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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 LT |
2 | /* |
3 | * linux/fs/block_dev.c | |
4 | * | |
5 | * Copyright (C) 1991, 1992 Linus Torvalds | |
6 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
7 | */ | |
8 | ||
1da177e4 LT |
9 | #include <linux/init.h> |
10 | #include <linux/mm.h> | |
11 | #include <linux/fcntl.h> | |
12 | #include <linux/slab.h> | |
13 | #include <linux/kmod.h> | |
14 | #include <linux/major.h> | |
7db9cfd3 | 15 | #include <linux/device_cgroup.h> |
1da177e4 LT |
16 | #include <linux/highmem.h> |
17 | #include <linux/blkdev.h> | |
66114cad | 18 | #include <linux/backing-dev.h> |
1da177e4 LT |
19 | #include <linux/module.h> |
20 | #include <linux/blkpg.h> | |
b502bd11 | 21 | #include <linux/magic.h> |
1da177e4 | 22 | #include <linux/buffer_head.h> |
ff01bb48 | 23 | #include <linux/swap.h> |
585d3bc0 | 24 | #include <linux/pagevec.h> |
811d736f | 25 | #include <linux/writeback.h> |
1da177e4 LT |
26 | #include <linux/mpage.h> |
27 | #include <linux/mount.h> | |
9030d16e | 28 | #include <linux/pseudo_fs.h> |
1da177e4 LT |
29 | #include <linux/uio.h> |
30 | #include <linux/namei.h> | |
1368c4f2 | 31 | #include <linux/log2.h> |
ff01bb48 | 32 | #include <linux/cleancache.h> |
189ce2b9 | 33 | #include <linux/task_io_accounting_ops.h> |
25f4c414 | 34 | #include <linux/falloc.h> |
7c0f6ba6 | 35 | #include <linux/uaccess.h> |
56939e01 | 36 | #include <linux/suspend.h> |
07f3f05c | 37 | #include "internal.h" |
1da177e4 LT |
38 | |
39 | struct bdev_inode { | |
40 | struct block_device bdev; | |
41 | struct inode vfs_inode; | |
42 | }; | |
43 | ||
4c54ac62 AB |
44 | static const struct address_space_operations def_blk_aops; |
45 | ||
1da177e4 LT |
46 | static inline struct bdev_inode *BDEV_I(struct inode *inode) |
47 | { | |
48 | return container_of(inode, struct bdev_inode, vfs_inode); | |
49 | } | |
50 | ||
ff5053f6 | 51 | struct block_device *I_BDEV(struct inode *inode) |
1da177e4 LT |
52 | { |
53 | return &BDEV_I(inode)->bdev; | |
54 | } | |
1da177e4 LT |
55 | EXPORT_SYMBOL(I_BDEV); |
56 | ||
dbd3ca50 | 57 | static void bdev_write_inode(struct block_device *bdev) |
564f00f6 | 58 | { |
dbd3ca50 VG |
59 | struct inode *inode = bdev->bd_inode; |
60 | int ret; | |
61 | ||
564f00f6 CH |
62 | spin_lock(&inode->i_lock); |
63 | while (inode->i_state & I_DIRTY) { | |
64 | spin_unlock(&inode->i_lock); | |
dbd3ca50 VG |
65 | ret = write_inode_now(inode, true); |
66 | if (ret) { | |
67 | char name[BDEVNAME_SIZE]; | |
68 | pr_warn_ratelimited("VFS: Dirty inode writeback failed " | |
69 | "for block device %s (err=%d).\n", | |
70 | bdevname(bdev, name), ret); | |
71 | } | |
564f00f6 CH |
72 | spin_lock(&inode->i_lock); |
73 | } | |
74 | spin_unlock(&inode->i_lock); | |
75 | } | |
76 | ||
f9a14399 | 77 | /* Kill _all_ buffers and pagecache , dirty or not.. */ |
3373a346 | 78 | static void kill_bdev(struct block_device *bdev) |
1da177e4 | 79 | { |
ff01bb48 AV |
80 | struct address_space *mapping = bdev->bd_inode->i_mapping; |
81 | ||
f9fe48be | 82 | if (mapping->nrpages == 0 && mapping->nrexceptional == 0) |
f9a14399 | 83 | return; |
ff01bb48 | 84 | |
f9a14399 | 85 | invalidate_bh_lrus(); |
ff01bb48 | 86 | truncate_inode_pages(mapping, 0); |
3373a346 | 87 | } |
ff01bb48 AV |
88 | |
89 | /* Invalidate clean unused buffers and pagecache. */ | |
90 | void invalidate_bdev(struct block_device *bdev) | |
91 | { | |
92 | struct address_space *mapping = bdev->bd_inode->i_mapping; | |
93 | ||
a5f6a6a9 AR |
94 | if (mapping->nrpages) { |
95 | invalidate_bh_lrus(); | |
96 | lru_add_drain_all(); /* make sure all lru add caches are flushed */ | |
97 | invalidate_mapping_pages(mapping, 0, -1); | |
98 | } | |
ff01bb48 AV |
99 | /* 99% of the time, we don't need to flush the cleancache on the bdev. |
100 | * But, for the strange corners, lets be cautious | |
101 | */ | |
3167760f | 102 | cleancache_invalidate_inode(mapping); |
ff01bb48 AV |
103 | } |
104 | EXPORT_SYMBOL(invalidate_bdev); | |
1da177e4 | 105 | |
04906b2f JK |
106 | static void set_init_blocksize(struct block_device *bdev) |
107 | { | |
6b7b181b | 108 | bdev->bd_inode->i_blkbits = blksize_bits(bdev_logical_block_size(bdev)); |
04906b2f JK |
109 | } |
110 | ||
1da177e4 LT |
111 | int set_blocksize(struct block_device *bdev, int size) |
112 | { | |
113 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 114 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
115 | return -EINVAL; |
116 | ||
117 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 118 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
119 | return -EINVAL; |
120 | ||
121 | /* Don't change the size if it is same as current */ | |
6b7b181b | 122 | if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 123 | sync_blockdev(bdev); |
1da177e4 LT |
124 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
125 | kill_bdev(bdev); | |
126 | } | |
127 | return 0; | |
128 | } | |
129 | ||
130 | EXPORT_SYMBOL(set_blocksize); | |
131 | ||
132 | int sb_set_blocksize(struct super_block *sb, int size) | |
133 | { | |
1da177e4 LT |
134 | if (set_blocksize(sb->s_bdev, size)) |
135 | return 0; | |
136 | /* If we get here, we know size is power of two | |
137 | * and it's value is between 512 and PAGE_SIZE */ | |
138 | sb->s_blocksize = size; | |
38885bd4 | 139 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
140 | return sb->s_blocksize; |
141 | } | |
142 | ||
143 | EXPORT_SYMBOL(sb_set_blocksize); | |
144 | ||
145 | int sb_min_blocksize(struct super_block *sb, int size) | |
146 | { | |
e1defc4f | 147 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
148 | if (size < minsize) |
149 | size = minsize; | |
150 | return sb_set_blocksize(sb, size); | |
151 | } | |
152 | ||
153 | EXPORT_SYMBOL(sb_min_blocksize); | |
154 | ||
155 | static int | |
156 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
157 | struct buffer_head *bh, int create) | |
158 | { | |
1da177e4 LT |
159 | bh->b_bdev = I_BDEV(inode); |
160 | bh->b_blocknr = iblock; | |
161 | set_buffer_mapped(bh); | |
162 | return 0; | |
163 | } | |
164 | ||
4ebb16ca DW |
165 | static struct inode *bdev_file_inode(struct file *file) |
166 | { | |
167 | return file->f_mapping->host; | |
168 | } | |
169 | ||
78250c02 JA |
170 | static unsigned int dio_bio_write_op(struct kiocb *iocb) |
171 | { | |
172 | unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; | |
173 | ||
174 | /* avoid the need for a I/O completion work item */ | |
175 | if (iocb->ki_flags & IOCB_DSYNC) | |
176 | op |= REQ_FUA; | |
177 | return op; | |
178 | } | |
179 | ||
189ce2b9 CH |
180 | #define DIO_INLINE_BIO_VECS 4 |
181 | ||
182 | static void blkdev_bio_end_io_simple(struct bio *bio) | |
183 | { | |
184 | struct task_struct *waiter = bio->bi_private; | |
185 | ||
186 | WRITE_ONCE(bio->bi_private, NULL); | |
0619317f | 187 | blk_wake_io_task(waiter); |
189ce2b9 CH |
188 | } |
189 | ||
190 | static ssize_t | |
191 | __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, | |
192 | int nr_pages) | |
193 | { | |
194 | struct file *file = iocb->ki_filp; | |
195 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
9fec4a21 | 196 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; |
189ce2b9 CH |
197 | loff_t pos = iocb->ki_pos; |
198 | bool should_dirty = false; | |
199 | struct bio bio; | |
200 | ssize_t ret; | |
201 | blk_qc_t qc; | |
189ce2b9 | 202 | |
9a794fb9 JA |
203 | if ((pos | iov_iter_alignment(iter)) & |
204 | (bdev_logical_block_size(bdev) - 1)) | |
189ce2b9 CH |
205 | return -EINVAL; |
206 | ||
72ecad22 JA |
207 | if (nr_pages <= DIO_INLINE_BIO_VECS) |
208 | vecs = inline_vecs; | |
209 | else { | |
6da2ec56 KC |
210 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), |
211 | GFP_KERNEL); | |
72ecad22 JA |
212 | if (!vecs) |
213 | return -ENOMEM; | |
214 | } | |
215 | ||
3a83f467 | 216 | bio_init(&bio, vecs, nr_pages); |
74d46992 | 217 | bio_set_dev(&bio, bdev); |
4d1a4765 | 218 | bio.bi_iter.bi_sector = pos >> 9; |
45d06cf7 | 219 | bio.bi_write_hint = iocb->ki_hint; |
189ce2b9 CH |
220 | bio.bi_private = current; |
221 | bio.bi_end_io = blkdev_bio_end_io_simple; | |
074111ca | 222 | bio.bi_ioprio = iocb->ki_ioprio; |
189ce2b9 CH |
223 | |
224 | ret = bio_iov_iter_get_pages(&bio, iter); | |
225 | if (unlikely(ret)) | |
9362dd11 | 226 | goto out; |
189ce2b9 CH |
227 | ret = bio.bi_iter.bi_size; |
228 | ||
229 | if (iov_iter_rw(iter) == READ) { | |
78250c02 | 230 | bio.bi_opf = REQ_OP_READ; |
189ce2b9 CH |
231 | if (iter_is_iovec(iter)) |
232 | should_dirty = true; | |
233 | } else { | |
78250c02 | 234 | bio.bi_opf = dio_bio_write_op(iocb); |
189ce2b9 CH |
235 | task_io_account_write(ret); |
236 | } | |
d1e36282 | 237 | if (iocb->ki_flags & IOCB_HIPRI) |
0bbb280d | 238 | bio_set_polled(&bio, iocb); |
189ce2b9 CH |
239 | |
240 | qc = submit_bio(&bio); | |
241 | for (;;) { | |
1ac5cd49 | 242 | set_current_state(TASK_UNINTERRUPTIBLE); |
189ce2b9 CH |
243 | if (!READ_ONCE(bio.bi_private)) |
244 | break; | |
245 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
0a1b8b87 | 246 | !blk_poll(bdev_get_queue(bdev), qc, true)) |
e6249cdd | 247 | blk_io_schedule(); |
189ce2b9 CH |
248 | } |
249 | __set_current_state(TASK_RUNNING); | |
250 | ||
9fec4a21 | 251 | bio_release_pages(&bio, should_dirty); |
4e4cbee9 | 252 | if (unlikely(bio.bi_status)) |
c6b1e36c | 253 | ret = blk_status_to_errno(bio.bi_status); |
9ae3b3f5 | 254 | |
9362dd11 MW |
255 | out: |
256 | if (vecs != inline_vecs) | |
257 | kfree(vecs); | |
258 | ||
9ae3b3f5 JA |
259 | bio_uninit(&bio); |
260 | ||
189ce2b9 CH |
261 | return ret; |
262 | } | |
263 | ||
542ff7bf CH |
264 | struct blkdev_dio { |
265 | union { | |
266 | struct kiocb *iocb; | |
267 | struct task_struct *waiter; | |
268 | }; | |
269 | size_t size; | |
270 | atomic_t ref; | |
271 | bool multi_bio : 1; | |
272 | bool should_dirty : 1; | |
273 | bool is_sync : 1; | |
274 | struct bio bio; | |
275 | }; | |
276 | ||
52190f8a | 277 | static struct bio_set blkdev_dio_pool; |
542ff7bf | 278 | |
eae83ce1 CH |
279 | static int blkdev_iopoll(struct kiocb *kiocb, bool wait) |
280 | { | |
281 | struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host); | |
