Merge tag 'scsi-fixes' of git://git.kernel.org/pub/scm/linux/kernel/git/jejb/scsi
[cris-mirror.git] / block / partition-generic.c
blob08dabcd8b6aefc6844bbb9d9e9c001e6ff71fb33
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Code extracted from drivers/block/genhd.c
4 * Copyright (C) 1991-1998 Linus Torvalds
5 * Re-organised Feb 1998 Russell King
7 * We now have independent partition support from the
8 * block drivers, which allows all the partition code to
9 * be grouped in one location, and it to be mostly self
10 * contained.
13 #include <linux/init.h>
14 #include <linux/module.h>
15 #include <linux/fs.h>
16 #include <linux/slab.h>
17 #include <linux/kmod.h>
18 #include <linux/ctype.h>
19 #include <linux/genhd.h>
20 #include <linux/blktrace_api.h>
22 #include "partitions/check.h"
24 #ifdef CONFIG_BLK_DEV_MD
25 extern void md_autodetect_dev(dev_t dev);
26 #endif
29 * disk_name() is used by partition check code and the genhd driver.
30 * It formats the devicename of the indicated disk into
31 * the supplied buffer (of size at least 32), and returns
32 * a pointer to that same buffer (for convenience).
35 char *disk_name(struct gendisk *hd, int partno, char *buf)
37 if (!partno)
38 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
39 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
40 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
41 else
42 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
44 return buf;
47 const char *bdevname(struct block_device *bdev, char *buf)
49 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
52 EXPORT_SYMBOL(bdevname);
54 const char *bio_devname(struct bio *bio, char *buf)
56 return disk_name(bio->bi_disk, bio->bi_partno, buf);
58 EXPORT_SYMBOL(bio_devname);
61 * There's very little reason to use this, you should really
62 * have a struct block_device just about everywhere and use
63 * bdevname() instead.
65 const char *__bdevname(dev_t dev, char *buffer)
67 scnprintf(buffer, BDEVNAME_SIZE, "unknown-block(%u,%u)",
68 MAJOR(dev), MINOR(dev));
69 return buffer;
72 EXPORT_SYMBOL(__bdevname);
74 static ssize_t part_partition_show(struct device *dev,
75 struct device_attribute *attr, char *buf)
77 struct hd_struct *p = dev_to_part(dev);
79 return sprintf(buf, "%d\n", p->partno);
82 static ssize_t part_start_show(struct device *dev,
83 struct device_attribute *attr, char *buf)
85 struct hd_struct *p = dev_to_part(dev);
87 return sprintf(buf, "%llu\n",(unsigned long long)p->start_sect);
90 ssize_t part_size_show(struct device *dev,
91 struct device_attribute *attr, char *buf)
93 struct hd_struct *p = dev_to_part(dev);
94 return sprintf(buf, "%llu\n",(unsigned long long)part_nr_sects_read(p));
97 static ssize_t part_ro_show(struct device *dev,
98 struct device_attribute *attr, char *buf)
100 struct hd_struct *p = dev_to_part(dev);
101 return sprintf(buf, "%d\n", p->policy ? 1 : 0);
104 static ssize_t part_alignment_offset_show(struct device *dev,
105 struct device_attribute *attr, char *buf)
107 struct hd_struct *p = dev_to_part(dev);
108 return sprintf(buf, "%llu\n", (unsigned long long)p->alignment_offset);
111 static ssize_t part_discard_alignment_show(struct device *dev,
112 struct device_attribute *attr, char *buf)
114 struct hd_struct *p = dev_to_part(dev);
115 return sprintf(buf, "%u\n", p->discard_alignment);
118 ssize_t part_stat_show(struct device *dev,
119 struct device_attribute *attr, char *buf)
121 struct hd_struct *p = dev_to_part(dev);
122 struct request_queue *q = part_to_disk(p)->queue;
123 unsigned int inflight[2];
124 int cpu;
126 cpu = part_stat_lock();
127 part_round_stats(q, cpu, p);
128 part_stat_unlock();
129 part_in_flight(q, p, inflight);
130 return sprintf(buf,
131 "%8lu %8lu %8llu %8u "
132 "%8lu %8lu %8llu %8u "
133 "%8u %8u %8u"
