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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/major.h>
  48#include <linux/blkdev.h>
  49#include <linux/blk-pm.h>
  50#include <linux/mutex.h>
  51#include <linux/slab.h>
  52#include <linux/pm_runtime.h>
  53#include <linux/uaccess.h>
  54
  55#include <asm/unaligned.h>
  56
  57#include <scsi/scsi.h>
  58#include <scsi/scsi_dbg.h>
  59#include <scsi/scsi_device.h>
  60#include <scsi/scsi_driver.h>
  61#include <scsi/scsi_cmnd.h>
  62#include <scsi/scsi_eh.h>
  63#include <scsi/scsi_host.h>
  64#include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
  65
  66#include "scsi_logging.h"
  67#include "sr.h"
  68
  69
  70MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
  71MODULE_LICENSE("GPL");
  72MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
  73MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
  74MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
  75
  76#define SR_DISKS	256
  77
  78#define SR_CAPABILITIES \
  79	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
  80	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
  81	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
  82	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
  83	 CDC_MRW|CDC_MRW_W|CDC_RAM)
  84
  85static int sr_probe(struct device *);
  86static int sr_remove(struct device *);
  87static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
  88static int sr_done(struct scsi_cmnd *);
  89static int sr_runtime_suspend(struct device *dev);
  90
  91static const struct dev_pm_ops sr_pm_ops = {
  92	.runtime_suspend	= sr_runtime_suspend,
  93};
  94
  95static struct scsi_driver sr_template = {
  96	.gendrv = {
  97		.name   	= "sr",
  98		.owner		= THIS_MODULE,
  99		.probe		= sr_probe,
 100		.remove		= sr_remove,
 101		.pm		= &sr_pm_ops,
 102	},
 103	.init_command		= sr_init_command,
 104	.done			= sr_done,
 105};
 106
 107static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
 108static DEFINE_SPINLOCK(sr_index_lock);
 109
 110static struct lock_class_key sr_bio_compl_lkclass;
 111
 112static int sr_open(struct cdrom_device_info *, int);
 113static void sr_release(struct cdrom_device_info *);
 114
 115static void get_sectorsize(struct scsi_cd *);
 116static int get_capabilities(struct scsi_cd *);
 117
 118static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 119				    unsigned int clearing, int slot);
 120static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 121static int sr_read_cdda_bpc(struct cdrom_device_info *cdi, void __user *ubuf,
 122		u32 lba, u32 nr, u8 *last_sense);
 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	.generic_packet		= sr_packet,
 137	.read_cdda_bpc		= sr_read_cdda_bpc,
 138	.capability		= SR_CAPABILITIES,
 139};
 140
 141static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
 142{
 143	return disk->private_data;
 144}
 145
 146static int sr_runtime_suspend(struct device *dev)
 147{
 148	struct scsi_cd *cd = dev_get_drvdata(dev);
 149
 150	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
 151		return 0;
 152
 153	if (cd->media_present)
 154		return -EBUSY;
 155	else
 156		return 0;
 157}
 158
 159static unsigned int sr_get_events(struct scsi_device *sdev)
 160{
 161	u8 buf[8];
 162	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
 163		     1,			/* polled */
 164		     0, 0,		/* reserved */
 165		     1 << 4,		/* notification class: media */
 166		     0, 0,		/* reserved */
 167		     0, sizeof(buf),	/* allocation length */
 168		     0,			/* control */
 169	};
 170	struct event_header *eh = (void *)buf;
 171	struct media_event_desc *med = (void *)(buf + 4);
 172	struct scsi_sense_hdr sshdr;
 173	const struct scsi_exec_args exec_args = {
 174		.sshdr = &sshdr,
 175	};
 176	int result;
 177
 178	result = scsi_execute_cmd(sdev, cmd, REQ_OP_DRV_IN, buf, sizeof(buf),
 179				  SR_TIMEOUT, MAX_RETRIES, &exec_args);
 180	if (result > 0 && scsi_sense_valid(&sshdr) &&
 181	    sshdr.sense_key == UNIT_ATTENTION)
 182		return DISK_EVENT_MEDIA_CHANGE;
 183
 184	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
 185		return 0;
 186
 187	if (eh->nea || eh->notification_class != 0x4)
 188		return 0;
 189
 190	if (med->media_event_code == 1)
 191		return DISK_EVENT_EJECT_REQUEST;
 192	else if (med->media_event_code == 2)
 193		return DISK_EVENT_MEDIA_CHANGE;
 194	else if (med->media_event_code == 3)
 195		return DISK_EVENT_MEDIA_CHANGE;
 196	return 0;
 197}
 198
 199/*
 200 * This function checks to see if the media has been changed or eject
 201 * button has been pressed.  It is possible that we have already
 202 * sensed a change, or the drive may have sensed one and not yet
 203 * reported it.  The past events are accumulated in sdev->changed and
 204 * returned together with the current state.
 205 */
 206static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 207				    unsigned int clearing, int slot)
 208{
 209	struct scsi_cd *cd = cdi->handle;
 210	bool last_present;
 211	struct scsi_sense_hdr sshdr;
 212	unsigned int events;
 213	int ret;
 214
 215	/* no changer support */
 216	if (CDSL_CURRENT != slot)
 217		return 0;
 218
 219	events = sr_get_events(cd->device);
 220	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
 221
 222	/*
 223	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
 224	 * for several times in a row.  We rely on TUR only for this likely
 225	 * broken device, to prevent generating incorrect media changed
 226	 * events for every open().
 227	 */
 228	if (cd->ignore_get_event) {
 229		events &= ~DISK_EVENT_MEDIA_CHANGE;
 230		goto do_tur;
 231	}
 232
 233	/*
 234	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
 235	 * is being cleared.  Note that there are devices which hang
 236	 * if asked to execute TUR repeatedly.
 237	 */
 238	if (cd->device->changed) {
 239		events |= DISK_EVENT_MEDIA_CHANGE;
 240		cd->device->changed = 0;
 241		cd->tur_changed = true;
 242	}
 243
 244	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
 245		return events;
 246do_tur:
 247	/* let's see whether the media is there with TUR */
 248	last_present = cd->media_present;
 249	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 250
 251	/*
 252	 * Media is considered to be present if TUR succeeds or fails with
 253	 * sense data indicating something other than media-not-present
 254	 * (ASC 0x3a).
 255	 */
 256	cd->media_present = scsi_status_is_good(ret) ||
 257		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
 258
 259	if (last_present != cd->media_present)
 260		cd->device->changed = 1;
 261
 262	if (cd->device->changed) {
 263		events |= DISK_EVENT_MEDIA_CHANGE;
 264		cd->device->changed = 0;
 265		cd->tur_changed = true;
 266	}
 267
 268	if (cd->ignore_get_event)
 269		return events;
 270
 271	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
 272	if (!cd->tur_changed) {
 273		if (cd->get_event_changed) {
 274			if (cd->tur_mismatch++ > 8) {
 275				sr_printk(KERN_WARNING, cd,
 276					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
 277				cd->ignore_get_event = true;
 278			}
 279		} else {
 280			cd->tur_mismatch = 0;
 281		}
 282	}
 283	cd->tur_changed = false;
 284	cd->get_event_changed = false;
 285
 286	return events;
 287}
 288
 289/*
 290 * sr_done is the interrupt routine for the device driver.
