xref: /kernel/linux/linux-5.10/drivers/scsi/sr.c (revision 8c2ecf20)
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 *  sr.c Copyright (C) 1992 David Giller
4 *           Copyright (C) 1993, 1994, 1995, 1999 Eric Youngdale
5 *
6 *  adapted from:
7 *      sd.c Copyright (C) 1992 Drew Eckhardt
8 *      Linux scsi disk driver by
9 *              Drew Eckhardt <drew@colorado.edu>
10 *
11 *	Modified by Eric Youngdale ericy@andante.org to
12 *	add scatter-gather, multiple outstanding request, and other
13 *	enhancements.
14 *
15 *      Modified by Eric Youngdale eric@andante.org to support loadable
16 *      low-level scsi drivers.
17 *
18 *      Modified by Thomas Quinot thomas@melchior.cuivre.fdn.fr to
19 *      provide auto-eject.
20 *
21 *      Modified by Gerd Knorr <kraxel@cs.tu-berlin.de> to support the
22 *      generic cdrom interface
23 *
24 *      Modified by Jens Axboe <axboe@suse.de> - Uniform sr_packet()
25 *      interface, capabilities probe additions, ioctl cleanups, etc.
26 *
27 *	Modified by Richard Gooch <rgooch@atnf.csiro.au> to support devfs
28 *
29 *	Modified by Jens Axboe <axboe@suse.de> - support DVD-RAM
30 *	transparently and lose the GHOST hack
31 *
32 *	Modified by Arnaldo Carvalho de Melo <acme@conectiva.com.br>
33 *	check resource allocation in sr_init and some cleanups
34 */
35
36#include <linux/module.h>
37#include <linux/fs.h>
38#include <linux/kernel.h>
39#include <linux/mm.h>
40#include <linux/bio.h>
41#include <linux/compat.h>
42#include <linux/string.h>
43#include <linux/errno.h>
44#include <linux/cdrom.h>
45#include <linux/interrupt.h>
46#include <linux/init.h>
47#include <linux/blkdev.h>
48#include <linux/blk-pm.h>
49#include <linux/mutex.h>
50#include <linux/slab.h>
51#include <linux/pm_runtime.h>
52#include <linux/uaccess.h>
53
54#include <asm/unaligned.h>
55
56#include <scsi/scsi.h>
57#include <scsi/scsi_dbg.h>
58#include <scsi/scsi_device.h>
59#include <scsi/scsi_driver.h>
60#include <scsi/scsi_cmnd.h>
61#include <scsi/scsi_eh.h>
62#include <scsi/scsi_host.h>
63#include <scsi/scsi_ioctl.h>	/* For the door lock/unlock commands */
64
65#include "scsi_logging.h"
66#include "sr.h"
67
68
69MODULE_DESCRIPTION("SCSI cdrom (sr) driver");
70MODULE_LICENSE("GPL");
71MODULE_ALIAS_BLOCKDEV_MAJOR(SCSI_CDROM_MAJOR);
72MODULE_ALIAS_SCSI_DEVICE(TYPE_ROM);
73MODULE_ALIAS_SCSI_DEVICE(TYPE_WORM);
74
75#define SR_DISKS	256
76
77#define SR_CAPABILITIES \
78	(CDC_CLOSE_TRAY|CDC_OPEN_TRAY|CDC_LOCK|CDC_SELECT_SPEED| \
79	 CDC_SELECT_DISC|CDC_MULTI_SESSION|CDC_MCN|CDC_MEDIA_CHANGED| \
80	 CDC_PLAY_AUDIO|CDC_RESET|CDC_DRIVE_STATUS| \
81	 CDC_CD_R|CDC_CD_RW|CDC_DVD|CDC_DVD_R|CDC_DVD_RAM|CDC_GENERIC_PACKET| \
82	 CDC_MRW|CDC_MRW_W|CDC_RAM)
83
84static int sr_probe(struct device *);
85static int sr_remove(struct device *);
86static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt);
87static int sr_done(struct scsi_cmnd *);
88static int sr_runtime_suspend(struct device *dev);
89
90static const struct dev_pm_ops sr_pm_ops = {
91	.runtime_suspend	= sr_runtime_suspend,
92};
93
94static struct scsi_driver sr_template = {
95	.gendrv = {
96		.name   	= "sr",
97		.owner		= THIS_MODULE,
98		.probe		= sr_probe,
99		.remove		= sr_remove,
100		.pm		= &sr_pm_ops,
101	},
102	.init_command		= sr_init_command,
103	.done			= sr_done,
104};
105
106static unsigned long sr_index_bits[SR_DISKS / BITS_PER_LONG];
107static DEFINE_SPINLOCK(sr_index_lock);
108
109/* This semaphore is used to mediate the 0->1 reference get in the
110 * face of object destruction (i.e. we can't allow a get on an
111 * object after last put) */
112static DEFINE_MUTEX(sr_ref_mutex);
113
