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1 /*
2  *  sr.c Copyright (C) 1992 David Giller
3  *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
4  *
5  *  adapted from:
6  *      sd.c Copyright (C) 1992 Drew Eckhardt
7  *      Linux scsi disk driver by
8  *              Drew Eckhardt <drew@colorado.edu>
9  *
10  *	Modified by Eric Youngdale ericy@andante.org to
11  *	add scatter-gather, multiple outstanding request, and other
12  *	enhancements.
13  *
14  *      Modified by Eric Youngdale eric@andante.org to support loadable
15  *      low-level scsi drivers.
16  *
17  *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
18  *      provide auto-eject.
19  *
20  *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
21  *      generic cdrom interface
22  *
23  *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
24  *      interface, capabilities probe additions, ioctl cleanups, etc.
25  *
26  *	Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
27  *
28  *	Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
29  *	transparently and lose the GHOST hack
30  *
31  *	Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
32  *	check resource allocation in sr_init and some cleanups
33  */
34 
35 #include <linux/module.h>
36 #include <linux/fs.h>
37 #include <linux/kernel.h>
38 #include <linux/mm.h>
39 #include <linux/bio.h>
40 #include <linux/string.h>
41 #include <linux/errno.h>
42 #include <linux/cdrom.h>
43 #include <linux/interrupt.h>
44 #include <linux/init.h>
45 #include <linux/blkdev.h>
46 #include <linux/mutex.h>
47 #include <linux/slab.h>
48 #include <linux/pm_runtime.h>
49 #include <asm/uaccess.h>
50 
51 #include <scsi/scsi.h>
52 #include <scsi/scsi_dbg.h>
53 #include <scsi/scsi_device.h>
54 #include <scsi/scsi_driver.h>
55 #include <scsi/scsi_cmnd.h>
56 #include <scsi/scsi_eh.h>
57 #include <scsi/scsi_host.h>
58 #include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
59 
60 #include "scsi_logging.h"
61 #include "sr.h"
62 
63 
64 MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
65 MODULE_LICENSE("GPL");
66 MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
67 MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
68 MODULE_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 
79 static DEFINE_MUTEX(sr_mutex);
80 static int sr_probe(struct device *);
81 static int sr_remove(struct device *);
82 static int sr_init_command(struct scsi_cmnd *SCpnt);
83 static int sr_done(struct scsi_cmnd *);
84 static int sr_runtime_suspend(struct device *dev);
85 
86 static struct dev_pm_ops sr_pm_ops = {
87 	.runtime_suspend	= sr_runtime_suspend,
88 };
89 
90 static 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 
102 static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
103 static 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) */
108 static DEFINE_MUTEX(sr_ref_mutex);
109 
110 static int sr_open(struct cdrom_device_info *, int);
111 static void sr_release(struct cdrom_device_info *);
112 
113 static void get_sectorsize(struct scsi_cd *);
114 static void get_capabilities(struct scsi_cd *);
115 
116 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
117 				    unsigned int clearing, int slot);
118 static int sr_packet(struct cdrom_device_info *, struct packet_command *);
119 
120 static 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 
136 static void sr_kref_release(struct kref *kref);
137 
scsi_cd(struct gendisk * disk)138 static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
139 {
140 	return container_of(disk->private_data, struct scsi_cd, driver);
141 }
142 
sr_runtime_suspend(struct device * dev)143 static 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  */
scsi_cd_get(struct gendisk * disk)160 static 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 
scsi_cd_put(struct scsi_cd * cd)178 static 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 
sr_get_events(struct scsi_device * sdev)188 static 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 	else if (med->media_event_code == 3)
220 		return DISK_EVENT_MEDIA_CHANGE;
221 	return 0;
222 }
223 
224 /*
225  * This function checks to see if the media has been changed or eject
226  * button has been pressed.  It is possible that we have already
227  * sensed a change, or the drive may have sensed one and not yet
228  * reported it.  The past events are accumulated in sdev->changed and
229  * returned together with the current state.
