s2io.c: Standardize statistics accessors
[linux-2.6/verdex.git] / fs / partitions / check.c
blobea4e6cb29e1394f709f834df066a7659e12b1d2e
1 /*
2 * fs/partitions/check.c
4 * Code extracted from drivers/block/genhd.c
5 * Copyright (C) 1991-1998 Linus Torvalds
6 * Re-organised Feb 1998 Russell King
8 * We now have independent partition support from the
9 * block drivers, which allows all the partition code to
10 * be grouped in one location, and it to be mostly self
11 * contained.
13 * Added needed MAJORS for new pairs, {hdi,hdj}, {hdk,hdl}
16 #include <linux/init.h>
17 #include <linux/module.h>
18 #include <linux/fs.h>
19 #include <linux/kmod.h>
20 #include <linux/ctype.h>
21 #include <linux/genhd.h>
22 #include <linux/blktrace_api.h>
24 #include "check.h"
26 #include "acorn.h"
27 #include "amiga.h"
28 #include "atari.h"
29 #include "ldm.h"
30 #include "mac.h"
31 #include "msdos.h"
32 #include "osf.h"
33 #include "sgi.h"
34 #include "sun.h"
35 #include "ibm.h"
36 #include "ultrix.h"
37 #include "efi.h"
38 #include "karma.h"
39 #include "sysv68.h"
41 #ifdef CONFIG_BLK_DEV_MD
42 extern void md_autodetect_dev(dev_t dev);
43 #endif
45 int warn_no_part = 1; /*This is ugly: should make genhd removable media aware*/
47 static int (*check_part[])(struct parsed_partitions *, struct block_device *) = {
49 * Probe partition formats with tables at disk address 0
50 * that also have an ADFS boot block at 0xdc0.
52 #ifdef CONFIG_ACORN_PARTITION_ICS
53 adfspart_check_ICS,
54 #endif
55 #ifdef CONFIG_ACORN_PARTITION_POWERTEC
56 adfspart_check_POWERTEC,
57 #endif
58 #ifdef CONFIG_ACORN_PARTITION_EESOX
59 adfspart_check_EESOX,
60 #endif
63 * Now move on to formats that only have partition info at
64 * disk address 0xdc0. Since these may also have stale
65 * PC/BIOS partition tables, they need to come before
66 * the msdos entry.
68 #ifdef CONFIG_ACORN_PARTITION_CUMANA
69 adfspart_check_CUMANA,
70 #endif
71 #ifdef CONFIG_ACORN_PARTITION_ADFS
72 adfspart_check_ADFS,
73 #endif
75 #ifdef CONFIG_EFI_PARTITION
76 efi_partition, /* this must come before msdos */
77 #endif
78 #ifdef CONFIG_SGI_PARTITION
79 sgi_partition,
80 #endif
81 #ifdef CONFIG_LDM_PARTITION
82 ldm_partition, /* this must come before msdos */
83 #endif
84 #ifdef CONFIG_MSDOS_PARTITION
85 msdos_partition,
86 #endif
87 #ifdef CONFIG_OSF_PARTITION
88 osf_partition,
89 #endif
90 #ifdef CONFIG_SUN_PARTITION
91 sun_partition,
92 #endif
93 #ifdef CONFIG_AMIGA_PARTITION
94 amiga_partition,
95 #endif
96 #ifdef CONFIG_ATARI_PARTITION
97 atari_partition,
98 #endif
99 #ifdef CONFIG_MAC_PARTITION
100 mac_partition,
101 #endif
102 #ifdef CONFIG_ULTRIX_PARTITION
103 ultrix_partition,
104 #endif
105 #ifdef CONFIG_IBM_PARTITION
106 ibm_partition,
107 #endif
108 #ifdef CONFIG_KARMA_PARTITION
109 karma_partition,
110 #endif
111 #ifdef CONFIG_SYSV68_PARTITION
112 sysv68_partition,
113 #endif
114 NULL
118 * disk_name() is used by partition check code and the genhd driver.
