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Source at commit be977234bfb4a6dca8a39e7c52165e4cd536ad71 created 12 years 9 months ago. By Lars-Peter Clausen, jz4740: Fix compile error | |
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1 | /* |
2 | * gendisk handling |
3 | */ |
4 | |
5 | #include <linux/module.h> |
6 | #include <linux/fs.h> |
7 | #include <linux/genhd.h> |
8 | #include <linux/kdev_t.h> |
9 | #include <linux/kernel.h> |
10 | #include <linux/blkdev.h> |
11 | #include <linux/init.h> |
12 | #include <linux/spinlock.h> |
13 | #include <linux/proc_fs.h> |
14 | #include <linux/seq_file.h> |
15 | #include <linux/slab.h> |
16 | #include <linux/kmod.h> |
17 | #include <linux/kobj_map.h> |
18 | #include <linux/buffer_head.h> |
19 | #include <linux/mutex.h> |
20 | #include <linux/idr.h> |
21 | #include <linux/log2.h> |
22 | |
23 | #include "blk.h" |
24 | |
25 | static DEFINE_MUTEX(block_class_lock); |
26 | struct kobject *block_depr; |
27 | |
28 | /* for extended dynamic devt allocation, currently only one major is used */ |
29 | #define MAX_EXT_DEVT (1 << MINORBITS) |
30 | |
31 | /* For extended devt allocation. ext_devt_mutex prevents look up |
32 | * results from going away underneath its user. |
33 | */ |
34 | static DEFINE_MUTEX(ext_devt_mutex); |
35 | static DEFINE_IDR(ext_devt_idr); |
36 | |
37 | static struct device_type disk_type; |
38 | |
39 | static void disk_add_events(struct gendisk *disk); |
40 | static void disk_del_events(struct gendisk *disk); |
41 | static void disk_release_events(struct gendisk *disk); |
42 | |
43 | /** |
44 | * disk_get_part - get partition |
45 | * @disk: disk to look partition from |
46 | * @partno: partition number |
47 | * |
48 | * Look for partition @partno from @disk. If found, increment |
49 | * reference count and return it. |
50 | * |
51 | * CONTEXT: |
52 | * Don't care. |
53 | * |
54 | * RETURNS: |
55 | * Pointer to the found partition on success, NULL if not found. |
56 | */ |
57 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) |
58 | { |
59 | struct hd_struct *part = NULL; |
60 | struct disk_part_tbl *ptbl; |
61 | |
62 | if (unlikely(partno < 0)) |
63 | return NULL; |
64 | |
65 | rcu_read_lock(); |
66 | |
67 | ptbl = rcu_dereference(disk->part_tbl); |
68 | if (likely(partno < ptbl->len)) { |
69 | part = rcu_dereference(ptbl->part[partno]); |
70 | if (part) |
71 | get_device(part_to_dev(part)); |
72 | } |
73 | |
74 | rcu_read_unlock(); |
75 | |
76 | return part; |
77 | } |
78 | EXPORT_SYMBOL_GPL(disk_get_part); |
79 | |
80 | /** |
81 | * disk_part_iter_init - initialize partition iterator |
82 | * @piter: iterator to initialize |
83 | * @disk: disk to iterate over |
84 | * @flags: DISK_PITER_* flags |
85 | * |
86 | * Initialize @piter so that it iterates over partitions of @disk. |
87 | * |
88 | * CONTEXT: |
89 | * Don't care. |
90 | */ |
91 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, |
92 | unsigned int flags) |
93 | { |
94 | struct disk_part_tbl *ptbl; |
95 | |
96 | rcu_read_lock(); |
97 | ptbl = rcu_dereference(disk->part_tbl); |
98 | |
99 | piter->disk = disk; |
100 | piter->part = NULL; |
101 | |
102 | if (flags & DISK_PITER_REVERSE) |
103 | piter->idx = ptbl->len - 1; |
104 | else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) |
105 | piter->idx = 0; |
106 | else |
107 | piter->idx = 1; |
108 | |
109 | piter->flags = flags; |
110 | |
111 | rcu_read_unlock(); |
112 | } |
113 | EXPORT_SYMBOL_GPL(disk_part_iter_init); |
114 | |
115 | /** |
116 | * disk_part_iter_next - proceed iterator to the next partition and return it |
117 | * @piter: iterator of interest |
118 | * |
119 | * Proceed @piter to the next partition and return it. |
120 | * |
121 | * CONTEXT: |
122 | * Don't care. |
123 | */ |
124 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) |
125 | { |
126 | struct disk_part_tbl *ptbl; |
127 | int inc, end; |
128 | |
129 | /* put the last partition */ |
130 | disk_put_part(piter->part); |
131 | piter->part = NULL; |
132 | |
133 | /* get part_tbl */ |
134 | rcu_read_lock(); |
135 | ptbl = rcu_dereference(piter->disk->part_tbl); |
136 | |
137 | /* determine iteration parameters */ |
138 | if (piter->flags & DISK_PITER_REVERSE) { |
139 | inc = -1; |
140 | if (piter->flags & (DISK_PITER_INCL_PART0 | |
141 | DISK_PITER_INCL_EMPTY_PART0)) |
142 | end = -1; |
143 | else |
144 | end = 0; |
145 | } else { |
146 | inc = 1; |
147 | end = ptbl->len; |
148 | } |
149 | |
150 | /* iterate to the next partition */ |
151 | for (; piter->idx != end; piter->idx += inc) { |
152 | struct hd_struct *part; |
153 | |
154 | part = rcu_dereference(ptbl->part[piter->idx]); |
155 | if (!part) |
156 | continue; |
157 | if (!part->nr_sects && |
158 | !(piter->flags & DISK_PITER_INCL_EMPTY) && |
159 | !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && |
160 | piter->idx == 0)) |
161 | continue; |
162 | |
163 | get_device(part_to_dev(part)); |
164 | piter->part = part; |
165 | piter->idx += inc; |
166 | break; |
167 | } |
168 | |
169 | rcu_read_unlock(); |
170 | |
171 | return piter->part; |
172 | } |
173 | EXPORT_SYMBOL_GPL(disk_part_iter_next); |
174 | |
175 | /** |
176 | * disk_part_iter_exit - finish up partition iteration |
177 | * @piter: iter of interest |
178 | * |
179 | * Called when iteration is over. Cleans up @piter. |
180 | * |
181 | * CONTEXT: |
182 | * Don't care. |
183 | */ |
184 | void disk_part_iter_exit(struct disk_part_iter *piter) |
185 | { |
186 | disk_put_part(piter->part); |
187 | piter->part = NULL; |
188 | } |
189 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); |
190 | |
191 | static inline int sector_in_part(struct hd_struct *part, sector_t sector) |
192 | { |
193 | return part->start_sect <= sector && |
194 | sector < part->start_sect + part->nr_sects; |
195 | } |
196 | |
197 | /** |
198 | * disk_map_sector_rcu - map sector to partition |
199 | * @disk: gendisk of interest |
200 | * @sector: sector to map |
201 | * |
202 | * Find out which partition @sector maps to on @disk. This is |
203 | * primarily used for stats accounting. |
204 | * |
205 | * CONTEXT: |
206 | * RCU read locked. The returned partition pointer is valid only |
207 | * while preemption is disabled. |
208 | * |
209 | * RETURNS: |
210 | * Found partition on success, part0 is returned if no partition matches |
211 | */ |
212 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) |
213 | { |
214 | struct disk_part_tbl *ptbl; |
215 | struct hd_struct *part; |
216 | int i; |
217 | |
218 | ptbl = rcu_dereference(disk->part_tbl); |
219 | |
220 | part = rcu_dereference(ptbl->last_lookup); |
221 | if (part && sector_in_part(part, sector)) |
222 | return part; |
223 | |
224 | for (i = 1; i < ptbl->len; i++) { |
225 | part = rcu_dereference(ptbl->part[i]); |
226 | |
227 | if (part && sector_in_part(part, sector)) { |
228 | rcu_assign_pointer(ptbl->last_lookup, part); |
229 | return part; |
230 | } |
231 | } |
232 | return &disk->part0; |
233 | } |
234 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); |
235 | |
236 | /* |
