linux/drivers/scsi/sr.c
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   1// SPDX-License-Identifier: GPL-2.0-only
   2/*
   3 *  sr.c Copyright (C) 1992 David Giller
   4 *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
   5 *
   6 *  adapted from:
   7 *      sd.c Copyright (C) 1992 Drew Eckhardt
   8 *      Linux scsi disk driver by
   9 *              Drew Eckhardt <drew@colorado.edu>
  10 *
  11 *      Modified by Eric Youngdale ericy@andante.org to
  12 *      add scatter-gather, multiple outstanding request, and other
  13 *      enhancements.
  14 *
  15 *      Modified by Eric Youngdale eric@andante.org to support loadable
  16 *      low-level scsi drivers.
  17 *
  18 *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
  19 *      provide auto-eject.
  20 *
  21 *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
  22 *      generic cdrom interface
  23 *
  24 *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
  25 *      interface, capabilities probe additions, ioctl cleanups, etc.
  26 *
  27 *      Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
  28 *
  29 *      Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
  30 *      transparently and lose the GHOST hack
  31 *
  32 *      Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
  33 *      check resource allocation in sr_init and some cleanups
  34 */
  35
  36#include <linux/module.h>
  37#include <linux/fs.h>
  38#include <linux/kernel.h>
  39#include <linux/mm.h>
  40#include <linux/bio.h>
  41#include <linux/compat.h>
  42#include <linux/string.h>
  43#include <linux/errno.h>
  44#include <linux/cdrom.h>
  45#include <linux/interrupt.h>
  46#include <linux/init.h>
  47#include <linux/blkdev.h>
  48#include <linux/blk-pm.h>
  49#include <linux/mutex.h>
  50#include <linux/slab.h>
  51#include <linux/pm_runtime.h>
  52#include <linux/uaccess.h>
  53
  54#include <asm/unaligned.h>
  55
  56#include <scsi/scsi.h>
  57#include <scsi/scsi_dbg.h>
  58#include <scsi/scsi_device.h>
  59#include <scsi/scsi_driver.h>
  60#include <scsi/scsi_cmnd.h>
  61#include <scsi/scsi_eh.h>
  62#include <scsi/scsi_host.h>
  63#include <scsi/scsi_ioctl.h>    /* For the door lock/unlock commands */
  64
  65#include "scsi_logging.h"
  66#include "sr.h"
  67
  68
  69MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
  70MODULE_LICENSE("GPL");
  71MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
  72MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
  73MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
  74
  75#define SR_DISKS        256
  76
  77#define SR_CAPABILITIES \
  78        (CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
  79         CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
  80         CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
  81         CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
  82         CDC_MRW|CDC_MRW_W|CDC_RAM)
  83
  84static int sr_probe(struct device *);
  85static int sr_remove(struct device *);
  86static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
  87static int sr_done(struct scsi_cmnd *);
  88static int sr_runtime_suspend(struct device *dev);
  89
  90static const struct dev_pm_ops sr_pm_ops = {
  91        .runtime_suspend        = sr_runtime_suspend,
  92};
  93
  94static struct scsi_driver sr_template = {
  95        .gendrv = {
  96                .name           = "sr",
  97                .owner          = THIS_MODULE,
  98                .probe          = sr_probe,
  99                .remove         = sr_remove,
 100                .pm             = &sr_pm_ops,
 101        },
 102        .init_command           = sr_init_command,
 103        .done                   = sr_done,
 104};
 105
 106static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
 107static DEFINE_SPINLOCK(sr_index_lock);
 108
 109/* This semaphore is used to mediate the 0->1 reference get in the
 110 * face of object destruction (i.e. we can't allow a get on an
 111 * object after last put) */
 112static DEFINE_MUTEX(sr_ref_mutex);
 113
 114static int sr_open(struct cdrom_device_info *, int);
 115static void sr_release(struct cdrom_device_info *);
 116
 117static void get_sectorsize(struct scsi_cd *);
 118static void get_capabilities(struct scsi_cd *);
 119
 120static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 121                                    unsigned int clearing, int slot);
 122static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 123
 124static const struct cdrom_device_ops sr_dops = {
 125        .open                   = sr_open,
 126        .release                = sr_release,
 127        .drive_status           = sr_drive_status,
 128        .check_events           = sr_check_events,
 129        .tray_move              = sr_tray_move,
 130        .lock_door              = sr_lock_door,
 131        .select_speed           = sr_select_speed,
 132        .get_last_session       = sr_get_last_session,
 133        .get_mcn                = sr_get_mcn,
 134        .reset                  = sr_reset,
 135        .audio_ioctl            = sr_audio_ioctl,
 136        .capability             = SR_CAPABILITIES,
 137        .generic_packet         = sr_packet,
 138};
 139
 140static void sr_kref_release(struct kref *kref);
 141
 142static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
 143{
 144        return container_of(disk->private_data, struct scsi_cd, driver);
 145}
 146
 147static int sr_runtime_suspend(struct device *dev)
 148{
 149        struct scsi_cd *cd = dev_get_drvdata(dev);
 150
 151        if (!cd)        /* E.g.: runtime suspend following sr_remove() */
 152                return 0;
 153
 154        if (cd->media_present)
 155                return -EBUSY;
 156        else
 157                return 0;
 158}
 159
 160/*
 161 * The get and put routines for the struct scsi_cd.  Note this entity
 162 * has a scsi_device pointer and owns a reference to this.