230  */
sr_check_events(struct cdrom_device_info * cdi,unsigned int clearing,int slot)231 static unsigned int sr_check_events(struct cdrom_device_info *cdi,
232 				    unsigned int clearing, int slot)
233 {
234 	struct scsi_cd *cd = cdi->handle;
235 	bool last_present;
236 	struct scsi_sense_hdr sshdr;
237 	unsigned int events;
238 	int ret;
239 
240 	/* no changer support */
241 	if (CDSL_CURRENT != slot)
242 		return 0;
243 
244 	events = sr_get_events(cd->device);
245 	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
246 
247 	/*
248 	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
249 	 * for several times in a row.  We rely on TUR only for this likely
250 	 * broken device, to prevent generating incorrect media changed
251 	 * events for every open().
252 	 */
253 	if (cd->ignore_get_event) {
254 		events &= ~DISK_EVENT_MEDIA_CHANGE;
255 		goto do_tur;
256 	}
257 
258 	/*
259 	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
260 	 * is being cleared.  Note that there are devices which hang
261 	 * if asked to execute TUR repeatedly.
262 	 */
263 	if (cd->device->changed) {
264 		events |= DISK_EVENT_MEDIA_CHANGE;
265 		cd->device->changed = 0;
266 		cd->tur_changed = true;
267 	}
268 
269 	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
270 		return events;
271 do_tur:
272 	/* let's see whether the media is there with TUR */
273 	last_present = cd->media_present;
274 	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
275 
276 	/*
277 	 * Media is considered to be present if TUR succeeds or fails with
278 	 * sense data indicating something other than media-not-present
279 	 * (ASC 0x3a).
280 	 */
281 	cd->media_present = scsi_status_is_good(ret) ||
282 		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
283 
284 	if (last_present != cd->media_present)
285 		cd->device->changed = 1;
286 
287 	if (cd->device->changed) {
288 		events |= DISK_EVENT_MEDIA_CHANGE;
289 		cd->device->changed = 0;
290 		cd->tur_changed = true;
291 	}
292 
293 	if (cd->ignore_get_event)
294 		return events;
295 
296 	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
297 	if (!cd->tur_changed) {
298 		if (cd->get_event_changed) {
299 			if (cd->tur_mismatch++ > 8) {
300 				sr_printk(KERN_WARNING, cd,
301 					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
302 				cd->ignore_get_event = true;
303 			}
304 		} else {
305 			cd->tur_mismatch = 0;
306 		}
307 	}
308 	cd->tur_changed = false;
309 	cd->get_event_changed = false;
310 
311 	return events;
312 }
313 
314 /*
315  * sr_done is the interrupt routine for the device driver.
316  *
317  * It will be notified on the end of a SCSI read / write, and will take one
318  * of several actions based on success or failure.
319  */
sr_done(struct scsi_cmnd * SCpnt)320 static int sr_done(struct scsi_cmnd *SCpnt)
321 {
322 	int result = SCpnt->result;
323 	int this_count = scsi_bufflen(SCpnt);
324 	int good_bytes = (result == 0 ? this_count : 0);
325 	int block_sectors = 0;
326 	long error_sector;
327 	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
328 
329 #ifdef DEBUG
330 	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
331 #endif
332 
333 	/*
334 	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
335 	 * success.  Since this is a relatively rare error condition, no
336 	 * care is taken to avoid unnecessary additional work such as
337 	 * memcpy's that could be avoided.