237 | * Can be deleted altogether. Later. |
238 | * |
239 | */ |
240 | static struct blk_major_name { |
241 | struct blk_major_name *next; |
242 | int major; |
243 | char name[16]; |
244 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; |
245 | |
246 | /* index in the above - for now: assume no multimajor ranges */ |
247 | static inline int major_to_index(unsigned major) |
248 | { |
249 | return major % BLKDEV_MAJOR_HASH_SIZE; |
250 | } |
251 | |
252 | #ifdef CONFIG_PROC_FS |
253 | void blkdev_show(struct seq_file *seqf, off_t offset) |
254 | { |
255 | struct blk_major_name *dp; |
256 | |
257 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { |
258 | mutex_lock(&block_class_lock); |
259 | for (dp = major_names[offset]; dp; dp = dp->next) |
260 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); |
261 | mutex_unlock(&block_class_lock); |
262 | } |
263 | } |
264 | #endif /* CONFIG_PROC_FS */ |
265 | |
266 | /** |
267 | * register_blkdev - register a new block device |
268 | * |
269 | * @major: the requested major device number [1..255]. If @major=0, try to |
270 | * allocate any unused major number. |
271 | * @name: the name of the new block device as a zero terminated string |
272 | * |
273 | * The @name must be unique within the system. |
274 | * |
275 | * The return value depends on the @major input parameter. |
276 | * - if a major device number was requested in range [1..255] then the |
277 | * function returns zero on success, or a negative error code |
278 | * - if any unused major number was requested with @major=0 parameter |
279 | * then the return value is the allocated major number in range |
280 | * [1..255] or a negative error code otherwise |
281 | */ |
282 | int register_blkdev(unsigned int major, const char *name) |
283 | { |
284 | struct blk_major_name **n, *p; |
285 | int index, ret = 0; |
286 | |
287 | mutex_lock(&block_class_lock); |
288 | |
289 | /* temporary */ |
290 | if (major == 0) { |
291 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { |
292 | if (major_names[index] == NULL) |
293 | break; |
294 | } |
295 | |
296 | if (index == 0) { |
297 | printk("register_blkdev: failed to get major for %s\n", |
298 | name); |
299 | ret = -EBUSY; |
300 | goto out; |
301 | } |
302 | major = index; |
303 | ret = major; |
304 | } |
305 | |
306 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); |
307 | if (p == NULL) { |
308 | ret = -ENOMEM; |
309 | goto out; |
310 | } |
311 | |
312 | p->major = major; |
313 | strlcpy(p->name, name, sizeof(p->name)); |
314 | p->next = NULL; |
315 | index = major_to_index(major); |
316 | |
317 | for (n = &major_names[index]; *n; n = &(*n)->next) { |
318 | if ((*n)->major == major) |
319 | break; |
320 | } |
321 | if (!*n) |
322 | *n = p; |
323 | else |
324 | ret = -EBUSY; |
325 | |
326 | if (ret < 0) { |
327 | printk("register_blkdev: cannot get major %d for %s\n", |
328 | major, name); |
329 | kfree(p); |
330 | } |
331 | out: |
332 | mutex_unlock(&block_class_lock); |
333 | return ret; |
334 | } |
335 | |
336 | EXPORT_SYMBOL(register_blkdev); |
337 | |
338 | void unregister_blkdev(unsigned int major, const char *name) |
339 | { |
340 | struct blk_major_name **n; |
341 | struct blk_major_name *p = NULL; |
342 | int index = major_to_index(major); |
343 | |
344 | mutex_lock(&block_class_lock); |
345 | for (n = &major_names[index]; *n; n = &(*n)->next) |
346 | if ((*n)->major == major) |
347 | break; |
348 | if (!*n || strcmp((*n)->name, name)) { |
349 | WARN_ON(1); |
350 | } else { |
351 | p = *n; |
352 | *n = p->next; |
353 | } |
354 | mutex_unlock(&block_class_lock); |
355 | kfree(p); |
356 | } |
357 | |
358 | EXPORT_SYMBOL(unregister_blkdev); |
359 | |
360 | static struct kobj_map *bdev_map; |
361 | |
362 | /** |
363 | * blk_mangle_minor - scatter minor numbers apart |
364 | * @minor: minor number to mangle |
365 | * |
366 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT |
367 | * is enabled. Mangling twice gives the original value. |
368 | * |
369 | * RETURNS: |
370 | * Mangled value. |
371 | * |
372 | * CONTEXT: |
373 | * Don't care. |
374 | */ |
375 | static int blk_mangle_minor(int minor) |
376 | { |
377 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT |
378 | int i; |
379 | |
380 | for (i = 0; i < MINORBITS / 2; i++) { |
381 | int low = minor & (1 << i); |
382 | int high = minor & (1 << (MINORBITS - 1 - i)); |
383 | int distance = MINORBITS - 1 - 2 * i; |
384 | |
385 | minor ^= low | high; /* clear both bits */ |
386 | low <<= distance; /* swap the positions */ |
387 | high >>= distance; |
388 | minor |= low | high; /* and set */ |
389 | } |
390 | #endif |
391 | return minor; |
392 | } |
393 | |
394 | /** |
395 | * blk_alloc_devt - allocate a dev_t for a partition |
396 | * @part: partition to allocate dev_t for |
397 | * @devt: out parameter for resulting dev_t |
398 | * |
399 | * Allocate a dev_t for block device. |
400 | * |
401 | * RETURNS: |
402 | * 0 on success, allocated dev_t is returned in *@devt. -errno on |
403 | * failure. |
404 | * |
405 | * CONTEXT: |
406 | * Might sleep. |
407 | */ |
408 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) |
409 | { |
410 | struct gendisk *disk = part_to_disk(part); |
411 | int idx, rc; |
412 | |
413 | /* in consecutive minor range? */ |
414 | if (part->partno < disk->minors) { |
415 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); |
416 | return 0; |
417 | } |
418 | |
419 | /* allocate ext devt */ |
420 | do { |
421 | if (!idr_pre_get(&ext_devt_idr, GFP_KERNEL)) |
422 | return -ENOMEM; |
423 | rc = idr_get_new(&ext_devt_idr, part, &idx); |
424 | } while (rc == -EAGAIN); |
425 | |
426 | if (rc) |
427 | return rc; |
428 | |
429 | if (idx > MAX_EXT_DEVT) { |
430 | idr_remove(&ext_devt_idr, idx); |
431 | return -EBUSY; |
432 | } |
433 | |
434 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); |
435 | return 0; |
436 | } |
437 | |
438 | /** |
439 | * blk_free_devt - free a dev_t |
440 | * @devt: dev_t to free |
441 | * |
442 | * Free @devt which was allocated using blk_alloc_devt(). |
443 | * |
444 | * CONTEXT: |
445 | * Might sleep. |
446 | */ |
447 | void blk_free_devt(dev_t devt) |
448 | { |
449 | might_sleep(); |
450 | |
451 | if (devt == MKDEV(0, 0)) |
452 | return; |
453 | |
454 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { |
455 | mutex_lock(&ext_devt_mutex); |
456 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); |
457 | mutex_unlock(&ext_devt_mutex); |
458 | } |
459 | } |
460 | |
461 | static char *bdevt_str(dev_t devt, char *buf) |
462 | { |
463 | if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { |
464 | char tbuf[BDEVT_SIZE]; |
465 | snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); |
466 | snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); |
467 | } else |
468 | snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); |
469 | |
470 | return buf; |
471 | } |
472 | |
473 | /* |
474 | * Register device numbers dev..(dev+range-1) |
475 | * range must be nonzero |
476 | * The hash chain is sorted on range, so that subranges can override. |
