[PATCH] fuse: clean up request accounting
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / block / genhd.c
blob5a8d3bf02f1715702fe94515339f1cdfbfd3d088
1 /*
2 * gendisk handling
3 */
5 #include <linux/config.h>
6 #include <linux/module.h>
7 #include <linux/fs.h>
8 #include <linux/genhd.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 static struct subsystem block_subsys;
22 static DEFINE_MUTEX(block_subsys_lock);
25 * Can be deleted altogether. Later.
28 static struct blk_major_name {
29 struct blk_major_name *next;
30 int major;
31 char name[16];
32 } *major_names[BLKDEV_MAJOR_HASH_SIZE];
34 /* index in the above - for now: assume no multimajor ranges */
35 static inline int major_to_index(int major)
37 return major % BLKDEV_MAJOR_HASH_SIZE;
40 #ifdef CONFIG_PROC_FS
42 void blkdev_show(struct seq_file *f, off_t offset)
44 struct blk_major_name *dp;
46 if (offset < BLKDEV_MAJOR_HASH_SIZE) {
47 mutex_lock(&block_subsys_lock);
48 for (dp = major_names[offset]; dp; dp = dp->next)
49 seq_printf(f, "%3d %s\n", dp->major, dp->name);
50 mutex_unlock(&block_subsys_lock);
54 #endif /* CONFIG_PROC_FS */
56 int register_blkdev(unsigned int major, const char *name)
58 struct blk_major_name **n, *p;
59 int index, ret = 0;
61 mutex_lock(&block_subsys_lock);
63 /* temporary */
64 if (major == 0) {
65 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
66 if (major_names[index] == NULL)
67 break;
70 if (index == 0) {
71 printk("register_blkdev: failed to get major for %s\n",
72 name);
73 ret = -EBUSY;
74 goto out;
76 major = index;
77 ret = major;
80 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
81 if (p == NULL) {
82 ret = -ENOMEM;
83 goto out;
86 p->major = major;
87 strlcpy(p->name, name, sizeof(p->name));
88 p->next = NULL;
89 index = major_to_index(major);
91 for (n = &major_names[index]; *n; n = &(*n)->next) {
92 if ((*n)->major == major)
93 break;
95 if (!*n)
96 *n = p;
97 else
98 ret = -EBUSY;
100 if (ret < 0) {
101 printk("register_blkdev: cannot get major %d for %s\n",
102 major, name);
103 kfree(p);
105 out:
106 mutex_unlock(&block_subsys_lock);
107 return ret;
110 EXPORT_SYMBOL(register_blkdev);
112 /* todo: make void - error printk here */
113 int unregister_blkdev(unsigned int major, const char *name)
115 struct blk_major_name **n;
116 struct blk_major_name *p = NULL;
117 int index = major_to_index(major);
118 int ret = 0;
120 mutex_lock(&block_subsys_lock);
121 for (n = &major_names[index]; *n; n = &(*n)->next)
122 if ((*n)->major == major)
123 break;
124 if (!*n || strcmp((*n)->name, name))
125 ret = -EINVAL;
126 else {
127 p = *n;
128 *n = p->next;
130 mutex_unlock(&block_subsys_lock);
131 kfree(p);
133 return ret;
136 EXPORT_SYMBOL(unregister_blkdev);
138 static struct kobj_map *bdev_map;
141 * Register device numbers dev..(dev+range-1)
142 * range must be nonzero
143 * The hash chain is sorted on range, so that subranges can override.
145 void blk_register_region(dev_t dev, unsigned long range, struct module *module,
146 struct kobject *(*probe)(dev_t, int *, void *),
147 int (*lock)(dev_t, void *), void *data)
149 kobj_map(bdev_map, dev, range, module, probe, lock, data);
152 EXPORT_SYMBOL(blk_register_region);
154 void blk_unregister_region(dev_t dev, unsigned long range)
156 kobj_unmap(bdev_map, dev, range);
159 EXPORT_SYMBOL(blk_unregister_region);
161 static struct kobject *exact_match(dev_t dev, int *part, void *data)
163 struct gendisk *p = data;
164 return &p->kobj;
167 static int exact_lock(dev_t dev, 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 disk->flags |= GENHD_FL_UP;
186 blk_register_region(MKDEV(disk->major, disk->first_minor),
187 disk->minors, NULL, exact_match, exact_lock, disk);
188 register_disk(disk);
189 blk_register_queue(disk);
192 EXPORT_SYMBOL(add_disk);
193 EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */
195 void unlink_gendisk(struct gendisk *disk)
197 blk_unregister_queue(disk);
198 blk_unregister_region(MKDEV(disk->major, disk->first_minor),
199 disk->minors);
202 #define to_disk(obj) container_of(obj,struct gendisk,kobj)
205 * get_gendisk - get partitioning information for a given device
206 * @dev: device to get partitioning information for
208 * This function gets the structure containing partitioning
209 * information for the given device @dev.
