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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/seq_file.h> | |
14 | #include <linux/slab.h> | |
15 | #include <linux/kmod.h> | |
16 | #include <linux/kobj_map.h> | |
17 | #include <linux/buffer_head.h> | |
18 | #include <linux/mutex.h> | |
19 | #include <linux/idr.h> | |
20 | ||
21 | #include "blk.h" | |
22 | ||
23 | static DEFINE_MUTEX(block_class_lock); | |
24 | #ifndef CONFIG_SYSFS_DEPRECATED | |
25 | struct kobject *block_depr; | |
26 | #endif | |
27 | ||
28 | /* for extended dynamic devt allocation, currently only one major is used */ | |
29 | #define MAX_EXT_DEVT (1 << MINORBITS) | |
30 | ||
31 | /* For extended devt allocation. ext_devt_mutex prevents look up | |
32 | * results from going away underneath its user. | |
33 | */ | |
34 | static DEFINE_MUTEX(ext_devt_mutex); | |
35 | static DEFINE_IDR(ext_devt_idr); | |
36 | ||
37 | static struct device_type disk_type; | |
38 | ||
39 | /** | |
40 | * disk_get_part - get partition | |
41 | * @disk: disk to look partition from | |
42 | * @partno: partition number | |
43 | * | |
44 | * Look for partition @partno from @disk. If found, increment | |
45 | * reference count and return it. | |
46 | * | |
47 | * CONTEXT: | |
48 | * Don't care. | |
49 | * | |
50 | * RETURNS: | |
51 | * Pointer to the found partition on success, NULL if not found. | |
52 | */ | |
53 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) | |
54 | { | |
55 | struct hd_struct *part = NULL; | |
56 | struct disk_part_tbl *ptbl; | |
57 | ||
58 | if (unlikely(partno < 0)) | |
59 | return NULL; | |
60 | ||
61 | rcu_read_lock(); | |
62 | ||
63 | ptbl = rcu_dereference(disk->part_tbl); | |
64 | if (likely(partno < ptbl->len)) { | |
65 | part = rcu_dereference(ptbl->part[partno]); | |
66 | if (part) | |
67 | get_device(part_to_dev(part)); | |
68 | } | |
69 | ||
70 | rcu_read_unlock(); | |
71 | ||
72 | return part; | |
73 | } | |
74 | EXPORT_SYMBOL_GPL(disk_get_part); | |
75 | ||
76 | /** | |
77 | * disk_part_iter_init - initialize partition iterator | |
78 | * @piter: iterator to initialize | |
79 | * @disk: disk to iterate over | |
80 | * @flags: DISK_PITER_* flags | |
81 | * | |
82 | * Initialize @piter so that it iterates over partitions of @disk. | |
83 | * | |
84 | * CONTEXT: | |
85 | * Don't care. | |
86 | */ | |
87 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, | |
88 | unsigned int flags) | |
89 | { | |
90 | struct disk_part_tbl *ptbl; | |
91 | ||
92 | rcu_read_lock(); | |
93 | ptbl = rcu_dereference(disk->part_tbl); | |
94 | ||
95 | piter->disk = disk; | |
96 | piter->part = NULL; | |
97 | ||
98 | if (flags & DISK_PITER_REVERSE) | |
99 | piter->idx = ptbl->len - 1; | |
100 | else if (flags & DISK_PITER_INCL_PART0) | |
101 | piter->idx = 0; | |
102 | else | |
103 | piter->idx = 1; | |
104 | ||
105 | piter->flags = flags; | |
106 | ||
107 | rcu_read_unlock(); | |
108 | } | |
109 | EXPORT_SYMBOL_GPL(disk_part_iter_init); | |
110 | ||
111 | /** | |
112 | * disk_part_iter_next - proceed iterator to the next partition and return it | |
113 | * @piter: iterator of interest | |
114 | * | |
115 | * Proceed @piter to the next partition and return it. | |
116 | * | |
117 | * CONTEXT: | |
118 | * Don't care. | |
119 | */ | |
120 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) | |
121 | { | |
122 | struct disk_part_tbl *ptbl; | |
123 | int inc, end; | |
124 | ||
125 | /* put the last partition */ | |
126 | disk_put_part(piter->part); | |
127 | piter->part = NULL; | |
128 | ||
129 | /* get part_tbl */ | |
130 | rcu_read_lock(); | |
131 | ptbl = rcu_dereference(piter->disk->part_tbl); | |
132 | ||
133 | /* determine iteration parameters */ | |
134 | if (piter->flags & DISK_PITER_REVERSE) { | |
135 | inc = -1; | |
136 | if (piter->flags & DISK_PITER_INCL_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 (!(piter->flags & DISK_PITER_INCL_EMPTY) && !part->nr_sects) | |
153 | continue; | |
154 | ||
155 | get_device(part_to_dev(part)); | |
156 | piter->part = part; | |
157 | piter->idx += inc; | |
158 | break; | |
159 | } | |
160 | ||
161 | rcu_read_unlock(); | |
162 | ||
163 | return piter->part; | |
164 | } | |
165 | EXPORT_SYMBOL_GPL(disk_part_iter_next); | |
166 | ||
167 | /** | |
168 | * disk_part_iter_exit - finish up partition iteration | |
169 | * @piter: iter of interest | |
170 | * | |
171 | * Called when iteration is over. Cleans up @piter. | |
172 | * | |
173 | * CONTEXT: | |
174 | * Don't care. | |
175 | */ | |
