Commit | Line | Data |
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457c8996 | 1 | // SPDX-License-Identifier: GPL-2.0-only |
1da177e4 | 2 | /* |
1da177e4 LT |
3 | * Copyright (C) 1991, 1992 Linus Torvalds |
4 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
7b51e703 | 5 | * Copyright (C) 2016 - 2020 Christoph Hellwig |
1da177e4 LT |
6 | */ |
7 | ||
1da177e4 LT |
8 | #include <linux/init.h> |
9 | #include <linux/mm.h> | |
10 | #include <linux/fcntl.h> | |
11 | #include <linux/slab.h> | |
12 | #include <linux/kmod.h> | |
13 | #include <linux/major.h> | |
7db9cfd3 | 14 | #include <linux/device_cgroup.h> |
1da177e4 LT |
15 | #include <linux/highmem.h> |
16 | #include <linux/blkdev.h> | |
66114cad | 17 | #include <linux/backing-dev.h> |
1da177e4 LT |
18 | #include <linux/module.h> |
19 | #include <linux/blkpg.h> | |
b502bd11 | 20 | #include <linux/magic.h> |
1da177e4 | 21 | #include <linux/buffer_head.h> |
ff01bb48 | 22 | #include <linux/swap.h> |
585d3bc0 | 23 | #include <linux/pagevec.h> |
811d736f | 24 | #include <linux/writeback.h> |
1da177e4 LT |
25 | #include <linux/mpage.h> |
26 | #include <linux/mount.h> | |
9030d16e | 27 | #include <linux/pseudo_fs.h> |
1da177e4 LT |
28 | #include <linux/uio.h> |
29 | #include <linux/namei.h> | |
1368c4f2 | 30 | #include <linux/log2.h> |
ff01bb48 | 31 | #include <linux/cleancache.h> |
189ce2b9 | 32 | #include <linux/task_io_accounting_ops.h> |
25f4c414 | 33 | #include <linux/falloc.h> |
15e3d2c5 | 34 | #include <linux/part_stat.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 | |
384d87ef JK |
106 | /* |
107 | * Drop all buffers & page cache for given bdev range. This function bails | |
108 | * with error if bdev has other exclusive owner (such as filesystem). | |
109 | */ | |
110 | int truncate_bdev_range(struct block_device *bdev, fmode_t mode, | |
111 | loff_t lstart, loff_t lend) | |
112 | { | |
384d87ef JK |
113 | /* |
114 | * If we don't hold exclusive handle for the device, upgrade to it | |
115 | * while we discard the buffer cache to avoid discarding buffers | |
116 | * under live filesystem. | |
117 | */ | |
118 | if (!(mode & FMODE_EXCL)) { | |
37c3fc9a | 119 | int err = bd_prepare_to_claim(bdev, truncate_bdev_range); |
384d87ef JK |
120 | if (err) |
121 | return err; | |
122 | } | |
37c3fc9a | 123 | |
384d87ef | 124 | truncate_inode_pages_range(bdev->bd_inode->i_mapping, lstart, lend); |
37c3fc9a CH |
125 | if (!(mode & FMODE_EXCL)) |
126 | bd_abort_claiming(bdev, truncate_bdev_range); | |
384d87ef JK |
127 | return 0; |
128 | } | |
384d87ef | 129 | |
04906b2f JK |
130 | static void set_init_blocksize(struct block_device *bdev) |
131 | { | |
8dc932d3 MM |
132 | unsigned int bsize = bdev_logical_block_size(bdev); |
133 | loff_t size = i_size_read(bdev->bd_inode); | |
134 | ||
135 | while (bsize < PAGE_SIZE) { | |
136 | if (size & bsize) | |
137 | break; | |
138 | bsize <<= 1; | |
139 | } | |
140 | bdev->bd_inode->i_blkbits = blksize_bits(bsize); | |
04906b2f JK |
141 | } |
142 | ||
1da177e4 LT |
143 | int set_blocksize(struct block_device *bdev, int size) |
144 | { | |
145 | /* Size must be a power of two, and between 512 and PAGE_SIZE */ | |
1368c4f2 | 146 | if (size > PAGE_SIZE || size < 512 || !is_power_of_2(size)) |
1da177e4 LT |
147 | return -EINVAL; |
148 | ||
149 | /* Size cannot be smaller than the size supported by the device */ | |
e1defc4f | 150 | if (size < bdev_logical_block_size(bdev)) |
1da177e4 LT |
151 | return -EINVAL; |
152 | ||
153 | /* Don't change the size if it is same as current */ | |
6b7b181b | 154 | if (bdev->bd_inode->i_blkbits != blksize_bits(size)) { |
1da177e4 | 155 | sync_blockdev(bdev); |
1da177e4 LT |
156 | bdev->bd_inode->i_blkbits = blksize_bits(size); |
157 | kill_bdev(bdev); | |
158 | } | |
159 | return 0; | |
160 | } | |
161 | ||
162 | EXPORT_SYMBOL(set_blocksize); | |
163 | ||
164 | int sb_set_blocksize(struct super_block *sb, int size) | |
165 | { | |
1da177e4 LT |
166 | if (set_blocksize(sb->s_bdev, size)) |
167 | return 0; | |
168 | /* If we get here, we know size is power of two | |
169 | * and it's value is between 512 and PAGE_SIZE */ | |
170 | sb->s_blocksize = size; | |
38885bd4 | 171 | sb->s_blocksize_bits = blksize_bits(size); |
1da177e4 LT |
172 | return sb->s_blocksize; |
173 | } | |
174 | ||
175 | EXPORT_SYMBOL(sb_set_blocksize); | |
176 | ||
177 | int sb_min_blocksize(struct super_block *sb, int size) | |
178 | { | |
e1defc4f | 179 | int minsize = bdev_logical_block_size(sb->s_bdev); |
1da177e4 LT |
180 | if (size < minsize) |
181 | size = minsize; | |
182 | return sb_set_blocksize(sb, size); | |
183 | } | |
184 | ||
185 | EXPORT_SYMBOL(sb_min_blocksize); | |
186 | ||
187 | static int | |
188 | blkdev_get_block(struct inode *inode, sector_t iblock, | |
189 | struct buffer_head *bh, int create) | |
190 | { | |
1da177e4 LT |
191 | bh->b_bdev = I_BDEV(inode); |
192 | bh->b_blocknr = iblock; | |
193 | set_buffer_mapped(bh); | |
194 | return 0; | |
195 | } | |
196 | ||
4ebb16ca DW |
197 | static struct inode *bdev_file_inode(struct file *file) |
198 | { | |
199 | return file->f_mapping->host; | |
200 | } | |
201 | ||
78250c02 JA |
202 | static unsigned int dio_bio_write_op(struct kiocb *iocb) |
203 | { | |
204 | unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; | |
205 | ||
206 | /* avoid the need for a I/O completion work item */ | |
207 | if (iocb->ki_flags & IOCB_DSYNC) | |
208 | op |= REQ_FUA; | |
209 | return op; | |
210 | } | |
211 | ||
189ce2b9 CH |
212 | #define DIO_INLINE_BIO_VECS 4 |
213 | ||
214 | static void blkdev_bio_end_io_simple(struct bio *bio) | |
215 | { | |
216 | struct task_struct *waiter = bio->bi_private; | |
217 | ||
218 | WRITE_ONCE(bio->bi_private, NULL); | |
0619317f | 219 | blk_wake_io_task(waiter); |
189ce2b9 CH |
220 | } |
221 | ||
222 | static ssize_t | |
223 | __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter, | |
5f7136db | 224 | unsigned int nr_pages) |
189ce2b9 CH |
225 | { |
226 | struct file *file = iocb->ki_filp; | |
227 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
9fec4a21 | 228 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; |
189ce2b9 CH |
229 | loff_t pos = iocb->ki_pos; |
230 | bool should_dirty = false; | |
231 | struct bio bio; | |
232 | ssize_t ret; | |
233 | blk_qc_t qc; | |
189ce2b9 | 234 | |
9a794fb9 JA |
235 | if ((pos | iov_iter_alignment(iter)) & |
236 | (bdev_logical_block_size(bdev) - 1)) | |
189ce2b9 CH |
237 | return -EINVAL; |
238 | ||
72ecad22 JA |
239 | if (nr_pages <= DIO_INLINE_BIO_VECS) |
240 | vecs = inline_vecs; | |
241 | else { | |
6da2ec56 KC |
242 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), |
243 | GFP_KERNEL); | |
72ecad22 JA |
244 | if (!vecs) |
245 | return -ENOMEM; | |
246 | } | |
247 | ||
3a83f467 | 248 | bio_init(&bio, vecs, nr_pages); |
74d46992 | 249 | bio_set_dev(&bio, bdev); |
4d1a4765 | 250 | bio.bi_iter.bi_sector = pos >> 9; |
45d06cf7 | 251 | bio.bi_write_hint = iocb->ki_hint; |
189ce2b9 CH |
252 | bio.bi_private = current; |
253 | bio.bi_end_io = blkdev_bio_end_io_simple; | |
074111ca | 254 | bio.bi_ioprio = iocb->ki_ioprio; |
189ce2b9 CH |
255 | |
256 | ret = bio_iov_iter_get_pages(&bio, iter); | |
257 | if (unlikely(ret)) | |
9362dd11 | 258 | goto out; |
189ce2b9 CH |
259 | ret = bio.bi_iter.bi_size; |
260 | ||
261 | if (iov_iter_rw(iter) == READ) { | |
78250c02 | 262 | bio.bi_opf = REQ_OP_READ; |
189ce2b9 CH |
263 | if (iter_is_iovec(iter)) |
264 | should_dirty = true; | |
265 | } else { | |
78250c02 | 266 | bio.bi_opf = dio_bio_write_op(iocb); |
189ce2b9 CH |
267 | task_io_account_write(ret); |
268 | } | |
d1e36282 | 269 | if (iocb->ki_flags & IOCB_HIPRI) |
0bbb280d | 270 | bio_set_polled(&bio, iocb); |
189ce2b9 CH |
271 | |
272 | qc = submit_bio(&bio); | |
273 | for (;;) { | |
1ac5cd49 | 274 | set_current_state(TASK_UNINTERRUPTIBLE); |
189ce2b9 CH |
275 | if (!READ_ONCE(bio.bi_private)) |
276 | break; | |
277 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
0a1b8b87 | 278 | !blk_poll(bdev_get_queue(bdev), qc, true)) |
e6249cdd | 279 | blk_io_schedule(); |
189ce2b9 CH |
280 | } |
281 | __set_current_state(TASK_RUNNING); | |
282 | ||
9fec4a21 | 283 | bio_release_pages(&bio, should_dirty); |
4e4cbee9 | 284 | if (unlikely(bio.bi_status)) |
c6b1e36c | 285 | ret = blk_status_to_errno(bio.bi_status); |
9ae3b3f5 | 286 | |
9362dd11 MW |
287 | out: |
288 | if (vecs != inline_vecs) | |
289 | kfree(vecs); | |
290 | ||
9ae3b3f5 JA |
291 | bio_uninit(&bio); |
292 | ||
189ce2b9 CH |
293 | return ret; |
294 | } | |
295 | ||
542ff7bf CH |
296 | struct blkdev_dio { |
297 | union { | |
298 | struct kiocb *iocb; | |
299 | struct task_struct *waiter; | |
300 | }; | |
301 | size_t size; | |
302 | atomic_t ref; | |
303 | bool multi_bio : 1; | |
304 | bool should_dirty : 1; | |
