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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * linux/drivers/block/loop.c | |
3 | * | |
4 | * Written by Theodore Ts'o, 3/29/93 | |
5 | * | |
6 | * Copyright 1993 by Theodore Ts'o. Redistribution of this file is | |
7 | * permitted under the GNU General Public License. | |
8 | * | |
9 | * DES encryption plus some minor changes by Werner Almesberger, 30-MAY-1993 | |
10 | * more DES encryption plus IDEA encryption by Nicholas J. Leon, June 20, 1996 | |
11 | * | |
12 | * Modularized and updated for 1.1.16 kernel - Mitch Dsouza 28th May 1994 | |
13 | * Adapted for 1.3.59 kernel - Andries Brouwer, 1 Feb 1996 | |
14 | * | |
15 | * Fixed do_loop_request() re-entrancy - Vincent.Renardias@waw.com Mar 20, 1997 | |
16 | * | |
17 | * Added devfs support - Richard Gooch <rgooch@atnf.csiro.au> 16-Jan-1998 | |
18 | * | |
19 | * Handle sparse backing files correctly - Kenn Humborg, Jun 28, 1998 | |
20 | * | |
21 | * Loadable modules and other fixes by AK, 1998 | |
22 | * | |
23 | * Make real block number available to downstream transfer functions, enables | |
24 | * CBC (and relatives) mode encryption requiring unique IVs per data block. | |
25 | * Reed H. Petty, rhp@draper.net | |
26 | * | |
27 | * Maximum number of loop devices now dynamic via max_loop module parameter. | |
28 | * Russell Kroll <rkroll@exploits.org> 19990701 | |
29 | * | |
30 | * Maximum number of loop devices when compiled-in now selectable by passing | |
31 | * max_loop=<1-255> to the kernel on boot. | |
96de0e25 | 32 | * Erik I. Bolsø, <eriki@himolde.no>, Oct 31, 1999 |
1da177e4 LT |
33 | * |
34 | * Completely rewrite request handling to be make_request_fn style and | |
35 | * non blocking, pushing work to a helper thread. Lots of fixes from | |
36 | * Al Viro too. | |
37 | * Jens Axboe <axboe@suse.de>, Nov 2000 | |
38 | * | |
39 | * Support up to 256 loop devices | |
40 | * Heinz Mauelshagen <mge@sistina.com>, Feb 2002 | |
41 | * | |
42 | * Support for falling back on the write file operation when the address space | |
4e02ed4b | 43 | * operations write_begin is not available on the backing filesystem. |
1da177e4 LT |
44 | * Anton Altaparmakov, 16 Feb 2005 |
45 | * | |
46 | * Still To Fix: | |
47 | * - Advisory locking is ignored here. | |
48 | * - Should use an own CAP_* category instead of CAP_SYS_ADMIN | |
49 | * | |
50 | */ | |
51 | ||
1da177e4 LT |
52 | #include <linux/module.h> |
53 | #include <linux/moduleparam.h> | |
54 | #include <linux/sched.h> | |
55 | #include <linux/fs.h> | |
56 | #include <linux/file.h> | |
57 | #include <linux/stat.h> | |
58 | #include <linux/errno.h> | |
59 | #include <linux/major.h> | |
60 | #include <linux/wait.h> | |
61 | #include <linux/blkdev.h> | |
62 | #include <linux/blkpg.h> | |
63 | #include <linux/init.h> | |
1da177e4 LT |
64 | #include <linux/smp_lock.h> |
65 | #include <linux/swap.h> | |
66 | #include <linux/slab.h> | |
67 | #include <linux/loop.h> | |
863d5b82 | 68 | #include <linux/compat.h> |
1da177e4 | 69 | #include <linux/suspend.h> |
83144186 | 70 | #include <linux/freezer.h> |
1da177e4 LT |
71 | #include <linux/writeback.h> |
72 | #include <linux/buffer_head.h> /* for invalidate_bdev() */ | |
73 | #include <linux/completion.h> | |
74 | #include <linux/highmem.h> | |
75 | #include <linux/gfp.h> | |
6c997918 | 76 | #include <linux/kthread.h> |
d6b29d7c | 77 | #include <linux/splice.h> |
1da177e4 LT |
78 | |
79 | #include <asm/uaccess.h> | |
80 | ||
73285082 KC |
81 | static LIST_HEAD(loop_devices); |
82 | static DEFINE_MUTEX(loop_devices_mutex); | |
1da177e4 | 83 | |
476a4813 LV |
84 | static int max_part; |
85 | static int part_shift; | |
86 | ||
1da177e4 LT |
87 | /* |
88 | * Transfer functions | |
89 | */ | |
90 | static int transfer_none(struct loop_device *lo, int cmd, | |
91 | struct page *raw_page, unsigned raw_off, | |
92 | struct page *loop_page, unsigned loop_off, | |
93 | int size, sector_t real_block) | |
94 | { | |
95 | char *raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off; | |
96 | char *loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off; | |
97 | ||
98 | if (cmd == READ) | |
99 | memcpy(loop_buf, raw_buf, size); | |
100 | else | |
101 | memcpy(raw_buf, loop_buf, size); | |
102 | ||
103 | kunmap_atomic(raw_buf, KM_USER0); | |
104 | kunmap_atomic(loop_buf, KM_USER1); | |
105 | cond_resched(); | |
106 | return 0; | |
107 | } | |
108 | ||
109 | static int transfer_xor(struct loop_device *lo, int cmd, | |
110 | struct page *raw_page, unsigned raw_off, | |
111 | struct page *loop_page, unsigned loop_off, | |
112 | int size, sector_t real_block) | |
113 | { | |
114 | char *raw_buf = kmap_atomic(raw_page, KM_USER0) + raw_off; | |
115 | char *loop_buf = kmap_atomic(loop_page, KM_USER1) + loop_off; | |
116 | char *in, *out, *key; | |
117 | int i, keysize; | |
118 | ||
119 | if (cmd == READ) { | |
120 | in = raw_buf; | |
121 | out = loop_buf; | |
122 | } else { | |
123 | in = loop_buf; | |
124 | out = raw_buf; | |
125 | } | |
126 | ||
127 | key = lo->lo_encrypt_key; | |
128 | keysize = lo->lo_encrypt_key_size; | |
129 | for (i = 0; i < size; i++) | |
130 | *out++ = *in++ ^ key[(i & 511) % keysize]; | |
131 | ||
132 | kunmap_atomic(raw_buf, KM_USER0); | |
133 | kunmap_atomic(loop_buf, KM_USER1); | |
134 | cond_resched(); | |
135 | return 0; | |
136 | } | |
137 | ||
138 | static int xor_init(struct loop_device *lo, const struct loop_info64 *info) | |
139 | { | |
140 | if (unlikely(info->lo_encrypt_key_size <= 0)) | |
141 | return -EINVAL; | |
142 | return 0; | |
143 | } | |
144 | ||
145 | static struct loop_func_table none_funcs = { | |
146 | .number = LO_CRYPT_NONE, | |
147 | .transfer = transfer_none, | |
148 | }; | |
149 | ||
150 | static struct loop_func_table xor_funcs = { | |
151 | .number = LO_CRYPT_XOR, | |
152 | .transfer = transfer_xor, | |
153 | .init = xor_init | |
154 | }; | |
155 | ||
156 | /* xfer_funcs[0] is special - its release function is never called */ | |
157 | static struct loop_func_table *xfer_funcs[MAX_LO_CRYPT] = { | |
158 | &none_funcs, | |
159 | &xor_funcs | |
160 | }; | |
161 | ||
162 | static loff_t get_loop_size(struct loop_device *lo, struct file *file) | |
163 | { | |
164 | loff_t size, offset, loopsize; | |
165 | ||
166 | /* Compute loopsize in bytes */ | |
167 | size = i_size_read(file->f_mapping->host); | |
168 | offset = lo->lo_offset; | |
169 | loopsize = size - offset; | |
170 | if (lo->lo_sizelimit > 0 && lo->lo_sizelimit < loopsize) | |
171 | loopsize = lo->lo_sizelimit; | |
172 | ||
173 | /* | |
174 | * Unfortunately, if we want to do I/O on the device, | |
175 | * the number of 512-byte sectors has to fit into a sector_t. | |
176 | */ | |
177 | return loopsize >> 9; | |
178 | } | |
179 | ||
180 | static int | |
181 | figure_loop_size(struct loop_device *lo) | |
182 | { | |
183 | loff_t size = get_loop_size(lo, lo->lo_backing_file); | |
184 | sector_t x = (sector_t)size; | |
185 | ||
186 | if (unlikely((loff_t)x != size)) | |
187 | return -EFBIG; | |
188 | ||
73285082 | 189 | set_capacity(lo->lo_disk, x); |
1da177e4 LT |
190 | return 0; |
191 | } | |
192 | ||
193 | static inline int | |
194 | lo_do_transfer(struct loop_device *lo, int cmd, | |
195 | struct page *rpage, unsigned roffs, | |
