pid_ns: (BUG 11391) change ->child_reaper when init->group_leader exits
[linux-2.6/mini2440.git] / block / genhd.c
blobe0ce23ac2ece84b24a283f9ae9203ec3291f2f78
1 /*
2 * gendisk handling
3 */
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>
20 #include "blk.h"
22 static DEFINE_MUTEX(block_class_lock);
23 #ifndef CONFIG_SYSFS_DEPRECATED
24 struct kobject *block_depr;
25 #endif
27 static struct device_type disk_type;
30 * Can be deleted altogether. Later.
33 static struct blk_major_name {
34 struct blk_major_name *next;
35 int major;
36 char name[16];
37 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
39 /* index in the above - for now: assume no multimajor ranges */
40 static inline int major_to_index(int major)
42 return major % BLKDEV_MAJOR_HASH_SIZE;
45 #ifdef CONFIG_PROC_FS
46 void blkdev_show(struct seq_file *f, off_t offset)
48 struct blk_major_name *dp;
50 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
51 mutex_lock(&block_class_lock);
52 for (dp = major_names[offset]; dp; dp = dp->next)
53 seq_printf(f, "%3d %s\n", dp->major, dp->name);
54 mutex_unlock(&block_class_lock);
57 #endif /* CONFIG_PROC_FS */
59 int register_blkdev(unsigned int major, const char *name)
61 struct blk_major_name **n, *p;
62 int index, ret = 0;
64 mutex_lock(&block_class_lock);
66 /* temporary */
67 if (major == 0) {
68 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
69 if (major_names[index] == NULL)
70 break;
73 if (index == 0) {
74 printk("register_blkdev: failed to get major for %s\n",
75 name);
76 ret = -EBUSY;
77 goto out;
79 major = index;
80 ret = major;
83 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
84 if (p == NULL) {
85 ret = -ENOMEM;
86 goto out;
89 p->major = major;
90 strlcpy(p->name, name, sizeof(p->name));
91 p->next = NULL;
92 index = major_to_index(major);
94 for (n = &major_names[index]; *n; n = &(*n)->next) {
95 if ((*n)->major == major)
96 break;
98 if (!*n)
99 *n = p;
100 else
101 ret = -EBUSY;
103 if (ret < 0) {
104 printk("register_blkdev: cannot get major %d for %s\n",
105 major, name);
106 kfree(p);
108 out:
109 mutex_unlock(&block_class_lock);
110 return ret;
113 EXPORT_SYMBOL(register_blkdev);
115 void unregister_blkdev(unsigned int major, const char *name)
117 struct blk_major_name **n;
118 struct blk_major_name *p = NULL;
119 int index = major_to_index(major);
121 mutex_lock(&block_class_lock);
122 for (n = &major_names[index]; *n; n = &(*n)->next)
123 if ((*n)->major == major)
124 break;
125 if (!*n || strcmp((*n)->name, name)) {
126 WARN_ON(1);
127 } else {
128 p = *n;
129 *n = p->next;
131 mutex_unlock(&block_class_lock);
132 kfree(p);
135 EXPORT_SYMBOL(unregister_blkdev);
137 static struct kobj_map *bdev_map;
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.
144 void blk_register_region(dev_t devt, unsigned long range, struct module *module,
145 struct kobject *(*probe)(dev_t, int *, void *),
146 int (*lock)(dev_t, void *), void *data)
148 kobj_map(bdev_map, devt, range, module, probe, lock, data);
151 EXPORT_SYMBOL(blk_register_region);
153 void blk_unregister_region(dev_t devt, unsigned long range)
155 kobj_unmap(bdev_map, devt, range);
158 EXPORT_SYMBOL(blk_unregister_region);
160 static struct kobject *exact_match(dev_t devt, int *part, void *data)
162 struct gendisk *p = data;
164 return &p->dev.kobj;
167 static int exact_lock(dev_t devt, void *data)
169 struct gendisk *p = data;
171 if (!get_disk(p))
172 return -1;
173 return 0;
177 * add_disk - add partitioning information to kernel list
178 * @disk: per-device partitioning information
180 * This function registers the partitioning information in @disk
181 * with the kernel.
