1/*
2 *  gendisk handling
3 */
4
5#include <linux/module.h>
6#include <linux/fs.h>
7#include <linux/genhd.h>
8#include <linux/kdev_t.h>
9#include <linux/kernel.h>
10#include <linux/blkdev.h>
11#include <linux/init.h>
12#include <linux/spinlock.h>
13#include <linux/seq_file.h>
14#include <linux/slab.h>
15#include <linux/kmod.h>
16#include <linux/kobj_map.h>
17#include <linux/buffer_head.h>
18#include <linux/mutex.h>
19
20struct kset block_subsys;
21static DEFINE_MUTEX(block_subsys_lock);
22
23/*
24 * Can be deleted altogether. Later.
25 *
26 */
27static struct blk_major_name {
28	struct blk_major_name *next;
29	int major;
30	char name[16];
31} *major_names[BLKDEV_MAJOR_HASH_SIZE];
32
33/* index in the above - for now: assume no multimajor ranges */
34static inline int major_to_index(int major)
35{
36	return major % BLKDEV_MAJOR_HASH_SIZE;
37}
38
39#ifdef CONFIG_PROC_FS
40
41void blkdev_show(struct seq_file *f, off_t offset)
42{
43	struct blk_major_name *dp;
44
45	if (offset < BLKDEV_MAJOR_HASH_SIZE) {
46		mutex_lock(&block_subsys_lock);
47		for (dp = major_names[offset]; dp; dp = dp->next)
48			seq_printf(f, "%3d %s\n", dp->major, dp->name);
49		mutex_unlock(&block_subsys_lock);
50	}
51}
52
53#endif /* CONFIG_PROC_FS */
54
55int register_blkdev(unsigned int major, const char *name)
56{
57	struct blk_major_name **n, *p;
58	int index, ret = 0;
59
60	mutex_lock(&block_subsys_lock);
61
62	/* temporary */
63	if (major == 0) {
64		for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
65			if (major_names[index] == NULL)
66				break;
67		}
68
69		if (index == 0) {
70			printk("register_blkdev: failed to get major for %s\n",
71			       name);
72			ret = -EBUSY;
73			goto out;
74		}
75		major = index;
76		ret = major;
77	}
78
79	p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
80	if (p == NULL) {
81		ret = -ENOMEM;
82		goto out;
83	}
84
85	p->major = major;
86	strlcpy(p->name, name, sizeof(p->name));
87	p->next = NULL;
88	index = major_to_index(major);
89
90	for (n = &major_names[index]; *n; n = &(*n)->next) {
91		if ((*n)->major == major)
92			break;
93	}
94	if (!*n)
95		*n = p;
96	else
97		ret = -EBUSY;
98
99	if (ret < 0) {
100		printk("register_blkdev: cannot get major %d for %s\n",
101		       major, name);
102		kfree(p);
103	}
104out:
105	mutex_unlock(&block_subsys_lock);
106	return ret;
107}
108
109EXPORT_SYMBOL(register_blkdev);
110
111/* todo: make void - error printk here */
112int unregister_blkdev(unsigned int major, const char *name)
113{
114	struct blk_major_name **n;
115	struct blk_major_name *p = NULL;
116	int index = major_to_index(major);
117	int ret = 0;
118
119	mutex_lock(&block_subsys_lock);
120	for (n = &major_names[index]; *n; n = &(*n)->next)
121		if ((*n)->major == major)
122			break;
123	if (!*n || strcmp((*n)->name, name))
124		ret = -EINVAL;
125	else {
126		p = *n;
127		*n = p->next;
128	}
129	mutex_unlock(&block_subsys_lock);
130	kfree(p);
131
132	return ret;
133}
134
135EXPORT_SYMBOL(unregister_blkdev);
136
137static struct kobj_map *bdev_map;
138
139/*
140 * Register device numbers dev..(dev+range-1)
141 * range must be nonzero
142 * The hash chain is sorted on range, so that subranges can override.
