linux/drivers/scsi/sr.c
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   1/*
   2 *  sr.c Copyright (C) 1992 David Giller
   3 *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
   4 *
   5 *  adapted from:
   6 *      sd.c Copyright (C) 1992 Drew Eckhardt
   7 *      Linux scsi disk driver by
   8 *              Drew Eckhardt <drew@colorado.edu>
   9 *
  10 *      Modified by Eric Youngdale ericy@andante.org to
  11 *      add scatter-gather, multiple outstanding request, and other
  12 *      enhancements.
  13 *
  14 *      Modified by Eric Youngdale eric@andante.org to support loadable
  15 *      low-level scsi drivers.
  16 *
  17 *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
  18 *      provide auto-eject.
  19 *
  20 *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
  21 *      generic cdrom interface
  22 *
  23 *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
  24 *      interface, capabilities probe additions, ioctl cleanups, etc.
  25 *
  26 *      Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
  27 *
  28 *      Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
  29 *      transparently and lose the GHOST hack
  30 *
  31 *      Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  32 *      check resource allocation in sr_init and some cleanups
  33 */
  34
  35#include <linux/module.h>
  36#include <linux/fs.h>
  37#include <linux/kernel.h>
  38#include <linux/mm.h>
  39#include <linux/bio.h>
  40#include <linux/string.h>
  41#include <linux/errno.h>
  42#include <linux/cdrom.h>
  43#include <linux/interrupt.h>
  44#include <linux/init.h>
  45#include <linux/blkdev.h>
  46#include <linux/mutex.h>
  47#include <linux/slab.h>
  48#include <linux/pm_runtime.h>
  49#include <asm/uaccess.h>
  50
  51#include <scsi/scsi.h>
  52#include <scsi/scsi_dbg.h>
  53#include <scsi/scsi_device.h>
  54#include <scsi/scsi_driver.h>
  55#include <scsi/scsi_cmnd.h>
  56#include <scsi/scsi_eh.h>
  57#include <scsi/scsi_host.h>
  58#include <scsi/scsi_ioctl.h>    /* For the door lock/unlock commands */
  59
  60#include "scsi_logging.h"
  61#include "sr.h"
  62
  63
  64MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
  65MODULE_LICENSE("GPL");
  66MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
  67MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
  68MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
  69
  70#define SR_DISKS        256
  71
  72#define SR_CAPABILITIES \
  73        (CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
  74         CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
  75         CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
  76         CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
  77         CDC_MRW|CDC_MRW_W|CDC_RAM)
  78
  79static DEFINE_MUTEX(sr_mutex);
  80static int sr_probe(struct device *);
  81static int sr_remove(struct device *);
  82static int sr_done(struct scsi_cmnd *);
  83static int sr_runtime_suspend(struct device *dev);
  84
  85static struct dev_pm_ops sr_pm_ops = {
  86        .runtime_suspend        = sr_runtime_suspend,
  87};
  88
  89static struct scsi_driver sr_template = {
  90        .owner                  = THIS_MODULE,
  91        .gendrv = {
  92                .name           = "sr",
  93                .probe          = sr_probe,
  94                .remove         = sr_remove,
  95                .pm             = &sr_pm_ops,
  96        },
  97        .done                   = sr_done,
  98};
  99
 100static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
 101static DEFINE_SPINLOCK(sr_index_lock);
 102
 103/* This semaphore is used to mediate the 0->1 reference get in the
 104 * face of object destruction (i.e. we can't allow a get on an
 105 * object after last put) */
 106static DEFINE_MUTEX(sr_ref_mutex);
 107
 108static int sr_open(struct cdrom_device_info *, int);
 109static void sr_release(struct cdrom_device_info *);
 110
 111static void get_sectorsize(struct scsi_cd *);
 112static void get_capabilities(struct scsi_cd *);
 113
 114static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 115                                    unsigned int clearing, int slot);
 116static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 117
 118static struct cdrom_device_ops sr_dops = {
 119        .open                   = sr_open,
 120        .release                = sr_release,
 121        .drive_status           = sr_drive_status,
 122        .check_events           = sr_check_events,
 123        .tray_move              = sr_tray_move,
 124        .lock_door              = sr_lock_door,
 125        .select_speed           = sr_select_speed,
 126        .get_last_session       = sr_get_last_session,
 127        .get_mcn                = sr_get_mcn,
 128        .reset                  = sr_reset,
 129        .audio_ioctl            = sr_audio_ioctl,
 130        .capability             = SR_CAPABILITIES,
 131        .generic_packet         = sr_packet,
 132};
 133
 134static void sr_kref_release(struct kref *kref);
 135
 136static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
 137{
 138        return container_of(disk->private_data, struct scsi_cd, driver);
 139}
 140
 141static int sr_runtime_suspend(struct device *dev)
 142{
 143        struct scsi_cd *cd = dev_get_drvdata(dev);
 144
 145        if (cd->media_present)
 146                return -EBUSY;
 147        else
 148                return 0;
 149}
 150
 151/*
 152 * The get and put routines for the struct scsi_cd.  Note this entity
 153 * has a scsi_device pointer and owns a reference to this.