 291 *
 292 * It will be notified on the end of a SCSI read / write, and will take one
 293 * of several actions based on success or failure.
 294 */
 295static int sr_done(struct scsi_cmnd *SCpnt)
 296{
 297	int result = SCpnt->result;
 298	int this_count = scsi_bufflen(SCpnt);
 299	int good_bytes = (result == 0 ? this_count : 0);
 300	int block_sectors = 0;
 301	long error_sector;
 302	struct request *rq = scsi_cmd_to_rq(SCpnt);
 303	struct scsi_cd *cd = scsi_cd(rq->q->disk);
 304
 305#ifdef DEBUG
 306	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
 307#endif
 308
 309	/*
 310	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
 311	 * success.  Since this is a relatively rare error condition, no
 312	 * care is taken to avoid unnecessary additional work such as
 313	 * memcpy's that could be avoided.
 314	 */
 315	if (scsi_status_is_check_condition(result) &&
 316	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
 317		switch (SCpnt->sense_buffer[2]) {
 318		case MEDIUM_ERROR:
 319		case VOLUME_OVERFLOW:
 320		case ILLEGAL_REQUEST:
 321			if (!(SCpnt->sense_buffer[0] & 0x90))
 322				break;
 323			error_sector =
 324				get_unaligned_be32(&SCpnt->sense_buffer[3]);
 325			if (rq->bio != NULL)
 326				block_sectors = bio_sectors(rq->bio);
 327			if (block_sectors < 4)
 328				block_sectors = 4;
 329			if (cd->device->sector_size == 2048)
 330				error_sector <<= 2;
 331			error_sector &= ~(block_sectors - 1);
 332			good_bytes = (error_sector - blk_rq_pos(rq)) << 9;
 333			if (good_bytes < 0 || good_bytes >= this_count)
 334				good_bytes = 0;
 335			/*
 336			 * The SCSI specification allows for the value
 337			 * returned by READ CAPACITY to be up to 75 2K
 338			 * sectors past the last readable block.
 339			 * Therefore, if we hit a medium error within the
 340			 * last 75 2K sectors, we decrease the saved size
 341			 * value.
 342			 */
 343			if (error_sector < get_capacity(cd->disk) &&
 344			    cd->capacity - error_sector < 4 * 75)
 345				set_capacity(cd->disk, error_sector);
 346			break;
 347
 348		case RECOVERED_ERROR:
 349			good_bytes = this_count;
 350			break;
 351
 352		default:
 353			break;
 354		}
 355	}
 356
 357	return good_bytes;
 358}
 359
 360static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
 361{
 362	int block = 0, this_count, s_size;
 363	struct scsi_cd *cd;
 364	struct request *rq = scsi_cmd_to_rq(SCpnt);
 365	blk_status_t ret;
 366
 367	ret = scsi_alloc_sgtables(SCpnt);
 368	if (ret != BLK_STS_OK)
 369		return ret;
 370	cd = scsi_cd(rq->q->disk);
 371
 372	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
 373		"Doing sr request, block = %d\n", block));
 374
 375	if (!cd->device || !scsi_device_online(cd->device)) {
 376		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 377			"Finishing %u sectors\n", blk_rq_sectors(rq)));
 378		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 379			"Retry with 0x%p\n", SCpnt));
 380		goto out;
 381	}
 382
 383	if (cd->device->changed) {
 384		/*
 385		 * quietly refuse to do anything to a changed disc until the
 386		 * changed bit has been reset
 387		 */
 388		goto out;
 389	}
 390
 391	s_size = cd->device->sector_size;
 392	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
 393		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
 394		goto out;
 395	}
 396
 397	switch (req_op(rq)) {
 398	case REQ_OP_WRITE:
 399		if (!cd->writeable)
 400			goto out;
 401		SCpnt->cmnd[0] = WRITE_10;
 402		cd->cdi.media_written = 1;
 403		break;
 404	case REQ_OP_READ:
 405		SCpnt->cmnd[0] = READ_10;
 406		break;
 407	default:
 408		blk_dump_rq_flags(rq, "Unknown sr command");
 409		goto out;
 410	}
 411
 412	{
 413		struct scatterlist *sg;
 414		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
 415
 416		scsi_for_each_sg(SCpnt, sg, sg_count, i)
 417			size += sg->length;
 418
 419		if (size != scsi_bufflen(SCpnt)) {
 420			scmd_printk(KERN_ERR, SCpnt,
 421				"mismatch count %d, bytes %d\n",
 422				size, scsi_bufflen(SCpnt));
 423			if (scsi_bufflen(SCpnt) > size)
 424				SCpnt->sdb.length = size;
 425		}
 426	}
 427
 428	/*
 429	 * request doesn't start on hw block boundary, add scatter pads
 430	 */
 431	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
 432	    (scsi_bufflen(SCpnt) % s_size)) {
 433		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
 434		goto out;
 435	}
 436
 437	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
 438
 439
 440	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 441					"%s %d/%u 512 byte blocks.\n",
 442					(rq_data_dir(rq) == WRITE) ?
 443					"writing" : "reading",
 444					this_count, blk_rq_sectors(rq)));
 445
 446	SCpnt->cmnd[1] = 0;
 447	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
 448
 449	if (this_count > 0xffff) {
 450		this_count = 0xffff;
 451		SCpnt->sdb.length = this_count * s_size;
 452	}
 453
 454	put_unaligned_be32(block, &SCpnt->cmnd[2]);
 455	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
 456	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
 457
 458	/*
 459	 * We shouldn't disconnect in the middle of a sector, so with a dumb
 460	 * host adapter, it's safe to assume that we can at least transfer
 461	 * this many bytes between each connect / disconnect.
 462	 */
 463	SCpnt->transfersize = cd->device->sector_size;
 464	SCpnt->underflow = this_count << 9;
 465	SCpnt->allowed = MAX_RETRIES;
 466	SCpnt->cmd_len = 10;
 467
 468	/*
 469	 * This indicates that the command is ready from our end to be queued.