134 "\n",
135 part_stat_read(p, ios[READ]),
136 part_stat_read(p, merges[READ]),
137 (unsigned long long)part_stat_read(p, sectors[READ]),
138 jiffies_to_msecs(part_stat_read(p, ticks[READ])),
139 part_stat_read(p, ios[WRITE]),
140 part_stat_read(p, merges[WRITE]),
141 (unsigned long long)part_stat_read(p, sectors[WRITE]),
142 jiffies_to_msecs(part_stat_read(p, ticks[WRITE])),
143 inflight[0],
144 jiffies_to_msecs(part_stat_read(p, io_ticks)),
145 jiffies_to_msecs(part_stat_read(p, time_in_queue)));
148 ssize_t part_inflight_show(struct device *dev,
149 struct device_attribute *attr, char *buf)
151 struct hd_struct *p = dev_to_part(dev);
153 return sprintf(buf, "%8u %8u\n", atomic_read(&p->in_flight[0]),
154 atomic_read(&p->in_flight[1]));
157 #ifdef CONFIG_FAIL_MAKE_REQUEST
158 ssize_t part_fail_show(struct device *dev,
159 struct device_attribute *attr, char *buf)
161 struct hd_struct *p = dev_to_part(dev);
163 return sprintf(buf, "%d\n", p->make_it_fail);
166 ssize_t part_fail_store(struct device *dev,
167 struct device_attribute *attr,
168 const char *buf, size_t count)
170 struct hd_struct *p = dev_to_part(dev);
171 int i;
173 if (count > 0 && sscanf(buf, "%d", &i) > 0)
174 p->make_it_fail = (i == 0) ? 0 : 1;
176 return count;
178 #endif
180 static DEVICE_ATTR(partition, S_IRUGO, part_partition_show, NULL);
181 static DEVICE_ATTR(start, S_IRUGO, part_start_show, NULL);
182 static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL);
183 static DEVICE_ATTR(ro, S_IRUGO, part_ro_show, NULL);
184 static DEVICE_ATTR(alignment_offset, S_IRUGO, part_alignment_offset_show, NULL);
185 static DEVICE_ATTR(discard_alignment, S_IRUGO, part_discard_alignment_show,
186 NULL);
187 static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL);
188 static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL);
189 #ifdef CONFIG_FAIL_MAKE_REQUEST
190 static struct device_attribute dev_attr_fail =
191 __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store);
192 #endif
194 static struct attribute *part_attrs[] = {
195 &dev_attr_partition.attr,
196 &dev_attr_start.attr,
197 &dev_attr_size.attr,
198 &dev_attr_ro.attr,
199 &dev_attr_alignment_offset.attr,
200 &dev_attr_discard_alignment.attr,
201 &dev_attr_stat.attr,
202 &dev_attr_inflight.attr,
203 #ifdef CONFIG_FAIL_MAKE_REQUEST
204 &dev_attr_fail.attr,
205 #endif
206 NULL
209 static struct attribute_group part_attr_group = {
210 .attrs = part_attrs,
213 static const struct attribute_group *part_attr_groups[] = {
214 &part_attr_group,
215 #ifdef CONFIG_BLK_DEV_IO_TRACE
216 &blk_trace_attr_group,
217 #endif
218 NULL
221 static void part_release(struct device *dev)
223 struct hd_struct *p = dev_to_part(dev);
224 blk_free_devt(dev->devt);
225 hd_free_part(p);
226 kfree(p);
229 static int part_uevent(struct device *dev, struct kobj_uevent_env *env)
231 struct hd_struct *part = dev_to_part(dev);
233 add_uevent_var(env, "PARTN=%u", part->partno);
234 if (part->info && part->info->volname[0])
235 add_uevent_var(env, "PARTNAME=%s", part->info->volname);
236 return 0;
239 struct device_type part_type = {
240 .name = "partition",
241 .groups = part_attr_groups,
242 .release = part_release,
243 .uevent = part_uevent,
246 static void delete_partition_rcu_cb(struct rcu_head *head)
248 struct hd_struct *part = container_of(head, struct hd_struct, rcu_head);
250 part->start_sect = 0;
251 part->nr_sects = 0;
252 part_stat_set_all(part, 0);
253 put_device(part_to_dev(part));
256 void __delete_partition(struct percpu_ref *ref)
258 struct hd_struct *part = container_of(ref, struct hd_struct, ref);
259 call_rcu(&part->rcu_head, delete_partition_rcu_cb);
263 * Must be called either with bd_mutex held, before a disk can be opened or
264 * after all disk users are gone.