338 	 */
339 	if (driver_byte(result) != 0 &&		/* An error occurred */
340 	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
341 		switch (SCpnt->sense_buffer[2]) {
342 		case MEDIUM_ERROR:
343 		case VOLUME_OVERFLOW:
344 		case ILLEGAL_REQUEST:
345 			if (!(SCpnt->sense_buffer[0] & 0x90))
346 				break;
347 			error_sector = (SCpnt->sense_buffer[3] << 24) |
348 				(SCpnt->sense_buffer[4] << 16) |
349 				(SCpnt->sense_buffer[5] << 8) |
350 				SCpnt->sense_buffer[6];
351 			if (SCpnt->request->bio != NULL)
352 				block_sectors =
353 					bio_sectors(SCpnt->request->bio);
354 			if (block_sectors < 4)
355 				block_sectors = 4;
356 			if (cd->device->sector_size == 2048)
357 				error_sector <<= 2;
358 			error_sector &= ~(block_sectors - 1);
359 			good_bytes = (error_sector -
360 				      blk_rq_pos(SCpnt->request)) << 9;
361 			if (good_bytes < 0 || good_bytes >= this_count)
362 				good_bytes = 0;
363 			/*
364 			 * The SCSI specification allows for the value
365 			 * returned by READ CAPACITY to be up to 75 2K
366 			 * sectors past the last readable block.
367 			 * Therefore, if we hit a medium error within the
368 			 * last 75 2K sectors, we decrease the saved size
369 			 * value.
370 			 */
371 			if (error_sector < get_capacity(cd->disk) &&
372 			    cd->capacity - error_sector < 4 * 75)
373 				set_capacity(cd->disk, error_sector);
374 			break;
375 
376 		case RECOVERED_ERROR:
377 			good_bytes = this_count;
378 			break;
379 
380 		default:
381 			break;
382 		}
383 	}
384 
385 	return good_bytes;
386 }
387 
sr_init_command(struct scsi_cmnd * SCpnt)388 static int sr_init_command(struct scsi_cmnd *SCpnt)
389 {
390 	int block = 0, this_count, s_size;
391 	struct scsi_cd *cd;
392 	struct request *rq = SCpnt->request;
393 	int ret;
394 
395 	ret = scsi_init_io(SCpnt);
396 	if (ret != BLKPREP_OK)
397 		goto out;
398 	SCpnt = rq->special;
399 	cd = scsi_cd(rq->rq_disk);
400 
401 	/* from here on until we're complete, any goto out
402 	 * is used for a killable error condition */
403 	ret = BLKPREP_KILL;
404 
405 	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
406 		"Doing sr request, block = %d\n", block));
407 
408 	if (!cd->device || !scsi_device_online(cd->device)) {
409 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
410 			"Finishing %u sectors\n", blk_rq_sectors(rq)));
411 		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
412 			"Retry with 0x%p\n", SCpnt));
413 		goto out;
414 	}
415 
416 	if (cd->device->changed) {
417 		/*
418 		 * quietly refuse to do anything to a changed disc until the
419 		 * changed bit has been reset
420 		 */
421 		goto out;
422 	}
423 
424 	/*
425 	 * we do lazy blocksize switching (when reading XA sectors,
426 	 * see CDROMREADMODE2 ioctl)
427 	 */
428 	s_size = cd->device->sector_size;
429 	if (s_size > 2048) {
430 		if (!in_interrupt())
431 			sr_set_blocklength(cd, 2048);
432 		else
433 			scmd_printk(KERN_INFO, SCpnt,
434 				    "can't switch blocksize: in interrupt\n");
435 	}
436 
437 	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
438 		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
439 		goto out;
440 	}
441 
442 	if (rq_data_dir(rq) == WRITE) {
443 		if (!cd->writeable)
444 			goto out;
445 		SCpnt->cmnd[0] = WRITE_10;
446 		cd->cdi.media_written = 1;
447 	} else if (rq_data_dir(rq) == READ) {
448 		SCpnt->cmnd[0] = READ_10;
449 	} else {
450 		blk_dump_rq_flags(rq, "Unknown sr command");
451 		goto out;
452 	}
453 
454 	{
455 		struct scatterlist *sg;
456 		int i, size = 0, sg_count = scsi_sg_count(SCpnt);
457 
458 		scsi_for_each_sg(SCpnt, sg, sg_count, i)
459 			size += sg->length;
460 
461 		if (size != scsi_bufflen(SCpnt)) {
462 			scmd_printk(KERN_ERR, SCpnt,
463 				"mismatch count %d, bytes %d\n",
464 				size, scsi_bufflen(SCpnt));
465 			if (scsi_bufflen(SCpnt) > size)
466 				SCpnt->sdb.length = size;
467 		}
468 	}
469 
470 	/*
471 	 * request doesn't start on hw block boundary, add scatter pads
472 	 */
473 	if (((unsigned int)blk_rq_pos(rq) % (s_size >> 9)) ||
474 	    (scsi_bufflen(SCpnt) % s_size)) {
475 		scmd_printk(KERN_NOTICE, SCpnt, "unaligned transfer\n");
476 		goto out;
477 	}
478 
479 	this_count = (scsi_bufflen(SCpnt) >> 9) / (s_size >> 9);
480 
481 
482 	SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
483 					"%s %d/%u 512 byte blocks.\n",
484 					(rq_data_dir(rq) == WRITE) ?