176 | void disk_part_iter_exit(struct disk_part_iter *piter) | |
177 | { | |
178 | disk_put_part(piter->part); | |
179 | piter->part = NULL; | |
180 | } | |
181 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); | |
182 | ||
183 | /** | |
184 | * disk_map_sector_rcu - map sector to partition | |
185 | * @disk: gendisk of interest | |
186 | * @sector: sector to map | |
187 | * | |
188 | * Find out which partition @sector maps to on @disk. This is | |
189 | * primarily used for stats accounting. | |
190 | * | |
191 | * CONTEXT: | |
192 | * RCU read locked. The returned partition pointer is valid only | |
193 | * while preemption is disabled. | |
194 | * | |
195 | * RETURNS: | |
196 | * Found partition on success, part0 is returned if no partition matches | |
197 | */ | |
198 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) | |
199 | { | |
200 | struct disk_part_tbl *ptbl; | |
201 | int i; | |
202 | ||
203 | ptbl = rcu_dereference(disk->part_tbl); | |
204 | ||
205 | for (i = 1; i < ptbl->len; i++) { | |
206 | struct hd_struct *part = rcu_dereference(ptbl->part[i]); | |
207 | ||
208 | if (part && part->start_sect <= sector && | |
209 | sector < part->start_sect + part->nr_sects) | |
210 | return part; | |
211 | } | |
212 | return &disk->part0; | |
213 | } | |
214 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); | |
215 | ||
216 | /* | |
217 | * Can be deleted altogether. Later. | |
218 | * | |
219 | */ | |
220 | static struct blk_major_name { | |
221 | struct blk_major_name *next; | |
222 | int major; | |
223 | char name[16]; | |
224 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; | |
225 | ||
226 | /* index in the above - for now: assume no multimajor ranges */ | |
227 | static inline int major_to_index(int major) | |
228 | { | |
229 | return major % BLKDEV_MAJOR_HASH_SIZE; | |
230 | } | |
231 | ||
232 | #ifdef CONFIG_PROC_FS | |
233 | void blkdev_show(struct seq_file *seqf, off_t offset) | |
234 | { | |
235 | struct blk_major_name *dp; | |
236 | ||
237 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { | |
238 | mutex_lock(&block_class_lock); | |
239 | for (dp = major_names[offset]; dp; dp = dp->next) | |
240 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); | |
241 | mutex_unlock(&block_class_lock); | |
242 | } | |
243 | } | |
244 | #endif /* CONFIG_PROC_FS */ | |
245 | ||
246 | int register_blkdev(unsigned int major, const char *name) | |
247 | { | |
248 | struct blk_major_name **n, *p; | |
249 | int index, ret = 0; | |
250 | ||
251 | mutex_lock(&block_class_lock); | |
252 | ||
253 | /* temporary */ | |
254 | if (major == 0) { | |
255 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { | |
256 | if (major_names[index] == NULL) | |
257 | break; | |
258 | } | |
259 | ||
260 | if (index == 0) { | |
261 | printk("register_blkdev: failed to get major for %s\n", | |
262 | name); | |
263 | ret = -EBUSY; | |
264 | goto out; | |
265 | } | |
266 | major = index; | |
267 | ret = major; | |
268 | } | |
269 | ||
270 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); | |
271 | if (p == NULL) { | |
272 | ret = -ENOMEM; | |
273 | goto out; | |
274 | } | |
275 | ||
276 | p->major = major; | |
277 | strlcpy(p->name, name, sizeof(p->name)); | |
278 | p->next = NULL; | |
279 | index = major_to_index(major); | |
280 | ||
281 | for (n = &major_names[index]; *n; n = &(*n)->next) { | |
282 | if ((*n)->major == major) | |
283 | break; | |
284 | } | |
285 | if (!*n) | |
286 | *n = p; | |
287 | else | |
288 | ret = -EBUSY; | |
289 | ||
290 | if (ret < 0) { | |
291 | printk("register_blkdev: cannot get major %d for %s\n", | |
292 | major, name); | |
293 | kfree(p); | |
294 | } | |
295 | out: | |
296 | mutex_unlock(&block_class_lock); | |
297 | return ret; | |
298 | } | |
299 | ||
300 | EXPORT_SYMBOL(register_blkdev); | |
301 | ||
302 | void unregister_blkdev(unsigned int major, const char *name) | |
303 | { | |
304 | struct blk_major_name **n; | |
305 | struct blk_major_name *p = NULL; | |
306 | int index = major_to_index(major); | |
307 | ||
308 | mutex_lock(&block_class_lock); | |
309 | for (n = &major_names[index]; *n; n = &(*n)->next) | |
310 | if ((*n)->major == major) | |
311 | break; | |
312 | if (!*n || strcmp((*n)->name, name)) { | |
313 | WARN_ON(1); | |
314 | } else { | |
315 | p = *n; | |
316 | *n = p->next; | |
317 | } | |
318 | mutex_unlock(&block_class_lock); | |
319 | kfree(p); | |
320 | } | |
321 | ||
322 | EXPORT_SYMBOL(unregister_blkdev); | |
323 | ||
324 | static struct kobj_map *bdev_map; | |
325 | ||
326 | /** | |