143 */
144void blk_register_region(dev_t dev, unsigned long range, struct module *module,
145			 struct kobject *(*probe)(dev_t, int *, void *),
146			 int (*lock)(dev_t, void *), void *data)
147{
148	kobj_map(bdev_map, dev, range, module, probe, lock, data);
149}
150
151EXPORT_SYMBOL(blk_register_region);
152
153void blk_unregister_region(dev_t dev, unsigned long range)
154{
155	kobj_unmap(bdev_map, dev, range);
156}
157
158EXPORT_SYMBOL(blk_unregister_region);
159
160static struct kobject *exact_match(dev_t dev, int *part, void *data)
161{
162	struct gendisk *p = data;
163	return &p->kobj;
164}
165
166static int exact_lock(dev_t dev, void *data)
167{
168	struct gendisk *p = data;
169
170	if (!get_disk(p))
171		return -1;
172	return 0;
173}
174
175/**
176 * add_disk - add partitioning information to kernel list
177 * @disk: per-device partitioning information
178 *
179 * This function registers the partitioning information in @disk
180 * with the kernel.
181 */
182void add_disk(struct gendisk *disk)
183{
184	disk->flags |= GENHD_FL_UP;
185	blk_register_region(MKDEV(disk->major, disk->first_minor),
186			    disk->minors, NULL, exact_match, exact_lock, disk);
187	register_disk(disk);
188	blk_register_queue(disk);
189}
190
191EXPORT_SYMBOL(add_disk);
192EXPORT_SYMBOL(del_gendisk);	/* in partitions/check.c */
193
194void unlink_gendisk(struct gendisk *disk)
195{
196	blk_unregister_queue(disk);
197	blk_unregister_region(MKDEV(disk->major, disk->first_minor),
198			      disk->minors);
199}
200
201#define to_disk(obj) container_of(obj,struct gendisk,kobj)
202
203/**
204 * get_gendisk - get partitioning information for a given device
205 * @dev: device to get partitioning information for
206 *
207 * This function gets the structure containing partitioning
208 * information for the given device @dev.
209 */
210struct gendisk *get_gendisk(dev_t dev, int *part)
211{
212	struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
213	return  kobj ? to_disk(kobj) : NULL;
214}
215
216/*
217 * print a full list of all partitions - intended for places where the root
218 * filesystem can't be mounted and thus to give the victim some idea of what
219 * went wrong
220 */
221void __init printk_all_partitions(void)
222{
223	int n;
224	struct gendisk *sgp;
225
226	mutex_lock(&block_subsys_lock);
227	/* For each block device... */
228	list_for_each_entry(sgp, &block_subsys.list, kobj.entry) {
229		char buf[BDEVNAME_SIZE];
230		/*
231		 * Don't show empty devices or things that have been surpressed
232		 */
233		if (get_capacity(sgp) == 0 ||
234		    (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
235			continue;
236
237		/*
238		 * Note, unlike /proc/partitions, I am showing the numbers in
239		 * hex - the same format as the root= option takes.
240		 */
241		printk("%02x%02x %10llu %s",
242			sgp->major, sgp->first_minor,
243			(unsigned long long)get_capacity(sgp) >> 1,
244			disk_name(sgp, 0, buf));
245		if (sgp->driverfs_dev != NULL &&
246		    sgp->driverfs_dev->driver != NULL)
247			printk(" driver: %s\n",
248				sgp->driverfs_dev->driver->name);
249		else
250			printk(" (driver?)\n");
251
252		/* now show the partitions */
253		for (n = 0; n < sgp->minors - 1; ++n) {
254			if (sgp->part[n] == NULL)
255				continue;
256			if (sgp->part[n]->nr_sects == 0)
257				continue;
258			printk("  %02x%02x %10llu %s\n",
259				sgp->major, n + 1 + sgp->first_minor,
260				(unsigned long long)sgp->part[n]->nr_sects >> 1,
261				disk_name(sgp, n + 1, buf));
262		} /* partition subloop */
263	} /* Block device loop */
264
265	mutex_unlock(&block_subsys_lock);
266	return;
267}
268
269#ifdef CONFIG_PROC_FS
270/* iterator */
271static void *part_start(struct seq_file *part, loff_t *pos)
272{
273	struct list_head *p;
274	loff_t l = *pos;
275
276	mutex_lock(&block_subsys_lock);
277	list_for_each(p, &block_subsys.list)
278		if (!l--)
279			return list_entry(p, struct gendisk, kobj.entry);
280	return NULL;
281}
282
283static void *part_next(struct seq_file *part, void *v, loff_t *pos)
284{
285	struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
286	++*pos;
