1 files changed, 17 insertions, 9 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index ec80a0077ace..cad9ef012a14 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1276,11 +1276,6 @@ static void sd_release(struct gendisk *disk, fmode_t mode)
 			scsi_set_medium_removal(sdev, SCSI_REMOVAL_ALLOW);
 	}
 
-	/*
-	 * XXX and what if there are packets in flight and this close()
-	 * XXX is followed by a "rmmod sd_mod"?
-	 */
-
 	scsi_disk_put(sdkp);
 }
 
@@ -2003,8 +1998,10 @@ static int sd_read_protection_type(struct scsi_disk *sdkp, unsigned char *buffer
 	u8 type;
 	int ret = 0;
 
-	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0)
+	if (scsi_device_protection(sdp) == 0 || (buffer[12] & 1) == 0) {
+		sdkp->protection_type = 0;
 		return ret;
+	}
 
 	type = ((buffer[12] >> 1) & 7) + 1; /* P_TYPE 0 = Type 1 */
 
@@ -2401,7 +2398,6 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
 	int res;
 	struct scsi_device *sdp = sdkp->device;
 	struct scsi_mode_data data;
-	int disk_ro = get_disk_ro(sdkp->disk);
 	int old_wp = sdkp->write_prot;
 
 	set_disk_ro(sdkp->disk, 0);
@@ -2442,7 +2438,7 @@ sd_read_write_protect_flag(struct scsi_disk *sdkp, unsigned char *buffer)
 			  "Test WP failed, assume Write Enabled\n");
 	} else {
 		sdkp->write_prot = ((data.device_specific & 0x80) != 0);
-		set_disk_ro(sdkp->disk, sdkp->write_prot || disk_ro);
+		set_disk_ro(sdkp->disk, sdkp->write_prot);
 		if (sdkp->first_scan || old_wp != sdkp->write_prot) {
 			sd_printk(KERN_NOTICE, sdkp, "Write Protect is %s\n",
 				  sdkp->write_prot ? "on" : "off");
@@ -3227,11 +3223,23 @@ static void scsi_disk_release(struct device *dev)
 {
 	struct scsi_disk *sdkp = to_scsi_disk(dev);
 	struct gendisk *disk = sdkp->disk;
-	
+	struct request_queue *q = disk->queue;
+
 	spin_lock(&sd_index_lock);
 	ida_remove(&sd_index_ida, sdkp->index);
 	spin_unlock(&sd_index_lock);
 
+	/*
+	 * Wait until all requests that are in progress have completed.
+	 * This is necessary to avoid that e.g. scsi_end_request() crashes
+	 * due to clearing the disk->private_data pointer. Wait from inside
+	 * scsi_disk_release() instead of from sd_release() to avoid that
+	 * freezing and unfreezing the request queue affects user space I/O
+	 * in case multiple processes open a /dev/sd... node concurrently.
+	 */
+	blk_mq_freeze_queue(q);
+	blk_mq_unfreeze_queue(q);
+
 	disk->private_data = NULL;
 	put_disk(disk);
 	put_device(&sdkp->device->sdev_gendev);