119 * It formats the devicename of the indicated disk into
120 * the supplied buffer (of size at least 32), and returns
121 * a pointer to that same buffer (for convenience).
124 char *disk_name(struct gendisk *hd, int partno, char *buf)
126 if (!partno)
127 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
128 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
129 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
130 else
131 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
133 return buf;
136 const char *bdevname(struct block_device *bdev, char *buf)
138 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
141 EXPORT_SYMBOL(bdevname);
144 * There's very little reason to use this, you should really
145 * have a struct block_device just about everywhere and use
146 * bdevname() instead.
148 const char *__bdevname(dev_t dev, char *buffer)
150 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
151 MAJOR(dev), MINOR(dev));
152 return buffer;
155 EXPORT_SYMBOL(__bdevname);
157 static struct parsed_partitions *
158 check_partition(struct gendisk *hd, struct block_device *bdev)
160 struct parsed_partitions *state;
161 int i, res, err;
163 state = kmalloc(sizeof(struct parsed_partitions), GFP_KERNEL);
164 if (!state)
165 return NULL;
167 disk_name(hd, 0, state->name);
168 printk(KERN_INFO " %s:", state->name);
169 if (isdigit(state->name[strlen(state->name)-1]))
170 sprintf(state->name, "p");
172 state->limit = disk_max_parts(hd);
173 i = res = err = 0;
174 while (!res && check_part[i]) {
175 memset(&state->parts, 0, sizeof(state->parts));
176 res = check_part[i++](state, bdev);
177 if (res < 0) {
178 /* We have hit an I/O error which we don't report now.
179 * But record it, and let the others do their job.
181 err = res;
182 res = 0;
186 if (res > 0)
187 return state;
188 if (err)
189 /* The partition is unrecognized. So report I/O errors if there were any */
190 res = err;
191 if (!res)
192 printk(" unknown partition table\n");
193 else if (warn_no_part)
194 printk(" unable to read partition table\n");
195 kfree(state);
196 return ERR_PTR(res);
199 static ssize_t part_partition_show(struct device *dev,
200 struct device_attribute *attr, char *buf)
202 struct hd_struct *p = dev_to_part(dev);
204 return sprintf(buf, "%d\n", p->partno);
207 static ssize_t part_start_show(struct device *dev,
208 struct device_attribute *attr, char *buf)
210 struct hd_struct *p = dev_to_part(dev);
212 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
215 ssize_t part_size_show(struct device *dev,
216 struct device_attribute *attr, char *buf)
218 struct hd_struct *p = dev_to_part(dev);
219 return sprintf(buf, "%llu\n",(unsigned long long)p->nr_sects);
222 ssize_t part_alignment_offset_show(struct device *dev,
223 struct device_attribute *attr, char *buf)
225 struct hd_struct *p = dev_to_part(dev);
226 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
229 ssize_t part_stat_show(struct device *dev,
230 struct device_attribute *attr, char *buf)
232 struct hd_struct *p = dev_to_part(dev);
233 int cpu;
235 cpu = part_stat_lock();
236 part_round_stats(cpu, p);
237 part_stat_unlock();
238 return sprintf(buf,
239 "%8lu %8lu %8llu %8u "
240 "%8lu %8lu %8llu %8u "
241 "%8u %8u %8u"
242 "\n",
243 part_stat_read(p, ios[READ]),
244 part_stat_read(p, merges[READ]),
245 (unsigned long long)part_stat_read(p, sectors[READ]),
246 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
247 part_stat_read(p, ios[WRITE]),
248 part_stat_read(p, merges[WRITE]),
249 (unsigned long long)part_stat_read(p, sectors[WRITE]),
250 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
251 p->in_flight,
252 jiffies_to_msecs(part_stat_read(p, io_ticks)),
253 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