485 					"writing" : "reading",
486 					this_count, blk_rq_sectors(rq)));
487 
488 	SCpnt->cmnd[1] = 0;
489 	block = (unsigned int)blk_rq_pos(rq) / (s_size >> 9);
490 
491 	if (this_count > 0xffff) {
492 		this_count = 0xffff;
493 		SCpnt->sdb.length = this_count * s_size;
494 	}
495 
496 	SCpnt->cmnd[2] = (unsigned char) (block >> 24) & 0xff;
497 	SCpnt->cmnd[3] = (unsigned char) (block >> 16) & 0xff;
498 	SCpnt->cmnd[4] = (unsigned char) (block >> 8) & 0xff;
499 	SCpnt->cmnd[5] = (unsigned char) block & 0xff;
500 	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
501 	SCpnt->cmnd[7] = (unsigned char) (this_count >> 8) & 0xff;
502 	SCpnt->cmnd[8] = (unsigned char) this_count & 0xff;
503 
504 	/*
505 	 * We shouldn't disconnect in the middle of a sector, so with a dumb
506 	 * host adapter, it's safe to assume that we can at least transfer
507 	 * this many bytes between each connect / disconnect.
508 	 */
509 	SCpnt->transfersize = cd->device->sector_size;
510 	SCpnt->underflow = this_count << 9;
511 	SCpnt->allowed = MAX_RETRIES;
512 
513 	/*
514 	 * This indicates that the command is ready from our end to be
515 	 * queued.
516 	 */
517 	ret = BLKPREP_OK;
518  out:
519 	return ret;
520 }
521 
sr_block_open(struct block_device * bdev,fmode_t mode)522 static int sr_block_open(struct block_device *bdev, fmode_t mode)
523 {
524 	struct scsi_cd *cd;
525 	struct scsi_device *sdev;
526 	int ret = -ENXIO;
527 
528 	cd = scsi_cd_get(bdev->bd_disk);
529 	if (!cd)
530 		goto out;
531 
532 	sdev = cd->device;
533 	scsi_autopm_get_device(sdev);
534 	check_disk_change(bdev);
535 
536 	mutex_lock(&sr_mutex);
537 	ret = cdrom_open(&cd->cdi, bdev, mode);
538 	mutex_unlock(&sr_mutex);
539 
540 	scsi_autopm_put_device(sdev);
541 	if (ret)
542 		scsi_cd_put(cd);
543 
544 out:
545 	return ret;
546 }
547 
sr_block_release(struct gendisk * disk,fmode_t mode)548 static void sr_block_release(struct gendisk *disk, fmode_t mode)
549 {
550 	struct scsi_cd *cd = scsi_cd(disk);
551 	mutex_lock(&sr_mutex);
552 	cdrom_release(&cd->cdi, mode);
553 	scsi_cd_put(cd);
554 	mutex_unlock(&sr_mutex);
555 }
556 
sr_block_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)557 static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
558 			  unsigned long arg)
559 {
560 	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
561 	struct scsi_device *sdev = cd->device;
562 	void __user *argp = (void __user *)arg;
563 	int ret;
564 
565 	mutex_lock(&sr_mutex);
566 
567 	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
568 			(mode & FMODE_NDELAY) != 0);
569 	if (ret)
570 		goto out;
571 
572 	scsi_autopm_get_device(sdev);
573 
574 	/*
575 	 * Send SCSI addressing ioctls directly to mid level, send other
576 	 * ioctls to cdrom/block level.
