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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/mutex.h> |
19 | #include <linux/idr.h> |
20 | #include <linux/log2.h> |
21 | #include <linux/pm_runtime.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 NR_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_check_events(struct disk_events *ev, |
40 | unsigned int *clearing_ptr); |
41 | static void disk_alloc_events(struct gendisk *disk); |
42 | static void disk_add_events(struct gendisk *disk); |
43 | static void disk_del_events(struct gendisk *disk); |
44 | static void disk_release_events(struct gendisk *disk); |
45 | |
46 | /** |
47 | * disk_get_part - get partition |
48 | * @disk: disk to look partition from |
49 | * @partno: partition number |
50 | * |
51 | * Look for partition @partno from @disk. If found, increment |
52 | * reference count and return it. |
53 | * |
54 | * CONTEXT: |
55 | * Don't care. |
56 | * |
57 | * RETURNS: |
58 | * Pointer to the found partition on success, NULL if not found. |
59 | */ |
60 | struct hd_struct *disk_get_part(struct gendisk *disk, int partno) |
61 | { |
62 | struct hd_struct *part = NULL; |
63 | struct disk_part_tbl *ptbl; |
64 | |
65 | if (unlikely(partno < 0)) |
66 | return NULL; |
67 | |
68 | rcu_read_lock(); |
69 | |
70 | ptbl = rcu_dereference(disk->part_tbl); |
71 | if (likely(partno < ptbl->len)) { |
72 | part = rcu_dereference(ptbl->part[partno]); |
73 | if (part) |
74 | get_device(part_to_dev(part)); |
75 | } |
76 | |
77 | rcu_read_unlock(); |
78 | |
79 | return part; |
80 | } |
81 | EXPORT_SYMBOL_GPL(disk_get_part); |
82 | |
83 | /** |
84 | * disk_part_iter_init - initialize partition iterator |
85 | * @piter: iterator to initialize |
86 | * @disk: disk to iterate over |
87 | * @flags: DISK_PITER_* flags |
88 | * |
89 | * Initialize @piter so that it iterates over partitions of @disk. |
90 | * |
91 | * CONTEXT: |
92 | * Don't care. |
93 | */ |
94 | void disk_part_iter_init(struct disk_part_iter *piter, struct gendisk *disk, |
95 | unsigned int flags) |
96 | { |
97 | struct disk_part_tbl *ptbl; |
98 | |
99 | rcu_read_lock(); |
100 | ptbl = rcu_dereference(disk->part_tbl); |
101 | |
102 | piter->disk = disk; |
103 | piter->part = NULL; |
104 | |
105 | if (flags & DISK_PITER_REVERSE) |
106 | piter->idx = ptbl->len - 1; |
107 | else if (flags & (DISK_PITER_INCL_PART0 | DISK_PITER_INCL_EMPTY_PART0)) |
108 | piter->idx = 0; |
109 | else |
110 | piter->idx = 1; |
111 | |
112 | piter->flags = flags; |
113 | |
114 | rcu_read_unlock(); |
115 | } |
116 | EXPORT_SYMBOL_GPL(disk_part_iter_init); |
117 | |
118 | /** |
119 | * disk_part_iter_next - proceed iterator to the next partition and return it |
120 | * @piter: iterator of interest |
121 | * |
122 | * Proceed @piter to the next partition and return it. |
123 | * |
124 | * CONTEXT: |
125 | * Don't care. |
126 | */ |
127 | struct hd_struct *disk_part_iter_next(struct disk_part_iter *piter) |
128 | { |
129 | struct disk_part_tbl *ptbl; |
130 | int inc, end; |
131 | |
132 | /* put the last partition */ |
133 | disk_put_part(piter->part); |
134 | piter->part = NULL; |
135 | |
136 | /* get part_tbl */ |
137 | rcu_read_lock(); |
138 | ptbl = rcu_dereference(piter->disk->part_tbl); |
139 | |
140 | /* determine iteration parameters */ |
141 | if (piter->flags & DISK_PITER_REVERSE) { |
142 | inc = -1; |
143 | if (piter->flags & (DISK_PITER_INCL_PART0 | |
144 | DISK_PITER_INCL_EMPTY_PART0)) |
145 | end = -1; |
146 | else |
147 | end = 0; |
148 | } else { |
149 | inc = 1; |
150 | end = ptbl->len; |
151 | } |
152 | |
153 | /* iterate to the next partition */ |
154 | for (; piter->idx != end; piter->idx += inc) { |
155 | struct hd_struct *part; |
156 | |
157 | part = rcu_dereference(ptbl->part[piter->idx]); |
158 | if (!part) |
159 | continue; |
160 | if (!part_nr_sects_read(part) && |
161 | !(piter->flags & DISK_PITER_INCL_EMPTY) && |
162 | !(piter->flags & DISK_PITER_INCL_EMPTY_PART0 && |
163 | piter->idx == 0)) |
164 | continue; |
165 | |
166 | get_device(part_to_dev(part)); |
167 | piter->part = part; |
168 | piter->idx += inc; |
169 | break; |
170 | } |
171 | |
172 | rcu_read_unlock(); |
173 | |
174 | return piter->part; |
175 | } |
176 | EXPORT_SYMBOL_GPL(disk_part_iter_next); |
177 | |
178 | /** |
179 | * disk_part_iter_exit - finish up partition iteration |
180 | * @piter: iter of interest |
181 | * |
182 | * Called when iteration is over. Cleans up @piter. |
183 | * |
184 | * CONTEXT: |
185 | * Don't care. |
186 | */ |
187 | void disk_part_iter_exit(struct disk_part_iter *piter) |
188 | { |
189 | disk_put_part(piter->part); |
190 | piter->part = NULL; |
191 | } |
192 | EXPORT_SYMBOL_GPL(disk_part_iter_exit); |
193 | |
194 | static inline int sector_in_part(struct hd_struct *part, sector_t sector) |
195 | { |
196 | return part->start_sect <= sector && |
197 | sector < part->start_sect + part_nr_sects_read(part); |
198 | } |
199 | |
200 | /** |
201 | * disk_map_sector_rcu - map sector to partition |
202 | * @disk: gendisk of interest |
203 | * @sector: sector to map |
204 | * |
205 | * Find out which partition @sector maps to on @disk. This is |
206 | * primarily used for stats accounting. |
207 | * |
208 | * CONTEXT: |
209 | * RCU read locked. The returned partition pointer is valid only |
210 | * while preemption is disabled. |
211 | * |
212 | * RETURNS: |
213 | * Found partition on success, part0 is returned if no partition matches |
214 | */ |
215 | struct hd_struct *disk_map_sector_rcu(struct gendisk *disk, sector_t sector) |
216 | { |
217 | struct disk_part_tbl *ptbl; |
218 | struct hd_struct *part; |
219 | int i; |
220 | |
221 | ptbl = rcu_dereference(disk->part_tbl); |
222 | |
223 | part = rcu_dereference(ptbl->last_lookup); |
224 | if (part && sector_in_part(part, sector)) |
225 | return part; |
226 | |
227 | for (i = 1; i < ptbl->len; i++) { |
228 | part = rcu_dereference(ptbl->part[i]); |
229 | |
230 | if (part && sector_in_part(part, sector)) { |
231 | rcu_assign_pointer(ptbl->last_lookup, part); |
232 | return part; |
233 | } |
234 | } |
235 | return &disk->part0; |
236 | } |
237 | EXPORT_SYMBOL_GPL(disk_map_sector_rcu); |
238 | |
239 | /* |
240 | * Can be deleted altogether. Later. |
241 | * |
242 | */ |
243 | static struct blk_major_name { |
244 | struct blk_major_name *next; |
245 | int major; |
246 | char name[16]; |
247 | } *major_names[BLKDEV_MAJOR_HASH_SIZE]; |
248 | |
249 | /* index in the above - for now: assume no multimajor ranges */ |
250 | static inline int major_to_index(unsigned major) |
251 | { |
252 | return major % BLKDEV_MAJOR_HASH_SIZE; |
253 | } |
254 | |
255 | #ifdef CONFIG_PROC_FS |
256 | void blkdev_show(struct seq_file *seqf, off_t offset) |
257 | { |
258 | struct blk_major_name *dp; |
259 | |
260 | if (offset < BLKDEV_MAJOR_HASH_SIZE) { |
261 | mutex_lock(&block_class_lock); |