 163 */
 164static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 165{
 166        struct scsi_cd *cd = NULL;
 167
 168        mutex_lock(&sr_ref_mutex);
 169        if (disk->private_data == NULL)
 170                goto out;
 171        cd = scsi_cd(disk);
 172        kref_get(&cd->kref);
 173        if (scsi_device_get(cd->device)) {
 174                kref_put(&cd->kref, sr_kref_release);
 175                cd = NULL;
 176        }
 177 out:
 178        mutex_unlock(&sr_ref_mutex);
 179        return cd;
 180}
 181
 182static void scsi_cd_put(struct scsi_cd *cd)
 183{
 184        struct scsi_device *sdev = cd->device;
 185
 186        mutex_lock(&sr_ref_mutex);
 187        kref_put(&cd->kref, sr_kref_release);
 188        scsi_device_put(sdev);
 189        mutex_unlock(&sr_ref_mutex);
 190}
 191
 192static unsigned int sr_get_events(struct scsi_device *sdev)
 193{
 194        u8 buf[8];
 195        u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
 196                     1,                 /* polled */
 197                     0, 0,              /* reserved */
 198                     1 << 4,            /* notification class: media */
 199                     0, 0,              /* reserved */
 200                     0, sizeof(buf),    /* allocation length */
 201                     0,                 /* control */
 202        };
 203        struct event_header *eh = (void *)buf;
 204        struct media_event_desc *med = (void *)(buf + 4);
 205        struct scsi_sense_hdr sshdr;
 206        int result;
 207
 208        result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
 209                                  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
 210        if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
 211                return DISK_EVENT_MEDIA_CHANGE;
 212
 213        if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
 214                return 0;
 215
 216        if (eh->nea || eh->notification_class != 0x4)
 217                return 0;
 218
 219        if (med->media_event_code == 1)
 220                return DISK_EVENT_EJECT_REQUEST;
 221        else if (med->media_event_code == 2)
 222                return DISK_EVENT_MEDIA_CHANGE;
 223        else if (med->media_event_code == 3)
 224                return DISK_EVENT_MEDIA_CHANGE;
 225        return 0;
 226}
 227
 228/*
 229 * This function checks to see if the media has been changed or eject
 230 * button has been pressed.  It is possible that we have already
 231 * sensed a change, or the drive may have sensed one and not yet
 232 * reported it.  The past events are accumulated in sdev->changed and
 233 * returned together with the current state.
 234 */
 235static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 236                                    unsigned int clearing, int slot)
 237{
 238        struct scsi_cd *cd = cdi->handle;
 239        bool last_present;
 240        struct scsi_sense_hdr sshdr;
 241        unsigned int events;
 242        int ret;
 243
 244        /* no changer support */
 245        if (CDSL_CURRENT != slot)
 246                return 0;
 247
 248        events = sr_get_events(cd->device);
 249        cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
 250
 251        /*
 252         * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
 253         * for several times in a row.  We rely on TUR only for this likely
 254         * broken device, to prevent generating incorrect media changed
 255         * events for every open().
 256         */
 257        if (cd->ignore_get_event) {
 258                events &= ~DISK_EVENT_MEDIA_CHANGE;
 259                goto do_tur;
 260        }
 261
 262        /*
 263         * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
 264         * is being cleared.  Note that there are devices which hang
 265         * if asked to execute TUR repeatedly.