211 struct gendisk *get_gendisk(dev_t dev, int *part)
213 struct kobject *kobj = kobj_lookup(bdev_map, dev, part);
214 return kobj ? to_disk(kobj) : NULL;
217 #ifdef CONFIG_PROC_FS
218 /* iterator */
219 static void *part_start(struct seq_file *part, loff_t *pos)
221 struct list_head *p;
222 loff_t l = *pos;
224 mutex_lock(&block_subsys_lock);
225 list_for_each(p, &block_subsys.kset.list)
226 if (!l--)
227 return list_entry(p, struct gendisk, kobj.entry);
228 return NULL;
231 static void *part_next(struct seq_file *part, void *v, loff_t *pos)
233 struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
234 ++*pos;
235 return p==&block_subsys.kset.list ? NULL :
236 list_entry(p, struct gendisk, kobj.entry);
239 static void part_stop(struct seq_file *part, void *v)
241 mutex_unlock(&block_subsys_lock);
244 static int show_partition(struct seq_file *part, void *v)
246 struct gendisk *sgp = v;
247 int n;
248 char buf[BDEVNAME_SIZE];
250 if (&sgp->kobj.entry == block_subsys.kset.list.next)
251 seq_puts(part, "major minor #blocks name\n\n");
253 /* Don't show non-partitionable removeable devices or empty devices */
254 if (!get_capacity(sgp) ||
255 (sgp->minors == 1 && (sgp->flags & GENHD_FL_REMOVABLE)))
256 return 0;
257 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
258 return 0;
260 /* show the full disk and all non-0 size partitions of it */
261 seq_printf(part, "%4d %4d %10llu %s\n",
262 sgp->major, sgp->first_minor,
263 (unsigned long long)get_capacity(sgp) >> 1,
264 disk_name(sgp, 0, buf));
265 for (n = 0; n < sgp->minors - 1; n++) {
266 if (!sgp->part[n])
267 continue;
268 if (sgp->part[n]->nr_sects == 0)
269 continue;
270 seq_printf(part, "%4d %4d %10llu %s\n",
271 sgp->major, n + 1 + sgp->first_minor,
272 (unsigned long long)sgp->part[n]->nr_sects >> 1 ,
273 disk_name(sgp, n + 1, buf));
276 return 0;
279 struct seq_operations partitions_op = {
280 .start =part_start,
281 .next = part_next,
282 .stop = part_stop,
283 .show = show_partition
285 #endif
288 extern int blk_dev_init(void);
290 static struct kobject *base_probe(dev_t dev, int *part, void *data)
292 if (request_module("block-major-%d-%d", MAJOR(dev), MINOR(dev)) > 0)
293 /* Make old-style 2.4 aliases work */
294 request_module("block-major-%d", MAJOR(dev));
295 return NULL;
298 static int __init genhd_device_init(void)
300 bdev_map = kobj_map_init(base_probe, &block_subsys_lock);
301 blk_dev_init();
302 subsystem_register(&block_subsys);
303 return 0;
306 subsys_initcall(genhd_device_init);
311 * kobject & sysfs bindings for block devices
313 static ssize_t disk_attr_show(struct kobject *kobj, struct attribute *attr,
314 char *page)
316 struct gendisk *disk = to_disk(kobj);
317 struct disk_attribute *disk_attr =
318 container_of(attr,struct disk_attribute,attr);
319 ssize_t ret = -EIO;
321 if (disk_attr->show)
322 ret = disk_attr->show(disk,page);
323 return ret;
326 static ssize_t disk_attr_store(struct kobject * kobj, struct attribute * attr,
327 const char *page, size_t count)
329 struct gendisk *disk = to_disk(kobj);
330 struct disk_attribute *disk_attr =
331 container_of(attr,struct disk_attribute,attr);
332 ssize_t ret = 0;
334 if (disk_attr->store)
335 ret = disk_attr->store(disk, page, count);
336 return ret;