287	return p==&block_subsys.list ? NULL :
288		list_entry(p, struct gendisk, kobj.entry);
289}
290
291static void part_stop(struct seq_file *part, void *v)
292{
293	mutex_unlock(&block_subsys_lock);
294}
295
296static int show_partition(struct seq_file *part, void *v)
297{
298	struct gendisk *sgp = v;
299	int n;
300	char buf[BDEVNAME_SIZE];
301
302	if (&sgp->kobj.entry == block_subsys.list.next)
303		seq_puts(part, "major minor  #blocks  name\n\n");
304
305	/* Don't show non-partitionable removeable devices or empty devices */
306	if (!get_capacity(sgp) ||
307			(sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
308		return 0;
309	if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
310		return 0;
311
312	/* show the full disk and all non-0 size partitions of it */
313	seq_printf(part, "%4d  %4d %10llu %s\n",
314		sgp->major, sgp->first_minor,
315		(unsigned long long)get_capacity(sgp) >> 1,
316		disk_name(sgp, 0, buf));
317	for (n = 0; n < sgp->minors - 1; n++) {
318		if (!sgp->part[n])
319			continue;
320		if (sgp->part[n]->nr_sects == 0)
321			continue;
322		seq_printf(part, "%4d  %4d %10llu %s\n",
323			sgp->major, n + 1 + sgp->first_minor,
324			(unsigned long long)sgp->part[n]->nr_sects >> 1 ,
325			disk_name(sgp, n + 1, buf));
326	}
327
328	return 0;
329}
330
331struct seq_operations partitions_op = {
332	.start =part_start,
333	.next =	part_next,
334	.stop =	part_stop,
335	.show =	show_partition
336};
337#endif
338
339
340extern int blk_dev_init(void);
341
342static struct kobject *base_probe(dev_t dev, int *part, void *data)
343{
344	if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
345		/* Make old-style 2.4 aliases work */
346		request_module("block-major-%d", MAJOR(dev));
347	return NULL;
348}
349
350static int __init genhd_device_init(void)
351{
352	int err;
353
354	bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
355	blk_dev_init();
356	err = subsystem_register(&block_subsys);
357	if (err < 0)
358		printk(KERN_WARNING "%s: subsystem_register error: %d\n",
359			__FUNCTION__, err);
360	return err;
361}
362
363subsys_initcall(genhd_device_init);
364
365
366
367/*
368 * kobject & sysfs bindings for block devices
369 */
370static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
371			      char *page)
372{
373	struct gendisk *disk = to_disk(kobj);
374	struct disk_attribute *disk_attr =
375		container_of(attr,struct disk_attribute,attr);
376	ssize_t ret = -EIO;
377
378	if (disk_attr->show)
379		ret = disk_attr->show(disk,page);
380	return ret;
381}
382
383static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
384			       const char *page, size_t count)
385{
386	struct gendisk *disk = to_disk(kobj);
387	struct disk_attribute *disk_attr =
388		container_of(attr,struct disk_attribute,attr);
389	ssize_t ret = 0;
390
391	if (disk_attr->store)
392		ret = disk_attr->store(disk, page, count);
393	return ret;
394}
395
396static struct sysfs_ops disk_sysfs_ops = {
397	.show	= &disk_attr_show,
398	.store	= &disk_attr_store,
399};
400
401static ssize_t disk_uevent_store(struct gendisk * disk,
402				 const char *buf, size_t count)
403{
404	kobject_uevent(&disk->kobj, KOBJ_ADD);
405	return count;
406}
407static ssize_t disk_dev_read(struct gendisk * disk, char *page)
408{
409	dev_t base = MKDEV(disk->major, disk->first_minor);
410	return print_dev_t(page, base);
411}
412static ssize_t disk_range_read(struct gendisk * disk, char *page)
413{
414	return sprintf(page, "%d\n", disk->minors);
415}
416static ssize_t disk_removable_read(struct gendisk * disk, char *page)
417{
418	return sprintf(page, "%d\n",
419		       (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
420
421}
422static ssize_t disk_size_read(struct gendisk * disk, char *page)
423{
424	return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
425}
426static ssize_t disk_capability_read(struct gendisk *disk, char *page)
427{
428	return sprintf(page, "%x\n", disk->flags);
429}
430static ssize_t disk_stats_read(struct gendisk * disk, char *page)
431{
432	preempt_disable();
433	disk_round_stats(disk);
434	preempt_enable();
435	return sprintf(page,
436		"%8lu %8lu %8llu %8u "
