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Message-Id: <1288637081-5183-7-git-send-email-tj@kernel.org>
Date: Mon, 1 Nov 2010 19:44:40 +0100
From: Tejun Heo <tj@...nel.org>
To: axboe@...nel.dk, linux-kernel@...r.kernel.org,
linux-scsi@...r.kernel.org, kay.sievers@...y.org, jack@...e.cz,
James.Bottomley@...senPartnership.com
Cc: Tejun Heo <tj@...nel.org>
Subject: [PATCH 6/7] sr: implement sr_check_events()
Replace sr_media_change() with sr_check_events(). It normally only
uses GET_EVENT_STATUS_NOTIFICATION to check both media change and
eject request. If @clearing includes DISK_EVENT_MEDIA_CHANGE, it
issues TUR and compares whether media presence has changed. The SCSI
specific media change uevent is kept for compatibility.
sr_media_change() was doing both media change check and revalidation.
The revalidation part is split into sr_block_revalidate_disk().
Signed-off-by: Tejun Heo <tj@...nel.org>
Cc: Kay Sievers <kay.sievers@...y.org>
---
drivers/scsi/sr.c | 149 +++++++++++++++++++++++++++++++++------------------
drivers/scsi/sr.h | 2 +-
include/scsi/scsi.h | 1 +
3 files changed, 98 insertions(+), 54 deletions(-)
diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
index 63cdbc6..edda30d 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,
@@ -165,65 +166,90 @@ static void scsi_cd_put(struct scsi_cd *cd)
mutex_unlock(&sr_ref_mutex);
}
+static unsigned int sr_get_events(struct scsi_device *sdev)
+{
+ 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;
+
+ 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 = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES,
- sshdr);
- if (host_byte(retval) || (scsi_sense_valid(sshdr) &&
- /* ASC 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);
- 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);
+ /*
+ * 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);
+ cd->media_present = !(host_byte(ret) || (scsi_sense_valid(&sshdr) &&
+ sshdr.asc == 0x3a));
+ 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.
*
@@ -508,10 +534,25 @@ 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 =
@@ -520,7 +561,8 @@ 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.
@@ -593,6 +635,7 @@ 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);
@@ -602,7 +645,7 @@ 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 = 0;
cd->use = 1;
cd->readcd_known = 0;
cd->readcd_cdda = 0;
diff --git a/drivers/scsi/sr.h b/drivers/scsi/sr.h
index 81fbc0b..e036f1d 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 */
diff --git a/include/scsi/scsi.h b/include/scsi/scsi.h
index 216af85..8675861 100644
--- a/include/scsi/scsi.h
+++ b/include/scsi/scsi.h
@@ -104,6 +104,7 @@ struct scsi_cmnd;
#define UNMAP 0x42
#define READ_TOC 0x43
#define READ_HEADER 0x44
+#define GET_EVENT_STATUS_NOTIFICATION 0x4a
#define LOG_SELECT 0x4c
#define LOG_SENSE 0x4d
#define XDWRITEREAD_10 0x53
--
1.7.1
--
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