[PATCH 1/4] libata: clean up variable name usage in xlat related functions

[PATCH 1/4] libata: clean up variable name usage in xlat related functions

[Tejun Heo]

Variable names in xlat functions are quite confusing now.  'scsicmd'
is used for CDB while qc->scsicmd points to struct scsi_cmnd while
'cmd' is used for struct scsi_cmnd.

This patch cleans up variable names in xlat functions such that 'scmd'
is used for struct scsi_cmnd and 'cdb' for CDB.  Also, 'scmd' local
variable is added if qc->scsicmd is used multiple times.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
Okay, separated as suggested and regenerated against
libata-dev#upstream-fixes.

Thanks.

 drivers/ata/libata-scsi.c |  217 ++++++++++++++++++++++-----------------------
 1 files changed, 105 insertions(+), 112 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index a4790be..1e42cde 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -51,7 +51,7 @@
 
 #define SECTOR_SIZE	512
 
-typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc, const u8 *scsicmd);
+typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc, const u8 *cdb);
 
 static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
 					const struct scsi_device *scsidev);
@@ -935,7 +935,7 @@ int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 /**
  *	ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
  *	@qc: Storage for translated ATA taskfile
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Sets up an ATA taskfile to issue STANDBY (to stop) or READ VERIFY
  *	(to start). Perhaps these commands should be preceded by
@@ -948,22 +948,22 @@ int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-
 static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc,
-					     const u8 *scsicmd)
+					     const u8 *cdb)
 {
+	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_taskfile *tf = &qc->tf;
 
 	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
 	tf->protocol = ATA_PROT_NODATA;
-	if (scsicmd[1] & 0x1) {
+	if (cdb[1] & 0x1) {
 		;	/* ignore IMMED bit, violates sat-r05 */
 	}
-	if (scsicmd[4] & 0x2)
+	if (cdb[4] & 0x2)
 		goto invalid_fld;       /* LOEJ bit set not supported */
-	if (((scsicmd[4] >> 4) & 0xf) != 0)
+	if (((cdb[4] >> 4) & 0xf) != 0)
 		goto invalid_fld;       /* power conditions not supported */
-	if (scsicmd[4] & 0x1) {
+	if (cdb[4] & 0x1) {
 		tf->nsect = 1;	/* 1 sector, lba=0 */
 
 		if (qc->dev->flags & ATA_DFLAG_LBA) {
@@ -996,7 +996,7 @@ static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc,
 	return 0;
 
 invalid_fld:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x24, 0x0);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
 	/* "Invalid field in cbd" */
 	return 1;
 }
@@ -1005,7 +1005,7 @@ invalid_fld:
 /**
  *	ata_scsi_flush_xlat - Translate SCSI SYNCHRONIZE CACHE command
  *	@qc: Storage for translated ATA taskfile
- *	@scsicmd: SCSI command to translate (ignored)
+ *	@cdb: SCSI command to translate (ignored)
  *
  *	Sets up an ATA taskfile to issue FLUSH CACHE or
  *	FLUSH CACHE EXT.
@@ -1016,8 +1016,7 @@ invalid_fld:
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-
-static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
+static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
 {
 	struct ata_taskfile *tf = &qc->tf;
 
@@ -1034,7 +1033,7 @@ static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc, const u8 *scs
 
 /**
  *	scsi_6_lba_len - Get LBA and transfer length
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Calculate LBA and transfer length for 6-byte commands.
  *
@@ -1042,18 +1041,17 @@ static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc, const u8 *scs
  *	@plba: the LBA
  *	@plen: the transfer length
  */
-
-static void scsi_6_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
+static void scsi_6_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
 {
 	u64 lba = 0;
 	u32 len = 0;
 
 	VPRINTK("six-byte command\n");
 
-	lba |= ((u64)scsicmd[2]) << 8;
-	lba |= ((u64)scsicmd[3]);
+	lba |= ((u64)cdb[2]) << 8;
+	lba |= ((u64)cdb[3]);
 
-	len |= ((u32)scsicmd[4]);
+	len |= ((u32)cdb[4]);
 
 	*plba = lba;
 	*plen = len;
@@ -1061,7 +1059,7 @@ static void scsi_6_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
 