 266         */
 267        if (cd->device->changed) {
 268                events |= DISK_EVENT_MEDIA_CHANGE;
 269                cd->device->changed = 0;
 270                cd->tur_changed = true;
 271        }
 272
 273        if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
 274                return events;
 275do_tur:
 276        /* let's see whether the media is there with TUR */
 277        last_present = cd->media_present;
 278        ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 279
 280        /*
 281         * Media is considered to be present if TUR succeeds or fails with
 282         * sense data indicating something other than media-not-present
 283         * (ASC 0x3a).
 284         */
 285        cd->media_present = scsi_status_is_good(ret) ||
 286                (scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 287
 288        if (last_present != cd->media_present)
 289                cd->device->changed = 1;
 290
 291        if (cd->device->changed) {
 292                events |= DISK_EVENT_MEDIA_CHANGE;
 293                cd->device->changed = 0;
 294                cd->tur_changed = true;
 295        }
 296
 297        if (cd->ignore_get_event)
 298                return events;
 299
 300        /* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
 301        if (!cd->tur_changed) {
 302                if (cd->get_event_changed) {
 303                        if (cd->tur_mismatch++ > 8) {
 304                                sr_printk(KERN_WARNING, cd,
 305                                          "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
 306                                cd->ignore_get_event = true;
 307                        }
 308                } else {
 309                        cd->tur_mismatch = 0;
 310                }
 311        }
 312        cd->tur_changed = false;
 313        cd->get_event_changed = false;
 314
 315        return events;
 316}
 317
 318/*
 319 * sr_done is the interrupt routine for the device driver.
 320 *
 321 * It will be notified on the end of a SCSI read / write, and will take one
 322 * of several actions based on success or failure.
 323 */
 324static int sr_done(struct scsi_cmnd *SCpnt)
 325{
 326        int result = SCpnt->result;
 327        int this_count = scsi_bufflen(SCpnt);
 328        int good_bytes = (result == 0 ? this_count : 0);
 329        int block_sectors = 0;
 330        long error_sector;
 331        struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
 332
 333#ifdef DEBUG
 334        scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
 335#endif
 336
 337        /*
 338         * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
 339         * success.  Since this is a relatively rare error condition, no
 340         * care is taken to avoid unnecessary additional work such as
 341         * memcpy's that could be avoided.
 342         */
 343        if (driver_byte(result) != 0 &&         /* An error occurred */
 344            (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
 345                switch (SCpnt->sense_buffer[2]) {
 346                case MEDIUM_ERROR:
 347                case VOLUME_OVERFLOW:
 348                case ILLEGAL_REQUEST:
 349                        if (!(SCpnt->sense_buffer[0] & 0x90))
 350                                break;
 351                        error_sector =
 352                                get_unaligned_be32(&SCpnt->sense_buffer[3]);
 353                        if (SCpnt->request->bio != NULL)
 354                                block_sectors =
 355                                        bio_sectors(SCpnt->request->bio);
 356                        if (block_sectors < 4)
 357                                block_sectors = 4;
 358                        if (cd->device->sector_size == 2048)
 359                                error_sector <<= 2;
 360                        error_sector &= ~(block_sectors - 1);
 361                        good_bytes = (error_sector -
 362                                      blk_rq_pos(SCpnt->request)) << 9;
 363                        if (good_bytes < 0 || good_bytes >= this_count)
 364                                good_bytes = 0;
 365                        /*
 366                         * The SCSI specification allows for the value
 367                         * returned by READ CAPACITY to be up to 75 2K
 368                         * sectors past the last readable block.
 369                         * Therefore, if we hit a medium error within the
 370                         * last 75 2K sectors, we decrease the saved size
 371                         * value.
