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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 | ||
22 | #include "blk.h" | |
23 | ||
24 | static DEFINE_MUTEX(block_class_lock); | |
25 | struct kobject *block_depr; | |
26 | ||
27 | /* for extended dynamic devt allocation, currently only one major is used */ | |
28 | #define MAX_EXT_DEVT (1 << MINORBITS) | |
29 | ||
30 | /* For extended devt allocation. ext_devt_mutex prevents look up | |
31 | * results from going away underneath its user. | |
32 | */ | |
33 | static DEFINE_MUTEX(ext_devt_mutex); | |
34 | static DEFINE_IDR(ext_devt_idr); | |
35 | ||
36 | static struct device_type disk_type; | |
37 | ||
38 | /** | |
39 | * disk_get_part - get partition | |
40 | * @disk: disk to look partition from | |
41 | * @partno: partition number | |
42 | * | |
43 | * Look for partition @partno from @disk. If found, increment | |
44 | * reference count and return it. | |
45 | * | |
46 | * CONTEXT: | |
47 | * Don't care. | |
48 | * | |
49 | * RETURNS: | |
50 | * Pointer to the found partition on success, NULL if not found. | |
51 | */ | |
52 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) | |
53 | { | |
54 | struct hd_struct *part = NULL; | |
55 | struct disk_part_tbl *ptbl; | |
56 | ||
57 | if (unlikely(partno < 0)) | |
58 | return NULL; | |
59 | ||
60 | rcu_read_lock(); | |
61 | ||
62 | ptbl = rcu_dereference(disk->part_tbl); | |
63 | if (likely(partno < ptbl->len)) { | |
64 | part = rcu_dereference(ptbl->part[partno]); | |
65 | if (part) | |
66 | get_device(part_to_dev(part)); | |
67 | } | |
68 | ||
69 | rcu_read_unlock(); | |
70 | ||
71 | return part; | |
72 | } | |
73 | EXPORT_SYMBOL_GPL(disk_get_part); | |
74 | ||
75 | /** | |
76 | * disk_part_iter_init - initialize partition iterator | |
77 | * @piter: iterator to initialize | |
78 | * @disk: disk to iterate over | |
79 | * @flags: DISK_PITER_* flags | |
80 | * | |
81 | * Initialize @piter so that it iterates over partitions of @disk. | |
82 | * | |
83 | * CONTEXT: | |
84 | * Don't care. | |
85 | */ | |
86 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, | |
87 | unsigned int flags) | |
88 | { | |
89 | struct disk_part_tbl *ptbl; | |
90 | ||
91 | rcu_read_lock(); | |
92 | ptbl = rcu_dereference(disk->part_tbl); | |
93 | ||
94 | piter->disk = disk; | |
95 | piter->part = NULL; | |
96 | ||
97 | if (flags & DISK_PITER_REVERSE) | |
98 | piter->idx = ptbl->len - 1; | |
99 | else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) | |
100 | piter->idx = 0; | |
101 | else | |
102 | piter->idx = 1; | |
103 | ||
104 | piter->flags = flags; | |
105 | ||
106 | rcu_read_unlock(); | |
107 | } | |
108 | EXPORT_SYMBOL_GPL(disk_part_iter_init); | |
109 | ||
110 | /** | |
111 | * disk_part_iter_next - proceed iterator to the next partition and return it | |
112 | * @piter: iterator of interest | |
113 | * | |
114 | * Proceed @piter to the next partition and return it. | |
115 | * | |
116 | * CONTEXT: | |
117 | * Don't care. | |
118 | */ | |
119 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) | |
120 | { | |
121 | struct disk_part_tbl *ptbl; | |
122 | int inc, end; | |
123 | ||
124 | /* put the last partition */ | |
125 | disk_put_part(piter->part); | |
126 | piter->part = NULL; | |
127 | ||
128 | /* get part_tbl */ | |
129 | rcu_read_lock(); | |
130 | ptbl = rcu_dereference(piter->disk->part_tbl); | |
131 | ||
132 | /* determine iteration parameters */ | |
133 | if (piter->flags & DISK_PITER_REVERSE) { | |
134 | inc = -1; | |
135 | if (piter->flags & (DISK_PITER_INCL_PART0 | | |
136 | DISK_PITER_INCL_EMPTY_PART0)) | |
137 | end = -1; | |
138 | else | |
139 | end = 0; | |
140 | } else { | |
141 | inc = 1; | |
142 | end = ptbl->len; | |
143 | } | |
144 | ||
145 | /* iterate to the next partition */ | |
146 | for (; piter->idx != end; piter->idx += inc) { | |
147 | struct hd_struct *part; | |
148 | ||
149 | part = rcu_dereference(ptbl->part[piter->idx]); | |
150 | if (!part) | |
151 | continue; | |
152 | if (!part->nr_sects && | |
153 | !(piter->flags & DISK_PITER_INCL_EMPTY) && | |
154 | !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && | |
155 | piter->idx == 0)) | |
156 | continue; | |
157 | ||
158 | get_device(part_to_dev(part)); | |
159 | piter->part = part; | |
160 | piter->idx += inc; | |
161 | break; | |
162 | } | |
163 | ||
164 | rcu_read_unlock(); | |
165 | ||
166 | return piter->part; | |
167 | } | |
168 | EXPORT_SYMBOL_GPL(disk_part_iter_next); | |
169 | ||
170 | /** | |
171 | * disk_part_iter_exit - finish up partition iteration | |
172 | * @piter: iter of interest | |
173 | * | |
174 | * Called when iteration is over. Cleans up @piter. | |
175 | * | |
176 | * CONTEXT: | |
177 | * Don't care. | |
178 | */ | |
179 | void disk_part_iter_exit(struct disk_part_iter *piter) | |
180 | { | |
181 | disk_put_part(piter->part); | |
182 | piter->part = NULL; | |
183 | } | |
184 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); | |
185 | ||
186 | static inline int sector_in_part(struct hd_struct *part, sector_t sector) | |
187 | { | |
188 | return part->start_sect <= sector && | |
189 | sector < part->start_sect + part->nr_sects; | |
190 | } | |