 /**
  *	scsi_10_lba_len - Get LBA and transfer length
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Calculate LBA and transfer length for 10-byte commands.
  *
@@ -1069,21 +1067,20 @@ static void scsi_6_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
  *	@plba: the LBA
  *	@plen: the transfer length
  */
-
-static void scsi_10_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
+static void scsi_10_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
 {
 	u64 lba = 0;
 	u32 len = 0;
 
 	VPRINTK("ten-byte command\n");
 
-	lba |= ((u64)scsicmd[2]) << 24;
-	lba |= ((u64)scsicmd[3]) << 16;
-	lba |= ((u64)scsicmd[4]) << 8;
-	lba |= ((u64)scsicmd[5]);
+	lba |= ((u64)cdb[2]) << 24;
+	lba |= ((u64)cdb[3]) << 16;
+	lba |= ((u64)cdb[4]) << 8;
+	lba |= ((u64)cdb[5]);
 
-	len |= ((u32)scsicmd[7]) << 8;
-	len |= ((u32)scsicmd[8]);
+	len |= ((u32)cdb[7]) << 8;
+	len |= ((u32)cdb[8]);
 
 	*plba = lba;
 	*plen = len;
@@ -1091,7 +1088,7 @@ static void scsi_10_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
 
 /**
  *	scsi_16_lba_len - Get LBA and transfer length
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Calculate LBA and transfer length for 16-byte commands.
  *
@@ -1099,27 +1096,26 @@ static void scsi_10_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
  *	@plba: the LBA
  *	@plen: the transfer length
  */
-
-static void scsi_16_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
+static void scsi_16_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
 {
 	u64 lba = 0;
 	u32 len = 0;
 
 	VPRINTK("sixteen-byte command\n");
 
-	lba |= ((u64)scsicmd[2]) << 56;
-	lba |= ((u64)scsicmd[3]) << 48;
-	lba |= ((u64)scsicmd[4]) << 40;
-	lba |= ((u64)scsicmd[5]) << 32;
-	lba |= ((u64)scsicmd[6]) << 24;
-	lba |= ((u64)scsicmd[7]) << 16;
-	lba |= ((u64)scsicmd[8]) << 8;
-	lba |= ((u64)scsicmd[9]);
+	lba |= ((u64)cdb[2]) << 56;
+	lba |= ((u64)cdb[3]) << 48;
+	lba |= ((u64)cdb[4]) << 40;
+	lba |= ((u64)cdb[5]) << 32;
+	lba |= ((u64)cdb[6]) << 24;
+	lba |= ((u64)cdb[7]) << 16;
+	lba |= ((u64)cdb[8]) << 8;
+	lba |= ((u64)cdb[9]);
 
-	len |= ((u32)scsicmd[10]) << 24;
-	len |= ((u32)scsicmd[11]) << 16;
-	len |= ((u32)scsicmd[12]) << 8;
-	len |= ((u32)scsicmd[13]);
+	len |= ((u32)cdb[10]) << 24;
+	len |= ((u32)cdb[11]) << 16;
+	len |= ((u32)cdb[12]) << 8;
+	len |= ((u32)cdb[13]);
 
 	*plba = lba;
 	*plen = len;
@@ -1128,7 +1124,7 @@ static void scsi_16_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
 /**
  *	ata_scsi_verify_xlat - Translate SCSI VERIFY command into an ATA one
  *	@qc: Storage for translated ATA taskfile
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Converts SCSI VERIFY command to an ATA READ VERIFY command.
  *
@@ -1138,9 +1134,9 @@ static void scsi_16_lba_len(const u8 *scsicmd, u64 *plba, u32 *plen)
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-
-static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
+static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
 {
+	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_taskfile *tf = &qc->tf;
 	struct ata_device *dev = qc->dev;
 	u64 dev_sectors = qc->dev->n_sectors;
@@ -1150,10 +1146,10 @@ static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc, const u8 *sc
 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
 	tf->protocol = ATA_PROT_NODATA;
 
-	if (scsicmd[0] == VERIFY)
-		scsi_10_lba_len(scsicmd, &block, &n_block);
-	else if (scsicmd[0] == VERIFY_16)
-		scsi_16_lba_len(scsicmd, &block, &n_block);
+	if (cdb[0] == VERIFY)
+		scsi_10_lba_len(cdb, &block, &n_block);
+	else if (cdb[0] == VERIFY_16)
+		scsi_16_lba_len(cdb, &block, &n_block);
 	else
 		goto invalid_fld;
 