262 | for (dp = major_names[offset]; dp; dp = dp->next) |
263 | seq_printf(seqf, "%3d %s\n", dp->major, dp->name); |
264 | mutex_unlock(&block_class_lock); |
265 | } |
266 | } |
267 | #endif /* CONFIG_PROC_FS */ |
268 | |
269 | /** |
270 | * register_blkdev - register a new block device |
271 | * |
272 | * @major: the requested major device number [1..255]. If @major=0, try to |
273 | * allocate any unused major number. |
274 | * @name: the name of the new block device as a zero terminated string |
275 | * |
276 | * The @name must be unique within the system. |
277 | * |
278 | * The return value depends on the @major input parameter. |
279 | * - if a major device number was requested in range [1..255] then the |
280 | * function returns zero on success, or a negative error code |
281 | * - if any unused major number was requested with @major=0 parameter |
282 | * then the return value is the allocated major number in range |
283 | * [1..255] or a negative error code otherwise |
284 | */ |
285 | int register_blkdev(unsigned int major, const char *name) |
286 | { |
287 | struct blk_major_name **n, *p; |
288 | int index, ret = 0; |
289 | |
290 | mutex_lock(&block_class_lock); |
291 | |
292 | /* temporary */ |
293 | if (major == 0) { |
294 | for (index = ARRAY_SIZE(major_names)-1; index > 0; index--) { |
295 | if (major_names[index] == NULL) |
296 | break; |
297 | } |
298 | |
299 | if (index == 0) { |
300 | printk("register_blkdev: failed to get major for %s\n", |
301 | name); |
302 | ret = -EBUSY; |
303 | goto out; |
304 | } |
305 | major = index; |
306 | ret = major; |
307 | } |
308 | |
309 | p = kmalloc(sizeof(struct blk_major_name), GFP_KERNEL); |
310 | if (p == NULL) { |
311 | ret = -ENOMEM; |
312 | goto out; |
313 | } |
314 | |
315 | p->major = major; |
316 | strlcpy(p->name, name, sizeof(p->name)); |
317 | p->next = NULL; |
318 | index = major_to_index(major); |
319 | |
320 | for (n = &major_names[index]; *n; n = &(*n)->next) { |
321 | if ((*n)->major == major) |
322 | break; |
323 | } |
324 | if (!*n) |
325 | *n = p; |
326 | else |
327 | ret = -EBUSY; |
328 | |
329 | if (ret < 0) { |
330 | printk("register_blkdev: cannot get major %d for %s\n", |
331 | major, name); |
332 | kfree(p); |
333 | } |
334 | out: |
335 | mutex_unlock(&block_class_lock); |
336 | return ret; |
337 | } |
338 | |
339 | EXPORT_SYMBOL(register_blkdev); |
340 | |
341 | void unregister_blkdev(unsigned int major, const char *name) |
342 | { |
343 | struct blk_major_name **n; |
344 | struct blk_major_name *p = NULL; |
345 | int index = major_to_index(major); |
346 | |
347 | mutex_lock(&block_class_lock); |
348 | for (n = &major_names[index]; *n; n = &(*n)->next) |
349 | if ((*n)->major == major) |
350 | break; |
351 | if (!*n || strcmp((*n)->name, name)) { |
352 | WARN_ON(1); |
353 | } else { |
354 | p = *n; |
355 | *n = p->next; |
356 | } |
357 | mutex_unlock(&block_class_lock); |
358 | kfree(p); |
359 | } |
360 | |
361 | EXPORT_SYMBOL(unregister_blkdev); |
362 | |
363 | static struct kobj_map *bdev_map; |
364 | |
365 | /** |
366 | * blk_mangle_minor - scatter minor numbers apart |
367 | * @minor: minor number to mangle |
368 | * |
369 | * Scatter consecutively allocated @minor number apart if MANGLE_DEVT |
370 | * is enabled. Mangling twice gives the original value. |
371 | * |
372 | * RETURNS: |
373 | * Mangled value. |
374 | * |
375 | * CONTEXT: |
376 | * Don't care. |
377 | */ |
378 | static int blk_mangle_minor(int minor) |
379 | { |
380 | #ifdef CONFIG_DEBUG_BLOCK_EXT_DEVT |
381 | int i; |
382 | |
383 | for (i = 0; i < MINORBITS / 2; i++) { |
384 | int low = minor & (1 << i); |
385 | int high = minor & (1 << (MINORBITS - 1 - i)); |
386 | int distance = MINORBITS - 1 - 2 * i; |
387 | |
388 | minor ^= low | high; /* clear both bits */ |
389 | low <<= distance; /* swap the positions */ |
390 | high >>= distance; |
391 | minor |= low | high; /* and set */ |
392 | } |
393 | #endif |
394 | return minor; |
395 | } |
396 | |
397 | /** |
398 | * blk_alloc_devt - allocate a dev_t for a partition |
399 | * @part: partition to allocate dev_t for |
400 | * @devt: out parameter for resulting dev_t |
401 | * |
402 | * Allocate a dev_t for block device. |
403 | * |
404 | * RETURNS: |
405 | * 0 on success, allocated dev_t is returned in *@devt. -errno on |
406 | * failure. |
407 | * |
408 | * CONTEXT: |
409 | * Might sleep. |
410 | */ |
411 | int blk_alloc_devt(struct hd_struct *part, dev_t *devt) |
412 | { |
413 | struct gendisk *disk = part_to_disk(part); |
414 | int idx; |
415 | |
416 | /* in consecutive minor range? */ |
417 | if (part->partno < disk->minors) { |
418 | *devt = MKDEV(disk->major, disk->first_minor + part->partno); |
419 | return 0; |
420 | } |
421 | |
422 | /* allocate ext devt */ |
423 | mutex_lock(&ext_devt_mutex); |
424 | idx = idr_alloc(&ext_devt_idr, part, 0, NR_EXT_DEVT, GFP_KERNEL); |
425 | mutex_unlock(&ext_devt_mutex); |
426 | if (idx < 0) |
427 | return idx == -ENOSPC ? -EBUSY : idx; |
428 | |
429 | *devt = MKDEV(BLOCK_EXT_MAJOR, blk_mangle_minor(idx)); |
430 | return 0; |
431 | } |
432 | |
433 | /** |
434 | * blk_free_devt - free a dev_t |
435 | * @devt: dev_t to free |
436 | * |
437 | * Free @devt which was allocated using blk_alloc_devt(). |
438 | * |
439 | * CONTEXT: |
440 | * Might sleep. |
441 | */ |
442 | void blk_free_devt(dev_t devt) |
443 | { |
444 | might_sleep(); |
445 | |
446 | if (devt == MKDEV(0, 0)) |
447 | return; |
448 | |
449 | if (MAJOR(devt) == BLOCK_EXT_MAJOR) { |
450 | mutex_lock(&ext_devt_mutex); |
451 | idr_remove(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); |
452 | mutex_unlock(&ext_devt_mutex); |
453 | } |
454 | } |
455 | |
456 | static char *bdevt_str(dev_t devt, char *buf) |
457 | { |
458 | if (MAJOR(devt) <= 0xff && MINOR(devt) <= 0xff) { |
459 | char tbuf[BDEVT_SIZE]; |
460 | snprintf(tbuf, BDEVT_SIZE, "%02x%02x", MAJOR(devt), MINOR(devt)); |
461 | snprintf(buf, BDEVT_SIZE, "%-9s", tbuf); |
462 | } else |
463 | snprintf(buf, BDEVT_SIZE, "%03x:%05x", MAJOR(devt), MINOR(devt)); |
464 | |
465 | return buf; |
466 | } |
467 | |
468 | /* |
469 | * Register device numbers dev..(dev+range-1) |
470 | * range must be nonzero |
471 | * The hash chain is sorted on range, so that subranges can override. |
472 | */ |
473 | void blk_register_region(dev_t devt, unsigned long range, struct module *module, |
474 | struct kobject *(*probe)(dev_t, int *, void *), |
475 | int (*lock)(dev_t, void *), void *data) |
476 | { |
477 | kobj_map(bdev_map, devt, range, module, probe, lock, data); |
478 | } |
479 | |
480 | EXPORT_SYMBOL(blk_register_region); |
481 | |
482 | void blk_unregister_region(dev_t devt, unsigned long range) |
483 | { |
484 | kobj_unmap(bdev_map, devt, range); |
485 | } |
486 | |
487 | EXPORT_SYMBOL(blk_unregister_region); |
488 | |
489 | static struct kobject *exact_match(dev_t devt, int *partno, void *data) |