477 | */ |
478 | void blk_register_region(dev_t devt, unsigned long range, struct module *module, |
479 | struct kobject *(*probe)(dev_t, int *, void *), |
480 | int (*lock)(dev_t, void *), void *data) |
481 | { |
482 | kobj_map(bdev_map, devt, range, module, probe, lock, data); |
483 | } |
484 | |
485 | EXPORT_SYMBOL(blk_register_region); |
486 | |
487 | void blk_unregister_region(dev_t devt, unsigned long range) |
488 | { |
489 | kobj_unmap(bdev_map, devt, range); |
490 | } |
491 | |
492 | EXPORT_SYMBOL(blk_unregister_region); |
493 | |
494 | static struct kobject *exact_match(dev_t devt, int *partno, void *data) |
495 | { |
496 | struct gendisk *p = data; |
497 | |
498 | return &disk_to_dev(p)->kobj; |
499 | } |
500 | |
501 | static int exact_lock(dev_t devt, void *data) |
502 | { |
503 | struct gendisk *p = data; |
504 | |
505 | if (!get_disk(p)) |
506 | return -1; |
507 | return 0; |
508 | } |
509 | |
510 | void register_disk(struct gendisk *disk) |
511 | { |
512 | struct device *ddev = disk_to_dev(disk); |
513 | struct block_device *bdev; |
514 | struct disk_part_iter piter; |
515 | struct hd_struct *part; |
516 | int err; |
517 | |
518 | ddev->parent = disk->driverfs_dev; |
519 | |
520 | dev_set_name(ddev, disk->disk_name); |
521 | |
522 | /* delay uevents, until we scanned partition table */ |
523 | dev_set_uevent_suppress(ddev, 1); |
524 | |
525 | if (device_add(ddev)) |
526 | return; |
527 | if (!sysfs_deprecated) { |
528 | err = sysfs_create_link(block_depr, &ddev->kobj, |
529 | kobject_name(&ddev->kobj)); |
530 | if (err) { |
531 | device_del(ddev); |
532 | return; |
533 | } |
534 | } |
535 | disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj); |
536 | disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); |
537 | |
538 | /* No minors to use for partitions */ |
539 | if (!disk_partitionable(disk)) |
540 | goto exit; |
541 | |
542 | /* No such device (e.g., media were just removed) */ |
543 | if (!get_capacity(disk)) |
544 | goto exit; |
545 | |
546 | bdev = bdget_disk(disk, 0); |
547 | if (!bdev) |
548 | goto exit; |
549 | |
550 | bdev->bd_invalidated = 1; |
551 | err = blkdev_get(bdev, FMODE_READ, NULL); |
552 | if (err < 0) |
553 | goto exit; |
554 | blkdev_put(bdev, FMODE_READ); |
555 | |
556 | exit: |
557 | /* announce disk after possible partitions are created */ |
558 | dev_set_uevent_suppress(ddev, 0); |
559 | kobject_uevent(&ddev->kobj, KOBJ_ADD); |
560 | |
561 | /* announce possible partitions */ |
562 | disk_part_iter_init(&piter, disk, 0); |
563 | while ((part = disk_part_iter_next(&piter))) |
564 | kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); |
565 | disk_part_iter_exit(&piter); |
566 | } |
567 | |
568 | /** |
569 | * add_disk - add partitioning information to kernel list |
570 | * @disk: per-device partitioning information |
571 | * |
572 | * This function registers the partitioning information in @disk |
573 | * with the kernel. |
574 | * |
575 | * FIXME: error handling |
576 | */ |
577 | void add_disk(struct gendisk *disk) |
578 | { |
579 | struct backing_dev_info *bdi; |
580 | dev_t devt; |
581 | int retval; |
582 | |
583 | /* minors == 0 indicates to use ext devt from part0 and should |
584 | * be accompanied with EXT_DEVT flag. Make sure all |
585 | * parameters make sense. |
586 | */ |
587 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); |
588 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); |
589 | |
590 | disk->flags |= GENHD_FL_UP; |
591 | |
592 | retval = blk_alloc_devt(&disk->part0, &devt); |
593 | if (retval) { |
594 | WARN_ON(1); |
595 | return; |
596 | } |
597 | disk_to_dev(disk)->devt = devt; |
598 | |
599 | /* ->major and ->first_minor aren't supposed to be |
600 | * dereferenced from here on, but set them just in case. |
601 | */ |
602 | disk->major = MAJOR(devt); |
603 | disk->first_minor = MINOR(devt); |
604 | |
605 | /* Register BDI before referencing it from bdev */ |
606 | bdi = &disk->queue->backing_dev_info; |
607 | bdi_register_dev(bdi, disk_devt(disk)); |
608 | |
609 | blk_register_region(disk_devt(disk), disk->minors, NULL, |
610 | exact_match, exact_lock, disk); |
611 | register_disk(disk); |
612 | blk_register_queue(disk); |
613 | |
614 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, |
615 | "bdi"); |
616 | WARN_ON(retval); |
617 | |
618 | disk_add_events(disk); |
619 | } |
620 | EXPORT_SYMBOL(add_disk); |
621 | |
622 | void del_gendisk(struct gendisk *disk) |
623 | { |
624 | struct disk_part_iter piter; |
625 | struct hd_struct *part; |
626 | |
627 | disk_del_events(disk); |
628 | |
629 | /* invalidate stuff */ |
630 | disk_part_iter_init(&piter, disk, |
631 | DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); |
632 | while ((part = disk_part_iter_next(&piter))) { |
633 | invalidate_partition(disk, part->partno); |
634 | delete_partition(disk, part->partno); |
635 | } |
636 | disk_part_iter_exit(&piter); |
637 | |
638 | invalidate_partition(disk, 0); |
639 | blk_free_devt(disk_to_dev(disk)->devt); |
640 | set_capacity(disk, 0); |
641 | disk->flags &= ~GENHD_FL_UP; |
642 | |
643 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); |
644 | bdi_unregister(&disk->queue->backing_dev_info); |
645 | blk_unregister_queue(disk); |
646 | blk_unregister_region(disk_devt(disk), disk->minors); |
647 | |
648 | part_stat_set_all(&disk->part0, 0); |
649 | disk->part0.stamp = 0; |
650 | |
651 | kobject_put(disk->part0.holder_dir); |
652 | kobject_put(disk->slave_dir); |
653 | disk->driverfs_dev = NULL; |
654 | if (!sysfs_deprecated) |
655 | sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); |
656 | device_del(disk_to_dev(disk)); |
657 | } |
658 | EXPORT_SYMBOL(del_gendisk); |
659 | |
660 | /** |
661 | * get_gendisk - get partitioning information for a given device |
662 | * @devt: device to get partitioning information for |
663 | * @partno: returned partition index |
664 | * |
665 | * This function gets the structure containing partitioning |
666 | * information for the given device @devt. |
667 | */ |
668 | struct gendisk *get_gendisk(dev_t devt, int *partno) |
669 | { |
670 | struct gendisk *disk = NULL; |
671 | |
672 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { |
673 | struct kobject *kobj; |
674 | |
675 | kobj = kobj_lookup(bdev_map, devt, partno); |
676 | if (kobj) |
677 | disk = dev_to_disk(kobj_to_dev(kobj)); |
678 | } else { |
679 | struct hd_struct *part; |
680 | |
681 | mutex_lock(&ext_devt_mutex); |
682 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); |
683 | if (part && get_disk(part_to_disk(part))) { |
684 | *partno = part->partno; |
685 | disk = part_to_disk(part); |
686 | } |
687 | mutex_unlock(&ext_devt_mutex); |
688 | } |
689 | |
690 | return disk; |
691 | } |
692 | EXPORT_SYMBOL(get_gendisk); |
693 | |
694 | /** |
695 | * bdget_disk - do bdget() by gendisk and partition number |
696 | * @disk: gendisk of interest |
697 | * @partno: partition number |
698 | * |
699 | * Find partition @partno from @disk, do bdget() on it. |
700 | * |
701 | * CONTEXT: |
