xref: /linux/drivers/scsi/sr.c (revision 17b121ad0c43342bc894632f6710b894849ca372)
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 
69 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
70 MODULE_LICENSE("GPL");
71 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
72 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
73 MODULE_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 
84 static int sr_probe(struct device *);
85 static int sr_remove(struct device *);
86 static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
87 static int sr_done(struct scsi_cmnd *);
88 static int sr_runtime_suspend(struct device *dev);
89 
90 static const struct dev_pm_ops sr_pm_ops = {
91 	.runtime_suspend	= sr_runtime_suspend,
92 };
93 
94 static 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 
106 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
107 static DEFINE_SPINLOCK(sr_index_lock);
108 
109 static struct lock_class_key sr_bio_compl_lkclass;
110 
111 /* This semaphore is used to mediate the 0->1 reference get in the
112  * face of object destruction (i.e. we can't allow a get on an
113  * object after last put) */
114 static DEFINE_MUTEX(sr_ref_mutex);
115 
116 static int sr_open(struct cdrom_device_info *, int);
117 static void sr_release(struct cdrom_device_info *);
118 
119 static void get_sectorsize(struct scsi_cd *);
120 static void get_capabilities(struct scsi_cd *);
121 
122 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
123 				    unsigned int clearing, int slot);
124 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
125 
126 static const struct cdrom_device_ops sr_dops = {
127 	.open			= sr_open,
128 	.release	 	= sr_release,
129 	.drive_status	 	= sr_drive_status,
130 	.check_events		= sr_check_events,
131 	.tray_move		= sr_tray_move,
132 	.lock_door		= sr_lock_door,
133 	.select_speed		= sr_select_speed,
134 	.get_last_session	= sr_get_last_session,
135 	.get_mcn		= sr_get_mcn,
136 	.reset			= sr_reset,
137 	.audio_ioctl		= sr_audio_ioctl,
138 	.capability		= SR_CAPABILITIES,
139 	.generic_packet		= sr_packet,
140 };
141 
142 static void sr_kref_release(struct kref *kref);
143 
144 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
145 {
146 	return container_of(disk->private_data, struct scsi_cd, driver);
147 }
148 
149 static int sr_runtime_suspend(struct device *dev)
150 {
151 	struct scsi_cd *cd = dev_get_drvdata(dev);
152 
153 	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
154 		return 0;
155 
156 	if (cd->media_present)
157 		return -EBUSY;
158 	else
159 		return 0;
160 }
161 
162 /*
163  * The get and put routines for the struct scsi_cd.  Note this entity
164  * has a scsi_device pointer and owns a reference to this.
165  */
166 static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
167 {
168 	struct scsi_cd *cd = NULL;
169 
170 	mutex_lock(&sr_ref_mutex);
171 	if (disk->private_data == NULL)
172 		goto out;
173 	cd = scsi_cd(disk);
174 	kref_get(&cd->kref);
175 	if (scsi_device_get(cd->device)) {
176 		kref_put(&cd->kref, sr_kref_release);
177 		cd = NULL;
178 	}
179  out:
180 	mutex_unlock(&sr_ref_mutex);
181 	return cd;
182 }
183 
184 static void scsi_cd_put(struct scsi_cd *cd)
185 {
186 	struct scsi_device *sdev = cd->device;
187 
188 	mutex_lock(&sr_ref_mutex);
189 	kref_put(&cd->kref, sr_kref_release);
190 	scsi_device_put(sdev);
191 	mutex_unlock(&sr_ref_mutex);
192 }
193 
194 static unsigned int sr_get_events(struct scsi_device *sdev)
195 {
196 	u8 buf[8];
197 	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
198 		     1,			/* polled */
199 		     0, 0,		/* reserved */
200 		     1 << 4,		/* notification class: media */
201 		     0, 0,		/* reserved */
202 		     0, sizeof(buf),	/* allocation length */
203 		     0,			/* control */
204 	};
205 	struct event_header *eh = (void *)buf;
206 	struct media_event_desc *med = (void *)(buf + 4);
207 	struct scsi_sense_hdr sshdr;
208 	int result;
209 
210 	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
211 				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
212 	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
213 		return DISK_EVENT_MEDIA_CHANGE;
214 
215 	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
216 		return 0;
217 
218 	if (eh->nea || eh->notification_class != 0x4)
219 		return 0;
220 
221 	if (med->media_event_code == 1)
222 		return DISK_EVENT_EJECT_REQUEST;
223 	else if (med->media_event_code == 2)
224 		return DISK_EVENT_MEDIA_CHANGE;
225 	else if (med->media_event_code == 3)
226 		return DISK_EVENT_MEDIA_CHANGE;
227 	return 0;
228 }
229 
230 /*
231  * This function checks to see if the media has been changed or eject
232  * button has been pressed.  It is possible that we have already
233  * sensed a change, or the drive may have sensed one and not yet
234  * reported it.  The past events are accumulated in sdev->changed and
235  * returned together with the current state.