339 static struct sysfs_ops disk_sysfs_ops = {
340 .show = &disk_attr_show,
341 .store = &disk_attr_store,
344 static ssize_t disk_uevent_store(struct gendisk * disk,
345 const char *buf, size_t count)
347 kobject_uevent(&disk->kobj, KOBJ_ADD);
348 return count;
350 static ssize_t disk_dev_read(struct gendisk * disk, char *page)
352 dev_t base = MKDEV(disk->major, disk->first_minor);
353 return print_dev_t(page, base);
355 static ssize_t disk_range_read(struct gendisk * disk, char *page)
357 return sprintf(page, "%d\n", disk->minors);
359 static ssize_t disk_removable_read(struct gendisk * disk, char *page)
361 return sprintf(page, "%d\n",
362 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
365 static ssize_t disk_size_read(struct gendisk * disk, char *page)
367 return sprintf(page, "%llu\n", (unsigned long long)get_capacity(disk));
370 static ssize_t disk_stats_read(struct gendisk * disk, char *page)
372 preempt_disable();
373 disk_round_stats(disk);
374 preempt_enable();
375 return sprintf(page,
376 "%8lu %8lu %8llu %8u "
377 "%8lu %8lu %8llu %8u "
378 "%8u %8u %8u"
379 "\n",
380 disk_stat_read(disk, ios[READ]),
381 disk_stat_read(disk, merges[READ]),
382 (unsigned long long)disk_stat_read(disk, sectors[READ]),
383 jiffies_to_msecs(disk_stat_read(disk, ticks[READ])),
384 disk_stat_read(disk, ios[WRITE]),
385 disk_stat_read(disk, merges[WRITE]),
386 (unsigned long long)disk_stat_read(disk, sectors[WRITE]),
387 jiffies_to_msecs(disk_stat_read(disk, ticks[WRITE])),
388 disk->in_flight,
389 jiffies_to_msecs(disk_stat_read(disk, io_ticks)),
390 jiffies_to_msecs(disk_stat_read(disk, time_in_queue)));
392 static struct disk_attribute disk_attr_uevent = {
393 .attr = {.name = "uevent", .mode = S_IWUSR },
394 .store = disk_uevent_store
396 static struct disk_attribute disk_attr_dev = {
397 .attr = {.name = "dev", .mode = S_IRUGO },
398 .show = disk_dev_read
400 static struct disk_attribute disk_attr_range = {
401 .attr = {.name = "range", .mode = S_IRUGO },
402 .show = disk_range_read
404 static struct disk_attribute disk_attr_removable = {
405 .attr = {.name = "removable", .mode = S_IRUGO },
406 .show = disk_removable_read
408 static struct disk_attribute disk_attr_size = {
409 .attr = {.name = "size", .mode = S_IRUGO },
410 .show = disk_size_read
412 static struct disk_attribute disk_attr_stat = {
413 .attr = {.name = "stat", .mode = S_IRUGO },
414 .show = disk_stats_read
417 static struct attribute * default_attrs[] = {
418 &disk_attr_uevent.attr,
419 &disk_attr_dev.attr,
420 &disk_attr_range.attr,
421 &disk_attr_removable.attr,
422 &disk_attr_size.attr,
423 &disk_attr_stat.attr,
424 NULL,
427 static void disk_release(struct kobject * kobj)
429 struct gendisk *disk = to_disk(kobj);
430 kfree(disk->random);
431 kfree(disk->part);
432 free_disk_stats(disk);
433 kfree(disk);
436 static struct kobj_type ktype_block = {
437 .release = disk_release,
438 .sysfs_ops = &disk_sysfs_ops,
439 .default_attrs = default_attrs,
442 extern struct kobj_type ktype_part;
444 static int block_uevent_filter(struct kset *kset, struct kobject *kobj)
446 struct kobj_type *ktype = get_ktype(kobj);
448 return ((ktype == &ktype_block) || (ktype == &ktype_part));
451 static int block_uevent(struct kset *kset, struct kobject *kobj, char **envp,
