xref: /linux/drivers/block/pktcdvd.c (revision 367b8112fe2ea5c39a7bb4d263dcdd9b612fae18)
1 /*
2  * Copyright (C) 2000 Jens Axboe <axboe@suse.de>
3  * Copyright (C) 2001-2004 Peter Osterlund <petero2@telia.com>
4  * Copyright (C) 2006 Thomas Maier <balagi@justmail.de>
5  *
6  * May be copied or modified under the terms of the GNU General Public
7  * License.  See linux/COPYING for more information.
8  *
9  * Packet writing layer for ATAPI and SCSI CD-RW, DVD+RW, DVD-RW and
10  * DVD-RAM devices.
11  *
12  * Theory of operation:
13  *
14  * At the lowest level, there is the standard driver for the CD/DVD device,
15  * typically ide-cd.c or sr.c. This driver can handle read and write requests,
16  * but it doesn't know anything about the special restrictions that apply to
17  * packet writing. One restriction is that write requests must be aligned to
18  * packet boundaries on the physical media, and the size of a write request
19  * must be equal to the packet size. Another restriction is that a
20  * GPCMD_FLUSH_CACHE command has to be issued to the drive before a read
21  * command, if the previous command was a write.
22  *
23  * The purpose of the packet writing driver is to hide these restrictions from
24  * higher layers, such as file systems, and present a block device that can be
25  * randomly read and written using 2kB-sized blocks.
26  *
27  * The lowest layer in the packet writing driver is the packet I/O scheduler.
28  * Its data is defined by the struct packet_iosched and includes two bio
29  * queues with pending read and write requests. These queues are processed
30  * by the pkt_iosched_process_queue() function. The write requests in this
31  * queue are already properly aligned and sized. This layer is responsible for
32  * issuing the flush cache commands and scheduling the I/O in a good order.
33  *
34  * The next layer transforms unaligned write requests to aligned writes. This
35  * transformation requires reading missing pieces of data from the underlying
36  * block device, assembling the pieces to full packets and queuing them to the
37  * packet I/O scheduler.
38  *
39  * At the top layer there is a custom make_request_fn function that forwards
40  * read requests directly to the iosched queue and puts write requests in the
41  * unaligned write queue. A kernel thread performs the necessary read
42  * gathering to convert the unaligned writes to aligned writes and then feeds
43  * them to the packet I/O scheduler.
44  *
45  *************************************************************************/
46 
47 #include <linux/pktcdvd.h>
48 #include <linux/module.h>
49 #include <linux/types.h>
50 #include <linux/kernel.h>
51 #include <linux/kthread.h>
52 #include <linux/errno.h>
53 #include <linux/spinlock.h>
54 #include <linux/file.h>
55 #include <linux/proc_fs.h>
56 #include <linux/seq_file.h>
57 #include <linux/miscdevice.h>
58 #include <linux/freezer.h>
59 #include <linux/mutex.h>
60 #include <scsi/scsi_cmnd.h>
61 #include <scsi/scsi_ioctl.h>
62 #include <scsi/scsi.h>
63 #include <linux/debugfs.h>
64 #include <linux/device.h>
65 
66 #include <asm/uaccess.h>
67 
68 #define DRIVER_NAME	"pktcdvd"
69 
70 #if PACKET_DEBUG
71 #define DPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
72 #else
73 #define DPRINTK(fmt, args...)
74 #endif
75 
76 #if PACKET_DEBUG > 1
77 #define VPRINTK(fmt, args...) printk(KERN_NOTICE fmt, ##args)
78 #else
79 #define VPRINTK(fmt, args...)
80 #endif
81 
82 #define MAX_SPEED 0xffff
83 
84 #define ZONE(sector, pd) (((sector) + (pd)->offset) & ~((pd)->settings.size - 1))
85 
86 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
87 static struct proc_dir_entry *pkt_proc;
88 static int pktdev_major;
89 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
90 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
91 static struct mutex ctl_mutex;	/* Serialize open/close/setup/teardown */
92 static mempool_t *psd_pool;
93 
94 static struct class	*class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
95 static struct dentry	*pkt_debugfs_root = NULL; /* /debug/pktcdvd */
96 
97 /* forward declaration */
98 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
99 static int pkt_remove_dev(dev_t pkt_dev);
100 static int pkt_seq_show(struct seq_file *m, void *p);
101 
102 
103 
104 /*
105  * create and register a pktcdvd kernel object.
106  */
107 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
108 					const char* name,
109 					struct kobject* parent,
110 					struct kobj_type* ktype)
111 {
112 	struct pktcdvd_kobj *p;
113 	int error;
114 
115 	p = kzalloc(sizeof(*p), GFP_KERNEL);
116 	if (!p)
117 		return NULL;
118 	p->pd = pd;
119 	error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
120 	if (error) {
121 		kobject_put(&p->kobj);
122 		return NULL;
123 	}
124 	kobject_uevent(&p->kobj, KOBJ_ADD);
125 	return p;
126 }
127 /*
128  * remove a pktcdvd kernel object.
129  */
130 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
131 {
132 	if (p)
133 		kobject_put(&p->kobj);
134 }
135 /*
136  * default release function for pktcdvd kernel objects.
137  */
138 static void pkt_kobj_release(struct kobject *kobj)
139 {
140 	kfree(to_pktcdvdkobj(kobj));
141 }
142 
143 
144 /**********************************************************
145  *
146  * sysfs interface for pktcdvd
147  * by (C) 2006  Thomas Maier <balagi@justmail.de>
148  *
149  **********************************************************/
150 
151 #define DEF_ATTR(_obj,_name,_mode) \
152 	static struct attribute _obj = { .name = _name, .mode = _mode }
153 
154 /**********************************************************
155   /sys/class/pktcdvd/pktcdvd[0-7]/
156                      stat/reset
157                      stat/packets_started
158                      stat/packets_finished
159                      stat/kb_written
160                      stat/kb_read
161                      stat/kb_read_gather
162                      write_queue/size
163                      write_queue/congestion_off
164                      write_queue/congestion_on
165  **********************************************************/
166 
167 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
168 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
169 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
170 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
171 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
172 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
173 
174 static struct attribute *kobj_pkt_attrs_stat[] = {
175 	&kobj_pkt_attr_st1,
176 	&kobj_pkt_attr_st2,
177 	&kobj_pkt_attr_st3,
178 	&kobj_pkt_attr_st4,
179 	&kobj_pkt_attr_st5,
180 	&kobj_pkt_attr_st6,
181 	NULL
182 };
183 
184 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
185 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
186 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
187 
188 static struct attribute *kobj_pkt_attrs_wqueue[] = {
189 	&kobj_pkt_attr_wq1,
190 	&kobj_pkt_attr_wq2,
191 	&kobj_pkt_attr_wq3,
192 	NULL
193 };
194 
195 static ssize_t kobj_pkt_show(struct kobject *kobj,
196 			struct attribute *attr, char *data)
197 {
198 	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
199 	int n = 0;
200 	int v;
201 	if (strcmp(attr->name, "packets_started") == 0) {
202 		n = sprintf(data, "%lu\n", pd->stats.pkt_started);
203 
204 	} else if (strcmp(attr->name, "packets_finished") == 0) {
205 		n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
206 
207 	} else if (strcmp(attr->name, "kb_written") == 0) {
208 		n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
209 
210 	} else if (strcmp(attr->name, "kb_read") == 0) {
211 		n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
212 
213 	} else if (strcmp(attr->name, "kb_read_gather") == 0) {
214 		n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
215 
216 	} else if (strcmp(attr->name, "size") == 0) {
217 		spin_lock(&pd->lock);
218 		v = pd->bio_queue_size;
219 		spin_unlock(&pd->lock);
220 		n = sprintf(data, "%d\n", v);
221 
222 	} else if (strcmp(attr->name, "congestion_off") == 0) {
223 		spin_lock(&pd->lock);
224 		v = pd->write_congestion_off;
225 		spin_unlock(&pd->lock);
226 		n = sprintf(data, "%d\n", v);
227 
228 	} else if (strcmp(attr->name, "congestion_on") == 0) {
229 		spin_lock(&pd->lock);
230 		v = pd->write_congestion_on;
231 		spin_unlock(&pd->lock);
232 		n = sprintf(data, "%d\n", v);
233 	}
234 	return n;
235 }
236 
237 static void init_write_congestion_marks(int* lo, int* hi)
238 {
239 	if (*hi > 0) {
240 		*hi = max(*hi, 500);
241 		*hi = min(*hi, 1000000);
242 		if (*lo <= 0)
243 			*lo = *hi - 100;
244 		else {
245 			*lo = min(*lo, *hi - 100);
246 			*lo = max(*lo, 100);
247 		}
248 	} else {
249 		*hi = -1;
250 		*lo = -1;
251 	}
252 }
253 
254 static ssize_t kobj_pkt_store(struct kobject *kobj,
255 			struct attribute *attr,
256 			const char *data, size_t len)
257 {
258 	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
259 	int val;
260 
261 	if (strcmp(attr->name, "reset") == 0 && len > 0) {
262 		pd->stats.pkt_started = 0;
263 		pd->stats.pkt_ended = 0;
264 		pd->stats.secs_w = 0;
265 		pd->stats.secs_rg = 0;
266 		pd->stats.secs_r = 0;
267 
268 	} else if (strcmp(attr->name, "congestion_off") == 0
269 		   && sscanf(data, "%d", &val) == 1) {
270 		spin_lock(&pd->lock);
271 		pd->write_congestion_off = val;
272 		init_write_congestion_marks(&pd->write_congestion_off,
273 					&pd->write_congestion_on);
274 		spin_unlock(&pd->lock);
275 
276 	} else if (strcmp(attr->name, "congestion_on") == 0
277 		   && sscanf(data, "%d", &val) == 1) {
278 		spin_lock(&pd->lock);
279 		pd->write_congestion_on = val;
280 		init_write_congestion_marks(&pd->write_congestion_off,
281 					&pd->write_congestion_on);
282 		spin_unlock(&pd->lock);
283 	}
284 	return len;
285 }
286 
287 static struct sysfs_ops kobj_pkt_ops = {
288 	.show = kobj_pkt_show,
289 	.store = kobj_pkt_store
290 };
291 static struct kobj_type kobj_pkt_type_stat = {
292 	.release = pkt_kobj_release,
293 	.sysfs_ops = &kobj_pkt_ops,
294 	.default_attrs = kobj_pkt_attrs_stat
295 };
296 static struct kobj_type kobj_pkt_type_wqueue = {
297 	.release = pkt_kobj_release,
298 	.sysfs_ops = &kobj_pkt_ops,
299 	.default_attrs = kobj_pkt_attrs_wqueue
300 };
301 
302 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
303 {
304 	if (class_pktcdvd) {
305 		pd->dev = device_create(class_pktcdvd, NULL, pd->pkt_dev, NULL,
306 					"%s", pd->name);
307 		if (IS_ERR(pd->dev))
308 			pd->dev = NULL;
309 	}
310 	if (pd->dev) {
311 		pd->kobj_stat = pkt_kobj_create(pd, "stat",
312 					&pd->dev->kobj,
313 					&kobj_pkt_type_stat);
314 		pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
315 					&pd->dev->kobj,
316 					&kobj_pkt_type_wqueue);
317 	}
318 }
319 
320 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
321 {
322 	pkt_kobj_remove(pd->kobj_stat);
323 	pkt_kobj_remove(pd->kobj_wqueue);
324 	if (class_pktcdvd)
325 		device_destroy(class_pktcdvd, pd->pkt_dev);
326 }
327 
328 
329 /********************************************************************
330   /sys/class/pktcdvd/
331                      add            map block device
332                      remove         unmap packet dev
333                      device_map     show mappings
334  *******************************************************************/
335 
336 static void class_pktcdvd_release(struct class *cls)
337 {
338 	kfree(cls);
339 }
340 static ssize_t class_pktcdvd_show_map(struct class *c, char *data)
341 {
342 	int n = 0;
343 	int idx;
344 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
345 	for (idx = 0; idx < MAX_WRITERS; idx++) {
346 		struct pktcdvd_device *pd = pkt_devs[idx];
347 		if (!pd)
348 			continue;
349 		n += sprintf(data+n, "%s %u:%u %u:%u\n",
350 			pd->name,
351 			MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
352 			MAJOR(pd->bdev->bd_dev),
353 			MINOR(pd->bdev->bd_dev));
354 	}
355 	mutex_unlock(&ctl_mutex);
356 	return n;
357 }
358 
359 static ssize_t class_pktcdvd_store_add(struct class *c, const char *buf,
360 					size_t count)
361 {
362 	unsigned int major, minor;
363 
364 	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
365 		/* pkt_setup_dev() expects caller to hold reference to self */
366 		if (!try_module_get(THIS_MODULE))
367 			return -ENODEV;
368 
369 		pkt_setup_dev(MKDEV(major, minor), NULL);
370 
371 		module_put(THIS_MODULE);
372 
373 		return count;
374 	}
375 
376 	return -EINVAL;
377 }
378 
379 static ssize_t class_pktcdvd_store_remove(struct class *c, const char *buf,
380 					size_t count)
381 {
382 	unsigned int major, minor;
383 	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
384 		pkt_remove_dev(MKDEV(major, minor));
385 		return count;
386 	}
387 	return -EINVAL;
388 }
389 
390 static struct class_attribute class_pktcdvd_attrs[] = {
391  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
392  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
393  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
394  __ATTR_NULL
395 };
396 
397 
398 static int pkt_sysfs_init(void)
399 {
400 	int ret = 0;
401 
402 	/*
403 	 * create control files in sysfs
404 	 * /sys/class/pktcdvd/...