@@ -1229,24 +1225,24 @@ static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc, const u8 *sc
 	return 0;
 
 invalid_fld:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x24, 0x0);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
 	/* "Invalid field in cbd" */
 	return 1;
 
 out_of_range:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x21, 0x0);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);
 	/* "Logical Block Address out of range" */
 	return 1;
 
 nothing_to_do:
-	qc->scsicmd->result = SAM_STAT_GOOD;
+	scmd->result = SAM_STAT_GOOD;
 	return 1;
 }
 
 /**
  *	ata_scsi_rw_xlat - Translate SCSI r/w command into an ATA one
  *	@qc: Storage for translated ATA taskfile
- *	@scsicmd: SCSI command to translate
+ *	@cdb: SCSI command to translate
  *
  *	Converts any of six SCSI read/write commands into the
  *	ATA counterpart, including starting sector (LBA),
@@ -1262,29 +1258,28 @@ nothing_to_do:
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-
-static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
+static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
 {
+	struct scsi_cmnd *scmd = qc->scsicmd;
 	unsigned int tf_flags = 0;
 	u64 block;
 	u32 n_block;
 	int rc;
 
-	if (scsicmd[0] == WRITE_10 || scsicmd[0] == WRITE_6 ||
-	    scsicmd[0] == WRITE_16)
+	if (cdb[0] == WRITE_10 || cdb[0] == WRITE_6 || cdb[0] == WRITE_16)
 		tf_flags |= ATA_TFLAG_WRITE;
 
 	/* Calculate the SCSI LBA, transfer length and FUA. */
-	switch (scsicmd[0]) {
+	switch (cdb[0]) {
 	case READ_10:
 	case WRITE_10:
-		scsi_10_lba_len(scsicmd, &block, &n_block);
-		if (unlikely(scsicmd[1] & (1 << 3)))
+		scsi_10_lba_len(cdb, &block, &n_block);
+		if (unlikely(cdb[1] & (1 << 3)))
 			tf_flags |= ATA_TFLAG_FUA;
 		break;
 	case READ_6:
 	case WRITE_6:
-		scsi_6_lba_len(scsicmd, &block, &n_block);
+		scsi_6_lba_len(cdb, &block, &n_block);
 
 		/* for 6-byte r/w commands, transfer length 0
 		 * means 256 blocks of data, not 0 block.
@@ -1294,8 +1289,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicm
 		break;
 	case READ_16:
 	case WRITE_16:
-		scsi_16_lba_len(scsicmd, &block, &n_block);
-		if (unlikely(scsicmd[1] & (1 << 3)))
+		scsi_16_lba_len(cdb, &block, &n_block);
+		if (unlikely(cdb[1] & (1 << 3)))
 			tf_flags |= ATA_TFLAG_FUA;
 		break;
 	default:
@@ -1326,17 +1321,17 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *scsicm
 		goto out_of_range;
 	/* treat all other errors as -EINVAL, fall through */
 invalid_fld:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x24, 0x0);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x0);
 	/* "Invalid field in cbd" */
 	return 1;
 
 out_of_range:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x21, 0x0);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x21, 0x0);
 	/* "Logical Block Address out of range" */
 	return 1;
 
 nothing_to_do:
-	qc->scsicmd->result = SAM_STAT_GOOD;
+	scmd->result = SAM_STAT_GOOD;
 	return 1;
 }
 
@@ -1456,7 +1451,7 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 			      ata_xlat_func_t xlat_func)
 {
 	struct ata_queued_cmd *qc;
-	u8 *scsicmd = cmd->cmnd;
+	u8 *cdb = cmd->cmnd;
 	int is_io = xlat_func == ata_scsi_rw_xlat;
 
 	VPRINTK("ENTER\n");
@@ -1488,7 +1483,7 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 
 	qc->complete_fn = ata_scsi_qc_complete;
 
-	if (xlat_func(qc, scsicmd))
+	if (xlat_func(qc, cdb))
 		goto early_finish;
 
