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6#include <linux/module.h>
7#include <linux/ctype.h>
8#include <linux/fs.h>
9#include <linux/genhd.h>
10#include <linux/kdev_t.h>
11#include <linux/kernel.h>
12#include <linux/blkdev.h>
13#include <linux/backing-dev.h>
14#include <linux/init.h>
15#include <linux/spinlock.h>
16#include <linux/proc_fs.h>
17#include <linux/seq_file.h>
18#include <linux/slab.h>
19#include <linux/kmod.h>
20#include <linux/kobj_map.h>
21#include <linux/mutex.h>
22#include <linux/idr.h>
23#include <linux/log2.h>
24#include <linux/pm_runtime.h>
25#include <linux/badblocks.h>
26
27#include "blk.h"
28
29static DEFINE_MUTEX(block_class_lock);
30static struct kobject *block_depr;
31
32
33#define NR_EXT_DEVT (1 << MINORBITS)
34
35
36
37
38static DEFINE_SPINLOCK(ext_devt_lock);
39static DEFINE_IDR(ext_devt_idr);
40
41static void disk_check_events(struct disk_events *ev,
42 unsigned int *clearing_ptr);
43static void disk_alloc_events(struct gendisk *disk);
44static void disk_add_events(struct gendisk *disk);
45static void disk_del_events(struct gendisk *disk);
46static void disk_release_events(struct gendisk *disk);
47
48
49
50
51
52void set_capacity_revalidate_and_notify(struct gendisk *disk, sector_t size,
53 bool revalidate)
54{
55 sector_t capacity = get_capacity(disk);
56
57 set_capacity(disk, size);
58
59 if (revalidate)
60 revalidate_disk(disk);
61
62 if (capacity != size && capacity != 0 && size != 0) {
63 char *envp[] = { "RESIZE=1", NULL };
64
65 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
66 }
67}
68
69EXPORT_SYMBOL_GPL(set_capacity_revalidate_and_notify);
70
71
72
73
74
75char *disk_name(struct gendisk *hd, int partno, char *buf)
76{
77 if (!partno)
78 snprintf(buf, BDEVNAME_SIZE, "%s", hd->disk_name);
79 else if (isdigit(hd->disk_name[strlen(hd->disk_name)-1]))
80 snprintf(buf, BDEVNAME_SIZE, "%sp%d", hd->disk_name, partno);
81 else
82 snprintf(buf, BDEVNAME_SIZE, "%s%d", hd->disk_name, partno);
83
84 return buf;
85}
86
87const char *bdevname(struct block_device *bdev, char *buf)
88{
89 return disk_name(bdev->bd_disk, bdev->bd_part->partno, buf);
90}
91EXPORT_SYMBOL(bdevname);
92
93static void part_stat_read_all(struct hd_struct *part, struct disk_stats *stat)
94{
95 int cpu;
96
97 memset(stat, 0, sizeof(struct disk_stats));
98 for_each_possible_cpu(cpu) {
99 struct disk_stats *ptr = per_cpu_ptr(part->dkstats, cpu);
100 int group;
101
102 for (group = 0; group < NR_STAT_GROUPS; group++) {
103 stat->nsecs[group] += ptr->nsecs[group];
104 stat->sectors[group] += ptr->sectors[group];
105 stat->ios[group] += ptr->ios[group];
106 stat->merges[group] += ptr->merges[group];
107 }
108
109 stat->io_ticks += ptr->io_ticks;
110 }
111}
112
113static unsigned int part_in_flight(struct request_queue *q,
114 struct hd_struct *part)
115{
116 unsigned int inflight = 0;
117 int cpu;
118
119 for_each_possible_cpu(cpu) {
120 inflight += part_stat_local_read_cpu(part, in_flight[0], cpu) +
121 part_stat_local_read_cpu(part, in_flight[1], cpu);
122 }
123 if ((int)inflight < 0)
124 inflight = 0;
125
126 return inflight;
127}
128
129static void part_in_flight_rw(struct request_queue *q, struct hd_struct *part,
130 unsigned int inflight[2])
131{
132 int cpu;
133
134 inflight[0] = 0;
135 inflight[1] = 0;
136 for_each_possible_cpu(cpu) {
137 inflight[0] += part_stat_local_read_cpu(part, in_flight[0], cpu);
138 inflight[1] += part_stat_local_read_cpu(part, in_flight[1], cpu);
139 }
140 if ((int)inflight[0] < 0)
141 inflight[0] = 0;
142 if ((int)inflight[1] < 0)
143 inflight[1] = 0;
144}
145
146struct hd_struct *__disk_get_part(struct gendisk *disk, int partno)
147{
148 struct disk_part_tbl *ptbl = rcu_dereference(disk->part_tbl);
149
150 if (unlikely(partno < 0 || partno >= ptbl->len))
151 return NULL;
152 return rcu_dereference(ptbl->part[partno]);
153}
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167
168
169struct hd_struct *disk_get_part(struct gendisk *disk, int partno)
170{
171 struct hd_struct *part;
172
173 rcu_read_lock();
174 part = __disk_get_part(disk, partno);
175 if (part)
176 get_device(part_to_dev(part));
177 rcu_read_unlock();
178
179 return part;
180}
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191
192
193void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk,
194 unsigned int flags)
195{
196 struct disk_part_tbl *ptbl;
197
198 rcu_read_lock();
199 ptbl = rcu_dereference(disk->part_tbl);
200
201 piter->disk = disk;
202 piter->part = NULL;
203
204 if (flags & DISK_PITER_REVERSE)
205 piter->idx = ptbl->len - 1;
206 else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0))
207 piter->idx = 0;
208 else
209 piter->idx = 1;
210
211 piter->flags = flags;
212
213 rcu_read_unlock();
214}
215EXPORT_SYMBOL_GPL(disk_part_iter_init);
216
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223
224
225
226struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter)
227{
228 struct disk_part_tbl *ptbl;
229 int inc, end;
230
231
232 disk_put_part(piter->part);
233 piter->part = NULL;
234
235
236 rcu_read_lock();
237 ptbl = rcu_dereference(piter->disk->part_tbl);
238
239
240 if (piter->flags & DISK_PITER_REVERSE) {
241 inc = -1;
242 if (piter->flags & (DISK_PITER_INCL_PART0 |
243 DISK_PITER_INCL_EMPTY_PART0))
244 end = -1;
245 else
246 end = 0;
247 } else {
248 inc = 1;
249 end = ptbl->len;
250 }
251
252
253 for (; piter->idx != end; piter->idx += inc) {
254 struct hd_struct *part;
255
256 part = rcu_dereference(ptbl->part[piter->idx]);
257 if (!part)
258 continue;
259 if (!part_nr_sects_read(part) &&
260 !(piter->flags & DISK_PITER_INCL_EMPTY) &&
261 !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 &&
262 piter->idx == 0))
263 continue;
264
265 get_device(part_to_dev(part));
266 piter->part = part;
267 piter->idx += inc;
268 break;
269 }
270
271 rcu_read_unlock();
272
273 return piter->part;
274}
275EXPORT_SYMBOL_GPL(disk_part_iter_next);
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285
286void disk_part_iter_exit(struct disk_part_iter *piter)
287{
288 disk_put_part(piter->part);
289 piter->part = NULL;
290}
291EXPORT_SYMBOL_GPL(disk_part_iter_exit);
292
293static inline int sector_in_part(struct hd_struct *part, sector_t sector)
294{
295 return part->start_sect <= sector &&