577 	 */
578 	switch (cmd) {
579 	case SCSI_IOCTL_GET_IDLUN:
580 	case SCSI_IOCTL_GET_BUS_NUMBER:
581 		ret = scsi_ioctl(sdev, cmd, argp);
582 		goto put;
583 	}
584 
585 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
586 	if (ret != -ENOSYS)
587 		goto put;
588 
589 	ret = scsi_ioctl(sdev, cmd, argp);
590 
591 put:
592 	scsi_autopm_put_device(sdev);
593 
594 out:
595 	mutex_unlock(&sr_mutex);
596 	return ret;
597 }
598 
sr_block_check_events(struct gendisk * disk,unsigned int clearing)599 static unsigned int sr_block_check_events(struct gendisk *disk,
600 					  unsigned int clearing)
601 {
602 	unsigned int ret = 0;
603 	struct scsi_cd *cd;
604 
605 	cd = scsi_cd_get(disk);
606 	if (!cd)
607 		return 0;
608 
609 	if (!atomic_read(&cd->device->disk_events_disable_depth))
610 		ret = cdrom_check_events(&cd->cdi, clearing);
611 
612 	scsi_cd_put(cd);
613 	return ret;
614 }
615 
sr_block_revalidate_disk(struct gendisk * disk)616 static int sr_block_revalidate_disk(struct gendisk *disk)
617 {
618 	struct scsi_sense_hdr sshdr;
619 	struct scsi_cd *cd;
620 
621 	cd = scsi_cd_get(disk);
622 	if (!cd)
623 		return -ENXIO;
624 
625 	/* if the unit is not ready, nothing more to do */
626 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
627 		goto out;
628 
629 	sr_cd_check(&cd->cdi);
630 	get_sectorsize(cd);
631 out:
632 	scsi_cd_put(cd);
633 	return 0;
634 }
635 
636 static const struct block_device_operations sr_bdops =
637 {
638 	.owner		= THIS_MODULE,
639 	.open		= sr_block_open,
640 	.release	= sr_block_release,
641 	.ioctl		= sr_block_ioctl,
642 	.check_events	= sr_block_check_events,
643 	.revalidate_disk = sr_block_revalidate_disk,
644 	/*
645 	 * No compat_ioctl for now because sr_block_ioctl never
646 	 * seems to pass arbitrary ioctls down to host drivers.
647 	 */
648 };
649 
sr_open(struct cdrom_device_info * cdi,int purpose)650 static int sr_open(struct cdrom_device_info *cdi, int purpose)
651 {
652 	struct scsi_cd *cd = cdi->handle;
653 	struct scsi_device *sdev = cd->device;
654 	int retval;
655 
656 	/*
657 	 * If the device is in error recovery, wait until it is done.
658 	 * If the device is offline, then disallow any access to it.