114static int sr_open(struct cdrom_device_info *, int);
115static void sr_release(struct cdrom_device_info *);
116
117static void get_sectorsize(struct scsi_cd *);
118static void get_capabilities(struct scsi_cd *);
119
120static unsigned int sr_check_events(struct cdrom_device_info *cdi,
121				    unsigned int clearing, int slot);
122static int sr_packet(struct cdrom_device_info *, struct packet_command *);
123
124static const struct cdrom_device_ops sr_dops = {
125	.open			= sr_open,
126	.release	 	= sr_release,
127	.drive_status	 	= sr_drive_status,
128	.check_events		= sr_check_events,
129	.tray_move		= sr_tray_move,
130	.lock_door		= sr_lock_door,
131	.select_speed		= sr_select_speed,
132	.get_last_session	= sr_get_last_session,
133	.get_mcn		= sr_get_mcn,
134	.reset			= sr_reset,
135	.audio_ioctl		= sr_audio_ioctl,
136	.capability		= SR_CAPABILITIES,
137	.generic_packet		= sr_packet,
138};
139
140static void sr_kref_release(struct kref *kref);
141
142static inline struct scsi_cd *scsi_cd(struct gendisk *disk)
143{
144	return container_of(disk->private_data, struct scsi_cd, driver);
145}
146
147static int sr_runtime_suspend(struct device *dev)
148{
149	struct scsi_cd *cd = dev_get_drvdata(dev);
150
151	if (!cd)	/* E.g.: runtime suspend following sr_remove() */
152		return 0;
153
154	if (cd->media_present)
155		return -EBUSY;
156	else
157		return 0;
158}
159
160/*
161 * The get and put routines for the struct scsi_cd.  Note this entity
162 * has a scsi_device pointer and owns a reference to this.
163 */
164static inline struct scsi_cd *scsi_cd_get(struct gendisk *disk)
165{
166	struct scsi_cd *cd = NULL;
167
168	mutex_lock(&sr_ref_mutex);
169	if (disk->private_data == NULL)
170		goto out;
171	cd = scsi_cd(disk);
172	kref_get(&cd->kref);
173	if (scsi_device_get(cd->device)) {
174		kref_put(&cd->kref, sr_kref_release);
175		cd = NULL;
176	}
177 out:
178	mutex_unlock(&sr_ref_mutex);
179	return cd;
180}
181
182static void scsi_cd_put(struct scsi_cd *cd)
183{
184	struct scsi_device *sdev = cd->device;
185
186	mutex_lock(&sr_ref_mutex);
187	kref_put(&cd->kref, sr_kref_release);
188	scsi_device_put(sdev);
189	mutex_unlock(&sr_ref_mutex);
190}
191
192static unsigned int sr_get_events(struct scsi_device *sdev)
193{
194	u8 buf[8];
195	u8 cmd[] = { GET_EVENT_STATUS_NOTIFICATION,
196		     1,			/* polled */
197		     0, 0,		/* reserved */
198		     1 << 4,		/* notification class: media */
199		     0, 0,		/* reserved */
200		     0, sizeof(buf),	/* allocation length */
201		     0,			/* control */
202	};
203	struct event_header *eh = (void *)buf;
204	struct media_event_desc *med = (void *)(buf + 4);
205	struct scsi_sense_hdr sshdr;
206	int result;
207
208	result = scsi_execute_req(sdev, cmd, DMA_FROM_DEVICE, buf, sizeof(buf),
209				  &sshdr, SR_TIMEOUT, MAX_RETRIES, NULL);
210	if (scsi_sense_valid(&sshdr) && sshdr.sense_key == UNIT_ATTENTION)
211		return DISK_EVENT_MEDIA_CHANGE;
212
213	if (result || be16_to_cpu(eh->data_len) < sizeof(*med))
214		return 0;
215
216	if (eh->nea || eh->notification_class != 0x4)
217		return 0;
218
219	if (med->media_event_code == 1)
220		return DISK_EVENT_EJECT_REQUEST;
221	else if (med->media_event_code == 2)
222		return DISK_EVENT_MEDIA_CHANGE;
223	else if (med->media_event_code == 3)
224		return DISK_EVENT_MEDIA_CHANGE;
225	return 0;
226}
227
228/*
229 * This function checks to see if the media has been changed or eject
230 * button has been pressed.  It is possible that we have already
231 * sensed a change, or the drive may have sensed one and not yet
232 * reported it.  The past events are accumulated in sdev->changed and
233 * returned together with the current state.
