transfer elements */
 	u_int               firsts[CH_TYPES];
 	u_int               counts[CH_TYPES];
-	u_int               unit_attention;
 	u_int		    voltags;
 	struct mutex	    lock;
 } scsi_changer;
@@ -186,17 +185,29 @@ static int
 ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 	   void *buffer, unsigned int buflength, enum req_op op)
 {
-	int errno, retries = 0, timeout, result;
+	int errno = 0, timeout, result;
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 3,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
 	timeout = (cmd[0] == INITIALIZE_ELEMENT_STATUS)
 		? timeout_init : timeout_move;
 
- retry:
-	errno = 0;
 	result = scsi_execute_cmd(ch->device, cmd, op, buffer, buflength,
 				  timeout * HZ, MAX_RETRIES, &exec_args);
 	if (result < 0)
@@ -205,14 +216,6 @@ ch_do_scsi(scsi_changer *ch, unsigned char *cmd, int cmd_len,
 		if (debug)
 			scsi_print_sense_hdr(ch->device, ch->name, &sshdr);
 		errno = ch_find_errno(&sshdr);
-
-		switch(sshdr.sense_key) {
-		case UNIT_ATTENTION:
-			ch->unit_attention = 1;
-			if (retries++ < 3)
-				goto retry;
-			break;
-		}
 	}
 	return errno;
 }

drivers/scsi/device_handler/scsi_dh_hp_sw.c

@@ -46,9 +46,6 @@ static int tur_done(struct scsi_device *sdev, struct hp_sw_dh_data *h,
 	int ret = SCSI_DH_IO;
 
 	switch (sshdr->sense_key) {
-	case UNIT_ATTENTION:
-		ret = SCSI_DH_IMM_RETRY;
-		break;
 	case NOT_READY:
 		if (sshdr->asc == 0x04 && sshdr->ascq == 2) {
 			/*
@@ -85,11 +82,24 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
 	int ret, res;
 	blk_opf_t opf = REQ_OP_DRV_IN | REQ_FAILFAST_DEV |
 				REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SCMD_FAILURE_NO_LIMIT,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
-retry:
 	res = scsi_execute_cmd(sdev, cmd, opf, NULL, 0, HP_SW_TIMEOUT,
 			       HP_SW_RETRIES, &exec_args);
 	if (res > 0 && scsi_sense_valid(&sshdr)) {
@@ -104,9 +114,6 @@ static int hp_sw_tur(struct scsi_device *sdev, struct hp_sw_dh_data *h)
 		ret = SCSI_DH_IO;
 	}
 
-	if (ret == SCSI_DH_IMM_RETRY)
-		goto retry;
-
 	return ret;
 }
 
@@ -122,14 +129,31 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
 	struct scsi_sense_hdr sshdr;
 	struct scsi_device *sdev = h->sdev;
 	int res, rc;
-	int retry_cnt = HP_SW_RETRIES;
 	blk_opf_t opf = REQ_OP_DRV_IN | REQ_FAILFAST_DEV |
 				REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
+	struct scsi_failure failure_defs[] = {
+		{
+			/*
+			 * LUN not ready - manual intervention required
+			 *
+			 * Switch-over in progress, retry.
+			 */
+			.sense = NOT_READY,
+			.asc = 0x04,
+			.ascq = 0x03,
+			.allowed = HP_SW_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
-retry:
 	res = scsi_execute_cmd(sdev, cmd, opf, NULL, 0, HP_SW_TIMEOUT,
 			       HP_SW_RETRIES, &exec_args);
 	if (!res) {
@@ -144,13 +168,6 @@ static int hp_sw_start_stop(struct hp_sw_dh_data *h)
 	switch (sshdr.sense_key) {
 	case NOT_READY:
 		if (sshdr.asc == 0x04 && sshdr.ascq == 3) {
-			/*
-			 * LUN not ready - manual intervention required
-			 *
-			 * Switch-over in progress, retry.
-			 */
-			if (--retry_cnt)
-				goto retry;
 			rc = SCSI_DH_RETRY;
 			break;
 		}

drivers/scsi/device_handler/scsi_dh_rdac.c

@@ -485,43 +485,17 @@ static int set_mode_select(struct scsi_device *sdev, struct rdac_dh_data *h)
 static int mode_select_handle_sense(struct scsi_device *sdev,
 				    struct scsi_sense_hdr *sense_hdr)
 {
-	int err = SCSI_DH_IO;
 	struct rdac_dh_data *h = sdev->handler_data;
 
 	if (!scsi_sense_valid(sense_hdr))
-		goto done;
-
-	switch (sense_hdr->sense_key) {
-	case NO_SENSE:
-	case ABORTED_COMMAND:
-	case UNIT_ATTENTION:
-		err = SCSI_DH_RETRY;
-		break;
-	case NOT_READY:
-		if (sense_hdr->asc == 0x04 && sense_hdr->ascq == 0x01)
-			/* LUN Not Ready and is in the Process of Becoming
-			 * Ready
-			 */
-			err = SCSI_DH_RETRY;
-		break;
-	case ILLEGAL_REQUEST:
-		if (sense_hdr->asc == 0x91 && sense_hdr->ascq == 0x36)
-			/*
-			 * Command Lock contention
-			 */
-			err = SCSI_DH_IMM_RETRY;
-		break;
-	default:
-		break;
-	}
+		return SCSI_DH_IO;
 
 	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
 		"MODE_SELECT returned with sense %02x/%02x/%02x",
 		(char *) h->ctlr->array_name, h->ctlr->index,
 		sense_hdr->sense_key, sense_hdr->asc, sense_hdr->ascq);
 