 372                         */
 373                        if (error_sector < get_capacity(cd->disk) &&
 374                            cd->capacity - error_sector < 4 * 75)
 375                                set_capacity(cd->disk, error_sector);
 376                        break;
 377
 378                case RECOVERED_ERROR:
 379                        good_bytes = this_count;
 380                        break;
 381
 382                default:
 383                        break;
 384                }
 385        }
 386
 387        return good_bytes;
 388}
 389
 390static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
 391{
 392        int block = 0, this_count, s_size;
 393        struct scsi_cd *cd;
 394        struct request *rq = SCpnt->request;
 395        blk_status_t ret;
 396
 397        ret = scsi_alloc_sgtables(SCpnt);
 398        if (ret != BLK_STS_OK)
 399                return ret;
 400        cd = scsi_cd(rq->rq_disk);
 401
 402        SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
 403                "Doing sr request, block = %d\n", block));
 404
 405        if (!cd->device || !scsi_device_online(cd->device)) {
 406                SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 407                        "Finishing %u sectors\n", blk_rq_sectors(rq)));
 408                SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 409                        "Retry with 0x%p\n", SCpnt));
 410                goto out;
 411        }
 412
 413        if (cd->device->changed) {
 414                /*
 415                 * quietly refuse to do anything to a changed disc until the
 416                 * changed bit has been reset
 417                 */
 418                goto out;
 419        }
 420
 421        s_size = cd->device->sector_size;
 422        if (s_size != 512 && s_size != 1024 && s_size != 2048) {
 423                scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
 424                goto out;
 425        }
 426
 427        switch (req_op(rq)) {
 428        case REQ_OP_WRITE:
 429                if (!cd->writeable)
 430                        goto out;
 431                SCpnt->cmnd[0] = WRITE_10;
 432                cd->cdi.media_written = 1;
 433                break;
 434        case REQ_OP_READ:
 435                SCpnt->cmnd[0] = READ_10;
 436                break;
 437        default:
 438                blk_dump_rq_flags(rq, "Unknown sr command");
 439                goto out;
 440        }
 441
 442        {
 443                struct scatterlist *sg;
 444                int i, size = 0, sg_count = scsi_sg_count(SCpnt);
 445
 446                scsi_for_each_sg(SCpnt, sg, sg_count, i)
 447                        size += sg->length;
 448
 449                if (size != scsi_bufflen(SCpnt)) {
 450                        scmd_printk(KERN_ERR, SCpnt,
 451                                "mismatch count %d, bytes %d\n",
 452                                size, scsi_bufflen(SCpnt));
 453                        if (scsi_bufflen(SCpnt) > size)
 454                                SCpnt->sdb.length = size;
 455                }
 456        }
 457
 458        /*
 459         * request doesn't start on hw block boundary, add scatter pads
 460         */
 461        if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
 462            (scsi_bufflen(SCpnt) % s_size)) {
 463                scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
 464                goto out;
 465        }
 466
 467        this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
 468
 469
 470        SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 471                                        "%s %d/%u 512 byte blocks.\n",
 472                                        (rq_data_dir(rq) == WRITE) ?
 473                                        "writing" : "reading",
 474                                        this_count, blk_rq_sectors(rq)));
 475
 476        SCpnt->cmnd[1] = 0;
 477        block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
 478
 479        if (this_count > 0xffff) {
 480                this_count = 0xffff;
 481                SCpnt->sdb.length = this_count * s_size;
 482        }
 483
 484        put_unaligned_be32(block, &SCpnt->cmnd[2]);
 485        SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
 486        put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
 487
 488        /*
 489         * We shouldn't disconnect in the middle of a sector, so with a dumb
 490         * host adapter, it's safe to assume that we can at least transfer
 491         * this many bytes between each connect / disconnect.
 492         */
 493        SCpnt->transfersize = cd->device->sector_size;
 494        SCpnt->underflow = this_count << 9;
 495        SCpnt->allowed = MAX_RETRIES;
 496        SCpnt->cmd_len = 10;
 497
 498        /*
 499         * This indicates that the command is ready from our end to be queued.