282 | struct request_queue *q = bdev_get_queue(bdev); | |
283 | ||
284 | return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait); | |
285 | } | |
286 | ||
542ff7bf CH |
287 | static void blkdev_bio_end_io(struct bio *bio) |
288 | { | |
289 | struct blkdev_dio *dio = bio->bi_private; | |
290 | bool should_dirty = dio->should_dirty; | |
291 | ||
a89afe58 JY |
292 | if (bio->bi_status && !dio->bio.bi_status) |
293 | dio->bio.bi_status = bio->bi_status; | |
294 | ||
295 | if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) { | |
542ff7bf CH |
296 | if (!dio->is_sync) { |
297 | struct kiocb *iocb = dio->iocb; | |
4e4cbee9 | 298 | ssize_t ret; |
542ff7bf | 299 | |
4e4cbee9 | 300 | if (likely(!dio->bio.bi_status)) { |
542ff7bf CH |
301 | ret = dio->size; |
302 | iocb->ki_pos += ret; | |
4e4cbee9 CH |
303 | } else { |
304 | ret = blk_status_to_errno(dio->bio.bi_status); | |
542ff7bf CH |
305 | } |
306 | ||
307 | dio->iocb->ki_complete(iocb, ret, 0); | |
531724ab CH |
308 | if (dio->multi_bio) |
309 | bio_put(&dio->bio); | |
542ff7bf CH |
310 | } else { |
311 | struct task_struct *waiter = dio->waiter; | |
312 | ||
313 | WRITE_ONCE(dio->waiter, NULL); | |
0619317f | 314 | blk_wake_io_task(waiter); |
542ff7bf CH |
315 | } |
316 | } | |
317 | ||
318 | if (should_dirty) { | |
319 | bio_check_pages_dirty(bio); | |
320 | } else { | |
57dfe3ce | 321 | bio_release_pages(bio, false); |
542ff7bf CH |
322 | bio_put(bio); |
323 | } | |
324 | } | |
325 | ||
b2e895db | 326 | static ssize_t |
542ff7bf | 327 | __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages) |
b2e895db AM |
328 | { |
329 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 330 | struct inode *inode = bdev_file_inode(file); |
542ff7bf | 331 | struct block_device *bdev = I_BDEV(inode); |
64d656a1 | 332 | struct blk_plug plug; |
542ff7bf CH |
333 | struct blkdev_dio *dio; |
334 | struct bio *bio; | |
cb700eb3 | 335 | bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0; |
690e5325 | 336 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
542ff7bf CH |
337 | loff_t pos = iocb->ki_pos; |
338 | blk_qc_t qc = BLK_QC_T_NONE; | |
7b6620d7 | 339 | int ret = 0; |
542ff7bf | 340 | |
9a794fb9 JA |
341 | if ((pos | iov_iter_alignment(iter)) & |
342 | (bdev_logical_block_size(bdev) - 1)) | |
542ff7bf CH |
343 | return -EINVAL; |
344 | ||
7b6620d7 | 345 | bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool); |
542ff7bf CH |
346 | |
347 | dio = container_of(bio, struct blkdev_dio, bio); | |
690e5325 | 348 | dio->is_sync = is_sync = is_sync_kiocb(iocb); |
531724ab | 349 | if (dio->is_sync) { |
542ff7bf | 350 | dio->waiter = current; |
531724ab CH |
351 | bio_get(bio); |
352 | } else { | |
542ff7bf | 353 | dio->iocb = iocb; |
531724ab | 354 | } |
542ff7bf CH |
355 | |
356 | dio->size = 0; | |
357 | dio->multi_bio = false; | |
00e23707 | 358 | dio->should_dirty = is_read && iter_is_iovec(iter); |
542ff7bf | 359 | |
cb700eb3 JA |
360 | /* |
361 | * Don't plug for HIPRI/polled IO, as those should go straight | |
362 | * to issue | |
363 | */ | |
364 | if (!is_poll) | |
365 | blk_start_plug(&plug); | |
366 | ||
542ff7bf | 367 | for (;;) { |
74d46992 | 368 | bio_set_dev(bio, bdev); |
4d1a4765 | 369 | bio->bi_iter.bi_sector = pos >> 9; |
45d06cf7 | 370 | bio->bi_write_hint = iocb->ki_hint; |
542ff7bf CH |
371 | bio->bi_private = dio; |
372 | bio->bi_end_io = blkdev_bio_end_io; | |
074111ca | 373 | bio->bi_ioprio = iocb->ki_ioprio; |
542ff7bf | 374 | |
e15c2ffa JA |
375 | ret = bio_iov_iter_get_pages(bio, iter); |
376 | if (unlikely(ret)) { | |
4e4cbee9 | 377 | bio->bi_status = BLK_STS_IOERR; |
542ff7bf CH |
378 | bio_endio(bio); |
379 | break; | |
380 | } | |
381 | ||
382 | if (is_read) { | |
383 | bio->bi_opf = REQ_OP_READ; | |
384 | if (dio->should_dirty) | |
385 | bio_set_pages_dirty(bio); | |
386 | } else { | |
387 | bio->bi_opf = dio_bio_write_op(iocb); | |
388 | task_io_account_write(bio->bi_iter.bi_size); | |
389 | } | |
390 | ||
7b6620d7 | 391 | dio->size += bio->bi_iter.bi_size; |
542ff7bf CH |
392 | pos += bio->bi_iter.bi_size; |
393 | ||
394 | nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES); | |
395 | if (!nr_pages) { | |
eae83ce1 CH |
396 | bool polled = false; |
397 | ||
398 | if (iocb->ki_flags & IOCB_HIPRI) { | |
0bbb280d | 399 | bio_set_polled(bio, iocb); |
eae83ce1 CH |
400 | polled = true; |
401 | } | |
d34513d3 | 402 | |
542ff7bf | 403 | qc = submit_bio(bio); |
eae83ce1 CH |
404 | |
405 | if (polled) | |
406 | WRITE_ONCE(iocb->ki_cookie, qc); | |
542ff7bf CH |
407 | break; |
408 | } | |
409 | ||
410 | if (!dio->multi_bio) { | |
531724ab CH |
411 | /* |
412 | * AIO needs an extra reference to ensure the dio | |
413 | * structure which is embedded into the first bio | |
414 | * stays around. | |
415 | */ | |
416 | if (!is_sync) | |
417 | bio_get(bio); | |
542ff7bf CH |
418 | dio->multi_bio = true; |
419 | atomic_set(&dio->ref, 2); | |
420 | } else { | |
421 | atomic_inc(&dio->ref); | |
422 | } | |
423 | ||
7b6620d7 JA |
424 | submit_bio(bio); |
425 | bio = bio_alloc(GFP_KERNEL, nr_pages); | |
542ff7bf | 426 | } |
cb700eb3 JA |
427 | |
428 | if (!is_poll) | |
429 | blk_finish_plug(&plug); | |
542ff7bf | 430 | |
690e5325 | 431 | if (!is_sync) |
542ff7bf CH |
432 | return -EIOCBQUEUED; |
433 | ||
434 | for (;;) { | |
1ac5cd49 | 435 | set_current_state(TASK_UNINTERRUPTIBLE); |
542ff7bf CH |
436 | if (!READ_ONCE(dio->waiter)) |
437 | break; | |
438 | ||
439 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
0a1b8b87 | 440 | !blk_poll(bdev_get_queue(bdev), qc, true)) |
e6249cdd | 441 | blk_io_schedule(); |
542ff7bf CH |
442 | } |
443 | __set_current_state(TASK_RUNNING); | |
444 | ||
36ffc6c1 | 445 | if (!ret) |
4e4cbee9 | 446 | ret = blk_status_to_errno(dio->bio.bi_status); |
e15c2ffa JA |
447 | if (likely(!ret)) |
448 | ret = dio->size; | |
542ff7bf CH |
449 | |
450 | bio_put(&dio->bio); | |
451 | return ret; | |
452 | } | |
453 | ||
454 | static ssize_t | |
455 | blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) | |
456 | { | |
189ce2b9 | 457 | int nr_pages; |
b2e895db | 458 | |
72ecad22 | 459 | nr_pages = iov_iter_npages(iter, BIO_MAX_PAGES + 1); |
189ce2b9 CH |
460 | if (!nr_pages) |
461 | return 0; | |
72ecad22 | 462 | if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) |
189ce2b9 | 463 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); |
542ff7bf CH |
464 | |
465 | return __blkdev_direct_IO(iocb, iter, min(nr_pages, BIO_MAX_PAGES)); | |
466 | } | |
467 | ||
468 | static __init int blkdev_init(void) | |
469 | { | |
52190f8a | 470 | return bioset_init(&blkdev_dio_pool, 4, offsetof(struct blkdev_dio, bio), BIOSET_NEED_BVECS); |
b2e895db | 471 | } |
542ff7bf | 472 | module_init(blkdev_init); |
b2e895db | 473 | |
5cee5815 JK |
474 | int __sync_blockdev(struct block_device *bdev, int wait) |
475 | { | |
476 | if (!bdev) | |
477 | return 0; | |
478 | if (!wait) | |
479 | return filemap_flush(bdev->bd_inode->i_mapping); | |
480 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
481 | } | |
482 | ||
585d3bc0 NP |
483 | /* |
484 | * Write out and wait upon all the dirty data associated with a block | |
485 | * device via its mapping. Does not take the superblock lock. | |
486 | */ | |
487 | int sync_blockdev(struct block_device *bdev) | |
488 | { | |
5cee5815 | 489 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
490 | } |
491 | EXPORT_SYMBOL(sync_blockdev); | |
492 | ||
493 | /* | |
494 | * Write out and wait upon all dirty data associated with this | |
495 | * device. Filesystem data as well as the underlying block | |
496 | * device. Takes the superblock lock. | |
497 | */ | |
498 | int fsync_bdev(struct block_device *bdev) | |
499 | { | |
500 | struct super_block *sb = get_super(bdev); | |
501 | if (sb) { | |
60b0680f | 502 | int res = sync_filesystem(sb); |
585d3bc0 NP |
503 | drop_super(sb); |
504 | return res; | |
505 | } | |
506 | return sync_blockdev(bdev); | |
507 | } | |
47e4491b | 508 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
509 | |
510 | /** | |
511 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
512 | * @bdev: blockdevice to lock | |
513 | * | |
585d3bc0 NP |
514 | * If a superblock is found on this device, we take the s_umount semaphore |
515 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
516 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
517 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
518 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
519 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
520 | * actually. | |
521 | */ | |
522 | struct super_block *freeze_bdev(struct block_device *bdev) | |
523 | { | |
524 | struct super_block *sb; | |
525 | int error = 0; | |
526 | ||
527 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a CH |
528 | if (++bdev->bd_fsfreeze_count > 1) { |
529 | /* | |
530 | * We don't even need to grab a reference - the first call | |
531 | * to freeze_bdev grab an active reference and only the last | |
532 | * thaw_bdev drops it. | |
533 | */ | |
585d3bc0 | 534 | sb = get_super(bdev); |
5bb53c0f AR |
535 | if (sb) |
536 | drop_super(sb); | |
4504230a CH |
537 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
538 | return sb; | |
539 | } | |
540 | ||
541 | sb = get_active_super(bdev); | |
542 | if (!sb) | |
543 | goto out; | |
48b6bca6 BM |
544 | if (sb->s_op->freeze_super) |
545 | error = sb->s_op->freeze_super(sb); | |
546 | else | |
547 | error = freeze_super(sb); | |
18e9e510 JB |
548 | if (error) { |
549 | deactivate_super(sb); | |
550 | bdev->bd_fsfreeze_count--; | |
585d3bc0 | 551 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
18e9e510 | 552 | return ERR_PTR(error); |
585d3bc0 | 553 | } |
18e9e510 | 554 | deactivate_super(sb); |
4504230a | 555 | out: |
585d3bc0 NP |
556 | sync_blockdev(bdev); |
557 | mutex_unlock(&bdev->bd_fsfreeze_mutex); | |
4fadd7bb | 558 | return sb; /* thaw_bdev releases s->s_umount */ |
585d3bc0 NP |
559 | } |
560 | EXPORT_SYMBOL(freeze_bdev); | |
561 | ||
562 | /** | |
563 | * thaw_bdev -- unlock filesystem | |
564 | * @bdev: blockdevice to unlock | |
565 | * @sb: associated superblock | |
566 | * | |
