linux/drivers/scsi/sr.c
Alan Stern 13b4389143 SCSI: fix crashes in sd and sr runtime PM
Runtime suspend during driver probe and removal can cause problems.
The driver's runtime_suspend or runtime_resume callbacks may invoked
before the driver has finished binding to the device or after the
driver has unbound from the device.

This problem shows up with the sd and sr drivers, and can cause disk
or CD/DVD drives to become unusable as a result.  The fix is simple.
The drivers store a pointer to the scsi_disk or scsi_cd structure as
their private device data when probing is finished, so we simply have
to be sure to clear the private data during removal and test it during
runtime suspend/resume.

This fixes <https://bugs.debian.org/801925>.

Signed-off-by: Alan Stern <stern@rowland.harvard.edu>
Reported-by: Paul Menzel <paul.menzel@giantmonkey.de>
Reported-by: Erich Schubert <erich@debian.org>
Reported-by: Alexandre Rossi <alexandre.rossi@gmail.com>
Tested-by: Paul Menzel <paul.menzel@giantmonkey.de>
Tested-by: Erich Schubert <erich@debian.org>
CC: <stable@vger.kernel.org>
Signed-off-by: James Bottomley <James.Bottomley@HansenPartnership.com>
2016-01-26 17:24:16 -08:00

1023 lines
25 KiB
C

/*
* sr.c Copyright (C) 1992 David Giller
* Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
*
* adapted from:
* sd.c Copyright (C) 1992 Drew Eckhardt
* Linux scsi disk driver by
* Drew Eckhardt <drew@colorado.edu>
*
* Modified by Eric Youngdale ericy@andante.org to
* add scatter-gather, multiple outstanding request, and other
* enhancements.
*
* Modified by Eric Youngdale eric@andante.org to support loadable
* low-level scsi drivers.
*
* Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
* provide auto-eject.
*
* Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
* generic cdrom interface
*
* Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
* interface, capabilities probe additions, ioctl cleanups, etc.
*
* Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
*
* Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
* transparently and lose the GHOST hack
*
* Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
* check resource allocation in sr_init and some cleanups
*/
#include <linux/module.h>
#include <linux/fs.h>
#include <linux/kernel.h>
#include <linux/mm.h>
#include <linux/bio.h>
#include <linux/string.h>
#include <linux/errno.h>
#include <linux/cdrom.h>
#include <linux/interrupt.h>
#include <linux/init.h>
#include <linux/blkdev.h>
#include <linux/mutex.h>
#include <linux/slab.h>
#include <linux/pm_runtime.h>
#include <asm/uaccess.h>
#include <scsi/scsi.h>
#include <scsi/scsi_dbg.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_driver.h>
#include <scsi/scsi_cmnd.h>
#include <scsi/scsi_eh.h>
#include <scsi/scsi_host.h>
#include <scsi/scsi_ioctl.h> /* For the door lock/unlock commands */
#include "scsi_logging.h"
#include "sr.h"
MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
MODULE_LICENSE("GPL");
MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
#define SR_DISKS 256
#define SR_CAPABILITIES \
(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
CDC_MRW|CDC_MRW_W|CDC_RAM)
static DEFINE_MUTEX(sr_mutex);
static int sr_probe(struct device *);
static int sr_remove(struct device *);
static int sr_init_command(struct scsi_cmnd *SCpnt);
static int sr_done(struct scsi_cmnd *);
static int sr_runtime_suspend(struct device *dev);
static struct dev_pm_ops sr_pm_ops = {
.runtime_suspend = sr_runtime_suspend,
};
static struct scsi_driver sr_template = {
.gendrv = {
.name = "sr",
.owner = THIS_MODULE,
.probe = sr_probe,
.remove = sr_remove,
.pm = &sr_pm_ops,
},
.init_command = sr_init_command,
.done = sr_done,
};
static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
static DEFINE_SPINLOCK(sr_index_lock);
/* This semaphore is used to mediate the 0->1 reference get in the
* face of object destruction (i.e. we can't allow a get on an
* object after last put) */
static DEFINE_MUTEX(sr_ref_mutex);
static int sr_open(struct cdrom_device_info *, int);
static void sr_release(struct cdrom_device_info *);
static void get_sectorsize(struct scsi_cd *);
static void get_capabilities(struct scsi_cd *);
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,
.check_events = sr_check_events,
.tray_move = sr_tray_move,
.lock_door = sr_lock_door,
.select_speed = sr_select_speed,
.get_last_session = sr_get_last_session,
.get_mcn = sr_get_mcn,
.reset = sr_reset,
.audio_ioctl = sr_audio_ioctl,
.capability = SR_CAPABILITIES,
.generic_packet = sr_packet,
};
static void sr_kref_release(struct kref *kref);
static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
{
return container_of(disk->private_data, struct scsi_cd, driver);
}
static int sr_runtime_suspend(struct device *dev)
{
struct scsi_cd *cd = dev_get_drvdata(dev);
if (!cd) /* E.g.: runtime suspend following sr_remove() */
return 0;
if (cd->media_present)
return -EBUSY;
else
return 0;
}
/*
* The get and put routines for the struct scsi_cd. Note this entity
* has a scsi_device pointer and owns a reference to this.