405 	 */
406 	class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
407 	if (!class_pktcdvd)
408 		return -ENOMEM;
409 	class_pktcdvd->name = DRIVER_NAME;
410 	class_pktcdvd->owner = THIS_MODULE;
411 	class_pktcdvd->class_release = class_pktcdvd_release;
412 	class_pktcdvd->class_attrs = class_pktcdvd_attrs;
413 	ret = class_register(class_pktcdvd);
414 	if (ret) {
415 		kfree(class_pktcdvd);
416 		class_pktcdvd = NULL;
417 		printk(DRIVER_NAME": failed to create class pktcdvd\n");
418 		return ret;
419 	}
420 	return 0;
421 }
422 
423 static void pkt_sysfs_cleanup(void)
424 {
425 	if (class_pktcdvd)
426 		class_destroy(class_pktcdvd);
427 	class_pktcdvd = NULL;
428 }
429 
430 /********************************************************************
431   entries in debugfs
432 
433   /debugfs/pktcdvd[0-7]/
434 			info
435 
436  *******************************************************************/
437 
438 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
439 {
440 	return pkt_seq_show(m, p);
441 }
442 
443 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
444 {
445 	return single_open(file, pkt_debugfs_seq_show, inode->i_private);
446 }
447 
448 static const struct file_operations debug_fops = {
449 	.open		= pkt_debugfs_fops_open,
450 	.read		= seq_read,
451 	.llseek		= seq_lseek,
452 	.release	= single_release,
453 	.owner		= THIS_MODULE,
454 };
455 
456 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
457 {
458 	if (!pkt_debugfs_root)
459 		return;
460 	pd->dfs_f_info = NULL;
461 	pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
462 	if (IS_ERR(pd->dfs_d_root)) {
463 		pd->dfs_d_root = NULL;
464 		return;
465 	}
466 	pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
467 				pd->dfs_d_root, pd, &debug_fops);
468 	if (IS_ERR(pd->dfs_f_info)) {
469 		pd->dfs_f_info = NULL;
470 		return;
471 	}
472 }
473 
474 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
475 {
476 	if (!pkt_debugfs_root)
477 		return;
478 	if (pd->dfs_f_info)
479 		debugfs_remove(pd->dfs_f_info);
480 	pd->dfs_f_info = NULL;
481 	if (pd->dfs_d_root)
482 		debugfs_remove(pd->dfs_d_root);
483 	pd->dfs_d_root = NULL;
484 }
485 
486 static void pkt_debugfs_init(void)
487 {
488 	pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
489 	if (IS_ERR(pkt_debugfs_root)) {
490 		pkt_debugfs_root = NULL;
491 		return;
492 	}
493 }
494 
495 static void pkt_debugfs_cleanup(void)
496 {
497 	if (!pkt_debugfs_root)
498 		return;
499 	debugfs_remove(pkt_debugfs_root);
500 	pkt_debugfs_root = NULL;
501 }
502 
503 /* ----------------------------------------------------------*/
504 
505 
506 static void pkt_bio_finished(struct pktcdvd_device *pd)
507 {
508 	BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
509 	if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
510 		VPRINTK(DRIVER_NAME": queue empty\n");
511 		atomic_set(&pd->iosched.attention, 1);
512 		wake_up(&pd->wqueue);
513 	}
514 }
515 
516 static void pkt_bio_destructor(struct bio *bio)
517 {
518 	kfree(bio->bi_io_vec);
519 	kfree(bio);
520 }
521 
522 static struct bio *pkt_bio_alloc(int nr_iovecs)
523 {
524 	struct bio_vec *bvl = NULL;
525 	struct bio *bio;
526 
527 	bio = kmalloc(sizeof(struct bio), GFP_KERNEL);
528 	if (!bio)
529 		goto no_bio;
530 	bio_init(bio);
531 
532 	bvl = kcalloc(nr_iovecs, sizeof(struct bio_vec), GFP_KERNEL);
533 	if (!bvl)
534 		goto no_bvl;
535 
536 	bio->bi_max_vecs = nr_iovecs;
537 	bio->bi_io_vec = bvl;
538 	bio->bi_destructor = pkt_bio_destructor;
539 
540 	return bio;
541 
542  no_bvl:
543 	kfree(bio);
544  no_bio:
545 	return NULL;
546 }
547 
548 /*
549  * Allocate a packet_data struct
550  */
551 static struct packet_data *pkt_alloc_packet_data(int frames)
552 {
553 	int i;
554 	struct packet_data *pkt;
555 
556 	pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
557 	if (!pkt)
558 		goto no_pkt;
559 
560 	pkt->frames = frames;
561 	pkt->w_bio = pkt_bio_alloc(frames);
562 	if (!pkt->w_bio)
563 		goto no_bio;
564 
565 	for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
566 		pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
567 		if (!pkt->pages[i])
568 			goto no_page;
569 	}
570 
571 	spin_lock_init(&pkt->lock);
572 
573 	for (i = 0; i < frames; i++) {
574 		struct bio *bio = pkt_bio_alloc(1);
575 		if (!bio)
576 			goto no_rd_bio;
577 		pkt->r_bios[i] = bio;
578 	}
579 
580 	return pkt;
581 
582 no_rd_bio:
583 	for (i = 0; i < frames; i++) {
584 		struct bio *bio = pkt->r_bios[i];
585 		if (bio)
586 			bio_put(bio);
587 	}
588 
589 no_page:
590 	for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
591 		if (pkt->pages[i])
592 			__free_page(pkt->pages[i]);
593 	bio_put(pkt->w_bio);
594 no_bio:
595 	kfree(pkt);
596 no_pkt:
597 	return NULL;
598 }
599 
600 /*
601  * Free a packet_data struct
602  */
603 static void pkt_free_packet_data(struct packet_data *pkt)
604 {
605 	int i;
606 
607 	for (i = 0; i < pkt->frames; i++) {
608 		struct bio *bio = pkt->r_bios[i];
609 		if (bio)
610 			bio_put(bio);
611 	}
612 	for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
613 		__free_page(pkt->pages[i]);
614 	bio_put(pkt->w_bio);
615 	kfree(pkt);
616 }
617 
618 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
619 {
620 	struct packet_data *pkt, *next;
621 
622 	BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
623 
624 	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
625 		pkt_free_packet_data(pkt);
626 	}
627 	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
628 }
629 
630 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
631 {
632 	struct packet_data *pkt;
633 
634 	BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
635 
636 	while (nr_packets > 0) {
637 		pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
638 		if (!pkt) {
639 			pkt_shrink_pktlist(pd);
640 			return 0;
641 		}
642 		pkt->id = nr_packets;
643 		pkt->pd = pd;
644 		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
645 		nr_packets--;
646 	}
647 	return 1;
648 }
649 
650 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
651 {
652 	struct rb_node *n = rb_next(&node->rb_node);
653 	if (!n)
654 		return NULL;
655 	return rb_entry(n, struct pkt_rb_node, rb_node);
656 }
657 
658 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
659 {
660 	rb_erase(&node->rb_node, &pd->bio_queue);
661 	mempool_free(node, pd->rb_pool);
662 	pd->bio_queue_size--;
663 	BUG_ON(pd->bio_queue_size < 0);
664 }
665 
666 /*
667  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
668  */
669 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
670 {
671 	struct rb_node *n = pd->bio_queue.rb_node;
672 	struct rb_node *next;
673 	struct pkt_rb_node *tmp;
674 
675 	if (!n) {
676 		BUG_ON(pd->bio_queue_size > 0);
677 		return NULL;
678 	}
679 
680 	for (;;) {
681 		tmp = rb_entry(n, struct pkt_rb_node, rb_node);
682 		if (s <= tmp->bio->bi_sector)
683 			next = n->rb_left;
684 		else
685 			next = n->rb_right;
686 		if (!next)
687 			break;
688 		n = next;
689 	}
690 
691 	if (s > tmp->bio->bi_sector) {
692 		tmp = pkt_rbtree_next(tmp);
693 		if (!tmp)
694 			return NULL;
695 	}
696 	BUG_ON(s > tmp->bio->bi_sector);
697 	return tmp;
698 }
699 
700 /*
701  * Insert a node into the pd->bio_queue rb tree.
702  */
703 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
704 {
705 	struct rb_node **p = &pd->bio_queue.rb_node;
706 	struct rb_node *parent = NULL;
707 	sector_t s = node->bio->bi_sector;
708 	struct pkt_rb_node *tmp;
709 
710 	while (*p) {
711 		parent = *p;
712 		tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
713 		if (s < tmp->bio->bi_sector)
714 			p = &(*p)->rb_left;
715 		else
716 			p = &(*p)->rb_right;
717 	}
718 	rb_link_node(&node->rb_node, parent, p);
719 	rb_insert_color(&node->rb_node, &pd->bio_queue);
720 	pd->bio_queue_size++;
721 }
722 
723 /*
724  * Add a bio to a single linked list defined by its head and tail pointers.
725  */
726 static void pkt_add_list_last(struct bio *bio, struct bio **list_head, struct bio **list_tail)
727 {
728 	bio->bi_next = NULL;
729 	if (*list_tail) {
730 		BUG_ON((*list_head) == NULL);
731 		(*list_tail)->bi_next = bio;
732 		(*list_tail) = bio;
733 	} else {
734 		BUG_ON((*list_head) != NULL);
735 		(*list_head) = bio;
736 		(*list_tail) = bio;
737 	}
738 }
739 
740 /*
741  * Remove and return the first bio from a single linked list defined by its
742  * head and tail pointers.
743  */
744 static inline struct bio *pkt_get_list_first(struct bio **list_head, struct bio **list_tail)
745 {
746 	struct bio *bio;
747 
748 	if (*list_head == NULL)
749 		return NULL;
750 
751 	bio = *list_head;
752 	*list_head = bio->bi_next;
753 	if (*list_head == NULL)
754 		*list_tail = NULL;
755 
756 	bio->bi_next = NULL;
757 	return bio;
758 }
759 
760 /*
761  * Send a packet_command to the underlying block device and
762  * wait for completion.
763  */
764 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
765 {
766 	struct request_queue *q = bdev_get_queue(pd->bdev);
767 	struct request *rq;
768 	int ret = 0;
769 
770 	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
771 			     WRITE : READ, __GFP_WAIT);
772 
773 	if (cgc->buflen) {
774 		if (blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen, __GFP_WAIT))
775 			goto out;
776 	}
777 
778 	rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
779 	memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
780 
781 	rq->timeout = 60*HZ;
782 	rq->cmd_type = REQ_TYPE_BLOCK_PC;
783 	rq->cmd_flags |= REQ_HARDBARRIER;
784 	if (cgc->quiet)
785 		rq->cmd_flags |= REQ_QUIET;
786 
787 	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
788 	if (rq->errors)
789 		ret = -EIO;
790 out:
791 	blk_put_request(rq);
792 	return ret;
793 }
794 
795 /*
796  * A generic sense dump / resolve mechanism should be implemented across
797  * all ATAPI + SCSI devices.
798  */
799 static void pkt_dump_sense(struct packet_command *cgc)
800 {
801 	static char *info[9] = { "No sense", "Recovered error", "Not ready",
802 				 "Medium error", "Hardware error", "Illegal request",
803 				 "Unit attention", "Data protect", "Blank check" };
804 	int i;
805 	struct request_sense *sense = cgc->sense;
806 
807 	printk(DRIVER_NAME":");
808 	for (i = 0; i < CDROM_PACKET_SIZE; i++)
809 		printk(" %02x", cgc->cmd[i]);
810 	printk(" - ");
811 
812 	if (sense == NULL) {
813 		printk("no sense\n");
814 		return;
815 	}
816 
817 	printk("sense %02x.%02x.%02x", sense->sense_key, sense->asc, sense->ascq);
818 
819 	if (sense->sense_key > 8) {
820 		printk(" (INVALID)\n");
821 		return;
822 	}
823 
824 	printk(" (%s)\n", info[sense->sense_key]);
825 }
826 
827 /*
828  * flush the drive cache to media
829  */
830 static int pkt_flush_cache(struct pktcdvd_device *pd)
831 {
832 	struct packet_command cgc;
833 
834 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
835 	cgc.cmd[0] = GPCMD_FLUSH_CACHE;
836 	cgc.quiet = 1;
837 
838 	/*
839 	 * the IMMED bit -- we default to not setting it, although that
840 	 * would allow a much faster close, this is safer
841 	 */
842 #if 0
843 	cgc.cmd[1] = 1 << 1;
844 #endif
845 	return pkt_generic_packet(pd, &cgc);
846 }
847 
848 /*
849  * speed is given as the normal factor, e.g. 4 for 4x
850  */
851 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
852 				unsigned write_speed, unsigned read_speed)
853 {
854 	struct packet_command cgc;
855 	struct request_sense sense;
856 	int ret;
857 
858 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
859 	cgc.sense = &sense;
860 	cgc.cmd[0] = GPCMD_SET_SPEED;
861 	cgc.cmd[2] = (read_speed >> 8) & 0xff;
862 	cgc.cmd[3] = read_speed & 0xff;
863 	cgc.cmd[4] = (write_speed >> 8) & 0xff;
864 	cgc.cmd[5] = write_speed & 0xff;
865 
866 	if ((ret = pkt_generic_packet(pd, &cgc)))
867 		pkt_dump_sense(&cgc);
868 
869 	return ret;
870 }
871 
872 /*
873  * Queue a bio for processing by the low-level CD device. Must be called
874  * from process context.