567 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
568 | */ | |
569 | int thaw_bdev(struct block_device *bdev, struct super_block *sb) | |
570 | { | |
4504230a | 571 | int error = -EINVAL; |
585d3bc0 NP |
572 | |
573 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 574 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 575 | goto out; |
4504230a CH |
576 | |
577 | error = 0; | |
578 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 579 | goto out; |
4504230a CH |
580 | |
581 | if (!sb) | |
18e9e510 | 582 | goto out; |
4504230a | 583 | |
48b6bca6 BM |
584 | if (sb->s_op->thaw_super) |
585 | error = sb->s_op->thaw_super(sb); | |
586 | else | |
587 | error = thaw_super(sb); | |
997198ba | 588 | if (error) |
18e9e510 | 589 | bdev->bd_fsfreeze_count++; |
18e9e510 | 590 | out: |
585d3bc0 | 591 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 592 | return error; |
585d3bc0 NP |
593 | } |
594 | EXPORT_SYMBOL(thaw_bdev); | |
595 | ||
1da177e4 LT |
596 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
597 | { | |
598 | return block_write_full_page(page, blkdev_get_block, wbc); | |
599 | } | |
600 | ||
601 | static int blkdev_readpage(struct file * file, struct page * page) | |
602 | { | |
603 | return block_read_full_page(page, blkdev_get_block); | |
604 | } | |
605 | ||
d4388340 | 606 | static void blkdev_readahead(struct readahead_control *rac) |
447f05bb | 607 | { |
d4388340 | 608 | mpage_readahead(rac, blkdev_get_block); |
447f05bb AM |
609 | } |
610 | ||
6272b5a5 NP |
611 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
612 | loff_t pos, unsigned len, unsigned flags, | |
613 | struct page **pagep, void **fsdata) | |
1da177e4 | 614 | { |
155130a4 CH |
615 | return block_write_begin(mapping, pos, len, flags, pagep, |
616 | blkdev_get_block); | |
1da177e4 LT |
617 | } |
618 | ||
6272b5a5 NP |
619 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
620 | loff_t pos, unsigned len, unsigned copied, | |
621 | struct page *page, void *fsdata) | |
1da177e4 | 622 | { |
6272b5a5 NP |
623 | int ret; |
624 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
625 | ||
626 | unlock_page(page); | |
09cbfeaf | 627 | put_page(page); |
6272b5a5 NP |
628 | |
629 | return ret; | |
1da177e4 LT |
630 | } |
631 | ||
632 | /* | |
633 | * private llseek: | |
496ad9aa | 634 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
635 | * so we compute the size by hand (just as in block_read/write above) |
636 | */ | |
965c8e59 | 637 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 638 | { |
4ebb16ca | 639 | struct inode *bd_inode = bdev_file_inode(file); |
1da177e4 LT |
640 | loff_t retval; |
641 | ||
5955102c | 642 | inode_lock(bd_inode); |
5d48f3a2 | 643 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
5955102c | 644 | inode_unlock(bd_inode); |
1da177e4 LT |
645 | return retval; |
646 | } | |
647 | ||
02c24a82 | 648 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 649 | { |
4ebb16ca | 650 | struct inode *bd_inode = bdev_file_inode(filp); |
b8af67e2 | 651 | struct block_device *bdev = I_BDEV(bd_inode); |
ab0a9735 | 652 | int error; |
da5aa861 | 653 | |
372cf243 | 654 | error = file_write_and_wait_range(filp, start, end); |
da5aa861 RW |
655 | if (error) |
656 | return error; | |
ab0a9735 | 657 | |
b8af67e2 AB |
658 | /* |
659 | * There is no need to serialise calls to blkdev_issue_flush with | |
660 | * i_mutex and doing so causes performance issues with concurrent | |
661 | * O_SYNC writers to a block device. | |
662 | */ | |
9398554f | 663 | error = blkdev_issue_flush(bdev, GFP_KERNEL); |
ab0a9735 CH |
664 | if (error == -EOPNOTSUPP) |
665 | error = 0; | |
b8af67e2 | 666 | |
ab0a9735 | 667 | return error; |
1da177e4 | 668 | } |
b1dd3b28 | 669 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 670 | |
47a191fd MW |
671 | /** |
672 | * bdev_read_page() - Start reading a page from a block device | |
673 | * @bdev: The device to read the page from | |
674 | * @sector: The offset on the device to read the page to (need not be aligned) | |
675 | * @page: The page to read | |
676 | * | |
677 | * On entry, the page should be locked. It will be unlocked when the page | |
678 | * has been read. If the block driver implements rw_page synchronously, | |
679 | * that will be true on exit from this function, but it need not be. | |
680 | * | |
681 | * Errors returned by this function are usually "soft", eg out of memory, or | |
682 | * queue full; callers should try a different route to read this page rather | |
683 | * than propagate an error back up the stack. | |
684 | * | |
685 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
686 | */ | |
687 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
688 | struct page *page) | |
689 | { | |
690 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
2e6edc95 DW |
691 | int result = -EOPNOTSUPP; |
692 | ||
f68eb1e7 | 693 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
2e6edc95 DW |
694 | return result; |
695 | ||
e556f6ba | 696 | result = blk_queue_enter(bdev->bd_disk->queue, 0); |
2e6edc95 DW |
697 | if (result) |
698 | return result; | |
3f289dcb TH |
699 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
700 | REQ_OP_READ); | |
e556f6ba | 701 | blk_queue_exit(bdev->bd_disk->queue); |
2e6edc95 | 702 | return result; |
47a191fd | 703 | } |
47a191fd MW |
704 | |
705 | /** | |
706 | * bdev_write_page() - Start writing a page to a block device | |
707 | * @bdev: The device to write the page to | |
708 | * @sector: The offset on the device to write the page to (need not be aligned) | |
709 | * @page: The page to write | |
710 | * @wbc: The writeback_control for the write | |
711 | * | |
712 | * On entry, the page should be locked and not currently under writeback. | |
713 | * On exit, if the write started successfully, the page will be unlocked and | |
714 | * under writeback. If the write failed already (eg the driver failed to | |
715 | * queue the page to the device), the page will still be locked. If the | |
716 | * caller is a ->writepage implementation, it will need to unlock the page. | |
717 | * | |
718 | * Errors returned by this function are usually "soft", eg out of memory, or | |
719 | * queue full; callers should try a different route to write this page rather | |
720 | * than propagate an error back up the stack. | |
721 | * | |
722 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
723 | */ | |
724 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
725 | struct page *page, struct writeback_control *wbc) | |
726 | { | |
727 | int result; | |
47a191fd | 728 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
2e6edc95 | 729 | |
f68eb1e7 | 730 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd | 731 | return -EOPNOTSUPP; |
e556f6ba | 732 | result = blk_queue_enter(bdev->bd_disk->queue, 0); |
2e6edc95 DW |
733 | if (result) |
734 | return result; | |
735 | ||
47a191fd | 736 | set_page_writeback(page); |
3f289dcb TH |
737 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
738 | REQ_OP_WRITE); | |
f892760a | 739 | if (result) { |
47a191fd | 740 | end_page_writeback(page); |
f892760a MW |
741 | } else { |
742 | clean_page_buffers(page); | |
47a191fd | 743 | unlock_page(page); |
f892760a | 744 | } |
e556f6ba | 745 | blk_queue_exit(bdev->bd_disk->queue); |
47a191fd MW |
746 | return result; |
747 | } | |
47a191fd | 748 | |
1da177e4 LT |
749 | /* |
750 | * pseudo-fs | |
751 | */ | |
752 | ||
753 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 754 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
755 | |
756 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
757 | { | |
e94b1766 | 758 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
1da177e4 LT |
759 | if (!ei) |
760 | return NULL; | |
761 | return &ei->vfs_inode; | |
762 | } | |
763 | ||
41149cb0 | 764 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 765 | { |
41149cb0 | 766 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
767 | } |
768 | ||
51cc5068 | 769 | static void init_once(void *foo) |
1da177e4 LT |
770 | { |
771 | struct bdev_inode *ei = (struct bdev_inode *) foo; | |
772 | struct block_device *bdev = &ei->bdev; | |
773 | ||
a35afb83 CL |
774 | memset(bdev, 0, sizeof(*bdev)); |
775 | mutex_init(&bdev->bd_mutex); | |
49731baa TH |
776 | #ifdef CONFIG_SYSFS |
777 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
778 | #endif | |
a5a79d00 | 779 | bdev->bd_bdi = &noop_backing_dev_info; |
a35afb83 | 780 | inode_init_once(&ei->vfs_inode); |
fcccf502 TS |
781 | /* Initialize mutex for freeze. */ |
782 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
1da177e4 LT |
783 | } |
784 | ||
b57922d9 | 785 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
786 | { |
787 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
91b0abe3 | 788 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 789 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 790 | clear_inode(inode); |
f759741d JK |
791 | /* Detach inode from wb early as bdi_put() may free bdi->wb */ |
792 | inode_detach_wb(inode); | |
a5a79d00 | 793 | if (bdev->bd_bdi != &noop_backing_dev_info) { |
b1d2dc56 | 794 | bdi_put(bdev->bd_bdi); |
a5a79d00 JK |
795 | bdev->bd_bdi = &noop_backing_dev_info; |
796 | } | |
1da177e4 LT |
797 | } |
798 | ||
ee9b6d61 | 799 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
800 | .statfs = simple_statfs, |
801 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 802 | .free_inode = bdev_free_inode, |
1da177e4 | 803 | .drop_inode = generic_delete_inode, |
b57922d9 | 804 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
805 | }; |
806 | ||
9030d16e | 807 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 808 | { |
9030d16e DH |
809 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
810 | if (!ctx) | |
811 | return -ENOMEM; | |
812 | fc->s_iflags |= SB_I_CGROUPWB; | |
813 | ctx->ops = &bdev_sops; | |
814 | return 0; | |
1da177e4 LT |
815 | } |
816 | ||
817 | static struct file_system_type bd_type = { | |
818 | .name = "bdev", | |
9030d16e | 819 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
820 | .kill_sb = kill_anon_super, |
821 | }; | |
822 | ||
a212b105 TH |
823 | struct super_block *blockdev_superblock __read_mostly; |
