xref: /openbmc/linux/drivers/block/pktcdvd.c (revision d2999e1b)
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 #define pr_fmt(fmt) KBUILD_MODNAME ": " fmt
48 
49 #include <linux/pktcdvd.h>
50 #include <linux/module.h>
51 #include <linux/types.h>
52 #include <linux/kernel.h>
53 #include <linux/compat.h>
54 #include <linux/kthread.h>
55 #include <linux/errno.h>
56 #include <linux/spinlock.h>
57 #include <linux/file.h>
58 #include <linux/proc_fs.h>
59 #include <linux/seq_file.h>
60 #include <linux/miscdevice.h>
61 #include <linux/freezer.h>
62 #include <linux/mutex.h>
63 #include <linux/slab.h>
64 #include <scsi/scsi_cmnd.h>
65 #include <scsi/scsi_ioctl.h>
66 #include <scsi/scsi.h>
67 #include <linux/debugfs.h>
68 #include <linux/device.h>
69 
70 #include <asm/uaccess.h>
71 
72 #define DRIVER_NAME	"pktcdvd"
73 
74 #define pkt_err(pd, fmt, ...)						\
75 	pr_err("%s: " fmt, pd->name, ##__VA_ARGS__)
76 #define pkt_notice(pd, fmt, ...)					\
77 	pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__)
78 #define pkt_info(pd, fmt, ...)						\
79 	pr_info("%s: " fmt, pd->name, ##__VA_ARGS__)
80 
81 #define pkt_dbg(level, pd, fmt, ...)					\
82 do {									\
83 	if (level == 2 && PACKET_DEBUG >= 2)				\
84 		pr_notice("%s: %s():" fmt,				\
85 			  pd->name, __func__, ##__VA_ARGS__);		\
86 	else if (level == 1 && PACKET_DEBUG >= 1)			\
87 		pr_notice("%s: " fmt, pd->name, ##__VA_ARGS__);		\
88 } while (0)
89 
90 #define MAX_SPEED 0xffff
91 
92 static DEFINE_MUTEX(pktcdvd_mutex);
93 static struct pktcdvd_device *pkt_devs[MAX_WRITERS];
94 static struct proc_dir_entry *pkt_proc;
95 static int pktdev_major;
96 static int write_congestion_on  = PKT_WRITE_CONGESTION_ON;
97 static int write_congestion_off = PKT_WRITE_CONGESTION_OFF;
98 static struct mutex ctl_mutex;	/* Serialize open/close/setup/teardown */
99 static mempool_t *psd_pool;
100 
101 static struct class	*class_pktcdvd = NULL;    /* /sys/class/pktcdvd */
102 static struct dentry	*pkt_debugfs_root = NULL; /* /sys/kernel/debug/pktcdvd */
103 
104 /* forward declaration */
105 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev);
106 static int pkt_remove_dev(dev_t pkt_dev);
107 static int pkt_seq_show(struct seq_file *m, void *p);
108 
109 static sector_t get_zone(sector_t sector, struct pktcdvd_device *pd)
110 {
111 	return (sector + pd->offset) & ~(sector_t)(pd->settings.size - 1);
112 }
113 
114 /*
115  * create and register a pktcdvd kernel object.
116  */
117 static struct pktcdvd_kobj* pkt_kobj_create(struct pktcdvd_device *pd,
118 					const char* name,
119 					struct kobject* parent,
120 					struct kobj_type* ktype)
121 {
122 	struct pktcdvd_kobj *p;
123 	int error;
124 
125 	p = kzalloc(sizeof(*p), GFP_KERNEL);
126 	if (!p)
127 		return NULL;
128 	p->pd = pd;
129 	error = kobject_init_and_add(&p->kobj, ktype, parent, "%s", name);
130 	if (error) {
131 		kobject_put(&p->kobj);
132 		return NULL;
133 	}
134 	kobject_uevent(&p->kobj, KOBJ_ADD);
135 	return p;
136 }
137 /*
138  * remove a pktcdvd kernel object.
139  */
140 static void pkt_kobj_remove(struct pktcdvd_kobj *p)
141 {
142 	if (p)
143 		kobject_put(&p->kobj);
144 }
145 /*
146  * default release function for pktcdvd kernel objects.
147  */
148 static void pkt_kobj_release(struct kobject *kobj)
149 {
150 	kfree(to_pktcdvdkobj(kobj));
151 }
152 
153 
154 /**********************************************************
155  *
156  * sysfs interface for pktcdvd
157  * by (C) 2006  Thomas Maier <balagi@justmail.de>
158  *
159  **********************************************************/
160 
161 #define DEF_ATTR(_obj,_name,_mode) \
162 	static struct attribute _obj = { .name = _name, .mode = _mode }
163 
164 /**********************************************************
165   /sys/class/pktcdvd/pktcdvd[0-7]/
166                      stat/reset
167                      stat/packets_started
168                      stat/packets_finished
169                      stat/kb_written
170                      stat/kb_read
171                      stat/kb_read_gather
172                      write_queue/size
173                      write_queue/congestion_off
174                      write_queue/congestion_on
175  **********************************************************/
176 
177 DEF_ATTR(kobj_pkt_attr_st1, "reset", 0200);
178 DEF_ATTR(kobj_pkt_attr_st2, "packets_started", 0444);
179 DEF_ATTR(kobj_pkt_attr_st3, "packets_finished", 0444);
180 DEF_ATTR(kobj_pkt_attr_st4, "kb_written", 0444);
181 DEF_ATTR(kobj_pkt_attr_st5, "kb_read", 0444);
182 DEF_ATTR(kobj_pkt_attr_st6, "kb_read_gather", 0444);
183 
184 static struct attribute *kobj_pkt_attrs_stat[] = {
185 	&kobj_pkt_attr_st1,
186 	&kobj_pkt_attr_st2,
187 	&kobj_pkt_attr_st3,
188 	&kobj_pkt_attr_st4,
189 	&kobj_pkt_attr_st5,
190 	&kobj_pkt_attr_st6,
191 	NULL
192 };
193 
194 DEF_ATTR(kobj_pkt_attr_wq1, "size", 0444);
195 DEF_ATTR(kobj_pkt_attr_wq2, "congestion_off", 0644);
196 DEF_ATTR(kobj_pkt_attr_wq3, "congestion_on",  0644);
197 
198 static struct attribute *kobj_pkt_attrs_wqueue[] = {
199 	&kobj_pkt_attr_wq1,
200 	&kobj_pkt_attr_wq2,
201 	&kobj_pkt_attr_wq3,
202 	NULL
203 };
204 
205 static ssize_t kobj_pkt_show(struct kobject *kobj,
206 			struct attribute *attr, char *data)
207 {
208 	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
209 	int n = 0;
210 	int v;
211 	if (strcmp(attr->name, "packets_started") == 0) {
212 		n = sprintf(data, "%lu\n", pd->stats.pkt_started);
213 
214 	} else if (strcmp(attr->name, "packets_finished") == 0) {
215 		n = sprintf(data, "%lu\n", pd->stats.pkt_ended);
216 
217 	} else if (strcmp(attr->name, "kb_written") == 0) {
218 		n = sprintf(data, "%lu\n", pd->stats.secs_w >> 1);
219 
220 	} else if (strcmp(attr->name, "kb_read") == 0) {
221 		n = sprintf(data, "%lu\n", pd->stats.secs_r >> 1);
222 
223 	} else if (strcmp(attr->name, "kb_read_gather") == 0) {
224 		n = sprintf(data, "%lu\n", pd->stats.secs_rg >> 1);
225 
226 	} else if (strcmp(attr->name, "size") == 0) {
227 		spin_lock(&pd->lock);
228 		v = pd->bio_queue_size;
229 		spin_unlock(&pd->lock);
230 		n = sprintf(data, "%d\n", v);
231 
232 	} else if (strcmp(attr->name, "congestion_off") == 0) {
233 		spin_lock(&pd->lock);
234 		v = pd->write_congestion_off;
235 		spin_unlock(&pd->lock);
236 		n = sprintf(data, "%d\n", v);
237 
238 	} else if (strcmp(attr->name, "congestion_on") == 0) {
239 		spin_lock(&pd->lock);
240 		v = pd->write_congestion_on;
241 		spin_unlock(&pd->lock);
242 		n = sprintf(data, "%d\n", v);
243 	}
244 	return n;
245 }
246 
247 static void init_write_congestion_marks(int* lo, int* hi)
248 {
249 	if (*hi > 0) {
250 		*hi = max(*hi, 500);
251 		*hi = min(*hi, 1000000);
252 		if (*lo <= 0)
253 			*lo = *hi - 100;
254 		else {
255 			*lo = min(*lo, *hi - 100);
256 			*lo = max(*lo, 100);
257 		}
258 	} else {
259 		*hi = -1;
260 		*lo = -1;
261 	}
262 }
263 
264 static ssize_t kobj_pkt_store(struct kobject *kobj,
265 			struct attribute *attr,
266 			const char *data, size_t len)
267 {
268 	struct pktcdvd_device *pd = to_pktcdvdkobj(kobj)->pd;
269 	int val;
270 
271 	if (strcmp(attr->name, "reset") == 0 && len > 0) {
272 		pd->stats.pkt_started = 0;
273 		pd->stats.pkt_ended = 0;
274 		pd->stats.secs_w = 0;
275 		pd->stats.secs_rg = 0;
276 		pd->stats.secs_r = 0;
277 
278 	} else if (strcmp(attr->name, "congestion_off") == 0
279 		   && sscanf(data, "%d", &val) == 1) {
280 		spin_lock(&pd->lock);
281 		pd->write_congestion_off = val;
282 		init_write_congestion_marks(&pd->write_congestion_off,
283 					&pd->write_congestion_on);
284 		spin_unlock(&pd->lock);
285 
286 	} else if (strcmp(attr->name, "congestion_on") == 0
287 		   && sscanf(data, "%d", &val) == 1) {
288 		spin_lock(&pd->lock);
289 		pd->write_congestion_on = val;
290 		init_write_congestion_marks(&pd->write_congestion_off,
291 					&pd->write_congestion_on);
292 		spin_unlock(&pd->lock);
293 	}
294 	return len;
295 }
296 
297 static const struct sysfs_ops kobj_pkt_ops = {
298 	.show = kobj_pkt_show,
299 	.store = kobj_pkt_store
300 };
301 static struct kobj_type kobj_pkt_type_stat = {
302 	.release = pkt_kobj_release,
303 	.sysfs_ops = &kobj_pkt_ops,
304 	.default_attrs = kobj_pkt_attrs_stat
305 };
306 static struct kobj_type kobj_pkt_type_wqueue = {
307 	.release = pkt_kobj_release,
308 	.sysfs_ops = &kobj_pkt_ops,
309 	.default_attrs = kobj_pkt_attrs_wqueue
310 };
311 
312 static void pkt_sysfs_dev_new(struct pktcdvd_device *pd)
313 {
314 	if (class_pktcdvd) {
315 		pd->dev = device_create(class_pktcdvd, NULL, MKDEV(0, 0), NULL,
316 					"%s", pd->name);
317 		if (IS_ERR(pd->dev))
318 			pd->dev = NULL;
319 	}
320 	if (pd->dev) {
321 		pd->kobj_stat = pkt_kobj_create(pd, "stat",
322 					&pd->dev->kobj,
323 					&kobj_pkt_type_stat);
324 		pd->kobj_wqueue = pkt_kobj_create(pd, "write_queue",
325 					&pd->dev->kobj,
326 					&kobj_pkt_type_wqueue);
327 	}
328 }
329 
330 static void pkt_sysfs_dev_remove(struct pktcdvd_device *pd)
331 {
332 	pkt_kobj_remove(pd->kobj_stat);
333 	pkt_kobj_remove(pd->kobj_wqueue);
334 	if (class_pktcdvd)
335 		device_unregister(pd->dev);
336 }
337 
338 
339 /********************************************************************
340   /sys/class/pktcdvd/
341                      add            map block device
342                      remove         unmap packet dev
343                      device_map     show mappings
344  *******************************************************************/
345 
346 static void class_pktcdvd_release(struct class *cls)
347 {
348 	kfree(cls);
349 }
350 static ssize_t class_pktcdvd_show_map(struct class *c,
351 					struct class_attribute *attr,
352 					char *data)
353 {
354 	int n = 0;
355 	int idx;
356 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
357 	for (idx = 0; idx < MAX_WRITERS; idx++) {
358 		struct pktcdvd_device *pd = pkt_devs[idx];
359 		if (!pd)
360 			continue;
361 		n += sprintf(data+n, "%s %u:%u %u:%u\n",
362 			pd->name,
363 			MAJOR(pd->pkt_dev), MINOR(pd->pkt_dev),
364 			MAJOR(pd->bdev->bd_dev),
365 			MINOR(pd->bdev->bd_dev));
366 	}
367 	mutex_unlock(&ctl_mutex);
368 	return n;
369 }
370 
371 static ssize_t class_pktcdvd_store_add(struct class *c,
372 					struct class_attribute *attr,
373 					const char *buf,
374 					size_t count)
375 {
376 	unsigned int major, minor;
377 
378 	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
379 		/* pkt_setup_dev() expects caller to hold reference to self */
380 		if (!try_module_get(THIS_MODULE))
381 			return -ENODEV;
382 
383 		pkt_setup_dev(MKDEV(major, minor), NULL);
384 
385 		module_put(THIS_MODULE);
386 
387 		return count;
388 	}
389 
390 	return -EINVAL;
391 }
392 
393 static ssize_t class_pktcdvd_store_remove(struct class *c,
394 					  struct class_attribute *attr,
395 					  const char *buf,
396 					size_t count)
397 {
398 	unsigned int major, minor;
399 	if (sscanf(buf, "%u:%u", &major, &minor) == 2) {
400 		pkt_remove_dev(MKDEV(major, minor));
401 		return count;
402 	}
403 	return -EINVAL;
404 }
405 
406 static struct class_attribute class_pktcdvd_attrs[] = {
407  __ATTR(add,            0200, NULL, class_pktcdvd_store_add),
408  __ATTR(remove,         0200, NULL, class_pktcdvd_store_remove),
409  __ATTR(device_map,     0444, class_pktcdvd_show_map, NULL),
410  __ATTR_NULL
411 };
412 
413 
414 static int pkt_sysfs_init(void)
415 {
416 	int ret = 0;
417 
418 	/*
419 	 * create control files in sysfs
420 	 * /sys/class/pktcdvd/...