196 | struct page *lpage, unsigned loffs, | |
197 | int size, sector_t rblock) | |
198 | { | |
199 | if (unlikely(!lo->transfer)) | |
200 | return 0; | |
201 | ||
202 | return lo->transfer(lo, cmd, rpage, roffs, lpage, loffs, size, rblock); | |
203 | } | |
204 | ||
205 | /** | |
206 | * do_lo_send_aops - helper for writing data to a loop device | |
207 | * | |
208 | * This is the fast version for backing filesystems which implement the address | |
afddba49 | 209 | * space operations write_begin and write_end. |
1da177e4 LT |
210 | */ |
211 | static int do_lo_send_aops(struct loop_device *lo, struct bio_vec *bvec, | |
511de73f | 212 | loff_t pos, struct page *unused) |
1da177e4 LT |
213 | { |
214 | struct file *file = lo->lo_backing_file; /* kudos to NFsckingS */ | |
215 | struct address_space *mapping = file->f_mapping; | |
1da177e4 LT |
216 | pgoff_t index; |
217 | unsigned offset, bv_offs; | |
994fc28c | 218 | int len, ret; |
1da177e4 | 219 | |
1b1dcc1b | 220 | mutex_lock(&mapping->host->i_mutex); |
1da177e4 LT |
221 | index = pos >> PAGE_CACHE_SHIFT; |
222 | offset = pos & ((pgoff_t)PAGE_CACHE_SIZE - 1); | |
223 | bv_offs = bvec->bv_offset; | |
224 | len = bvec->bv_len; | |
225 | while (len > 0) { | |
226 | sector_t IV; | |
afddba49 | 227 | unsigned size, copied; |
1da177e4 | 228 | int transfer_result; |
afddba49 NP |
229 | struct page *page; |
230 | void *fsdata; | |
1da177e4 LT |
231 | |
232 | IV = ((sector_t)index << (PAGE_CACHE_SHIFT - 9))+(offset >> 9); | |
233 | size = PAGE_CACHE_SIZE - offset; | |
234 | if (size > len) | |
235 | size = len; | |
afddba49 NP |
236 | |
237 | ret = pagecache_write_begin(file, mapping, pos, size, 0, | |
238 | &page, &fsdata); | |
239 | if (ret) | |
1da177e4 | 240 | goto fail; |
afddba49 | 241 | |
1da177e4 LT |
242 | transfer_result = lo_do_transfer(lo, WRITE, page, offset, |
243 | bvec->bv_page, bv_offs, size, IV); | |
afddba49 | 244 | copied = size; |
1da177e4 | 245 | if (unlikely(transfer_result)) |
afddba49 NP |
246 | copied = 0; |
247 | ||
248 | ret = pagecache_write_end(file, mapping, pos, size, copied, | |
249 | page, fsdata); | |
8268f5a7 | 250 | if (ret < 0 || ret != copied) |
afddba49 | 251 | goto fail; |
afddba49 NP |
252 | |
253 | if (unlikely(transfer_result)) | |
254 | goto fail; | |
255 | ||
256 | bv_offs += copied; | |
257 | len -= copied; | |
1da177e4 LT |
258 | offset = 0; |
259 | index++; | |
afddba49 | 260 | pos += copied; |
1da177e4 | 261 | } |
994fc28c | 262 | ret = 0; |
1da177e4 | 263 | out: |
1b1dcc1b | 264 | mutex_unlock(&mapping->host->i_mutex); |
1da177e4 | 265 | return ret; |
1da177e4 LT |
266 | fail: |
267 | ret = -1; | |
268 | goto out; | |
269 | } | |
270 | ||
271 | /** | |
272 | * __do_lo_send_write - helper for writing data to a loop device | |
273 | * | |
274 | * This helper just factors out common code between do_lo_send_direct_write() | |
275 | * and do_lo_send_write(). | |
276 | */ | |
858119e1 | 277 | static int __do_lo_send_write(struct file *file, |
98ae6ccd | 278 | u8 *buf, const int len, loff_t pos) |
1da177e4 LT |
279 | { |
280 | ssize_t bw; | |
281 | mm_segment_t old_fs = get_fs(); | |
282 | ||
283 | set_fs(get_ds()); | |
284 | bw = file->f_op->write(file, buf, len, &pos); | |
285 | set_fs(old_fs); | |
286 | if (likely(bw == len)) | |
287 | return 0; | |
288 | printk(KERN_ERR "loop: Write error at byte offset %llu, length %i.\n", | |
289 | (unsigned long long)pos, len); | |
290 | if (bw >= 0) | |
291 | bw = -EIO; | |
292 | return bw; | |
293 | } | |
294 | ||
295 | /** | |
296 | * do_lo_send_direct_write - helper for writing data to a loop device | |
297 | * | |
298 | * This is the fast, non-transforming version for backing filesystems which do | |
afddba49 | 299 | * not implement the address space operations write_begin and write_end. |
1da177e4 LT |
300 | * It uses the write file operation which should be present on all writeable |
301 | * filesystems. | |
302 | */ | |
303 | static int do_lo_send_direct_write(struct loop_device *lo, | |
511de73f | 304 | struct bio_vec *bvec, loff_t pos, struct page *page) |
1da177e4 LT |
305 | { |
306 | ssize_t bw = __do_lo_send_write(lo->lo_backing_file, | |
98ae6ccd | 307 | kmap(bvec->bv_page) + bvec->bv_offset, |
1da177e4 LT |
308 | bvec->bv_len, pos); |
309 | kunmap(bvec->bv_page); | |
310 | cond_resched(); | |
311 | return bw; | |
312 | } | |
313 | ||
314 | /** | |
315 | * do_lo_send_write - helper for writing data to a loop device | |
316 | * | |
317 | * This is the slow, transforming version for filesystems which do not | |
afddba49 | 318 | * implement the address space operations write_begin and write_end. It |
1da177e4 LT |
319 | * uses the write file operation which should be present on all writeable |
320 | * filesystems. | |
321 | * | |
322 | * Using fops->write is slower than using aops->{prepare,commit}_write in the | |
323 | * transforming case because we need to double buffer the data as we cannot do | |
324 | * the transformations in place as we do not have direct access to the | |
325 | * destination pages of the backing file. | |
326 | */ | |
327 | static int do_lo_send_write(struct loop_device *lo, struct bio_vec *bvec, | |
511de73f | 328 | loff_t pos, struct page *page) |
1da177e4 LT |
329 | { |
330 | int ret = lo_do_transfer(lo, WRITE, page, 0, bvec->bv_page, | |
331 | bvec->bv_offset, bvec->bv_len, pos >> 9); | |
332 | if (likely(!ret)) | |
333 | return __do_lo_send_write(lo->lo_backing_file, | |
98ae6ccd | 334 | page_address(page), bvec->bv_len, |
1da177e4 LT |
335 | pos); |
336 | printk(KERN_ERR "loop: Transfer error at byte offset %llu, " | |
337 | "length %i.\n", (unsigned long long)pos, bvec->bv_len); | |
338 | if (ret > 0) | |
339 | ret = -EIO; | |
340 | return ret; | |
341 | } | |
342 | ||
511de73f | 343 | static int lo_send(struct loop_device *lo, struct bio *bio, loff_t pos) |
1da177e4 | 344 | { |
511de73f | 345 | int (*do_lo_send)(struct loop_device *, struct bio_vec *, loff_t, |
1da177e4 LT |
346 | struct page *page); |
347 | struct bio_vec *bvec; | |
348 | struct page *page = NULL; | |
349 | int i, ret = 0; | |
350 | ||
351 | do_lo_send = do_lo_send_aops; | |
352 | if (!(lo->lo_flags & LO_FLAGS_USE_AOPS)) { | |
353 | do_lo_send = do_lo_send_direct_write; | |
354 | if (lo->transfer != transfer_none) { | |
355 | page = alloc_page(GFP_NOIO | __GFP_HIGHMEM); | |
356 | if (unlikely(!page)) | |
357 | goto fail; | |
358 | kmap(page); | |
359 | do_lo_send = do_lo_send_write; | |
360 | } | |
361 | } | |
362 | bio_for_each_segment(bvec, bio, i) { | |
511de73f | 363 | ret = do_lo_send(lo, bvec, pos, page); |
1da177e4 LT |
364 | if (ret < 0) |
365 | break; | |
366 | pos += bvec->bv_len; | |
367 | } | |
368 | if (page) { | |
369 | kunmap(page); | |
370 | __free_page(page); | |
371 | } | |
372 | out: | |
373 | return ret; | |
374 | fail: | |
375 | printk(KERN_ERR "loop: Failed to allocate temporary page for write.\n"); | |
376 | ret = -ENOMEM; | |
377 | goto out; | |
378 | } | |
379 | ||
380 | struct lo_read_data { | |
381 | struct loop_device *lo; | |
382 | struct page *page; | |
383 | unsigned offset; | |
384 | int bsize; | |
385 | }; | |
386 | ||
387 | static int | |
fd582140 JA |
388 | lo_splice_actor(struct pipe_inode_info *pipe, struct pipe_buffer *buf, |
389 | struct splice_desc *sd) | |
1da177e4 | 390 | { |