 470	 */
 471	return BLK_STS_OK;
 472 out:
 473	scsi_free_sgtables(SCpnt);
 474	return BLK_STS_IOERR;
 475}
 476
 477static void sr_revalidate_disk(struct scsi_cd *cd)
 478{
 479	struct scsi_sense_hdr sshdr;
 480
 481	/* if the unit is not ready, nothing more to do */
 482	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 483		return;
 484	sr_cd_check(&cd->cdi);
 485	get_sectorsize(cd);
 486}
 487
 488static int sr_block_open(struct gendisk *disk, blk_mode_t mode)
 489{
 490	struct scsi_cd *cd = scsi_cd(disk);
 491	struct scsi_device *sdev = cd->device;
 492	int ret;
 493
 494	if (scsi_device_get(cd->device))
 495		return -ENXIO;
 496
 497	scsi_autopm_get_device(sdev);
 498	if (disk_check_media_change(disk))
 499		sr_revalidate_disk(cd);
 500
 501	mutex_lock(&cd->lock);
 502	ret = cdrom_open(&cd->cdi, mode);
 503	mutex_unlock(&cd->lock);
 504
 505	scsi_autopm_put_device(sdev);
 506	if (ret)
 507		scsi_device_put(cd->device);
 508	return ret;
 509}
 510
 511static void sr_block_release(struct gendisk *disk)
 512{
 513	struct scsi_cd *cd = scsi_cd(disk);
 514
 515	mutex_lock(&cd->lock);
 516	cdrom_release(&cd->cdi);
 517	mutex_unlock(&cd->lock);
 518
 519	scsi_device_put(cd->device);
 520}
 521
 522static int sr_block_ioctl(struct block_device *bdev, blk_mode_t mode,
 523		unsigned cmd, unsigned long arg)
 524{
 525	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 526	struct scsi_device *sdev = cd->device;
 527	void __user *argp = (void __user *)arg;
 528	int ret;
 529
 530	if (bdev_is_partition(bdev) && !capable(CAP_SYS_RAWIO))
 531		return -ENOIOCTLCMD;
 532
 533	mutex_lock(&cd->lock);
 534
 535	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
 536			(mode & BLK_OPEN_NDELAY));
 537	if (ret)
 538		goto out;
 539
 540	scsi_autopm_get_device(sdev);
 541
 542	if (cmd != CDROMCLOSETRAY && cmd != CDROMEJECT) {
 543		ret = cdrom_ioctl(&cd->cdi, bdev, cmd, arg);
 544		if (ret != -ENOSYS)
 545			goto put;
 546	}
 547	ret = scsi_ioctl(sdev, mode & BLK_OPEN_WRITE, cmd, argp);
 548
 549put:
 550	scsi_autopm_put_device(sdev);
 551out:
 552	mutex_unlock(&cd->lock);
 553	return ret;
 554}
 555
 556static unsigned int sr_block_check_events(struct gendisk *disk,
 557					  unsigned int clearing)
 558{
 559	struct scsi_cd *cd = disk->private_data;
 560
 561	if (atomic_read(&cd->device->disk_events_disable_depth))
 562		return 0;
 563	return cdrom_check_events(&cd->cdi, clearing);
 564}
 565
 566static void sr_free_disk(struct gendisk *disk)
 567{
 568	struct scsi_cd *cd = disk->private_data;
 569
 570	spin_lock(&sr_index_lock);
 571	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
 572	spin_unlock(&sr_index_lock);
 573
 574	unregister_cdrom(&cd->cdi);
 575	mutex_destroy(&cd->lock);
 576	kfree(cd);
 577}
 578
 579static const struct block_device_operations sr_bdops =
 580{
 581	.owner		= THIS_MODULE,
 582	.open		= sr_block_open,
 583	.release	= sr_block_release,
 584	.ioctl		= sr_block_ioctl,
 585	.compat_ioctl	= blkdev_compat_ptr_ioctl,
 586	.check_events	= sr_block_check_events,
 587	.free_disk	= sr_free_disk,
 588};
 589
 590static int sr_open(struct cdrom_device_info *cdi, int purpose)
 591{
 592	struct scsi_cd *cd = cdi->handle;
 593	struct scsi_device *sdev = cd->device;
 594
 595	/*
 596	 * If the device is in error recovery, wait until it is done.
 597	 * If the device is offline, then disallow any access to it.
 598	 */
 599	if (!scsi_block_when_processing_errors(sdev))
 600		return -ENXIO;
 601
 602	return 0;
 603}
 604
 605static void sr_release(struct cdrom_device_info *cdi)
 606{
 607}
 608
 609static int sr_probe(struct device *dev)
 610{
 611	struct scsi_device *sdev = to_scsi_device(dev);
 612	struct gendisk *disk;
 613	struct scsi_cd *cd;
 614	int minor, error;
 615
 616	scsi_autopm_get_device(sdev);
 617	error = -ENODEV;
 618	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
 619		goto fail;
 620
 621	error = -ENOMEM;
 622	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 623	if (!cd)
 624		goto fail;
 625
 626	disk = blk_mq_alloc_disk_for_queue(sdev->request_queue,
 627					   &sr_bio_compl_lkclass);
 628	if (!disk)
 629		goto fail_free;
 630	mutex_init(&cd->lock);
 631
 632	spin_lock(&sr_index_lock);
 633	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
 634	if (minor == SR_DISKS) {
 635		spin_unlock(&sr_index_lock);
 636		error = -EBUSY;
 637		goto fail_put;
 638	}
 639	__set_bit(minor, sr_index_bits);
 640	spin_unlock(&sr_index_lock);
 641
 642	disk->major = SCSI_CDROM_MAJOR;
 643	disk->first_minor = minor;
 644	disk->minors = 1;
 645	sprintf(disk->disk_name, "sr%d", minor);
 646	disk->fops = &sr_bdops;
 647	disk->flags |= GENHD_FL_REMOVABLE | GENHD_FL_NO_PART;
 648	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 649	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT |
 650				DISK_EVENT_FLAG_BLOCK_ON_EXCL_WRITE;
 651
 652	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 653
 654	cd->device = sdev;
 655	cd->disk = disk;
 656	cd->capacity = 0x1fffff;
 657	cd->device->changed = 1;	/* force recheck CD type */
 658	cd->media_present = 1;
 659	cd->use = 1;
 660	cd->readcd_known = 0;
 661	cd->readcd_cdda = 0;
 662
 663	cd->cdi.ops = &sr_dops;
 664	cd->cdi.handle = cd;
 665	cd->cdi.mask = 0;
 666	cd->cdi.capacity = 1;
 667	sprintf(cd->cdi.name, "sr%d", minor);
 668
 669	sdev->sector_size = 2048;	/* A guess, just in case */
 670
 671	error = -ENOMEM;
 672	if (get_capabilities(cd))
 673		goto fail_minor;
 674	sr_vendor_init(cd);
 675
 676	set_capacity(disk, cd->capacity);
 677	disk->private_data = cd;
 678
 679	if (register_cdrom(disk, &cd->cdi))
 680		goto fail_minor;
 681
 682	/*
 683	 * Initialize block layer runtime PM stuffs before the
 684	 * periodic event checking request gets started in add_disk.
