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1 | /* | |
2 | * gendisk handling | |
3 | */ | |
4 | ||
5 | #include <linux/module.h> | |
6 | #include <linux/fs.h> | |
7 | #include <linux/genhd.h> | |
8 | #include <linux/kdev_t.h> | |
9 | #include <linux/kernel.h> | |
10 | #include <linux/blkdev.h> | |
11 | #include <linux/init.h> | |
12 | #include <linux/spinlock.h> | |
13 | #include <linux/proc_fs.h> | |
14 | #include <linux/seq_file.h> | |
15 | #include <linux/slab.h> | |
16 | #include <linux/kmod.h> | |
17 | #include <linux/kobj_map.h> | |
18 | #include <linux/buffer_head.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/idr.h> | |
21 | #include <linux/log2.h> | |
22 | ||
23 | #include "blk.h" | |
24 | ||
25 | static DEFINE_MUTEX(block_class_lock); | |
26 | struct kobject *block_depr; | |
27 | ||
28 | /* for extended dynamic devt allocation, currently only one major is used */ | |
29 | #define MAX_EXT_DEVT (1 << MINORBITS) | |
30 | ||
31 | /* For extended devt allocation. ext_devt_mutex prevents look up | |
32 | * results from going away underneath its user. | |
33 | */ | |
34 | static DEFINE_MUTEX(ext_devt_mutex); | |
35 | static DEFINE_IDR(ext_devt_idr); | |
36 | ||
37 | static struct device_type disk_type; | |
38 | ||
39 | static void disk_add_events(struct gendisk *disk); | |
40 | static void disk_del_events(struct gendisk *disk); | |
41 | static void disk_release_events(struct gendisk *disk); | |
42 | ||
43 | /** | |
44 | * disk_get_part - get partition | |
45 | * @disk: disk to look partition from | |
46 | * @partno: partition number | |
47 | * | |
48 | * Look for partition @partno from @disk. If found, increment | |
49 | * reference count and return it. | |
50 | * | |
51 | * CONTEXT: | |
52 | * Don't care. | |
53 | * | |
54 | * RETURNS: | |
55 | * Pointer to the found partition on success, NULL if not found. | |
56 | */ | |
57 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) | |
58 | { | |
59 | struct hd_struct *part = NULL; | |
60 | struct disk_part_tbl *ptbl; | |
61 | ||
62 | if (unlikely(partno < 0)) | |
63 | return NULL; | |
64 | ||
65 | rcu_read_lock(); | |
66 | ||
67 | ptbl = rcu_dereference(disk->part_tbl); | |
68 | if (likely(partno < ptbl->len)) { | |
69 | part = rcu_dereference(ptbl->part[partno]); | |
70 | if (part) | |
71 | get_device(part_to_dev(part)); | |
72 | } | |
73 | ||
74 | rcu_read_unlock(); | |
75 | ||
76 | return part; | |
77 | } | |
78 | EXPORT_SYMBOL_GPL(disk_get_part); | |
79 | ||
80 | /** | |
81 | * disk_part_iter_init - initialize partition iterator | |
82 | * @piter: iterator to initialize | |
83 | * @disk: disk to iterate over | |
84 | * @flags: DISK_PITER_* flags | |
85 | * | |
86 | * Initialize @piter so that it iterates over partitions of @disk. | |
87 | * | |
88 | * CONTEXT: | |
89 | * Don't care. | |
90 | */ | |
91 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, | |
92 | unsigned int flags) | |
93 | { | |
94 | struct disk_part_tbl *ptbl; | |
95 | ||
96 | rcu_read_lock(); | |
97 | ptbl = rcu_dereference(disk->part_tbl); | |
98 | ||
99 | piter->disk = disk; | |
100 | piter->part = NULL; | |
101 | ||
102 | if (flags & DISK_PITER_REVERSE) | |
103 | piter->idx = ptbl->len - 1; | |
104 | else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) | |
105 | piter->idx = 0; | |
106 | else | |
107 | piter->idx = 1; | |
108 | ||
109 | piter->flags = flags; | |
110 | ||
111 | rcu_read_unlock(); | |
112 | } | |
113 | EXPORT_SYMBOL_GPL(disk_part_iter_init); | |
114 | ||
115 | /** | |
116 | * disk_part_iter_next - proceed iterator to the next partition and return it | |
117 | * @piter: iterator of interest | |
118 | * | |
119 | * Proceed @piter to the next partition and return it. | |
120 | * | |
121 | * CONTEXT: | |
122 | * Don't care. | |
123 | */ | |
124 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) | |
125 | { | |
126 | struct disk_part_tbl *ptbl; | |
127 | int inc, end; | |
128 | ||
129 | /* put the last partition */ | |
130 | disk_put_part(piter->part); | |
131 | piter->part = NULL; | |
132 | ||
133 | /* get part_tbl */ | |
134 | rcu_read_lock(); | |
135 | ptbl = rcu_dereference(piter->disk->part_tbl); | |
136 | ||
137 | /* determine iteration parameters */ | |
138 | if (piter->flags & DISK_PITER_REVERSE) { | |
139 | inc = -1; | |
140 | if (piter->flags & (DISK_PITER_INCL_PART0 | | |
141 | DISK_PITER_INCL_EMPTY_PART0)) | |
142 | end = -1; | |
143 | else | |
144 | end = 0; | |
145 | } else { | |
146 | inc = 1; | |
147 | end = ptbl->len; | |
148 | } | |
149 | ||
150 | /* iterate to the next partition */ | |
151 | for (; piter->idx != end; piter->idx += inc) { | |
152 | struct hd_struct *part; | |
153 | ||
154 | part = rcu_dereference(ptbl->part[piter->idx]); | |
155 | if (!part) | |
156 | continue; | |
157 | if (!part->nr_sects && | |
158 | !(piter->flags & DISK_PITER_INCL_EMPTY) && | |
159 | !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && | |
160 | piter->idx == 0)) | |
161 | continue; | |
162 | ||
163 | get_device(part_to_dev(part)); | |
164 | piter->part = part; | |
165 | piter->idx += inc; | |
166 | break; | |
167 | } | |
168 | ||
169 | rcu_read_unlock(); | |
170 | ||
171 | return piter->part; | |
172 | } | |
173 | EXPORT_SYMBOL_GPL(disk_part_iter_next); | |
174 | ||
175 | /** | |
176 | * disk_part_iter_exit - finish up partition iteration | |
177 | * @piter: iter of interest | |
178 | * | |
179 | * Called when iteration is over. Cleans up @piter. | |
180 | * | |
181 | * CONTEXT: | |
182 | * Don't care. | |
183 | */ | |
184 | void disk_part_iter_exit(struct disk_part_iter *piter) | |
185 | { | |
186 | disk_put_part(piter->part); | |
187 | piter->part = NULL; | |
188 | } | |
189 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); | |
190 | ||
191 | static inline int sector_in_part(struct hd_struct *part, sector_t sector) | |
192 | { | |
193 | return part->start_sect <= sector && | |
194 | sector < part->start_sect + part->nr_sects; | |
195 | } | |
196 | ||
197 | /** | |
198 | * disk_map_sector_rcu - map sector to partition | |
199 | * @disk: gendisk of interest | |
200 | * @sector: sector to map | |
201 | * | |
202 | * Find out which partition @sector maps to on @disk. This is | |
203 | * primarily used for stats accounting. | |
204 | * | |
205 | * CONTEXT: | |
206 | * RCU read locked. The returned partition pointer is valid only | |
207 | * while preemption is disabled. | |
208 | * | |
209 | * RETURNS: | |
210 | * Found partition on success, part0 is returned if no partition matches | |
211 | */ | |
212 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) | |
213 | { | |
214 | struct disk_part_tbl *ptbl; | |
215 | struct hd_struct *part; | |
216 | int i; | |
217 | ||
218 | ptbl = rcu_dereference(disk->part_tbl); | |
219 | ||
220 | part = rcu_dereference(ptbl->last_lookup); | |
221 | if (part && sector_in_part(part, sector)) | |
222 | return part; | |
223 | ||
224 | for (i = 1; i < ptbl->len; i++) { | |
225 | part = rcu_dereference(ptbl->part[i]); | |
226 | ||
227 | if (part && sector_in_part(part, sector)) { | |
228 | rcu_assign_pointer(ptbl->last_lookup, part); | |
229 | return part; | |
230 | } | |
231 | } | |
232 | return &disk->part0; | |
233 | } | |
234 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); | |
235 | ||
236 | /* | |
237 | * Can be deleted altogether. Later. | |
238 | * | |
239 | */ | |
240 | static struct blk_major_name { | |
241 | struct blk_major_name *next; | |
242 | int major; | |
243 | char name[16]; | |