234 */
235static unsigned int sr_check_events(struct cdrom_device_info *cdi,
236				    unsigned int clearing, int slot)
237{
238	struct scsi_cd *cd = cdi->handle;
239	bool last_present;
240	struct scsi_sense_hdr sshdr;
241	unsigned int events;
242	int ret;
243
244	/* no changer support */
245	if (CDSL_CURRENT != slot)
246		return 0;
247
248	events = sr_get_events(cd->device);
249	cd->get_event_changed |= events & DISK_EVENT_MEDIA_CHANGE;
250
251	/*
252	 * If earlier GET_EVENT_STATUS_NOTIFICATION and TUR did not agree
253	 * for several times in a row.  We rely on TUR only for this likely
254	 * broken device, to prevent generating incorrect media changed
255	 * events for every open().
256	 */
257	if (cd->ignore_get_event) {
258		events &= ~DISK_EVENT_MEDIA_CHANGE;
259		goto do_tur;
260	}
261
262	/*
263	 * GET_EVENT_STATUS_NOTIFICATION is enough unless MEDIA_CHANGE
264	 * is being cleared.  Note that there are devices which hang
265	 * if asked to execute TUR repeatedly.
266	 */
267	if (cd->device->changed) {
268		events |= DISK_EVENT_MEDIA_CHANGE;
269		cd->device->changed = 0;
270		cd->tur_changed = true;
271	}
272
273	if (!(clearing & DISK_EVENT_MEDIA_CHANGE))
274		return events;
275do_tur:
276	/* let's see whether the media is there with TUR */
277	last_present = cd->media_present;
278	ret = scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
279
280	/*
281	 * Media is considered to be present if TUR succeeds or fails with
282	 * sense data indicating something other than media-not-present
283	 * (ASC 0x3a).
284	 */
285	cd->media_present = scsi_status_is_good(ret) ||
286		(scsi_sense_valid(&sshdr) && sshdr.asc != 0x3a);
287
288	if (last_present != cd->media_present)
289		cd->device->changed = 1;
290
291	if (cd->device->changed) {
292		events |= DISK_EVENT_MEDIA_CHANGE;
293		cd->device->changed = 0;
294		cd->tur_changed = true;
295	}
296
297	if (cd->ignore_get_event)
298		return events;
299
300	/* check whether GET_EVENT is reporting spurious MEDIA_CHANGE */
301	if (!cd->tur_changed) {
302		if (cd->get_event_changed) {
303			if (cd->tur_mismatch++ > 8) {
304				sr_printk(KERN_WARNING, cd,
305					  "GET_EVENT and TUR disagree continuously, suppress GET_EVENT events\n");
306				cd->ignore_get_event = true;
307			}
308		} else {
309			cd->tur_mismatch = 0;
310		}
311	}
312	cd->tur_changed = false;
313	cd->get_event_changed = false;
314
315	return events;
316}
317
318/*
319 * sr_done is the interrupt routine for the device driver.
320 *
321 * It will be notified on the end of a SCSI read / write, and will take one
322 * of several actions based on success or failure.
323 */
324static int sr_done(struct scsi_cmnd *SCpnt)
325{
326	int result = SCpnt->result;
327	int this_count = scsi_bufflen(SCpnt);
328	int good_bytes = (result == 0 ? this_count : 0);
329	int block_sectors = 0;
330	long error_sector;
331	struct scsi_cd *cd = scsi_cd(SCpnt->request->rq_disk);
332
333#ifdef DEBUG
334	scmd_printk(KERN_INFO, SCpnt, "done: %x\n", result);
335#endif
336
337	/*
338	 * Handle MEDIUM ERRORs or VOLUME OVERFLOWs that indicate partial
339	 * success.  Since this is a relatively rare error condition, no
340	 * care is taken to avoid unnecessary additional work such as
341	 * memcpy's that could be avoided.
342	 */
343	if (driver_byte(result) != 0 &&		/* An error occurred */
344	    (SCpnt->sense_buffer[0] & 0x7f) == 0x70) { /* Sense current */
345		switch (SCpnt->sense_buffer[2]) {
346		case MEDIUM_ERROR:
347		case VOLUME_OVERFLOW:
348		case ILLEGAL_REQUEST:
349			if (!(SCpnt->sense_buffer[0] & 0x90))
350				break;
351			error_sector =
352				get_unaligned_be32(&SCpnt->sense_buffer[3]);
353			if (SCpnt->request->bio != NULL)
354				block_sectors =
355					bio_sectors(SCpnt->request->bio);
356			if (block_sectors < 4)
357				block_sectors = 4;
358			if (cd->device->sector_size == 2048)
359				error_sector <<= 2;
360			error_sector &= ~(block_sectors - 1);
361			good_bytes = (error_sector -
362				      blk_rq_pos(SCpnt->request)) << 9;
363			if (good_bytes < 0 || good_bytes >= this_count)
364				good_bytes = 0;
365			/*
366			 * The SCSI specification allows for the value
367			 * returned by READ CAPACITY to be up to 75 2K
368			 * sectors past the last readable block.
