Merge branch 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block

* 'for-2.6.38/core' of git://git.kernel.dk/linux-2.6-block: (43 commits)
  block: ensure that completion error gets properly traced
  blktrace: add missing probe argument to block_bio_complete
  block cfq: don't use atomic_t for cfq_group
  block cfq: don't use atomic_t for cfq_queue
  block: trace event block fix unassigned field
  block: add internal hd part table references
  block: fix accounting bug on cross partition merges
  kref: add kref_test_and_get
  bio-integrity: mark kintegrityd_wq highpri and CPU intensive
  block: make kblockd_workqueue smarter
  Revert "sd: implement sd_check_events()"
  block: Clean up exit_io_context() source code.
  Fix compile warnings due to missing removal of a 'ret' variable
  fs/block: type signature of major_to_index(int) to major_to_index(unsigned)
  block: convert !IS_ERR(p) && p to !IS_ERR_NOR_NULL(p)
  cfq-iosched: don't check cfqg in choose_service_tree()
  fs/splice: Pull buf->ops->confirm() from splice_from_pipe actors
  cdrom: export cdrom_check_events()
  sd: implement sd_check_events()
  sr: implement sr_check_events()
  ...

5 files changed, 103 insertions, 99 deletions

diff --git a/drivers/scsi/scsi_lib.c b/drivers/scsi/scsi_lib.c
index 501f67bef71..9045c52abd2 100644
--- a/drivers/scsi/scsi_lib.c
+++ b/drivers/scsi/scsi_lib.c
@@ -1977,8 +1977,7 @@ EXPORT_SYMBOL(scsi_mode_sense);
  *		in.
  *
  *	Returns zero if unsuccessful or an error if TUR failed.  For
- *	removable media, a return of NOT_READY or UNIT_ATTENTION is
- *	translated to success, with the ->changed flag updated.
+ *	removable media, UNIT_ATTENTION sets ->changed flag.
  **/
 int
 scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
@@ -2005,16 +2004,6 @@ scsi_test_unit_ready(struct scsi_device *sdev, int timeout, int retries,
 	} while (scsi_sense_valid(sshdr) &&
 		 sshdr->sense_key == UNIT_ATTENTION && --retries);
 
-	if (!sshdr)
-		/* could not allocate sense buffer, so can't process it */
-		return result;
-
-	if (sdev->removable && scsi_sense_valid(sshdr) &&
-	    (sshdr->sense_key == UNIT_ATTENTION ||
-	     sshdr->sense_key == NOT_READY)) {
-		sdev->changed = 1;
-		result = 0;
-	}
 	if (!sshdr_external)
 		kfree(sshdr);
 	return result;
diff --git a/drivers/scsi/sd.c b/drivers/scsi/sd.c
index 365024b0c40..b65e65aa07e 100644
--- a/drivers/scsi/sd.c
+++ b/drivers/scsi/sd.c
@@ -1043,15 +1043,7 @@ 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)) {
+	if (retval) {
 		set_media_not_present(sdkp);
 		goto out;
 	}
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index d7b383c96d5..be6baf8ad70 100644
--- a/drivers/scsi/sr.c
+++ b/drivers/scsi/sr.c
@@ -104,14 +104,15 @@ static void sr_release(struct cdrom_device_info *);
 static void get_sectorsize(struct scsi_cd *);
 static void get_capabilities(struct scsi_cd *);
 
-static int sr_media_change(struct cdrom_device_info *, int);
+static unsigned int sr_check_events(struct cdrom_device_info *cdi,
+				    unsigned int clearing, int slot);
 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 
 static struct cdrom_device_ops sr_dops = {
 	.open			= sr_open,
 	.release	 	= sr_release,
 	.drive_status	 	= sr_drive_status,
-	.media_changed		= sr_media_change,
+	.check_events		= sr_check_events,
 	.tray_move		= sr_tray_move,
 	.lock_door		= sr_lock_door,
 	.select_speed		= sr_select_speed,
@@ -165,90 +166,96 @@ static void scsi_cd_put(struct scsi_cd *cd)
 	mutex_unlock(&sr_ref_mutex);
 }
 
-/* identical to scsi_test_unit_ready except that it doesn't
- * eat the NOT_READY returns for removable media */
-int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr)
+static unsigned int sr_get_events(struct scsi_device *sdev)
 {
-	int retries = MAX_RETRIES;
-	int the_result;
-	u8 cmd[] = {TEST_UNIT_READY, 0, 0, 0, 0, 0 };
+	u8 buf[8];
+	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
+		     1,			/* polled */
+		     0, 0,		/* reserved */
+		     1 << 4,		/* notification class: media */
+		     0, 0,		/* reserved */
+		     0, sizeof(buf),	/* allocation length */
+		     0,			/* control */
+	};
+	struct event_header *eh = (void *)buf;
+	struct media_event_desc *med = (void *)(buf + 4);
+	struct scsi_sense_hdr sshdr;
+	int result;
 