659 	 */
660 	retval = -ENXIO;
661 	if (!scsi_block_when_processing_errors(sdev))
662 		goto error_out;
663 
664 	return 0;
665 
666 error_out:
667 	return retval;
668 }
669 
sr_release(struct cdrom_device_info * cdi)670 static void sr_release(struct cdrom_device_info *cdi)
671 {
672 	struct scsi_cd *cd = cdi->handle;
673 
674 	if (cd->device->sector_size > 2048)
675 		sr_set_blocklength(cd, 2048);
676 
677 }
678 
sr_probe(struct device * dev)679 static int sr_probe(struct device *dev)
680 {
681 	struct scsi_device *sdev = to_scsi_device(dev);
682 	struct gendisk *disk;
683 	struct scsi_cd *cd;
684 	int minor, error;
685 
686 	scsi_autopm_get_device(sdev);
687 	error = -ENODEV;
688 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
689 		goto fail;
690 
691 	error = -ENOMEM;
692 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
693 	if (!cd)
694 		goto fail;
695 
696 	kref_init(&cd->kref);
697 
698 	disk = alloc_disk(1);
699 	if (!disk)
700 		goto fail_free;
701 
702 	spin_lock(&sr_index_lock);
703 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
704 	if (minor == SR_DISKS) {
705 		spin_unlock(&sr_index_lock);
706 		error = -EBUSY;
707 		goto fail_put;
708 	}
709 	__set_bit(minor, sr_index_bits);
710 	spin_unlock(&sr_index_lock);
711 
712 	disk->major = SCSI_CDROM_MAJOR;
713 	disk->first_minor = minor;
714 	sprintf(disk->disk_name, "sr%d", minor);
715 	disk->fops = &sr_bdops;
716 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
717 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
718 
719 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
720 
721 	cd->device = sdev;
722 	cd->disk = disk;
723 	cd->driver = &sr_template;
724 	cd->disk = disk;
725 	cd->capacity = 0x1fffff;
726 	cd->device->changed = 1;	/* force recheck CD type */
727 	cd->media_present = 1;
728 	cd->use = 1;
729 	cd->readcd_known = 0;
730 	cd->readcd_cdda = 0;
731 
732 	cd->cdi.ops = &sr_dops;
733 	cd->cdi.handle = cd;
734 	cd->cdi.mask = 0;
735 	cd->cdi.capacity = 1;
736 	sprintf(cd->cdi.name, "sr%d", minor);
737 
738 	sdev->sector_size = 2048;	/* A guess, just in case */
739 
740 	/* FIXME: need to handle a get_capabilities failure properly ?? */
741 	get_capabilities(cd);
742 	sr_vendor_init(cd);
743 
744 	disk->driverfs_dev = &sdev->sdev_gendev;
745 	set_capacity(disk, cd->capacity);
746 	disk->private_data = &cd->driver;
747 	disk->queue = sdev->request_queue;
748 	cd->cdi.disk = disk;
749 
750 	if (register_cdrom(&cd->cdi))
751 		goto fail_minor;
752 
753 	/*
754 	 * Initialize block layer runtime PM stuffs before the
755 	 * periodic event checking request gets started in add_disk.
756 	 */
757 	blk_pm_runtime_init(sdev->request_queue, dev);
758 
759 	dev_set_drvdata(dev, cd);
760 	disk->flags |= GENHD_FL_REMOVABLE;
761 	add_disk(disk);
762 
763 	sdev_printk(KERN_DEBUG, sdev,
764 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
765 	scsi_autopm_put_device(cd->device);
766 
767 	return 0;
768 
769 fail_minor:
770 	spin_lock(&sr_index_lock);
771 	clear_bit(minor, sr_index_bits);
772 	spin_unlock(&sr_index_lock);
773 fail_put:
774 	put_disk(disk);
775 fail_free:
776 	kfree(cd);
777 fail:
778 	scsi_autopm_put_device(sdev);
779 	return error;
780 }
781 
782 
get_sectorsize(struct scsi_cd * cd)783 static void get_sectorsize(struct scsi_cd *cd)
784 {
785 	unsigned char cmd[10];
786 	unsigned char buffer[8];
787 	int the_result, retries = 3;
788 	int sector_size;
789 	struct request_queue *queue;
790 
791 	do {
792 		cmd[0] = READ_CAPACITY;
793 		memset((void *) &cmd[1], 0, 9);
794 		memset(buffer, 0, sizeof(buffer));
795 
796 		/* Do the command and wait.. */
797 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
798 					      buffer, sizeof(buffer), NULL,
799 					      SR_TIMEOUT, MAX_RETRIES, NULL);
800 
801 		retries--;
802 
803 	} while (the_result && retries);
804 
805 
806 	if (the_result) {
807 		cd->capacity = 0x1fffff;
808 		sector_size = 2048;	/* A guess, just in case */
809 	} else {
810 		long last_written;
811 
812 		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
813 				    (buffer[2] << 8) | buffer[3]);
814 		/*
815 		 * READ_CAPACITY doesn't return the correct size on
816 		 * certain UDF media.  If last_written is larger, use
817 		 * it instead.