-done:
-	return err;
+	return SCSI_DH_IO;
 }
 
 static void send_mode_select(struct work_struct *work)
@@ -530,7 +504,7 @@ static void send_mode_select(struct work_struct *work)
 		container_of(work, struct rdac_controller, ms_work);
 	struct scsi_device *sdev = ctlr->ms_sdev;
 	struct rdac_dh_data *h = sdev->handler_data;
-	int rc, err, retry_cnt = RDAC_RETRY_COUNT;
+	int rc, err;
 	struct rdac_queue_data *tmp, *qdata;
 	LIST_HEAD(list);
 	unsigned char cdb[MAX_COMMAND_SIZE];
@@ -538,8 +512,49 @@ static void send_mode_select(struct work_struct *work)
 	unsigned int data_size;
 	blk_opf_t opf = REQ_OP_DRV_OUT | REQ_FAILFAST_DEV |
 				REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = NO_SENSE,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = ABORTED_COMMAND,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* LUN Not Ready and is in the Process of Becoming Ready */
+		{
+			.sense = NOT_READY,
+			.asc = 0x04,
+			.ascq = 0x01,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Command Lock contention */
+		{
+			.sense = ILLEGAL_REQUEST,
+			.asc = 0x91,
+			.ascq = 0x36,
+			.allowed = SCMD_FAILURE_NO_LIMIT,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.total_allowed = RDAC_RETRY_COUNT,
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
 	spin_lock(&ctlr->ms_lock);
@@ -548,15 +563,12 @@ static void send_mode_select(struct work_struct *work)
 	ctlr->ms_sdev = NULL;
 	spin_unlock(&ctlr->ms_lock);
 
- retry:
 	memset(cdb, 0, sizeof(cdb));
 
 	data_size = rdac_failover_get(ctlr, &list, cdb);
 
-	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, "
-		"%s MODE_SELECT command",
-		(char *) h->ctlr->array_name, h->ctlr->index,
-		(retry_cnt == RDAC_RETRY_COUNT) ? "queueing" : "retrying");
+	RDAC_LOG(RDAC_LOG_FAILOVER, sdev, "array %s, ctlr %d, queueing MODE_SELECT command",
+		(char *)h->ctlr->array_name, h->ctlr->index);
 
 	rc = scsi_execute_cmd(sdev, cdb, opf, &h->ctlr->mode_select, data_size,
 			      RDAC_TIMEOUT * HZ, RDAC_RETRIES, &exec_args);
@@ -570,10 +582,6 @@ static void send_mode_select(struct work_struct *work)
 		err = SCSI_DH_IO;
 	} else {
 		err = mode_select_handle_sense(sdev, &sshdr);
-		if (err == SCSI_DH_RETRY && retry_cnt--)
-			goto retry;
-		if (err == SCSI_DH_IMM_RETRY)
-			goto retry;
 	}
 
 	list_for_each_entry_safe(qdata, tmp, &list, entry) {

drivers/scsi/scsi_lib.c

@@ -184,6 +184,92 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
 	__scsi_queue_insert(cmd, reason, true);
 }
 
+void scsi_failures_reset_retries(struct scsi_failures *failures)
+{
+	struct scsi_failure *failure;
+
+	failures->total_retries = 0;
+
+	for (failure = failures->failure_definitions; failure->result;
+	     failure++)
+		failure->retries = 0;
+}
+EXPORT_SYMBOL_GPL(scsi_failures_reset_retries);
+
+/**
+ * scsi_check_passthrough - Determine if passthrough scsi_cmnd needs a retry.
+ * @scmd: scsi_cmnd to check.
+ * @failures: scsi_failures struct that lists failures to check for.
+ *
+ * Returns -EAGAIN if the caller should retry else 0.
+ */
+static int scsi_check_passthrough(struct scsi_cmnd *scmd,
+				  struct scsi_failures *failures)
+{
+	struct scsi_failure *failure;
+	struct scsi_sense_hdr sshdr;
+	enum sam_status status;
+
+	if (!failures)
+		return 0;
+
+	for (failure = failures->failure_definitions; failure->result;
+	     failure++) {
+		if (failure->result == SCMD_FAILURE_RESULT_ANY)
+			goto maybe_retry;
+
+		if (host_byte(scmd->result) &&
+		    host_byte(scmd->result) == host_byte(failure->result))
+			goto maybe_retry;
+
+		status = status_byte(scmd->result);
+		if (!status)
+			continue;
+
+		if (failure->result == SCMD_FAILURE_STAT_ANY &&
+		    !scsi_status_is_good(scmd->result))
+			goto maybe_retry;
+
+		if (status != status_byte(failure->result))
+			continue;
+
+		if (status_byte(failure->result) != SAM_STAT_CHECK_CONDITION ||
+		    failure->sense == SCMD_FAILURE_SENSE_ANY)
+			goto maybe_retry;
+
+		if (!scsi_command_normalize_sense(scmd, &sshdr))
+			return 0;
+
+		if (failure->sense != sshdr.sense_key)
+			continue;
+
+		if (failure->asc == SCMD_FAILURE_ASC_ANY)
+			goto maybe_retry;
+
+		if (failure->asc != sshdr.asc)
+			continue;
+
+		if (failure->ascq == SCMD_FAILURE_ASCQ_ANY ||
+		    failure->ascq == sshdr.ascq)
+			goto maybe_retry;
+	}
+
+	return 0;
+
+maybe_retry:
+	if (failure->allowed) {
+		if (failure->allowed == SCMD_FAILURE_NO_LIMIT ||
+		    ++failure->retries <= failure->allowed)
+			return -EAGAIN;
+	} else {
+		if (failures->total_allowed == SCMD_FAILURE_NO_LIMIT ||
+		    ++failures->total_retries <= failures->total_allowed)
+			return -EAGAIN;
+	}
+
+	return 0;
+}
+
 /**
  * scsi_execute_cmd - insert request and wait for the result
  * @sdev:	scsi_device
@@ -192,7 +278,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  * @buffer:	data buffer
  * @bufflen:	len of buffer
  * @timeout:	request timeout in HZ
- * @retries:	number of times to retry request
+ * @ml_retries:	number of times SCSI midlayer will retry request
  * @args:	Optional args. See struct definition for field descriptions
  *
  * Returns the scsi_cmnd result field if a command was executed, or a negative
@@ -200,7 +286,7 @@ void scsi_queue_insert(struct scsi_cmnd *cmd, int reason)
  */
 int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
 		     blk_opf_t opf, void *buffer, unsigned int bufflen,
-		     int timeout, int retries,
+		     int timeout, int ml_retries,
 		     const struct scsi_exec_args *args)
 {
 	static const struct scsi_exec_args default_args;
@@ -214,6 +300,7 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
 			      args->sense_len != SCSI_SENSE_BUFFERSIZE))
 		return -EINVAL;
 