421 	 */
422 	class_pktcdvd = kzalloc(sizeof(*class_pktcdvd), GFP_KERNEL);
423 	if (!class_pktcdvd)
424 		return -ENOMEM;
425 	class_pktcdvd->name = DRIVER_NAME;
426 	class_pktcdvd->owner = THIS_MODULE;
427 	class_pktcdvd->class_release = class_pktcdvd_release;
428 	class_pktcdvd->class_attrs = class_pktcdvd_attrs;
429 	ret = class_register(class_pktcdvd);
430 	if (ret) {
431 		kfree(class_pktcdvd);
432 		class_pktcdvd = NULL;
433 		pr_err("failed to create class pktcdvd\n");
434 		return ret;
435 	}
436 	return 0;
437 }
438 
439 static void pkt_sysfs_cleanup(void)
440 {
441 	if (class_pktcdvd)
442 		class_destroy(class_pktcdvd);
443 	class_pktcdvd = NULL;
444 }
445 
446 /********************************************************************
447   entries in debugfs
448 
449   /sys/kernel/debug/pktcdvd[0-7]/
450 			info
451 
452  *******************************************************************/
453 
454 static int pkt_debugfs_seq_show(struct seq_file *m, void *p)
455 {
456 	return pkt_seq_show(m, p);
457 }
458 
459 static int pkt_debugfs_fops_open(struct inode *inode, struct file *file)
460 {
461 	return single_open(file, pkt_debugfs_seq_show, inode->i_private);
462 }
463 
464 static const struct file_operations debug_fops = {
465 	.open		= pkt_debugfs_fops_open,
466 	.read		= seq_read,
467 	.llseek		= seq_lseek,
468 	.release	= single_release,
469 	.owner		= THIS_MODULE,
470 };
471 
472 static void pkt_debugfs_dev_new(struct pktcdvd_device *pd)
473 {
474 	if (!pkt_debugfs_root)
475 		return;
476 	pd->dfs_d_root = debugfs_create_dir(pd->name, pkt_debugfs_root);
477 	if (!pd->dfs_d_root)
478 		return;
479 
480 	pd->dfs_f_info = debugfs_create_file("info", S_IRUGO,
481 				pd->dfs_d_root, pd, &debug_fops);
482 }
483 
484 static void pkt_debugfs_dev_remove(struct pktcdvd_device *pd)
485 {
486 	if (!pkt_debugfs_root)
487 		return;
488 	debugfs_remove(pd->dfs_f_info);
489 	debugfs_remove(pd->dfs_d_root);
490 	pd->dfs_f_info = NULL;
491 	pd->dfs_d_root = NULL;
492 }
493 
494 static void pkt_debugfs_init(void)
495 {
496 	pkt_debugfs_root = debugfs_create_dir(DRIVER_NAME, NULL);
497 }
498 
499 static void pkt_debugfs_cleanup(void)
500 {
501 	debugfs_remove(pkt_debugfs_root);
502 	pkt_debugfs_root = NULL;
503 }
504 
505 /* ----------------------------------------------------------*/
506 
507 
508 static void pkt_bio_finished(struct pktcdvd_device *pd)
509 {
510 	BUG_ON(atomic_read(&pd->cdrw.pending_bios) <= 0);
511 	if (atomic_dec_and_test(&pd->cdrw.pending_bios)) {
512 		pkt_dbg(2, pd, "queue empty\n");
513 		atomic_set(&pd->iosched.attention, 1);
514 		wake_up(&pd->wqueue);
515 	}
516 }
517 
518 /*
519  * Allocate a packet_data struct
520  */
521 static struct packet_data *pkt_alloc_packet_data(int frames)
522 {
523 	int i;
524 	struct packet_data *pkt;
525 
526 	pkt = kzalloc(sizeof(struct packet_data), GFP_KERNEL);
527 	if (!pkt)
528 		goto no_pkt;
529 
530 	pkt->frames = frames;
531 	pkt->w_bio = bio_kmalloc(GFP_KERNEL, frames);
532 	if (!pkt->w_bio)
533 		goto no_bio;
534 
535 	for (i = 0; i < frames / FRAMES_PER_PAGE; i++) {
536 		pkt->pages[i] = alloc_page(GFP_KERNEL|__GFP_ZERO);
537 		if (!pkt->pages[i])
538 			goto no_page;
539 	}
540 
541 	spin_lock_init(&pkt->lock);
542 	bio_list_init(&pkt->orig_bios);
543 
544 	for (i = 0; i < frames; i++) {
545 		struct bio *bio = bio_kmalloc(GFP_KERNEL, 1);
546 		if (!bio)
547 			goto no_rd_bio;
548 
549 		pkt->r_bios[i] = bio;
550 	}
551 
552 	return pkt;
553 
554 no_rd_bio:
555 	for (i = 0; i < frames; i++) {
556 		struct bio *bio = pkt->r_bios[i];
557 		if (bio)
558 			bio_put(bio);
559 	}
560 
561 no_page:
562 	for (i = 0; i < frames / FRAMES_PER_PAGE; i++)
563 		if (pkt->pages[i])
564 			__free_page(pkt->pages[i]);
565 	bio_put(pkt->w_bio);
566 no_bio:
567 	kfree(pkt);
568 no_pkt:
569 	return NULL;
570 }
571 
572 /*
573  * Free a packet_data struct
574  */
575 static void pkt_free_packet_data(struct packet_data *pkt)
576 {
577 	int i;
578 
579 	for (i = 0; i < pkt->frames; i++) {
580 		struct bio *bio = pkt->r_bios[i];
581 		if (bio)
582 			bio_put(bio);
583 	}
584 	for (i = 0; i < pkt->frames / FRAMES_PER_PAGE; i++)
585 		__free_page(pkt->pages[i]);
586 	bio_put(pkt->w_bio);
587 	kfree(pkt);
588 }
589 
590 static void pkt_shrink_pktlist(struct pktcdvd_device *pd)
591 {
592 	struct packet_data *pkt, *next;
593 
594 	BUG_ON(!list_empty(&pd->cdrw.pkt_active_list));
595 
596 	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_free_list, list) {
597 		pkt_free_packet_data(pkt);
598 	}
599 	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
600 }
601 
602 static int pkt_grow_pktlist(struct pktcdvd_device *pd, int nr_packets)
603 {
604 	struct packet_data *pkt;
605 
606 	BUG_ON(!list_empty(&pd->cdrw.pkt_free_list));
607 
608 	while (nr_packets > 0) {
609 		pkt = pkt_alloc_packet_data(pd->settings.size >> 2);
610 		if (!pkt) {
611 			pkt_shrink_pktlist(pd);
612 			return 0;
613 		}
614 		pkt->id = nr_packets;
615 		pkt->pd = pd;
616 		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
617 		nr_packets--;
618 	}
619 	return 1;
620 }
621 
622 static inline struct pkt_rb_node *pkt_rbtree_next(struct pkt_rb_node *node)
623 {
624 	struct rb_node *n = rb_next(&node->rb_node);
625 	if (!n)
626 		return NULL;
627 	return rb_entry(n, struct pkt_rb_node, rb_node);
628 }
629 
630 static void pkt_rbtree_erase(struct pktcdvd_device *pd, struct pkt_rb_node *node)
631 {
632 	rb_erase(&node->rb_node, &pd->bio_queue);
633 	mempool_free(node, pd->rb_pool);
634 	pd->bio_queue_size--;
635 	BUG_ON(pd->bio_queue_size < 0);
636 }
637 
638 /*
639  * Find the first node in the pd->bio_queue rb tree with a starting sector >= s.
640  */
641 static struct pkt_rb_node *pkt_rbtree_find(struct pktcdvd_device *pd, sector_t s)
642 {
643 	struct rb_node *n = pd->bio_queue.rb_node;
644 	struct rb_node *next;
645 	struct pkt_rb_node *tmp;
646 
647 	if (!n) {
648 		BUG_ON(pd->bio_queue_size > 0);
649 		return NULL;
650 	}
651 
652 	for (;;) {
653 		tmp = rb_entry(n, struct pkt_rb_node, rb_node);
654 		if (s <= tmp->bio->bi_iter.bi_sector)
655 			next = n->rb_left;
656 		else
657 			next = n->rb_right;
658 		if (!next)
659 			break;
660 		n = next;
661 	}
662 
663 	if (s > tmp->bio->bi_iter.bi_sector) {
664 		tmp = pkt_rbtree_next(tmp);
665 		if (!tmp)
666 			return NULL;
667 	}
668 	BUG_ON(s > tmp->bio->bi_iter.bi_sector);
669 	return tmp;
670 }
671 
672 /*
673  * Insert a node into the pd->bio_queue rb tree.
674  */
675 static void pkt_rbtree_insert(struct pktcdvd_device *pd, struct pkt_rb_node *node)
676 {
677 	struct rb_node **p = &pd->bio_queue.rb_node;
678 	struct rb_node *parent = NULL;
679 	sector_t s = node->bio->bi_iter.bi_sector;
680 	struct pkt_rb_node *tmp;
681 
682 	while (*p) {
683 		parent = *p;
684 		tmp = rb_entry(parent, struct pkt_rb_node, rb_node);
685 		if (s < tmp->bio->bi_iter.bi_sector)
686 			p = &(*p)->rb_left;
687 		else
688 			p = &(*p)->rb_right;
689 	}
690 	rb_link_node(&node->rb_node, parent, p);
691 	rb_insert_color(&node->rb_node, &pd->bio_queue);
692 	pd->bio_queue_size++;
693 }
694 
695 /*
696  * Send a packet_command to the underlying block device and
697  * wait for completion.
698  */
699 static int pkt_generic_packet(struct pktcdvd_device *pd, struct packet_command *cgc)
700 {
701 	struct request_queue *q = bdev_get_queue(pd->bdev);
702 	struct request *rq;
703 	int ret = 0;
704 
705 	rq = blk_get_request(q, (cgc->data_direction == CGC_DATA_WRITE) ?
706 			     WRITE : READ, __GFP_WAIT);
707 	blk_rq_set_block_pc(rq);
708 
709 	if (cgc->buflen) {
710 		ret = blk_rq_map_kern(q, rq, cgc->buffer, cgc->buflen,
711 				      __GFP_WAIT);
712 		if (ret)
713 			goto out;
714 	}
715 
716 	rq->cmd_len = COMMAND_SIZE(cgc->cmd[0]);
717 	memcpy(rq->cmd, cgc->cmd, CDROM_PACKET_SIZE);
718 
719 	rq->timeout = 60*HZ;
720 	if (cgc->quiet)
721 		rq->cmd_flags |= REQ_QUIET;
722 
723 	blk_execute_rq(rq->q, pd->bdev->bd_disk, rq, 0);
724 	if (rq->errors)
725 		ret = -EIO;
726 out:
727 	blk_put_request(rq);
728 	return ret;
729 }
730 
731 static const char *sense_key_string(__u8 index)
732 {
733 	static const char * const info[] = {
734 		"No sense", "Recovered error", "Not ready",
735 		"Medium error", "Hardware error", "Illegal request",
736 		"Unit attention", "Data protect", "Blank check",
737 	};
738 
739 	return index < ARRAY_SIZE(info) ? info[index] : "INVALID";
740 }
741 
742 /*
743  * A generic sense dump / resolve mechanism should be implemented across
744  * all ATAPI + SCSI devices.
745  */
746 static void pkt_dump_sense(struct pktcdvd_device *pd,
747 			   struct packet_command *cgc)
748 {
749 	struct request_sense *sense = cgc->sense;
750 
751 	if (sense)
752 		pkt_err(pd, "%*ph - sense %02x.%02x.%02x (%s)\n",
753 			CDROM_PACKET_SIZE, cgc->cmd,
754 			sense->sense_key, sense->asc, sense->ascq,
755 			sense_key_string(sense->sense_key));
756 	else
757 		pkt_err(pd, "%*ph - no sense\n", CDROM_PACKET_SIZE, cgc->cmd);
758 }
759 
760 /*
761  * flush the drive cache to media
762  */
763 static int pkt_flush_cache(struct pktcdvd_device *pd)
764 {
765 	struct packet_command cgc;
766 
767 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
768 	cgc.cmd[0] = GPCMD_FLUSH_CACHE;
769 	cgc.quiet = 1;
770 
771 	/*
772 	 * the IMMED bit -- we default to not setting it, although that
773 	 * would allow a much faster close, this is safer
774 	 */
775 #if 0
776 	cgc.cmd[1] = 1 << 1;
777 #endif
778 	return pkt_generic_packet(pd, &cgc);
779 }
780 
781 /*
782  * speed is given as the normal factor, e.g. 4 for 4x
783  */
784 static noinline_for_stack int pkt_set_speed(struct pktcdvd_device *pd,
785 				unsigned write_speed, unsigned read_speed)
786 {
787 	struct packet_command cgc;
788 	struct request_sense sense;
789 	int ret;
790 
791 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
792 	cgc.sense = &sense;
793 	cgc.cmd[0] = GPCMD_SET_SPEED;
794 	cgc.cmd[2] = (read_speed >> 8) & 0xff;
795 	cgc.cmd[3] = read_speed & 0xff;
796 	cgc.cmd[4] = (write_speed >> 8) & 0xff;
797 	cgc.cmd[5] = write_speed & 0xff;
798 
799 	if ((ret = pkt_generic_packet(pd, &cgc)))
800 		pkt_dump_sense(pd, &cgc);
801 
802 	return ret;
803 }
804 
805 /*
806  * Queue a bio for processing by the low-level CD device. Must be called
807  * from process context.
808  */
809 static void pkt_queue_bio(struct pktcdvd_device *pd, struct bio *bio)
810 {
811 	spin_lock(&pd->iosched.lock);
812 	if (bio_data_dir(bio) == READ)
813 		bio_list_add(&pd->iosched.read_queue, bio);
814 	else
815 		bio_list_add(&pd->iosched.write_queue, bio);
816 	spin_unlock(&pd->iosched.lock);
817 
818 	atomic_set(&pd->iosched.attention, 1);
819 	wake_up(&pd->wqueue);
820 }
821 
822 /*
823  * Process the queued read/write requests. This function handles special
824  * requirements for CDRW drives:
825  * - A cache flush command must be inserted before a read request if the
826  *   previous request was a write.
827  * - Switching between reading and writing is slow, so don't do it more often
828  *   than necessary.
829  * - Optimize for throughput at the expense of latency. This means that streaming
830  *   writes will never be interrupted by a read, but if the drive has to seek
831  *   before the next write, switch to reading instead if there are any pending
832  *   read requests.
833  * - Set the read speed according to current usage pattern. When only reading
834  *   from the device, it's best to use the highest possible read speed, but
835  *   when switching often between reading and writing, it's better to have the
836  *   same read and write speeds.