244 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; | |
245 | ||
246 | /* index in the above - for now: assume no multimajor ranges */ | |
247 | static inline int major_to_index(unsigned major) | |
248 | { | |
249 | return major % BLKDEV_MAJOR_HASH_SIZE; | |
250 | } | |
251 | ||
252 | #ifdef CONFIG_PROC_FS | |
253 | void blkdev_show(struct seq_file *seqf, off_t offset) | |
254 | { | |
255 | struct blk_major_name *dp; | |
256 | ||
257 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { | |
258 | mutex_lock(&block_class_lock); | |
259 | for (dp = major_names[offset]; dp; dp = dp->next) | |
260 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); | |
261 | mutex_unlock(&block_class_lock); | |
262 | } | |
263 | } | |
264 | #endif /* CONFIG_PROC_FS */ | |
265 | ||
266 | /** | |
267 | * register_blkdev - register a new block device | |
268 | * | |
269 | * @major: the requested major device number [1..255]. If @major=0, try to | |
270 | * allocate any unused major number. | |
271 | * @name: the name of the new block device as a zero terminated string | |
272 | * | |
273 | * The @name must be unique within the system. | |
274 | * | |
275 | * The return value depends on the @major input parameter. | |
276 | * - if a major device number was requested in range [1..255] then the | |
277 | * function returns zero on success, or a negative error code | |
278 | * - if any unused major number was requested with @major=0 parameter | |
279 | * then the return value is the allocated major number in range | |
280 | * [1..255] or a negative error code otherwise | |
281 | */ | |
282 | int register_blkdev(unsigned int major, const char *name) | |
283 | { | |
284 | struct blk_major_name **n, *p; | |
285 | int index, ret = 0; | |
286 | ||
287 | mutex_lock(&block_class_lock); | |
288 | ||
289 | /* temporary */ | |
290 | if (major == 0) { | |
291 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { | |
292 | if (major_names[index] == NULL) | |
293 | break; | |
294 | } | |
295 | ||
296 | if (index == 0) { | |
297 | printk("register_blkdev: failed to get major for %s\n", | |
298 | name); | |
299 | ret = -EBUSY; | |
300 | goto out; | |
301 | } | |
302 | major = index; | |
303 | ret = major; | |
304 | } | |
305 | ||
306 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); | |
307 | if (p == NULL) { | |
308 | ret = -ENOMEM; | |
309 | goto out; | |
310 | } | |
311 | ||
312 | p->major = major; | |
313 | strlcpy(p->name, name, sizeof(p->name)); | |
314 | p->next = NULL; | |
315 | index = major_to_index(major); | |
316 | ||
317 | for (n = &major_names[index]; *n; n = &(*n)->next) { | |
318 | if ((*n)->major == major) | |
319 | break; | |
320 | } | |
321 | if (!*n) | |
322 | *n = p; | |
323 | else | |
324 | ret = -EBUSY; | |
325 | ||
326 | if (ret < 0) { | |
327 | printk("register_blkdev: cannot get major %d for %s\n", | |
328 | major, name); | |
329 | kfree(p); | |
330 | } | |
331 | out: | |
332 | mutex_unlock(&block_class_lock); | |
333 | return ret; | |
334 | } | |
335 | ||
336 | EXPORT_SYMBOL(register_blkdev); | |
337 | ||
338 | void unregister_blkdev(unsigned int major, const char *name) | |
339 | { | |
340 | struct blk_major_name **n; | |
341 | struct blk_major_name *p = NULL; | |
342 | int index = major_to_index(major); | |
343 | ||
344 | mutex_lock(&block_class_lock); | |
345 | for (n = &major_names[index]; *n; n = &(*n)->next) | |
346 | if ((*n)->major == major) | |
347 | break; | |
348 | if (!*n || strcmp((*n)->name, name)) { | |
349 | WARN_ON(1); | |
350 | } else { | |
351 | p = *n; | |
352 | *n = p->next; | |
353 | } | |
354 | mutex_unlock(&block_class_lock); | |
355 | kfree(p); | |
356 | } | |
357 | ||
358 | EXPORT_SYMBOL(unregister_blkdev); | |
359 | ||
360 | static struct kobj_map *bdev_map; | |
361 | ||
362 | /** | |
363 | * blk_mangle_minor - scatter minor numbers apart | |
364 | * @minor: minor number to mangle | |
365 | * | |
366 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT | |
367 | * is enabled. Mangling twice gives the original value. | |
368 | * | |
369 | * RETURNS: | |
370 | * Mangled value. | |
371 | * | |
372 | * CONTEXT: | |
373 | * Don't care. | |
374 | */ | |
375 | static int blk_mangle_minor(int minor) | |
376 | { | |
377 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT | |
378 | int i; | |
379 | ||
380 | for (i = 0; i < MINORBITS / 2; i++) { | |
381 | int low = minor & (1 << i); | |
382 | int high = minor & (1 << (MINORBITS - 1 - i)); | |
383 | int distance = MINORBITS - 1 - 2 * i; | |
384 | ||
385 | minor ^= low | high; /* clear both bits */ | |
386 | low <<= distance; /* swap the positions */ | |
387 | high >>= distance; | |
388 | minor |= low | high; /* and set */ | |
389 | } | |
390 | #endif | |
391 | return minor; | |
392 | } | |
393 | ||
394 | /** | |
395 | * blk_alloc_devt - allocate a dev_t for a partition | |
396 | * @part: partition to allocate dev_t for | |
397 | * @devt: out parameter for resulting dev_t | |
398 | * | |
399 | * Allocate a dev_t for block device. | |
400 | * | |
401 | * RETURNS: | |
402 | * 0 on success, allocated dev_t is returned in *@devt. -errno on | |
403 | * failure. | |
404 | * | |
405 | * CONTEXT: | |
406 | * Might sleep. | |
407 | */ | |
408 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) | |
409 | { | |
410 | struct gendisk *disk = part_to_disk(part); | |
411 | int idx, rc; | |
412 | ||
413 | /* in consecutive minor range? */ | |
414 | if (part->partno < disk->minors) { | |
415 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); | |
416 | return 0; | |
417 | } | |
418 | ||
419 | /* allocate ext devt */ | |
420 | do { | |
421 | if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL)) | |
422 | return -ENOMEM; | |
423 | rc = idr_get_new(&ext_devt_idr, part, &idx); | |
424 | } while (rc == -EAGAIN); | |
425 | ||
426 | if (rc) | |
427 | return rc; | |
428 | ||
429 | if (idx > MAX_EXT_DEVT) { | |
430 | idr_remove(&ext_devt_idr, idx); | |
431 | return -EBUSY; | |
432 | } | |
433 | ||
434 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); | |
435 | return 0; | |
436 | } | |
437 | ||
438 | /** | |
439 | * blk_free_devt - free a dev_t | |
440 | * @devt: dev_t to free | |
441 | * | |
442 | * Free @devt which was allocated using blk_alloc_devt(). | |
443 | * | |
444 | * CONTEXT: | |
445 | * Might sleep. | |
446 | */ | |
447 | void blk_free_devt(dev_t devt) | |
448 | { | |
449 | might_sleep(); | |
450 | ||
451 | if (devt == MKDEV(0, 0)) | |
452 | return; | |
453 | ||
454 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { | |
455 | mutex_lock(&ext_devt_mutex); | |
456 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
457 | mutex_unlock(&ext_devt_mutex); | |
458 | } | |
459 | } | |
460 | ||
461 | static char *bdevt_str(dev_t devt, char *buf) | |
462 | { | |
463 | if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { | |
464 | char tbuf[BDEVT_SIZE]; | |
465 | snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); | |
466 | snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); | |
467 | } else | |
468 | snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); | |
469 | ||
470 | return buf; | |
471 | } | |
472 | ||
473 | /* | |
474 | * Register device numbers dev..(dev+range-1) | |
475 | * range must be nonzero | |
476 | * The hash chain is sorted on range, so that subranges can override. | |
477 | */ | |
478 | void blk_register_region(dev_t devt, unsigned long range, struct module *module, | |