 	/* select device, send command to hardware */
@@ -2344,7 +2339,7 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
 /**
  *	atapi_xlat - Initialize PACKET taskfile
  *	@qc: command structure to be initialized
- *	@scsicmd: SCSI CDB associated with this PACKET command
+ *	@cdb: SCSI CDB associated with this PACKET command
  *
  *	LOCKING:
  *	spin_lock_irqsave(host lock)
@@ -2352,25 +2347,24 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
  *	RETURNS:
  *	Zero on success, non-zero on failure.
  */
-
-static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
+static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
 {
-	struct scsi_cmnd *cmd = qc->scsicmd;
+	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_device *dev = qc->dev;
 	int using_pio = (dev->flags & ATA_DFLAG_PIO);
-	int nodata = (cmd->sc_data_direction == DMA_NONE);
+	int nodata = (scmd->sc_data_direction == DMA_NONE);
 
 	if (!using_pio)
 		/* Check whether ATAPI DMA is safe */
 		if (ata_check_atapi_dma(qc))
 			using_pio = 1;
 
-	memcpy(&qc->cdb, scsicmd, dev->cdb_len);
+	memcpy(&qc->cdb, cdb, dev->cdb_len);
 
 	qc->complete_fn = atapi_qc_complete;
 
 	qc->tf.flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
-	if (cmd->sc_data_direction == DMA_TO_DEVICE) {
+	if (scmd->sc_data_direction == DMA_TO_DEVICE) {
 		qc->tf.flags |= ATA_TFLAG_WRITE;
 		DPRINTK("direction: write\n");
 	}
@@ -2392,12 +2386,12 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *scsicmd)
 		qc->tf.protocol = ATA_PROT_ATAPI_DMA;
 		qc->tf.feature |= ATAPI_PKT_DMA;
 
-		if (atapi_dmadir && (cmd->sc_data_direction != DMA_TO_DEVICE))
+		if (atapi_dmadir && (scmd->sc_data_direction != DMA_TO_DEVICE))
 			/* some SATA bridges need us to indicate data xfer direction */
 			qc->tf.feature |= ATAPI_DMADIR;
 	}
 
-	qc->nbytes = cmd->request_bufflen;
+	qc->nbytes = scmd->request_bufflen;
 
 	return 0;
 }
@@ -2517,28 +2511,27 @@ ata_scsi_map_proto(u8 byte1)
 /**
  *	ata_scsi_pass_thru - convert ATA pass-thru CDB to taskfile
  *	@qc: command structure to be initialized
- *	@scsicmd: SCSI command to convert
+ *	@cdb: SCSI command to convert
  *
  *	Handles either 12 or 16-byte versions of the CDB.
  *
  *	RETURNS:
  *	Zero on success, non-zero on failure.
  */
-static unsigned int
-ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
+static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *cdb)
 {
 	struct ata_taskfile *tf = &(qc->tf);
-	struct scsi_cmnd *cmd = qc->scsicmd;
+	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_device *dev = qc->dev;
 
-	if ((tf->protocol = ata_scsi_map_proto(scsicmd[1])) == ATA_PROT_UNKNOWN)
+	if ((tf->protocol = ata_scsi_map_proto(cdb[1])) == ATA_PROT_UNKNOWN)
 		goto invalid_fld;
 
 	/* We may not issue DMA commands if no DMA mode is set */
 	if (tf->protocol == ATA_PROT_DMA && dev->dma_mode == 0)
 		goto invalid_fld;
 
-	if (scsicmd[1] & 0xe0)
+	if (cdb[1] & 0xe0)
 		/* PIO multi not supported yet */
 		goto invalid_fld;
 
@@ -2546,18 +2539,18 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 	 * 12 and 16 byte CDBs use different offsets to
 	 * provide the various register values.
 	 */
-	if (scsicmd[0] == ATA_16) {
+	if (cdb[0] == ATA_16) {
 		/*
 		 * 16-byte CDB - may contain extended commands.
 		 *
 		 * If that is the case, copy the upper byte register values.
 		 */
-		if (scsicmd[1] & 0x01) {
-			tf->hob_feature = scsicmd[3];
-			tf->hob_nsect = scsicmd[5];
-			tf->hob_lbal = scsicmd[7];
-			tf->hob_lbam = scsicmd[9];
-			tf->hob_lbah = scsicmd[11];
+		if (cdb[1] & 0x01) {
+			tf->hob_feature = cdb[3];
+			tf->hob_nsect = cdb[5];
+			tf->hob_lbal = cdb[7];
+			tf->hob_lbam = cdb[9];
+			tf->hob_lbah = cdb[11];
 			tf->flags |= ATA_TFLAG_LBA48;
 		} else
 			tf->flags &= ~ATA_TFLAG_LBA48;
@@ -2565,26 +2558,26 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 		/*
 		 * Always copy low byte, device and command registers.
 		 */
-		tf->feature = scsicmd[4];
-		tf->nsect = scsicmd[6];
-		tf->lbal = scsicmd[8];
-		tf->lbam = scsicmd[10];
-		tf->lbah = scsicmd[12];
-		tf->device = scsicmd[13];
-		tf->command = scsicmd[14];
+		tf->feature = cdb[4];
+		tf->nsect = cdb[6];
+		tf->lbal = cdb[8];
+		tf->lbam = cdb[10];
+		tf->lbah = cdb[12];
+		tf->device = cdb[13];
+		tf->command = cdb[14];
 	} else {
 		/*
 		 * 12-byte CDB - incapable of extended commands.
 		 */
 		tf->flags &= ~ATA_TFLAG_LBA48;
 