191 | ||
192 | /** | |
193 | * disk_map_sector_rcu - map sector to partition | |
194 | * @disk: gendisk of interest | |
195 | * @sector: sector to map | |
196 | * | |
197 | * Find out which partition @sector maps to on @disk. This is | |
198 | * primarily used for stats accounting. | |
199 | * | |
200 | * CONTEXT: | |
201 | * RCU read locked. The returned partition pointer is valid only | |
202 | * while preemption is disabled. | |
203 | * | |
204 | * RETURNS: | |
205 | * Found partition on success, part0 is returned if no partition matches | |
206 | */ | |
207 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) | |
208 | { | |
209 | struct disk_part_tbl *ptbl; | |
210 | struct hd_struct *part; | |
211 | int i; | |
212 | ||
213 | ptbl = rcu_dereference(disk->part_tbl); | |
214 | ||
215 | part = rcu_dereference(ptbl->last_lookup); | |
216 | if (part && sector_in_part(part, sector)) | |
217 | return part; | |
218 | ||
219 | for (i = 1; i < ptbl->len; i++) { | |
220 | part = rcu_dereference(ptbl->part[i]); | |
221 | ||
222 | if (part && sector_in_part(part, sector)) { | |
223 | rcu_assign_pointer(ptbl->last_lookup, part); | |
224 | return part; | |
225 | } | |
226 | } | |
227 | return &disk->part0; | |
228 | } | |
229 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); | |
230 | ||
231 | /* | |
232 | * Can be deleted altogether. Later. | |
233 | * | |
234 | */ | |
235 | static struct blk_major_name { | |
236 | struct blk_major_name *next; | |
237 | int major; | |
238 | char name[16]; | |
239 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; | |
240 | ||
241 | /* index in the above - for now: assume no multimajor ranges */ | |
242 | static inline int major_to_index(int major) | |
243 | { | |
244 | return major % BLKDEV_MAJOR_HASH_SIZE; | |
245 | } | |
246 | ||
247 | #ifdef CONFIG_PROC_FS | |
248 | void blkdev_show(struct seq_file *seqf, off_t offset) | |
249 | { | |
250 | struct blk_major_name *dp; | |
251 | ||
252 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { | |
253 | mutex_lock(&block_class_lock); | |
254 | for (dp = major_names[offset]; dp; dp = dp->next) | |
255 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); | |
256 | mutex_unlock(&block_class_lock); | |
257 | } | |
258 | } | |
259 | #endif /* CONFIG_PROC_FS */ | |
260 | ||
261 | /** | |
262 | * register_blkdev - register a new block device | |
263 | * | |
264 | * @major: the requested major device number [1..255]. If @major=0, try to | |
265 | * allocate any unused major number. | |
266 | * @name: the name of the new block device as a zero terminated string | |
267 | * | |
268 | * The @name must be unique within the system. | |
269 | * | |
270 | * The return value depends on the @major input parameter. | |
271 | * - if a major device number was requested in range [1..255] then the | |
272 | * function returns zero on success, or a negative error code | |
273 | * - if any unused major number was requested with @major=0 parameter | |
274 | * then the return value is the allocated major number in range | |
275 | * [1..255] or a negative error code otherwise | |
276 | */ | |
277 | int register_blkdev(unsigned int major, const char *name) | |
278 | { | |
279 | struct blk_major_name **n, *p; | |
280 | int index, ret = 0; | |
281 | ||
282 | mutex_lock(&block_class_lock); | |
283 | ||
284 | /* temporary */ | |
285 | if (major == 0) { | |
286 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { | |
287 | if (major_names[index] == NULL) | |
288 | break; | |
289 | } | |
290 | ||
291 | if (index == 0) { | |
292 | printk("register_blkdev: failed to get major for %s\n", | |
293 | name); | |
294 | ret = -EBUSY; | |
295 | goto out; | |
296 | } | |
297 | major = index; | |
298 | ret = major; | |
299 | } | |
300 | ||
301 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); | |
302 | if (p == NULL) { | |
303 | ret = -ENOMEM; | |
304 | goto out; | |
305 | } | |
306 | ||
307 | p->major = major; | |
308 | strlcpy(p->name, name, sizeof(p->name)); | |
309 | p->next = NULL; | |
310 | index = major_to_index(major); | |
311 | ||
312 | for (n = &major_names[index]; *n; n = &(*n)->next) { | |
313 | if ((*n)->major == major) | |
314 | break; | |
315 | } | |
316 | if (!*n) | |
317 | *n = p; | |
318 | else | |
319 | ret = -EBUSY; | |
320 | ||
321 | if (ret < 0) { | |
322 | printk("register_blkdev: cannot get major %d for %s\n", | |
323 | major, name); | |
324 | kfree(p); | |
325 | } | |
326 | out: | |
327 | mutex_unlock(&block_class_lock); | |
328 | return ret; | |
329 | } | |
330 | ||
331 | EXPORT_SYMBOL(register_blkdev); | |
332 | ||
333 | void unregister_blkdev(unsigned int major, const char *name) | |
334 | { | |
335 | struct blk_major_name **n; | |
336 | struct blk_major_name *p = NULL; | |
337 | int index = major_to_index(major); | |
338 | ||
339 | mutex_lock(&block_class_lock); | |
340 | for (n = &major_names[index]; *n; n = &(*n)->next) | |
341 | if ((*n)->major == major) | |
342 | break; | |
343 | if (!*n || strcmp((*n)->name, name)) { | |
344 | WARN_ON(1); | |
345 | } else { | |
346 | p = *n; | |
347 | *n = p->next; | |
348 | } | |
349 | mutex_unlock(&block_class_lock); | |
350 | kfree(p); | |
351 | } | |