490 | { |
491 | struct gendisk *p = data; |
492 | |
493 | return &disk_to_dev(p)->kobj; |
494 | } |
495 | |
496 | static int exact_lock(dev_t devt, void *data) |
497 | { |
498 | struct gendisk *p = data; |
499 | |
500 | if (!get_disk(p)) |
501 | return -1; |
502 | return 0; |
503 | } |
504 | |
505 | static void register_disk(struct gendisk *disk) |
506 | { |
507 | struct device *ddev = disk_to_dev(disk); |
508 | struct block_device *bdev; |
509 | struct disk_part_iter piter; |
510 | struct hd_struct *part; |
511 | int err; |
512 | |
513 | ddev->parent = disk->driverfs_dev; |
514 | |
515 | dev_set_name(ddev, disk->disk_name); |
516 | |
517 | /* delay uevents, until we scanned partition table */ |
518 | dev_set_uevent_suppress(ddev, 1); |
519 | |
520 | if (device_add(ddev)) |
521 | return; |
522 | if (!sysfs_deprecated) { |
523 | err = sysfs_create_link(block_depr, &ddev->kobj, |
524 | kobject_name(&ddev->kobj)); |
525 | if (err) { |
526 | device_del(ddev); |
527 | return; |
528 | } |
529 | } |
530 | |
531 | /* |
532 | * avoid probable deadlock caused by allocating memory with |
533 | * GFP_KERNEL in runtime_resume callback of its all ancestor |
534 | * devices |
535 | */ |
536 | pm_runtime_set_memalloc_noio(ddev, true); |
537 | |
538 | disk->part0.holder_dir = kobject_create_and_add("holders", &ddev->kobj); |
539 | disk->slave_dir = kobject_create_and_add("slaves", &ddev->kobj); |
540 | |
541 | /* No minors to use for partitions */ |
542 | if (!disk_part_scan_enabled(disk)) |
543 | goto exit; |
544 | |
545 | /* No such device (e.g., media were just removed) */ |
546 | if (!get_capacity(disk)) |
547 | goto exit; |
548 | |
549 | bdev = bdget_disk(disk, 0); |
550 | if (!bdev) |
551 | goto exit; |
552 | |
553 | bdev->bd_invalidated = 1; |
554 | err = blkdev_get(bdev, FMODE_READ, NULL); |
555 | if (err < 0) |
556 | goto exit; |
557 | blkdev_put(bdev, FMODE_READ); |
558 | |
559 | exit: |
560 | /* announce disk after possible partitions are created */ |
561 | dev_set_uevent_suppress(ddev, 0); |
562 | kobject_uevent(&ddev->kobj, KOBJ_ADD); |
563 | |
564 | /* announce possible partitions */ |
565 | disk_part_iter_init(&piter, disk, 0); |
566 | while ((part = disk_part_iter_next(&piter))) |
567 | kobject_uevent(&part_to_dev(part)->kobj, KOBJ_ADD); |
568 | disk_part_iter_exit(&piter); |
569 | } |
570 | |
571 | /** |
572 | * add_disk - add partitioning information to kernel list |
573 | * @disk: per-device partitioning information |
574 | * |
575 | * This function registers the partitioning information in @disk |
576 | * with the kernel. |
577 | * |
578 | * FIXME: error handling |
579 | */ |
580 | void add_disk(struct gendisk *disk) |
581 | { |
582 | struct backing_dev_info *bdi; |
583 | dev_t devt; |
584 | int retval; |
585 | |
586 | /* minors == 0 indicates to use ext devt from part0 and should |
587 | * be accompanied with EXT_DEVT flag. Make sure all |
588 | * parameters make sense. |
589 | */ |
590 | WARN_ON(disk->minors && !(disk->major || disk->first_minor)); |
591 | WARN_ON(!disk->minors && !(disk->flags & GENHD_FL_EXT_DEVT)); |
592 | |
593 | disk->flags |= GENHD_FL_UP; |
594 | |
595 | retval = blk_alloc_devt(&disk->part0, &devt); |
596 | if (retval) { |
597 | WARN_ON(1); |
598 | return; |
599 | } |
600 | disk_to_dev(disk)->devt = devt; |
601 | |
602 | /* ->major and ->first_minor aren't supposed to be |
603 | * dereferenced from here on, but set them just in case. |
604 | */ |
605 | disk->major = MAJOR(devt); |
606 | disk->first_minor = MINOR(devt); |
607 | |
608 | disk_alloc_events(disk); |
609 | |
610 | /* Register BDI before referencing it from bdev */ |
611 | bdi = &disk->queue->backing_dev_info; |
612 | bdi_register_dev(bdi, disk_devt(disk)); |
613 | |
614 | blk_register_region(disk_devt(disk), disk->minors, NULL, |
615 | exact_match, exact_lock, disk); |
616 | register_disk(disk); |
617 | blk_register_queue(disk); |
618 | |
619 | /* |
620 | * Take an extra ref on queue which will be put on disk_release() |
621 | * so that it sticks around as long as @disk is there. |
622 | */ |
623 | WARN_ON_ONCE(!blk_get_queue(disk->queue)); |
624 | |
625 | retval = sysfs_create_link(&disk_to_dev(disk)->kobj, &bdi->dev->kobj, |
626 | "bdi"); |
627 | WARN_ON(retval); |
628 | |
629 | disk_add_events(disk); |
630 | } |
631 | EXPORT_SYMBOL(add_disk); |
632 | |
633 | void del_gendisk(struct gendisk *disk) |
634 | { |
635 | struct disk_part_iter piter; |
636 | struct hd_struct *part; |
637 | |
638 | disk_del_events(disk); |
639 | |
640 | /* invalidate stuff */ |
641 | disk_part_iter_init(&piter, disk, |
642 | DISK_PITER_INCL_EMPTY | DISK_PITER_REVERSE); |
643 | while ((part = disk_part_iter_next(&piter))) { |
644 | invalidate_partition(disk, part->partno); |
645 | delete_partition(disk, part->partno); |
646 | } |
647 | disk_part_iter_exit(&piter); |
648 | |
649 | invalidate_partition(disk, 0); |
650 | set_capacity(disk, 0); |
651 | disk->flags &= ~GENHD_FL_UP; |
652 | |
653 | sysfs_remove_link(&disk_to_dev(disk)->kobj, "bdi"); |
654 | bdi_unregister(&disk->queue->backing_dev_info); |
655 | blk_unregister_queue(disk); |
656 | blk_unregister_region(disk_devt(disk), disk->minors); |
657 | |
658 | part_stat_set_all(&disk->part0, 0); |
659 | disk->part0.stamp = 0; |
660 | |
661 | kobject_put(disk->part0.holder_dir); |
662 | kobject_put(disk->slave_dir); |
663 | disk->driverfs_dev = NULL; |
664 | if (!sysfs_deprecated) |
665 | sysfs_remove_link(block_depr, dev_name(disk_to_dev(disk))); |
666 | pm_runtime_set_memalloc_noio(disk_to_dev(disk), false); |
667 | device_del(disk_to_dev(disk)); |
668 | blk_free_devt(disk_to_dev(disk)->devt); |
669 | } |
670 | EXPORT_SYMBOL(del_gendisk); |
671 | |
672 | /** |
673 | * get_gendisk - get partitioning information for a given device |
674 | * @devt: device to get partitioning information for |
675 | * @partno: returned partition index |
676 | * |
677 | * This function gets the structure containing partitioning |
678 | * information for the given device @devt. |
679 | */ |
680 | struct gendisk *get_gendisk(dev_t devt, int *partno) |
681 | { |
682 | struct gendisk *disk = NULL; |
683 | |
684 | if (MAJOR(devt) != BLOCK_EXT_MAJOR) { |
685 | struct kobject *kobj; |
686 | |
687 | kobj = kobj_lookup(bdev_map, devt, partno); |
688 | if (kobj) |
689 | disk = dev_to_disk(kobj_to_dev(kobj)); |
690 | } else { |
691 | struct hd_struct *part; |
692 | |
693 | mutex_lock(&ext_devt_mutex); |
694 | part = idr_find(&ext_devt_idr, blk_mangle_minor(MINOR(devt))); |
695 | if (part && get_disk(part_to_disk(part))) { |
696 | *partno = part->partno; |
697 | disk = part_to_disk(part); |
698 | } |
699 | mutex_unlock(&ext_devt_mutex); |
700 | } |
701 | |
702 | return disk; |
703 | } |
704 | EXPORT_SYMBOL(get_gendisk); |
705 | |
706 | /** |
707 | * bdget_disk - do bdget() by gendisk and partition number |
708 | * @disk: gendisk of interest |
