Commit | Line | Data |
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09c434b8 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
9db5579b NP |
2 | /* |
3 | * Ram backed block device driver. | |
4 | * | |
5 | * Copyright (C) 2007 Nick Piggin | |
6 | * Copyright (C) 2007 Novell Inc. | |
7 | * | |
8 | * Parts derived from drivers/block/rd.c, and drivers/block/loop.c, copyright | |
9 | * of their respective owners. | |
10 | */ | |
11 | ||
12 | #include <linux/init.h> | |
287f3ca5 | 13 | #include <linux/initrd.h> |
9db5579b NP |
14 | #include <linux/module.h> |
15 | #include <linux/moduleparam.h> | |
16 | #include <linux/major.h> | |
17 | #include <linux/blkdev.h> | |
18 | #include <linux/bio.h> | |
19 | #include <linux/highmem.h> | |
2a48fc0a | 20 | #include <linux/mutex.h> |
4ee60ec1 | 21 | #include <linux/pagemap.h> |
9db5579b | 22 | #include <linux/radix-tree.h> |
ff01bb48 | 23 | #include <linux/fs.h> |
5a0e3ad6 | 24 | #include <linux/slab.h> |
23c47d2a | 25 | #include <linux/backing-dev.h> |
f4be591f | 26 | #include <linux/debugfs.h> |
9db5579b | 27 | |
7c0f6ba6 | 28 | #include <linux/uaccess.h> |
9db5579b | 29 | |
9db5579b NP |
30 | #define PAGE_SECTORS_SHIFT (PAGE_SHIFT - SECTOR_SHIFT) |
31 | #define PAGE_SECTORS (1 << PAGE_SECTORS_SHIFT) | |
32 | ||
33 | /* | |
34 | * Each block ramdisk device has a radix_tree brd_pages of pages that stores | |
35 | * the pages containing the block device's contents. A brd page's ->index is | |
36 | * its offset in PAGE_SIZE units. This is similar to, but in no way connected | |
37 | * with, the kernel's pagecache or buffer cache (which sit above our block | |
38 | * device). | |
39 | */ | |
40 | struct brd_device { | |
7f9b348c | 41 | int brd_number; |
9db5579b NP |
42 | struct gendisk *brd_disk; |
43 | struct list_head brd_list; | |
44 | ||
45 | /* | |
46 | * Backing store of pages and lock to protect it. This is the contents | |
47 | * of the block device. | |
48 | */ | |
49 | spinlock_t brd_lock; | |
50 | struct radix_tree_root brd_pages; | |
f4be591f | 51 | u64 brd_nr_pages; |
9db5579b NP |
52 | }; |
53 | ||
54 | /* | |
55 | * Look up and return a brd's page for a given sector. | |
56 | */ | |
57 | static struct page *brd_lookup_page(struct brd_device *brd, sector_t sector) | |
58 | { | |
59 | pgoff_t idx; | |
60 | struct page *page; | |
61 | ||
62 | /* | |
63 | * The page lifetime is protected by the fact that we have opened the | |
64 | * device node -- brd pages will never be deleted under us, so we | |
65 | * don't need any further locking or refcounting. | |
66 | * | |
67 | * This is strictly true for the radix-tree nodes as well (ie. we | |
68 | * don't actually need the rcu_read_lock()), however that is not a | |
69 | * documented feature of the radix-tree API so it is better to be | |
70 | * safe here (we don't have total exclusion from radix tree updates | |
71 | * here, only deletes). | |
72 | */ | |
73 | rcu_read_lock(); | |
74 | idx = sector >> PAGE_SECTORS_SHIFT; /* sector to page index */ | |
75 | page = radix_tree_lookup(&brd->brd_pages, idx); | |
76 | rcu_read_unlock(); | |
77 | ||
78 | BUG_ON(page && page->index != idx); | |
79 | ||
80 | return page; | |
81 | } | |
82 | ||
83 | /* | |
84 | * Look up and return a brd's page for a given sector. | |