296 sector < part->start_sect + part_nr_sects_read(part);
297}
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315
316struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector)
317{
318 struct disk_part_tbl *ptbl;
319 struct hd_struct *part;
320 int i;
321
322 rcu_read_lock();
323 ptbl = rcu_dereference(disk->part_tbl);
324
325 part = rcu_dereference(ptbl->last_lookup);
326 if (part && sector_in_part(part, sector) && hd_struct_try_get(part))
327 goto out_unlock;
328
329 for (i = 1; i < ptbl->len; i++) {
330 part = rcu_dereference(ptbl->part[i]);
331
332 if (part && sector_in_part(part, sector)) {
333
334
335
336
337
338 if (!hd_struct_try_get(part))
339 break;
340 rcu_assign_pointer(ptbl->last_lookup, part);
341 goto out_unlock;
342 }
343 }
344
345 part = &disk->part0;
346out_unlock:
347 rcu_read_unlock();
348 return part;
349}
350
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363
364bool disk_has_partitions(struct gendisk *disk)
365{
366 struct disk_part_tbl *ptbl;
367 int i;
368 bool ret = false;
369
370 rcu_read_lock();
371 ptbl = rcu_dereference(disk->part_tbl);
372
373
374 for (i = 1; i < ptbl->len; i++) {
375 if (rcu_dereference(ptbl->part[i])) {
376 ret = true;
377 break;
378 }
379 }
380
381 rcu_read_unlock();
382
383 return ret;
384}
385EXPORT_SYMBOL_GPL(disk_has_partitions);
386
387
388
389
390
391#define BLKDEV_MAJOR_HASH_SIZE 255
392static struct blk_major_name {
393 struct blk_major_name *next;
394 int major;
395 char name[16];
396} *major_names[BLKDEV_MAJOR_HASH_SIZE];
397
398
399static inline int major_to_index(unsigned major)
400{
401 return major % BLKDEV_MAJOR_HASH_SIZE;
402}
403
404#ifdef CONFIG_PROC_FS
405void blkdev_show(struct seq_file *seqf, off_t offset)
406{
407 struct blk_major_name *dp;
408
409 mutex_lock(&block_class_lock);
410 for (dp = major_names[major_to_index(offset)]; dp; dp = dp->next)
411 if (dp->major == offset)
412 seq_printf(seqf, "%3d %s\n", dp->major, dp->name);
413 mutex_unlock(&block_class_lock);
414}
415#endif
416
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435
436
437int register_blkdev(unsigned int major, const char *name)
438{
439 struct blk_major_name **n, *p;
440 int index, ret = 0;
441
442 mutex_lock(&block_class_lock);
443
444
445 if (major == 0) {
446 for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) {
447 if (major_names[index] == NULL)
448 break;
449 }
450
451 if (index == 0) {
452 printk("%s: failed to get major for %s\n",
453 __func__, name);
454 ret = -EBUSY;
455 goto out;
456 }
457 major = index;
458 ret = major;
459 }
460
461 if (major >= BLKDEV_MAJOR_MAX) {
462 pr_err("%s: major requested (%u) is greater than the maximum (%u) for %s\n",
463 __func__, major, BLKDEV_MAJOR_MAX-1, name);
464
465 ret = -EINVAL;
466 goto out;
467 }
468
469 p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL);
470 if (p == NULL) {
471 ret = -ENOMEM;
472 goto out;
473 }
474
475 p->major = major;
476 strlcpy(p->name, name, sizeof(p->name));
477 p->next = NULL;
478 index = major_to_index(major);
479
480 for (n = &major_names[index]; *n; n = &(*n)->next) {
481 if ((*n)->major == major)
482 break;
483 }
484 if (!*n)
485 *n = p;
486 else
487 ret = -EBUSY;
488
489 if (ret < 0) {
490 printk("register_blkdev: cannot get major %u for %s\n",
491 major, name);
492 kfree(p);
493 }
494out:
495 mutex_unlock(&block_class_lock);
496 return ret;
497}
498
499EXPORT_SYMBOL(register_blkdev);
500
501void unregister_blkdev(unsigned int major, const char *name)
502{
503 struct blk_major_name **n;
504 struct blk_major_name *p = NULL;
505 int index = major_to_index(major);
506
507 mutex_lock(&block_class_lock);
508 for (n = &major_names[index]; *n; n = &(*n)->next)
509 if ((*n)->major == major)
510 break;
511 if (!*n || strcmp((*n)->name, name)) {
512 WARN_ON(1);
513 } else {
514 p = *n;
515 *n = p->next;
516 }
517 mutex_unlock(&block_class_lock);
518 kfree(p);
519}
520
521EXPORT_SYMBOL(unregister_blkdev);
522
523static struct kobj_map *bdev_map;
524
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537
538static int blk_mangle_minor(int minor)
539{
540#ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT
541 int i;
542
543 for (i = 0; i < MINORBITS / 2; i++) {
544 int low = minor & (1 << i);
545 int high = minor & (1 << (MINORBITS - 1 - i));
546 int distance = MINORBITS - 1 - 2 * i;
547
548 minor ^= low | high;
549 low <<= distance;
550 high >>= distance;
551 minor |= low | high;
552 }
553#endif
554 return minor;
555}
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570
571int blk_alloc_devt(struct hd_struct *part, dev_t *devt)
572{
573 struct gendisk *disk = part_to_disk(part);
574 int idx;
575
576
577 if (part->partno < disk->minors) {
578 *devt = MKDEV(disk->major, disk->first_minor + part->partno);
579 return 0;
580 }
581
582
583 idr_preload(GFP_KERNEL);
584
585 spin_lock_bh(&ext_devt_lock);
586 idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT);
587 spin_unlock_bh(&ext_devt_lock);
588
589 idr_preload_end();
590 if (idx < 0)
591 return idx == -ENOSPC ? -EBUSY : idx;
592
593 *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx));
594 return 0;
595}
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604
605
606void blk_free_devt(dev_t devt)
607{
608 if (devt == MKDEV(0, 0))
609 return;
610
611 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
612 spin_lock_bh(&ext_devt_lock);
613 idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
614 spin_unlock_bh(&ext_devt_lock);
615 }
616}
617
618
619
620
621void blk_invalidate_devt(dev_t devt)
622{
623 if (MAJOR(devt) == BLOCK_EXT_MAJOR) {
624 spin_lock_bh(&ext_devt_lock);
625 idr_replace(&ext_devt_idr, NULL, blk_mangle_minor(MINOR(devt)));
626 spin_unlock_bh(&ext_devt_lock);
627 }
628}
629
630static char *bdevt_str(dev_t devt, char *buf)
631{
632 if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) {
633 char tbuf[BDEVT_SIZE];
634 snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt));
635 snprintf(buf, BDEVT_SIZE, "%-9s", tbuf);
636 } else
637 snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt));
638
639 return buf;
640}
641
642
643
644
645
646
647void blk_register_region(dev_t devt, unsigned long range, struct module *module,
648 struct kobject *(*probe)(dev_t, int *, void *),
649 int (*lock)(dev_t, void *), void *data)