 685	 */
 686	blk_pm_runtime_init(sdev->request_queue, dev);
 687
 688	dev_set_drvdata(dev, cd);
 689	sr_revalidate_disk(cd);
 690
 691	error = device_add_disk(&sdev->sdev_gendev, disk, NULL);
 692	if (error)
 693		goto unregister_cdrom;
 694
 695	sdev_printk(KERN_DEBUG, sdev,
 696		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
 697	scsi_autopm_put_device(cd->device);
 698
 699	return 0;
 700
 701unregister_cdrom:
 702	unregister_cdrom(&cd->cdi);
 703fail_minor:
 704	spin_lock(&sr_index_lock);
 705	clear_bit(minor, sr_index_bits);
 706	spin_unlock(&sr_index_lock);
 707fail_put:
 708	put_disk(disk);
 709	mutex_destroy(&cd->lock);
 710fail_free:
 711	kfree(cd);
 712fail:
 713	scsi_autopm_put_device(sdev);
 714	return error;
 715}
 716
 717
 718static void get_sectorsize(struct scsi_cd *cd)
 719{
 720	unsigned char cmd[10];
 721	unsigned char buffer[8];
 722	int the_result, retries = 3;
 723	int sector_size;
 724	struct request_queue *queue;
 725
 726	do {
 727		cmd[0] = READ_CAPACITY;
 728		memset((void *) &cmd[1], 0, 9);
 729		memset(buffer, 0, sizeof(buffer));
 730
 731		/* Do the command and wait.. */
 732		the_result = scsi_execute_cmd(cd->device, cmd, REQ_OP_DRV_IN,
 733					      buffer, sizeof(buffer),
 734					      SR_TIMEOUT, MAX_RETRIES, NULL);
 735
 736		retries--;
 737
 738	} while (the_result && retries);
 739
 740
 741	if (the_result) {
 742		cd->capacity = 0x1fffff;
 743		sector_size = 2048;	/* A guess, just in case */
 744	} else {
 745		long last_written;
 746
 747		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
 748		/*
 749		 * READ_CAPACITY doesn't return the correct size on
 750		 * certain UDF media.  If last_written is larger, use
 751		 * it instead.
 752		 *
 753		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
 754		 */
 755		if (!cdrom_get_last_written(&cd->cdi, &last_written))
 756			cd->capacity = max_t(long, cd->capacity, last_written);
 757
 758		sector_size = get_unaligned_be32(&buffer[4]);
 759		switch (sector_size) {
 760			/*
 761			 * HP 4020i CD-Recorder reports 2340 byte sectors
 762			 * Philips CD-Writers report 2352 byte sectors
 763			 *
 764			 * Use 2k sectors for them..
 765			 */
 766		case 0:
 767		case 2340:
 768		case 2352:
 769			sector_size = 2048;
 770			fallthrough;
 771		case 2048:
 772			cd->capacity *= 4;
 773			fallthrough;
 774		case 512:
 775			break;
 776		default:
 777			sr_printk(KERN_INFO, cd,
 778				  "unsupported sector size %d.", sector_size);
 779			cd->capacity = 0;
 780		}
 781
 782		cd->device->sector_size = sector_size;
 783
 784		/*
 785		 * Add this so that we have the ability to correctly gauge
 786		 * what the device is capable of.
 787		 */
 788		set_capacity(cd->disk, cd->capacity);
 789	}
 790
 791	queue = cd->device->request_queue;
 792	blk_queue_logical_block_size(queue, sector_size);
 793
 794	return;
 795}
 796
 797static int get_capabilities(struct scsi_cd *cd)
 798{
 799	unsigned char *buffer;
 800	struct scsi_mode_data data;
 801	struct scsi_sense_hdr sshdr;
 802	unsigned int ms_len = 128;
 803	int rc, n;
 804
 805	static const char *loadmech[] =
 806	{
 807		"caddy",
 808		"tray",
 809		"pop-up",
 810		"",
 811		"changer",
 812		"cartridge changer",
 813		"",
 814		""
 815	};
 816
 817
 818	/* allocate transfer buffer */
 819	buffer = kmalloc(512, GFP_KERNEL);
 820	if (!buffer) {
 821		sr_printk(KERN_ERR, cd, "out of memory.\n");
 822		return -ENOMEM;
 823	}
 824
 825	/* eat unit attentions */
 826	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 827
 828	/* ask for mode page 0x2a */
 829	rc = scsi_mode_sense(cd->device, 0, 0x2a, 0, buffer, ms_len,
 830			     SR_TIMEOUT, 3, &data, NULL);
 831
 832	if (rc < 0 || data.length > ms_len ||
 833	    data.header_length + data.block_descriptor_length > data.length) {
 834		/* failed, drive doesn't have capabilities mode page */
 835		cd->cdi.speed = 1;
 836		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
 837				 CDC_DVD | CDC_DVD_RAM |
 838				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
 839				 CDC_MRW | CDC_MRW_W | CDC_RAM);
 840		kfree(buffer);
 841		sr_printk(KERN_INFO, cd, "scsi-1 drive");
 842		return 0;
 843	}
 844
 845	n = data.header_length + data.block_descriptor_length;
 846	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
 847	cd->readcd_known = 1;
 848	cd->readcd_cdda = buffer[n + 5] & 0x01;
 849	/* print some capability bits */
 850	sr_printk(KERN_INFO, cd,
 851		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
 852		  get_unaligned_be16(&buffer[n + 14]) / 176,
 853		  cd->cdi.speed,
 854		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 855		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
 856		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
 857		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
 858		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
 859		  loadmech[buffer[n + 6] >> 5]);
 860	if ((buffer[n + 6] >> 5) == 0)
 861		/* caddy drives can't close tray... */
 862		cd->cdi.mask |= CDC_CLOSE_TRAY;
 863	if ((buffer[n + 2] & 0x8) == 0)
 864		/* not a DVD drive */
 865		cd->cdi.mask |= CDC_DVD;
 866	if ((buffer[n + 3] & 0x20) == 0)
 867		/* can't write DVD-RAM media */
 868		cd->cdi.mask |= CDC_DVD_RAM;
 869	if ((buffer[n + 3] & 0x10) == 0)
 870		/* can't write DVD-R media */
 871		cd->cdi.mask |= CDC_DVD_R;
 872	if ((buffer[n + 3] & 0x2) == 0)
 873		/* can't write CD-RW media */
 874		cd->cdi.mask |= CDC_CD_RW;
 875	if ((buffer[n + 3] & 0x1) == 0)
 876		/* can't write CD-R media */
 877		cd->cdi.mask |= CDC_CD_R;
 878	if ((buffer[n + 6] & 0x8) == 0)
 879		/* can't eject */
 880		cd->cdi.mask |= CDC_OPEN_TRAY;
 881
 882	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
 883	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
 884		cd->cdi.capacity =
 885		    cdrom_number_of_slots(&cd->cdi);
 886	if (cd->cdi.capacity <= 1)
 887		/* not a changer */
 888		cd->cdi.mask |= CDC_SELECT_DISC;
 889	/*else    I don't think it can close its tray
 890		cd->cdi.mask |= CDC_CLOSE_TRAY; */
 891
 892	/*
 893	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
 894	 */
 895	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
 896			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
 897		cd->writeable = 1;
 898	}
 899
 900	kfree(buffer);
 901	return 0;
 902}
 903
 904/*
 905 * sr_packet() is the entry point for the generic commands generated
 906 * by the Uniform CD-ROM layer.