702 | * Don't care. |
703 | * |
704 | * RETURNS: |
705 | * Resulting block_device on success, NULL on failure. |
706 | */ |
707 | struct block_device *bdget_disk(struct gendisk *disk, int partno) |
708 | { |
709 | struct hd_struct *part; |
710 | struct block_device *bdev = NULL; |
711 | |
712 | part = disk_get_part(disk, partno); |
713 | if (part) |
714 | bdev = bdget(part_devt(part)); |
715 | disk_put_part(part); |
716 | |
717 | return bdev; |
718 | } |
719 | EXPORT_SYMBOL(bdget_disk); |
720 | |
721 | /* |
722 | * print a full list of all partitions - intended for places where the root |
723 | * filesystem can't be mounted and thus to give the victim some idea of what |
724 | * went wrong |
725 | */ |
726 | void __init printk_all_partitions(void) |
727 | { |
728 | struct class_dev_iter iter; |
729 | struct device *dev; |
730 | |
731 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); |
732 | while ((dev = class_dev_iter_next(&iter))) { |
733 | struct gendisk *disk = dev_to_disk(dev); |
734 | struct disk_part_iter piter; |
735 | struct hd_struct *part; |
736 | char name_buf[BDEVNAME_SIZE]; |
737 | char devt_buf[BDEVT_SIZE]; |
738 | u8 uuid[PARTITION_META_INFO_UUIDLTH * 2 + 1]; |
739 | |
740 | /* |
741 | * Don't show empty devices or things that have been |
742 | * suppressed |
743 | */ |
744 | if (get_capacity(disk) == 0 || |
745 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) |
746 | continue; |
747 | |
748 | /* |
749 | * Note, unlike /proc/partitions, I am showing the |
750 | * numbers in hex - the same format as the root= |
751 | * option takes. |
752 | */ |
753 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); |
754 | while ((part = disk_part_iter_next(&piter))) { |
755 | bool is_part0 = part == &disk->part0; |
756 | |
757 | uuid[0] = 0; |
758 | if (part->info) |
759 | part_unpack_uuid(part->info->uuid, uuid); |
760 | |
761 | printk("%s%s %10llu %s %s", is_part0 ? "" : " ", |
762 | bdevt_str(part_devt(part), devt_buf), |
763 | (unsigned long long)part->nr_sects >> 1, |
764 | disk_name(disk, part->partno, name_buf), uuid); |
765 | if (is_part0) { |
766 | if (disk->driverfs_dev != NULL && |
767 | disk->driverfs_dev->driver != NULL) |
768 | printk(" driver: %s\n", |
769 | disk->driverfs_dev->driver->name); |
770 | else |
771 | printk(" (driver?)\n"); |
772 | } else |
773 | printk("\n"); |
774 | } |
775 | disk_part_iter_exit(&piter); |
776 | } |
777 | class_dev_iter_exit(&iter); |
778 | } |
779 | |
780 | #ifdef CONFIG_PROC_FS |
781 | /* iterator */ |
782 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) |
783 | { |
784 | loff_t skip = *pos; |
785 | struct class_dev_iter *iter; |
786 | struct device *dev; |
787 | |
788 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); |
789 | if (!iter) |
790 | return ERR_PTR(-ENOMEM); |
791 | |
792 | seqf->private = iter; |
793 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); |
794 | do { |
795 | dev = class_dev_iter_next(iter); |
796 | if (!dev) |
797 | return NULL; |
798 | } while (skip--); |
799 | |
800 | return dev_to_disk(dev); |
801 | } |
802 | |
803 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) |
804 | { |
805 | struct device *dev; |
806 | |
807 | (*pos)++; |
808 | dev = class_dev_iter_next(seqf->private); |
809 | if (dev) |
810 | return dev_to_disk(dev); |
811 | |
812 | return NULL; |
813 | } |
814 | |
815 | static void disk_seqf_stop(struct seq_file *seqf, void *v) |
816 | { |
817 | struct class_dev_iter *iter = seqf->private; |
818 | |
819 | /* stop is called even after start failed :-( */ |
820 | if (iter) { |
821 | class_dev_iter_exit(iter); |
822 | kfree(iter); |
823 | } |
824 | } |
825 | |
826 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) |
827 | { |
828 | static void *p; |
829 | |
830 | p = disk_seqf_start(seqf, pos); |
831 | if (!IS_ERR_OR_NULL(p) && !*pos) |
832 | seq_puts(seqf, "major minor #blocks name\n\n"); |
833 | return p; |
834 | } |
835 | |
836 | static int show_partition(struct seq_file *seqf, void *v) |
837 | { |
838 | struct gendisk *sgp = v; |
839 | struct disk_part_iter piter; |
840 | struct hd_struct *part; |
841 | char buf[BDEVNAME_SIZE]; |
842 | |
843 | /* Don't show non-partitionable removeable devices or empty devices */ |
844 | if (!get_capacity(sgp) || (!disk_partitionable(sgp) && |
845 | (sgp->flags & GENHD_FL_REMOVABLE))) |
846 | return 0; |
847 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) |
848 | return 0; |
849 | |
850 | /* show the full disk and all non-0 size partitions of it */ |
851 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); |
852 | while ((part = disk_part_iter_next(&piter))) |
853 | seq_printf(seqf, "%4d %7d %10llu %s\n", |
854 | MAJOR(part_devt(part)), MINOR(part_devt(part)), |
855 | (unsigned long long)part->nr_sects >> 1, |
856 | disk_name(sgp, part->partno, buf)); |
857 | disk_part_iter_exit(&piter); |
858 | |
859 | return 0; |
860 | } |
861 | |
862 | static const struct seq_operations partitions_op = { |
863 | .start = show_partition_start, |
864 | .next = disk_seqf_next, |
865 | .stop = disk_seqf_stop, |
866 | .show = show_partition |
867 | }; |
868 | |
869 | static int partitions_open(struct inode *inode, struct file *file) |
870 | { |
871 | return seq_open(file, &partitions_op); |
872 | } |
873 | |
874 | static const struct file_operations proc_partitions_operations = { |
875 | .open = partitions_open, |
876 | .read = seq_read, |
877 | .llseek = seq_lseek, |
878 | .release = seq_release, |
879 | }; |
880 | #endif |
881 | |
882 | |
883 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) |
884 | { |
885 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) |
886 | /* Make old-style 2.4 aliases work */ |
887 | request_module("block-major-%d", MAJOR(devt)); |
888 | return NULL; |
889 | } |
890 | |
891 | static int __init genhd_device_init(void) |
892 | { |
893 | int error; |
894 | |
895 | block_class.dev_kobj = sysfs_dev_block_kobj; |
896 | error = class_register(&block_class); |
897 | if (unlikely(error)) |
898 | return error; |
899 | bdev_map = kobj_map_init(base_probe, &block_class_lock); |
900 | blk_dev_init(); |
901 | |
902 | register_blkdev(BLOCK_EXT_MAJOR, "blkext"); |
903 | |
904 | /* create top-level block dir */ |
905 | if (!sysfs_deprecated) |
906 | block_depr = kobject_create_and_add("block", NULL); |
907 | return 0; |
908 | } |
909 | |
910 | subsys_initcall(genhd_device_init); |
911 | |
912 | static ssize_t disk_range_show(struct device *dev, |
913 | struct device_attribute *attr, char *buf) |
914 | { |
915 | struct gendisk *disk = dev_to_disk(dev); |
916 | |
917 | return sprintf(buf, "%d\n", disk->minors); |
918 | } |
919 | |
920 | static ssize_t disk_ext_range_show(struct device *dev, |
921 | struct device_attribute *attr, char *buf) |
922 | { |
923 | struct gendisk *disk = dev_to_disk(dev); |
924 | |
925 | return sprintf(buf, "%d\n", disk_max_parts(disk)); |
926 | } |
927 | |
928 | static ssize_t disk_removable_show(struct device *dev, |
929 | struct device_attribute *attr, char *buf) |
930 | { |
931 | struct gendisk *disk = dev_to_disk(dev); |