-		tf->feature = scsicmd[3];
-		tf->nsect = scsicmd[4];
-		tf->lbal = scsicmd[5];
-		tf->lbam = scsicmd[6];
-		tf->lbah = scsicmd[7];
-		tf->device = scsicmd[8];
-		tf->command = scsicmd[9];
+		tf->feature = cdb[3];
+		tf->nsect = cdb[4];
+		tf->lbal = cdb[5];
+		tf->lbam = cdb[6];
+		tf->lbah = cdb[7];
+		tf->device = cdb[8];
+		tf->command = cdb[9];
 	}
 	/*
 	 * If slave is possible, enforce correct master/slave bit
@@ -2611,7 +2604,7 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 	 */
 	tf->flags |= (ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE);
 
-	if (cmd->sc_data_direction == DMA_TO_DEVICE)
+	if (scmd->sc_data_direction == DMA_TO_DEVICE)
 		tf->flags |= ATA_TFLAG_WRITE;
 
 	/*
@@ -2620,7 +2613,7 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 	 * TODO: find out if we need to do more here to
 	 *       cover scatter/gather case.
 	 */
-	qc->nsect = cmd->request_bufflen / ATA_SECT_SIZE;
+	qc->nsect = scmd->request_bufflen / ATA_SECT_SIZE;
 
 	/* request result TF */
 	qc->flags |= ATA_QCFLAG_RESULT_TF;
@@ -2628,7 +2621,7 @@ ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *scsicmd)
 	return 0;
 
  invalid_fld:
-	ata_scsi_set_sense(qc->scsicmd, ILLEGAL_REQUEST, 0x24, 0x00);
+	ata_scsi_set_sense(scmd, ILLEGAL_REQUEST, 0x24, 0x00);
 	/* "Invalid field in cdb" */
 	return 1;
 }
@@ -2701,7 +2694,7 @@ static inline void ata_scsi_dump_cdb(struct ata_port *ap,
 #endif
 }
 
-static inline int __ata_scsi_queuecmd(struct scsi_cmnd *cmd,
+static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 				      void (*done)(struct scsi_cmnd *),
 				      struct ata_device *dev)
 {
@@ -2709,14 +2702,14 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *cmd,
 
 	if (dev->class == ATA_DEV_ATA) {
 		ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
-							      cmd->cmnd[0]);
+							      scmd->cmnd[0]);
 
 		if (xlat_func)
-			rc = ata_scsi_translate(dev, cmd, done, xlat_func);
+			rc = ata_scsi_translate(dev, scmd, done, xlat_func);
 		else
-			ata_scsi_simulate(dev, cmd, done);
+			ata_scsi_simulate(dev, scmd, done);
 	} else
-		rc = ata_scsi_translate(dev, cmd, done, atapi_xlat);
+		rc = ata_scsi_translate(dev, scmd, done, atapi_xlat);
 
 	return rc;
 }
-- 
1.4.4.2

[PATCH 2/4] libata: kill @cdb argument from xlat methods

[Tejun Heo]

xlat function will be updated to consider qc->scsicmd->cmd_len and
many xlat functions deference qc->scsicmd already.  It doesn't make
sense to pass qc->scsicmd->cmnd as @cdb separately.  Kill the
argument.