+retry:
 	req = scsi_alloc_request(sdev->request_queue, opf, args->req_flags);
 	if (IS_ERR(req))
 		return PTR_ERR(req);
@@ -227,7 +314,7 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
 	scmd = blk_mq_rq_to_pdu(req);
 	scmd->cmd_len = COMMAND_SIZE(cmd[0]);
 	memcpy(scmd->cmnd, cmd, scmd->cmd_len);
-	scmd->allowed = retries;
+	scmd->allowed = ml_retries;
 	scmd->flags |= args->scmd_flags;
 	req->timeout = timeout;
 	req->rq_flags |= RQF_QUIET;
@@ -237,6 +324,11 @@ int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
 	 */
 	blk_execute_rq(req, true);
 
+	if (scsi_check_passthrough(scmd, args->failures) == -EAGAIN) {
+		blk_mq_free_request(req);
+		goto retry;
+	}
+
 	/*
 	 * Some devices (USB mass-storage in particular) may transfer
 	 * garbage data together with a residue indicating that the data
@@ -2170,11 +2262,25 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage,
 	unsigned char cmd[12];
 	int use_10_for_ms;
 	int header_length;
-	int result, retry_count = retries;
+	int result;
 	struct scsi_sense_hdr my_sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = retries,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		/* caller might not be interested in sense, but we need it */
 		.sshdr = sshdr ? : &my_sshdr,
+		.failures = &failures,
 	};
 
 	memset(data, 0, sizeof(*data));
@@ -2236,12 +2342,6 @@ scsi_mode_sense(struct scsi_device *sdev, int dbd, int modepage, int subpage,
 					goto retry;
 				}
 			}
-			if (scsi_status_is_check_condition(result) &&
-			    sshdr->sense_key == UNIT_ATTENTION &&
-			    retry_count) {
-				retry_count--;
-				goto retry;
-			}
 		}
 		return -EIO;
 	}
@@ -3334,3 +3434,7 @@ void scsi_build_sense(struct scsi_cmnd *scmd, int desc, u8 key, u8 asc, u8 ascq)
 	scmd->result = SAM_STAT_CHECK_CONDITION;
 }
 EXPORT_SYMBOL_GPL(scsi_build_sense);
+
+#ifdef CONFIG_SCSI_KUNIT_TEST
+#include "scsi_lib_test.c"
+#endif