85 | * If one does not exist, allocate an empty page, and insert that. Then | |
86 | * return it. | |
87 | */ | |
88 | static struct page *brd_insert_page(struct brd_device *brd, sector_t sector) | |
89 | { | |
90 | pgoff_t idx; | |
91 | struct page *page; | |
75acb9cd | 92 | gfp_t gfp_flags; |
9db5579b NP |
93 | |
94 | page = brd_lookup_page(brd, sector); | |
95 | if (page) | |
96 | return page; | |
97 | ||
98 | /* | |
99 | * Must use NOIO because we don't want to recurse back into the | |
100 | * block or filesystem layers from page reclaim. | |
101 | */ | |
f6b50160 | 102 | gfp_flags = GFP_NOIO | __GFP_ZERO | __GFP_HIGHMEM; |
26defe34 | 103 | page = alloc_page(gfp_flags); |
9db5579b NP |
104 | if (!page) |
105 | return NULL; | |
106 | ||
107 | if (radix_tree_preload(GFP_NOIO)) { | |
108 | __free_page(page); | |
109 | return NULL; | |
110 | } | |
111 | ||
112 | spin_lock(&brd->brd_lock); | |
113 | idx = sector >> PAGE_SECTORS_SHIFT; | |
dfd20b2b | 114 | page->index = idx; |
9db5579b NP |
115 | if (radix_tree_insert(&brd->brd_pages, idx, page)) { |
116 | __free_page(page); | |
117 | page = radix_tree_lookup(&brd->brd_pages, idx); | |
118 | BUG_ON(!page); | |
119 | BUG_ON(page->index != idx); | |
f4be591f CO |
120 | } else { |
121 | brd->brd_nr_pages++; | |
dfd20b2b | 122 | } |
9db5579b NP |
123 | spin_unlock(&brd->brd_lock); |
124 | ||
125 | radix_tree_preload_end(); | |
126 | ||
127 | return page; | |
128 | } | |
129 | ||
130 | /* | |
131 | * Free all backing store pages and radix tree. This must only be called when | |
132 | * there are no other users of the device. | |
133 | */ | |
134 | #define FREE_BATCH 16 | |
135 | static void brd_free_pages(struct brd_device *brd) | |
136 | { | |
137 | unsigned long pos = 0; | |
138 | struct page *pages[FREE_BATCH]; | |
139 | int nr_pages; | |
140 | ||
141 | do { | |
142 | int i; | |
143 | ||
144 | nr_pages = radix_tree_gang_lookup(&brd->brd_pages, | |
145 | (void **)pages, pos, FREE_BATCH); | |
146 | ||
147 | for (i = 0; i < nr_pages; i++) { | |
148 | void *ret; | |
149 | ||
150 | BUG_ON(pages[i]->index < pos); | |
151 | pos = pages[i]->index; | |
152 | ret = radix_tree_delete(&brd->brd_pages, pos); | |
153 | BUG_ON(!ret || ret != pages[i]); | |
154 | __free_page(pages[i]); | |
155 | } | |
156 | ||
157 | pos++; | |
158 | ||
936b33f7 MP |
159 | /* |
160 | * It takes 3.4 seconds to remove 80GiB ramdisk. | |
161 | * So, we need cond_resched to avoid stalling the CPU. | |
162 | */ | |
163 | cond_resched(); | |
164 | ||
9db5579b NP |
165 | /* |
166 | * This assumes radix_tree_gang_lookup always returns as | |
167 | * many pages as possible. If the radix-tree code changes, | |
168 | * so will this have to. | |
169 | */ | |
170 | } while (nr_pages == FREE_BATCH); | |
171 | } | |
172 | ||
173 | /* | |
174 | * copy_to_brd_setup must be called before copy_to_brd. It may sleep. | |
175 | */ | |
176 | static int copy_to_brd_setup(struct brd_device *brd, sector_t sector, size_t n) | |
177 | { | |
178 | unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; | |
179 | size_t copy; | |
180 | ||
181 | copy = min_t(size_t, n, PAGE_SIZE - offset); | |
182 | if (!brd_insert_page(brd, sector)) | |
96f8d8e0 | 183 | return -ENOSPC; |
