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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/backing-dev.h> | |
12 | #include <linux/init.h> | |
13 | #include <linux/spinlock.h> | |
14 | #include <linux/proc_fs.h> | |
15 | #include <linux/seq_file.h> | |
16 | #include <linux/slab.h> | |
17 | #include <linux/kmod.h> | |
18 | #include <linux/kobj_map.h> | |
19 | #include <linux/mutex.h> | |
20 | #include <linux/idr.h> | |
21 | #include <linux/log2.h> | |
22 | #include <linux/pm_runtime.h> | |
23 | #include <linux/badblocks.h> | |
24 | ||
25 | #include "blk.h" | |
26 | ||
27 | static DEFINE_MUTEX(block_class_lock); | |
28 | struct kobject *block_depr; | |
29 | ||
30 | /* for extended dynamic devt allocation, currently only one major is used */ | |
31 | #define NR_EXT_DEVT (1 << MINORBITS) | |
32 | ||
33 | /* For extended devt allocation. ext_devt_lock prevents look up | |
34 | * results from going away underneath its user. | |
35 | */ | |
36 | static DEFINE_SPINLOCK(ext_devt_lock); | |
37 | static DEFINE_IDR(ext_devt_idr); | |
38 | ||
39 | static const struct device_type disk_type; | |
40 | ||
41 | static void disk_check_events(struct disk_events *ev, | |
42 | unsigned int *clearing_ptr); | |
43 | static void disk_alloc_events(struct gendisk *disk); | |
44 | static void disk_add_events(struct gendisk *disk); | |
45 | static void disk_del_events(struct gendisk *disk); | |
46 | static void disk_release_events(struct gendisk *disk); | |
47 | ||
48 | /** | |
49 | * disk_get_part - get partition | |
50 | * @disk: disk to look partition from | |
51 | * @partno: partition number | |
52 | * | |
53 | * Look for partition @partno from @disk. If found, increment | |
54 | * reference count and return it. | |
55 | * | |
56 | * CONTEXT: | |
57 | * Don't care. | |
58 | * | |
59 | * RETURNS: | |
60 | * Pointer to the found partition on success, NULL if not found. | |
61 | */ | |
62 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) | |
63 | { | |
64 | struct hd_struct *part = NULL; | |
65 | struct disk_part_tbl *ptbl; | |
66 | ||
67 | if (unlikely(partno < 0)) | |
68 | return NULL; | |
69 | ||
70 | rcu_read_lock(); | |
71 | ||
72 | ptbl = rcu_dereference(disk->part_tbl); | |
73 | if (likely(partno < ptbl->len)) { | |
74 | part = rcu_dereference(ptbl->part[partno]); | |
75 | if (part) | |
76 | get_device(part_to_dev(part)); | |
77 | } | |
78 | ||
79 | rcu_read_unlock(); | |
80 | ||
81 | return part; | |
82 | } | |
83 | EXPORT_SYMBOL_GPL(disk_get_part); | |
84 | ||
85 | /** | |
86 | * disk_part_iter_init - initialize partition iterator | |
87 | * @piter: iterator to initialize | |
88 | * @disk: disk to iterate over | |
89 | * @flags: DISK_PITER_* flags | |
90 | * | |
91 | * Initialize @piter so that it iterates over partitions of @disk. | |
92 | * | |
93 | * CONTEXT: | |
94 | * Don't care. | |
95 | */ | |
96 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, | |
97 | unsigned int flags) | |
98 | { | |
99 | struct disk_part_tbl *ptbl; | |
100 | ||
101 | rcu_read_lock(); | |
102 | ptbl = rcu_dereference(disk->part_tbl); | |
103 | ||
104 | piter->disk = disk; | |
105 | piter->part = NULL; | |
106 | ||
107 | if (flags & DISK_PITER_REVERSE) | |
108 | piter->idx = ptbl->len - 1; | |
109 | else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) | |
110 | piter->idx = 0; | |
111 | else | |
112 | piter->idx = 1; | |
113 | ||
114 | piter->flags = flags; | |
115 | ||
116 | rcu_read_unlock(); | |
117 | } | |
118 | EXPORT_SYMBOL_GPL(disk_part_iter_init); | |
119 | ||
120 | /** | |
121 | * disk_part_iter_next - proceed iterator to the next partition and return it | |
122 | * @piter: iterator of interest | |
123 | * | |
124 | * Proceed @piter to the next partition and return it. | |
125 | * | |
126 | * CONTEXT: | |
127 | * Don't care. | |
128 | */ | |
129 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) | |
130 | { | |
131 | struct disk_part_tbl *ptbl; | |
132 | int inc, end; | |
133 | ||
134 | /* put the last partition */ | |
135 | disk_put_part(piter->part); | |
136 | piter->part = NULL; | |
137 | ||
138 | /* get part_tbl */ | |
139 | rcu_read_lock(); | |
140 | ptbl = rcu_dereference(piter->disk->part_tbl); | |
141 | ||
142 | /* determine iteration parameters */ | |
143 | if (piter->flags & DISK_PITER_REVERSE) { | |
144 | inc = -1; | |
145 | if (piter->flags & (DISK_PITER_INCL_PART0 | | |
146 | DISK_PITER_INCL_EMPTY_PART0)) | |
147 | end = -1; | |
148 | else | |
149 | end = 0; | |
150 | } else { | |
151 | inc = 1; | |
152 | end = ptbl->len; | |
153 | } | |
154 | ||
155 | /* iterate to the next partition */ | |
156 | for (; piter->idx != end; piter->idx += inc) { | |
157 | struct hd_struct *part; | |
158 | ||
159 | part = rcu_dereference(ptbl->part[piter->idx]); | |
160 | if (!part) | |
161 | continue; | |
162 | if (!part_nr_sects_read(part) && | |
163 | !(piter->flags & DISK_PITER_INCL_EMPTY) && | |
164 | !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && | |
165 | piter->idx == 0)) | |
166 | continue; | |
167 | ||
168 | get_device(part_to_dev(part)); | |
169 | piter->part = part; | |
170 | piter->idx += inc; | |
171 | break; | |
172 | } | |
173 | ||
174 | rcu_read_unlock(); | |
175 | ||
176 | return piter->part; | |
177 | } | |
178 | EXPORT_SYMBOL_GPL(disk_part_iter_next); | |
179 | ||
180 | /** | |
181 | * disk_part_iter_exit - finish up partition iteration | |
182 | * @piter: iter of interest | |
183 | * | |
184 | * Called when iteration is over. Cleans up @piter. | |
185 | * | |
186 | * CONTEXT: | |
187 | * Don't care. | |
188 | */ | |
189 | void disk_part_iter_exit(struct disk_part_iter *piter) | |
190 | { | |
191 | disk_put_part(piter->part); | |
192 | piter->part = NULL; | |
193 | } | |
194 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); | |
195 | ||
196 | static inline int sector_in_part(struct hd_struct *part, sector_t sector) | |
197 | { | |
198 | return part->start_sect <= sector && | |
199 | sector < part->start_sect + part_nr_sects_read(part); | |
200 | } | |
201 | ||
202 | /** | |
203 | * disk_map_sector_rcu - map sector to partition | |
204 | * @disk: gendisk of interest | |
205 | * @sector: sector to map | |
206 | * | |
207 | * Find out which partition @sector maps to on @disk. This is | |
208 | * primarily used for stats accounting. | |
209 | * | |
210 | * CONTEXT: | |
211 | * RCU read locked. The returned partition pointer is valid only | |
212 | * while preemption is disabled. | |
213 | * | |
214 | * RETURNS: | |
215 | * Found partition on success, part0 is returned if no partition matches | |
216 | */ | |
217 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) | |
218 | { | |
219 | struct disk_part_tbl *ptbl; | |
220 | struct hd_struct *part; | |
221 | int i; | |
222 | ||
223 | ptbl = rcu_dereference(disk->part_tbl); | |
224 | ||
225 | part = rcu_dereference(ptbl->last_lookup); | |
226 | if (part && sector_in_part(part, sector)) | |
227 | return part; | |
228 | ||
229 | for (i = 1; i < ptbl->len; i++) { | |
230 | part = rcu_dereference(ptbl->part[i]); | |
231 | ||
232 | if (part && sector_in_part(part, sector)) { | |
233 | rcu_assign_pointer(ptbl->last_lookup, part); | |
234 | return part; | |
235 | } | |
236 | } | |
237 | return &disk->part0; | |
238 | } | |
239 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); | |
240 | ||
241 | /* | |
242 | * Can be deleted altogether. Later. | |
243 | * | |
244 | */ | |
245 | static struct blk_major_name { | |
246 | struct blk_major_name *next; | |
247 | int major; | |
248 | char name[16]; | |
249 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; | |
250 | ||
251 | /* index in the above - for now: assume no multimajor ranges */ | |