818 		 *
819 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
820 		 */
821 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
822 			cd->capacity = max_t(long, cd->capacity, last_written);
823 
824 		sector_size = (buffer[4] << 24) |
825 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
826 		switch (sector_size) {
827 			/*
828 			 * HP 4020i CD-Recorder reports 2340 byte sectors
829 			 * Philips CD-Writers report 2352 byte sectors
830 			 *
831 			 * Use 2k sectors for them..
832 			 */
833 		case 0:
834 		case 2340:
835 		case 2352:
836 			sector_size = 2048;
837 			/* fall through */
838 		case 2048:
839 			cd->capacity *= 4;
840 			/* fall through */
841 		case 512:
842 			break;
843 		default:
844 			sr_printk(KERN_INFO, cd,
845 				  "unsupported sector size %d.", sector_size);
846 			cd->capacity = 0;
847 		}
848 
849 		cd->device->sector_size = sector_size;
850 
851 		/*
852 		 * Add this so that we have the ability to correctly gauge
853 		 * what the device is capable of.
854 		 */
855 		set_capacity(cd->disk, cd->capacity);
856 	}
857 
858 	queue = cd->device->request_queue;
859 	blk_queue_logical_block_size(queue, sector_size);
860 
861 	return;
862 }
863 
get_capabilities(struct scsi_cd * cd)864 static void get_capabilities(struct scsi_cd *cd)
865 {
866 	unsigned char *buffer;
867 	struct scsi_mode_data data;
868 	struct scsi_sense_hdr sshdr;
869 	unsigned int ms_len = 128;
870 	int rc, n;
871 
872 	static const char *loadmech[] =
873 	{
874 		"caddy",
875 		"tray",
876 		"pop-up",
877 		"",
878 		"changer",
879 		"cartridge changer",
880 		"",
881 		""
882 	};
883 
884 
885 	/* allocate transfer buffer */
886 	buffer = kmalloc(512, GFP_KERNEL);
887 	if (!buffer) {
888 		sr_printk(KERN_ERR, cd, "out of memory.\n");
889 		return;
890 	}
891 
892 	/* eat unit attentions */
893 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
894 
895 	/* ask for mode page 0x2a */
896 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
897 			     SR_TIMEOUT, 3, &data, NULL);
898 
899 	if (!scsi_status_is_good(rc) || data.length > ms_len ||
900 	    data.header_length + data.block_descriptor_length > data.length) {
901 		/* failed, drive doesn't have capabilities mode page */
902 		cd->cdi.speed = 1;
903 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
904 				 CDC_DVD | CDC_DVD_RAM |
905 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
906 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
907 		kfree(buffer);
908 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
909 		return;
910 	}
911 
912 	n = data.header_length + data.block_descriptor_length;
913 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
914 	cd->readcd_known = 1;
915 	cd->readcd_cdda = buffer[n + 5] & 0x01;
916 	/* print some capability bits */
917 	sr_printk(KERN_INFO, cd,
918 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
919 		  ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
920 		  cd->cdi.speed,
921 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
922 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
923 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
924 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
925 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
926 		  loadmech[buffer[n + 6] >> 5]);
927 	if ((buffer[n + 6] >> 5) == 0)
928 		/* caddy drives can't close tray... */
929 		cd->cdi.mask |= CDC_CLOSE_TRAY;
930 	if ((buffer[n + 2] & 0x8) == 0)
931 		/* not a DVD drive */
932 		cd->cdi.mask |= CDC_DVD;
933 	if ((buffer[n + 3] & 0x20) == 0)
934 		/* can't write DVD-RAM media */