*/
static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
{
struct scsi_cd *cd = NULL;
mutex_lock(&sr_ref_mutex);
if (disk->private_data == NULL)
goto out;
cd = scsi_cd(disk);
kref_get(&cd->kref);
if (scsi_device_get(cd->device)) {
kref_put(&cd->kref, sr_kref_release);
cd = NULL;
}
out:
mutex_unlock(&sr_ref_mutex);
return cd;
}
static void scsi_cd_put(struct scsi_cd *cd)
{
struct scsi_device *sdev = cd->device;
mutex_lock(&sr_ref_mutex);
kref_put(&cd->kref, sr_kref_release);
scsi_device_put(sdev);
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 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;
bool last_present;
struct scsi_sense_hdr sshdr;
unsigned int events;
int ret;
/* no changer support */
if (CDSL_CURRENT != slot)
return 0;
events = sr_get_events(cd->device);
cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
/*
* If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
* for several times in a row. We rely on TUR only for this likely
* broken device, to prevent generating incorrect media changed
* events for every open().
*/
if (cd->ignore_get_event) {
events &= ~DISK_EVENT_MEDIA_CHANGE;
goto do_tur;
}
/*
* 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 (cd->device->changed) {
events |= DISK_EVENT_MEDIA_CHANGE;
cd->device->changed = 0;
cd->tur_changed = true;
}
if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
return events;
do_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);
if (last_present != cd->media_present)
cd->device->changed = 1;
if (cd->device->changed) {
events |= DISK_EVENT_MEDIA_CHANGE;
cd->device->changed = 0;
cd->tur_changed = true;
}
if (cd->ignore_get_event)
return events;
/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
if (!cd->tur_changed) {
if (cd->get_event_changed) {
if (cd->tur_mismatch++ > 8) {
sr_printk(KERN_WARNING, cd,
"GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
cd->ignore_get_event = true;
}
} else {
cd->tur_mismatch = 0;
}
}
cd->tur_changed = false;
cd->get_event_changed = false;
return events;
}
/*
* sr_done is the interrupt routine for the device driver.
*
* It will be notified on the end of a SCSI read / write, and will take one
* of several actions based on success or failure.
*/
static int sr_done(struct scsi_cmnd *SCpnt)
{
int result = SCpnt->result;
int this_count = scsi_bufflen(SCpnt);
int good_bytes = (result == 0 ? this_count : 0);
int block_sectors = 0;
long error_sector;
struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
#ifdef DEBUG
scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
#endif
/*
* Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
* success. Since this is a relatively rare error condition, no
* care is taken to avoid unnecessary additional work such as
* memcpy's that could be avoided.