266 void delete_partition(struct gendisk *disk, int partno)
268 struct disk_part_tbl *ptbl =
269 rcu_dereference_protected(disk->part_tbl, 1);
270 struct hd_struct *part;
272 if (partno >= ptbl->len)
273 return;
275 part = rcu_dereference_protected(ptbl->part[partno], 1);
276 if (!part)
277 return;
279 rcu_assign_pointer(ptbl->part[partno], NULL);
280 rcu_assign_pointer(ptbl->last_lookup, NULL);
281 kobject_put(part->holder_dir);
282 device_del(part_to_dev(part));
284 hd_struct_kill(part);
287 static ssize_t whole_disk_show(struct device *dev,
288 struct device_attribute *attr, char *buf)
290 return 0;
292 static DEVICE_ATTR(whole_disk, S_IRUSR | S_IRGRP | S_IROTH,
293 whole_disk_show, NULL);
296 * Must be called either with bd_mutex held, before a disk can be opened or
297 * after all disk users are gone.
299 struct hd_struct *add_partition(struct gendisk *disk, int partno,
300 sector_t start, sector_t len, int flags,
301 struct partition_meta_info *info)
303 struct hd_struct *p;
304 dev_t devt = MKDEV(0, 0);
305 struct device *ddev = disk_to_dev(disk);
306 struct device *pdev;
307 struct disk_part_tbl *ptbl;
308 const char *dname;
309 int err;
311 err = disk_expand_part_tbl(disk, partno);
312 if (err)
313 return ERR_PTR(err);
314 ptbl = rcu_dereference_protected(disk->part_tbl, 1);
316 if (ptbl->part[partno])
317 return ERR_PTR(-EBUSY);
319 p = kzalloc(sizeof(*p), GFP_KERNEL);
320 if (!p)
321 return ERR_PTR(-EBUSY);
323 if (!init_part_stats(p)) {
324 err = -ENOMEM;
325 goto out_free;
328 seqcount_init(&p->nr_sects_seq);
329 pdev = part_to_dev(p);
331 p->start_sect = start;
332 p->alignment_offset =
333 queue_limit_alignment_offset(&disk->queue->limits, start);
334 p->discard_alignment =
335 queue_limit_discard_alignment(&disk->queue->limits, start);
336 p->nr_sects = len;
337 p->partno = partno;
338 p->policy = get_disk_ro(disk);
340 if (info) {
341 struct partition_meta_info *pinfo = alloc_part_info(disk);
342 if (!pinfo) {
343 err = -ENOMEM;
344 goto out_free_stats;
346 memcpy(pinfo, info, sizeof(*info));
347 p->info = pinfo;
350 dname = dev_name(ddev);
351 if (isdigit(dname[strlen(dname) - 1]))
352 dev_set_name(pdev, "%sp%d", dname, partno);
353 else
354 dev_set_name(pdev, "%s%d", dname, partno);
356 device_initialize(pdev);
357 pdev->class = &block_class;
358 pdev->type = &part_type;
359 pdev->parent = ddev;
361 err = blk_alloc_devt(p, &devt);
362 if (err)
363 goto out_free_info;
364 pdev->devt = devt;
366 /* delay uevent until 'holders' subdir is created */
367 dev_set_uevent_suppress(pdev, 1);
368 err = device_add(pdev);
369 if (err)
370 goto out_put;
372 err = -ENOMEM;
373 p->holder_dir = kobject_create_and_add("holders", &pdev->kobj);
374 if (!p->holder_dir)
375 goto out_del;
377 dev_set_uevent_suppress(pdev, 0);
378 if (flags & ADDPART_FLAG_WHOLEDISK) {
379 err = device_create_file(pdev, &dev_attr_whole_disk);
380 if (err)
381 goto out_del;
384 err = hd_ref_init(p);
385 if (err) {
386 if (flags & ADDPART_FLAG_WHOLEDISK)
387 goto out_remove_file;
388 goto out_del;
391 /* everything is up and running, commence */
392 rcu_assign_pointer(ptbl->part[partno], p);
394 /* suppress uevent if the disk suppresses it */
395 if (!dev_get_uevent_suppress(ddev))
396 kobject_uevent(&pdev->kobj, KOBJ_ADD);
397 return p;
399 out_free_info:
400 free_part_info(p);
401 out_free_stats:
402 free_part_stats(p);