875  */
876 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
877 {
878 	spin_lock(&pd->iosched.lock);
879 	if (bio_data_dir(bio) == READ) {
880 		pkt_add_list_last(bio, &pd->iosched.read_queue,
881 				  &pd->iosched.read_queue_tail);
882 	} else {
883 		pkt_add_list_last(bio, &pd->iosched.write_queue,
884 				  &pd->iosched.write_queue_tail);
885 	}
886 	spin_unlock(&pd->iosched.lock);
887 
888 	atomic_set(&pd->iosched.attention, 1);
889 	wake_up(&pd->wqueue);
890 }
891 
892 /*
893  * Process the queued read/write requests. This function handles special
894  * requirements for CDRW drives:
895  * - A cache flush command must be inserted before a read request if the
896  *   previous request was a write.
897  * - Switching between reading and writing is slow, so don't do it more often
898  *   than necessary.
899  * - Optimize for throughput at the expense of latency. This means that streaming
900  *   writes will never be interrupted by a read, but if the drive has to seek
901  *   before the next write, switch to reading instead if there are any pending
902  *   read requests.
903  * - Set the read speed according to current usage pattern. When only reading
904  *   from the device, it's best to use the highest possible read speed, but
905  *   when switching often between reading and writing, it's better to have the
906  *   same read and write speeds.
907  */
908 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
909 {
910 
911 	if (atomic_read(&pd->iosched.attention) == 0)
912 		return;
913 	atomic_set(&pd->iosched.attention, 0);
914 
915 	for (;;) {
916 		struct bio *bio;
917 		int reads_queued, writes_queued;
918 
919 		spin_lock(&pd->iosched.lock);
920 		reads_queued = (pd->iosched.read_queue != NULL);
921 		writes_queued = (pd->iosched.write_queue != NULL);
922 		spin_unlock(&pd->iosched.lock);
923 
924 		if (!reads_queued && !writes_queued)
925 			break;
926 
927 		if (pd->iosched.writing) {
928 			int need_write_seek = 1;
929 			spin_lock(&pd->iosched.lock);
930 			bio = pd->iosched.write_queue;
931 			spin_unlock(&pd->iosched.lock);
932 			if (bio && (bio->bi_sector == pd->iosched.last_write))
933 				need_write_seek = 0;
934 			if (need_write_seek && reads_queued) {
935 				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
936 					VPRINTK(DRIVER_NAME": write, waiting\n");
937 					break;
938 				}
939 				pkt_flush_cache(pd);
940 				pd->iosched.writing = 0;
941 			}
942 		} else {
943 			if (!reads_queued && writes_queued) {
944 				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
945 					VPRINTK(DRIVER_NAME": read, waiting\n");
946 					break;
947 				}
948 				pd->iosched.writing = 1;
949 			}
950 		}
951 
952 		spin_lock(&pd->iosched.lock);
953 		if (pd->iosched.writing) {
954 			bio = pkt_get_list_first(&pd->iosched.write_queue,
955 						 &pd->iosched.write_queue_tail);
956 		} else {
957 			bio = pkt_get_list_first(&pd->iosched.read_queue,
958 						 &pd->iosched.read_queue_tail);
959 		}
960 		spin_unlock(&pd->iosched.lock);
961 
962 		if (!bio)
963 			continue;
964 
965 		if (bio_data_dir(bio) == READ)
966 			pd->iosched.successive_reads += bio->bi_size >> 10;
967 		else {
968 			pd->iosched.successive_reads = 0;
969 			pd->iosched.last_write = bio->bi_sector + bio_sectors(bio);
970 		}
971 		if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
972 			if (pd->read_speed == pd->write_speed) {
973 				pd->read_speed = MAX_SPEED;
974 				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
975 			}
976 		} else {
977 			if (pd->read_speed != pd->write_speed) {
978 				pd->read_speed = pd->write_speed;
979 				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
980 			}
981 		}
982 
983 		atomic_inc(&pd->cdrw.pending_bios);
984 		generic_make_request(bio);
985 	}
986 }
987 
988 /*
989  * Special care is needed if the underlying block device has a small
990  * max_phys_segments value.
991  */
992 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
993 {
994 	if ((pd->settings.size << 9) / CD_FRAMESIZE <= q->max_phys_segments) {
995 		/*
996 		 * The cdrom device can handle one segment/frame
997 		 */
998 		clear_bit(PACKET_MERGE_SEGS, &pd->flags);
999 		return 0;
1000 	} else if ((pd->settings.size << 9) / PAGE_SIZE <= q->max_phys_segments) {
1001 		/*
1002 		 * We can handle this case at the expense of some extra memory
1003 		 * copies during write operations
1004 		 */
1005 		set_bit(PACKET_MERGE_SEGS, &pd->flags);
1006 		return 0;
1007 	} else {
1008 		printk(DRIVER_NAME": cdrom max_phys_segments too small\n");
1009 		return -EIO;
1010 	}
1011 }
1012 
1013 /*
1014  * Copy CD_FRAMESIZE bytes from src_bio into a destination page
1015  */
1016 static void pkt_copy_bio_data(struct bio *src_bio, int seg, int offs, struct page *dst_page, int dst_offs)
1017 {
1018 	unsigned int copy_size = CD_FRAMESIZE;
1019 
1020 	while (copy_size > 0) {
1021 		struct bio_vec *src_bvl = bio_iovec_idx(src_bio, seg);
1022 		void *vfrom = kmap_atomic(src_bvl->bv_page, KM_USER0) +
1023 			src_bvl->bv_offset + offs;
1024 		void *vto = page_address(dst_page) + dst_offs;
1025 		int len = min_t(int, copy_size, src_bvl->bv_len - offs);
1026 
1027 		BUG_ON(len < 0);
1028 		memcpy(vto, vfrom, len);
1029 		kunmap_atomic(vfrom, KM_USER0);
1030 
1031 		seg++;
1032 		offs = 0;
1033 		dst_offs += len;
1034 		copy_size -= len;
1035 	}
1036 }
1037 
1038 /*
1039  * Copy all data for this packet to pkt->pages[], so that
1040  * a) The number of required segments for the write bio is minimized, which
1041  *    is necessary for some scsi controllers.
1042  * b) The data can be used as cache to avoid read requests if we receive a
1043  *    new write request for the same zone.
1044  */
1045 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
1046 {
1047 	int f, p, offs;
1048 
1049 	/* Copy all data to pkt->pages[] */
1050 	p = 0;
1051 	offs = 0;
1052 	for (f = 0; f < pkt->frames; f++) {
1053 		if (bvec[f].bv_page != pkt->pages[p]) {
1054 			void *vfrom = kmap_atomic(bvec[f].bv_page, KM_USER0) + bvec[f].bv_offset;
1055 			void *vto = page_address(pkt->pages[p]) + offs;
1056 			memcpy(vto, vfrom, CD_FRAMESIZE);
1057 			kunmap_atomic(vfrom, KM_USER0);
1058 			bvec[f].bv_page = pkt->pages[p];
1059 			bvec[f].bv_offset = offs;
1060 		} else {
1061 			BUG_ON(bvec[f].bv_offset != offs);
1062 		}
1063 		offs += CD_FRAMESIZE;
1064 		if (offs >= PAGE_SIZE) {
1065 			offs = 0;
1066 			p++;
1067 		}
1068 	}
1069 }
1070 
1071 static void pkt_end_io_read(struct bio *bio, int err)
1072 {
1073 	struct packet_data *pkt = bio->bi_private;
1074 	struct pktcdvd_device *pd = pkt->pd;
1075 	BUG_ON(!pd);
1076 
1077 	VPRINTK("pkt_end_io_read: bio=%p sec0=%llx sec=%llx err=%d\n", bio,
1078 		(unsigned long long)pkt->sector, (unsigned long long)bio->bi_sector, err);
1079 
1080 	if (err)
1081 		atomic_inc(&pkt->io_errors);
1082 	if (atomic_dec_and_test(&pkt->io_wait)) {
1083 		atomic_inc(&pkt->run_sm);
1084 		wake_up(&pd->wqueue);
1085 	}
1086 	pkt_bio_finished(pd);
1087 }
1088 
1089 static void pkt_end_io_packet_write(struct bio *bio, int err)
1090 {
1091 	struct packet_data *pkt = bio->bi_private;
1092 	struct pktcdvd_device *pd = pkt->pd;
1093 	BUG_ON(!pd);
1094 
1095 	VPRINTK("pkt_end_io_packet_write: id=%d, err=%d\n", pkt->id, err);
1096 
1097 	pd->stats.pkt_ended++;
1098 
1099 	pkt_bio_finished(pd);
1100 	atomic_dec(&pkt->io_wait);
1101 	atomic_inc(&pkt->run_sm);
1102 	wake_up(&pd->wqueue);
1103 }
1104 
1105 /*
1106  * Schedule reads for the holes in a packet
1107  */
1108 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1109 {
1110 	int frames_read = 0;
1111 	struct bio *bio;
1112 	int f;
1113 	char written[PACKET_MAX_SIZE];
1114 
1115 	BUG_ON(!pkt->orig_bios);
1116 
1117 	atomic_set(&pkt->io_wait, 0);
1118 	atomic_set(&pkt->io_errors, 0);
1119 
1120 	/*
1121 	 * Figure out which frames we need to read before we can write.
1122 	 */
1123 	memset(written, 0, sizeof(written));
1124 	spin_lock(&pkt->lock);
1125 	for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1126 		int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1127 		int num_frames = bio->bi_size / CD_FRAMESIZE;
1128 		pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1129 		BUG_ON(first_frame < 0);
1130 		BUG_ON(first_frame + num_frames > pkt->frames);
1131 		for (f = first_frame; f < first_frame + num_frames; f++)
1132 			written[f] = 1;
1133 	}
1134 	spin_unlock(&pkt->lock);
1135 
1136 	if (pkt->cache_valid) {
1137 		VPRINTK("pkt_gather_data: zone %llx cached\n",
1138 			(unsigned long long)pkt->sector);
1139 		goto out_account;
1140 	}
1141 
1142 	/*
1143 	 * Schedule reads for missing parts of the packet.
1144 	 */
1145 	for (f = 0; f < pkt->frames; f++) {
1146 		struct bio_vec *vec;
1147 
1148 		int p, offset;
1149 		if (written[f])
1150 			continue;
1151 		bio = pkt->r_bios[f];
1152 		vec = bio->bi_io_vec;
1153 		bio_init(bio);
1154 		bio->bi_max_vecs = 1;
1155 		bio->bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1156 		bio->bi_bdev = pd->bdev;
1157 		bio->bi_end_io = pkt_end_io_read;
1158 		bio->bi_private = pkt;
1159 		bio->bi_io_vec = vec;
1160 		bio->bi_destructor = pkt_bio_destructor;
1161 
1162 		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1163 		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1164 		VPRINTK("pkt_gather_data: Adding frame %d, page:%p offs:%d\n",
1165 			f, pkt->pages[p], offset);
1166 		if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1167 			BUG();
1168 
1169 		atomic_inc(&pkt->io_wait);
1170 		bio->bi_rw = READ;
1171 		pkt_queue_bio(pd, bio);
1172 		frames_read++;
1173 	}
1174 
1175 out_account:
1176 	VPRINTK("pkt_gather_data: need %d frames for zone %llx\n",
1177 		frames_read, (unsigned long long)pkt->sector);
1178 	pd->stats.pkt_started++;
1179 	pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1180 }
1181 
1182 /*
1183  * Find a packet matching zone, or the least recently used packet if
1184  * there is no match.