824 | EXPORT_SYMBOL_GPL(blockdev_superblock); | |
1da177e4 LT |
825 | |
826 | void __init bdev_cache_init(void) | |
827 | { | |
828 | int err; | |
ace8577a | 829 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 830 | |
1da177e4 | 831 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 832 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 833 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 834 | init_once); |
1da177e4 LT |
835 | err = register_filesystem(&bd_type); |
836 | if (err) | |
837 | panic("Cannot register bdev pseudo-fs"); | |
838 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
839 | if (IS_ERR(bd_mnt)) |
840 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 841 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
842 | } |
843 | ||
844 | /* | |
845 | * Most likely _very_ bad one - but then it's hardly critical for small | |
846 | * /dev and can be fixed when somebody will need really large one. | |
847 | * Keep in mind that it will be fed through icache hash function too. | |
848 | */ | |
849 | static inline unsigned long hash(dev_t dev) | |
850 | { | |
851 | return MAJOR(dev)+MINOR(dev); | |
852 | } | |
853 | ||
854 | static int bdev_test(struct inode *inode, void *data) | |
855 | { | |
856 | return BDEV_I(inode)->bdev.bd_dev == *(dev_t *)data; | |
857 | } | |
858 | ||
859 | static int bdev_set(struct inode *inode, void *data) | |
860 | { | |
861 | BDEV_I(inode)->bdev.bd_dev = *(dev_t *)data; | |
862 | return 0; | |
863 | } | |
864 | ||
1da177e4 LT |
865 | struct block_device *bdget(dev_t dev) |
866 | { | |
867 | struct block_device *bdev; | |
868 | struct inode *inode; | |
869 | ||
c2acf7b9 | 870 | inode = iget5_locked(blockdev_superblock, hash(dev), |
1da177e4 LT |
871 | bdev_test, bdev_set, &dev); |
872 | ||
873 | if (!inode) | |
874 | return NULL; | |
875 | ||
876 | bdev = &BDEV_I(inode)->bdev; | |
877 | ||
878 | if (inode->i_state & I_NEW) { | |
879 | bdev->bd_contains = NULL; | |
782b94cd | 880 | bdev->bd_super = NULL; |
1da177e4 | 881 | bdev->bd_inode = inode; |
1da177e4 LT |
882 | bdev->bd_part_count = 0; |
883 | bdev->bd_invalidated = 0; | |
884 | inode->i_mode = S_IFBLK; | |
885 | inode->i_rdev = dev; | |
886 | inode->i_bdev = bdev; | |
887 | inode->i_data.a_ops = &def_blk_aops; | |
888 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
1da177e4 LT |
889 | unlock_new_inode(inode); |
890 | } | |
891 | return bdev; | |
892 | } | |
893 | ||
894 | EXPORT_SYMBOL(bdget); | |
895 | ||
dddac6a7 AJ |
896 | /** |
897 | * bdgrab -- Grab a reference to an already referenced block device | |
898 | * @bdev: Block device to grab a reference to. | |
899 | */ | |
900 | struct block_device *bdgrab(struct block_device *bdev) | |
901 | { | |
7de9c6ee | 902 | ihold(bdev->bd_inode); |
dddac6a7 AJ |
903 | return bdev; |
904 | } | |
c1681bf8 | 905 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 906 | |
1da177e4 LT |
907 | long nr_blockdev_pages(void) |
908 | { | |
1008fe6d | 909 | struct inode *inode; |
1da177e4 | 910 | long ret = 0; |
1008fe6d CH |
911 | |
912 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
913 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
914 | ret += inode->i_mapping->nrpages; | |
915 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
916 | ||
1da177e4 LT |
917 | return ret; |
918 | } | |
919 | ||
920 | void bdput(struct block_device *bdev) | |
921 | { | |
922 | iput(bdev->bd_inode); | |
923 | } | |
924 | ||
925 | EXPORT_SYMBOL(bdput); | |
926 | ||
927 | static struct block_device *bd_acquire(struct inode *inode) | |
928 | { | |
929 | struct block_device *bdev; | |
09d967c6 | 930 | |
1da177e4 LT |
931 | spin_lock(&bdev_lock); |
932 | bdev = inode->i_bdev; | |
cccd9fb9 | 933 | if (bdev && !inode_unhashed(bdev->bd_inode)) { |
ed8a9d2c | 934 | bdgrab(bdev); |
1da177e4 LT |
935 | spin_unlock(&bdev_lock); |
936 | return bdev; | |
937 | } | |
938 | spin_unlock(&bdev_lock); | |
09d967c6 | 939 | |
cccd9fb9 JK |
940 | /* |
941 | * i_bdev references block device inode that was already shut down | |
942 | * (corresponding device got removed). Remove the reference and look | |
943 | * up block device inode again just in case new device got | |
944 | * reestablished under the same device number. | |
945 | */ | |
946 | if (bdev) | |
947 | bd_forget(inode); | |
948 | ||
1da177e4 LT |
949 | bdev = bdget(inode->i_rdev); |
950 | if (bdev) { | |
951 | spin_lock(&bdev_lock); | |
09d967c6 OH |
952 | if (!inode->i_bdev) { |
953 | /* | |
7de9c6ee | 954 | * We take an additional reference to bd_inode, |
09d967c6 OH |
955 | * and it's released in clear_inode() of inode. |
956 | * So, we can access it via ->i_mapping always | |
957 | * without igrab(). | |
958 | */ | |
ed8a9d2c | 959 | bdgrab(bdev); |
09d967c6 OH |
960 | inode->i_bdev = bdev; |
961 | inode->i_mapping = bdev->bd_inode->i_mapping; | |
09d967c6 | 962 | } |
1da177e4 LT |
963 | spin_unlock(&bdev_lock); |
964 | } | |
965 | return bdev; | |
966 | } | |
967 | ||
968 | /* Call when you free inode */ | |
969 | ||
970 | void bd_forget(struct inode *inode) | |
971 | { | |
09d967c6 OH |
972 | struct block_device *bdev = NULL; |
973 | ||
1da177e4 | 974 | spin_lock(&bdev_lock); |
b4ea2eaa YH |
975 | if (!sb_is_blkdev_sb(inode->i_sb)) |
976 | bdev = inode->i_bdev; | |
a4a4f943 AV |
977 | inode->i_bdev = NULL; |
978 | inode->i_mapping = &inode->i_data; | |
1da177e4 | 979 | spin_unlock(&bdev_lock); |
09d967c6 OH |
980 | |
981 | if (bdev) | |
ed8a9d2c | 982 | bdput(bdev); |
1da177e4 LT |
983 | } |
984 | ||
1a3cbbc5 TH |
985 | /** |
986 | * bd_may_claim - test whether a block device can be claimed | |
987 | * @bdev: block device of interest | |
988 | * @whole: whole block device containing @bdev, may equal @bdev | |
989 | * @holder: holder trying to claim @bdev | |
990 | * | |
25985edc | 991 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
992 | * |
993 | * CONTEXT: | |
994 | * spin_lock(&bdev_lock). | |
995 | * | |
996 | * RETURNS: | |
997 | * %true if @bdev can be claimed, %false otherwise. | |
998 | */ | |
999 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
1000 | void *holder) | |
1da177e4 | 1001 | { |
1da177e4 | 1002 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 1003 | return true; /* already a holder */ |
1da177e4 | 1004 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 1005 | return false; /* held by someone else */ |
bcc7f5b4 | 1006 | else if (whole == bdev) |
1a3cbbc5 | 1007 | return true; /* is a whole device which isn't held */ |
1da177e4 | 1008 | |
e525fd89 | 1009 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
1010 | return true; /* is a partition of a device that is being partitioned */ |
1011 | else if (whole->bd_holder != NULL) | |
1012 | return false; /* is a partition of a held device */ | |
1da177e4 | 1013 | else |
1a3cbbc5 TH |
1014 | return true; /* is a partition of an un-held device */ |
1015 | } | |
1016 | ||
6b4517a7 | 1017 | /** |
58e46ed9 | 1018 | * bd_prepare_to_claim - claim a block device |
6b4517a7 TH |
1019 | * @bdev: block device of interest |
1020 | * @whole: the whole device containing @bdev, may equal @bdev | |
1021 | * @holder: holder trying to claim @bdev | |
1022 | * | |
58e46ed9 CH |
1023 | * Claim @bdev. This function fails if @bdev is already claimed by another |
1024 | * holder and waits if another claiming is in progress. return, the caller | |
1025 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
1026 | * |
1027 | * RETURNS: | |
1028 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
1029 | */ | |
ecbe6bc0 CH |
1030 | int bd_prepare_to_claim(struct block_device *bdev, struct block_device *whole, |
1031 | void *holder) | |
6b4517a7 TH |
1032 | { |
1033 | retry: | |
58e46ed9 | 1034 | spin_lock(&bdev_lock); |
6b4517a7 | 1035 | /* if someone else claimed, fail */ |
58e46ed9 CH |
1036 | if (!bd_may_claim(bdev, whole, holder)) { |
1037 | spin_unlock(&bdev_lock); | |
6b4517a7 | 1038 | return -EBUSY; |
58e46ed9 | 1039 | } |
6b4517a7 | 1040 | |
e75aa858 TH |
1041 | /* if claiming is already in progress, wait for it to finish */ |
1042 | if (whole->bd_claiming) { | |
6b4517a7 TH |
1043 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
1044 | DEFINE_WAIT(wait); | |
1045 | ||
1046 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
1047 | spin_unlock(&bdev_lock); | |
1048 | schedule(); | |
1049 | finish_wait(wq, &wait); | |
6b4517a7 TH |
1050 | goto retry; |
1051 | } | |
1052 | ||
1053 | /* yay, all mine */ | |
58e46ed9 CH |
1054 | whole->bd_claiming = holder; |
1055 | spin_unlock(&bdev_lock); | |
6b4517a7 TH |
1056 | return 0; |
1057 | } | |
ecbe6bc0 | 1058 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 1059 | |
560e7cb2 JK |
1060 | static struct gendisk *bdev_get_gendisk(struct block_device *bdev, int *partno) |
1061 | { | |
1062 | struct gendisk *disk = get_gendisk(bdev->bd_dev, partno); | |
1063 | ||
1064 | if (!disk) | |
1065 | return NULL; | |
1066 | /* | |
1067 | * Now that we hold gendisk reference we make sure bdev we looked up is | |
1068 | * not stale. If it is, it means device got removed and created before | |
1069 | * we looked up gendisk and we fail open in such case. Associating | |
1070 | * unhashed bdev with newly created gendisk could lead to two bdevs | |
1071 | * (and thus two independent caches) being associated with one device | |
1072 | * which is bad. | |
1073 | */ | |
1074 | if (inode_unhashed(bdev->bd_inode)) { | |
1075 | put_disk_and_module(disk); | |
1076 | return NULL; | |
1077 | } | |
1078 | return disk; | |
1079 | } | |
1080 | ||
89e524c0 JK |
1081 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
1082 | { | |
1083 | lockdep_assert_held(&bdev_lock); | |
1084 | /* tell others that we're done */ | |
1085 | BUG_ON(whole->bd_claiming != holder); | |
1086 | whole->bd_claiming = NULL; | |
1087 | wake_up_bit(&whole->bd_claiming, 0); | |
1088 | } | |
1089 | ||
1090 | /** | |
1091 | * bd_finish_claiming - finish claiming of a block device | |
1092 | * @bdev: block device of interest | |
5b642d8b | 1093 | * @whole: whole block device |
89e524c0 JK |
1094 | * @holder: holder that has claimed @bdev |
1095 | * | |
1096 | * Finish exclusive open of a block device. Mark the device as exlusively | |