403 out_free:
404 kfree(p);
405 return ERR_PTR(err);
406 out_remove_file:
407 device_remove_file(pdev, &dev_attr_whole_disk);
408 out_del:
409 kobject_put(p->holder_dir);
410 device_del(pdev);
411 out_put:
412 put_device(pdev);
413 return ERR_PTR(err);
416 static bool disk_unlock_native_capacity(struct gendisk *disk)
418 const struct block_device_operations *bdops = disk->fops;
420 if (bdops->unlock_native_capacity &&
421 !(disk->flags & GENHD_FL_NATIVE_CAPACITY)) {
422 printk(KERN_CONT "enabling native capacity\n");
423 bdops->unlock_native_capacity(disk);
424 disk->flags |= GENHD_FL_NATIVE_CAPACITY;
425 return true;
426 } else {
427 printk(KERN_CONT "truncated\n");
428 return false;
432 static int drop_partitions(struct gendisk *disk, struct block_device *bdev)
434 struct disk_part_iter piter;
435 struct hd_struct *part;
436 int res;
438 if (bdev->bd_part_count || bdev->bd_super)
439 return -EBUSY;
440 res = invalidate_partition(disk, 0);
441 if (res)
442 return res;
444 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
445 while ((part = disk_part_iter_next(&piter)))
446 delete_partition(disk, part->partno);
447 disk_part_iter_exit(&piter);
449 return 0;
452 static bool part_zone_aligned(struct gendisk *disk,
453 struct block_device *bdev,
454 sector_t from, sector_t size)
456 unsigned int zone_sectors = bdev_zone_sectors(bdev);
459 * If this function is called, then the disk is a zoned block device
460 * (host-aware or host-managed). This can be detected even if the
461 * zoned block device support is disabled (CONFIG_BLK_DEV_ZONED not
462 * set). In this case, however, only host-aware devices will be seen
463 * as a block device is not created for host-managed devices. Without
464 * zoned block device support, host-aware drives can still be used as
465 * regular block devices (no zone operation) and their zone size will
466 * be reported as 0. Allow this case.
468 if (!zone_sectors)
469 return true;
472 * Check partition start and size alignement. If the drive has a
473 * smaller last runt zone, ignore it and allow the partition to
474 * use it. Check the zone size too: it should be a power of 2 number
475 * of sectors.
477 if (WARN_ON_ONCE(!is_power_of_2(zone_sectors))) {
478 u32 rem;
480 div_u64_rem(from, zone_sectors, &rem);
481 if (rem)
482 return false;
483 if ((from + size) < get_capacity(disk)) {
484 div_u64_rem(size, zone_sectors, &rem);
485 if (rem)
486 return false;
489 } else {
491 if (from & (zone_sectors - 1))
492 return false;
493 if ((from + size) < get_capacity(disk) &&
494 (size & (zone_sectors - 1)))
495 return false;
499 return true;
502 int rescan_partitions(struct gendisk *disk, struct block_device *bdev)
504 struct parsed_partitions *state = NULL;
505 struct hd_struct *part;
506 int p, highest, res;
507 rescan:
508 if (state && !IS_ERR(state)) {
509 free_partitions(state);
510 state = NULL;
513 res = drop_partitions(disk, bdev);
514 if (res)
515 return res;
517 if (disk->fops->revalidate_disk)
518 disk->fops->revalidate_disk(disk);
519 check_disk_size_change(disk, bdev);
520 bdev->bd_invalidated = 0;
521 if (!get_capacity(disk) || !(state = check_partition(disk, bdev)))
522 return 0;
523 if (IS_ERR(state)) {
525 * I/O error reading the partition table. If any
526 * partition code tried to read beyond EOD, retry
527 * after unlocking native capacity.