369			 * Therefore, if we hit a medium error within the
370			 * last 75 2K sectors, we decrease the saved size
371			 * value.
372			 */
373			if (error_sector < get_capacity(cd->disk) &&
374			    cd->capacity - error_sector < 4 * 75)
375				set_capacity(cd->disk, error_sector);
376			break;
377
378		case RECOVERED_ERROR:
379			good_bytes = this_count;
380			break;
381
382		default:
383			break;
384		}
385	}
386
387	return good_bytes;
388}
389
390static blk_status_t sr_init_command(struct scsi_cmnd *SCpnt)
391{
392	int block = 0, this_count, s_size;
393	struct scsi_cd *cd;
394	struct request *rq = SCpnt->request;
395	blk_status_t ret;
396
397	ret = scsi_alloc_sgtables(SCpnt);
398	if (ret != BLK_STS_OK)
399		return ret;
400	cd = scsi_cd(rq->rq_disk);
401
402	SCSI_LOG_HLQUEUE(1, scmd_printk(KERN_INFO, SCpnt,
403		"Doing sr request, block = %d\n", block));
404
405	if (!cd->device || !scsi_device_online(cd->device)) {
406		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
407			"Finishing %u sectors\n", blk_rq_sectors(rq)));
408		SCSI_LOG_HLQUEUE(2, scmd_printk(KERN_INFO, SCpnt,
409			"Retry with 0x%p\n", SCpnt));
410		goto out;
411	}
412
413	if (cd->device->changed) {
414		/*
415		 * quietly refuse to do anything to a changed disc until the
416		 * changed bit has been reset
417		 */
418		goto out;
419	}
420
421	/*
422	 * we do lazy blocksize switching (when reading XA sectors,
423	 * see CDROMREADMODE2 ioctl)
424	 */
425	s_size = cd->device->sector_size;
426	if (s_size > 2048) {
427		if (!in_interrupt())
428			sr_set_blocklength(cd, 2048);
429		else
430			scmd_printk(KERN_INFO, SCpnt,
431				    "can't switch blocksize: in interrupt\n");
432	}
433
434	if (s_size != 512 && s_size != 1024 && s_size != 2048) {
435		scmd_printk(KERN_ERR, SCpnt, "bad sector size %d\n", s_size);
436		goto out;
437	}
438
439	switch (req_op(rq)) {
440	case REQ_OP_WRITE:
441		if (!cd->writeable)
442			goto out;
443		SCpnt->cmnd[0] = WRITE_10;
444		cd->cdi.media_written = 1;
445		break;
446	case REQ_OP_READ:
447		SCpnt->cmnd[0] = READ_10;
448		break;
449	default:
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	put_unaligned_be32(block, &SCpnt->cmnd[2]);
497	SCpnt->cmnd[6] = SCpnt->cmnd[9] = 0;
498	put_unaligned_be16(this_count, &SCpnt->cmnd[7]);
499
500	/*
501	 * We shouldn't disconnect in the middle of a sector, so with a dumb
502	 * host adapter, it's safe to assume that we can at least transfer
503	 * this many bytes between each connect / disconnect.
504	 */
505	SCpnt->transfersize = cd->device->sector_size;
506	SCpnt->underflow = this_count << 9;
507	SCpnt->allowed = MAX_RETRIES;
508	SCpnt->cmd_len = 10;
509
510	/*
511	 * This indicates that the command is ready from our end to be queued.
512	 */
513	return BLK_STS_OK;
514 out:
515	scsi_free_sgtables(SCpnt);
516	return BLK_STS_IOERR;
517}
518
519static void sr_revalidate_disk(struct scsi_cd *cd)
520{
521	struct scsi_sense_hdr sshdr;
522
523	/* if the unit is not ready, nothing more to do */
524	if (scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr))
525		return;
526	sr_cd_check(&cd->cdi);
527	get_sectorsize(cd);
528}
529
530static int sr_block_open(struct block_device *bdev, fmode_t mode)
531{
532	struct scsi_cd *cd;
533	struct scsi_device *sdev;
534	int ret = -ENXIO;
535
536	cd = scsi_cd_get(bdev->bd_disk);
537	if (!cd)
538		goto out;
539
540	sdev = cd->device;
541	scsi_autopm_get_device(sdev);
542	if (bdev_check_media_change(bdev))
543		sr_revalidate_disk(cd);
544
545	mutex_lock(&cd->lock);
546	ret = cdrom_open(&cd->cdi, bdev, mode);
547	mutex_unlock(&cd->lock);
548
549	scsi_autopm_put_device(sdev);
550	if (ret)
551		scsi_cd_put(cd);
552
553out:
554	return ret;
555}
556
557static void sr_block_release(struct gendisk *disk, fmode_t mode)
558{
559	struct scsi_cd *cd = scsi_cd(disk);
560
561	mutex_lock(&cd->lock);
562	cdrom_release(&cd->cdi, mode);
563	mutex_unlock(&cd->lock);
564
565	scsi_cd_put(cd);
566}
567
568static int sr_block_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
569			  unsigned long arg)
570{
571	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
572	struct scsi_device *sdev = cd->device;
573	void __user *argp = (void __user *)arg;
574	int ret;
575
576	mutex_lock(&cd->lock);
577
578	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
579			(mode & FMODE_NDELAY) != 0);
580	if (ret)
581		goto out;
582
583	scsi_autopm_get_device(sdev);
584
585	/*
586	 * Send SCSI addressing ioctls directly to mid level, send other
587	 * ioctls to cdrom/block level.