1097 | * open by the holder and wake up all waiters for exclusive open to finish. | |
1098 | */ | |
764b23bd CH |
1099 | static void bd_finish_claiming(struct block_device *bdev, |
1100 | struct block_device *whole, void *holder) | |
89e524c0 JK |
1101 | { |
1102 | spin_lock(&bdev_lock); | |
1103 | BUG_ON(!bd_may_claim(bdev, whole, holder)); | |
1104 | /* | |
1105 | * Note that for a whole device bd_holders will be incremented twice, | |
1106 | * and bd_holder will be set to bd_may_claim before being set to holder | |
1107 | */ | |
1108 | whole->bd_holders++; | |
1109 | whole->bd_holder = bd_may_claim; | |
1110 | bdev->bd_holders++; | |
1111 | bdev->bd_holder = holder; | |
1112 | bd_clear_claiming(whole, holder); | |
1113 | spin_unlock(&bdev_lock); | |
1114 | } | |
89e524c0 JK |
1115 | |
1116 | /** | |
1117 | * bd_abort_claiming - abort claiming of a block device | |
1118 | * @bdev: block device of interest | |
5b642d8b | 1119 | * @whole: whole block device |
89e524c0 JK |
1120 | * @holder: holder that has claimed @bdev |
1121 | * | |
1122 | * Abort claiming of a block device when the exclusive open failed. This can be | |
1123 | * also used when exclusive open is not actually desired and we just needed | |
1124 | * to block other exclusive openers for a while. | |
1125 | */ | |
1126 | void bd_abort_claiming(struct block_device *bdev, struct block_device *whole, | |
1127 | void *holder) | |
1128 | { | |
1129 | spin_lock(&bdev_lock); | |
1130 | bd_clear_claiming(whole, holder); | |
1131 | spin_unlock(&bdev_lock); | |
1132 | } | |
1133 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 1134 | |
641dc636 | 1135 | #ifdef CONFIG_SYSFS |
49731baa TH |
1136 | struct bd_holder_disk { |
1137 | struct list_head list; | |
1138 | struct gendisk *disk; | |
1139 | int refcnt; | |
1140 | }; | |
1141 | ||
1142 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
1143 | struct gendisk *disk) | |
1144 | { | |
1145 | struct bd_holder_disk *holder; | |
1146 | ||
1147 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
1148 | if (holder->disk == disk) | |
1149 | return holder; | |
1150 | return NULL; | |
1151 | } | |
1152 | ||
4d7dd8fd | 1153 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 1154 | { |
4d7dd8fd | 1155 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
1156 | } |
1157 | ||
1158 | static void del_symlink(struct kobject *from, struct kobject *to) | |
1159 | { | |
641dc636 JN |
1160 | sysfs_remove_link(from, kobject_name(to)); |
1161 | } | |
1162 | ||
df6c0cd9 | 1163 | /** |
e09b457b TH |
1164 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
1165 | * @bdev: the claimed slave bdev | |
1166 | * @disk: the holding disk | |
df6c0cd9 | 1167 | * |
49731baa TH |
1168 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
1169 | * | |
e09b457b | 1170 | * This functions creates the following sysfs symlinks. |
641dc636 | 1171 | * |
e09b457b TH |
1172 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
1173 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 1174 | * |
e09b457b TH |
1175 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
1176 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 1177 | * |
e09b457b TH |
1178 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
1179 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 1180 | * |
e09b457b TH |
1181 | * The caller must have claimed @bdev before calling this function and |
1182 | * ensure that both @bdev and @disk are valid during the creation and | |
1183 | * lifetime of these symlinks. | |
641dc636 | 1184 | * |
e09b457b TH |
1185 | * CONTEXT: |
1186 | * Might sleep. | |
641dc636 | 1187 | * |
e09b457b TH |
1188 | * RETURNS: |
1189 | * 0 on success, -errno on failure. | |
641dc636 | 1190 | */ |
e09b457b | 1191 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 1192 | { |
49731baa | 1193 | struct bd_holder_disk *holder; |
e09b457b | 1194 | int ret = 0; |
641dc636 | 1195 | |
2e7b651d | 1196 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 1197 | |
49731baa | 1198 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 1199 | |
e09b457b TH |
1200 | /* FIXME: remove the following once add_disk() handles errors */ |
1201 | if (WARN_ON(!disk->slave_dir || !bdev->bd_part->holder_dir)) | |
1202 | goto out_unlock; | |
4e91672c | 1203 | |
49731baa TH |
1204 | holder = bd_find_holder_disk(bdev, disk); |
1205 | if (holder) { | |
1206 | holder->refcnt++; | |
e09b457b | 1207 | goto out_unlock; |
49731baa | 1208 | } |
641dc636 | 1209 | |
49731baa TH |
1210 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
1211 | if (!holder) { | |
1212 | ret = -ENOMEM; | |
e09b457b TH |
1213 | goto out_unlock; |
1214 | } | |
641dc636 | 1215 | |
49731baa TH |
1216 | INIT_LIST_HEAD(&holder->list); |
1217 | holder->disk = disk; | |
1218 | holder->refcnt = 1; | |
1219 | ||
1220 | ret = add_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1221 | if (ret) | |
1222 | goto out_free; | |
1223 | ||
1224 | ret = add_symlink(bdev->bd_part->holder_dir, &disk_to_dev(disk)->kobj); | |
1225 | if (ret) | |
1226 | goto out_del; | |
e7407d16 TH |
1227 | /* |
1228 | * bdev could be deleted beneath us which would implicitly destroy | |
1229 | * the holder directory. Hold on to it. | |
1230 | */ | |
1231 | kobject_get(bdev->bd_part->holder_dir); | |
49731baa TH |
1232 | |
1233 | list_add(&holder->list, &bdev->bd_holder_disks); | |
1234 | goto out_unlock; | |
1235 | ||
1236 | out_del: | |
1237 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1238 | out_free: | |
1239 | kfree(holder); | |
e09b457b | 1240 | out_unlock: |
b4cf1b72 | 1241 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 1242 | return ret; |
641dc636 | 1243 | } |
e09b457b | 1244 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 1245 | |
49731baa TH |
1246 | /** |
1247 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
1248 | * @bdev: the calimed slave bdev | |
1249 | * @disk: the holding disk | |
1250 | * | |
1251 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
1252 | * | |
1253 | * CONTEXT: | |
1254 | * Might sleep. | |
1255 | */ | |
1256 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 1257 | { |
49731baa | 1258 | struct bd_holder_disk *holder; |
641dc636 | 1259 | |
49731baa | 1260 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 1261 | |
49731baa TH |
1262 | holder = bd_find_holder_disk(bdev, disk); |
1263 | ||
1264 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
1265 | del_symlink(disk->slave_dir, &part_to_dev(bdev->bd_part)->kobj); | |
1266 | del_symlink(bdev->bd_part->holder_dir, | |
1267 | &disk_to_dev(disk)->kobj); | |
e7407d16 | 1268 | kobject_put(bdev->bd_part->holder_dir); |
49731baa TH |
1269 | list_del_init(&holder->list); |
1270 | kfree(holder); | |
1271 | } | |
1272 | ||
1273 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 1274 | } |
49731baa | 1275 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 1276 | #endif |
1da177e4 | 1277 | |
c3279d14 | 1278 | /** |
57d1b536 | 1279 | * check_disk_size_change - checks for disk size change and adjusts bdev size. |
c3279d14 AP |
1280 | * @disk: struct gendisk to check |
1281 | * @bdev: struct bdev to adjust. | |
5afb7835 | 1282 | * @verbose: if %true log a message about a size change if there is any |
c3279d14 AP |
1283 | * |
1284 | * This routine checks to see if the bdev size does not match the disk size | |
849cf559 | 1285 | * and adjusts it if it differs. When shrinking the bdev size, its all caches |
1286 | * are freed. | |
c3279d14 | 1287 | */ |
a1548b67 CH |
1288 | static void check_disk_size_change(struct gendisk *disk, |
1289 | struct block_device *bdev, bool verbose) | |
c3279d14 AP |
1290 | { |
1291 | loff_t disk_size, bdev_size; | |
1292 | ||
1293 | disk_size = (loff_t)get_capacity(disk) << 9; | |
1294 | bdev_size = i_size_read(bdev->bd_inode); | |
1295 | if (disk_size != bdev_size) { | |
5afb7835 CH |
1296 | if (verbose) { |
1297 | printk(KERN_INFO | |
1298 | "%s: detected capacity change from %lld to %lld\n", | |
1299 | disk->disk_name, bdev_size, disk_size); | |
1300 | } | |
c3279d14 | 1301 | i_size_write(bdev->bd_inode, disk_size); |
9a3ffbbc CH |
1302 | if (bdev_size > disk_size && __invalidate_device(bdev, false)) |
1303 | pr_warn("VFS: busy inodes on resized disk %s\n", | |
1304 | disk->disk_name); | |
c3279d14 | 1305 | } |
979c690d | 1306 | bdev->bd_invalidated = 0; |
c3279d14 | 1307 | } |
c3279d14 | 1308 | |
0c002c2f | 1309 | /** |
57d1b536 | 1310 | * revalidate_disk - wrapper for lower-level driver's revalidate_disk call-back |
0c002c2f AP |
1311 | * @disk: struct gendisk to be revalidated |
1312 | * | |
1313 | * This routine is a wrapper for lower-level driver's revalidate_disk | |
1314 | * call-backs. It is used to do common pre and post operations needed | |
1315 | * for all revalidate_disk operations. | |
1316 | */ | |
1317 | int revalidate_disk(struct gendisk *disk) | |
1318 | { | |
1319 | int ret = 0; | |
1320 | ||
1321 | if (disk->fops->revalidate_disk) | |
1322 | ret = disk->fops->revalidate_disk(disk); | |
c3279d14 | 1323 | |
31cb1d64 JK |
1324 | /* |
1325 | * Hidden disks don't have associated bdev so there's no point in | |
1326 | * revalidating it. | |
1327 | */ | |
1328 | if (!(disk->flags & GENHD_FL_HIDDEN)) { | |
1329 | struct block_device *bdev = bdget_disk(disk, 0); | |
1330 | ||
1331 | if (!bdev) | |
1332 | return ret; | |
1333 | ||
1334 | mutex_lock(&bdev->bd_mutex); | |
1335 | check_disk_size_change(disk, bdev, ret == 0); | |
31cb1d64 JK |
1336 | mutex_unlock(&bdev->bd_mutex); |
1337 | bdput(bdev); | |
1338 | } | |
0c002c2f AP |
1339 | return ret; |
1340 | } | |
1341 | EXPORT_SYMBOL(revalidate_disk); | |
1342 | ||
1da177e4 LT |
1343 | /* |
1344 | * This routine checks whether a removable media has been changed, | |
1345 | * and invalidates all buffer-cache-entries in that case. This | |
1346 | * is a relatively slow routine, so we have to try to minimize using | |
1347 | * it. Thus it is called only upon a 'mount' or 'open'. This | |
1348 | * is the best way of combining speed and utility, I think. | |
1349 | * People changing diskettes in the middle of an operation deserve | |
1350 | * to lose :-) | |