256 #ifdef CONFIG_FAIL_MAKE_REQUEST
257 ssize_t part_fail_show(struct device *dev,
258 struct device_attribute *attr, char *buf)
260 struct hd_struct *p = dev_to_part(dev);
262 return sprintf(buf, "%d\n", p->make_it_fail);
265 ssize_t part_fail_store(struct device *dev,
266 struct device_attribute *attr,
267 const char *buf, size_t count)
269 struct hd_struct *p = dev_to_part(dev);
270 int i;
272 if (count > 0 && sscanf(buf, "%d", &i) > 0)
273 p->make_it_fail = (i == 0) ? 0 : 1;
275 return count;
277 #endif
279 static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
280 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
281 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
282 static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
283 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
284 #ifdef CONFIG_FAIL_MAKE_REQUEST
285 static struct device_attribute dev_attr_fail =
286 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
287 #endif
289 static struct attribute *part_attrs[] = {
290 &dev_attr_partition.attr,
291 &dev_attr_start.attr,
292 &dev_attr_size.attr,
293 &dev_attr_alignment_offset.attr,
294 &dev_attr_stat.attr,
295 #ifdef CONFIG_FAIL_MAKE_REQUEST
296 &dev_attr_fail.attr,
297 #endif
298 NULL
301 static struct attribute_group part_attr_group = {
302 .attrs = part_attrs,
305 static struct attribute_group *part_attr_groups[] = {
306 &part_attr_group,
307 #ifdef CONFIG_BLK_DEV_IO_TRACE
308 &blk_trace_attr_group,
309 #endif
310 NULL
313 static void part_release(struct device *dev)
315 struct hd_struct *p = dev_to_part(dev);
316 free_part_stats(p);
317 kfree(p);
320 struct device_type part_type = {
321 .name = "partition",
322 .groups = part_attr_groups,
323 .release = part_release,
326 static void delete_partition_rcu_cb(struct rcu_head *head)
328 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
330 part->start_sect = 0;
331 part->nr_sects = 0;
332 part_stat_set_all(part, 0);
333 put_device(part_to_dev(part));
336 void delete_partition(struct gendisk *disk, int partno)
338 struct disk_part_tbl *ptbl = disk->part_tbl;
339 struct hd_struct *part;
341 if (partno >= ptbl->len)
342 return;
344 part = ptbl->part[partno];
345 if (!part)
346 return;
348 blk_free_devt(part_devt(part));
349 rcu_assign_pointer(ptbl->part[partno], NULL);
350 rcu_assign_pointer(ptbl->last_lookup, NULL);
351 kobject_put(part->holder_dir);
352 device_del(part_to_dev(part));
354 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
357 static ssize_t whole_disk_show(struct device *dev,
358 struct device_attribute *attr, char *buf)
360 return 0;
362 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
363 whole_disk_show, NULL);
365 struct hd_struct *add_partition(struct gendisk *disk, int partno,
366 sector_t start, sector_t len, int flags)
368 struct hd_struct *p;
369 dev_t devt = MKDEV(0, 0);
370 struct device *ddev = disk_to_dev(disk);
371 struct device *pdev;
372 struct disk_part_tbl *ptbl;
373 const char *dname;
374 int err;
376 err = disk_expand_part_tbl(disk, partno);
377 if (err)
378 return ERR_PTR(err);
379 ptbl = disk->part_tbl;
381 if (ptbl->part[partno])
382 return ERR_PTR(-EBUSY);
384 p = kzalloc(sizeof(*p), GFP_KERNEL);
385 if (!p)
386 return ERR_PTR(-EBUSY);
388 if (!init_part_stats(p)) {
389 err = -ENOMEM;
390 goto out_free;
392 pdev = part_to_dev(p);
394 p->start_sect = start;
395 p->alignment_offset = queue_sector_alignment_offset(disk->queue, start);
396 p->nr_sects = len;
397 p->partno = partno;
398 p->policy = get_disk_ro(disk);
400 dname = dev_name(ddev);
401 if (isdigit(dname[strlen(dname) - 1]))
402 dev_set_name(pdev, "%sp%d", dname, partno);
403 else
404 dev_set_name(pdev, "%s%d", dname, partno);
406 device_initialize(pdev);