Signed-off-by: Tejun Heo <htejun@gmail.com>
---
 drivers/ata/libata-scsi.c |   30 +++++++++++++-----------------
 1 files changed, 13 insertions(+), 17 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 1e42cde..307910b 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -51,7 +51,7 @@
 
 #define SECTOR_SIZE	512
 
-typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc, const u8 *cdb);
+typedef unsigned int (*ata_xlat_func_t)(struct ata_queued_cmd *qc);
 
 static struct ata_device * __ata_scsi_find_dev(struct ata_port *ap,
 					const struct scsi_device *scsidev);
@@ -935,7 +935,6 @@ int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
 /**
  *	ata_scsi_start_stop_xlat - Translate SCSI START STOP UNIT command
  *	@qc: Storage for translated ATA taskfile
- *	@cdb: SCSI command to translate
  *
  *	Sets up an ATA taskfile to issue STANDBY (to stop) or READ VERIFY
  *	(to start). Perhaps these commands should be preceded by
@@ -948,11 +947,11 @@ int ata_scsi_change_queue_depth(struct scsi_device *sdev, int queue_depth)
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc,
-					     const u8 *cdb)
+static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_taskfile *tf = &qc->tf;
+	const u8 *cdb = scmd->cmnd;
 
 	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
 	tf->protocol = ATA_PROT_NODATA;
@@ -1005,7 +1004,6 @@ invalid_fld:
 /**
  *	ata_scsi_flush_xlat - Translate SCSI SYNCHRONIZE CACHE command
  *	@qc: Storage for translated ATA taskfile
- *	@cdb: SCSI command to translate (ignored)
  *
  *	Sets up an ATA taskfile to issue FLUSH CACHE or
  *	FLUSH CACHE EXT.
@@ -1016,7 +1014,7 @@ invalid_fld:
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
+static unsigned int ata_scsi_flush_xlat(struct ata_queued_cmd *qc)
 {
 	struct ata_taskfile *tf = &qc->tf;
 
@@ -1124,7 +1122,6 @@ static void scsi_16_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
 /**
  *	ata_scsi_verify_xlat - Translate SCSI VERIFY command into an ATA one
  *	@qc: Storage for translated ATA taskfile
- *	@cdb: SCSI command to translate
  *
  *	Converts SCSI VERIFY command to an ATA READ VERIFY command.
  *
@@ -1134,12 +1131,13 @@ static void scsi_16_lba_len(const u8 *cdb, u64 *plba, u32 *plen)
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
+static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_taskfile *tf = &qc->tf;
 	struct ata_device *dev = qc->dev;
 	u64 dev_sectors = qc->dev->n_sectors;
+	const u8 *cdb = scmd->cmnd;
 	u64 block;
 	u32 n_block;
 
@@ -1242,7 +1240,6 @@ nothing_to_do:
 /**
  *	ata_scsi_rw_xlat - Translate SCSI r/w command into an ATA one
  *	@qc: Storage for translated ATA taskfile
- *	@cdb: SCSI command to translate
  *
  *	Converts any of six SCSI read/write commands into the
  *	ATA counterpart, including starting sector (LBA),
@@ -1258,9 +1255,10 @@ nothing_to_do:
  *	RETURNS:
  *	Zero on success, non-zero on error.
  */
-static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
+static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *scmd = qc->scsicmd;
+	const u8 *cdb = scmd->cmnd;
 	unsigned int tf_flags = 0;
 	u64 block;
 	u32 n_block;
@@ -1451,7 +1449,6 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 			      ata_xlat_func_t xlat_func)
 {
 	struct ata_queued_cmd *qc;
-	u8 *cdb = cmd->cmnd;
 	int is_io = xlat_func == ata_scsi_rw_xlat;
 
 	VPRINTK("ENTER\n");
@@ -1483,7 +1480,7 @@ static int ata_scsi_translate(struct ata_device *dev, struct scsi_cmnd *cmd,
 
 	qc->complete_fn = ata_scsi_qc_complete;
 
-	if (xlat_func(qc, cdb))
+	if (xlat_func(qc))
 		goto early_finish;
 
 	/* select device, send command to hardware */
@@ -2339,7 +2336,6 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
 /**
  *	atapi_xlat - Initialize PACKET taskfile
  *	@qc: command structure to be initialized
- *	@cdb: SCSI CDB associated with this PACKET command
  *
  *	LOCKING:
  *	spin_lock_irqsave(host lock)
@@ -2347,7 +2343,7 @@ static void atapi_qc_complete(struct ata_queued_cmd *qc)
  *	RETURNS:
  *	Zero on success, non-zero on failure.
  */
-static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
+static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
 {
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_device *dev = qc->dev;
@@ -2359,7 +2355,7 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc, const u8 *cdb)
 		if (ata_check_atapi_dma(qc))
 			using_pio = 1;
 