fd582140 | 391 | struct lo_read_data *p = sd->u.data; |
1da177e4 | 392 | struct loop_device *lo = p->lo; |
fd582140 | 393 | struct page *page = buf->page; |
1da177e4 | 394 | sector_t IV; |
a3941ec1 | 395 | int size, ret; |
1da177e4 | 396 | |
cac36bb0 | 397 | ret = buf->ops->confirm(pipe, buf); |
fd582140 JA |
398 | if (unlikely(ret)) |
399 | return ret; | |
1da177e4 | 400 | |
fd582140 JA |
401 | IV = ((sector_t) page->index << (PAGE_CACHE_SHIFT - 9)) + |
402 | (buf->offset >> 9); | |
403 | size = sd->len; | |
404 | if (size > p->bsize) | |
405 | size = p->bsize; | |
1da177e4 | 406 | |
fd582140 | 407 | if (lo_do_transfer(lo, READ, page, buf->offset, p->page, p->offset, size, IV)) { |
1da177e4 LT |
408 | printk(KERN_ERR "loop: transfer error block %ld\n", |
409 | page->index); | |
fd582140 | 410 | size = -EINVAL; |
1da177e4 LT |
411 | } |
412 | ||
413 | flush_dcache_page(p->page); | |
414 | ||
fd582140 JA |
415 | if (size > 0) |
416 | p->offset += size; | |
417 | ||
1da177e4 LT |
418 | return size; |
419 | } | |
420 | ||
fd582140 JA |
421 | static int |
422 | lo_direct_splice_actor(struct pipe_inode_info *pipe, struct splice_desc *sd) | |
423 | { | |
424 | return __splice_from_pipe(pipe, sd, lo_splice_actor); | |
425 | } | |
426 | ||
1da177e4 LT |
427 | static int |
428 | do_lo_receive(struct loop_device *lo, | |
429 | struct bio_vec *bvec, int bsize, loff_t pos) | |
430 | { | |
431 | struct lo_read_data cookie; | |
fd582140 | 432 | struct splice_desc sd; |
1da177e4 | 433 | struct file *file; |
fd582140 | 434 | long retval; |
1da177e4 LT |
435 | |
436 | cookie.lo = lo; | |
437 | cookie.page = bvec->bv_page; | |
438 | cookie.offset = bvec->bv_offset; | |
439 | cookie.bsize = bsize; | |
fd582140 JA |
440 | |
441 | sd.len = 0; | |
442 | sd.total_len = bvec->bv_len; | |
443 | sd.flags = 0; | |
444 | sd.pos = pos; | |
445 | sd.u.data = &cookie; | |
446 | ||
1da177e4 | 447 | file = lo->lo_backing_file; |
fd582140 JA |
448 | retval = splice_direct_to_actor(file, &sd, lo_direct_splice_actor); |
449 | ||
450 | if (retval < 0) | |
451 | return retval; | |
452 | ||
453 | return 0; | |
1da177e4 LT |
454 | } |
455 | ||
456 | static int | |
457 | lo_receive(struct loop_device *lo, struct bio *bio, int bsize, loff_t pos) | |
458 | { | |
459 | struct bio_vec *bvec; | |
460 | int i, ret = 0; | |
461 | ||
462 | bio_for_each_segment(bvec, bio, i) { | |
463 | ret = do_lo_receive(lo, bvec, bsize, pos); | |
464 | if (ret < 0) | |
465 | break; | |
466 | pos += bvec->bv_len; | |
467 | } | |
468 | return ret; | |
469 | } | |
470 | ||
471 | static int do_bio_filebacked(struct loop_device *lo, struct bio *bio) | |
472 | { | |
473 | loff_t pos; | |
474 | int ret; | |
475 | ||
476 | pos = ((loff_t) bio->bi_sector << 9) + lo->lo_offset; | |
477 | if (bio_rw(bio) == WRITE) | |
511de73f | 478 | ret = lo_send(lo, bio, pos); |
1da177e4 LT |
479 | else |
480 | ret = lo_receive(lo, bio, lo->lo_blocksize, pos); | |
481 | return ret; | |
482 | } | |
483 | ||
484 | /* | |
485 | * Add bio to back of pending list | |
486 | */ | |
487 | static void loop_add_bio(struct loop_device *lo, struct bio *bio) | |
488 | { | |
1da177e4 LT |
489 | if (lo->lo_biotail) { |
490 | lo->lo_biotail->bi_next = bio; | |
491 | lo->lo_biotail = bio; | |
492 | } else | |
493 | lo->lo_bio = lo->lo_biotail = bio; | |
1da177e4 LT |
494 | } |
495 | ||
496 | /* | |
497 | * Grab first pending buffer | |
498 | */ | |
499 | static struct bio *loop_get_bio(struct loop_device *lo) | |
500 | { | |
501 | struct bio *bio; | |
502 | ||
1da177e4 LT |
503 | if ((bio = lo->lo_bio)) { |
504 | if (bio == lo->lo_biotail) | |
505 | lo->lo_biotail = NULL; | |
506 | lo->lo_bio = bio->bi_next; | |
507 | bio->bi_next = NULL; | |
508 | } | |
1da177e4 LT |
509 | |
510 | return bio; | |
511 | } | |
512 | ||
165125e1 | 513 | static int loop_make_request(struct request_queue *q, struct bio *old_bio) |
1da177e4 LT |
514 | { |
515 | struct loop_device *lo = q->queuedata; | |
516 | int rw = bio_rw(old_bio); | |
517 | ||
35a82d1a NP |
518 | if (rw == READA) |
519 | rw = READ; | |
520 | ||
521 | BUG_ON(!lo || (rw != READ && rw != WRITE)); | |
1da177e4 LT |
522 | |
523 | spin_lock_irq(&lo->lo_lock); | |
524 | if (lo->lo_state != Lo_bound) | |
35a82d1a NP |
525 | goto out; |
526 | if (unlikely(rw == WRITE && (lo->lo_flags & LO_FLAGS_READ_ONLY))) | |
527 | goto out; | |
1da177e4 | 528 | loop_add_bio(lo, old_bio); |
6c997918 | 529 | wake_up(&lo->lo_event); |
35a82d1a | 530 | spin_unlock_irq(&lo->lo_lock); |
1da177e4 | 531 | return 0; |
35a82d1a | 532 | |
1da177e4 | 533 | out: |
35a82d1a | 534 | spin_unlock_irq(&lo->lo_lock); |
6712ecf8 | 535 | bio_io_error(old_bio); |
1da177e4 | 536 | return 0; |
1da177e4 LT |
537 | } |
538 | ||
539 | /* | |
540 | * kick off io on the underlying address space | |
541 | */ | |
165125e1 | 542 | static void loop_unplug(struct request_queue *q) |
1da177e4 LT |
543 | { |
544 | struct loop_device *lo = q->queuedata; | |
545 | ||
75ad23bc | 546 | queue_flag_clear_unlocked(QUEUE_FLAG_PLUGGED, q); |
1da177e4 LT |
547 | blk_run_address_space(lo->lo_backing_file->f_mapping); |
548 | } | |
549 | ||
550 | struct switch_request { | |
551 | struct file *file; | |
552 | struct completion wait; | |
553 | }; | |
554 | ||
555 | static void do_loop_switch(struct loop_device *, struct switch_request *); | |
556 | ||
557 | static inline void loop_handle_bio(struct loop_device *lo, struct bio *bio) | |
558 | { | |
1da177e4 LT |
559 | if (unlikely(!bio->bi_bdev)) { |
560 | do_loop_switch(lo, bio->bi_private); | |
561 | bio_put(bio); | |
562 | } else { | |
35a82d1a | 563 | int ret = do_bio_filebacked(lo, bio); |
6712ecf8 | 564 | bio_endio(bio, ret); |
1da177e4 LT |
565 | } |
566 | } | |
567 | ||
568 | /* | |
569 | * worker thread that handles reads/writes to file backed loop devices, | |
570 | * to avoid blocking in our make_request_fn. it also does loop decrypting | |
571 | * on reads for block backed loop, as that is too heavy to do from | |
572 | * b_end_io context where irqs may be disabled. | |
6c997918 SH |
573 | * |
574 | * Loop explanation: loop_clr_fd() sets lo_state to Lo_rundown before | |
575 | * calling kthread_stop(). Therefore once kthread_should_stop() is | |
576 | * true, make_request will not place any more requests. Therefore | |
577 | * once kthread_should_stop() is true and lo_bio is NULL, we are | |
578 | * done with the loop. | |
1da177e4 LT |
579 | */ |
580 | static int loop_thread(void *data) | |
581 | { | |
582 | struct loop_device *lo = data; | |
583 | struct bio *bio; | |
584 | ||
1da177e4 LT |
585 | set_user_nice(current, -20); |
586 | ||
6c997918 | 587 | while (!kthread_should_stop() || lo->lo_bio) { |
09c0dc68 | 588 | |
6c997918 SH |
589 | wait_event_interruptible(lo->lo_event, |
590 | lo->lo_bio || kthread_should_stop()); | |
35a82d1a | 591 | |
6c997918 | 592 | if (!lo->lo_bio) |
35a82d1a | 593 | continue; |
35a82d1a | 594 | spin_lock_irq(&lo->lo_lock); |
1da177e4 | 595 | bio = loop_get_bio(lo); |
35a82d1a NP |
596 | spin_unlock_irq(&lo->lo_lock); |
597 | ||
598 | BUG_ON(!bio); | |
1da177e4 | 599 | loop_handle_bio(lo, bio); |
1da177e4 LT |
600 | } |
601 | ||
1da177e4 LT |
602 | return 0; |
603 | } | |
604 | ||
605 | /* | |
606 | * loop_switch performs the hard work of switching a backing store. | |