452 int num_envp, char *buffer, int buffer_size)
454 struct kobj_type *ktype = get_ktype(kobj);
455 struct device *physdev;
456 struct gendisk *disk;
457 struct hd_struct *part;
458 int length = 0;
459 int i = 0;
461 if (ktype == &ktype_block) {
462 disk = container_of(kobj, struct gendisk, kobj);
463 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
464 &length, "MINOR=%u", disk->first_minor);
465 } else if (ktype == &ktype_part) {
466 disk = container_of(kobj->parent, struct gendisk, kobj);
467 part = container_of(kobj, struct hd_struct, kobj);
468 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
469 &length, "MINOR=%u",
470 disk->first_minor + part->partno);
471 } else
472 return 0;
474 add_uevent_var(envp, num_envp, &i, buffer, buffer_size, &length,
475 "MAJOR=%u", disk->major);
477 /* add physical device, backing this device */
478 physdev = disk->driverfs_dev;
479 if (physdev) {
480 char *path = kobject_get_path(&physdev->kobj, GFP_KERNEL);
482 add_uevent_var(envp, num_envp, &i, buffer, buffer_size,
483 &length, "PHYSDEVPATH=%s", path);
484 kfree(path);
486 if (physdev->bus)
487 add_uevent_var(envp, num_envp, &i,
488 buffer, buffer_size, &length,
489 "PHYSDEVBUS=%s",
490 physdev->bus->name);
492 if (physdev->driver)
493 add_uevent_var(envp, num_envp, &i,
494 buffer, buffer_size, &length,
495 "PHYSDEVDRIVER=%s",
496 physdev->driver->name);
499 /* terminate, set to next free slot, shrink available space */
500 envp[i] = NULL;
501 envp = &envp[i];
502 num_envp -= i;
503 buffer = &buffer[length];
504 buffer_size -= length;
506 return 0;
509 static struct kset_uevent_ops block_uevent_ops = {
510 .filter = block_uevent_filter,
511 .uevent = block_uevent,
514 /* declare block_subsys. */
515 static decl_subsys(block, &ktype_block, &block_uevent_ops);
519 * aggregate disk stat collector. Uses the same stats that the sysfs
520 * entries do, above, but makes them available through one seq_file.
521 * Watching a few disks may be efficient through sysfs, but watching
522 * all of them will be more efficient through this interface.
524 * The output looks suspiciously like /proc/partitions with a bunch of
525 * extra fields.
528 /* iterator */
529 static void *diskstats_start(struct seq_file *part, loff_t *pos)
531 loff_t k = *pos;
532 struct list_head *p;
534 mutex_lock(&block_subsys_lock);
535 list_for_each(p, &block_subsys.kset.list)
536 if (!k--)
537 return list_entry(p, struct gendisk, kobj.entry);
538 return NULL;
541 static void *diskstats_next(struct seq_file *part, void *v, loff_t *pos)
543 struct list_head *p = ((struct gendisk *)v)->kobj.entry.next;
544 ++*pos;
545 return p==&block_subsys.kset.list ? NULL :
546 list_entry(p, struct gendisk, kobj.entry);
549 static void diskstats_stop(struct seq_file *part, void *v)
551 mutex_unlock(&block_subsys_lock);
554 static int diskstats_show(struct seq_file *s, void *v)
556 struct gendisk *gp = v;
557 char buf[BDEVNAME_SIZE];
558 int n = 0;
561 if (&sgp->kobj.entry == block_subsys.kset.list.next)
562 seq_puts(s, "major minor name"
563 " rio rmerge rsect ruse wio wmerge "
564 "wsect wuse running use aveq"
565 "\n\n");
568 preempt_disable();
569 disk_round_stats(gp);
570 preempt_enable();
571 seq_printf(s, "%4d %4d %s %lu %lu %llu %u %lu %lu %llu %u %u %u %u\n",