709 | * @partno: partition number |
710 | * |
711 | * Find partition @partno from @disk, do bdget() on it. |
712 | * |
713 | * CONTEXT: |
714 | * Don't care. |
715 | * |
716 | * RETURNS: |
717 | * Resulting block_device on success, NULL on failure. |
718 | */ |
719 | struct block_device *bdget_disk(struct gendisk *disk, int partno) |
720 | { |
721 | struct hd_struct *part; |
722 | struct block_device *bdev = NULL; |
723 | |
724 | part = disk_get_part(disk, partno); |
725 | if (part) |
726 | bdev = bdget(part_devt(part)); |
727 | disk_put_part(part); |
728 | |
729 | return bdev; |
730 | } |
731 | EXPORT_SYMBOL(bdget_disk); |
732 | |
733 | /* |
734 | * print a full list of all partitions - intended for places where the root |
735 | * filesystem can't be mounted and thus to give the victim some idea of what |
736 | * went wrong |
737 | */ |
738 | void __init printk_all_partitions(void) |
739 | { |
740 | struct class_dev_iter iter; |
741 | struct device *dev; |
742 | |
743 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); |
744 | while ((dev = class_dev_iter_next(&iter))) { |
745 | struct gendisk *disk = dev_to_disk(dev); |
746 | struct disk_part_iter piter; |
747 | struct hd_struct *part; |
748 | char name_buf[BDEVNAME_SIZE]; |
749 | char devt_buf[BDEVT_SIZE]; |
750 | |
751 | /* |
752 | * Don't show empty devices or things that have been |
753 | * suppressed |
754 | */ |
755 | if (get_capacity(disk) == 0 || |
756 | (disk->flags & GENHD_FL_SUPPRESS_PARTITION_INFO)) |
757 | continue; |
758 | |
759 | /* |
760 | * Note, unlike /proc/partitions, I am showing the |
761 | * numbers in hex - the same format as the root= |
762 | * option takes. |
763 | */ |
764 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_PART0); |
765 | while ((part = disk_part_iter_next(&piter))) { |
766 | bool is_part0 = part == &disk->part0; |
767 | |
768 | printk("%s%s %10llu %s %s", is_part0 ? "" : " ", |
769 | bdevt_str(part_devt(part), devt_buf), |
770 | (unsigned long long)part_nr_sects_read(part) >> 1 |
771 | , disk_name(disk, part->partno, name_buf), |
772 | part->info ? part->info->uuid : ""); |
773 | if (is_part0) { |
774 | if (disk->driverfs_dev != NULL && |
775 | disk->driverfs_dev->driver != NULL) |
776 | printk(" driver: %s\n", |
777 | disk->driverfs_dev->driver->name); |
778 | else |
779 | printk(" (driver?)\n"); |
780 | } else |
781 | printk("\n"); |
782 | } |
783 | disk_part_iter_exit(&piter); |
784 | } |
785 | class_dev_iter_exit(&iter); |
786 | } |
787 | |
788 | #ifdef CONFIG_PROC_FS |
789 | /* iterator */ |
790 | static void *disk_seqf_start(struct seq_file *seqf, loff_t *pos) |
791 | { |
792 | loff_t skip = *pos; |
793 | struct class_dev_iter *iter; |
794 | struct device *dev; |
795 | |
796 | iter = kmalloc(sizeof(*iter), GFP_KERNEL); |
797 | if (!iter) |
798 | return ERR_PTR(-ENOMEM); |
799 | |
800 | seqf->private = iter; |
801 | class_dev_iter_init(iter, &block_class, NULL, &disk_type); |
802 | do { |
803 | dev = class_dev_iter_next(iter); |
804 | if (!dev) |
805 | return NULL; |
806 | } while (skip--); |
807 | |
808 | return dev_to_disk(dev); |
809 | } |
810 | |
811 | static void *disk_seqf_next(struct seq_file *seqf, void *v, loff_t *pos) |
812 | { |
813 | struct device *dev; |
814 | |
815 | (*pos)++; |
816 | dev = class_dev_iter_next(seqf->private); |
817 | if (dev) |
818 | return dev_to_disk(dev); |
819 | |
820 | return NULL; |
821 | } |
822 | |
823 | static void disk_seqf_stop(struct seq_file *seqf, void *v) |
824 | { |
825 | struct class_dev_iter *iter = seqf->private; |
826 | |
827 | /* stop is called even after start failed :-( */ |
828 | if (iter) { |
829 | class_dev_iter_exit(iter); |
830 | kfree(iter); |
831 | } |
832 | } |
833 | |
834 | static void *show_partition_start(struct seq_file *seqf, loff_t *pos) |
835 | { |
836 | void *p; |
837 | |
838 | p = disk_seqf_start(seqf, pos); |
839 | if (!IS_ERR_OR_NULL(p) && !*pos) |
840 | seq_puts(seqf, "major minor #blocks name\n\n"); |
841 | return p; |
842 | } |
843 | |
844 | static int show_partition(struct seq_file *seqf, void *v) |
845 | { |
846 | struct gendisk *sgp = v; |
847 | struct disk_part_iter piter; |
848 | struct hd_struct *part; |
849 | char buf[BDEVNAME_SIZE]; |
850 | |
851 | /* Don't show non-partitionable removeable devices or empty devices */ |
852 | if (!get_capacity(sgp) || (!disk_max_parts(sgp) && |
853 | (sgp->flags & GENHD_FL_REMOVABLE))) |
854 | return 0; |
855 | if (sgp->flags & GENHD_FL_SUPPRESS_PARTITION_INFO) |
856 | return 0; |
857 | |
858 | /* show the full disk and all non-0 size partitions of it */ |
859 | disk_part_iter_init(&piter, sgp, DISK_PITER_INCL_PART0); |
860 | while ((part = disk_part_iter_next(&piter))) |
861 | seq_printf(seqf, "%4d %7d %10llu %s\n", |
862 | MAJOR(part_devt(part)), MINOR(part_devt(part)), |
863 | (unsigned long long)part_nr_sects_read(part) >> 1, |
864 | disk_name(sgp, part->partno, buf)); |
865 | disk_part_iter_exit(&piter); |
866 | |
867 | return 0; |
868 | } |
869 | |
870 | static const struct seq_operations partitions_op = { |
871 | .start = show_partition_start, |
872 | .next = disk_seqf_next, |
873 | .stop = disk_seqf_stop, |
874 | .show = show_partition |
875 | }; |
876 | |
877 | static int partitions_open(struct inode *inode, struct file *file) |
878 | { |
879 | return seq_open(file, &partitions_op); |
880 | } |
881 | |
882 | static const struct file_operations proc_partitions_operations = { |
883 | .open = partitions_open, |
884 | .read = seq_read, |
885 | .llseek = seq_lseek, |
886 | .release = seq_release, |
887 | }; |
888 | #endif |
889 | |
890 | |
891 | static struct kobject *base_probe(dev_t devt, int *partno, void *data) |
892 | { |
893 | if (request_module("block-major-%d-%d", MAJOR(devt), MINOR(devt)) > 0) |
894 | /* Make old-style 2.4 aliases work */ |
895 | request_module("block-major-%d", MAJOR(devt)); |
896 | return NULL; |
897 | } |
898 | |
899 | static int __init genhd_device_init(void) |
900 | { |
901 | int error; |
902 | |
903 | block_class.dev_kobj = sysfs_dev_block_kobj; |
904 | error = class_register(&block_class); |
905 | if (unlikely(error)) |
906 | return error; |
907 | bdev_map = kobj_map_init(base_probe, &block_class_lock); |
908 | blk_dev_init(); |
909 | |
910 | register_blkdev(BLOCK_EXT_MAJOR, "blkext"); |
911 | |
912 | /* create top-level block dir */ |
913 | if (!sysfs_deprecated) |
914 | block_depr = kobject_create_and_add("block", NULL); |
915 | return 0; |
916 | } |
917 | |
918 | subsys_initcall(genhd_device_init); |
919 | |
920 | static ssize_t disk_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->minors); |
926 | } |
927 | |
928 | static ssize_t disk_ext_range_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", disk_max_parts(disk)); |
934 | } |
935 | |
936 | static ssize_t disk_removable_show(struct device *dev, |
937 | struct device_attribute *attr, char *buf) |