-	/* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
-	 * conditions are gone, or a timeout happens
-	 */
-	do {
-		the_result = scsi_execute_req(sdev, cmd, DMA_NONE, NULL,
-					      0, sshdr, SR_TIMEOUT,
-					      retries--, NULL);
-		if (scsi_sense_valid(sshdr) &&
-		    sshdr->sense_key == UNIT_ATTENTION)
-			sdev->changed = 1;
-
-	} while (retries > 0 &&
-		 (!scsi_status_is_good(the_result) ||
-		  (scsi_sense_valid(sshdr) &&
-		   sshdr->sense_key == UNIT_ATTENTION)));
-	return the_result;
+	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
+				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
+	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
+		return DISK_EVENT_MEDIA_CHANGE;
+
+	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
+		return 0;
+
+	if (eh->nea || eh->notification_class != 0x4)
+		return 0;
+
+	if (med->media_event_code == 1)
+		return DISK_EVENT_EJECT_REQUEST;
+	else if (med->media_event_code == 2)
+		return DISK_EVENT_MEDIA_CHANGE;
+	return 0;
 }
 
 /*
- * This function checks to see if the media has been changed in the
- * CDROM drive.  It is possible that we have already sensed a change,
- * or the drive may have sensed one and not yet reported it.  We must
- * be ready for either case. This function always reports the current
- * value of the changed bit.  If flag is 0, then the changed bit is reset.
- * This function could be done as an ioctl, but we would need to have
- * an inode for that to work, and we do not always have one.
+ * This function checks to see if the media has been changed or eject
+ * button has been pressed.  It is possible that we have already
+ * sensed a change, or the drive may have sensed one and not yet
+ * reported it.  The past events are accumulated in sdev->changed and
+ * returned together with the current state.
  */
-
-static int sr_media_change(struct cdrom_device_info *cdi, int slot)
+static unsigned int sr_check_events(struct cdrom_device_info *cdi,
+				    unsigned int clearing, int slot)
 {
 	struct scsi_cd *cd = cdi->handle;
-	int retval;
-	struct scsi_sense_hdr *sshdr;
+	bool last_present;
+	struct scsi_sense_hdr sshdr;
+	unsigned int events;
+	int ret;
 
-	if (CDSL_CURRENT != slot) {
-		/* no changer support */
-		return -EINVAL;
-	}
+	/* no changer support */
+	if (CDSL_CURRENT != slot)
+		return 0;
 
-	sshdr =  kzalloc(sizeof(*sshdr), GFP_KERNEL);
-	retval = sr_test_unit_ready(cd->device, sshdr);
-	if (retval || (scsi_sense_valid(sshdr) &&
-		       /* 0x3a is medium not present */
-		       sshdr->asc == 0x3a)) {
-		/* Media not present or 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.
-		 */
-		cd->device->changed = 1;
-		/* This will force a flush, if called from check_disk_change */
-		retval = 1;
-		goto out;
-	};
+	events = sr_get_events(cd->device);
+	/*
+	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
+	 * is being cleared.  Note that there are devices which hang
+	 * if asked to execute TUR repeatedly.
+	 */
+	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
+		goto skip_tur;
+
+	/* let's see whether the media is there with TUR */
+	last_present = cd->media_present;
+	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
+
+	/*
+	 * Media is considered to be present if TUR succeeds or fails with
+	 * sense data indicating something other than media-not-present
+	 * (ASC 0x3a).
+	 */
+	cd->media_present = scsi_status_is_good(ret) ||
+		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 
-	retval = cd->device->changed;
-	cd->device->changed = 0;
-	/* If the disk changed, the capacity will now be different,
-	 * so we force a re-read of this information */
-	if (retval) {
-		/* check multisession offset etc */
-		sr_cd_check(cdi);
-		get_sectorsize(cd);
+	if (last_present != cd->media_present)
+		events |= DISK_EVENT_MEDIA_CHANGE;
+skip_tur:
+	if (cd->device->changed) {
+		events |= DISK_EVENT_MEDIA_CHANGE;
+		cd->device->changed = 0;
 	}
 