252 | static inline int major_to_index(unsigned major) | |
253 | { | |
254 | return major % BLKDEV_MAJOR_HASH_SIZE; | |
255 | } | |
256 | ||
257 | #ifdef CONFIG_PROC_FS | |
258 | void blkdev_show(struct seq_file *seqf, off_t offset) | |
259 | { | |
260 | struct blk_major_name *dp; | |
261 | ||
262 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { | |
263 | mutex_lock(&block_class_lock); | |
264 | for (dp = major_names[offset]; dp; dp = dp->next) | |
265 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); | |
266 | mutex_unlock(&block_class_lock); | |
267 | } | |
268 | } | |
269 | #endif /* CONFIG_PROC_FS */ | |
270 | ||
271 | /** | |
272 | * register_blkdev - register a new block device | |
273 | * | |
274 | * @major: the requested major device number [1..255]. If @major = 0, try to | |
275 | * allocate any unused major number. | |
276 | * @name: the name of the new block device as a zero terminated string | |
277 | * | |
278 | * The @name must be unique within the system. | |
279 | * | |
280 | * The return value depends on the @major input parameter: | |
281 | * | |
282 | * - if a major device number was requested in range [1..255] then the | |
283 | * function returns zero on success, or a negative error code | |
284 | * - if any unused major number was requested with @major = 0 parameter | |
285 | * then the return value is the allocated major number in range | |
286 | * [1..255] or a negative error code otherwise | |
287 | */ | |
288 | int register_blkdev(unsigned int major, const char *name) | |
289 | { | |
290 | struct blk_major_name **n, *p; | |
291 | int index, ret = 0; | |
292 | ||
293 | mutex_lock(&block_class_lock); | |
294 | ||
295 | /* temporary */ | |
296 | if (major == 0) { | |
297 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { | |
298 | if (major_names[index] == NULL) | |
299 | break; | |
300 | } | |
301 | ||
302 | if (index == 0) { | |
303 | printk("register_blkdev: failed to get major for %s\n", | |
304 | name); | |
305 | ret = -EBUSY; | |
306 | goto out; | |
307 | } | |
308 | major = index; | |
309 | ret = major; | |
310 | } | |
311 | ||
312 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); | |
313 | if (p == NULL) { | |
314 | ret = -ENOMEM; | |
315 | goto out; | |
316 | } | |
317 | ||
318 | p->major = major; | |
319 | strlcpy(p->name, name, sizeof(p->name)); | |
320 | p->next = NULL; | |
321 | index = major_to_index(major); | |
322 | ||
323 | for (n = &major_names[index]; *n; n = &(*n)->next) { | |
324 | if ((*n)->major == major) | |
325 | break; | |
326 | } | |
327 | if (!*n) | |
328 | *n = p; | |
329 | else | |
330 | ret = -EBUSY; | |
331 | ||
332 | if (ret < 0) { | |
333 | printk("register_blkdev: cannot get major %d for %s\n", | |
334 | major, name); | |
335 | kfree(p); | |
336 | } | |
337 | out: | |
338 | mutex_unlock(&block_class_lock); | |
339 | return ret; | |
340 | } | |
341 | ||
342 | EXPORT_SYMBOL(register_blkdev); | |
343 | ||
344 | void unregister_blkdev(unsigned int major, const char *name) | |
345 | { | |
346 | struct blk_major_name **n; | |
347 | struct blk_major_name *p = NULL; | |
348 | int index = major_to_index(major); | |
349 | ||
350 | mutex_lock(&block_class_lock); | |
351 | for (n = &major_names[index]; *n; n = &(*n)->next) | |
352 | if ((*n)->major == major) | |
353 | break; | |
354 | if (!*n || strcmp((*n)->name, name)) { | |
355 | WARN_ON(1); | |
356 | } else { | |
357 | p = *n; | |
358 | *n = p->next; | |
359 | } | |
360 | mutex_unlock(&block_class_lock); | |
361 | kfree(p); | |
362 | } | |
363 | ||
364 | EXPORT_SYMBOL(unregister_blkdev); | |
365 | ||
366 | static struct kobj_map *bdev_map; | |
367 | ||
368 | /** | |
369 | * blk_mangle_minor - scatter minor numbers apart | |
370 | * @minor: minor number to mangle | |
371 | * | |
372 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT | |
373 | * is enabled. Mangling twice gives the original value. | |
374 | * | |
375 | * RETURNS: | |
376 | * Mangled value. | |
377 | * | |
378 | * CONTEXT: | |
379 | * Don't care. | |
380 | */ | |
381 | static int blk_mangle_minor(int minor) | |
382 | { | |
383 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT | |
384 | int i; | |
385 | ||
386 | for (i = 0; i < MINORBITS / 2; i++) { | |
387 | int low = minor & (1 << i); | |
388 | int high = minor & (1 << (MINORBITS - 1 - i)); | |
389 | int distance = MINORBITS - 1 - 2 * i; | |
390 | ||
391 | minor ^= low | high; /* clear both bits */ | |
392 | low <<= distance; /* swap the positions */ | |
393 | high >>= distance; | |
394 | minor |= low | high; /* and set */ | |
395 | } | |
396 | #endif | |
397 | return minor; | |
398 | } | |
399 | ||
400 | /** | |
401 | * blk_alloc_devt - allocate a dev_t for a partition | |
402 | * @part: partition to allocate dev_t for | |
403 | * @devt: out parameter for resulting dev_t | |
404 | * | |
405 | * Allocate a dev_t for block device. | |
406 | * | |
407 | * RETURNS: | |
408 | * 0 on success, allocated dev_t is returned in *@devt. -errno on | |
409 | * failure. | |
410 | * | |
411 | * CONTEXT: | |
412 | * Might sleep. | |
413 | */ | |
414 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) | |
415 | { | |
416 | struct gendisk *disk = part_to_disk(part); | |
417 | int idx; | |
418 | ||
419 | /* in consecutive minor range? */ | |
420 | if (part->partno < disk->minors) { | |
421 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); | |
422 | return 0; | |
423 | } | |
424 | ||
425 | /* allocate ext devt */ | |
426 | idr_preload(GFP_KERNEL); | |
427 | ||
428 | spin_lock_bh(&ext_devt_lock); | |
429 | idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_NOWAIT); | |
430 | spin_unlock_bh(&ext_devt_lock); | |
431 | ||
432 | idr_preload_end(); | |
433 | if (idx < 0) | |
434 | return idx == -ENOSPC ? -EBUSY : idx; | |
435 | ||
436 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); | |
437 | return 0; | |
438 | } | |
439 | ||
440 | /** | |
441 | * blk_free_devt - free a dev_t | |
442 | * @devt: dev_t to free | |
443 | * | |
444 | * Free @devt which was allocated using blk_alloc_devt(). | |
445 | * | |
446 | * CONTEXT: | |
447 | * Might sleep. | |
448 | */ | |
449 | void blk_free_devt(dev_t devt) | |
450 | { | |
451 | if (devt == MKDEV(0, 0)) | |
452 | return; | |
453 | ||
454 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { | |
455 | spin_lock_bh(&ext_devt_lock); | |
456 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
457 | spin_unlock_bh(&ext_devt_lock); | |
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 | static void register_disk(struct device *parent, 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 = parent; | |
519 | ||
520 | dev_set_name(ddev, "%s", 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 | ||
536 | /* | |
537 | * avoid probable deadlock caused by allocating memory with | |
538 | * GFP_KERNEL in runtime_resume callback of its all ancestor | |
539 | * devices | |
540 | */ | |
541 | pm_runtime_set_memalloc_noio(ddev, true); | |
542 | ||
543 | disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj); | |
544 | disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); | |
545 | ||
546 | /* No minors to use for partitions */ | |
547 | if (!disk_part_scan_enabled(disk)) | |
548 | goto exit; | |
549 | ||
550 | /* No such device (e.g., media were just removed) */ | |
551 | if (!get_capacity(disk)) | |
552 | goto exit; | |
553 | ||
554 | bdev = bdget_disk(disk, 0); | |
555 | if (!bdev) | |
556 | goto exit; | |
557 | ||
558 | bdev->bd_invalidated = 1; | |
559 | err = blkdev_get(bdev, FMODE_READ, NULL); | |
560 | if (err < 0) | |
561 | goto exit; | |
562 | blkdev_put(bdev, FMODE_READ); | |
563 | ||