650{
651 kobj_map(bdev_map, devt, range, module, probe, lock, data);
652}
653
654EXPORT_SYMBOL(blk_register_region);
655
656void blk_unregister_region(dev_t devt, unsigned long range)
657{
658 kobj_unmap(bdev_map, devt, range);
659}
660
661EXPORT_SYMBOL(blk_unregister_region);
662
663static struct kobject *exact_match(dev_t devt, int *partno, void *data)
664{
665 struct gendisk *p = data;
666
667 return &disk_to_dev(p)->kobj;
668}
669
670static int exact_lock(dev_t devt, void *data)
671{
672 struct gendisk *p = data;
673
674 if (!get_disk_and_module(p))
675 return -1;
676 return 0;
677}
678
679static void register_disk(struct device *parent, struct gendisk *disk,
680 const struct attribute_group **groups)
681{
682 struct device *ddev = disk_to_dev(disk);
683 struct block_device *bdev;
684 struct disk_part_iter piter;
685 struct hd_struct *part;
686 int err;
687
688 ddev->parent = parent;
689
690 dev_set_name(ddev, "%s", disk->disk_name);
691
692
693 dev_set_uevent_suppress(ddev, 1);
694
695 if (groups) {
696 WARN_ON(ddev->groups);
697 ddev->groups = groups;
698 }
699 if (device_add(ddev))
700 return;
701 if (!sysfs_deprecated) {
702 err = sysfs_create_link(block_depr, &ddev->kobj,
703 kobject_name(&ddev->kobj));
704 if (err) {
705 device_del(ddev);
706 return;
707 }
708 }
709
710
711
712
713
714
715 pm_runtime_set_memalloc_noio(ddev, true);
716
717 disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj);
718 disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj);
719
720 if (disk->flags & GENHD_FL_HIDDEN) {
721 dev_set_uevent_suppress(ddev, 0);
722 return;
723 }
724
725
726 if (!disk_part_scan_enabled(disk))
727 goto exit;
728
729
730 if (!get_capacity(disk))
731 goto exit;
732
733 bdev = bdget_disk(disk, 0);
734 if (!bdev)
735 goto exit;
736
737 bdev->bd_invalidated = 1;
738 err = blkdev_get(bdev, FMODE_READ, NULL);
739 if (err < 0)
740 goto exit;
741 blkdev_put(bdev, FMODE_READ);
742
743exit:
744
745 dev_set_uevent_suppress(ddev, 0);
746 kobject_uevent(&ddev->kobj, KOBJ_ADD);
747
748
749 disk_part_iter_init(&piter, disk, 0);
750 while ((part = disk_part_iter_next(&piter)))
751 kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD);
752 disk_part_iter_exit(&piter);
753
754 if (disk->queue->backing_dev_info->dev) {
755 err = sysfs_create_link(&ddev->kobj,
756 &disk->queue->backing_dev_info->dev->kobj,
757 "bdi");
758 WARN_ON(err);
759 }
760}
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773
774static void __device_add_disk(struct device *parent, struct gendisk *disk,
775 const struct attribute_group **groups,
776 bool register_queue)
777{
778 dev_t devt;
779 int retval;
780
781
782
783
784
785
786
787 if (register_queue)
788 elevator_init_mq(disk->queue);
789
790
791
792
793
794 WARN_ON(disk->minors && !(disk->major || disk->first_minor));
795 WARN_ON(!disk->minors &&
796 !(disk->flags & (GENHD_FL_EXT_DEVT | GENHD_FL_HIDDEN)));
797
798 disk->flags |= GENHD_FL_UP;
799
800 retval = blk_alloc_devt(&disk->part0, &devt);
801 if (retval) {
802 WARN_ON(1);
803 return;
804 }
805 disk->major = MAJOR(devt);
806 disk->first_minor = MINOR(devt);
807
808 disk_alloc_events(disk);
809
810 if (disk->flags & GENHD_FL_HIDDEN) {
811
812
813
814
815 disk->flags |= GENHD_FL_SUPPRESS_PARTITION_INFO;
816 disk->flags |= GENHD_FL_NO_PART_SCAN;
817 } else {
818 struct backing_dev_info *bdi = disk->queue->backing_dev_info;
819 struct device *dev = disk_to_dev(disk);
820 int ret;
821
822
823 dev->devt = devt;
824 ret = bdi_register(bdi, "%u:%u", MAJOR(devt), MINOR(devt));
825 WARN_ON(ret);
826 bdi_set_owner(bdi, dev);
827 blk_register_region(disk_devt(disk), disk->minors, NULL,
828 exact_match, exact_lock, disk);
829 }
830 register_disk(parent, disk, groups);
831 if (register_queue)
832 blk_register_queue(disk);
833
834
835
836
837
838 WARN_ON_ONCE(!blk_get_queue(disk->queue));
839
840 disk_add_events(disk);
841 blk_integrity_add(disk);
842}
843
844void device_add_disk(struct device *parent, struct gendisk *disk,
845 const struct attribute_group **groups)
846
847{
848 __device_add_disk(parent, disk, groups, true);
849}
850EXPORT_SYMBOL(device_add_disk);
851
852void device_add_disk_no_queue_reg(struct device *parent, struct gendisk *disk)
853{
854 __device_add_disk(parent, disk, NULL, false);
855}
856EXPORT_SYMBOL(device_add_disk_no_queue_reg);
857
858static void invalidate_partition(struct gendisk *disk, int partno)
859{
860 struct block_device *bdev;
861
862 bdev = bdget_disk(disk, partno);
863 if (!bdev)
864 return;
865
866 fsync_bdev(bdev);
867 __invalidate_device(bdev, true);
868
869
870
871
872
873 remove_inode_hash(bdev->bd_inode);
874 bdput(bdev);
875}
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896void del_gendisk(struct gendisk *disk)
897{
898 struct disk_part_iter piter;
899 struct hd_struct *part;
900
901 might_sleep();
902
903 blk_integrity_del(disk);
904 disk_del_events(disk);
905
906
907
908
909
910 down_write(&disk->lookup_sem);
911
912 disk_part_iter_init(&piter, disk,
913 DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE);
914 while ((part = disk_part_iter_next(&piter))) {
915 invalidate_partition(disk, part->partno);
916 delete_partition(disk, part);
917 }
918 disk_part_iter_exit(&piter);
919
920 invalidate_partition(disk, 0);
921 set_capacity(disk, 0);
922 disk->flags &= ~GENHD_FL_UP;
923 up_write(&disk->lookup_sem);
924
925 if (!(disk->flags & GENHD_FL_HIDDEN))
926 sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi");
927 if (disk->queue) {
928
929
930
931
932 if (!(disk->flags & GENHD_FL_HIDDEN))
933 bdi_unregister(disk->queue->backing_dev_info);
934 blk_unregister_queue(disk);
935 } else {
936 WARN_ON(1);
937 }
938
939 if (!(disk->flags & GENHD_FL_HIDDEN))
940 blk_unregister_region(disk_devt(disk), disk->minors);
941
942
943
944
945
946
947 blk_invalidate_devt(disk_devt(disk));
948
949 kobject_put(disk->part0.holder_dir);
950 kobject_put(disk->slave_dir);
951
952 part_stat_set_all(&disk->part0, 0);
953 disk->part0.stamp = 0;
954 if (!sysfs_deprecated)
955 sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk)));
956 pm_runtime_set_memalloc_noio(disk_to_dev(disk), false);
957 device_del(disk_to_dev(disk));
958}
959EXPORT_SYMBOL(del_gendisk);
960
961
962static ssize_t disk_badblocks_show(struct device *dev,