236  */
237 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
238 				    unsigned int clearing, int slot)
239 {
240 	struct scsi_cd *cd = cdi->handle;
241 	bool last_present;
242 	struct scsi_sense_hdr sshdr;
243 	unsigned int events;
244 	int ret;
245 
246 	/* no changer support */
247 	if (CDSL_CURRENT != slot)
248 		return 0;
249 
250 	events = sr_get_events(cd->device);
251 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
252 
253 	/*
254 	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
255 	 * for several times in a row.  We rely on TUR only for this likely
256 	 * broken device, to prevent generating incorrect media changed
257 	 * events for every open().
258 	 */
259 	if (cd->ignore_get_event) {
260 		events &= ~DISK_EVENT_MEDIA_CHANGE;
261 		goto do_tur;
262 	}
263 
264 	/*
265 	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
266 	 * is being cleared.  Note that there are devices which hang
267 	 * if asked to execute TUR repeatedly.
268 	 */
269 	if (cd->device->changed) {
270 		events |= DISK_EVENT_MEDIA_CHANGE;
271 		cd->device->changed = 0;
272 		cd->tur_changed = true;
273 	}
274 
275 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
276 		return events;
277 do_tur:
278 	/* let's see whether the media is there with TUR */
279 	last_present = cd->media_present;
280 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
281 
282 	/*
283 	 * Media is considered to be present if TUR succeeds or fails with
284 	 * sense data indicating something other than media-not-present
285 	 * (ASC 0x3a).
286 	 */
287 	cd->media_present = scsi_status_is_good(ret) ||
288 		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
289 
290 	if (last_present != cd->media_present)
291 		cd->device->changed = 1;
292 
293 	if (cd->device->changed) {
294 		events |= DISK_EVENT_MEDIA_CHANGE;
295 		cd->device->changed = 0;
296 		cd->tur_changed = true;
297 	}
298 
299 	if (cd->ignore_get_event)
300 		return events;
301 
302 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
303 	if (!cd->tur_changed) {
304 		if (cd->get_event_changed) {
305 			if (cd->tur_mismatch++ > 8) {
306 				sr_printk(KERN_WARNING, cd,
307 					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
308 				cd->ignore_get_event = true;
309 			}
310 		} else {
311 			cd->tur_mismatch = 0;
312 		}
313 	}
314 	cd->tur_changed = false;
315 	cd->get_event_changed = false;
316 
317 	return events;
318 }
319 
320 /*
321  * sr_done is the interrupt routine for the device driver.
322  *
323  * It will be notified on the end of a SCSI read / write, and will take one
324  * of several actions based on success or failure.