588	 */
589	switch (cmd) {
590	case SCSI_IOCTL_GET_IDLUN:
591	case SCSI_IOCTL_GET_BUS_NUMBER:
592		ret = scsi_ioctl(sdev, cmd, argp);
593		goto put;
594	}
595
596	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, arg);
597	if (ret != -ENOSYS)
598		goto put;
599
600	ret = scsi_ioctl(sdev, cmd, argp);
601
602put:
603	scsi_autopm_put_device(sdev);
604
605out:
606	mutex_unlock(&cd->lock);
607	return ret;
608}
609
610#ifdef CONFIG_COMPAT
611static int sr_block_compat_ioctl(struct block_device *bdev, fmode_t mode, unsigned cmd,
612			  unsigned long arg)
613{
614	struct scsi_cd *cd = scsi_cd(bdev->bd_disk);
615	struct scsi_device *sdev = cd->device;
616	void __user *argp = compat_ptr(arg);
617	int ret;
618
619	mutex_lock(&cd->lock);
620
621	ret = scsi_ioctl_block_when_processing_errors(sdev, cmd,
622			(mode & FMODE_NDELAY) != 0);
623	if (ret)
624		goto out;
625
626	scsi_autopm_get_device(sdev);
627
628	/*
629	 * Send SCSI addressing ioctls directly to mid level, send other
630	 * ioctls to cdrom/block level.
631	 */
632	switch (cmd) {
633	case SCSI_IOCTL_GET_IDLUN:
634	case SCSI_IOCTL_GET_BUS_NUMBER:
635		ret = scsi_compat_ioctl(sdev, cmd, argp);
636		goto put;
637	}
638
639	ret = cdrom_ioctl(&cd->cdi, bdev, mode, cmd, (unsigned long)argp);
640	if (ret != -ENOSYS)
641		goto put;
642
643	ret = scsi_compat_ioctl(sdev, cmd, argp);
644
645put:
646	scsi_autopm_put_device(sdev);
647
648out:
649	mutex_unlock(&cd->lock);
650	return ret;
651
652}
653#endif
654
655static unsigned int sr_block_check_events(struct gendisk *disk,
656					  unsigned int clearing)
657{
658	unsigned int ret = 0;
659	struct scsi_cd *cd;
660
661	cd = scsi_cd_get(disk);
662	if (!cd)
663		return 0;
664
665	if (!atomic_read(&cd->device->disk_events_disable_depth))
666		ret = cdrom_check_events(&cd->cdi, clearing);
667
668	scsi_cd_put(cd);
669	return ret;
670}
671
672static const struct block_device_operations sr_bdops =
673{
674	.owner		= THIS_MODULE,
675	.open		= sr_block_open,
676	.release	= sr_block_release,
677	.ioctl		= sr_block_ioctl,
678#ifdef CONFIG_COMPAT
679	.compat_ioctl	= sr_block_compat_ioctl,
680#endif
681	.check_events	= sr_block_check_events,
682};
683
684static int sr_open(struct cdrom_device_info *cdi, int purpose)
685{
686	struct scsi_cd *cd = cdi->handle;
687	struct scsi_device *sdev = cd->device;
688	int retval;
689
690	/*
691	 * If the device is in error recovery, wait until it is done.
692	 * If the device is offline, then disallow any access to it.