1351 | */ | |
1352 | int check_disk_change(struct block_device *bdev) | |
1353 | { | |
1354 | struct gendisk *disk = bdev->bd_disk; | |
83d5cde4 | 1355 | const struct block_device_operations *bdops = disk->fops; |
77ea887e | 1356 | unsigned int events; |
1da177e4 | 1357 | |
77ea887e TH |
1358 | events = disk_clear_events(disk, DISK_EVENT_MEDIA_CHANGE | |
1359 | DISK_EVENT_EJECT_REQUEST); | |
1360 | if (!(events & DISK_EVENT_MEDIA_CHANGE)) | |
1da177e4 LT |
1361 | return 0; |
1362 | ||
9a3ffbbc CH |
1363 | if (__invalidate_device(bdev, true)) |
1364 | pr_warn("VFS: busy inodes on changed media %s\n", | |
1365 | disk->disk_name); | |
1366 | bdev->bd_invalidated = 1; | |
1da177e4 LT |
1367 | if (bdops->revalidate_disk) |
1368 | bdops->revalidate_disk(bdev->bd_disk); | |
1da177e4 LT |
1369 | return 1; |
1370 | } | |
1371 | ||
1372 | EXPORT_SYMBOL(check_disk_change); | |
1373 | ||
1374 | void bd_set_size(struct block_device *bdev, loff_t size) | |
1375 | { | |
5955102c | 1376 | inode_lock(bdev->bd_inode); |
d646a02a | 1377 | i_size_write(bdev->bd_inode, size); |
5955102c | 1378 | inode_unlock(bdev->bd_inode); |
1da177e4 LT |
1379 | } |
1380 | EXPORT_SYMBOL(bd_set_size); | |
1381 | ||
4385bab1 | 1382 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1383 | |
142fe8f4 | 1384 | int bdev_disk_changed(struct block_device *bdev, bool invalidate) |
a1548b67 | 1385 | { |
142fe8f4 | 1386 | struct gendisk *disk = bdev->bd_disk; |
a1548b67 CH |
1387 | int ret; |
1388 | ||
f0b870df CH |
1389 | lockdep_assert_held(&bdev->bd_mutex); |
1390 | ||
a1548b67 | 1391 | rescan: |
d46430bf | 1392 | ret = blk_drop_partitions(bdev); |
a1548b67 CH |
1393 | if (ret) |
1394 | return ret; | |
1395 | ||
d981cb5b CH |
1396 | /* |
1397 | * Historically we only set the capacity to zero for devices that | |
1398 | * support partitions (independ of actually having partitions created). | |
1399 | * Doing that is rather inconsistent, but changing it broke legacy | |
1400 | * udisks polling for legacy ide-cdrom devices. Use the crude check | |
1401 | * below to get the sane behavior for most device while not breaking | |
1402 | * userspace for this particular setup. | |
1403 | */ | |
1404 | if (invalidate) { | |
1405 | if (disk_part_scan_enabled(disk) || | |
1406 | !(disk->flags & GENHD_FL_REMOVABLE)) | |
1407 | set_capacity(disk, 0); | |
1408 | } else { | |
1409 | if (disk->fops->revalidate_disk) | |
1410 | disk->fops->revalidate_disk(disk); | |
1411 | } | |
a1548b67 CH |
1412 | |
1413 | check_disk_size_change(disk, bdev, !invalidate); | |
a1548b67 | 1414 | |
142fe8f4 CH |
1415 | if (get_capacity(disk)) { |
1416 | ret = blk_add_partitions(disk, bdev); | |
1417 | if (ret == -EAGAIN) | |
1418 | goto rescan; | |
490547ca | 1419 | } else if (invalidate) { |
a1548b67 CH |
1420 | /* |
1421 | * Tell userspace that the media / partition table may have | |
1422 | * changed. | |
1423 | */ | |
1424 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); | |
a1548b67 CH |
1425 | } |
1426 | ||
a1548b67 CH |
1427 | return ret; |
1428 | } | |
f0b870df CH |
1429 | /* |
1430 | * Only exported for for loop and dasd for historic reasons. Don't use in new | |
1431 | * code! | |
1432 | */ | |
1433 | EXPORT_SYMBOL_GPL(bdev_disk_changed); | |
a1548b67 | 1434 | |
6d740cd5 PZ |
1435 | /* |
1436 | * bd_mutex locking: | |
1437 | * | |
1438 | * mutex_lock(part->bd_mutex) | |
1439 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1440 | */ | |
1441 | ||
5b642d8b CH |
1442 | static int __blkdev_get(struct block_device *bdev, fmode_t mode, void *holder, |
1443 | int for_part) | |
1da177e4 | 1444 | { |
5b642d8b | 1445 | struct block_device *whole = NULL, *claiming = NULL; |
1da177e4 | 1446 | struct gendisk *disk; |
7db9cfd3 | 1447 | int ret; |
cf771cb5 | 1448 | int partno; |
fe6e9c1f | 1449 | int perm = 0; |
5b642d8b | 1450 | bool first_open = false, unblock_events = true, need_restart; |
fe6e9c1f | 1451 | |
572c4892 | 1452 | if (mode & FMODE_READ) |
fe6e9c1f | 1453 | perm |= MAY_READ; |
572c4892 | 1454 | if (mode & FMODE_WRITE) |
fe6e9c1f AV |
1455 | perm |= MAY_WRITE; |
1456 | /* | |
1457 | * hooks: /n/, see "layering violations". | |
1458 | */ | |
b7300b78 CW |
1459 | if (!for_part) { |
1460 | ret = devcgroup_inode_permission(bdev->bd_inode, perm); | |
2d3a8e2d | 1461 | if (ret != 0) |
b7300b78 | 1462 | return ret; |
82666020 | 1463 | } |
7db9cfd3 | 1464 | |
d3374825 | 1465 | restart: |
c5638ab4 | 1466 | need_restart = false; |
89f97496 | 1467 | ret = -ENXIO; |
560e7cb2 | 1468 | disk = bdev_get_gendisk(bdev, &partno); |
0762b8bd | 1469 | if (!disk) |
6e9624b8 | 1470 | goto out; |
1da177e4 | 1471 | |
5b642d8b CH |
1472 | if (partno) { |
1473 | whole = bdget_disk(disk, 0); | |
1474 | if (!whole) { | |
1475 | ret = -ENOMEM; | |
1476 | goto out_put_disk; | |
1477 | } | |
1478 | } | |
1479 | ||
1480 | if (!for_part && (mode & FMODE_EXCL)) { | |
1481 | WARN_ON_ONCE(!holder); | |
1482 | if (whole) | |
1483 | claiming = whole; | |
1484 | else | |
1485 | claiming = bdev; | |
1486 | ret = bd_prepare_to_claim(bdev, claiming, holder); | |
1487 | if (ret) | |
1488 | goto out_put_whole; | |
1489 | } | |
1490 | ||
69e02c59 | 1491 | disk_block_events(disk); |
6796bf54 | 1492 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
1da177e4 | 1493 | if (!bdev->bd_openers) { |
89736653 | 1494 | first_open = true; |
1da177e4 LT |
1495 | bdev->bd_disk = disk; |
1496 | bdev->bd_contains = bdev; | |
c2ee070f | 1497 | bdev->bd_partno = partno; |
03cdadb0 | 1498 | |
cf771cb5 | 1499 | if (!partno) { |
89f97496 TH |
1500 | ret = -ENXIO; |
1501 | bdev->bd_part = disk_get_part(disk, partno); | |
1502 | if (!bdev->bd_part) | |
1503 | goto out_clear; | |
1504 | ||
1196f8b8 | 1505 | ret = 0; |
1da177e4 | 1506 | if (disk->fops->open) { |
572c4892 | 1507 | ret = disk->fops->open(bdev, mode); |
c5638ab4 CH |
1508 | /* |
1509 | * If we lost a race with 'disk' being deleted, | |
1510 | * try again. See md.c | |
1511 | */ | |
1512 | if (ret == -ERESTARTSYS) | |
1513 | need_restart = true; | |
1da177e4 | 1514 | } |
7e69723f | 1515 | |
04906b2f | 1516 | if (!ret) { |
7e69723f | 1517 | bd_set_size(bdev,(loff_t)get_capacity(disk)<<9); |
04906b2f JK |
1518 | set_init_blocksize(bdev); |
1519 | } | |
7e69723f | 1520 | |
1196f8b8 TH |
1521 | /* |
1522 | * If the device is invalidated, rescan partition | |
1523 | * if open succeeded or failed with -ENOMEDIUM. | |
1524 | * The latter is necessary to prevent ghost | |
1525 | * partitions on a removed medium. | |
1526 | */ | |
731dc486 JK |
1527 | if (bdev->bd_invalidated && |
1528 | (!ret || ret == -ENOMEDIUM)) | |
1529 | bdev_disk_changed(bdev, ret == -ENOMEDIUM); | |
5a023cdb | 1530 | |
1196f8b8 TH |
1531 | if (ret) |
1532 | goto out_clear; | |
1da177e4 | 1533 | } else { |
37be4124 | 1534 | BUG_ON(for_part); |
5b642d8b CH |
1535 | ret = __blkdev_get(whole, mode, NULL, 1); |
1536 | if (ret) | |
0762b8bd | 1537 | goto out_clear; |
5b642d8b | 1538 | bdev->bd_contains = bdgrab(whole); |
89f97496 | 1539 | bdev->bd_part = disk_get_part(disk, partno); |
e71bf0d0 | 1540 | if (!(disk->flags & GENHD_FL_UP) || |
89f97496 | 1541 | !bdev->bd_part || !bdev->bd_part->nr_sects) { |
1da177e4 | 1542 | ret = -ENXIO; |
0762b8bd | 1543 | goto out_clear; |
1da177e4 | 1544 | } |
89f97496 | 1545 | bd_set_size(bdev, (loff_t)bdev->bd_part->nr_sects << 9); |
04906b2f | 1546 | set_init_blocksize(bdev); |
1da177e4 | 1547 | } |
03e26279 JK |
1548 | |
1549 | if (bdev->bd_bdi == &noop_backing_dev_info) | |
1550 | bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info); | |
1da177e4 | 1551 | } else { |
1da177e4 | 1552 | if (bdev->bd_contains == bdev) { |
1196f8b8 TH |
1553 | ret = 0; |
1554 | if (bdev->bd_disk->fops->open) | |
572c4892 | 1555 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1556 | /* the same as first opener case, read comment there */ |
731dc486 JK |
1557 | if (bdev->bd_invalidated && |
1558 | (!ret || ret == -ENOMEDIUM)) | |
1559 | bdev_disk_changed(bdev, ret == -ENOMEDIUM); | |
1196f8b8 TH |
1560 | if (ret) |
1561 | goto out_unlock_bdev; | |
1da177e4 LT |
1562 | } |
1563 | } | |
1564 | bdev->bd_openers++; | |
37be4124 N |
1565 | if (for_part) |
1566 | bdev->bd_part_count++; | |
5b642d8b CH |
1567 | if (claiming) |
1568 | bd_finish_claiming(bdev, claiming, holder); | |
1569 | ||
1570 | /* | |
1571 | * Block event polling for write claims if requested. Any write holder | |
1572 | * makes the write_holder state stick until all are released. This is | |
1573 | * good enough and tracking individual writeable reference is too | |
1574 | * fragile given the way @mode is used in blkdev_get/put(). | |
1575 | */ | |
1576 | if (claiming && (mode & FMODE_WRITE) && !bdev->bd_write_holder && | |
1577 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
1578 | bdev->bd_write_holder = true; | |
1579 | unblock_events = false; | |
1580 | } | |
c039e313 | 1581 | mutex_unlock(&bdev->bd_mutex); |
5b642d8b CH |
1582 | |
1583 | if (unblock_events) | |
1584 | disk_unblock_events(disk); | |
1585 | ||
89736653 JK |
1586 | /* only one opener holds refs to the module and disk */ |
1587 | if (!first_open) | |
1588 | put_disk_and_module(disk); | |
5b642d8b CH |
1589 | if (whole) |
1590 | bdput(whole); | |
1da177e4 LT |
1591 | return 0; |
1592 | ||
0762b8bd | 1593 | out_clear: |
89f97496 | 1594 | disk_put_part(bdev->bd_part); |
1da177e4 | 1595 | bdev->bd_disk = NULL; |
0762b8bd | 1596 | bdev->bd_part = NULL; |
1da177e4 | 1597 | if (bdev != bdev->bd_contains) |
572c4892 | 1598 | __blkdev_put(bdev->bd_contains, mode, 1); |
1da177e4 | 1599 | bdev->bd_contains = NULL; |
0762b8bd | 1600 | out_unlock_bdev: |
5b642d8b CH |
1601 | if (claiming) |
1602 | bd_abort_claiming(bdev, claiming, holder); | |
c039e313 | 1603 | mutex_unlock(&bdev->bd_mutex); |
69e02c59 | 1604 | disk_unblock_events(disk); |
5b642d8b CH |
1605 | out_put_whole: |
1606 | if (whole) | |
1607 | bdput(whole); | |
1608 | out_put_disk: | |
9df6c299 | 1609 | put_disk_and_module(disk); |
c5638ab4 CH |
1610 | if (need_restart) |
1611 | goto restart; | |
4345caba | 1612 | out: |
1da177e4 LT |
1613 | return ret; |
1614 | } | |
1615 | ||
d4d77629 TH |
1616 | /** |
1617 | * blkdev_get - open a block device | |