*/
if (driver_byte(result) != 0 && /* An error occurred */
(SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
switch (SCpnt->sense_buffer[2]) {
case MEDIUM_ERROR:
case VOLUME_OVERFLOW:
case ILLEGAL_REQUEST:
if (!(SCpnt->sense_buffer[0] & 0x90))
break;
error_sector = (SCpnt->sense_buffer[3] << 24) |
(SCpnt->sense_buffer[4] << 16) |
(SCpnt->sense_buffer[5] << 8) |
SCpnt->sense_buffer[6];
if (SCpnt->request->bio != NULL)
block_sectors =
bio_sectors(SCpnt->request->bio);
if (block_sectors < 4)
block_sectors = 4;
if (cd->device->sector_size == 2048)
error_sector <<= 2;
error_sector &= ~(block_sectors - 1);
good_bytes = (error_sector -
blk_rq_pos(SCpnt->request)) << 9;
if (good_bytes < 0 || good_bytes >= this_count)
good_bytes = 0;
/*
* The SCSI specification allows for the value
* returned by READ CAPACITY to be up to 75 2K
* sectors past the last readable block.
* Therefore, if we hit a medium error within the
* last 75 2K sectors, we decrease the saved size
* value.
*/
if (error_sector < get_capacity(cd->disk) &&
cd->capacity - error_sector < 4 * 75)
set_capacity(cd->disk, error_sector);
break;
case RECOVERED_ERROR:
good_bytes = this_count;
break;
default:
break;
}
}
return good_bytes;
}
static int sr_init_command(struct scsi_cmnd *SCpnt)
{
int block = 0, this_count, s_size;
struct scsi_cd *cd;
struct request *rq = SCpnt->request;
int ret;
ret = scsi_init_io(SCpnt);
if (ret != BLKPREP_OK)
goto out;
SCpnt = rq->special;
cd = scsi_cd(rq->rq_disk);
/* from here on until we're complete, any goto out
* is used for a killable error condition */
ret = BLKPREP_KILL;
SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
"Doing sr request, block = %d\n", block));
if (!cd->device || !scsi_device_online(cd->device)) {
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
"Finishing %u sectors\n", blk_rq_sectors(rq)));
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
"Retry with 0x%p\n", SCpnt));
goto out;
}
if (cd->device->changed) {
/*
* quietly refuse to do anything to a changed disc until the
* changed bit has been reset
*/
goto out;
}
/*
* we do lazy blocksize switching (when reading XA sectors,
* see CDROMREADMODE2 ioctl)
*/
s_size = cd->device->sector_size;
if (s_size > 2048) {
if (!in_interrupt())
sr_set_blocklength(cd, 2048);
else
scmd_printk(KERN_INFO, SCpnt,
"can't switch blocksize: in interrupt\n");
}
if (s_size != 512 && s_size != 1024 && s_size != 2048) {
scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
goto out;
}
if (rq_data_dir(rq) == WRITE) {
if (!cd->writeable)
goto out;
SCpnt->cmnd[0] = WRITE_10;
cd->cdi.media_written = 1;
} else if (rq_data_dir(rq) == READ) {
SCpnt->cmnd[0] = READ_10;
} else {
blk_dump_rq_flags(rq, "Unknown sr command");
goto out;
}
{
struct scatterlist *sg;
int i, size = 0, sg_count = scsi_sg_count(SCpnt);
scsi_for_each_sg(SCpnt, sg, sg_count, i)
size += sg->length;
if (size != scsi_bufflen(SCpnt)) {
scmd_printk(KERN_ERR, SCpnt,
"mismatch count %d, bytes %d\n",
size, scsi_bufflen(SCpnt));
if (scsi_bufflen(SCpnt) > size)
SCpnt->sdb.length = size;
}
}
/*
* request doesn't start on hw block boundary, add scatter pads
*/
if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
(scsi_bufflen(SCpnt) % s_size)) {
scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
goto out;
}
this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
"%s %d/%u 512 byte blocks.\n",
(rq_data_dir(rq) == WRITE) ?
"writing" : "reading",
this_count, blk_rq_sectors(rq)));
SCpnt->cmnd[1] = 0;
block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
if (this_count > 0xffff) {
this_count = 0xffff;
SCpnt->sdb.length = this_count * s_size;
}
SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
SCpnt->cmnd[5] = (unsigned char) block & 0xff;
SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
/*
* We shouldn't disconnect in the middle of a sector, so with a dumb
* host adapter, it's safe to assume that we can at least transfer
* this many bytes between each connect / disconnect.
*/
SCpnt->transfersize = cd->device->sector_size;
SCpnt->underflow = this_count << 9;
SCpnt->allowed = MAX_RETRIES;
/*
* This indicates that the command is ready from our end to be
* queued.