327 | * blk_mangle_minor - scatter minor numbers apart | |
328 | * @minor: minor number to mangle | |
329 | * | |
330 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT | |
331 | * is enabled. Mangling twice gives the original value. | |
332 | * | |
333 | * RETURNS: | |
334 | * Mangled value. | |
335 | * | |
336 | * CONTEXT: | |
337 | * Don't care. | |
338 | */ | |
339 | static int blk_mangle_minor(int minor) | |
340 | { | |
341 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT | |
342 | int i; | |
343 | ||
344 | for (i = 0; i < MINORBITS / 2; i++) { | |
345 | int low = minor & (1 << i); | |
346 | int high = minor & (1 << (MINORBITS - 1 - i)); | |
347 | int distance = MINORBITS - 1 - 2 * i; | |
348 | ||
349 | minor ^= low | high; /* clear both bits */ | |
350 | low <<= distance; /* swap the positions */ | |
351 | high >>= distance; | |
352 | minor |= low | high; /* and set */ | |
353 | } | |
354 | #endif | |
355 | return minor; | |
356 | } | |
357 | ||
358 | /** | |
359 | * blk_alloc_devt - allocate a dev_t for a partition | |
360 | * @part: partition to allocate dev_t for | |
361 | * @gfp_mask: memory allocation flag | |
362 | * @devt: out parameter for resulting dev_t | |
363 | * | |
364 | * Allocate a dev_t for block device. | |
365 | * | |
366 | * RETURNS: | |
367 | * 0 on success, allocated dev_t is returned in *@devt. -errno on | |
368 | * failure. | |
369 | * | |
370 | * CONTEXT: | |
371 | * Might sleep. | |
372 | */ | |
373 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) | |
374 | { | |
375 | struct gendisk *disk = part_to_disk(part); | |
376 | int idx, rc; | |
377 | ||
378 | /* in consecutive minor range? */ | |
379 | if (part->partno < disk->minors) { | |
380 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); | |
381 | return 0; | |
382 | } | |
383 | ||
384 | /* allocate ext devt */ | |
385 | do { | |
386 | if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL)) | |
387 | return -ENOMEM; | |
388 | rc = idr_get_new(&ext_devt_idr, part, &idx); | |
389 | } while (rc == -EAGAIN); | |
390 | ||
391 | if (rc) | |
392 | return rc; | |
393 | ||
394 | if (idx > MAX_EXT_DEVT) { | |
395 | idr_remove(&ext_devt_idr, idx); | |
396 | return -EBUSY; | |
397 | } | |
398 | ||
399 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); | |
400 | return 0; | |
401 | } | |
402 | ||
403 | /** | |
404 | * blk_free_devt - free a dev_t | |
405 | * @devt: dev_t to free | |
406 | * | |
407 | * Free @devt which was allocated using blk_alloc_devt(). | |
408 | * | |
409 | * CONTEXT: | |
410 | * Might sleep. | |
411 | */ | |
412 | void blk_free_devt(dev_t devt) | |
413 | { | |
414 | might_sleep(); | |
415 | ||
416 | if (devt == MKDEV(0, 0)) | |
417 | return; | |
418 | ||
419 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { | |
420 | mutex_lock(&ext_devt_mutex); | |
421 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
422 | mutex_unlock(&ext_devt_mutex); | |
423 | } | |
424 | } | |
425 | ||
426 | static char *bdevt_str(dev_t devt, char *buf) | |
427 | { | |
428 | if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { | |
429 | char tbuf[BDEVT_SIZE]; | |
430 | snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); | |
431 | snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); | |
432 | } else | |
433 | snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); | |
434 | ||
435 | return buf; | |
436 | } | |
437 | ||
438 | /* | |
439 | * Register device numbers dev..(dev+range-1) | |
440 | * range must be nonzero | |
441 | * The hash chain is sorted on range, so that subranges can override. | |
442 | */ | |
443 | void blk_register_region(dev_t devt, unsigned long range, struct module *module, | |
444 | struct kobject *(*probe)(dev_t, int *, void *), | |
445 | int (*lock)(dev_t, void *), void *data) | |
446 | { | |
447 | kobj_map(bdev_map, devt, range, module, probe, lock, data); | |
448 | } | |
449 | ||
450 | EXPORT_SYMBOL(blk_register_region); | |
451 | ||
452 | void blk_unregister_region(dev_t devt, unsigned long range) | |
453 | { | |
454 | kobj_unmap(bdev_map, devt, range); | |
455 | } | |
456 | ||
457 | EXPORT_SYMBOL(blk_unregister_region); | |
458 | ||
459 | static struct kobject *exact_match(dev_t devt, int *partno, void *data) | |
460 | { | |
461 | struct gendisk *p = data; | |
462 | ||
463 | return &disk_to_dev(p)->kobj; | |
464 | } | |
465 | ||
466 | static int exact_lock(dev_t devt, void *data) | |
467 | { | |
468 | struct gendisk *p = data; | |
469 | ||
470 | if (!get_disk(p)) | |
471 | return -1; | |