837  */
838 static void pkt_iosched_process_queue(struct pktcdvd_device *pd)
839 {
840 
841 	if (atomic_read(&pd->iosched.attention) == 0)
842 		return;
843 	atomic_set(&pd->iosched.attention, 0);
844 
845 	for (;;) {
846 		struct bio *bio;
847 		int reads_queued, writes_queued;
848 
849 		spin_lock(&pd->iosched.lock);
850 		reads_queued = !bio_list_empty(&pd->iosched.read_queue);
851 		writes_queued = !bio_list_empty(&pd->iosched.write_queue);
852 		spin_unlock(&pd->iosched.lock);
853 
854 		if (!reads_queued && !writes_queued)
855 			break;
856 
857 		if (pd->iosched.writing) {
858 			int need_write_seek = 1;
859 			spin_lock(&pd->iosched.lock);
860 			bio = bio_list_peek(&pd->iosched.write_queue);
861 			spin_unlock(&pd->iosched.lock);
862 			if (bio && (bio->bi_iter.bi_sector ==
863 				    pd->iosched.last_write))
864 				need_write_seek = 0;
865 			if (need_write_seek && reads_queued) {
866 				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
867 					pkt_dbg(2, pd, "write, waiting\n");
868 					break;
869 				}
870 				pkt_flush_cache(pd);
871 				pd->iosched.writing = 0;
872 			}
873 		} else {
874 			if (!reads_queued && writes_queued) {
875 				if (atomic_read(&pd->cdrw.pending_bios) > 0) {
876 					pkt_dbg(2, pd, "read, waiting\n");
877 					break;
878 				}
879 				pd->iosched.writing = 1;
880 			}
881 		}
882 
883 		spin_lock(&pd->iosched.lock);
884 		if (pd->iosched.writing)
885 			bio = bio_list_pop(&pd->iosched.write_queue);
886 		else
887 			bio = bio_list_pop(&pd->iosched.read_queue);
888 		spin_unlock(&pd->iosched.lock);
889 
890 		if (!bio)
891 			continue;
892 
893 		if (bio_data_dir(bio) == READ)
894 			pd->iosched.successive_reads +=
895 				bio->bi_iter.bi_size >> 10;
896 		else {
897 			pd->iosched.successive_reads = 0;
898 			pd->iosched.last_write = bio_end_sector(bio);
899 		}
900 		if (pd->iosched.successive_reads >= HI_SPEED_SWITCH) {
901 			if (pd->read_speed == pd->write_speed) {
902 				pd->read_speed = MAX_SPEED;
903 				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
904 			}
905 		} else {
906 			if (pd->read_speed != pd->write_speed) {
907 				pd->read_speed = pd->write_speed;
908 				pkt_set_speed(pd, pd->write_speed, pd->read_speed);
909 			}
910 		}
911 
912 		atomic_inc(&pd->cdrw.pending_bios);
913 		generic_make_request(bio);
914 	}
915 }
916 
917 /*
918  * Special care is needed if the underlying block device has a small
919  * max_phys_segments value.
920  */
921 static int pkt_set_segment_merging(struct pktcdvd_device *pd, struct request_queue *q)
922 {
923 	if ((pd->settings.size << 9) / CD_FRAMESIZE
924 	    <= queue_max_segments(q)) {
925 		/*
926 		 * The cdrom device can handle one segment/frame
927 		 */
928 		clear_bit(PACKET_MERGE_SEGS, &pd->flags);
929 		return 0;
930 	} else if ((pd->settings.size << 9) / PAGE_SIZE
931 		   <= queue_max_segments(q)) {
932 		/*
933 		 * We can handle this case at the expense of some extra memory
934 		 * copies during write operations
935 		 */
936 		set_bit(PACKET_MERGE_SEGS, &pd->flags);
937 		return 0;
938 	} else {
939 		pkt_err(pd, "cdrom max_phys_segments too small\n");
940 		return -EIO;
941 	}
942 }
943 
944 /*
945  * Copy all data for this packet to pkt->pages[], so that
946  * a) The number of required segments for the write bio is minimized, which
947  *    is necessary for some scsi controllers.
948  * b) The data can be used as cache to avoid read requests if we receive a
949  *    new write request for the same zone.
950  */
951 static void pkt_make_local_copy(struct packet_data *pkt, struct bio_vec *bvec)
952 {
953 	int f, p, offs;
954 
955 	/* Copy all data to pkt->pages[] */
956 	p = 0;
957 	offs = 0;
958 	for (f = 0; f < pkt->frames; f++) {
959 		if (bvec[f].bv_page != pkt->pages[p]) {
960 			void *vfrom = kmap_atomic(bvec[f].bv_page) + bvec[f].bv_offset;
961 			void *vto = page_address(pkt->pages[p]) + offs;
962 			memcpy(vto, vfrom, CD_FRAMESIZE);
963 			kunmap_atomic(vfrom);
964 			bvec[f].bv_page = pkt->pages[p];
965 			bvec[f].bv_offset = offs;
966 		} else {
967 			BUG_ON(bvec[f].bv_offset != offs);
968 		}
969 		offs += CD_FRAMESIZE;
970 		if (offs >= PAGE_SIZE) {
971 			offs = 0;
972 			p++;
973 		}
974 	}
975 }
976 
977 static void pkt_end_io_read(struct bio *bio, int err)
978 {
979 	struct packet_data *pkt = bio->bi_private;
980 	struct pktcdvd_device *pd = pkt->pd;
981 	BUG_ON(!pd);
982 
983 	pkt_dbg(2, pd, "bio=%p sec0=%llx sec=%llx err=%d\n",
984 		bio, (unsigned long long)pkt->sector,
985 		(unsigned long long)bio->bi_iter.bi_sector, err);
986 
987 	if (err)
988 		atomic_inc(&pkt->io_errors);
989 	if (atomic_dec_and_test(&pkt->io_wait)) {
990 		atomic_inc(&pkt->run_sm);
991 		wake_up(&pd->wqueue);
992 	}
993 	pkt_bio_finished(pd);
994 }
995 
996 static void pkt_end_io_packet_write(struct bio *bio, int err)
997 {
998 	struct packet_data *pkt = bio->bi_private;
999 	struct pktcdvd_device *pd = pkt->pd;
1000 	BUG_ON(!pd);
1001 
1002 	pkt_dbg(2, pd, "id=%d, err=%d\n", pkt->id, err);
1003 
1004 	pd->stats.pkt_ended++;
1005 
1006 	pkt_bio_finished(pd);
1007 	atomic_dec(&pkt->io_wait);
1008 	atomic_inc(&pkt->run_sm);
1009 	wake_up(&pd->wqueue);
1010 }
1011 
1012 /*
1013  * Schedule reads for the holes in a packet
1014  */
1015 static void pkt_gather_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1016 {
1017 	int frames_read = 0;
1018 	struct bio *bio;
1019 	int f;
1020 	char written[PACKET_MAX_SIZE];
1021 
1022 	BUG_ON(bio_list_empty(&pkt->orig_bios));
1023 
1024 	atomic_set(&pkt->io_wait, 0);
1025 	atomic_set(&pkt->io_errors, 0);
1026 
1027 	/*
1028 	 * Figure out which frames we need to read before we can write.
1029 	 */
1030 	memset(written, 0, sizeof(written));
1031 	spin_lock(&pkt->lock);
1032 	bio_list_for_each(bio, &pkt->orig_bios) {
1033 		int first_frame = (bio->bi_iter.bi_sector - pkt->sector) /
1034 			(CD_FRAMESIZE >> 9);
1035 		int num_frames = bio->bi_iter.bi_size / CD_FRAMESIZE;
1036 		pd->stats.secs_w += num_frames * (CD_FRAMESIZE >> 9);
1037 		BUG_ON(first_frame < 0);
1038 		BUG_ON(first_frame + num_frames > pkt->frames);
1039 		for (f = first_frame; f < first_frame + num_frames; f++)
1040 			written[f] = 1;
1041 	}
1042 	spin_unlock(&pkt->lock);
1043 
1044 	if (pkt->cache_valid) {
1045 		pkt_dbg(2, pd, "zone %llx cached\n",
1046 			(unsigned long long)pkt->sector);
1047 		goto out_account;
1048 	}
1049 
1050 	/*
1051 	 * Schedule reads for missing parts of the packet.
1052 	 */
1053 	for (f = 0; f < pkt->frames; f++) {
1054 		int p, offset;
1055 
1056 		if (written[f])
1057 			continue;
1058 
1059 		bio = pkt->r_bios[f];
1060 		bio_reset(bio);
1061 		bio->bi_iter.bi_sector = pkt->sector + f * (CD_FRAMESIZE >> 9);
1062 		bio->bi_bdev = pd->bdev;
1063 		bio->bi_end_io = pkt_end_io_read;
1064 		bio->bi_private = pkt;
1065 
1066 		p = (f * CD_FRAMESIZE) / PAGE_SIZE;
1067 		offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1068 		pkt_dbg(2, pd, "Adding frame %d, page:%p offs:%d\n",
1069 			f, pkt->pages[p], offset);
1070 		if (!bio_add_page(bio, pkt->pages[p], CD_FRAMESIZE, offset))
1071 			BUG();
1072 
1073 		atomic_inc(&pkt->io_wait);
1074 		bio->bi_rw = READ;
1075 		pkt_queue_bio(pd, bio);
1076 		frames_read++;
1077 	}
1078 
1079 out_account:
1080 	pkt_dbg(2, pd, "need %d frames for zone %llx\n",
1081 		frames_read, (unsigned long long)pkt->sector);
1082 	pd->stats.pkt_started++;
1083 	pd->stats.secs_rg += frames_read * (CD_FRAMESIZE >> 9);
1084 }
1085 
1086 /*
1087  * Find a packet matching zone, or the least recently used packet if
1088  * there is no match.
1089  */
1090 static struct packet_data *pkt_get_packet_data(struct pktcdvd_device *pd, int zone)
1091 {
1092 	struct packet_data *pkt;
1093 
1094 	list_for_each_entry(pkt, &pd->cdrw.pkt_free_list, list) {
1095 		if (pkt->sector == zone || pkt->list.next == &pd->cdrw.pkt_free_list) {
1096 			list_del_init(&pkt->list);
1097 			if (pkt->sector != zone)
1098 				pkt->cache_valid = 0;
1099 			return pkt;
1100 		}
1101 	}
1102 	BUG();
1103 	return NULL;
1104 }
1105 
1106 static void pkt_put_packet_data(struct pktcdvd_device *pd, struct packet_data *pkt)
1107 {
1108 	if (pkt->cache_valid) {
1109 		list_add(&pkt->list, &pd->cdrw.pkt_free_list);
1110 	} else {
1111 		list_add_tail(&pkt->list, &pd->cdrw.pkt_free_list);
1112 	}
1113 }
1114 
1115 /*
1116  * recover a failed write, query for relocation if possible
1117  *
1118  * returns 1 if recovery is possible, or 0 if not
1119  *
1120  */
1121 static int pkt_start_recovery(struct packet_data *pkt)
1122 {
1123 	/*
1124 	 * FIXME. We need help from the file system to implement
1125 	 * recovery handling.
1126 	 */
1127 	return 0;
1128 #if 0
1129 	struct request *rq = pkt->rq;
1130 	struct pktcdvd_device *pd = rq->rq_disk->private_data;
1131 	struct block_device *pkt_bdev;
1132 	struct super_block *sb = NULL;
1133 	unsigned long old_block, new_block;
1134 	sector_t new_sector;
1135 
1136 	pkt_bdev = bdget(kdev_t_to_nr(pd->pkt_dev));
1137 	if (pkt_bdev) {
1138 		sb = get_super(pkt_bdev);
1139 		bdput(pkt_bdev);
1140 	}
1141 
1142 	if (!sb)
1143 		return 0;
1144 
1145 	if (!sb->s_op->relocate_blocks)
1146 		goto out;
1147 
1148 	old_block = pkt->sector / (CD_FRAMESIZE >> 9);
1149 	if (sb->s_op->relocate_blocks(sb, old_block, &new_block))
1150 		goto out;
1151 
1152 	new_sector = new_block * (CD_FRAMESIZE >> 9);
1153 	pkt->sector = new_sector;
1154 
1155 	bio_reset(pkt->bio);
1156 	pkt->bio->bi_bdev = pd->bdev;
1157 	pkt->bio->bi_rw = REQ_WRITE;
1158 	pkt->bio->bi_iter.bi_sector = new_sector;
1159 	pkt->bio->bi_iter.bi_size = pkt->frames * CD_FRAMESIZE;
1160 	pkt->bio->bi_vcnt = pkt->frames;
1161 
1162 	pkt->bio->bi_end_io = pkt_end_io_packet_write;
1163 	pkt->bio->bi_private = pkt;
1164 
1165 	drop_super(sb);
1166 	return 1;
1167 
1168 out:
1169 	drop_super(sb);
1170 	return 0;
1171 #endif
1172 }
1173 
1174 static inline void pkt_set_state(struct packet_data *pkt, enum packet_data_state state)
1175 {
1176 #if PACKET_DEBUG > 1
1177 	static const char *state_name[] = {
1178 		"IDLE", "WAITING", "READ_WAIT", "WRITE_WAIT", "RECOVERY", "FINISHED"
1179 	};
1180 	enum packet_data_state old_state = pkt->state;
1181 	pkt_dbg(2, pd, "pkt %2d : s=%6llx %s -> %s\n",
1182 		pkt->id, (unsigned long long)pkt->sector,
1183 		state_name[old_state], state_name[state]);
1184 #endif
1185 	pkt->state = state;
1186 }
1187 
1188 /*
1189  * Scan the work queue to see if we can start a new packet.
1190  * returns non-zero if any work was done.
1191  */
1192 static int pkt_handle_queue(struct pktcdvd_device *pd)
1193 {
1194 	struct packet_data *pkt, *p;
1195 	struct bio *bio = NULL;
1196 	sector_t zone = 0; /* Suppress gcc warning */
1197 	struct pkt_rb_node *node, *first_node;
1198 	struct rb_node *n;
1199 	int wakeup;
1200 
1201 	atomic_set(&pd->scan_queue, 0);
1202 
1203 	if (list_empty(&pd->cdrw.pkt_free_list)) {
1204 		pkt_dbg(2, pd, "no pkt\n");
1205 		return 0;
1206 	}
1207 
1208 	/*
1209 	 * Try to find a zone we are not already working on.