325  */
326 static int sr_done(struct scsi_cmnd *SCpnt)
327 {
328 	int result = SCpnt->result;
329 	int this_count = scsi_bufflen(SCpnt);
330 	int good_bytes = (result == 0 ? this_count : 0);
331 	int block_sectors = 0;
332 	long error_sector;
333 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
334 
335 #ifdef DEBUG
336 	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
337 #endif
338 
339 	/*
340 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
341 	 * success.  Since this is a relatively rare error condition, no
342 	 * care is taken to avoid unnecessary additional work such as
343 	 * memcpy's that could be avoided.
344 	 */
345 	if (scsi_status_is_check_condition(result) &&
346 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
347 		switch (SCpnt->sense_buffer[2]) {
348 		case MEDIUM_ERROR:
349 		case VOLUME_OVERFLOW:
350 		case ILLEGAL_REQUEST:
351 			if (!(SCpnt->sense_buffer[0] & 0x90))
352 				break;
353 			error_sector =
354 				get_unaligned_be32(&SCpnt->sense_buffer[3]);
355 			if (SCpnt->request->bio != NULL)
356 				block_sectors =
357 					bio_sectors(SCpnt->request->bio);
358 			if (block_sectors < 4)
359 				block_sectors = 4;
360 			if (cd->device->sector_size == 2048)
361 				error_sector <<= 2;
362 			error_sector &= ~(block_sectors - 1);
363 			good_bytes = (error_sector -
364 				      blk_rq_pos(SCpnt->request)) << 9;
365 			if (good_bytes < 0 || good_bytes >= this_count)
366 				good_bytes = 0;
367 			/*
368 			 * The SCSI specification allows for the value
369 			 * returned by READ CAPACITY to be up to 75 2K
370 			 * sectors past the last readable block.
371 			 * Therefore, if we hit a medium error within the
372 			 * last 75 2K sectors, we decrease the saved size
373 			 * value.
374 			 */
375 			if (error_sector < get_capacity(cd->disk) &&
376 			    cd->capacity - error_sector < 4 * 75)
377 				set_capacity(cd->disk, error_sector);
378 			break;
379 
380 		case RECOVERED_ERROR:
381 			good_bytes = this_count;
382 			break;
383 
384 		default:
385 			break;
386 		}
387 	}
388 
389 	return good_bytes;
390 }
391 
392 static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
393 {
394 	int block = 0, this_count, s_size;
395 	struct scsi_cd *cd;
396 	struct request *rq = SCpnt->request;
397 	blk_status_t ret;
398 
399 	ret = scsi_alloc_sgtables(SCpnt);
400 	if (ret != BLK_STS_OK)
401 		return ret;
402 	cd = scsi_cd(rq->rq_disk);
403 
404 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
405 		"Doing sr request, block = %d\n", block));
406 
407 	if (!cd->device || !scsi_device_online(cd->device)) {
408 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
409 			"Finishing %u sectors\n", blk_rq_sectors(rq)));
410 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
411 			"Retry with 0x%p\n", SCpnt));
412 		goto out;
413 	}
414 
415 	if (cd->device->changed) {
416 		/*
417 		 * quietly refuse to do anything to a changed disc until the
418 		 * changed bit has been reset
419 		 */
420 		goto out;
421 	}
422 
423 	s_size = cd->device->sector_size;
424 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
425 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
426 		goto out;
427 	}
428 
429 	switch (req_op(rq)) {
430 	case REQ_OP_WRITE:
431 		if (!cd->writeable)
432 			goto out;
433 		SCpnt->cmnd[0] = WRITE_10;
434 		cd->cdi.media_written = 1;
435 		break;
436 	case REQ_OP_READ:
437 		SCpnt->cmnd[0] = READ_10;
438 		break;
439 	default:
440 		blk_dump_rq_flags(rq, "Unknown sr command");
441 		goto out;
442 	}
443 
444 	{
445 		struct scatterlist *sg;
446 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
447 
448 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
449 			size += sg->length;
450 
451 		if (size != scsi_bufflen(SCpnt)) {
452 			scmd_printk(KERN_ERR, SCpnt,
453 				"mismatch count %d, bytes %d\n",
454 				size, scsi_bufflen(SCpnt));
455 			if (scsi_bufflen(SCpnt) > size)
456 				SCpnt->sdb.length = size;
457 		}
458 	}
459 
460 	/*
461 	 * request doesn't start on hw block boundary, add scatter pads
462 	 */
463 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
464 	    (scsi_bufflen(SCpnt) % s_size)) {
465 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
466 		goto out;
467 	}
468 
469 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
470 
471 
472 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
473 					"%s %d/%u 512 byte blocks.\n",
474 					(rq_data_dir(rq) == WRITE) ?