963 struct device_attribute *attr,
964 char *page)
965{
966 struct gendisk *disk = dev_to_disk(dev);
967
968 if (!disk->bb)
969 return sprintf(page, "\n");
970
971 return badblocks_show(disk->bb, page, 0);
972}
973
974static ssize_t disk_badblocks_store(struct device *dev,
975 struct device_attribute *attr,
976 const char *page, size_t len)
977{
978 struct gendisk *disk = dev_to_disk(dev);
979
980 if (!disk->bb)
981 return -ENXIO;
982
983 return badblocks_store(disk->bb, page, len, 0);
984}
985
986
987
988
989
990
991
992
993
994
995
996struct gendisk *get_gendisk(dev_t devt, int *partno)
997{
998 struct gendisk *disk = NULL;
999
1000 might_sleep();
1001
1002 if (MAJOR(devt) != BLOCK_EXT_MAJOR) {
1003 struct kobject *kobj;
1004
1005 kobj = kobj_lookup(bdev_map, devt, partno);
1006 if (kobj)
1007 disk = dev_to_disk(kobj_to_dev(kobj));
1008 } else {
1009 struct hd_struct *part;
1010
1011 spin_lock_bh(&ext_devt_lock);
1012 part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt)));
1013 if (part && get_disk_and_module(part_to_disk(part))) {
1014 *partno = part->partno;
1015 disk = part_to_disk(part);
1016 }
1017 spin_unlock_bh(&ext_devt_lock);
1018 }
1019
1020 if (!disk)
1021 return NULL;
1022
1023
1024
1025
1026
1027 down_read(&disk->lookup_sem);
1028 if (unlikely((disk->flags & GENHD_FL_HIDDEN) ||
1029 !(disk->flags & GENHD_FL_UP))) {
1030 up_read(&disk->lookup_sem);
1031 put_disk_and_module(disk);
1032 disk = NULL;
1033 } else {
1034 up_read(&disk->lookup_sem);
1035 }
1036 return disk;
1037}
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052struct block_device *bdget_disk(struct gendisk *disk, int partno)
1053{
1054 struct hd_struct *part;
1055 struct block_device *bdev = NULL;
1056
1057 part = disk_get_part(disk, partno);
1058 if (part)
1059 bdev = bdget(part_devt(part));
1060 disk_put_part(part);
1061
1062 return bdev;
1063}
1064EXPORT_SYMBOL(bdget_disk);
1065
1066
1067
1068
1069
1070
1071void __init printk_all_partitions(void)
1072{
1073 struct class_dev_iter iter;
1074 struct device *dev;
1075
1076 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1077 while ((dev = class_dev_iter_next(&iter))) {
1078 struct gendisk *disk = dev_to_disk(dev);
1079 struct disk_part_iter piter;
1080 struct hd_struct *part;
1081 char name_buf[BDEVNAME_SIZE];
1082 char devt_buf[BDEVT_SIZE];
1083
1084
1085
1086
1087
1088 if (get_capacity(disk) == 0 ||
1089 (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO))
1090 continue;
1091
1092
1093
1094
1095
1096
1097 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0);
1098 while ((part = disk_part_iter_next(&piter))) {
1099 bool is_part0 = part == &disk->part0;
1100
1101 printk("%s%s %10llu %s %s", is_part0 ? "" : " ",
1102 bdevt_str(part_devt(part), devt_buf),
1103 (unsigned long long)part_nr_sects_read(part) >> 1
1104 , disk_name(disk, part->partno, name_buf),
1105 part->info ? part->info->uuid : "");
1106 if (is_part0) {
1107 if (dev->parent && dev->parent->driver)
1108 printk(" driver: %s\n",
1109 dev->parent->driver->name);
1110 else
1111 printk(" (driver?)\n");
1112 } else
1113 printk("\n");
1114 }
1115 disk_part_iter_exit(&piter);
1116 }
1117 class_dev_iter_exit(&iter);
1118}
1119
1120#ifdef CONFIG_PROC_FS
1121
1122static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos)
1123{
1124 loff_t skip = *pos;
1125 struct class_dev_iter *iter;
1126 struct device *dev;
1127
1128 iter = kmalloc(sizeof(*iter), GFP_KERNEL);
1129 if (!iter)
1130 return ERR_PTR(-ENOMEM);
1131
1132 seqf->private = iter;
1133 class_dev_iter_init(iter, &block_class, NULL, &disk_type);
1134 do {
1135 dev = class_dev_iter_next(iter);
1136 if (!dev)
1137 return NULL;
1138 } while (skip--);
1139
1140 return dev_to_disk(dev);
1141}
1142
1143static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos)
1144{
1145 struct device *dev;
1146
1147 (*pos)++;
1148 dev = class_dev_iter_next(seqf->private);
1149 if (dev)
1150 return dev_to_disk(dev);
1151
1152 return NULL;
1153}
1154
1155static void disk_seqf_stop(struct seq_file *seqf, void *v)
1156{
1157 struct class_dev_iter *iter = seqf->private;
1158
1159
1160 if (iter) {
1161 class_dev_iter_exit(iter);
1162 kfree(iter);
1163 seqf->private = NULL;
1164 }
1165}
1166
1167static void *show_partition_start(struct seq_file *seqf, loff_t *pos)
1168{
1169 void *p;
1170
1171 p = disk_seqf_start(seqf, pos);
1172 if (!IS_ERR_OR_NULL(p) && !*pos)
1173 seq_puts(seqf, "major minor #blocks name\n\n");
1174 return p;
1175}
1176
1177static int show_partition(struct seq_file *seqf, void *v)
1178{
1179 struct gendisk *sgp = v;
1180 struct disk_part_iter piter;
1181 struct hd_struct *part;
1182 char buf[BDEVNAME_SIZE];
1183
1184
1185 if (!get_capacity(sgp) || (!disk_max_parts(sgp) &&
1186 (sgp->flags & GENHD_FL_REMOVABLE)))
1187 return 0;
1188 if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)
1189 return 0;
1190
1191
1192 disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0);
1193 while ((part = disk_part_iter_next(&piter)))
1194 seq_printf(seqf, "%4d %7d %10llu %s\n",
1195 MAJOR(part_devt(part)), MINOR(part_devt(part)),
1196 (unsigned long long)part_nr_sects_read(part) >> 1,
1197 disk_name(sgp, part->partno, buf));
1198 disk_part_iter_exit(&piter);
1199
1200 return 0;
1201}
1202
1203static const struct seq_operations partitions_op = {
1204 .start = show_partition_start,
1205 .next = disk_seqf_next,
1206 .stop = disk_seqf_stop,
1207 .show = show_partition
1208};
1209#endif
1210
1211
1212static struct kobject *base_probe(dev_t devt, int *partno, void *data)
1213{
1214 if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0)
1215
1216 request_module("block-major-%d", MAJOR(devt));
1217 return NULL;
1218}
1219
1220static int __init genhd_device_init(void)
1221{
1222 int error;
1223
1224 block_class.dev_kobj = sysfs_dev_block_kobj;
1225 error = class_register(&block_class);
1226 if (unlikely(error))
1227 return error;
1228 bdev_map = kobj_map_init(base_probe, &block_class_lock);
1229 blk_dev_init();
1230
1231 register_blkdev(BLOCK_EXT_MAJOR, "blkext");
1232
1233
1234 if (!sysfs_deprecated)
1235 block_depr = kobject_create_and_add("block", NULL);
1236 return 0;
1237}
1238
1239subsys_initcall(genhd_device_init);
1240
1241static ssize_t disk_range_show(struct device *dev,