352 | ||
353 | EXPORT_SYMBOL(unregister_blkdev); | |
354 | ||
355 | static struct kobj_map *bdev_map; | |
356 | ||
357 | /** | |
358 | * blk_mangle_minor - scatter minor numbers apart | |
359 | * @minor: minor number to mangle | |
360 | * | |
361 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT | |
362 | * is enabled. Mangling twice gives the original value. | |
363 | * | |
364 | * RETURNS: | |
365 | * Mangled value. | |
366 | * | |
367 | * CONTEXT: | |
368 | * Don't care. | |
369 | */ | |
370 | static int blk_mangle_minor(int minor) | |
371 | { | |
372 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT | |
373 | int i; | |
374 | ||
375 | for (i = 0; i < MINORBITS / 2; i++) { | |
376 | int low = minor & (1 << i); | |
377 | int high = minor & (1 << (MINORBITS - 1 - i)); | |
378 | int distance = MINORBITS - 1 - 2 * i; | |
379 | ||
380 | minor ^= low | high; /* clear both bits */ | |
381 | low <<= distance; /* swap the positions */ | |
382 | high >>= distance; | |
383 | minor |= low | high; /* and set */ | |
384 | } | |
385 | #endif | |
386 | return minor; | |
387 | } | |
388 | ||
389 | /** | |
390 | * blk_alloc_devt - allocate a dev_t for a partition | |
391 | * @part: partition to allocate dev_t for | |
392 | * @devt: out parameter for resulting dev_t | |
393 | * | |
394 | * Allocate a dev_t for block device. | |
395 | * | |
396 | * RETURNS: | |
397 | * 0 on success, allocated dev_t is returned in *@devt. -errno on | |
398 | * failure. | |
399 | * | |
400 | * CONTEXT: | |
401 | * Might sleep. | |
402 | */ | |
403 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) | |
404 | { | |
405 | struct gendisk *disk = part_to_disk(part); | |
406 | int idx, rc; | |
407 | ||
408 | /* in consecutive minor range? */ | |
409 | if (part->partno < disk->minors) { | |
410 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); | |
411 | return 0; | |
412 | } | |
413 | ||
414 | /* allocate ext devt */ | |
415 | do { | |
416 | if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL)) | |
417 | return -ENOMEM; | |
418 | rc = idr_get_new(&ext_devt_idr, part, &idx); | |
419 | } while (rc == -EAGAIN); | |
420 | ||
421 | if (rc) | |
422 | return rc; | |
423 | ||
424 | if (idx > MAX_EXT_DEVT) { | |
425 | idr_remove(&ext_devt_idr, idx); | |
426 | return -EBUSY; | |
427 | } | |
428 | ||
429 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); | |
430 | return 0; | |
431 | } | |
432 | ||
433 | /** | |
434 | * blk_free_devt - free a dev_t | |
435 | * @devt: dev_t to free | |
436 | * | |
437 | * Free @devt which was allocated using blk_alloc_devt(). | |
438 | * | |
439 | * CONTEXT: | |
440 | * Might sleep. | |
441 | */ | |
442 | void blk_free_devt(dev_t devt) | |
443 | { | |
444 | might_sleep(); | |
445 | ||
446 | if (devt == MKDEV(0, 0)) | |
447 | return; | |
448 | ||
449 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { | |
450 | mutex_lock(&ext_devt_mutex); | |
451 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
452 | mutex_unlock(&ext_devt_mutex); | |
453 | } | |
454 | } | |
455 | ||
456 | static char *bdevt_str(dev_t devt, char *buf) | |
457 | { | |
458 | if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { | |
459 | char tbuf[BDEVT_SIZE]; | |
460 | snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); | |
461 | snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); | |
462 | } else | |
463 | snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); | |
464 | ||
465 | return buf; | |
466 | } | |
467 | ||
468 | /* | |
469 | * Register device numbers dev..(dev+range-1) | |
470 | * range must be nonzero | |
471 | * The hash chain is sorted on range, so that subranges can override. | |
472 | */ | |
473 | void blk_register_region(dev_t devt, unsigned long range, struct module *module, | |
474 | struct kobject *(*probe)(dev_t, int *, void *), | |
475 | int (*lock)(dev_t, void *), void *data) | |
476 | { | |
477 | kobj_map(bdev_map, devt, range, module, probe, lock, data); | |
478 | } | |
479 | ||
480 | EXPORT_SYMBOL(blk_register_region); | |
481 | ||
482 | void blk_unregister_region(dev_t devt, unsigned long range) | |
483 | { | |
484 | kobj_unmap(bdev_map, devt, range); | |
485 | } | |
486 | ||
487 | EXPORT_SYMBOL(blk_unregister_region); | |
488 | ||
489 | static struct kobject *exact_match(dev_t devt, int *partno, void *data) | |
490 | { | |
491 | struct gendisk *p = data; | |
492 | ||
493 | return &disk_to_dev(p)->kobj; | |
494 | } | |
495 | ||
496 | static int exact_lock(dev_t devt, void *data) | |
497 | { | |
498 | struct gendisk *p = data; | |
499 | ||
500 | if (!get_disk(p)) | |
501 | return -1; | |
502 | return 0; | |
503 | } | |
504 | ||
505 | /** | |
506 | * add_disk - add partitioning information to kernel list | |
507 | * @disk: per-device partitioning information | |
508 | * | |
509 | * This function registers the partitioning information in @disk | |
510 | * with the kernel. | |
511 | * | |
512 | * FIXME: error handling | |
513 | */ | |
514 | void add_disk(struct gendisk *disk) | |
515 | { | |
516 | struct backing_dev_info *bdi; | |
517 | dev_t devt; | |
518 | int retval; | |
519 | ||
520 | /* minors == 0 indicates to use ext devt from part0 and should | |