305 | bool is_sync : 1; | |
306 | struct bio bio; | |
307 | }; | |
308 | ||
52190f8a | 309 | static struct bio_set blkdev_dio_pool; |
542ff7bf | 310 | |
eae83ce1 CH |
311 | static int blkdev_iopoll(struct kiocb *kiocb, bool wait) |
312 | { | |
313 | struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host); | |
314 | struct request_queue *q = bdev_get_queue(bdev); | |
315 | ||
316 | return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait); | |
317 | } | |
318 | ||
542ff7bf CH |
319 | static void blkdev_bio_end_io(struct bio *bio) |
320 | { | |
321 | struct blkdev_dio *dio = bio->bi_private; | |
322 | bool should_dirty = dio->should_dirty; | |
323 | ||
a89afe58 JY |
324 | if (bio->bi_status && !dio->bio.bi_status) |
325 | dio->bio.bi_status = bio->bi_status; | |
326 | ||
327 | if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) { | |
542ff7bf CH |
328 | if (!dio->is_sync) { |
329 | struct kiocb *iocb = dio->iocb; | |
4e4cbee9 | 330 | ssize_t ret; |
542ff7bf | 331 | |
4e4cbee9 | 332 | if (likely(!dio->bio.bi_status)) { |
542ff7bf CH |
333 | ret = dio->size; |
334 | iocb->ki_pos += ret; | |
4e4cbee9 CH |
335 | } else { |
336 | ret = blk_status_to_errno(dio->bio.bi_status); | |
542ff7bf CH |
337 | } |
338 | ||
339 | dio->iocb->ki_complete(iocb, ret, 0); | |
531724ab CH |
340 | if (dio->multi_bio) |
341 | bio_put(&dio->bio); | |
542ff7bf CH |
342 | } else { |
343 | struct task_struct *waiter = dio->waiter; | |
344 | ||
345 | WRITE_ONCE(dio->waiter, NULL); | |
0619317f | 346 | blk_wake_io_task(waiter); |
542ff7bf CH |
347 | } |
348 | } | |
349 | ||
350 | if (should_dirty) { | |
351 | bio_check_pages_dirty(bio); | |
352 | } else { | |
57dfe3ce | 353 | bio_release_pages(bio, false); |
542ff7bf CH |
354 | bio_put(bio); |
355 | } | |
356 | } | |
357 | ||
5f7136db MWO |
358 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, |
359 | unsigned int nr_pages) | |
b2e895db AM |
360 | { |
361 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 362 | struct inode *inode = bdev_file_inode(file); |
542ff7bf | 363 | struct block_device *bdev = I_BDEV(inode); |
64d656a1 | 364 | struct blk_plug plug; |
542ff7bf CH |
365 | struct blkdev_dio *dio; |
366 | struct bio *bio; | |
cb700eb3 | 367 | bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0; |
690e5325 | 368 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
542ff7bf CH |
369 | loff_t pos = iocb->ki_pos; |
370 | blk_qc_t qc = BLK_QC_T_NONE; | |
7b6620d7 | 371 | int ret = 0; |
542ff7bf | 372 | |
9a794fb9 JA |
373 | if ((pos | iov_iter_alignment(iter)) & |
374 | (bdev_logical_block_size(bdev) - 1)) | |
542ff7bf CH |
375 | return -EINVAL; |
376 | ||
7b6620d7 | 377 | bio = bio_alloc_bioset(GFP_KERNEL, nr_pages, &blkdev_dio_pool); |
542ff7bf CH |
378 | |
379 | dio = container_of(bio, struct blkdev_dio, bio); | |
690e5325 | 380 | dio->is_sync = is_sync = is_sync_kiocb(iocb); |
531724ab | 381 | if (dio->is_sync) { |
542ff7bf | 382 | dio->waiter = current; |
531724ab CH |
383 | bio_get(bio); |
384 | } else { | |
542ff7bf | 385 | dio->iocb = iocb; |
531724ab | 386 | } |
542ff7bf CH |
387 | |
388 | dio->size = 0; | |
389 | dio->multi_bio = false; | |
00e23707 | 390 | dio->should_dirty = is_read && iter_is_iovec(iter); |
542ff7bf | 391 | |
cb700eb3 JA |
392 | /* |
393 | * Don't plug for HIPRI/polled IO, as those should go straight | |
394 | * to issue | |
395 | */ | |
396 | if (!is_poll) | |
397 | blk_start_plug(&plug); | |
398 | ||
542ff7bf | 399 | for (;;) { |
74d46992 | 400 | bio_set_dev(bio, bdev); |
4d1a4765 | 401 | bio->bi_iter.bi_sector = pos >> 9; |
45d06cf7 | 402 | bio->bi_write_hint = iocb->ki_hint; |
542ff7bf CH |
403 | bio->bi_private = dio; |
404 | bio->bi_end_io = blkdev_bio_end_io; | |
074111ca | 405 | bio->bi_ioprio = iocb->ki_ioprio; |
542ff7bf | 406 | |
e15c2ffa JA |
407 | ret = bio_iov_iter_get_pages(bio, iter); |
408 | if (unlikely(ret)) { | |
4e4cbee9 | 409 | bio->bi_status = BLK_STS_IOERR; |
542ff7bf CH |
410 | bio_endio(bio); |
411 | break; | |
412 | } | |
413 | ||
414 | if (is_read) { | |
415 | bio->bi_opf = REQ_OP_READ; | |
416 | if (dio->should_dirty) | |
417 | bio_set_pages_dirty(bio); | |
418 | } else { | |
419 | bio->bi_opf = dio_bio_write_op(iocb); | |
420 | task_io_account_write(bio->bi_iter.bi_size); | |
421 | } | |
422 | ||
7b6620d7 | 423 | dio->size += bio->bi_iter.bi_size; |
542ff7bf CH |
424 | pos += bio->bi_iter.bi_size; |
425 | ||
3e1a88ec | 426 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES); |
542ff7bf | 427 | if (!nr_pages) { |
eae83ce1 CH |
428 | bool polled = false; |
429 | ||
430 | if (iocb->ki_flags & IOCB_HIPRI) { | |
0bbb280d | 431 | bio_set_polled(bio, iocb); |
eae83ce1 CH |
432 | polled = true; |
433 | } | |
d34513d3 | 434 | |
542ff7bf | 435 | qc = submit_bio(bio); |
eae83ce1 CH |
436 | |
437 | if (polled) | |
438 | WRITE_ONCE(iocb->ki_cookie, qc); | |
542ff7bf CH |
439 | break; |
440 | } | |
441 | ||
442 | if (!dio->multi_bio) { | |
531724ab CH |
443 | /* |
444 | * AIO needs an extra reference to ensure the dio | |
445 | * structure which is embedded into the first bio | |
446 | * stays around. | |
447 | */ | |
448 | if (!is_sync) | |
449 | bio_get(bio); | |
542ff7bf CH |
450 | dio->multi_bio = true; |
451 | atomic_set(&dio->ref, 2); | |
452 | } else { | |
453 | atomic_inc(&dio->ref); | |
454 | } | |
455 | ||
7b6620d7 JA |
456 | submit_bio(bio); |
457 | bio = bio_alloc(GFP_KERNEL, nr_pages); | |
542ff7bf | 458 | } |
cb700eb3 JA |
459 | |
460 | if (!is_poll) | |
461 | blk_finish_plug(&plug); | |
542ff7bf | 462 | |
690e5325 | 463 | if (!is_sync) |
542ff7bf CH |
464 | return -EIOCBQUEUED; |
465 | ||
466 | for (;;) { | |
1ac5cd49 | 467 | set_current_state(TASK_UNINTERRUPTIBLE); |
542ff7bf CH |
468 | if (!READ_ONCE(dio->waiter)) |
469 | break; | |
470 | ||
471 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
0a1b8b87 | 472 | !blk_poll(bdev_get_queue(bdev), qc, true)) |
e6249cdd | 473 | blk_io_schedule(); |
542ff7bf CH |
474 | } |
475 | __set_current_state(TASK_RUNNING); | |
476 | ||
36ffc6c1 | 477 | if (!ret) |
4e4cbee9 | 478 | ret = blk_status_to_errno(dio->bio.bi_status); |
e15c2ffa JA |
479 | if (likely(!ret)) |
480 | ret = dio->size; | |
542ff7bf CH |
481 | |
482 | bio_put(&dio->bio); | |
483 | return ret; | |
484 | } | |
485 | ||
486 | static ssize_t | |
487 | blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) | |
488 | { | |
5f7136db | 489 | unsigned int nr_pages; |
b2e895db | 490 | |
3e1a88ec | 491 | if (!iov_iter_count(iter)) |
189ce2b9 | 492 | return 0; |
3e1a88ec PB |
493 | |
494 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_PAGES + 1); | |
72ecad22 | 495 | if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_PAGES) |
189ce2b9 | 496 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); |
542ff7bf | 497 | |
5f7136db | 498 | return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); |
542ff7bf CH |
499 | } |
500 | ||
501 | static __init int blkdev_init(void) | |
502 | { | |
52190f8a | 503 | return bioset_init(&blkdev_dio_pool, 4, offsetof(struct blkdev_dio, bio), BIOSET_NEED_BVECS); |
b2e895db | 504 | } |
542ff7bf | 505 | module_init(blkdev_init); |
b2e895db | 506 | |
5cee5815 JK |
507 | int __sync_blockdev(struct block_device *bdev, int wait) |
508 | { | |
509 | if (!bdev) | |
510 | return 0; | |
511 | if (!wait) | |
512 | return filemap_flush(bdev->bd_inode->i_mapping); | |
513 | return filemap_write_and_wait(bdev->bd_inode->i_mapping); | |
514 | } | |
515 | ||
585d3bc0 NP |
516 | /* |
517 | * Write out and wait upon all the dirty data associated with a block | |
518 | * device via its mapping. Does not take the superblock lock. | |
519 | */ | |
520 | int sync_blockdev(struct block_device *bdev) | |
521 | { | |
5cee5815 | 522 | return __sync_blockdev(bdev, 1); |
585d3bc0 NP |
523 | } |
524 | EXPORT_SYMBOL(sync_blockdev); | |
525 | ||
526 | /* | |
527 | * Write out and wait upon all dirty data associated with this | |
528 | * device. Filesystem data as well as the underlying block | |
529 | * device. Takes the superblock lock. | |
530 | */ | |
531 | int fsync_bdev(struct block_device *bdev) | |
532 | { | |
533 | struct super_block *sb = get_super(bdev); | |
534 | if (sb) { | |
60b0680f | 535 | int res = sync_filesystem(sb); |
585d3bc0 NP |
536 | drop_super(sb); |
537 | return res; | |
538 | } | |
539 | return sync_blockdev(bdev); | |
540 | } | |
47e4491b | 541 | EXPORT_SYMBOL(fsync_bdev); |
585d3bc0 NP |
542 | |
543 | /** | |
544 | * freeze_bdev -- lock a filesystem and force it into a consistent state | |
545 | * @bdev: blockdevice to lock | |
546 | * | |
585d3bc0 NP |
547 | * If a superblock is found on this device, we take the s_umount semaphore |
548 | * on it to make sure nobody unmounts until the snapshot creation is done. | |
549 | * The reference counter (bd_fsfreeze_count) guarantees that only the last | |