1242 struct device_attribute *attr, char *buf)
1243{
1244 struct gendisk *disk = dev_to_disk(dev);
1245
1246 return sprintf(buf, "%d\n", disk->minors);
1247}
1248
1249static ssize_t disk_ext_range_show(struct device *dev,
1250 struct device_attribute *attr, char *buf)
1251{
1252 struct gendisk *disk = dev_to_disk(dev);
1253
1254 return sprintf(buf, "%d\n", disk_max_parts(disk));
1255}
1256
1257static ssize_t disk_removable_show(struct device *dev,
1258 struct device_attribute *attr, char *buf)
1259{
1260 struct gendisk *disk = dev_to_disk(dev);
1261
1262 return sprintf(buf, "%d\n",
1263 (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0));
1264}
1265
1266static ssize_t disk_hidden_show(struct device *dev,
1267 struct device_attribute *attr, char *buf)
1268{
1269 struct gendisk *disk = dev_to_disk(dev);
1270
1271 return sprintf(buf, "%d\n",
1272 (disk->flags & GENHD_FL_HIDDEN ? 1 : 0));
1273}
1274
1275static ssize_t disk_ro_show(struct device *dev,
1276 struct device_attribute *attr, char *buf)
1277{
1278 struct gendisk *disk = dev_to_disk(dev);
1279
1280 return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0);
1281}
1282
1283ssize_t part_size_show(struct device *dev,
1284 struct device_attribute *attr, char *buf)
1285{
1286 struct hd_struct *p = dev_to_part(dev);
1287
1288 return sprintf(buf, "%llu\n",
1289 (unsigned long long)part_nr_sects_read(p));
1290}
1291
1292ssize_t part_stat_show(struct device *dev,
1293 struct device_attribute *attr, char *buf)
1294{
1295 struct hd_struct *p = dev_to_part(dev);
1296 struct request_queue *q = part_to_disk(p)->queue;
1297 struct disk_stats stat;
1298 unsigned int inflight;
1299
1300 part_stat_read_all(p, &stat);
1301 if (queue_is_mq(q))
1302 inflight = blk_mq_in_flight(q, p);
1303 else
1304 inflight = part_in_flight(q, p);
1305
1306 return sprintf(buf,
1307 "%8lu %8lu %8llu %8u "
1308 "%8lu %8lu %8llu %8u "
1309 "%8u %8u %8u "
1310 "%8lu %8lu %8llu %8u "
1311 "%8lu %8u"
1312 "\n",
1313 stat.ios[STAT_READ],
1314 stat.merges[STAT_READ],
1315 (unsigned long long)stat.sectors[STAT_READ],
1316 (unsigned int)div_u64(stat.nsecs[STAT_READ], NSEC_PER_MSEC),
1317 stat.ios[STAT_WRITE],
1318 stat.merges[STAT_WRITE],
1319 (unsigned long long)stat.sectors[STAT_WRITE],
1320 (unsigned int)div_u64(stat.nsecs[STAT_WRITE], NSEC_PER_MSEC),
1321 inflight,
1322 jiffies_to_msecs(stat.io_ticks),
1323 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1324 stat.nsecs[STAT_WRITE] +
1325 stat.nsecs[STAT_DISCARD] +
1326 stat.nsecs[STAT_FLUSH],
1327 NSEC_PER_MSEC),
1328 stat.ios[STAT_DISCARD],
1329 stat.merges[STAT_DISCARD],
1330 (unsigned long long)stat.sectors[STAT_DISCARD],
1331 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD], NSEC_PER_MSEC),
1332 stat.ios[STAT_FLUSH],
1333 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH], NSEC_PER_MSEC));
1334}
1335
1336ssize_t part_inflight_show(struct device *dev, struct device_attribute *attr,
1337 char *buf)
1338{
1339 struct hd_struct *p = dev_to_part(dev);
1340 struct request_queue *q = part_to_disk(p)->queue;
1341 unsigned int inflight[2];
1342
1343 if (queue_is_mq(q))
1344 blk_mq_in_flight_rw(q, p, inflight);
1345 else
1346 part_in_flight_rw(q, p, inflight);
1347
1348 return sprintf(buf, "%8u %8u\n", inflight[0], inflight[1]);
1349}
1350
1351static ssize_t disk_capability_show(struct device *dev,
1352 struct device_attribute *attr, char *buf)
1353{
1354 struct gendisk *disk = dev_to_disk(dev);
1355
1356 return sprintf(buf, "%x\n", disk->flags);
1357}
1358
1359static ssize_t disk_alignment_offset_show(struct device *dev,
1360 struct device_attribute *attr,
1361 char *buf)
1362{
1363 struct gendisk *disk = dev_to_disk(dev);
1364
1365 return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue));
1366}
1367
1368static ssize_t disk_discard_alignment_show(struct device *dev,
1369 struct device_attribute *attr,
1370 char *buf)
1371{
1372 struct gendisk *disk = dev_to_disk(dev);
1373
1374 return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue));
1375}
1376
1377static DEVICE_ATTR(range, 0444, disk_range_show, NULL);
1378static DEVICE_ATTR(ext_range, 0444, disk_ext_range_show, NULL);
1379static DEVICE_ATTR(removable, 0444, disk_removable_show, NULL);
1380static DEVICE_ATTR(hidden, 0444, disk_hidden_show, NULL);
1381static DEVICE_ATTR(ro, 0444, disk_ro_show, NULL);
1382static DEVICE_ATTR(size, 0444, part_size_show, NULL);
1383static DEVICE_ATTR(alignment_offset, 0444, disk_alignment_offset_show, NULL);
1384static DEVICE_ATTR(discard_alignment, 0444, disk_discard_alignment_show, NULL);
1385static DEVICE_ATTR(capability, 0444, disk_capability_show, NULL);
1386static DEVICE_ATTR(stat, 0444, part_stat_show, NULL);
1387static DEVICE_ATTR(inflight, 0444, part_inflight_show, NULL);
1388static DEVICE_ATTR(badblocks, 0644, disk_badblocks_show, disk_badblocks_store);
1389
1390#ifdef CONFIG_FAIL_MAKE_REQUEST
1391ssize_t part_fail_show(struct device *dev,
1392 struct device_attribute *attr, char *buf)
1393{
1394 struct hd_struct *p = dev_to_part(dev);
1395
1396 return sprintf(buf, "%d\n", p->make_it_fail);
1397}
1398
1399ssize_t part_fail_store(struct device *dev,
1400 struct device_attribute *attr,
1401 const char *buf, size_t count)
1402{
1403 struct hd_struct *p = dev_to_part(dev);
1404 int i;
1405
1406 if (count > 0 && sscanf(buf, "%d", &i) > 0)
1407 p->make_it_fail = (i == 0) ? 0 : 1;
1408
1409 return count;
1410}
1411
1412static struct device_attribute dev_attr_fail =
1413 __ATTR(make-it-fail, 0644, part_fail_show, part_fail_store);
1414#endif
1415
1416#ifdef CONFIG_FAIL_IO_TIMEOUT
1417static struct device_attribute dev_attr_fail_timeout =
1418 __ATTR(io-timeout-fail, 0644, part_timeout_show, part_timeout_store);
1419#endif
1420
1421static struct attribute *disk_attrs[] = {
1422 &dev_attr_range.attr,
1423 &dev_attr_ext_range.attr,
1424 &dev_attr_removable.attr,
1425 &dev_attr_hidden.attr,
1426 &dev_attr_ro.attr,
1427 &dev_attr_size.attr,
1428 &dev_attr_alignment_offset.attr,
1429 &dev_attr_discard_alignment.attr,
1430 &dev_attr_capability.attr,
1431 &dev_attr_stat.attr,
1432 &dev_attr_inflight.attr,
1433 &dev_attr_badblocks.attr,
1434#ifdef CONFIG_FAIL_MAKE_REQUEST
1435 &dev_attr_fail.attr,
1436#endif
1437#ifdef CONFIG_FAIL_IO_TIMEOUT
