Linux-2.6.12-rc2v2.6.12-rc2

Initial git repository build. I'm not bothering with the full history,
even though we have it. We can create a separate "historical" git
archive of that later if we want to, and in the meantime it's about
3.2GB when imported into git - space that would just make the early
git days unnecessarily complicated, when we don't have a lot of good
infrastructure for it.

Let it rip!

1 files changed, 965 insertions, 0 deletions

diff --git a/drivers/scsi/sr.c b/drivers/scsi/sr.c
new file mode 100644
index 000000000000..2f259f249522
--- /dev/null
+++ b/drivers/scsi/sr.c
@@ -0,0 +1,965 @@
+/*
+ *  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/sched.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 <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_eh.h>
+#include <scsi/scsi_host.h>
+#include <scsi/scsi_ioctl.h>    /* For the door lock/unlock commands */
+#include <scsi/scsi_request.h>
+
+#include "scsi_logging.h"
+#include "sr.h"
+
+
+#define SR_DISKS        256
+
+#define MAX_RETRIES     3
+#define SR_TIMEOUT      (30 * HZ)
+#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_IOCTLS|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 int sr_probe(struct device *);
+static int sr_remove(struct device *);
+static int sr_init_command(struct scsi_cmnd *);
+
+static struct scsi_driver sr_template = {
+        .owner                  = THIS_MODULE,
+        .gendrv = {
+                .name           = "sr",
+                .probe          = sr_probe,
+                .remove         = sr_remove,
+        },
+        .init_command           = sr_init_command,
+};
+
+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 DECLARE_MUTEX(sr_ref_sem);
+
+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 int sr_media_change(struct cdrom_device_info *, int);
+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,
+        .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,
+        .dev_ioctl              = sr_dev_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);
+}
+
+/*
+ * 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;
+
+        down(&sr_ref_sem);
+        if (disk->private_data == NULL)
+                goto out;
+        cd = scsi_cd(disk);
+        kref_get(&cd->kref);
+        if (scsi_device_get(cd->device))
+                goto out_put;
+        goto out;
+
+ out_put:
+        kref_put(&cd->kref, sr_kref_release);
+        cd = NULL;
+ out:
+        up(&sr_ref_sem);
+        return cd;
+}
+
+static inline void scsi_cd_put(struct scsi_cd *cd)
+{
+        struct scsi_device *sdev = cd->device;
+
+        down(&sr_ref_sem);
+        kref_put(&cd->kref, sr_kref_release);
+        scsi_device_put(sdev);
+        up(&sr_ref_sem);
+}
+
+/*
+ * 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.
+ */
+
+int sr_media_change(struct cdrom_device_info *cdi, int slot)
+{
+        struct scsi_cd *cd = cdi->handle;
+        int retval;
+
+        if (CDSL_CURRENT != slot) {
+                /* no changer support */
+                return -EINVAL;
+        }
+
+        retval = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES);
+        if (retval) {
+                /* 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;
+                return 1;       /* This will force a flush, if called from
+                                 * check_disk_change */
+        };
+
+        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);
+
+                /* 
+                 * If the disk changed, the capacity will now be different,
+                 * so we force a re-read of this information 
+                 * Force 2048 for the sector size so that filesystems won't
+                 * be trying to use something that is too small if the disc
+                 * has changed.
+                 */
+                cd->needs_sector_size = 1;
+                cd->device->sector_size = 2048;
+        }
+        return retval;
+}
+ 
+/*
+ * rw_intr is the interrupt routine for the device driver.
+ *
+ * It will be notified on the end of a SCSI read / write, and will take on
+ * of several actions based on success or failure.
+ */
+static void rw_intr(struct scsi_cmnd * SCpnt)
+{
+        int result = SCpnt->result;
+        int this_count = SCpnt->bufflen;
+        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
+        printk("sr.c 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;
+                        if (!blk_fs_request(SCpnt->request))
+                                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 - SCpnt->request->sector) << 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:
+
+                        /*
+                         * An error occured, but it recovered.  Inform the
+                         * user, but make sure that it's not treated as a
+                         * hard error.
+                         */
+                        scsi_print_sense("sr", SCpnt);
+                        SCpnt->result = 0;
+                        SCpnt->sense_buffer[0] = 0x0;
+                        good_bytes = this_count;
+                        break;
+
+                default:
+                        break;
+                }
+        }
+
+        /*
+         * This calls the generic completion function, now that we know
+         * how many actual sectors finished, and how many sectors we need
+         * to say have failed.