693	 */
694	retval = -ENXIO;
695	if (!scsi_block_when_processing_errors(sdev))
696		goto error_out;
697
698	return 0;
699
700error_out:
701	return retval;
702}
703
704static void sr_release(struct cdrom_device_info *cdi)
705{
706	struct scsi_cd *cd = cdi->handle;
707
708	if (cd->device->sector_size > 2048)
709		sr_set_blocklength(cd, 2048);
710
711}
712
713static int sr_probe(struct device *dev)
714{
715	struct scsi_device *sdev = to_scsi_device(dev);
716	struct gendisk *disk;
717	struct scsi_cd *cd;
718	int minor, error;
719
720	scsi_autopm_get_device(sdev);
721	error = -ENODEV;
722	if (sdev->type != TYPE_ROM && sdev->type != TYPE_WORM)
723		goto fail;
724
725	error = -ENOMEM;
726	cd = kzalloc(sizeof(*cd), GFP_KERNEL);
727	if (!cd)
728		goto fail;
729
730	kref_init(&cd->kref);
731
732	disk = alloc_disk(1);
733	if (!disk)
734		goto fail_free;
735	mutex_init(&cd->lock);
736
737	spin_lock(&sr_index_lock);
738	minor = find_first_zero_bit(sr_index_bits, SR_DISKS);
739	if (minor == SR_DISKS) {
740		spin_unlock(&sr_index_lock);
741		error = -EBUSY;
742		goto fail_put;
743	}
744	__set_bit(minor, sr_index_bits);
745	spin_unlock(&sr_index_lock);
746
747	disk->major = SCSI_CDROM_MAJOR;
748	disk->first_minor = minor;
749	sprintf(disk->disk_name, "sr%d", minor);
750	disk->fops = &sr_bdops;
751	disk->flags = GENHD_FL_CD | GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE;
752	disk->events = DISK_EVENT_MEDIA_CHANGE | DISK_EVENT_EJECT_REQUEST;
753	disk->event_flags = DISK_EVENT_FLAG_POLL | DISK_EVENT_FLAG_UEVENT;
754
755	blk_queue_rq_timeout(sdev->request_queue, SR_TIMEOUT);
756
757	cd->device = sdev;
758	cd->disk = disk;
759	cd->driver = &sr_template;
760	cd->disk = disk;
761	cd->capacity = 0x1fffff;
762	cd->device->changed = 1;	/* force recheck CD type */
763	cd->media_present = 1;
764	cd->use = 1;
765	cd->readcd_known = 0;
766	cd->readcd_cdda = 0;
767
768	cd->cdi.ops = &sr_dops;
769	cd->cdi.handle = cd;
770	cd->cdi.mask = 0;
771	cd->cdi.capacity = 1;
772	sprintf(cd->cdi.name, "sr%d", minor);
773
774	sdev->sector_size = 2048;	/* A guess, just in case */
775
776	/* FIXME: need to handle a get_capabilities failure properly ?? */
777	get_capabilities(cd);
778	sr_vendor_init(cd);
779
780	set_capacity(disk, cd->capacity);
781	disk->private_data = &cd->driver;
782	disk->queue = sdev->request_queue;
783
784	if (register_cdrom(disk, &cd->cdi))
785		goto fail_minor;
786
787	/*
788	 * Initialize block layer runtime PM stuffs before the
789	 * periodic event checking request gets started in add_disk.
790	 */
791	blk_pm_runtime_init(sdev->request_queue, dev);
792
793	dev_set_drvdata(dev, cd);
794	disk->flags |= GENHD_FL_REMOVABLE;
795	sr_revalidate_disk(cd);
796	device_add_disk(&sdev->sdev_gendev, disk, NULL);
797
798	sdev_printk(KERN_DEBUG, sdev,
799		    "Attached scsi CD-ROM %s\n", cd->cdi.name);
800	scsi_autopm_put_device(cd->device);
801
802	return 0;
803
804fail_minor:
805	spin_lock(&sr_index_lock);
806	clear_bit(minor, sr_index_bits);
807	spin_unlock(&sr_index_lock);
808fail_put:
809	put_disk(disk);
810	mutex_destroy(&cd->lock);
811fail_free:
812	kfree(cd);
813fail:
814	scsi_autopm_put_device(sdev);
815	return error;
816}
817
818
819static void get_sectorsize(struct scsi_cd *cd)
820{
821	unsigned char cmd[10];
822	unsigned char buffer[8];
823	int the_result, retries = 3;
824	int sector_size;
825	struct request_queue *queue;
826
827	do {
828		cmd[0] = READ_CAPACITY;
829		memset((void *) &cmd[1], 0, 9);
830		memset(buffer, 0, sizeof(buffer));
831
832		/* Do the command and wait.. */
833		the_result = scsi_execute_req(cd->device, cmd, DMA_FROM_DEVICE,
834					      buffer, sizeof(buffer), NULL,
835					      SR_TIMEOUT, MAX_RETRIES, NULL);
836
837		retries--;
838
839	} while (the_result && retries);
840
841
842	if (the_result) {
843		cd->capacity = 0x1fffff;
844		sector_size = 2048;	/* A guess, just in case */
845	} else {
846		long last_written;
847
848		cd->capacity = 1 + get_unaligned_be32(&buffer[0]);
849		/*
850		 * READ_CAPACITY doesn't return the correct size on
851		 * certain UDF media.  If last_written is larger, use
852		 * it instead.