472 | return 0; | |
473 | } | |
474 | ||
475 | /** | |
476 | * add_disk - add partitioning information to kernel list | |
477 | * @disk: per-device partitioning information | |
478 | * | |
479 | * This function registers the partitioning information in @disk | |
480 | * with the kernel. | |
481 | * | |
482 | * FIXME: error handling | |
483 | */ | |
484 | void add_disk(struct gendisk *disk) | |
485 | { | |
486 | struct backing_dev_info *bdi; | |
487 | dev_t devt; | |
488 | int retval; | |
489 | ||
490 | /* minors == 0 indicates to use ext devt from part0 and should | |
491 | * be accompanied with EXT_DEVT flag. Make sure all | |
492 | * parameters make sense. | |
493 | */ | |
494 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); | |
495 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); | |
496 | ||
497 | disk->flags |= GENHD_FL_UP; | |
498 | ||
499 | retval = blk_alloc_devt(&disk->part0, &devt); | |
500 | if (retval) { | |
501 | WARN_ON(1); | |
502 | return; | |
503 | } | |
504 | disk_to_dev(disk)->devt = devt; | |
505 | ||
506 | /* ->major and ->first_minor aren't supposed to be | |
507 | * dereferenced from here on, but set them just in case. | |
508 | */ | |
509 | disk->major = MAJOR(devt); | |
510 | disk->first_minor = MINOR(devt); | |
511 | ||
512 | blk_register_region(disk_devt(disk), disk->minors, NULL, | |
513 | exact_match, exact_lock, disk); | |
514 | register_disk(disk); | |
515 | blk_register_queue(disk); | |
516 | ||
517 | bdi = &disk->queue->backing_dev_info; | |
518 | bdi_register_dev(bdi, disk_devt(disk)); | |
519 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, | |
520 | "bdi"); | |
521 | WARN_ON(retval); | |
522 | } | |
523 | ||
524 | EXPORT_SYMBOL(add_disk); | |
525 | EXPORT_SYMBOL(del_gendisk); /* in partitions/check.c */ | |
526 | ||
527 | void unlink_gendisk(struct gendisk *disk) | |
528 | { | |
529 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); | |
530 | bdi_unregister(&disk->queue->backing_dev_info); | |
531 | blk_unregister_queue(disk); | |
532 | blk_unregister_region(disk_devt(disk), disk->minors); | |
533 | } | |
534 | ||
535 | /** | |
536 | * get_gendisk - get partitioning information for a given device | |
537 | * @devt: device to get partitioning information for | |
538 | * @part: returned partition index | |
539 | * | |
540 | * This function gets the structure containing partitioning | |
541 | * information for the given device @devt. | |
542 | */ | |
543 | struct gendisk *get_gendisk(dev_t devt, int *partno) | |
544 | { | |
545 | struct gendisk *disk = NULL; | |
546 | ||
547 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { | |
548 | struct kobject *kobj; | |
549 | ||
550 | kobj = kobj_lookup(bdev_map, devt, partno); | |
551 | if (kobj) | |
552 | disk = dev_to_disk(kobj_to_dev(kobj)); | |
553 | } else { | |
554 | struct hd_struct *part; | |
555 | ||
556 | mutex_lock(&ext_devt_mutex); | |
557 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); | |
558 | if (part && get_disk(part_to_disk(part))) { | |
559 | *partno = part->partno; | |
560 | disk = part_to_disk(part); | |
561 | } | |
562 | mutex_unlock(&ext_devt_mutex); | |
563 | } | |
564 | ||
565 | return disk; | |
566 | } | |
567 | ||
568 | /** | |
569 | * bdget_disk - do bdget() by gendisk and partition number | |
570 | * @disk: gendisk of interest | |
571 | * @partno: partition number | |
572 | * | |
573 | * Find partition @partno from @disk, do bdget() on it. | |
574 | * | |
575 | * CONTEXT: | |
576 | * Don't care. | |
577 | * | |
578 | * RETURNS: | |
579 | * Resulting block_device on success, NULL on failure. | |
580 | */ | |
581 | extern struct block_device *bdget_disk(struct gendisk *disk, int partno) | |
582 | { | |
583 | struct hd_struct *part; | |
584 | struct block_device *bdev = NULL; | |
585 | ||
586 | part = disk_get_part(disk, partno); | |
587 | if (part && (part->nr_sects || partno == 0)) | |
588 | bdev = bdget(part_devt(part)); | |
589 | disk_put_part(part); | |
590 | ||
591 | return bdev; | |
592 | } | |
593 | EXPORT_SYMBOL(bdget_disk); | |
594 | ||
595 | /* | |
596 | * print a full list of all partitions - intended for places where the root | |
597 | * filesystem can't be mounted and thus to give the victim some idea of what | |
598 | * went wrong | |
599 | */ | |
600 | void __init printk_all_partitions(void) | |
601 | { | |
602 | struct class_dev_iter iter; | |
603 | struct device *dev; | |
604 | ||
605 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