932 | |
933 | return sprintf(buf, "%d\n", |
934 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); |
935 | } |
936 | |
937 | static ssize_t disk_ro_show(struct device *dev, |
938 | struct device_attribute *attr, char *buf) |
939 | { |
940 | struct gendisk *disk = dev_to_disk(dev); |
941 | |
942 | return sprintf(buf, "%d\n", get_disk_ro(disk) ? 1 : 0); |
943 | } |
944 | |
945 | static ssize_t disk_capability_show(struct device *dev, |
946 | struct device_attribute *attr, char *buf) |
947 | { |
948 | struct gendisk *disk = dev_to_disk(dev); |
949 | |
950 | return sprintf(buf, "%x\n", disk->flags); |
951 | } |
952 | |
953 | static ssize_t disk_alignment_offset_show(struct device *dev, |
954 | struct device_attribute *attr, |
955 | char *buf) |
956 | { |
957 | struct gendisk *disk = dev_to_disk(dev); |
958 | |
959 | return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue)); |
960 | } |
961 | |
962 | static ssize_t disk_discard_alignment_show(struct device *dev, |
963 | struct device_attribute *attr, |
964 | char *buf) |
965 | { |
966 | struct gendisk *disk = dev_to_disk(dev); |
967 | |
968 | return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue)); |
969 | } |
970 | |
971 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); |
972 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); |
973 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); |
974 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); |
975 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); |
976 | static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL); |
977 | static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show, |
978 | NULL); |
979 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); |
980 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); |
981 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); |
982 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
983 | static struct device_attribute dev_attr_fail = |
984 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); |
985 | #endif |
986 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
987 | static struct device_attribute dev_attr_fail_timeout = |
988 | __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, |
989 | part_timeout_store); |
990 | #endif |
991 | |
992 | static struct attribute *disk_attrs[] = { |
993 | &dev_attr_range.attr, |
994 | &dev_attr_ext_range.attr, |
995 | &dev_attr_removable.attr, |
996 | &dev_attr_ro.attr, |
997 | &dev_attr_size.attr, |
998 | &dev_attr_alignment_offset.attr, |
999 | &dev_attr_discard_alignment.attr, |
1000 | &dev_attr_capability.attr, |
1001 | &dev_attr_stat.attr, |
1002 | &dev_attr_inflight.attr, |
1003 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
1004 | &dev_attr_fail.attr, |
1005 | #endif |
1006 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
1007 | &dev_attr_fail_timeout.attr, |
1008 | #endif |
1009 | NULL |
1010 | }; |
1011 | |
1012 | static struct attribute_group disk_attr_group = { |
1013 | .attrs = disk_attrs, |
1014 | }; |
1015 | |
1016 | static const struct attribute_group *disk_attr_groups[] = { |
1017 | &disk_attr_group, |
1018 | NULL |
1019 | }; |
1020 | |
1021 | static void disk_free_ptbl_rcu_cb(struct rcu_head *head) |
1022 | { |
1023 | struct disk_part_tbl *ptbl = |
1024 | container_of(head, struct disk_part_tbl, rcu_head); |
1025 | |
1026 | kfree(ptbl); |
1027 | } |
1028 | |
1029 | /** |
1030 | * disk_replace_part_tbl - replace disk->part_tbl in RCU-safe way |
1031 | * @disk: disk to replace part_tbl for |
1032 | * @new_ptbl: new part_tbl to install |
1033 | * |
1034 | * Replace disk->part_tbl with @new_ptbl in RCU-safe way. The |
1035 | * original ptbl is freed using RCU callback. |
1036 | * |
1037 | * LOCKING: |
1038 | * Matching bd_mutx locked. |
1039 | */ |
1040 | static void disk_replace_part_tbl(struct gendisk *disk, |
1041 | struct disk_part_tbl *new_ptbl) |
1042 | { |
1043 | struct disk_part_tbl *old_ptbl = disk->part_tbl; |
1044 | |
1045 | rcu_assign_pointer(disk->part_tbl, new_ptbl); |
1046 | |
1047 | if (old_ptbl) { |
1048 | rcu_assign_pointer(old_ptbl->last_lookup, NULL); |
1049 | call_rcu(&old_ptbl->rcu_head, disk_free_ptbl_rcu_cb); |
1050 | } |
1051 | } |
1052 | |
1053 | /** |
1054 | * disk_expand_part_tbl - expand disk->part_tbl |
1055 | * @disk: disk to expand part_tbl for |
1056 | * @partno: expand such that this partno can fit in |
1057 | * |
1058 | * Expand disk->part_tbl such that @partno can fit in. disk->part_tbl |
1059 | * uses RCU to allow unlocked dereferencing for stats and other stuff. |
1060 | * |
1061 | * LOCKING: |
1062 | * Matching bd_mutex locked, might sleep. |
1063 | * |
1064 | * RETURNS: |
1065 | * 0 on success, -errno on failure. |
1066 | */ |
1067 | int disk_expand_part_tbl(struct gendisk *disk, int partno) |
1068 | { |
1069 | struct disk_part_tbl *old_ptbl = disk->part_tbl; |
1070 | struct disk_part_tbl *new_ptbl; |
1071 | int len = old_ptbl ? old_ptbl->len : 0; |
1072 | int target = partno + 1; |
1073 | size_t size; |
1074 | int i; |
1075 | |
1076 | /* disk_max_parts() is zero during initialization, ignore if so */ |
1077 | if (disk_max_parts(disk) && target > disk_max_parts(disk)) |
1078 | return -EINVAL; |
1079 | |
1080 | if (target <= len) |
1081 | return 0; |
1082 | |
1083 | size = sizeof(*new_ptbl) + target * sizeof(new_ptbl->part[0]); |
1084 | new_ptbl = kzalloc_node(size, GFP_KERNEL, disk->node_id); |
1085 | if (!new_ptbl) |
1086 | return -ENOMEM; |
1087 | |
1088 | new_ptbl->len = target; |
1089 | |
1090 | for (i = 0; i < len; i++) |
1091 | rcu_assign_pointer(new_ptbl->part[i], old_ptbl->part[i]); |
1092 | |
1093 | disk_replace_part_tbl(disk, new_ptbl); |
1094 | return 0; |
1095 | } |
1096 | |
1097 | static void disk_release(struct device *dev) |
1098 | { |
1099 | struct gendisk *disk = dev_to_disk(dev); |
1100 | |
1101 | disk_release_events(disk); |
1102 | kfree(disk->random); |
1103 | disk_replace_part_tbl(disk, NULL); |
1104 | free_part_stats(&disk->part0); |
1105 | free_part_info(&disk->part0); |
1106 | kfree(disk); |
1107 | } |
1108 | struct class block_class = { |
1109 | .name = "block", |
1110 | }; |
1111 | |
1112 | static char *block_devnode(struct device *dev, mode_t *mode) |
1113 | { |
1114 | struct gendisk *disk = dev_to_disk(dev); |
1115 | |
1116 | if (disk->devnode) |
1117 | return disk->devnode(disk, mode); |
1118 | return NULL; |
1119 | } |
1120 | |
1121 | static struct device_type disk_type = { |
1122 | .name = "disk", |
1123 | .groups = disk_attr_groups, |
1124 | .release = disk_release, |
1125 | .devnode = block_devnode, |
1126 | }; |
1127 | |
1128 | #ifdef CONFIG_PROC_FS |
1129 | /* |
1130 | * aggregate disk stat collector. Uses the same stats that the sysfs |
1131 | * entries do, above, but makes them available through one seq_file. |
1132 | * |
1133 | * The output looks suspiciously like /proc/partitions with a bunch of |
1134 | * extra fields. |
1135 | */ |
1136 | static int diskstats_show(struct seq_file *seqf, void *v) |
1137 | { |
1138 | struct gendisk *gp = v; |