*/
ret = BLKPREP_OK;
out:
return ret;
}
static int sr_block_open(struct block_device *bdev, fmode_t mode)
{
struct scsi_cd *cd;
int ret = -ENXIO;
mutex_lock(&sr_mutex);
cd = scsi_cd_get(bdev->bd_disk);
if (cd) {
ret = cdrom_open(&cd->cdi, bdev, mode);
if (ret)
scsi_cd_put(cd);
}
mutex_unlock(&sr_mutex);
return ret;
}
static void sr_block_release(struct gendisk *disk, fmode_t mode)
{
struct scsi_cd *cd = scsi_cd(disk);
mutex_lock(&sr_mutex);
cdrom_release(&cd->cdi, mode);
scsi_cd_put(cd);
mutex_unlock(&sr_mutex);
}
static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
unsigned long arg)
{
struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
struct scsi_device *sdev = cd->device;
void __user *argp = (void __user *)arg;
int ret;
mutex_lock(&sr_mutex);
ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
(mode & FMODE_NDELAY) != 0);
if (ret)
goto out;
/*
* Send SCSI addressing ioctls directly to mid level, send other
* ioctls to cdrom/block level.
*/
switch (cmd) {
case SCSI_IOCTL_GET_IDLUN:
case SCSI_IOCTL_GET_BUS_NUMBER:
ret = scsi_ioctl(sdev, cmd, argp);
goto out;
}
ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
if (ret != -ENOSYS)
goto out;
ret = scsi_ioctl(sdev, cmd, argp);
out:
mutex_unlock(&sr_mutex);
return ret;
}
static unsigned int sr_block_check_events(struct gendisk *disk,
unsigned int clearing)
{
struct scsi_cd *cd = scsi_cd(disk);
if (atomic_read(&cd->device->disk_events_disable_depth))
return 0;
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))
goto out;
sr_cd_check(&cd->cdi);
get_sectorsize(cd);
out:
return 0;
}
static const struct block_device_operations sr_bdops =
{
.owner = THIS_MODULE,
.open = sr_block_open,
.release = sr_block_release,
.ioctl = sr_block_ioctl,
.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 arbitrary ioctls down to host drivers.
*/
};
static int sr_open(struct cdrom_device_info *cdi, int purpose)
{
struct scsi_cd *cd = cdi->handle;
struct scsi_device *sdev = cd->device;
int retval;
/*
* If the device is in error recovery, wait until it is done.
* If the device is offline, then disallow any access to it.
*/
retval = -ENXIO;
if (!scsi_block_when_processing_errors(sdev))
goto error_out;
return 0;
error_out:
return retval;
}
static void sr_release(struct cdrom_device_info *cdi)
{
struct scsi_cd *cd = cdi->handle;
if (cd->device->sector_size > 2048)
sr_set_blocklength(cd, 2048);
}
static int sr_probe(struct device *dev)
{
struct scsi_device *sdev = to_scsi_device(dev);
struct gendisk *disk;
struct scsi_cd *cd;
int minor, error;
scsi_autopm_get_device(sdev);
error = -ENODEV;
if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
goto fail;
error = -ENOMEM;
cd = kzalloc(sizeof(*cd), GFP_KERNEL);
if (!cd)
goto fail;
kref_init(&cd->kref);
disk = alloc_disk(1);
if (!disk)
goto fail_free;
spin_lock(&sr_index_lock);
minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
if (minor == SR_DISKS) {
spin_unlock(&sr_index_lock);
error = -EBUSY;
goto fail_put;
}
__set_bit(minor, sr_index_bits);
spin_unlock(&sr_index_lock);
disk->major = SCSI_CDROM_MAJOR;
disk->first_minor = minor;
sprintf(disk->disk_name, "sr%d", minor);
disk->fops = &sr_bdops;
disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
cd->device = sdev;
cd->disk = disk;
cd->driver = &sr_template;
cd->disk = disk;
cd->capacity = 0x1fffff;
cd->device->changed = 1; /* force recheck CD type */
cd->media_present = 1;
cd->use = 1;
cd->readcd_known = 0;
cd->readcd_cdda = 0;
cd->cdi.ops = &sr_dops;
cd->cdi.handle = cd;
cd->cdi.mask = 0;
cd->cdi.capacity = 1;
sprintf(cd->cdi.name, "sr%d", minor);
sdev->sector_size = 2048; /* A guess, just in case */
/* FIXME: need to handle a get_capabilities failure properly ?? */
get_capabilities(cd);
sr_vendor_init(cd);
disk->driverfs_dev = &sdev->sdev_gendev;
set_capacity(disk, cd->capacity);
disk->private_data = &cd->driver;
disk->queue = sdev->request_queue;
cd->cdi.disk = disk;
if (register_cdrom(&cd->cdi))
goto fail_put;
/*
* Initialize block layer runtime PM stuffs before the
* periodic event checking request gets started in add_disk.