606 | while ((dev = class_dev_iter_next(&iter))) { | |
607 | struct gendisk *disk = dev_to_disk(dev); | |
608 | struct disk_part_iter piter; | |
609 | struct hd_struct *part; | |
610 | char name_buf[BDEVNAME_SIZE]; | |
611 | char devt_buf[BDEVT_SIZE]; | |
612 | ||
613 | /* | |
614 | * Don't show empty devices or things that have been | |
615 | * surpressed | |
616 | */ | |
617 | if (get_capacity(disk) == 0 || | |
618 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) | |
619 | continue; | |
620 | ||
621 | /* | |
622 | * Note, unlike /proc/partitions, I am showing the | |
623 | * numbers in hex - the same format as the root= | |
624 | * option takes. | |
625 | */ | |
626 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); | |
627 | while ((part = disk_part_iter_next(&piter))) { | |
628 | bool is_part0 = part == &disk->part0; | |
629 | ||
630 | printk("%s%s %10llu %s", is_part0 ? "" : " ", | |
631 | bdevt_str(part_devt(part), devt_buf), | |
632 | (unsigned long long)part->nr_sects >> 1, | |
633 | disk_name(disk, part->partno, name_buf)); | |
634 | if (is_part0) { | |
635 | if (disk->driverfs_dev != NULL && | |
636 | disk->driverfs_dev->driver != NULL) | |
637 | printk(" driver: %s\n", | |
638 | disk->driverfs_dev->driver->name); | |
639 | else | |
640 | printk(" (driver?)\n"); | |
641 | } else | |
642 | printk("\n"); | |
643 | } | |
644 | disk_part_iter_exit(&piter); | |
645 | } | |
646 | class_dev_iter_exit(&iter); | |
647 | } | |
648 | ||
649 | #ifdef CONFIG_PROC_FS | |
650 | /* iterator */ | |
651 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) | |
652 | { | |
653 | loff_t skip = *pos; | |
654 | struct class_dev_iter *iter; | |
655 | struct device *dev; | |
656 | ||
657 | iter = kmalloc(GFP_KERNEL, sizeof(*iter)); | |
658 | if (!iter) | |
659 | return ERR_PTR(-ENOMEM); | |
660 | ||
661 | seqf->private = iter; | |
662 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); | |
663 | do { | |
664 | dev = class_dev_iter_next(iter); | |
665 | if (!dev) | |
666 | return NULL; | |
667 | } while (skip--); | |
668 | ||
669 | return dev_to_disk(dev); | |
670 | } | |
671 | ||
672 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) | |
673 | { | |
674 | struct device *dev; | |
675 | ||
676 | (*pos)++; | |
677 | dev = class_dev_iter_next(seqf->private); | |
678 | if (dev) | |
679 | return dev_to_disk(dev); | |
680 | ||
681 | return NULL; | |
682 | } | |
683 | ||
684 | static void disk_seqf_stop(struct seq_file *seqf, void *v) | |
685 | { | |
686 | struct class_dev_iter *iter = seqf->private; | |
687 | ||
688 | /* stop is called even after start failed :-( */ | |
689 | if (iter) { | |
690 | class_dev_iter_exit(iter); | |
691 | kfree(iter); | |
692 | } | |
693 | } | |
694 | ||
695 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) | |
696 | { | |
697 | static void *p; | |
698 | ||
699 | p = disk_seqf_start(seqf, pos); | |
700 | if (!IS_ERR(p) && p) | |
701 | seq_puts(seqf, "major minor #blocks name\n\n"); | |
702 | return p; | |
703 | } | |
704 | ||
705 | static int show_partition(struct seq_file *seqf, void *v) | |
706 | { | |
707 | struct gendisk *sgp = v; | |
708 | struct disk_part_iter piter; | |
709 | struct hd_struct *part; | |
710 | char buf[BDEVNAME_SIZE]; | |
711 | ||
712 | /* Don't show non-partitionable removeable devices or empty devices */ | |
713 | if (!get_capacity(sgp) || (!disk_partitionable(sgp) && | |
714 | (sgp->flags & GENHD_FL_REMOVABLE))) | |
715 | return 0; | |
716 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) | |
717 | return 0; | |
718 | ||
719 | /* show the full disk and all non-0 size partitions of it */ | |
720 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); | |
721 | while ((part = disk_part_iter_next(&piter))) | |
722 | seq_printf(seqf, "%4d %7d %10llu %s\n", | |
723 | MAJOR(part_devt(part)), MINOR(part_devt(part)), | |
724 | (unsigned long long)part->nr_sects >> 1, | |
725 | disk_name(sgp, part->partno, buf)); | |
726 | disk_part_iter_exit(&piter); | |
727 | ||
728 | return 0; | |
729 | } | |
730 | ||
731 | const struct seq_operations partitions_op = { | |
732 | .start = show_partition_start, | |
733 | .next = disk_seqf_next, | |
734 | .stop = disk_seqf_stop, | |
735 | .show = show_partition | |
736 | }; | |
737 | #endif | |
738 | ||
739 | ||
740 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) | |
741 | { | |
742 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) | |
743 | /* Make old-style 2.4 aliases work */ | |
744 | request_module("block-major-%d", MAJOR(devt)); | |
745 | return NULL; | |