479 | struct kobject *(*probe)(dev_t, int *, void *), | |
480 | int (*lock)(dev_t, void *), void *data) | |
481 | { | |
482 | kobj_map(bdev_map, devt, range, module, probe, lock, data); | |
483 | } | |
484 | ||
485 | EXPORT_SYMBOL(blk_register_region); | |
486 | ||
487 | void blk_unregister_region(dev_t devt, unsigned long range) | |
488 | { | |
489 | kobj_unmap(bdev_map, devt, range); | |
490 | } | |
491 | ||
492 | EXPORT_SYMBOL(blk_unregister_region); | |
493 | ||
494 | static struct kobject *exact_match(dev_t devt, int *partno, void *data) | |
495 | { | |
496 | struct gendisk *p = data; | |
497 | ||
498 | return &disk_to_dev(p)->kobj; | |
499 | } | |
500 | ||
501 | static int exact_lock(dev_t devt, void *data) | |
502 | { | |
503 | struct gendisk *p = data; | |
504 | ||
505 | if (!get_disk(p)) | |
506 | return -1; | |
507 | return 0; | |
508 | } | |
509 | ||
510 | void register_disk(struct gendisk *disk) | |
511 | { | |
512 | struct device *ddev = disk_to_dev(disk); | |
513 | struct block_device *bdev; | |
514 | struct disk_part_iter piter; | |
515 | struct hd_struct *part; | |
516 | int err; | |
517 | ||
518 | ddev->parent = disk->driverfs_dev; | |
519 | ||
520 | dev_set_name(ddev, disk->disk_name); | |
521 | ||
522 | /* delay uevents, until we scanned partition table */ | |
523 | dev_set_uevent_suppress(ddev, 1); | |
524 | ||
525 | if (device_add(ddev)) | |
526 | return; | |
527 | if (!sysfs_deprecated) { | |
528 | err = sysfs_create_link(block_depr, &ddev->kobj, | |
529 | kobject_name(&ddev->kobj)); | |
530 | if (err) { | |
531 | device_del(ddev); | |
532 | return; | |
533 | } | |
534 | } | |
535 | disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj); | |
536 | disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); | |
537 | ||
538 | /* No minors to use for partitions */ | |
539 | if (!disk_partitionable(disk)) | |
540 | goto exit; | |
541 | ||
542 | /* No such device (e.g., media were just removed) */ | |
543 | if (!get_capacity(disk)) | |
544 | goto exit; | |
545 | ||
546 | bdev = bdget_disk(disk, 0); | |
547 | if (!bdev) | |
548 | goto exit; | |
549 | ||
550 | bdev->bd_invalidated = 1; | |
551 | err = blkdev_get(bdev, FMODE_READ, NULL); | |
552 | if (err < 0) | |
553 | goto exit; | |
554 | blkdev_put(bdev, FMODE_READ); | |
555 | ||
556 | exit: | |
557 | /* announce disk after possible partitions are created */ | |
558 | dev_set_uevent_suppress(ddev, 0); | |
559 | kobject_uevent(&ddev->kobj, KOBJ_ADD); | |
560 | ||
561 | /* announce possible partitions */ | |
562 | disk_part_iter_init(&piter, disk, 0); | |
563 | while ((part = disk_part_iter_next(&piter))) | |
564 | kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); | |
565 | disk_part_iter_exit(&piter); | |
566 | } | |
567 | ||
568 | /** | |
569 | * add_disk - add partitioning information to kernel list | |
570 | * @disk: per-device partitioning information | |
571 | * | |
572 | * This function registers the partitioning information in @disk | |
573 | * with the kernel. | |
574 | * | |
575 | * FIXME: error handling | |
576 | */ | |
577 | void add_disk(struct gendisk *disk) | |
578 | { | |
579 | struct backing_dev_info *bdi; | |
580 | dev_t devt; | |
581 | int retval; | |
582 | ||
583 | /* minors == 0 indicates to use ext devt from part0 and should | |
584 | * be accompanied with EXT_DEVT flag. Make sure all | |
585 | * parameters make sense. | |
586 | */ | |
587 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); | |
588 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); | |
589 | ||
590 | disk->flags |= GENHD_FL_UP; | |
591 | ||
592 | retval = blk_alloc_devt(&disk->part0, &devt); | |
593 | if (retval) { | |
594 | WARN_ON(1); | |
595 | return; | |
596 | } | |
597 | disk_to_dev(disk)->devt = devt; | |
598 | ||
599 | /* ->major and ->first_minor aren't supposed to be | |
600 | * dereferenced from here on, but set them just in case. | |
601 | */ | |
602 | disk->major = MAJOR(devt); | |
603 | disk->first_minor = MINOR(devt); | |
604 | ||
605 | /* Register BDI before referencing it from bdev */ | |
606 | bdi = &disk->queue->backing_dev_info; | |
607 | bdi_register_dev(bdi, disk_devt(disk)); | |
608 | ||
609 | blk_register_region(disk_devt(disk), disk->minors, NULL, | |
610 | exact_match, exact_lock, disk); | |
611 | register_disk(disk); | |
612 | blk_register_queue(disk); | |
613 | ||
614 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, | |
615 | "bdi"); | |
616 | WARN_ON(retval); | |
617 | ||
618 | disk_add_events(disk); | |
619 | } | |
620 | EXPORT_SYMBOL(add_disk); | |
621 | ||
622 | void del_gendisk(struct gendisk *disk) | |
623 | { | |
624 | struct disk_part_iter piter; | |
625 | struct hd_struct *part; | |
626 | ||
627 | disk_del_events(disk); | |
628 | ||
629 | /* invalidate stuff */ | |
630 | disk_part_iter_init(&piter, disk, | |
631 | DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); | |
632 | while ((part = disk_part_iter_next(&piter))) { | |
633 | invalidate_partition(disk, part->partno); | |
634 | delete_partition(disk, part->partno); | |
635 | } | |
636 | disk_part_iter_exit(&piter); | |
637 | ||
638 | invalidate_partition(disk, 0); | |
639 | blk_free_devt(disk_to_dev(disk)->devt); | |
640 | set_capacity(disk, 0); | |
641 | disk->flags &= ~GENHD_FL_UP; | |
642 | ||
643 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); | |
644 | bdi_unregister(&disk->queue->backing_dev_info); | |
645 | blk_unregister_queue(disk); | |
646 | blk_unregister_region(disk_devt(disk), disk->minors); | |
647 | ||
648 | part_stat_set_all(&disk->part0, 0); | |
649 | disk->part0.stamp = 0; | |
650 | ||
651 | kobject_put(disk->part0.holder_dir); | |
652 | kobject_put(disk->slave_dir); | |
653 | disk->driverfs_dev = NULL; | |
654 | if (!sysfs_deprecated) | |
655 | sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); | |
656 | device_del(disk_to_dev(disk)); | |
657 | } | |
658 | EXPORT_SYMBOL(del_gendisk); | |
659 | ||
660 | /** | |
661 | * get_gendisk - get partitioning information for a given device | |
662 | * @devt: device to get partitioning information for | |
663 | * @partno: returned partition index | |
664 | * | |
665 | * This function gets the structure containing partitioning | |
666 | * information for the given device @devt. | |
667 | */ | |
668 | struct gendisk *get_gendisk(dev_t devt, int *partno) | |
669 | { | |
670 | struct gendisk *disk = NULL; | |
671 | ||
672 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { | |
673 | struct kobject *kobj; | |
674 | ||
675 | kobj = kobj_lookup(bdev_map, devt, partno); | |
676 | if (kobj) | |
677 | disk = dev_to_disk(kobj_to_dev(kobj)); | |
678 | } else { | |
679 | struct hd_struct *part; | |
680 | ||
681 | mutex_lock(&ext_devt_mutex); | |
682 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
683 | if (part && get_disk(part_to_disk(part))) { | |
684 | *partno = part->partno; | |
685 | disk = part_to_disk(part); | |
686 | } | |
687 | mutex_unlock(&ext_devt_mutex); | |
688 | } | |
689 | ||
690 | return disk; | |
691 | } | |
692 | EXPORT_SYMBOL(get_gendisk); | |
693 | ||
694 | /** | |
695 | * bdget_disk - do bdget() by gendisk and partition number | |
696 | * @disk: gendisk of interest | |
697 | * @partno: partition number | |
698 | * | |
699 | * Find partition @partno from @disk, do bdget() on it. | |
700 | * | |
701 | * CONTEXT: | |
702 | * Don't care. | |
703 | * | |
704 | * RETURNS: | |
705 | * Resulting block_device on success, NULL on failure. | |
706 | */ | |