183 void add_disk(struct gendisk *disk)
185 struct backing_dev_info *bdi;
186 int retval;
188 disk->flags |= GENHD_FL_UP;
189 blk_register_region(MKDEV(disk->major, disk->first_minor),
190 disk->minors, NULL, exact_match, exact_lock, disk);
191 register_disk(disk);
192 blk_register_queue(disk);
194 bdi = &disk->queue->backing_dev_info;
195 bdi_register_dev(bdi, MKDEV(disk->major, disk->first_minor));
196 retval = sysfs_create_link(&disk->dev.kobj, &bdi->dev->kobj, "bdi");
197 WARN_ON(retval);
200 EXPORT_SYMBOL(add_disk);
201 EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */
203 void unlink_gendisk(struct gendisk *disk)
205 sysfs_remove_link(&disk->dev.kobj, "bdi");
206 bdi_unregister(&disk->queue->backing_dev_info);
207 blk_unregister_queue(disk);
208 blk_unregister_region(MKDEV(disk->major, disk->first_minor),
209 disk->minors);
213 * get_gendisk - get partitioning information for a given device
214 * @dev: device to get partitioning information for
216 * This function gets the structure containing partitioning
217 * information for the given device @dev.
219 struct gendisk *get_gendisk(dev_t devt, int *part)
221 struct kobject *kobj = kobj_lookup(bdev_map, devt, part);
222 struct device *dev = kobj_to_dev(kobj);
224 return kobj ? dev_to_disk(dev) : NULL;
228 * print a partitions - intended for places where the root filesystem can't be
229 * mounted and thus to give the victim some idea of what went wrong
231 static int printk_partition(struct device *dev, void *data)
233 struct gendisk *sgp;
234 char buf[BDEVNAME_SIZE];
235 int n;
237 if (dev->type != &disk_type)
238 goto exit;
240 sgp = dev_to_disk(dev);
242 * Don't show empty devices or things that have been surpressed
244 if (get_capacity(sgp) == 0 ||
245 (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
246 goto exit;
249 * Note, unlike /proc/partitions, I am showing the numbers in
250 * hex - the same format as the root= option takes.
252 printk("%02x%02x %10llu %s",
253 sgp->major, sgp->first_minor,
254 (unsigned long long)get_capacity(sgp) >> 1,
255 disk_name(sgp, 0, buf));
256 if (sgp->driverfs_dev != NULL &&
257 sgp->driverfs_dev->driver != NULL)
258 printk(" driver: %s\n",
259 sgp->driverfs_dev->driver->name);
260 else
261 printk(" (driver?)\n");
263 /* now show the partitions */
264 for (n = 0; n < sgp->minors - 1; ++n) {
265 if (sgp->part[n] == NULL)
266 goto exit;
267 if (sgp->part[n]->nr_sects == 0)
268 goto exit;
269 printk(" %02x%02x %10llu %s\n",
270 sgp->major, n + 1 + sgp->first_minor,
271 (unsigned long long)sgp->part[n]->nr_sects >> 1,
272 disk_name(sgp, n + 1, buf));
274 exit:
275 return 0;
279 * print a full list of all partitions - intended for places where the root
280 * filesystem can't be mounted and thus to give the victim some idea of what
281 * went wrong
283 void __init printk_all_partitions(void)
285 mutex_lock(&block_class_lock);
286 class_for_each_device(&block_class, NULL, NULL, printk_partition);
287 mutex_unlock(&block_class_lock);
290 #ifdef CONFIG_PROC_FS
291 /* iterator */
292 static int find_start(struct device *dev, void *data)
294 loff_t *k = data;
296 if (dev->type != &disk_type)
297 return 0;
298 if (!*k)
299 return 1;
300 (*k)--;
301 return 0;
304 static void *part_start(struct seq_file *part, loff_t *pos)
306 struct device *dev;
307 loff_t k = *pos;
309 if (!k)
310 part->private = (void *)1LU; /* tell show to print header */
312 mutex_lock(&block_class_lock);