 154 */
 155static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 156{
 157        struct scsi_cd *cd = NULL;
 158
 159        mutex_lock(&sr_ref_mutex);
 160        if (disk->private_data == NULL)
 161                goto out;
 162        cd = scsi_cd(disk);
 163        kref_get(&cd->kref);
 164        if (scsi_device_get(cd->device))
 165                goto out_put;
 166        if (!scsi_autopm_get_device(cd->device))
 167                goto out;
 168
 169 out_put:
 170        kref_put(&cd->kref, sr_kref_release);
 171        cd = NULL;
 172 out:
 173        mutex_unlock(&sr_ref_mutex);
 174        return cd;
 175}
 176
 177static void scsi_cd_put(struct scsi_cd *cd)
 178{
 179        struct scsi_device *sdev = cd->device;
 180
 181        mutex_lock(&sr_ref_mutex);
 182        kref_put(&cd->kref, sr_kref_release);
 183        scsi_autopm_put_device(sdev);
 184        scsi_device_put(sdev);
 185        mutex_unlock(&sr_ref_mutex);
 186}
 187
 188static unsigned int sr_get_events(struct scsi_device *sdev)
 189{
 190        u8 buf[8];
 191        u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
 192                     1,                 /* polled */
 193                     0, 0,              /* reserved */
 194                     1 << 4,            /* notification class: media */
 195                     0, 0,              /* reserved */
 196                     0, sizeof(buf),    /* allocation length */
 197                     0,                 /* control */
 198        };
 199        struct event_header *eh = (void *)buf;
 200        struct media_event_desc *med = (void *)(buf + 4);
 201        struct scsi_sense_hdr sshdr;
 202        int result;
 203
 204        result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
 205                                  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
 206        if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
 207                return DISK_EVENT_MEDIA_CHANGE;
 208
 209        if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
 210                return 0;
 211
 212        if (eh->nea || eh->notification_class != 0x4)
 213                return 0;
 214
 215        if (med->media_event_code == 1)
 216                return DISK_EVENT_EJECT_REQUEST;
 217        else if (med->media_event_code == 2)
 218                return DISK_EVENT_MEDIA_CHANGE;
 219        return 0;
 220}
 221
 222/*
 223 * This function checks to see if the media has been changed or eject
 224 * button has been pressed.  It is possible that we have already
 225 * sensed a change, or the drive may have sensed one and not yet
 226 * reported it.  The past events are accumulated in sdev->changed and
 227 * returned together with the current state.
 228 */
 229static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 230                                    unsigned int clearing, int slot)
 231{
 232        struct scsi_cd *cd = cdi->handle;
 233        bool last_present;
 234        struct scsi_sense_hdr sshdr;
 235        unsigned int events;
 236        int ret;
 237
 238        /* no changer support */
 239        if (CDSL_CURRENT != slot)
 240                return 0;
 241
 242        events = sr_get_events(cd->device);
 243        cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
 244
 245        /*
 246         * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
 247         * for several times in a row.  We rely on TUR only for this likely
 248         * broken device, to prevent generating incorrect media changed
 249         * events for every open().
 250         */
 251        if (cd->ignore_get_event) {
 252                events &= ~DISK_EVENT_MEDIA_CHANGE;
 253                goto do_tur;
 254        }
 255
 256        /*
 257         * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
 258         * is being cleared.  Note that there are devices which hang
 259         * if asked to execute TUR repeatedly.