707 | struct block_device *bdget_disk(struct gendisk *disk, int partno) | |
708 | { | |
709 | struct hd_struct *part; | |
710 | struct block_device *bdev = NULL; | |
711 | ||
712 | part = disk_get_part(disk, partno); | |
713 | if (part) | |
714 | bdev = bdget(part_devt(part)); | |
715 | disk_put_part(part); | |
716 | ||
717 | return bdev; | |
718 | } | |
719 | EXPORT_SYMBOL(bdget_disk); | |
720 | ||
721 | /* | |
722 | * print a full list of all partitions - intended for places where the root | |
723 | * filesystem can't be mounted and thus to give the victim some idea of what | |
724 | * went wrong | |
725 | */ | |
726 | void __init printk_all_partitions(void) | |
727 | { | |
728 | struct class_dev_iter iter; | |
729 | struct device *dev; | |
730 | ||
731 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
732 | while ((dev = class_dev_iter_next(&iter))) { | |
733 | struct gendisk *disk = dev_to_disk(dev); | |
734 | struct disk_part_iter piter; | |
735 | struct hd_struct *part; | |
736 | char name_buf[BDEVNAME_SIZE]; | |
737 | char devt_buf[BDEVT_SIZE]; | |
738 | u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1]; | |
739 | ||
740 | /* | |
741 | * Don't show empty devices or things that have been | |
742 | * suppressed | |
743 | */ | |
744 | if (get_capacity(disk) == 0 || | |
745 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) | |
746 | continue; | |
747 | ||
748 | /* | |
749 | * Note, unlike /proc/partitions, I am showing the | |
750 | * numbers in hex - the same format as the root= | |
751 | * option takes. | |
752 | */ | |
753 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); | |
754 | while ((part = disk_part_iter_next(&piter))) { | |
755 | bool is_part0 = part == &disk->part0; | |
756 | ||
757 | uuid[0] = 0; | |
758 | if (part->info) | |
759 | part_unpack_uuid(part->info->uuid, uuid); | |
760 | ||
761 | printk("%s%s %10llu %s %s", is_part0 ? "" : " ", | |
762 | bdevt_str(part_devt(part), devt_buf), | |
763 | (unsigned long long)part->nr_sects >> 1, | |
764 | disk_name(disk, part->partno, name_buf), uuid); | |
765 | if (is_part0) { | |
766 | if (disk->driverfs_dev != NULL && | |
767 | disk->driverfs_dev->driver != NULL) | |
768 | printk(" driver: %s\n", | |
769 | disk->driverfs_dev->driver->name); | |
770 | else | |
771 | printk(" (driver?)\n"); | |
772 | } else | |
773 | printk("\n"); | |
774 | } | |
775 | disk_part_iter_exit(&piter); | |
776 | } | |
777 | class_dev_iter_exit(&iter); | |
778 | } | |
779 | ||
780 | #ifdef CONFIG_PROC_FS | |
781 | /* iterator */ | |
782 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) | |
783 | { | |
784 | loff_t skip = *pos; | |
785 | struct class_dev_iter *iter; | |
786 | struct device *dev; | |
787 | ||
788 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); | |
789 | if (!iter) | |
790 | return ERR_PTR(-ENOMEM); | |
791 | ||
792 | seqf->private = iter; | |
793 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); | |
794 | do { | |
795 | dev = class_dev_iter_next(iter); | |
796 | if (!dev) | |
797 | return NULL; | |
798 | } while (skip--); | |
799 | ||
800 | return dev_to_disk(dev); | |
801 | } | |
802 | ||
803 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) | |
804 | { | |
805 | struct device *dev; | |
806 | ||
807 | (*pos)++; | |
808 | dev = class_dev_iter_next(seqf->private); | |
809 | if (dev) | |
810 | return dev_to_disk(dev); | |
811 | ||
812 | return NULL; | |
813 | } | |
814 | ||
815 | static void disk_seqf_stop(struct seq_file *seqf, void *v) | |
816 | { | |
817 | struct class_dev_iter *iter = seqf->private; | |
818 | ||
819 | /* stop is called even after start failed :-( */ | |
820 | if (iter) { | |
821 | class_dev_iter_exit(iter); | |
822 | kfree(iter); | |
823 | } | |
824 | } | |
825 | ||
826 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) | |
827 | { | |
828 | static void *p; | |
829 | ||
830 | p = disk_seqf_start(seqf, pos); | |
831 | if (!IS_ERR_OR_NULL(p) && !*pos) | |
832 | seq_puts(seqf, "major minor #blocks name\n\n"); | |
833 | return p; | |
834 | } | |
835 | ||
836 | static int show_partition(struct seq_file *seqf, void *v) | |
837 | { | |
838 | struct gendisk *sgp = v; | |
839 | struct disk_part_iter piter; | |
840 | struct hd_struct *part; | |
841 | char buf[BDEVNAME_SIZE]; | |
842 | ||
843 | /* Don't show non-partitionable removeable devices or empty devices */ | |
844 | if (!get_capacity(sgp) || (!disk_partitionable(sgp) && | |
845 | (sgp->flags & GENHD_FL_REMOVABLE))) | |
846 | return 0; | |
847 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) | |
848 | return 0; | |
849 | ||
850 | /* show the full disk and all non-0 size partitions of it */ | |
851 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); | |
852 | while ((part = disk_part_iter_next(&piter))) | |
853 | seq_printf(seqf, "%4d %7d %10llu %s\n", | |
854 | MAJOR(part_devt(part)), MINOR(part_devt(part)), | |
855 | (unsigned long long)part->nr_sects >> 1, | |
856 | disk_name(sgp, part->partno, buf)); | |
857 | disk_part_iter_exit(&piter); | |
858 | ||
859 | return 0; | |
860 | } | |
861 | ||
862 | static const struct seq_operations partitions_op = { | |
863 | .start = show_partition_start, | |
864 | .next = disk_seqf_next, | |
865 | .stop = disk_seqf_stop, | |
866 | .show = show_partition | |
867 | }; | |
868 | ||
869 | static int partitions_open(struct inode *inode, struct file *file) | |
870 | { | |
871 | return seq_open(file, &partitions_op); | |
872 | } | |
873 | ||
874 | static const struct file_operations proc_partitions_operations = { | |
875 | .open = partitions_open, | |
876 | .read = seq_read, | |
877 | .llseek = seq_lseek, | |
878 | .release = seq_release, | |
879 | }; | |
880 | #endif | |
881 | ||
882 | ||
883 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) | |
884 | { | |
885 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) | |
886 | /* Make old-style 2.4 aliases work */ | |
887 | request_module("block-major-%d", MAJOR(devt)); | |
888 | return NULL; | |
889 | } | |
890 | ||
891 | static int __init genhd_device_init(void) | |
892 | { | |
893 | int error; | |
894 | ||
895 | block_class.dev_kobj = sysfs_dev_block_kobj; | |
896 | error = class_register(&block_class); | |
897 | if (unlikely(error)) | |
898 | return error; | |
899 | bdev_map = kobj_map_init(base_probe, &block_class_lock); | |
900 | blk_dev_init(); | |
901 | ||
902 | register_blkdev(BLOCK_EXT_MAJOR, "blkext"); | |
903 | ||
904 | /* create top-level block dir */ | |
905 | if (!sysfs_deprecated) | |
906 | block_depr = kobject_create_and_add("block", NULL); | |
907 | return 0; | |
908 | } | |
909 | ||
910 | subsys_initcall(genhd_device_init); | |
911 | ||
912 | static ssize_t disk_range_show(struct device *dev, | |
913 | struct device_attribute *attr, char *buf) | |
914 | { | |
915 | struct gendisk *disk = dev_to_disk(dev); | |
916 | ||
917 | return sprintf(buf, "%d\n", disk->minors); | |
918 | } | |
919 | ||
920 | static ssize_t disk_ext_range_show(struct device *dev, | |
921 | struct device_attribute *attr, char *buf) | |
922 | { | |
923 | struct gendisk *disk = dev_to_disk(dev); | |
924 | ||
925 | return sprintf(buf, "%d\n", disk_max_parts(disk)); | |
926 | } | |
927 | ||
928 | static ssize_t disk_removable_show(struct device *dev, | |
929 | struct device_attribute *attr, char *buf) | |
930 | { | |
931 | struct gendisk *disk = dev_to_disk(dev); | |
932 | ||
933 | return sprintf(buf, "%d\n", | |
934 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); | |
935 | } | |
936 | ||