9db5579b NP |
184 | if (copy < n) { |
185 | sector += copy >> SECTOR_SHIFT; | |
186 | if (!brd_insert_page(brd, sector)) | |
96f8d8e0 | 187 | return -ENOSPC; |
9db5579b NP |
188 | } |
189 | return 0; | |
190 | } | |
191 | ||
192 | /* | |
193 | * Copy n bytes from src to the brd starting at sector. Does not sleep. | |
194 | */ | |
195 | static void copy_to_brd(struct brd_device *brd, const void *src, | |
196 | sector_t sector, size_t n) | |
197 | { | |
198 | struct page *page; | |
199 | void *dst; | |
200 | unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; | |
201 | size_t copy; | |
202 | ||
203 | copy = min_t(size_t, n, PAGE_SIZE - offset); | |
204 | page = brd_lookup_page(brd, sector); | |
205 | BUG_ON(!page); | |
206 | ||
cfd8005c | 207 | dst = kmap_atomic(page); |
9db5579b | 208 | memcpy(dst + offset, src, copy); |
cfd8005c | 209 | kunmap_atomic(dst); |
9db5579b NP |
210 | |
211 | if (copy < n) { | |
212 | src += copy; | |
213 | sector += copy >> SECTOR_SHIFT; | |
214 | copy = n - copy; | |
215 | page = brd_lookup_page(brd, sector); | |
216 | BUG_ON(!page); | |
217 | ||
cfd8005c | 218 | dst = kmap_atomic(page); |
9db5579b | 219 | memcpy(dst, src, copy); |
cfd8005c | 220 | kunmap_atomic(dst); |
9db5579b NP |
221 | } |
222 | } | |
223 | ||
224 | /* | |
225 | * Copy n bytes to dst from the brd starting at sector. Does not sleep. | |
226 | */ | |
227 | static void copy_from_brd(void *dst, struct brd_device *brd, | |
228 | sector_t sector, size_t n) | |
229 | { | |
230 | struct page *page; | |
231 | void *src; | |
232 | unsigned int offset = (sector & (PAGE_SECTORS-1)) << SECTOR_SHIFT; | |
233 | size_t copy; | |
234 | ||
235 | copy = min_t(size_t, n, PAGE_SIZE - offset); | |
236 | page = brd_lookup_page(brd, sector); | |
237 | if (page) { | |
cfd8005c | 238 | src = kmap_atomic(page); |
9db5579b | 239 | memcpy(dst, src + offset, copy); |
cfd8005c | 240 | kunmap_atomic(src); |
9db5579b NP |
241 | } else |
242 | memset(dst, 0, copy); | |
243 | ||
244 | if (copy < n) { | |
245 | dst += copy; | |
246 | sector += copy >> SECTOR_SHIFT; | |
247 | copy = n - copy; | |
248 | page = brd_lookup_page(brd, sector); | |
249 | if (page) { | |
cfd8005c | 250 | src = kmap_atomic(page); |
9db5579b | 251 | memcpy(dst, src, copy); |
cfd8005c | 252 | kunmap_atomic(src); |
9db5579b NP |
253 | } else |
254 | memset(dst, 0, copy); | |
255 | } | |
256 | } | |
257 | ||
258 | /* | |
259 | * Process a single bvec of a bio. | |
260 | */ | |
261 | static int brd_do_bvec(struct brd_device *brd, struct page *page, | |
3f289dcb | 262 | unsigned int len, unsigned int off, unsigned int op, |
9db5579b NP |
263 | sector_t sector) |
264 | { | |
265 | void *mem; | |
266 | int err = 0; | |
267 | ||
3f289dcb | 268 | if (op_is_write(op)) { |
9db5579b NP |
269 | err = copy_to_brd_setup(brd, sector, len); |
270 | if (err) | |
271 | goto out; | |
272 | } | |
273 | ||
cfd8005c | 274 | mem = kmap_atomic(page); |
3f289dcb | 275 | if (!op_is_write(op)) { |
9db5579b NP |
276 | copy_from_brd(mem + off, brd, sector, len); |
277 | flush_dcache_page(page); | |
c2572f2b NP |
278 | } else { |
279 | flush_dcache_page(page); | |
9db5579b | 280 | copy_to_brd(brd, mem + off, sector, len); |
c2572f2b | 281 | } |
cfd8005c | 282 | kunmap_atomic(mem); |