 907 */
 908static int sr_packet(struct cdrom_device_info *cdi,
 909		struct packet_command *cgc)
 910{
 911	struct scsi_cd *cd = cdi->handle;
 912	struct scsi_device *sdev = cd->device;
 913
 914	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
 915		return -EDRIVE_CANT_DO_THIS;
 916
 917	if (cgc->timeout <= 0)
 918		cgc->timeout = IOCTL_TIMEOUT;
 919
 920	sr_do_ioctl(cd, cgc);
 921
 922	return cgc->stat;
 923}
 924
 925static int sr_read_cdda_bpc(struct cdrom_device_info *cdi, void __user *ubuf,
 926		u32 lba, u32 nr, u8 *last_sense)
 927{
 928	struct gendisk *disk = cdi->disk;
 929	u32 len = nr * CD_FRAMESIZE_RAW;
 930	struct scsi_cmnd *scmd;
 931	struct request *rq;
 932	struct bio *bio;
 933	int ret;
 934
 935	rq = scsi_alloc_request(disk->queue, REQ_OP_DRV_IN, 0);
 936	if (IS_ERR(rq))
 937		return PTR_ERR(rq);
 938	scmd = blk_mq_rq_to_pdu(rq);
 939
 940	ret = blk_rq_map_user(disk->queue, rq, NULL, ubuf, len, GFP_KERNEL);
 941	if (ret)
 942		goto out_put_request;
 943
 944	scmd->cmnd[0] = GPCMD_READ_CD;
 945	scmd->cmnd[1] = 1 << 2;
 946	scmd->cmnd[2] = (lba >> 24) & 0xff;
 947	scmd->cmnd[3] = (lba >> 16) & 0xff;
 948	scmd->cmnd[4] = (lba >>  8) & 0xff;
 949	scmd->cmnd[5] = lba & 0xff;
 950	scmd->cmnd[6] = (nr >> 16) & 0xff;
 951	scmd->cmnd[7] = (nr >>  8) & 0xff;
 952	scmd->cmnd[8] = nr & 0xff;
 953	scmd->cmnd[9] = 0xf8;
 954	scmd->cmd_len = 12;
 955	rq->timeout = 60 * HZ;
 956	bio = rq->bio;
 957
 958	blk_execute_rq(rq, false);
 959	if (scmd->result) {
 960		struct scsi_sense_hdr sshdr;
 961
 962		scsi_normalize_sense(scmd->sense_buffer, scmd->sense_len,
 963				     &sshdr);
 964		*last_sense = sshdr.sense_key;
 965		ret = -EIO;
 966	}
 967
 968	if (blk_rq_unmap_user(bio))
 969		ret = -EFAULT;
 970out_put_request:
 971	blk_mq_free_request(rq);
 972	return ret;
 973}
 974
 975static int sr_remove(struct device *dev)
 976{
 977	struct scsi_cd *cd = dev_get_drvdata(dev);
 978
 979	scsi_autopm_get_device(cd->device);
 980
 981	del_gendisk(cd->disk);
 982	put_disk(cd->disk);
 983
 984	return 0;
 985}
 986
 987static int __init init_sr(void)
 988{
 989	int rc;
 990
 991	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
 992	if (rc)
 993		return rc;
 994	rc = scsi_register_driver(&sr_template.gendrv);
 995	if (rc)
 996		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
 997
 998	return rc;
 999}
1000
1001static void __exit exit_sr(void)
1002{
1003	scsi_unregister_driver(&sr_template.gendrv);
1004	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1005}
1006
1007module_init(init_sr);
1008module_exit(exit_sr);
1009MODULE_LICENSE("GPL");
   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 <linux/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_init_command(struct scsi_cmnd *SCpnt);
  83static int sr_done(struct scsi_cmnd *);
  84static int sr_runtime_suspend(struct device *dev);
  85
  86static const struct dev_pm_ops sr_pm_ops = {
  87	.runtime_suspend	= sr_runtime_suspend,
  88};
  89
  90static struct scsi_driver sr_template = {
  91	.gendrv = {
  92		.name   	= "sr",
  93		.owner		= THIS_MODULE,
  94		.probe		= sr_probe,
  95		.remove		= sr_remove,
  96		.pm		= &sr_pm_ops,
  97	},
  98	.init_command		= sr_init_command,
  99	.done			= sr_done,
 100};
 101
 102static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
 103static DEFINE_SPINLOCK(sr_index_lock);
 104
 105/* This semaphore is used to mediate the 0->1 reference get in the
 106 * face of object destruction (i.e. we can't allow a get on an
 107 * object after last put) */
 108static DEFINE_MUTEX(sr_ref_mutex);
 109
 110static int sr_open(struct cdrom_device_info *, int);
 111static void sr_release(struct cdrom_device_info *);
 112
 113static void get_sectorsize(struct scsi_cd *);
 114static void get_capabilities(struct scsi_cd *);
 115
 116static unsigned int sr_check_events(struct cdrom_device_info *cdi,
 117				    unsigned int clearing, int slot);
 118static int sr_packet(struct cdrom_device_info *, struct packet_command *);
 119
 120static struct cdrom_device_ops sr_dops = {
 121	.open			= sr_open,
 122	.release	 	= sr_release,
 123	.drive_status	 	= sr_drive_status,
 124	.check_events		= sr_check_events,
 125	.tray_move		= sr_tray_move,
 126	.lock_door		= sr_lock_door,
 127	.select_speed		= sr_select_speed,
 128	.get_last_session	= sr_get_last_session,
 129	.get_mcn		= sr_get_mcn,
 130	.reset			= sr_reset,
 131	.audio_ioctl		= sr_audio_ioctl,
 132	.capability		= SR_CAPABILITIES,
 133	.generic_packet		= sr_packet,
 134};
 135
 136static void sr_kref_release(struct kref *kref);
 137
 138static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
 139{
 140	return container_of(disk->private_data, struct scsi_cd, driver);
 141}
 142
 143static int sr_runtime_suspend(struct device *dev)
 144{
 145	struct scsi_cd *cd = dev_get_drvdata(dev);
 146
 147	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
 148		return 0;
 149
 150	if (cd->media_present)
 151		return -EBUSY;
 152	else
 153		return 0;
 154}
 155
 156/*
 157 * The get and put routines for the struct scsi_cd.  Note this entity
 158 * has a scsi_device pointer and owns a reference to this.