937 | static ssize_t disk_ro_show(struct device *dev, | |
938 | struct device_attribute *attr, char *buf) | |
939 | { | |
940 | struct gendisk *disk = dev_to_disk(dev); | |
941 | ||
942 | return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); | |
943 | } | |
944 | ||
945 | static ssize_t disk_capability_show(struct device *dev, | |
946 | struct device_attribute *attr, char *buf) | |
947 | { | |
948 | struct gendisk *disk = dev_to_disk(dev); | |
949 | ||
950 | return sprintf(buf, "%x\n", disk->flags); | |
951 | } | |
952 | ||
953 | static ssize_t disk_alignment_offset_show(struct device *dev, | |
954 | struct device_attribute *attr, | |
955 | char *buf) | |
956 | { | |
957 | struct gendisk *disk = dev_to_disk(dev); | |
958 | ||
959 | return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue)); | |
960 | } | |
961 | ||
962 | static ssize_t disk_discard_alignment_show(struct device *dev, | |
963 | struct device_attribute *attr, | |
964 | char *buf) | |
965 | { | |
966 | struct gendisk *disk = dev_to_disk(dev); | |
967 | ||
968 | return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue)); | |
969 | } | |
970 | ||
971 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); | |
972 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); | |
973 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); | |
974 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); | |
975 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); | |
976 | static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL); | |
977 | static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show, | |
978 | NULL); | |
979 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); | |
980 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); | |
981 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); | |
982 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
983 | static struct device_attribute dev_attr_fail = | |
984 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); | |
985 | #endif | |
986 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
987 | static struct device_attribute dev_attr_fail_timeout = | |
988 | __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, | |
989 | part_timeout_store); | |
990 | #endif | |
991 | ||
992 | static struct attribute *disk_attrs[] = { | |
993 | &dev_attr_range.attr, | |
994 | &dev_attr_ext_range.attr, | |
995 | &dev_attr_removable.attr, | |
996 | &dev_attr_ro.attr, | |
997 | &dev_attr_size.attr, | |
998 | &dev_attr_alignment_offset.attr, | |
999 | &dev_attr_discard_alignment.attr, | |
1000 | &dev_attr_capability.attr, | |
1001 | &dev_attr_stat.attr, | |
1002 | &dev_attr_inflight.attr, | |
1003 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
1004 | &dev_attr_fail.attr, | |
1005 | #endif | |
1006 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
1007 | &dev_attr_fail_timeout.attr, | |
1008 | #endif | |
1009 | NULL | |
1010 | }; | |
1011 | ||
1012 | static struct attribute_group disk_attr_group = { | |
1013 | .attrs = disk_attrs, | |
1014 | }; | |
1015 | ||
1016 | static const struct attribute_group *disk_attr_groups[] = { | |
1017 | &disk_attr_group, | |
1018 | NULL | |
1019 | }; | |
1020 | ||
1021 | static void disk_free_ptbl_rcu_cb(struct rcu_head *head) | |
1022 | { | |
1023 | struct disk_part_tbl *ptbl = | |
1024 | container_of(head, struct disk_part_tbl, rcu_head); | |
1025 | ||
1026 | kfree(ptbl); | |
1027 | } | |
1028 | ||
1029 | /** | |
1030 | * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way | |
1031 | * @disk: disk to replace part_tbl for | |
1032 | * @new_ptbl: new part_tbl to install | |
1033 | * | |
1034 | * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The | |
1035 | * original ptbl is freed using RCU callback. | |
1036 | * | |
1037 | * LOCKING: | |
1038 | * Matching bd_mutx locked. | |
1039 | */ | |
1040 | static void disk_replace_part_tbl(struct gendisk *disk, | |
1041 | struct disk_part_tbl *new_ptbl) | |
1042 | { | |
1043 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
1044 | ||
1045 | rcu_assign_pointer(disk->part_tbl, new_ptbl); | |
1046 | ||
1047 | if (old_ptbl) { | |
1048 | rcu_assign_pointer(old_ptbl->last_lookup, NULL); | |
1049 | call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb); | |
1050 | } | |
1051 | } | |
1052 | ||
1053 | /** | |
1054 | * disk_expand_part_tbl - expand disk->part_tbl | |
1055 | * @disk: disk to expand part_tbl for | |
1056 | * @partno: expand such that this partno can fit in | |
1057 | * | |
1058 | * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl | |
1059 | * uses RCU to allow unlocked dereferencing for stats and other stuff. | |
1060 | * | |
1061 | * LOCKING: | |
1062 | * Matching bd_mutex locked, might sleep. | |
1063 | * | |
1064 | * RETURNS: | |
1065 | * 0 on success, -errno on failure. | |
1066 | */ | |
1067 | int disk_expand_part_tbl(struct gendisk *disk, int partno) | |
1068 | { | |
1069 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
1070 | struct disk_part_tbl *new_ptbl; | |
1071 | int len = old_ptbl ? old_ptbl->len : 0; | |
1072 | int target = partno + 1; | |
1073 | size_t size; | |
1074 | int i; | |
1075 | ||
1076 | /* disk_max_parts() is zero during initialization, ignore if so */ | |
1077 | if (disk_max_parts(disk) && target > disk_max_parts(disk)) | |
1078 | return -EINVAL; | |
1079 | ||
1080 | if (target <= len) | |
1081 | return 0; | |
1082 | ||
1083 | size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); | |
1084 | new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); | |
1085 | if (!new_ptbl) | |
1086 | return -ENOMEM; | |
1087 | ||
1088 | new_ptbl->len = target; | |
1089 | ||
1090 | for (i = 0; i < len; i++) | |
1091 | rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); | |
1092 | ||
1093 | disk_replace_part_tbl(disk, new_ptbl); | |
1094 | return 0; | |
1095 | } | |
1096 | ||
1097 | static void disk_release(struct device *dev) | |
1098 | { | |
1099 | struct gendisk *disk = dev_to_disk(dev); | |
1100 | ||
1101 | disk_release_events(disk); | |
1102 | kfree(disk->random); | |
1103 | disk_replace_part_tbl(disk, NULL); | |
1104 | free_part_stats(&disk->part0); | |
1105 | free_part_info(&disk->part0); | |
1106 | kfree(disk); | |
1107 | } | |
1108 | struct class block_class = { | |
1109 | .name = "block", | |
1110 | }; | |
1111 | ||
1112 | static char *block_devnode(struct device *dev, mode_t *mode) | |
1113 | { | |
1114 | struct gendisk *disk = dev_to_disk(dev); | |
1115 | ||
1116 | if (disk->devnode) | |
1117 | return disk->devnode(disk, mode); | |
1118 | return NULL; | |
1119 | } | |
1120 | ||
1121 | static struct device_type disk_type = { | |
1122 | .name = "disk", | |
1123 | .groups = disk_attr_groups, | |
1124 | .release = disk_release, | |
1125 | .devnode = block_devnode, | |
1126 | }; | |
1127 | ||
1128 | #ifdef CONFIG_PROC_FS | |
1129 | /* | |
1130 | * aggregate disk stat collector. Uses the same stats that the sysfs | |
1131 | * entries do, above, but makes them available through one seq_file. | |
1132 | * | |
1133 | * The output looks suspiciously like /proc/partitions with a bunch of | |
1134 | * extra fields. | |
1135 | */ | |
1136 | static int diskstats_show(struct seq_file *seqf, void *v) | |
1137 | { | |
1138 | struct gendisk *gp = v; | |
1139 | struct disk_part_iter piter; | |
1140 | struct hd_struct *hd; | |
1141 | char buf[BDEVNAME_SIZE]; | |
1142 | int cpu; | |
1143 | ||
1144 | /* | |
1145 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) | |