9db5579b NP |
283 | |
284 | out: | |
285 | return err; | |
286 | } | |
287 | ||
c62b37d9 | 288 | static blk_qc_t brd_submit_bio(struct bio *bio) |
9db5579b | 289 | { |
309dca30 | 290 | struct brd_device *brd = bio->bi_bdev->bd_disk->private_data; |
74cb8994 | 291 | sector_t sector = bio->bi_iter.bi_sector; |
7988613b | 292 | struct bio_vec bvec; |
7988613b | 293 | struct bvec_iter iter; |
9db5579b | 294 | |
7988613b KO |
295 | bio_for_each_segment(bvec, bio, iter) { |
296 | unsigned int len = bvec.bv_len; | |
4246a0b6 CH |
297 | int err; |
298 | ||
f1acbf21 ML |
299 | /* Don't support un-aligned buffer */ |
300 | WARN_ON_ONCE((bvec.bv_offset & (SECTOR_SIZE - 1)) || | |
301 | (len & (SECTOR_SIZE - 1))); | |
302 | ||
c11f0c0b | 303 | err = brd_do_bvec(brd, bvec.bv_page, len, bvec.bv_offset, |
3f289dcb | 304 | bio_op(bio), sector); |
9db5579b | 305 | if (err) |
4246a0b6 | 306 | goto io_error; |
9db5579b NP |
307 | sector += len >> SECTOR_SHIFT; |
308 | } | |
309 | ||
4246a0b6 | 310 | bio_endio(bio); |
dece1635 | 311 | return BLK_QC_T_NONE; |
4246a0b6 CH |
312 | io_error: |
313 | bio_io_error(bio); | |
dece1635 | 314 | return BLK_QC_T_NONE; |
9db5579b NP |
315 | } |
316 | ||
a72132c3 | 317 | static int brd_rw_page(struct block_device *bdev, sector_t sector, |
3f289dcb | 318 | struct page *page, unsigned int op) |
a72132c3 MW |
319 | { |
320 | struct brd_device *brd = bdev->bd_disk->private_data; | |
98cc093c HY |
321 | int err; |
322 | ||
323 | if (PageTransHuge(page)) | |
324 | return -ENOTSUPP; | |
3f289dcb TH |
325 | err = brd_do_bvec(brd, page, PAGE_SIZE, 0, op, sector); |
326 | page_endio(page, op_is_write(op), err); | |
a72132c3 MW |
327 | return err; |
328 | } | |
329 | ||
83d5cde4 | 330 | static const struct block_device_operations brd_fops = { |
75acb9cd | 331 | .owner = THIS_MODULE, |
c62b37d9 | 332 | .submit_bio = brd_submit_bio, |
a72132c3 | 333 | .rw_page = brd_rw_page, |
9db5579b NP |
334 | }; |
335 | ||
336 | /* | |
337 | * And now the modules code and kernel interface. | |
338 | */ | |
937af5ec | 339 | static int rd_nr = CONFIG_BLK_DEV_RAM_COUNT; |
5657a819 | 340 | module_param(rd_nr, int, 0444); |
9db5579b | 341 | MODULE_PARM_DESC(rd_nr, "Maximum number of brd devices"); |
937af5ec | 342 | |
366f4aea | 343 | unsigned long rd_size = CONFIG_BLK_DEV_RAM_SIZE; |
5657a819 | 344 | module_param(rd_size, ulong, 0444); |
9db5579b | 345 | MODULE_PARM_DESC(rd_size, "Size of each RAM disk in kbytes."); |
937af5ec BH |
346 | |
347 | static int max_part = 1; | |
5657a819 | 348 | module_param(max_part, int, 0444); |
937af5ec BH |
349 | MODULE_PARM_DESC(max_part, "Num Minors to reserve between devices"); |
350 | ||
9db5579b NP |
351 | MODULE_LICENSE("GPL"); |
352 | MODULE_ALIAS_BLOCKDEV_MAJOR(RAMDISK_MAJOR); | |
efedf51c | 353 | MODULE_ALIAS("rd"); |
9db5579b NP |
354 | |
355 | #ifndef MODULE | |
356 | /* Legacy boot options - nonmodular */ | |
357 | static int __init ramdisk_size(char *str) | |
358 | { | |
359 | rd_size = simple_strtol(str, NULL, 0); | |
360 | return 1; | |
361 | } | |
1adbee50 | 362 | __setup("ramdisk_size=", ramdisk_size); |
9db5579b NP |
363 | #endif |
364 | ||
365 | /* | |
366 | * The device scheme is derived from loop.c. Keep them in synch where possible | |