475 					"writing" : "reading",
476 					this_count, blk_rq_sectors(rq)));
477 
478 	SCpnt->cmnd[1] = 0;
479 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
480 
481 	if (this_count > 0xffff) {
482 		this_count = 0xffff;
483 		SCpnt->sdb.length = this_count * s_size;
484 	}
485 
486 	put_unaligned_be32(block, &SCpnt->cmnd[2]);
487 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
488 	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
489 
490 	/*
491 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
492 	 * host adapter, it's safe to assume that we can at least transfer
493 	 * this many bytes between each connect / disconnect.
494 	 */
495 	SCpnt->transfersize = cd->device->sector_size;
496 	SCpnt->underflow = this_count << 9;
497 	SCpnt->allowed = MAX_RETRIES;
498 	SCpnt->cmd_len = 10;
499 
500 	/*
501 	 * This indicates that the command is ready from our end to be queued.
502 	 */
503 	return BLK_STS_OK;
504  out:
505 	scsi_free_sgtables(SCpnt);
506 	return BLK_STS_IOERR;
507 }
508 
509 static void sr_revalidate_disk(struct scsi_cd *cd)
510 {
511 	struct scsi_sense_hdr sshdr;
512 
513 	/* if the unit is not ready, nothing more to do */
514 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
515 		return;
516 	sr_cd_check(&cd->cdi);
517 	get_sectorsize(cd);
518 }
519 
520 static int sr_block_open(struct block_device *bdev, fmode_t mode)
521 {
522 	struct scsi_cd *cd;
523 	struct scsi_device *sdev;
524 	int ret = -ENXIO;
525 
526 	cd = scsi_cd_get(bdev->bd_disk);
527 	if (!cd)
528 		goto out;
529 
530 	sdev = cd->device;
531 	scsi_autopm_get_device(sdev);
532 	if (bdev_check_media_change(bdev))
533 		sr_revalidate_disk(cd);
534 
535 	mutex_lock(&cd->lock);
536 	ret = cdrom_open(&cd->cdi, bdev, mode);
537 	mutex_unlock(&cd->lock);
538 
539 	scsi_autopm_put_device(sdev);
540 	if (ret)
541 		scsi_cd_put(cd);
542 
543 out:
544 	return ret;
545 }
546 
547 static void sr_block_release(struct gendisk *disk, fmode_t mode)
548 {
549 	struct scsi_cd *cd = scsi_cd(disk);
550 
551 	mutex_lock(&cd->lock);
552 	cdrom_release(&cd->cdi, mode);
553 	mutex_unlock(&cd->lock);
554 
555 	scsi_cd_put(cd);
556 }
557 
558 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
559 			  unsigned long arg)
560 {
561 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
562 	struct scsi_device *sdev = cd->device;
563 	void __user *argp = (void __user *)arg;
564 	int ret;
565 
566 	mutex_lock(&cd->lock);
567 
568 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
569 			(mode & FMODE_NDELAY) != 0);
570 	if (ret)
571 		goto out;
572 
573 	scsi_autopm_get_device(sdev);
574 
575 	/*
576 	 * Send SCSI addressing ioctls directly to mid level, send other
577 	 * ioctls to cdrom/block level.
