1 files changed, 109 insertions, 69 deletions

diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 956496182c8..e56730214c0 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -583,7 +583,7 @@ static int sd_prep_fn(struct request_queue *q, struct request *rq)
 		 * quietly refuse to do anything to a changed disc until 
 		 * the changed bit has been reset
 		 */
-		/* printk("SCSI disk has been changed. Prohibiting further I/O.\n"); */
+		/* printk("SCSI disk has been changed or is not present. Prohibiting further I/O.\n"); */
 		goto out;
 	}
 
@@ -990,30 +990,51 @@ out:
 
 static void set_media_not_present(struct scsi_disk *sdkp)
 {
-	sdkp->media_present = 0;
-	sdkp->capacity = 0;
-	sdkp->device->changed = 1;
+	if (sdkp->media_present)
+		sdkp->device->changed = 1;
+
+	if (sdkp->device->removable) {
+		sdkp->media_present = 0;
+		sdkp->capacity = 0;
+	}
+}
+
+static int media_not_present(struct scsi_disk *sdkp,
+			     struct scsi_sense_hdr *sshdr)
+{
+	if (!scsi_sense_valid(sshdr))
+		return 0;
+
+	/* not invoked for commands that could return deferred errors */
+	switch (sshdr->sense_key) {
+	case UNIT_ATTENTION:
+	case NOT_READY:
+		/* medium not present */
+		if (sshdr->asc == 0x3A) {
+			set_media_not_present(sdkp);
+			return 1;
+		}
+	}
+	return 0;
 }
 
 /**
- *	sd_media_changed - check if our medium changed
- *	@disk: kernel device descriptor 
+ *	sd_check_events - check media events
+ *	@disk: kernel device descriptor
+ *	@clearing: disk events currently being cleared
  *
- *	Returns 0 if not applicable or no change; 1 if change
+ *	Returns mask of DISK_EVENT_*.
  *
  *	Note: this function is invoked from the block subsystem.
  **/
-static int sd_media_changed(struct gendisk *disk)
+static unsigned int sd_check_events(struct gendisk *disk, unsigned int clearing)
 {
 	struct scsi_disk *sdkp = scsi_disk(disk);
 	struct scsi_device *sdp = sdkp->device;
 	struct scsi_sense_hdr *sshdr = NULL;
 	int retval;
 
-	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_media_changed\n"));
-
-	if (!sdp->removable)
-		return 0;
+	SCSI_LOG_HLQUEUE(3, sd_printk(KERN_INFO, sdkp, "sd_check_events\n"));
 
 	/*
 	 * If the device is offline, don't send any commands - just pretend as
@@ -1023,7 +1044,6 @@ static int sd_media_changed(struct gendisk *disk)
 	 */
 	if (!scsi_device_online(sdp)) {
 		set_media_not_present(sdkp);
-		retval = 1;
 		goto out;
 	}
 
@@ -1044,34 +1064,32 @@ static int sd_media_changed(struct gendisk *disk)
 					      sshdr);
 	}
 
-	/*
-	 * Unable to test, unit probably not ready.   This usually
-	 * means there is no disc in the drive.  Mark as changed,
-	 * and we will figure it out later once the drive is
-	 * available again.
-	 */
-	if (retval || (scsi_sense_valid(sshdr) &&
-		       /* 0x3a is medium not present */
-		       sshdr->asc == 0x3a)) {
+	/* failed to execute TUR, assume media not present */
+	if (host_byte(retval)) {
 		set_media_not_present(sdkp);
-		retval = 1;
 		goto out;
 	}
 
+	if (media_not_present(sdkp, sshdr))
+		goto out;
+
 	/*
 	 * For removable scsi disk we have to recognise the presence
-	 * of a disk in the drive. This is kept in the struct scsi_disk
-	 * struct and tested at open !  Daniel Roche (dan@lectra.fr)
+	 * of a disk in the drive.
 	 */
+	if (!sdkp->media_present)
+		sdp->changed = 1;
 	sdkp->media_present = 1;
-
-	retval = sdp->changed;
-	sdp->changed = 0;
 out:
-	if (retval != sdkp->previous_state)
-		sdev_evt_send_simple(sdp, SDEV_EVT_MEDIA_CHANGE, GFP_KERNEL);
-	sdkp->previous_state = retval;
+	/*
+	 * sdp->changed is set under the following conditions:
+	 *
+	 *	Medium present state has changed in either direction.
+	 *	Device has indicated UNIT_ATTENTION.
+	 */
 	kfree(sshdr);
+	retval = sdp->changed ? DISK_EVENT_MEDIA_CHANGE : 0;
+	sdp->changed = 0;
 	return retval;
 }
 
@@ -1164,7 +1182,7 @@ static const struct block_device_operations sd_fops = {
 #ifdef CONFIG_COMPAT
 	.compat_ioctl		= sd_compat_ioctl,
 #endif
-	.media_changed		= sd_media_changed,
+	.check_events		= sd_check_events,
 	.revalidate_disk	= sd_revalidate_disk,
 	.unlock_native_capacity	= sd_unlock_native_capacity,
 };
@@ -1175,6 +1193,12 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 	u64 end_lba = blk_rq_pos(scmd->request) + (scsi_bufflen(scmd) / 512);
 	u64 bad_lba;
 	int info_valid;
+	/*
+	 * resid is optional but mostly filled in.  When it's unused,
+	 * its value is zero, so we assume the whole buffer transferred
+	 */
+	unsigned int transferred = scsi_bufflen(scmd) - scsi_get_resid(scmd);
+	unsigned int good_bytes;
 
 	if (scmd->request->cmd_type != REQ_TYPE_FS)
 		return 0;
@@ -1208,7 +1232,8 @@ static unsigned int sd_completed_bytes(struct scsi_cmnd *scmd)
 	/* This computation should always be done in terms of
 	 * the resolution of the device's medium.
 	 */
-	return (bad_lba - start_lba) * scmd->device->sector_size;
+	good_bytes = (bad_lba - start_lba) * scmd->device->sector_size;
+	return min(good_bytes, transferred);
 }
 