367 | * (should share code eventually). | |
368 | */ | |
369 | static LIST_HEAD(brd_devices); | |
370 | static DEFINE_MUTEX(brd_devices_mutex); | |
f4be591f | 371 | static struct dentry *brd_debugfs_dir; |
9db5579b | 372 | |
7f9b348c | 373 | static int brd_alloc(int i) |
9db5579b NP |
374 | { |
375 | struct brd_device *brd; | |
376 | struct gendisk *disk; | |
f4be591f | 377 | char buf[DISK_NAME_LEN]; |
9db5579b NP |
378 | |
379 | brd = kzalloc(sizeof(*brd), GFP_KERNEL); | |
380 | if (!brd) | |
7f9b348c | 381 | return -ENOMEM; |
9db5579b NP |
382 | brd->brd_number = i; |
383 | spin_lock_init(&brd->brd_lock); | |
384 | INIT_RADIX_TREE(&brd->brd_pages, GFP_ATOMIC); | |
385 | ||
f4be591f CO |
386 | snprintf(buf, DISK_NAME_LEN, "ram%d", i); |
387 | if (!IS_ERR_OR_NULL(brd_debugfs_dir)) | |
388 | debugfs_create_u64(buf, 0444, brd_debugfs_dir, | |
389 | &brd->brd_nr_pages); | |
390 | ||
7f9b348c | 391 | disk = brd->brd_disk = blk_alloc_disk(NUMA_NO_NODE); |
9db5579b | 392 | if (!disk) |
7f9b348c CH |
393 | goto out_free_dev; |
394 | ||
9db5579b | 395 | disk->major = RAMDISK_MAJOR; |
937af5ec | 396 | disk->first_minor = i * max_part; |
7f9b348c | 397 | disk->minors = max_part; |
9db5579b NP |
398 | disk->fops = &brd_fops; |
399 | disk->private_data = brd; | |
937af5ec | 400 | disk->flags = GENHD_FL_EXT_DEVT; |
f4be591f | 401 | strlcpy(disk->disk_name, buf, DISK_NAME_LEN); |
9db5579b | 402 | set_capacity(disk, rd_size * 2); |
7f9b348c CH |
403 | |
404 | /* | |
405 | * This is so fdisk will align partitions on 4k, because of | |
406 | * direct_access API needing 4k alignment, returning a PFN | |
407 | * (This is only a problem on very small devices <= 4M, | |
408 | * otherwise fdisk will align on 1M. Regardless this call | |
409 | * is harmless) | |
410 | */ | |
411 | blk_queue_physical_block_size(disk->queue, PAGE_SIZE); | |
9db5579b | 412 | |
316ba573 | 413 | /* Tell the block layer that this is not a rotational device */ |
7f9b348c CH |
414 | blk_queue_flag_set(QUEUE_FLAG_NONROT, disk->queue); |
415 | blk_queue_flag_clear(QUEUE_FLAG_ADD_RANDOM, disk->queue); | |
416 | add_disk(disk); | |
417 | list_add_tail(&brd->brd_list, &brd_devices); | |
316ba573 | 418 | |
7f9b348c | 419 | return 0; |
9db5579b | 420 | |
9db5579b NP |
421 | out_free_dev: |
422 | kfree(brd); | |
7f9b348c | 423 | return -ENOMEM; |
9db5579b NP |
424 | } |
425 | ||
7cc178a6 | 426 | static void brd_probe(dev_t dev) |
9db5579b | 427 | { |
7cc178a6 | 428 | int i = MINOR(dev) / max_part; |
7f9b348c | 429 | struct brd_device *brd; |
9db5579b | 430 | |
7cc178a6 | 431 | mutex_lock(&brd_devices_mutex); |
9db5579b NP |
432 | list_for_each_entry(brd, &brd_devices, brd_list) { |
433 | if (brd->brd_number == i) | |
7cc178a6 | 434 | goto out_unlock; |
9db5579b NP |
435 | } |
436 | ||
7f9b348c | 437 | brd_alloc(i); |
7cc178a6 CH |
438 | out_unlock: |
439 | mutex_unlock(&brd_devices_mutex); | |
9db5579b NP |
440 | } |
441 | ||
442 | static void brd_del_one(struct brd_device *brd) | |
443 | { | |
444 | list_del(&brd->brd_list); | |
445 | del_gendisk(brd->brd_disk); | |
7f9b348c CH |
446 | blk_cleanup_disk(brd->brd_disk); |
447 | brd_free_pages(brd); | |
448 | kfree(brd); | |
9db5579b NP |
449 | } |
450 | ||
c8ab4225 ZL |