746 | } | |
747 | ||
748 | static int __init genhd_device_init(void) | |
749 | { | |
750 | int error; | |
751 | ||
752 | block_class.dev_kobj = sysfs_dev_block_kobj; | |
753 | error = class_register(&block_class); | |
754 | if (unlikely(error)) | |
755 | return error; | |
756 | bdev_map = kobj_map_init(base_probe, &block_class_lock); | |
757 | blk_dev_init(); | |
758 | ||
759 | #ifndef CONFIG_SYSFS_DEPRECATED | |
760 | /* create top-level block dir */ | |
761 | block_depr = kobject_create_and_add("block", NULL); | |
762 | #endif | |
763 | return 0; | |
764 | } | |
765 | ||
766 | subsys_initcall(genhd_device_init); | |
767 | ||
768 | static ssize_t disk_range_show(struct device *dev, | |
769 | struct device_attribute *attr, char *buf) | |
770 | { | |
771 | struct gendisk *disk = dev_to_disk(dev); | |
772 | ||
773 | return sprintf(buf, "%d\n", disk->minors); | |
774 | } | |
775 | ||
776 | static ssize_t disk_ext_range_show(struct device *dev, | |
777 | struct device_attribute *attr, char *buf) | |
778 | { | |
779 | struct gendisk *disk = dev_to_disk(dev); | |
780 | ||
781 | return sprintf(buf, "%d\n", disk_max_parts(disk)); | |
782 | } | |
783 | ||
784 | static ssize_t disk_removable_show(struct device *dev, | |
785 | struct device_attribute *attr, char *buf) | |
786 | { | |
787 | struct gendisk *disk = dev_to_disk(dev); | |
788 | ||
789 | return sprintf(buf, "%d\n", | |
790 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); | |
791 | } | |
792 | ||
793 | static ssize_t disk_ro_show(struct device *dev, | |
794 | struct device_attribute *attr, char *buf) | |
795 | { | |
796 | struct gendisk *disk = dev_to_disk(dev); | |
797 | ||
798 | return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); | |
799 | } | |
800 | ||
801 | static ssize_t disk_capability_show(struct device *dev, | |
802 | struct device_attribute *attr, char *buf) | |
803 | { | |
804 | struct gendisk *disk = dev_to_disk(dev); | |
805 | ||
806 | return sprintf(buf, "%x\n", disk->flags); | |
807 | } | |
808 | ||
809 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); | |
810 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); | |
811 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); | |
812 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); | |
813 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); | |
814 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); | |
815 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); | |
816 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
817 | static struct device_attribute dev_attr_fail = | |
818 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); | |
819 | #endif | |
820 | ||
821 | static struct attribute *disk_attrs[] = { | |
822 | &dev_attr_range.attr, | |
823 | &dev_attr_ext_range.attr, | |
824 | &dev_attr_removable.attr, | |
825 | &dev_attr_ro.attr, | |
826 | &dev_attr_size.attr, | |
827 | &dev_attr_capability.attr, | |
828 | &dev_attr_stat.attr, | |
829 | #ifdef CONFIG_FAIL_MAKE_REQUEST | |
830 | &dev_attr_fail.attr, | |
831 | #endif | |
832 | NULL | |
833 | }; | |
834 | ||
835 | static struct attribute_group disk_attr_group = { | |
836 | .attrs = disk_attrs, | |
837 | }; | |
838 | ||
839 | static struct attribute_group *disk_attr_groups[] = { | |
840 | &disk_attr_group, | |
841 | NULL | |
842 | }; | |
843 | ||
844 | static void disk_free_ptbl_rcu_cb(struct rcu_head *head) | |
845 | { | |
846 | struct disk_part_tbl *ptbl = | |
847 | container_of(head, struct disk_part_tbl, rcu_head); | |
848 | ||
849 | kfree(ptbl); | |
850 | } | |
851 | ||
852 | /** | |
853 | * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way | |
854 | * @disk: disk to replace part_tbl for | |
855 | * @new_ptbl: new part_tbl to install | |
856 | * | |
857 | * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The | |
858 | * original ptbl is freed using RCU callback. | |
859 | * | |
860 | * LOCKING: | |
861 | * Matching bd_mutx locked. | |
862 | */ | |
863 | static void disk_replace_part_tbl(struct gendisk *disk, | |
864 | struct disk_part_tbl *new_ptbl) | |
865 | { | |
866 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
867 | ||
868 | rcu_assign_pointer(disk->part_tbl, new_ptbl); | |
869 | if (old_ptbl) | |
870 | call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb); | |
871 | } | |
872 | ||
873 | /** | |
874 | * disk_expand_part_tbl - expand disk->part_tbl | |
875 | * @disk: disk to expand part_tbl for | |
876 | * @partno: expand such that this partno can fit in | |
877 | * | |
