From: David Milburn <dmilburn@redhat.com>
Subject: [RHEL5.1] libata-scsi-ata_task_ioctl-should-return-ata-registers (RESEND)
Date: Wed, 28 Mar 2007 16:58:59 -0500
Bugzilla: 218553
Message-Id: <20070328215859.GA9761@dhcp-210.hsv.redhat.com>
Changelog: [scsi] ata_task_ioctl should return ata registers


This patch fixes HDIO_DRIVE_TASK ioctl to copy ATA registers
back to user-space. This was causing the smartctl application
to report that overall health was good even when there was
a disk failure. This patch fixes ata_task_ioctl() to report
back failure status and to copy over upper four LBA bits
passed in from the ioctl before executing the command. Both
changes are upstream, please ACK or comment.

Thanks,
David

--- linux-2.6.18.i686/drivers/scsi/libata-scsi.c.smart
+++ linux-2.6.18.i686/drivers/scsi/libata-scsi.c
@@ -241,8 +241,8 @@ int ata_task_ioctl(struct scsi_device *s
 {
 	int rc = 0;
 	u8 scsi_cmd[MAX_COMMAND_SIZE];
-	u8 args[7];
-	struct scsi_sense_hdr sshdr;
+	u8 args[7], *sensebuf = NULL;
+	int cmd_result;
 
 	if (arg == NULL)
 		return -EINVAL;
@@ -250,24 +250,64 @@ int ata_task_ioctl(struct scsi_device *s
 	if (copy_from_user(args, arg, sizeof(args)))
 		return -EFAULT;
 
+	sensebuf = kzalloc(SCSI_SENSE_BUFFERSIZE, GFP_NOIO);
+	if (!sensebuf)
+		return -ENOMEM;
+
 	memset(scsi_cmd, 0, sizeof(scsi_cmd));
 	scsi_cmd[0]  = ATA_16;
 	scsi_cmd[1]  = (3 << 1); /* Non-data */
-	/* scsi_cmd[2] is already 0 -- no off.line, cc, or data xfer */
+	scsi_cmd[2]  = 0x20;     /* cc but no off.line or data xfer */
 	scsi_cmd[4]  = args[1];
 	scsi_cmd[6]  = args[2];
 	scsi_cmd[8]  = args[3];
 	scsi_cmd[10] = args[4];
 	scsi_cmd[12] = args[5];
+	scsi_cmd[13] = args[6] & 0x0f;
 	scsi_cmd[14] = args[0];
 
 	/* Good values for timeout and retries?  Values below
 	   from scsi_ioctl_send_command() for default case... */
-	if (scsi_execute_req(scsidev, scsi_cmd, DMA_NONE, NULL, 0, &sshdr,
-			     (10*HZ), 5))
+	cmd_result = scsi_execute(scsidev, scsi_cmd, DMA_NONE, NULL, 0,
+				  sensebuf, (10*HZ), 5, 0);
+
+	if (driver_byte(cmd_result) == DRIVER_SENSE) {/* sense data available */
+		u8 *desc = sensebuf + 8;
+		cmd_result &= ~(0xFF<<24); /* DRIVER_SENSE is not an error */
+		
+		/* If we set cc the ATA pass-through will cause a
+		 * check condition even if no error. Filter that. */
+		if (cmd_result & SAM_STAT_CHECK_CONDITION) {
+			struct scsi_sense_hdr sshdr;
+			scsi_normalize_sense(sensebuf, SCSI_SENSE_BUFFERSIZE,
+					     &sshdr);
+			if (sshdr.sense_key==0 && 
+			    sshdr.asc==0 && sshdr.ascq==0)
+				cmd_result &= ~SAM_STAT_CHECK_CONDITION;
+		}
+
+		/* Send userspace ATA registers */
+		if (sensebuf[0] == 0x72 &&     /* format is "descriptor" */
+		    desc[0] ==0x09) {          /* code is "ATA Descriptor" */
+			args[0] = desc[13];    /* status */
+			args[1] = desc[3];     /* error */
+			args[2] = desc[5];     /* sector count (0:7) */
+			args[3] = desc[7];     /* lbal */
+			args[4] = desc[9];     /* lbam */
+			args[5] = desc[11];    /* lbah */
+			args[6] = desc[12];    /* select */
+			if (copy_to_user(arg, args, sizeof(args)))
+				rc = -EFAULT;
+		}
+	}
+
+	if (cmd_result) {
 		rc = -EIO;
+		goto error;
+	}
 
-	/* Need code to retrieve data from check condition? */
+ error:
+	kfree(sensebuf);
 	return rc;
 }