564 | exit: | |
565 | /* announce disk after possible partitions are created */ | |
566 | dev_set_uevent_suppress(ddev, 0); | |
567 | kobject_uevent(&ddev->kobj, KOBJ_ADD); | |
568 | ||
569 | /* announce possible partitions */ | |
570 | disk_part_iter_init(&piter, disk, 0); | |
571 | while ((part = disk_part_iter_next(&piter))) | |
572 | kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); | |
573 | disk_part_iter_exit(&piter); | |
574 | } | |
575 | ||
576 | /** | |
577 | * device_add_disk - add partitioning information to kernel list | |
578 | * @parent: parent device for the disk | |
579 | * @disk: per-device partitioning information | |
580 | * | |
581 | * This function registers the partitioning information in @disk | |
582 | * with the kernel. | |
583 | * | |
584 | * FIXME: error handling | |
585 | */ | |
586 | void device_add_disk(struct device *parent, struct gendisk *disk) | |
587 | { | |
588 | struct backing_dev_info *bdi; | |
589 | dev_t devt; | |
590 | int retval; | |
591 | ||
592 | /* minors == 0 indicates to use ext devt from part0 and should | |
593 | * be accompanied with EXT_DEVT flag. Make sure all | |
594 | * parameters make sense. | |
595 | */ | |
596 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); | |
597 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); | |
598 | ||
599 | disk->flags |= GENHD_FL_UP; | |
600 | ||
601 | retval = blk_alloc_devt(&disk->part0, &devt); | |
602 | if (retval) { | |
603 | WARN_ON(1); | |
604 | return; | |
605 | } | |
606 | disk_to_dev(disk)->devt = devt; | |
607 | ||
608 | /* ->major and ->first_minor aren't supposed to be | |
609 | * dereferenced from here on, but set them just in case. | |
610 | */ | |
611 | disk->major = MAJOR(devt); | |
612 | disk->first_minor = MINOR(devt); | |
613 | ||
614 | disk_alloc_events(disk); | |
615 | ||
616 | /* Register BDI before referencing it from bdev */ | |
617 | bdi = disk->queue->backing_dev_info; | |
618 | bdi_register_owner(bdi, disk_to_dev(disk)); | |
619 | ||
620 | blk_register_region(disk_devt(disk), disk->minors, NULL, | |
621 | exact_match, exact_lock, disk); | |
622 | register_disk(parent, disk); | |
623 | blk_register_queue(disk); | |
624 | ||
625 | /* | |
626 | * Take an extra ref on queue which will be put on disk_release() | |
627 | * so that it sticks around as long as @disk is there. | |
628 | */ | |
629 | WARN_ON_ONCE(!blk_get_queue(disk->queue)); | |
630 | ||
631 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, | |
632 | "bdi"); | |
633 | WARN_ON(retval); | |
634 | ||
635 | disk_add_events(disk); | |
636 | blk_integrity_add(disk); | |
637 | } | |
638 | EXPORT_SYMBOL(device_add_disk); | |
639 | ||
640 | void del_gendisk(struct gendisk *disk) | |
641 | { | |
642 | struct disk_part_iter piter; | |
643 | struct hd_struct *part; | |
644 | ||
645 | blk_integrity_del(disk); | |
646 | disk_del_events(disk); | |
647 | ||
648 | /* invalidate stuff */ | |
649 | disk_part_iter_init(&piter, disk, | |
650 | DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); | |
651 | while ((part = disk_part_iter_next(&piter))) { | |
652 | invalidate_partition(disk, part->partno); | |
653 | bdev_unhash_inode(part_devt(part)); | |
654 | delete_partition(disk, part->partno); | |
655 | } | |
656 | disk_part_iter_exit(&piter); | |
657 | ||
658 | invalidate_partition(disk, 0); | |
659 | bdev_unhash_inode(disk_devt(disk)); | |
660 | set_capacity(disk, 0); | |
661 | disk->flags &= ~GENHD_FL_UP; | |
662 | ||
663 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); | |
664 | if (disk->queue) { | |
665 | /* | |
666 | * Unregister bdi before releasing device numbers (as they can | |
667 | * get reused and we'd get clashes in sysfs). | |
668 | */ | |
669 | bdi_unregister(disk->queue->backing_dev_info); | |
670 | blk_unregister_queue(disk); | |
671 | } else { | |
672 | WARN_ON(1); | |
673 | } | |
674 | blk_unregister_region(disk_devt(disk), disk->minors); | |
675 | ||
676 | part_stat_set_all(&disk->part0, 0); | |
677 | disk->part0.stamp = 0; | |
678 | ||
679 | kobject_put(disk->part0.holder_dir); | |
680 | kobject_put(disk->slave_dir); | |
681 | if (!sysfs_deprecated) | |
682 | sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); | |
683 | pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); | |
684 | device_del(disk_to_dev(disk)); | |
685 | } | |
686 | EXPORT_SYMBOL(del_gendisk); | |
687 | ||
688 | /* sysfs access to bad-blocks list. */ | |
689 | static ssize_t disk_badblocks_show(struct device *dev, | |
690 | struct device_attribute *attr, | |
691 | char *page) | |
692 | { | |
693 | struct gendisk *disk = dev_to_disk(dev); | |
694 | ||
695 | if (!disk->bb) | |
696 | return sprintf(page, "\n"); | |
697 | ||
698 | return badblocks_show(disk->bb, page, 0); | |
699 | } | |
700 | ||
701 | static ssize_t disk_badblocks_store(struct device *dev, | |
702 | struct device_attribute *attr, | |
703 | const char *page, size_t len) | |
704 | { | |
705 | struct gendisk *disk = dev_to_disk(dev); | |
706 | ||
707 | if (!disk->bb) | |
708 | return -ENXIO; | |
709 | ||
710 | return badblocks_store(disk->bb, page, len, 0); | |
711 | } | |
712 | ||
713 | /** | |
714 | * get_gendisk - get partitioning information for a given device | |
715 | * @devt: device to get partitioning information for | |
716 | * @partno: returned partition index | |
717 | * | |
718 | * This function gets the structure containing partitioning | |
719 | * information for the given device @devt. | |
720 | */ | |
721 | struct gendisk *get_gendisk(dev_t devt, int *partno) | |
722 | { | |
723 | struct gendisk *disk = NULL; | |
724 | ||
725 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { | |
726 | struct kobject *kobj; | |
727 | ||
728 | kobj = kobj_lookup(bdev_map, devt, partno); | |
729 | if (kobj) | |
730 | disk = dev_to_disk(kobj_to_dev(kobj)); | |
731 | } else { | |
732 | struct hd_struct *part; | |
733 | ||
734 | spin_lock_bh(&ext_devt_lock); | |
735 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
736 | if (part && get_disk(part_to_disk(part))) { | |
737 | *partno = part->partno; | |
738 | disk = part_to_disk(part); | |
739 | } | |
740 | spin_unlock_bh(&ext_devt_lock); | |
741 | } | |
742 | ||
743 | return disk; | |
744 | } | |
745 | EXPORT_SYMBOL(get_gendisk); | |
746 | ||
747 | /** | |
748 | * bdget_disk - do bdget() by gendisk and partition number | |
749 | * @disk: gendisk of interest | |
750 | * @partno: partition number | |
751 | * | |
752 | * Find partition @partno from @disk, do bdget() on it. | |
753 | * | |
754 | * CONTEXT: | |
755 | * Don't care. | |
756 | * | |
757 | * RETURNS: | |
758 | * Resulting block_device on success, NULL on failure. | |
759 | */ | |
760 | struct block_device *bdget_disk(struct gendisk *disk, int partno) | |
761 | { | |
762 | struct hd_struct *part; | |
763 | struct block_device *bdev = NULL; | |
764 | ||
765 | part = disk_get_part(disk, partno); | |
766 | if (part) | |
767 | bdev = bdget(part_devt(part)); | |
768 | disk_put_part(part); | |
769 | ||
770 | return bdev; | |
771 | } | |
772 | EXPORT_SYMBOL(bdget_disk); | |
773 | ||
774 | /* | |
775 | * print a full list of all partitions - intended for places where the root | |
776 | * filesystem can't be mounted and thus to give the victim some idea of what | |
777 | * went wrong | |
778 | */ | |
779 | void __init printk_all_partitions(void) | |
780 | { | |
781 | struct class_dev_iter iter; | |
782 | struct device *dev; | |
783 | ||
784 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
785 | while ((dev = class_dev_iter_next(&iter))) { | |
786 | struct gendisk *disk = dev_to_disk(dev); | |
787 | struct disk_part_iter piter; | |
788 | struct hd_struct *part; | |