607 | * First it needs to flush existing IO, it does this by sending a magic | |
608 | * BIO down the pipe. The completion of this BIO does the actual switch. | |
609 | */ | |
610 | static int loop_switch(struct loop_device *lo, struct file *file) | |
611 | { | |
612 | struct switch_request w; | |
a24eab1e | 613 | struct bio *bio = bio_alloc(GFP_KERNEL, 0); |
1da177e4 LT |
614 | if (!bio) |
615 | return -ENOMEM; | |
616 | init_completion(&w.wait); | |
617 | w.file = file; | |
618 | bio->bi_private = &w; | |
619 | bio->bi_bdev = NULL; | |
620 | loop_make_request(lo->lo_queue, bio); | |
621 | wait_for_completion(&w.wait); | |
622 | return 0; | |
623 | } | |
624 | ||
14f27939 MB |
625 | /* |
626 | * Helper to flush the IOs in loop, but keeping loop thread running | |
627 | */ | |
628 | static int loop_flush(struct loop_device *lo) | |
629 | { | |
630 | /* loop not yet configured, no running thread, nothing to flush */ | |
631 | if (!lo->lo_thread) | |
632 | return 0; | |
633 | ||
634 | return loop_switch(lo, NULL); | |
635 | } | |
636 | ||
1da177e4 LT |
637 | /* |
638 | * Do the actual switch; called from the BIO completion routine | |
639 | */ | |
640 | static void do_loop_switch(struct loop_device *lo, struct switch_request *p) | |
641 | { | |
642 | struct file *file = p->file; | |
643 | struct file *old_file = lo->lo_backing_file; | |
14f27939 MB |
644 | struct address_space *mapping; |
645 | ||
646 | /* if no new file, only flush of queued bios requested */ | |
647 | if (!file) | |
648 | goto out; | |
1da177e4 | 649 | |
14f27939 | 650 | mapping = file->f_mapping; |
1da177e4 LT |
651 | mapping_set_gfp_mask(old_file->f_mapping, lo->old_gfp_mask); |
652 | lo->lo_backing_file = file; | |
ba52de12 TT |
653 | lo->lo_blocksize = S_ISBLK(mapping->host->i_mode) ? |
654 | mapping->host->i_bdev->bd_block_size : PAGE_SIZE; | |
1da177e4 LT |
655 | lo->old_gfp_mask = mapping_gfp_mask(mapping); |
656 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); | |
14f27939 | 657 | out: |
1da177e4 LT |
658 | complete(&p->wait); |
659 | } | |
660 | ||
661 | ||
662 | /* | |
663 | * loop_change_fd switched the backing store of a loopback device to | |
664 | * a new file. This is useful for operating system installers to free up | |
665 | * the original file and in High Availability environments to switch to | |
666 | * an alternative location for the content in case of server meltdown. | |
667 | * This can only work if the loop device is used read-only, and if the | |
668 | * new backing store is the same size and type as the old backing store. | |
669 | */ | |
bb214884 AV |
670 | static int loop_change_fd(struct loop_device *lo, struct block_device *bdev, |
671 | unsigned int arg) | |
1da177e4 LT |
672 | { |
673 | struct file *file, *old_file; | |
674 | struct inode *inode; | |
675 | int error; | |
676 | ||
677 | error = -ENXIO; | |
678 | if (lo->lo_state != Lo_bound) | |
679 | goto out; | |
680 | ||
681 | /* the loop device has to be read-only */ | |
682 | error = -EINVAL; | |
683 | if (!(lo->lo_flags & LO_FLAGS_READ_ONLY)) | |
684 | goto out; | |
685 | ||
686 | error = -EBADF; | |
687 | file = fget(arg); | |
688 | if (!file) | |
689 | goto out; | |
690 | ||
691 | inode = file->f_mapping->host; | |
692 | old_file = lo->lo_backing_file; | |
693 | ||
694 | error = -EINVAL; | |
695 | ||
696 | if (!S_ISREG(inode->i_mode) && !S_ISBLK(inode->i_mode)) | |
697 | goto out_putf; | |
698 | ||
fd582140 JA |
699 | /* new backing store needs to support loop (eg splice_read) */ |
700 | if (!inode->i_fop->splice_read) | |
1da177e4 LT |
701 | goto out_putf; |
702 | ||
703 | /* size of the new backing store needs to be the same */ | |
704 | if (get_loop_size(lo, file) != get_loop_size(lo, old_file)) | |
705 | goto out_putf; | |
706 | ||
707 | /* and ... switch */ | |
708 | error = loop_switch(lo, file); | |
709 | if (error) | |
710 | goto out_putf; | |
711 | ||
712 | fput(old_file); | |
476a4813 LV |
713 | if (max_part > 0) |
714 | ioctl_by_bdev(bdev, BLKRRPART, 0); | |
1da177e4 LT |
715 | return 0; |
716 | ||
717 | out_putf: | |
718 | fput(file); | |
719 | out: | |
720 | return error; | |
721 | } | |
722 | ||
723 | static inline int is_loop_device(struct file *file) | |
724 | { | |
725 | struct inode *i = file->f_mapping->host; | |
726 | ||
727 | return i && S_ISBLK(i->i_mode) && MAJOR(i->i_rdev) == LOOP_MAJOR; | |
728 | } | |
729 | ||
bb214884 | 730 | static int loop_set_fd(struct loop_device *lo, fmode_t mode, |
1da177e4 LT |
731 | struct block_device *bdev, unsigned int arg) |
732 | { | |
733 | struct file *file, *f; | |
734 | struct inode *inode; | |
735 | struct address_space *mapping; | |
736 | unsigned lo_blocksize; | |
737 | int lo_flags = 0; | |
738 | int error; | |
739 | loff_t size; | |
740 | ||
741 | /* This is safe, since we have a reference from open(). */ | |
742 | __module_get(THIS_MODULE); | |
743 | ||
744 | error = -EBADF; | |
745 | file = fget(arg); | |
746 | if (!file) | |
747 | goto out; | |
748 | ||
749 | error = -EBUSY; | |
750 | if (lo->lo_state != Lo_unbound) | |
751 | goto out_putf; | |
752 | ||
753 | /* Avoid recursion */ | |
754 | f = file; | |
755 | while (is_loop_device(f)) { | |
756 | struct loop_device *l; | |
757 | ||
bb214884 | 758 | if (f->f_mapping->host->i_bdev == bdev) |
1da177e4 LT |
759 | goto out_putf; |
760 | ||
761 | l = f->f_mapping->host->i_bdev->bd_disk->private_data; | |
762 | if (l->lo_state == Lo_unbound) { | |
763 | error = -EINVAL; | |
764 | goto out_putf; | |
765 | } | |
766 | f = l->lo_backing_file; | |
767 | } | |
768 | ||
769 | mapping = file->f_mapping; | |
770 | inode = mapping->host; | |
771 | ||
772 | if (!(file->f_mode & FMODE_WRITE)) | |
773 | lo_flags |= LO_FLAGS_READ_ONLY; | |
774 | ||
775 | error = -EINVAL; | |
776 | if (S_ISREG(inode->i_mode) || S_ISBLK(inode->i_mode)) { | |
f5e54d6e | 777 | const struct address_space_operations *aops = mapping->a_ops; |
1da177e4 LT |
778 | /* |
779 | * If we can't read - sorry. If we only can't write - well, | |
780 | * it's going to be read-only. | |
781 | */ | |
fd582140 | 782 | if (!file->f_op->splice_read) |
1da177e4 | 783 | goto out_putf; |
4e02ed4b | 784 | if (aops->write_begin) |
1da177e4 LT |
785 | lo_flags |= LO_FLAGS_USE_AOPS; |
786 | if (!(lo_flags & LO_FLAGS_USE_AOPS) && !file->f_op->write) | |
787 | lo_flags |= LO_FLAGS_READ_ONLY; | |
788 | ||
ba52de12 TT |
789 | lo_blocksize = S_ISBLK(inode->i_mode) ? |
790 | inode->i_bdev->bd_block_size : PAGE_SIZE; | |
791 | ||
1da177e4 LT |
792 | error = 0; |
793 | } else { | |
794 | goto out_putf; | |
795 | } | |
796 | ||
797 | size = get_loop_size(lo, file); | |
798 | ||
799 | if ((loff_t)(sector_t)size != size) { | |
800 | error = -EFBIG; | |
801 | goto out_putf; | |
802 | } | |
803 | ||
bb214884 | 804 | if (!(mode & FMODE_WRITE)) |
1da177e4 LT |
805 | lo_flags |= LO_FLAGS_READ_ONLY; |
806 | ||
807 | set_device_ro(bdev, (lo_flags & LO_FLAGS_READ_ONLY) != 0); | |
808 | ||
809 | lo->lo_blocksize = lo_blocksize; | |
810 | lo->lo_device = bdev; | |
811 | lo->lo_flags = lo_flags; | |
812 | lo->lo_backing_file = file; | |
eefe85ee | 813 | lo->transfer = transfer_none; |
1da177e4 LT |
814 | lo->ioctl = NULL; |
815 | lo->lo_sizelimit = 0; | |
816 | lo->old_gfp_mask = mapping_gfp_mask(mapping); | |
