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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 	.owner			= THIS_MODULE,
92 	.gendrv = {
93 		.name   	= "sr",
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 	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  */
sr_check_events(struct cdrom_device_info * cdi,unsigned int clearing,int slot)229 static 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;
269 do_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  */
sr_done(struct scsi_cmnd * SCpnt)318 static 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 
sr_init_command(struct scsi_cmnd * SCpnt)386 static 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, GFP_ATOMIC);
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 
sr_block_open(struct block_device * bdev,fmode_t mode)520 static 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 
sr_block_release(struct gendisk * disk,fmode_t mode)536 static 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 
sr_block_ioctl(struct block_device * bdev,fmode_t mode,unsigned cmd,unsigned long arg)545 static 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 	/*
556 	 * Send SCSI addressing ioctls directly to mid level, send other
557 	 * ioctls to cdrom/block level.
558 	 */
559 	switch (cmd) {
560 	case SCSI_IOCTL_GET_IDLUN:
561 	case SCSI_IOCTL_GET_BUS_NUMBER:
562 		ret = scsi_ioctl(sdev, cmd, argp);
563 		goto out;
564 	}
565 
566 	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
567 	if (ret != -ENOSYS)
568 		goto out;
569 
570 	/*
571 	 * ENODEV means that we didn't recognise the ioctl, or that we
572 	 * cannot execute it in the current device state.  In either
573 	 * case fall through to scsi_ioctl, which will return ENDOEV again
574 	 * if it doesn't recognise the ioctl
575 	 */
576 	ret = scsi_nonblockable_ioctl(sdev, cmd, argp,
577 					(mode & FMODE_NDELAY) != 0);
578 	if (ret != -ENODEV)
579 		goto out;
580 	ret = scsi_ioctl(sdev, cmd, argp);
581 
582 out:
583 	mutex_unlock(&sr_mutex);
584 	return ret;
585 }
586 
sr_block_check_events(struct gendisk * disk,unsigned int clearing)587 static unsigned int sr_block_check_events(struct gendisk *disk,
588 					  unsigned int clearing)
589 {
590 	struct scsi_cd *cd = scsi_cd(disk);
591 
592 	if (atomic_read(&cd->device->disk_events_disable_depth))
593 		return 0;
594 
595 	return cdrom_check_events(&cd->cdi, clearing);
596 }
597 
sr_block_revalidate_disk(struct gendisk * disk)598 static int sr_block_revalidate_disk(struct gendisk *disk)
599 {
600 	struct scsi_cd *cd = scsi_cd(disk);
601 	struct scsi_sense_hdr sshdr;
602 
603 	/* if the unit is not ready, nothing more to do */
604 	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
605 		goto out;
606 
607 	sr_cd_check(&cd->cdi);
608 	get_sectorsize(cd);
609 out:
610 	return 0;
611 }
612 
613 static const struct block_device_operations sr_bdops =
614 {
615 	.owner		= THIS_MODULE,
616 	.open		= sr_block_open,
617 	.release	= sr_block_release,
618 	.ioctl		= sr_block_ioctl,
619 	.check_events	= sr_block_check_events,
620 	.revalidate_disk = sr_block_revalidate_disk,
621 	/*
622 	 * No compat_ioctl for now because sr_block_ioctl never
623 	 * seems to pass arbitrary ioctls down to host drivers.
624 	 */
625 };
626 
sr_open(struct cdrom_device_info * cdi,int purpose)627 static int sr_open(struct cdrom_device_info *cdi, int purpose)
628 {
629 	struct scsi_cd *cd = cdi->handle;
630 	struct scsi_device *sdev = cd->device;
631 	int retval;
632 
633 	/*
634 	 * If the device is in error recovery, wait until it is done.
635 	 * If the device is offline, then disallow any access to it.