 260         */
 261        if (cd->device->changed) {
 262                events |= DISK_EVENT_MEDIA_CHANGE;
 263                cd->device->changed = 0;
 264                cd->tur_changed = true;
 265        }
 266
 267        if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
 268                return events;
 269do_tur:
 270        /* let's see whether the media is there with TUR */
 271        last_present = cd->media_present;
 272        ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 273
 274        /*
 275         * Media is considered to be present if TUR succeeds or fails with
 276         * sense data indicating something other than media-not-present
 277         * (ASC 0x3a).
 278         */
 279        cd->media_present = scsi_status_is_good(ret) ||
 280                (scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 281
 282        if (last_present != cd->media_present)
 283                cd->device->changed = 1;
 284
 285        if (cd->device->changed) {
 286                events |= DISK_EVENT_MEDIA_CHANGE;
 287                cd->device->changed = 0;
 288                cd->tur_changed = true;
 289        }
 290
 291        if (cd->ignore_get_event)
 292                return events;
 293
 294        /* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
 295        if (!cd->tur_changed) {
 296                if (cd->get_event_changed) {
 297                        if (cd->tur_mismatch++ > 8) {
 298                                sdev_printk(KERN_WARNING, cd->device,
 299                                            "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
 300                                cd->ignore_get_event = true;
 301                        }
 302                } else {
 303                        cd->tur_mismatch = 0;
 304                }
 305        }
 306        cd->tur_changed = false;
 307        cd->get_event_changed = false;
 308
 309        return events;
 310}
 311
 312/*
 313 * sr_done is the interrupt routine for the device driver.
 314 *
 315 * It will be notified on the end of a SCSI read / write, and will take one
 316 * of several actions based on success or failure.
 317 */
 318static int sr_done(struct scsi_cmnd *SCpnt)
 319{
 320        int result = SCpnt->result;
 321        int this_count = scsi_bufflen(SCpnt);
 322        int good_bytes = (result == 0 ? this_count : 0);
 323        int block_sectors = 0;
 324        long error_sector;
 325        struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
 326
 327#ifdef DEBUG
 328        printk("sr.c done: %x\n", result);
 329#endif
 330
 331        /*
 332         * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
 333         * success.  Since this is a relatively rare error condition, no
 334         * care is taken to avoid unnecessary additional work such as
 335         * memcpy's that could be avoided.
 336         */
 337        if (driver_byte(result) != 0 &&         /* An error occurred */
 338            (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
 339                switch (SCpnt->sense_buffer[2]) {
 340                case MEDIUM_ERROR:
 341                case VOLUME_OVERFLOW:
 342                case ILLEGAL_REQUEST:
 343                        if (!(SCpnt->sense_buffer[0] & 0x90))
 344                                break;
 345                        error_sector = (SCpnt->sense_buffer[3] << 24) |
 346                                (SCpnt->sense_buffer[4] << 16) |
 347                                (SCpnt->sense_buffer[5] << 8) |
 348                                SCpnt->sense_buffer[6];
 349                        if (SCpnt->request->bio != NULL)
 350                                block_sectors =
 351                                        bio_sectors(SCpnt->request->bio);
 352                        if (block_sectors < 4)
 353                                block_sectors = 4;
 354                        if (cd->device->sector_size == 2048)
 355                                error_sector <<= 2;
 356                        error_sector &= ~(block_sectors - 1);
 357                        good_bytes = (error_sector -
 358                                      blk_rq_pos(SCpnt->request)) << 9;
 359                        if (good_bytes < 0 || good_bytes >= this_count)
 360                                good_bytes = 0;
 361                        /*
 362                         * The SCSI specification allows for the value
 363                         * returned by READ CAPACITY to be up to 75 2K
 364                         * sectors past the last readable block.
 365                         * Therefore, if we hit a medium error within the
 366                         * last 75 2K sectors, we decrease the saved size
 367                         * value.