521 | * be accompanied with EXT_DEVT flag. Make sure all | |
522 | * parameters make sense. | |
523 | */ | |
524 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); | |
525 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); | |
526 | ||
527 | disk->flags |= GENHD_FL_UP; | |
528 | ||
529 | retval = blk_alloc_devt(&disk->part0, &devt); | |
530 | if (retval) { | |
531 | WARN_ON(1); | |
532 | return; | |
533 | } | |
534 | disk_to_dev(disk)->devt = devt; | |
535 | ||
536 | /* ->major and ->first_minor aren't supposed to be | |
537 | * dereferenced from here on, but set them just in case. | |
538 | */ | |
539 | disk->major = MAJOR(devt); | |
540 | disk->first_minor = MINOR(devt); | |
541 | ||
542 | /* Register BDI before referencing it from bdev */ | |
543 | bdi = &disk->queue->backing_dev_info; | |
544 | bdi_register_dev(bdi, disk_devt(disk)); | |
545 | ||
546 | blk_register_region(disk_devt(disk), disk->minors, NULL, | |
547 | exact_match, exact_lock, disk); | |
548 | register_disk(disk); | |
549 | blk_register_queue(disk); | |
550 | ||
551 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, | |
552 | "bdi"); | |
553 | WARN_ON(retval); | |
554 | } | |
555 | ||
556 | EXPORT_SYMBOL(add_disk); | |
557 | EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */ | |
558 | ||
559 | void unlink_gendisk(struct gendisk *disk) | |
560 | { | |
561 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); | |
562 | bdi_unregister(&disk->queue->backing_dev_info); | |
563 | blk_unregister_queue(disk); | |
564 | blk_unregister_region(disk_devt(disk), disk->minors); | |
565 | } | |
566 | ||
567 | /** | |
568 | * get_gendisk - get partitioning information for a given device | |
569 | * @devt: device to get partitioning information for | |
570 | * @partno: returned partition index | |
571 | * | |
572 | * This function gets the structure containing partitioning | |
573 | * information for the given device @devt. | |
574 | */ | |
575 | struct gendisk *get_gendisk(dev_t devt, int *partno) | |
576 | { | |
577 | struct gendisk *disk = NULL; | |
578 | ||
579 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { | |
580 | struct kobject *kobj; | |
581 | ||
582 | kobj = kobj_lookup(bdev_map, devt, partno); | |
583 | if (kobj) | |
584 | disk = dev_to_disk(kobj_to_dev(kobj)); | |
585 | } else { | |
586 | struct hd_struct *part; | |
587 | ||
588 | mutex_lock(&ext_devt_mutex); | |
589 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
590 | if (part && get_disk(part_to_disk(part))) { | |
591 | *partno = part->partno; | |
592 | disk = part_to_disk(part); | |
593 | } | |
594 | mutex_unlock(&ext_devt_mutex); | |
595 | } | |
596 | ||
597 | return disk; | |
598 | } | |
599 | EXPORT_SYMBOL(get_gendisk); | |
600 | ||
601 | /** | |
602 | * bdget_disk - do bdget() by gendisk and partition number | |
603 | * @disk: gendisk of interest | |
604 | * @partno: partition number | |
605 | * | |
606 | * Find partition @partno from @disk, do bdget() on it. | |
607 | * | |
608 | * CONTEXT: | |
609 | * Don't care. | |
610 | * | |
611 | * RETURNS: | |
612 | * Resulting block_device on success, NULL on failure. | |
613 | */ | |
614 | struct block_device *bdget_disk(struct gendisk *disk, int partno) | |
615 | { | |
616 | struct hd_struct *part; | |
617 | struct block_device *bdev = NULL; | |
618 | ||
619 | part = disk_get_part(disk, partno); | |
620 | if (part) | |
621 | bdev = bdget(part_devt(part)); | |
622 | disk_put_part(part); | |
623 | ||
624 | return bdev; | |
625 | } | |
626 | EXPORT_SYMBOL(bdget_disk); | |
627 | ||
628 | /* | |
629 | * print a full list of all partitions - intended for places where the root | |
630 | * filesystem can't be mounted and thus to give the victim some idea of what | |
631 | * went wrong | |
632 | */ | |
633 | void __init printk_all_partitions(void) | |
634 | { | |
635 | struct class_dev_iter iter; | |
636 | struct device *dev; | |
637 | ||
638 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
639 | while ((dev = class_dev_iter_next(&iter))) { | |
640 | struct gendisk *disk = dev_to_disk(dev); | |
641 | struct disk_part_iter piter; | |
642 | struct hd_struct *part; | |
643 | char name_buf[BDEVNAME_SIZE]; | |
644 | char devt_buf[BDEVT_SIZE]; | |
645 | u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1]; | |
646 | ||
647 | /* | |
648 | * Don't show empty devices or things that have been | |
649 | * surpressed | |
650 | */ | |
651 | if (get_capacity(disk) == 0 || | |
652 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) | |
653 | continue; | |
654 | ||
655 | /* | |
656 | * Note, unlike /proc/partitions, I am showing the | |
657 | * numbers in hex - the same format as the root= | |
658 | * option takes. | |
659 | */ | |
660 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); | |
661 | while ((part = disk_part_iter_next(&piter))) { | |
662 | bool is_part0 = part == &disk->part0; | |
663 | ||
664 | uuid[0] = 0; | |
665 | if (part->info) | |
666 | part_unpack_uuid(part->info->uuid, uuid); | |
667 | ||
668 | printk("%s%s %10llu %s %s", is_part0 ? "" : " ", | |
669 | bdevt_str(part_devt(part), devt_buf), | |
670 | (unsigned long long)part->nr_sects >> 1, | |