817 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask & ~(__GFP_IO|__GFP_FS)); | |
818 | ||
819 | lo->lo_bio = lo->lo_biotail = NULL; | |
820 | ||
821 | /* | |
822 | * set queue make_request_fn, and add limits based on lower level | |
823 | * device | |
824 | */ | |
825 | blk_queue_make_request(lo->lo_queue, loop_make_request); | |
826 | lo->lo_queue->queuedata = lo; | |
827 | lo->lo_queue->unplug_fn = loop_unplug; | |
828 | ||
73285082 | 829 | set_capacity(lo->lo_disk, size); |
1da177e4 LT |
830 | bd_set_size(bdev, size << 9); |
831 | ||
832 | set_blocksize(bdev, lo_blocksize); | |
833 | ||
6c997918 SH |
834 | lo->lo_thread = kthread_create(loop_thread, lo, "loop%d", |
835 | lo->lo_number); | |
836 | if (IS_ERR(lo->lo_thread)) { | |
837 | error = PTR_ERR(lo->lo_thread); | |
a7422bf8 | 838 | goto out_clr; |
6c997918 SH |
839 | } |
840 | lo->lo_state = Lo_bound; | |
841 | wake_up_process(lo->lo_thread); | |
476a4813 LV |
842 | if (max_part > 0) |
843 | ioctl_by_bdev(bdev, BLKRRPART, 0); | |
1da177e4 LT |
844 | return 0; |
845 | ||
a7422bf8 SH |
846 | out_clr: |
847 | lo->lo_thread = NULL; | |
848 | lo->lo_device = NULL; | |
849 | lo->lo_backing_file = NULL; | |
850 | lo->lo_flags = 0; | |
73285082 | 851 | set_capacity(lo->lo_disk, 0); |
f98393a6 | 852 | invalidate_bdev(bdev); |
a7422bf8 SH |
853 | bd_set_size(bdev, 0); |
854 | mapping_set_gfp_mask(mapping, lo->old_gfp_mask); | |
855 | lo->lo_state = Lo_unbound; | |
1da177e4 LT |
856 | out_putf: |
857 | fput(file); | |
858 | out: | |
859 | /* This is safe: open() is still holding a reference. */ | |
860 | module_put(THIS_MODULE); | |
861 | return error; | |
862 | } | |
863 | ||
864 | static int | |
865 | loop_release_xfer(struct loop_device *lo) | |
866 | { | |
867 | int err = 0; | |
868 | struct loop_func_table *xfer = lo->lo_encryption; | |
869 | ||
870 | if (xfer) { | |
871 | if (xfer->release) | |
872 | err = xfer->release(lo); | |
873 | lo->transfer = NULL; | |
874 | lo->lo_encryption = NULL; | |
875 | module_put(xfer->owner); | |
876 | } | |
877 | return err; | |
878 | } | |
879 | ||
880 | static int | |
881 | loop_init_xfer(struct loop_device *lo, struct loop_func_table *xfer, | |
882 | const struct loop_info64 *i) | |
883 | { | |
884 | int err = 0; | |
885 | ||
886 | if (xfer) { | |
887 | struct module *owner = xfer->owner; | |
888 | ||
889 | if (!try_module_get(owner)) | |
890 | return -EINVAL; | |
891 | if (xfer->init) | |
892 | err = xfer->init(lo, i); | |
893 | if (err) | |
894 | module_put(owner); | |
895 | else | |
896 | lo->lo_encryption = xfer; | |
897 | } | |
898 | return err; | |
899 | } | |
900 | ||
901 | static int loop_clr_fd(struct loop_device *lo, struct block_device *bdev) | |
902 | { | |
903 | struct file *filp = lo->lo_backing_file; | |
b4e3ca1a | 904 | gfp_t gfp = lo->old_gfp_mask; |
1da177e4 LT |
905 | |
906 | if (lo->lo_state != Lo_bound) | |
907 | return -ENXIO; | |
908 | ||
909 | if (lo->lo_refcnt > 1) /* we needed one fd for the ioctl */ | |
910 | return -EBUSY; | |
911 | ||
912 | if (filp == NULL) | |
913 | return -EINVAL; | |
914 | ||
915 | spin_lock_irq(&lo->lo_lock); | |
916 | lo->lo_state = Lo_rundown; | |
1da177e4 LT |
917 | spin_unlock_irq(&lo->lo_lock); |
918 | ||
6c997918 | 919 | kthread_stop(lo->lo_thread); |
1da177e4 | 920 | |
8ae30b89 | 921 | lo->lo_queue->unplug_fn = NULL; |
1da177e4 LT |
922 | lo->lo_backing_file = NULL; |
923 | ||
924 | loop_release_xfer(lo); | |
925 | lo->transfer = NULL; | |
926 | lo->ioctl = NULL; | |
927 | lo->lo_device = NULL; | |
928 | lo->lo_encryption = NULL; | |
929 | lo->lo_offset = 0; | |
930 | lo->lo_sizelimit = 0; | |
931 | lo->lo_encrypt_key_size = 0; | |
932 | lo->lo_flags = 0; | |
6c997918 | 933 | lo->lo_thread = NULL; |
1da177e4 LT |
934 | memset(lo->lo_encrypt_key, 0, LO_KEY_SIZE); |
935 | memset(lo->lo_crypt_name, 0, LO_NAME_SIZE); | |
936 | memset(lo->lo_file_name, 0, LO_NAME_SIZE); | |
bb214884 AV |
937 | if (bdev) |
938 | invalidate_bdev(bdev); | |
73285082 | 939 | set_capacity(lo->lo_disk, 0); |
bb214884 AV |
940 | if (bdev) |
941 | bd_set_size(bdev, 0); | |
1da177e4 LT |
942 | mapping_set_gfp_mask(filp->f_mapping, gfp); |
943 | lo->lo_state = Lo_unbound; | |
944 | fput(filp); | |
945 | /* This is safe: open() is still holding a reference. */ | |
946 | module_put(THIS_MODULE); | |
476a4813 LV |
947 | if (max_part > 0) |
948 | ioctl_by_bdev(bdev, BLKRRPART, 0); | |
1da177e4 LT |
949 | return 0; |
950 | } | |
951 | ||
952 | static int | |
953 | loop_set_status(struct loop_device *lo, const struct loop_info64 *info) | |
954 | { | |
955 | int err; | |
956 | struct loop_func_table *xfer; | |
b0fafa81 | 957 | uid_t uid = current_uid(); |
1da177e4 | 958 | |
b0fafa81 DH |
959 | if (lo->lo_encrypt_key_size && |
960 | lo->lo_key_owner != uid && | |
1da177e4 LT |
961 | !capable(CAP_SYS_ADMIN)) |
962 | return -EPERM; | |
963 | if (lo->lo_state != Lo_bound) | |
964 | return -ENXIO; | |
965 | if ((unsigned int) info->lo_encrypt_key_size > LO_KEY_SIZE) | |
966 | return -EINVAL; | |
967 | ||
968 | err = loop_release_xfer(lo); | |
969 | if (err) | |
970 | return err; | |
971 | ||
972 | if (info->lo_encrypt_type) { | |
973 | unsigned int type = info->lo_encrypt_type; | |
974 | ||
975 | if (type >= MAX_LO_CRYPT) | |
976 | return -EINVAL; | |
977 | xfer = xfer_funcs[type]; | |
978 | if (xfer == NULL) | |
979 | return -EINVAL; | |
980 | } else | |
981 | xfer = NULL; | |
982 | ||
983 | err = loop_init_xfer(lo, xfer, info); | |
984 | if (err) | |
985 | return err; | |
986 | ||
987 | if (lo->lo_offset != info->lo_offset || | |
988 | lo->lo_sizelimit != info->lo_sizelimit) { | |
989 | lo->lo_offset = info->lo_offset; | |
990 | lo->lo_sizelimit = info->lo_sizelimit; | |
991 | if (figure_loop_size(lo)) | |
992 | return -EFBIG; | |
993 | } | |
994 | ||
995 | memcpy(lo->lo_file_name, info->lo_file_name, LO_NAME_SIZE); | |
996 | memcpy(lo->lo_crypt_name, info->lo_crypt_name, LO_NAME_SIZE); | |
997 | lo->lo_file_name[LO_NAME_SIZE-1] = 0; | |
998 | lo->lo_crypt_name[LO_NAME_SIZE-1] = 0; | |
999 | ||
1000 | if (!xfer) | |
1001 | xfer = &none_funcs; | |
1002 | lo->transfer = xfer->transfer; | |
1003 | lo->ioctl = xfer->ioctl; | |
1004 | ||
96c58655 DW |
1005 | if ((lo->lo_flags & LO_FLAGS_AUTOCLEAR) != |
1006 | (info->lo_flags & LO_FLAGS_AUTOCLEAR)) | |
1007 | lo->lo_flags ^= LO_FLAGS_AUTOCLEAR; | |
1008 | ||
1da177e4 LT |
1009 | lo->lo_encrypt_key_size = info->lo_encrypt_key_size; |
1010 | lo->lo_init[0] = info->lo_init[0]; | |
1011 | lo->lo_init[1] = info->lo_init[1]; | |
1012 | if (info->lo_encrypt_key_size) { | |
1013 | memcpy(lo->lo_encrypt_key, info->lo_encrypt_key, | |
1014 | info->lo_encrypt_key_size); | |
b0fafa81 | 1015 | lo->lo_key_owner = uid; |
1da177e4 LT |
1016 | } |
1017 | ||
1018 | return 0; | |
1019 | } | |
1020 | ||
1021 | static int | |
1022 | loop_get_status(struct loop_device *lo, struct loop_info64 *info) | |
1023 | { | |
1024 | struct file *file = lo->lo_backing_file; | |
1025 | struct kstat stat; | |
1026 | int error; | |
1027 | ||
1028 | if (lo->lo_state != Lo_bound) | |
1029 | return -ENXIO; | |
6c648be6 | 1030 | error = vfs_getattr(file->f_path.mnt, file->f_path.dentry, &stat); |
1da177e4 LT |
1031 | if (error) |
1032 | return error; | |
1033 | memset(info, 0, sizeof(*info)); | |
1034 | info->lo_number = lo->lo_number; | |