550 | * unfreeze process can unfreeze the frozen filesystem actually when multiple | |
551 | * freeze requests arrive simultaneously. It counts up in freeze_bdev() and | |
552 | * count down in thaw_bdev(). When it becomes 0, thaw_bdev() will unfreeze | |
553 | * actually. | |
554 | */ | |
040f04bd | 555 | int freeze_bdev(struct block_device *bdev) |
585d3bc0 NP |
556 | { |
557 | struct super_block *sb; | |
558 | int error = 0; | |
559 | ||
560 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
040f04bd CH |
561 | if (++bdev->bd_fsfreeze_count > 1) |
562 | goto done; | |
4504230a CH |
563 | |
564 | sb = get_active_super(bdev); | |
565 | if (!sb) | |
040f04bd | 566 | goto sync; |
48b6bca6 BM |
567 | if (sb->s_op->freeze_super) |
568 | error = sb->s_op->freeze_super(sb); | |
569 | else | |
570 | error = freeze_super(sb); | |
040f04bd CH |
571 | deactivate_super(sb); |
572 | ||
18e9e510 | 573 | if (error) { |
18e9e510 | 574 | bdev->bd_fsfreeze_count--; |
040f04bd | 575 | goto done; |
585d3bc0 | 576 | } |
040f04bd CH |
577 | bdev->bd_fsfreeze_sb = sb; |
578 | ||
579 | sync: | |
585d3bc0 | 580 | sync_blockdev(bdev); |
040f04bd | 581 | done: |
585d3bc0 | 582 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
040f04bd | 583 | return error; |
585d3bc0 NP |
584 | } |
585 | EXPORT_SYMBOL(freeze_bdev); | |
586 | ||
587 | /** | |
588 | * thaw_bdev -- unlock filesystem | |
589 | * @bdev: blockdevice to unlock | |
585d3bc0 NP |
590 | * |
591 | * Unlocks the filesystem and marks it writeable again after freeze_bdev(). | |
592 | */ | |
040f04bd | 593 | int thaw_bdev(struct block_device *bdev) |
585d3bc0 | 594 | { |
040f04bd | 595 | struct super_block *sb; |
4504230a | 596 | int error = -EINVAL; |
585d3bc0 NP |
597 | |
598 | mutex_lock(&bdev->bd_fsfreeze_mutex); | |
4504230a | 599 | if (!bdev->bd_fsfreeze_count) |
18e9e510 | 600 | goto out; |
4504230a CH |
601 | |
602 | error = 0; | |
603 | if (--bdev->bd_fsfreeze_count > 0) | |
18e9e510 | 604 | goto out; |
4504230a | 605 | |
040f04bd | 606 | sb = bdev->bd_fsfreeze_sb; |
4504230a | 607 | if (!sb) |
18e9e510 | 608 | goto out; |
4504230a | 609 | |
48b6bca6 BM |
610 | if (sb->s_op->thaw_super) |
611 | error = sb->s_op->thaw_super(sb); | |
612 | else | |
613 | error = thaw_super(sb); | |
997198ba | 614 | if (error) |
18e9e510 | 615 | bdev->bd_fsfreeze_count++; |
04a6a536 ST |
616 | else |
617 | bdev->bd_fsfreeze_sb = NULL; | |
18e9e510 | 618 | out: |
585d3bc0 | 619 | mutex_unlock(&bdev->bd_fsfreeze_mutex); |
997198ba | 620 | return error; |
585d3bc0 NP |
621 | } |
622 | EXPORT_SYMBOL(thaw_bdev); | |
623 | ||
1da177e4 LT |
624 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
625 | { | |
626 | return block_write_full_page(page, blkdev_get_block, wbc); | |
627 | } | |
628 | ||
629 | static int blkdev_readpage(struct file * file, struct page * page) | |
630 | { | |
631 | return block_read_full_page(page, blkdev_get_block); | |
632 | } | |
633 | ||
d4388340 | 634 | static void blkdev_readahead(struct readahead_control *rac) |
447f05bb | 635 | { |
d4388340 | 636 | mpage_readahead(rac, blkdev_get_block); |
447f05bb AM |
637 | } |
638 | ||
6272b5a5 NP |
639 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, |
640 | loff_t pos, unsigned len, unsigned flags, | |
641 | struct page **pagep, void **fsdata) | |
1da177e4 | 642 | { |
155130a4 CH |
643 | return block_write_begin(mapping, pos, len, flags, pagep, |
644 | blkdev_get_block); | |
1da177e4 LT |
645 | } |
646 | ||
6272b5a5 NP |
647 | static int blkdev_write_end(struct file *file, struct address_space *mapping, |
648 | loff_t pos, unsigned len, unsigned copied, | |
649 | struct page *page, void *fsdata) | |
1da177e4 | 650 | { |
6272b5a5 NP |
651 | int ret; |
652 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
653 | ||
654 | unlock_page(page); | |
09cbfeaf | 655 | put_page(page); |
6272b5a5 NP |
656 | |
657 | return ret; | |
1da177e4 LT |
658 | } |
659 | ||
660 | /* | |
661 | * private llseek: | |
496ad9aa | 662 | * for a block special file file_inode(file)->i_size is zero |
1da177e4 LT |
663 | * so we compute the size by hand (just as in block_read/write above) |
664 | */ | |
965c8e59 | 665 | static loff_t block_llseek(struct file *file, loff_t offset, int whence) |
1da177e4 | 666 | { |
4ebb16ca | 667 | struct inode *bd_inode = bdev_file_inode(file); |
1da177e4 LT |
668 | loff_t retval; |
669 | ||
5955102c | 670 | inode_lock(bd_inode); |
5d48f3a2 | 671 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); |
5955102c | 672 | inode_unlock(bd_inode); |
1da177e4 LT |
673 | return retval; |
674 | } | |
675 | ||
02c24a82 | 676 | int blkdev_fsync(struct file *filp, loff_t start, loff_t end, int datasync) |
1da177e4 | 677 | { |
4ebb16ca | 678 | struct inode *bd_inode = bdev_file_inode(filp); |
b8af67e2 | 679 | struct block_device *bdev = I_BDEV(bd_inode); |
ab0a9735 | 680 | int error; |
da5aa861 | 681 | |
372cf243 | 682 | error = file_write_and_wait_range(filp, start, end); |
da5aa861 RW |
683 | if (error) |
684 | return error; | |
ab0a9735 | 685 | |
b8af67e2 AB |
686 | /* |
687 | * There is no need to serialise calls to blkdev_issue_flush with | |
688 | * i_mutex and doing so causes performance issues with concurrent | |
689 | * O_SYNC writers to a block device. | |
690 | */ | |
c6bf3f0e | 691 | error = blkdev_issue_flush(bdev); |
ab0a9735 CH |
692 | if (error == -EOPNOTSUPP) |
693 | error = 0; | |
b8af67e2 | 694 | |
ab0a9735 | 695 | return error; |
1da177e4 | 696 | } |
b1dd3b28 | 697 | EXPORT_SYMBOL(blkdev_fsync); |
1da177e4 | 698 | |
47a191fd MW |
699 | /** |
700 | * bdev_read_page() - Start reading a page from a block device | |
701 | * @bdev: The device to read the page from | |
702 | * @sector: The offset on the device to read the page to (need not be aligned) | |
703 | * @page: The page to read | |
704 | * | |
705 | * On entry, the page should be locked. It will be unlocked when the page | |
706 | * has been read. If the block driver implements rw_page synchronously, | |
707 | * that will be true on exit from this function, but it need not be. | |
708 | * | |
709 | * Errors returned by this function are usually "soft", eg out of memory, or | |
710 | * queue full; callers should try a different route to read this page rather | |
711 | * than propagate an error back up the stack. | |
712 | * | |
713 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
714 | */ | |
715 | int bdev_read_page(struct block_device *bdev, sector_t sector, | |
716 | struct page *page) | |
717 | { | |
718 | const struct block_device_operations *ops = bdev->bd_disk->fops; | |
2e6edc95 DW |
719 | int result = -EOPNOTSUPP; |
720 | ||
f68eb1e7 | 721 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
2e6edc95 DW |
722 | return result; |
723 | ||
e556f6ba | 724 | result = blk_queue_enter(bdev->bd_disk->queue, 0); |
2e6edc95 DW |
725 | if (result) |
726 | return result; | |
3f289dcb TH |
727 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
728 | REQ_OP_READ); | |
e556f6ba | 729 | blk_queue_exit(bdev->bd_disk->queue); |
2e6edc95 | 730 | return result; |
47a191fd | 731 | } |
47a191fd MW |
732 | |
733 | /** | |
734 | * bdev_write_page() - Start writing a page to a block device | |
735 | * @bdev: The device to write the page to | |
736 | * @sector: The offset on the device to write the page to (need not be aligned) | |
737 | * @page: The page to write | |
738 | * @wbc: The writeback_control for the write | |
739 | * | |
740 | * On entry, the page should be locked and not currently under writeback. | |
741 | * On exit, if the write started successfully, the page will be unlocked and | |
742 | * under writeback. If the write failed already (eg the driver failed to | |
743 | * queue the page to the device), the page will still be locked. If the | |
744 | * caller is a ->writepage implementation, it will need to unlock the page. | |
745 | * | |
746 | * Errors returned by this function are usually "soft", eg out of memory, or | |
747 | * queue full; callers should try a different route to write this page rather | |
748 | * than propagate an error back up the stack. | |
749 | * | |
750 | * Return: negative errno if an error occurs, 0 if submission was successful. | |
751 | */ | |
752 | int bdev_write_page(struct block_device *bdev, sector_t sector, | |
753 | struct page *page, struct writeback_control *wbc) | |
754 | { | |
755 | int result; | |
47a191fd | 756 | const struct block_device_operations *ops = bdev->bd_disk->fops; |
2e6edc95 | 757 | |
f68eb1e7 | 758 | if (!ops->rw_page || bdev_get_integrity(bdev)) |
47a191fd | 759 | return -EOPNOTSUPP; |
e556f6ba | 760 | result = blk_queue_enter(bdev->bd_disk->queue, 0); |
2e6edc95 DW |
761 | if (result) |
762 | return result; | |
763 | ||
47a191fd | 764 | set_page_writeback(page); |