1185  */
1186 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1187 {
1188 	struct packet_data *pkt;
1189 
1190 	list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1191 		if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1192 			list_del_init(&pkt->list);
1193 			if (pkt->sector != zone)
1194 				pkt->cache_valid = 0;
1195 			return pkt;
1196 		}
1197 	}
1198 	BUG();
1199 	return NULL;
1200 }
1201 
1202 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1203 {
1204 	if (pkt->cache_valid) {
1205 		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1206 	} else {
1207 		list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1208 	}
1209 }
1210 
1211 /*
1212  * recover a failed write, query for relocation if possible
1213  *
1214  * returns 1 if recovery is possible, or 0 if not
1215  *
1216  */
1217 static int pkt_start_recovery(struct packet_data *pkt)
1218 {
1219 	/*
1220 	 * FIXME. We need help from the file system to implement
1221 	 * recovery handling.
1222 	 */
1223 	return 0;
1224 #if 0
1225 	struct request *rq = pkt->rq;
1226 	struct pktcdvd_device *pd = rq->rq_disk->private_data;
1227 	struct block_device *pkt_bdev;
1228 	struct super_block *sb = NULL;
1229 	unsigned long old_block, new_block;
1230 	sector_t new_sector;
1231 
1232 	pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1233 	if (pkt_bdev) {
1234 		sb = get_super(pkt_bdev);
1235 		bdput(pkt_bdev);
1236 	}
1237 
1238 	if (!sb)
1239 		return 0;
1240 
1241 	if (!sb->s_op || !sb->s_op->relocate_blocks)
1242 		goto out;
1243 
1244 	old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1245 	if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1246 		goto out;
1247 
1248 	new_sector = new_block * (CD_FRAMESIZE >> 9);
1249 	pkt->sector = new_sector;
1250 
1251 	pkt->bio->bi_sector = new_sector;
1252 	pkt->bio->bi_next = NULL;
1253 	pkt->bio->bi_flags = 1 << BIO_UPTODATE;
1254 	pkt->bio->bi_idx = 0;
1255 
1256 	BUG_ON(pkt->bio->bi_rw != (1 << BIO_RW));
1257 	BUG_ON(pkt->bio->bi_vcnt != pkt->frames);
1258 	BUG_ON(pkt->bio->bi_size != pkt->frames * CD_FRAMESIZE);
1259 	BUG_ON(pkt->bio->bi_end_io != pkt_end_io_packet_write);
1260 	BUG_ON(pkt->bio->bi_private != pkt);
1261 
1262 	drop_super(sb);
1263 	return 1;
1264 
1265 out:
1266 	drop_super(sb);
1267 	return 0;
1268 #endif
1269 }
1270 
1271 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1272 {
1273 #if PACKET_DEBUG > 1
1274 	static const char *state_name[] = {
1275 		"IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1276 	};
1277 	enum packet_data_state old_state = pkt->state;
1278 	VPRINTK("pkt %2d : s=%6llx %s -> %s\n", pkt->id, (unsigned long long)pkt->sector,
1279 		state_name[old_state], state_name[state]);
1280 #endif
1281 	pkt->state = state;
1282 }
1283 
1284 /*
1285  * Scan the work queue to see if we can start a new packet.
1286  * returns non-zero if any work was done.
1287  */
1288 static int pkt_handle_queue(struct pktcdvd_device *pd)
1289 {
1290 	struct packet_data *pkt, *p;
1291 	struct bio *bio = NULL;
1292 	sector_t zone = 0; /* Suppress gcc warning */
1293 	struct pkt_rb_node *node, *first_node;
1294 	struct rb_node *n;
1295 	int wakeup;
1296 
1297 	VPRINTK("handle_queue\n");
1298 
1299 	atomic_set(&pd->scan_queue, 0);
1300 
1301 	if (list_empty(&pd->cdrw.pkt_free_list)) {
1302 		VPRINTK("handle_queue: no pkt\n");
1303 		return 0;
1304 	}
1305 
1306 	/*
1307 	 * Try to find a zone we are not already working on.
1308 	 */
1309 	spin_lock(&pd->lock);
1310 	first_node = pkt_rbtree_find(pd, pd->current_sector);
1311 	if (!first_node) {
1312 		n = rb_first(&pd->bio_queue);
1313 		if (n)
1314 			first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1315 	}
1316 	node = first_node;
1317 	while (node) {
1318 		bio = node->bio;
1319 		zone = ZONE(bio->bi_sector, pd);
1320 		list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1321 			if (p->sector == zone) {
1322 				bio = NULL;
1323 				goto try_next_bio;
1324 			}
1325 		}
1326 		break;
1327 try_next_bio:
1328 		node = pkt_rbtree_next(node);
1329 		if (!node) {
1330 			n = rb_first(&pd->bio_queue);
1331 			if (n)
1332 				node = rb_entry(n, struct pkt_rb_node, rb_node);
1333 		}
1334 		if (node == first_node)
1335 			node = NULL;
1336 	}
1337 	spin_unlock(&pd->lock);
1338 	if (!bio) {
1339 		VPRINTK("handle_queue: no bio\n");
1340 		return 0;
1341 	}
1342 
1343 	pkt = pkt_get_packet_data(pd, zone);
1344 
1345 	pd->current_sector = zone + pd->settings.size;
1346 	pkt->sector = zone;
1347 	BUG_ON(pkt->frames != pd->settings.size >> 2);
1348 	pkt->write_size = 0;
1349 
1350 	/*
1351 	 * Scan work queue for bios in the same zone and link them
1352 	 * to this packet.
1353 	 */
1354 	spin_lock(&pd->lock);
1355 	VPRINTK("pkt_handle_queue: looking for zone %llx\n", (unsigned long long)zone);
1356 	while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1357 		bio = node->bio;
1358 		VPRINTK("pkt_handle_queue: found zone=%llx\n",
1359 			(unsigned long long)ZONE(bio->bi_sector, pd));
1360 		if (ZONE(bio->bi_sector, pd) != zone)
1361 			break;
1362 		pkt_rbtree_erase(pd, node);
1363 		spin_lock(&pkt->lock);
1364 		pkt_add_list_last(bio, &pkt->orig_bios, &pkt->orig_bios_tail);
1365 		pkt->write_size += bio->bi_size / CD_FRAMESIZE;
1366 		spin_unlock(&pkt->lock);
1367 	}
1368 	/* check write congestion marks, and if bio_queue_size is
1369 	   below, wake up any waiters */
1370 	wakeup = (pd->write_congestion_on > 0
1371 	 		&& pd->bio_queue_size <= pd->write_congestion_off);
1372 	spin_unlock(&pd->lock);
1373 	if (wakeup)
1374 		clear_bdi_congested(&pd->disk->queue->backing_dev_info, WRITE);
1375 
1376 	pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1377 	pkt_set_state(pkt, PACKET_WAITING_STATE);
1378 	atomic_set(&pkt->run_sm, 1);
1379 
1380 	spin_lock(&pd->cdrw.active_list_lock);
1381 	list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1382 	spin_unlock(&pd->cdrw.active_list_lock);
1383 
1384 	return 1;
1385 }
1386 
1387 /*
1388  * Assemble a bio to write one packet and queue the bio for processing
1389  * by the underlying block device.
1390  */
1391 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1392 {
1393 	struct bio *bio;
1394 	int f;
1395 	int frames_write;
1396 	struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1397 
1398 	for (f = 0; f < pkt->frames; f++) {
1399 		bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1400 		bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1401 	}
1402 
1403 	/*
1404 	 * Fill-in bvec with data from orig_bios.
1405 	 */
1406 	frames_write = 0;
1407 	spin_lock(&pkt->lock);
1408 	for (bio = pkt->orig_bios; bio; bio = bio->bi_next) {
1409 		int segment = bio->bi_idx;
1410 		int src_offs = 0;
1411 		int first_frame = (bio->bi_sector - pkt->sector) / (CD_FRAMESIZE >> 9);
1412 		int num_frames = bio->bi_size / CD_FRAMESIZE;
1413 		BUG_ON(first_frame < 0);
1414 		BUG_ON(first_frame + num_frames > pkt->frames);
1415 		for (f = first_frame; f < first_frame + num_frames; f++) {
1416 			struct bio_vec *src_bvl = bio_iovec_idx(bio, segment);
1417 
1418 			while (src_offs >= src_bvl->bv_len) {
1419 				src_offs -= src_bvl->bv_len;
1420 				segment++;
1421 				BUG_ON(segment >= bio->bi_vcnt);
1422 				src_bvl = bio_iovec_idx(bio, segment);
1423 			}
1424 
1425 			if (src_bvl->bv_len - src_offs >= CD_FRAMESIZE) {
1426 				bvec[f].bv_page = src_bvl->bv_page;
1427 				bvec[f].bv_offset = src_bvl->bv_offset + src_offs;
1428 			} else {
1429 				pkt_copy_bio_data(bio, segment, src_offs,
1430 						  bvec[f].bv_page, bvec[f].bv_offset);
1431 			}
1432 			src_offs += CD_FRAMESIZE;
1433 			frames_write++;
1434 		}
1435 	}
1436 	pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1437 	spin_unlock(&pkt->lock);
1438 
1439 	VPRINTK("pkt_start_write: Writing %d frames for zone %llx\n",
1440 		frames_write, (unsigned long long)pkt->sector);
1441 	BUG_ON(frames_write != pkt->write_size);
1442 
1443 	if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1444 		pkt_make_local_copy(pkt, bvec);
1445 		pkt->cache_valid = 1;
1446 	} else {
1447 		pkt->cache_valid = 0;
1448 	}
1449 
1450 	/* Start the write request */
1451 	bio_init(pkt->w_bio);
1452 	pkt->w_bio->bi_max_vecs = PACKET_MAX_SIZE;
1453 	pkt->w_bio->bi_sector = pkt->sector;
1454 	pkt->w_bio->bi_bdev = pd->bdev;
1455 	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1456 	pkt->w_bio->bi_private = pkt;
1457 	pkt->w_bio->bi_io_vec = bvec;
1458 	pkt->w_bio->bi_destructor = pkt_bio_destructor;
1459 	for (f = 0; f < pkt->frames; f++)
1460 		if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1461 			BUG();
1462 	VPRINTK(DRIVER_NAME": vcnt=%d\n", pkt->w_bio->bi_vcnt);
1463 
1464 	atomic_set(&pkt->io_wait, 1);
1465 	pkt->w_bio->bi_rw = WRITE;
1466 	pkt_queue_bio(pd, pkt->w_bio);
1467 }
1468 
1469 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1470 {
1471 	struct bio *bio, *next;
1472 
1473 	if (!uptodate)
1474 		pkt->cache_valid = 0;
1475 
1476 	/* Finish all bios corresponding to this packet */
1477 	bio = pkt->orig_bios;
1478 	while (bio) {
1479 		next = bio->bi_next;
1480 		bio->bi_next = NULL;
1481 		bio_endio(bio, uptodate ? 0 : -EIO);
1482 		bio = next;
1483 	}
1484 	pkt->orig_bios = pkt->orig_bios_tail = NULL;
1485 }
1486 
1487 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1488 {
1489 	int uptodate;
1490 
1491 	VPRINTK("run_state_machine: pkt %d\n", pkt->id);
1492 
1493 	for (;;) {
1494 		switch (pkt->state) {
1495 		case PACKET_WAITING_STATE:
1496 			if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1497 				return;
1498 
1499 			pkt->sleep_time = 0;
1500 			pkt_gather_data(pd, pkt);
1501 			pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1502 			break;
1503 
1504 		case PACKET_READ_WAIT_STATE:
1505 			if (atomic_read(&pkt->io_wait) > 0)
1506 				return;
1507 
1508 			if (atomic_read(&pkt->io_errors) > 0) {
1509 				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1510 			} else {
1511 				pkt_start_write(pd, pkt);
1512 			}
1513 			break;
1514 
1515 		case PACKET_WRITE_WAIT_STATE:
1516 			if (atomic_read(&pkt->io_wait) > 0)
1517 				return;
1518 
1519 			if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1520 				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1521 			} else {
1522 				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1523 			}
1524 			break;
1525 
1526 		case PACKET_RECOVERY_STATE:
1527 			if (pkt_start_recovery(pkt)) {
1528 				pkt_start_write(pd, pkt);
1529 			} else {
1530 				VPRINTK("No recovery possible\n");
1531 				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1532 			}
1533 			break;
1534 
1535 		case PACKET_FINISHED_STATE:
1536 			uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1537 			pkt_finish_packet(pkt, uptodate);
1538 			return;
1539 
1540 		default:
1541 			BUG();
1542 			break;
1543 		}
1544 	}
1545 }
1546 
1547 static void pkt_handle_packets(struct pktcdvd_device *pd)
1548 {
1549 	struct packet_data *pkt, *next;
1550 
1551 	VPRINTK("pkt_handle_packets\n");
1552 
1553 	/*
1554 	 * Run state machine for active packets
1555 	 */
1556 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1557 		if (atomic_read(&pkt->run_sm) > 0) {
1558 			atomic_set(&pkt->run_sm, 0);
1559 			pkt_run_state_machine(pd, pkt);
1560 		}
1561 	}
1562 
1563 	/*
1564 	 * Move no longer active packets to the free list
1565 	 */
1566 	spin_lock(&pd->cdrw.active_list_lock);
1567 	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1568 		if (pkt->state == PACKET_FINISHED_STATE) {
1569 			list_del(&pkt->list);
1570 			pkt_put_packet_data(pd, pkt);
1571 			pkt_set_state(pkt, PACKET_IDLE_STATE);
1572 			atomic_set(&pd->scan_queue, 1);
1573 		}
1574 	}
1575 	spin_unlock(&pd->cdrw.active_list_lock);
1576 }
1577 
1578 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1579 {
1580 	struct packet_data *pkt;
1581 	int i;
1582 
1583 	for (i = 0; i < PACKET_NUM_STATES; i++)
1584 		states[i] = 0;
1585 
1586 	spin_lock(&pd->cdrw.active_list_lock);
1587 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1588 		states[pkt->state]++;
1589 	}
1590 	spin_unlock(&pd->cdrw.active_list_lock);
1591 }
1592 
1593 /*
1594  * kcdrwd is woken up when writes have been queued for one of our
1595  * registered devices
1596  */
1597 static int kcdrwd(void *foobar)
1598 {
1599 	struct pktcdvd_device *pd = foobar;
1600 	struct packet_data *pkt;
1601 	long min_sleep_time, residue;
1602 
1603 	set_user_nice(current, -20);
1604 	set_freezable();
1605 
1606 	for (;;) {
1607 		DECLARE_WAITQUEUE(wait, current);
1608 
1609 		/*
1610 		 * Wait until there is something to do
1611 		 */
1612 		add_wait_queue(&pd->wqueue, &wait);
1613 		for (;;) {
1614 			set_current_state(TASK_INTERRUPTIBLE);
1615 
1616 			/* Check if we need to run pkt_handle_queue */
1617 			if (atomic_read(&pd->scan_queue) > 0)
1618 				goto work_to_do;
1619 
1620 			/* Check if we need to run the state machine for some packet */
1621 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1622 				if (atomic_read(&pkt->run_sm) > 0)
1623 					goto work_to_do;
1624 			}
1625 
1626 			/* Check if we need to process the iosched queues */
1627 			if (atomic_read(&pd->iosched.attention) != 0)
1628 				goto work_to_do;
1629 
1630 			/* Otherwise, go to sleep */
1631 			if (PACKET_DEBUG > 1) {
1632 				int states[PACKET_NUM_STATES];
1633 				pkt_count_states(pd, states);
1634 				VPRINTK("kcdrwd: i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1635 					states[0], states[1], states[2], states[3],
1636 					states[4], states[5]);
1637 			}
1638 
1639 			min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1640 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1641 				if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1642 					min_sleep_time = pkt->sleep_time;
1643 			}
1644 
1645 			generic_unplug_device(bdev_get_queue(pd->bdev));
1646 
1647 			VPRINTK("kcdrwd: sleeping\n");
1648 			residue = schedule_timeout(min_sleep_time);
1649 			VPRINTK("kcdrwd: wake up\n");
1650 
1651 			/* make swsusp happy with our thread */
1652 			try_to_freeze();
1653 
1654 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1655 				if (!pkt->sleep_time)
1656 					continue;
1657 				pkt->sleep_time -= min_sleep_time - residue;
1658 				if (pkt->sleep_time <= 0) {
1659 					pkt->sleep_time = 0;
1660 					atomic_inc(&pkt->run_sm);
1661 				}
1662 			}
1663 
1664 			if (kthread_should_stop())
1665 				break;
1666 		}
1667 work_to_do:
1668 		set_current_state(TASK_RUNNING);
1669 		remove_wait_queue(&pd->wqueue, &wait);
1670 
1671 		if (kthread_should_stop())
1672 			break;
1673 
1674 		/*
1675 		 * if pkt_handle_queue returns true, we can queue
1676 		 * another request.