+         */
+        scsi_io_completion(SCpnt, good_bytes, block_sectors << 9);
+}
+
+static int sr_init_command(struct scsi_cmnd * SCpnt)
+{
+        int block=0, this_count, s_size, timeout = SR_TIMEOUT;
+        struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
+
+        SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
+                                cd->disk->disk_name, block));
+
+        if (!cd->device || !scsi_device_online(cd->device)) {
+                SCSI_LOG_HLQUEUE(2, printk("Finishing %ld sectors\n",
+                                        SCpnt->request->nr_sectors));
+                SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
+                return 0;
+        }
+
+        if (cd->device->changed) {
+                /*
+                 * quietly refuse to do anything to a changed disc until the
+                 * changed bit has been reset
+                 */
+                return 0;
+        }
+
+        /*
+         * these are already setup, just copy cdb basically
+         */
+        if (SCpnt->request->flags & REQ_BLOCK_PC) {
+                struct request *rq = SCpnt->request;
+
+                if (sizeof(rq->cmd) > sizeof(SCpnt->cmnd))
+                        return 0;
+
+                memcpy(SCpnt->cmnd, rq->cmd, sizeof(SCpnt->cmnd));
+                if (!rq->data_len)
+                        SCpnt->sc_data_direction = DMA_NONE;
+                else if (rq_data_dir(rq) == WRITE)
+                        SCpnt->sc_data_direction = DMA_TO_DEVICE;
+                else
+                        SCpnt->sc_data_direction = DMA_FROM_DEVICE;
+
+                this_count = rq->data_len;
+                if (rq->timeout)
+                        timeout = rq->timeout;
+
+                SCpnt->transfersize = rq->data_len;
+                goto queue;
+        }
+
+        if (!(SCpnt->request->flags & REQ_CMD)) {
+                blk_dump_rq_flags(SCpnt->request, "sr unsup command");
+                return 0;
+        }
+
+        /*
+         * 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
+                        printk("sr: can't switch blocksize: in interrupt\n");
+        }
+
+        if (s_size != 512 && s_size != 1024 && s_size != 2048) {
+                printk("sr: bad sector size %d\n", s_size);
+                return 0;
+        }
+
+        if (rq_data_dir(SCpnt->request) == WRITE) {
+                if (!cd->device->writeable)
+                        return 0;
+                SCpnt->cmnd[0] = WRITE_10;
+                SCpnt->sc_data_direction = DMA_TO_DEVICE;
+                cd->cdi.media_written = 1;
+        } else if (rq_data_dir(SCpnt->request) == READ) {
+                SCpnt->cmnd[0] = READ_10;
+                SCpnt->sc_data_direction = DMA_FROM_DEVICE;
+        } else {
+                blk_dump_rq_flags(SCpnt->request, "Unknown sr command");
+                return 0;
+        }
+
+        {
+                struct scatterlist *sg = SCpnt->request_buffer;
+                int i, size = 0;
+                for (i = 0; i < SCpnt->use_sg; i++)
+                        size += sg[i].length;
+
+                if (size != SCpnt->request_bufflen && SCpnt->use_sg) {
+                        printk(KERN_ERR "sr: mismatch count %d, bytes %d\n",
+                                        size, SCpnt->request_bufflen);
+                        if (SCpnt->request_bufflen > size)
+                                SCpnt->request_bufflen = SCpnt->bufflen = size;
+                }
+        }
+
+        /*
+         * request doesn't start on hw block boundary, add scatter pads
+         */
+        if (((unsigned int)SCpnt->request->sector % (s_size >> 9)) ||
+            (SCpnt->request_bufflen % s_size)) {
+                printk("sr: unaligned transfer\n");
+                return 0;
+        }
+
+        this_count = (SCpnt->request_bufflen >> 9) / (s_size >> 9);
+
+
+        SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%ld 512 byte blocks.\n",
+                                cd->cdi.name,
+                                (rq_data_dir(SCpnt->request) == WRITE) ?
+                                        "writing" : "reading",
+                                this_count, SCpnt->request->nr_sectors));
+
+        SCpnt->cmnd[1] = 0;
+        block = (unsigned int)SCpnt->request->sector / (s_size >> 9);
+
+        if (this_count > 0xffff) {
+                this_count = 0xffff;
+                SCpnt->request_bufflen = SCpnt->bufflen =
+                                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;
+
+queue:
+        SCpnt->allowed = MAX_RETRIES;
+        SCpnt->timeout_per_command = timeout;
+
+        /*
+         * This is the completion routine we use.  This is matched in terms
+         * of capability to this function.
+         */
+        SCpnt->done = rw_intr;
+
+        /*
+         * This indicates that the command is ready from our end to be
+         * queued.