drivers/scsi/scsi_lib_test.c

+// SPDX-License-Identifier: GPL-2.0
+/*
+ * KUnit tests for scsi_lib.c.
+ *
+ * Copyright (C) 2023, Oracle Corporation
+ */
+#include <kunit/test.h>
+
+#include <scsi/scsi_proto.h>
+#include <scsi/scsi_cmnd.h>
+#include <scsi/scsi_device.h>
+
+#define SCSI_LIB_TEST_MAX_ALLOWED 3
+#define SCSI_LIB_TEST_TOTAL_MAX_ALLOWED 5
+
+static void scsi_lib_test_multiple_sense(struct kunit *test)
+{
+	struct scsi_failure multiple_sense_failure_defs[] = {
+		{
+			.sense = DATA_PROTECT,
+			.asc = 0x1,
+			.ascq = 0x1,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x11,
+			.ascq = 0x0,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = 0x11,
+			.ascq = 0x22,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = ABORTED_COMMAND,
+			.asc = 0x11,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = HARDWARE_ERROR,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = ILLEGAL_REQUEST,
+			.asc = 0x91,
+			.ascq = 0x36,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = multiple_sense_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/* Match end of array */
+	scsi_build_sense(&sc, 0, ILLEGAL_REQUEST, 0x91, 0x36);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* Basic match in array */
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x11, 0x0);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* No matching sense entry */
+	scsi_build_sense(&sc, 0, MISCOMPARE, 0x11, 0x11);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Match using SCMD_FAILURE_ASCQ_ANY */
+	scsi_build_sense(&sc, 0, ABORTED_COMMAND, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* Fail to match */
+	scsi_build_sense(&sc, 0, ABORTED_COMMAND, 0x22, 0x22);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Match using SCMD_FAILURE_ASC_ANY */
+	scsi_build_sense(&sc, 0, HARDWARE_ERROR, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	/* No matching status entry */
+	sc.result = SAM_STAT_RESERVATION_CONFLICT;
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	/* Test hitting allowed limit */
+	scsi_build_sense(&sc, 0, NOT_READY, 0x11, 0x22);
+	for (i = 0; i < SCSI_LIB_TEST_MAX_ALLOWED; i++)
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	/* reset retries so we can retest */
+	failures.failure_definitions = multiple_sense_failure_defs;
+	scsi_failures_reset_retries(&failures);
+
+	/* Test no retries allowed */
+	scsi_build_sense(&sc, 0, DATA_PROTECT, 0x1, 0x1);
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_sense(struct kunit *test)
+{
+	struct scsi_failure any_sense_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_SENSE_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_sense_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Match using SCMD_FAILURE_SENSE_ANY */
+	failures.failure_definitions = any_sense_failure_defs;
+	scsi_build_sense(&sc, 0, MEDIUM_ERROR, 0x11, 0x22);
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_host(struct kunit *test)
+{
+	struct scsi_failure retryable_host_failure_defs[] = {
+		{
+			.result = DID_TRANSPORT_DISRUPTED << 16,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{
+			.result = DID_TIME_OUT << 16,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = retryable_host_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* No matching host byte entry */
+	failures.failure_definitions = retryable_host_failure_defs;
+	sc.result = DID_NO_CONNECT << 16;
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+	/* Matching host byte entry */
+	sc.result = DID_TIME_OUT << 16;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_failure(struct kunit *test)
+{
+	struct scsi_failure any_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Match SCMD_FAILURE_RESULT_ANY */
+	failures.failure_definitions = any_failure_defs;
+	sc.result = DID_TRANSPORT_FAILFAST << 16;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_any_status(struct kunit *test)
+{
+	struct scsi_failure any_status_failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_STAT_ANY,
+			.allowed = SCSI_LIB_TEST_MAX_ALLOWED,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = any_status_failure_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+
+	/* Test any status handling */
+	failures.failure_definitions = any_status_failure_defs;
+	sc.result = SAM_STAT_RESERVATION_CONFLICT;
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_total_allowed(struct kunit *test)
+{
+	struct scsi_failure total_allowed_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Fail all CCs except the UA above */
+		{
+			.sense = SCMD_FAILURE_SENSE_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Retry any other errors not listed above */
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = total_allowed_defs,
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/* Test total_allowed */
+	failures.failure_definitions = total_allowed_defs;
+	scsi_failures_reset_retries(&failures);
+	failures.total_allowed = SCSI_LIB_TEST_TOTAL_MAX_ALLOWED;
+
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	sc.result = DID_TIME_OUT << 16;
+	/* We have now hit the total_allowed limit so no more retries */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_mixed_total(struct kunit *test)
+{
+	struct scsi_failure mixed_total_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x28,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.allowed = 1,
+			.result = DID_TIME_OUT << 16,
+		},
+		{}
+	};
+	u8 sense[SCSI_SENSE_BUFFERSIZE] = {};
+	struct scsi_failures failures = {
+		.failure_definitions = mixed_total_defs,
+	};
+	struct scsi_cmnd sc = {
+		.sense_buffer = sense,
+	};
+	int i;
+
+	/*
+	 * Test total_allowed when there is a mix of per failure allowed
+	 * and total_allowed limits.
+	 */
+	failures.failure_definitions = mixed_total_defs;
+	scsi_failures_reset_retries(&failures);
+	failures.total_allowed = SCSI_LIB_TEST_TOTAL_MAX_ALLOWED;
+
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	/* Do not retry since we are now over total_allowed limit */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+
+	scsi_failures_reset_retries(&failures);
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x28, 0x0);
+	for (i = 0; i < SCSI_LIB_TEST_TOTAL_MAX_ALLOWED; i++)
+		/* Retry since we under the total_allowed limit */
+		KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc,
+				&failures));
+	sc.result = DID_TIME_OUT << 16;
+	/* Retry because this failure has a per failure limit */
+	KUNIT_EXPECT_EQ(test, -EAGAIN, scsi_check_passthrough(&sc, &failures));
+	scsi_build_sense(&sc, 0, UNIT_ATTENTION, 0x29, 0x0);
+	/* total_allowed is now hit so no more retries */
+	KUNIT_EXPECT_EQ(test, 0, scsi_check_passthrough(&sc, &failures));
+}
+
+static void scsi_lib_test_check_passthough(struct kunit *test)
+{
+	scsi_lib_test_multiple_sense(test);
+	scsi_lib_test_any_sense(test);
+	scsi_lib_test_host(test);
+	scsi_lib_test_any_failure(test);
+	scsi_lib_test_any_status(test);
+	scsi_lib_test_total_allowed(test);
+	scsi_lib_test_mixed_total(test);
+}
+
+static struct kunit_case scsi_lib_test_cases[] = {
+	KUNIT_CASE(scsi_lib_test_check_passthough),
+	{}
+};
+
+static struct kunit_suite scsi_lib_test_suite = {
+	.name = "scsi_lib",
+	.test_cases = scsi_lib_test_cases,
+};
+
+kunit_test_suite(scsi_lib_test_suite);

drivers/scsi/scsi_scan.c

@@ -626,6 +626,7 @@ void scsi_sanitize_inquiry_string(unsigned char *s, int len)
 }
 EXPORT_SYMBOL(scsi_sanitize_inquiry_string);
 