1677 		 */
1678 		while (pkt_handle_queue(pd))
1679 			;
1680 
1681 		/*
1682 		 * Handle packet state machine
1683 		 */
1684 		pkt_handle_packets(pd);
1685 
1686 		/*
1687 		 * Handle iosched queues
1688 		 */
1689 		pkt_iosched_process_queue(pd);
1690 	}
1691 
1692 	return 0;
1693 }
1694 
1695 static void pkt_print_settings(struct pktcdvd_device *pd)
1696 {
1697 	printk(DRIVER_NAME": %s packets, ", pd->settings.fp ? "Fixed" : "Variable");
1698 	printk("%u blocks, ", pd->settings.size >> 2);
1699 	printk("Mode-%c disc\n", pd->settings.block_mode == 8 ? '1' : '2');
1700 }
1701 
1702 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1703 {
1704 	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1705 
1706 	cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1707 	cgc->cmd[2] = page_code | (page_control << 6);
1708 	cgc->cmd[7] = cgc->buflen >> 8;
1709 	cgc->cmd[8] = cgc->buflen & 0xff;
1710 	cgc->data_direction = CGC_DATA_READ;
1711 	return pkt_generic_packet(pd, cgc);
1712 }
1713 
1714 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1715 {
1716 	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1717 	memset(cgc->buffer, 0, 2);
1718 	cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1719 	cgc->cmd[1] = 0x10;		/* PF */
1720 	cgc->cmd[7] = cgc->buflen >> 8;
1721 	cgc->cmd[8] = cgc->buflen & 0xff;
1722 	cgc->data_direction = CGC_DATA_WRITE;
1723 	return pkt_generic_packet(pd, cgc);
1724 }
1725 
1726 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1727 {
1728 	struct packet_command cgc;
1729 	int ret;
1730 
1731 	/* set up command and get the disc info */
1732 	init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1733 	cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1734 	cgc.cmd[8] = cgc.buflen = 2;
1735 	cgc.quiet = 1;
1736 
1737 	if ((ret = pkt_generic_packet(pd, &cgc)))
1738 		return ret;
1739 
1740 	/* not all drives have the same disc_info length, so requeue
1741 	 * packet with the length the drive tells us it can supply
1742 	 */
1743 	cgc.buflen = be16_to_cpu(di->disc_information_length) +
1744 		     sizeof(di->disc_information_length);
1745 
1746 	if (cgc.buflen > sizeof(disc_information))
1747 		cgc.buflen = sizeof(disc_information);
1748 
1749 	cgc.cmd[8] = cgc.buflen;
1750 	return pkt_generic_packet(pd, &cgc);
1751 }
1752 
1753 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1754 {
1755 	struct packet_command cgc;
1756 	int ret;
1757 
1758 	init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1759 	cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1760 	cgc.cmd[1] = type & 3;
1761 	cgc.cmd[4] = (track & 0xff00) >> 8;
1762 	cgc.cmd[5] = track & 0xff;
1763 	cgc.cmd[8] = 8;
1764 	cgc.quiet = 1;
1765 
1766 	if ((ret = pkt_generic_packet(pd, &cgc)))
1767 		return ret;
1768 
1769 	cgc.buflen = be16_to_cpu(ti->track_information_length) +
1770 		     sizeof(ti->track_information_length);
1771 
1772 	if (cgc.buflen > sizeof(track_information))
1773 		cgc.buflen = sizeof(track_information);
1774 
1775 	cgc.cmd[8] = cgc.buflen;
1776 	return pkt_generic_packet(pd, &cgc);
1777 }
1778 
1779 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1780 						long *last_written)
1781 {
1782 	disc_information di;
1783 	track_information ti;
1784 	__u32 last_track;
1785 	int ret = -1;
1786 
1787 	if ((ret = pkt_get_disc_info(pd, &di)))
1788 		return ret;
1789 
1790 	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1791 	if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1792 		return ret;
1793 
1794 	/* if this track is blank, try the previous. */
1795 	if (ti.blank) {
1796 		last_track--;
1797 		if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1798 			return ret;
1799 	}
1800 
1801 	/* if last recorded field is valid, return it. */
1802 	if (ti.lra_v) {
1803 		*last_written = be32_to_cpu(ti.last_rec_address);
1804 	} else {
1805 		/* make it up instead */
1806 		*last_written = be32_to_cpu(ti.track_start) +
1807 				be32_to_cpu(ti.track_size);
1808 		if (ti.free_blocks)
1809 			*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1810 	}
1811 	return 0;
1812 }
1813 
1814 /*
1815  * write mode select package based on pd->settings
1816  */
1817 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1818 {
1819 	struct packet_command cgc;
1820 	struct request_sense sense;
1821 	write_param_page *wp;
1822 	char buffer[128];
1823 	int ret, size;
1824 
1825 	/* doesn't apply to DVD+RW or DVD-RAM */
1826 	if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1827 		return 0;
1828 
1829 	memset(buffer, 0, sizeof(buffer));
1830 	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1831 	cgc.sense = &sense;
1832 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1833 		pkt_dump_sense(&cgc);
1834 		return ret;
1835 	}
1836 
1837 	size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1838 	pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1839 	if (size > sizeof(buffer))
1840 		size = sizeof(buffer);
1841 
1842 	/*
1843 	 * now get it all
1844 	 */
1845 	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1846 	cgc.sense = &sense;
1847 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1848 		pkt_dump_sense(&cgc);
1849 		return ret;
1850 	}
1851 
1852 	/*
1853 	 * write page is offset header + block descriptor length
1854 	 */
1855 	wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1856 
1857 	wp->fp = pd->settings.fp;
1858 	wp->track_mode = pd->settings.track_mode;
1859 	wp->write_type = pd->settings.write_type;
1860 	wp->data_block_type = pd->settings.block_mode;
1861 
1862 	wp->multi_session = 0;
1863 
1864 #ifdef PACKET_USE_LS
1865 	wp->link_size = 7;
1866 	wp->ls_v = 1;
1867 #endif
1868 
1869 	if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1870 		wp->session_format = 0;
1871 		wp->subhdr2 = 0x20;
1872 	} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1873 		wp->session_format = 0x20;
1874 		wp->subhdr2 = 8;
1875 #if 0
1876 		wp->mcn[0] = 0x80;
1877 		memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1878 #endif
1879 	} else {
1880 		/*
1881 		 * paranoia
1882 		 */
1883 		printk(DRIVER_NAME": write mode wrong %d\n", wp->data_block_type);
1884 		return 1;
1885 	}
1886 	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1887 
1888 	cgc.buflen = cgc.cmd[8] = size;
1889 	if ((ret = pkt_mode_select(pd, &cgc))) {
1890 		pkt_dump_sense(&cgc);
1891 		return ret;
1892 	}
1893 
1894 	pkt_print_settings(pd);
1895 	return 0;
1896 }
1897 
1898 /*
1899  * 1 -- we can write to this track, 0 -- we can't
1900  */
1901 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1902 {
1903 	switch (pd->mmc3_profile) {
1904 		case 0x1a: /* DVD+RW */
1905 		case 0x12: /* DVD-RAM */
1906 			/* The track is always writable on DVD+RW/DVD-RAM */
1907 			return 1;
1908 		default:
1909 			break;
1910 	}
1911 
1912 	if (!ti->packet || !ti->fp)
1913 		return 0;
1914 
1915 	/*
1916 	 * "good" settings as per Mt Fuji.
1917 	 */
1918 	if (ti->rt == 0 && ti->blank == 0)
1919 		return 1;
1920 
1921 	if (ti->rt == 0 && ti->blank == 1)
1922 		return 1;
1923 
1924 	if (ti->rt == 1 && ti->blank == 0)
1925 		return 1;
1926 
1927 	printk(DRIVER_NAME": bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1928 	return 0;
1929 }
1930 
1931 /*
1932  * 1 -- we can write to this disc, 0 -- we can't
1933  */
1934 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1935 {
1936 	switch (pd->mmc3_profile) {
1937 		case 0x0a: /* CD-RW */
1938 		case 0xffff: /* MMC3 not supported */
1939 			break;
1940 		case 0x1a: /* DVD+RW */
1941 		case 0x13: /* DVD-RW */
1942 		case 0x12: /* DVD-RAM */
1943 			return 1;
1944 		default:
1945 			VPRINTK(DRIVER_NAME": Wrong disc profile (%x)\n", pd->mmc3_profile);
1946 			return 0;
1947 	}
1948 
1949 	/*
1950 	 * for disc type 0xff we should probably reserve a new track.
1951 	 * but i'm not sure, should we leave this to user apps? probably.