1210 	 */
1211 	spin_lock(&pd->lock);
1212 	first_node = pkt_rbtree_find(pd, pd->current_sector);
1213 	if (!first_node) {
1214 		n = rb_first(&pd->bio_queue);
1215 		if (n)
1216 			first_node = rb_entry(n, struct pkt_rb_node, rb_node);
1217 	}
1218 	node = first_node;
1219 	while (node) {
1220 		bio = node->bio;
1221 		zone = get_zone(bio->bi_iter.bi_sector, pd);
1222 		list_for_each_entry(p, &pd->cdrw.pkt_active_list, list) {
1223 			if (p->sector == zone) {
1224 				bio = NULL;
1225 				goto try_next_bio;
1226 			}
1227 		}
1228 		break;
1229 try_next_bio:
1230 		node = pkt_rbtree_next(node);
1231 		if (!node) {
1232 			n = rb_first(&pd->bio_queue);
1233 			if (n)
1234 				node = rb_entry(n, struct pkt_rb_node, rb_node);
1235 		}
1236 		if (node == first_node)
1237 			node = NULL;
1238 	}
1239 	spin_unlock(&pd->lock);
1240 	if (!bio) {
1241 		pkt_dbg(2, pd, "no bio\n");
1242 		return 0;
1243 	}
1244 
1245 	pkt = pkt_get_packet_data(pd, zone);
1246 
1247 	pd->current_sector = zone + pd->settings.size;
1248 	pkt->sector = zone;
1249 	BUG_ON(pkt->frames != pd->settings.size >> 2);
1250 	pkt->write_size = 0;
1251 
1252 	/*
1253 	 * Scan work queue for bios in the same zone and link them
1254 	 * to this packet.
1255 	 */
1256 	spin_lock(&pd->lock);
1257 	pkt_dbg(2, pd, "looking for zone %llx\n", (unsigned long long)zone);
1258 	while ((node = pkt_rbtree_find(pd, zone)) != NULL) {
1259 		bio = node->bio;
1260 		pkt_dbg(2, pd, "found zone=%llx\n", (unsigned long long)
1261 			get_zone(bio->bi_iter.bi_sector, pd));
1262 		if (get_zone(bio->bi_iter.bi_sector, pd) != zone)
1263 			break;
1264 		pkt_rbtree_erase(pd, node);
1265 		spin_lock(&pkt->lock);
1266 		bio_list_add(&pkt->orig_bios, bio);
1267 		pkt->write_size += bio->bi_iter.bi_size / CD_FRAMESIZE;
1268 		spin_unlock(&pkt->lock);
1269 	}
1270 	/* check write congestion marks, and if bio_queue_size is
1271 	   below, wake up any waiters */
1272 	wakeup = (pd->write_congestion_on > 0
1273 	 		&& pd->bio_queue_size <= pd->write_congestion_off);
1274 	spin_unlock(&pd->lock);
1275 	if (wakeup) {
1276 		clear_bdi_congested(&pd->disk->queue->backing_dev_info,
1277 					BLK_RW_ASYNC);
1278 	}
1279 
1280 	pkt->sleep_time = max(PACKET_WAIT_TIME, 1);
1281 	pkt_set_state(pkt, PACKET_WAITING_STATE);
1282 	atomic_set(&pkt->run_sm, 1);
1283 
1284 	spin_lock(&pd->cdrw.active_list_lock);
1285 	list_add(&pkt->list, &pd->cdrw.pkt_active_list);
1286 	spin_unlock(&pd->cdrw.active_list_lock);
1287 
1288 	return 1;
1289 }
1290 
1291 /*
1292  * Assemble a bio to write one packet and queue the bio for processing
1293  * by the underlying block device.
1294  */
1295 static void pkt_start_write(struct pktcdvd_device *pd, struct packet_data *pkt)
1296 {
1297 	int f;
1298 	struct bio_vec *bvec = pkt->w_bio->bi_io_vec;
1299 
1300 	bio_reset(pkt->w_bio);
1301 	pkt->w_bio->bi_iter.bi_sector = pkt->sector;
1302 	pkt->w_bio->bi_bdev = pd->bdev;
1303 	pkt->w_bio->bi_end_io = pkt_end_io_packet_write;
1304 	pkt->w_bio->bi_private = pkt;
1305 
1306 	/* XXX: locking? */
1307 	for (f = 0; f < pkt->frames; f++) {
1308 		bvec[f].bv_page = pkt->pages[(f * CD_FRAMESIZE) / PAGE_SIZE];
1309 		bvec[f].bv_offset = (f * CD_FRAMESIZE) % PAGE_SIZE;
1310 		if (!bio_add_page(pkt->w_bio, bvec[f].bv_page, CD_FRAMESIZE, bvec[f].bv_offset))
1311 			BUG();
1312 	}
1313 	pkt_dbg(2, pd, "vcnt=%d\n", pkt->w_bio->bi_vcnt);
1314 
1315 	/*
1316 	 * Fill-in bvec with data from orig_bios.
1317 	 */
1318 	spin_lock(&pkt->lock);
1319 	bio_copy_data(pkt->w_bio, pkt->orig_bios.head);
1320 
1321 	pkt_set_state(pkt, PACKET_WRITE_WAIT_STATE);
1322 	spin_unlock(&pkt->lock);
1323 
1324 	pkt_dbg(2, pd, "Writing %d frames for zone %llx\n",
1325 		pkt->write_size, (unsigned long long)pkt->sector);
1326 
1327 	if (test_bit(PACKET_MERGE_SEGS, &pd->flags) || (pkt->write_size < pkt->frames)) {
1328 		pkt_make_local_copy(pkt, bvec);
1329 		pkt->cache_valid = 1;
1330 	} else {
1331 		pkt->cache_valid = 0;
1332 	}
1333 
1334 	/* Start the write request */
1335 	atomic_set(&pkt->io_wait, 1);
1336 	pkt->w_bio->bi_rw = WRITE;
1337 	pkt_queue_bio(pd, pkt->w_bio);
1338 }
1339 
1340 static void pkt_finish_packet(struct packet_data *pkt, int uptodate)
1341 {
1342 	struct bio *bio;
1343 
1344 	if (!uptodate)
1345 		pkt->cache_valid = 0;
1346 
1347 	/* Finish all bios corresponding to this packet */
1348 	while ((bio = bio_list_pop(&pkt->orig_bios)))
1349 		bio_endio(bio, uptodate ? 0 : -EIO);
1350 }
1351 
1352 static void pkt_run_state_machine(struct pktcdvd_device *pd, struct packet_data *pkt)
1353 {
1354 	int uptodate;
1355 
1356 	pkt_dbg(2, pd, "pkt %d\n", pkt->id);
1357 
1358 	for (;;) {
1359 		switch (pkt->state) {
1360 		case PACKET_WAITING_STATE:
1361 			if ((pkt->write_size < pkt->frames) && (pkt->sleep_time > 0))
1362 				return;
1363 
1364 			pkt->sleep_time = 0;
1365 			pkt_gather_data(pd, pkt);
1366 			pkt_set_state(pkt, PACKET_READ_WAIT_STATE);
1367 			break;
1368 
1369 		case PACKET_READ_WAIT_STATE:
1370 			if (atomic_read(&pkt->io_wait) > 0)
1371 				return;
1372 
1373 			if (atomic_read(&pkt->io_errors) > 0) {
1374 				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1375 			} else {
1376 				pkt_start_write(pd, pkt);
1377 			}
1378 			break;
1379 
1380 		case PACKET_WRITE_WAIT_STATE:
1381 			if (atomic_read(&pkt->io_wait) > 0)
1382 				return;
1383 
1384 			if (test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags)) {
1385 				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1386 			} else {
1387 				pkt_set_state(pkt, PACKET_RECOVERY_STATE);
1388 			}
1389 			break;
1390 
1391 		case PACKET_RECOVERY_STATE:
1392 			if (pkt_start_recovery(pkt)) {
1393 				pkt_start_write(pd, pkt);
1394 			} else {
1395 				pkt_dbg(2, pd, "No recovery possible\n");
1396 				pkt_set_state(pkt, PACKET_FINISHED_STATE);
1397 			}
1398 			break;
1399 
1400 		case PACKET_FINISHED_STATE:
1401 			uptodate = test_bit(BIO_UPTODATE, &pkt->w_bio->bi_flags);
1402 			pkt_finish_packet(pkt, uptodate);
1403 			return;
1404 
1405 		default:
1406 			BUG();
1407 			break;
1408 		}
1409 	}
1410 }
1411 
1412 static void pkt_handle_packets(struct pktcdvd_device *pd)
1413 {
1414 	struct packet_data *pkt, *next;
1415 
1416 	/*
1417 	 * Run state machine for active packets
1418 	 */
1419 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1420 		if (atomic_read(&pkt->run_sm) > 0) {
1421 			atomic_set(&pkt->run_sm, 0);
1422 			pkt_run_state_machine(pd, pkt);
1423 		}
1424 	}
1425 
1426 	/*
1427 	 * Move no longer active packets to the free list
1428 	 */
1429 	spin_lock(&pd->cdrw.active_list_lock);
1430 	list_for_each_entry_safe(pkt, next, &pd->cdrw.pkt_active_list, list) {
1431 		if (pkt->state == PACKET_FINISHED_STATE) {
1432 			list_del(&pkt->list);
1433 			pkt_put_packet_data(pd, pkt);
1434 			pkt_set_state(pkt, PACKET_IDLE_STATE);
1435 			atomic_set(&pd->scan_queue, 1);
1436 		}
1437 	}
1438 	spin_unlock(&pd->cdrw.active_list_lock);
1439 }
1440 
1441 static void pkt_count_states(struct pktcdvd_device *pd, int *states)
1442 {
1443 	struct packet_data *pkt;
1444 	int i;
1445 
1446 	for (i = 0; i < PACKET_NUM_STATES; i++)
1447 		states[i] = 0;
1448 
1449 	spin_lock(&pd->cdrw.active_list_lock);
1450 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1451 		states[pkt->state]++;
1452 	}
1453 	spin_unlock(&pd->cdrw.active_list_lock);
1454 }
1455 
1456 /*
1457  * kcdrwd is woken up when writes have been queued for one of our
1458  * registered devices
1459  */
1460 static int kcdrwd(void *foobar)
1461 {
1462 	struct pktcdvd_device *pd = foobar;
1463 	struct packet_data *pkt;
1464 	long min_sleep_time, residue;
1465 
1466 	set_user_nice(current, MIN_NICE);
1467 	set_freezable();
1468 
1469 	for (;;) {
1470 		DECLARE_WAITQUEUE(wait, current);
1471 
1472 		/*
1473 		 * Wait until there is something to do
1474 		 */
1475 		add_wait_queue(&pd->wqueue, &wait);
1476 		for (;;) {
1477 			set_current_state(TASK_INTERRUPTIBLE);
1478 
1479 			/* Check if we need to run pkt_handle_queue */
1480 			if (atomic_read(&pd->scan_queue) > 0)
1481 				goto work_to_do;
1482 
1483 			/* Check if we need to run the state machine for some packet */
1484 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1485 				if (atomic_read(&pkt->run_sm) > 0)
1486 					goto work_to_do;
1487 			}
1488 
1489 			/* Check if we need to process the iosched queues */
1490 			if (atomic_read(&pd->iosched.attention) != 0)
1491 				goto work_to_do;
1492 
1493 			/* Otherwise, go to sleep */
1494 			if (PACKET_DEBUG > 1) {
1495 				int states[PACKET_NUM_STATES];
1496 				pkt_count_states(pd, states);
1497 				pkt_dbg(2, pd, "i:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
1498 					states[0], states[1], states[2],
1499 					states[3], states[4], states[5]);
1500 			}
1501 
1502 			min_sleep_time = MAX_SCHEDULE_TIMEOUT;
1503 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1504 				if (pkt->sleep_time && pkt->sleep_time < min_sleep_time)
1505 					min_sleep_time = pkt->sleep_time;
1506 			}
1507 
1508 			pkt_dbg(2, pd, "sleeping\n");
1509 			residue = schedule_timeout(min_sleep_time);
1510 			pkt_dbg(2, pd, "wake up\n");
1511 
1512 			/* make swsusp happy with our thread */
1513 			try_to_freeze();
1514 
1515 			list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
1516 				if (!pkt->sleep_time)
1517 					continue;
1518 				pkt->sleep_time -= min_sleep_time - residue;
1519 				if (pkt->sleep_time <= 0) {
1520 					pkt->sleep_time = 0;
1521 					atomic_inc(&pkt->run_sm);
1522 				}
1523 			}
1524 
1525 			if (kthread_should_stop())
1526 				break;
1527 		}
1528 work_to_do:
1529 		set_current_state(TASK_RUNNING);
1530 		remove_wait_queue(&pd->wqueue, &wait);
1531 
1532 		if (kthread_should_stop())
1533 			break;
1534 
1535 		/*
1536 		 * if pkt_handle_queue returns true, we can queue
1537 		 * another request.