 500         */
 501        return BLK_STS_OK;
 502 out:
 503        scsi_free_sgtables(SCpnt);
 504        return BLK_STS_IOERR;
 505}
 506
 507static void sr_revalidate_disk(struct scsi_cd *cd)
 508{
 509        struct scsi_sense_hdr sshdr;
 510
 511        /* if the unit is not ready, nothing more to do */
 512        if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 513                return;
 514        sr_cd_check(&cd->cdi);
 515        get_sectorsize(cd);
 516}
 517
 518static int sr_block_open(struct block_device *bdev, fmode_t mode)
 519{
 520        struct scsi_cd *cd;
 521        struct scsi_device *sdev;
 522        int ret = -ENXIO;
 523
 524        cd = scsi_cd_get(bdev->bd_disk);
 525        if (!cd)
 526                goto out;
 527
 528        sdev = cd->device;
 529        scsi_autopm_get_device(sdev);
 530        if (bdev_check_media_change(bdev))
 531                sr_revalidate_disk(cd);
 532
 533        mutex_lock(&cd->lock);
 534        ret = cdrom_open(&cd->cdi, bdev, mode);
 535        mutex_unlock(&cd->lock);
 536
 537        scsi_autopm_put_device(sdev);
 538        if (ret)
 539                scsi_cd_put(cd);
 540
 541out:
 542        return ret;
 543}
 544
 545static void sr_block_release(struct gendisk *disk, fmode_t mode)
 546{
 547        struct scsi_cd *cd = scsi_cd(disk);
 548
 549        mutex_lock(&cd->lock);
 550        cdrom_release(&cd->cdi, mode);
 551        mutex_unlock(&cd->lock);
 552
 553        scsi_cd_put(cd);
 554}
 555
 556static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 557                          unsigned long arg)
 558{
 559        struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 560        struct scsi_device *sdev = cd->device;
 561        void __user *argp = (void __user *)arg;
 562        int ret;
 563
 564        mutex_lock(&cd->lock);
 565
 566        ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
 567                        (mode & FMODE_NDELAY) != 0);
 568        if (ret)
 569                goto out;
 570
 571        scsi_autopm_get_device(sdev);
 572
 573        /*
 574         * Send SCSI addressing ioctls directly to mid level, send other
 575         * ioctls to cdrom/block level.
 576         */
 577        switch (cmd) {
 578        case SCSI_IOCTL_GET_IDLUN:
 579        case SCSI_IOCTL_GET_BUS_NUMBER:
 580                ret = scsi_ioctl(sdev, cmd, argp);
 581                goto put;
 582        }
 583
 584        ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
 585        if (ret != -ENOSYS)
 586                goto put;
 587
 588        ret = scsi_ioctl(sdev, cmd, argp);
 589
 590put:
 591        scsi_autopm_put_device(sdev);
 592
 593out:
 594        mutex_unlock(&cd->lock);
 595        return ret;
 596}
 597
 598#ifdef CONFIG_COMPAT
 599static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 600                          unsigned long arg)
 601{
 602        struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 603        struct scsi_device *sdev = cd->device;
 604        void __user *argp = compat_ptr(arg);
 605        int ret;
 606
 607        mutex_lock(&cd->lock);
 608
 609        ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
 610                        (mode & FMODE_NDELAY) != 0);
 611        if (ret)
 612                goto out;
 613
 614        scsi_autopm_get_device(sdev);
 615
 616        /*
 617         * Send SCSI addressing ioctls directly to mid level, send other
 618         * ioctls to cdrom/block level.
 619         */
 620        switch (cmd) {
 621        case SCSI_IOCTL_GET_IDLUN:
 622        case SCSI_IOCTL_GET_BUS_NUMBER:
 623                ret = scsi_compat_ioctl(sdev, cmd, argp);
 624                goto put;
 625        }
 626
 627        ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
 628        if (ret != -ENOSYS)
 629                goto put;
 630
 631        ret = scsi_compat_ioctl(sdev, cmd, argp);
 632
 633put:
 634        scsi_autopm_put_device(sdev);
 635
 636out:
 637        mutex_unlock(&cd->lock);
 638        return ret;
 639
 640}
 641#endif
 642
 643static unsigned int sr_block_check_events(struct gendisk *disk,
 644                                          unsigned int clearing)
 645{
 646        unsigned int ret = 0;
 647        struct scsi_cd *cd;
 648
 649        cd = scsi_cd_get(disk);
 650        if (!cd)
 651                return 0;
 652
 653        if (!atomic_read(&cd->device->disk_events_disable_depth))
 654                ret = cdrom_check_events(&cd->cdi, clearing);
 655
 656        scsi_cd_put(cd);
 657        return ret;
 658}
 659
 660static const struct block_device_operations sr_bdops =
 661{
 662        .owner          = THIS_MODULE,
 663        .open           = sr_block_open,
 664        .release        = sr_block_release,
 665        .ioctl          = sr_block_ioctl,
 666#ifdef CONFIG_COMPAT
 667        .compat_ioctl   = sr_block_compat_ioctl,
 668#endif
 669        .check_events   = sr_block_check_events,
 670};
 671
 672static int sr_open(struct cdrom_device_info *cdi, int purpose)
 673{
 674        struct scsi_cd *cd = cdi->handle;
 675        struct scsi_device *sdev = cd->device;
 676        int retval;
 677
 678        /*
 679         * If the device is in error recovery, wait until it is done.