313 dev = class_find_device(&block_class, NULL, &k, find_start);
314 if (dev) {
315 put_device(dev);
316 return dev_to_disk(dev);
318 return NULL;
321 static int find_next(struct device *dev, void *data)
323 if (dev->type == &disk_type)
324 return 1;
325 return 0;
328 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
330 struct gendisk *gp = v;
331 struct device *dev;
332 ++*pos;
333 dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
334 if (dev) {
335 put_device(dev);
336 return dev_to_disk(dev);
338 return NULL;
341 static void part_stop(struct seq_file *part, void *v)
343 mutex_unlock(&block_class_lock);
346 static int show_partition(struct seq_file *part, void *v)
348 struct gendisk *sgp = v;
349 int n;
350 char buf[BDEVNAME_SIZE];
353 * Print header if start told us to do. This is to preserve
354 * the original behavior of not printing header if no
355 * partition exists. This hackery will be removed later with
356 * class iteration clean up.
358 if (part->private) {
359 seq_puts(part, "major minor #blocks name\n\n");
360 part->private = NULL;
363 /* Don't show non-partitionable removeable devices or empty devices */
364 if (!get_capacity(sgp) ||
365 (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
366 return 0;
367 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
368 return 0;
370 /* show the full disk and all non-0 size partitions of it */
371 seq_printf(part, "%4d %4d %10llu %s\n",
372 sgp->major, sgp->first_minor,
373 (unsigned long long)get_capacity(sgp) >> 1,
374 disk_name(sgp, 0, buf));
375 for (n = 0; n < sgp->minors - 1; n++) {
376 if (!sgp->part[n])
377 continue;
378 if (sgp->part[n]->nr_sects == 0)
379 continue;
380 seq_printf(part, "%4d %4d %10llu %s\n",
381 sgp->major, n + 1 + sgp->first_minor,
382 (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
383 disk_name(sgp, n + 1, buf));
386 return 0;
389 const struct seq_operations partitions_op = {
390 .start = part_start,
391 .next = part_next,
392 .stop = part_stop,
393 .show = show_partition
395 #endif
398 static struct kobject *base_probe(dev_t devt, int *part, void *data)
400 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
401 /* Make old-style 2.4 aliases work */
402 request_module("block-major-%d", MAJOR(devt));
403 return NULL;
406 static int __init genhd_device_init(void)
408 int error;
410 block_class.dev_kobj = sysfs_dev_block_kobj;
411 error = class_register(&block_class);
412 if (unlikely(error))
413 return error;
414 bdev_map = kobj_map_init(base_probe, &block_class_lock);
415 blk_dev_init();
417 #ifndef CONFIG_SYSFS_DEPRECATED
418 /* create top-level block dir */
419 block_depr = kobject_create_and_add("block", NULL);
420 #endif
421 return 0;
424 subsys_initcall(genhd_device_init);
426 static ssize_t disk_range_show(struct device *dev,
427 struct device_attribute *attr, char *buf)
429 struct gendisk *disk = dev_to_disk(dev);
431 return sprintf(buf, "%d\n", disk->minors);
434 static ssize_t disk_removable_show(struct device *dev,
435 struct device_attribute *attr, char *buf)
437 struct gendisk *disk = dev_to_disk(dev);
439 return sprintf(buf, "%d\n",
440 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
443 static ssize_t disk_ro_show(struct device *dev,
444 struct device_attribute *attr, char *buf)
446 struct gendisk *disk = dev_to_disk(dev);
448 return sprintf(buf, "%d\n", disk->policy ? 1 : 0);
451 static ssize_t disk_size_show(struct device *dev,
452 struct device_attribute *attr, char *buf)
