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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@kernel.org>
Cc: Kay Sievers <kay.sievers@vrfy.org>
Signed-off-by: Jens Axboe <jaxboe@fusionio.com>
This commit is contained in:
Tejun Heo 2010-12-16 17:52:17 +01:00 committed by Jens Axboe
parent 9f8a2c23c6
commit 93aae17af1
3 changed files with 100 additions and 54 deletions
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145
drivers/scsi/sr.c
View File

@ -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,
@ -165,67 +166,94 @@ static void scsi_cd_put(struct scsi_cd *cd)
mutex_unlock(&sr_ref_mutex);
}
/*
* 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.
*/
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;
static int sr_media_change(struct cdrom_device_info *cdi, int slot)
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 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 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;
}
if (CDSL_CURRENT != slot)
return 0;
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);
sshdr = kzalloc(sizeof(*sshdr), GFP_KERNEL);
retval = 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).
*/
if (!scsi_status_is_good(retval) &&
(!scsi_sense_valid(sshdr) || sshdr->asc == 0x3a)) {
/*
* Probably no media in the device. 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;
};
cd->media_present = scsi_status_is_good(ret) ||
(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
retval = cd->device->changed;
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;
/* 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);
}
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;
}
/*
@ -512,10 +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 =
@ -524,7 +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.
@ -597,6 +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);
@ -606,7 +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;

2
drivers/scsi/sr.h
View File

@ -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 */

1
include/scsi/scsi.h
View File

@ -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