572 gp->major, n + gp->first_minor, disk_name(gp, n, buf),
573 disk_stat_read(gp, ios[0]), disk_stat_read(gp, merges[0]),
574 (unsigned long long)disk_stat_read(gp, sectors[0]),
575 jiffies_to_msecs(disk_stat_read(gp, ticks[0])),
576 disk_stat_read(gp, ios[1]), disk_stat_read(gp, merges[1]),
577 (unsigned long long)disk_stat_read(gp, sectors[1]),
578 jiffies_to_msecs(disk_stat_read(gp, ticks[1])),
579 gp->in_flight,
580 jiffies_to_msecs(disk_stat_read(gp, io_ticks)),
581 jiffies_to_msecs(disk_stat_read(gp, time_in_queue)));
583 /* now show all non-0 size partitions of it */
584 for (n = 0; n < gp->minors - 1; n++) {
585 struct hd_struct *hd = gp->part[n];
587 if (hd && hd->nr_sects)
588 seq_printf(s, "%4d %4d %s %u %u %u %u\n",
589 gp->major, n + gp->first_minor + 1,
590 disk_name(gp, n + 1, buf),
591 hd->ios[0], hd->sectors[0],
592 hd->ios[1], hd->sectors[1]);
595 return 0;
598 struct seq_operations diskstats_op = {
599 .start = diskstats_start,
600 .next = diskstats_next,
601 .stop = diskstats_stop,
602 .show = diskstats_show
605 struct gendisk *alloc_disk(int minors)
607 return alloc_disk_node(minors, -1);
610 struct gendisk *alloc_disk_node(int minors, int node_id)
612 struct gendisk *disk;
614 disk = kmalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
615 if (disk) {
616 memset(disk, 0, sizeof(struct gendisk));
617 if (!init_disk_stats(disk)) {
618 kfree(disk);
619 return NULL;
621 if (minors > 1) {
622 int size = (minors - 1) * sizeof(struct hd_struct *);
623 disk->part = kmalloc_node(size, GFP_KERNEL, node_id);
624 if (!disk->part) {
625 kfree(disk);
626 return NULL;
628 memset(disk->part, 0, size);
630 disk->minors = minors;
631 kobj_set_kset_s(disk,block_subsys);
632 kobject_init(&disk->kobj);
633 rand_initialize_disk(disk);
635 return disk;
638 EXPORT_SYMBOL(alloc_disk);
639 EXPORT_SYMBOL(alloc_disk_node);
641 struct kobject *get_disk(struct gendisk *disk)
643 struct module *owner;
644 struct kobject *kobj;
646 if (!disk->fops)
647 return NULL;
648 owner = disk->fops->owner;
649 if (owner && !try_module_get(owner))
650 return NULL;
651 kobj = kobject_get(&disk->kobj);
652 if (kobj == NULL) {
653 module_put(owner);
654 return NULL;
656 return kobj;
660 EXPORT_SYMBOL(get_disk);
662 void put_disk(struct gendisk *disk)
664 if (disk)
665 kobject_put(&disk->kobj);
668 EXPORT_SYMBOL(put_disk);
670 void set_device_ro(struct block_device *bdev, int flag)
672 if (bdev->bd_contains != bdev)
673 bdev->bd_part->policy = flag;
674 else
675 bdev->bd_disk->policy = flag;
678 EXPORT_SYMBOL(set_device_ro);
680 void set_disk_ro(struct gendisk *disk, int flag)
682 int i;
683 disk->policy = flag;
684 for (i = 0; i < disk->minors - 1; i++)
685 if (disk->part[i]) disk->part[i]->policy = flag;
688 EXPORT_SYMBOL(set_disk_ro);
690 int bdev_read_only(struct block_device *bdev)
692 if (!bdev)
693 return 0;
694 else if (bdev->bd_contains != bdev)
695 return bdev->bd_part->policy;
696 else
697 return bdev->bd_disk->policy;
700 EXPORT_SYMBOL(bdev_read_only);
702 int invalidate_partition(struct gendisk *disk, int index)
704 int res = 0;
705 struct block_device *bdev = bdget_disk(disk, index);
706 if (bdev) {
707 fsync_bdev(bdev);
708 res = __invalidate_device(bdev);
709 bdput(bdev);
711 return res;
714 EXPORT_SYMBOL(invalidate_partition);