407 pdev->class = &block_class;
408 pdev->type = &part_type;
409 pdev->parent = ddev;
411 err = blk_alloc_devt(p, &devt);
412 if (err)
413 goto out_free_stats;
414 pdev->devt = devt;
416 /* delay uevent until 'holders' subdir is created */
417 dev_set_uevent_suppress(pdev, 1);
418 err = device_add(pdev);
419 if (err)
420 goto out_put;
422 err = -ENOMEM;
423 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
424 if (!p->holder_dir)
425 goto out_del;
427 dev_set_uevent_suppress(pdev, 0);
428 if (flags & ADDPART_FLAG_WHOLEDISK) {
429 err = device_create_file(pdev, &dev_attr_whole_disk);
430 if (err)
431 goto out_del;
434 /* everything is up and running, commence */
435 INIT_RCU_HEAD(&p->rcu_head);
436 rcu_assign_pointer(ptbl->part[partno], p);
438 /* suppress uevent if the disk supresses it */
439 if (!dev_get_uevent_suppress(ddev))
440 kobject_uevent(&pdev->kobj, KOBJ_ADD);
442 return p;
444 out_free_stats:
445 free_part_stats(p);
446 out_free:
447 kfree(p);
448 return ERR_PTR(err);
449 out_del:
450 kobject_put(p->holder_dir);
451 device_del(pdev);
452 out_put:
453 put_device(pdev);
454 blk_free_devt(devt);
455 return ERR_PTR(err);
458 /* Not exported, helper to add_disk(). */
459 void register_disk(struct gendisk *disk)
461 struct device *ddev = disk_to_dev(disk);
462 struct block_device *bdev;
463 struct disk_part_iter piter;
464 struct hd_struct *part;
465 int err;
467 ddev->parent = disk->driverfs_dev;
469 dev_set_name(ddev, disk->disk_name);
471 /* delay uevents, until we scanned partition table */
472 dev_set_uevent_suppress(ddev, 1);
474 if (device_add(ddev))
475 return;
476 #ifndef CONFIG_SYSFS_DEPRECATED
477 err = sysfs_create_link(block_depr, &ddev->kobj,
478 kobject_name(&ddev->kobj));
479 if (err) {
480 device_del(ddev);
481 return;
483 #endif
484 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
485 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
487 /* No minors to use for partitions */
488 if (!disk_partitionable(disk))
489 goto exit;
491 /* No such device (e.g., media were just removed) */
492 if (!get_capacity(disk))
493 goto exit;
495 bdev = bdget_disk(disk, 0);
496 if (!bdev)
497 goto exit;
499 bdev->bd_invalidated = 1;
500 err = blkdev_get(bdev, FMODE_READ);
501 if (err < 0)
502 goto exit;
503 blkdev_put(bdev, FMODE_READ);
505 exit:
506 /* announce disk after possible partitions are created */
507 dev_set_uevent_suppress(ddev, 0);
508 kobject_uevent(&ddev->kobj, KOBJ_ADD);
510 /* announce possible partitions */
511 disk_part_iter_init(&piter, disk, 0);
512 while ((part = disk_part_iter_next(&piter)))
513 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
514 disk_part_iter_exit(&piter);
517 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
519 struct disk_part_iter piter;
520 struct hd_struct *part;
521 struct parsed_partitions *state;
522 int p, highest, res;
524 if (bdev->bd_part_count)
525 return -EBUSY;
526 res = invalidate_partition(disk, 0);
527 if (res)
528 return res;
530 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
531 while ((part = disk_part_iter_next(&piter)))
532 delete_partition(disk, part->partno);
533 disk_part_iter_exit(&piter);
535 if (disk->fops->revalidate_disk)
536 disk->fops->revalidate_disk(disk);
537 check_disk_size_change(disk, bdev);
538 bdev->bd_invalidated = 0;
539 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
540 return 0;
541 if (IS_ERR(state)) /* I/O error reading the partition table */
542 return -EIO;
544 /* tell userspace that the media / partition table may have changed */
545 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
547 /* Detect the highest partition number and preallocate
548 * disk->part_tbl. This is an optimization and not strictly
549 * necessary.