-	memcpy(&qc->cdb, cdb, dev->cdb_len);
+	memcpy(&qc->cdb, scmd->cmnd, dev->cdb_len);
 
 	qc->complete_fn = atapi_qc_complete;
 
@@ -2511,18 +2507,18 @@ ata_scsi_map_proto(u8 byte1)
 /**
  *	ata_scsi_pass_thru - convert ATA pass-thru CDB to taskfile
  *	@qc: command structure to be initialized
- *	@cdb: SCSI command to convert
  *
  *	Handles either 12 or 16-byte versions of the CDB.
  *
  *	RETURNS:
  *	Zero on success, non-zero on failure.
  */
-static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc, const u8 *cdb)
+static unsigned int ata_scsi_pass_thru(struct ata_queued_cmd *qc)
 {
 	struct ata_taskfile *tf = &(qc->tf);
 	struct scsi_cmnd *scmd = qc->scsicmd;
 	struct ata_device *dev = qc->dev;
+	const u8 *cdb = scmd->cmnd;
 
 	if ((tf->protocol = ata_scsi_map_proto(cdb[1])) == ATA_PROT_UNKNOWN)
 		goto invalid_fld;
-- 
1.4.4.2

[PATCH 3/4] libata: take scmd->cmd_len into account when translating SCSI commands

[Tejun Heo]

libata depended on SCSI command to have the correct length when
tranlating it into an ATA command.  This generally worked for commands
issued by SCSI HLD but user could issue arbitrary broken command using
sg interface.

Also, when building ATAPI command, full command size was always
copied.  Because some ATAPI devices needs bytes after CDB cleared, if
upper layer doesn't clear bytes after CDB, such devices will
malfunction.  This necessiated recent clear-garbage-after-CDB fix in
sg interfaces.  However, scsi_execute() isn't fixed yet and HL-DT-ST
DVD-RAM GSA-H30N malfunctions on initialization commands issued from
SCSI.

This patch makes xlat functions always consider SCSI cmd_len.  Each
translation function checks for proper cmd_len and ATAPI translaation
clears bytes after CDB.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Douglas Gilbert <dougg@torque.net>
---
 drivers/ata/libata-scsi.c |   29 +++++++++++++++++++++++++----
 1 files changed, 25 insertions(+), 4 deletions(-)

diff --git a/drivers/ata/libata-scsi.c b/drivers/ata/libata-scsi.c
index 307910b..836947d 100644
--- a/drivers/ata/libata-scsi.c
+++ b/drivers/ata/libata-scsi.c
@@ -953,6 +953,9 @@ static unsigned int ata_scsi_start_stop_xlat(struct ata_queued_cmd *qc)
 	struct ata_taskfile *tf = &qc->tf;
 	const u8 *cdb = scmd->cmnd;
 
+	if (scmd->cmd_len < 5)
+		goto invalid_fld;
+
 	tf->flags |= ATA_TFLAG_DEVICE | ATA_TFLAG_ISADDR;
 	tf->protocol = ATA_PROT_NODATA;
 	if (cdb[1] & 0x1) {
@@ -1144,11 +1147,15 @@ static unsigned int ata_scsi_verify_xlat(struct ata_queued_cmd *qc)
 	tf->flags |= ATA_TFLAG_ISADDR | ATA_TFLAG_DEVICE;
 	tf->protocol = ATA_PROT_NODATA;
 
-	if (cdb[0] == VERIFY)
+	if (cdb[0] == VERIFY) {
+		if (scmd->cmd_len < 10)
+			goto invalid_fld;
 		scsi_10_lba_len(cdb, &block, &n_block);
-	else if (cdb[0] == VERIFY_16)
+	} else if (cdb[0] == VERIFY_16) {
+		if (scmd->cmd_len < 16)
+			goto invalid_fld;
 		scsi_16_lba_len(cdb, &block, &n_block);
-	else
+	} else
 		goto invalid_fld;
 
 	if (!n_block)
@@ -1271,12 +1278,16 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
 	switch (cdb[0]) {
 	case READ_10:
 	case WRITE_10:
+		if (unlikely(scmd->cmd_len < 10))
+			goto invalid_fld;
 		scsi_10_lba_len(cdb, &block, &n_block);
 		if (unlikely(cdb[1] & (1 << 3)))
 			tf_flags |= ATA_TFLAG_FUA;
 		break;
 	case READ_6:
 	case WRITE_6:
+		if (unlikely(scmd->cmd_len < 6))
+			goto invalid_fld;
 		scsi_6_lba_len(cdb, &block, &n_block);
 