671 | disk_name(disk, part->partno, name_buf), uuid); | |
672 | if (is_part0) { | |
673 | if (disk->driverfs_dev != NULL && | |
674 | disk->driverfs_dev->driver != NULL) | |
675 | printk(" driver: %s\n", | |
676 | disk->driverfs_dev->driver->name); | |
677 | else | |
678 | printk(" (driver?)\n"); | |
679 | } else | |
680 | printk("\n"); | |
681 | } | |
682 | disk_part_iter_exit(&piter); | |
683 | } | |
684 | class_dev_iter_exit(&iter); | |
685 | } | |
686 | ||
687 | #ifdef CONFIG_PROC_FS | |
688 | /* iterator */ | |
689 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) | |
690 | { | |
691 | loff_t skip = *pos; | |
692 | struct class_dev_iter *iter; | |
693 | struct device *dev; | |
694 | ||
695 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); | |
696 | if (!iter) | |
697 | return ERR_PTR(-ENOMEM); | |
698 | ||
699 | seqf->private = iter; | |
700 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); | |
701 | do { | |
702 | dev = class_dev_iter_next(iter); | |
703 | if (!dev) | |
704 | return NULL; | |
705 | } while (skip--); | |
706 | ||
707 | return dev_to_disk(dev); | |
708 | } | |
709 | ||
710 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) | |
711 | { | |
712 | struct device *dev; | |
713 | ||
714 | (*pos)++; | |
715 | dev = class_dev_iter_next(seqf->private); | |
716 | if (dev) | |
717 | return dev_to_disk(dev); | |
718 | ||
719 | return NULL; | |
720 | } | |
721 | ||
722 | static void disk_seqf_stop(struct seq_file *seqf, void *v) | |
723 | { | |
724 | struct class_dev_iter *iter = seqf->private; | |
725 | ||
726 | /* stop is called even after start failed :-( */ | |
727 | if (iter) { | |
728 | class_dev_iter_exit(iter); | |
729 | kfree(iter); | |
730 | } | |
731 | } | |
732 | ||
733 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) | |
734 | { | |
735 | static void *p; | |
736 | ||
737 | p = disk_seqf_start(seqf, pos); | |
738 | if (!IS_ERR(p) && p && !*pos) | |
739 | seq_puts(seqf, "major minor #blocks name\n\n"); | |
740 | return p; | |
741 | } | |
742 | ||
743 | static int show_partition(struct seq_file *seqf, void *v) | |
744 | { | |
745 | struct gendisk *sgp = v; | |
746 | struct disk_part_iter piter; | |
747 | struct hd_struct *part; | |
748 | char buf[BDEVNAME_SIZE]; | |
749 | ||
750 | /* Don't show non-partitionable removeable devices or empty devices */ | |
751 | if (!get_capacity(sgp) || (!disk_partitionable(sgp) && | |
752 | (sgp->flags & GENHD_FL_REMOVABLE))) | |
753 | return 0; | |
754 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) | |
755 | return 0; | |
756 | ||
757 | /* show the full disk and all non-0 size partitions of it */ | |
758 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); | |
759 | while ((part = disk_part_iter_next(&piter))) | |
760 | seq_printf(seqf, "%4d %7d %10llu %s\n", | |
761 | MAJOR(part_devt(part)), MINOR(part_devt(part)), | |
762 | (unsigned long long)part->nr_sects >> 1, | |
763 | disk_name(sgp, part->partno, buf)); | |
764 | disk_part_iter_exit(&piter); | |
765 | ||
766 | return 0; | |
767 | } | |
768 | ||
769 | static const struct seq_operations partitions_op = { | |
770 | .start = show_partition_start, | |
771 | .next = disk_seqf_next, | |
772 | .stop = disk_seqf_stop, | |
773 | .show = show_partition | |
774 | }; | |
775 | ||
776 | static int partitions_open(struct inode *inode, struct file *file) | |
777 | { | |
778 | return seq_open(file, &partitions_op); | |
779 | } | |
780 | ||
781 | static const struct file_operations proc_partitions_operations = { | |
782 | .open = partitions_open, | |
783 | .read = seq_read, | |
784 | .llseek = seq_lseek, | |
785 | .release = seq_release, | |
786 | }; | |
787 | #endif | |
788 | ||
789 | ||
790 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) | |
791 | { | |
792 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) | |
793 | /* Make old-style 2.4 aliases work */ | |
794 | request_module("block-major-%d", MAJOR(devt)); | |
795 | return NULL; | |
796 | } | |
797 | ||
798 | static int __init genhd_device_init(void) | |
799 | { | |
800 | int error; | |
801 | ||
802 | block_class.dev_kobj = sysfs_dev_block_kobj; | |
803 | error = class_register(&block_class); | |
804 | if (unlikely(error)) | |
805 | return error; | |
806 | bdev_map = kobj_map_init(base_probe, &block_class_lock); | |
807 | blk_dev_init(); | |
808 | ||
809 | register_blkdev(BLOCK_EXT_MAJOR, "blkext"); | |
810 | ||
811 | /* create top-level block dir */ | |
812 | if (!sysfs_deprecated) | |
813 | block_depr = kobject_create_and_add("block", NULL); | |
814 | return 0; | |
815 | } | |
816 | ||
817 | subsys_initcall(genhd_device_init); | |
818 | ||
819 | static ssize_t disk_range_show(struct device *dev, | |
820 | struct device_attribute *attr, char *buf) | |
821 | { | |
822 | struct gendisk *disk = dev_to_disk(dev); | |
823 | ||
824 | return sprintf(buf, "%d\n", disk->minors); | |
825 | } | |
826 | ||
827 | static ssize_t disk_ext_range_show(struct device *dev, | |
828 | struct device_attribute *attr, char *buf) | |
829 | { | |
830 | struct gendisk *disk = dev_to_disk(dev); | |
831 | ||
832 | return sprintf(buf, "%d\n", disk_max_parts(disk)); | |
833 | } | |
834 | ||