1139 | struct disk_part_iter piter; |
1140 | struct hd_struct *hd; |
1141 | char buf[BDEVNAME_SIZE]; |
1142 | int cpu; |
1143 | |
1144 | /* |
1145 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) |
1146 | seq_puts(seqf, "major minor name" |
1147 | " rio rmerge rsect ruse wio wmerge " |
1148 | "wsect wuse running use aveq" |
1149 | "\n\n"); |
1150 | */ |
1151 | |
1152 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); |
1153 | while ((hd = disk_part_iter_next(&piter))) { |
1154 | cpu = part_stat_lock(); |
1155 | part_round_stats(cpu, hd); |
1156 | part_stat_unlock(); |
1157 | seq_printf(seqf, "%4d %7d %s %lu %lu %llu " |
1158 | "%u %lu %lu %llu %u %u %u %u\n", |
1159 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), |
1160 | disk_name(gp, hd->partno, buf), |
1161 | part_stat_read(hd, ios[READ]), |
1162 | part_stat_read(hd, merges[READ]), |
1163 | (unsigned long long)part_stat_read(hd, sectors[READ]), |
1164 | jiffies_to_msecs(part_stat_read(hd, ticks[READ])), |
1165 | part_stat_read(hd, ios[WRITE]), |
1166 | part_stat_read(hd, merges[WRITE]), |
1167 | (unsigned long long)part_stat_read(hd, sectors[WRITE]), |
1168 | jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])), |
1169 | part_in_flight(hd), |
1170 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), |
1171 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) |
1172 | ); |
1173 | } |
1174 | disk_part_iter_exit(&piter); |
1175 | |
1176 | return 0; |
1177 | } |
1178 | |
1179 | static const struct seq_operations diskstats_op = { |
1180 | .start = disk_seqf_start, |
1181 | .next = disk_seqf_next, |
1182 | .stop = disk_seqf_stop, |
1183 | .show = diskstats_show |
1184 | }; |
1185 | |
1186 | static int diskstats_open(struct inode *inode, struct file *file) |
1187 | { |
1188 | return seq_open(file, &diskstats_op); |
1189 | } |
1190 | |
1191 | static const struct file_operations proc_diskstats_operations = { |
1192 | .open = diskstats_open, |
1193 | .read = seq_read, |
1194 | .llseek = seq_lseek, |
1195 | .release = seq_release, |
1196 | }; |
1197 | |
1198 | static int __init proc_genhd_init(void) |
1199 | { |
1200 | proc_create("diskstats", 0, NULL, &proc_diskstats_operations); |
1201 | proc_create("partitions", 0, NULL, &proc_partitions_operations); |
1202 | return 0; |
1203 | } |
1204 | module_init(proc_genhd_init); |
1205 | #endif /* CONFIG_PROC_FS */ |
1206 | |
1207 | dev_t blk_lookup_devt(const char *name, int partno) |
1208 | { |
1209 | dev_t devt = MKDEV(0, 0); |
1210 | struct class_dev_iter iter; |
1211 | struct device *dev; |
1212 | |
1213 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); |
1214 | while ((dev = class_dev_iter_next(&iter))) { |
1215 | struct gendisk *disk = dev_to_disk(dev); |
1216 | struct hd_struct *part; |
1217 | |
1218 | if (strcmp(dev_name(dev), name)) |
1219 | continue; |
1220 | |
1221 | if (partno < disk->minors) { |
1222 | /* We need to return the right devno, even |
1223 | * if the partition doesn't exist yet. |
1224 | */ |
1225 | devt = MKDEV(MAJOR(dev->devt), |
1226 | MINOR(dev->devt) + partno); |
1227 | break; |
1228 | } |
1229 | part = disk_get_part(disk, partno); |
1230 | if (part) { |
1231 | devt = part_devt(part); |
1232 | disk_put_part(part); |
1233 | break; |
1234 | } |
1235 | disk_put_part(part); |
1236 | } |
1237 | class_dev_iter_exit(&iter); |
1238 | return devt; |
1239 | } |
1240 | EXPORT_SYMBOL(blk_lookup_devt); |
1241 | |
1242 | struct gendisk *alloc_disk(int minors) |
1243 | { |
1244 | return alloc_disk_node(minors, -1); |
1245 | } |
1246 | EXPORT_SYMBOL(alloc_disk); |
1247 | |
1248 | struct gendisk *alloc_disk_node(int minors, int node_id) |
1249 | { |
1250 | struct gendisk *disk; |
1251 | |
1252 | disk = kmalloc_node(sizeof(struct gendisk), |
1253 | GFP_KERNEL | __GFP_ZERO, node_id); |
1254 | if (disk) { |
1255 | if (!init_part_stats(&disk->part0)) { |
1256 | kfree(disk); |
1257 | return NULL; |
1258 | } |
1259 | disk->node_id = node_id; |
1260 | if (disk_expand_part_tbl(disk, 0)) { |
1261 | free_part_stats(&disk->part0); |
1262 | kfree(disk); |
1263 | return NULL; |
1264 | } |
1265 | disk->part_tbl->part[0] = &disk->part0; |
1266 | |
1267 | hd_ref_init(&disk->part0); |
1268 | |
1269 | disk->minors = minors; |
1270 | rand_initialize_disk(disk); |
1271 | disk_to_dev(disk)->class = &block_class; |
1272 | disk_to_dev(disk)->type = &disk_type; |
1273 | device_initialize(disk_to_dev(disk)); |
1274 | } |
1275 | return disk; |
1276 | } |
1277 | EXPORT_SYMBOL(alloc_disk_node); |
1278 | |
1279 | struct kobject *get_disk(struct gendisk *disk) |
1280 | { |
1281 | struct module *owner; |
1282 | struct kobject *kobj; |
1283 | |
1284 | if (!disk->fops) |
1285 | return NULL; |
1286 | owner = disk->fops->owner; |
1287 | if (owner && !try_module_get(owner)) |
1288 | return NULL; |
1289 | kobj = kobject_get(&disk_to_dev(disk)->kobj); |
1290 | if (kobj == NULL) { |
1291 | module_put(owner); |
1292 | return NULL; |
1293 | } |
1294 | return kobj; |
1295 | |
1296 | } |
1297 | |
1298 | EXPORT_SYMBOL(get_disk); |
1299 | |
1300 | void put_disk(struct gendisk *disk) |
1301 | { |
1302 | if (disk) |
1303 | kobject_put(&disk_to_dev(disk)->kobj); |
1304 | } |
1305 | |
1306 | EXPORT_SYMBOL(put_disk); |
1307 | |
1308 | static void set_disk_ro_uevent(struct gendisk *gd, int ro) |
1309 | { |
1310 | char event[] = "DISK_RO=1"; |
1311 | char *envp[] = { event, NULL }; |
1312 | |
1313 | if (!ro) |
1314 | event[8] = '0'; |
1315 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); |
1316 | } |
1317 | |
1318 | void set_device_ro(struct block_device *bdev, int flag) |
1319 | { |
1320 | bdev->bd_part->policy = flag; |
1321 | } |
1322 | |
1323 | EXPORT_SYMBOL(set_device_ro); |
1324 | |
1325 | void set_disk_ro(struct gendisk *disk, int flag) |
1326 | { |
1327 | struct disk_part_iter piter; |
1328 | struct hd_struct *part; |
1329 | |
1330 | if (disk->part0.policy != flag) { |
1331 | set_disk_ro_uevent(disk, flag); |
1332 | disk->part0.policy = flag; |
1333 | } |
1334 | |
1335 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); |
1336 | while ((part = disk_part_iter_next(&piter))) |
1337 | part->policy = flag; |
1338 | disk_part_iter_exit(&piter); |
1339 | } |
1340 | |
1341 | EXPORT_SYMBOL(set_disk_ro); |
1342 | |
1343 | int bdev_read_only(struct block_device *bdev) |
1344 | { |
1345 | if (!bdev) |
1346 | return 0; |
1347 | return bdev->bd_part->policy; |
1348 | } |
1349 | |
1350 | EXPORT_SYMBOL(bdev_read_only); |
1351 | |
1352 | int invalidate_partition(struct gendisk *disk, int partno) |
1353 | { |
1354 | int res = 0; |
1355 | struct block_device *bdev = bdget_disk(disk, partno); |
1356 | if (bdev) { |
1357 | fsync_bdev(bdev); |
1358 | res = __invalidate_device(bdev, true); |
1359 | bdput(bdev); |
1360 | } |
1361 | return res; |
1362 | } |
1363 | |
1364 | EXPORT_SYMBOL(invalidate_partition); |
1365 | |
1366 | /* |
1367 | * Disk events - monitor disk events like media change and eject request. |
1368 | */ |
1369 | struct disk_events { |
1370 | struct list_head node; /* all disk_event's */ |