+         */
+        return 1;
+}
+
+static int sr_block_open(struct inode *inode, struct file *file)
+{
+        struct gendisk *disk = inode->i_bdev->bd_disk;
+        struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
+        int ret = 0;
+
+        if(!(cd = scsi_cd_get(disk)))
+                return -ENXIO;
+
+        if((ret = cdrom_open(&cd->cdi, inode, file)) != 0)
+                scsi_cd_put(cd);
+
+        return ret;
+}
+
+static int sr_block_release(struct inode *inode, struct file *file)
+{
+        int ret;
+        struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
+        ret = cdrom_release(&cd->cdi, file);
+        if(ret)
+                return ret;
+        
+        scsi_cd_put(cd);
+
+        return 0;
+}
+
+static int sr_block_ioctl(struct inode *inode, struct file *file, unsigned cmd,
+                          unsigned long arg)
+{
+        struct scsi_cd *cd = scsi_cd(inode->i_bdev->bd_disk);
+        struct scsi_device *sdev = cd->device;
+
+        /*
+         * 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:
+                        return scsi_ioctl(sdev, cmd, (void __user *)arg);
+        }
+        return cdrom_ioctl(file, &cd->cdi, inode, cmd, arg);
+}
+
+static int sr_block_media_changed(struct gendisk *disk)
+{
+        struct scsi_cd *cd = scsi_cd(disk);
+        return cdrom_media_changed(&cd->cdi);
+}
+
+static struct block_device_operations sr_bdops =
+{
+        .owner          = THIS_MODULE,
+        .open           = sr_block_open,
+        .release        = sr_block_release,
+        .ioctl          = sr_block_ioctl,
+        .media_changed  = sr_block_media_changed,
+        /* 
+         * No compat_ioctl for now because sr_block_ioctl never
+         * seems to pass arbitary 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;
+
+        /*
+         * If this device did not have media in the drive at boot time, then
+         * we would have been unable to get the sector size.  Check to see if
+         * this is the case, and try again.
+         */
+        if (cd->needs_sector_size)
+                get_sectorsize(cd);
+        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;
+
+        error = -ENODEV;
+        if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
+                goto fail;
+
+        error = -ENOMEM;
+        cd = kmalloc(sizeof(*cd), GFP_KERNEL);
+        if (!cd)
+                goto fail;
+        memset(cd, 0, sizeof(*cd));
+
+        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;
+
+        cd->device = sdev;
+        cd->disk = disk;
+        cd->driver = &sr_template;
+        cd->disk = disk;
+        cd->capacity = 0x1fffff;
+        cd->needs_sector_size = 1;
+        cd->device->changed = 1;        /* force recheck CD type */
+        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);
+
+        snprintf(disk->devfs_name, sizeof(disk->devfs_name),
+                        "%s/cd", sdev->devfs_name);
+        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;
+
+        dev_set_drvdata(dev, cd);
+        disk->flags |= GENHD_FL_REMOVABLE;
+        add_disk(disk);
+
+        printk(KERN_DEBUG
+            "Attached scsi CD-ROM %s at scsi%d, channel %d, id %d, lun %d\n",
+            cd->cdi.name, sdev->host->host_no, sdev->channel,
+            sdev->id, sdev->lun);
+        return 0;
+
+fail_put:
+        put_disk(disk);
+fail_free:
+        kfree(cd);
+fail:
+        return error;
+}
+
+
+static void get_sectorsize(struct scsi_cd *cd)
+{
+        unsigned char cmd[10];
+        unsigned char *buffer;
+        int the_result, retries = 3;
+        int sector_size;
+        struct scsi_request *SRpnt = NULL;
+        request_queue_t *queue;
+
+        buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+        if (!buffer)
+                goto Enomem;
+        SRpnt = scsi_allocate_request(cd->device, GFP_KERNEL);
+        if (!SRpnt)
+                goto Enomem;
+
+        do {
+                cmd[0] = READ_CAPACITY;
+                memset((void *) &cmd[1], 0, 9);
+                /* Mark as really busy */
+                SRpnt->sr_request->rq_status = RQ_SCSI_BUSY;
+                SRpnt->sr_cmd_len = 0;
+
+                memset(buffer, 0, 8);
+
+                /* Do the command and wait.. */
+                SRpnt->sr_data_direction = DMA_FROM_DEVICE;
+                scsi_wait_req(SRpnt, (void *) cmd, (void *) buffer,
+                              8, SR_TIMEOUT, MAX_RETRIES);
+
+                the_result = SRpnt->sr_result;
+                retries--;
+
+        } while (the_result && retries);
+
+
+        scsi_release_request(SRpnt);
+        SRpnt = NULL;
+
+        if (the_result) {
+                cd->capacity = 0x1fffff;
+                sector_size = 2048;     /* A guess, just in case */
+                cd->needs_sector_size = 1;
+        } else {
+#if 0
+                if (cdrom_get_last_written(&cd->cdi,
+                                           &cd->capacity))
+#endif
+                        cd->capacity = 1 + ((buffer[0] << 24) |
+                                                    (buffer[1] << 16) |
+                                                    (buffer[2] << 8) |
+                                                    buffer[3]);
+                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:
+                        printk("%s: unsupported sector size %d.\n",
+                               cd->cdi.name, sector_size);
+                        cd->capacity = 0;
+                        cd->needs_sector_size = 1;
+                }
+
+                cd->device->sector_size = sector_size;
+
+                /*
+                 * Add this so that we have the ability to correctly gauge
+                 * what the device is capable of.