 368                         */
 369                        if (error_sector < get_capacity(cd->disk) &&
 370                            cd->capacity - error_sector < 4 * 75)
 371                                set_capacity(cd->disk, error_sector);
 372                        break;
 373
 374                case RECOVERED_ERROR:
 375                        good_bytes = this_count;
 376                        break;
 377
 378                default:
 379                        break;
 380                }
 381        }
 382
 383        return good_bytes;
 384}
 385
 386static int sr_prep_fn(struct request_queue *q, struct request *rq)
 387{
 388        int block = 0, this_count, s_size;
 389        struct scsi_cd *cd;
 390        struct scsi_cmnd *SCpnt;
 391        struct scsi_device *sdp = q->queuedata;
 392        int ret;
 393
 394        if (rq->cmd_type == REQ_TYPE_BLOCK_PC) {
 395                ret = scsi_setup_blk_pc_cmnd(sdp, rq);
 396                goto out;
 397        } else if (rq->cmd_type != REQ_TYPE_FS) {
 398                ret = BLKPREP_KILL;
 399                goto out;
 400        }
 401        ret = scsi_setup_fs_cmnd(sdp, rq);
 402        if (ret != BLKPREP_OK)
 403                goto out;
 404        SCpnt = rq->special;
 405        cd = scsi_cd(rq->rq_disk);
 406
 407        /* from here on until we're complete, any goto out
 408         * is used for a killable error condition */
 409        ret = BLKPREP_KILL;
 410
 411        SCSI_LOG_HLQUEUE(1, printk("Doing sr request, dev = %s, block = %d\n",
 412                                cd->disk->disk_name, block));
 413
 414        if (!cd->device || !scsi_device_online(cd->device)) {
 415                SCSI_LOG_HLQUEUE(2, printk("Finishing %u sectors\n",
 416                                           blk_rq_sectors(rq)));
 417                SCSI_LOG_HLQUEUE(2, printk("Retry with 0x%p\n", SCpnt));
 418                goto out;
 419        }
 420
 421        if (cd->device->changed) {
 422                /*
 423                 * quietly refuse to do anything to a changed disc until the
 424                 * changed bit has been reset
 425                 */
 426                goto out;
 427        }
 428
 429        /*
 430         * we do lazy blocksize switching (when reading XA sectors,
 431         * see CDROMREADMODE2 ioctl) 
 432         */
 433        s_size = cd->device->sector_size;
 434        if (s_size > 2048) {
 435                if (!in_interrupt())
 436                        sr_set_blocklength(cd, 2048);
 437                else
 438                        printk("sr: can't switch blocksize: in interrupt\n");
 439        }
 440
 441        if (s_size != 512 && s_size != 1024 && s_size != 2048) {
 442                scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
 443                goto out;
 444        }
 445
 446        if (rq_data_dir(rq) == WRITE) {
 447                if (!cd->device->writeable)
 448                        goto out;
 449                SCpnt->cmnd[0] = WRITE_10;
 450                SCpnt->sc_data_direction = DMA_TO_DEVICE;
 451                cd->cdi.media_written = 1;
 452        } else if (rq_data_dir(rq) == READ) {
 453                SCpnt->cmnd[0] = READ_10;
 454                SCpnt->sc_data_direction = DMA_FROM_DEVICE;
 455        } else {
 456                blk_dump_rq_flags(rq, "Unknown sr command");
 457                goto out;
 458        }
 459
 460        {
 461                struct scatterlist *sg;
 462                int i, size = 0, sg_count = scsi_sg_count(SCpnt);
 463
 464                scsi_for_each_sg(SCpnt, sg, sg_count, i)
 465                        size += sg->length;
 466
 467                if (size != scsi_bufflen(SCpnt)) {
 468                        scmd_printk(KERN_ERR, SCpnt,
 469                                "mismatch count %d, bytes %d\n",
 470                                size, scsi_bufflen(SCpnt));
 471                        if (scsi_bufflen(SCpnt) > size)
 472                                SCpnt->sdb.length = size;
 473                }
 474        }
 475
 476        /*
 477         * request doesn't start on hw block boundary, add scatter pads
 478         */
 479        if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
 480            (scsi_bufflen(SCpnt) % s_size)) {
 481                scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
 482                goto out;
 483        }
 484
 485        this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
 486
 487
 488        SCSI_LOG_HLQUEUE(2, printk("%s : %s %d/%u 512 byte blocks.\n",
 489                                cd->cdi.name,
 490                                (rq_data_dir(rq) == WRITE) ?
 491                                        "writing" : "reading",
 492                                this_count, blk_rq_sectors(rq)));
 493
 494        SCpnt->cmnd[1] = 0;
 495        block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
 496
 497        if (this_count > 0xffff) {
 498                this_count = 0xffff;
 499                SCpnt->sdb.length = this_count * s_size;
 500        }
 501
 502        SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
 503        SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
 504        SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
 505        SCpnt->cmnd[5] = (unsigned char) block & 0xff;
 506        SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
 507        SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
 508        SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
 509
 510        /*
 511         * We shouldn't disconnect in the middle of a sector, so with a dumb
 512         * host adapter, it's safe to assume that we can at least transfer
 513         * this many bytes between each connect / disconnect.