3f289dcb TH |
765 | result = ops->rw_page(bdev, sector + get_start_sect(bdev), page, |
766 | REQ_OP_WRITE); | |
f892760a | 767 | if (result) { |
47a191fd | 768 | end_page_writeback(page); |
f892760a MW |
769 | } else { |
770 | clean_page_buffers(page); | |
47a191fd | 771 | unlock_page(page); |
f892760a | 772 | } |
e556f6ba | 773 | blk_queue_exit(bdev->bd_disk->queue); |
47a191fd MW |
774 | return result; |
775 | } | |
47a191fd | 776 | |
1da177e4 LT |
777 | /* |
778 | * pseudo-fs | |
779 | */ | |
780 | ||
781 | static __cacheline_aligned_in_smp DEFINE_SPINLOCK(bdev_lock); | |
e18b890b | 782 | static struct kmem_cache * bdev_cachep __read_mostly; |
1da177e4 LT |
783 | |
784 | static struct inode *bdev_alloc_inode(struct super_block *sb) | |
785 | { | |
e94b1766 | 786 | struct bdev_inode *ei = kmem_cache_alloc(bdev_cachep, GFP_KERNEL); |
2d2f6f1b | 787 | |
1da177e4 LT |
788 | if (!ei) |
789 | return NULL; | |
2d2f6f1b CH |
790 | memset(&ei->bdev, 0, sizeof(ei->bdev)); |
791 | ei->bdev.bd_bdi = &noop_backing_dev_info; | |
1da177e4 LT |
792 | return &ei->vfs_inode; |
793 | } | |
794 | ||
41149cb0 | 795 | static void bdev_free_inode(struct inode *inode) |
1da177e4 | 796 | { |
15e3d2c5 CH |
797 | struct block_device *bdev = I_BDEV(inode); |
798 | ||
799 | free_percpu(bdev->bd_stats); | |
231926db | 800 | kfree(bdev->bd_meta_info); |
15e3d2c5 | 801 | |
41149cb0 | 802 | kmem_cache_free(bdev_cachep, BDEV_I(inode)); |
fa0d7e3d NP |
803 | } |
804 | ||
e6cb5382 | 805 | static void init_once(void *data) |
1da177e4 | 806 | { |
e6cb5382 | 807 | struct bdev_inode *ei = data; |
1da177e4 | 808 | |
a35afb83 | 809 | inode_init_once(&ei->vfs_inode); |
1da177e4 LT |
810 | } |
811 | ||
b57922d9 | 812 | static void bdev_evict_inode(struct inode *inode) |
1da177e4 LT |
813 | { |
814 | struct block_device *bdev = &BDEV_I(inode)->bdev; | |
91b0abe3 | 815 | truncate_inode_pages_final(&inode->i_data); |
b57922d9 | 816 | invalidate_inode_buffers(inode); /* is it needed here? */ |
dbd5768f | 817 | clear_inode(inode); |
f759741d JK |
818 | /* Detach inode from wb early as bdi_put() may free bdi->wb */ |
819 | inode_detach_wb(inode); | |
a5a79d00 | 820 | if (bdev->bd_bdi != &noop_backing_dev_info) { |
b1d2dc56 | 821 | bdi_put(bdev->bd_bdi); |
a5a79d00 JK |
822 | bdev->bd_bdi = &noop_backing_dev_info; |
823 | } | |
1da177e4 LT |
824 | } |
825 | ||
ee9b6d61 | 826 | static const struct super_operations bdev_sops = { |
1da177e4 LT |
827 | .statfs = simple_statfs, |
828 | .alloc_inode = bdev_alloc_inode, | |
41149cb0 | 829 | .free_inode = bdev_free_inode, |
1da177e4 | 830 | .drop_inode = generic_delete_inode, |
b57922d9 | 831 | .evict_inode = bdev_evict_inode, |
1da177e4 LT |
832 | }; |
833 | ||
9030d16e | 834 | static int bd_init_fs_context(struct fs_context *fc) |
1da177e4 | 835 | { |
9030d16e DH |
836 | struct pseudo_fs_context *ctx = init_pseudo(fc, BDEVFS_MAGIC); |
837 | if (!ctx) | |
838 | return -ENOMEM; | |
839 | fc->s_iflags |= SB_I_CGROUPWB; | |
840 | ctx->ops = &bdev_sops; | |
841 | return 0; | |
1da177e4 LT |
842 | } |
843 | ||
844 | static struct file_system_type bd_type = { | |
845 | .name = "bdev", | |
9030d16e | 846 | .init_fs_context = bd_init_fs_context, |
1da177e4 LT |
847 | .kill_sb = kill_anon_super, |
848 | }; | |
849 | ||
a212b105 TH |
850 | struct super_block *blockdev_superblock __read_mostly; |
851 | EXPORT_SYMBOL_GPL(blockdev_superblock); | |
1da177e4 LT |
852 | |
853 | void __init bdev_cache_init(void) | |
854 | { | |
855 | int err; | |
ace8577a | 856 | static struct vfsmount *bd_mnt; |
c2acf7b9 | 857 | |
1da177e4 | 858 | bdev_cachep = kmem_cache_create("bdev_cache", sizeof(struct bdev_inode), |
fffb60f9 | 859 | 0, (SLAB_HWCACHE_ALIGN|SLAB_RECLAIM_ACCOUNT| |
5d097056 | 860 | SLAB_MEM_SPREAD|SLAB_ACCOUNT|SLAB_PANIC), |
20c2df83 | 861 | init_once); |
1da177e4 LT |
862 | err = register_filesystem(&bd_type); |
863 | if (err) | |
864 | panic("Cannot register bdev pseudo-fs"); | |
865 | bd_mnt = kern_mount(&bd_type); | |
1da177e4 LT |
866 | if (IS_ERR(bd_mnt)) |
867 | panic("Cannot create bdev pseudo-fs"); | |
ace8577a | 868 | blockdev_superblock = bd_mnt->mnt_sb; /* For writeback */ |
1da177e4 LT |
869 | } |
870 | ||
22ae8ce8 | 871 | struct block_device *bdev_alloc(struct gendisk *disk, u8 partno) |
1da177e4 LT |
872 | { |
873 | struct block_device *bdev; | |
874 | struct inode *inode; | |
875 | ||
22ae8ce8 | 876 | inode = new_inode(blockdev_superblock); |
1da177e4 LT |
877 | if (!inode) |
878 | return NULL; | |
22ae8ce8 CH |
879 | inode->i_mode = S_IFBLK; |
880 | inode->i_rdev = 0; | |
881 | inode->i_data.a_ops = &def_blk_aops; | |
882 | mapping_set_gfp_mask(&inode->i_data, GFP_USER); | |
883 | ||
884 | bdev = I_BDEV(inode); | |
e6cb5382 CH |
885 | mutex_init(&bdev->bd_mutex); |
886 | mutex_init(&bdev->bd_fsfreeze_mutex); | |
22ae8ce8 CH |
887 | spin_lock_init(&bdev->bd_size_lock); |
888 | bdev->bd_disk = disk; | |
889 | bdev->bd_partno = partno; | |
22ae8ce8 | 890 | bdev->bd_inode = inode; |
e6cb5382 CH |
891 | #ifdef CONFIG_SYSFS |
892 | INIT_LIST_HEAD(&bdev->bd_holder_disks); | |
893 | #endif | |
15e3d2c5 CH |
894 | bdev->bd_stats = alloc_percpu(struct disk_stats); |
895 | if (!bdev->bd_stats) { | |
896 | iput(inode); | |
897 | return NULL; | |
898 | } | |
22ae8ce8 CH |
899 | return bdev; |
900 | } | |
1da177e4 | 901 | |
22ae8ce8 CH |
902 | void bdev_add(struct block_device *bdev, dev_t dev) |
903 | { | |
904 | bdev->bd_dev = dev; | |
905 | bdev->bd_inode->i_rdev = dev; | |
906 | bdev->bd_inode->i_ino = dev; | |
907 | insert_inode_hash(bdev->bd_inode); | |
908 | } | |
1da177e4 | 909 | |
22ae8ce8 CH |
910 | static struct block_device *bdget(dev_t dev) |
911 | { | |
912 | struct inode *inode; | |
913 | ||
914 | inode = ilookup(blockdev_superblock, dev); | |
915 | if (!inode) | |
916 | return NULL; | |
917 | return &BDEV_I(inode)->bdev; | |
1da177e4 LT |
918 | } |
919 | ||
dddac6a7 AJ |
920 | /** |
921 | * bdgrab -- Grab a reference to an already referenced block device | |
922 | * @bdev: Block device to grab a reference to. | |
3a4174e6 CH |
923 | * |
924 | * Returns the block_device with an additional reference when successful, | |
925 | * or NULL if the inode is already beeing freed. | |
dddac6a7 AJ |
926 | */ |
927 | struct block_device *bdgrab(struct block_device *bdev) | |
928 | { | |
3a4174e6 CH |
929 | if (!igrab(bdev->bd_inode)) |
930 | return NULL; | |
dddac6a7 AJ |
931 | return bdev; |
932 | } | |
c1681bf8 | 933 | EXPORT_SYMBOL(bdgrab); |
dddac6a7 | 934 | |
1da177e4 LT |
935 | long nr_blockdev_pages(void) |
936 | { | |
1008fe6d | 937 | struct inode *inode; |
1da177e4 | 938 | long ret = 0; |
1008fe6d CH |
939 | |
940 | spin_lock(&blockdev_superblock->s_inode_list_lock); | |
941 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) | |
942 | ret += inode->i_mapping->nrpages; | |
943 | spin_unlock(&blockdev_superblock->s_inode_list_lock); | |
944 | ||
1da177e4 LT |
945 | return ret; |
946 | } | |
947 | ||
948 | void bdput(struct block_device *bdev) | |
949 | { | |
950 | iput(bdev->bd_inode); | |
951 | } | |
1da177e4 LT |
952 | EXPORT_SYMBOL(bdput); |
953 | ||
1a3cbbc5 TH |
954 | /** |
955 | * bd_may_claim - test whether a block device can be claimed | |
956 | * @bdev: block device of interest | |
957 | * @whole: whole block device containing @bdev, may equal @bdev | |
958 | * @holder: holder trying to claim @bdev | |
959 | * | |
25985edc | 960 | * Test whether @bdev can be claimed by @holder. |
1a3cbbc5 TH |
961 | * |
962 | * CONTEXT: | |
963 | * spin_lock(&bdev_lock). | |
964 | * | |
965 | * RETURNS: | |
966 | * %true if @bdev can be claimed, %false otherwise. | |
967 | */ | |
968 | static bool bd_may_claim(struct block_device *bdev, struct block_device *whole, | |
969 | void *holder) | |
1da177e4 | 970 | { |
1da177e4 | 971 | if (bdev->bd_holder == holder) |
1a3cbbc5 | 972 | return true; /* already a holder */ |
1da177e4 | 973 | else if (bdev->bd_holder != NULL) |
1a3cbbc5 | 974 | return false; /* held by someone else */ |
bcc7f5b4 | 975 | else if (whole == bdev) |
1a3cbbc5 | 976 | return true; /* is a whole device which isn't held */ |
1da177e4 | 977 | |
e525fd89 | 978 | else if (whole->bd_holder == bd_may_claim) |
1a3cbbc5 TH |
979 | return true; /* is a partition of a device that is being partitioned */ |
980 | else if (whole->bd_holder != NULL) | |
981 | return false; /* is a partition of a held device */ | |
1da177e4 | 982 | else |
1a3cbbc5 TH |
983 | return true; /* is a partition of an un-held device */ |
984 | } | |
985 | ||
6b4517a7 | 986 | /** |
58e46ed9 | 987 | * bd_prepare_to_claim - claim a block device |
6b4517a7 | 988 | * @bdev: block device of interest |
6b4517a7 TH |
989 | * @holder: holder trying to claim @bdev |
990 | * | |
58e46ed9 CH |
991 | * Claim @bdev. This function fails if @bdev is already claimed by another |