578 	 */
579 	switch (cmd) {
580 	case SCSI_IOCTL_GET_IDLUN:
581 	case SCSI_IOCTL_GET_BUS_NUMBER:
582 		ret = scsi_ioctl(sdev, cmd, argp);
583 		goto put;
584 	}
585 
586 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
587 	if (ret != -ENOSYS)
588 		goto put;
589 
590 	ret = scsi_ioctl(sdev, cmd, argp);
591 
592 put:
593 	scsi_autopm_put_device(sdev);
594 
595 out:
596 	mutex_unlock(&cd->lock);
597 	return ret;
598 }
599 
600 #ifdef CONFIG_COMPAT
601 static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
602 			  unsigned long arg)
603 {
604 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
605 	struct scsi_device *sdev = cd->device;
606 	void __user *argp = compat_ptr(arg);
607 	int ret;
608 
609 	mutex_lock(&cd->lock);
610 
611 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
612 			(mode & FMODE_NDELAY) != 0);
613 	if (ret)
614 		goto out;
615 
616 	scsi_autopm_get_device(sdev);
617 
618 	/*
619 	 * Send SCSI addressing ioctls directly to mid level, send other
620 	 * ioctls to cdrom/block level.
621 	 */
622 	switch (cmd) {
623 	case SCSI_IOCTL_GET_IDLUN:
624 	case SCSI_IOCTL_GET_BUS_NUMBER:
625 		ret = scsi_compat_ioctl(sdev, cmd, argp);
626 		goto put;
627 	}
628 
629 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
630 	if (ret != -ENOSYS)
631 		goto put;
632 
633 	ret = scsi_compat_ioctl(sdev, cmd, argp);
634 
635 put:
636 	scsi_autopm_put_device(sdev);
637 
638 out:
639 	mutex_unlock(&cd->lock);
640 	return ret;
641 
642 }
643 #endif
644 
645 static unsigned int sr_block_check_events(struct gendisk *disk,
646 					  unsigned int clearing)
647 {
648 	unsigned int ret = 0;
649 	struct scsi_cd *cd;
650 
651 	cd = scsi_cd_get(disk);
652 	if (!cd)
653 		return 0;
654 
655 	if (!atomic_read(&cd->device->disk_events_disable_depth))
656 		ret = cdrom_check_events(&cd->cdi, clearing);
657 
658 	scsi_cd_put(cd);
659 	return ret;
660 }
661 
662 static const struct block_device_operations sr_bdops =
663 {
664 	.owner		= THIS_MODULE,
665 	.open		= sr_block_open,
666 	.release	= sr_block_release,
667 	.ioctl		= sr_block_ioctl,
668 #ifdef CONFIG_COMPAT
669 	.compat_ioctl	= sr_block_compat_ioctl,
670 #endif
671 	.check_events	= sr_block_check_events,
672 };
673 
674 static int sr_open(struct cdrom_device_info *cdi, int purpose)
675 {
676 	struct scsi_cd *cd = cdi->handle;
677 	struct scsi_device *sdev = cd->device;
678 	int retval;
679 
680 	/*
681 	 * If the device is in error recovery, wait until it is done.
682 	 * If the device is offline, then disallow any access to it.