1538 		 */
1539 		while (pkt_handle_queue(pd))
1540 			;
1541 
1542 		/*
1543 		 * Handle packet state machine
1544 		 */
1545 		pkt_handle_packets(pd);
1546 
1547 		/*
1548 		 * Handle iosched queues
1549 		 */
1550 		pkt_iosched_process_queue(pd);
1551 	}
1552 
1553 	return 0;
1554 }
1555 
1556 static void pkt_print_settings(struct pktcdvd_device *pd)
1557 {
1558 	pkt_info(pd, "%s packets, %u blocks, Mode-%c disc\n",
1559 		 pd->settings.fp ? "Fixed" : "Variable",
1560 		 pd->settings.size >> 2,
1561 		 pd->settings.block_mode == 8 ? '1' : '2');
1562 }
1563 
1564 static int pkt_mode_sense(struct pktcdvd_device *pd, struct packet_command *cgc, int page_code, int page_control)
1565 {
1566 	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1567 
1568 	cgc->cmd[0] = GPCMD_MODE_SENSE_10;
1569 	cgc->cmd[2] = page_code | (page_control << 6);
1570 	cgc->cmd[7] = cgc->buflen >> 8;
1571 	cgc->cmd[8] = cgc->buflen & 0xff;
1572 	cgc->data_direction = CGC_DATA_READ;
1573 	return pkt_generic_packet(pd, cgc);
1574 }
1575 
1576 static int pkt_mode_select(struct pktcdvd_device *pd, struct packet_command *cgc)
1577 {
1578 	memset(cgc->cmd, 0, sizeof(cgc->cmd));
1579 	memset(cgc->buffer, 0, 2);
1580 	cgc->cmd[0] = GPCMD_MODE_SELECT_10;
1581 	cgc->cmd[1] = 0x10;		/* PF */
1582 	cgc->cmd[7] = cgc->buflen >> 8;
1583 	cgc->cmd[8] = cgc->buflen & 0xff;
1584 	cgc->data_direction = CGC_DATA_WRITE;
1585 	return pkt_generic_packet(pd, cgc);
1586 }
1587 
1588 static int pkt_get_disc_info(struct pktcdvd_device *pd, disc_information *di)
1589 {
1590 	struct packet_command cgc;
1591 	int ret;
1592 
1593 	/* set up command and get the disc info */
1594 	init_cdrom_command(&cgc, di, sizeof(*di), CGC_DATA_READ);
1595 	cgc.cmd[0] = GPCMD_READ_DISC_INFO;
1596 	cgc.cmd[8] = cgc.buflen = 2;
1597 	cgc.quiet = 1;
1598 
1599 	if ((ret = pkt_generic_packet(pd, &cgc)))
1600 		return ret;
1601 
1602 	/* not all drives have the same disc_info length, so requeue
1603 	 * packet with the length the drive tells us it can supply
1604 	 */
1605 	cgc.buflen = be16_to_cpu(di->disc_information_length) +
1606 		     sizeof(di->disc_information_length);
1607 
1608 	if (cgc.buflen > sizeof(disc_information))
1609 		cgc.buflen = sizeof(disc_information);
1610 
1611 	cgc.cmd[8] = cgc.buflen;
1612 	return pkt_generic_packet(pd, &cgc);
1613 }
1614 
1615 static int pkt_get_track_info(struct pktcdvd_device *pd, __u16 track, __u8 type, track_information *ti)
1616 {
1617 	struct packet_command cgc;
1618 	int ret;
1619 
1620 	init_cdrom_command(&cgc, ti, 8, CGC_DATA_READ);
1621 	cgc.cmd[0] = GPCMD_READ_TRACK_RZONE_INFO;
1622 	cgc.cmd[1] = type & 3;
1623 	cgc.cmd[4] = (track & 0xff00) >> 8;
1624 	cgc.cmd[5] = track & 0xff;
1625 	cgc.cmd[8] = 8;
1626 	cgc.quiet = 1;
1627 
1628 	if ((ret = pkt_generic_packet(pd, &cgc)))
1629 		return ret;
1630 
1631 	cgc.buflen = be16_to_cpu(ti->track_information_length) +
1632 		     sizeof(ti->track_information_length);
1633 
1634 	if (cgc.buflen > sizeof(track_information))
1635 		cgc.buflen = sizeof(track_information);
1636 
1637 	cgc.cmd[8] = cgc.buflen;
1638 	return pkt_generic_packet(pd, &cgc);
1639 }
1640 
1641 static noinline_for_stack int pkt_get_last_written(struct pktcdvd_device *pd,
1642 						long *last_written)
1643 {
1644 	disc_information di;
1645 	track_information ti;
1646 	__u32 last_track;
1647 	int ret = -1;
1648 
1649 	if ((ret = pkt_get_disc_info(pd, &di)))
1650 		return ret;
1651 
1652 	last_track = (di.last_track_msb << 8) | di.last_track_lsb;
1653 	if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1654 		return ret;
1655 
1656 	/* if this track is blank, try the previous. */
1657 	if (ti.blank) {
1658 		last_track--;
1659 		if ((ret = pkt_get_track_info(pd, last_track, 1, &ti)))
1660 			return ret;
1661 	}
1662 
1663 	/* if last recorded field is valid, return it. */
1664 	if (ti.lra_v) {
1665 		*last_written = be32_to_cpu(ti.last_rec_address);
1666 	} else {
1667 		/* make it up instead */
1668 		*last_written = be32_to_cpu(ti.track_start) +
1669 				be32_to_cpu(ti.track_size);
1670 		if (ti.free_blocks)
1671 			*last_written -= (be32_to_cpu(ti.free_blocks) + 7);
1672 	}
1673 	return 0;
1674 }
1675 
1676 /*
1677  * write mode select package based on pd->settings
1678  */
1679 static noinline_for_stack int pkt_set_write_settings(struct pktcdvd_device *pd)
1680 {
1681 	struct packet_command cgc;
1682 	struct request_sense sense;
1683 	write_param_page *wp;
1684 	char buffer[128];
1685 	int ret, size;
1686 
1687 	/* doesn't apply to DVD+RW or DVD-RAM */
1688 	if ((pd->mmc3_profile == 0x1a) || (pd->mmc3_profile == 0x12))
1689 		return 0;
1690 
1691 	memset(buffer, 0, sizeof(buffer));
1692 	init_cdrom_command(&cgc, buffer, sizeof(*wp), CGC_DATA_READ);
1693 	cgc.sense = &sense;
1694 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1695 		pkt_dump_sense(pd, &cgc);
1696 		return ret;
1697 	}
1698 
1699 	size = 2 + ((buffer[0] << 8) | (buffer[1] & 0xff));
1700 	pd->mode_offset = (buffer[6] << 8) | (buffer[7] & 0xff);
1701 	if (size > sizeof(buffer))
1702 		size = sizeof(buffer);
1703 
1704 	/*
1705 	 * now get it all
1706 	 */
1707 	init_cdrom_command(&cgc, buffer, size, CGC_DATA_READ);
1708 	cgc.sense = &sense;
1709 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WRITE_PARMS_PAGE, 0))) {
1710 		pkt_dump_sense(pd, &cgc);
1711 		return ret;
1712 	}
1713 
1714 	/*
1715 	 * write page is offset header + block descriptor length
1716 	 */
1717 	wp = (write_param_page *) &buffer[sizeof(struct mode_page_header) + pd->mode_offset];
1718 
1719 	wp->fp = pd->settings.fp;
1720 	wp->track_mode = pd->settings.track_mode;
1721 	wp->write_type = pd->settings.write_type;
1722 	wp->data_block_type = pd->settings.block_mode;
1723 
1724 	wp->multi_session = 0;
1725 
1726 #ifdef PACKET_USE_LS
1727 	wp->link_size = 7;
1728 	wp->ls_v = 1;
1729 #endif
1730 
1731 	if (wp->data_block_type == PACKET_BLOCK_MODE1) {
1732 		wp->session_format = 0;
1733 		wp->subhdr2 = 0x20;
1734 	} else if (wp->data_block_type == PACKET_BLOCK_MODE2) {
1735 		wp->session_format = 0x20;
1736 		wp->subhdr2 = 8;
1737 #if 0
1738 		wp->mcn[0] = 0x80;
1739 		memcpy(&wp->mcn[1], PACKET_MCN, sizeof(wp->mcn) - 1);
1740 #endif
1741 	} else {
1742 		/*
1743 		 * paranoia
1744 		 */
1745 		pkt_err(pd, "write mode wrong %d\n", wp->data_block_type);
1746 		return 1;
1747 	}
1748 	wp->packet_size = cpu_to_be32(pd->settings.size >> 2);
1749 
1750 	cgc.buflen = cgc.cmd[8] = size;
1751 	if ((ret = pkt_mode_select(pd, &cgc))) {
1752 		pkt_dump_sense(pd, &cgc);
1753 		return ret;
1754 	}
1755 
1756 	pkt_print_settings(pd);
1757 	return 0;
1758 }
1759 
1760 /*
1761  * 1 -- we can write to this track, 0 -- we can't
1762  */
1763 static int pkt_writable_track(struct pktcdvd_device *pd, track_information *ti)
1764 {
1765 	switch (pd->mmc3_profile) {
1766 		case 0x1a: /* DVD+RW */
1767 		case 0x12: /* DVD-RAM */
1768 			/* The track is always writable on DVD+RW/DVD-RAM */
1769 			return 1;
1770 		default:
1771 			break;
1772 	}
1773 
1774 	if (!ti->packet || !ti->fp)
1775 		return 0;
1776 
1777 	/*
1778 	 * "good" settings as per Mt Fuji.
1779 	 */
1780 	if (ti->rt == 0 && ti->blank == 0)
1781 		return 1;
1782 
1783 	if (ti->rt == 0 && ti->blank == 1)
1784 		return 1;
1785 
1786 	if (ti->rt == 1 && ti->blank == 0)
1787 		return 1;
1788 
1789 	pkt_err(pd, "bad state %d-%d-%d\n", ti->rt, ti->blank, ti->packet);
1790 	return 0;
1791 }
1792 
1793 /*
1794  * 1 -- we can write to this disc, 0 -- we can't
1795  */
1796 static int pkt_writable_disc(struct pktcdvd_device *pd, disc_information *di)
1797 {
1798 	switch (pd->mmc3_profile) {
1799 		case 0x0a: /* CD-RW */
1800 		case 0xffff: /* MMC3 not supported */
1801 			break;
1802 		case 0x1a: /* DVD+RW */
1803 		case 0x13: /* DVD-RW */
1804 		case 0x12: /* DVD-RAM */
1805 			return 1;
1806 		default:
1807 			pkt_dbg(2, pd, "Wrong disc profile (%x)\n",
1808 				pd->mmc3_profile);
1809 			return 0;
1810 	}
1811 
1812 	/*
1813 	 * for disc type 0xff we should probably reserve a new track.
1814 	 * but i'm not sure, should we leave this to user apps? probably.
1815 	 */
1816 	if (di->disc_type == 0xff) {
1817 		pkt_notice(pd, "unknown disc - no track?\n");
1818 		return 0;
1819 	}
1820 
1821 	if (di->disc_type != 0x20 && di->disc_type != 0) {
1822 		pkt_err(pd, "wrong disc type (%x)\n", di->disc_type);
1823 		return 0;
1824 	}
1825 
1826 	if (di->erasable == 0) {
1827 		pkt_notice(pd, "disc not erasable\n");
1828 		return 0;
1829 	}
1830 
1831 	if (di->border_status == PACKET_SESSION_RESERVED) {
1832 		pkt_err(pd, "can't write to last track (reserved)\n");
1833 		return 0;
1834 	}
1835 
1836 	return 1;
1837 }
1838 
1839 static noinline_for_stack int pkt_probe_settings(struct pktcdvd_device *pd)
1840 {
1841 	struct packet_command cgc;
1842 	unsigned char buf[12];
1843 	disc_information di;
1844 	track_information ti;
1845 	int ret, track;
1846 
1847 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1848 	cgc.cmd[0] = GPCMD_GET_CONFIGURATION;
1849 	cgc.cmd[8] = 8;
1850 	ret = pkt_generic_packet(pd, &cgc);
1851 	pd->mmc3_profile = ret ? 0xffff : buf[6] << 8 | buf[7];
1852 
1853 	memset(&di, 0, sizeof(disc_information));
1854 	memset(&ti, 0, sizeof(track_information));
1855 
1856 	if ((ret = pkt_get_disc_info(pd, &di))) {
1857 		pkt_err(pd, "failed get_disc\n");
1858 		return ret;
1859 	}
1860 
1861 	if (!pkt_writable_disc(pd, &di))
1862 		return -EROFS;
1863 
1864 	pd->type = di.erasable ? PACKET_CDRW : PACKET_CDR;
1865 
1866 	track = 1; /* (di.last_track_msb << 8) | di.last_track_lsb; */
1867 	if ((ret = pkt_get_track_info(pd, track, 1, &ti))) {
1868 		pkt_err(pd, "failed get_track\n");
1869 		return ret;
1870 	}
1871 
1872 	if (!pkt_writable_track(pd, &ti)) {
1873 		pkt_err(pd, "can't write to this track\n");
1874 		return -EROFS;
1875 	}
1876 
1877 	/*
1878 	 * we keep packet size in 512 byte units, makes it easier to
1879 	 * deal with request calculations.
1880 	 */
1881 	pd->settings.size = be32_to_cpu(ti.fixed_packet_size) << 2;
1882 	if (pd->settings.size == 0) {
1883 		pkt_notice(pd, "detected zero packet size!\n");
1884 		return -ENXIO;
1885 	}
1886 	if (pd->settings.size > PACKET_MAX_SECTORS) {
1887 		pkt_err(pd, "packet size is too big\n");
1888 		return -EROFS;
1889 	}
1890 	pd->settings.fp = ti.fp;
1891 	pd->offset = (be32_to_cpu(ti.track_start) << 2) & (pd->settings.size - 1);
1892 
1893 	if (ti.nwa_v) {
1894 		pd->nwa = be32_to_cpu(ti.next_writable);
1895 		set_bit(PACKET_NWA_VALID, &pd->flags);
1896 	}
1897 
1898 	/*
1899 	 * in theory we could use lra on -RW media as well and just zero
1900 	 * blocks that haven't been written yet, but in practice that
1901 	 * is just a no-go. we'll use that for -R, naturally.