992 | * holder and waits if another claiming is in progress. return, the caller | |
993 | * has ownership of bd_claiming and bd_holder[s]. | |
6b4517a7 TH |
994 | * |
995 | * RETURNS: | |
996 | * 0 if @bdev can be claimed, -EBUSY otherwise. | |
997 | */ | |
37c3fc9a | 998 | int bd_prepare_to_claim(struct block_device *bdev, void *holder) |
6b4517a7 | 999 | { |
37c3fc9a CH |
1000 | struct block_device *whole = bdev_whole(bdev); |
1001 | ||
1002 | if (WARN_ON_ONCE(!holder)) | |
1003 | return -EINVAL; | |
6b4517a7 | 1004 | retry: |
58e46ed9 | 1005 | spin_lock(&bdev_lock); |
6b4517a7 | 1006 | /* if someone else claimed, fail */ |
58e46ed9 CH |
1007 | if (!bd_may_claim(bdev, whole, holder)) { |
1008 | spin_unlock(&bdev_lock); | |
6b4517a7 | 1009 | return -EBUSY; |
58e46ed9 | 1010 | } |
6b4517a7 | 1011 | |
e75aa858 TH |
1012 | /* if claiming is already in progress, wait for it to finish */ |
1013 | if (whole->bd_claiming) { | |
6b4517a7 TH |
1014 | wait_queue_head_t *wq = bit_waitqueue(&whole->bd_claiming, 0); |
1015 | DEFINE_WAIT(wait); | |
1016 | ||
1017 | prepare_to_wait(wq, &wait, TASK_UNINTERRUPTIBLE); | |
1018 | spin_unlock(&bdev_lock); | |
1019 | schedule(); | |
1020 | finish_wait(wq, &wait); | |
6b4517a7 TH |
1021 | goto retry; |
1022 | } | |
1023 | ||
1024 | /* yay, all mine */ | |
58e46ed9 CH |
1025 | whole->bd_claiming = holder; |
1026 | spin_unlock(&bdev_lock); | |
6b4517a7 TH |
1027 | return 0; |
1028 | } | |
ecbe6bc0 | 1029 | EXPORT_SYMBOL_GPL(bd_prepare_to_claim); /* only for the loop driver */ |
6b4517a7 | 1030 | |
89e524c0 JK |
1031 | static void bd_clear_claiming(struct block_device *whole, void *holder) |
1032 | { | |
1033 | lockdep_assert_held(&bdev_lock); | |
1034 | /* tell others that we're done */ | |
1035 | BUG_ON(whole->bd_claiming != holder); | |
1036 | whole->bd_claiming = NULL; | |
1037 | wake_up_bit(&whole->bd_claiming, 0); | |
1038 | } | |
1039 | ||
1040 | /** | |
1041 | * bd_finish_claiming - finish claiming of a block device | |
1042 | * @bdev: block device of interest | |
89e524c0 JK |
1043 | * @holder: holder that has claimed @bdev |
1044 | * | |
1045 | * Finish exclusive open of a block device. Mark the device as exlusively | |
1046 | * open by the holder and wake up all waiters for exclusive open to finish. | |
1047 | */ | |
37c3fc9a | 1048 | static void bd_finish_claiming(struct block_device *bdev, void *holder) |
89e524c0 | 1049 | { |
37c3fc9a CH |
1050 | struct block_device *whole = bdev_whole(bdev); |
1051 | ||
89e524c0 JK |
1052 | spin_lock(&bdev_lock); |
1053 | BUG_ON(!bd_may_claim(bdev, whole, holder)); | |
1054 | /* | |
1055 | * Note that for a whole device bd_holders will be incremented twice, | |
1056 | * and bd_holder will be set to bd_may_claim before being set to holder | |
1057 | */ | |
1058 | whole->bd_holders++; | |
1059 | whole->bd_holder = bd_may_claim; | |
1060 | bdev->bd_holders++; | |
1061 | bdev->bd_holder = holder; | |
1062 | bd_clear_claiming(whole, holder); | |
1063 | spin_unlock(&bdev_lock); | |
1064 | } | |
89e524c0 JK |
1065 | |
1066 | /** | |
1067 | * bd_abort_claiming - abort claiming of a block device | |
1068 | * @bdev: block device of interest | |
89e524c0 JK |
1069 | * @holder: holder that has claimed @bdev |
1070 | * | |
1071 | * Abort claiming of a block device when the exclusive open failed. This can be | |
1072 | * also used when exclusive open is not actually desired and we just needed | |
1073 | * to block other exclusive openers for a while. | |
1074 | */ | |
37c3fc9a | 1075 | void bd_abort_claiming(struct block_device *bdev, void *holder) |
89e524c0 JK |
1076 | { |
1077 | spin_lock(&bdev_lock); | |
37c3fc9a | 1078 | bd_clear_claiming(bdev_whole(bdev), holder); |
89e524c0 JK |
1079 | spin_unlock(&bdev_lock); |
1080 | } | |
1081 | EXPORT_SYMBOL(bd_abort_claiming); | |
6b4517a7 | 1082 | |
641dc636 | 1083 | #ifdef CONFIG_SYSFS |
49731baa TH |
1084 | struct bd_holder_disk { |
1085 | struct list_head list; | |
1086 | struct gendisk *disk; | |
1087 | int refcnt; | |
1088 | }; | |
1089 | ||
1090 | static struct bd_holder_disk *bd_find_holder_disk(struct block_device *bdev, | |
1091 | struct gendisk *disk) | |
1092 | { | |
1093 | struct bd_holder_disk *holder; | |
1094 | ||
1095 | list_for_each_entry(holder, &bdev->bd_holder_disks, list) | |
1096 | if (holder->disk == disk) | |
1097 | return holder; | |
1098 | return NULL; | |
1099 | } | |
1100 | ||
4d7dd8fd | 1101 | static int add_symlink(struct kobject *from, struct kobject *to) |
641dc636 | 1102 | { |
4d7dd8fd | 1103 | return sysfs_create_link(from, to, kobject_name(to)); |
641dc636 JN |
1104 | } |
1105 | ||
1106 | static void del_symlink(struct kobject *from, struct kobject *to) | |
1107 | { | |
641dc636 JN |
1108 | sysfs_remove_link(from, kobject_name(to)); |
1109 | } | |
1110 | ||
df6c0cd9 | 1111 | /** |
e09b457b TH |
1112 | * bd_link_disk_holder - create symlinks between holding disk and slave bdev |
1113 | * @bdev: the claimed slave bdev | |
1114 | * @disk: the holding disk | |
df6c0cd9 | 1115 | * |
49731baa TH |
1116 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. |
1117 | * | |
e09b457b | 1118 | * This functions creates the following sysfs symlinks. |
641dc636 | 1119 | * |
e09b457b TH |
1120 | * - from "slaves" directory of the holder @disk to the claimed @bdev |
1121 | * - from "holders" directory of the @bdev to the holder @disk | |
641dc636 | 1122 | * |
e09b457b TH |
1123 | * For example, if /dev/dm-0 maps to /dev/sda and disk for dm-0 is |
1124 | * passed to bd_link_disk_holder(), then: | |
641dc636 | 1125 | * |
e09b457b TH |
1126 | * /sys/block/dm-0/slaves/sda --> /sys/block/sda |
1127 | * /sys/block/sda/holders/dm-0 --> /sys/block/dm-0 | |
641dc636 | 1128 | * |
e09b457b TH |
1129 | * The caller must have claimed @bdev before calling this function and |
1130 | * ensure that both @bdev and @disk are valid during the creation and | |
1131 | * lifetime of these symlinks. | |
641dc636 | 1132 | * |
e09b457b TH |
1133 | * CONTEXT: |
1134 | * Might sleep. | |
641dc636 | 1135 | * |
e09b457b TH |
1136 | * RETURNS: |
1137 | * 0 on success, -errno on failure. | |
641dc636 | 1138 | */ |
e09b457b | 1139 | int bd_link_disk_holder(struct block_device *bdev, struct gendisk *disk) |
641dc636 | 1140 | { |
49731baa | 1141 | struct bd_holder_disk *holder; |
e09b457b | 1142 | int ret = 0; |
641dc636 | 1143 | |
2e7b651d | 1144 | mutex_lock(&bdev->bd_mutex); |
df6c0cd9 | 1145 | |
49731baa | 1146 | WARN_ON_ONCE(!bdev->bd_holder); |
4e91672c | 1147 | |
e09b457b | 1148 | /* FIXME: remove the following once add_disk() handles errors */ |
1bdd5ae0 | 1149 | if (WARN_ON(!disk->slave_dir || !bdev->bd_holder_dir)) |
e09b457b | 1150 | goto out_unlock; |
4e91672c | 1151 | |
49731baa TH |
1152 | holder = bd_find_holder_disk(bdev, disk); |
1153 | if (holder) { | |
1154 | holder->refcnt++; | |
e09b457b | 1155 | goto out_unlock; |
49731baa | 1156 | } |
641dc636 | 1157 | |
49731baa TH |
1158 | holder = kzalloc(sizeof(*holder), GFP_KERNEL); |
1159 | if (!holder) { | |
1160 | ret = -ENOMEM; | |
e09b457b TH |
1161 | goto out_unlock; |
1162 | } | |
641dc636 | 1163 | |
49731baa TH |
1164 | INIT_LIST_HEAD(&holder->list); |
1165 | holder->disk = disk; | |
1166 | holder->refcnt = 1; | |
1167 | ||
8d65269f | 1168 | ret = add_symlink(disk->slave_dir, bdev_kobj(bdev)); |
49731baa TH |
1169 | if (ret) |
1170 | goto out_free; | |
1171 | ||
1bdd5ae0 | 1172 | ret = add_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); |
49731baa TH |
1173 | if (ret) |
1174 | goto out_del; | |
e7407d16 TH |
1175 | /* |
1176 | * bdev could be deleted beneath us which would implicitly destroy | |
1177 | * the holder directory. Hold on to it. | |
1178 | */ | |
1bdd5ae0 | 1179 | kobject_get(bdev->bd_holder_dir); |
49731baa TH |
1180 | |
1181 | list_add(&holder->list, &bdev->bd_holder_disks); | |
1182 | goto out_unlock; | |
1183 | ||
1184 | out_del: | |
8d65269f | 1185 | del_symlink(disk->slave_dir, bdev_kobj(bdev)); |
49731baa TH |
1186 | out_free: |
1187 | kfree(holder); | |
e09b457b | 1188 | out_unlock: |
b4cf1b72 | 1189 | mutex_unlock(&bdev->bd_mutex); |
e09b457b | 1190 | return ret; |
641dc636 | 1191 | } |
e09b457b | 1192 | EXPORT_SYMBOL_GPL(bd_link_disk_holder); |
641dc636 | 1193 | |
49731baa TH |
1194 | /** |
1195 | * bd_unlink_disk_holder - destroy symlinks created by bd_link_disk_holder() | |
1196 | * @bdev: the calimed slave bdev | |
1197 | * @disk: the holding disk | |
1198 | * | |
1199 | * DON'T USE THIS UNLESS YOU'RE ALREADY USING IT. | |
1200 | * | |
1201 | * CONTEXT: | |
1202 | * Might sleep. | |
1203 | */ | |
1204 | void bd_unlink_disk_holder(struct block_device *bdev, struct gendisk *disk) | |
641dc636 | 1205 | { |
49731baa | 1206 | struct bd_holder_disk *holder; |
641dc636 | 1207 | |