1438 &dev_attr_fail_timeout.attr,
1439#endif
1440 NULL
1441};
1442
1443static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n)
1444{
1445 struct device *dev = container_of(kobj, typeof(*dev), kobj);
1446 struct gendisk *disk = dev_to_disk(dev);
1447
1448 if (a == &dev_attr_badblocks.attr && !disk->bb)
1449 return 0;
1450 return a->mode;
1451}
1452
1453static struct attribute_group disk_attr_group = {
1454 .attrs = disk_attrs,
1455 .is_visible = disk_visible,
1456};
1457
1458static const struct attribute_group *disk_attr_groups[] = {
1459 &disk_attr_group,
1460 NULL
1461};
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474static void disk_replace_part_tbl(struct gendisk *disk,
1475 struct disk_part_tbl *new_ptbl)
1476{
1477 struct disk_part_tbl *old_ptbl =
1478 rcu_dereference_protected(disk->part_tbl, 1);
1479
1480 rcu_assign_pointer(disk->part_tbl, new_ptbl);
1481
1482 if (old_ptbl) {
1483 rcu_assign_pointer(old_ptbl->last_lookup, NULL);
1484 kfree_rcu(old_ptbl, rcu_head);
1485 }
1486}
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503int disk_expand_part_tbl(struct gendisk *disk, int partno)
1504{
1505 struct disk_part_tbl *old_ptbl =
1506 rcu_dereference_protected(disk->part_tbl, 1);
1507 struct disk_part_tbl *new_ptbl;
1508 int len = old_ptbl ? old_ptbl->len : 0;
1509 int i, target;
1510
1511
1512
1513
1514
1515 target = partno + 1;
1516 if (target < 0)
1517 return -EINVAL;
1518
1519
1520 if (disk_max_parts(disk) && target > disk_max_parts(disk))
1521 return -EINVAL;
1522
1523 if (target <= len)
1524 return 0;
1525
1526 new_ptbl = kzalloc_node(struct_size(new_ptbl, part, target), GFP_KERNEL,
1527 disk->node_id);
1528 if (!new_ptbl)
1529 return -ENOMEM;
1530
1531 new_ptbl->len = target;
1532
1533 for (i = 0; i < len; i++)
1534 rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]);
1535
1536 disk_replace_part_tbl(disk, new_ptbl);
1537 return 0;
1538}
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559static void disk_release(struct device *dev)
1560{
1561 struct gendisk *disk = dev_to_disk(dev);
1562
1563 might_sleep();
1564
1565 blk_free_devt(dev->devt);
1566 disk_release_events(disk);
1567 kfree(disk->random);
1568 disk_replace_part_tbl(disk, NULL);
1569 hd_free_part(&disk->part0);
1570 if (disk->queue)
1571 blk_put_queue(disk->queue);
1572 kfree(disk);
1573}
1574struct class block_class = {
1575 .name = "block",
1576};
1577
1578static char *block_devnode(struct device *dev, umode_t *mode,
1579 kuid_t *uid, kgid_t *gid)
1580{
1581 struct gendisk *disk = dev_to_disk(dev);
1582
1583 if (disk->fops->devnode)
1584 return disk->fops->devnode(disk, mode);
1585 return NULL;
1586}
1587
1588const struct device_type disk_type = {
1589 .name = "disk",
1590 .groups = disk_attr_groups,
1591 .release = disk_release,
1592 .devnode = block_devnode,
1593};
1594
1595#ifdef CONFIG_PROC_FS
1596
1597
1598
1599
1600
1601
1602
1603static int diskstats_show(struct seq_file *seqf, void *v)
1604{
1605 struct gendisk *gp = v;
1606 struct disk_part_iter piter;
1607 struct hd_struct *hd;
1608 char buf[BDEVNAME_SIZE];
1609 unsigned int inflight;
1610 struct disk_stats stat;
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620 disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0);
1621 while ((hd = disk_part_iter_next(&piter))) {
1622 part_stat_read_all(hd, &stat);
1623 if (queue_is_mq(gp->queue))
1624 inflight = blk_mq_in_flight(gp->queue, hd);
1625 else
1626 inflight = part_in_flight(gp->queue, hd);
1627
1628 seq_printf(seqf, "%4d %7d %s "
1629 "%lu %lu %lu %u "
1630 "%lu %lu %lu %u "
1631 "%u %u %u "
1632 "%lu %lu %lu %u "
1633 "%lu %u"
1634 "\n",
1635 MAJOR(part_devt(hd)), MINOR(part_devt(hd)),
1636 disk_name(gp, hd->partno, buf),
1637 stat.ios[STAT_READ],
1638 stat.merges[STAT_READ],
1639 stat.sectors[STAT_READ],
1640 (unsigned int)div_u64(stat.nsecs[STAT_READ],
1641 NSEC_PER_MSEC),
1642 stat.ios[STAT_WRITE],
1643 stat.merges[STAT_WRITE],
1644 stat.sectors[STAT_WRITE],
1645 (unsigned int)div_u64(stat.nsecs[STAT_WRITE],
1646 NSEC_PER_MSEC),
1647 inflight,
1648 jiffies_to_msecs(stat.io_ticks),
1649 (unsigned int)div_u64(stat.nsecs[STAT_READ] +
1650 stat.nsecs[STAT_WRITE] +
1651 stat.nsecs[STAT_DISCARD] +
1652 stat.nsecs[STAT_FLUSH],
1653 NSEC_PER_MSEC),
1654 stat.ios[STAT_DISCARD],
1655 stat.merges[STAT_DISCARD],
1656 stat.sectors[STAT_DISCARD],
1657 (unsigned int)div_u64(stat.nsecs[STAT_DISCARD],
1658 NSEC_PER_MSEC),
1659 stat.ios[STAT_FLUSH],
1660 (unsigned int)div_u64(stat.nsecs[STAT_FLUSH],
1661 NSEC_PER_MSEC)
1662 );
1663 }
1664 disk_part_iter_exit(&piter);
1665
1666 return 0;
1667}
1668
1669static const struct seq_operations diskstats_op = {
1670 .start = disk_seqf_start,
1671 .next = disk_seqf_next,
1672 .stop = disk_seqf_stop,
1673 .show = diskstats_show
1674};
1675
1676static int __init proc_genhd_init(void)
1677{
1678 proc_create_seq("diskstats", 0, NULL, &diskstats_op);
1679 proc_create_seq("partitions", 0, NULL, &partitions_op);
1680 return 0;
1681}
1682module_init(proc_genhd_init);
1683#endif
1684
1685dev_t blk_lookup_devt(const char *name, int partno)
1686{
1687 dev_t devt = MKDEV(0, 0);
1688 struct class_dev_iter iter;
1689 struct device *dev;
1690
1691 class_dev_iter_init(&iter, &block_class, NULL, &disk_type);
1692 while ((dev = class_dev_iter_next(&iter))) {
1693 struct gendisk *disk = dev_to_disk(dev);
1694 struct hd_struct *part;
1695
1696 if (strcmp(dev_name(dev), name))
1697 continue;
1698
1699 if (partno < disk->minors) {
1700
1701
1702
1703 devt = MKDEV(MAJOR(dev->devt),
1704 MINOR(dev->devt) + partno);
1705 break;
1706 }
1707 part = disk_get_part(disk, partno);
1708 if (part) {
1709 devt = part_devt(part);
1710 disk_put_part(part);
1711 break;
1712 }
1713 disk_put_part(part);
1714 }
1715 class_dev_iter_exit(&iter);
1716 return devt;
1717}
1718
1719struct gendisk *__alloc_disk_node(int minors, int node_id)
1720{
1721 struct gendisk *disk;
1722 struct disk_part_tbl *ptbl;
1723
1724 if (minors > DISK_MAX_PARTS) {
1725 printk(KERN_ERR
1726 "block: can't allocate more than %d partitions\n",
1727 DISK_MAX_PARTS);
1728 minors = DISK_MAX_PARTS;
1729 }
1730
1731 disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id);
1732 if (disk) {
1733 disk->part0.dkstats = alloc_percpu(struct disk_stats);