853		 *
854		 * http://bugzilla.kernel.org/show_bug.cgi?id=9668
855		 */
856		if (!cdrom_get_last_written(&cd->cdi, &last_written))
857			cd->capacity = max_t(long, cd->capacity, last_written);
858
859		sector_size = get_unaligned_be32(&buffer[4]);
860		switch (sector_size) {
861			/*
862			 * HP 4020i CD-Recorder reports 2340 byte sectors
863			 * Philips CD-Writers report 2352 byte sectors
864			 *
865			 * Use 2k sectors for them..
866			 */
867		case 0:
868		case 2340:
869		case 2352:
870			sector_size = 2048;
871			fallthrough;
872		case 2048:
873			cd->capacity *= 4;
874			fallthrough;
875		case 512:
876			break;
877		default:
878			sr_printk(KERN_INFO, cd,
879				  "unsupported sector size %d.", sector_size);
880			cd->capacity = 0;
881		}
882
883		cd->device->sector_size = sector_size;
884
885		/*
886		 * Add this so that we have the ability to correctly gauge
887		 * what the device is capable of.
888		 */
889		set_capacity(cd->disk, cd->capacity);
890	}
891
892	queue = cd->device->request_queue;
893	blk_queue_logical_block_size(queue, sector_size);
894
895	return;
896}
897
898static void get_capabilities(struct scsi_cd *cd)
899{
900	unsigned char *buffer;
901	struct scsi_mode_data data;
902	struct scsi_sense_hdr sshdr;
903	unsigned int ms_len = 128;
904	int rc, n;
905
906	static const char *loadmech[] =
907	{
908		"caddy",
909		"tray",
910		"pop-up",
911		"",
912		"changer",
913		"cartridge changer",
914		"",
915		""
916	};
917
918
919	/* allocate transfer buffer */
920	buffer = kmalloc(512, GFP_KERNEL);
921	if (!buffer) {
922		sr_printk(KERN_ERR, cd, "out of memory.\n");
923		return;
924	}
925
926	/* eat unit attentions */
927	scsi_test_unit_ready(cd->device, SR_TIMEOUT, MAX_RETRIES, &sshdr);
928
929	/* ask for mode page 0x2a */
930	rc = scsi_mode_sense(cd->device, 0, 0x2a, buffer, ms_len,
931			     SR_TIMEOUT, 3, &data, NULL);
932
933	if (rc < 0 || data.length > ms_len ||
934	    data.header_length + data.block_descriptor_length > data.length) {
935		/* failed, drive doesn't have capabilities mode page */
936		cd->cdi.speed = 1;
937		cd->cdi.mask |= (CDC_CD_R | CDC_CD_RW | CDC_DVD_R |
938				 CDC_DVD | CDC_DVD_RAM |
939				 CDC_SELECT_DISC | CDC_SELECT_SPEED |
940				 CDC_MRW | CDC_MRW_W | CDC_RAM);
941		kfree(buffer);
942		sr_printk(KERN_INFO, cd, "scsi-1 drive");
943		return;
944	}
945
946	n = data.header_length + data.block_descriptor_length;
947	cd->cdi.speed = get_unaligned_be16(&buffer[n + 8]) / 176;
948	cd->readcd_known = 1;
949	cd->readcd_cdda = buffer[n + 5] & 0x01;
950	/* print some capability bits */
951	sr_printk(KERN_INFO, cd,
952		  "scsi3-mmc drive: %dx/%dx %s%s%s%s%s%s\n",
953		  get_unaligned_be16(&buffer[n + 14]) / 176,
954		  cd->cdi.speed,
955		  buffer[n + 3] & 0x01 ? "writer " : "", /* CD Writer */
956		  buffer[n + 3] & 0x20 ? "dvd-ram " : "",
957		  buffer[n + 2] & 0x02 ? "cd/rw " : "", /* can read rewriteable */
958		  buffer[n + 4] & 0x20 ? "xa/form2 " : "",	/* can read xa/from2 */
959		  buffer[n + 5] & 0x01 ? "cdda " : "", /* can read audio data */
960		  loadmech[buffer[n + 6] >> 5]);
961	if ((buffer[n + 6] >> 5) == 0)
962		/* caddy drives can't close tray... */
963		cd->cdi.mask |= CDC_CLOSE_TRAY;
964	if ((buffer[n + 2] & 0x8) == 0)
965		/* not a DVD drive */
966		cd->cdi.mask |= CDC_DVD;
967	if ((buffer[n + 3] & 0x20) == 0)
968		/* can't write DVD-RAM media */