789 | char name_buf[BDEVNAME_SIZE]; | |
790 | char devt_buf[BDEVT_SIZE]; | |
791 | ||
792 | /* | |
793 | * Don't show empty devices or things that have been | |
794 | * suppressed | |
795 | */ | |
796 | if (get_capacity(disk) == 0 || | |
797 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) | |
798 | continue; | |
799 | ||
800 | /* | |
801 | * Note, unlike /proc/partitions, I am showing the | |
802 | * numbers in hex - the same format as the root= | |
803 | * option takes. | |
804 | */ | |
805 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); | |
806 | while ((part = disk_part_iter_next(&piter))) { | |
807 | bool is_part0 = part == &disk->part0; | |
808 | ||
809 | printk("%s%s %10llu %s %s", is_part0 ? "" : " ", | |
810 | bdevt_str(part_devt(part), devt_buf), | |
811 | (unsigned long long)part_nr_sects_read(part) >> 1 | |
812 | , disk_name(disk, part->partno, name_buf), | |
813 | part->info ? part->info->uuid : ""); | |
814 | if (is_part0) { | |
815 | if (dev->parent && dev->parent->driver) | |
816 | printk(" driver: %s\n", | |
817 | dev->parent->driver->name); | |
818 | else | |
819 | printk(" (driver?)\n"); | |
820 | } else | |
821 | printk("\n"); | |
822 | } | |
823 | disk_part_iter_exit(&piter); | |
824 | } | |
825 | class_dev_iter_exit(&iter); | |
826 | } | |
827 | ||
828 | #ifdef CONFIG_PROC_FS | |
829 | /* iterator */ | |
830 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) | |
831 | { | |
832 | loff_t skip = *pos; | |
833 | struct class_dev_iter *iter; | |
834 | struct device *dev; | |
835 | ||
836 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); | |
837 | if (!iter) | |
838 | return ERR_PTR(-ENOMEM); | |
839 | ||
840 | seqf->private = iter; | |
841 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); | |
842 | do { | |
843 | dev = class_dev_iter_next(iter); | |
844 | if (!dev) | |
845 | return NULL; | |
846 | } while (skip--); | |
847 | ||
848 | return dev_to_disk(dev); | |
849 | } | |
850 | ||
851 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) | |
852 | { | |
853 | struct device *dev; | |
854 | ||
855 | (*pos)++; | |
856 | dev = class_dev_iter_next(seqf->private); | |
857 | if (dev) | |
858 | return dev_to_disk(dev); | |
859 | ||
860 | return NULL; | |
861 | } | |
862 | ||
863 | static void disk_seqf_stop(struct seq_file *seqf, void *v) | |
864 | { | |
865 | struct class_dev_iter *iter = seqf->private; | |
866 | ||
867 | /* stop is called even after start failed :-( */ | |
868 | if (iter) { | |
869 | class_dev_iter_exit(iter); | |
870 | kfree(iter); | |
871 | seqf->private = NULL; | |
872 | } | |
873 | } | |
874 | ||
875 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) | |
876 | { | |
877 | void *p; | |
878 | ||
879 | p = disk_seqf_start(seqf, pos); | |
880 | if (!IS_ERR_OR_NULL(p) && !*pos) | |
881 | seq_puts(seqf, "major minor #blocks name\n\n"); | |
882 | return p; | |
883 | } | |
884 | ||
885 | static int show_partition(struct seq_file *seqf, void *v) | |
886 | { | |
887 | struct gendisk *sgp = v; | |
888 | struct disk_part_iter piter; | |
889 | struct hd_struct *part; | |
890 | char buf[BDEVNAME_SIZE]; | |
891 | ||
892 | /* Don't show non-partitionable removeable devices or empty devices */ | |
893 | if (!get_capacity(sgp) || (!disk_max_parts(sgp) && | |
894 | (sgp->flags & GENHD_FL_REMOVABLE))) | |
895 | return 0; | |
896 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) | |
897 | return 0; | |
898 | ||
899 | /* show the full disk and all non-0 size partitions of it */ | |
900 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); | |
901 | while ((part = disk_part_iter_next(&piter))) | |
902 | seq_printf(seqf, "%4d %7d %10llu %s\n", | |
903 | MAJOR(part_devt(part)), MINOR(part_devt(part)), | |
904 | (unsigned long long)part_nr_sects_read(part) >> 1, | |
905 | disk_name(sgp, part->partno, buf)); | |
906 | disk_part_iter_exit(&piter); | |
907 | ||
908 | return 0; | |
909 | } | |
910 | ||
911 | static const struct seq_operations partitions_op = { | |
912 | .start = show_partition_start, | |
913 | .next = disk_seqf_next, | |
914 | .stop = disk_seqf_stop, | |
915 | .show = show_partition | |
916 | }; | |
917 | ||
918 | static int partitions_open(struct inode *inode, struct file *file) | |
919 | { | |
920 | return seq_open(file, &partitions_op); | |
921 | } | |
922 | ||
923 | static const struct file_operations proc_partitions_operations = { | |
924 | .open = partitions_open, | |
925 | .read = seq_read, | |
926 | .llseek = seq_lseek, | |
927 | .release = seq_release, | |
928 | }; | |
929 | #endif | |
930 | ||
931 | ||
932 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) | |
933 | { | |
934 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) | |
935 | /* Make old-style 2.4 aliases work */ | |
936 | request_module("block-major-%d", MAJOR(devt)); | |
937 | return NULL; | |
938 | } | |
939 | ||
940 | static int __init genhd_device_init(void) | |
941 | { | |
942 | int error; | |
943 | ||
944 | block_class.dev_kobj = sysfs_dev_block_kobj; | |
945 | error = class_register(&block_class); | |
946 | if (unlikely(error)) | |
947 | return error; | |
948 | bdev_map = kobj_map_init(base_probe, &block_class_lock); | |
949 | blk_dev_init(); | |
950 | ||
951 | register_blkdev(BLOCK_EXT_MAJOR, "blkext"); | |
952 | ||
953 | /* create top-level block dir */ | |
954 | if (!sysfs_deprecated) | |
955 | block_depr = kobject_create_and_add("block", NULL); | |
956 | return 0; | |
957 | } | |
958 | ||
959 | subsys_initcall(genhd_device_init); | |
960 | ||
961 | static ssize_t disk_range_show(struct device *dev, | |
962 | struct device_attribute *attr, char *buf) | |
963 | { | |
964 | struct gendisk *disk = dev_to_disk(dev); | |
965 | ||
966 | return sprintf(buf, "%d\n", disk->minors); | |
967 | } | |
968 | ||
969 | static ssize_t disk_ext_range_show(struct device *dev, | |
970 | struct device_attribute *attr, char *buf) | |
971 | { | |
972 | struct gendisk *disk = dev_to_disk(dev); | |
973 | ||
974 | return sprintf(buf, "%d\n", disk_max_parts(disk)); | |
975 | } | |
976 | ||
977 | static ssize_t disk_removable_show(struct device *dev, | |
978 | struct device_attribute *attr, char *buf) | |
979 | { | |
980 | struct gendisk *disk = dev_to_disk(dev); | |
981 | ||
982 | return sprintf(buf, "%d\n", | |
983 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); | |
984 | } | |
985 | ||
986 | static ssize_t disk_ro_show(struct device *dev, | |
987 | struct device_attribute *attr, char *buf) | |
988 | { | |
989 | struct gendisk *disk = dev_to_disk(dev); | |
990 | ||
991 | return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); | |
992 | } | |
993 | ||
994 | static ssize_t disk_capability_show(struct device *dev, | |
995 | struct device_attribute *attr, char *buf) | |
996 | { | |
997 | struct gendisk *disk = dev_to_disk(dev); | |
998 | ||
999 | return sprintf(buf, "%x\n", disk->flags); | |
1000 | } | |
1001 | ||
1002 | static ssize_t disk_alignment_offset_show(struct device *dev, | |
1003 | struct device_attribute *attr, | |
1004 | char *buf) | |
1005 | { | |
1006 | struct gendisk *disk = dev_to_disk(dev); | |
1007 | ||
1008 | return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue)); | |
1009 | } | |
1010 | ||
1011 | static ssize_t disk_discard_alignment_show(struct device *dev, | |
1012 | struct device_attribute *attr, | |
1013 | char *buf) | |
1014 | { | |
1015 | struct gendisk *disk = dev_to_disk(dev); | |
1016 | ||
1017 | return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue)); | |
1018 | } | |
1019 | ||
1020 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); | |
1021 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); | |