1952 	 */
1953 	if (di->disc_type == 0xff) {
1954 		printk(DRIVER_NAME": Unknown disc. No track?\n");
1955 		return 0;
1956 	}
1957 
1958 	if (di->disc_type != 0x20 && di->disc_type != 0) {
1959 		printk(DRIVER_NAME": Wrong disc type (%x)\n", di->disc_type);
1960 		return 0;
1961 	}
1962 
1963 	if (di->erasable == 0) {
1964 		printk(DRIVER_NAME": Disc not erasable\n");
1965 		return 0;
1966 	}
1967 
1968 	if (di->border_status == PACKET_SESSION_RESERVED) {
1969 		printk(DRIVER_NAME": Can't write to last track (reserved)\n");
1970 		return 0;
1971 	}
1972 
1973 	return 1;
1974 }
1975 
1976 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1977 {
1978 	struct packet_command cgc;
1979 	unsigned char buf[12];
1980 	disc_information di;
1981 	track_information ti;
1982 	int ret, track;
1983 
1984 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1985 	cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1986 	cgc.cmd[8] = 8;
1987 	ret = pkt_generic_packet(pd, &cgc);
1988 	pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1989 
1990 	memset(&di, 0, sizeof(disc_information));
1991 	memset(&ti, 0, sizeof(track_information));
1992 
1993 	if ((ret = pkt_get_disc_info(pd, &di))) {
1994 		printk("failed get_disc\n");
1995 		return ret;
1996 	}
1997 
1998 	if (!pkt_writable_disc(pd, &di))
1999 		return -EROFS;
2000 
2001 	pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
2002 
2003 	track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
2004 	if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
2005 		printk(DRIVER_NAME": failed get_track\n");
2006 		return ret;
2007 	}
2008 
2009 	if (!pkt_writable_track(pd, &ti)) {
2010 		printk(DRIVER_NAME": can't write to this track\n");
2011 		return -EROFS;
2012 	}
2013 
2014 	/*
2015 	 * we keep packet size in 512 byte units, makes it easier to
2016 	 * deal with request calculations.
2017 	 */
2018 	pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
2019 	if (pd->settings.size == 0) {
2020 		printk(DRIVER_NAME": detected zero packet size!\n");
2021 		return -ENXIO;
2022 	}
2023 	if (pd->settings.size > PACKET_MAX_SECTORS) {
2024 		printk(DRIVER_NAME": packet size is too big\n");
2025 		return -EROFS;
2026 	}
2027 	pd->settings.fp = ti.fp;
2028 	pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
2029 
2030 	if (ti.nwa_v) {
2031 		pd->nwa = be32_to_cpu(ti.next_writable);
2032 		set_bit(PACKET_NWA_VALID, &pd->flags);
2033 	}
2034 
2035 	/*
2036 	 * in theory we could use lra on -RW media as well and just zero
2037 	 * blocks that haven't been written yet, but in practice that
2038 	 * is just a no-go. we'll use that for -R, naturally.
2039 	 */
2040 	if (ti.lra_v) {
2041 		pd->lra = be32_to_cpu(ti.last_rec_address);
2042 		set_bit(PACKET_LRA_VALID, &pd->flags);
2043 	} else {
2044 		pd->lra = 0xffffffff;
2045 		set_bit(PACKET_LRA_VALID, &pd->flags);
2046 	}
2047 
2048 	/*
2049 	 * fine for now
2050 	 */
2051 	pd->settings.link_loss = 7;
2052 	pd->settings.write_type = 0;	/* packet */
2053 	pd->settings.track_mode = ti.track_mode;
2054 
2055 	/*
2056 	 * mode1 or mode2 disc
2057 	 */
2058 	switch (ti.data_mode) {
2059 		case PACKET_MODE1:
2060 			pd->settings.block_mode = PACKET_BLOCK_MODE1;
2061 			break;
2062 		case PACKET_MODE2:
2063 			pd->settings.block_mode = PACKET_BLOCK_MODE2;
2064 			break;
2065 		default:
2066 			printk(DRIVER_NAME": unknown data mode\n");
2067 			return -EROFS;
2068 	}
2069 	return 0;
2070 }
2071 
2072 /*
2073  * enable/disable write caching on drive
2074  */
2075 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
2076 						int set)
2077 {
2078 	struct packet_command cgc;
2079 	struct request_sense sense;
2080 	unsigned char buf[64];
2081 	int ret;
2082 
2083 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
2084 	cgc.sense = &sense;
2085 	cgc.buflen = pd->mode_offset + 12;
2086 
2087 	/*
2088 	 * caching mode page might not be there, so quiet this command
2089 	 */
2090 	cgc.quiet = 1;
2091 
2092 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
2093 		return ret;
2094 
2095 	buf[pd->mode_offset + 10] |= (!!set << 2);
2096 
2097 	cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
2098 	ret = pkt_mode_select(pd, &cgc);
2099 	if (ret) {
2100 		printk(DRIVER_NAME": write caching control failed\n");
2101 		pkt_dump_sense(&cgc);
2102 	} else if (!ret && set)
2103 		printk(DRIVER_NAME": enabled write caching on %s\n", pd->name);
2104 	return ret;
2105 }
2106 
2107 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
2108 {
2109 	struct packet_command cgc;
2110 
2111 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2112 	cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
2113 	cgc.cmd[4] = lockflag ? 1 : 0;
2114 	return pkt_generic_packet(pd, &cgc);
2115 }
2116 
2117 /*
2118  * Returns drive maximum write speed
2119  */
2120 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
2121 						unsigned *write_speed)
2122 {
2123 	struct packet_command cgc;
2124 	struct request_sense sense;
2125 	unsigned char buf[256+18];
2126 	unsigned char *cap_buf;
2127 	int ret, offset;
2128 
2129 	cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
2130 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
2131 	cgc.sense = &sense;
2132 
2133 	ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2134 	if (ret) {
2135 		cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
2136 			     sizeof(struct mode_page_header);
2137 		ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2138 		if (ret) {
2139 			pkt_dump_sense(&cgc);
2140 			return ret;
2141 		}
2142 	}
2143 
2144 	offset = 20;			    /* Obsoleted field, used by older drives */
2145 	if (cap_buf[1] >= 28)
2146 		offset = 28;		    /* Current write speed selected */
2147 	if (cap_buf[1] >= 30) {
2148 		/* If the drive reports at least one "Logical Unit Write
2149 		 * Speed Performance Descriptor Block", use the information
2150 		 * in the first block. (contains the highest speed)
2151 		 */
2152 		int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2153 		if (num_spdb > 0)
2154 			offset = 34;
2155 	}
2156 
2157 	*write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2158 	return 0;
2159 }
2160 
2161 /* These tables from cdrecord - I don't have orange book */
2162 /* standard speed CD-RW (1-4x) */
2163 static char clv_to_speed[16] = {
2164 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2165 	   0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2166 };
2167 /* high speed CD-RW (-10x) */
2168 static char hs_clv_to_speed[16] = {
2169 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2170 	   0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2171 };
2172 /* ultra high speed CD-RW */
2173 static char us_clv_to_speed[16] = {
2174 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2175 	   0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2176 };
2177 
2178 /*
2179  * reads the maximum media speed from ATIP
2180  */
2181 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2182 						unsigned *speed)
2183 {
2184 	struct packet_command cgc;
2185 	struct request_sense sense;
2186 	unsigned char buf[64];
2187 	unsigned int size, st, sp;
2188 	int ret;
2189 
2190 	init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2191 	cgc.sense = &sense;
2192 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2193 	cgc.cmd[1] = 2;
2194 	cgc.cmd[2] = 4; /* READ ATIP */
2195 	cgc.cmd[8] = 2;
2196 	ret = pkt_generic_packet(pd, &cgc);
2197 	if (ret) {
2198 		pkt_dump_sense(&cgc);
2199 		return ret;
2200 	}
2201 	size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2202 	if (size > sizeof(buf))
2203 		size = sizeof(buf);
2204 
2205 	init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2206 	cgc.sense = &sense;
2207 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2208 	cgc.cmd[1] = 2;
2209 	cgc.cmd[2] = 4;
2210 	cgc.cmd[8] = size;
2211 	ret = pkt_generic_packet(pd, &cgc);
2212 	if (ret) {
2213 		pkt_dump_sense(&cgc);
2214 		return ret;
2215 	}
2216 
2217 	if (!(buf[6] & 0x40)) {
2218 		printk(DRIVER_NAME": Disc type is not CD-RW\n");
2219 		return 1;
2220 	}
2221 	if (!(buf[6] & 0x4)) {
2222 		printk(DRIVER_NAME": A1 values on media are not valid, maybe not CDRW?\n");
2223 		return 1;
2224 	}
2225 
2226 	st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2227 
2228 	sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2229 
2230 	/* Info from cdrecord */
2231 	switch (st) {
2232 		case 0: /* standard speed */
2233 			*speed = clv_to_speed[sp];
2234 			break;
2235 		case 1: /* high speed */
2236 			*speed = hs_clv_to_speed[sp];
2237 			break;
2238 		case 2: /* ultra high speed */
2239 			*speed = us_clv_to_speed[sp];
2240 			break;
2241 		default:
2242 			printk(DRIVER_NAME": Unknown disc sub-type %d\n",st);
2243 			return 1;
2244 	}
2245 	if (*speed) {
2246 		printk(DRIVER_NAME": Max. media speed: %d\n",*speed);
2247 		return 0;
2248 	} else {
2249 		printk(DRIVER_NAME": Unknown speed %d for sub-type %d\n",sp,st);
2250 		return 1;
2251 	}
2252 }
2253 
2254 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2255 {
2256 	struct packet_command cgc;
2257 	struct request_sense sense;
2258 	int ret;
2259 
2260 	VPRINTK(DRIVER_NAME": Performing OPC\n");
2261 
2262 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2263 	cgc.sense = &sense;
2264 	cgc.timeout = 60*HZ;
2265 	cgc.cmd[0] = GPCMD_SEND_OPC;
2266 	cgc.cmd[1] = 1;
2267 	if ((ret = pkt_generic_packet(pd, &cgc)))
2268 		pkt_dump_sense(&cgc);
2269 	return ret;
2270 }
2271 
2272 static int pkt_open_write(struct pktcdvd_device *pd)
2273 {
2274 	int ret;
2275 	unsigned int write_speed, media_write_speed, read_speed;
2276 
2277 	if ((ret = pkt_probe_settings(pd))) {
2278 		VPRINTK(DRIVER_NAME": %s failed probe\n", pd->name);
2279 		return ret;
2280 	}
2281 
2282 	if ((ret = pkt_set_write_settings(pd))) {
2283 		DPRINTK(DRIVER_NAME": %s failed saving write settings\n", pd->name);
2284 		return -EIO;
2285 	}
2286 
2287 	pkt_write_caching(pd, USE_WCACHING);
2288 
2289 	if ((ret = pkt_get_max_speed(pd, &write_speed)))
2290 		write_speed = 16 * 177;
2291 	switch (pd->mmc3_profile) {
2292 		case 0x13: /* DVD-RW */
2293 		case 0x1a: /* DVD+RW */
2294 		case 0x12: /* DVD-RAM */
2295 			DPRINTK(DRIVER_NAME": write speed %ukB/s\n", write_speed);
2296 			break;
2297 		default:
2298 			if ((ret = pkt_media_speed(pd, &media_write_speed)))
2299 				media_write_speed = 16;
2300 			write_speed = min(write_speed, media_write_speed * 177);
2301 			DPRINTK(DRIVER_NAME": write speed %ux\n", write_speed / 176);
2302 			break;
2303 	}
2304 	read_speed = write_speed;
2305 
2306 	if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2307 		DPRINTK(DRIVER_NAME": %s couldn't set write speed\n", pd->name);
2308 		return -EIO;
2309 	}
2310 	pd->write_speed = write_speed;
2311 	pd->read_speed = read_speed;
2312 
2313 	if ((ret = pkt_perform_opc(pd))) {
2314 		DPRINTK(DRIVER_NAME": %s Optimum Power Calibration failed\n", pd->name);
2315 	}
2316 
2317 	return 0;
2318 }
2319 
2320 /*
2321  * called at open time.
2322  */
2323 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2324 {
2325 	int ret;
2326 	long lba;
2327 	struct request_queue *q;
2328 
2329 	/*
2330 	 * We need to re-open the cdrom device without O_NONBLOCK to be able
2331 	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
2332 	 * so bdget() can't fail.
2333 	 */
2334 	bdget(pd->bdev->bd_dev);
2335 	if ((ret = blkdev_get(pd->bdev, FMODE_READ)))
2336 		goto out;
2337 
2338 	if ((ret = bd_claim(pd->bdev, pd)))
2339 		goto out_putdev;
2340 
2341 	if ((ret = pkt_get_last_written(pd, &lba))) {
2342 		printk(DRIVER_NAME": pkt_get_last_written failed\n");
2343 		goto out_unclaim;
2344 	}
2345 
2346 	set_capacity(pd->disk, lba << 2);
2347 	set_capacity(pd->bdev->bd_disk, lba << 2);
2348 	bd_set_size(pd->bdev, (loff_t)lba << 11);
2349 
2350 	q = bdev_get_queue(pd->bdev);
2351 	if (write) {
2352 		if ((ret = pkt_open_write(pd)))
2353 			goto out_unclaim;
2354 		/*
2355 		 * Some CDRW drives can not handle writes larger than one packet,
2356 		 * even if the size is a multiple of the packet size.