+                 */
+                cd->needs_sector_size = 0;
+                set_capacity(cd->disk, cd->capacity);
+        }
+
+        queue = cd->device->request_queue;
+        blk_queue_hardsect_size(queue, sector_size);
+out:
+        kfree(buffer);
+        return;
+
+Enomem:
+        cd->capacity = 0x1fffff;
+        sector_size = 2048;     /* A guess, just in case */
+        cd->needs_sector_size = 1;
+        if (SRpnt)
+                scsi_release_request(SRpnt);
+        goto out;
+}
+
+static void get_capabilities(struct scsi_cd *cd)
+{
+        unsigned char *buffer;
+        struct scsi_mode_data data;
+        struct scsi_request *SRpnt;
+        unsigned char cmd[MAX_COMMAND_SIZE];
+        unsigned int the_result;
+        int retries, rc, n;
+
+        static char *loadmech[] =
+        {
+                "caddy",
+                "tray",
+                "pop-up",
+                "",
+                "changer",
+                "cartridge changer",
+                "",
+                ""
+        };
+
+        /* allocate a request for the TEST_UNIT_READY */
+        SRpnt = scsi_allocate_request(cd->device, GFP_KERNEL);
+        if (!SRpnt) {
+                printk(KERN_WARNING "(get_capabilities:) Request allocation "
+                       "failure.\n");
+                return;
+        }
+
+        /* allocate transfer buffer */
+        buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
+        if (!buffer) {
+                printk(KERN_ERR "sr: out of memory.\n");
+                scsi_release_request(SRpnt);
+                return;
+        }
+
+        /* issue TEST_UNIT_READY until the initial startup UNIT_ATTENTION
+         * conditions are gone, or a timeout happens
+         */
+        retries = 0;
+        do {
+                memset((void *)cmd, 0, MAX_COMMAND_SIZE);
+                cmd[0] = TEST_UNIT_READY;
+
+                SRpnt->sr_cmd_len = 0;
+                SRpnt->sr_sense_buffer[0] = 0;
+                SRpnt->sr_sense_buffer[2] = 0;
+                SRpnt->sr_data_direction = DMA_NONE;
+
+                scsi_wait_req (SRpnt, (void *) cmd, buffer,
+                               0, SR_TIMEOUT, MAX_RETRIES);
+
+                the_result = SRpnt->sr_result;
+                retries++;
+        } while (retries < 5 && 
+                 (!scsi_status_is_good(the_result) ||
+                  ((driver_byte(the_result) & DRIVER_SENSE) &&
+                   SRpnt->sr_sense_buffer[2] == UNIT_ATTENTION)));
+
+        /* ask for mode page 0x2a */
+        rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
+                             SR_TIMEOUT, 3, &data);
+
+        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);
+                scsi_release_request(SRpnt);
+                kfree(buffer);
+                printk("%s: scsi-1 drive\n", cd->cdi.name);
+                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 */
+        printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
+               ((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->device->writeable = 1;
+        }
+
+        scsi_release_request(SRpnt);
+        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)
+{
+        if (cgc->timeout <= 0)
+                cgc->timeout = IOCTL_TIMEOUT;
+
+        sr_do_ioctl(cdi->handle, cgc);
+
+        return cgc->stat;
+}
+
+/**
+ *      sr_kref_release - Called to free the scsi_cd structure
+ *      @kref: pointer to embedded kref
+ *
+ *      sr_ref_sem 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(disk->first_minor, 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);
+
+        del_gendisk(cd->disk);
+
+        down(&sr_ref_sem);
+        kref_put(&cd->kref, sr_kref_release);
+        up(&sr_ref_sem);
+
+        return 0;
+}
+
+static int __init init_sr(void)
+{
+        int rc;
+
+        rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
+        if (rc)
+                return rc;
+        return scsi_register_driver(&sr_template.gendrv);
+}
+
+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");