1022 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); | |
1023 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); | |
1024 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); | |
1025 | static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL); | |
1026 | static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show, | |
1027 | NULL); | |
1028 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); | |
1029 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); | |
1030 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); | |
1031 | static DEVICE_ATTR(badblocks, S_IRUGO | S_IWUSR, disk_badblocks_show, | |
1032 | disk_badblocks_store); | |
1033 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
1034 | static struct device_attribute dev_attr_fail = | |
1035 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); | |
1036 | #endif | |
1037 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
1038 | static struct device_attribute dev_attr_fail_timeout = | |
1039 | __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, | |
1040 | part_timeout_store); | |
1041 | #endif | |
1042 | ||
1043 | static struct attribute *disk_attrs[] = { | |
1044 | &dev_attr_range.attr, | |
1045 | &dev_attr_ext_range.attr, | |
1046 | &dev_attr_removable.attr, | |
1047 | &dev_attr_ro.attr, | |
1048 | &dev_attr_size.attr, | |
1049 | &dev_attr_alignment_offset.attr, | |
1050 | &dev_attr_discard_alignment.attr, | |
1051 | &dev_attr_capability.attr, | |
1052 | &dev_attr_stat.attr, | |
1053 | &dev_attr_inflight.attr, | |
1054 | &dev_attr_badblocks.attr, | |
1055 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
1056 | &dev_attr_fail.attr, | |
1057 | #endif | |
1058 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
1059 | &dev_attr_fail_timeout.attr, | |
1060 | #endif | |
1061 | NULL | |
1062 | }; | |
1063 | ||
1064 | static umode_t disk_visible(struct kobject *kobj, struct attribute *a, int n) | |
1065 | { | |
1066 | struct device *dev = container_of(kobj, typeof(*dev), kobj); | |
1067 | struct gendisk *disk = dev_to_disk(dev); | |
1068 | ||
1069 | if (a == &dev_attr_badblocks.attr && !disk->bb) | |
1070 | return 0; | |
1071 | return a->mode; | |
1072 | } | |
1073 | ||
1074 | static struct attribute_group disk_attr_group = { | |
1075 | .attrs = disk_attrs, | |
1076 | .is_visible = disk_visible, | |
1077 | }; | |
1078 | ||
1079 | static const struct attribute_group *disk_attr_groups[] = { | |
1080 | &disk_attr_group, | |
1081 | NULL | |
1082 | }; | |
1083 | ||
1084 | /** | |
1085 | * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way | |
1086 | * @disk: disk to replace part_tbl for | |
1087 | * @new_ptbl: new part_tbl to install | |
1088 | * | |
1089 | * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The | |
1090 | * original ptbl is freed using RCU callback. | |
1091 | * | |
1092 | * LOCKING: | |
1093 | * Matching bd_mutx locked. | |
1094 | */ | |
1095 | static void disk_replace_part_tbl(struct gendisk *disk, | |
1096 | struct disk_part_tbl *new_ptbl) | |
1097 | { | |
1098 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
1099 | ||
1100 | rcu_assign_pointer(disk->part_tbl, new_ptbl); | |
1101 | ||
1102 | if (old_ptbl) { | |
1103 | rcu_assign_pointer(old_ptbl->last_lookup, NULL); | |
1104 | kfree_rcu(old_ptbl, rcu_head); | |
1105 | } | |
1106 | } | |
1107 | ||
1108 | /** | |
1109 | * disk_expand_part_tbl - expand disk->part_tbl | |
1110 | * @disk: disk to expand part_tbl for | |
1111 | * @partno: expand such that this partno can fit in | |
1112 | * | |
1113 | * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl | |
1114 | * uses RCU to allow unlocked dereferencing for stats and other stuff. | |
1115 | * | |
1116 | * LOCKING: | |
1117 | * Matching bd_mutex locked, might sleep. | |
1118 | * | |
1119 | * RETURNS: | |
1120 | * 0 on success, -errno on failure. | |
1121 | */ | |
1122 | int disk_expand_part_tbl(struct gendisk *disk, int partno) | |
1123 | { | |
1124 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
1125 | struct disk_part_tbl *new_ptbl; | |
1126 | int len = old_ptbl ? old_ptbl->len : 0; | |
1127 | int i, target; | |
1128 | size_t size; | |
1129 | ||
1130 | /* | |
1131 | * check for int overflow, since we can get here from blkpg_ioctl() | |
1132 | * with a user passed 'partno'. | |
1133 | */ | |
1134 | target = partno + 1; | |
1135 | if (target < 0) | |
1136 | return -EINVAL; | |
1137 | ||
1138 | /* disk_max_parts() is zero during initialization, ignore if so */ | |
1139 | if (disk_max_parts(disk) && target > disk_max_parts(disk)) | |
1140 | return -EINVAL; | |
1141 | ||
1142 | if (target <= len) | |
1143 | return 0; | |
1144 | ||
1145 | size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); | |
1146 | new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); | |
1147 | if (!new_ptbl) | |
1148 | return -ENOMEM; | |
1149 | ||
1150 | new_ptbl->len = target; | |
1151 | ||
1152 | for (i = 0; i < len; i++) | |
1153 | rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); | |
1154 | ||
1155 | disk_replace_part_tbl(disk, new_ptbl); | |
1156 | return 0; | |
1157 | } | |
1158 | ||
1159 | static void disk_release(struct device *dev) | |
1160 | { | |
1161 | struct gendisk *disk = dev_to_disk(dev); | |
1162 | ||
1163 | blk_free_devt(dev->devt); | |
1164 | disk_release_events(disk); | |
1165 | kfree(disk->random); | |
1166 | disk_replace_part_tbl(disk, NULL); | |
1167 | hd_free_part(&disk->part0); | |
1168 | if (disk->queue) | |
1169 | blk_put_queue(disk->queue); | |
1170 | kfree(disk); | |
1171 | } | |
1172 | struct class block_class = { | |
1173 | .name = "block", | |
1174 | }; | |
1175 | ||
1176 | static char *block_devnode(struct device *dev, umode_t *mode, | |
1177 | kuid_t *uid, kgid_t *gid) | |
1178 | { | |
1179 | struct gendisk *disk = dev_to_disk(dev); | |
1180 | ||
1181 | if (disk->devnode) | |
1182 | return disk->devnode(disk, mode); | |
1183 | return NULL; | |
1184 | } | |
1185 | ||
1186 | static const struct device_type disk_type = { | |
1187 | .name = "disk", | |
1188 | .groups = disk_attr_groups, | |
1189 | .release = disk_release, | |
1190 | .devnode = block_devnode, | |
1191 | }; | |
1192 | ||
1193 | #ifdef CONFIG_PROC_FS | |
1194 | /* | |
1195 | * aggregate disk stat collector. Uses the same stats that the sysfs | |
1196 | * entries do, above, but makes them available through one seq_file. | |
1197 | * | |
1198 | * The output looks suspiciously like /proc/partitions with a bunch of | |
1199 | * extra fields. | |
1200 | */ | |
1201 | static int diskstats_show(struct seq_file *seqf, void *v) | |
1202 | { | |
1203 | struct gendisk *gp = v; | |
1204 | struct disk_part_iter piter; | |
1205 | struct hd_struct *hd; | |
1206 | char buf[BDEVNAME_SIZE]; | |
1207 | int cpu; | |
1208 | ||
1209 | /* | |
1210 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) | |
1211 | seq_puts(seqf, "major minor name" | |
1212 | " rio rmerge rsect ruse wio wmerge " | |
1213 | "wsect wuse running use aveq" | |
1214 | "\n\n"); | |
1215 | */ | |
1216 | ||
1217 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); | |
1218 | while ((hd = disk_part_iter_next(&piter))) { | |
1219 | cpu = part_stat_lock(); | |
1220 | part_round_stats(cpu, hd); | |
1221 | part_stat_unlock(); | |
1222 | seq_printf(seqf, "%4d %7d %s %lu %lu %lu " | |
1223 | "%u %lu %lu %lu %u %u %u %u\n", | |
1224 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), | |
1225 | disk_name(gp, hd->partno, buf), | |
1226 | part_stat_read(hd, ios[READ]), | |
1227 | part_stat_read(hd, merges[READ]), | |
1228 | part_stat_read(hd, sectors[READ]), | |
1229 | jiffies_to_msecs(part_stat_read(hd, ticks[READ])), | |