 514         */
 515        SCpnt->transfersize = cd->device->sector_size;
 516        SCpnt->underflow = this_count << 9;
 517        SCpnt->allowed = MAX_RETRIES;
 518
 519        /*
 520         * This indicates that the command is ready from our end to be
 521         * queued.
 522         */
 523        ret = BLKPREP_OK;
 524 out:
 525        return scsi_prep_return(q, rq, ret);
 526}
 527
 528static int sr_block_open(struct block_device *bdev, fmode_t mode)
 529{
 530        struct scsi_cd *cd;
 531        int ret = -ENXIO;
 532
 533        mutex_lock(&sr_mutex);
 534        cd = scsi_cd_get(bdev->bd_disk);
 535        if (cd) {
 536                ret = cdrom_open(&cd->cdi, bdev, mode);
 537                if (ret)
 538                        scsi_cd_put(cd);
 539        }
 540        mutex_unlock(&sr_mutex);
 541        return ret;
 542}
 543
 544static void sr_block_release(struct gendisk *disk, fmode_t mode)
 545{
 546        struct scsi_cd *cd = scsi_cd(disk);
 547        mutex_lock(&sr_mutex);
 548        cdrom_release(&cd->cdi, mode);
 549        scsi_cd_put(cd);
 550        mutex_unlock(&sr_mutex);
 551}
 552
 553static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 554                          unsigned long arg)
 555{
 556        struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 557        struct scsi_device *sdev = cd->device;
 558        void __user *argp = (void __user *)arg;
 559        int ret;
 560
 561        scsi_autopm_get_device(cd->device);
 562
 563        mutex_lock(&sr_mutex);
 564
 565        /*
 566         * Send SCSI addressing ioctls directly to mid level, send other
 567         * ioctls to cdrom/block level.
 568         */
 569        switch (cmd) {
 570        case SCSI_IOCTL_GET_IDLUN:
 571        case SCSI_IOCTL_GET_BUS_NUMBER:
 572                ret = scsi_ioctl(sdev, cmd, argp);
 573                goto out;
 574        }
 575
 576        ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
 577        if (ret != -ENOSYS)
 578                goto out;
 579
 580        /*
 581         * ENODEV means that we didn't recognise the ioctl, or that we
 582         * cannot execute it in the current device state.  In either
 583         * case fall through to scsi_ioctl, which will return ENDOEV again
 584         * if it doesn't recognise the ioctl
 585         */
 586        ret = scsi_nonblockable_ioctl(sdev, cmd, argp,
 587                                        (mode & FMODE_NDELAY) != 0);
 588        if (ret != -ENODEV)
 589                goto out;
 590        ret = scsi_ioctl(sdev, cmd, argp);
 591
 592out:
 593        mutex_unlock(&sr_mutex);
 594        scsi_autopm_put_device(cd->device);
 595        return ret;
 596}
 597
 598static unsigned int sr_block_check_events(struct gendisk *disk,
 599                                          unsigned int clearing)
 600{
 601        struct scsi_cd *cd = scsi_cd(disk);
 602        unsigned int ret;
 603
 604        if (atomic_read(&cd->device->disk_events_disable_depth) == 0) {
 605                scsi_autopm_get_device(cd->device);
 606                ret = cdrom_check_events(&cd->cdi, clearing);
 607                scsi_autopm_put_device(cd->device);
 608        } else {
 609                ret = 0;
 610        }
 611
 612        return ret;
 613}
 614
 615static int sr_block_revalidate_disk(struct gendisk *disk)
 616{
 617        struct scsi_cd *cd = scsi_cd(disk);
 618        struct scsi_sense_hdr sshdr;
 619
 620        scsi_autopm_get_device(cd->device);
 621
 622        /* if the unit is not ready, nothing more to do */
 623        if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 624                goto out;
 625
 626        sr_cd_check(&cd->cdi);
 627        get_sectorsize(cd);
 628out:
 629        scsi_autopm_put_device(cd->device);
 630        return 0;
 631}
 632
 633static const struct block_device_operations sr_bdops =
 634{
 635        .owner          = THIS_MODULE,
 636        .open           = sr_block_open,
 637        .release        = sr_block_release,
 638        .ioctl          = sr_block_ioctl,
 639        .check_events   = sr_block_check_events,
 640        .revalidate_disk = sr_block_revalidate_disk,
 641        /* 
 642         * No compat_ioctl for now because sr_block_ioctl never
 643         * seems to pass arbitrary ioctls down to host drivers.