437		"%8lu %8lu %8llu %8u "
438		"%8u %8u %8u"
439		"\n",
440		disk_stat_read(disk, ios[READ]),
441		disk_stat_read(disk, merges[READ]),
442		(unsigned long long)disk_stat_read(disk, sectors[READ]),
443		jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
444		disk_stat_read(disk, ios[WRITE]),
445		disk_stat_read(disk, merges[WRITE]),
446		(unsigned long long)disk_stat_read(disk, sectors[WRITE]),
447		jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
448		disk->in_flight,
449		jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
450		jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
451}
452static struct disk_attribute disk_attr_uevent = {
453	.attr = {.name = "uevent", .mode = S_IWUSR },
454	.store	= disk_uevent_store
455};
456static struct disk_attribute disk_attr_dev = {
457	.attr = {.name = "dev", .mode = S_IRUGO },
458	.show	= disk_dev_read
459};
460static struct disk_attribute disk_attr_range = {
461	.attr = {.name = "range", .mode = S_IRUGO },
462	.show	= disk_range_read
463};
464static struct disk_attribute disk_attr_removable = {
465	.attr = {.name = "removable", .mode = S_IRUGO },
466	.show	= disk_removable_read
467};
468static struct disk_attribute disk_attr_size = {
469	.attr = {.name = "size", .mode = S_IRUGO },
470	.show	= disk_size_read
471};
472static struct disk_attribute disk_attr_capability = {
473	.attr = {.name = "capability", .mode = S_IRUGO },
474	.show	= disk_capability_read
475};
476static struct disk_attribute disk_attr_stat = {
477	.attr = {.name = "stat", .mode = S_IRUGO },
478	.show	= disk_stats_read
479};
480
481#ifdef CONFIG_FAIL_MAKE_REQUEST
482
483static ssize_t disk_fail_store(struct gendisk * disk,
484			       const char *buf, size_t count)
485{
486	int i;
487
488	if (count > 0 && sscanf(buf, "%d", &i) > 0) {
489		if (i == 0)
490			disk->flags &= ~GENHD_FL_FAIL;
491		else
492			disk->flags |= GENHD_FL_FAIL;
493	}
494
495	return count;
496}
497static ssize_t disk_fail_read(struct gendisk * disk, char *page)
498{
499	return sprintf(page, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
500}
501static struct disk_attribute disk_attr_fail = {
502	.attr = {.name = "make-it-fail", .mode = S_IRUGO | S_IWUSR },
503	.store	= disk_fail_store,
504	.show	= disk_fail_read
505};
506
507#endif
508
509static struct attribute * default_attrs[] = {
510	&disk_attr_uevent.attr,
511	&disk_attr_dev.attr,
512	&disk_attr_range.attr,
513	&disk_attr_removable.attr,
514	&disk_attr_size.attr,
515	&disk_attr_stat.attr,
516	&disk_attr_capability.attr,
517#ifdef CONFIG_FAIL_MAKE_REQUEST
518	&disk_attr_fail.attr,
519#endif
520	NULL,
521};
522
523static void disk_release(struct kobject * kobj)
524{
525	struct gendisk *disk = to_disk(kobj);
526	kfree(disk->random);
527	kfree(disk->part);
528	free_disk_stats(disk);
529	kfree(disk);
530}
531
532static struct kobj_type ktype_block = {
533	.release	= disk_release,
534	.sysfs_ops	= &disk_sysfs_ops,
535	.default_attrs	= default_attrs,
536};
537
538extern struct kobj_type ktype_part;
539
540static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
541{
542	struct kobj_type *ktype = get_ktype(kobj);
543
544	return ((ktype == &ktype_block) || (ktype == &ktype_part));
545}
546
547static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
548			 int num_envp, char *buffer, int buffer_size)
549{
550	struct kobj_type *ktype = get_ktype(kobj);
551	struct device *physdev;
552	struct gendisk *disk;
553	struct hd_struct *part;
554	int length = 0;
555	int i = 0;
556
557	if (ktype == &ktype_block) {
558		disk = container_of(kobj, struct gendisk, kobj);
559		add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
560			       &length, "MINOR=%u", disk->first_minor);
561	} else if (ktype == &ktype_part) {
562		disk = container_of(kobj->parent, struct gendisk, kobj);
563		part = container_of(kobj, struct hd_struct, kobj);
564		add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
565			       &length, "MINOR=%u",
566			       disk->first_minor + part->partno);
567	} else
568		return 0;
569
570	add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
571		       "MAJOR=%u", disk->major);