2357 		 */
2358 		spin_lock_irq(q->queue_lock);
2359 		blk_queue_max_sectors(q, pd->settings.size);
2360 		spin_unlock_irq(q->queue_lock);
2361 		set_bit(PACKET_WRITABLE, &pd->flags);
2362 	} else {
2363 		pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2364 		clear_bit(PACKET_WRITABLE, &pd->flags);
2365 	}
2366 
2367 	if ((ret = pkt_set_segment_merging(pd, q)))
2368 		goto out_unclaim;
2369 
2370 	if (write) {
2371 		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2372 			printk(DRIVER_NAME": not enough memory for buffers\n");
2373 			ret = -ENOMEM;
2374 			goto out_unclaim;
2375 		}
2376 		printk(DRIVER_NAME": %lukB available on disc\n", lba << 1);
2377 	}
2378 
2379 	return 0;
2380 
2381 out_unclaim:
2382 	bd_release(pd->bdev);
2383 out_putdev:
2384 	blkdev_put(pd->bdev, FMODE_READ);
2385 out:
2386 	return ret;
2387 }
2388 
2389 /*
2390  * called when the device is closed. makes sure that the device flushes
2391  * the internal cache before we close.
2392  */
2393 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2394 {
2395 	if (flush && pkt_flush_cache(pd))
2396 		DPRINTK(DRIVER_NAME": %s not flushing cache\n", pd->name);
2397 
2398 	pkt_lock_door(pd, 0);
2399 
2400 	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2401 	bd_release(pd->bdev);
2402 	blkdev_put(pd->bdev, FMODE_READ);
2403 
2404 	pkt_shrink_pktlist(pd);
2405 }
2406 
2407 static struct pktcdvd_device *pkt_find_dev_from_minor(int dev_minor)
2408 {
2409 	if (dev_minor >= MAX_WRITERS)
2410 		return NULL;
2411 	return pkt_devs[dev_minor];
2412 }
2413 
2414 static int pkt_open(struct block_device *bdev, fmode_t mode)
2415 {
2416 	struct pktcdvd_device *pd = NULL;
2417 	int ret;
2418 
2419 	VPRINTK(DRIVER_NAME": entering open\n");
2420 
2421 	mutex_lock(&ctl_mutex);
2422 	pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2423 	if (!pd) {
2424 		ret = -ENODEV;
2425 		goto out;
2426 	}
2427 	BUG_ON(pd->refcnt < 0);
2428 
2429 	pd->refcnt++;
2430 	if (pd->refcnt > 1) {
2431 		if ((mode & FMODE_WRITE) &&
2432 		    !test_bit(PACKET_WRITABLE, &pd->flags)) {
2433 			ret = -EBUSY;
2434 			goto out_dec;
2435 		}
2436 	} else {
2437 		ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2438 		if (ret)
2439 			goto out_dec;
2440 		/*
2441 		 * needed here as well, since ext2 (among others) may change
2442 		 * the blocksize at mount time
2443 		 */
2444 		set_blocksize(bdev, CD_FRAMESIZE);
2445 	}
2446 
2447 	mutex_unlock(&ctl_mutex);
2448 	return 0;
2449 
2450 out_dec:
2451 	pd->refcnt--;
2452 out:
2453 	VPRINTK(DRIVER_NAME": failed open (%d)\n", ret);
2454 	mutex_unlock(&ctl_mutex);
2455 	return ret;
2456 }
2457 
2458 static int pkt_close(struct gendisk *disk, fmode_t mode)
2459 {
2460 	struct pktcdvd_device *pd = disk->private_data;
2461 	int ret = 0;
2462 
2463 	mutex_lock(&ctl_mutex);
2464 	pd->refcnt--;
2465 	BUG_ON(pd->refcnt < 0);
2466 	if (pd->refcnt == 0) {
2467 		int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2468 		pkt_release_dev(pd, flush);
2469 	}
2470 	mutex_unlock(&ctl_mutex);
2471 	return ret;
2472 }
2473 
2474 
2475 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2476 {
2477 	struct packet_stacked_data *psd = bio->bi_private;
2478 	struct pktcdvd_device *pd = psd->pd;
2479 
2480 	bio_put(bio);
2481 	bio_endio(psd->bio, err);
2482 	mempool_free(psd, psd_pool);
2483 	pkt_bio_finished(pd);
2484 }
2485 
2486 static int pkt_make_request(struct request_queue *q, struct bio *bio)
2487 {
2488 	struct pktcdvd_device *pd;
2489 	char b[BDEVNAME_SIZE];
2490 	sector_t zone;
2491 	struct packet_data *pkt;
2492 	int was_empty, blocked_bio;
2493 	struct pkt_rb_node *node;
2494 
2495 	pd = q->queuedata;
2496 	if (!pd) {
2497 		printk(DRIVER_NAME": %s incorrect request queue\n", bdevname(bio->bi_bdev, b));
2498 		goto end_io;
2499 	}
2500 
2501 	/*
2502 	 * Clone READ bios so we can have our own bi_end_io callback.
2503 	 */
2504 	if (bio_data_dir(bio) == READ) {
2505 		struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2506 		struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2507 
2508 		psd->pd = pd;
2509 		psd->bio = bio;
2510 		cloned_bio->bi_bdev = pd->bdev;
2511 		cloned_bio->bi_private = psd;
2512 		cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2513 		pd->stats.secs_r += bio->bi_size >> 9;
2514 		pkt_queue_bio(pd, cloned_bio);
2515 		return 0;
2516 	}
2517 
2518 	if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2519 		printk(DRIVER_NAME": WRITE for ro device %s (%llu)\n",
2520 			pd->name, (unsigned long long)bio->bi_sector);
2521 		goto end_io;
2522 	}
2523 
2524 	if (!bio->bi_size || (bio->bi_size % CD_FRAMESIZE)) {
2525 		printk(DRIVER_NAME": wrong bio size\n");
2526 		goto end_io;
2527 	}
2528 
2529 	blk_queue_bounce(q, &bio);
2530 
2531 	zone = ZONE(bio->bi_sector, pd);
2532 	VPRINTK("pkt_make_request: start = %6llx stop = %6llx\n",
2533 		(unsigned long long)bio->bi_sector,
2534 		(unsigned long long)(bio->bi_sector + bio_sectors(bio)));
2535 
2536 	/* Check if we have to split the bio */
2537 	{
2538 		struct bio_pair *bp;
2539 		sector_t last_zone;
2540 		int first_sectors;
2541 
2542 		last_zone = ZONE(bio->bi_sector + bio_sectors(bio) - 1, pd);
2543 		if (last_zone != zone) {
2544 			BUG_ON(last_zone != zone + pd->settings.size);
2545 			first_sectors = last_zone - bio->bi_sector;
2546 			bp = bio_split(bio, first_sectors);
2547 			BUG_ON(!bp);
2548 			pkt_make_request(q, &bp->bio1);
2549 			pkt_make_request(q, &bp->bio2);
2550 			bio_pair_release(bp);
2551 			return 0;
2552 		}
2553 	}
2554 
2555 	/*
2556 	 * If we find a matching packet in state WAITING or READ_WAIT, we can
2557 	 * just append this bio to that packet.
2558 	 */
2559 	spin_lock(&pd->cdrw.active_list_lock);
2560 	blocked_bio = 0;
2561 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2562 		if (pkt->sector == zone) {
2563 			spin_lock(&pkt->lock);
2564 			if ((pkt->state == PACKET_WAITING_STATE) ||
2565 			    (pkt->state == PACKET_READ_WAIT_STATE)) {
2566 				pkt_add_list_last(bio, &pkt->orig_bios,
2567 						  &pkt->orig_bios_tail);
2568 				pkt->write_size += bio->bi_size / CD_FRAMESIZE;
2569 				if ((pkt->write_size >= pkt->frames) &&
2570 				    (pkt->state == PACKET_WAITING_STATE)) {
2571 					atomic_inc(&pkt->run_sm);
2572 					wake_up(&pd->wqueue);
2573 				}
2574 				spin_unlock(&pkt->lock);
2575 				spin_unlock(&pd->cdrw.active_list_lock);
2576 				return 0;
2577 			} else {
2578 				blocked_bio = 1;
2579 			}
2580 			spin_unlock(&pkt->lock);
2581 		}
2582 	}
2583 	spin_unlock(&pd->cdrw.active_list_lock);
2584 
2585  	/*
2586 	 * Test if there is enough room left in the bio work queue
2587 	 * (queue size >= congestion on mark).
2588 	 * If not, wait till the work queue size is below the congestion off mark.
2589 	 */
2590 	spin_lock(&pd->lock);
2591 	if (pd->write_congestion_on > 0
2592 	    && pd->bio_queue_size >= pd->write_congestion_on) {
2593 		set_bdi_congested(&q->backing_dev_info, WRITE);
2594 		do {
2595 			spin_unlock(&pd->lock);
2596 			congestion_wait(WRITE, HZ);
2597 			spin_lock(&pd->lock);
2598 		} while(pd->bio_queue_size > pd->write_congestion_off);
2599 	}
2600 	spin_unlock(&pd->lock);
2601 
2602 	/*
2603 	 * No matching packet found. Store the bio in the work queue.
2604 	 */
2605 	node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2606 	node->bio = bio;
2607 	spin_lock(&pd->lock);
2608 	BUG_ON(pd->bio_queue_size < 0);
2609 	was_empty = (pd->bio_queue_size == 0);
2610 	pkt_rbtree_insert(pd, node);
2611 	spin_unlock(&pd->lock);
2612 
2613 	/*
2614 	 * Wake up the worker thread.
2615 	 */
2616 	atomic_set(&pd->scan_queue, 1);
2617 	if (was_empty) {
2618 		/* This wake_up is required for correct operation */
2619 		wake_up(&pd->wqueue);
2620 	} else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2621 		/*
2622 		 * This wake up is not required for correct operation,
2623 		 * but improves performance in some cases.
2624 		 */
2625 		wake_up(&pd->wqueue);
2626 	}
2627 	return 0;
2628 end_io:
2629 	bio_io_error(bio);
2630 	return 0;
2631 }
2632 
2633 
2634 
2635 static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2636 			  struct bio_vec *bvec)
2637 {
2638 	struct pktcdvd_device *pd = q->queuedata;
2639 	sector_t zone = ZONE(bmd->bi_sector, pd);
2640 	int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
2641 	int remaining = (pd->settings.size << 9) - used;
2642 	int remaining2;
2643 
2644 	/*
2645 	 * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2646 	 * boundary, pkt_make_request() will split the bio.
2647 	 */
2648 	remaining2 = PAGE_SIZE - bmd->bi_size;
2649 	remaining = max(remaining, remaining2);
2650 
2651 	BUG_ON(remaining < 0);
2652 	return remaining;
2653 }
2654 
2655 static void pkt_init_queue(struct pktcdvd_device *pd)
2656 {
2657 	struct request_queue *q = pd->disk->queue;
2658 
2659 	blk_queue_make_request(q, pkt_make_request);
2660 	blk_queue_hardsect_size(q, CD_FRAMESIZE);
2661 	blk_queue_max_sectors(q, PACKET_MAX_SECTORS);
2662 	blk_queue_merge_bvec(q, pkt_merge_bvec);
2663 	q->queuedata = pd;
2664 }
2665 
2666 static int pkt_seq_show(struct seq_file *m, void *p)
2667 {
2668 	struct pktcdvd_device *pd = m->private;
2669 	char *msg;
2670 	char bdev_buf[BDEVNAME_SIZE];
2671 	int states[PACKET_NUM_STATES];
2672 
2673 	seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2674 		   bdevname(pd->bdev, bdev_buf));
2675 
2676 	seq_printf(m, "\nSettings:\n");
2677 	seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2678 
2679 	if (pd->settings.write_type == 0)
2680 		msg = "Packet";
2681 	else
2682 		msg = "Unknown";
2683 	seq_printf(m, "\twrite type:\t\t%s\n", msg);
2684 
2685 	seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2686 	seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2687 
2688 	seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2689 
2690 	if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2691 		msg = "Mode 1";
2692 	else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2693 		msg = "Mode 2";
2694 	else
2695 		msg = "Unknown";
2696 	seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2697 
2698 	seq_printf(m, "\nStatistics:\n");
2699 	seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2700 	seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2701 	seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2702 	seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2703 	seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2704 
2705 	seq_printf(m, "\nMisc:\n");
2706 	seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2707 	seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2708 	seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2709 	seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2710 	seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2711 	seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2712 
2713 	seq_printf(m, "\nQueue state:\n");
2714 	seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2715 	seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2716 	seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2717 
2718 	pkt_count_states(pd, states);
2719 	seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2720 		   states[0], states[1], states[2], states[3], states[4], states[5]);
2721 
2722 	seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2723 			pd->write_congestion_off,
2724 			pd->write_congestion_on);
2725 	return 0;
2726 }
2727 
2728 static int pkt_seq_open(struct inode *inode, struct file *file)
2729 {
2730 	return single_open(file, pkt_seq_show, PDE(inode)->data);
2731 }
2732 
2733 static const struct file_operations pkt_proc_fops = {
2734 	.open	= pkt_seq_open,
2735 	.read	= seq_read,
2736 	.llseek	= seq_lseek,
2737 	.release = single_release
2738 };
2739 
2740 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2741 {
2742 	int i;
2743 	int ret = 0;
2744 	char b[BDEVNAME_SIZE];
2745 	struct block_device *bdev;
2746 
2747 	if (pd->pkt_dev == dev) {
2748 		printk(DRIVER_NAME": Recursive setup not allowed\n");
2749 		return -EBUSY;
2750 	}
2751 	for (i = 0; i < MAX_WRITERS; i++) {
2752 		struct pktcdvd_device *pd2 = pkt_devs[i];
2753 		if (!pd2)
2754 			continue;
2755 		if (pd2->bdev->bd_dev == dev) {
2756 			printk(DRIVER_NAME": %s already setup\n", bdevname(pd2->bdev, b));
2757 			return -EBUSY;
2758 		}
2759 		if (pd2->pkt_dev == dev) {
2760 			printk(DRIVER_NAME": Can't chain pktcdvd devices\n");
2761 			return -EBUSY;
2762 		}
2763 	}
2764 
2765 	bdev = bdget(dev);
2766 	if (!bdev)
2767 		return -ENOMEM;
2768 	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY);
2769 	if (ret)
2770 		return ret;
2771 
2772 	/* This is safe, since we have a reference from open(). */
2773 	__module_get(THIS_MODULE);
2774 
2775 	pd->bdev = bdev;
2776 	set_blocksize(bdev, CD_FRAMESIZE);
2777 
2778 	pkt_init_queue(pd);
2779 
2780 	atomic_set(&pd->cdrw.pending_bios, 0);
2781 	pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2782 	if (IS_ERR(pd->cdrw.thread)) {
2783 		printk(DRIVER_NAME": can't start kernel thread\n");
2784 		ret = -ENOMEM;
2785 		goto out_mem;
2786 	}
2787 
2788 	proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2789 	DPRINTK(DRIVER_NAME": writer %s mapped to %s\n", pd->name, bdevname(bdev, b));
2790 	return 0;
2791 
2792 out_mem:
2793 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE);
2794 	/* This is safe: open() is still holding a reference. */
2795 	module_put(THIS_MODULE);
2796 	return ret;
2797 }
2798 
2799 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2800 {
2801 	struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2802 
2803 	VPRINTK("pkt_ioctl: cmd %x, dev %d:%d\n", cmd,
2804 		MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2805 
2806 	switch (cmd) {
2807 	case CDROMEJECT:
2808 		/*
2809 		 * The door gets locked when the device is opened, so we
2810 		 * have to unlock it or else the eject command fails.