1902 	 */
1903 	if (ti.lra_v) {
1904 		pd->lra = be32_to_cpu(ti.last_rec_address);
1905 		set_bit(PACKET_LRA_VALID, &pd->flags);
1906 	} else {
1907 		pd->lra = 0xffffffff;
1908 		set_bit(PACKET_LRA_VALID, &pd->flags);
1909 	}
1910 
1911 	/*
1912 	 * fine for now
1913 	 */
1914 	pd->settings.link_loss = 7;
1915 	pd->settings.write_type = 0;	/* packet */
1916 	pd->settings.track_mode = ti.track_mode;
1917 
1918 	/*
1919 	 * mode1 or mode2 disc
1920 	 */
1921 	switch (ti.data_mode) {
1922 		case PACKET_MODE1:
1923 			pd->settings.block_mode = PACKET_BLOCK_MODE1;
1924 			break;
1925 		case PACKET_MODE2:
1926 			pd->settings.block_mode = PACKET_BLOCK_MODE2;
1927 			break;
1928 		default:
1929 			pkt_err(pd, "unknown data mode\n");
1930 			return -EROFS;
1931 	}
1932 	return 0;
1933 }
1934 
1935 /*
1936  * enable/disable write caching on drive
1937  */
1938 static noinline_for_stack int pkt_write_caching(struct pktcdvd_device *pd,
1939 						int set)
1940 {
1941 	struct packet_command cgc;
1942 	struct request_sense sense;
1943 	unsigned char buf[64];
1944 	int ret;
1945 
1946 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_READ);
1947 	cgc.sense = &sense;
1948 	cgc.buflen = pd->mode_offset + 12;
1949 
1950 	/*
1951 	 * caching mode page might not be there, so quiet this command
1952 	 */
1953 	cgc.quiet = 1;
1954 
1955 	if ((ret = pkt_mode_sense(pd, &cgc, GPMODE_WCACHING_PAGE, 0)))
1956 		return ret;
1957 
1958 	buf[pd->mode_offset + 10] |= (!!set << 2);
1959 
1960 	cgc.buflen = cgc.cmd[8] = 2 + ((buf[0] << 8) | (buf[1] & 0xff));
1961 	ret = pkt_mode_select(pd, &cgc);
1962 	if (ret) {
1963 		pkt_err(pd, "write caching control failed\n");
1964 		pkt_dump_sense(pd, &cgc);
1965 	} else if (!ret && set)
1966 		pkt_notice(pd, "enabled write caching\n");
1967 	return ret;
1968 }
1969 
1970 static int pkt_lock_door(struct pktcdvd_device *pd, int lockflag)
1971 {
1972 	struct packet_command cgc;
1973 
1974 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
1975 	cgc.cmd[0] = GPCMD_PREVENT_ALLOW_MEDIUM_REMOVAL;
1976 	cgc.cmd[4] = lockflag ? 1 : 0;
1977 	return pkt_generic_packet(pd, &cgc);
1978 }
1979 
1980 /*
1981  * Returns drive maximum write speed
1982  */
1983 static noinline_for_stack int pkt_get_max_speed(struct pktcdvd_device *pd,
1984 						unsigned *write_speed)
1985 {
1986 	struct packet_command cgc;
1987 	struct request_sense sense;
1988 	unsigned char buf[256+18];
1989 	unsigned char *cap_buf;
1990 	int ret, offset;
1991 
1992 	cap_buf = &buf[sizeof(struct mode_page_header) + pd->mode_offset];
1993 	init_cdrom_command(&cgc, buf, sizeof(buf), CGC_DATA_UNKNOWN);
1994 	cgc.sense = &sense;
1995 
1996 	ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
1997 	if (ret) {
1998 		cgc.buflen = pd->mode_offset + cap_buf[1] + 2 +
1999 			     sizeof(struct mode_page_header);
2000 		ret = pkt_mode_sense(pd, &cgc, GPMODE_CAPABILITIES_PAGE, 0);
2001 		if (ret) {
2002 			pkt_dump_sense(pd, &cgc);
2003 			return ret;
2004 		}
2005 	}
2006 
2007 	offset = 20;			    /* Obsoleted field, used by older drives */
2008 	if (cap_buf[1] >= 28)
2009 		offset = 28;		    /* Current write speed selected */
2010 	if (cap_buf[1] >= 30) {
2011 		/* If the drive reports at least one "Logical Unit Write
2012 		 * Speed Performance Descriptor Block", use the information
2013 		 * in the first block. (contains the highest speed)
2014 		 */
2015 		int num_spdb = (cap_buf[30] << 8) + cap_buf[31];
2016 		if (num_spdb > 0)
2017 			offset = 34;
2018 	}
2019 
2020 	*write_speed = (cap_buf[offset] << 8) | cap_buf[offset + 1];
2021 	return 0;
2022 }
2023 
2024 /* These tables from cdrecord - I don't have orange book */
2025 /* standard speed CD-RW (1-4x) */
2026 static char clv_to_speed[16] = {
2027 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2028 	   0, 2, 4, 6, 8, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2029 };
2030 /* high speed CD-RW (-10x) */
2031 static char hs_clv_to_speed[16] = {
2032 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2033 	   0, 2, 4, 6, 10, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0
2034 };
2035 /* ultra high speed CD-RW */
2036 static char us_clv_to_speed[16] = {
2037 	/* 0  1  2  3  4  5  6  7  8  9 10 11 12 13 14 15 */
2038 	   0, 2, 4, 8, 0, 0,16, 0,24,32,40,48, 0, 0, 0, 0
2039 };
2040 
2041 /*
2042  * reads the maximum media speed from ATIP
2043  */
2044 static noinline_for_stack int pkt_media_speed(struct pktcdvd_device *pd,
2045 						unsigned *speed)
2046 {
2047 	struct packet_command cgc;
2048 	struct request_sense sense;
2049 	unsigned char buf[64];
2050 	unsigned int size, st, sp;
2051 	int ret;
2052 
2053 	init_cdrom_command(&cgc, buf, 2, CGC_DATA_READ);
2054 	cgc.sense = &sense;
2055 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2056 	cgc.cmd[1] = 2;
2057 	cgc.cmd[2] = 4; /* READ ATIP */
2058 	cgc.cmd[8] = 2;
2059 	ret = pkt_generic_packet(pd, &cgc);
2060 	if (ret) {
2061 		pkt_dump_sense(pd, &cgc);
2062 		return ret;
2063 	}
2064 	size = ((unsigned int) buf[0]<<8) + buf[1] + 2;
2065 	if (size > sizeof(buf))
2066 		size = sizeof(buf);
2067 
2068 	init_cdrom_command(&cgc, buf, size, CGC_DATA_READ);
2069 	cgc.sense = &sense;
2070 	cgc.cmd[0] = GPCMD_READ_TOC_PMA_ATIP;
2071 	cgc.cmd[1] = 2;
2072 	cgc.cmd[2] = 4;
2073 	cgc.cmd[8] = size;
2074 	ret = pkt_generic_packet(pd, &cgc);
2075 	if (ret) {
2076 		pkt_dump_sense(pd, &cgc);
2077 		return ret;
2078 	}
2079 
2080 	if (!(buf[6] & 0x40)) {
2081 		pkt_notice(pd, "disc type is not CD-RW\n");
2082 		return 1;
2083 	}
2084 	if (!(buf[6] & 0x4)) {
2085 		pkt_notice(pd, "A1 values on media are not valid, maybe not CDRW?\n");
2086 		return 1;
2087 	}
2088 
2089 	st = (buf[6] >> 3) & 0x7; /* disc sub-type */
2090 
2091 	sp = buf[16] & 0xf; /* max speed from ATIP A1 field */
2092 
2093 	/* Info from cdrecord */
2094 	switch (st) {
2095 		case 0: /* standard speed */
2096 			*speed = clv_to_speed[sp];
2097 			break;
2098 		case 1: /* high speed */
2099 			*speed = hs_clv_to_speed[sp];
2100 			break;
2101 		case 2: /* ultra high speed */
2102 			*speed = us_clv_to_speed[sp];
2103 			break;
2104 		default:
2105 			pkt_notice(pd, "unknown disc sub-type %d\n", st);
2106 			return 1;
2107 	}
2108 	if (*speed) {
2109 		pkt_info(pd, "maximum media speed: %d\n", *speed);
2110 		return 0;
2111 	} else {
2112 		pkt_notice(pd, "unknown speed %d for sub-type %d\n", sp, st);
2113 		return 1;
2114 	}
2115 }
2116 
2117 static noinline_for_stack int pkt_perform_opc(struct pktcdvd_device *pd)
2118 {
2119 	struct packet_command cgc;
2120 	struct request_sense sense;
2121 	int ret;
2122 
2123 	pkt_dbg(2, pd, "Performing OPC\n");
2124 
2125 	init_cdrom_command(&cgc, NULL, 0, CGC_DATA_NONE);
2126 	cgc.sense = &sense;
2127 	cgc.timeout = 60*HZ;
2128 	cgc.cmd[0] = GPCMD_SEND_OPC;
2129 	cgc.cmd[1] = 1;
2130 	if ((ret = pkt_generic_packet(pd, &cgc)))
2131 		pkt_dump_sense(pd, &cgc);
2132 	return ret;
2133 }
2134 
2135 static int pkt_open_write(struct pktcdvd_device *pd)
2136 {
2137 	int ret;
2138 	unsigned int write_speed, media_write_speed, read_speed;
2139 
2140 	if ((ret = pkt_probe_settings(pd))) {
2141 		pkt_dbg(2, pd, "failed probe\n");
2142 		return ret;
2143 	}
2144 
2145 	if ((ret = pkt_set_write_settings(pd))) {
2146 		pkt_dbg(1, pd, "failed saving write settings\n");
2147 		return -EIO;
2148 	}
2149 
2150 	pkt_write_caching(pd, USE_WCACHING);
2151 
2152 	if ((ret = pkt_get_max_speed(pd, &write_speed)))
2153 		write_speed = 16 * 177;
2154 	switch (pd->mmc3_profile) {
2155 		case 0x13: /* DVD-RW */
2156 		case 0x1a: /* DVD+RW */
2157 		case 0x12: /* DVD-RAM */
2158 			pkt_dbg(1, pd, "write speed %ukB/s\n", write_speed);
2159 			break;
2160 		default:
2161 			if ((ret = pkt_media_speed(pd, &media_write_speed)))
2162 				media_write_speed = 16;
2163 			write_speed = min(write_speed, media_write_speed * 177);
2164 			pkt_dbg(1, pd, "write speed %ux\n", write_speed / 176);
2165 			break;
2166 	}
2167 	read_speed = write_speed;
2168 
2169 	if ((ret = pkt_set_speed(pd, write_speed, read_speed))) {
2170 		pkt_dbg(1, pd, "couldn't set write speed\n");
2171 		return -EIO;
2172 	}
2173 	pd->write_speed = write_speed;
2174 	pd->read_speed = read_speed;
2175 
2176 	if ((ret = pkt_perform_opc(pd))) {
2177 		pkt_dbg(1, pd, "Optimum Power Calibration failed\n");
2178 	}
2179 
2180 	return 0;
2181 }
2182 
2183 /*
2184  * called at open time.
2185  */
2186 static int pkt_open_dev(struct pktcdvd_device *pd, fmode_t write)
2187 {
2188 	int ret;
2189 	long lba;
2190 	struct request_queue *q;
2191 
2192 	/*
2193 	 * We need to re-open the cdrom device without O_NONBLOCK to be able
2194 	 * to read/write from/to it. It is already opened in O_NONBLOCK mode
2195 	 * so bdget() can't fail.
2196 	 */
2197 	bdget(pd->bdev->bd_dev);
2198 	if ((ret = blkdev_get(pd->bdev, FMODE_READ | FMODE_EXCL, pd)))
2199 		goto out;
2200 
2201 	if ((ret = pkt_get_last_written(pd, &lba))) {
2202 		pkt_err(pd, "pkt_get_last_written failed\n");
2203 		goto out_putdev;
2204 	}
2205 
2206 	set_capacity(pd->disk, lba << 2);
2207 	set_capacity(pd->bdev->bd_disk, lba << 2);
2208 	bd_set_size(pd->bdev, (loff_t)lba << 11);
2209 
2210 	q = bdev_get_queue(pd->bdev);
2211 	if (write) {
2212 		if ((ret = pkt_open_write(pd)))
2213 			goto out_putdev;
2214 		/*
2215 		 * Some CDRW drives can not handle writes larger than one packet,
2216 		 * even if the size is a multiple of the packet size.
2217 		 */
2218 		spin_lock_irq(q->queue_lock);
2219 		blk_queue_max_hw_sectors(q, pd->settings.size);
2220 		spin_unlock_irq(q->queue_lock);
2221 		set_bit(PACKET_WRITABLE, &pd->flags);
2222 	} else {
2223 		pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2224 		clear_bit(PACKET_WRITABLE, &pd->flags);
2225 	}
2226 
2227 	if ((ret = pkt_set_segment_merging(pd, q)))
2228 		goto out_putdev;
2229 
2230 	if (write) {
2231 		if (!pkt_grow_pktlist(pd, CONFIG_CDROM_PKTCDVD_BUFFERS)) {
2232 			pkt_err(pd, "not enough memory for buffers\n");
2233 			ret = -ENOMEM;
2234 			goto out_putdev;
2235 		}
2236 		pkt_info(pd, "%lukB available on disc\n", lba << 1);
2237 	}
2238 
2239 	return 0;
2240 
2241 out_putdev:
2242 	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2243 out:
2244 	return ret;
2245 }
2246 
2247 /*
2248  * called when the device is closed. makes sure that the device flushes
2249  * the internal cache before we close.
2250  */
2251 static void pkt_release_dev(struct pktcdvd_device *pd, int flush)
2252 {
2253 	if (flush && pkt_flush_cache(pd))
2254 		pkt_dbg(1, pd, "not flushing cache\n");
2255 
2256 	pkt_lock_door(pd, 0);
2257 
2258 	pkt_set_speed(pd, MAX_SPEED, MAX_SPEED);
2259 	blkdev_put(pd->bdev, FMODE_READ | FMODE_EXCL);
2260 
2261 	pkt_shrink_pktlist(pd);
2262 }
2263 
2264 static struct pktcdvd_device *pkt_find_dev_from_minor(unsigned int dev_minor)
2265 {
2266 	if (dev_minor >= MAX_WRITERS)
2267 		return NULL;
2268 	return pkt_devs[dev_minor];
2269 }
2270 
2271 static int pkt_open(struct block_device *bdev, fmode_t mode)
2272 {
2273 	struct pktcdvd_device *pd = NULL;
2274 	int ret;
2275 
2276 	mutex_lock(&pktcdvd_mutex);
2277 	mutex_lock(&ctl_mutex);
2278 	pd = pkt_find_dev_from_minor(MINOR(bdev->bd_dev));
2279 	if (!pd) {
2280 		ret = -ENODEV;
2281 		goto out;
2282 	}
2283 	BUG_ON(pd->refcnt < 0);
2284 
2285 	pd->refcnt++;
2286 	if (pd->refcnt > 1) {
2287 		if ((mode & FMODE_WRITE) &&
2288 		    !test_bit(PACKET_WRITABLE, &pd->flags)) {
2289 			ret = -EBUSY;
2290 			goto out_dec;
2291 		}
2292 	} else {
2293 		ret = pkt_open_dev(pd, mode & FMODE_WRITE);
2294 		if (ret)
2295 			goto out_dec;
2296 		/*
2297 		 * needed here as well, since ext2 (among others) may change
2298 		 * the blocksize at mount time
2299 		 */
2300 		set_blocksize(bdev, CD_FRAMESIZE);
2301 	}
2302 
2303 	mutex_unlock(&ctl_mutex);
2304 	mutex_unlock(&pktcdvd_mutex);
2305 	return 0;
2306 
2307 out_dec:
2308 	pd->refcnt--;
2309 out:
2310 	mutex_unlock(&ctl_mutex);
2311 	mutex_unlock(&pktcdvd_mutex);
2312 	return ret;
2313 }
2314 
2315 static void pkt_close(struct gendisk *disk, fmode_t mode)
2316 {
2317 	struct pktcdvd_device *pd = disk->private_data;
2318 
2319 	mutex_lock(&pktcdvd_mutex);
2320 	mutex_lock(&ctl_mutex);
2321 	pd->refcnt--;
2322 	BUG_ON(pd->refcnt < 0);
2323 	if (pd->refcnt == 0) {
2324 		int flush = test_bit(PACKET_WRITABLE, &pd->flags);
2325 		pkt_release_dev(pd, flush);
2326 	}
2327 	mutex_unlock(&ctl_mutex);
2328 	mutex_unlock(&pktcdvd_mutex);
2329 }
2330 
2331 
2332 static void pkt_end_io_read_cloned(struct bio *bio, int err)
2333 {
2334 	struct packet_stacked_data *psd = bio->bi_private;
2335 	struct pktcdvd_device *pd = psd->pd;
2336 
2337 	bio_put(bio);
2338 	bio_endio(psd->bio, err);
2339 	mempool_free(psd, psd_pool);
2340 	pkt_bio_finished(pd);
2341 }
2342 
2343 static void pkt_make_request_read(struct pktcdvd_device *pd, struct bio *bio)
2344 {
2345 	struct bio *cloned_bio = bio_clone(bio, GFP_NOIO);
2346 	struct packet_stacked_data *psd = mempool_alloc(psd_pool, GFP_NOIO);
2347 
2348 	psd->pd = pd;
2349 	psd->bio = bio;
2350 	cloned_bio->bi_bdev = pd->bdev;
2351 	cloned_bio->bi_private = psd;
2352 	cloned_bio->bi_end_io = pkt_end_io_read_cloned;
2353 	pd->stats.secs_r += bio_sectors(bio);
2354 	pkt_queue_bio(pd, cloned_bio);
2355 }
2356 
2357 static void pkt_make_request_write(struct request_queue *q, struct bio *bio)
2358 {
2359 	struct pktcdvd_device *pd = q->queuedata;
2360 	sector_t zone;
2361 	struct packet_data *pkt;
2362 	int was_empty, blocked_bio;
2363 	struct pkt_rb_node *node;
2364 
2365 	zone = get_zone(bio->bi_iter.bi_sector, pd);
2366 
2367 	/*
2368 	 * If we find a matching packet in state WAITING or READ_WAIT, we can
2369 	 * just append this bio to that packet.