636 	 */
637 	retval = -ENXIO;
638 	if (!scsi_block_when_processing_errors(sdev))
639 		goto error_out;
640 
641 	return 0;
642 
643 error_out:
644 	return retval;
645 }
646 
sr_release(struct cdrom_device_info * cdi)647 static void sr_release(struct cdrom_device_info *cdi)
648 {
649 	struct scsi_cd *cd = cdi->handle;
650 
651 	if (cd->device->sector_size > 2048)
652 		sr_set_blocklength(cd, 2048);
653 
654 }
655 
sr_probe(struct device * dev)656 static int sr_probe(struct device *dev)
657 {
658 	struct scsi_device *sdev = to_scsi_device(dev);
659 	struct gendisk *disk;
660 	struct scsi_cd *cd;
661 	int minor, error;
662 
663 	scsi_autopm_get_device(sdev);
664 	error = -ENODEV;
665 	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
666 		goto fail;
667 
668 	error = -ENOMEM;
669 	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
670 	if (!cd)
671 		goto fail;
672 
673 	kref_init(&cd->kref);
674 
675 	disk = alloc_disk(1);
676 	if (!disk)
677 		goto fail_free;
678 
679 	spin_lock(&sr_index_lock);
680 	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
681 	if (minor == SR_DISKS) {
682 		spin_unlock(&sr_index_lock);
683 		error = -EBUSY;
684 		goto fail_put;
685 	}
686 	__set_bit(minor, sr_index_bits);
687 	spin_unlock(&sr_index_lock);
688 
689 	disk->major = SCSI_CDROM_MAJOR;
690 	disk->first_minor = minor;
691 	sprintf(disk->disk_name, "sr%d", minor);
692 	disk->fops = &sr_bdops;
693 	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
694 	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
695 
696 	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
697 
698 	cd->device = sdev;
699 	cd->disk = disk;
700 	cd->driver = &sr_template;
701 	cd->disk = disk;
702 	cd->capacity = 0x1fffff;
703 	cd->device->changed = 1;	/* force recheck CD type */
704 	cd->media_present = 1;
705 	cd->use = 1;
706 	cd->readcd_known = 0;
707 	cd->readcd_cdda = 0;
708 
709 	cd->cdi.ops = &sr_dops;
710 	cd->cdi.handle = cd;
711 	cd->cdi.mask = 0;
712 	cd->cdi.capacity = 1;
713 	sprintf(cd->cdi.name, "sr%d", minor);
714 
715 	sdev->sector_size = 2048;	/* A guess, just in case */
716 
717 	/* FIXME: need to handle a get_capabilities failure properly ?? */
718 	get_capabilities(cd);
719 	sr_vendor_init(cd);
720 
721 	disk->driverfs_dev = &sdev->sdev_gendev;
722 	set_capacity(disk, cd->capacity);
723 	disk->private_data = &cd->driver;
724 	disk->queue = sdev->request_queue;
725 	cd->cdi.disk = disk;
726 
727 	if (register_cdrom(&cd->cdi))
728 		goto fail_put;
729 
730 	/*
731 	 * Initialize block layer runtime PM stuffs before the
732 	 * periodic event checking request gets started in add_disk.
733 	 */
734 	blk_pm_runtime_init(sdev->request_queue, dev);
735 
736 	dev_set_drvdata(dev, cd);
737 	disk->flags |= GENHD_FL_REMOVABLE;
738 	add_disk(disk);
739 
740 	sdev_printk(KERN_DEBUG, sdev,
741 		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
742 	scsi_autopm_put_device(cd->device);
743 
744 	return 0;
745 
746 fail_put:
747 	put_disk(disk);
748 fail_free:
749 	kfree(cd);
750 fail:
751 	scsi_autopm_put_device(sdev);
752 	return error;
753 }
754 
755 
get_sectorsize(struct scsi_cd * cd)756 static void get_sectorsize(struct scsi_cd *cd)
757 {
758 	unsigned char cmd[10];
759 	unsigned char buffer[8];
760 	int the_result, retries = 3;
761 	int sector_size;
762 	struct request_queue *queue;
763 
764 	do {
765 		cmd[0] = READ_CAPACITY;
766 		memset((void *) &cmd[1], 0, 9);
767 		memset(buffer, 0, sizeof(buffer));
768 
769 		/* Do the command and wait.. */
770 		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
771 					      buffer, sizeof(buffer), NULL,
772 					      SR_TIMEOUT, MAX_RETRIES, NULL);
773 
774 		retries--;
775 
776 	} while (the_result && retries);
777 
778 
779 	if (the_result) {
780 		cd->capacity = 0x1fffff;
781 		sector_size = 2048;	/* A guess, just in case */
782 	} else {
783 		long last_written;
784 
785 		cd->capacity = 1 + ((buffer[0] << 24) | (buffer[1] << 16) |
786 				    (buffer[2] << 8) | buffer[3]);
787 		/*
788 		 * READ_CAPACITY doesn't return the correct size on
789 		 * certain UDF media.  If last_written is larger, use
790 		 * it instead.