1371 | struct gendisk *disk; /* the associated disk */ |
1372 | spinlock_t lock; |
1373 | |
1374 | int block; /* event blocking depth */ |
1375 | unsigned int pending; /* events already sent out */ |
1376 | unsigned int clearing; /* events being cleared */ |
1377 | |
1378 | long poll_msecs; /* interval, -1 for default */ |
1379 | struct delayed_work dwork; |
1380 | }; |
1381 | |
1382 | static const char *disk_events_strs[] = { |
1383 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change", |
1384 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request", |
1385 | }; |
1386 | |
1387 | static char *disk_uevents[] = { |
1388 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1", |
1389 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1", |
1390 | }; |
1391 | |
1392 | /* list of all disk_events */ |
1393 | static DEFINE_MUTEX(disk_events_mutex); |
1394 | static LIST_HEAD(disk_events); |
1395 | |
1396 | /* disable in-kernel polling by default */ |
1397 | static unsigned long disk_events_dfl_poll_msecs = 0; |
1398 | |
1399 | static unsigned long disk_events_poll_jiffies(struct gendisk *disk) |
1400 | { |
1401 | struct disk_events *ev = disk->ev; |
1402 | long intv_msecs = 0; |
1403 | |
1404 | /* |
1405 | * If device-specific poll interval is set, always use it. If |
1406 | * the default is being used, poll iff there are events which |
1407 | * can't be monitored asynchronously. |
1408 | */ |
1409 | if (ev->poll_msecs >= 0) |
1410 | intv_msecs = ev->poll_msecs; |
1411 | else if (disk->events & ~disk->async_events) |
1412 | intv_msecs = disk_events_dfl_poll_msecs; |
1413 | |
1414 | return msecs_to_jiffies(intv_msecs); |
1415 | } |
1416 | |
1417 | static void __disk_block_events(struct gendisk *disk, bool sync) |
1418 | { |
1419 | struct disk_events *ev = disk->ev; |
1420 | unsigned long flags; |
1421 | bool cancel; |
1422 | |
1423 | spin_lock_irqsave(&ev->lock, flags); |
1424 | cancel = !ev->block++; |
1425 | spin_unlock_irqrestore(&ev->lock, flags); |
1426 | |
1427 | if (cancel) { |
1428 | if (sync) |
1429 | cancel_delayed_work_sync(&disk->ev->dwork); |
1430 | else |
1431 | cancel_delayed_work(&disk->ev->dwork); |
1432 | } |
1433 | } |
1434 | |
1435 | static void __disk_unblock_events(struct gendisk *disk, bool check_now) |
1436 | { |
1437 | struct disk_events *ev = disk->ev; |
1438 | unsigned long intv; |
1439 | unsigned long flags; |
1440 | |
1441 | spin_lock_irqsave(&ev->lock, flags); |
1442 | |
1443 | if (WARN_ON_ONCE(ev->block <= 0)) |
1444 | goto out_unlock; |
1445 | |
1446 | if (--ev->block) |
1447 | goto out_unlock; |
1448 | |
1449 | /* |
1450 | * Not exactly a latency critical operation, set poll timer |
1451 | * slack to 25% and kick event check. |
1452 | */ |
1453 | intv = disk_events_poll_jiffies(disk); |
1454 | set_timer_slack(&ev->dwork.timer, intv / 4); |
1455 | if (check_now) |
1456 | queue_delayed_work(system_nrt_wq, &ev->dwork, 0); |
1457 | else if (intv) |
1458 | queue_delayed_work(system_nrt_wq, &ev->dwork, intv); |
1459 | out_unlock: |
1460 | spin_unlock_irqrestore(&ev->lock, flags); |
1461 | } |
1462 | |
1463 | /** |
1464 | * disk_block_events - block and flush disk event checking |
1465 | * @disk: disk to block events for |
1466 | * |
1467 | * On return from this function, it is guaranteed that event checking |
1468 | * isn't in progress and won't happen until unblocked by |
1469 | * disk_unblock_events(). Events blocking is counted and the actual |
1470 | * unblocking happens after the matching number of unblocks are done. |
1471 | * |
1472 | * Note that this intentionally does not block event checking from |
1473 | * disk_clear_events(). |
1474 | * |
1475 | * CONTEXT: |
1476 | * Might sleep. |
1477 | */ |
1478 | void disk_block_events(struct gendisk *disk) |
1479 | { |
1480 | if (disk->ev) |
1481 | __disk_block_events(disk, true); |
1482 | } |
1483 | |
1484 | /** |
1485 | * disk_unblock_events - unblock disk event checking |
1486 | * @disk: disk to unblock events for |
1487 | * |
1488 | * Undo disk_block_events(). When the block count reaches zero, it |
1489 | * starts events polling if configured. |
1490 | * |
1491 | * CONTEXT: |
1492 | * Don't care. Safe to call from irq context. |
1493 | */ |
1494 | void disk_unblock_events(struct gendisk *disk) |
1495 | { |
1496 | if (disk->ev) |
1497 | __disk_unblock_events(disk, false); |
1498 | } |
1499 | |
1500 | /** |
1501 | * disk_check_events - schedule immediate event checking |
1502 | * @disk: disk to check events for |
1503 | * |
1504 | * Schedule immediate event checking on @disk if not blocked. |
1505 | * |
1506 | * CONTEXT: |
1507 | * Don't care. Safe to call from irq context. |
1508 | */ |
1509 | void disk_check_events(struct gendisk *disk) |
1510 | { |
1511 | if (disk->ev) { |
1512 | __disk_block_events(disk, false); |
1513 | __disk_unblock_events(disk, true); |
1514 | } |
1515 | } |
1516 | EXPORT_SYMBOL_GPL(disk_check_events); |
1517 | |
1518 | /** |
1519 | * disk_clear_events - synchronously check, clear and return pending events |
1520 | * @disk: disk to fetch and clear events from |
1521 | * @mask: mask of events to be fetched and clearted |
1522 | * |
1523 | * Disk events are synchronously checked and pending events in @mask |
1524 | * are cleared and returned. This ignores the block count. |
1525 | * |
1526 | * CONTEXT: |
1527 | * Might sleep. |
1528 | */ |
1529 | unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) |
1530 | { |
1531 | const struct block_device_operations *bdops = disk->fops; |
1532 | struct disk_events *ev = disk->ev; |
1533 | unsigned int pending; |
1534 | |
1535 | if (!ev) { |
1536 | /* for drivers still using the old ->media_changed method */ |
1537 | if ((mask & DISK_EVENT_MEDIA_CHANGE) && |
1538 | bdops->media_changed && bdops->media_changed(disk)) |
1539 | return DISK_EVENT_MEDIA_CHANGE; |
1540 | return 0; |
1541 | } |
1542 | |
1543 | /* tell the workfn about the events being cleared */ |
1544 | spin_lock_irq(&ev->lock); |
1545 | ev->clearing |= mask; |
1546 | spin_unlock_irq(&ev->lock); |
1547 | |
1548 | /* uncondtionally schedule event check and wait for it to finish */ |
1549 | __disk_block_events(disk, true); |
1550 | queue_delayed_work(system_nrt_wq, &ev->dwork, 0); |
1551 | flush_delayed_work(&ev->dwork); |
1552 | __disk_unblock_events(disk, false); |
1553 | |
1554 | /* then, fetch and clear pending events */ |
1555 | spin_lock_irq(&ev->lock); |
1556 | WARN_ON_ONCE(ev->clearing & mask); /* cleared by workfn */ |
1557 | pending = ev->pending & mask; |
1558 | ev->pending &= ~mask; |
1559 | spin_unlock_irq(&ev->lock); |
1560 | |
1561 | return pending; |
1562 | } |
1563 | |
1564 | static void disk_events_workfn(struct work_struct *work) |
1565 | { |
1566 | struct delayed_work *dwork = to_delayed_work(work); |
1567 | struct disk_events *ev = container_of(dwork, struct disk_events, dwork); |
1568 | struct gendisk *disk = ev->disk; |
1569 | char *envp[ARRAY_SIZE(disk_uevents) + 1] = { }; |
1570 | unsigned int clearing = ev->clearing; |
1571 | unsigned int events; |
1572 | unsigned long intv; |
