1 files changed, 58 insertions, 19 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 8fa3d0b..80f39b8 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -142,7 +142,7 @@ sd_store_cache_type(struct device *dev, struct device_attribute *attr,
 	char *buffer_data;
 	struct scsi_mode_data data;
 	struct scsi_sense_hdr sshdr;
-	const char *temp = "temporary ";
+	static const char temp[] = "temporary ";
 	int len;
 
 	if (sdp->type != TYPE_DISK)
@@ -442,8 +442,10 @@ sd_store_write_same_blocks(struct device *dev, struct device_attribute *attr,
 
 	if (max == 0)
 		sdp->no_write_same = 1;
-	else if (max <= SD_MAX_WS16_BLOCKS)
+	else if (max <= SD_MAX_WS16_BLOCKS) {
+		sdp->no_write_same = 0;
 		sdkp->max_ws_blocks = max;
+	}
 
 	sd_config_write_same(sdkp);
 
@@ -504,6 +506,16 @@ static struct scsi_driver sd_template = {
 };
 
 /*
+ * Dummy kobj_map->probe function.
+ * The default ->probe function will call modprobe, which is
+ * pointless as this module is already loaded.
+ */
+static struct kobject *sd_default_probe(dev_t devt, int *partno, void *data)
+{
+	return NULL;
+}
+
+/*
  * Device no to disk mapping:
  * 
  *       major         disc2     disc  p1
@@ -740,7 +752,6 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
 {
 	struct request_queue *q = sdkp->disk->queue;
 	unsigned int logical_block_size = sdkp->device->sector_size;
-	unsigned int blocks = 0;
 
 	if (sdkp->device->no_write_same) {
 		sdkp->max_ws_blocks = 0;
@@ -752,18 +763,20 @@ static void sd_config_write_same(struct scsi_disk *sdkp)
 	 * blocks per I/O unless the device explicitly advertises a
 	 * bigger limit.
 	 */
-	if (sdkp->max_ws_blocks == 0)
-		sdkp->max_ws_blocks = SD_MAX_WS10_BLOCKS;
-
-	if (sdkp->ws16 || sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
-		blocks = min_not_zero(sdkp->max_ws_blocks,
-				      (u32)SD_MAX_WS16_BLOCKS);
-	else
-		blocks = min_not_zero(sdkp->max_ws_blocks,
-				      (u32)SD_MAX_WS10_BLOCKS);
+	if (sdkp->max_ws_blocks > SD_MAX_WS10_BLOCKS)
+		sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
+						   (u32)SD_MAX_WS16_BLOCKS);
+	else if (sdkp->ws16 || sdkp->ws10 || sdkp->device->no_report_opcodes)
+		sdkp->max_ws_blocks = min_not_zero(sdkp->max_ws_blocks,
+						   (u32)SD_MAX_WS10_BLOCKS);
+	else {
+		sdkp->device->no_write_same = 1;
+		sdkp->max_ws_blocks = 0;
+	}
 
 out:
-	blk_queue_max_write_same_sectors(q, blocks * (logical_block_size >> 9));
+	blk_queue_max_write_same_sectors(q, sdkp->max_ws_blocks *
+					 (logical_block_size >> 9));
 }
 
 /**
@@ -2635,9 +2648,24 @@ static void sd_read_block_provisioning(struct scsi_disk *sdkp)
 
 static void sd_read_write_same(struct scsi_disk *sdkp, unsigned char *buffer)
 {
-	if (scsi_report_opcode(sdkp->device, buffer, SD_BUF_SIZE,
-			       WRITE_SAME_16))
+	struct scsi_device *sdev = sdkp->device;
+
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, INQUIRY) < 0) {
+		sdev->no_report_opcodes = 1;
+
+		/* Disable WRITE SAME if REPORT SUPPORTED OPERATION
+		 * CODES is unsupported and the device has an ATA
+		 * Information VPD page (SAT).
+		 */
+		if (!scsi_get_vpd_page(sdev, 0x89, buffer, SD_BUF_SIZE))
+			sdev->no_write_same = 1;
+	}
+
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME_16) == 1)
 		sdkp->ws16 = 1;
+
+	if (scsi_report_opcode(sdev, buffer, SD_BUF_SIZE, WRITE_SAME) == 1)
+		sdkp->ws10 = 1;
 }
 
 static int sd_try_extended_inquiry(struct scsi_device *sdp)
@@ -2970,8 +2998,10 @@ static int sd_probe(struct device *dev)
 static int sd_remove(struct device *dev)
 {
 	struct scsi_disk *sdkp;
+	dev_t devt;
 
 	sdkp = dev_get_drvdata(dev);
+	devt = disk_devt(sdkp->disk);
 	scsi_autopm_get_device(sdkp->device);
 
 	async_synchronize_full_domain(&scsi_sd_probe_domain);
@@ -2981,6 +3011,9 @@ static int sd_remove(struct device *dev)
 	del_gendisk(sdkp->disk);
 	sd_shutdown(dev);
 
+	blk_register_region(devt, SD_MINORS, NULL,
+			    sd_default_probe, NULL, NULL);
+
 	mutex_lock(&sd_ref_mutex);
 	dev_set_drvdata(dev, NULL);
 	put_device(&sdkp->dev);
@@ -3124,9 +3157,13 @@ static int __init init_sd(void)
 
 	SCSI_LOG_HLQUEUE(3, printk("init_sd: sd driver entry point\n"));
 
-	for (i = 0; i < SD_MAJORS; i++)
-		if (register_blkdev(sd_major(i), "sd") == 0)
-			majors++;
+	for (i = 0; i < SD_MAJORS; i++) {
+		if (register_blkdev(sd_major(i), "sd") != 0)
+			continue;
+		majors++;
+		blk_register_region(sd_major(i), SD_MINORS, NULL,
+				    sd_default_probe, NULL, NULL);
+	}
 
 	if (!majors)
 		return -ENODEV;
@@ -3185,8 +3222,10 @@ static void __exit exit_sd(void)
 
 	class_unregister(&sd_disk_class);
 
-	for (i = 0; i < SD_MAJORS; i++)
+	for (i = 0; i < SD_MAJORS; i++) {
+		blk_unregister_region(sd_major(i), SD_MINORS);
 		unregister_blkdev(sd_major(i), "sd");
+	}
 }
 
 module_init(init_sd);