 644         */
 645};
 646
 647static int sr_open(struct cdrom_device_info *cdi, int purpose)
 648{
 649        struct scsi_cd *cd = cdi->handle;
 650        struct scsi_device *sdev = cd->device;
 651        int retval;
 652
 653        /*
 654         * If the device is in error recovery, wait until it is done.
 655         * If the device is offline, then disallow any access to it.
 656         */
 657        retval = -ENXIO;
 658        if (!scsi_block_when_processing_errors(sdev))
 659                goto error_out;
 660
 661        return 0;
 662
 663error_out:
 664        return retval;  
 665}
 666
 667static void sr_release(struct cdrom_device_info *cdi)
 668{
 669        struct scsi_cd *cd = cdi->handle;
 670
 671        if (cd->device->sector_size > 2048)
 672                sr_set_blocklength(cd, 2048);
 673
 674}
 675
 676static int sr_probe(struct device *dev)
 677{
 678        struct scsi_device *sdev = to_scsi_device(dev);
 679        struct gendisk *disk;
 680        struct scsi_cd *cd;
 681        int minor, error;
 682
 683        error = -ENODEV;
 684        if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
 685                goto fail;
 686
 687        error = -ENOMEM;
 688        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 689        if (!cd)
 690                goto fail;
 691
 692        kref_init(&cd->kref);
 693
 694        disk = alloc_disk(1);
 695        if (!disk)
 696                goto fail_free;
 697
 698        spin_lock(&sr_index_lock);
 699        minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
 700        if (minor == SR_DISKS) {
 701                spin_unlock(&sr_index_lock);
 702                error = -EBUSY;
 703                goto fail_put;
 704        }
 705        __set_bit(minor, sr_index_bits);
 706        spin_unlock(&sr_index_lock);
 707
 708        disk->major = SCSI_CDROM_MAJOR;
 709        disk->first_minor = minor;
 710        sprintf(disk->disk_name, "sr%d", minor);
 711        disk->fops = &sr_bdops;
 712        disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 713        disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 714
 715        blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 716
 717        cd->device = sdev;
 718        cd->disk = disk;
 719        cd->driver = &sr_template;
 720        cd->disk = disk;
 721        cd->capacity = 0x1fffff;
 722        cd->device->changed = 1;        /* force recheck CD type */
 723        cd->media_present = 1;
 724        cd->use = 1;
 725        cd->readcd_known = 0;
 726        cd->readcd_cdda = 0;
 727
 728        cd->cdi.ops = &sr_dops;
 729        cd->cdi.handle = cd;
 730        cd->cdi.mask = 0;
 731        cd->cdi.capacity = 1;
 732        sprintf(cd->cdi.name, "sr%d", minor);
 733
 734        sdev->sector_size = 2048;       /* A guess, just in case */
 735
 736        /* FIXME: need to handle a get_capabilities failure properly ?? */
 737        get_capabilities(cd);
 738        blk_queue_prep_rq(sdev->request_queue, sr_prep_fn);
 739        sr_vendor_init(cd);
 740
 741        disk->driverfs_dev = &sdev->sdev_gendev;
 742        set_capacity(disk, cd->capacity);
 743        disk->private_data = &cd->driver;
 744        disk->queue = sdev->request_queue;
 745        cd->cdi.disk = disk;
 746
 747        if (register_cdrom(&cd->cdi))
 748                goto fail_put;
 749
 750        dev_set_drvdata(dev, cd);
 751        disk->flags |= GENHD_FL_REMOVABLE;
 752        add_disk(disk);
 753
 754        sdev_printk(KERN_DEBUG, sdev,
 755                    "Attached scsi CD-ROM %s\n", cd->cdi.name);
 756        scsi_autopm_put_device(cd->device);
 757
 758        return 0;
 759
 760fail_put:
 761        put_disk(disk);
 762fail_free:
 763        kfree(cd);
 764fail:
 765        return error;
 766}
 767
 768
 769static void get_sectorsize(struct scsi_cd *cd)
 770{
 771        unsigned char cmd[10];
 772        unsigned char buffer[8];
 773        int the_result, retries = 3;
 774        int sector_size;
 775        struct request_queue *queue;
 776
 777        do {
 778                cmd[0] = READ_CAPACITY;
 779                memset((void *) &cmd[1], 0, 9);
 780                memset(buffer, 0, sizeof(buffer));
 781
 782                /* Do the command and wait.. */
 783                the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
 784                                              buffer, sizeof(buffer), NULL,
 785                                              SR_TIMEOUT, MAX_RETRIES, NULL);
 786
 787                retries--;
 788
 789        } while (the_result && retries);
 790
 791
 792        if (the_result) {
 793                cd->capacity = 0x1fffff;
 794                sector_size = 2048;     /* A guess, just in case */
 795        } else {
 796                long last_written;
 797
 798                cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
 799                                    (buffer[2] << 8) | buffer[3]);
 800                /*
 801                 * READ_CAPACITY doesn't return the correct size on
 802                 * certain UDF media.  If last_written is larger, use
 803                 * it instead.