1035 | info->lo_device = huge_encode_dev(stat.dev); | |
1036 | info->lo_inode = stat.ino; | |
1037 | info->lo_rdevice = huge_encode_dev(lo->lo_device ? stat.rdev : stat.dev); | |
1038 | info->lo_offset = lo->lo_offset; | |
1039 | info->lo_sizelimit = lo->lo_sizelimit; | |
1040 | info->lo_flags = lo->lo_flags; | |
1041 | memcpy(info->lo_file_name, lo->lo_file_name, LO_NAME_SIZE); | |
1042 | memcpy(info->lo_crypt_name, lo->lo_crypt_name, LO_NAME_SIZE); | |
1043 | info->lo_encrypt_type = | |
1044 | lo->lo_encryption ? lo->lo_encryption->number : 0; | |
1045 | if (lo->lo_encrypt_key_size && capable(CAP_SYS_ADMIN)) { | |
1046 | info->lo_encrypt_key_size = lo->lo_encrypt_key_size; | |
1047 | memcpy(info->lo_encrypt_key, lo->lo_encrypt_key, | |
1048 | lo->lo_encrypt_key_size); | |
1049 | } | |
1050 | return 0; | |
1051 | } | |
1052 | ||
1053 | static void | |
1054 | loop_info64_from_old(const struct loop_info *info, struct loop_info64 *info64) | |
1055 | { | |
1056 | memset(info64, 0, sizeof(*info64)); | |
1057 | info64->lo_number = info->lo_number; | |
1058 | info64->lo_device = info->lo_device; | |
1059 | info64->lo_inode = info->lo_inode; | |
1060 | info64->lo_rdevice = info->lo_rdevice; | |
1061 | info64->lo_offset = info->lo_offset; | |
1062 | info64->lo_sizelimit = 0; | |
1063 | info64->lo_encrypt_type = info->lo_encrypt_type; | |
1064 | info64->lo_encrypt_key_size = info->lo_encrypt_key_size; | |
1065 | info64->lo_flags = info->lo_flags; | |
1066 | info64->lo_init[0] = info->lo_init[0]; | |
1067 | info64->lo_init[1] = info->lo_init[1]; | |
1068 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) | |
1069 | memcpy(info64->lo_crypt_name, info->lo_name, LO_NAME_SIZE); | |
1070 | else | |
1071 | memcpy(info64->lo_file_name, info->lo_name, LO_NAME_SIZE); | |
1072 | memcpy(info64->lo_encrypt_key, info->lo_encrypt_key, LO_KEY_SIZE); | |
1073 | } | |
1074 | ||
1075 | static int | |
1076 | loop_info64_to_old(const struct loop_info64 *info64, struct loop_info *info) | |
1077 | { | |
1078 | memset(info, 0, sizeof(*info)); | |
1079 | info->lo_number = info64->lo_number; | |
1080 | info->lo_device = info64->lo_device; | |
1081 | info->lo_inode = info64->lo_inode; | |
1082 | info->lo_rdevice = info64->lo_rdevice; | |
1083 | info->lo_offset = info64->lo_offset; | |
1084 | info->lo_encrypt_type = info64->lo_encrypt_type; | |
1085 | info->lo_encrypt_key_size = info64->lo_encrypt_key_size; | |
1086 | info->lo_flags = info64->lo_flags; | |
1087 | info->lo_init[0] = info64->lo_init[0]; | |
1088 | info->lo_init[1] = info64->lo_init[1]; | |
1089 | if (info->lo_encrypt_type == LO_CRYPT_CRYPTOAPI) | |
1090 | memcpy(info->lo_name, info64->lo_crypt_name, LO_NAME_SIZE); | |
1091 | else | |
1092 | memcpy(info->lo_name, info64->lo_file_name, LO_NAME_SIZE); | |
1093 | memcpy(info->lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); | |
1094 | ||
1095 | /* error in case values were truncated */ | |
1096 | if (info->lo_device != info64->lo_device || | |
1097 | info->lo_rdevice != info64->lo_rdevice || | |
1098 | info->lo_inode != info64->lo_inode || | |
1099 | info->lo_offset != info64->lo_offset) | |
1100 | return -EOVERFLOW; | |
1101 | ||
1102 | return 0; | |
1103 | } | |
1104 | ||
1105 | static int | |
1106 | loop_set_status_old(struct loop_device *lo, const struct loop_info __user *arg) | |
1107 | { | |
1108 | struct loop_info info; | |
1109 | struct loop_info64 info64; | |
1110 | ||
1111 | if (copy_from_user(&info, arg, sizeof (struct loop_info))) | |
1112 | return -EFAULT; | |
1113 | loop_info64_from_old(&info, &info64); | |
1114 | return loop_set_status(lo, &info64); | |
1115 | } | |
1116 | ||
1117 | static int | |
1118 | loop_set_status64(struct loop_device *lo, const struct loop_info64 __user *arg) | |
1119 | { | |
1120 | struct loop_info64 info64; | |
1121 | ||
1122 | if (copy_from_user(&info64, arg, sizeof (struct loop_info64))) | |
1123 | return -EFAULT; | |
1124 | return loop_set_status(lo, &info64); | |
1125 | } | |
1126 | ||
1127 | static int | |
1128 | loop_get_status_old(struct loop_device *lo, struct loop_info __user *arg) { | |
1129 | struct loop_info info; | |
1130 | struct loop_info64 info64; | |
1131 | int err = 0; | |
1132 | ||
1133 | if (!arg) | |
1134 | err = -EINVAL; | |
1135 | if (!err) | |
1136 | err = loop_get_status(lo, &info64); | |
1137 | if (!err) | |
1138 | err = loop_info64_to_old(&info64, &info); | |
1139 | if (!err && copy_to_user(arg, &info, sizeof(info))) | |
1140 | err = -EFAULT; | |
1141 | ||
1142 | return err; | |
1143 | } | |
1144 | ||
1145 | static int | |
1146 | loop_get_status64(struct loop_device *lo, struct loop_info64 __user *arg) { | |
1147 | struct loop_info64 info64; | |
1148 | int err = 0; | |
1149 | ||
1150 | if (!arg) | |
1151 | err = -EINVAL; | |
1152 | if (!err) | |
1153 | err = loop_get_status(lo, &info64); | |
1154 | if (!err && copy_to_user(arg, &info64, sizeof(info64))) | |
1155 | err = -EFAULT; | |
1156 | ||
1157 | return err; | |
1158 | } | |
1159 | ||
bb214884 | 1160 | static int lo_ioctl(struct block_device *bdev, fmode_t mode, |
1da177e4 LT |
1161 | unsigned int cmd, unsigned long arg) |
1162 | { | |
bb214884 | 1163 | struct loop_device *lo = bdev->bd_disk->private_data; |
1da177e4 LT |
1164 | int err; |
1165 | ||
f85221dd | 1166 | mutex_lock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1167 | switch (cmd) { |
1168 | case LOOP_SET_FD: | |
bb214884 | 1169 | err = loop_set_fd(lo, mode, bdev, arg); |
1da177e4 LT |
1170 | break; |
1171 | case LOOP_CHANGE_FD: | |
bb214884 | 1172 | err = loop_change_fd(lo, bdev, arg); |
1da177e4 LT |
1173 | break; |
1174 | case LOOP_CLR_FD: | |
bb214884 | 1175 | err = loop_clr_fd(lo, bdev); |
1da177e4 LT |
1176 | break; |
1177 | case LOOP_SET_STATUS: | |
1178 | err = loop_set_status_old(lo, (struct loop_info __user *) arg); | |
1179 | break; | |
1180 | case LOOP_GET_STATUS: | |
1181 | err = loop_get_status_old(lo, (struct loop_info __user *) arg); | |
1182 | break; | |
1183 | case LOOP_SET_STATUS64: | |
1184 | err = loop_set_status64(lo, (struct loop_info64 __user *) arg); | |
1185 | break; | |
1186 | case LOOP_GET_STATUS64: | |
1187 | err = loop_get_status64(lo, (struct loop_info64 __user *) arg); | |
1188 | break; | |
1189 | default: | |
1190 | err = lo->ioctl ? lo->ioctl(lo, cmd, arg) : -EINVAL; | |
1191 | } | |
f85221dd | 1192 | mutex_unlock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1193 | return err; |
1194 | } | |
1195 | ||
863d5b82 DH |
1196 | #ifdef CONFIG_COMPAT |
1197 | struct compat_loop_info { | |
1198 | compat_int_t lo_number; /* ioctl r/o */ | |
1199 | compat_dev_t lo_device; /* ioctl r/o */ | |
1200 | compat_ulong_t lo_inode; /* ioctl r/o */ | |
1201 | compat_dev_t lo_rdevice; /* ioctl r/o */ | |
1202 | compat_int_t lo_offset; | |
1203 | compat_int_t lo_encrypt_type; | |
1204 | compat_int_t lo_encrypt_key_size; /* ioctl w/o */ | |
1205 | compat_int_t lo_flags; /* ioctl r/o */ | |
1206 | char lo_name[LO_NAME_SIZE]; | |
1207 | unsigned char lo_encrypt_key[LO_KEY_SIZE]; /* ioctl w/o */ | |
1208 | compat_ulong_t lo_init[2]; | |
1209 | char reserved[4]; | |
1210 | }; | |
1211 | ||
1212 | /* | |
1213 | * Transfer 32-bit compatibility structure in userspace to 64-bit loop info | |
1214 | * - noinlined to reduce stack space usage in main part of driver | |