454 struct gendisk *disk = dev_to_disk(dev);
456 return sprintf(buf, "%llu\n", (unsigned long long)get_capacity(disk));
459 static ssize_t disk_capability_show(struct device *dev,
460 struct device_attribute *attr, char *buf)
462 struct gendisk *disk = dev_to_disk(dev);
464 return sprintf(buf, "%x\n", disk->flags);
467 static ssize_t disk_stat_show(struct device *dev,
468 struct device_attribute *attr, char *buf)
470 struct gendisk *disk = dev_to_disk(dev);
472 preempt_disable();
473 disk_round_stats(disk);
474 preempt_enable();
475 return sprintf(buf,
476 "%8lu %8lu %8llu %8u "
477 "%8lu %8lu %8llu %8u "
478 "%8u %8u %8u"
479 "\n",
480 disk_stat_read(disk, ios[READ]),
481 disk_stat_read(disk, merges[READ]),
482 (unsigned long long)disk_stat_read(disk, sectors[READ]),
483 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
484 disk_stat_read(disk, ios[WRITE]),
485 disk_stat_read(disk, merges[WRITE]),
486 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
487 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
488 disk->in_flight,
489 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
490 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
493 #ifdef CONFIG_FAIL_MAKE_REQUEST
494 static ssize_t disk_fail_show(struct device *dev,
495 struct device_attribute *attr, char *buf)
497 struct gendisk *disk = dev_to_disk(dev);
499 return sprintf(buf, "%d\n", disk->flags & GENHD_FL_FAIL ? 1 : 0);
502 static ssize_t disk_fail_store(struct device *dev,
503 struct device_attribute *attr,
504 const char *buf, size_t count)
506 struct gendisk *disk = dev_to_disk(dev);
507 int i;
509 if (count > 0 && sscanf(buf, "%d", &i) > 0) {
510 if (i == 0)
511 disk->flags &= ~GENHD_FL_FAIL;
512 else
513 disk->flags |= GENHD_FL_FAIL;
516 return count;
519 #endif
521 static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL);
522 static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL);
523 static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL);
524 static DEVICE_ATTR(size, S_IRUGO, disk_size_show, NULL);
525 static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL);
526 static DEVICE_ATTR(stat, S_IRUGO, disk_stat_show, NULL);
527 #ifdef CONFIG_FAIL_MAKE_REQUEST
528 static struct device_attribute dev_attr_fail =
529 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, disk_fail_show, disk_fail_store);
530 #endif
532 static struct attribute *disk_attrs[] = {
533 &dev_attr_range.attr,
534 &dev_attr_removable.attr,
535 &dev_attr_ro.attr,
536 &dev_attr_size.attr,
537 &dev_attr_capability.attr,
538 &dev_attr_stat.attr,
539 #ifdef CONFIG_FAIL_MAKE_REQUEST
540 &dev_attr_fail.attr,
541 #endif
542 NULL
545 static struct attribute_group disk_attr_group = {
546 .attrs = disk_attrs,
549 static struct attribute_group *disk_attr_groups[] = {
550 &disk_attr_group,
551 NULL
554 static void disk_release(struct device *dev)
556 struct gendisk *disk = dev_to_disk(dev);
558 kfree(disk->random);
559 kfree(disk->part);
560 free_disk_stats(disk);
561 kfree(disk);
563 struct class block_class = {
564 .name = "block",
567 static struct device_type disk_type = {
568 .name = "disk",
569 .groups = disk_attr_groups,
570 .release = disk_release,
573 #ifdef CONFIG_PROC_FS
575 * aggregate disk stat collector. Uses the same stats that the sysfs
576 * entries do, above, but makes them available through one seq_file.
578 * The output looks suspiciously like /proc/partitions with a bunch of
579 * extra fields.