1734 if (!disk->part0.dkstats) {
1735 kfree(disk);
1736 return NULL;
1737 }
1738 init_rwsem(&disk->lookup_sem);
1739 disk->node_id = node_id;
1740 if (disk_expand_part_tbl(disk, 0)) {
1741 free_percpu(disk->part0.dkstats);
1742 kfree(disk);
1743 return NULL;
1744 }
1745 ptbl = rcu_dereference_protected(disk->part_tbl, 1);
1746 rcu_assign_pointer(ptbl->part[0], &disk->part0);
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757 hd_sects_seq_init(&disk->part0);
1758 if (hd_ref_init(&disk->part0)) {
1759 hd_free_part(&disk->part0);
1760 kfree(disk);
1761 return NULL;
1762 }
1763
1764 disk->minors = minors;
1765 rand_initialize_disk(disk);
1766 disk_to_dev(disk)->class = &block_class;
1767 disk_to_dev(disk)->type = &disk_type;
1768 device_initialize(disk_to_dev(disk));
1769 }
1770 return disk;
1771}
1772EXPORT_SYMBOL(__alloc_disk_node);
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783struct kobject *get_disk_and_module(struct gendisk *disk)
1784{
1785 struct module *owner;
1786 struct kobject *kobj;
1787
1788 if (!disk->fops)
1789 return NULL;
1790 owner = disk->fops->owner;
1791 if (owner && !try_module_get(owner))
1792 return NULL;
1793 kobj = kobject_get_unless_zero(&disk_to_dev(disk)->kobj);
1794 if (kobj == NULL) {
1795 module_put(owner);
1796 return NULL;
1797 }
1798 return kobj;
1799
1800}
1801EXPORT_SYMBOL(get_disk_and_module);
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813void put_disk(struct gendisk *disk)
1814{
1815 if (disk)
1816 kobject_put(&disk_to_dev(disk)->kobj);
1817}
1818EXPORT_SYMBOL(put_disk);
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830void put_disk_and_module(struct gendisk *disk)
1831{
1832 if (disk) {
1833 struct module *owner = disk->fops->owner;
1834
1835 put_disk(disk);
1836 module_put(owner);
1837 }
1838}
1839EXPORT_SYMBOL(put_disk_and_module);
1840
1841static void set_disk_ro_uevent(struct gendisk *gd, int ro)
1842{
1843 char event[] = "DISK_RO=1";
1844 char *envp[] = { event, NULL };
1845
1846 if (!ro)
1847 event[8] = '0';
1848 kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp);
1849}
1850
1851void set_device_ro(struct block_device *bdev, int flag)
1852{
1853 bdev->bd_part->policy = flag;
1854}
1855
1856EXPORT_SYMBOL(set_device_ro);
1857
1858void set_disk_ro(struct gendisk *disk, int flag)
1859{
1860 struct disk_part_iter piter;
1861 struct hd_struct *part;
1862
1863 if (disk->part0.policy != flag) {
1864 set_disk_ro_uevent(disk, flag);
1865 disk->part0.policy = flag;
1866 }
1867
1868 disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY);
1869 while ((part = disk_part_iter_next(&piter)))
1870 part->policy = flag;
1871 disk_part_iter_exit(&piter);
1872}
1873
1874EXPORT_SYMBOL(set_disk_ro);
1875
1876int bdev_read_only(struct block_device *bdev)
1877{
1878 if (!bdev)
1879 return 0;
1880 return bdev->bd_part->policy;
1881}
1882
1883EXPORT_SYMBOL(bdev_read_only);
1884
1885
1886
1887
1888struct disk_events {
1889 struct list_head node;
1890 struct gendisk *disk;
1891 spinlock_t lock;
1892
1893 struct mutex block_mutex;
1894 int block;
1895 unsigned int pending;
1896 unsigned int clearing;
1897
1898 long poll_msecs;
1899 struct delayed_work dwork;
1900};
1901
1902static const char *disk_events_strs[] = {
1903 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change",
1904 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request",
1905};
1906
1907static char *disk_uevents[] = {
1908 [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1",
1909 [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1",
1910};
1911
1912
1913static DEFINE_MUTEX(disk_events_mutex);
1914static LIST_HEAD(disk_events);
1915
1916
1917static unsigned long disk_events_dfl_poll_msecs;
1918
1919static unsigned long disk_events_poll_jiffies(struct gendisk *disk)
1920{
1921 struct disk_events *ev = disk->ev;
1922 long intv_msecs = 0;
1923
1924
1925
1926
1927
1928 if (ev->poll_msecs >= 0)
1929 intv_msecs = ev->poll_msecs;
1930 else if (disk->event_flags & DISK_EVENT_FLAG_POLL)
1931 intv_msecs = disk_events_dfl_poll_msecs;
1932
1933 return msecs_to_jiffies(intv_msecs);
1934}
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951void disk_block_events(struct gendisk *disk)
1952{
1953 struct disk_events *ev = disk->ev;
1954 unsigned long flags;
1955 bool cancel;
1956
1957 if (!ev)
1958 return;
1959
1960
1961
1962
1963
1964 mutex_lock(&ev->block_mutex);
1965
1966 spin_lock_irqsave(&ev->lock, flags);
1967 cancel = !ev->block++;
1968 spin_unlock_irqrestore(&ev->lock, flags);
1969
1970 if (cancel)
1971 cancel_delayed_work_sync(&disk->ev->dwork);
1972
1973 mutex_unlock(&ev->block_mutex);
1974}
1975
1976static void __disk_unblock_events(struct gendisk *disk, bool check_now)
1977{
1978 struct disk_events *ev = disk->ev;
1979 unsigned long intv;
1980 unsigned long flags;
1981
1982 spin_lock_irqsave(&ev->lock, flags);
1983
1984 if (WARN_ON_ONCE(ev->block <= 0))
1985 goto out_unlock;
1986
1987 if (--ev->block)
1988 goto out_unlock;
1989
1990 intv = disk_events_poll_jiffies(disk);
1991 if (check_now)
1992 queue_delayed_work(system_freezable_power_efficient_wq,
1993 &ev->dwork, 0);
1994 else if (intv)
1995 queue_delayed_work(system_freezable_power_efficient_wq,
1996 &ev->dwork, intv);
1997out_unlock:
1998 spin_unlock_irqrestore(&ev->lock, flags);
1999}
2000
2001
2002
2003
2004
2005
2006
2007
2008
2009
2010
2011void disk_unblock_events(struct gendisk *disk)
2012{
2013 if (disk->ev)
2014 __disk_unblock_events(disk, false);
2015}
2016
2017
2018
2019
2020
2021
2022
2023
2024
2025
2026
2027
2028
2029void disk_flush_events(struct gendisk *disk, unsigned int mask)
2030{
2031 struct disk_events *ev = disk->ev;
2032
2033 if (!ev)
2034 return;
2035
2036 spin_lock_irq(&ev->lock);
2037 ev->clearing |= mask;
2038 if (!ev->block)
2039 mod_delayed_work(system_freezable_power_efficient_wq,
2040 &ev->dwork, 0);
2041 spin_unlock_irq(&ev->lock);
2042}
2043
2044
2045
2046
2047
2048
2049
2050
2051
2052
2053
2054
2055unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask)
2056{
2057 struct disk_events *ev = disk->ev;
2058 unsigned int pending;
2059 unsigned int clearing = mask;
2060
2061 if (!ev)
2062 return 0;
2063
2064 disk_block_events(disk);
2065
2066
2067
2068
2069
2070
2071 spin_lock_irq(&ev->lock);
2072 clearing |= ev->clearing;