683 	 */
684 	retval = -ENXIO;
685 	if (!scsi_block_when_processing_errors(sdev))
686 		goto error_out;
687 
688 	return 0;
689 
690 error_out:
691 	return retval;
692 }
693 
694 static void sr_release(struct cdrom_device_info *cdi)
695 {
696 }
697 
698 static int sr_probe(struct device *dev)
699 {
700 	struct scsi_device *sdev = to_scsi_device(dev);
701 	struct gendisk *disk;
702 	struct scsi_cd *cd;
703 	int minor, error;
704 
705 	scsi_autopm_get_device(sdev);
706 	error = -ENODEV;
707 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
708 		goto fail;
709 
710 	error = -ENOMEM;
711 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
712 	if (!cd)
713 		goto fail;
714 
715 	kref_init(&cd->kref);
716 
717 	disk = __alloc_disk_node(sdev->request_queue, NUMA_NO_NODE,
718 				 &sr_bio_compl_lkclass);
719 	if (!disk)
720 		goto fail_free;
721 	mutex_init(&cd->lock);
722 
723 	spin_lock(&sr_index_lock);
724 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
725 	if (minor == SR_DISKS) {
726 		spin_unlock(&sr_index_lock);
727 		error = -EBUSY;
728 		goto fail_put;
729 	}
730 	__set_bit(minor, sr_index_bits);
731 	spin_unlock(&sr_index_lock);
732 
733 	disk->major = SCSI_CDROM_MAJOR;
734 	disk->first_minor = minor;
735 	disk->minors = 1;
736 	sprintf(disk->disk_name, "sr%d", minor);
737 	disk->fops = &sr_bdops;
738 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
739 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
740 	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
741 
742 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
743 
744 	cd->device = sdev;
745 	cd->disk = disk;
746 	cd->driver = &sr_template;
747 	cd->disk = disk;
748 	cd->capacity = 0x1fffff;
749 	cd->device->changed = 1;	/* force recheck CD type */
750 	cd->media_present = 1;
751 	cd->use = 1;
752 	cd->readcd_known = 0;
753 	cd->readcd_cdda = 0;
754 
755 	cd->cdi.ops = &sr_dops;
756 	cd->cdi.handle = cd;
757 	cd->cdi.mask = 0;
758 	cd->cdi.capacity = 1;
759 	sprintf(cd->cdi.name, "sr%d", minor);
760 
761 	sdev->sector_size = 2048;	/* A guess, just in case */
762 
763 	/* FIXME: need to handle a get_capabilities failure properly ?? */
764 	get_capabilities(cd);
765 	sr_vendor_init(cd);
766 
767 	set_capacity(disk, cd->capacity);
768 	disk->private_data = &cd->driver;
769 
770 	if (register_cdrom(disk, &cd->cdi))
771 		goto fail_minor;
772 
773 	/*
774 	 * Initialize block layer runtime PM stuffs before the
775 	 * periodic event checking request gets started in add_disk.
776 	 */
777 	blk_pm_runtime_init(sdev->request_queue, dev);
778 
779 	dev_set_drvdata(dev, cd);
780 	disk->flags |= GENHD_FL_REMOVABLE;
781 	sr_revalidate_disk(cd);
782 	device_add_disk(&sdev->sdev_gendev, disk, NULL);
783 
784 	sdev_printk(KERN_DEBUG, sdev,
785 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
786 	scsi_autopm_put_device(cd->device);
787 
788 	return 0;
789 
790 fail_minor:
791 	spin_lock(&sr_index_lock);
792 	clear_bit(minor, sr_index_bits);
793 	spin_unlock(&sr_index_lock);
794 fail_put:
795 	put_disk(disk);
796 	mutex_destroy(&cd->lock);
797 fail_free:
798 	kfree(cd);
799 fail:
800 	scsi_autopm_put_device(sdev);
801 	return error;
802 }
803 
804 
805 static void get_sectorsize(struct scsi_cd *cd)
806 {
807 	unsigned char cmd[10];
808 	unsigned char buffer[8];
809 	int the_result, retries = 3;
810 	int sector_size;
811 	struct request_queue *queue;
812 
813 	do {
814 		cmd[0] = READ_CAPACITY;
815 		memset((void *) &cmd[1], 0, 9);
816 		memset(buffer, 0, sizeof(buffer));
817 
818 		/* Do the command and wait.. */
819 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
820 					      buffer, sizeof(buffer), NULL,
821 					      SR_TIMEOUT, MAX_RETRIES, NULL);
822 
823 		retries--;
824 
825 	} while (the_result && retries);
826 
827 
828 	if (the_result) {
829 		cd->capacity = 0x1fffff;
830 		sector_size = 2048;	/* A guess, just in case */
831 	} else {
832 		long last_written;
833 
834 		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
835 		/*
836 		 * READ_CAPACITY doesn't return the correct size on
837 		 * certain UDF media.  If last_written is larger, use
838 		 * it instead.