 /**
@@ -1300,23 +1325,6 @@ static int sd_done(struct scsi_cmnd *SCpnt)
 	return good_bytes;
 }
 
-static int media_not_present(struct scsi_disk *sdkp,
-			     struct scsi_sense_hdr *sshdr)
-{
-
-	if (!scsi_sense_valid(sshdr))
-		return 0;
-	/* not invoked for commands that could return deferred errors */
-	if (sshdr->sense_key != NOT_READY &&
-	    sshdr->sense_key != UNIT_ATTENTION)
-		return 0;
-	if (sshdr->asc != 0x3A) /* medium not present */
-		return 0;
-
-	set_media_not_present(sdkp);
-	return 1;
-}
-
 /*
  * spinup disk - called only in sd_revalidate_disk()
  */
@@ -1491,7 +1499,7 @@ static void read_capacity_error(struct scsi_disk *sdkp, struct scsi_device *sdp,
 	 */
 	if (sdp->removable &&
 	    sense_valid && sshdr->sense_key == NOT_READY)
-		sdp->changed = 1;
+		set_media_not_present(sdkp);
 
 	/*
 	 * We used to set media_present to 0 here to indicate no media
@@ -1902,10 +1910,14 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 	int old_rcd = sdkp->RCD;
 	int old_dpofua = sdkp->DPOFUA;
 
-	if (sdp->skip_ms_page_8)
-		goto defaults;
-
-	if (sdp->type == TYPE_RBC) {
+	if (sdp->skip_ms_page_8) {
+		if (sdp->type == TYPE_RBC)
+			goto defaults;
+		else {
+			modepage = 0x3F;
+			dbd = 0;
+		}
+	} else if (sdp->type == TYPE_RBC) {
 		modepage = 6;
 		dbd = 8;
 	} else {
@@ -1933,13 +1945,11 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 	 */
 	if (len < 3)
 		goto bad_sense;
-	if (len > 20)
-		len = 20;
-
-	/* Take headers and block descriptors into account */
-	len += data.header_length + data.block_descriptor_length;
-	if (len > SD_BUF_SIZE)
-		goto bad_sense;
+	else if (len > SD_BUF_SIZE) {
+		sd_printk(KERN_NOTICE, sdkp, "Truncating mode parameter "
+			  "data from %d to %d bytes\n", len, SD_BUF_SIZE);
+		len = SD_BUF_SIZE;
+	}
 
 	/* Get the data */
 	res = sd_do_mode_sense(sdp, dbd, modepage, buffer, len, &data, &sshdr);
@@ -1947,16 +1957,45 @@ sd_read_cache_type(struct scsi_disk *sdkp, unsigned char *buffer)
 	if (scsi_status_is_good(res)) {
 		int offset = data.header_length + data.block_descriptor_length;
 
-		if (offset >= SD_BUF_SIZE - 2) {
-			sd_printk(KERN_ERR, sdkp, "Malformed MODE SENSE response\n");
-			goto defaults;
+		while (offset < len) {
+			u8 page_code = buffer[offset] & 0x3F;
+			u8 spf       = buffer[offset] & 0x40;
+
+			if (page_code == 8 || page_code == 6) {
+				/* We're interested only in the first 3 bytes.
+				 */
+				if (len - offset <= 2) {
+					sd_printk(KERN_ERR, sdkp, "Incomplete "
+						  "mode parameter data\n");
+					goto defaults;
+				} else {
+					modepage = page_code;
+					goto Page_found;
+				}
+			} else {
+				/* Go to the next page */
+				if (spf && len - offset > 3)
+					offset += 4 + (buffer[offset+2] << 8) +
+						buffer[offset+3];
+				else if (!spf && len - offset > 1)
+					offset += 2 + buffer[offset+1];
+				else {
+					sd_printk(KERN_ERR, sdkp, "Incomplete "
+						  "mode parameter data\n");
+					goto defaults;
+				}
+			}
 		}
 
-		if ((buffer[offset] & 0x3f) != modepage) {
+		if (modepage == 0x3F) {
+			sd_printk(KERN_ERR, sdkp, "No Caching mode page "
+				  "present\n");
+			goto defaults;
+		} else if ((buffer[offset] & 0x3f) != modepage) {
 			sd_printk(KERN_ERR, sdkp, "Got wrong page\n");
 			goto defaults;
 		}
-
+	Page_found:
 		if (modepage == 8) {
 			sdkp->WCE = ((buffer[offset + 2] & 0x04) != 0);
 			sdkp->RCD = ((buffer[offset + 2] & 0x01) != 0);
@@ -2346,8 +2385,10 @@ static void sd_probe_async(void *data, async_cookie_t cookie)
 
 	gd->driverfs_dev = &sdp->sdev_gendev;
 	gd->flags = GENHD_FL_EXT_DEVT;
-	if (sdp->removable)
+	if (sdp->removable) {
 		gd->flags |= GENHD_FL_REMOVABLE;
+		gd->events |= DISK_EVENT_MEDIA_CHANGE;
+	}
 
 	add_disk(gd);
 	sd_dif_config_host(sdkp);
@@ -2429,7 +2470,6 @@ static int sd_probe(struct device *dev)
 	sdkp->disk = gd;
 	sdkp->index = index;
 	atomic_set(&sdkp->openers, 0);
-	sdkp->previous_state = 1;
 
 	if (!sdp->request_queue->rq_timeout) {
 		if (sdp->type != TYPE_MOD)