 804                 *
 805                 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
 806                 */
 807                if (!cdrom_get_last_written(&cd->cdi, &last_written))
 808                        cd->capacity = max_t(long, cd->capacity, last_written);
 809
 810                sector_size = (buffer[4] << 24) |
 811                    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
 812                switch (sector_size) {
 813                        /*
 814                         * HP 4020i CD-Recorder reports 2340 byte sectors
 815                         * Philips CD-Writers report 2352 byte sectors
 816                         *
 817                         * Use 2k sectors for them..
 818                         */
 819                case 0:
 820                case 2340:
 821                case 2352:
 822                        sector_size = 2048;
 823                        /* fall through */
 824                case 2048:
 825                        cd->capacity *= 4;
 826                        /* fall through */
 827                case 512:
 828                        break;
 829                default:
 830                        printk("%s: unsupported sector size %d.\n",
 831                               cd->cdi.name, sector_size);
 832                        cd->capacity = 0;
 833                }
 834
 835                cd->device->sector_size = sector_size;
 836
 837                /*
 838                 * Add this so that we have the ability to correctly gauge
 839                 * what the device is capable of.
 840                 */
 841                set_capacity(cd->disk, cd->capacity);
 842        }
 843
 844        queue = cd->device->request_queue;
 845        blk_queue_logical_block_size(queue, sector_size);
 846
 847        return;
 848}
 849
 850static void get_capabilities(struct scsi_cd *cd)
 851{
 852        unsigned char *buffer;
 853        struct scsi_mode_data data;
 854        struct scsi_sense_hdr sshdr;
 855        int rc, n;
 856
 857        static const char *loadmech[] =
 858        {
 859                "caddy",
 860                "tray",
 861                "pop-up",
 862                "",
 863                "changer",
 864                "cartridge changer",
 865                "",
 866                ""
 867        };
 868
 869
 870        /* allocate transfer buffer */
 871        buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 872        if (!buffer) {
 873                printk(KERN_ERR "sr: out of memory.\n");
 874                return;
 875        }
 876
 877        /* eat unit attentions */
 878        scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 879
 880        /* ask for mode page 0x2a */
 881        rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
 882                             SR_TIMEOUT, 3, &data, NULL);
 883
 884        if (!scsi_status_is_good(rc)) {
 885                /* failed, drive doesn't have capabilities mode page */
 886                cd->cdi.speed = 1;
 887                cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
 888                                 CDC_DVD | CDC_DVD_RAM |
 889                                 CDC_SELECT_DISC | CDC_SELECT_SPEED |
 890                                 CDC_MRW | CDC_MRW_W | CDC_RAM);
 891                kfree(buffer);
 892                printk("%s: scsi-1 drive\n", cd->cdi.name);
 893                return;
 894        }
 895
 896        n = data.header_length + data.block_descriptor_length;
 897        cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
 898        cd->readcd_known = 1;
 899        cd->readcd_cdda = buffer[n + 5] & 0x01;
 900        /* print some capability bits */
 901        printk("%s: scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n", cd->cdi.name,
 902               ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
 903               cd->cdi.speed,
 904               buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 905               buffer[n + 3] & 0x20 ? "dvd-ram " : "",
 906               buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
 907               buffer[n + 4] & 0x20 ? "xa/form2 " : "", /* can read xa/from2 */
 908               buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
 909               loadmech[buffer[n + 6] >> 5]);
 910        if ((buffer[n + 6] >> 5) == 0)