1573 | int nr_events = 0, i; |
1574 | |
1575 | /* check events */ |
1576 | events = disk->fops->check_events(disk, clearing); |
1577 | |
1578 | /* accumulate pending events and schedule next poll if necessary */ |
1579 | spin_lock_irq(&ev->lock); |
1580 | |
1581 | events &= ~ev->pending; |
1582 | ev->pending |= events; |
1583 | ev->clearing &= ~clearing; |
1584 | |
1585 | intv = disk_events_poll_jiffies(disk); |
1586 | if (!ev->block && intv) |
1587 | queue_delayed_work(system_nrt_wq, &ev->dwork, intv); |
1588 | |
1589 | spin_unlock_irq(&ev->lock); |
1590 | |
1591 | /* |
1592 | * Tell userland about new events. Only the events listed in |
1593 | * @disk->events are reported. Unlisted events are processed the |
1594 | * same internally but never get reported to userland. |
1595 | */ |
1596 | for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) |
1597 | if (events & disk->events & (1 << i)) |
1598 | envp[nr_events++] = disk_uevents[i]; |
1599 | |
1600 | if (nr_events) |
1601 | kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); |
1602 | } |
1603 | |
1604 | /* |
1605 | * A disk events enabled device has the following sysfs nodes under |
1606 | * its /sys/block/X/ directory. |
1607 | * |
1608 | * events : list of all supported events |
1609 | * events_async : list of events which can be detected w/o polling |
1610 | * events_poll_msecs : polling interval, 0: disable, -1: system default |
1611 | */ |
1612 | static ssize_t __disk_events_show(unsigned int events, char *buf) |
1613 | { |
1614 | const char *delim = ""; |
1615 | ssize_t pos = 0; |
1616 | int i; |
1617 | |
1618 | for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++) |
1619 | if (events & (1 << i)) { |
1620 | pos += sprintf(buf + pos, "%s%s", |
1621 | delim, disk_events_strs[i]); |
1622 | delim = " "; |
1623 | } |
1624 | if (pos) |
1625 | pos += sprintf(buf + pos, "\n"); |
1626 | return pos; |
1627 | } |
1628 | |
1629 | static ssize_t disk_events_show(struct device *dev, |
1630 | struct device_attribute *attr, char *buf) |
1631 | { |
1632 | struct gendisk *disk = dev_to_disk(dev); |
1633 | |
1634 | return __disk_events_show(disk->events, buf); |
1635 | } |
1636 | |
1637 | static ssize_t disk_events_async_show(struct device *dev, |
1638 | struct device_attribute *attr, char *buf) |
1639 | { |
1640 | struct gendisk *disk = dev_to_disk(dev); |
1641 | |
1642 | return __disk_events_show(disk->async_events, buf); |
1643 | } |
1644 | |
1645 | static ssize_t disk_events_poll_msecs_show(struct device *dev, |
1646 | struct device_attribute *attr, |
1647 | char *buf) |
1648 | { |
1649 | struct gendisk *disk = dev_to_disk(dev); |
1650 | |
1651 | return sprintf(buf, "%ld\n", disk->ev->poll_msecs); |
1652 | } |
1653 | |
1654 | static ssize_t disk_events_poll_msecs_store(struct device *dev, |
1655 | struct device_attribute *attr, |
1656 | const char *buf, size_t count) |
1657 | { |
1658 | struct gendisk *disk = dev_to_disk(dev); |
1659 | long intv; |
1660 | |
1661 | if (!count || !sscanf(buf, "%ld", &intv)) |
1662 | return -EINVAL; |
1663 | |
1664 | if (intv < 0 && intv != -1) |
1665 | return -EINVAL; |
1666 | |
1667 | __disk_block_events(disk, true); |
1668 | disk->ev->poll_msecs = intv; |
1669 | __disk_unblock_events(disk, true); |
1670 | |
1671 | return count; |
1672 | } |
1673 | |
1674 | static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL); |
1675 | static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL); |
1676 | static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR, |
1677 | disk_events_poll_msecs_show, |
1678 | disk_events_poll_msecs_store); |
1679 | |
1680 | static const struct attribute *disk_events_attrs[] = { |
1681 | &dev_attr_events.attr, |
1682 | &dev_attr_events_async.attr, |
1683 | &dev_attr_events_poll_msecs.attr, |
1684 | NULL, |
1685 | }; |
1686 | |
1687 | /* |
1688 | * The default polling interval can be specified by the kernel |
1689 | * parameter block.events_dfl_poll_msecs which defaults to 0 |
1690 | * (disable). This can also be modified runtime by writing to |
1691 | * /sys/module/block/events_dfl_poll_msecs. |
1692 | */ |
1693 | static int disk_events_set_dfl_poll_msecs(const char *val, |
1694 | const struct kernel_param *kp) |
1695 | { |
1696 | struct disk_events *ev; |
1697 | int ret; |
1698 | |
1699 | ret = param_set_ulong(val, kp); |
1700 | if (ret < 0) |
1701 | return ret; |
1702 | |
1703 | mutex_lock(&disk_events_mutex); |
1704 | |
1705 | list_for_each_entry(ev, &disk_events, node) |
1706 | disk_check_events(ev->disk); |
1707 | |
1708 | mutex_unlock(&disk_events_mutex); |
1709 | |
1710 | return 0; |
1711 | } |
1712 | |
1713 | static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = { |
1714 | .set = disk_events_set_dfl_poll_msecs, |
1715 | .get = param_get_ulong, |
1716 | }; |
1717 | |
1718 | #undef MODULE_PARAM_PREFIX |
1719 | #define MODULE_PARAM_PREFIX "block." |
1720 | |
1721 | module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, |
1722 | &disk_events_dfl_poll_msecs, 0644); |
1723 | |
1724 | /* |
1725 | * disk_{add|del|release}_events - initialize and destroy disk_events. |
1726 | */ |
1727 | static void disk_add_events(struct gendisk *disk) |
1728 | { |
1729 | struct disk_events *ev; |
1730 | |
1731 | if (!disk->fops->check_events || !(disk->events | disk->async_events)) |
1732 | return; |
1733 | |
1734 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); |
1735 | if (!ev) { |
1736 | pr_warn("%s: failed to initialize events\n", disk->disk_name); |
1737 | return; |
1738 | } |
1739 | |
1740 | if (sysfs_create_files(&disk_to_dev(disk)->kobj, |
1741 | disk_events_attrs) < 0) { |
1742 | pr_warn("%s: failed to create sysfs files for events\n", |
1743 | disk->disk_name); |
1744 | kfree(ev); |
1745 | return; |
1746 | } |
1747 | |
1748 | disk->ev = ev; |
1749 | |
1750 | INIT_LIST_HEAD(&ev->node); |
1751 | ev->disk = disk; |
1752 | spin_lock_init(&ev->lock); |
1753 | ev->block = 1; |
1754 | ev->poll_msecs = -1; |
1755 | INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); |
1756 | |
1757 | mutex_lock(&disk_events_mutex); |
1758 | list_add_tail(&ev->node, &disk_events); |
1759 | mutex_unlock(&disk_events_mutex); |
1760 | |
1761 | /* |
1762 | * Block count is initialized to 1 and the following initial |
1763 | * unblock kicks it into action. |
1764 | */ |
1765 | __disk_unblock_events(disk, true); |
1766 | } |
1767 | |
1768 | static void disk_del_events(struct gendisk *disk) |
1769 | { |
1770 | if (!disk->ev) |
1771 | return; |
1772 | |
1773 | __disk_block_events(disk, true); |
1774 | |
1775 | mutex_lock(&disk_events_mutex); |
1776 | list_del_init(&disk->ev->node); |
1777 | mutex_unlock(&disk_events_mutex); |
1778 | |
1779 | sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); |
1780 | } |
1781 | |
1782 | static void disk_release_events(struct gendisk *disk) |
1783 | { |
1784 | /* the block count should be 1 from disk_del_events() */ |
1785 | WARN_ON_ONCE(disk->ev && disk->ev->block != 1); |
1786 | kfree(disk->ev); |
1787 | } |
1788 |
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