1618 | * @bdev: block_device to open | |
1619 | * @mode: FMODE_* mask | |
1620 | * @holder: exclusive holder identifier | |
1621 | * | |
1622 | * Open @bdev with @mode. If @mode includes %FMODE_EXCL, @bdev is | |
1623 | * open with exclusive access. Specifying %FMODE_EXCL with %NULL | |
1624 | * @holder is invalid. Exclusive opens may nest for the same @holder. | |
1625 | * | |
1626 | * On success, the reference count of @bdev is unchanged. On failure, | |
1627 | * @bdev is put. | |
1628 | * | |
1629 | * CONTEXT: | |
1630 | * Might sleep. | |
1631 | * | |
1632 | * RETURNS: | |
1633 | * 0 on success, -errno on failure. | |
1634 | */ | |
e525fd89 | 1635 | int blkdev_get(struct block_device *bdev, fmode_t mode, void *holder) |
1da177e4 | 1636 | { |
e525fd89 TH |
1637 | int res; |
1638 | ||
5b642d8b | 1639 | res =__blkdev_get(bdev, mode, holder, 0); |
2d3a8e2d JY |
1640 | if (res) |
1641 | bdput(bdev); | |
e525fd89 | 1642 | return res; |
37be4124 | 1643 | } |
1da177e4 LT |
1644 | EXPORT_SYMBOL(blkdev_get); |
1645 | ||
d4d77629 TH |
1646 | /** |
1647 | * blkdev_get_by_path - open a block device by name | |
1648 | * @path: path to the block device to open | |
1649 | * @mode: FMODE_* mask | |
1650 | * @holder: exclusive holder identifier | |
1651 | * | |
1652 | * Open the blockdevice described by the device file at @path. @mode | |
1653 | * and @holder are identical to blkdev_get(). | |
1654 | * | |
1655 | * On success, the returned block_device has reference count of one. | |
1656 | * | |
1657 | * CONTEXT: | |
1658 | * Might sleep. | |
1659 | * | |
1660 | * RETURNS: | |
1661 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1662 | */ | |
1663 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1664 | void *holder) | |
1665 | { | |
1666 | struct block_device *bdev; | |
1667 | int err; | |
1668 | ||
1669 | bdev = lookup_bdev(path); | |
1670 | if (IS_ERR(bdev)) | |
1671 | return bdev; | |
1672 | ||
1673 | err = blkdev_get(bdev, mode, holder); | |
1674 | if (err) | |
1675 | return ERR_PTR(err); | |
1676 | ||
e51900f7 CE |
1677 | if ((mode & FMODE_WRITE) && bdev_read_only(bdev)) { |
1678 | blkdev_put(bdev, mode); | |
1679 | return ERR_PTR(-EACCES); | |
1680 | } | |
1681 | ||
d4d77629 TH |
1682 | return bdev; |
1683 | } | |
1684 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1685 | ||
1686 | /** | |
1687 | * blkdev_get_by_dev - open a block device by device number | |
1688 | * @dev: device number of block device to open | |
1689 | * @mode: FMODE_* mask | |
1690 | * @holder: exclusive holder identifier | |
1691 | * | |
1692 | * Open the blockdevice described by device number @dev. @mode and | |
1693 | * @holder are identical to blkdev_get(). | |
1694 | * | |
1695 | * Use it ONLY if you really do not have anything better - i.e. when | |
1696 | * you are behind a truly sucky interface and all you are given is a | |
1697 | * device number. _Never_ to be used for internal purposes. If you | |
1698 | * ever need it - reconsider your API. | |
1699 | * | |
1700 | * On success, the returned block_device has reference count of one. | |
1701 | * | |
1702 | * CONTEXT: | |
1703 | * Might sleep. | |
1704 | * | |
1705 | * RETURNS: | |
1706 | * Pointer to block_device on success, ERR_PTR(-errno) on failure. | |
1707 | */ | |
1708 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) | |
1709 | { | |
1710 | struct block_device *bdev; | |
1711 | int err; | |
1712 | ||
1713 | bdev = bdget(dev); | |
1714 | if (!bdev) | |
1715 | return ERR_PTR(-ENOMEM); | |
1716 | ||
1717 | err = blkdev_get(bdev, mode, holder); | |
1718 | if (err) | |
1719 | return ERR_PTR(err); | |
1720 | ||
1721 | return bdev; | |
1722 | } | |
1723 | EXPORT_SYMBOL(blkdev_get_by_dev); | |
1724 | ||
1da177e4 LT |
1725 | static int blkdev_open(struct inode * inode, struct file * filp) |
1726 | { | |
1727 | struct block_device *bdev; | |
1da177e4 LT |
1728 | |
1729 | /* | |
1730 | * Preserve backwards compatibility and allow large file access | |
1731 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1732 | * binary needs it. We might want to drop this workaround | |
1733 | * during an unstable branch. | |
1734 | */ | |
1735 | filp->f_flags |= O_LARGEFILE; | |
1736 | ||
a304f074 | 1737 | filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; |
c35fc7a5 | 1738 | |
572c4892 AV |
1739 | if (filp->f_flags & O_NDELAY) |
1740 | filp->f_mode |= FMODE_NDELAY; | |
1741 | if (filp->f_flags & O_EXCL) | |
1742 | filp->f_mode |= FMODE_EXCL; | |
1743 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1744 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1745 | ||
1da177e4 | 1746 | bdev = bd_acquire(inode); |
6a2aae06 PE |
1747 | if (bdev == NULL) |
1748 | return -ENOMEM; | |
1da177e4 | 1749 | |
572c4892 | 1750 | filp->f_mapping = bdev->bd_inode->i_mapping; |
5660e13d | 1751 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); |
572c4892 | 1752 | |
e525fd89 | 1753 | return blkdev_get(bdev, filp->f_mode, filp); |
1da177e4 LT |
1754 | } |
1755 | ||
4385bab1 | 1756 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1757 | { |
2e7b651d | 1758 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1759 | struct block_device *victim = NULL; |
2e7b651d | 1760 | |
b849dd84 DA |
1761 | /* |
1762 | * Sync early if it looks like we're the last one. If someone else | |
1763 | * opens the block device between now and the decrement of bd_openers | |
1764 | * then we did a sync that we didn't need to, but that's not the end | |
1765 | * of the world and we want to avoid long (could be several minute) | |
1766 | * syncs while holding the mutex. | |
1767 | */ | |
1768 | if (bdev->bd_openers == 1) | |
1769 | sync_blockdev(bdev); | |
1770 | ||
6796bf54 | 1771 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1772 | if (for_part) |
1773 | bdev->bd_part_count--; | |
1774 | ||
2e7b651d | 1775 | if (!--bdev->bd_openers) { |
6a027eff | 1776 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1777 | sync_blockdev(bdev); |
1778 | kill_bdev(bdev); | |
43d1c0eb ID |
1779 | |
1780 | bdev_write_inode(bdev); | |
2e7b651d PZ |
1781 | } |
1782 | if (bdev->bd_contains == bdev) { | |
1783 | if (disk->fops->release) | |
db2a144b | 1784 | disk->fops->release(disk, mode); |
2e7b651d PZ |
1785 | } |
1786 | if (!bdev->bd_openers) { | |
0762b8bd TH |
1787 | disk_put_part(bdev->bd_part); |
1788 | bdev->bd_part = NULL; | |
2e7b651d | 1789 | bdev->bd_disk = NULL; |
37be4124 N |
1790 | if (bdev != bdev->bd_contains) |
1791 | victim = bdev->bd_contains; | |
2e7b651d | 1792 | bdev->bd_contains = NULL; |
523e1d39 | 1793 | |
9df6c299 | 1794 | put_disk_and_module(disk); |
2e7b651d | 1795 | } |
2e7b651d PZ |
1796 | mutex_unlock(&bdev->bd_mutex); |
1797 | bdput(bdev); | |
37be4124 | 1798 | if (victim) |
9a1c3542 | 1799 | __blkdev_put(victim, mode, 1); |
2e7b651d PZ |
1800 | } |
1801 | ||
4385bab1 | 1802 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1803 | { |
85ef06d1 TH |
1804 | mutex_lock(&bdev->bd_mutex); |
1805 | ||
e525fd89 | 1806 | if (mode & FMODE_EXCL) { |
6a027eff TH |
1807 | bool bdev_free; |
1808 | ||
1809 | /* | |
1810 | * Release a claim on the device. The holder fields | |
1811 | * are protected with bdev_lock. bd_mutex is to | |
1812 | * synchronize disk_holder unlinking. | |
1813 | */ | |
6a027eff TH |
1814 | spin_lock(&bdev_lock); |
1815 | ||
1816 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
1817 | WARN_ON_ONCE(--bdev->bd_contains->bd_holders < 0); | |
1818 | ||
1819 | /* bd_contains might point to self, check in a separate step */ | |
1820 | if ((bdev_free = !bdev->bd_holders)) | |
1821 | bdev->bd_holder = NULL; | |
1822 | if (!bdev->bd_contains->bd_holders) | |
1823 | bdev->bd_contains->bd_holder = NULL; | |
1824 | ||
1825 | spin_unlock(&bdev_lock); | |
1826 | ||
77ea887e TH |
1827 | /* |
1828 | * If this was the last claim, remove holder link and | |
1829 | * unblock evpoll if it was a write holder. | |
1830 | */ | |
85ef06d1 TH |
1831 | if (bdev_free && bdev->bd_write_holder) { |
1832 | disk_unblock_events(bdev->bd_disk); | |
1833 | bdev->bd_write_holder = false; | |
77ea887e | 1834 | } |
6936217c | 1835 | } |
77ea887e | 1836 | |
85ef06d1 TH |
1837 | /* |
1838 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1839 | * event. This is to ensure detection of media removal commanded | |
1840 | * from userland - e.g. eject(1). | |
1841 | */ | |
1842 | disk_flush_events(bdev->bd_disk, DISK_EVENT_MEDIA_CHANGE); | |
1843 | ||
1844 | mutex_unlock(&bdev->bd_mutex); | |
1845 | ||
4385bab1 | 1846 | __blkdev_put(bdev, mode, 0); |
37be4124 | 1847 | } |
2e7b651d PZ |
1848 | EXPORT_SYMBOL(blkdev_put); |
1849 | ||
1da177e4 LT |
1850 | static int blkdev_close(struct inode * inode, struct file * filp) |
1851 | { | |
4ebb16ca | 1852 | struct block_device *bdev = I_BDEV(bdev_file_inode(filp)); |
4385bab1 AV |
1853 | blkdev_put(bdev, filp->f_mode); |
1854 | return 0; | |
1da177e4 LT |
1855 | } |
1856 | ||
bb93e3a5 | 1857 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1858 | { |
4ebb16ca | 1859 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); |
56b26add | 1860 | fmode_t mode = file->f_mode; |
fd4ce1ac CH |
1861 | |
1862 | /* | |
1863 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1864 | * to updated it before every ioctl. | |
1865 | */ | |
56b26add | 1866 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1867 | mode |= FMODE_NDELAY; |
1868 | else | |
1869 | mode &= ~FMODE_NDELAY; | |
1870 | ||
56b26add | 1871 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1872 | } |
1873 | ||
eef99380 CH |
1874 | /* |
1875 | * Write data to the block device. Only intended for the block device itself | |
1876 | * and the raw driver which basically is a fake block device. | |
1877 | * | |
1878 | * Does not take i_mutex for the write and thus is not for general purpose | |
1879 | * use. | |
1880 | */ | |
1456c0a8 | 1881 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
eef99380 CH |
1882 | { |
1883 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1884 | struct inode *bd_inode = bdev_file_inode(file); |
7ec7b94a | 1885 | loff_t size = i_size_read(bd_inode); |
53362a05 | 1886 | struct blk_plug plug; |
eef99380 | 1887 | ssize_t ret; |
5f380c7f | 1888 | |