835 | static ssize_t disk_removable_show(struct device *dev, | |
836 | struct device_attribute *attr, char *buf) | |
837 | { | |
838 | struct gendisk *disk = dev_to_disk(dev); | |
839 | ||
840 | return sprintf(buf, "%d\n", | |
841 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); | |
842 | } | |
843 | ||
844 | static ssize_t disk_ro_show(struct device *dev, | |
845 | struct device_attribute *attr, char *buf) | |
846 | { | |
847 | struct gendisk *disk = dev_to_disk(dev); | |
848 | ||
849 | return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); | |
850 | } | |
851 | ||
852 | static ssize_t disk_capability_show(struct device *dev, | |
853 | struct device_attribute *attr, char *buf) | |
854 | { | |
855 | struct gendisk *disk = dev_to_disk(dev); | |
856 | ||
857 | return sprintf(buf, "%x\n", disk->flags); | |
858 | } | |
859 | ||
860 | static ssize_t disk_alignment_offset_show(struct device *dev, | |
861 | struct device_attribute *attr, | |
862 | char *buf) | |
863 | { | |
864 | struct gendisk *disk = dev_to_disk(dev); | |
865 | ||
866 | return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue)); | |
867 | } | |
868 | ||
869 | static ssize_t disk_discard_alignment_show(struct device *dev, | |
870 | struct device_attribute *attr, | |
871 | char *buf) | |
872 | { | |
873 | struct gendisk *disk = dev_to_disk(dev); | |
874 | ||
875 | return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue)); | |
876 | } | |
877 | ||
878 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); | |
879 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); | |
880 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); | |
881 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); | |
882 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); | |
883 | static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL); | |
884 | static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show, | |
885 | NULL); | |
886 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); | |
887 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); | |
888 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); | |
889 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
890 | static struct device_attribute dev_attr_fail = | |
891 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); | |
892 | #endif | |
893 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
894 | static struct device_attribute dev_attr_fail_timeout = | |
895 | __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, | |
896 | part_timeout_store); | |
897 | #endif | |
898 | ||
899 | static struct attribute *disk_attrs[] = { | |
900 | &dev_attr_range.attr, | |
901 | &dev_attr_ext_range.attr, | |
902 | &dev_attr_removable.attr, | |
903 | &dev_attr_ro.attr, | |
904 | &dev_attr_size.attr, | |
905 | &dev_attr_alignment_offset.attr, | |
906 | &dev_attr_discard_alignment.attr, | |
907 | &dev_attr_capability.attr, | |
908 | &dev_attr_stat.attr, | |
909 | &dev_attr_inflight.attr, | |
910 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
911 | &dev_attr_fail.attr, | |
912 | #endif | |
913 | #ifdef CONFIG_FAIL_IO_TIMEOUT | |
914 | &dev_attr_fail_timeout.attr, | |
915 | #endif | |
916 | NULL | |
917 | }; | |
918 | ||
919 | static struct attribute_group disk_attr_group = { | |
920 | .attrs = disk_attrs, | |
921 | }; | |
922 | ||
923 | static const struct attribute_group *disk_attr_groups[] = { | |
924 | &disk_attr_group, | |
925 | NULL | |
926 | }; | |
927 | ||
928 | static void disk_free_ptbl_rcu_cb(struct rcu_head *head) | |
929 | { | |
930 | struct disk_part_tbl *ptbl = | |
931 | container_of(head, struct disk_part_tbl, rcu_head); | |
932 | ||
933 | kfree(ptbl); | |
934 | } | |
935 | ||
936 | /** | |
937 | * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way | |
938 | * @disk: disk to replace part_tbl for | |
939 | * @new_ptbl: new part_tbl to install | |
940 | * | |
941 | * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The | |
942 | * original ptbl is freed using RCU callback. | |
943 | * | |
944 | * LOCKING: | |
945 | * Matching bd_mutx locked. | |
946 | */ | |
947 | static void disk_replace_part_tbl(struct gendisk *disk, | |
948 | struct disk_part_tbl *new_ptbl) | |
949 | { | |
950 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
951 | ||
952 | rcu_assign_pointer(disk->part_tbl, new_ptbl); | |
953 | ||
954 | if (old_ptbl) { | |
955 | rcu_assign_pointer(old_ptbl->last_lookup, NULL); | |
956 | call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb); | |
957 | } | |
958 | } | |
959 | ||
960 | /** | |
961 | * disk_expand_part_tbl - expand disk->part_tbl | |
962 | * @disk: disk to expand part_tbl for | |
963 | * @partno: expand such that this partno can fit in | |
964 | * | |
965 | * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl | |
966 | * uses RCU to allow unlocked dereferencing for stats and other stuff. | |
967 | * | |
968 | * LOCKING: | |
969 | * Matching bd_mutex locked, might sleep. | |
970 | * | |
971 | * RETURNS: | |
972 | * 0 on success, -errno on failure. | |
973 | */ | |
974 | int disk_expand_part_tbl(struct gendisk *disk, int partno) | |
975 | { | |
976 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