 680         * If the device is offline, then disallow any access to it.
 681         */
 682        retval = -ENXIO;
 683        if (!scsi_block_when_processing_errors(sdev))
 684                goto error_out;
 685
 686        return 0;
 687
 688error_out:
 689        return retval;  
 690}
 691
 692static void sr_release(struct cdrom_device_info *cdi)
 693{
 694}
 695
 696static int sr_probe(struct device *dev)
 697{
 698        struct scsi_device *sdev = to_scsi_device(dev);
 699        struct gendisk *disk;
 700        struct scsi_cd *cd;
 701        int minor, error;
 702
 703        scsi_autopm_get_device(sdev);
 704        error = -ENODEV;
 705        if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
 706                goto fail;
 707
 708        error = -ENOMEM;
 709        cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 710        if (!cd)
 711                goto fail;
 712
 713        kref_init(&cd->kref);
 714
 715        disk = alloc_disk(1);
 716        if (!disk)
 717                goto fail_free;
 718        mutex_init(&cd->lock);
 719
 720        spin_lock(&sr_index_lock);
 721        minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
 722        if (minor == SR_DISKS) {
 723                spin_unlock(&sr_index_lock);
 724                error = -EBUSY;
 725                goto fail_put;
 726        }
 727        __set_bit(minor, sr_index_bits);
 728        spin_unlock(&sr_index_lock);
 729
 730        disk->major = SCSI_CDROM_MAJOR;
 731        disk->first_minor = minor;
 732        sprintf(disk->disk_name, "sr%d", minor);
 733        disk->fops = &sr_bdops;
 734        disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 735        disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 736        disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
 737
 738        blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 739
 740        cd->device = sdev;
 741        cd->disk = disk;
 742        cd->driver = &sr_template;
 743        cd->disk = disk;
 744        cd->capacity = 0x1fffff;
 745        cd->device->changed = 1;        /* force recheck CD type */
 746        cd->media_present = 1;
 747        cd->use = 1;
 748        cd->readcd_known = 0;
 749        cd->readcd_cdda = 0;
 750
 751        cd->cdi.ops = &sr_dops;
 752        cd->cdi.handle = cd;
 753        cd->cdi.mask = 0;
 754        cd->cdi.capacity = 1;
 755        sprintf(cd->cdi.name, "sr%d", minor);
 756
 757        sdev->sector_size = 2048;       /* A guess, just in case */
 758
 759        /* FIXME: need to handle a get_capabilities failure properly ?? */
 760        get_capabilities(cd);
 761        sr_vendor_init(cd);
 762
 763        set_capacity(disk, cd->capacity);
 764        disk->private_data = &cd->driver;
 765        disk->queue = sdev->request_queue;
 766
 767        if (register_cdrom(disk, &cd->cdi))
 768                goto fail_minor;
 769
 770        /*
 771         * Initialize block layer runtime PM stuffs before the
 772         * periodic event checking request gets started in add_disk.
 773         */
 774        blk_pm_runtime_init(sdev->request_queue, dev);
 775
 776        dev_set_drvdata(dev, cd);
 777        disk->flags |= GENHD_FL_REMOVABLE;
 778        sr_revalidate_disk(cd);
 779        device_add_disk(&sdev->sdev_gendev, disk, NULL);
 780
 781        sdev_printk(KERN_DEBUG, sdev,
 782                    "Attached scsi CD-ROM %s\n", cd->cdi.name);
 783        scsi_autopm_put_device(cd->device);
 784
 785        return 0;
 786
 787fail_minor:
 788        spin_lock(&sr_index_lock);
 789        clear_bit(minor, sr_index_bits);
 790        spin_unlock(&sr_index_lock);
 791fail_put:
 792        put_disk(disk);
 793        mutex_destroy(&cd->lock);
 794fail_free:
 795        kfree(cd);
 796fail:
 797        scsi_autopm_put_device(sdev);
 798        return error;
 799}
 800
 801
 802static void get_sectorsize(struct scsi_cd *cd)
 803{
 804        unsigned char cmd[10];
 805        unsigned char buffer[8];
 806        int the_result, retries = 3;
 807        int sector_size;
 808        struct request_queue *queue;
 809
 810        do {
 811                cmd[0] = READ_CAPACITY;
 812                memset((void *) &cmd[1], 0, 9);
 813                memset(buffer, 0, sizeof(buffer));
 814
 815                /* Do the command and wait.. */
 816                the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
 817                                              buffer, sizeof(buffer), NULL,
 818                                              SR_TIMEOUT, MAX_RETRIES, NULL);
 819
 820                retries--;
 821
 822        } while (the_result && retries);
 823
 824
 825        if (the_result) {
 826                cd->capacity = 0x1fffff;
 827                sector_size = 2048;     /* A guess, just in case */
 828        } else {
 829                long last_written;
 830
 831                cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
 832                /*
 833                 * READ_CAPACITY doesn't return the correct size on
 834                 * certain UDF media.  If last_written is larger, use
 835                 * it instead.