791 		 *
792 		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
793 		 */
794 		if (!cdrom_get_last_written(&cd->cdi, &last_written))
795 			cd->capacity = max_t(long, cd->capacity, last_written);
796 
797 		sector_size = (buffer[4] << 24) |
798 		    (buffer[5] << 16) | (buffer[6] << 8) | buffer[7];
799 		switch (sector_size) {
800 			/*
801 			 * HP 4020i CD-Recorder reports 2340 byte sectors
802 			 * Philips CD-Writers report 2352 byte sectors
803 			 *
804 			 * Use 2k sectors for them..
805 			 */
806 		case 0:
807 		case 2340:
808 		case 2352:
809 			sector_size = 2048;
810 			/* fall through */
811 		case 2048:
812 			cd->capacity *= 4;
813 			/* fall through */
814 		case 512:
815 			break;
816 		default:
817 			sr_printk(KERN_INFO, cd,
818 				  "unsupported sector size %d.", sector_size);
819 			cd->capacity = 0;
820 		}
821 
822 		cd->device->sector_size = sector_size;
823 
824 		/*
825 		 * Add this so that we have the ability to correctly gauge
826 		 * what the device is capable of.
827 		 */
828 		set_capacity(cd->disk, cd->capacity);
829 	}
830 
831 	queue = cd->device->request_queue;
832 	blk_queue_logical_block_size(queue, sector_size);
833 
834 	return;
835 }
836 
get_capabilities(struct scsi_cd * cd)837 static void get_capabilities(struct scsi_cd *cd)
838 {
839 	unsigned char *buffer;
840 	struct scsi_mode_data data;
841 	struct scsi_sense_hdr sshdr;
842 	unsigned int ms_len = 128;
843 	int rc, n;
844 
845 	static const char *loadmech[] =
846 	{
847 		"caddy",
848 		"tray",
849 		"pop-up",
850 		"",
851 		"changer",
852 		"cartridge changer",
853 		"",
854 		""
855 	};
856 
857 
858 	/* allocate transfer buffer */
859 	buffer = kmalloc(512, GFP_KERNEL | GFP_DMA);
860 	if (!buffer) {
861 		sr_printk(KERN_ERR, cd, "out of memory.\n");
862 		return;
863 	}
864 
865 	/* eat unit attentions */
866 	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
867 
868 	/* ask for mode page 0x2a */
869 	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
870 			     SR_TIMEOUT, 3, &data, NULL);
871 
872 	if (!scsi_status_is_good(rc) || data.length > ms_len ||
873 	    data.header_length + data.block_descriptor_length > data.length) {
874 		/* failed, drive doesn't have capabilities mode page */
875 		cd->cdi.speed = 1;
876 		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
877 				 CDC_DVD | CDC_DVD_RAM |
878 				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
879 				 CDC_MRW | CDC_MRW_W | CDC_RAM);
880 		kfree(buffer);
881 		sr_printk(KERN_INFO, cd, "scsi-1 drive");
882 		return;
883 	}
884 
885 	n = data.header_length + data.block_descriptor_length;
886 	cd->cdi.speed = ((buffer[n + 8] << 8) + buffer[n + 9]) / 176;
887 	cd->readcd_known = 1;
888 	cd->readcd_cdda = buffer[n + 5] & 0x01;
889 	/* print some capability bits */
890 	sr_printk(KERN_INFO, cd,
891 		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
892 		  ((buffer[n + 14] << 8) + buffer[n + 15]) / 176,
893 		  cd->cdi.speed,
894 		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
895 		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
896 		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
897 		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
898 		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
899 		  loadmech[buffer[n + 6] >> 5]);
900 	if ((buffer[n + 6] >> 5) == 0)
901 		/* caddy drives can't close tray... */
902 		cd->cdi.mask |= CDC_CLOSE_TRAY;
903 	if ((buffer[n + 2] & 0x8) == 0)
904 		/* not a DVD drive */
905 		cd->cdi.mask |= CDC_DVD;
906 	if ((buffer[n + 3] & 0x20) == 0)