551 for (p = 1, highest = 0; p < state->limit; p++)
552 if (state->parts[p].size)
553 highest = p;
555 disk_expand_part_tbl(disk, highest);
557 /* add partitions */
558 for (p = 1; p < state->limit; p++) {
559 sector_t size, from;
560 try_scan:
561 size = state->parts[p].size;
562 if (!size)
563 continue;
565 from = state->parts[p].from;
566 if (from >= get_capacity(disk)) {
567 printk(KERN_WARNING
568 "%s: p%d ignored, start %llu is behind the end of the disk\n",
569 disk->disk_name, p, (unsigned long long) from);
570 continue;
573 if (from + size > get_capacity(disk)) {
574 struct block_device_operations *bdops = disk->fops;
575 unsigned long long capacity;
577 printk(KERN_WARNING
578 "%s: p%d size %llu exceeds device capacity, ",
579 disk->disk_name, p, (unsigned long long) size);
581 if (bdops->set_capacity &&
582 (disk->flags & GENHD_FL_NATIVE_CAPACITY) == 0) {
583 printk(KERN_CONT "enabling native capacity\n");
584 capacity = bdops->set_capacity(disk, ~0ULL);
585 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
586 if (capacity > get_capacity(disk)) {
587 set_capacity(disk, capacity);
588 check_disk_size_change(disk, bdev);
589 bdev->bd_invalidated = 0;
591 goto try_scan;
592 } else {
594 * we can not ignore partitions of broken tables
595 * created by for example camera firmware, but
596 * we limit them to the end of the disk to avoid
597 * creating invalid block devices
599 printk(KERN_CONT "limited to end of disk\n");
600 size = get_capacity(disk) - from;
603 part = add_partition(disk, p, from, size,
604 state->parts[p].flags);
605 if (IS_ERR(part)) {
606 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
607 disk->disk_name, p, -PTR_ERR(part));
608 continue;
610 #ifdef CONFIG_BLK_DEV_MD
611 if (state->parts[p].flags & ADDPART_FLAG_RAID)
612 md_autodetect_dev(part_to_dev(part)->devt);
613 #endif
615 kfree(state);
616 return 0;
619 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
621 struct address_space *mapping = bdev->bd_inode->i_mapping;
622 struct page *page;
624 page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_CACHE_SHIFT-9)),
625 NULL);
626 if (!IS_ERR(page)) {
627 if (PageError(page))
628 goto fail;
629 p->v = page;
630 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_CACHE_SHIFT - 9)) - 1)) << 9);
631 fail:
632 page_cache_release(page);
634 p->v = NULL;
635 return NULL;
638 EXPORT_SYMBOL(read_dev_sector);
640 void del_gendisk(struct gendisk *disk)
642 struct disk_part_iter piter;
643 struct hd_struct *part;
645 /* invalidate stuff */
646 disk_part_iter_init(&piter, disk,
647 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
648 while ((part = disk_part_iter_next(&piter))) {
649 invalidate_partition(disk, part->partno);
650 delete_partition(disk, part->partno);
652 disk_part_iter_exit(&piter);
654 invalidate_partition(disk, 0);
655 blk_free_devt(disk_to_dev(disk)->devt);
656 set_capacity(disk, 0);
657 disk->flags &= ~GENHD_FL_UP;
658 unlink_gendisk(disk);
659 part_stat_set_all(&disk->part0, 0);
660 disk->part0.stamp = 0;
662 kobject_put(disk->part0.holder_dir);
663 kobject_put(disk->slave_dir);
664 disk->driverfs_dev = NULL;
665 #ifndef CONFIG_SYSFS_DEPRECATED
666 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
667 #endif
668 device_del(disk_to_dev(disk));