 159 */
 160static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
 161{
 162	struct scsi_cd *cd = NULL;
 163
 164	mutex_lock(&sr_ref_mutex);
 165	if (disk->private_data == NULL)
 166		goto out;
 167	cd = scsi_cd(disk);
 168	kref_get(&cd->kref);
 169	if (scsi_device_get(cd->device)) {
 170		kref_put(&cd->kref, sr_kref_release);
 171		cd = NULL;
 172	}
 173 out:
 174	mutex_unlock(&sr_ref_mutex);
 175	return cd;
 176}
 177
 178static void scsi_cd_put(struct scsi_cd *cd)
 179{
 180	struct scsi_device *sdev = cd->device;
 181
 182	mutex_lock(&sr_ref_mutex);
 183	kref_put(&cd->kref, sr_kref_release);
 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				sr_printk(KERN_WARNING, cd,
 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	scmd_printk(KERN_INFO, SCpnt, "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_init_command(struct scsi_cmnd *SCpnt)
 387{
 388	int block = 0, this_count, s_size;
 389	struct scsi_cd *cd;
 390	struct request *rq = SCpnt->request;
 391	int ret;
 392
 393	ret = scsi_init_io(SCpnt);
 394	if (ret != BLKPREP_OK)
 395		goto out;
 396	SCpnt = rq->special;
 397	cd = scsi_cd(rq->rq_disk);
 398
 399	/* from here on until we're complete, any goto out
 400	 * is used for a killable error condition */
 401	ret = BLKPREP_KILL;
 402
 403	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
 404		"Doing sr request, block = %d\n", block));
 405
 406	if (!cd->device || !scsi_device_online(cd->device)) {
 407		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 408			"Finishing %u sectors\n", blk_rq_sectors(rq)));
 409		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 410			"Retry with 0x%p\n", SCpnt));
 411		goto out;
 412	}
 413
 414	if (cd->device->changed) {
 415		/*
 416		 * quietly refuse to do anything to a changed disc until the
 417		 * changed bit has been reset
 418		 */
 419		goto out;
 420	}
 421
 422	/*
 423	 * we do lazy blocksize switching (when reading XA sectors,
 424	 * see CDROMREADMODE2 ioctl) 
 425	 */
 426	s_size = cd->device->sector_size;
 427	if (s_size > 2048) {
 428		if (!in_interrupt())
 429			sr_set_blocklength(cd, 2048);
 430		else
 431			scmd_printk(KERN_INFO, SCpnt,
 432				    "can't switch blocksize: in interrupt\n");
 433	}
 434
 435	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
 436		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
 437		goto out;
 438	}
 439
 440	if (rq_data_dir(rq) == WRITE) {
 441		if (!cd->writeable)
 442			goto out;
 443		SCpnt->cmnd[0] = WRITE_10;
 444		cd->cdi.media_written = 1;
 445	} else if (rq_data_dir(rq) == READ) {
 446		SCpnt->cmnd[0] = READ_10;
 447	} else {
 448		blk_dump_rq_flags(rq, "Unknown sr command");
 449		goto out;
 450	}
 451
 452	{
 453		struct scatterlist *sg;
 454		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
 455
 456		scsi_for_each_sg(SCpnt, sg, sg_count, i)
 457			size += sg->length;
 458
 459		if (size != scsi_bufflen(SCpnt)) {
 460			scmd_printk(KERN_ERR, SCpnt,
 461				"mismatch count %d, bytes %d\n",
 462				size, scsi_bufflen(SCpnt));
 463			if (scsi_bufflen(SCpnt) > size)
 464				SCpnt->sdb.length = size;
 465		}
 466	}
 467
 468	/*
 469	 * request doesn't start on hw block boundary, add scatter pads
 470	 */
 471	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
 472	    (scsi_bufflen(SCpnt) % s_size)) {
 473		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
 474		goto out;
 475	}
 476
 477	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
 478
 479
 480	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
 481					"%s %d/%u 512 byte blocks.\n",
 482					(rq_data_dir(rq) == WRITE) ?
 483					"writing" : "reading",
 484					this_count, blk_rq_sectors(rq)));
 485
 486	SCpnt->cmnd[1] = 0;
 487	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
 488
 489	if (this_count > 0xffff) {
 490		this_count = 0xffff;
 491		SCpnt->sdb.length = this_count * s_size;
 492	}
 493
 494	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
 495	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
 496	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
 497	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
 498	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
 499	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
 500	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
 501
 502	/*
 503	 * We shouldn't disconnect in the middle of a sector, so with a dumb
 504	 * host adapter, it's safe to assume that we can at least transfer
 505	 * this many bytes between each connect / disconnect.
 506	 */
 507	SCpnt->transfersize = cd->device->sector_size;
 508	SCpnt->underflow = this_count << 9;
 509	SCpnt->allowed = MAX_RETRIES;
 510
 511	/*
 512	 * This indicates that the command is ready from our end to be
 513	 * queued.
 514	 */
 515	ret = BLKPREP_OK;
 516 out:
 517	return ret;
 518}
 519
 520static int sr_block_open(struct block_device *bdev, fmode_t mode)
 521{
 522	struct scsi_cd *cd;
 523	int ret = -ENXIO;
 524
 525	mutex_lock(&sr_mutex);
 526	cd = scsi_cd_get(bdev->bd_disk);
 527	if (cd) {
 528		ret = cdrom_open(&cd->cdi, bdev, mode);
 529		if (ret)
 530			scsi_cd_put(cd);
 531	}
 532	mutex_unlock(&sr_mutex);
 533	return ret;
 534}
 535
 536static void sr_block_release(struct gendisk *disk, fmode_t mode)
 537{
 538	struct scsi_cd *cd = scsi_cd(disk);
 539	mutex_lock(&sr_mutex);
 540	cdrom_release(&cd->cdi, mode);
 541	scsi_cd_put(cd);
 542	mutex_unlock(&sr_mutex);
 543}
 544
 545static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
 546			  unsigned long arg)
 547{
 548	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
 549	struct scsi_device *sdev = cd->device;
 550	void __user *argp = (void __user *)arg;
 551	int ret;
 552
 553	mutex_lock(&sr_mutex);
 554
 555	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
 556			(mode & FMODE_NDELAY) != 0);
 557	if (ret)
 558		goto out;
 559
 560	/*
 561	 * Send SCSI addressing ioctls directly to mid level, send other
 562	 * ioctls to cdrom/block level.