907 		/* can't write DVD-RAM media */
908 		cd->cdi.mask |= CDC_DVD_RAM;
909 	if ((buffer[n + 3] & 0x10) == 0)
910 		/* can't write DVD-R media */
911 		cd->cdi.mask |= CDC_DVD_R;
912 	if ((buffer[n + 3] & 0x2) == 0)
913 		/* can't write CD-RW media */
914 		cd->cdi.mask |= CDC_CD_RW;
915 	if ((buffer[n + 3] & 0x1) == 0)
916 		/* can't write CD-R media */
917 		cd->cdi.mask |= CDC_CD_R;
918 	if ((buffer[n + 6] & 0x8) == 0)
919 		/* can't eject */
920 		cd->cdi.mask |= CDC_OPEN_TRAY;
921 
922 	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
923 	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
924 		cd->cdi.capacity =
925 		    cdrom_number_of_slots(&cd->cdi);
926 	if (cd->cdi.capacity <= 1)
927 		/* not a changer */
928 		cd->cdi.mask |= CDC_SELECT_DISC;
929 	/*else    I don't think it can close its tray
930 		cd->cdi.mask |= CDC_CLOSE_TRAY; */
931 
932 	/*
933 	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
934 	 */
935 	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
936 			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
937 		cd->writeable = 1;
938 	}
939 
940 	kfree(buffer);
941 }
942 
943 /*
944  * sr_packet() is the entry point for the generic commands generated
945  * by the Uniform CD-ROM layer.
946  */
sr_packet(struct cdrom_device_info * cdi,struct packet_command * cgc)947 static int sr_packet(struct cdrom_device_info *cdi,
948 		struct packet_command *cgc)
949 {
950 	struct scsi_cd *cd = cdi->handle;
951 	struct scsi_device *sdev = cd->device;
952 
953 	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
954 		return -EDRIVE_CANT_DO_THIS;
955 
956 	if (cgc->timeout <= 0)
957 		cgc->timeout = IOCTL_TIMEOUT;
958 
959 	sr_do_ioctl(cd, cgc);
960 
961 	return cgc->stat;
962 }
963 
964 /**
965  *	sr_kref_release - Called to free the scsi_cd structure
966  *	@kref: pointer to embedded kref
967  *
968  *	sr_ref_mutex must be held entering this routine.  Because it is
969  *	called on last put, you should always use the scsi_cd_get()
970  *	scsi_cd_put() helpers which manipulate the semaphore directly
971  *	and never do a direct kref_put().
972  **/
sr_kref_release(struct kref * kref)973 static void sr_kref_release(struct kref *kref)
974 {
975 	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
976 	struct gendisk *disk = cd->disk;
977 
978 	spin_lock(&sr_index_lock);
979 	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
980 	spin_unlock(&sr_index_lock);
981 
982 	unregister_cdrom(&cd->cdi);
983 
984 	disk->private_data = NULL;
985 
986 	put_disk(disk);
987 
988 	kfree(cd);
989 }
990 
sr_remove(struct device * dev)991 static int sr_remove(struct device *dev)
992 {
993 	struct scsi_cd *cd = dev_get_drvdata(dev);
994 
995 	scsi_autopm_get_device(cd->device);
996 
997 	del_gendisk(cd->disk);
998 	dev_set_drvdata(dev, NULL);
999 
1000 	mutex_lock(&sr_ref_mutex);
1001 	kref_put(&cd->kref, sr_kref_release);
1002 	mutex_unlock(&sr_ref_mutex);
1003 
1004 	return 0;
1005 }
1006 
init_sr(void)1007 static int __init init_sr(void)
1008 {
1009 	int rc;
1010 
1011 	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1012 	if (rc)
1013 		return rc;
1014 	rc = scsi_register_driver(&sr_template.gendrv);
1015 	if (rc)
1016 		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1017 
1018 	return rc;
1019 }
1020 
exit_sr(void)1021 static void __exit exit_sr(void)
1022 {
1023 	scsi_unregister_driver(&sr_template.gendrv);
1024 	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1025 }
1026 
1027 module_init(init_sr);
1028 module_exit(exit_sr);
1029 MODULE_LICENSE("GPL");
1030