1215 | */ | |
1216 | static noinline int | |
ba674cfc | 1217 | loop_info64_from_compat(const struct compat_loop_info __user *arg, |
863d5b82 DH |
1218 | struct loop_info64 *info64) |
1219 | { | |
1220 | struct compat_loop_info info; | |
1221 | ||
1222 | if (copy_from_user(&info, arg, sizeof(info))) | |
1223 | return -EFAULT; | |
1224 | ||
1225 | memset(info64, 0, sizeof(*info64)); | |
1226 | info64->lo_number = info.lo_number; | |
1227 | info64->lo_device = info.lo_device; | |
1228 | info64->lo_inode = info.lo_inode; | |
1229 | info64->lo_rdevice = info.lo_rdevice; | |
1230 | info64->lo_offset = info.lo_offset; | |
1231 | info64->lo_sizelimit = 0; | |
1232 | info64->lo_encrypt_type = info.lo_encrypt_type; | |
1233 | info64->lo_encrypt_key_size = info.lo_encrypt_key_size; | |
1234 | info64->lo_flags = info.lo_flags; | |
1235 | info64->lo_init[0] = info.lo_init[0]; | |
1236 | info64->lo_init[1] = info.lo_init[1]; | |
1237 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) | |
1238 | memcpy(info64->lo_crypt_name, info.lo_name, LO_NAME_SIZE); | |
1239 | else | |
1240 | memcpy(info64->lo_file_name, info.lo_name, LO_NAME_SIZE); | |
1241 | memcpy(info64->lo_encrypt_key, info.lo_encrypt_key, LO_KEY_SIZE); | |
1242 | return 0; | |
1243 | } | |
1244 | ||
1245 | /* | |
1246 | * Transfer 64-bit loop info to 32-bit compatibility structure in userspace | |
1247 | * - noinlined to reduce stack space usage in main part of driver | |
1248 | */ | |
1249 | static noinline int | |
1250 | loop_info64_to_compat(const struct loop_info64 *info64, | |
1251 | struct compat_loop_info __user *arg) | |
1252 | { | |
1253 | struct compat_loop_info info; | |
1254 | ||
1255 | memset(&info, 0, sizeof(info)); | |
1256 | info.lo_number = info64->lo_number; | |
1257 | info.lo_device = info64->lo_device; | |
1258 | info.lo_inode = info64->lo_inode; | |
1259 | info.lo_rdevice = info64->lo_rdevice; | |
1260 | info.lo_offset = info64->lo_offset; | |
1261 | info.lo_encrypt_type = info64->lo_encrypt_type; | |
1262 | info.lo_encrypt_key_size = info64->lo_encrypt_key_size; | |
1263 | info.lo_flags = info64->lo_flags; | |
1264 | info.lo_init[0] = info64->lo_init[0]; | |
1265 | info.lo_init[1] = info64->lo_init[1]; | |
1266 | if (info.lo_encrypt_type == LO_CRYPT_CRYPTOAPI) | |
1267 | memcpy(info.lo_name, info64->lo_crypt_name, LO_NAME_SIZE); | |
1268 | else | |
1269 | memcpy(info.lo_name, info64->lo_file_name, LO_NAME_SIZE); | |
1270 | memcpy(info.lo_encrypt_key, info64->lo_encrypt_key, LO_KEY_SIZE); | |
1271 | ||
1272 | /* error in case values were truncated */ | |
1273 | if (info.lo_device != info64->lo_device || | |
1274 | info.lo_rdevice != info64->lo_rdevice || | |
1275 | info.lo_inode != info64->lo_inode || | |
1276 | info.lo_offset != info64->lo_offset || | |
1277 | info.lo_init[0] != info64->lo_init[0] || | |
1278 | info.lo_init[1] != info64->lo_init[1]) | |
1279 | return -EOVERFLOW; | |
1280 | ||
1281 | if (copy_to_user(arg, &info, sizeof(info))) | |
1282 | return -EFAULT; | |
1283 | return 0; | |
1284 | } | |
1285 | ||
1286 | static int | |
1287 | loop_set_status_compat(struct loop_device *lo, | |
1288 | const struct compat_loop_info __user *arg) | |
1289 | { | |
1290 | struct loop_info64 info64; | |
1291 | int ret; | |
1292 | ||
1293 | ret = loop_info64_from_compat(arg, &info64); | |
1294 | if (ret < 0) | |
1295 | return ret; | |
1296 | return loop_set_status(lo, &info64); | |
1297 | } | |
1298 | ||
1299 | static int | |
1300 | loop_get_status_compat(struct loop_device *lo, | |
1301 | struct compat_loop_info __user *arg) | |
1302 | { | |
1303 | struct loop_info64 info64; | |
1304 | int err = 0; | |
1305 | ||
1306 | if (!arg) | |
1307 | err = -EINVAL; | |
1308 | if (!err) | |
1309 | err = loop_get_status(lo, &info64); | |
1310 | if (!err) | |
1311 | err = loop_info64_to_compat(&info64, arg); | |
1312 | return err; | |
1313 | } | |
1314 | ||
bb214884 AV |
1315 | static int lo_compat_ioctl(struct block_device *bdev, fmode_t mode, |
1316 | unsigned int cmd, unsigned long arg) | |
863d5b82 | 1317 | { |
bb214884 | 1318 | struct loop_device *lo = bdev->bd_disk->private_data; |
863d5b82 DH |
1319 | int err; |
1320 | ||
863d5b82 DH |
1321 | switch(cmd) { |
1322 | case LOOP_SET_STATUS: | |
1323 | mutex_lock(&lo->lo_ctl_mutex); | |
1324 | err = loop_set_status_compat( | |
1325 | lo, (const struct compat_loop_info __user *) arg); | |
1326 | mutex_unlock(&lo->lo_ctl_mutex); | |
1327 | break; | |
1328 | case LOOP_GET_STATUS: | |
1329 | mutex_lock(&lo->lo_ctl_mutex); | |
1330 | err = loop_get_status_compat( | |
1331 | lo, (struct compat_loop_info __user *) arg); | |
1332 | mutex_unlock(&lo->lo_ctl_mutex); | |
1333 | break; | |
1334 | case LOOP_CLR_FD: | |
1335 | case LOOP_GET_STATUS64: | |
1336 | case LOOP_SET_STATUS64: | |
1337 | arg = (unsigned long) compat_ptr(arg); | |
1338 | case LOOP_SET_FD: | |
1339 | case LOOP_CHANGE_FD: | |
bb214884 | 1340 | err = lo_ioctl(bdev, mode, cmd, arg); |
863d5b82 DH |
1341 | break; |
1342 | default: | |
1343 | err = -ENOIOCTLCMD; | |
1344 | break; | |
1345 | } | |
863d5b82 DH |
1346 | return err; |
1347 | } | |
1348 | #endif | |
1349 | ||
bb214884 | 1350 | static int lo_open(struct block_device *bdev, fmode_t mode) |
1da177e4 | 1351 | { |
bb214884 | 1352 | struct loop_device *lo = bdev->bd_disk->private_data; |
1da177e4 | 1353 | |
f85221dd | 1354 | mutex_lock(&lo->lo_ctl_mutex); |
1da177e4 | 1355 | lo->lo_refcnt++; |
f85221dd | 1356 | mutex_unlock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1357 | |
1358 | return 0; | |
1359 | } | |
1360 | ||
bb214884 | 1361 | static int lo_release(struct gendisk *disk, fmode_t mode) |
1da177e4 | 1362 | { |
bb214884 | 1363 | struct loop_device *lo = disk->private_data; |
1da177e4 | 1364 | |
f85221dd | 1365 | mutex_lock(&lo->lo_ctl_mutex); |
96c58655 | 1366 | |
14f27939 MB |
1367 | if (--lo->lo_refcnt) |
1368 | goto out; | |
1369 | ||
1370 | if (lo->lo_flags & LO_FLAGS_AUTOCLEAR) { | |
1371 | /* | |
1372 | * In autoclear mode, stop the loop thread | |
1373 | * and remove configuration after last close. | |
1374 | */ | |
bb214884 | 1375 | loop_clr_fd(lo, NULL); |
14f27939 MB |
1376 | } else { |
1377 | /* | |
1378 | * Otherwise keep thread (if running) and config, | |
1379 | * but flush possible ongoing bios in thread. | |
1380 | */ | |
1381 | loop_flush(lo); | |
1382 | } | |
96c58655 | 1383 | |
14f27939 | 1384 | out: |
f85221dd | 1385 | mutex_unlock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1386 | |
1387 | return 0; | |
1388 | } | |
1389 | ||
1390 | static struct block_device_operations lo_fops = { | |
1391 | .owner = THIS_MODULE, | |
bb214884 AV |
1392 | .open = lo_open, |
1393 | .release = lo_release, | |
1394 | .ioctl = lo_ioctl, | |
863d5b82 | 1395 | #ifdef CONFIG_COMPAT |
bb214884 | 1396 | .compat_ioctl = lo_compat_ioctl, |
863d5b82 | 1397 | #endif |
1da177e4 LT |
1398 | }; |
1399 | ||
1400 | /* | |
1401 | * And now the modules code and kernel interface. | |
1402 | */ | |
73285082 | 1403 | static int max_loop; |
1da177e4 | 1404 | module_param(max_loop, int, 0); |
a47653fc | 1405 | MODULE_PARM_DESC(max_loop, "Maximum number of loop devices"); |
476a4813 LV |
1406 | module_param(max_part, int, 0); |
1407 | MODULE_PARM_DESC(max_part, "Maximum number of partitions per loop device"); | |