878 | * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl | |
879 | * uses RCU to allow unlocked dereferencing for stats and other stuff. | |
880 | * | |
881 | * LOCKING: | |
882 | * Matching bd_mutex locked, might sleep. | |
883 | * | |
884 | * RETURNS: | |
885 | * 0 on success, -errno on failure. | |
886 | */ | |
887 | int disk_expand_part_tbl(struct gendisk *disk, int partno) | |
888 | { | |
889 | struct disk_part_tbl *old_ptbl = disk->part_tbl; | |
890 | struct disk_part_tbl *new_ptbl; | |
891 | int len = old_ptbl ? old_ptbl->len : 0; | |
892 | int target = partno + 1; | |
893 | size_t size; | |
894 | int i; | |
895 | ||
896 | /* disk_max_parts() is zero during initialization, ignore if so */ | |
897 | if (disk_max_parts(disk) && target > disk_max_parts(disk)) | |
898 | return -EINVAL; | |
899 | ||
900 | if (target <= len) | |
901 | return 0; | |
902 | ||
903 | size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); | |
904 | new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); | |
905 | if (!new_ptbl) | |
906 | return -ENOMEM; | |
907 | ||
908 | INIT_RCU_HEAD(&new_ptbl->rcu_head); | |
909 | new_ptbl->len = target; | |
910 | ||
911 | for (i = 0; i < len; i++) | |
912 | rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); | |
913 | ||
914 | disk_replace_part_tbl(disk, new_ptbl); | |
915 | return 0; | |
916 | } | |
917 | ||
918 | static void disk_release(struct device *dev) | |
919 | { | |
920 | struct gendisk *disk = dev_to_disk(dev); | |
921 | ||
922 | kfree(disk->random); | |
923 | disk_replace_part_tbl(disk, NULL); | |
924 | free_part_stats(&disk->part0); | |
925 | kfree(disk); | |
926 | } | |
927 | struct class block_class = { | |
928 | .name = "block", | |
929 | }; | |
930 | ||
931 | static struct device_type disk_type = { | |
932 | .name = "disk", | |
933 | .groups = disk_attr_groups, | |
934 | .release = disk_release, | |
935 | }; | |
936 | ||
937 | #ifdef CONFIG_PROC_FS | |
938 | /* | |
939 | * aggregate disk stat collector. Uses the same stats that the sysfs | |
940 | * entries do, above, but makes them available through one seq_file. | |
941 | * | |
942 | * The output looks suspiciously like /proc/partitions with a bunch of | |
943 | * extra fields. | |
944 | */ | |
945 | static int diskstats_show(struct seq_file *seqf, void *v) | |
946 | { | |
947 | struct gendisk *gp = v; | |
948 | struct disk_part_iter piter; | |
949 | struct hd_struct *hd; | |
950 | char buf[BDEVNAME_SIZE]; | |
951 | int cpu; | |
952 | ||
953 | /* | |
954 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) | |
955 | seq_puts(seqf, "major minor name" | |
956 | " rio rmerge rsect ruse wio wmerge " | |
957 | "wsect wuse running use aveq" | |
958 | "\n\n"); | |
959 | */ | |
960 | ||
961 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_PART0); | |
962 | while ((hd = disk_part_iter_next(&piter))) { | |
963 | cpu = part_stat_lock(); | |
964 | part_round_stats(cpu, hd); | |
965 | part_stat_unlock(); | |
966 | seq_printf(seqf, "%4d %7d %s %lu %lu %llu " | |
967 | "%u %lu %lu %llu %u %u %u %u\n", | |
968 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), | |
969 | disk_name(gp, hd->partno, buf), | |
970 | part_stat_read(hd, ios[0]), | |
971 | part_stat_read(hd, merges[0]), | |
972 | (unsigned long long)part_stat_read(hd, sectors[0]), | |
973 | jiffies_to_msecs(part_stat_read(hd, ticks[0])), | |
974 | part_stat_read(hd, ios[1]), | |
975 | part_stat_read(hd, merges[1]), | |
976 | (unsigned long long)part_stat_read(hd, sectors[1]), | |
977 | jiffies_to_msecs(part_stat_read(hd, ticks[1])), | |
978 | hd->in_flight, | |
979 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), | |
980 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) | |
981 | ); | |
982 | } | |
983 | disk_part_iter_exit(&piter); | |
984 | ||
985 | return 0; | |
986 | } | |
987 | ||
988 | const struct seq_operations diskstats_op = { | |
989 | .start = disk_seqf_start, | |
990 | .next = disk_seqf_next, | |
991 | .stop = disk_seqf_stop, | |
992 | .show = diskstats_show | |
993 | }; | |
994 | #endif /* CONFIG_PROC_FS */ | |
995 | ||
996 | static void media_change_notify_thread(struct work_struct *work) | |
997 | { | |
998 | struct gendisk *gd = container_of(work, struct gendisk, async_notify); | |
999 | char event[] = "MEDIA_CHANGE=1"; | |
1000 | char *envp[] = { event, NULL }; | |
1001 | ||
1002 | /* | |
1003 | * set enviroment vars to indicate which event this is for | |
1004 | * so that user space will know to go check the media status. | |
1005 | */ | |