839 		 *
840 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
841 		 */
842 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
843 			cd->capacity = max_t(long, cd->capacity, last_written);
844 
845 		sector_size = get_unaligned_be32(&buffer[4]);
846 		switch (sector_size) {
847 			/*
848 			 * HP 4020i CD-Recorder reports 2340 byte sectors
849 			 * Philips CD-Writers report 2352 byte sectors
850 			 *
851 			 * Use 2k sectors for them..
852 			 */
853 		case 0:
854 		case 2340:
855 		case 2352:
856 			sector_size = 2048;
857 			fallthrough;
858 		case 2048:
859 			cd->capacity *= 4;
860 			fallthrough;
861 		case 512:
862 			break;
863 		default:
864 			sr_printk(KERN_INFO, cd,
865 				  "unsupported sector size %d.", sector_size);
866 			cd->capacity = 0;
867 		}
868 
869 		cd->device->sector_size = sector_size;
870 
871 		/*
872 		 * Add this so that we have the ability to correctly gauge
873 		 * what the device is capable of.
874 		 */
875 		set_capacity(cd->disk, cd->capacity);
876 	}
877 
878 	queue = cd->device->request_queue;
879 	blk_queue_logical_block_size(queue, sector_size);
880 
881 	return;
882 }
883 
884 static void get_capabilities(struct scsi_cd *cd)
885 {
886 	unsigned char *buffer;
887 	struct scsi_mode_data data;
888 	struct scsi_sense_hdr sshdr;
889 	unsigned int ms_len = 128;
890 	int rc, n;
891 
892 	static const char *loadmech[] =
893 	{
894 		"caddy",
895 		"tray",
896 		"pop-up",
897 		"",
898 		"changer",
899 		"cartridge changer",
900 		"",
901 		""
902 	};
903 
904 
905 	/* allocate transfer buffer */
906 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
907 	if (!buffer) {
908 		sr_printk(KERN_ERR, cd, "out of memory.\n");
909 		return;
910 	}
911 
912 	/* eat unit attentions */
913 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
914 
915 	/* ask for mode page 0x2a */
916 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
917 			     SR_TIMEOUT, 3, &data, NULL);
918 
919 	if (rc < 0 || data.length > ms_len ||
920 	    data.header_length + data.block_descriptor_length > data.length) {
921 		/* failed, drive doesn't have capabilities mode page */
922 		cd->cdi.speed = 1;
923 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
924 				 CDC_DVD | CDC_DVD_RAM |
925 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
926 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
927 		kfree(buffer);
928 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
929 		return;
930 	}
931 
932 	n = data.header_length + data.block_descriptor_length;
933 	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
934 	cd->readcd_known = 1;
935 	cd->readcd_cdda = buffer[n + 5] & 0x01;
936 	/* print some capability bits */
937 	sr_printk(KERN_INFO, cd,
938 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
939 		  get_unaligned_be16(&buffer[n + 14]) / 176,
940 		  cd->cdi.speed,
941 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
942 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
943 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
944 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
945 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
946 		  loadmech[buffer[n + 6] >> 5]);
947 	if ((buffer[n + 6] >> 5) == 0)
948 		/* caddy drives can't close tray... */
949 		cd->cdi.mask |= CDC_CLOSE_TRAY;
950 	if ((buffer[n + 2] & 0x8) == 0)
951 		/* not a DVD drive */
952 		cd->cdi.mask |= CDC_DVD;
953 	if ((buffer[n + 3] & 0x20) == 0)
954 		/* can't write DVD-RAM media */