1da177e4 LT |
1408 | MODULE_LICENSE("GPL"); |
1409 | MODULE_ALIAS_BLOCKDEV_MAJOR(LOOP_MAJOR); | |
1410 | ||
1411 | int loop_register_transfer(struct loop_func_table *funcs) | |
1412 | { | |
1413 | unsigned int n = funcs->number; | |
1414 | ||
1415 | if (n >= MAX_LO_CRYPT || xfer_funcs[n]) | |
1416 | return -EINVAL; | |
1417 | xfer_funcs[n] = funcs; | |
1418 | return 0; | |
1419 | } | |
1420 | ||
1421 | int loop_unregister_transfer(int number) | |
1422 | { | |
1423 | unsigned int n = number; | |
1424 | struct loop_device *lo; | |
1425 | struct loop_func_table *xfer; | |
1426 | ||
1427 | if (n == 0 || n >= MAX_LO_CRYPT || (xfer = xfer_funcs[n]) == NULL) | |
1428 | return -EINVAL; | |
1429 | ||
1430 | xfer_funcs[n] = NULL; | |
1431 | ||
73285082 | 1432 | list_for_each_entry(lo, &loop_devices, lo_list) { |
f85221dd | 1433 | mutex_lock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1434 | |
1435 | if (lo->lo_encryption == xfer) | |
1436 | loop_release_xfer(lo); | |
1437 | ||
f85221dd | 1438 | mutex_unlock(&lo->lo_ctl_mutex); |
1da177e4 LT |
1439 | } |
1440 | ||
1441 | return 0; | |
1442 | } | |
1443 | ||
1444 | EXPORT_SYMBOL(loop_register_transfer); | |
1445 | EXPORT_SYMBOL(loop_unregister_transfer); | |
1446 | ||
a47653fc | 1447 | static struct loop_device *loop_alloc(int i) |
73285082 KC |
1448 | { |
1449 | struct loop_device *lo; | |
1450 | struct gendisk *disk; | |
1451 | ||
1452 | lo = kzalloc(sizeof(*lo), GFP_KERNEL); | |
1453 | if (!lo) | |
1454 | goto out; | |
1455 | ||
1456 | lo->lo_queue = blk_alloc_queue(GFP_KERNEL); | |
1457 | if (!lo->lo_queue) | |
1458 | goto out_free_dev; | |
1459 | ||
476a4813 | 1460 | disk = lo->lo_disk = alloc_disk(1 << part_shift); |
73285082 KC |
1461 | if (!disk) |
1462 | goto out_free_queue; | |
1463 | ||
1464 | mutex_init(&lo->lo_ctl_mutex); | |
1465 | lo->lo_number = i; | |
1466 | lo->lo_thread = NULL; | |
1467 | init_waitqueue_head(&lo->lo_event); | |
1468 | spin_lock_init(&lo->lo_lock); | |
1469 | disk->major = LOOP_MAJOR; | |
476a4813 | 1470 | disk->first_minor = i << part_shift; |
73285082 KC |
1471 | disk->fops = &lo_fops; |
1472 | disk->private_data = lo; | |
1473 | disk->queue = lo->lo_queue; | |
1474 | sprintf(disk->disk_name, "loop%d", i); | |
73285082 KC |
1475 | return lo; |
1476 | ||
1477 | out_free_queue: | |
1478 | blk_cleanup_queue(lo->lo_queue); | |
1479 | out_free_dev: | |
1480 | kfree(lo); | |
1481 | out: | |
07002e99 | 1482 | return NULL; |
73285082 KC |
1483 | } |
1484 | ||
a47653fc | 1485 | static void loop_free(struct loop_device *lo) |
1da177e4 | 1486 | { |
73285082 KC |
1487 | blk_cleanup_queue(lo->lo_queue); |
1488 | put_disk(lo->lo_disk); | |
1489 | list_del(&lo->lo_list); | |
1490 | kfree(lo); | |
1491 | } | |
1da177e4 | 1492 | |
a47653fc KC |
1493 | static struct loop_device *loop_init_one(int i) |
1494 | { | |
1495 | struct loop_device *lo; | |
1496 | ||
1497 | list_for_each_entry(lo, &loop_devices, lo_list) { | |
1498 | if (lo->lo_number == i) | |
1499 | return lo; | |
1500 | } | |
1501 | ||
1502 | lo = loop_alloc(i); | |
1503 | if (lo) { | |
1504 | add_disk(lo->lo_disk); | |
1505 | list_add_tail(&lo->lo_list, &loop_devices); | |
1506 | } | |
1507 | return lo; | |
1508 | } | |
1509 | ||
1510 | static void loop_del_one(struct loop_device *lo) | |
1511 | { | |
1512 | del_gendisk(lo->lo_disk); | |
1513 | loop_free(lo); | |
1514 | } | |
1515 | ||
73285082 KC |
1516 | static struct kobject *loop_probe(dev_t dev, int *part, void *data) |
1517 | { | |
705962cc | 1518 | struct loop_device *lo; |
07002e99 | 1519 | struct kobject *kobj; |
73285082 | 1520 | |
705962cc AV |
1521 | mutex_lock(&loop_devices_mutex); |
1522 | lo = loop_init_one(dev & MINORMASK); | |
07002e99 | 1523 | kobj = lo ? get_disk(lo->lo_disk) : ERR_PTR(-ENOMEM); |
73285082 KC |
1524 | mutex_unlock(&loop_devices_mutex); |
1525 | ||
1526 | *part = 0; | |
07002e99 | 1527 | return kobj; |
73285082 KC |
1528 | } |
1529 | ||
1530 | static int __init loop_init(void) | |
1531 | { | |
a47653fc KC |
1532 | int i, nr; |
1533 | unsigned long range; | |
1534 | struct loop_device *lo, *next; | |
1535 | ||
1536 | /* | |
1537 | * loop module now has a feature to instantiate underlying device | |
1538 | * structure on-demand, provided that there is an access dev node. | |
1539 | * However, this will not work well with user space tool that doesn't | |
1540 | * know about such "feature". In order to not break any existing | |
1541 | * tool, we do the following: | |
1542 | * | |
1543 | * (1) if max_loop is specified, create that many upfront, and this | |
1544 | * also becomes a hard limit. | |
1545 | * (2) if max_loop is not specified, create 8 loop device on module | |
1546 | * load, user can further extend loop device by create dev node | |
1547 | * themselves and have kernel automatically instantiate actual | |
1548 | * device on-demand. | |
1549 | */ | |
476a4813 LV |
1550 | |
1551 | part_shift = 0; | |
1552 | if (max_part > 0) | |
1553 | part_shift = fls(max_part); | |
1554 | ||
1555 | if (max_loop > 1UL << (MINORBITS - part_shift)) | |
a47653fc | 1556 | return -EINVAL; |
1da177e4 | 1557 | |
73285082 | 1558 | if (max_loop) { |
a47653fc KC |
1559 | nr = max_loop; |
1560 | range = max_loop; | |
1561 | } else { | |
1562 | nr = 8; | |
476a4813 | 1563 | range = 1UL << (MINORBITS - part_shift); |
a47653fc KC |
1564 | } |
1565 | ||
1566 | if (register_blkdev(LOOP_MAJOR, "loop")) | |
1567 | return -EIO; | |
1da177e4 | 1568 | |
a47653fc KC |
1569 | for (i = 0; i < nr; i++) { |
1570 | lo = loop_alloc(i); | |
1571 | if (!lo) | |
1572 | goto Enomem; | |
1573 | list_add_tail(&lo->lo_list, &loop_devices); | |
1da177e4 | 1574 | } |
a47653fc KC |
1575 | |
1576 | /* point of no return */ | |
1577 | ||
1578 | list_for_each_entry(lo, &loop_devices, lo_list) | |
1579 | add_disk(lo->lo_disk); | |
1580 | ||
1581 | blk_register_region(MKDEV(LOOP_MAJOR, 0), range, | |
1582 | THIS_MODULE, loop_probe, NULL, NULL); | |
1583 | ||
73285082 | 1584 | printk(KERN_INFO "loop: module loaded\n"); |
1da177e4 | 1585 | return 0; |
a47653fc KC |
1586 | |
1587 | Enomem: | |
1588 | printk(KERN_INFO "loop: out of memory\n"); | |
1589 | ||
1590 | list_for_each_entry_safe(lo, next, &loop_devices, lo_list) | |
1591 | loop_free(lo); | |
1592 | ||
1593 | unregister_blkdev(LOOP_MAJOR, "loop"); | |
1594 | return -ENOMEM; | |
1da177e4 LT |
1595 | } |
1596 | ||
73285082 | 1597 | static void __exit loop_exit(void) |
1da177e4 | 1598 | { |
a47653fc | 1599 | unsigned long range; |
73285082 | 1600 | struct loop_device *lo, *next; |
1da177e4 | 1601 | |
476a4813 | 1602 | range = max_loop ? max_loop : 1UL << (MINORBITS - part_shift); |
a47653fc | 1603 | |
73285082 KC |
1604 | list_for_each_entry_safe(lo, next, &loop_devices, lo_list) |
1605 | loop_del_one(lo); | |
1606 | ||
a47653fc | 1607 | blk_unregister_region(MKDEV(LOOP_MAJOR, 0), range); |
00d59405 | 1608 | unregister_blkdev(LOOP_MAJOR, "loop"); |
1da177e4 LT |
1609 | } |
1610 | ||
1611 | module_init(loop_init); | |
1612 | module_exit(loop_exit); | |
1613 | ||
1614 | #ifndef MODULE | |
1615 | static int __init max_loop_setup(char *str) | |
1616 | { | |
1617 | max_loop = simple_strtol(str, NULL, 0); | |
1618 | return 1; | |
1619 | } | |
1620 | ||
1621 | __setup("max_loop=", max_loop_setup); | |
1622 | #endif |