 836                 *
 837                 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
 838                 */
 839                if (!cdrom_get_last_written(&cd->cdi, &last_written))
 840                        cd->capacity = max_t(long, cd->capacity, last_written);
 841
 842                sector_size = get_unaligned_be32(&buffer[4]);
 843                switch (sector_size) {
 844                        /*
 845                         * HP 4020i CD-Recorder reports 2340 byte sectors
 846                         * Philips CD-Writers report 2352 byte sectors
 847                         *
 848                         * Use 2k sectors for them..
 849                         */
 850                case 0:
 851                case 2340:
 852                case 2352:
 853                        sector_size = 2048;
 854                        fallthrough;
 855                case 2048:
 856                        cd->capacity *= 4;
 857                        fallthrough;
 858                case 512:
 859                        break;
 860                default:
 861                        sr_printk(KERN_INFO, cd,
 862                                  "unsupported sector size %d.", sector_size);
 863                        cd->capacity = 0;
 864                }
 865
 866                cd->device->sector_size = sector_size;
 867
 868                /*
 869                 * Add this so that we have the ability to correctly gauge
 870                 * what the device is capable of.
 871                 */
 872                set_capacity(cd->disk, cd->capacity);
 873        }
 874
 875        queue = cd->device->request_queue;
 876        blk_queue_logical_block_size(queue, sector_size);
 877
 878        return;
 879}
 880
 881static void get_capabilities(struct scsi_cd *cd)
 882{
 883        unsigned char *buffer;
 884        struct scsi_mode_data data;
 885        struct scsi_sense_hdr sshdr;
 886        unsigned int ms_len = 128;
 887        int rc, n;
 888
 889        static const char *loadmech[] =
 890        {
 891                "caddy",
 892                "tray",
 893                "pop-up",
 894                "",
 895                "changer",
 896                "cartridge changer",
 897                "",
 898                ""
 899        };
 900
 901
 902        /* allocate transfer buffer */
 903        buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 904        if (!buffer) {
 905                sr_printk(KERN_ERR, cd, "out of memory.\n");
 906                return;
 907        }
 908
 909        /* eat unit attentions */
 910        scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 911
 912        /* ask for mode page 0x2a */
 913        rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
 914                             SR_TIMEOUT, 3, &data, NULL);
 915
 916        if (rc < 0 || data.length > ms_len ||
 917            data.header_length + data.block_descriptor_length > data.length) {
 918                /* failed, drive doesn't have capabilities mode page */
 919                cd->cdi.speed = 1;
 920                cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
 921                                 CDC_DVD | CDC_DVD_RAM |
 922                                 CDC_SELECT_DISC | CDC_SELECT_SPEED |
 923                                 CDC_MRW | CDC_MRW_W | CDC_RAM);
 924                kfree(buffer);
 925                sr_printk(KERN_INFO, cd, "scsi-1 drive");
 926                return;
 927        }
 928
 929        n = data.header_length + data.block_descriptor_length;
 930        cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
 931        cd->readcd_known = 1;
 932        cd->readcd_cdda = buffer[n + 5] & 0x01;
 933        /* print some capability bits */
 934        sr_printk(KERN_INFO, cd,
 935                  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
 936                  get_unaligned_be16(&buffer[n + 14]) / 176,
 937                  cd->cdi.speed,
 938                  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 939                  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
 940                  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
 941                  buffer[n + 4] & 0x20 ? "xa/form2 " : "",      /* can read xa/from2 */
 942                  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
 943                  loadmech[buffer[n + 6] >> 5]);