938 | { |
939 | struct gendisk *disk = dev_to_disk(dev); |
940 | |
941 | return sprintf(buf, "%d\n", |
942 | (disk->flags & GENHD_FL_REMOVABLE ? 1 : 0)); |
943 | } |
944 | |
945 | static ssize_t disk_ro_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, "%d\n", get_disk_ro(disk) ? 1 : 0); |
951 | } |
952 | |
953 | static ssize_t disk_capability_show(struct device *dev, |
954 | struct device_attribute *attr, char *buf) |
955 | { |
956 | struct gendisk *disk = dev_to_disk(dev); |
957 | |
958 | return sprintf(buf, "%x\n", disk->flags); |
959 | } |
960 | |
961 | static ssize_t disk_alignment_offset_show(struct device *dev, |
962 | struct device_attribute *attr, |
963 | char *buf) |
964 | { |
965 | struct gendisk *disk = dev_to_disk(dev); |
966 | |
967 | return sprintf(buf, "%d\n", queue_alignment_offset(disk->queue)); |
968 | } |
969 | |
970 | static ssize_t disk_discard_alignment_show(struct device *dev, |
971 | struct device_attribute *attr, |
972 | char *buf) |
973 | { |
974 | struct gendisk *disk = dev_to_disk(dev); |
975 | |
976 | return sprintf(buf, "%d\n", queue_discard_alignment(disk->queue)); |
977 | } |
978 | |
979 | static DEVICE_ATTR(range, S_IRUGO, disk_range_show, NULL); |
980 | static DEVICE_ATTR(ext_range, S_IRUGO, disk_ext_range_show, NULL); |
981 | static DEVICE_ATTR(removable, S_IRUGO, disk_removable_show, NULL); |
982 | static DEVICE_ATTR(ro, S_IRUGO, disk_ro_show, NULL); |
983 | static DEVICE_ATTR(size, S_IRUGO, part_size_show, NULL); |
984 | static DEVICE_ATTR(alignment_offset, S_IRUGO, disk_alignment_offset_show, NULL); |
985 | static DEVICE_ATTR(discard_alignment, S_IRUGO, disk_discard_alignment_show, |
986 | NULL); |
987 | static DEVICE_ATTR(capability, S_IRUGO, disk_capability_show, NULL); |
988 | static DEVICE_ATTR(stat, S_IRUGO, part_stat_show, NULL); |
989 | static DEVICE_ATTR(inflight, S_IRUGO, part_inflight_show, NULL); |
990 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
991 | static struct device_attribute dev_attr_fail = |
992 | __ATTR(make-it-fail, S_IRUGO|S_IWUSR, part_fail_show, part_fail_store); |
993 | #endif |
994 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
995 | static struct device_attribute dev_attr_fail_timeout = |
996 | __ATTR(io-timeout-fail, S_IRUGO|S_IWUSR, part_timeout_show, |
997 | part_timeout_store); |
998 | #endif |
999 | |
1000 | static struct attribute *disk_attrs[] = { |
1001 | &dev_attr_range.attr, |
1002 | &dev_attr_ext_range.attr, |
1003 | &dev_attr_removable.attr, |
1004 | &dev_attr_ro.attr, |
1005 | &dev_attr_size.attr, |
1006 | &dev_attr_alignment_offset.attr, |
1007 | &dev_attr_discard_alignment.attr, |
1008 | &dev_attr_capability.attr, |
1009 | &dev_attr_stat.attr, |
1010 | &dev_attr_inflight.attr, |
1011 | #ifdef CONFIG_FAIL_MAKE_REQUEST |
1012 | &dev_attr_fail.attr, |
1013 | #endif |
1014 | #ifdef CONFIG_FAIL_IO_TIMEOUT |
1015 | &dev_attr_fail_timeout.attr, |
1016 | #endif |
1017 | NULL |
1018 | }; |
1019 | |
1020 | static struct attribute_group disk_attr_group = { |
1021 | .attrs = disk_attrs, |
1022 | }; |
1023 | |
1024 | static const struct attribute_group *disk_attr_groups[] = { |
1025 | &disk_attr_group, |
1026 | NULL |
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 | kfree_rcu(old_ptbl, rcu_head); |
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 | if (disk->queue) |
1107 | blk_put_queue(disk->queue); |
1108 | kfree(disk); |
1109 | } |
1110 | struct class block_class = { |
1111 | .name = "block", |
1112 | }; |
1113 | |
1114 | static char *block_devnode(struct device *dev, umode_t *mode) |
1115 | { |
1116 | struct gendisk *disk = dev_to_disk(dev); |
1117 | |
1118 | if (disk->devnode) |
1119 | return disk->devnode(disk, mode); |
1120 | return NULL; |
1121 | } |
1122 | |
1123 | static struct device_type disk_type = { |
1124 | .name = "disk", |
1125 | .groups = disk_attr_groups, |
1126 | .release = disk_release, |
1127 | .devnode = block_devnode, |
1128 | }; |
1129 | |
1130 | #ifdef CONFIG_PROC_FS |
1131 | /* |
1132 | * aggregate disk stat collector. Uses the same stats that the sysfs |
1133 | * entries do, above, but makes them available through one seq_file. |
1134 | * |
1135 | * The output looks suspiciously like /proc/partitions with a bunch of |
1136 | * extra fields. |
1137 | */ |
1138 | static int diskstats_show(struct seq_file *seqf, void *v) |
1139 | { |
1140 | struct gendisk *gp = v; |
1141 | struct disk_part_iter piter; |
1142 | struct hd_struct *hd; |
1143 | char buf[BDEVNAME_SIZE]; |
1144 | int cpu; |
1145 | |
1146 | /* |
1147 | if (&disk_to_dev(gp)->kobj.entry == block_class.devices.next) |
1148 | seq_puts(seqf, "major minor name" |
1149 | " rio rmerge rsect ruse wio wmerge " |
1150 | "wsect wuse running use aveq" |
1151 | "\n\n"); |
1152 | */ |
1153 | |
1154 | disk_part_iter_init(&piter, gp, DISK_PITER_INCL_EMPTY_PART0); |
1155 | while ((hd = disk_part_iter_next(&piter))) { |
1156 | cpu = part_stat_lock(); |
1157 | part_round_stats(cpu, hd); |
1158 | part_stat_unlock(); |
1159 | seq_printf(seqf, "%4d %7d %s %lu %lu %lu " |
1160 | "%u %lu %lu %lu %u %u %u %u\n", |
1161 | MAJOR(part_devt(hd)), MINOR(part_devt(hd)), |
1162 | disk_name(gp, hd->partno, buf), |
1163 | part_stat_read(hd, ios[READ]), |
1164 | part_stat_read(hd, merges[READ]), |
1165 | part_stat_read(hd, sectors[READ]), |
1166 | jiffies_to_msecs(part_stat_read(hd, ticks[READ])), |
1167 | part_stat_read(hd, ios[WRITE]), |
1168 | part_stat_read(hd, merges[WRITE]), |
1169 | part_stat_read(hd, sectors[WRITE]), |
1170 | jiffies_to_msecs(part_stat_read(hd, ticks[WRITE])), |
1171 | part_in_flight(hd), |
1172 | jiffies_to_msecs(part_stat_read(hd, io_ticks)), |
1173 | jiffies_to_msecs(part_stat_read(hd, time_in_queue)) |
1174 | ); |
1175 | } |
1176 | disk_part_iter_exit(&piter); |
1177 | |
1178 | return 0; |
1179 | } |
1180 | |
1181 | static const struct seq_operations diskstats_op = { |
1182 | .start = disk_seqf_start, |
1183 | .next = disk_seqf_next, |
1184 | .stop = disk_seqf_stop, |
1185 | .show = diskstats_show |
1186 | }; |
1187 | |
1188 | static int diskstats_open(struct inode *inode, struct file *file) |
1189 | { |
1190 | return seq_open(file, &diskstats_op); |
1191 | } |
1192 | |
1193 | static const struct file_operations proc_diskstats_operations = { |
1194 | .open = diskstats_open, |
1195 | .read = seq_read, |
1196 | .llseek = seq_lseek, |
1197 | .release = seq_release, |
1198 | }; |
1199 | |
1200 | static int __init proc_genhd_init(void) |
1201 | { |
1202 | proc_create("diskstats", 0, NULL, &proc_diskstats_operations); |
1203 | proc_create("partitions", 0, NULL, &proc_partitions_operations); |
1204 | return 0; |
1205 | } |
1206 | module_init(proc_genhd_init); |
1207 | #endif /* CONFIG_PROC_FS */ |
1208 | |
1209 | dev_t blk_lookup_devt(const char *name, int partno) |
1210 | { |
1211 | dev_t devt = MKDEV(0, 0); |
1212 | struct class_dev_iter iter; |