2370 	 */
2371 	spin_lock(&pd->cdrw.active_list_lock);
2372 	blocked_bio = 0;
2373 	list_for_each_entry(pkt, &pd->cdrw.pkt_active_list, list) {
2374 		if (pkt->sector == zone) {
2375 			spin_lock(&pkt->lock);
2376 			if ((pkt->state == PACKET_WAITING_STATE) ||
2377 			    (pkt->state == PACKET_READ_WAIT_STATE)) {
2378 				bio_list_add(&pkt->orig_bios, bio);
2379 				pkt->write_size +=
2380 					bio->bi_iter.bi_size / CD_FRAMESIZE;
2381 				if ((pkt->write_size >= pkt->frames) &&
2382 				    (pkt->state == PACKET_WAITING_STATE)) {
2383 					atomic_inc(&pkt->run_sm);
2384 					wake_up(&pd->wqueue);
2385 				}
2386 				spin_unlock(&pkt->lock);
2387 				spin_unlock(&pd->cdrw.active_list_lock);
2388 				return;
2389 			} else {
2390 				blocked_bio = 1;
2391 			}
2392 			spin_unlock(&pkt->lock);
2393 		}
2394 	}
2395 	spin_unlock(&pd->cdrw.active_list_lock);
2396 
2397  	/*
2398 	 * Test if there is enough room left in the bio work queue
2399 	 * (queue size >= congestion on mark).
2400 	 * If not, wait till the work queue size is below the congestion off mark.
2401 	 */
2402 	spin_lock(&pd->lock);
2403 	if (pd->write_congestion_on > 0
2404 	    && pd->bio_queue_size >= pd->write_congestion_on) {
2405 		set_bdi_congested(&q->backing_dev_info, BLK_RW_ASYNC);
2406 		do {
2407 			spin_unlock(&pd->lock);
2408 			congestion_wait(BLK_RW_ASYNC, HZ);
2409 			spin_lock(&pd->lock);
2410 		} while(pd->bio_queue_size > pd->write_congestion_off);
2411 	}
2412 	spin_unlock(&pd->lock);
2413 
2414 	/*
2415 	 * No matching packet found. Store the bio in the work queue.
2416 	 */
2417 	node = mempool_alloc(pd->rb_pool, GFP_NOIO);
2418 	node->bio = bio;
2419 	spin_lock(&pd->lock);
2420 	BUG_ON(pd->bio_queue_size < 0);
2421 	was_empty = (pd->bio_queue_size == 0);
2422 	pkt_rbtree_insert(pd, node);
2423 	spin_unlock(&pd->lock);
2424 
2425 	/*
2426 	 * Wake up the worker thread.
2427 	 */
2428 	atomic_set(&pd->scan_queue, 1);
2429 	if (was_empty) {
2430 		/* This wake_up is required for correct operation */
2431 		wake_up(&pd->wqueue);
2432 	} else if (!list_empty(&pd->cdrw.pkt_free_list) && !blocked_bio) {
2433 		/*
2434 		 * This wake up is not required for correct operation,
2435 		 * but improves performance in some cases.
2436 		 */
2437 		wake_up(&pd->wqueue);
2438 	}
2439 }
2440 
2441 static void pkt_make_request(struct request_queue *q, struct bio *bio)
2442 {
2443 	struct pktcdvd_device *pd;
2444 	char b[BDEVNAME_SIZE];
2445 	struct bio *split;
2446 
2447 	pd = q->queuedata;
2448 	if (!pd) {
2449 		pr_err("%s incorrect request queue\n",
2450 		       bdevname(bio->bi_bdev, b));
2451 		goto end_io;
2452 	}
2453 
2454 	pkt_dbg(2, pd, "start = %6llx stop = %6llx\n",
2455 		(unsigned long long)bio->bi_iter.bi_sector,
2456 		(unsigned long long)bio_end_sector(bio));
2457 
2458 	/*
2459 	 * Clone READ bios so we can have our own bi_end_io callback.
2460 	 */
2461 	if (bio_data_dir(bio) == READ) {
2462 		pkt_make_request_read(pd, bio);
2463 		return;
2464 	}
2465 
2466 	if (!test_bit(PACKET_WRITABLE, &pd->flags)) {
2467 		pkt_notice(pd, "WRITE for ro device (%llu)\n",
2468 			   (unsigned long long)bio->bi_iter.bi_sector);
2469 		goto end_io;
2470 	}
2471 
2472 	if (!bio->bi_iter.bi_size || (bio->bi_iter.bi_size % CD_FRAMESIZE)) {
2473 		pkt_err(pd, "wrong bio size\n");
2474 		goto end_io;
2475 	}
2476 
2477 	blk_queue_bounce(q, &bio);
2478 
2479 	do {
2480 		sector_t zone = get_zone(bio->bi_iter.bi_sector, pd);
2481 		sector_t last_zone = get_zone(bio_end_sector(bio) - 1, pd);
2482 
2483 		if (last_zone != zone) {
2484 			BUG_ON(last_zone != zone + pd->settings.size);
2485 
2486 			split = bio_split(bio, last_zone -
2487 					  bio->bi_iter.bi_sector,
2488 					  GFP_NOIO, fs_bio_set);
2489 			bio_chain(split, bio);
2490 		} else {
2491 			split = bio;
2492 		}
2493 
2494 		pkt_make_request_write(q, split);
2495 	} while (split != bio);
2496 
2497 	return;
2498 end_io:
2499 	bio_io_error(bio);
2500 }
2501 
2502 
2503 
2504 static int pkt_merge_bvec(struct request_queue *q, struct bvec_merge_data *bmd,
2505 			  struct bio_vec *bvec)
2506 {
2507 	struct pktcdvd_device *pd = q->queuedata;
2508 	sector_t zone = get_zone(bmd->bi_sector, pd);
2509 	int used = ((bmd->bi_sector - zone) << 9) + bmd->bi_size;
2510 	int remaining = (pd->settings.size << 9) - used;
2511 	int remaining2;
2512 
2513 	/*
2514 	 * A bio <= PAGE_SIZE must be allowed. If it crosses a packet
2515 	 * boundary, pkt_make_request() will split the bio.
2516 	 */
2517 	remaining2 = PAGE_SIZE - bmd->bi_size;
2518 	remaining = max(remaining, remaining2);
2519 
2520 	BUG_ON(remaining < 0);
2521 	return remaining;
2522 }
2523 
2524 static void pkt_init_queue(struct pktcdvd_device *pd)
2525 {
2526 	struct request_queue *q = pd->disk->queue;
2527 
2528 	blk_queue_make_request(q, pkt_make_request);
2529 	blk_queue_logical_block_size(q, CD_FRAMESIZE);
2530 	blk_queue_max_hw_sectors(q, PACKET_MAX_SECTORS);
2531 	blk_queue_merge_bvec(q, pkt_merge_bvec);
2532 	q->queuedata = pd;
2533 }
2534 
2535 static int pkt_seq_show(struct seq_file *m, void *p)
2536 {
2537 	struct pktcdvd_device *pd = m->private;
2538 	char *msg;
2539 	char bdev_buf[BDEVNAME_SIZE];
2540 	int states[PACKET_NUM_STATES];
2541 
2542 	seq_printf(m, "Writer %s mapped to %s:\n", pd->name,
2543 		   bdevname(pd->bdev, bdev_buf));
2544 
2545 	seq_printf(m, "\nSettings:\n");
2546 	seq_printf(m, "\tpacket size:\t\t%dkB\n", pd->settings.size / 2);
2547 
2548 	if (pd->settings.write_type == 0)
2549 		msg = "Packet";
2550 	else
2551 		msg = "Unknown";
2552 	seq_printf(m, "\twrite type:\t\t%s\n", msg);
2553 
2554 	seq_printf(m, "\tpacket type:\t\t%s\n", pd->settings.fp ? "Fixed" : "Variable");
2555 	seq_printf(m, "\tlink loss:\t\t%d\n", pd->settings.link_loss);
2556 
2557 	seq_printf(m, "\ttrack mode:\t\t%d\n", pd->settings.track_mode);
2558 
2559 	if (pd->settings.block_mode == PACKET_BLOCK_MODE1)
2560 		msg = "Mode 1";
2561 	else if (pd->settings.block_mode == PACKET_BLOCK_MODE2)
2562 		msg = "Mode 2";
2563 	else
2564 		msg = "Unknown";
2565 	seq_printf(m, "\tblock mode:\t\t%s\n", msg);
2566 
2567 	seq_printf(m, "\nStatistics:\n");
2568 	seq_printf(m, "\tpackets started:\t%lu\n", pd->stats.pkt_started);
2569 	seq_printf(m, "\tpackets ended:\t\t%lu\n", pd->stats.pkt_ended);
2570 	seq_printf(m, "\twritten:\t\t%lukB\n", pd->stats.secs_w >> 1);
2571 	seq_printf(m, "\tread gather:\t\t%lukB\n", pd->stats.secs_rg >> 1);
2572 	seq_printf(m, "\tread:\t\t\t%lukB\n", pd->stats.secs_r >> 1);
2573 
2574 	seq_printf(m, "\nMisc:\n");
2575 	seq_printf(m, "\treference count:\t%d\n", pd->refcnt);
2576 	seq_printf(m, "\tflags:\t\t\t0x%lx\n", pd->flags);
2577 	seq_printf(m, "\tread speed:\t\t%ukB/s\n", pd->read_speed);
2578 	seq_printf(m, "\twrite speed:\t\t%ukB/s\n", pd->write_speed);
2579 	seq_printf(m, "\tstart offset:\t\t%lu\n", pd->offset);
2580 	seq_printf(m, "\tmode page offset:\t%u\n", pd->mode_offset);
2581 
2582 	seq_printf(m, "\nQueue state:\n");
2583 	seq_printf(m, "\tbios queued:\t\t%d\n", pd->bio_queue_size);
2584 	seq_printf(m, "\tbios pending:\t\t%d\n", atomic_read(&pd->cdrw.pending_bios));
2585 	seq_printf(m, "\tcurrent sector:\t\t0x%llx\n", (unsigned long long)pd->current_sector);
2586 
2587 	pkt_count_states(pd, states);
2588 	seq_printf(m, "\tstate:\t\t\ti:%d ow:%d rw:%d ww:%d rec:%d fin:%d\n",
2589 		   states[0], states[1], states[2], states[3], states[4], states[5]);
2590 
2591 	seq_printf(m, "\twrite congestion marks:\toff=%d on=%d\n",
2592 			pd->write_congestion_off,
2593 			pd->write_congestion_on);
2594 	return 0;
2595 }
2596 
2597 static int pkt_seq_open(struct inode *inode, struct file *file)
2598 {
2599 	return single_open(file, pkt_seq_show, PDE_DATA(inode));
2600 }
2601 
2602 static const struct file_operations pkt_proc_fops = {
2603 	.open	= pkt_seq_open,
2604 	.read	= seq_read,
2605 	.llseek	= seq_lseek,
2606 	.release = single_release
2607 };
2608 
2609 static int pkt_new_dev(struct pktcdvd_device *pd, dev_t dev)
2610 {
2611 	int i;
2612 	int ret = 0;
2613 	char b[BDEVNAME_SIZE];
2614 	struct block_device *bdev;
2615 
2616 	if (pd->pkt_dev == dev) {
2617 		pkt_err(pd, "recursive setup not allowed\n");
2618 		return -EBUSY;
2619 	}
2620 	for (i = 0; i < MAX_WRITERS; i++) {
2621 		struct pktcdvd_device *pd2 = pkt_devs[i];
2622 		if (!pd2)
2623 			continue;
2624 		if (pd2->bdev->bd_dev == dev) {
2625 			pkt_err(pd, "%s already setup\n",
2626 				bdevname(pd2->bdev, b));
2627 			return -EBUSY;
2628 		}
2629 		if (pd2->pkt_dev == dev) {
2630 			pkt_err(pd, "can't chain pktcdvd devices\n");
2631 			return -EBUSY;
2632 		}
2633 	}
2634 
2635 	bdev = bdget(dev);
2636 	if (!bdev)
2637 		return -ENOMEM;
2638 	ret = blkdev_get(bdev, FMODE_READ | FMODE_NDELAY, NULL);
2639 	if (ret)
2640 		return ret;
2641 
2642 	/* This is safe, since we have a reference from open(). */
2643 	__module_get(THIS_MODULE);
2644 
2645 	pd->bdev = bdev;
2646 	set_blocksize(bdev, CD_FRAMESIZE);
2647 
2648 	pkt_init_queue(pd);
2649 
2650 	atomic_set(&pd->cdrw.pending_bios, 0);
2651 	pd->cdrw.thread = kthread_run(kcdrwd, pd, "%s", pd->name);
2652 	if (IS_ERR(pd->cdrw.thread)) {
2653 		pkt_err(pd, "can't start kernel thread\n");
2654 		ret = -ENOMEM;
2655 		goto out_mem;
2656 	}
2657 
2658 	proc_create_data(pd->name, 0, pkt_proc, &pkt_proc_fops, pd);
2659 	pkt_dbg(1, pd, "writer mapped to %s\n", bdevname(bdev, b));
2660 	return 0;
2661 
2662 out_mem:
2663 	blkdev_put(bdev, FMODE_READ | FMODE_NDELAY);
2664 	/* This is safe: open() is still holding a reference. */
2665 	module_put(THIS_MODULE);
2666 	return ret;
2667 }
2668 
2669 static int pkt_ioctl(struct block_device *bdev, fmode_t mode, unsigned int cmd, unsigned long arg)
2670 {
2671 	struct pktcdvd_device *pd = bdev->bd_disk->private_data;
2672 	int ret;
2673 
2674 	pkt_dbg(2, pd, "cmd %x, dev %d:%d\n",
2675 		cmd, MAJOR(bdev->bd_dev), MINOR(bdev->bd_dev));
2676 
2677 	mutex_lock(&pktcdvd_mutex);
2678 	switch (cmd) {
2679 	case CDROMEJECT:
2680 		/*
2681 		 * The door gets locked when the device is opened, so we
2682 		 * have to unlock it or else the eject command fails.