+
 /**
  * scsi_probe_lun - probe a single LUN using a SCSI INQUIRY
  * @sdev:	scsi_device to probe
@@ -647,10 +648,36 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 	int first_inquiry_len, try_inquiry_len, next_inquiry_len;
 	int response_len = 0;
 	int pass, count, result, resid;
-	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		/*
+		 * not-ready to ready transition [asc/ascq=0x28/0x0] or
+		 * power-on, reset [asc/ascq=0x29/0x0], continue. INQUIRY
+		 * should not yield UNIT_ATTENTION but many buggy devices do
+		 * so anyway.
+		 */
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x28,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.allowed = 1,
+			.result = DID_TIME_OUT << 16,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.total_allowed = 3,
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
-		.sshdr = &sshdr,
 		.resid = &resid,
+		.failures = &failures,
 	};
 
 	*bflags = 0;
@@ -668,6 +695,8 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 				pass, try_inquiry_len));
 
 	/* Each pass gets up to three chances to ignore Unit Attention */
+	scsi_failures_reset_retries(&failures);
+
 	for (count = 0; count < 3; ++count) {
 		memset(scsi_cmd, 0, 6);
 		scsi_cmd[0] = INQUIRY;
@@ -684,22 +713,7 @@ static int scsi_probe_lun(struct scsi_device *sdev, unsigned char *inq_result,
 				"scsi scan: INQUIRY %s with code 0x%x\n",
 				result ? "failed" : "successful", result));
 
-		if (result > 0) {
-			/*
-			 * not-ready to ready transition [asc/ascq=0x28/0x0]
-			 * or power-on, reset [asc/ascq=0x29/0x0], continue.
-			 * INQUIRY should not yield UNIT_ATTENTION
-			 * but many buggy devices do so anyway. 
-			 */
-			if (scsi_status_is_check_condition(result) &&
-			    scsi_sense_valid(&sshdr)) {
-				if ((sshdr.sense_key == UNIT_ATTENTION) &&
-				    ((sshdr.asc == 0x28) ||
-				     (sshdr.asc == 0x29)) &&
-				    (sshdr.ascq == 0))
-					continue;
-			}
-		} else if (result == 0) {
+		if (result == 0) {
 			/*
 			 * if nothing was transferred, we try
 			 * again. It's a workaround for some USB
@@ -1402,14 +1416,34 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag
 	unsigned int length;
 	u64 lun;
 	unsigned int num_luns;
-	unsigned int retries;
 	int result;
 	struct scsi_lun *lunp, *lun_data;
-	struct scsi_sense_hdr sshdr;
 	struct scsi_device *sdev;
 	struct Scsi_Host *shost = dev_to_shost(&starget->dev);
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Fail all CCs except the UA above */
+		{
+			.sense = SCMD_FAILURE_SENSE_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Retry any other errors not listed above */
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.total_allowed = 3,
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
-		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 	int ret = 0;
 
@@ -1480,29 +1514,18 @@ static int scsi_report_lun_scan(struct scsi_target *starget, blist_flags_t bflag
 	 * should come through as a check condition, and will not generate
 	 * a retry.
 	 */
-	for (retries = 0; retries < 3; retries++) {
+	scsi_failures_reset_retries(&failures);
+
 	SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
-				"scsi scan: Sending REPORT LUNS to (try %d)\n",
-				retries));
+			  "scsi scan: Sending REPORT LUNS\n"));
 
-		result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN,
-					  lun_data, length,
-					  SCSI_REPORT_LUNS_TIMEOUT, 3,
+	result = scsi_execute_cmd(sdev, scsi_cmd, REQ_OP_DRV_IN, lun_data,
+				  length, SCSI_REPORT_LUNS_TIMEOUT, 3,
 				  &exec_args);
 
 	SCSI_LOG_SCAN_BUS(3, sdev_printk (KERN_INFO, sdev,
-				"scsi scan: REPORT LUNS"
-				" %s (try %d) result 0x%x\n",
-				result ?  "failed" : "successful",
-				retries, result));
-		if (result == 0)
-			break;
-		else if (scsi_sense_valid(&sshdr)) {
-			if (sshdr.sense_key != UNIT_ATTENTION)
-				break;
-		}
-	}
-
+			  "scsi scan: REPORT LUNS  %s result 0x%x\n",
+			  result ?  "failed" : "successful", result));
 	if (result) {
 		/*
 		 * The device probably does not support a REPORT LUN command

drivers/scsi/scsi_transport_spi.c

@@ -108,29 +108,30 @@ static int spi_execute(struct scsi_device *sdev, const void *cmd,
 		       enum req_op op, void *buffer, unsigned int bufflen,
 		       struct scsi_sense_hdr *sshdr)
 {
-	int i, result;
-	struct scsi_sense_hdr sshdr_tmp;
 	blk_opf_t opf = op | REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT |
 			REQ_FAILFAST_DRIVER;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = DV_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
+		/* bypass the SDEV_QUIESCE state with BLK_MQ_REQ_PM */
 		.req_flags = BLK_MQ_REQ_PM,
-		.sshdr = sshdr ? : &sshdr_tmp,
+		.sshdr = sshdr,
+		.failures = &failures,
 	};
 