572
573	/* add physical device, backing this device  */
574	physdev = disk->driverfs_dev;
575	if (physdev) {
576		char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
577
578		add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
579			       &length, "PHYSDEVPATH=%s", path);
580		kfree(path);
581
582		if (physdev->bus)
583			add_uevent_var(envp, num_envp, &i,
584				       buffer, buffer_size, &length,
585				       "PHYSDEVBUS=%s",
586				       physdev->bus->name);
587
588		if (physdev->driver)
589			add_uevent_var(envp, num_envp, &i,
590				       buffer, buffer_size, &length,
591				       "PHYSDEVDRIVER=%s",
592				       physdev->driver->name);
593	}
594
595	/* terminate, set to next free slot, shrink available space */
596	envp[i] = NULL;
597	envp = &envp[i];
598	num_envp -= i;
599	buffer = &buffer[length];
600	buffer_size -= length;
601
602	return 0;
603}
604
605static struct kset_uevent_ops block_uevent_ops = {
606	.filter		= block_uevent_filter,
607	.uevent		= block_uevent,
608};
609
610decl_subsys(block, &ktype_block, &block_uevent_ops);
611
612/*
613 * aggregate disk stat collector.  Uses the same stats that the sysfs
614 * entries do, above, but makes them available through one seq_file.
615 * Watching a few disks may be efficient through sysfs, but watching
616 * all of them will be more efficient through this interface.
617 *
618 * The output looks suspiciously like /proc/partitions with a bunch of
619 * extra fields.
620 */
621
622/* iterator */
623static void *diskstats_start(struct seq_file *part, loff_t *pos)
624{
625	loff_t k = *pos;
626	struct list_head *p;
627
628	mutex_lock(&block_subsys_lock);
629	list_for_each(p, &block_subsys.list)
630		if (!k--)
631			return list_entry(p, struct gendisk, kobj.entry);
632	return NULL;
633}
634
635static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
636{
637	struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
638	++*pos;
639	return p==&block_subsys.list ? NULL :
640		list_entry(p, struct gendisk, kobj.entry);
641}
642
643static void diskstats_stop(struct seq_file *part, void *v)
644{
645	mutex_unlock(&block_subsys_lock);
646}
647
648static int diskstats_show(struct seq_file *s, void *v)
649{
650	struct gendisk *gp = v;
651	char buf[BDEVNAME_SIZE];
652	int n = 0;
653
654	/*
655	if (&sgp->kobj.entry == block_subsys.kset.list.next)
656		seq_puts(s,	"major minor name"
657				"     rio rmerge rsect ruse wio wmerge "
658				"wsect wuse running use aveq"
659				"\n\n");
660	*/
661
662	preempt_disable();
663	disk_round_stats(gp);
664	preempt_enable();
665	seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
666		gp->major, n + gp->first_minor, disk_name(gp, n, buf),
667		disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
668		(unsigned long long)disk_stat_read(gp, sectors[0]),
669		jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
670		disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
671		(unsigned long long)disk_stat_read(gp, sectors[1]),
672		jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
673		gp->in_flight,
674		jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
675		jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
676
677	/* now show all non-0 size partitions of it */
678	for (n = 0; n < gp->minors - 1; n++) {
679		struct hd_struct *hd = gp->part[n];
680
681		if (hd && hd->nr_sects)
682			seq_printf(s, "%4d %4d %s %u %u %u %u\n",
683				gp->major, n + gp->first_minor + 1,
684				disk_name(gp, n + 1, buf),
685				hd->ios[0], hd->sectors[0],
686				hd->ios[1], hd->sectors[1]);
687	}
688
689	return 0;
690}
691
692struct seq_operations diskstats_op = {
693	.start	= diskstats_start,
694	.next	= diskstats_next,
695	.stop	= diskstats_stop,
696	.show	= diskstats_show
697};
698
699static void media_change_notify_thread(struct work_struct *work)
700{
701	struct gendisk *gd = container_of(work, struct gendisk, async_notify);
702	char event[] = "MEDIA_CHANGE=1";
703	char *envp[] = { event, NULL };
704
705	/*
706	 * set enviroment vars to indicate which event this is for
707	 * so that user space will know to go check the media status.