1213 | struct device *dev; |
1214 | |
1215 | class_dev_iter_init(&iter, &block_class, NULL, &disk_type); |
1216 | while ((dev = class_dev_iter_next(&iter))) { |
1217 | struct gendisk *disk = dev_to_disk(dev); |
1218 | struct hd_struct *part; |
1219 | |
1220 | if (strcmp(dev_name(dev), name)) |
1221 | continue; |
1222 | |
1223 | if (partno < disk->minors) { |
1224 | /* We need to return the right devno, even |
1225 | * if the partition doesn't exist yet. |
1226 | */ |
1227 | devt = MKDEV(MAJOR(dev->devt), |
1228 | MINOR(dev->devt) + partno); |
1229 | break; |
1230 | } |
1231 | part = disk_get_part(disk, partno); |
1232 | if (part) { |
1233 | devt = part_devt(part); |
1234 | disk_put_part(part); |
1235 | break; |
1236 | } |
1237 | disk_put_part(part); |
1238 | } |
1239 | class_dev_iter_exit(&iter); |
1240 | return devt; |
1241 | } |
1242 | EXPORT_SYMBOL(blk_lookup_devt); |
1243 | |
1244 | struct gendisk *alloc_disk(int minors) |
1245 | { |
1246 | return alloc_disk_node(minors, NUMA_NO_NODE); |
1247 | } |
1248 | EXPORT_SYMBOL(alloc_disk); |
1249 | |
1250 | struct gendisk *alloc_disk_node(int minors, int node_id) |
1251 | { |
1252 | struct gendisk *disk; |
1253 | |
1254 | disk = kmalloc_node(sizeof(struct gendisk), |
1255 | GFP_KERNEL | __GFP_ZERO, node_id); |
1256 | if (disk) { |
1257 | if (!init_part_stats(&disk->part0)) { |
1258 | kfree(disk); |
1259 | return NULL; |
1260 | } |
1261 | disk->node_id = node_id; |
1262 | if (disk_expand_part_tbl(disk, 0)) { |
1263 | free_part_stats(&disk->part0); |
1264 | kfree(disk); |
1265 | return NULL; |
1266 | } |
1267 | disk->part_tbl->part[0] = &disk->part0; |
1268 | |
1269 | /* |
1270 | * set_capacity() and get_capacity() currently don't use |
1271 | * seqcounter to read/update the part0->nr_sects. Still init |
1272 | * the counter as we can read the sectors in IO submission |
1273 | * patch using seqence counters. |
1274 | * |
1275 | * TODO: Ideally set_capacity() and get_capacity() should be |
1276 | * converted to make use of bd_mutex and sequence counters. |
1277 | */ |
1278 | seqcount_init(&disk->part0.nr_sects_seq); |
1279 | hd_ref_init(&disk->part0); |
1280 | |
1281 | disk->minors = minors; |
1282 | rand_initialize_disk(disk); |
1283 | disk_to_dev(disk)->class = &block_class; |
1284 | disk_to_dev(disk)->type = &disk_type; |
1285 | device_initialize(disk_to_dev(disk)); |
1286 | } |
1287 | return disk; |
1288 | } |
1289 | EXPORT_SYMBOL(alloc_disk_node); |
1290 | |
1291 | struct kobject *get_disk(struct gendisk *disk) |
1292 | { |
1293 | struct module *owner; |
1294 | struct kobject *kobj; |
1295 | |
1296 | if (!disk->fops) |
1297 | return NULL; |
1298 | owner = disk->fops->owner; |
1299 | if (owner && !try_module_get(owner)) |
1300 | return NULL; |
1301 | kobj = kobject_get(&disk_to_dev(disk)->kobj); |
1302 | if (kobj == NULL) { |
1303 | module_put(owner); |
1304 | return NULL; |
1305 | } |
1306 | return kobj; |
1307 | |
1308 | } |
1309 | |
1310 | EXPORT_SYMBOL(get_disk); |
1311 | |
1312 | void put_disk(struct gendisk *disk) |
1313 | { |
1314 | if (disk) |
1315 | kobject_put(&disk_to_dev(disk)->kobj); |
1316 | } |
1317 | |
1318 | EXPORT_SYMBOL(put_disk); |
1319 | |
1320 | static void set_disk_ro_uevent(struct gendisk *gd, int ro) |
1321 | { |
1322 | char event[] = "DISK_RO=1"; |
1323 | char *envp[] = { event, NULL }; |
1324 | |
1325 | if (!ro) |
1326 | event[8] = '0'; |
1327 | kobject_uevent_env(&disk_to_dev(gd)->kobj, KOBJ_CHANGE, envp); |
1328 | } |
1329 | |
1330 | void set_device_ro(struct block_device *bdev, int flag) |
1331 | { |
1332 | bdev->bd_part->policy = flag; |
1333 | } |
1334 | |
1335 | EXPORT_SYMBOL(set_device_ro); |
1336 | |
1337 | void set_disk_ro(struct gendisk *disk, int flag) |
1338 | { |
1339 | struct disk_part_iter piter; |
1340 | struct hd_struct *part; |
1341 | |
1342 | if (disk->part0.policy != flag) { |
1343 | set_disk_ro_uevent(disk, flag); |
1344 | disk->part0.policy = flag; |
1345 | } |
1346 | |
1347 | disk_part_iter_init(&piter, disk, DISK_PITER_INCL_EMPTY); |
1348 | while ((part = disk_part_iter_next(&piter))) |
1349 | part->policy = flag; |
1350 | disk_part_iter_exit(&piter); |
1351 | } |
1352 | |
1353 | EXPORT_SYMBOL(set_disk_ro); |
1354 | |
1355 | int bdev_read_only(struct block_device *bdev) |
1356 | { |
1357 | if (!bdev) |
1358 | return 0; |
1359 | return bdev->bd_part->policy; |
1360 | } |
1361 | |
1362 | EXPORT_SYMBOL(bdev_read_only); |
1363 | |
1364 | int invalidate_partition(struct gendisk *disk, int partno) |
1365 | { |
1366 | int res = 0; |
1367 | struct block_device *bdev = bdget_disk(disk, partno); |
1368 | if (bdev) { |
1369 | fsync_bdev(bdev); |
1370 | res = __invalidate_device(bdev, true); |
1371 | bdput(bdev); |
1372 | } |
1373 | return res; |
1374 | } |
1375 | |
1376 | EXPORT_SYMBOL(invalidate_partition); |
1377 | |
1378 | /* |
1379 | * Disk events - monitor disk events like media change and eject request. |
1380 | */ |
1381 | struct disk_events { |
1382 | struct list_head node; /* all disk_event's */ |
1383 | struct gendisk *disk; /* the associated disk */ |
1384 | spinlock_t lock; |
1385 | |
1386 | struct mutex block_mutex; /* protects blocking */ |
1387 | int block; /* event blocking depth */ |
1388 | unsigned int pending; /* events already sent out */ |
1389 | unsigned int clearing; /* events being cleared */ |
1390 | |
1391 | long poll_msecs; /* interval, -1 for default */ |
1392 | struct delayed_work dwork; |
1393 | }; |
1394 | |
1395 | static const char *disk_events_strs[] = { |
1396 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "media_change", |
1397 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "eject_request", |
1398 | }; |
1399 | |
1400 | static char *disk_uevents[] = { |
1401 | [ilog2(DISK_EVENT_MEDIA_CHANGE)] = "DISK_MEDIA_CHANGE=1", |
1402 | [ilog2(DISK_EVENT_EJECT_REQUEST)] = "DISK_EJECT_REQUEST=1", |
1403 | }; |
1404 | |
1405 | /* list of all disk_events */ |
1406 | static DEFINE_MUTEX(disk_events_mutex); |
1407 | static LIST_HEAD(disk_events); |
1408 | |
1409 | /* disable in-kernel polling by default */ |
1410 | static unsigned long disk_events_dfl_poll_msecs = 0; |
1411 | |
1412 | static unsigned long disk_events_poll_jiffies(struct gendisk *disk) |
1413 | { |
1414 | struct disk_events *ev = disk->ev; |
1415 | long intv_msecs = 0; |
1416 | |
1417 | /* |
1418 | * If device-specific poll interval is set, always use it. If |
1419 | * the default is being used, poll iff there are events which |
1420 | * can't be monitored asynchronously. |
1421 | */ |
1422 | if (ev->poll_msecs >= 0) |
1423 | intv_msecs = ev->poll_msecs; |
1424 | else if (disk->events & ~disk->async_events) |
1425 | intv_msecs = disk_events_dfl_poll_msecs; |
1426 | |
1427 | return msecs_to_jiffies(intv_msecs); |
1428 | } |
1429 | |
1430 | /** |
1431 | * disk_block_events - block and flush disk event checking |
1432 | * @disk: disk to block events for |