955 		cd->cdi.mask |= CDC_DVD_RAM;
956 	if ((buffer[n + 3] & 0x10) == 0)
957 		/* can't write DVD-R media */
958 		cd->cdi.mask |= CDC_DVD_R;
959 	if ((buffer[n + 3] & 0x2) == 0)
960 		/* can't write CD-RW media */
961 		cd->cdi.mask |= CDC_CD_RW;
962 	if ((buffer[n + 3] & 0x1) == 0)
963 		/* can't write CD-R media */
964 		cd->cdi.mask |= CDC_CD_R;
965 	if ((buffer[n + 6] & 0x8) == 0)
966 		/* can't eject */
967 		cd->cdi.mask |= CDC_OPEN_TRAY;
968 
969 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
970 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
971 		cd->cdi.capacity =
972 		    cdrom_number_of_slots(&cd->cdi);
973 	if (cd->cdi.capacity <= 1)
974 		/* not a changer */
975 		cd->cdi.mask |= CDC_SELECT_DISC;
976 	/*else    I don't think it can close its tray
977 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
978 
979 	/*
980 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
981 	 */
982 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
983 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
984 		cd->writeable = 1;
985 	}
986 
987 	kfree(buffer);
988 }
989 
990 /*
991  * sr_packet() is the entry point for the generic commands generated
992  * by the Uniform CD-ROM layer.
993  */
994 static int sr_packet(struct cdrom_device_info *cdi,
995 		struct packet_command *cgc)
996 {
997 	struct scsi_cd *cd = cdi->handle;
998 	struct scsi_device *sdev = cd->device;
999 
1000 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
1001 		return -EDRIVE_CANT_DO_THIS;
1002 
1003 	if (cgc->timeout <= 0)
1004 		cgc->timeout = IOCTL_TIMEOUT;
1005 
1006 	sr_do_ioctl(cd, cgc);
1007 
1008 	return cgc->stat;
1009 }
1010 
1011 /**
1012  *	sr_kref_release - Called to free the scsi_cd structure
1013  *	@kref: pointer to embedded kref
1014  *
1015  *	sr_ref_mutex must be held entering this routine.  Because it is
1016  *	called on last put, you should always use the scsi_cd_get()
1017  *	scsi_cd_put() helpers which manipulate the semaphore directly
1018  *	and never do a direct kref_put().
1019  **/
1020 static void sr_kref_release(struct kref *kref)
1021 {
1022 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1023 	struct gendisk *disk = cd->disk;
1024 
1025 	spin_lock(&sr_index_lock);
1026 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1027 	spin_unlock(&sr_index_lock);
1028 
1029 	unregister_cdrom(&cd->cdi);
1030 
1031 	disk->private_data = NULL;
1032 
1033 	put_disk(disk);
1034 
1035 	mutex_destroy(&cd->lock);
1036 
1037 	kfree(cd);
1038 }
1039 
1040 static int sr_remove(struct device *dev)
1041 {
1042 	struct scsi_cd *cd = dev_get_drvdata(dev);
1043 
1044 	scsi_autopm_get_device(cd->device);
1045 
1046 	del_gendisk(cd->disk);
1047 	dev_set_drvdata(dev, NULL);
1048 
1049 	mutex_lock(&sr_ref_mutex);
1050 	kref_put(&cd->kref, sr_kref_release);
1051 	mutex_unlock(&sr_ref_mutex);
1052 
1053 	return 0;
1054 }
1055 
1056 static int __init init_sr(void)
1057 {
1058 	int rc;
1059 
1060 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1061 	if (rc)
1062 		return rc;
1063 	rc = scsi_register_driver(&sr_template.gendrv);
1064 	if (rc)
1065 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1066 
1067 	return rc;
1068 }
1069 
1070 static void __exit exit_sr(void)
1071 {
1072 	scsi_unregister_driver(&sr_template.gendrv);
1073 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1074 }
1075 
1076 module_init(init_sr);
1077 module_exit(exit_sr);
1078 MODULE_LICENSE("GPL");
1079