977 | struct disk_part_tbl *new_ptbl; | |
978 | int len = old_ptbl ? old_ptbl->len : 0; | |
979 | int target = partno + 1; | |
980 | size_t size; | |
981 | int i; | |
982 | ||
983 | /* disk_max_parts() is zero during initialization, ignore if so */ | |
984 | if (disk_max_parts(disk) && target > disk_max_parts(disk)) | |
985 | return -EINVAL; | |
986 | ||
987 | if (target <= len) | |
988 | return 0; | |
989 | ||
990 | size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); | |
991 | new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); | |
992 | if (!new_ptbl) | |
993 | return -ENOMEM; | |
994 | ||
995 | new_ptbl->len = target; | |
996 | ||
997 | for (i = 0; i < len; i++) | |
998 | rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); | |
999 | ||
1000 | disk_replace_part_tbl(disk, new_ptbl); | |
1001 | return 0; | |
1002 | } | |
1003 | ||
1004 | static void disk_release(struct device *dev) | |
1005 | { | |
1006 | struct gendisk *disk = dev_to_disk(dev); | |
1007 | ||
1008 | kfree(disk->random); | |
1009 | disk_replace_part_tbl(disk, NULL); | |
1010 | free_part_stats(&disk->part0); | |
1011 | free_part_info(&disk->part0); | |
1012 | kfree(disk); | |
1013 | } | |
1014 | struct class block_class = { | |
1015 | .name = "block", | |
1016 | }; | |
1017 | ||
1018 | static char *block_devnode(struct device *dev, mode_t *mode) | |
1019 | { | |
1020 | struct gendisk *disk = dev_to_disk(dev); | |
1021 | ||
1022 | if (disk->devnode) | |
1023 | return disk->devnode(disk, mode); | |
1024 | return NULL; | |
1025 | } | |
1026 | ||
1027 | static struct device_type disk_type = { | |
1028 | .name = "disk", | |
1029 | .groups = disk_attr_groups, | |
1030 | .release = disk_release, | |
1031 | .devnode = block_devnode, | |
1032 | }; | |
1033 | ||
1034 | #ifdef CONFIG_PROC_FS | |
1035 | /* | |
1036 | * aggregate disk stat collector. Uses the same stats that the sysfs | |
1037 | * entries do, above, but makes them available through one seq_file. | |
1038 | * | |
1039 | * The output looks suspiciously like /proc/partitions with a bunch of | |
1040 | * extra fields. | |
1041 | */ | |
1042 | static int diskstats_show(struct seq_file *seqf, void *v) | |
1043 | { | |
1044 | struct gendisk *gp = v; | |
1045 | struct disk_part_iter piter; | |
1046 | struct hd_struct *hd; | |
1047 | char buf[BDEVNAME_SIZE]; | |
1048 | int cpu; | |
1049 | ||
1050 | /* | |
1051 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) | |
1052 | seq_puts(seqf, "major minor name" | |
1053 | " rio rmerge rsect ruse wio wmerge " | |
1054 | "wsect wuse running use aveq" | |
1055 | "\n\n"); | |
1056 | */ | |
1057 | ||
1058 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); | |
1059 | while ((hd = disk_part_iter_next(&piter))) { | |
1060 | cpu = part_stat_lock(); | |
1061 | part_round_stats(cpu, hd); | |
1062 | part_stat_unlock(); | |
1063 | seq_printf(seqf, "%4d %7d %s %lu %lu %llu " | |
1064 | "%u %lu %lu %llu %u %u %u %u\n", | |
1065 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), | |
1066 | disk_name(gp, hd->partno, buf), | |
1067 | part_stat_read(hd, ios[0]), | |
1068 | part_stat_read(hd, merges[0]), | |
1069 | (unsigned long long)part_stat_read(hd, sectors[0]), | |
1070 | jiffies_to_msecs(part_stat_read(hd, ticks[0])), | |
1071 | part_stat_read(hd, ios[1]), | |
1072 | part_stat_read(hd, merges[1]), | |
1073 | (unsigned long long)part_stat_read(hd, sectors[1]), | |
1074 | jiffies_to_msecs(part_stat_read(hd, ticks[1])), | |
1075 | part_in_flight(hd), | |
1076 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), | |
1077 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) | |
1078 | ); | |
1079 | } | |
1080 | disk_part_iter_exit(&piter); | |
1081 | ||
1082 | return 0; | |
1083 | } | |
1084 | ||
1085 | static const struct seq_operations diskstats_op = { | |
1086 | .start = disk_seqf_start, | |
1087 | .next = disk_seqf_next, | |
1088 | .stop = disk_seqf_stop, | |
1089 | .show = diskstats_show | |
1090 | }; | |
1091 | ||
1092 | static int diskstats_open(struct inode *inode, struct file *file) | |
1093 | { | |
1094 | return seq_open(file, &diskstats_op); | |
1095 | } | |
1096 | ||
1097 | static const struct file_operations proc_diskstats_operations = { | |
1098 | .open = diskstats_open, | |
1099 | .read = seq_read, | |
1100 | .llseek = seq_lseek, | |
1101 | .release = seq_release, | |
1102 | }; | |
1103 | ||
1104 | static int __init proc_genhd_init(void) | |
1105 | { | |
1106 | proc_create("diskstats", 0, NULL, &proc_diskstats_operations); | |
1107 | proc_create("partitions", 0, NULL, &proc_partitions_operations); | |
1108 | return 0; | |
1109 | } | |
1110 | module_init(proc_genhd_init); | |
1111 | #endif /* CONFIG_PROC_FS */ | |
1112 | ||
1113 | static void media_change_notify_thread(struct work_struct *work) | |
1114 | { | |
1115 | struct gendisk *gd = container_of(work, struct gendisk, async_notify); | |
1116 | char event[] = "MEDIA_CHANGE=1"; | |
1117 | char *envp[] = { event, NULL }; | |
1118 | ||
1119 | /* | |
1120 | * set enviroment vars to indicate which event this is for | |
1121 | * so that user space will know to go check the media status. | |
1122 | */ | |