1230 | part_stat_read(hd, ios[WRITE]), | |
1231 | part_stat_read(hd, merges[WRITE]), | |
1232 | part_stat_read(hd, sectors[WRITE]), | |
1233 | jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])), | |
1234 | part_in_flight(hd), | |
1235 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), | |
1236 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) | |
1237 | ); | |
1238 | } | |
1239 | disk_part_iter_exit(&piter); | |
1240 | ||
1241 | return 0; | |
1242 | } | |
1243 | ||
1244 | static const struct seq_operations diskstats_op = { | |
1245 | .start = disk_seqf_start, | |
1246 | .next = disk_seqf_next, | |
1247 | .stop = disk_seqf_stop, | |
1248 | .show = diskstats_show | |
1249 | }; | |
1250 | ||
1251 | static int diskstats_open(struct inode *inode, struct file *file) | |
1252 | { | |
1253 | return seq_open(file, &diskstats_op); | |
1254 | } | |
1255 | ||
1256 | static const struct file_operations proc_diskstats_operations = { | |
1257 | .open = diskstats_open, | |
1258 | .read = seq_read, | |
1259 | .llseek = seq_lseek, | |
1260 | .release = seq_release, | |
1261 | }; | |
1262 | ||
1263 | static int __init proc_genhd_init(void) | |
1264 | { | |
1265 | proc_create("diskstats", 0, NULL, &proc_diskstats_operations); | |
1266 | proc_create("partitions", 0, NULL, &proc_partitions_operations); | |
1267 | return 0; | |
1268 | } | |
1269 | module_init(proc_genhd_init); | |
1270 | #endif /* CONFIG_PROC_FS */ | |
1271 | ||
1272 | dev_t blk_lookup_devt(const char *name, int partno) | |
1273 | { | |
1274 | dev_t devt = MKDEV(0, 0); | |
1275 | struct class_dev_iter iter; | |
1276 | struct device *dev; | |
1277 | ||
1278 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
1279 | while ((dev = class_dev_iter_next(&iter))) { | |
1280 | struct gendisk *disk = dev_to_disk(dev); | |
1281 | struct hd_struct *part; | |
1282 | ||
1283 | if (strcmp(dev_name(dev), name)) | |
1284 | continue; | |
1285 | ||
1286 | if (partno < disk->minors) { | |
1287 | /* We need to return the right devno, even | |
1288 | * if the partition doesn't exist yet. | |
1289 | */ | |
1290 | devt = MKDEV(MAJOR(dev->devt), | |
1291 | MINOR(dev->devt) + partno); | |
1292 | break; | |
1293 | } | |
1294 | part = disk_get_part(disk, partno); | |
1295 | if (part) { | |
1296 | devt = part_devt(part); | |
1297 | disk_put_part(part); | |
1298 | break; | |
1299 | } | |
1300 | disk_put_part(part); | |
1301 | } | |
1302 | class_dev_iter_exit(&iter); | |
1303 | return devt; | |
1304 | } | |
1305 | EXPORT_SYMBOL(blk_lookup_devt); | |
1306 | ||
1307 | struct gendisk *alloc_disk(int minors) | |
1308 | { | |
1309 | return alloc_disk_node(minors, NUMA_NO_NODE); | |
1310 | } | |
1311 | EXPORT_SYMBOL(alloc_disk); | |
1312 | ||
1313 | struct gendisk *alloc_disk_node(int minors, int node_id) | |
1314 | { | |
1315 | struct gendisk *disk; | |
1316 | ||
1317 | disk = kzalloc_node(sizeof(struct gendisk), GFP_KERNEL, node_id); | |
1318 | if (disk) { | |
1319 | if (!init_part_stats(&disk->part0)) { | |
1320 | kfree(disk); | |
1321 | return NULL; | |
1322 | } | |
1323 | disk->node_id = node_id; | |
1324 | if (disk_expand_part_tbl(disk, 0)) { | |
1325 | free_part_stats(&disk->part0); | |
1326 | kfree(disk); | |
1327 | return NULL; | |
1328 | } | |
1329 | disk->part_tbl->part[0] = &disk->part0; | |
1330 | ||
1331 | /* | |
1332 | * set_capacity() and get_capacity() currently don't use | |
1333 | * seqcounter to read/update the part0->nr_sects. Still init | |
1334 | * the counter as we can read the sectors in IO submission | |
1335 | * patch using seqence counters. | |
1336 | * | |
1337 | * TODO: Ideally set_capacity() and get_capacity() should be | |
1338 | * converted to make use of bd_mutex and sequence counters. | |
1339 | */ | |
1340 | seqcount_init(&disk->part0.nr_sects_seq); | |
1341 | if (hd_ref_init(&disk->part0)) { | |
1342 | hd_free_part(&disk->part0); | |
1343 | kfree(disk); | |
1344 | return NULL; | |
1345 | } | |
1346 | ||
1347 | disk->minors = minors; | |
1348 | rand_initialize_disk(disk); | |
1349 | disk_to_dev(disk)->class = &block_class; | |
1350 | disk_to_dev(disk)->type = &disk_type; | |
1351 | device_initialize(disk_to_dev(disk)); | |
1352 | } | |
1353 | return disk; | |
1354 | } | |
1355 | EXPORT_SYMBOL(alloc_disk_node); | |
1356 | ||
1357 | struct kobject *get_disk(struct gendisk *disk) | |
1358 | { | |
1359 | struct module *owner; | |
1360 | struct kobject *kobj; | |
1361 | ||
1362 | if (!disk->fops) | |
1363 | return NULL; | |
1364 | owner = disk->fops->owner; | |
1365 | if (owner && !try_module_get(owner)) | |
1366 | return NULL; | |
1367 | kobj = kobject_get_unless_zero(&disk_to_dev(disk)->kobj); | |
1368 | if (kobj == NULL) { | |
1369 | module_put(owner); | |
1370 | return NULL; | |
1371 | } | |
1372 | return kobj; | |
1373 | ||
1374 | } | |
1375 | ||
1376 | EXPORT_SYMBOL(get_disk); | |
1377 | ||
1378 | void put_disk(struct gendisk *disk) | |
1379 | { | |
1380 | if (disk) | |
1381 | kobject_put(&disk_to_dev(disk)->kobj); | |
1382 | } | |
1383 | ||
1384 | EXPORT_SYMBOL(put_disk); | |
1385 | ||
1386 | static void set_disk_ro_uevent(struct gendisk *gd, int ro) | |
1387 | { | |
1388 | char event[] = "DISK_RO=1"; | |
1389 | char *envp[] = { event, NULL }; | |
1390 | ||
1391 | if (!ro) | |
1392 | event[8] = '0'; | |
1393 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); | |
1394 | } | |
1395 | ||
1396 | void set_device_ro(struct block_device *bdev, int flag) | |
1397 | { | |
1398 | bdev->bd_part->policy = flag; | |
1399 | } | |
1400 | ||
1401 | EXPORT_SYMBOL(set_device_ro); | |
1402 | ||
1403 | void set_disk_ro(struct gendisk *disk, int flag) | |
1404 | { | |
1405 | struct disk_part_iter piter; | |
1406 | struct hd_struct *part; | |
1407 | ||
1408 | if (disk->part0.policy != flag) { | |
1409 | set_disk_ro_uevent(disk, flag); | |
1410 | disk->part0.policy = flag; | |
1411 | } | |
1412 | ||
1413 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); | |
1414 | while ((part = disk_part_iter_next(&piter))) | |
1415 | part->policy = flag; | |
1416 | disk_part_iter_exit(&piter); | |
1417 | } | |
1418 | ||
1419 | EXPORT_SYMBOL(set_disk_ro); | |
1420 | ||
1421 | int bdev_read_only(struct block_device *bdev) | |
1422 | { | |
1423 | if (!bdev) | |
1424 | return 0; | |
1425 | return bdev->bd_part->policy; | |
1426 | } | |
1427 | ||
1428 | EXPORT_SYMBOL(bdev_read_only); | |
1429 | ||
1430 | int invalidate_partition(struct gendisk *disk, int partno) | |
1431 | { | |
1432 | int res = 0; | |
1433 | struct block_device *bdev = bdget_disk(disk, partno); | |
1434 | if (bdev) { | |
1435 | fsync_bdev(bdev); | |
1436 | res = __invalidate_device(bdev, true); | |
1437 | bdput(bdev); | |
1438 | } | |
1439 | return res; | |
1440 | } | |
1441 | ||
1442 | EXPORT_SYMBOL(invalidate_partition); | |
1443 | ||
1444 | /* | |
1445 | * Disk events - monitor disk events like media change and eject request. | |
1446 | */ | |
1447 | struct disk_events { | |
1448 | struct list_head node; /* all disk_event's */ | |
1449 | struct gendisk *disk; /* the associated disk */ | |
1450 | spinlock_t lock; | |
1451 | ||
1452 | struct mutex block_mutex; /* protects blocking */ | |
1453 | int block; /* event blocking depth */ | |
1454 | unsigned int pending; /* events already sent out */ | |
1455 | unsigned int clearing; /* events being cleared */ | |
1456 | ||
1457 | long poll_msecs; /* interval, -1 for default */ | |
1458 | struct delayed_work dwork; | |
1459 | }; | |
1460 | ||
1461 | static const char *disk_events_strs[] = { | |
1462 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change", | |
1463 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request", | |
1464 | }; | |