969		cd->cdi.mask |= CDC_DVD_RAM;
970	if ((buffer[n + 3] & 0x10) == 0)
971		/* can't write DVD-R media */
972		cd->cdi.mask |= CDC_DVD_R;
973	if ((buffer[n + 3] & 0x2) == 0)
974		/* can't write CD-RW media */
975		cd->cdi.mask |= CDC_CD_RW;
976	if ((buffer[n + 3] & 0x1) == 0)
977		/* can't write CD-R media */
978		cd->cdi.mask |= CDC_CD_R;
979	if ((buffer[n + 6] & 0x8) == 0)
980		/* can't eject */
981		cd->cdi.mask |= CDC_OPEN_TRAY;
982
983	if ((buffer[n + 6] >> 5) == mechtype_individual_changer ||
984	    (buffer[n + 6] >> 5) == mechtype_cartridge_changer)
985		cd->cdi.capacity =
986		    cdrom_number_of_slots(&cd->cdi);
987	if (cd->cdi.capacity <= 1)
988		/* not a changer */
989		cd->cdi.mask |= CDC_SELECT_DISC;
990	/*else    I don't think it can close its tray
991		cd->cdi.mask |= CDC_CLOSE_TRAY; */
992
993	/*
994	 * if DVD-RAM, MRW-W or CD-RW, we are randomly writable
995	 */
996	if ((cd->cdi.mask & (CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) !=
997			(CDC_DVD_RAM | CDC_MRW_W | CDC_RAM | CDC_CD_RW)) {
998		cd->writeable = 1;
999	}
1000
1001	kfree(buffer);
1002}
1003
1004/*
1005 * sr_packet() is the entry point for the generic commands generated
1006 * by the Uniform CD-ROM layer.
1007 */
1008static int sr_packet(struct cdrom_device_info *cdi,
1009		struct packet_command *cgc)
1010{
1011	struct scsi_cd *cd = cdi->handle;
1012	struct scsi_device *sdev = cd->device;
1013
1014	if (cgc->cmd[0] == GPCMD_READ_DISC_INFO && sdev->no_read_disc_info)
1015		return -EDRIVE_CANT_DO_THIS;
1016
1017	if (cgc->timeout <= 0)
1018		cgc->timeout = IOCTL_TIMEOUT;
1019
1020	sr_do_ioctl(cd, cgc);
1021
1022	return cgc->stat;
1023}
1024
1025/**
1026 *	sr_kref_release - Called to free the scsi_cd structure
1027 *	@kref: pointer to embedded kref
1028 *
1029 *	sr_ref_mutex must be held entering this routine.  Because it is
1030 *	called on last put, you should always use the scsi_cd_get()
1031 *	scsi_cd_put() helpers which manipulate the semaphore directly
1032 *	and never do a direct kref_put().
1033 **/
1034static void sr_kref_release(struct kref *kref)
1035{
1036	struct scsi_cd *cd = container_of(kref, struct scsi_cd, kref);
1037	struct gendisk *disk = cd->disk;
1038
1039	spin_lock(&sr_index_lock);
1040	clear_bit(MINOR(disk_devt(disk)), sr_index_bits);
1041	spin_unlock(&sr_index_lock);
1042
1043	unregister_cdrom(&cd->cdi);
1044
1045	disk->private_data = NULL;
1046
1047	put_disk(disk);
1048
1049	mutex_destroy(&cd->lock);
1050
1051	kfree(cd);
1052}
1053
1054static int sr_remove(struct device *dev)
1055{
1056	struct scsi_cd *cd = dev_get_drvdata(dev);
1057
1058	scsi_autopm_get_device(cd->device);
1059
1060	del_gendisk(cd->disk);
1061	dev_set_drvdata(dev, NULL);
1062
1063	mutex_lock(&sr_ref_mutex);
1064	kref_put(&cd->kref, sr_kref_release);
1065	mutex_unlock(&sr_ref_mutex);
1066
1067	return 0;
1068}
1069
1070static int __init init_sr(void)
1071{
1072	int rc;
1073
1074	rc = register_blkdev(SCSI_CDROM_MAJOR, "sr");
1075	if (rc)
1076		return rc;
1077	rc = scsi_register_driver(&sr_template.gendrv);
1078	if (rc)
1079		unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1080
1081	return rc;
1082}
1083
1084static void __exit exit_sr(void)
1085{
1086	scsi_unregister_driver(&sr_template.gendrv);
1087	unregister_blkdev(SCSI_CDROM_MAJOR, "sr");
1088}
1089
1090module_init(init_sr);
1091module_exit(exit_sr);
1092MODULE_LICENSE("GPL");
1093