935 		cd->cdi.mask |= CDC_DVD_RAM;
936 	if ((buffer[n + 3] & 0x10) == 0)
937 		/* can't write DVD-R media */
938 		cd->cdi.mask |= CDC_DVD_R;
939 	if ((buffer[n + 3] & 0x2) == 0)
940 		/* can't write CD-RW media */
941 		cd->cdi.mask |= CDC_CD_RW;
942 	if ((buffer[n + 3] & 0x1) == 0)
943 		/* can't write CD-R media */
944 		cd->cdi.mask |= CDC_CD_R;
945 	if ((buffer[n + 6] & 0x8) == 0)
946 		/* can't eject */
947 		cd->cdi.mask |= CDC_OPEN_TRAY;
948 
949 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
950 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
951 		cd->cdi.capacity =
952 		    cdrom_number_of_slots(&cd->cdi);
953 	if (cd->cdi.capacity <= 1)
954 		/* not a changer */
955 		cd->cdi.mask |= CDC_SELECT_DISC;
956 	/*else    I don't think it can close its tray
957 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
958 
959 	/*
960 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
961 	 */
962 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
963 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
964 		cd->writeable = 1;
965 	}
966 
967 	kfree(buffer);
968 }
969 
970 /*
971  * sr_packet() is the entry point for the generic commands generated
972  * by the Uniform CD-ROM layer.
973  */
sr_packet(struct cdrom_device_info * cdi,struct packet_command * cgc)974 static int sr_packet(struct cdrom_device_info *cdi,
975 		struct packet_command *cgc)
976 {
977 	struct scsi_cd *cd = cdi->handle;
978 	struct scsi_device *sdev = cd->device;
979 
980 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
981 		return -EDRIVE_CANT_DO_THIS;
982 
983 	if (cgc->timeout <= 0)
984 		cgc->timeout = IOCTL_TIMEOUT;
985 
986 	sr_do_ioctl(cd, cgc);
987 
988 	return cgc->stat;
989 }
990 
991 /**
992  *	sr_kref_release - Called to free the scsi_cd structure
993  *	@kref: pointer to embedded kref
994  *
995  *	sr_ref_mutex must be held entering this routine.  Because it is
996  *	called on last put, you should always use the scsi_cd_get()
997  *	scsi_cd_put() helpers which manipulate the semaphore directly
998  *	and never do a direct kref_put().
999  **/
sr_kref_release(struct kref * kref)1000 static void sr_kref_release(struct kref *kref)
1001 {
1002 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1003 	struct gendisk *disk = cd->disk;
1004 
1005 	spin_lock(&sr_index_lock);
1006 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1007 	spin_unlock(&sr_index_lock);
1008 
1009 	unregister_cdrom(&cd->cdi);
1010 
1011 	disk->private_data = NULL;
1012 
1013 	put_disk(disk);
1014 
1015 	kfree(cd);
1016 }
1017 
sr_remove(struct device * dev)1018 static int sr_remove(struct device *dev)
1019 {
1020 	struct scsi_cd *cd = dev_get_drvdata(dev);
1021 
1022 	scsi_autopm_get_device(cd->device);
1023 
1024 	del_gendisk(cd->disk);
1025 	dev_set_drvdata(dev, NULL);
1026 
1027 	mutex_lock(&sr_ref_mutex);
1028 	kref_put(&cd->kref, sr_kref_release);
1029 	mutex_unlock(&sr_ref_mutex);
1030 
1031 	return 0;
1032 }
1033 
init_sr(void)1034 static int __init init_sr(void)
1035 {
1036 	int rc;
1037 
1038 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1039 	if (rc)
1040 		return rc;
1041 	rc = scsi_register_driver(&sr_template.gendrv);
1042 	if (rc)
1043 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1044 
1045 	return rc;
1046 }
1047 
exit_sr(void)1048 static void __exit exit_sr(void)
1049 {
1050 	scsi_unregister_driver(&sr_template.gendrv);
1051 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1052 }
1053 
1054 module_init(init_sr);
1055 module_exit(exit_sr);
1056 MODULE_LICENSE("GPL");
1057