451 | static inline void brd_check_and_reset_par(void) |
452 | { | |
453 | if (unlikely(!max_part)) | |
454 | max_part = 1; | |
455 | ||
456 | /* | |
457 | * make sure 'max_part' can be divided exactly by (1U << MINORBITS), | |
458 | * otherwise, it is possiable to get same dev_t when adding partitions. | |
459 | */ | |
460 | if ((1U << MINORBITS) % max_part != 0) | |
461 | max_part = 1UL << fls(max_part); | |
462 | ||
463 | if (max_part > DISK_MAX_PARTS) { | |
464 | pr_info("brd: max_part can't be larger than %d, reset max_part = %d.\n", | |
465 | DISK_MAX_PARTS, DISK_MAX_PARTS); | |
466 | max_part = DISK_MAX_PARTS; | |
467 | } | |
468 | } | |
469 | ||
9db5579b NP |
470 | static int __init brd_init(void) |
471 | { | |
9db5579b | 472 | struct brd_device *brd, *next; |
7f9b348c | 473 | int err, i; |
9db5579b NP |
474 | |
475 | /* | |
476 | * brd module now has a feature to instantiate underlying device | |
477 | * structure on-demand, provided that there is an access dev node. | |
9db5579b | 478 | * |
937af5ec BH |
479 | * (1) if rd_nr is specified, create that many upfront. else |
480 | * it defaults to CONFIG_BLK_DEV_RAM_COUNT | |
481 | * (2) User can further extend brd devices by create dev node themselves | |
482 | * and have kernel automatically instantiate actual device | |
483 | * on-demand. Example: | |
484 | * mknod /path/devnod_name b 1 X # 1 is the rd major | |
485 | * fdisk -l /path/devnod_name | |
486 | * If (X / max_part) was not already created it will be created | |
487 | * dynamically. | |
9db5579b | 488 | */ |
d7853d1f | 489 | |
7cc178a6 | 490 | if (__register_blkdev(RAMDISK_MAJOR, "ramdisk", brd_probe)) |
9db5579b NP |
491 | return -EIO; |
492 | ||
c8ab4225 | 493 | brd_check_and_reset_par(); |
937af5ec | 494 | |
f4be591f CO |
495 | brd_debugfs_dir = debugfs_create_dir("ramdisk_pages", NULL); |
496 | ||
7cc178a6 | 497 | mutex_lock(&brd_devices_mutex); |
937af5ec | 498 | for (i = 0; i < rd_nr; i++) { |
7f9b348c CH |
499 | err = brd_alloc(i); |
500 | if (err) | |
9db5579b | 501 | goto out_free; |
9db5579b NP |
502 | } |
503 | ||
7cc178a6 | 504 | mutex_unlock(&brd_devices_mutex); |
9db5579b | 505 | |
937af5ec | 506 | pr_info("brd: module loaded\n"); |
9db5579b NP |
507 | return 0; |
508 | ||
509 | out_free: | |
f4be591f CO |
510 | debugfs_remove_recursive(brd_debugfs_dir); |
511 | ||
7f9b348c CH |
512 | list_for_each_entry_safe(brd, next, &brd_devices, brd_list) |
513 | brd_del_one(brd); | |
7cc178a6 | 514 | mutex_unlock(&brd_devices_mutex); |
c82f2966 | 515 | unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); |
9db5579b | 516 | |
937af5ec | 517 | pr_info("brd: module NOT loaded !!!\n"); |
7f9b348c | 518 | return err; |
9db5579b NP |
519 | } |
520 | ||
521 | static void __exit brd_exit(void) | |
522 | { | |
9db5579b NP |
523 | struct brd_device *brd, *next; |
524 | ||
f4be591f CO |
525 | debugfs_remove_recursive(brd_debugfs_dir); |
526 | ||
9db5579b NP |
527 | list_for_each_entry_safe(brd, next, &brd_devices, brd_list) |
528 | brd_del_one(brd); | |
529 | ||
9db5579b | 530 | unregister_blkdev(RAMDISK_MAJOR, "ramdisk"); |
937af5ec BH |
531 | |
532 | pr_info("brd: module unloaded\n"); | |
9db5579b NP |
533 | } |
534 | ||
535 | module_init(brd_init); | |
536 | module_exit(brd_exit); | |
537 |