2073 ev->clearing = 0;
2074 spin_unlock_irq(&ev->lock);
2075
2076 disk_check_events(ev, &clearing);
2077
2078
2079
2080
2081 __disk_unblock_events(disk, ev->clearing ? true : false);
2082
2083
2084 spin_lock_irq(&ev->lock);
2085 pending = ev->pending & mask;
2086 ev->pending &= ~mask;
2087 spin_unlock_irq(&ev->lock);
2088 WARN_ON_ONCE(clearing & mask);
2089
2090 return pending;
2091}
2092
2093
2094
2095
2096
2097static void disk_events_workfn(struct work_struct *work)
2098{
2099 struct delayed_work *dwork = to_delayed_work(work);
2100 struct disk_events *ev = container_of(dwork, struct disk_events, dwork);
2101
2102 disk_check_events(ev, &ev->clearing);
2103}
2104
2105static void disk_check_events(struct disk_events *ev,
2106 unsigned int *clearing_ptr)
2107{
2108 struct gendisk *disk = ev->disk;
2109 char *envp[ARRAY_SIZE(disk_uevents) + 1] = { };
2110 unsigned int clearing = *clearing_ptr;
2111 unsigned int events;
2112 unsigned long intv;
2113 int nr_events = 0, i;
2114
2115
2116 events = disk->fops->check_events(disk, clearing);
2117
2118
2119 spin_lock_irq(&ev->lock);
2120
2121 events &= ~ev->pending;
2122 ev->pending |= events;
2123 *clearing_ptr &= ~clearing;
2124
2125 intv = disk_events_poll_jiffies(disk);
2126 if (!ev->block && intv)
2127 queue_delayed_work(system_freezable_power_efficient_wq,
2128 &ev->dwork, intv);
2129
2130 spin_unlock_irq(&ev->lock);
2131
2132
2133
2134
2135
2136
2137
2138 for (i = 0; i < ARRAY_SIZE(disk_uevents); i++)
2139 if ((events & disk->events & (1 << i)) &&
2140 (disk->event_flags & DISK_EVENT_FLAG_UEVENT))
2141 envp[nr_events++] = disk_uevents[i];
2142
2143 if (nr_events)
2144 kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp);
2145}
2146
2147
2148
2149
2150
2151
2152
2153
2154
2155
2156static ssize_t __disk_events_show(unsigned int events, char *buf)
2157{
2158 const char *delim = "";
2159 ssize_t pos = 0;
2160 int i;
2161
2162 for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++)
2163 if (events & (1 << i)) {
2164 pos += sprintf(buf + pos, "%s%s",
2165 delim, disk_events_strs[i]);
2166 delim = " ";
2167 }
2168 if (pos)
2169 pos += sprintf(buf + pos, "\n");
2170 return pos;
2171}
2172
2173static ssize_t disk_events_show(struct device *dev,
2174 struct device_attribute *attr, char *buf)
2175{
2176 struct gendisk *disk = dev_to_disk(dev);
2177
2178 if (!(disk->event_flags & DISK_EVENT_FLAG_UEVENT))
2179 return 0;
2180
2181 return __disk_events_show(disk->events, buf);
2182}
2183
2184static ssize_t disk_events_async_show(struct device *dev,
2185 struct device_attribute *attr, char *buf)
2186{
2187 return 0;
2188}
2189
2190static ssize_t disk_events_poll_msecs_show(struct device *dev,
2191 struct device_attribute *attr,
2192 char *buf)
2193{
2194 struct gendisk *disk = dev_to_disk(dev);
2195
2196 if (!disk->ev)
2197 return sprintf(buf, "-1\n");
2198
2199 return sprintf(buf, "%ld\n", disk->ev->poll_msecs);
2200}
2201
2202static ssize_t disk_events_poll_msecs_store(struct device *dev,
2203 struct device_attribute *attr,
2204 const char *buf, size_t count)
2205{
2206 struct gendisk *disk = dev_to_disk(dev);
2207 long intv;
2208
2209 if (!count || !sscanf(buf, "%ld", &intv))
2210 return -EINVAL;
2211
2212 if (intv < 0 && intv != -1)
2213 return -EINVAL;
2214
2215 if (!disk->ev)
2216 return -ENODEV;
2217
2218 disk_block_events(disk);
2219 disk->ev->poll_msecs = intv;
2220 __disk_unblock_events(disk, true);
2221
2222 return count;
2223}
2224
2225static const DEVICE_ATTR(events, 0444, disk_events_show, NULL);
2226static const DEVICE_ATTR(events_async, 0444, disk_events_async_show, NULL);
2227static const DEVICE_ATTR(events_poll_msecs, 0644,
2228 disk_events_poll_msecs_show,
2229 disk_events_poll_msecs_store);
2230
2231static const struct attribute *disk_events_attrs[] = {
2232 &dev_attr_events.attr,
2233 &dev_attr_events_async.attr,
2234 &dev_attr_events_poll_msecs.attr,
2235 NULL,
2236};
2237
2238
2239
2240
2241
2242
2243
2244static int disk_events_set_dfl_poll_msecs(const char *val,
2245 const struct kernel_param *kp)
2246{
2247 struct disk_events *ev;
2248 int ret;
2249
2250 ret = param_set_ulong(val, kp);
2251 if (ret < 0)
2252 return ret;
2253
2254 mutex_lock(&disk_events_mutex);
2255
2256 list_for_each_entry(ev, &disk_events, node)
2257 disk_flush_events(ev->disk, 0);
2258
2259 mutex_unlock(&disk_events_mutex);
2260
2261 return 0;
2262}
2263
2264static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = {
2265 .set = disk_events_set_dfl_poll_msecs,
2266 .get = param_get_ulong,
2267};
2268
2269#undef MODULE_PARAM_PREFIX
2270#define MODULE_PARAM_PREFIX "block."
2271
2272module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops,
2273 &disk_events_dfl_poll_msecs, 0644);
2274
2275
2276
2277
2278static void disk_alloc_events(struct gendisk *disk)
2279{
2280 struct disk_events *ev;
2281
2282 if (!disk->fops->check_events || !disk->events)
2283 return;
2284
2285 ev = kzalloc(sizeof(*ev), GFP_KERNEL);
2286 if (!ev) {
2287 pr_warn("%s: failed to initialize events\n", disk->disk_name);
2288 return;
2289 }
2290
2291 INIT_LIST_HEAD(&ev->node);
2292 ev->disk = disk;
2293 spin_lock_init(&ev->lock);
2294 mutex_init(&ev->block_mutex);
2295 ev->block = 1;
2296 ev->poll_msecs = -1;
2297 INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn);
2298
2299 disk->ev = ev;
2300}
2301
2302static void disk_add_events(struct gendisk *disk)
2303{
2304
2305 if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0)
2306 pr_warn("%s: failed to create sysfs files for events\n",
2307 disk->disk_name);
2308
2309 if (!disk->ev)
2310 return;
2311
2312 mutex_lock(&disk_events_mutex);
2313 list_add_tail(&disk->ev->node, &disk_events);
2314 mutex_unlock(&disk_events_mutex);
2315
2316
2317
2318
2319
2320 __disk_unblock_events(disk, true);
2321}
2322
2323static void disk_del_events(struct gendisk *disk)
2324{
2325 if (disk->ev) {
2326 disk_block_events(disk);
2327
2328 mutex_lock(&disk_events_mutex);
2329 list_del_init(&disk->ev->node);
2330 mutex_unlock(&disk_events_mutex);
2331 }
2332
2333 sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs);
2334}
2335
2336static void disk_release_events(struct gendisk *disk)
2337{
2338
2339 WARN_ON_ONCE(disk->ev && disk->ev->block != 1);
2340 kfree(disk->ev);
2341}
2342