1146 | seq_puts(seqf, "major minor name" | |
1147 | " rio rmerge rsect ruse wio wmerge " | |
1148 | "wsect wuse running use aveq" | |
1149 | "\n\n"); | |
1150 | */ | |
1151 | ||
1152 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); | |
1153 | while ((hd = disk_part_iter_next(&piter))) { | |
1154 | cpu = part_stat_lock(); | |
1155 | part_round_stats(cpu, hd); | |
1156 | part_stat_unlock(); | |
1157 | seq_printf(seqf, "%4d %7d %s %lu %lu %llu " | |
1158 | "%u %lu %lu %llu %u %u %u %u\n", | |
1159 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), | |
1160 | disk_name(gp, hd->partno, buf), | |
1161 | part_stat_read(hd, ios[READ]), | |
1162 | part_stat_read(hd, merges[READ]), | |
1163 | (unsigned long long)part_stat_read(hd, sectors[READ]), | |
1164 | jiffies_to_msecs(part_stat_read(hd, ticks[READ])), | |
1165 | part_stat_read(hd, ios[WRITE]), | |
1166 | part_stat_read(hd, merges[WRITE]), | |
1167 | (unsigned long long)part_stat_read(hd, sectors[WRITE]), | |
1168 | jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])), | |
1169 | part_in_flight(hd), | |
1170 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), | |
1171 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) | |
1172 | ); | |
1173 | } | |
1174 | disk_part_iter_exit(&piter); | |
1175 | ||
1176 | return 0; | |
1177 | } | |
1178 | ||
1179 | static const struct seq_operations diskstats_op = { | |
1180 | .start = disk_seqf_start, | |
1181 | .next = disk_seqf_next, | |
1182 | .stop = disk_seqf_stop, | |
1183 | .show = diskstats_show | |
1184 | }; | |
1185 | ||
1186 | static int diskstats_open(struct inode *inode, struct file *file) | |
1187 | { | |
1188 | return seq_open(file, &diskstats_op); | |
1189 | } | |
1190 | ||
1191 | static const struct file_operations proc_diskstats_operations = { | |
1192 | .open = diskstats_open, | |
1193 | .read = seq_read, | |
1194 | .llseek = seq_lseek, | |
1195 | .release = seq_release, | |
1196 | }; | |
1197 | ||
1198 | static int __init proc_genhd_init(void) | |
1199 | { | |
1200 | proc_create("diskstats", 0, NULL, &proc_diskstats_operations); | |
1201 | proc_create("partitions", 0, NULL, &proc_partitions_operations); | |
1202 | return 0; | |
1203 | } | |
1204 | module_init(proc_genhd_init); | |
1205 | #endif /* CONFIG_PROC_FS */ | |
1206 | ||
1207 | dev_t blk_lookup_devt(const char *name, int partno) | |
1208 | { | |
1209 | dev_t devt = MKDEV(0, 0); | |
1210 | struct class_dev_iter iter; | |
1211 | struct device *dev; | |
1212 | ||
1213 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
1214 | while ((dev = class_dev_iter_next(&iter))) { | |
1215 | struct gendisk *disk = dev_to_disk(dev); | |
1216 | struct hd_struct *part; | |
1217 | ||
1218 | if (strcmp(dev_name(dev), name)) | |
1219 | continue; | |
1220 | ||
1221 | if (partno < disk->minors) { | |
1222 | /* We need to return the right devno, even | |
1223 | * if the partition doesn't exist yet. | |
1224 | */ | |
1225 | devt = MKDEV(MAJOR(dev->devt), | |
1226 | MINOR(dev->devt) + partno); | |
1227 | break; | |
1228 | } | |
1229 | part = disk_get_part(disk, partno); | |
1230 | if (part) { | |
1231 | devt = part_devt(part); | |
1232 | disk_put_part(part); | |
1233 | break; | |
1234 | } | |
1235 | disk_put_part(part); | |
1236 | } | |
1237 | class_dev_iter_exit(&iter); | |
1238 | return devt; | |
1239 | } | |
1240 | EXPORT_SYMBOL(blk_lookup_devt); | |
1241 | ||
1242 | struct gendisk *alloc_disk(int minors) | |
1243 | { | |
1244 | return alloc_disk_node(minors, -1); | |
1245 | } | |
1246 | EXPORT_SYMBOL(alloc_disk); | |
1247 | ||
1248 | struct gendisk *alloc_disk_node(int minors, int node_id) | |
1249 | { | |
1250 | struct gendisk *disk; | |
1251 | ||
1252 | disk = kmalloc_node(sizeof(struct gendisk), | |
1253 | GFP_KERNEL | __GFP_ZERO, node_id); | |
1254 | if (disk) { | |
1255 | if (!init_part_stats(&disk->part0)) { | |
1256 | kfree(disk); | |
1257 | return NULL; | |
1258 | } | |
1259 | disk->node_id = node_id; | |
1260 | if (disk_expand_part_tbl(disk, 0)) { | |
1261 | free_part_stats(&disk->part0); | |
1262 | kfree(disk); | |
1263 | return NULL; | |
1264 | } | |
1265 | disk->part_tbl->part[0] = &disk->part0; | |
1266 | ||
1267 | hd_ref_init(&disk->part0); | |
1268 | ||
1269 | disk->minors = minors; | |
1270 | rand_initialize_disk(disk); | |
1271 | disk_to_dev(disk)->class = &block_class; | |
1272 | disk_to_dev(disk)->type = &disk_type; | |
1273 | device_initialize(disk_to_dev(disk)); | |
1274 | } | |
1275 | return disk; | |
1276 | } | |
1277 | EXPORT_SYMBOL(alloc_disk_node); | |
1278 | ||
1279 | struct kobject *get_disk(struct gendisk *disk) | |
1280 | { | |
1281 | struct module *owner; | |
1282 | struct kobject *kobj; | |
1283 | ||
1284 | if (!disk->fops) | |
1285 | return NULL; | |
1286 | owner = disk->fops->owner; | |
1287 | if (owner && !try_module_get(owner)) | |
1288 | return NULL; | |
1289 | kobj = kobject_get(&disk_to_dev(disk)->kobj); | |
1290 | if (kobj == NULL) { | |
1291 | module_put(owner); | |
1292 | return NULL; | |
1293 | } | |
1294 | return kobj; | |
1295 | ||
1296 | } | |
1297 | ||
1298 | EXPORT_SYMBOL(get_disk); | |
1299 | ||
1300 | void put_disk(struct gendisk *disk) | |
1301 | { | |
1302 | if (disk) | |
1303 | kobject_put(&disk_to_dev(disk)->kobj); | |
1304 | } | |
1305 | ||
1306 | EXPORT_SYMBOL(put_disk); | |
1307 | ||
1308 | static void set_disk_ro_uevent(struct gendisk *gd, int ro) | |
1309 | { | |
1310 | char event[] = "DISK_RO=1"; | |
1311 | char *envp[] = { event, NULL }; | |
1312 | ||
1313 | if (!ro) | |
1314 | event[8] = '0'; | |
1315 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); | |
1316 | } | |
1317 | ||
1318 | void set_device_ro(struct block_device *bdev, int flag) | |
1319 | { | |
1320 | bdev->bd_part->policy = flag; | |
1321 | } | |
1322 | ||
1323 | EXPORT_SYMBOL(set_device_ro); | |
1324 | ||
1325 | void set_disk_ro(struct gendisk *disk, int flag) | |
1326 | { | |
1327 | struct disk_part_iter piter; | |
1328 | struct hd_struct *part; | |
1329 | ||
1330 | if (disk->part0.policy != flag) { | |
1331 | set_disk_ro_uevent(disk, flag); | |
1332 | disk->part0.policy = flag; | |
1333 | } | |
1334 | ||
1335 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); | |
1336 | while ((part = disk_part_iter_next(&piter))) | |
1337 | part->policy = flag; | |
1338 | disk_part_iter_exit(&piter); | |
1339 | } | |
1340 | ||
1341 | EXPORT_SYMBOL(set_disk_ro); | |
1342 | ||
1343 | int bdev_read_only(struct block_device *bdev) | |
1344 | { | |
1345 | if (!bdev) | |
1346 | return 0; | |
1347 | return bdev->bd_part->policy; | |
1348 | } | |
1349 | ||
1350 | EXPORT_SYMBOL(bdev_read_only); | |
1351 | ||
1352 | int invalidate_partition(struct gendisk *disk, int partno) | |
1353 | { | |
1354 | int res = 0; | |
1355 | struct block_device *bdev = bdget_disk(disk, partno); | |
1356 | if (bdev) { | |
1357 | fsync_bdev(bdev); | |
1358 | res = __invalidate_device(bdev, true); | |
1359 | bdput(bdev); | |
1360 | } | |
1361 | return res; | |
1362 | } | |
1363 | ||
1364 | EXPORT_SYMBOL(invalidate_partition); | |
1365 | ||
1366 | /* | |
1367 | * Disk events - monitor disk events like media change and eject request. | |
1368 | */ | |
1369 | struct disk_events { | |
1370 | struct list_head node; /* all disk_event's */ | |
1371 | struct gendisk *disk; /* the associated disk */ | |
1372 | spinlock_t lock; | |
1373 | ||
1374 | struct mutex block_mutex; /* protects blocking */ | |
1375 | int block; /* event blocking depth */ | |