1433 | * |
1434 | * On return from this function, it is guaranteed that event checking |
1435 | * isn't in progress and won't happen until unblocked by |
1436 | * disk_unblock_events(). Events blocking is counted and the actual |
1437 | * unblocking happens after the matching number of unblocks are done. |
1438 | * |
1439 | * Note that this intentionally does not block event checking from |
1440 | * disk_clear_events(). |
1441 | * |
1442 | * CONTEXT: |
1443 | * Might sleep. |
1444 | */ |
1445 | void disk_block_events(struct gendisk *disk) |
1446 | { |
1447 | struct disk_events *ev = disk->ev; |
1448 | unsigned long flags; |
1449 | bool cancel; |
1450 | |
1451 | if (!ev) |
1452 | return; |
1453 | |
1454 | /* |
1455 | * Outer mutex ensures that the first blocker completes canceling |
1456 | * the event work before further blockers are allowed to finish. |
1457 | */ |
1458 | mutex_lock(&ev->block_mutex); |
1459 | |
1460 | spin_lock_irqsave(&ev->lock, flags); |
1461 | cancel = !ev->block++; |
1462 | spin_unlock_irqrestore(&ev->lock, flags); |
1463 | |
1464 | if (cancel) |
1465 | cancel_delayed_work_sync(&disk->ev->dwork); |
1466 | |
1467 | mutex_unlock(&ev->block_mutex); |
1468 | } |
1469 | |
1470 | static void __disk_unblock_events(struct gendisk *disk, bool check_now) |
1471 | { |
1472 | struct disk_events *ev = disk->ev; |
1473 | unsigned long intv; |
1474 | unsigned long flags; |
1475 | |
1476 | spin_lock_irqsave(&ev->lock, flags); |
1477 | |
1478 | if (WARN_ON_ONCE(ev->block <= 0)) |
1479 | goto out_unlock; |
1480 | |
1481 | if (--ev->block) |
1482 | goto out_unlock; |
1483 | |
1484 | /* |
1485 | * Not exactly a latency critical operation, set poll timer |
1486 | * slack to 25% and kick event check. |
1487 | */ |
1488 | intv = disk_events_poll_jiffies(disk); |
1489 | set_timer_slack(&ev->dwork.timer, intv / 4); |
1490 | if (check_now) |
1491 | queue_delayed_work(system_freezable_wq, &ev->dwork, 0); |
1492 | else if (intv) |
1493 | queue_delayed_work(system_freezable_wq, &ev->dwork, intv); |
1494 | out_unlock: |
1495 | spin_unlock_irqrestore(&ev->lock, flags); |
1496 | } |
1497 | |
1498 | /** |
1499 | * disk_unblock_events - unblock disk event checking |
1500 | * @disk: disk to unblock events for |
1501 | * |
1502 | * Undo disk_block_events(). When the block count reaches zero, it |
1503 | * starts events polling if configured. |
1504 | * |
1505 | * CONTEXT: |
1506 | * Don't care. Safe to call from irq context. |
1507 | */ |
1508 | void disk_unblock_events(struct gendisk *disk) |
1509 | { |
1510 | if (disk->ev) |
1511 | __disk_unblock_events(disk, false); |
1512 | } |
1513 | |
1514 | /** |
1515 | * disk_flush_events - schedule immediate event checking and flushing |
1516 | * @disk: disk to check and flush events for |
1517 | * @mask: events to flush |
1518 | * |
1519 | * Schedule immediate event checking on @disk if not blocked. Events in |
1520 | * @mask are scheduled to be cleared from the driver. Note that this |
1521 | * doesn't clear the events from @disk->ev. |
1522 | * |
1523 | * CONTEXT: |
1524 | * If @mask is non-zero must be called with bdev->bd_mutex held. |
1525 | */ |
1526 | void disk_flush_events(struct gendisk *disk, unsigned int mask) |
1527 | { |
1528 | struct disk_events *ev = disk->ev; |
1529 | |
1530 | if (!ev) |
1531 | return; |
1532 | |
1533 | spin_lock_irq(&ev->lock); |
1534 | ev->clearing |= mask; |
1535 | if (!ev->block) |
1536 | mod_delayed_work(system_freezable_wq, &ev->dwork, 0); |
1537 | spin_unlock_irq(&ev->lock); |
1538 | } |
1539 | |
1540 | /** |
1541 | * disk_clear_events - synchronously check, clear and return pending events |
1542 | * @disk: disk to fetch and clear events from |
1543 | * @mask: mask of events to be fetched and clearted |
1544 | * |
1545 | * Disk events are synchronously checked and pending events in @mask |
1546 | * are cleared and returned. This ignores the block count. |
1547 | * |
1548 | * CONTEXT: |
1549 | * Might sleep. |
1550 | */ |
1551 | unsigned int disk_clear_events(struct gendisk *disk, unsigned int mask) |
1552 | { |
1553 | const struct block_device_operations *bdops = disk->fops; |
1554 | struct disk_events *ev = disk->ev; |
1555 | unsigned int pending; |
1556 | unsigned int clearing = mask; |
1557 | |
1558 | if (!ev) { |
1559 | /* for drivers still using the old ->media_changed method */ |
1560 | if ((mask & DISK_EVENT_MEDIA_CHANGE) && |
1561 | bdops->media_changed && bdops->media_changed(disk)) |
1562 | return DISK_EVENT_MEDIA_CHANGE; |
1563 | return 0; |
1564 | } |
1565 | |
1566 | disk_block_events(disk); |
1567 | |
1568 | /* |
1569 | * store the union of mask and ev->clearing on the stack so that the |
1570 | * race with disk_flush_events does not cause ambiguity (ev->clearing |
1571 | * can still be modified even if events are blocked). |
1572 | */ |
1573 | spin_lock_irq(&ev->lock); |
1574 | clearing |= ev->clearing; |
1575 | ev->clearing = 0; |
1576 | spin_unlock_irq(&ev->lock); |
1577 | |
1578 | disk_check_events(ev, &clearing); |
1579 | /* |
1580 | * if ev->clearing is not 0, the disk_flush_events got called in the |
1581 | * middle of this function, so we want to run the workfn without delay. |
1582 | */ |
1583 | __disk_unblock_events(disk, ev->clearing ? true : false); |
1584 | |
1585 | /* then, fetch and clear pending events */ |
1586 | spin_lock_irq(&ev->lock); |
1587 | pending = ev->pending & mask; |
1588 | ev->pending &= ~mask; |
1589 | spin_unlock_irq(&ev->lock); |
1590 | WARN_ON_ONCE(clearing & mask); |
1591 | |
1592 | return pending; |
1593 | } |
1594 | |
1595 | /* |
1596 | * Separate this part out so that a different pointer for clearing_ptr can be |
1597 | * passed in for disk_clear_events. |
1598 | */ |
1599 | static void disk_events_workfn(struct work_struct *work) |
1600 | { |
1601 | struct delayed_work *dwork = to_delayed_work(work); |
1602 | struct disk_events *ev = container_of(dwork, struct disk_events, dwork); |
1603 | |
1604 | disk_check_events(ev, &ev->clearing); |
1605 | } |
1606 | |
1607 | static void disk_check_events(struct disk_events *ev, |
1608 | unsigned int *clearing_ptr) |
1609 | { |
1610 | struct gendisk *disk = ev->disk; |
1611 | char *envp[ARRAY_SIZE(disk_uevents) + 1] = { }; |
1612 | unsigned int clearing = *clearing_ptr; |
1613 | unsigned int events; |
1614 | unsigned long intv; |
1615 | int nr_events = 0, i; |
1616 | |
1617 | /* check events */ |
1618 | events = disk->fops->check_events(disk, clearing); |
1619 | |
1620 | /* accumulate pending events and schedule next poll if necessary */ |
1621 | spin_lock_irq(&ev->lock); |
1622 | |
1623 | events &= ~ev->pending; |
1624 | ev->pending |= events; |
1625 | *clearing_ptr &= ~clearing; |
1626 | |
1627 | intv = disk_events_poll_jiffies(disk); |
1628 | if (!ev->block && intv) |
1629 | queue_delayed_work(system_freezable_wq, &ev->dwork, intv); |
1630 | |
