1 files changed, 80 insertions, 22 deletions

diff --git a/drivers/scsi/scsi.c b/drivers/scsi/scsi.c
index 76d369343c7a..518a252eb6aa 100644
--- a/drivers/scsi/scsi.c
+++ b/drivers/scsi/scsi.c
@@ -55,7 +55,7 @@
 #include <linux/notifier.h>
 #include <linux/cpu.h>
 #include <linux/mutex.h>
-#include <asm/unaligned.h>
+#include <linux/unaligned.h>
 
 #include <scsi/scsi.h>
 #include <scsi/scsi_cmnd.h>
@@ -328,21 +328,46 @@ static int scsi_vpd_inquiry(struct scsi_device *sdev, unsigned char *buffer,
 	return result + 4;
 }
 
+enum scsi_vpd_parameters {
+	SCSI_VPD_HEADER_SIZE = 4,
+	SCSI_VPD_LIST_SIZE = 36,
+};
+
 static int scsi_get_vpd_size(struct scsi_device *sdev, u8 page)
 {
-	unsigned char vpd_header[SCSI_VPD_HEADER_SIZE] __aligned(4);
+	unsigned char vpd[SCSI_VPD_LIST_SIZE] __aligned(4);
 	int result;
 
 	if (sdev->no_vpd_size)
 		return SCSI_DEFAULT_VPD_LEN;
 
 	/*
+	 * Fetch the supported pages VPD and validate that the requested page
+	 * number is present.
+	 */
+	if (page != 0) {
+		result = scsi_vpd_inquiry(sdev, vpd, 0, sizeof(vpd));
+		if (result < SCSI_VPD_HEADER_SIZE)
+			return 0;
+
+		if (result > sizeof(vpd)) {
+			dev_warn_once(&sdev->sdev_gendev,
+				      "%s: long VPD page 0 length: %d bytes\n",
+				      __func__, result);
+			result = sizeof(vpd);
+		}
+
+		result -= SCSI_VPD_HEADER_SIZE;
+		if (!memchr(&vpd[SCSI_VPD_HEADER_SIZE], page, result))
+			return 0;
+	}
+	/*
 	 * Fetch the VPD page header to find out how big the page
 	 * is. This is done to prevent problems on legacy devices
 	 * which can not handle allocation lengths as large as
 	 * potentially requested by the caller.
 	 */
-	result = scsi_vpd_inquiry(sdev, vpd_header, page, sizeof(vpd_header));
+	result = scsi_vpd_inquiry(sdev, vpd, page, SCSI_VPD_HEADER_SIZE);
 	if (result < 0)
 		return 0;
 
@@ -485,20 +510,34 @@ void scsi_attach_vpd(struct scsi_device *sdev)
 		return;
 
 	for (i = 4; i < vpd_buf->len; i++) {
-		if (vpd_buf->data[i] == 0x0)
+		switch (vpd_buf->data[i]) {
+		case 0x0:
 			scsi_update_vpd_page(sdev, 0x0, &sdev->vpd_pg0);
-		if (vpd_buf->data[i] == 0x80)
+			break;
+		case 0x80:
 			scsi_update_vpd_page(sdev, 0x80, &sdev->vpd_pg80);
-		if (vpd_buf->data[i] == 0x83)
+			break;
+		case 0x83:
 			scsi_update_vpd_page(sdev, 0x83, &sdev->vpd_pg83);
-		if (vpd_buf->data[i] == 0x89)
+			break;
+		case 0x89:
 			scsi_update_vpd_page(sdev, 0x89, &sdev->vpd_pg89);
-		if (vpd_buf->data[i] == 0xb0)
+			break;
+		case 0xb0:
 			scsi_update_vpd_page(sdev, 0xb0, &sdev->vpd_pgb0);
-		if (vpd_buf->data[i] == 0xb1)
+			break;
+		case 0xb1:
 			scsi_update_vpd_page(sdev, 0xb1, &sdev->vpd_pgb1);
-		if (vpd_buf->data[i] == 0xb2)
+			break;
+		case 0xb2:
 			scsi_update_vpd_page(sdev, 0xb2, &sdev->vpd_pgb2);
+			break;
+		case 0xb7:
+			scsi_update_vpd_page(sdev, 0xb7, &sdev->vpd_pgb7);
+			break;
+		default:
+			break;
+		}
 	}
 	kfree(vpd_buf);
 }
@@ -646,6 +685,13 @@ void scsi_cdl_check(struct scsi_device *sdev)
 		sdev->use_10_for_rw = 0;
 
 		sdev->cdl_supported = 1;
+
+		/*
+		 * If the device supports CDL, make sure that the current drive
+		 * feature status is consistent with the user controlled
+		 * cdl_enable state.
+		 */
+		scsi_cdl_enable(sdev, sdev->cdl_enable);
 	} else {
 		sdev->cdl_supported = 0;
 	}
@@ -661,26 +707,23 @@ void scsi_cdl_check(struct scsi_device *sdev)
  */
 int scsi_cdl_enable(struct scsi_device *sdev, bool enable)
 {
-	struct scsi_mode_data data;
-	struct scsi_sense_hdr sshdr;
-	struct scsi_vpd *vpd;
-	bool is_ata = false;
 	char buf[64];
+	bool is_ata;
 	int ret;
 
 	if (!sdev->cdl_supported)
 		return -EOPNOTSUPP;
 
 	rcu_read_lock();
-	vpd = rcu_dereference(sdev->vpd_pg89);
-	if (vpd)
-		is_ata = true;
+	is_ata = rcu_dereference(sdev->vpd_pg89);
 	rcu_read_unlock();
 
 	/*
 	 * For ATA devices, CDL needs to be enabled with a SET FEATURES command.
 	 */
 	if (is_ata) {
+		struct scsi_mode_data data;
+		struct scsi_sense_hdr sshdr;
 		char *buf_data;
 		int len;
 
@@ -689,16 +732,30 @@ int scsi_cdl_enable(struct scsi_device *sdev, bool enable)
 		if (ret)
 			return -EINVAL;
 
-		/* Enable CDL using the ATA feature page */
+		/* Enable or disable CDL using the ATA feature page */
 		len = min_t(size_t, sizeof(buf),
 			    data.length - data.header_length -
 			    data.block_descriptor_length);
 		buf_data = buf + data.header_length +
 			data.block_descriptor_length;
-		if (enable)
-			buf_data[4] = 0x02;
-		else
-			buf_data[4] = 0;
+
+		/*
+		 * If we want to enable CDL and CDL is already enabled on the
+		 * device, do nothing. This avoids needlessly resetting the CDL
+		 * statistics on the device as that is implied by the CDL enable
+		 * action. Similar to this, there is no need to do anything if
+		 * we want to disable CDL and CDL is already disabled.
+		 */
+		if (enable) {
+			if ((buf_data[4] & 0x03) == 0x02)
+				goto out;
+			buf_data[4] &= ~0x03;
+			buf_data[4] |= 0x02;
+		} else {
+			if ((buf_data[4] & 0x03) == 0x00)
+				goto out;
+			buf_data[4] &= ~0x03;
+		}
 
 		ret = scsi_mode_select(sdev, 1, 0, buf_data, len, 5 * HZ, 3,
 				       &data, &sshdr);
@@ -710,6 +767,7 @@ int scsi_cdl_enable(struct scsi_device *sdev, bool enable)
 		}
 	}
 
+out:
 	sdev->cdl_enable = enable;
 
 	return 0;