49731baa | 1208 | mutex_lock(&bdev->bd_mutex); |
641dc636 | 1209 | |
49731baa TH |
1210 | holder = bd_find_holder_disk(bdev, disk); |
1211 | ||
1212 | if (!WARN_ON_ONCE(holder == NULL) && !--holder->refcnt) { | |
8d65269f | 1213 | del_symlink(disk->slave_dir, bdev_kobj(bdev)); |
1bdd5ae0 CH |
1214 | del_symlink(bdev->bd_holder_dir, &disk_to_dev(disk)->kobj); |
1215 | kobject_put(bdev->bd_holder_dir); | |
49731baa TH |
1216 | list_del_init(&holder->list); |
1217 | kfree(holder); | |
1218 | } | |
1219 | ||
1220 | mutex_unlock(&bdev->bd_mutex); | |
1da177e4 | 1221 | } |
49731baa | 1222 | EXPORT_SYMBOL_GPL(bd_unlink_disk_holder); |
641dc636 | 1223 | #endif |
1da177e4 | 1224 | |
4385bab1 | 1225 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part); |
37be4124 | 1226 | |
142fe8f4 | 1227 | int bdev_disk_changed(struct block_device *bdev, bool invalidate) |
a1548b67 | 1228 | { |
142fe8f4 | 1229 | struct gendisk *disk = bdev->bd_disk; |
a1548b67 CH |
1230 | int ret; |
1231 | ||
f0b870df CH |
1232 | lockdep_assert_held(&bdev->bd_mutex); |
1233 | ||
38430f08 | 1234 | clear_bit(GD_NEED_PART_SCAN, &bdev->bd_disk->state); |
6540fbf6 | 1235 | |
a1548b67 | 1236 | rescan: |
d46430bf | 1237 | ret = blk_drop_partitions(bdev); |
a1548b67 CH |
1238 | if (ret) |
1239 | return ret; | |
1240 | ||
d981cb5b CH |
1241 | /* |
1242 | * Historically we only set the capacity to zero for devices that | |
1243 | * support partitions (independ of actually having partitions created). | |
1244 | * Doing that is rather inconsistent, but changing it broke legacy | |
1245 | * udisks polling for legacy ide-cdrom devices. Use the crude check | |
1246 | * below to get the sane behavior for most device while not breaking | |
1247 | * userspace for this particular setup. | |
1248 | */ | |
1249 | if (invalidate) { | |
1250 | if (disk_part_scan_enabled(disk) || | |
1251 | !(disk->flags & GENHD_FL_REMOVABLE)) | |
1252 | set_capacity(disk, 0); | |
1253 | } else { | |
1254 | if (disk->fops->revalidate_disk) | |
1255 | disk->fops->revalidate_disk(disk); | |
1256 | } | |
a1548b67 | 1257 | |
142fe8f4 CH |
1258 | if (get_capacity(disk)) { |
1259 | ret = blk_add_partitions(disk, bdev); | |
1260 | if (ret == -EAGAIN) | |
1261 | goto rescan; | |
490547ca | 1262 | } else if (invalidate) { |
a1548b67 CH |
1263 | /* |
1264 | * Tell userspace that the media / partition table may have | |
1265 | * changed. | |
1266 | */ | |
1267 | kobject_uevent(&disk_to_dev(disk)->kobj, KOBJ_CHANGE); | |
a1548b67 CH |
1268 | } |
1269 | ||
a1548b67 CH |
1270 | return ret; |
1271 | } | |
f0b870df | 1272 | /* |
3d742d4b | 1273 | * Only exported for loop and dasd for historic reasons. Don't use in new |
f0b870df CH |
1274 | * code! |
1275 | */ | |
1276 | EXPORT_SYMBOL_GPL(bdev_disk_changed); | |
a1548b67 | 1277 | |
6d740cd5 PZ |
1278 | /* |
1279 | * bd_mutex locking: | |
1280 | * | |
1281 | * mutex_lock(part->bd_mutex) | |
1282 | * mutex_lock_nested(whole->bd_mutex, 1) | |
1283 | */ | |
22ae8ce8 | 1284 | static int __blkdev_get(struct block_device *bdev, fmode_t mode) |
1da177e4 | 1285 | { |
22ae8ce8 | 1286 | struct gendisk *disk = bdev->bd_disk; |
cb8432d6 | 1287 | int ret = 0; |
5b642d8b | 1288 | |
1da177e4 | 1289 | if (!bdev->bd_openers) { |
a954ea81 | 1290 | if (!bdev_is_partition(bdev)) { |
1196f8b8 | 1291 | ret = 0; |
5b56b6ed | 1292 | if (disk->fops->open) |
572c4892 | 1293 | ret = disk->fops->open(bdev, mode); |
7e69723f | 1294 | |
a782483c | 1295 | if (!ret) |
04906b2f | 1296 | set_init_blocksize(bdev); |
7e69723f | 1297 | |
1196f8b8 TH |
1298 | /* |
1299 | * If the device is invalidated, rescan partition | |
1300 | * if open succeeded or failed with -ENOMEDIUM. | |
1301 | * The latter is necessary to prevent ghost | |
1302 | * partitions on a removed medium. | |
1303 | */ | |
38430f08 | 1304 | if (test_bit(GD_NEED_PART_SCAN, &disk->state) && |
731dc486 JK |
1305 | (!ret || ret == -ENOMEDIUM)) |
1306 | bdev_disk_changed(bdev, ret == -ENOMEDIUM); | |
5a023cdb | 1307 | |
1196f8b8 | 1308 | if (ret) |
cb8432d6 | 1309 | return ret; |
1da177e4 | 1310 | } else { |
977115c0 | 1311 | struct block_device *whole = bdgrab(disk->part0); |
5b56b6ed CH |
1312 | |
1313 | mutex_lock_nested(&whole->bd_mutex, 1); | |
22ae8ce8 | 1314 | ret = __blkdev_get(whole, mode); |
5b56b6ed CH |
1315 | if (ret) { |
1316 | mutex_unlock(&whole->bd_mutex); | |
1317 | bdput(whole); | |
cb8432d6 | 1318 | return ret; |
5b56b6ed CH |
1319 | } |
1320 | whole->bd_part_count++; | |
1321 | mutex_unlock(&whole->bd_mutex); | |
1322 | ||
e71bf0d0 | 1323 | if (!(disk->flags & GENHD_FL_UP) || |
cb8432d6 | 1324 | !bdev_nr_sectors(bdev)) { |
5b56b6ed | 1325 | __blkdev_put(whole, mode, 1); |
63d9932c | 1326 | bdput(whole); |
cb8432d6 | 1327 | return -ENXIO; |
1da177e4 | 1328 | } |
04906b2f | 1329 | set_init_blocksize(bdev); |
1da177e4 | 1330 | } |
03e26279 JK |
1331 | |
1332 | if (bdev->bd_bdi == &noop_backing_dev_info) | |
1333 | bdev->bd_bdi = bdi_get(disk->queue->backing_dev_info); | |
1da177e4 | 1334 | } else { |
a954ea81 | 1335 | if (!bdev_is_partition(bdev)) { |
1196f8b8 | 1336 | if (bdev->bd_disk->fops->open) |
572c4892 | 1337 | ret = bdev->bd_disk->fops->open(bdev, mode); |
1196f8b8 | 1338 | /* the same as first opener case, read comment there */ |
38430f08 | 1339 | if (test_bit(GD_NEED_PART_SCAN, &disk->state) && |
731dc486 JK |
1340 | (!ret || ret == -ENOMEDIUM)) |
1341 | bdev_disk_changed(bdev, ret == -ENOMEDIUM); | |
1196f8b8 | 1342 | if (ret) |
5b56b6ed | 1343 | return ret; |
1da177e4 LT |
1344 | } |
1345 | } | |
1346 | bdev->bd_openers++; | |
1da177e4 | 1347 | return 0; |
1da177e4 LT |
1348 | } |
1349 | ||
22ae8ce8 CH |
1350 | struct block_device *blkdev_get_no_open(dev_t dev) |
1351 | { | |
1352 | struct block_device *bdev; | |
1353 | struct gendisk *disk; | |
1354 | ||
1355 | down_read(&bdev_lookup_sem); | |
1356 | bdev = bdget(dev); | |
1357 | if (!bdev) { | |
1358 | up_read(&bdev_lookup_sem); | |
1359 | blk_request_module(dev); | |
1360 | down_read(&bdev_lookup_sem); | |
1361 | ||
1362 | bdev = bdget(dev); | |
1363 | if (!bdev) | |
1364 | goto unlock; | |
1365 | } | |
1366 | ||
1367 | disk = bdev->bd_disk; | |
1368 | if (!kobject_get_unless_zero(&disk_to_dev(disk)->kobj)) | |
1369 | goto bdput; | |
1370 | if ((disk->flags & (GENHD_FL_UP | GENHD_FL_HIDDEN)) != GENHD_FL_UP) | |
1371 | goto put_disk; | |
1372 | if (!try_module_get(bdev->bd_disk->fops->owner)) | |
1373 | goto put_disk; | |
1374 | up_read(&bdev_lookup_sem); | |
1375 | return bdev; | |
1376 | put_disk: | |
1377 | put_disk(disk); | |
1378 | bdput: | |
1379 | bdput(bdev); | |
1380 | unlock: | |
1381 | up_read(&bdev_lookup_sem); | |
1382 | return NULL; | |
1383 | } | |
1384 | ||
1385 | void blkdev_put_no_open(struct block_device *bdev) | |
1386 | { | |
1387 | module_put(bdev->bd_disk->fops->owner); | |
1388 | put_disk(bdev->bd_disk); | |
1389 | bdput(bdev); | |
1390 | } | |
1391 | ||
d4d77629 | 1392 | /** |
4e7b5671 CH |
1393 | * blkdev_get_by_dev - open a block device by device number |
1394 | * @dev: device number of block device to open | |
d4d77629 TH |
1395 | * @mode: FMODE_* mask |
1396 | * @holder: exclusive holder identifier | |
1397 | * | |
4e7b5671 CH |
1398 | * Open the block device described by device number @dev. If @mode includes |
1399 | * %FMODE_EXCL, the block device is opened with exclusive access. Specifying | |
1400 | * %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may nest for | |
1401 | * the same @holder. | |
d4d77629 | 1402 | * |
4e7b5671 CH |
1403 | * Use this interface ONLY if you really do not have anything better - i.e. when |
1404 | * you are behind a truly sucky interface and all you are given is a device | |
1405 | * number. Everything else should use blkdev_get_by_path(). | |
d4d77629 TH |
1406 | * |
1407 | * CONTEXT: | |
1408 | * Might sleep. | |
1409 | * | |
1410 | * RETURNS: | |
4e7b5671 | 1411 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 | 1412 | */ |
4e7b5671 | 1413 | struct block_device *blkdev_get_by_dev(dev_t dev, fmode_t mode, void *holder) |
1da177e4 | 1414 | { |
5b56b6ed | 1415 | bool unblock_events = true; |
4e7b5671 | 1416 | struct block_device *bdev; |
5b56b6ed | 1417 | struct gendisk *disk; |
5b56b6ed | 1418 | int ret; |
e525fd89 | 1419 | |
7918f0f6 | 1420 | ret = devcgroup_check_permission(DEVCG_DEV_BLOCK, |
4e7b5671 | 1421 | MAJOR(dev), MINOR(dev), |
7918f0f6 CH |
1422 | ((mode & FMODE_READ) ? DEVCG_ACC_READ : 0) | |
1423 | ((mode & FMODE_WRITE) ? DEVCG_ACC_WRITE : 0)); | |
e5c7fb40 | 1424 | if (ret) |
4e7b5671 CH |
1425 | return ERR_PTR(ret); |
1426 | ||
5b56b6ed CH |
1427 | /* |
1428 | * If we lost a race with 'disk' being deleted, try again. See md.c. | |
1429 | */ | |
1430 | retry: | |
22ae8ce8 CH |
1431 | bdev = blkdev_get_no_open(dev); |
1432 | if (!bdev) | |
1433 | return ERR_PTR(-ENXIO); | |