582 static void *diskstats_start(struct seq_file *part, loff_t *pos)
584 struct device *dev;
585 loff_t k = *pos;
587 mutex_lock(&block_class_lock);
588 dev = class_find_device(&block_class, NULL, &k, find_start);
589 if (dev) {
590 put_device(dev);
591 return dev_to_disk(dev);
593 return NULL;
596 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
598 struct gendisk *gp = v;
599 struct device *dev;
601 ++*pos;
602 dev = class_find_device(&block_class, &gp->dev, NULL, find_next);
603 if (dev) {
604 put_device(dev);
605 return dev_to_disk(dev);
607 return NULL;
610 static void diskstats_stop(struct seq_file *part, void *v)
612 mutex_unlock(&block_class_lock);
615 static int diskstats_show(struct seq_file *s, void *v)
617 struct gendisk *gp = v;
618 char buf[BDEVNAME_SIZE];
619 int n = 0;
622 if (&gp->dev.kobj.entry == block_class.devices.next)
623 seq_puts(s, "major minor name"
624 " rio rmerge rsect ruse wio wmerge "
625 "wsect wuse running use aveq"
626 "\n\n");
629 preempt_disable();
630 disk_round_stats(gp);
631 preempt_enable();
632 seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
633 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
634 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
635 (unsigned long long)disk_stat_read(gp, sectors[0]),
636 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
637 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
638 (unsigned long long)disk_stat_read(gp, sectors[1]),
639 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
640 gp->in_flight,
641 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
642 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
644 /* now show all non-0 size partitions of it */
645 for (n = 0; n < gp->minors - 1; n++) {
646 struct hd_struct *hd = gp->part[n];
648 if (!hd || !hd->nr_sects)
649 continue;
651 preempt_disable();
652 part_round_stats(hd);
653 preempt_enable();
654 seq_printf(s, "%4d %4d %s %lu %lu %llu "
655 "%u %lu %lu %llu %u %u %u %u\n",
656 gp->major, n + gp->first_minor + 1,
657 disk_name(gp, n + 1, buf),
658 part_stat_read(hd, ios[0]),
659 part_stat_read(hd, merges[0]),
660 (unsigned long long)part_stat_read(hd, sectors[0]),
661 jiffies_to_msecs(part_stat_read(hd, ticks[0])),
662 part_stat_read(hd, ios[1]),
663 part_stat_read(hd, merges[1]),
664 (unsigned long long)part_stat_read(hd, sectors[1]),
665 jiffies_to_msecs(part_stat_read(hd, ticks[1])),
666 hd->in_flight,
667 jiffies_to_msecs(part_stat_read(hd, io_ticks)),
668 jiffies_to_msecs(part_stat_read(hd, time_in_queue))
672 return 0;
675 const struct seq_operations diskstats_op = {
676 .start = diskstats_start,
677 .next = diskstats_next,
678 .stop = diskstats_stop,
679 .show = diskstats_show
681 #endif /* CONFIG_PROC_FS */
683 static void media_change_notify_thread(struct work_struct *work)
685 struct gendisk *gd = container_of(work, struct gendisk, async_notify);
686 char event[] = "MEDIA_CHANGE=1";
687 char *envp[] = { event, NULL };
690 * set enviroment vars to indicate which event this is for
691 * so that user space will know to go check the media status.