-	sshdr = exec_args.sshdr;
-
-	for(i = 0; i < DV_RETRIES; i++) {
-		/*
-		 * The purpose of the RQF_PM flag below is to bypass the
-		 * SDEV_QUIESCE state.
-		 */
-		result = scsi_execute_cmd(sdev, cmd, opf, buffer, bufflen,
-					  DV_TIMEOUT, 1, &exec_args);
-		if (result < 0 || !scsi_sense_valid(sshdr) ||
-		    sshdr->sense_key != UNIT_ATTENTION)
-			break;
-	}
-	return result;
+	return scsi_execute_cmd(sdev, cmd, opf, buffer, bufflen, DV_TIMEOUT, 1,
+				&exec_args);
 }
 
 static struct {

drivers/scsi/sd.c

@@ -1645,36 +1645,35 @@ static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 
 static int sd_sync_cache(struct scsi_disk *sdkp)
 {
-	int retries, res;
+	int res;
 	struct scsi_device *sdp = sdkp->device;
 	const int timeout = sdp->request_queue->rq_timeout
 		* SD_FLUSH_TIMEOUT_MULTIPLIER;
+	/* Leave the rest of the command zero to indicate flush everything. */
+	const unsigned char cmd[16] = { sdp->use_16_for_sync ?
+				SYNCHRONIZE_CACHE_16 : SYNCHRONIZE_CACHE };
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.allowed = 3,
+			.result = SCMD_FAILURE_RESULT_ANY,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.req_flags = BLK_MQ_REQ_PM,
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
 	if (!scsi_device_online(sdp))
 		return -ENODEV;
 
-	for (retries = 3; retries > 0; --retries) {
-		unsigned char cmd[16] = { 0 };
-
-		if (sdp->use_16_for_sync)
-			cmd[0] = SYNCHRONIZE_CACHE_16;
-		else
-			cmd[0] = SYNCHRONIZE_CACHE;
-		/*
-		 * Leave the rest of the command zero to indicate
-		 * flush everything.
-		 */
-		res = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN, NULL, 0,
-				       timeout, sdkp->max_retries, &exec_args);
-		if (res == 0)
-			break;
-	}
-
+	res = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN, NULL, 0, timeout,
+			       sdkp->max_retries, &exec_args);
 	if (res) {
 		sd_print_result(sdkp, "Synchronize Cache(10) failed", res);
 
@@ -1801,8 +1800,22 @@ static int sd_pr_in_command(struct block_device *bdev, u8 sa,
 	struct scsi_device *sdev = sdkp->device;
 	struct scsi_sense_hdr sshdr;
 	u8 cmd[10] = { PERSISTENT_RESERVE_IN, sa };
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 5,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 	int result;
 
@@ -1889,8 +1902,22 @@ static int sd_pr_out_command(struct block_device *bdev, u8 sa, u64 key,
 	struct scsi_disk *sdkp = scsi_disk(bdev->bd_disk);
 	struct scsi_device *sdev = sdkp->device;
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = 5,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 	int result;
 	u8 cmd[16] = { 0, };
@@ -2235,40 +2262,59 @@ static int sd_done(struct scsi_cmnd *SCpnt)
 static void
 sd_spinup_disk(struct scsi_disk *sdkp)
 {
-	unsigned char cmd[10];
+	static const u8 cmd[10] = { TEST_UNIT_READY };
 	unsigned long spintime_expire = 0;
-	int retries, spintime;
+	int spintime, sense_valid = 0;
 	unsigned int the_result;
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		/* Do not retry Medium Not Present */
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x3A,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = 0x3A,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Retry when scsi_status_is_good would return false 3 times */
+		{
+			.result = SCMD_FAILURE_STAT_ANY,
+			.allowed = 3,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
-	int sense_valid = 0;
 
 	spintime = 0;
 
 	/* Spin up drives, as required.  Only do this at boot time */
 	/* Spinup needs to be done for module loads too. */
-	do {
-		retries = 0;
-
 	do {
 		bool media_was_present = sdkp->media_present;
 
-			cmd[0] = TEST_UNIT_READY;
-			memset((void *) &cmd[1], 0, 9);
+		scsi_failures_reset_retries(&failures);
+
+		the_result = scsi_execute_cmd(sdkp->device, cmd, REQ_OP_DRV_IN,
+					      NULL, 0, SD_TIMEOUT,
+					      sdkp->max_retries, &exec_args);
 
-			the_result = scsi_execute_cmd(sdkp->device, cmd,
-						      REQ_OP_DRV_IN, NULL, 0,
-						      SD_TIMEOUT,
-						      sdkp->max_retries,
-						      &exec_args);
 
 		if (the_result > 0) {
 			/*
-				 * If the drive has indicated to us that it
-				 * doesn't have any media in it, don't bother
-				 * with any more polling.
+			 * If the drive has indicated to us that it doesn't
+			 * have any media in it, don't bother with any more
+			 * polling.
 			 */
 			if (media_not_present(sdkp, &sshdr)) {
 				if (media_was_present)
@@ -2276,14 +2322,8 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 						  "Media removed, stopped polling\n");
 				return;
 			}
-
 			sense_valid = scsi_sense_valid(&sshdr);
 		}
-			retries++;
-		} while (retries < 3 &&
-			 (!scsi_status_is_good(the_result) ||
-			  (scsi_status_is_check_condition(the_result) &&
-			  sense_valid && sshdr.sense_key == UNIT_ATTENTION)));
 