1465 | ||
1466 | static char *disk_uevents[] = { | |
1467 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1", | |
1468 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1", | |
1469 | }; | |
1470 | ||
1471 | /* list of all disk_events */ | |
1472 | static DEFINE_MUTEX(disk_events_mutex); | |
1473 | static LIST_HEAD(disk_events); | |
1474 | ||
1475 | /* disable in-kernel polling by default */ | |
1476 | static unsigned long disk_events_dfl_poll_msecs; | |
1477 | ||
1478 | static unsigned long disk_events_poll_jiffies(struct gendisk *disk) | |
1479 | { | |
1480 | struct disk_events *ev = disk->ev; | |
1481 | long intv_msecs = 0; | |
1482 | ||
1483 | /* | |
1484 | * If device-specific poll interval is set, always use it. If | |
1485 | * the default is being used, poll iff there are events which | |
1486 | * can't be monitored asynchronously. | |
1487 | */ | |
1488 | if (ev->poll_msecs >= 0) | |
1489 | intv_msecs = ev->poll_msecs; | |
1490 | else if (disk->events & ~disk->async_events) | |
1491 | intv_msecs = disk_events_dfl_poll_msecs; | |
1492 | ||
1493 | return msecs_to_jiffies(intv_msecs); | |
1494 | } | |
1495 | ||
1496 | /** | |
1497 | * disk_block_events - block and flush disk event checking | |
1498 | * @disk: disk to block events for | |
1499 | * | |
1500 | * On return from this function, it is guaranteed that event checking | |
1501 | * isn't in progress and won't happen until unblocked by | |
1502 | * disk_unblock_events(). Events blocking is counted and the actual | |
1503 | * unblocking happens after the matching number of unblocks are done. | |
1504 | * | |
1505 | * Note that this intentionally does not block event checking from | |
1506 | * disk_clear_events(). | |
1507 | * | |
1508 | * CONTEXT: | |
1509 | * Might sleep. | |
1510 | */ | |
1511 | void disk_block_events(struct gendisk *disk) | |
1512 | { | |
1513 | struct disk_events *ev = disk->ev; | |
1514 | unsigned long flags; | |
1515 | bool cancel; | |
1516 | ||
1517 | if (!ev) | |
1518 | return; | |
1519 | ||
1520 | /* | |
1521 | * Outer mutex ensures that the first blocker completes canceling | |
1522 | * the event work before further blockers are allowed to finish. | |
1523 | */ | |
1524 | mutex_lock(&ev->block_mutex); | |
1525 | ||
1526 | spin_lock_irqsave(&ev->lock, flags); | |
1527 | cancel = !ev->block++; | |
1528 | spin_unlock_irqrestore(&ev->lock, flags); | |
1529 | ||
1530 | if (cancel) | |
1531 | cancel_delayed_work_sync(&disk->ev->dwork); | |
1532 | ||
1533 | mutex_unlock(&ev->block_mutex); | |
1534 | } | |
1535 | ||
1536 | static void __disk_unblock_events(struct gendisk *disk, bool check_now) | |
1537 | { | |
1538 | struct disk_events *ev = disk->ev; | |
1539 | unsigned long intv; | |
1540 | unsigned long flags; | |
1541 | ||
1542 | spin_lock_irqsave(&ev->lock, flags); | |
1543 | ||
1544 | if (WARN_ON_ONCE(ev->block <= 0)) | |
1545 | goto out_unlock; | |
1546 | ||
1547 | if (--ev->block) | |
1548 | goto out_unlock; | |
1549 | ||
1550 | intv = disk_events_poll_jiffies(disk); | |
1551 | if (check_now) | |
1552 | queue_delayed_work(system_freezable_power_efficient_wq, | |
1553 | &ev->dwork, 0); | |
1554 | else if (intv) | |
1555 | queue_delayed_work(system_freezable_power_efficient_wq, | |
1556 | &ev->dwork, intv); | |
1557 | out_unlock: | |
1558 | spin_unlock_irqrestore(&ev->lock, flags); | |
1559 | } | |
1560 | ||
1561 | /** | |
1562 | * disk_unblock_events - unblock disk event checking | |
1563 | * @disk: disk to unblock events for | |
1564 | * | |
1565 | * Undo disk_block_events(). When the block count reaches zero, it | |
1566 | * starts events polling if configured. | |
1567 | * | |
1568 | * CONTEXT: | |
1569 | * Don't care. Safe to call from irq context. | |
1570 | */ | |
1571 | void disk_unblock_events(struct gendisk *disk) | |
1572 | { | |
1573 | if (disk->ev) | |
1574 | __disk_unblock_events(disk, false); | |
1575 | } | |
1576 | ||
1577 | /** | |
1578 | * disk_flush_events - schedule immediate event checking and flushing | |
1579 | * @disk: disk to check and flush events for | |
1580 | * @mask: events to flush | |
1581 | * | |
1582 | * Schedule immediate event checking on @disk if not blocked. Events in | |
1583 | * @mask are scheduled to be cleared from the driver. Note that this | |
1584 | * doesn't clear the events from @disk->ev. | |
1585 | * | |
1586 | * CONTEXT: | |
1587 | * If @mask is non-zero must be called with bdev->bd_mutex held. | |
1588 | */ | |
1589 | void disk_flush_events(struct gendisk *disk, unsigned int mask) | |
1590 | { | |
1591 | struct disk_events *ev = disk->ev; | |
1592 | ||
1593 | if (!ev) | |
1594 | return; | |
1595 | ||
1596 | spin_lock_irq(&ev->lock); | |
1597 | ev->clearing |= mask; | |
1598 | if (!ev->block) | |
1599 | mod_delayed_work(system_freezable_power_efficient_wq, | |
1600 | &ev->dwork, 0); | |
1601 | spin_unlock_irq(&ev->lock); | |
1602 | } | |
1603 | ||
1604 | /** | |
1605 | * disk_clear_events - synchronously check, clear and return pending events | |
1606 | * @disk: disk to fetch and clear events from | |
1607 | * @mask: mask of events to be fetched and cleared | |
1608 | * | |
1609 | * Disk events are synchronously checked and pending events in @mask | |
1610 | * are cleared and returned. This ignores the block count. | |
1611 | * | |
1612 | * CONTEXT: | |
1613 | * Might sleep. | |
1614 | */ | |
1615 | unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) | |
1616 | { | |
1617 | const struct block_device_operations *bdops = disk->fops; | |
1618 | struct disk_events *ev = disk->ev; | |
1619 | unsigned int pending; | |
1620 | unsigned int clearing = mask; | |
1621 | ||
1622 | if (!ev) { | |
1623 | /* for drivers still using the old ->media_changed method */ | |
1624 | if ((mask & DISK_EVENT_MEDIA_CHANGE) && | |
1625 | bdops->media_changed && bdops->media_changed(disk)) | |
1626 | return DISK_EVENT_MEDIA_CHANGE; | |
1627 | return 0; | |
1628 | } | |
1629 | ||
1630 | disk_block_events(disk); | |
1631 | ||
1632 | /* | |
1633 | * store the union of mask and ev->clearing on the stack so that the | |
1634 | * race with disk_flush_events does not cause ambiguity (ev->clearing | |
1635 | * can still be modified even if events are blocked). | |
1636 | */ | |
1637 | spin_lock_irq(&ev->lock); | |
1638 | clearing |= ev->clearing; | |
1639 | ev->clearing = 0; | |
1640 | spin_unlock_irq(&ev->lock); | |
1641 | ||
1642 | disk_check_events(ev, &clearing); | |
1643 | /* | |
1644 | * if ev->clearing is not 0, the disk_flush_events got called in the | |
1645 | * middle of this function, so we want to run the workfn without delay. | |
1646 | */ | |
1647 | __disk_unblock_events(disk, ev->clearing ? true : false); | |
1648 | ||
1649 | /* then, fetch and clear pending events */ | |
1650 | spin_lock_irq(&ev->lock); | |
1651 | pending = ev->pending & mask; | |
1652 | ev->pending &= ~mask; | |
1653 | spin_unlock_irq(&ev->lock); | |
1654 | WARN_ON_ONCE(clearing & mask); | |
1655 | ||
1656 | return pending; | |
1657 | } | |
1658 | ||
1659 | /* | |
1660 | * Separate this part out so that a different pointer for clearing_ptr can be | |
1661 | * passed in for disk_clear_events. | |
1662 | */ | |
1663 | static void disk_events_workfn(struct work_struct *work) | |
1664 | { | |
1665 | struct delayed_work *dwork = to_delayed_work(work); | |
1666 | struct disk_events *ev = container_of(dwork, struct disk_events, dwork); | |
1667 | ||
1668 | disk_check_events(ev, &ev->clearing); | |
1669 | } | |
1670 | ||
1671 | static void disk_check_events(struct disk_events *ev, | |
1672 | unsigned int *clearing_ptr) | |
1673 | { | |
1674 | struct gendisk *disk = ev->disk; | |
1675 | char *envp[ARRAY_SIZE(disk_uevents) + 1] = { }; | |