708	 */
709	kobject_uevent_env(&gd->kobj, KOBJ_CHANGE, envp);
710	put_device(gd->driverfs_dev);
711}
712
713void genhd_media_change_notify(struct gendisk *disk)
714{
715	get_device(disk->driverfs_dev);
716	schedule_work(&disk->async_notify);
717}
718EXPORT_SYMBOL_GPL(genhd_media_change_notify);
719
720struct gendisk *alloc_disk(int minors)
721{
722	return alloc_disk_node(minors, -1);
723}
724
725struct gendisk *alloc_disk_node(int minors, int node_id)
726{
727	struct gendisk *disk;
728
729	disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
730	if (disk) {
731		memset(disk, 0, sizeof(struct gendisk));
732		if (!init_disk_stats(disk)) {
733			kfree(disk);
734			return NULL;
735		}
736		if (minors > 1) {
737			int size = (minors - 1) * sizeof(struct hd_struct *);
738			disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
739			if (!disk->part) {
740				kfree(disk);
741				return NULL;
742			}
743			memset(disk->part, 0, size);
744		}
745		disk->minors = minors;
746		kobj_set_kset_s(disk,block_subsys);
747		kobject_init(&disk->kobj);
748		rand_initialize_disk(disk);
749		INIT_WORK(&disk->async_notify,
750			media_change_notify_thread);
751	}
752	return disk;
753}
754
755EXPORT_SYMBOL(alloc_disk);
756EXPORT_SYMBOL(alloc_disk_node);
757
758struct kobject *get_disk(struct gendisk *disk)
759{
760	struct module *owner;
761	struct kobject *kobj;
762
763	if (!disk->fops)
764		return NULL;
765	owner = disk->fops->owner;
766	if (owner && !try_module_get(owner))
767		return NULL;
768	kobj = kobject_get(&disk->kobj);
769	if (kobj == NULL) {
770		module_put(owner);
771		return NULL;
772	}
773	return kobj;
774
775}
776
777EXPORT_SYMBOL(get_disk);
778
779void put_disk(struct gendisk *disk)
780{
781	if (disk)
782		kobject_put(&disk->kobj);
783}
784
785EXPORT_SYMBOL(put_disk);
786
787void set_device_ro(struct block_device *bdev, int flag)
788{
789	if (bdev->bd_contains != bdev)
790		bdev->bd_part->policy = flag;
791	else
792		bdev->bd_disk->policy = flag;
793}
794
795EXPORT_SYMBOL(set_device_ro);
796
797void set_disk_ro(struct gendisk *disk, int flag)
798{
799	int i;
800	disk->policy = flag;
801	for (i = 0; i < disk->minors - 1; i++)
802		if (disk->part[i]) disk->part[i]->policy = flag;
803}
804
805EXPORT_SYMBOL(set_disk_ro);
806
807int bdev_read_only(struct block_device *bdev)
808{
809	if (!bdev)
810		return 0;
811	else if (bdev->bd_contains != bdev)
812		return bdev->bd_part->policy;
813	else
814		return bdev->bd_disk->policy;
815}
816
817EXPORT_SYMBOL(bdev_read_only);
818
819int invalidate_partition(struct gendisk *disk, int index)
820{
821	int res = 0;
822	struct block_device *bdev = bdget_disk(disk, index);
823	if (bdev) {
824		fsync_bdev(bdev);
825		res = __invalidate_device(bdev);
826		bdput(bdev);
827	}
828	return res;
829}
830
831EXPORT_SYMBOL(invalidate_partition);
832