-out:
-	/* Notify userspace, that media has changed. */
-	if (retval != cd->previous_state)
+	/* for backward compatibility */
+	if (events & DISK_EVENT_MEDIA_CHANGE)
 		sdev_evt_send_simple(cd->device, SDEV_EVT_MEDIA_CHANGE,
 				     GFP_KERNEL);
-	cd->previous_state = retval;
-	kfree(sshdr);
-
-	return retval;
+	return events;
 }
- 
+
 /*
  * sr_done is the interrupt routine for the device driver.
  *
@@ -533,10 +540,25 @@ out:
 	return ret;
 }
 
-static int sr_block_media_changed(struct gendisk *disk)
+static unsigned int sr_block_check_events(struct gendisk *disk,
+					  unsigned int clearing)
 {
 	struct scsi_cd *cd = scsi_cd(disk);
-	return cdrom_media_changed(&cd->cdi);
+	return cdrom_check_events(&cd->cdi, clearing);
+}
+
+static int sr_block_revalidate_disk(struct gendisk *disk)
+{
+	struct scsi_cd *cd = scsi_cd(disk);
+	struct scsi_sense_hdr sshdr;
+
+	/* if the unit is not ready, nothing more to do */
+	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
+		return 0;
+
+	sr_cd_check(&cd->cdi);
+	get_sectorsize(cd);
+	return 0;
 }
 
 static const struct block_device_operations sr_bdops =
@@ -545,7 +567,8 @@ static const struct block_device_operations sr_bdops =
 	.open		= sr_block_open,
 	.release	= sr_block_release,
 	.ioctl		= sr_block_ioctl,
-	.media_changed	= sr_block_media_changed,
+	.check_events	= sr_block_check_events,
+	.revalidate_disk = sr_block_revalidate_disk,
 	/* 
 	 * No compat_ioctl for now because sr_block_ioctl never
 	 * seems to pass arbitary ioctls down to host drivers.
@@ -618,6 +641,7 @@ static int sr_probe(struct device *dev)
 	sprintf(disk->disk_name, "sr%d", minor);
 	disk->fops = &sr_bdops;
 	disk->flags = GENHD_FL_CD;
+	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 
 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 
@@ -627,7 +651,7 @@ static int sr_probe(struct device *dev)
 	cd->disk = disk;
 	cd->capacity = 0x1fffff;
 	cd->device->changed = 1;	/* force recheck CD type */
-	cd->previous_state = 1;
+	cd->media_present = 1;
 	cd->use = 1;
 	cd->readcd_known = 0;
 	cd->readcd_cdda = 0;
@@ -780,7 +804,7 @@ static void get_capabilities(struct scsi_cd *cd)
 	}
 
 	/* eat unit attentions */
-	sr_test_unit_ready(cd->device, &sshdr);
+	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 
 	/* ask for mode page 0x2a */
 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
diff --git a/drivers/scsi/sr.h b/drivers/scsi/sr.h
index 1e144dfdbd4..e036f1dc83c 100644
--- a/drivers/scsi/sr.h
+++ b/drivers/scsi/sr.h
@@ -40,7 +40,7 @@ typedef struct scsi_cd {
 	unsigned xa_flag:1;	/* CD has XA sectors ? */
 	unsigned readcd_known:1;	/* drive supports READ_CD (0xbe) */
 	unsigned readcd_cdda:1;	/* reading audio data using READ_CD */
-	unsigned previous_state:1;	/* media has changed */
+	unsigned media_present:1;	/* media is present */
 	struct cdrom_device_info cdi;
 	/* We hold gendisk and scsi_device references on probe and use
 	 * the refs on this kref to decide when to release them */
@@ -61,7 +61,6 @@ int sr_select_speed(struct cdrom_device_info *cdi, int speed);
 int sr_audio_ioctl(struct cdrom_device_info *, unsigned int, void *);
 
 int sr_is_xa(Scsi_CD *);
-int sr_test_unit_ready(struct scsi_device *sdev, struct scsi_sense_hdr *sshdr);
 
 /* sr_vendor.c */
 void sr_vendor_init(Scsi_CD *);
diff --git a/drivers/scsi/sr_ioctl.c b/drivers/scsi/sr_ioctl.c
index 3cd8ffbad57..8be30554119 100644
--- a/drivers/scsi/sr_ioctl.c
+++ b/drivers/scsi/sr_ioctl.c
@@ -307,7 +307,7 @@ int sr_drive_status(struct cdrom_device_info *cdi, int slot)
 		/* we have no changer support */
 		return -EINVAL;
 	}
-	if (0 == sr_test_unit_ready(cd->device, &sshdr))
+	if (!scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 		return CDS_DISC_OK;
 
 	/* SK/ASC/ASCQ of 2/4/1 means "unit is becoming ready" */