 563	 */
 564	switch (cmd) {
 565	case SCSI_IOCTL_GET_IDLUN:
 566	case SCSI_IOCTL_GET_BUS_NUMBER:
 567		ret = scsi_ioctl(sdev, cmd, argp);
 568		goto out;
 569	}
 570
 571	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
 572	if (ret != -ENOSYS)
 573		goto out;
 574
 575	ret = scsi_ioctl(sdev, cmd, argp);
 576
 577out:
 578	mutex_unlock(&sr_mutex);
 579	return ret;
 580}
 581
 582static unsigned int sr_block_check_events(struct gendisk *disk,
 583					  unsigned int clearing)
 584{
 585	struct scsi_cd *cd = scsi_cd(disk);
 586
 587	if (atomic_read(&cd->device->disk_events_disable_depth))
 588		return 0;
 589
 590	return cdrom_check_events(&cd->cdi, clearing);
 591}
 592
 593static int sr_block_revalidate_disk(struct gendisk *disk)
 594{
 595	struct scsi_cd *cd = scsi_cd(disk);
 596	struct scsi_sense_hdr sshdr;
 597
 598	/* if the unit is not ready, nothing more to do */
 599	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
 600		goto out;
 601
 602	sr_cd_check(&cd->cdi);
 603	get_sectorsize(cd);
 604out:
 605	return 0;
 606}
 607
 608static const struct block_device_operations sr_bdops =
 609{
 610	.owner		= THIS_MODULE,
 611	.open		= sr_block_open,
 612	.release	= sr_block_release,
 613	.ioctl		= sr_block_ioctl,
 614	.check_events	= sr_block_check_events,
 615	.revalidate_disk = sr_block_revalidate_disk,
 616	/* 
 617	 * No compat_ioctl for now because sr_block_ioctl never
 618	 * seems to pass arbitrary ioctls down to host drivers.
 619	 */
 620};
 621
 622static int sr_open(struct cdrom_device_info *cdi, int purpose)
 623{
 624	struct scsi_cd *cd = cdi->handle;
 625	struct scsi_device *sdev = cd->device;
 626	int retval;
 627
 628	/*
 629	 * If the device is in error recovery, wait until it is done.
 630	 * If the device is offline, then disallow any access to it.
 631	 */
 632	retval = -ENXIO;
 633	if (!scsi_block_when_processing_errors(sdev))
 634		goto error_out;
 635
 636	return 0;
 637
 638error_out:
 639	return retval;	
 640}
 641
 642static void sr_release(struct cdrom_device_info *cdi)
 643{
 644	struct scsi_cd *cd = cdi->handle;
 645
 646	if (cd->device->sector_size > 2048)
 647		sr_set_blocklength(cd, 2048);
 648
 649}
 650
 651static int sr_probe(struct device *dev)
 652{
 653	struct scsi_device *sdev = to_scsi_device(dev);
 654	struct gendisk *disk;
 655	struct scsi_cd *cd;
 656	int minor, error;
 657
 658	scsi_autopm_get_device(sdev);
 659	error = -ENODEV;
 660	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
 661		goto fail;
 662
 663	error = -ENOMEM;
 664	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
 665	if (!cd)
 666		goto fail;
 667
 668	kref_init(&cd->kref);
 669
 670	disk = alloc_disk(1);
 671	if (!disk)
 672		goto fail_free;
 673
 674	spin_lock(&sr_index_lock);
 675	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
 676	if (minor == SR_DISKS) {
 677		spin_unlock(&sr_index_lock);
 678		error = -EBUSY;
 679		goto fail_put;
 680	}
 681	__set_bit(minor, sr_index_bits);
 682	spin_unlock(&sr_index_lock);
 683
 684	disk->major = SCSI_CDROM_MAJOR;
 685	disk->first_minor = minor;
 686	sprintf(disk->disk_name, "sr%d", minor);
 687	disk->fops = &sr_bdops;
 688	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
 689	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
 690
 691	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
 692
 693	cd->device = sdev;
 694	cd->disk = disk;
 695	cd->driver = &sr_template;
 696	cd->disk = disk;
 697	cd->capacity = 0x1fffff;
 698	cd->device->changed = 1;	/* force recheck CD type */
 699	cd->media_present = 1;
 700	cd->use = 1;
 701	cd->readcd_known = 0;
 702	cd->readcd_cdda = 0;
 703
 704	cd->cdi.ops = &sr_dops;
 705	cd->cdi.handle = cd;
 706	cd->cdi.mask = 0;
 707	cd->cdi.capacity = 1;
 708	sprintf(cd->cdi.name, "sr%d", minor);
 709
 710	sdev->sector_size = 2048;	/* A guess, just in case */
 711
 712	/* FIXME: need to handle a get_capabilities failure properly ?? */
 713	get_capabilities(cd);
 714	sr_vendor_init(cd);
 715
 716	set_capacity(disk, cd->capacity);
 717	disk->private_data = &cd->driver;
 718	disk->queue = sdev->request_queue;
 719	cd->cdi.disk = disk;
 720
 721	if (register_cdrom(&cd->cdi))
 722		goto fail_put;
 723
 724	/*
 725	 * Initialize block layer runtime PM stuffs before the
 726	 * periodic event checking request gets started in add_disk.
 727	 */
 728	blk_pm_runtime_init(sdev->request_queue, dev);
 729
 730	dev_set_drvdata(dev, cd);
 731	disk->flags |= GENHD_FL_REMOVABLE;
 732	device_add_disk(&sdev->sdev_gendev, disk);
 733
 734	sdev_printk(KERN_DEBUG, sdev,
 735		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
 736	scsi_autopm_put_device(cd->device);
 737
 738	return 0;
 739
 740fail_put:
 741	put_disk(disk);
 742fail_free:
 743	kfree(cd);
 744fail:
 745	scsi_autopm_put_device(sdev);
 746	return error;
 747}
 748
 749
 750static void get_sectorsize(struct scsi_cd *cd)
 751{
 752	unsigned char cmd[10];
 753	unsigned char buffer[8];
 754	int the_result, retries = 3;
 755	int sector_size;
 756	struct request_queue *queue;
 757
 758	do {
 759		cmd[0] = READ_CAPACITY;
 760		memset((void *) &cmd[1], 0, 9);
 761		memset(buffer, 0, sizeof(buffer));
 762
 763		/* Do the command and wait.. */
 764		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
 765					      buffer, sizeof(buffer), NULL,
 766					      SR_TIMEOUT, MAX_RETRIES, NULL);
 767
 768		retries--;
 769
 770	} while (the_result && retries);
 771
 772
 773	if (the_result) {
 774		cd->capacity = 0x1fffff;
 775		sector_size = 2048;	/* A guess, just in case */
 776	} else {
 777		long last_written;
 778
 779		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
 780				    (buffer[2] << 8) | buffer[3]);
 781		/*
 782		 * READ_CAPACITY doesn't return the correct size on
 783		 * certain UDF media.  If last_written is larger, use
 784		 * it instead.
 785		 *
 786		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
 787		 */
 788		if (!cdrom_get_last_written(&cd->cdi, &last_written))
 789			cd->capacity = max_t(long, cd->capacity, last_written);
 790
 791		sector_size = (buffer[4] << 24) |
 792		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
 793		switch (sector_size) {
 794			/*
 795			 * HP 4020i CD-Recorder reports 2340 byte sectors
 796			 * Philips CD-Writers report 2352 byte sectors
 797			 *
 798			 * Use 2k sectors for them..