529 if (PTR_ERR(state) == -ENOSPC) {
530 printk(KERN_WARNING "%s: partition table beyond EOD, ",
531 disk->disk_name);
532 if (disk_unlock_native_capacity(disk))
533 goto rescan;
535 return -EIO;
538 * If any partition code tried to read beyond EOD, try
539 * unlocking native capacity even if partition table is
540 * successfully read as we could be missing some partitions.
542 if (state->access_beyond_eod) {
543 printk(KERN_WARNING
544 "%s: partition table partially beyond EOD, ",
545 disk->disk_name);
546 if (disk_unlock_native_capacity(disk))
547 goto rescan;
550 /* tell userspace that the media / partition table may have changed */
551 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
553 /* Detect the highest partition number and preallocate
554 * disk->part_tbl. This is an optimization and not strictly
555 * necessary.
557 for (p = 1, highest = 0; p < state->limit; p++)
558 if (state->parts[p].size)
559 highest = p;
561 disk_expand_part_tbl(disk, highest);
563 /* add partitions */
564 for (p = 1; p < state->limit; p++) {
565 sector_t size, from;
567 size = state->parts[p].size;
568 if (!size)
569 continue;
571 from = state->parts[p].from;
572 if (from >= get_capacity(disk)) {
573 printk(KERN_WARNING
574 "%s: p%d start %llu is beyond EOD, ",
575 disk->disk_name, p, (unsigned long long) from);
576 if (disk_unlock_native_capacity(disk))
577 goto rescan;
578 continue;
581 if (from + size > get_capacity(disk)) {
582 printk(KERN_WARNING
583 "%s: p%d size %llu extends beyond EOD, ",
584 disk->disk_name, p, (unsigned long long) size);
586 if (disk_unlock_native_capacity(disk)) {
587 /* free state and restart */
588 goto rescan;
589 } else {
591 * we can not ignore partitions of broken tables
592 * created by for example camera firmware, but
593 * we limit them to the end of the disk to avoid
594 * creating invalid block devices
596 size = get_capacity(disk) - from;
601 * On a zoned block device, partitions should be aligned on the
602 * device zone size (i.e. zone boundary crossing not allowed).
603 * Otherwise, resetting the write pointer of the last zone of
604 * one partition may impact the following partition.
606 if (bdev_is_zoned(bdev) &&
607 !part_zone_aligned(disk, bdev, from, size)) {
608 printk(KERN_WARNING
609 "%s: p%d start %llu+%llu is not zone aligned\n",
610 disk->disk_name, p, (unsigned long long) from,
611 (unsigned long long) size);
612 continue;
615 part = add_partition(disk, p, from, size,
616 state->parts[p].flags,
617 &state->parts[p].info);
618 if (IS_ERR(part)) {
619 printk(KERN_ERR " %s: p%d could not be added: %ld\n",
620 disk->disk_name, p, -PTR_ERR(part));
621 continue;
623 #ifdef CONFIG_BLK_DEV_MD
624 if (state->parts[p].flags & ADDPART_FLAG_RAID)
625 md_autodetect_dev(part_to_dev(part)->devt);
626 #endif
628 free_partitions(state);
629 return 0;
632 int invalidate_partitions(struct gendisk *disk, struct block_device *bdev)
634 int res;
636 if (!bdev->bd_invalidated)
637 return 0;
639 res = drop_partitions(disk, bdev);
640 if (res)
641 return res;
643 set_capacity(disk, 0);
644 check_disk_size_change(disk, bdev);
645 bdev->bd_invalidated = 0;
646 /* tell userspace that the media / partition table may have changed */
647 kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE);
649 return 0;
652 unsigned char *read_dev_sector(struct block_device *bdev, sector_t n, Sector *p)
654 struct address_space *mapping = bdev->bd_inode->i_mapping;
655 struct page *page;
657 page = read_mapping_page(mapping, (pgoff_t)(n >> (PAGE_SHIFT-9)), NULL);
658 if (!IS_ERR(page)) {
659 if (PageError(page))
660 goto fail;
661 p->v = page;
662 return (unsigned char *)page_address(page) + ((n & ((1 << (PAGE_SHIFT - 9)) - 1)) << 9);
663 fail:
664 put_page(page);
666 p->v = NULL;
667 return NULL;
670 EXPORT_SYMBOL(read_dev_sector);