 		/* for 6-byte r/w commands, transfer length 0
@@ -1287,6 +1298,8 @@ static unsigned int ata_scsi_rw_xlat(struct ata_queued_cmd *qc)
 		break;
 	case READ_16:
 	case WRITE_16:
+		if (unlikely(scmd->cmd_len < 16))
+			goto invalid_fld;
 		scsi_16_lba_len(cdb, &block, &n_block);
 		if (unlikely(cdb[1] & (1 << 3)))
 			tf_flags |= ATA_TFLAG_FUA;
@@ -2355,7 +2368,8 @@ static unsigned int atapi_xlat(struct ata_queued_cmd *qc)
 		if (ata_check_atapi_dma(qc))
 			using_pio = 1;
 
-	memcpy(&qc->cdb, scmd->cmnd, dev->cdb_len);
+	memset(qc->cdb, 0, dev->cdb_len);
+	memcpy(qc->cdb, scmd->cmnd, scmd->cmd_len);
 
 	qc->complete_fn = atapi_qc_complete;
 
@@ -2696,6 +2710,13 @@ static inline int __ata_scsi_queuecmd(struct scsi_cmnd *scmd,
 {
 	int rc = 0;
 
+	if (unlikely(!scmd->cmd_len)) {
+		ata_dev_printk(dev, KERN_WARNING, "WARNING: zero len CDB\n");
+		scmd->result = DID_ERROR << 16;
+		done(scmd);
+		return 0;
+	}
+
 	if (dev->class == ATA_DEV_ATA) {
 		ata_xlat_func_t xlat_func = ata_get_xlat_func(dev,
 							      scmd->cmnd[0]);
-- 
1.4.4.2

[PATCH 4/4] SCSI: revert clear-garbage-after-CDB fix

[Tejun Heo]

Upper layer is already passing in enough information via req->cmd_len
and requiring it to do the same thing twice makes it easy to miss -
scsi_execute() doesn't do it.

Now that libata is updated to handle garbage after CDB, remove
unnecessary CDB clearing.

Signed-off-by: Tejun Heo <htejun@gmail.com>
Cc: Jens Axboe <jens.axboe@oracle.com>
Cc: Douglas Gilbert <dougg@torque.net>
---
 block/scsi_ioctl.c      |    1 -
 drivers/scsi/scsi_lib.c |    1 -
 2 files changed, 0 insertions(+), 2 deletions(-)

diff --git a/block/scsi_ioctl.c b/block/scsi_ioctl.c
index f322b6a..513d82c 100644
--- a/block/scsi_ioctl.c
+++ b/block/scsi_ioctl.c
@@ -262,7 +262,6 @@ static int sg_io(struct file *file, request_queue_t *q,
 	 * fill in request structure
 	 */
 	rq->cmd_len = hdr->cmd_len;
-	memset(rq->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
 	memcpy(rq->cmd, cmd, hdr->cmd_len);
 
 	memset(sense, 0, sizeof(sense));
diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 1748e27..a1df156 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -410,7 +410,6 @@ int scsi_execute_async(struct scsi_device *sdev, const unsigned char *cmd,
 		goto free_req;
 
 	req->cmd_len = cmd_len;
-	memset(req->cmd, 0, BLK_MAX_CDB); /* ATAPI hates garbage after CDB */
 	memcpy(req->cmd, cmd, req->cmd_len);
 	req->sense = sioc->sense;
 	req->sense_len = 0;
-- 
1.4.4.2

Re: [PATCH 1/4] libata: clean up variable name usage in xlat related functions

[Jeff Garzik]

Tejun Heo wrote:
> Variable names in xlat functions are quite confusing now.  'scsicmd'
> is used for CDB while qc->scsicmd points to struct scsi_cmnd while
> 'cmd' is used for struct scsi_cmnd.
> 
> This patch cleans up variable names in xlat functions such that 'scmd'
> is used for struct scsi_cmnd and 'cdb' for CDB.  Also, 'scmd' local
> variable is added if qc->scsicmd is used multiple times.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>
> ---
> Okay, separated as suggested and regenerated against
> libata-dev#upstream-fixes.

applied 1-3 to #upstream-fixes