 944        if ((buffer[n + 6] >> 5) == 0)
 945                /* caddy drives can't close tray... */
 946                cd->cdi.mask |= CDC_CLOSE_TRAY;
 947        if ((buffer[n + 2] & 0x8) == 0)
 948                /* not a DVD drive */
 949                cd->cdi.mask |= CDC_DVD;
 950        if ((buffer[n + 3] & 0x20) == 0)
 951                /* can't write DVD-RAM media */
 952                cd->cdi.mask |= CDC_DVD_RAM;
 953        if ((buffer[n + 3] & 0x10) == 0)
 954                /* can't write DVD-R media */
 955                cd->cdi.mask |= CDC_DVD_R;
 956        if ((buffer[n + 3] & 0x2) == 0)
 957                /* can't write CD-RW media */
 958                cd->cdi.mask |= CDC_CD_RW;
 959        if ((buffer[n + 3] & 0x1) == 0)
 960                /* can't write CD-R media */
 961                cd->cdi.mask |= CDC_CD_R;
 962        if ((buffer[n + 6] & 0x8) == 0)
 963                /* can't eject */
 964                cd->cdi.mask |= CDC_OPEN_TRAY;
 965
 966        if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
 967            (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
 968                cd->cdi.capacity =
 969                    cdrom_number_of_slots(&cd->cdi);
 970        if (cd->cdi.capacity <= 1)
 971                /* not a changer */
 972                cd->cdi.mask |= CDC_SELECT_DISC;
 973        /*else    I don't think it can close its tray
 974                cd->cdi.mask |= CDC_CLOSE_TRAY; */
 975
 976        /*
 977         * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
 978         */
 979        if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
 980                        (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
 981                cd->writeable = 1;
 982        }
 983
 984        kfree(buffer);
 985}
 986
 987/*
 988 * sr_packet() is the entry point for the generic commands generated
 989 * by the Uniform CD-ROM layer.
 990 */
 991static int sr_packet(struct cdrom_device_info *cdi,
 992                struct packet_command *cgc)
 993{
 994        struct scsi_cd *cd = cdi->handle;
 995        struct scsi_device *sdev = cd->device;
 996
 997        if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
 998                return -EDRIVE_CANT_DO_THIS;
 999
1000        if (cgc->timeout <= 0)
1001                cgc->timeout = IOCTL_TIMEOUT;
1002
1003        sr_do_ioctl(cd, cgc);
1004
1005        return cgc->stat;
1006}
1007
1008/**
1009 *      sr_kref_release - Called to free the scsi_cd structure
1010 *      @kref: pointer to embedded kref
1011 *
1012 *      sr_ref_mutex must be held entering this routine.  Because it is
1013 *      called on last put, you should always use the scsi_cd_get()
1014 *      scsi_cd_put() helpers which manipulate the semaphore directly
1015 *      and never do a direct kref_put().
1016 **/
1017static void sr_kref_release(struct kref *kref)
1018{
1019        struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1020        struct gendisk *disk = cd->disk;
1021
1022        spin_lock(&sr_index_lock);
1023        clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1024        spin_unlock(&sr_index_lock);
1025
1026        unregister_cdrom(&cd->cdi);
1027
1028        disk->private_data = NULL;
1029
1030        put_disk(disk);
1031
1032        mutex_destroy(&cd->lock);
1033
1034        kfree(cd);
1035}
1036
1037static int sr_remove(struct device *dev)
1038{
1039        struct scsi_cd *cd = dev_get_drvdata(dev);
1040
1041        scsi_autopm_get_device(cd->device);
1042
1043        del_gendisk(cd->disk);
1044        dev_set_drvdata(dev, NULL);
1045
1046        mutex_lock(&sr_ref_mutex);
1047        kref_put(&cd->kref, sr_kref_release);
1048        mutex_unlock(&sr_ref_mutex);
1049
1050        return 0;
1051}
1052
1053static int __init init_sr(void)
1054{
1055        int rc;
1056
1057        rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1058        if (rc)
1059                return rc;
1060        rc = scsi_register_driver(&sr_template.gendrv);
1061        if (rc)
1062                unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1063
1064        return rc;
1065}
1066
1067static void __exit exit_sr(void)
1068{
1069        scsi_unregister_driver(&sr_template.gendrv);
1070        unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1071}
1072
1073module_init(init_sr);
1074module_exit(exit_sr);
1075MODULE_LICENSE("GPL");
1076