1676 | unsigned int clearing = *clearing_ptr; | |
1677 | unsigned int events; | |
1678 | unsigned long intv; | |
1679 | int nr_events = 0, i; | |
1680 | ||
1681 | /* check events */ | |
1682 | events = disk->fops->check_events(disk, clearing); | |
1683 | ||
1684 | /* accumulate pending events and schedule next poll if necessary */ | |
1685 | spin_lock_irq(&ev->lock); | |
1686 | ||
1687 | events &= ~ev->pending; | |
1688 | ev->pending |= events; | |
1689 | *clearing_ptr &= ~clearing; | |
1690 | ||
1691 | intv = disk_events_poll_jiffies(disk); | |
1692 | if (!ev->block && intv) | |
1693 | queue_delayed_work(system_freezable_power_efficient_wq, | |
1694 | &ev->dwork, intv); | |
1695 | ||
1696 | spin_unlock_irq(&ev->lock); | |
1697 | ||
1698 | /* | |
1699 | * Tell userland about new events. Only the events listed in | |
1700 | * @disk->events are reported. Unlisted events are processed the | |
1701 | * same internally but never get reported to userland. | |
1702 | */ | |
1703 | for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) | |
1704 | if (events & disk->events & (1 << i)) | |
1705 | envp[nr_events++] = disk_uevents[i]; | |
1706 | ||
1707 | if (nr_events) | |
1708 | kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); | |
1709 | } | |
1710 | ||
1711 | /* | |
1712 | * A disk events enabled device has the following sysfs nodes under | |
1713 | * its /sys/block/X/ directory. | |
1714 | * | |
1715 | * events : list of all supported events | |
1716 | * events_async : list of events which can be detected w/o polling | |
1717 | * events_poll_msecs : polling interval, 0: disable, -1: system default | |
1718 | */ | |
1719 | static ssize_t __disk_events_show(unsigned int events, char *buf) | |
1720 | { | |
1721 | const char *delim = ""; | |
1722 | ssize_t pos = 0; | |
1723 | int i; | |
1724 | ||
1725 | for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++) | |
1726 | if (events & (1 << i)) { | |
1727 | pos += sprintf(buf + pos, "%s%s", | |
1728 | delim, disk_events_strs[i]); | |
1729 | delim = " "; | |
1730 | } | |
1731 | if (pos) | |
1732 | pos += sprintf(buf + pos, "\n"); | |
1733 | return pos; | |
1734 | } | |
1735 | ||
1736 | static ssize_t disk_events_show(struct device *dev, | |
1737 | struct device_attribute *attr, char *buf) | |
1738 | { | |
1739 | struct gendisk *disk = dev_to_disk(dev); | |
1740 | ||
1741 | return __disk_events_show(disk->events, buf); | |
1742 | } | |
1743 | ||
1744 | static ssize_t disk_events_async_show(struct device *dev, | |
1745 | struct device_attribute *attr, char *buf) | |
1746 | { | |
1747 | struct gendisk *disk = dev_to_disk(dev); | |
1748 | ||
1749 | return __disk_events_show(disk->async_events, buf); | |
1750 | } | |
1751 | ||
1752 | static ssize_t disk_events_poll_msecs_show(struct device *dev, | |
1753 | struct device_attribute *attr, | |
1754 | char *buf) | |
1755 | { | |
1756 | struct gendisk *disk = dev_to_disk(dev); | |
1757 | ||
1758 | return sprintf(buf, "%ld\n", disk->ev->poll_msecs); | |
1759 | } | |
1760 | ||
1761 | static ssize_t disk_events_poll_msecs_store(struct device *dev, | |
1762 | struct device_attribute *attr, | |
1763 | const char *buf, size_t count) | |
1764 | { | |
1765 | struct gendisk *disk = dev_to_disk(dev); | |
1766 | long intv; | |
1767 | ||
1768 | if (!count || !sscanf(buf, "%ld", &intv)) | |
1769 | return -EINVAL; | |
1770 | ||
1771 | if (intv < 0 && intv != -1) | |
1772 | return -EINVAL; | |
1773 | ||
1774 | disk_block_events(disk); | |
1775 | disk->ev->poll_msecs = intv; | |
1776 | __disk_unblock_events(disk, true); | |
1777 | ||
1778 | return count; | |
1779 | } | |
1780 | ||
1781 | static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL); | |
1782 | static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL); | |
1783 | static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR, | |
1784 | disk_events_poll_msecs_show, | |
1785 | disk_events_poll_msecs_store); | |
1786 | ||
1787 | static const struct attribute *disk_events_attrs[] = { | |
1788 | &dev_attr_events.attr, | |
1789 | &dev_attr_events_async.attr, | |
1790 | &dev_attr_events_poll_msecs.attr, | |
1791 | NULL, | |
1792 | }; | |
1793 | ||
1794 | /* | |
1795 | * The default polling interval can be specified by the kernel | |
1796 | * parameter block.events_dfl_poll_msecs which defaults to 0 | |
1797 | * (disable). This can also be modified runtime by writing to | |
1798 | * /sys/module/block/events_dfl_poll_msecs. | |
1799 | */ | |
1800 | static int disk_events_set_dfl_poll_msecs(const char *val, | |
1801 | const struct kernel_param *kp) | |
1802 | { | |
1803 | struct disk_events *ev; | |
1804 | int ret; | |
1805 | ||
1806 | ret = param_set_ulong(val, kp); | |
1807 | if (ret < 0) | |
1808 | return ret; | |
1809 | ||
1810 | mutex_lock(&disk_events_mutex); | |
1811 | ||
1812 | list_for_each_entry(ev, &disk_events, node) | |
1813 | disk_flush_events(ev->disk, 0); | |
1814 | ||
1815 | mutex_unlock(&disk_events_mutex); | |
1816 | ||
1817 | return 0; | |
1818 | } | |
1819 | ||
1820 | static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = { | |
1821 | .set = disk_events_set_dfl_poll_msecs, | |
1822 | .get = param_get_ulong, | |
1823 | }; | |
1824 | ||
1825 | #undef MODULE_PARAM_PREFIX | |
1826 | #define MODULE_PARAM_PREFIX "block." | |
1827 | ||
1828 | module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, | |
1829 | &disk_events_dfl_poll_msecs, 0644); | |
1830 | ||
1831 | /* | |
1832 | * disk_{alloc|add|del|release}_events - initialize and destroy disk_events. | |
1833 | */ | |
1834 | static void disk_alloc_events(struct gendisk *disk) | |
1835 | { | |
1836 | struct disk_events *ev; | |
1837 | ||
1838 | if (!disk->fops->check_events) | |
1839 | return; | |
1840 | ||
1841 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); | |
1842 | if (!ev) { | |
1843 | pr_warn("%s: failed to initialize events\n", disk->disk_name); | |
1844 | return; | |
1845 | } | |
1846 | ||
1847 | INIT_LIST_HEAD(&ev->node); | |
1848 | ev->disk = disk; | |
1849 | spin_lock_init(&ev->lock); | |
1850 | mutex_init(&ev->block_mutex); | |
1851 | ev->block = 1; | |
1852 | ev->poll_msecs = -1; | |
1853 | INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); | |
1854 | ||
1855 | disk->ev = ev; | |
1856 | } | |
1857 | ||
1858 | static void disk_add_events(struct gendisk *disk) | |
1859 | { | |
1860 | if (!disk->ev) | |
1861 | return; | |
1862 | ||
1863 | /* FIXME: error handling */ | |
1864 | if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0) | |
1865 | pr_warn("%s: failed to create sysfs files for events\n", | |
1866 | disk->disk_name); | |
1867 | ||
1868 | mutex_lock(&disk_events_mutex); | |
1869 | list_add_tail(&disk->ev->node, &disk_events); | |
1870 | mutex_unlock(&disk_events_mutex); | |
1871 | ||
1872 | /* | |
1873 | * Block count is initialized to 1 and the following initial | |
1874 | * unblock kicks it into action. | |
1875 | */ | |
1876 | __disk_unblock_events(disk, true); | |
1877 | } | |
1878 | ||
1879 | static void disk_del_events(struct gendisk *disk) | |
1880 | { | |
1881 | if (!disk->ev) | |
1882 | return; | |
1883 | ||
1884 | disk_block_events(disk); | |
1885 | ||
1886 | mutex_lock(&disk_events_mutex); | |
1887 | list_del_init(&disk->ev->node); | |
1888 | mutex_unlock(&disk_events_mutex); | |
1889 | ||
1890 | sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); | |
1891 | } | |
1892 | ||
1893 | static void disk_release_events(struct gendisk *disk) | |
1894 | { | |
1895 | /* the block count should be 1 from disk_del_events() */ | |
1896 | WARN_ON_ONCE(disk->ev && disk->ev->block != 1); | |
1897 | kfree(disk->ev); | |
1898 | } |