7ec7b94a AV |
1889 | if (bdev_read_only(I_BDEV(bd_inode))) |
1890 | return -EPERM; | |
5f380c7f | 1891 | |
ad1e4f74 | 1892 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode)) |
dc617f29 DW |
1893 | return -ETXTBSY; |
1894 | ||
7ec7b94a | 1895 | if (!iov_iter_count(from)) |
5f380c7f AV |
1896 | return 0; |
1897 | ||
7ec7b94a AV |
1898 | if (iocb->ki_pos >= size) |
1899 | return -ENOSPC; | |
1900 | ||
c35fc7a5 CH |
1901 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) |
1902 | return -EOPNOTSUPP; | |
1903 | ||
7ec7b94a | 1904 | iov_iter_truncate(from, size - iocb->ki_pos); |
eef99380 | 1905 | |
53362a05 | 1906 | blk_start_plug(&plug); |
1456c0a8 | 1907 | ret = __generic_file_write_iter(iocb, from); |
e2592217 CH |
1908 | if (ret > 0) |
1909 | ret = generic_write_sync(iocb, ret); | |
53362a05 | 1910 | blk_finish_plug(&plug); |
eef99380 CH |
1911 | return ret; |
1912 | } | |
1456c0a8 | 1913 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
eef99380 | 1914 | |
b2de525f | 1915 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
684c9aae LT |
1916 | { |
1917 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1918 | struct inode *bd_inode = bdev_file_inode(file); |
684c9aae | 1919 | loff_t size = i_size_read(bd_inode); |
a886038b | 1920 | loff_t pos = iocb->ki_pos; |
684c9aae LT |
1921 | |
1922 | if (pos >= size) | |
1923 | return 0; | |
1924 | ||
1925 | size -= pos; | |
a886038b AV |
1926 | iov_iter_truncate(to, size); |
1927 | return generic_file_read_iter(iocb, to); | |
684c9aae | 1928 | } |
b2de525f | 1929 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
684c9aae | 1930 | |
87d8fe1e TT |
1931 | /* |
1932 | * Try to release a page associated with block device when the system | |
1933 | * is under memory pressure. | |
1934 | */ | |
1935 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1936 | { | |
1937 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1938 | ||
1939 | if (super && super->s_op->bdev_try_to_free_page) | |
1940 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1941 | ||
1942 | return try_to_free_buffers(page); | |
1943 | } | |
1944 | ||
7f6d5b52 RZ |
1945 | static int blkdev_writepages(struct address_space *mapping, |
1946 | struct writeback_control *wbc) | |
1947 | { | |
7f6d5b52 RZ |
1948 | return generic_writepages(mapping, wbc); |
1949 | } | |
1950 | ||
4c54ac62 | 1951 | static const struct address_space_operations def_blk_aops = { |
1da177e4 | 1952 | .readpage = blkdev_readpage, |
d4388340 | 1953 | .readahead = blkdev_readahead, |
1da177e4 | 1954 | .writepage = blkdev_writepage, |
6272b5a5 NP |
1955 | .write_begin = blkdev_write_begin, |
1956 | .write_end = blkdev_write_end, | |
7f6d5b52 | 1957 | .writepages = blkdev_writepages, |
87d8fe1e | 1958 | .releasepage = blkdev_releasepage, |
1da177e4 | 1959 | .direct_IO = blkdev_direct_IO, |
88dbcbb3 | 1960 | .migratepage = buffer_migrate_page_norefs, |
b4597226 | 1961 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1962 | }; |
1963 | ||
25f4c414 DW |
1964 | #define BLKDEV_FALLOC_FL_SUPPORTED \ |
1965 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
1966 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
1967 | ||
1968 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
1969 | loff_t len) | |
1970 | { | |
1971 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
25f4c414 DW |
1972 | struct address_space *mapping; |
1973 | loff_t end = start + len - 1; | |
1974 | loff_t isize; | |
1975 | int error; | |
1976 | ||
1977 | /* Fail if we don't recognize the flags. */ | |
1978 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
1979 | return -EOPNOTSUPP; | |
1980 | ||
1981 | /* Don't go off the end of the device. */ | |
1982 | isize = i_size_read(bdev->bd_inode); | |
1983 | if (start >= isize) | |
1984 | return -EINVAL; | |
1985 | if (end >= isize) { | |
1986 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
1987 | len = isize - start; | |
1988 | end = start + len - 1; | |
1989 | } else | |
1990 | return -EINVAL; | |
1991 | } | |
1992 | ||
1993 | /* | |
1994 | * Don't allow IO that isn't aligned to logical block size. | |
1995 | */ | |
1996 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
1997 | return -EINVAL; | |
1998 | ||
1999 | /* Invalidate the page cache, including dirty pages. */ | |
2000 | mapping = bdev->bd_inode->i_mapping; | |
2001 | truncate_inode_pages_range(mapping, start, end); | |
2002 | ||
2003 | switch (mode) { | |
2004 | case FALLOC_FL_ZERO_RANGE: | |
2005 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
2006 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, | |
ee472d83 | 2007 | GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); |
25f4c414 DW |
2008 | break; |
2009 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
34045129 CH |
2010 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, |
2011 | GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); | |
25f4c414 DW |
2012 | break; |
2013 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
25f4c414 DW |
2014 | error = blkdev_issue_discard(bdev, start >> 9, len >> 9, |
2015 | GFP_KERNEL, 0); | |
2016 | break; | |
2017 | default: | |
2018 | return -EOPNOTSUPP; | |
2019 | } | |
2020 | if (error) | |
2021 | return error; | |
2022 | ||
2023 | /* | |
2024 | * Invalidate again; if someone wandered in and dirtied a page, | |
2025 | * the caller will be given -EBUSY. The third argument is | |
2026 | * inclusive, so the rounding here is safe. | |
2027 | */ | |
2028 | return invalidate_inode_pages2_range(mapping, | |
2029 | start >> PAGE_SHIFT, | |
2030 | end >> PAGE_SHIFT); | |
2031 | } | |
2032 | ||
4b6f5d20 | 2033 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
2034 | .open = blkdev_open, |
2035 | .release = blkdev_close, | |
2036 | .llseek = block_llseek, | |
a886038b | 2037 | .read_iter = blkdev_read_iter, |
1456c0a8 | 2038 | .write_iter = blkdev_write_iter, |
eae83ce1 | 2039 | .iopoll = blkdev_iopoll, |
acc93d30 | 2040 | .mmap = generic_file_mmap, |
b1dd3b28 | 2041 | .fsync = blkdev_fsync, |
bb93e3a5 | 2042 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
2043 | #ifdef CONFIG_COMPAT |
2044 | .compat_ioctl = compat_blkdev_ioctl, | |
2045 | #endif | |
1e8b3332 | 2046 | .splice_read = generic_file_splice_read, |
8d020765 | 2047 | .splice_write = iter_file_splice_write, |
25f4c414 | 2048 | .fallocate = blkdev_fallocate, |
1da177e4 LT |
2049 | }; |
2050 | ||
1da177e4 LT |
2051 | /** |
2052 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 2053 | * @pathname: special file representing the block device |
1da177e4 | 2054 | * |
57d1b536 | 2055 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
2056 | * namespace if possible and return it. Return ERR_PTR(error) |
2057 | * otherwise. | |
2058 | */ | |
421748ec | 2059 | struct block_device *lookup_bdev(const char *pathname) |
1da177e4 LT |
2060 | { |
2061 | struct block_device *bdev; | |
2062 | struct inode *inode; | |
421748ec | 2063 | struct path path; |
1da177e4 LT |
2064 | int error; |
2065 | ||
421748ec | 2066 | if (!pathname || !*pathname) |
1da177e4 LT |
2067 | return ERR_PTR(-EINVAL); |
2068 | ||
421748ec | 2069 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 LT |
2070 | if (error) |
2071 | return ERR_PTR(error); | |
2072 | ||
bb668734 | 2073 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
2074 | error = -ENOTBLK; |
2075 | if (!S_ISBLK(inode->i_mode)) | |
2076 | goto fail; | |
2077 | error = -EACCES; | |
a2982cc9 | 2078 | if (!may_open_dev(&path)) |
1da177e4 LT |
2079 | goto fail; |
2080 | error = -ENOMEM; | |
2081 | bdev = bd_acquire(inode); | |
2082 | if (!bdev) | |
2083 | goto fail; | |
2084 | out: | |
421748ec | 2085 | path_put(&path); |
1da177e4 LT |
2086 | return bdev; |
2087 | fail: | |
2088 | bdev = ERR_PTR(error); | |
2089 | goto out; | |
2090 | } | |
d5686b44 | 2091 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 2092 | |
93b270f7 | 2093 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
2094 | { |
2095 | struct super_block *sb = get_super(bdev); | |
2096 | int res = 0; | |
2097 | ||
2098 | if (sb) { | |
2099 | /* | |
2100 | * no need to lock the super, get_super holds the | |
2101 | * read mutex so the filesystem cannot go away | |
2102 | * under us (->put_super runs with the write lock | |
2103 | * hold). | |
2104 | */ | |
2105 | shrink_dcache_sb(sb); | |
93b270f7 | 2106 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
2107 | drop_super(sb); |
2108 | } | |
f98393a6 | 2109 | invalidate_bdev(bdev); |
b71e8a4c DH |
2110 | return res; |
2111 | } | |
2112 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
2113 | |
2114 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
2115 | { | |
2116 | struct inode *inode, *old_inode = NULL; | |
2117 | ||
74278da9 | 2118 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2119 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
2120 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 2121 | struct block_device *bdev; |
5c0d6b60 JK |
2122 | |
2123 | spin_lock(&inode->i_lock); | |
2124 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
2125 | mapping->nrpages == 0) { | |
2126 | spin_unlock(&inode->i_lock); | |
2127 | continue; | |
2128 | } | |
2129 | __iget(inode); | |
2130 | spin_unlock(&inode->i_lock); | |
74278da9 | 2131 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2132 | /* |
2133 | * We hold a reference to 'inode' so it couldn't have been | |
2134 | * removed from s_inodes list while we dropped the | |
74278da9 | 2135 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 2136 | * be holding the last reference and we cannot iput it under |
74278da9 | 2137 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
2138 | * later. |
2139 | */ | |
2140 | iput(old_inode); | |
2141 | old_inode = inode; | |
af309226 | 2142 | bdev = I_BDEV(inode); |
5c0d6b60 | 2143 | |
af309226 RV |
2144 | mutex_lock(&bdev->bd_mutex); |
2145 | if (bdev->bd_openers) | |
2146 | func(bdev, arg); | |
2147 | mutex_unlock(&bdev->bd_mutex); | |
5c0d6b60 | 2148 | |
74278da9 | 2149 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 2150 | } |
74278da9 | 2151 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
2152 | iput(old_inode); |
2153 | } |