*/
blk_pm_runtime_init(sdev->request_queue, dev);
dev_set_drvdata(dev, cd);
disk->flags |= GENHD_FL_REMOVABLE;
add_disk(disk);
sdev_printk(KERN_DEBUG, sdev,
"Attached scsi CD-ROM %s\n", cd->cdi.name);
scsi_autopm_put_device(cd->device);
return 0;
fail_put:
put_disk(disk);
fail_free:
kfree(cd);
fail:
scsi_autopm_put_device(sdev);
return error;
}
static void get_sectorsize(struct scsi_cd *cd)
{
unsigned char cmd[10];
unsigned char buffer[8];
int the_result, retries = 3;
int sector_size;
struct request_queue *queue;
do {
cmd[0] = READ_CAPACITY;
memset((void *) &cmd[1], 0, 9);
memset(buffer, 0, sizeof(buffer));
/* Do the command and wait.. */
the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
buffer, sizeof(buffer), NULL,
SR_TIMEOUT, MAX_RETRIES, NULL);
retries--;
} while (the_result && retries);
if (the_result) {
cd->capacity = 0x1fffff;
sector_size = 2048; /* A guess, just in case */
} else {
long last_written;
cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
(buffer[2] << 8) | buffer[3]);
/*
* READ_CAPACITY doesn't return the correct size on
* certain UDF media. If last_written is larger, use
* it instead.
*
* http://bugzilla.kernel.org/show_bug.cgi?id=9668
*/
if (!cdrom_get_last_written(&cd->cdi, &last_written))
cd->capacity = max_t(long, cd->capacity, last_written);
sector_size = (buffer[4] << 24) |
(buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
switch (sector_size) {
/*
* HP 4020i CD-Recorder reports 2340 byte sectors
* Philips CD-Writers report 2352 byte sectors
*
* Use 2k sectors for them..
*/
case 0:
case 2340:
case 2352:
sector_size = 2048;
/* fall through */
case 2048:
cd->capacity *= 4;
/* fall through */
case 512:
break;
default:
sr_printk(KERN_INFO, cd,
"unsupported sector size %d.", sector_size);
cd->capacity = 0;
}
cd->device->sector_size = sector_size;
/*
* Add this so that we have the ability to correctly gauge
* what the device is capable of.