1006 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); | |
1007 | put_device(gd->driverfs_dev); | |
1008 | } | |
1009 | ||
1010 | #if 0 | |
1011 | void genhd_media_change_notify(struct gendisk *disk) | |
1012 | { | |
1013 | get_device(disk->driverfs_dev); | |
1014 | schedule_work(&disk->async_notify); | |
1015 | } | |
1016 | EXPORT_SYMBOL_GPL(genhd_media_change_notify); | |
1017 | #endif /* 0 */ | |
1018 | ||
1019 | dev_t blk_lookup_devt(const char *name, int partno) | |
1020 | { | |
1021 | dev_t devt = MKDEV(0, 0); | |
1022 | struct class_dev_iter iter; | |
1023 | struct device *dev; | |
1024 | ||
1025 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); | |
1026 | while ((dev = class_dev_iter_next(&iter))) { | |
1027 | struct gendisk *disk = dev_to_disk(dev); | |
1028 | struct hd_struct *part; | |
1029 | ||
1030 | if (strcmp(dev->bus_id, name)) | |
1031 | continue; | |
1032 | ||
1033 | part = disk_get_part(disk, partno); | |
1034 | if (part && (part->nr_sects || partno == 0)) { | |
1035 | devt = part_devt(part); | |
1036 | disk_put_part(part); | |
1037 | break; | |
1038 | } | |
1039 | disk_put_part(part); | |
1040 | } | |
1041 | class_dev_iter_exit(&iter); | |
1042 | return devt; | |
1043 | } | |
1044 | EXPORT_SYMBOL(blk_lookup_devt); | |
1045 | ||
1046 | struct gendisk *alloc_disk(int minors) | |
1047 | { | |
1048 | return alloc_disk_node(minors, -1); | |
1049 | } | |
1050 | EXPORT_SYMBOL(alloc_disk); | |
1051 | ||
1052 | struct gendisk *alloc_disk_node(int minors, int node_id) | |
1053 | { | |
1054 | struct gendisk *disk; | |
1055 | ||
1056 | disk = kmalloc_node(sizeof(struct gendisk), | |
1057 | GFP_KERNEL | __GFP_ZERO, node_id); | |
1058 | if (disk) { | |
1059 | if (!init_part_stats(&disk->part0)) { | |
1060 | kfree(disk); | |
1061 | return NULL; | |
1062 | } | |
1063 | if (disk_expand_part_tbl(disk, 0)) { | |
1064 | free_part_stats(&disk->part0); | |
1065 | kfree(disk); | |
1066 | return NULL; | |
1067 | } | |
1068 | disk->part_tbl->part[0] = &disk->part0; | |
1069 | ||
1070 | disk->minors = minors; | |
1071 | rand_initialize_disk(disk); | |
1072 | disk_to_dev(disk)->class = &block_class; | |
1073 | disk_to_dev(disk)->type = &disk_type; | |
1074 | device_initialize(disk_to_dev(disk)); | |
1075 | INIT_WORK(&disk->async_notify, | |
1076 | media_change_notify_thread); | |
1077 | disk->node_id = node_id; | |
1078 | } | |
1079 | return disk; | |
1080 | } | |
1081 | EXPORT_SYMBOL(alloc_disk_node); | |
1082 | ||
1083 | struct kobject *get_disk(struct gendisk *disk) | |
1084 | { | |
1085 | struct module *owner; | |
1086 | struct kobject *kobj; | |
1087 | ||
1088 | if (!disk->fops) | |
1089 | return NULL; | |
1090 | owner = disk->fops->owner; | |
1091 | if (owner && !try_module_get(owner)) | |
1092 | return NULL; | |
1093 | kobj = kobject_get(&disk_to_dev(disk)->kobj); | |
1094 | if (kobj == NULL) { | |
1095 | module_put(owner); | |
1096 | return NULL; | |
1097 | } | |
1098 | return kobj; | |
1099 | ||
1100 | } | |
1101 | ||
1102 | EXPORT_SYMBOL(get_disk); | |
1103 | ||
1104 | void put_disk(struct gendisk *disk) | |
1105 | { | |
1106 | if (disk) | |
1107 | kobject_put(&disk_to_dev(disk)->kobj); | |
1108 | } | |
1109 | ||
1110 | EXPORT_SYMBOL(put_disk); | |
1111 | ||
1112 | void set_device_ro(struct block_device *bdev, int flag) | |
1113 | { | |
1114 | bdev->bd_part->policy = flag; | |
1115 | } | |
1116 | ||
1117 | EXPORT_SYMBOL(set_device_ro); | |
1118 | ||
1119 | void set_disk_ro(struct gendisk *disk, int flag) | |
1120 | { | |
1121 | struct disk_part_iter piter; | |
1122 | struct hd_struct *part; | |
1123 | ||
1124 | disk_part_iter_init(&piter, disk, | |
1125 | DISK_PITER_INCL_EMPTY | DISK_PITER_INCL_PART0); | |
1126 | while ((part = disk_part_iter_next(&piter))) | |
1127 | part->policy = flag; | |
1128 | disk_part_iter_exit(&piter); | |
1129 | } | |
1130 | ||
1131 | EXPORT_SYMBOL(set_disk_ro); | |
1132 | ||
1133 | int bdev_read_only(struct block_device *bdev) | |
1134 | { | |
1135 | if (!bdev) | |
1136 | return 0; | |
1137 | return bdev->bd_part->policy; | |
1138 | } | |
1139 | ||
1140 | EXPORT_SYMBOL(bdev_read_only); | |
1141 | ||
1142 | int invalidate_partition(struct gendisk *disk, int partno) | |
1143 | { | |
1144 | int res = 0; | |
1145 | struct block_device *bdev = bdget_disk(disk, partno); | |
1146 | if (bdev) { | |
1147 | fsync_bdev(bdev); | |
1148 | res = __invalidate_device(bdev); | |
1149 | bdput(bdev); | |
1150 | } | |
1151 | return res; | |
1152 | } | |
1153 | ||
1154 | EXPORT_SYMBOL(invalidate_partition); |