693 kobject_uevent_env(&gd->dev.kobj, KOBJ_CHANGE, envp);
694 put_device(gd->driverfs_dev);
697 #if 0
698 void genhd_media_change_notify(struct gendisk *disk)
700 get_device(disk->driverfs_dev);
701 schedule_work(&disk->async_notify);
703 EXPORT_SYMBOL_GPL(genhd_media_change_notify);
704 #endif /* 0 */
706 struct find_block {
707 const char *name;
708 int part;
711 static int match_id(struct device *dev, void *data)
713 struct find_block *find = data;
715 if (dev->type != &disk_type)
716 return 0;
717 if (strcmp(dev->bus_id, find->name) == 0) {
718 struct gendisk *disk = dev_to_disk(dev);
719 if (find->part < disk->minors)
720 return 1;
722 return 0;
725 dev_t blk_lookup_devt(const char *name, int part)
727 struct device *dev;
728 dev_t devt = MKDEV(0, 0);
729 struct find_block find;
731 mutex_lock(&block_class_lock);
732 find.name = name;
733 find.part = part;
734 dev = class_find_device(&block_class, NULL, &find, match_id);
735 if (dev) {
736 put_device(dev);
737 devt = MKDEV(MAJOR(dev->devt),
738 MINOR(dev->devt) + part);
740 mutex_unlock(&block_class_lock);
742 return devt;
744 EXPORT_SYMBOL(blk_lookup_devt);
746 struct gendisk *alloc_disk(int minors)
748 return alloc_disk_node(minors, -1);
751 struct gendisk *alloc_disk_node(int minors, int node_id)
753 struct gendisk *disk;
755 disk = kmalloc_node(sizeof(struct gendisk),
756 GFP_KERNEL | __GFP_ZERO, node_id);
757 if (disk) {
758 if (!init_disk_stats(disk)) {
759 kfree(disk);
760 return NULL;
762 if (minors > 1) {
763 int size = (minors - 1) * sizeof(struct hd_struct *);
764 disk->part = kmalloc_node(size,
765 GFP_KERNEL | __GFP_ZERO, node_id);
766 if (!disk->part) {
767 free_disk_stats(disk);
768 kfree(disk);
769 return NULL;
772 disk->minors = minors;
773 rand_initialize_disk(disk);
774 disk->dev.class = &block_class;
775 disk->dev.type = &disk_type;
776 device_initialize(&disk->dev);
777 INIT_WORK(&disk->async_notify,
778 media_change_notify_thread);
780 return disk;
783 EXPORT_SYMBOL(alloc_disk);
784 EXPORT_SYMBOL(alloc_disk_node);
786 struct kobject *get_disk(struct gendisk *disk)
788 struct module *owner;
789 struct kobject *kobj;
791 if (!disk->fops)
792 return NULL;
793 owner = disk->fops->owner;
794 if (owner && !try_module_get(owner))
795 return NULL;
796 kobj = kobject_get(&disk->dev.kobj);
797 if (kobj == NULL) {
798 module_put(owner);
799 return NULL;
801 return kobj;
805 EXPORT_SYMBOL(get_disk);
807 void put_disk(struct gendisk *disk)
809 if (disk)
810 kobject_put(&disk->dev.kobj);
813 EXPORT_SYMBOL(put_disk);
815 void set_device_ro(struct block_device *bdev, int flag)
817 if (bdev->bd_contains != bdev)
818 bdev->bd_part->policy = flag;
819 else
820 bdev->bd_disk->policy = flag;
823 EXPORT_SYMBOL(set_device_ro);
825 void set_disk_ro(struct gendisk *disk, int flag)
827 int i;
828 disk->policy = flag;
829 for (i = 0; i < disk->minors - 1; i++)
830 if (disk->part[i]) disk->part[i]->policy = flag;
833 EXPORT_SYMBOL(set_disk_ro);
835 int bdev_read_only(struct block_device *bdev)
837 if (!bdev)
838 return 0;
839 else if (bdev->bd_contains != bdev)
840 return bdev->bd_part->policy;
841 else
842 return bdev->bd_disk->policy;
845 EXPORT_SYMBOL(bdev_read_only);
847 int invalidate_partition(struct gendisk *disk, int index)
849 int res = 0;
850 struct block_device *bdev = bdget_disk(disk, index);
851 if (bdev) {
852 fsync_bdev(bdev);
853 res = __invalidate_device(bdev);
854 bdput(bdev);
856 return res;
859 EXPORT_SYMBOL(invalidate_partition);