 799			 */
 800		case 0:
 801		case 2340:
 802		case 2352:
 803			sector_size = 2048;
 804			/* fall through */
 805		case 2048:
 806			cd->capacity *= 4;
 807			/* fall through */
 808		case 512:
 809			break;
 810		default:
 811			sr_printk(KERN_INFO, cd,
 812				  "unsupported sector size %d.", sector_size);
 813			cd->capacity = 0;
 814		}
 815
 816		cd->device->sector_size = sector_size;
 817
 818		/*
 819		 * Add this so that we have the ability to correctly gauge
 820		 * what the device is capable of.
 821		 */
 822		set_capacity(cd->disk, cd->capacity);
 823	}
 824
 825	queue = cd->device->request_queue;
 826	blk_queue_logical_block_size(queue, sector_size);
 827
 828	return;
 829}
 830
 831static void get_capabilities(struct scsi_cd *cd)
 832{
 833	unsigned char *buffer;
 834	struct scsi_mode_data data;
 835	struct scsi_sense_hdr sshdr;
 836	int rc, n;
 837
 838	static const char *loadmech[] =
 839	{
 840		"caddy",
 841		"tray",
 842		"pop-up",
 843		"",
 844		"changer",
 845		"cartridge changer",
 846		"",
 847		""
 848	};
 849
 850
 851	/* allocate transfer buffer */
 852	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
 853	if (!buffer) {
 854		sr_printk(KERN_ERR, cd, "out of memory.\n");
 855		return;
 856	}
 857
 858	/* eat unit attentions */
 859	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
 860
 861	/* ask for mode page 0x2a */
 862	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, 128,
 863			     SR_TIMEOUT, 3, &data, NULL);
 864
 865	if (!scsi_status_is_good(rc)) {
 866		/* failed, drive doesn't have capabilities mode page */
 867		cd->cdi.speed = 1;
 868		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
 869				 CDC_DVD | CDC_DVD_RAM |
 870				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
 871				 CDC_MRW | CDC_MRW_W | CDC_RAM);
 872		kfree(buffer);
 873		sr_printk(KERN_INFO, cd, "scsi-1 drive");
 874		return;
 875	}
 876
 877	n = data.header_length + data.block_descriptor_length;
 878	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
 879	cd->readcd_known = 1;
 880	cd->readcd_cdda = buffer[n + 5] & 0x01;
 881	/* print some capability bits */
 882	sr_printk(KERN_INFO, cd,
 883		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
 884		  ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
 885		  cd->cdi.speed,
 886		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
 887		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
 888		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
 889		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
 890		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
 891		  loadmech[buffer[n + 6] >> 5]);
 892	if ((buffer[n + 6] >> 5) == 0)
 893		/* caddy drives can't close tray... */
 894		cd->cdi.mask |= CDC_CLOSE_TRAY;
 895	if ((buffer[n + 2] & 0x8) == 0)
 896		/* not a DVD drive */
 897		cd->cdi.mask |= CDC_DVD;
 898	if ((buffer[n + 3] & 0x20) == 0)
 899		/* can't write DVD-RAM media */
 900		cd->cdi.mask |= CDC_DVD_RAM;
 901	if ((buffer[n + 3] & 0x10) == 0)
 902		/* can't write DVD-R media */
 903		cd->cdi.mask |= CDC_DVD_R;
 904	if ((buffer[n + 3] & 0x2) == 0)
 905		/* can't write CD-RW media */
 906		cd->cdi.mask |= CDC_CD_RW;
 907	if ((buffer[n + 3] & 0x1) == 0)
 908		/* can't write CD-R media */
 909		cd->cdi.mask |= CDC_CD_R;
 910	if ((buffer[n + 6] & 0x8) == 0)
 911		/* can't eject */
 912		cd->cdi.mask |= CDC_OPEN_TRAY;
 913
 914	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
 915	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
 916		cd->cdi.capacity =
 917		    cdrom_number_of_slots(&cd->cdi);
 918	if (cd->cdi.capacity <= 1)
 919		/* not a changer */
 920		cd->cdi.mask |= CDC_SELECT_DISC;
 921	/*else    I don't think it can close its tray
 922		cd->cdi.mask |= CDC_CLOSE_TRAY; */
 923
 924	/*
 925	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
 926	 */
 927	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
 928			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
 929		cd->writeable = 1;
 930	}
 931
 932	kfree(buffer);
 933}
 934
 935/*
 936 * sr_packet() is the entry point for the generic commands generated
 937 * by the Uniform CD-ROM layer.
 938 */
 939static int sr_packet(struct cdrom_device_info *cdi,
 940		struct packet_command *cgc)
 941{
 942	struct scsi_cd *cd = cdi->handle;
 943	struct scsi_device *sdev = cd->device;
 944
 945	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
 946		return -EDRIVE_CANT_DO_THIS;
 947
 948	if (cgc->timeout <= 0)
 949		cgc->timeout = IOCTL_TIMEOUT;
 950
 951	sr_do_ioctl(cd, cgc);
 952
 953	return cgc->stat;
 954}
 955
 956/**
 957 *	sr_kref_release - Called to free the scsi_cd structure
 958 *	@kref: pointer to embedded kref
 959 *
 960 *	sr_ref_mutex must be held entering this routine.  Because it is
 961 *	called on last put, you should always use the scsi_cd_get()
 962 *	scsi_cd_put() helpers which manipulate the semaphore directly
 963 *	and never do a direct kref_put().
 964 **/
 965static void sr_kref_release(struct kref *kref)
 966{
 967	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
 968	struct gendisk *disk = cd->disk;
 969
 970	spin_lock(&sr_index_lock);
 971	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
 972	spin_unlock(&sr_index_lock);
 973
 974	unregister_cdrom(&cd->cdi);
 975
 976	disk->private_data = NULL;
 977
 978	put_disk(disk);
 979
 980	kfree(cd);
 981}
 982
 983static int sr_remove(struct device *dev)
 984{
 985	struct scsi_cd *cd = dev_get_drvdata(dev);
 986
 987	scsi_autopm_get_device(cd->device);
 988
 989	del_gendisk(cd->disk);
 990	dev_set_drvdata(dev, NULL);
 991
 992	mutex_lock(&sr_ref_mutex);
 993	kref_put(&cd->kref, sr_kref_release);
 994	mutex_unlock(&sr_ref_mutex);
 995
 996	return 0;
 997}
 998
 999static int __init init_sr(void)
1000{
1001	int rc;
1002
1003	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1004	if (rc)
1005		return rc;
1006	rc = scsi_register_driver(&sr_template.gendrv);
1007	if (rc)
1008		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1009
1010	return rc;
1011}
1012
1013static void __exit exit_sr(void)
1014{
1015	scsi_unregister_driver(&sr_template.gendrv);
1016	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1017}
1018
1019module_init(init_sr);
1020module_exit(exit_sr);
1021MODULE_LICENSE("GPL");