2811 		 */
2812 		if (pd->refcnt == 1)
2813 			pkt_lock_door(pd, 0);
2814 		/* fallthru */
2815 	/*
2816 	 * forward selected CDROM ioctls to CD-ROM, for UDF
2817 	 */
2818 	case CDROMMULTISESSION:
2819 	case CDROMREADTOCENTRY:
2820 	case CDROM_LAST_WRITTEN:
2821 	case CDROM_SEND_PACKET:
2822 	case SCSI_IOCTL_SEND_COMMAND:
2823 		return __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2824 
2825 	default:
2826 		VPRINTK(DRIVER_NAME": Unknown ioctl for %s (%x)\n", pd->name, cmd);
2827 		return -ENOTTY;
2828 	}
2829 
2830 	return 0;
2831 }
2832 
2833 static int pkt_media_changed(struct gendisk *disk)
2834 {
2835 	struct pktcdvd_device *pd = disk->private_data;
2836 	struct gendisk *attached_disk;
2837 
2838 	if (!pd)
2839 		return 0;
2840 	if (!pd->bdev)
2841 		return 0;
2842 	attached_disk = pd->bdev->bd_disk;
2843 	if (!attached_disk)
2844 		return 0;
2845 	return attached_disk->fops->media_changed(attached_disk);
2846 }
2847 
2848 static struct block_device_operations pktcdvd_ops = {
2849 	.owner =		THIS_MODULE,
2850 	.open =			pkt_open,
2851 	.release =		pkt_close,
2852 	.locked_ioctl =		pkt_ioctl,
2853 	.media_changed =	pkt_media_changed,
2854 };
2855 
2856 /*
2857  * Set up mapping from pktcdvd device to CD-ROM device.
2858  */
2859 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2860 {
2861 	int idx;
2862 	int ret = -ENOMEM;
2863 	struct pktcdvd_device *pd;
2864 	struct gendisk *disk;
2865 
2866 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2867 
2868 	for (idx = 0; idx < MAX_WRITERS; idx++)
2869 		if (!pkt_devs[idx])
2870 			break;
2871 	if (idx == MAX_WRITERS) {
2872 		printk(DRIVER_NAME": max %d writers supported\n", MAX_WRITERS);
2873 		ret = -EBUSY;
2874 		goto out_mutex;
2875 	}
2876 
2877 	pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2878 	if (!pd)
2879 		goto out_mutex;
2880 
2881 	pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2882 						  sizeof(struct pkt_rb_node));
2883 	if (!pd->rb_pool)
2884 		goto out_mem;
2885 
2886 	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2887 	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2888 	spin_lock_init(&pd->cdrw.active_list_lock);
2889 
2890 	spin_lock_init(&pd->lock);
2891 	spin_lock_init(&pd->iosched.lock);
2892 	sprintf(pd->name, DRIVER_NAME"%d", idx);
2893 	init_waitqueue_head(&pd->wqueue);
2894 	pd->bio_queue = RB_ROOT;
2895 
2896 	pd->write_congestion_on  = write_congestion_on;
2897 	pd->write_congestion_off = write_congestion_off;
2898 
2899 	disk = alloc_disk(1);
2900 	if (!disk)
2901 		goto out_mem;
2902 	pd->disk = disk;
2903 	disk->major = pktdev_major;
2904 	disk->first_minor = idx;
2905 	disk->fops = &pktcdvd_ops;
2906 	disk->flags = GENHD_FL_REMOVABLE;
2907 	strcpy(disk->disk_name, pd->name);
2908 	disk->private_data = pd;
2909 	disk->queue = blk_alloc_queue(GFP_KERNEL);
2910 	if (!disk->queue)
2911 		goto out_mem2;
2912 
2913 	pd->pkt_dev = MKDEV(pktdev_major, idx);
2914 	ret = pkt_new_dev(pd, dev);
2915 	if (ret)
2916 		goto out_new_dev;
2917 
2918 	add_disk(disk);
2919 
2920 	pkt_sysfs_dev_new(pd);
2921 	pkt_debugfs_dev_new(pd);
2922 
2923 	pkt_devs[idx] = pd;
2924 	if (pkt_dev)
2925 		*pkt_dev = pd->pkt_dev;
2926 
2927 	mutex_unlock(&ctl_mutex);
2928 	return 0;
2929 
2930 out_new_dev:
2931 	blk_cleanup_queue(disk->queue);
2932 out_mem2:
2933 	put_disk(disk);
2934 out_mem:
2935 	if (pd->rb_pool)
2936 		mempool_destroy(pd->rb_pool);
2937 	kfree(pd);
2938 out_mutex:
2939 	mutex_unlock(&ctl_mutex);
2940 	printk(DRIVER_NAME": setup of pktcdvd device failed\n");
2941 	return ret;
2942 }
2943 
2944 /*
2945  * Tear down mapping from pktcdvd device to CD-ROM device.
2946  */
2947 static int pkt_remove_dev(dev_t pkt_dev)
2948 {
2949 	struct pktcdvd_device *pd;
2950 	int idx;
2951 	int ret = 0;
2952 
2953 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2954 
2955 	for (idx = 0; idx < MAX_WRITERS; idx++) {
2956 		pd = pkt_devs[idx];
2957 		if (pd && (pd->pkt_dev == pkt_dev))
2958 			break;
2959 	}
2960 	if (idx == MAX_WRITERS) {
2961 		DPRINTK(DRIVER_NAME": dev not setup\n");
2962 		ret = -ENXIO;
2963 		goto out;
2964 	}
2965 
2966 	if (pd->refcnt > 0) {
2967 		ret = -EBUSY;
2968 		goto out;
2969 	}
2970 	if (!IS_ERR(pd->cdrw.thread))
2971 		kthread_stop(pd->cdrw.thread);
2972 
2973 	pkt_devs[idx] = NULL;
2974 
2975 	pkt_debugfs_dev_remove(pd);
2976 	pkt_sysfs_dev_remove(pd);
2977 
2978 	blkdev_put(pd->bdev, FMODE_READ|FMODE_WRITE);
2979 
2980 	remove_proc_entry(pd->name, pkt_proc);
2981 	DPRINTK(DRIVER_NAME": writer %s unmapped\n", pd->name);
2982 
2983 	del_gendisk(pd->disk);
2984 	blk_cleanup_queue(pd->disk->queue);
2985 	put_disk(pd->disk);
2986 
2987 	mempool_destroy(pd->rb_pool);
2988 	kfree(pd);
2989 
2990 	/* This is safe: open() is still holding a reference. */
2991 	module_put(THIS_MODULE);
2992 
2993 out:
2994 	mutex_unlock(&ctl_mutex);
2995 	return ret;
2996 }
2997 
2998 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2999 {
3000 	struct pktcdvd_device *pd;
3001 
3002 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
3003 
3004 	pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
3005 	if (pd) {
3006 		ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
3007 		ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
3008 	} else {
3009 		ctrl_cmd->dev = 0;
3010 		ctrl_cmd->pkt_dev = 0;
3011 	}
3012 	ctrl_cmd->num_devices = MAX_WRITERS;
3013 
3014 	mutex_unlock(&ctl_mutex);
3015 }
3016 
3017 static int pkt_ctl_ioctl(struct inode *inode, struct file *file, unsigned int cmd, unsigned long arg)
3018 {
3019 	void __user *argp = (void __user *)arg;
3020 	struct pkt_ctrl_command ctrl_cmd;
3021 	int ret = 0;
3022 	dev_t pkt_dev = 0;
3023 
3024 	if (cmd != PACKET_CTRL_CMD)
3025 		return -ENOTTY;
3026 
3027 	if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
3028 		return -EFAULT;
3029 
3030 	switch (ctrl_cmd.command) {
3031 	case PKT_CTRL_CMD_SETUP:
3032 		if (!capable(CAP_SYS_ADMIN))
3033 			return -EPERM;
3034 		ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
3035 		ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
3036 		break;
3037 	case PKT_CTRL_CMD_TEARDOWN:
3038 		if (!capable(CAP_SYS_ADMIN))
3039 			return -EPERM;
3040 		ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
3041 		break;
3042 	case PKT_CTRL_CMD_STATUS:
3043 		pkt_get_status(&ctrl_cmd);
3044 		break;
3045 	default:
3046 		return -ENOTTY;
3047 	}
3048 
3049 	if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
3050 		return -EFAULT;
3051 	return ret;
3052 }
3053 
3054 
3055 static const struct file_operations pkt_ctl_fops = {
3056 	.ioctl	 = pkt_ctl_ioctl,
3057 	.owner	 = THIS_MODULE,
3058 };
3059 
3060 static struct miscdevice pkt_misc = {
3061 	.minor 		= MISC_DYNAMIC_MINOR,
3062 	.name  		= DRIVER_NAME,
3063 	.fops  		= &pkt_ctl_fops
3064 };
3065 
3066 static int __init pkt_init(void)
3067 {
3068 	int ret;
3069 
3070 	mutex_init(&ctl_mutex);
3071 
3072 	psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
3073 					sizeof(struct packet_stacked_data));
3074 	if (!psd_pool)
3075 		return -ENOMEM;
3076 
3077 	ret = register_blkdev(pktdev_major, DRIVER_NAME);
3078 	if (ret < 0) {
3079 		printk(DRIVER_NAME": Unable to register block device\n");
3080 		goto out2;
3081 	}
3082 	if (!pktdev_major)
3083 		pktdev_major = ret;
3084 
3085 	ret = pkt_sysfs_init();
3086 	if (ret)
3087 		goto out;
3088 
3089 	pkt_debugfs_init();
3090 
3091 	ret = misc_register(&pkt_misc);
3092 	if (ret) {
3093 		printk(DRIVER_NAME": Unable to register misc device\n");
3094 		goto out_misc;
3095 	}
3096 
3097 	pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
3098 
3099 	return 0;
3100 
3101 out_misc:
3102 	pkt_debugfs_cleanup();
3103 	pkt_sysfs_cleanup();
3104 out:
3105 	unregister_blkdev(pktdev_major, DRIVER_NAME);
3106 out2:
3107 	mempool_destroy(psd_pool);
3108 	return ret;
3109 }
3110 
3111 static void __exit pkt_exit(void)
3112 {
3113 	remove_proc_entry("driver/"DRIVER_NAME, NULL);
3114 	misc_deregister(&pkt_misc);
3115 
3116 	pkt_debugfs_cleanup();
3117 	pkt_sysfs_cleanup();
3118 
3119 	unregister_blkdev(pktdev_major, DRIVER_NAME);
3120 	mempool_destroy(psd_pool);
3121 }
3122 
3123 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3124 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3125 MODULE_LICENSE("GPL");
3126 
3127 module_init(pkt_init);
3128 module_exit(pkt_exit);
3129