1434 | disk = bdev->bd_disk; | |
e5c7fb40 | 1435 | |
5b56b6ed | 1436 | if (mode & FMODE_EXCL) { |
37c3fc9a | 1437 | ret = bd_prepare_to_claim(bdev, holder); |
5b56b6ed | 1438 | if (ret) |
37c3fc9a | 1439 | goto put_blkdev; |
5b56b6ed CH |
1440 | } |
1441 | ||
1442 | disk_block_events(disk); | |
1443 | ||
1444 | mutex_lock(&bdev->bd_mutex); | |
22ae8ce8 CH |
1445 | ret =__blkdev_get(bdev, mode); |
1446 | if (ret) | |
1447 | goto abort_claiming; | |
1448 | if (mode & FMODE_EXCL) { | |
37c3fc9a | 1449 | bd_finish_claiming(bdev, holder); |
5b56b6ed CH |
1450 | |
1451 | /* | |
1452 | * Block event polling for write claims if requested. Any write | |
1453 | * holder makes the write_holder state stick until all are | |
1454 | * released. This is good enough and tracking individual | |
1455 | * writeable reference is too fragile given the way @mode is | |
1456 | * used in blkdev_get/put(). | |
1457 | */ | |
1458 | if ((mode & FMODE_WRITE) && !bdev->bd_write_holder && | |
1459 | (disk->flags & GENHD_FL_BLOCK_EVENTS_ON_EXCL_WRITE)) { | |
1460 | bdev->bd_write_holder = true; | |
1461 | unblock_events = false; | |
1462 | } | |
1463 | } | |
1464 | mutex_unlock(&bdev->bd_mutex); | |
1465 | ||
1466 | if (unblock_events) | |
1467 | disk_unblock_events(disk); | |
22ae8ce8 | 1468 | return bdev; |
5b56b6ed | 1469 | |
22ae8ce8 CH |
1470 | abort_claiming: |
1471 | if (mode & FMODE_EXCL) | |
37c3fc9a | 1472 | bd_abort_claiming(bdev, holder); |
22ae8ce8 CH |
1473 | mutex_unlock(&bdev->bd_mutex); |
1474 | disk_unblock_events(disk); | |
22ae8ce8 CH |
1475 | put_blkdev: |
1476 | blkdev_put_no_open(bdev); | |
5b56b6ed CH |
1477 | if (ret == -ERESTARTSYS) |
1478 | goto retry; | |
22ae8ce8 | 1479 | return ERR_PTR(ret); |
37be4124 | 1480 | } |
4e7b5671 | 1481 | EXPORT_SYMBOL(blkdev_get_by_dev); |
1da177e4 | 1482 | |
d4d77629 TH |
1483 | /** |
1484 | * blkdev_get_by_path - open a block device by name | |
1485 | * @path: path to the block device to open | |
1486 | * @mode: FMODE_* mask | |
1487 | * @holder: exclusive holder identifier | |
1488 | * | |
4e7b5671 CH |
1489 | * Open the block device described by the device file at @path. If @mode |
1490 | * includes %FMODE_EXCL, the block device is opened with exclusive access. | |
1491 | * Specifying %FMODE_EXCL with a %NULL @holder is invalid. Exclusive opens may | |
1492 | * nest for the same @holder. | |
d4d77629 TH |
1493 | * |
1494 | * CONTEXT: | |
1495 | * Might sleep. | |
1496 | * | |
1497 | * RETURNS: | |
4e7b5671 | 1498 | * Reference to the block_device on success, ERR_PTR(-errno) on failure. |
d4d77629 TH |
1499 | */ |
1500 | struct block_device *blkdev_get_by_path(const char *path, fmode_t mode, | |
1501 | void *holder) | |
1502 | { | |
1503 | struct block_device *bdev; | |
4e7b5671 CH |
1504 | dev_t dev; |
1505 | int error; | |
d4d77629 | 1506 | |
4e7b5671 CH |
1507 | error = lookup_bdev(path, &dev); |
1508 | if (error) | |
1509 | return ERR_PTR(error); | |
d4d77629 | 1510 | |
4e7b5671 CH |
1511 | bdev = blkdev_get_by_dev(dev, mode, holder); |
1512 | if (!IS_ERR(bdev) && (mode & FMODE_WRITE) && bdev_read_only(bdev)) { | |
e51900f7 CE |
1513 | blkdev_put(bdev, mode); |
1514 | return ERR_PTR(-EACCES); | |
1515 | } | |
1516 | ||
d4d77629 TH |
1517 | return bdev; |
1518 | } | |
1519 | EXPORT_SYMBOL(blkdev_get_by_path); | |
1520 | ||
1da177e4 LT |
1521 | static int blkdev_open(struct inode * inode, struct file * filp) |
1522 | { | |
1523 | struct block_device *bdev; | |
1da177e4 LT |
1524 | |
1525 | /* | |
1526 | * Preserve backwards compatibility and allow large file access | |
1527 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
1528 | * binary needs it. We might want to drop this workaround | |
1529 | * during an unstable branch. | |
1530 | */ | |
1531 | filp->f_flags |= O_LARGEFILE; | |
1532 | ||
a304f074 | 1533 | filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; |
c35fc7a5 | 1534 | |
572c4892 AV |
1535 | if (filp->f_flags & O_NDELAY) |
1536 | filp->f_mode |= FMODE_NDELAY; | |
1537 | if (filp->f_flags & O_EXCL) | |
1538 | filp->f_mode |= FMODE_EXCL; | |
1539 | if ((filp->f_flags & O_ACCMODE) == 3) | |
1540 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
1541 | ||
4e7b5671 CH |
1542 | bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); |
1543 | if (IS_ERR(bdev)) | |
1544 | return PTR_ERR(bdev); | |
572c4892 | 1545 | filp->f_mapping = bdev->bd_inode->i_mapping; |
5660e13d | 1546 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); |
4e7b5671 | 1547 | return 0; |
1da177e4 LT |
1548 | } |
1549 | ||
4385bab1 | 1550 | static void __blkdev_put(struct block_device *bdev, fmode_t mode, int for_part) |
2e7b651d | 1551 | { |
2e7b651d | 1552 | struct gendisk *disk = bdev->bd_disk; |
37be4124 | 1553 | struct block_device *victim = NULL; |
2e7b651d | 1554 | |
b849dd84 DA |
1555 | /* |
1556 | * Sync early if it looks like we're the last one. If someone else | |
1557 | * opens the block device between now and the decrement of bd_openers | |
1558 | * then we did a sync that we didn't need to, but that's not the end | |
1559 | * of the world and we want to avoid long (could be several minute) | |
1560 | * syncs while holding the mutex. | |
1561 | */ | |
1562 | if (bdev->bd_openers == 1) | |
1563 | sync_blockdev(bdev); | |
1564 | ||
6796bf54 | 1565 | mutex_lock_nested(&bdev->bd_mutex, for_part); |
37be4124 N |
1566 | if (for_part) |
1567 | bdev->bd_part_count--; | |
1568 | ||
2e7b651d | 1569 | if (!--bdev->bd_openers) { |
6a027eff | 1570 | WARN_ON_ONCE(bdev->bd_holders); |
2e7b651d PZ |
1571 | sync_blockdev(bdev); |
1572 | kill_bdev(bdev); | |
43d1c0eb | 1573 | bdev_write_inode(bdev); |
ec5d4514 | 1574 | if (bdev_is_partition(bdev)) |
a954ea81 | 1575 | victim = bdev_whole(bdev); |
2e7b651d | 1576 | } |
cb8432d6 CH |
1577 | |
1578 | if (!bdev_is_partition(bdev) && disk->fops->release) | |
1579 | disk->fops->release(disk, mode); | |
2e7b651d | 1580 | mutex_unlock(&bdev->bd_mutex); |
63d9932c | 1581 | if (victim) { |
9a1c3542 | 1582 | __blkdev_put(victim, mode, 1); |
63d9932c CH |
1583 | bdput(victim); |
1584 | } | |
2e7b651d PZ |
1585 | } |
1586 | ||
4385bab1 | 1587 | void blkdev_put(struct block_device *bdev, fmode_t mode) |
37be4124 | 1588 | { |
5b56b6ed CH |
1589 | struct gendisk *disk = bdev->bd_disk; |
1590 | ||
85ef06d1 TH |
1591 | mutex_lock(&bdev->bd_mutex); |
1592 | ||
e525fd89 | 1593 | if (mode & FMODE_EXCL) { |
a954ea81 | 1594 | struct block_device *whole = bdev_whole(bdev); |
6a027eff TH |
1595 | bool bdev_free; |
1596 | ||
1597 | /* | |
1598 | * Release a claim on the device. The holder fields | |
1599 | * are protected with bdev_lock. bd_mutex is to | |
1600 | * synchronize disk_holder unlinking. | |
1601 | */ | |
6a027eff TH |
1602 | spin_lock(&bdev_lock); |
1603 | ||
1604 | WARN_ON_ONCE(--bdev->bd_holders < 0); | |
a954ea81 | 1605 | WARN_ON_ONCE(--whole->bd_holders < 0); |
6a027eff | 1606 | |
6a027eff TH |
1607 | if ((bdev_free = !bdev->bd_holders)) |
1608 | bdev->bd_holder = NULL; | |
a954ea81 CH |
1609 | if (!whole->bd_holders) |
1610 | whole->bd_holder = NULL; | |
6a027eff TH |
1611 | |
1612 | spin_unlock(&bdev_lock); | |
1613 | ||
77ea887e TH |
1614 | /* |
1615 | * If this was the last claim, remove holder link and | |
1616 | * unblock evpoll if it was a write holder. | |
1617 | */ | |
85ef06d1 | 1618 | if (bdev_free && bdev->bd_write_holder) { |
5b56b6ed | 1619 | disk_unblock_events(disk); |
85ef06d1 | 1620 | bdev->bd_write_holder = false; |
77ea887e | 1621 | } |
6936217c | 1622 | } |
77ea887e | 1623 | |
85ef06d1 TH |
1624 | /* |
1625 | * Trigger event checking and tell drivers to flush MEDIA_CHANGE | |
1626 | * event. This is to ensure detection of media removal commanded | |
1627 | * from userland - e.g. eject(1). | |
1628 | */ | |
5b56b6ed | 1629 | disk_flush_events(disk, DISK_EVENT_MEDIA_CHANGE); |
85ef06d1 TH |
1630 | mutex_unlock(&bdev->bd_mutex); |
1631 | ||
4385bab1 | 1632 | __blkdev_put(bdev, mode, 0); |
22ae8ce8 | 1633 | blkdev_put_no_open(bdev); |
37be4124 | 1634 | } |
2e7b651d PZ |
1635 | EXPORT_SYMBOL(blkdev_put); |
1636 | ||
1da177e4 LT |
1637 | static int blkdev_close(struct inode * inode, struct file * filp) |
1638 | { | |
4ebb16ca | 1639 | struct block_device *bdev = I_BDEV(bdev_file_inode(filp)); |
4385bab1 AV |
1640 | blkdev_put(bdev, filp->f_mode); |
1641 | return 0; | |
1da177e4 LT |
1642 | } |
1643 | ||
bb93e3a5 | 1644 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) |
1da177e4 | 1645 | { |
4ebb16ca | 1646 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); |
56b26add | 1647 | fmode_t mode = file->f_mode; |
fd4ce1ac CH |
1648 | |
1649 | /* | |
1650 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
1651 | * to updated it before every ioctl. | |
1652 | */ | |
56b26add | 1653 | if (file->f_flags & O_NDELAY) |
fd4ce1ac CH |