1376 | unsigned int pending; /* events already sent out */ | |
1377 | unsigned int clearing; /* events being cleared */ | |
1378 | ||
1379 | long poll_msecs; /* interval, -1 for default */ | |
1380 | struct delayed_work dwork; | |
1381 | }; | |
1382 | ||
1383 | static const char *disk_events_strs[] = { | |
1384 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change", | |
1385 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request", | |
1386 | }; | |
1387 | ||
1388 | static char *disk_uevents[] = { | |
1389 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1", | |
1390 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1", | |
1391 | }; | |
1392 | ||
1393 | /* list of all disk_events */ | |
1394 | static DEFINE_MUTEX(disk_events_mutex); | |
1395 | static LIST_HEAD(disk_events); | |
1396 | ||
1397 | /* disable in-kernel polling by default */ | |
1398 | static unsigned long disk_events_dfl_poll_msecs = 0; | |
1399 | ||
1400 | static unsigned long disk_events_poll_jiffies(struct gendisk *disk) | |
1401 | { | |
1402 | struct disk_events *ev = disk->ev; | |
1403 | long intv_msecs = 0; | |
1404 | ||
1405 | /* | |
1406 | * If device-specific poll interval is set, always use it. If | |
1407 | * the default is being used, poll iff there are events which | |
1408 | * can't be monitored asynchronously. | |
1409 | */ | |
1410 | if (ev->poll_msecs >= 0) | |
1411 | intv_msecs = ev->poll_msecs; | |
1412 | else if (disk->events & ~disk->async_events) | |
1413 | intv_msecs = disk_events_dfl_poll_msecs; | |
1414 | ||
1415 | return msecs_to_jiffies(intv_msecs); | |
1416 | } | |
1417 | ||
1418 | /** | |
1419 | * disk_block_events - block and flush disk event checking | |
1420 | * @disk: disk to block events for | |
1421 | * | |
1422 | * On return from this function, it is guaranteed that event checking | |
1423 | * isn't in progress and won't happen until unblocked by | |
1424 | * disk_unblock_events(). Events blocking is counted and the actual | |
1425 | * unblocking happens after the matching number of unblocks are done. | |
1426 | * | |
1427 | * Note that this intentionally does not block event checking from | |
1428 | * disk_clear_events(). | |
1429 | * | |
1430 | * CONTEXT: | |
1431 | * Might sleep. | |
1432 | */ | |
1433 | void disk_block_events(struct gendisk *disk) | |
1434 | { | |
1435 | struct disk_events *ev = disk->ev; | |
1436 | unsigned long flags; | |
1437 | bool cancel; | |
1438 | ||
1439 | if (!ev) | |
1440 | return; | |
1441 | ||
1442 | /* | |
1443 | * Outer mutex ensures that the first blocker completes canceling | |
1444 | * the event work before further blockers are allowed to finish. | |
1445 | */ | |
1446 | mutex_lock(&ev->block_mutex); | |
1447 | ||
1448 | spin_lock_irqsave(&ev->lock, flags); | |
1449 | cancel = !ev->block++; | |
1450 | spin_unlock_irqrestore(&ev->lock, flags); | |
1451 | ||
1452 | if (cancel) | |
1453 | cancel_delayed_work_sync(&disk->ev->dwork); | |
1454 | ||
1455 | mutex_unlock(&ev->block_mutex); | |
1456 | } | |
1457 | ||
1458 | static void __disk_unblock_events(struct gendisk *disk, bool check_now) | |
1459 | { | |
1460 | struct disk_events *ev = disk->ev; | |
1461 | unsigned long intv; | |
1462 | unsigned long flags; | |
1463 | ||
1464 | spin_lock_irqsave(&ev->lock, flags); | |
1465 | ||
1466 | if (WARN_ON_ONCE(ev->block <= 0)) | |
1467 | goto out_unlock; | |
1468 | ||
1469 | if (--ev->block) | |
1470 | goto out_unlock; | |
1471 | ||
1472 | /* | |
1473 | * Not exactly a latency critical operation, set poll timer | |
1474 | * slack to 25% and kick event check. | |
1475 | */ | |
1476 | intv = disk_events_poll_jiffies(disk); | |
1477 | set_timer_slack(&ev->dwork.timer, intv / 4); | |
1478 | if (check_now) | |
1479 | queue_delayed_work(system_nrt_wq, &ev->dwork, 0); | |
1480 | else if (intv) | |
1481 | queue_delayed_work(system_nrt_wq, &ev->dwork, intv); | |
1482 | out_unlock: | |
1483 | spin_unlock_irqrestore(&ev->lock, flags); | |
1484 | } | |
1485 | ||
1486 | /** | |
1487 | * disk_unblock_events - unblock disk event checking | |
1488 | * @disk: disk to unblock events for | |
1489 | * | |
1490 | * Undo disk_block_events(). When the block count reaches zero, it | |
1491 | * starts events polling if configured. | |
1492 | * | |
1493 | * CONTEXT: | |
1494 | * Don't care. Safe to call from irq context. | |
1495 | */ | |
1496 | void disk_unblock_events(struct gendisk *disk) | |
1497 | { | |
1498 | if (disk->ev) | |
1499 | __disk_unblock_events(disk, false); | |
1500 | } | |
1501 | ||
1502 | /** | |
1503 | * disk_check_events - schedule immediate event checking | |
1504 | * @disk: disk to check events for | |
1505 | * | |
1506 | * Schedule immediate event checking on @disk if not blocked. | |
1507 | * | |
1508 | * CONTEXT: | |
1509 | * Don't care. Safe to call from irq context. | |
1510 | */ | |
1511 | void disk_check_events(struct gendisk *disk) | |
1512 | { | |
1513 | struct disk_events *ev = disk->ev; | |
1514 | unsigned long flags; | |
1515 | ||
1516 | if (!ev) | |
1517 | return; | |
1518 | ||
1519 | spin_lock_irqsave(&ev->lock, flags); | |
1520 | if (!ev->block) { | |
1521 | cancel_delayed_work(&ev->dwork); | |
1522 | queue_delayed_work(system_nrt_wq, &ev->dwork, 0); | |
1523 | } | |
1524 | spin_unlock_irqrestore(&ev->lock, flags); | |
1525 | } | |
1526 | EXPORT_SYMBOL_GPL(disk_check_events); | |
1527 | ||
1528 | /** | |
1529 | * disk_clear_events - synchronously check, clear and return pending events | |
1530 | * @disk: disk to fetch and clear events from | |
1531 | * @mask: mask of events to be fetched and clearted | |
1532 | * | |
1533 | * Disk events are synchronously checked and pending events in @mask | |
1534 | * are cleared and returned. This ignores the block count. | |
1535 | * | |
1536 | * CONTEXT: | |
1537 | * Might sleep. | |
1538 | */ | |
1539 | unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) | |
1540 | { | |
1541 | const struct block_device_operations *bdops = disk->fops; | |
1542 | struct disk_events *ev = disk->ev; | |
1543 | unsigned int pending; | |
1544 | ||
1545 | if (!ev) { | |
1546 | /* for drivers still using the old ->media_changed method */ | |
1547 | if ((mask & DISK_EVENT_MEDIA_CHANGE) && | |
1548 | bdops->media_changed && bdops->media_changed(disk)) | |
1549 | return DISK_EVENT_MEDIA_CHANGE; | |
1550 | return 0; | |
1551 | } | |
1552 | ||
1553 | /* tell the workfn about the events being cleared */ | |
1554 | spin_lock_irq(&ev->lock); | |
1555 | ev->clearing |= mask; | |
1556 | spin_unlock_irq(&ev->lock); | |
1557 | ||
1558 | /* uncondtionally schedule event check and wait for it to finish */ | |
1559 | disk_block_events(disk); | |
1560 | queue_delayed_work(system_nrt_wq, &ev->dwork, 0); | |
1561 | flush_delayed_work(&ev->dwork); | |
1562 | __disk_unblock_events(disk, false); | |
1563 | ||
1564 | /* then, fetch and clear pending events */ | |
1565 | spin_lock_irq(&ev->lock); | |
1566 | WARN_ON_ONCE(ev->clearing & mask); /* cleared by workfn */ | |
1567 | pending = ev->pending & mask; | |
1568 | ev->pending &= ~mask; | |
1569 | spin_unlock_irq(&ev->lock); | |
1570 | ||
1571 | return pending; | |
1572 | } | |
1573 | ||
1574 | static void disk_events_workfn(struct work_struct *work) | |
1575 | { | |
1576 | struct delayed_work *dwork = to_delayed_work(work); | |
1577 | struct disk_events *ev = container_of(dwork, struct disk_events, dwork); | |
1578 | struct gendisk *disk = ev->disk; | |
1579 | char *envp[ARRAY_SIZE(disk_uevents) + 1] = { }; | |