1631 | spin_unlock_irq(&ev->lock); |
1632 | |
1633 | /* |
1634 | * Tell userland about new events. Only the events listed in |
1635 | * @disk->events are reported. Unlisted events are processed the |
1636 | * same internally but never get reported to userland. |
1637 | */ |
1638 | for (i = 0; i < ARRAY_SIZE(disk_uevents); i++) |
1639 | if (events & disk->events & (1 << i)) |
1640 | envp[nr_events++] = disk_uevents[i]; |
1641 | |
1642 | if (nr_events) |
1643 | kobject_uevent_env(&disk_to_dev(disk)->kobj, KOBJ_CHANGE, envp); |
1644 | } |
1645 | |
1646 | /* |
1647 | * A disk events enabled device has the following sysfs nodes under |
1648 | * its /sys/block/X/ directory. |
1649 | * |
1650 | * events : list of all supported events |
1651 | * events_async : list of events which can be detected w/o polling |
1652 | * events_poll_msecs : polling interval, 0: disable, -1: system default |
1653 | */ |
1654 | static ssize_t __disk_events_show(unsigned int events, char *buf) |
1655 | { |
1656 | const char *delim = ""; |
1657 | ssize_t pos = 0; |
1658 | int i; |
1659 | |
1660 | for (i = 0; i < ARRAY_SIZE(disk_events_strs); i++) |
1661 | if (events & (1 << i)) { |
1662 | pos += sprintf(buf + pos, "%s%s", |
1663 | delim, disk_events_strs[i]); |
1664 | delim = " "; |
1665 | } |
1666 | if (pos) |
1667 | pos += sprintf(buf + pos, "\n"); |
1668 | return pos; |
1669 | } |
1670 | |
1671 | static ssize_t disk_events_show(struct device *dev, |
1672 | struct device_attribute *attr, char *buf) |
1673 | { |
1674 | struct gendisk *disk = dev_to_disk(dev); |
1675 | |
1676 | return __disk_events_show(disk->events, buf); |
1677 | } |
1678 | |
1679 | static ssize_t disk_events_async_show(struct device *dev, |
1680 | struct device_attribute *attr, char *buf) |
1681 | { |
1682 | struct gendisk *disk = dev_to_disk(dev); |
1683 | |
1684 | return __disk_events_show(disk->async_events, buf); |
1685 | } |
1686 | |
1687 | static ssize_t disk_events_poll_msecs_show(struct device *dev, |
1688 | struct device_attribute *attr, |
1689 | char *buf) |
1690 | { |
1691 | struct gendisk *disk = dev_to_disk(dev); |
1692 | |
1693 | return sprintf(buf, "%ld\n", disk->ev->poll_msecs); |
1694 | } |
1695 | |
1696 | static ssize_t disk_events_poll_msecs_store(struct device *dev, |
1697 | struct device_attribute *attr, |
1698 | const char *buf, size_t count) |
1699 | { |
1700 | struct gendisk *disk = dev_to_disk(dev); |
1701 | long intv; |
1702 | |
1703 | if (!count || !sscanf(buf, "%ld", &intv)) |
1704 | return -EINVAL; |
1705 | |
1706 | if (intv < 0 && intv != -1) |
1707 | return -EINVAL; |
1708 | |
1709 | disk_block_events(disk); |
1710 | disk->ev->poll_msecs = intv; |
1711 | __disk_unblock_events(disk, true); |
1712 | |
1713 | return count; |
1714 | } |
1715 | |
1716 | static const DEVICE_ATTR(events, S_IRUGO, disk_events_show, NULL); |
1717 | static const DEVICE_ATTR(events_async, S_IRUGO, disk_events_async_show, NULL); |
1718 | static const DEVICE_ATTR(events_poll_msecs, S_IRUGO|S_IWUSR, |
1719 | disk_events_poll_msecs_show, |
1720 | disk_events_poll_msecs_store); |
1721 | |
1722 | static const struct attribute *disk_events_attrs[] = { |
1723 | &dev_attr_events.attr, |
1724 | &dev_attr_events_async.attr, |
1725 | &dev_attr_events_poll_msecs.attr, |
1726 | NULL, |
1727 | }; |
1728 | |
1729 | /* |
1730 | * The default polling interval can be specified by the kernel |
1731 | * parameter block.events_dfl_poll_msecs which defaults to 0 |
1732 | * (disable). This can also be modified runtime by writing to |
1733 | * /sys/module/block/events_dfl_poll_msecs. |
1734 | */ |
1735 | static int disk_events_set_dfl_poll_msecs(const char *val, |
1736 | const struct kernel_param *kp) |
1737 | { |
1738 | struct disk_events *ev; |
1739 | int ret; |
1740 | |
1741 | ret = param_set_ulong(val, kp); |
1742 | if (ret < 0) |
1743 | return ret; |
1744 | |
1745 | mutex_lock(&disk_events_mutex); |
1746 | |
1747 | list_for_each_entry(ev, &disk_events, node) |
1748 | disk_flush_events(ev->disk, 0); |
1749 | |
1750 | mutex_unlock(&disk_events_mutex); |
1751 | |
1752 | return 0; |
1753 | } |
1754 | |
1755 | static const struct kernel_param_ops disk_events_dfl_poll_msecs_param_ops = { |
1756 | .set = disk_events_set_dfl_poll_msecs, |
1757 | .get = param_get_ulong, |
1758 | }; |
1759 | |
1760 | #undef MODULE_PARAM_PREFIX |
1761 | #define MODULE_PARAM_PREFIX "block." |
1762 | |
1763 | module_param_cb(events_dfl_poll_msecs, &disk_events_dfl_poll_msecs_param_ops, |
1764 | &disk_events_dfl_poll_msecs, 0644); |
1765 | |
1766 | /* |
1767 | * disk_{alloc|add|del|release}_events - initialize and destroy disk_events. |
1768 | */ |
1769 | static void disk_alloc_events(struct gendisk *disk) |
1770 | { |
1771 | struct disk_events *ev; |
1772 | |
1773 | if (!disk->fops->check_events) |
1774 | return; |
1775 | |
1776 | ev = kzalloc(sizeof(*ev), GFP_KERNEL); |
1777 | if (!ev) { |
1778 | pr_warn("%s: failed to initialize events\n", disk->disk_name); |
1779 | return; |
1780 | } |
1781 | |
1782 | INIT_LIST_HEAD(&ev->node); |
1783 | ev->disk = disk; |
1784 | spin_lock_init(&ev->lock); |
1785 | mutex_init(&ev->block_mutex); |
1786 | ev->block = 1; |
1787 | ev->poll_msecs = -1; |
1788 | INIT_DELAYED_WORK(&ev->dwork, disk_events_workfn); |
1789 | |
1790 | disk->ev = ev; |
1791 | } |
1792 | |
1793 | static void disk_add_events(struct gendisk *disk) |
1794 | { |
1795 | if (!disk->ev) |
1796 | return; |
1797 | |
1798 | /* FIXME: error handling */ |
1799 | if (sysfs_create_files(&disk_to_dev(disk)->kobj, disk_events_attrs) < 0) |
1800 | pr_warn("%s: failed to create sysfs files for events\n", |
1801 | disk->disk_name); |
1802 | |
1803 | mutex_lock(&disk_events_mutex); |
1804 | list_add_tail(&disk->ev->node, &disk_events); |
1805 | mutex_unlock(&disk_events_mutex); |
1806 | |
1807 | /* |
1808 | * Block count is initialized to 1 and the following initial |
1809 | * unblock kicks it into action. |
1810 | */ |
1811 | __disk_unblock_events(disk, true); |
1812 | } |
1813 | |
1814 | static void disk_del_events(struct gendisk *disk) |
1815 | { |
1816 | if (!disk->ev) |
1817 | return; |
1818 | |
1819 | disk_block_events(disk); |
1820 | |
1821 | mutex_lock(&disk_events_mutex); |
1822 | list_del_init(&disk->ev->node); |
1823 | mutex_unlock(&disk_events_mutex); |
1824 | |
1825 | sysfs_remove_files(&disk_to_dev(disk)->kobj, disk_events_attrs); |
1826 | } |
1827 | |
1828 | static void disk_release_events(struct gendisk *disk) |
1829 | { |
1830 | /* the block count should be 1 from disk_del_events() */ |
1831 | WARN_ON_ONCE(disk->ev && disk->ev->block != 1); |
1832 | kfree(disk->ev); |
1833 | } |
1834 |
Branches:
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ben-wpan-stefan
javiroman/ks7010
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jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master
Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9