 		if (!scsi_status_is_check_condition(the_result)) {
 			/* no sense, TUR either succeeded or failed
@@ -2318,14 +2358,16 @@ sd_spinup_disk(struct scsi_disk *sdkp)
 			 * Issue command to spin up drive when not ready
 			 */
 			if (!spintime) {
+				/* Return immediately and start spin cycle */
+				const u8 start_cmd[10] = {
+					[0] = START_STOP,
+					[1] = 1,
+					[4] = sdkp->device->start_stop_pwr_cond ?
+						0x11 : 1,
+				};
+
 				sd_printk(KERN_NOTICE, sdkp, "Spinning up disk...");
-				cmd[0] = START_STOP;
-				cmd[1] = 1;	/* Return immediately */
-				memset((void *) &cmd[2], 0, 8);
-				cmd[4] = 1;	/* Start spin cycle */
-				if (sdkp->device->start_stop_pwr_cond)
-					cmd[4] |= 1 << 4;
-				scsi_execute_cmd(sdkp->device, cmd,
+				scsi_execute_cmd(sdkp->device, start_cmd,
 						 REQ_OP_DRV_IN, NULL, 0,
 						 SD_TIMEOUT, sdkp->max_retries,
 						 &exec_args);
@@ -2546,42 +2588,58 @@ static int read_capacity_16(struct scsi_disk *sdkp, struct scsi_device *sdp,
 static int read_capacity_10(struct scsi_disk *sdkp, struct scsi_device *sdp,
 						unsigned char *buffer)
 {
-	unsigned char cmd[16];
+	static const u8 cmd[10] = { READ_CAPACITY };
 	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		/* Do not retry Medium Not Present */
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x3A,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = 0x3A,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		 /* Device reset might occur several times so retry a lot */
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.allowed = READ_CAPACITY_RETRIES_ON_RESET,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		/* Any other error not listed above retry 3 times */
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+			.allowed = 3,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
 		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 	int sense_valid = 0;
 	int the_result;
-	int retries = 3, reset_retries = READ_CAPACITY_RETRIES_ON_RESET;
 	sector_t lba;
 	unsigned sector_size;
 
-	do {
-		cmd[0] = READ_CAPACITY;
-		memset(&cmd[1], 0, 9);
 	memset(buffer, 0, 8);
 
 	the_result = scsi_execute_cmd(sdp, cmd, REQ_OP_DRV_IN, buffer,
 				      8, SD_TIMEOUT, sdkp->max_retries,
 				      &exec_args);
 
-		if (media_not_present(sdkp, &sshdr))
-			return -ENODEV;
-
 	if (the_result > 0) {
 		sense_valid = scsi_sense_valid(&sshdr);
-			if (sense_valid &&
-			    sshdr.sense_key == UNIT_ATTENTION &&
-			    sshdr.asc == 0x29 && sshdr.ascq == 0x00)
-				/* Device reset might occur several times,
-				 * give it one more chance */
-				if (--reset_retries > 0)
-					continue;
-		}
-		retries--;
 
-	} while (the_result && retries);
+		if (media_not_present(sdkp, &sshdr))
+			return -ENODEV;
+	}
 
 	if (the_result) {
 		sd_print_result(sdkp, "Read Capacity(10) failed", the_result);

drivers/scsi/ses.c

@@ -87,19 +87,32 @@ static int ses_recv_diag(struct scsi_device *sdev, int page_code,
 		0
 	};
 	unsigned char recv_page_code;
-	unsigned int retries = SES_RETRIES;
-	struct scsi_sense_hdr sshdr;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SES_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SES_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
-		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
-	do {
 	ret = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buf, bufflen,
 			       SES_TIMEOUT, 1, &exec_args);
-	} while (ret > 0 && --retries && scsi_sense_valid(&sshdr) &&
-		 (sshdr.sense_key == NOT_READY ||
-		  (sshdr.sense_key == UNIT_ATTENTION && sshdr.asc == 0x29)));
-
 	if (unlikely(ret))
 		return ret;
 
@@ -131,19 +144,32 @@ static int ses_send_diag(struct scsi_device *sdev, int page_code,
 		bufflen & 0xff,
 		0
 	};
-	struct scsi_sense_hdr sshdr;
-	unsigned int retries = SES_RETRIES;
+	struct scsi_failure failure_defs[] = {
+		{
+			.sense = UNIT_ATTENTION,
+			.asc = 0x29,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SES_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{
+			.sense = NOT_READY,
+			.asc = SCMD_FAILURE_ASC_ANY,
+			.ascq = SCMD_FAILURE_ASCQ_ANY,
+			.allowed = SES_RETRIES,
+			.result = SAM_STAT_CHECK_CONDITION,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args exec_args = {
-		.sshdr = &sshdr,
+		.failures = &failures,
 	};
 
-	do {
-		result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, buf,
-					  bufflen, SES_TIMEOUT, 1, &exec_args);
-	} while (result > 0 && --retries && scsi_sense_valid(&sshdr) &&
-		 (sshdr.sense_key == NOT_READY ||
-		  (sshdr.sense_key == UNIT_ATTENTION && sshdr.asc == 0x29)));
-
+	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_OUT, buf, bufflen,
+				  SES_TIMEOUT, 1, &exec_args);
 	if (result)
 		sdev_printk(KERN_ERR, sdev, "SEND DIAGNOSTIC result: %8x\n",
 			    result);

drivers/scsi/sr.c

@@ -717,27 +717,29 @@ static int sr_probe(struct device *dev)
 
 static void get_sectorsize(struct scsi_cd *cd)
 {
-	unsigned char cmd[10];
-	unsigned char buffer[8];
-	int the_result, retries = 3;
+	static const u8 cmd[10] = { READ_CAPACITY };
+	unsigned char buffer[8] = { };
+	int the_result;
 	int sector_size;
 	struct request_queue *queue;
-
-	do {
-		cmd[0] = READ_CAPACITY;
-		memset((void *) &cmd[1], 0, 9);
-		memset(buffer, 0, sizeof(buffer));
+	struct scsi_failure failure_defs[] = {
+		{
+			.result = SCMD_FAILURE_RESULT_ANY,
+			.allowed = 3,
+		},
+		{}
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
+	const struct scsi_exec_args exec_args = {
+		.failures = &failures,
+	};
 