 911                /* caddy drives can't close tray... */
 912                cd->cdi.mask |= CDC_CLOSE_TRAY;
 913        if ((buffer[n + 2] & 0x8) == 0)
 914                /* not a DVD drive */
 915                cd->cdi.mask |= CDC_DVD;
 916        if ((buffer[n + 3] & 0x20) == 0) 
 917                /* can't write DVD-RAM media */
 918                cd->cdi.mask |= CDC_DVD_RAM;
 919        if ((buffer[n + 3] & 0x10) == 0)
 920                /* can't write DVD-R media */
 921                cd->cdi.mask |= CDC_DVD_R;
 922        if ((buffer[n + 3] & 0x2) == 0)
 923                /* can't write CD-RW media */
 924                cd->cdi.mask |= CDC_CD_RW;
 925        if ((buffer[n + 3] & 0x1) == 0)
 926                /* can't write CD-R media */
 927                cd->cdi.mask |= CDC_CD_R;
 928        if ((buffer[n + 6] & 0x8) == 0)
 929                /* can't eject */
 930                cd->cdi.mask |= CDC_OPEN_TRAY;
 931
 932        if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
 933            (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
 934                cd->cdi.capacity =
 935                    cdrom_number_of_slots(&cd->cdi);
 936        if (cd->cdi.capacity <= 1)
 937                /* not a changer */
 938                cd->cdi.mask |= CDC_SELECT_DISC;
 939        /*else    I don't think it can close its tray
 940                cd->cdi.mask |= CDC_CLOSE_TRAY; */
 941
 942        /*
 943         * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
 944         */
 945        if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
 946                        (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
 947                cd->device->writeable = 1;
 948        }
 949
 950        kfree(buffer);
 951}
 952
 953/*
 954 * sr_packet() is the entry point for the generic commands generated
 955 * by the Uniform CD-ROM layer. 
 956 */
 957static int sr_packet(struct cdrom_device_info *cdi,
 958                struct packet_command *cgc)
 959{
 960        struct scsi_cd *cd = cdi->handle;
 961        struct scsi_device *sdev = cd->device;
 962
 963        if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
 964                return -EDRIVE_CANT_DO_THIS;
 965
 966        if (cgc->timeout <= 0)
 967                cgc->timeout = IOCTL_TIMEOUT;
 968
 969        sr_do_ioctl(cd, cgc);
 970
 971        return cgc->stat;
 972}
 973
 974/**
 975 *      sr_kref_release - Called to free the scsi_cd structure
 976 *      @kref: pointer to embedded kref
 977 *
 978 *      sr_ref_mutex must be held entering this routine.  Because it is
 979 *      called on last put, you should always use the scsi_cd_get()
 980 *      scsi_cd_put() helpers which manipulate the semaphore directly
 981 *      and never do a direct kref_put().
 982 **/
 983static void sr_kref_release(struct kref *kref)
 984{
 985        struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
 986        struct gendisk *disk = cd->disk;
 987
 988        spin_lock(&sr_index_lock);
 989        clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
 990        spin_unlock(&sr_index_lock);
 991
 992        unregister_cdrom(&cd->cdi);
 993
 994        disk->private_data = NULL;
 995
 996        put_disk(disk);
 997
 998        kfree(cd);
 999}
1000
1001static int sr_remove(struct device *dev)
1002{
1003        struct scsi_cd *cd = dev_get_drvdata(dev);
1004
1005        scsi_autopm_get_device(cd->device);
1006
1007        blk_queue_prep_rq(cd->device->request_queue, scsi_prep_fn);
1008        del_gendisk(cd->disk);
1009
1010        mutex_lock(&sr_ref_mutex);
1011        kref_put(&cd->kref, sr_kref_release);
1012        mutex_unlock(&sr_ref_mutex);
1013
1014        return 0;
1015}
1016
1017static int __init init_sr(void)
1018{
1019        int rc;
1020
1021        rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1022        if (rc)
1023                return rc;
1024        rc = scsi_register_driver(&sr_template.gendrv);
1025        if (rc)
1026                unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1027
1028        return rc;
1029}
1030
1031static void __exit exit_sr(void)
1032{
1033        scsi_unregister_driver(&sr_template.gendrv);
1034        unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1035}
1036
1037module_init(init_sr);
1038module_exit(exit_sr);
1039MODULE_LICENSE("GPL");
1040
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