1123 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); | |
1124 | put_device(gd->driverfs_dev); | |
1125 | } | |
1126 | ||
1127 | #if 0 | |
1128 | void genhd_media_change_notify(struct gendisk *disk) | |
1129 | { | |
1130 | get_device(disk->driverfs_dev); | |
1131 | schedule_work(&disk->async_notify); | |
1132 | } | |
1133 | EXPORT_SYMBOL_GPL(genhd_media_change_notify); | |
1134 | #endif /* 0 */ | |
1135 | ||
1136 | dev_t blk_lookup_devt(const char *name, int partno) | |
1137 | { | |
1138 | dev_t devt = MKDEV(0, 0); | |
1139 | struct class_dev_iter iter; | |
1140 | struct device *dev; | |
1141 | ||
1142 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
1143 | while ((dev = class_dev_iter_next(&iter))) { | |
1144 | struct gendisk *disk = dev_to_disk(dev); | |
1145 | struct hd_struct *part; | |
1146 | ||
1147 | if (strcmp(dev_name(dev), name)) | |
1148 | continue; | |
1149 | ||
1150 | if (partno < disk->minors) { | |
1151 | /* We need to return the right devno, even | |
1152 | * if the partition doesn't exist yet. | |
1153 | */ | |
1154 | devt = MKDEV(MAJOR(dev->devt), | |
1155 | MINOR(dev->devt) + partno); | |
1156 | break; | |
1157 | } | |
1158 | part = disk_get_part(disk, partno); | |
1159 | if (part) { | |
1160 | devt = part_devt(part); | |
1161 | disk_put_part(part); | |
1162 | break; | |
1163 | } | |
1164 | disk_put_part(part); | |
1165 | } | |
1166 | class_dev_iter_exit(&iter); | |
1167 | return devt; | |
1168 | } | |
1169 | EXPORT_SYMBOL(blk_lookup_devt); | |
1170 | ||
1171 | struct gendisk *alloc_disk(int minors) | |
1172 | { | |
1173 | return alloc_disk_node(minors, -1); | |
1174 | } | |
1175 | EXPORT_SYMBOL(alloc_disk); | |
1176 | ||
1177 | struct gendisk *alloc_disk_node(int minors, int node_id) | |
1178 | { | |
1179 | struct gendisk *disk; | |
1180 | ||
1181 | disk = kmalloc_node(sizeof(struct gendisk), | |
1182 | GFP_KERNEL | __GFP_ZERO, node_id); | |
1183 | if (disk) { | |
1184 | if (!init_part_stats(&disk->part0)) { | |
1185 | kfree(disk); | |
1186 | return NULL; | |
1187 | } | |
1188 | disk->node_id = node_id; | |
1189 | if (disk_expand_part_tbl(disk, 0)) { | |
1190 | free_part_stats(&disk->part0); | |
1191 | kfree(disk); | |
1192 | return NULL; | |
1193 | } | |
1194 | disk->part_tbl->part[0] = &disk->part0; | |
1195 | ||
1196 | disk->minors = minors; | |
1197 | rand_initialize_disk(disk); | |
1198 | disk_to_dev(disk)->class = &block_class; | |
1199 | disk_to_dev(disk)->type = &disk_type; | |
1200 | device_initialize(disk_to_dev(disk)); | |
1201 | INIT_WORK(&disk->async_notify, | |
1202 | media_change_notify_thread); | |
1203 | } | |
1204 | return disk; | |
1205 | } | |
1206 | EXPORT_SYMBOL(alloc_disk_node); | |
1207 | ||
1208 | struct kobject *get_disk(struct gendisk *disk) | |
1209 | { | |
1210 | struct module *owner; | |
1211 | struct kobject *kobj; | |
1212 | ||
1213 | if (!disk->fops) | |
1214 | return NULL; | |
1215 | owner = disk->fops->owner; | |
1216 | if (owner && !try_module_get(owner)) | |
1217 | return NULL; | |
1218 | kobj = kobject_get(&disk_to_dev(disk)->kobj); | |
1219 | if (kobj == NULL) { | |
1220 | module_put(owner); | |
1221 | return NULL; | |
1222 | } | |
1223 | return kobj; | |
1224 | ||
1225 | } | |
1226 | ||
1227 | EXPORT_SYMBOL(get_disk); | |
1228 | ||
1229 | void put_disk(struct gendisk *disk) | |
1230 | { | |
1231 | if (disk) | |
1232 | kobject_put(&disk_to_dev(disk)->kobj); | |
1233 | } | |
1234 | ||
1235 | EXPORT_SYMBOL(put_disk); | |
1236 | ||
1237 | static void set_disk_ro_uevent(struct gendisk *gd, int ro) | |
1238 | { | |
1239 | char event[] = "DISK_RO=1"; | |
1240 | char *envp[] = { event, NULL }; | |
1241 | ||
1242 | if (!ro) | |
1243 | event[8] = '0'; | |
1244 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); | |
1245 | } | |
1246 | ||
1247 | void set_device_ro(struct block_device *bdev, int flag) | |
1248 | { | |
1249 | bdev->bd_part->policy = flag; | |
1250 | } | |
1251 | ||
1252 | EXPORT_SYMBOL(set_device_ro); | |
1253 | ||
1254 | void set_disk_ro(struct gendisk *disk, int flag) | |
1255 | { | |
1256 | struct disk_part_iter piter; | |
1257 | struct hd_struct *part; | |
1258 | ||
1259 | if (disk->part0.policy != flag) { | |
1260 | set_disk_ro_uevent(disk, flag); | |
1261 | disk->part0.policy = flag; | |
1262 | } | |
1263 | ||
1264 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); | |
1265 | while ((part = disk_part_iter_next(&piter))) | |
1266 | part->policy = flag; | |
1267 | disk_part_iter_exit(&piter); | |
1268 | } | |
1269 | ||
1270 | EXPORT_SYMBOL(set_disk_ro); | |
1271 | ||
1272 | int bdev_read_only(struct block_device *bdev) | |
1273 | { | |
1274 | if (!bdev) | |
1275 | return 0; | |
1276 | return bdev->bd_part->policy; | |
1277 | } | |
1278 | ||
1279 | EXPORT_SYMBOL(bdev_read_only); | |
1280 | ||
1281 | int invalidate_partition(struct gendisk *disk, int partno) | |
1282 | { | |
1283 | int res = 0; | |
1284 | struct block_device *bdev = bdget_disk(disk, partno); | |
1285 | if (bdev) { | |
1286 | fsync_bdev(bdev); | |
1287 | res = __invalidate_device(bdev); | |
1288 | bdput(bdev); | |
1289 | } | |
1290 | return res; | |
1291 | } | |
1292 | ||
1293 | EXPORT_SYMBOL(invalidate_partition); |