 	/* Do the command and wait.. */
-		the_result = scsi_execute_cmd(cd->device, cmd, REQ_OP_DRV_IN,
-					      buffer, sizeof(buffer),
-					      SR_TIMEOUT, MAX_RETRIES, NULL);
-
-		retries--;
-
-	} while (the_result && retries);
-
-
+	the_result = scsi_execute_cmd(cd->device, cmd, REQ_OP_DRV_IN, buffer,
+				      sizeof(buffer), SR_TIMEOUT, MAX_RETRIES,
+				      &exec_args);
 	if (the_result) {
 		cd->capacity = 0x1fffff;
 		sector_size = 2048;	/* A guess, just in case */

drivers/ufs/core/ufshcd.c

@@ -9519,7 +9519,17 @@ static int ufshcd_execute_start_stop(struct scsi_device *sdev,
 				     struct scsi_sense_hdr *sshdr)
 {
 	const unsigned char cdb[6] = { START_STOP, 0, 0, 0, pwr_mode << 4, 0 };
+	struct scsi_failure failure_defs[] = {
+		{
+			.allowed = 2,
+			.result = SCMD_FAILURE_RESULT_ANY,
+		},
+	};
+	struct scsi_failures failures = {
+		.failure_definitions = failure_defs,
+	};
 	const struct scsi_exec_args args = {
+		.failures = &failures,
 		.sshdr = sshdr,
 		.req_flags = BLK_MQ_REQ_PM,
 		.scmd_flags = SCMD_FAIL_IF_RECOVERING,
@@ -9545,7 +9555,7 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
 	struct scsi_sense_hdr sshdr;
 	struct scsi_device *sdp;
 	unsigned long flags;
-	int ret, retries;
+	int ret;
 
 	spin_lock_irqsave(hba->host->host_lock, flags);
 	sdp = hba->ufs_device_wlun;
@@ -9571,15 +9581,7 @@ static int ufshcd_set_dev_pwr_mode(struct ufs_hba *hba,
 	 * callbacks hence set the RQF_PM flag so that it doesn't resume the
 	 * already suspended childs.
 	 */
-	for (retries = 3; retries > 0; --retries) {
 	ret = ufshcd_execute_start_stop(sdp, pwr_mode, &sshdr);
-		/*
-		 * scsi_execute() only returns a negative value if the request
-		 * queue is dying.
-		 */
-		if (ret <= 0)
-			break;
-	}
 	if (ret) {
 		sdev_printk(KERN_WARNING, sdp,
 			    "START_STOP failed for power mode: %d, result %x\n",

include/scsi/scsi_device.h

@@ -489,6 +489,52 @@ extern int scsi_is_sdev_device(const struct device *);
 extern int scsi_is_target_device(const struct device *);
 extern void scsi_sanitize_inquiry_string(unsigned char *s, int len);
 
+/*
+ * scsi_execute_cmd users can set scsi_failure.result to have
+ * scsi_check_passthrough fail/retry a command. scsi_failure.result can be a
+ * specific host byte or message code, or SCMD_FAILURE_RESULT_ANY can be used
+ * to match any host or message code.
+ */
+#define SCMD_FAILURE_RESULT_ANY	0x7fffffff
+/*
+ * Set scsi_failure.result to SCMD_FAILURE_STAT_ANY to fail/retry any failure
+ * scsi_status_is_good returns false for.
+ */
+#define SCMD_FAILURE_STAT_ANY	0xff
+/*
+ * The following can be set to the scsi_failure sense, asc and ascq fields to
+ * match on any sense, ASC, or ASCQ value.
+ */
+#define SCMD_FAILURE_SENSE_ANY	0xff
+#define SCMD_FAILURE_ASC_ANY	0xff
+#define SCMD_FAILURE_ASCQ_ANY	0xff
+/* Always retry a matching failure. */
+#define SCMD_FAILURE_NO_LIMIT	-1
+
+struct scsi_failure {
+	int result;
+	u8 sense;
+	u8 asc;
+	u8 ascq;
+	/*
+	 * Number of times scsi_execute_cmd will retry the failure. It does
+	 * not count for the total_allowed.
+	 */
+	s8 allowed;
+	/* Number of times the failure has been retried. */
+	s8 retries;
+};
+
+struct scsi_failures {
+	/*
+	 * If a scsi_failure does not have a retry limit setup this limit will
+	 * be used.
+	 */
+	int total_allowed;
+	int total_retries;
+	struct scsi_failure *failure_definitions;
+};
+
 /* Optional arguments to scsi_execute_cmd */
 struct scsi_exec_args {
 	unsigned char *sense;		/* sense buffer */
@@ -497,12 +543,14 @@ struct scsi_exec_args {
 	blk_mq_req_flags_t req_flags;	/* BLK_MQ_REQ flags */
 	int scmd_flags;			/* SCMD flags */
 	int *resid;			/* residual length */
+	struct scsi_failures *failures;	/* failures to retry */
 };
 
 int scsi_execute_cmd(struct scsi_device *sdev, const unsigned char *cmd,
 		     blk_opf_t opf, void *buffer, unsigned int bufflen,
 		     int timeout, int retries,
 		     const struct scsi_exec_args *args);
+void scsi_failures_reset_retries(struct scsi_failures *failures);
 
 extern void sdev_disable_disk_events(struct scsi_device *sdev);
 extern void sdev_enable_disk_events(struct scsi_device *sdev);