1580 | unsigned int clearing = ev->clearing; | |
1581 | unsigned int events; | |
1582 | unsigned long intv; | |
1583 | int nr_events = 0, i; | |
1584 | ||
1585 | /* check events */ | |
1586 | events = disk->fops->check_events(disk, clearing); | |
1587 | ||
1588 | /* accumulate pending events and schedule next poll if necessary */ | |
1589 | spin_lock_irq(&ev->lock); | |
1590 | ||
1591 | events &= ~ev->pending; | |
1592 | ev->pending |= events; | |
1593 | ev->clearing &= ~clearing; | |
1594 | ||
1595 | intv = disk_events_poll_jiffies(disk); | |
1596 | if (!ev->block && intv) | |
1597 | queue_delayed_work(system_nrt_wq, &ev->dwork, intv); | |
1598 | ||
1599 | spin_unlock_irq(&ev->lock); | |
1600 | ||
1601 | /* | |
1602 | * Tell userland about new events. Only the events listed in | |
1603 | * @disk->events are reported. Unlisted events are processed the | |
1604 | * same internally but never get reported to userland. | |
1605 | */ | |
1606 | for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) | |
1607 | if (events & disk->events & (1 << i)) | |
1608 | envp[nr_events++] = disk_uevents[i]; | |
1609 | ||
1610 | if (nr_events) | |
1611 | kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); | |
1612 | } | |
1613 | ||
1614 | /* | |
1615 | * A disk events enabled device has the following sysfs nodes under | |
1616 | * its /sys/block/X/ directory. | |
1617 | * | |
1618 | * events : list of all supported events | |
1619 | * events_async : list of events which can be detected w/o polling | |
1620 | * events_poll_msecs : polling interval, 0: disable, -1: system default | |
1621 | */ | |
1622 | static ssize_t __disk_events_show(unsigned int events, char *buf) | |
1623 | { | |
1624 | const char *delim = ""; | |
1625 | ssize_t pos = 0; | |
1626 | int i; | |
1627 | ||
1628 | for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++) | |
1629 | if (events & (1 << i)) { | |
1630 | pos += sprintf(buf + pos, "%s%s", | |
1631 | delim, disk_events_strs[i]); | |
1632 | delim = " "; | |
1633 | } | |
1634 | if (pos) | |
1635 | pos += sprintf(buf + pos, "\n"); | |
1636 | return pos; | |
1637 | } | |
1638 | ||
1639 | static ssize_t disk_events_show(struct device *dev, | |
1640 | struct device_attribute *attr, char *buf) | |
1641 | { | |
1642 | struct gendisk *disk = dev_to_disk(dev); | |
1643 | ||
1644 | return __disk_events_show(disk->events, buf); | |
1645 | } | |
1646 | ||
1647 | static ssize_t disk_events_async_show(struct device *dev, | |
1648 | struct device_attribute *attr, char *buf) | |
1649 | { | |
1650 | struct gendisk *disk = dev_to_disk(dev); | |
1651 | ||
1652 | return __disk_events_show(disk->async_events, buf); | |
1653 | } | |
1654 | ||
1655 | static ssize_t disk_events_poll_msecs_show(struct device *dev, | |
1656 | struct device_attribute *attr, | |
1657 | char *buf) | |
1658 | { | |
1659 | struct gendisk *disk = dev_to_disk(dev); | |
1660 | ||
1661 | return sprintf(buf, "%ld\n", disk->ev->poll_msecs); | |
1662 | } | |
1663 | ||
1664 | static ssize_t disk_events_poll_msecs_store(struct device *dev, | |
1665 | struct device_attribute *attr, | |
1666 | const char *buf, size_t count) | |
1667 | { | |
1668 | struct gendisk *disk = dev_to_disk(dev); | |
1669 | long intv; | |
1670 | ||
1671 | if (!count || !sscanf(buf, "%ld", &intv)) | |
1672 | return -EINVAL; | |
1673 | ||
1674 | if (intv < 0 && intv != -1) | |
1675 | return -EINVAL; | |
1676 | ||
1677 | disk_block_events(disk); | |
1678 | disk->ev->poll_msecs = intv; | |
1679 | __disk_unblock_events(disk, true); | |
1680 | ||
1681 | return count; | |
1682 | } | |
1683 | ||
1684 | static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL); | |
1685 | static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL); | |
1686 | static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR, | |
1687 | disk_events_poll_msecs_show, | |
1688 | disk_events_poll_msecs_store); | |
1689 | ||
1690 | static const struct attribute *disk_events_attrs[] = { | |
1691 | &dev_attr_events.attr, | |
1692 | &dev_attr_events_async.attr, | |
1693 | &dev_attr_events_poll_msecs.attr, | |
1694 | NULL, | |
1695 | }; | |
1696 | ||
1697 | /* | |
1698 | * The default polling interval can be specified by the kernel | |
1699 | * parameter block.events_dfl_poll_msecs which defaults to 0 | |
1700 | * (disable). This can also be modified runtime by writing to | |
1701 | * /sys/module/block/events_dfl_poll_msecs. | |
1702 | */ | |
1703 | static int disk_events_set_dfl_poll_msecs(const char *val, | |
1704 | const struct kernel_param *kp) | |
1705 | { | |
1706 | struct disk_events *ev; | |
1707 | int ret; | |
1708 | ||
1709 | ret = param_set_ulong(val, kp); | |
1710 | if (ret < 0) | |
1711 | return ret; | |
1712 | ||
1713 | mutex_lock(&disk_events_mutex); | |
1714 | ||
1715 | list_for_each_entry(ev, &disk_events, node) | |
1716 | disk_check_events(ev->disk); | |
1717 | ||
1718 | mutex_unlock(&disk_events_mutex); | |
1719 | ||
1720 | return 0; | |
1721 | } | |
1722 | ||
1723 | static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = { | |
1724 | .set = disk_events_set_dfl_poll_msecs, | |
1725 | .get = param_get_ulong, | |
1726 | }; | |
1727 | ||
1728 | #undef MODULE_PARAM_PREFIX | |
1729 | #define MODULE_PARAM_PREFIX "block." | |
1730 | ||
1731 | module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, | |
1732 | &disk_events_dfl_poll_msecs, 0644); | |
1733 | ||
1734 | /* | |
1735 | * disk_{add|del|release}_events - initialize and destroy disk_events. | |
1736 | */ | |
1737 | static void disk_add_events(struct gendisk *disk) | |
1738 | { | |
1739 | struct disk_events *ev; | |
1740 | ||
1741 | if (!disk->fops->check_events) | |
1742 | return; | |
1743 | ||
1744 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
1745 | if (!ev) { | |
1746 | pr_warn("%s: failed to initialize events\n", disk->disk_name); | |
1747 | return; | |
1748 | } | |
1749 | ||
1750 | if (sysfs_create_files(&disk_to_dev(disk)->kobj, | |
1751 | disk_events_attrs) < 0) { | |
1752 | pr_warn("%s: failed to create sysfs files for events\n", | |
1753 | disk->disk_name); | |
1754 | kfree(ev); | |
1755 | return; | |
1756 | } | |
1757 | ||
1758 | disk->ev = ev; | |
1759 | ||
1760 | INIT_LIST_HEAD(&ev->node); | |
1761 | ev->disk = disk; | |
1762 | spin_lock_init(&ev->lock); | |
1763 | mutex_init(&ev->block_mutex); | |
1764 | ev->block = 1; | |
1765 | ev->poll_msecs = -1; | |
1766 | INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); | |
1767 | ||
1768 | mutex_lock(&disk_events_mutex); | |
1769 | list_add_tail(&ev->node, &disk_events); | |
1770 | mutex_unlock(&disk_events_mutex); | |
1771 | ||
1772 | /* | |
1773 | * Block count is initialized to 1 and the following initial | |
1774 | * unblock kicks it into action. | |
1775 | */ | |
1776 | __disk_unblock_events(disk, true); | |
1777 | } | |
1778 | ||
1779 | static void disk_del_events(struct gendisk *disk) | |
1780 | { | |
1781 | if (!disk->ev) | |
1782 | return; | |
1783 | ||
1784 | disk_block_events(disk); | |
1785 | ||
1786 | mutex_lock(&disk_events_mutex); | |
1787 | list_del_init(&disk->ev->node); | |
1788 | mutex_unlock(&disk_events_mutex); | |
1789 | ||
1790 | sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); | |
1791 | } | |
1792 | ||
1793 | static void disk_release_events(struct gendisk *disk) | |
1794 | { | |
1795 | /* the block count should be 1 from disk_del_events() */ | |
1796 | WARN_ON_ONCE(disk->ev && disk->ev->block != 1); | |
1797 | kfree(disk->ev); | |
1798 | } |