2683 		 */
2684 		if (pd->refcnt == 1)
2685 			pkt_lock_door(pd, 0);
2686 		/* fallthru */
2687 	/*
2688 	 * forward selected CDROM ioctls to CD-ROM, for UDF
2689 	 */
2690 	case CDROMMULTISESSION:
2691 	case CDROMREADTOCENTRY:
2692 	case CDROM_LAST_WRITTEN:
2693 	case CDROM_SEND_PACKET:
2694 	case SCSI_IOCTL_SEND_COMMAND:
2695 		ret = __blkdev_driver_ioctl(pd->bdev, mode, cmd, arg);
2696 		break;
2697 
2698 	default:
2699 		pkt_dbg(2, pd, "Unknown ioctl (%x)\n", cmd);
2700 		ret = -ENOTTY;
2701 	}
2702 	mutex_unlock(&pktcdvd_mutex);
2703 
2704 	return ret;
2705 }
2706 
2707 static unsigned int pkt_check_events(struct gendisk *disk,
2708 				     unsigned int clearing)
2709 {
2710 	struct pktcdvd_device *pd = disk->private_data;
2711 	struct gendisk *attached_disk;
2712 
2713 	if (!pd)
2714 		return 0;
2715 	if (!pd->bdev)
2716 		return 0;
2717 	attached_disk = pd->bdev->bd_disk;
2718 	if (!attached_disk || !attached_disk->fops->check_events)
2719 		return 0;
2720 	return attached_disk->fops->check_events(attached_disk, clearing);
2721 }
2722 
2723 static const struct block_device_operations pktcdvd_ops = {
2724 	.owner =		THIS_MODULE,
2725 	.open =			pkt_open,
2726 	.release =		pkt_close,
2727 	.ioctl =		pkt_ioctl,
2728 	.check_events =		pkt_check_events,
2729 };
2730 
2731 static char *pktcdvd_devnode(struct gendisk *gd, umode_t *mode)
2732 {
2733 	return kasprintf(GFP_KERNEL, "pktcdvd/%s", gd->disk_name);
2734 }
2735 
2736 /*
2737  * Set up mapping from pktcdvd device to CD-ROM device.
2738  */
2739 static int pkt_setup_dev(dev_t dev, dev_t* pkt_dev)
2740 {
2741 	int idx;
2742 	int ret = -ENOMEM;
2743 	struct pktcdvd_device *pd;
2744 	struct gendisk *disk;
2745 
2746 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2747 
2748 	for (idx = 0; idx < MAX_WRITERS; idx++)
2749 		if (!pkt_devs[idx])
2750 			break;
2751 	if (idx == MAX_WRITERS) {
2752 		pr_err("max %d writers supported\n", MAX_WRITERS);
2753 		ret = -EBUSY;
2754 		goto out_mutex;
2755 	}
2756 
2757 	pd = kzalloc(sizeof(struct pktcdvd_device), GFP_KERNEL);
2758 	if (!pd)
2759 		goto out_mutex;
2760 
2761 	pd->rb_pool = mempool_create_kmalloc_pool(PKT_RB_POOL_SIZE,
2762 						  sizeof(struct pkt_rb_node));
2763 	if (!pd->rb_pool)
2764 		goto out_mem;
2765 
2766 	INIT_LIST_HEAD(&pd->cdrw.pkt_free_list);
2767 	INIT_LIST_HEAD(&pd->cdrw.pkt_active_list);
2768 	spin_lock_init(&pd->cdrw.active_list_lock);
2769 
2770 	spin_lock_init(&pd->lock);
2771 	spin_lock_init(&pd->iosched.lock);
2772 	bio_list_init(&pd->iosched.read_queue);
2773 	bio_list_init(&pd->iosched.write_queue);
2774 	sprintf(pd->name, DRIVER_NAME"%d", idx);
2775 	init_waitqueue_head(&pd->wqueue);
2776 	pd->bio_queue = RB_ROOT;
2777 
2778 	pd->write_congestion_on  = write_congestion_on;
2779 	pd->write_congestion_off = write_congestion_off;
2780 
2781 	disk = alloc_disk(1);
2782 	if (!disk)
2783 		goto out_mem;
2784 	pd->disk = disk;
2785 	disk->major = pktdev_major;
2786 	disk->first_minor = idx;
2787 	disk->fops = &pktcdvd_ops;
2788 	disk->flags = GENHD_FL_REMOVABLE;
2789 	strcpy(disk->disk_name, pd->name);
2790 	disk->devnode = pktcdvd_devnode;
2791 	disk->private_data = pd;
2792 	disk->queue = blk_alloc_queue(GFP_KERNEL);
2793 	if (!disk->queue)
2794 		goto out_mem2;
2795 
2796 	pd->pkt_dev = MKDEV(pktdev_major, idx);
2797 	ret = pkt_new_dev(pd, dev);
2798 	if (ret)
2799 		goto out_new_dev;
2800 
2801 	/* inherit events of the host device */
2802 	disk->events = pd->bdev->bd_disk->events;
2803 	disk->async_events = pd->bdev->bd_disk->async_events;
2804 
2805 	add_disk(disk);
2806 
2807 	pkt_sysfs_dev_new(pd);
2808 	pkt_debugfs_dev_new(pd);
2809 
2810 	pkt_devs[idx] = pd;
2811 	if (pkt_dev)
2812 		*pkt_dev = pd->pkt_dev;
2813 
2814 	mutex_unlock(&ctl_mutex);
2815 	return 0;
2816 
2817 out_new_dev:
2818 	blk_cleanup_queue(disk->queue);
2819 out_mem2:
2820 	put_disk(disk);
2821 out_mem:
2822 	if (pd->rb_pool)
2823 		mempool_destroy(pd->rb_pool);
2824 	kfree(pd);
2825 out_mutex:
2826 	mutex_unlock(&ctl_mutex);
2827 	pr_err("setup of pktcdvd device failed\n");
2828 	return ret;
2829 }
2830 
2831 /*
2832  * Tear down mapping from pktcdvd device to CD-ROM device.
2833  */
2834 static int pkt_remove_dev(dev_t pkt_dev)
2835 {
2836 	struct pktcdvd_device *pd;
2837 	int idx;
2838 	int ret = 0;
2839 
2840 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2841 
2842 	for (idx = 0; idx < MAX_WRITERS; idx++) {
2843 		pd = pkt_devs[idx];
2844 		if (pd && (pd->pkt_dev == pkt_dev))
2845 			break;
2846 	}
2847 	if (idx == MAX_WRITERS) {
2848 		pr_debug("dev not setup\n");
2849 		ret = -ENXIO;
2850 		goto out;
2851 	}
2852 
2853 	if (pd->refcnt > 0) {
2854 		ret = -EBUSY;
2855 		goto out;
2856 	}
2857 	if (!IS_ERR(pd->cdrw.thread))
2858 		kthread_stop(pd->cdrw.thread);
2859 
2860 	pkt_devs[idx] = NULL;
2861 
2862 	pkt_debugfs_dev_remove(pd);
2863 	pkt_sysfs_dev_remove(pd);
2864 
2865 	blkdev_put(pd->bdev, FMODE_READ | FMODE_NDELAY);
2866 
2867 	remove_proc_entry(pd->name, pkt_proc);
2868 	pkt_dbg(1, pd, "writer unmapped\n");
2869 
2870 	del_gendisk(pd->disk);
2871 	blk_cleanup_queue(pd->disk->queue);
2872 	put_disk(pd->disk);
2873 
2874 	mempool_destroy(pd->rb_pool);
2875 	kfree(pd);
2876 
2877 	/* This is safe: open() is still holding a reference. */
2878 	module_put(THIS_MODULE);
2879 
2880 out:
2881 	mutex_unlock(&ctl_mutex);
2882 	return ret;
2883 }
2884 
2885 static void pkt_get_status(struct pkt_ctrl_command *ctrl_cmd)
2886 {
2887 	struct pktcdvd_device *pd;
2888 
2889 	mutex_lock_nested(&ctl_mutex, SINGLE_DEPTH_NESTING);
2890 
2891 	pd = pkt_find_dev_from_minor(ctrl_cmd->dev_index);
2892 	if (pd) {
2893 		ctrl_cmd->dev = new_encode_dev(pd->bdev->bd_dev);
2894 		ctrl_cmd->pkt_dev = new_encode_dev(pd->pkt_dev);
2895 	} else {
2896 		ctrl_cmd->dev = 0;
2897 		ctrl_cmd->pkt_dev = 0;
2898 	}
2899 	ctrl_cmd->num_devices = MAX_WRITERS;
2900 
2901 	mutex_unlock(&ctl_mutex);
2902 }
2903 
2904 static long pkt_ctl_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2905 {
2906 	void __user *argp = (void __user *)arg;
2907 	struct pkt_ctrl_command ctrl_cmd;
2908 	int ret = 0;
2909 	dev_t pkt_dev = 0;
2910 
2911 	if (cmd != PACKET_CTRL_CMD)
2912 		return -ENOTTY;
2913 
2914 	if (copy_from_user(&ctrl_cmd, argp, sizeof(struct pkt_ctrl_command)))
2915 		return -EFAULT;
2916 
2917 	switch (ctrl_cmd.command) {
2918 	case PKT_CTRL_CMD_SETUP:
2919 		if (!capable(CAP_SYS_ADMIN))
2920 			return -EPERM;
2921 		ret = pkt_setup_dev(new_decode_dev(ctrl_cmd.dev), &pkt_dev);
2922 		ctrl_cmd.pkt_dev = new_encode_dev(pkt_dev);
2923 		break;
2924 	case PKT_CTRL_CMD_TEARDOWN:
2925 		if (!capable(CAP_SYS_ADMIN))
2926 			return -EPERM;
2927 		ret = pkt_remove_dev(new_decode_dev(ctrl_cmd.pkt_dev));
2928 		break;
2929 	case PKT_CTRL_CMD_STATUS:
2930 		pkt_get_status(&ctrl_cmd);
2931 		break;
2932 	default:
2933 		return -ENOTTY;
2934 	}
2935 
2936 	if (copy_to_user(argp, &ctrl_cmd, sizeof(struct pkt_ctrl_command)))
2937 		return -EFAULT;
2938 	return ret;
2939 }
2940 
2941 #ifdef CONFIG_COMPAT
2942 static long pkt_ctl_compat_ioctl(struct file *file, unsigned int cmd, unsigned long arg)
2943 {
2944 	return pkt_ctl_ioctl(file, cmd, (unsigned long)compat_ptr(arg));
2945 }
2946 #endif
2947 
2948 static const struct file_operations pkt_ctl_fops = {
2949 	.open		= nonseekable_open,
2950 	.unlocked_ioctl	= pkt_ctl_ioctl,
2951 #ifdef CONFIG_COMPAT
2952 	.compat_ioctl	= pkt_ctl_compat_ioctl,
2953 #endif
2954 	.owner		= THIS_MODULE,
2955 	.llseek		= no_llseek,
2956 };
2957 
2958 static struct miscdevice pkt_misc = {
2959 	.minor 		= MISC_DYNAMIC_MINOR,
2960 	.name  		= DRIVER_NAME,
2961 	.nodename	= "pktcdvd/control",
2962 	.fops  		= &pkt_ctl_fops
2963 };
2964 
2965 static int __init pkt_init(void)
2966 {
2967 	int ret;
2968 
2969 	mutex_init(&ctl_mutex);
2970 
2971 	psd_pool = mempool_create_kmalloc_pool(PSD_POOL_SIZE,
2972 					sizeof(struct packet_stacked_data));
2973 	if (!psd_pool)
2974 		return -ENOMEM;
2975 
2976 	ret = register_blkdev(pktdev_major, DRIVER_NAME);
2977 	if (ret < 0) {
2978 		pr_err("unable to register block device\n");
2979 		goto out2;
2980 	}
2981 	if (!pktdev_major)
2982 		pktdev_major = ret;
2983 
2984 	ret = pkt_sysfs_init();
2985 	if (ret)
2986 		goto out;
2987 
2988 	pkt_debugfs_init();
2989 
2990 	ret = misc_register(&pkt_misc);
2991 	if (ret) {
2992 		pr_err("unable to register misc device\n");
2993 		goto out_misc;
2994 	}
2995 
2996 	pkt_proc = proc_mkdir("driver/"DRIVER_NAME, NULL);
2997 
2998 	return 0;
2999 
3000 out_misc:
3001 	pkt_debugfs_cleanup();
3002 	pkt_sysfs_cleanup();
3003 out:
3004 	unregister_blkdev(pktdev_major, DRIVER_NAME);
3005 out2:
3006 	mempool_destroy(psd_pool);
3007 	return ret;
3008 }
3009 
3010 static void __exit pkt_exit(void)
3011 {
3012 	remove_proc_entry("driver/"DRIVER_NAME, NULL);
3013 	misc_deregister(&pkt_misc);
3014 
3015 	pkt_debugfs_cleanup();
3016 	pkt_sysfs_cleanup();
3017 
3018 	unregister_blkdev(pktdev_major, DRIVER_NAME);
3019 	mempool_destroy(psd_pool);
3020 }
3021 
3022 MODULE_DESCRIPTION("Packet writing layer for CD/DVD drives");
3023 MODULE_AUTHOR("Jens Axboe <axboe@suse.de>");
3024 MODULE_LICENSE("GPL");
3025 
3026 module_init(pkt_init);
3027 module_exit(pkt_exit);
3028