*/
set_capacity(cd->disk, cd->capacity);
}
queue = cd->device->request_queue;
blk_queue_logical_block_size(queue, sector_size);
return;
}
static void get_capabilities(struct scsi_cd *cd)
{
unsigned char *buffer;
struct scsi_mode_data data;
struct scsi_sense_hdr sshdr;
int rc, n;
static const char *loadmech[] =
{
"caddy",
"tray",
"pop-up",
"",
"changer",
"cartridge changer",
"",
""
};
/* allocate transfer buffer */
buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
if (!buffer) {
sr_printk(KERN_ERR, cd, "out of memory.\n");
return;
}
/* eat unit attentions */
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,
SR_TIMEOUT, 3, &data, NULL);
if (!scsi_status_is_good(rc)) {
/* failed, drive doesn't have capabilities mode page */
cd->cdi.speed = 1;
cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
CDC_DVD | CDC_DVD_RAM |
CDC_SELECT_DISC | CDC_SELECT_SPEED |
CDC_MRW | CDC_MRW_W | CDC_RAM);
kfree(buffer);
sr_printk(KERN_INFO, cd, "scsi-1 drive");
return;
}
n = data.header_length + data.block_descriptor_length;
cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
cd->readcd_known = 1;
cd->readcd_cdda = buffer[n + 5] & 0x01;
/* print some capability bits */
sr_printk(KERN_INFO, cd,
"scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
cd->cdi.speed,
buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
buffer[n + 3] & 0x20 ? "dvd-ram " : "",
buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
buffer[n + 4] & 0x20 ? "xa/form2 " : "", /* can read xa/from2 */
buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
loadmech[buffer[n + 6] >> 5]);
if ((buffer[n + 6] >> 5) == 0)
/* caddy drives can't close tray... */
cd->cdi.mask |= CDC_CLOSE_TRAY;
if ((buffer[n + 2] & 0x8) == 0)
/* not a DVD drive */
cd->cdi.mask |= CDC_DVD;
if ((buffer[n + 3] & 0x20) == 0)
/* can't write DVD-RAM media */
cd->cdi.mask |= CDC_DVD_RAM;
if ((buffer[n + 3] & 0x10) == 0)
/* can't write DVD-R media */
cd->cdi.mask |= CDC_DVD_R;
if ((buffer[n + 3] & 0x2) == 0)
/* can't write CD-RW media */
cd->cdi.mask |= CDC_CD_RW;
if ((buffer[n + 3] & 0x1) == 0)
/* can't write CD-R media */
cd->cdi.mask |= CDC_CD_R;
if ((buffer[n + 6] & 0x8) == 0)
/* can't eject */
cd->cdi.mask |= CDC_OPEN_TRAY;
if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
(buffer[n + 6] >> 5) == mechtype_cartridge_changer)
cd->cdi.capacity =
cdrom_number_of_slots(&cd->cdi);
if (cd->cdi.capacity <= 1)
/* not a changer */
cd->cdi.mask |= CDC_SELECT_DISC;
/*else I don't think it can close its tray
cd->cdi.mask |= CDC_CLOSE_TRAY; */
/*
* if DVD-RAM, MRW-W or CD-RW, we are randomly writable
*/
if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
cd->writeable = 1;
}
kfree(buffer);
}
/*
* sr_packet() is the entry point for the generic commands generated
* by the Uniform CD-ROM layer.
*/
static int sr_packet(struct cdrom_device_info *cdi,
struct packet_command *cgc)
{
struct scsi_cd *cd = cdi->handle;
struct scsi_device *sdev = cd->device;
if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
return -EDRIVE_CANT_DO_THIS;
if (cgc->timeout <= 0)
cgc->timeout = IOCTL_TIMEOUT;
sr_do_ioctl(cd, cgc);
return cgc->stat;
}
/**
* sr_kref_release - Called to free the scsi_cd structure
* @kref: pointer to embedded kref
*
* sr_ref_mutex must be held entering this routine. Because it is
* called on last put, you should always use the scsi_cd_get()
* scsi_cd_put() helpers which manipulate the semaphore directly
* and never do a direct kref_put().
**/
static void sr_kref_release(struct kref *kref)
{
struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
struct gendisk *disk = cd->disk;
spin_lock(&sr_index_lock);
clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
spin_unlock(&sr_index_lock);
unregister_cdrom(&cd->cdi);
disk->private_data = NULL;
put_disk(disk);
kfree(cd);
}
static int sr_remove(struct device *dev)
{
struct scsi_cd *cd = dev_get_drvdata(dev);
scsi_autopm_get_device(cd->device);
del_gendisk(cd->disk);
dev_set_drvdata(dev, NULL);
mutex_lock(&sr_ref_mutex);
kref_put(&cd->kref, sr_kref_release);
mutex_unlock(&sr_ref_mutex);
return 0;
}
static int __init init_sr(void)
{
int rc;
rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
if (rc)
return rc;
rc = scsi_register_driver(&sr_template.gendrv);
if (rc)
unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
return rc;
}
static void __exit exit_sr(void)
{
scsi_unregister_driver(&sr_template.gendrv);
unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
}
module_init(init_sr);
module_exit(exit_sr);
MODULE_LICENSE("GPL");