1654 | mode |= FMODE_NDELAY; |
1655 | else | |
1656 | mode &= ~FMODE_NDELAY; | |
1657 | ||
56b26add | 1658 | return blkdev_ioctl(bdev, mode, cmd, arg); |
1da177e4 LT |
1659 | } |
1660 | ||
eef99380 CH |
1661 | /* |
1662 | * Write data to the block device. Only intended for the block device itself | |
1663 | * and the raw driver which basically is a fake block device. | |
1664 | * | |
1665 | * Does not take i_mutex for the write and thus is not for general purpose | |
1666 | * use. | |
1667 | */ | |
1456c0a8 | 1668 | ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) |
eef99380 CH |
1669 | { |
1670 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1671 | struct inode *bd_inode = bdev_file_inode(file); |
7ec7b94a | 1672 | loff_t size = i_size_read(bd_inode); |
53362a05 | 1673 | struct blk_plug plug; |
eef99380 | 1674 | ssize_t ret; |
5f380c7f | 1675 | |
7ec7b94a AV |
1676 | if (bdev_read_only(I_BDEV(bd_inode))) |
1677 | return -EPERM; | |
5f380c7f | 1678 | |
bb3247a3 | 1679 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) |
dc617f29 DW |
1680 | return -ETXTBSY; |
1681 | ||
7ec7b94a | 1682 | if (!iov_iter_count(from)) |
5f380c7f AV |
1683 | return 0; |
1684 | ||
7ec7b94a AV |
1685 | if (iocb->ki_pos >= size) |
1686 | return -ENOSPC; | |
1687 | ||
c35fc7a5 CH |
1688 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) |
1689 | return -EOPNOTSUPP; | |
1690 | ||
7ec7b94a | 1691 | iov_iter_truncate(from, size - iocb->ki_pos); |
eef99380 | 1692 | |
53362a05 | 1693 | blk_start_plug(&plug); |
1456c0a8 | 1694 | ret = __generic_file_write_iter(iocb, from); |
e2592217 CH |
1695 | if (ret > 0) |
1696 | ret = generic_write_sync(iocb, ret); | |
53362a05 | 1697 | blk_finish_plug(&plug); |
eef99380 CH |
1698 | return ret; |
1699 | } | |
1456c0a8 | 1700 | EXPORT_SYMBOL_GPL(blkdev_write_iter); |
eef99380 | 1701 | |
b2de525f | 1702 | ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) |
684c9aae LT |
1703 | { |
1704 | struct file *file = iocb->ki_filp; | |
4ebb16ca | 1705 | struct inode *bd_inode = bdev_file_inode(file); |
684c9aae | 1706 | loff_t size = i_size_read(bd_inode); |
a886038b | 1707 | loff_t pos = iocb->ki_pos; |
684c9aae LT |
1708 | |
1709 | if (pos >= size) | |
1710 | return 0; | |
1711 | ||
1712 | size -= pos; | |
a886038b AV |
1713 | iov_iter_truncate(to, size); |
1714 | return generic_file_read_iter(iocb, to); | |
684c9aae | 1715 | } |
b2de525f | 1716 | EXPORT_SYMBOL_GPL(blkdev_read_iter); |
684c9aae | 1717 | |
87d8fe1e TT |
1718 | /* |
1719 | * Try to release a page associated with block device when the system | |
1720 | * is under memory pressure. | |
1721 | */ | |
1722 | static int blkdev_releasepage(struct page *page, gfp_t wait) | |
1723 | { | |
1724 | struct super_block *super = BDEV_I(page->mapping->host)->bdev.bd_super; | |
1725 | ||
1726 | if (super && super->s_op->bdev_try_to_free_page) | |
1727 | return super->s_op->bdev_try_to_free_page(super, page, wait); | |
1728 | ||
1729 | return try_to_free_buffers(page); | |
1730 | } | |
1731 | ||
7f6d5b52 RZ |
1732 | static int blkdev_writepages(struct address_space *mapping, |
1733 | struct writeback_control *wbc) | |
1734 | { | |
7f6d5b52 RZ |
1735 | return generic_writepages(mapping, wbc); |
1736 | } | |
1737 | ||
4c54ac62 | 1738 | static const struct address_space_operations def_blk_aops = { |
1da177e4 | 1739 | .readpage = blkdev_readpage, |
d4388340 | 1740 | .readahead = blkdev_readahead, |
1da177e4 | 1741 | .writepage = blkdev_writepage, |
6272b5a5 NP |
1742 | .write_begin = blkdev_write_begin, |
1743 | .write_end = blkdev_write_end, | |
7f6d5b52 | 1744 | .writepages = blkdev_writepages, |
87d8fe1e | 1745 | .releasepage = blkdev_releasepage, |
1da177e4 | 1746 | .direct_IO = blkdev_direct_IO, |
88dbcbb3 | 1747 | .migratepage = buffer_migrate_page_norefs, |
b4597226 | 1748 | .is_dirty_writeback = buffer_check_dirty_writeback, |
1da177e4 LT |
1749 | }; |
1750 | ||
25f4c414 DW |
1751 | #define BLKDEV_FALLOC_FL_SUPPORTED \ |
1752 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
1753 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
1754 | ||
1755 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
1756 | loff_t len) | |
1757 | { | |
1758 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
25f4c414 DW |
1759 | loff_t end = start + len - 1; |
1760 | loff_t isize; | |
1761 | int error; | |
1762 | ||
1763 | /* Fail if we don't recognize the flags. */ | |
1764 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
1765 | return -EOPNOTSUPP; | |
1766 | ||
1767 | /* Don't go off the end of the device. */ | |
1768 | isize = i_size_read(bdev->bd_inode); | |
1769 | if (start >= isize) | |
1770 | return -EINVAL; | |
1771 | if (end >= isize) { | |
1772 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
1773 | len = isize - start; | |
1774 | end = start + len - 1; | |
1775 | } else | |
1776 | return -EINVAL; | |
1777 | } | |
1778 | ||
1779 | /* | |
1780 | * Don't allow IO that isn't aligned to logical block size. | |
1781 | */ | |
1782 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
1783 | return -EINVAL; | |
1784 | ||
1785 | /* Invalidate the page cache, including dirty pages. */ | |
384d87ef JK |
1786 | error = truncate_bdev_range(bdev, file->f_mode, start, end); |
1787 | if (error) | |
1788 | return error; | |
25f4c414 DW |
1789 | |
1790 | switch (mode) { | |
1791 | case FALLOC_FL_ZERO_RANGE: | |
1792 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
1793 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, | |
ee472d83 | 1794 | GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); |
25f4c414 DW |
1795 | break; |
1796 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
34045129 CH |
1797 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, |
1798 | GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); | |
25f4c414 DW |
1799 | break; |
1800 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
25f4c414 DW |
1801 | error = blkdev_issue_discard(bdev, start >> 9, len >> 9, |
1802 | GFP_KERNEL, 0); | |
1803 | break; | |
1804 | default: | |
1805 | return -EOPNOTSUPP; | |
1806 | } | |
1807 | if (error) | |
1808 | return error; | |
1809 | ||
1810 | /* | |
767630c6 JK |
1811 | * Invalidate the page cache again; if someone wandered in and dirtied |
1812 | * a page, we just discard it - userspace has no way of knowing whether | |
1813 | * the write happened before or after discard completing... | |
25f4c414 | 1814 | */ |
767630c6 | 1815 | return truncate_bdev_range(bdev, file->f_mode, start, end); |
25f4c414 DW |
1816 | } |
1817 | ||
4b6f5d20 | 1818 | const struct file_operations def_blk_fops = { |
1da177e4 LT |
1819 | .open = blkdev_open, |
1820 | .release = blkdev_close, | |
1821 | .llseek = block_llseek, | |
a886038b | 1822 | .read_iter = blkdev_read_iter, |
1456c0a8 | 1823 | .write_iter = blkdev_write_iter, |
eae83ce1 | 1824 | .iopoll = blkdev_iopoll, |
acc93d30 | 1825 | .mmap = generic_file_mmap, |
b1dd3b28 | 1826 | .fsync = blkdev_fsync, |
bb93e3a5 | 1827 | .unlocked_ioctl = block_ioctl, |
1da177e4 LT |
1828 | #ifdef CONFIG_COMPAT |
1829 | .compat_ioctl = compat_blkdev_ioctl, | |
1830 | #endif | |
1e8b3332 | 1831 | .splice_read = generic_file_splice_read, |
8d020765 | 1832 | .splice_write = iter_file_splice_write, |
25f4c414 | 1833 | .fallocate = blkdev_fallocate, |
1da177e4 LT |
1834 | }; |
1835 | ||
1da177e4 LT |
1836 | /** |
1837 | * lookup_bdev - lookup a struct block_device by name | |
94e2959e | 1838 | * @pathname: special file representing the block device |
875b2376 | 1839 | * @dev: return value of the block device's dev_t |
1da177e4 | 1840 | * |
57d1b536 | 1841 | * Get a reference to the blockdevice at @pathname in the current |
1da177e4 LT |
1842 | * namespace if possible and return it. Return ERR_PTR(error) |
1843 | * otherwise. | |
1844 | */ | |
4e7b5671 | 1845 | int lookup_bdev(const char *pathname, dev_t *dev) |
1da177e4 | 1846 | { |
1da177e4 | 1847 | struct inode *inode; |
421748ec | 1848 | struct path path; |
1da177e4 LT |
1849 | int error; |
1850 | ||
421748ec | 1851 | if (!pathname || !*pathname) |
4e7b5671 | 1852 | return -EINVAL; |
1da177e4 | 1853 | |
421748ec | 1854 | error = kern_path(pathname, LOOKUP_FOLLOW, &path); |
1da177e4 | 1855 | if (error) |
4e7b5671 | 1856 | return error; |
1da177e4 | 1857 | |
bb668734 | 1858 | inode = d_backing_inode(path.dentry); |
1da177e4 LT |
1859 | error = -ENOTBLK; |
1860 | if (!S_ISBLK(inode->i_mode)) | |
4e7b5671 | 1861 | goto out_path_put; |
1da177e4 | 1862 | error = -EACCES; |
a2982cc9 | 1863 | if (!may_open_dev(&path)) |
4e7b5671 CH |
1864 | goto out_path_put; |
1865 | ||
1866 | *dev = inode->i_rdev; | |
1867 | error = 0; | |
1868 | out_path_put: | |
421748ec | 1869 | path_put(&path); |
4e7b5671 | 1870 | return error; |
1da177e4 | 1871 | } |
d5686b44 | 1872 | EXPORT_SYMBOL(lookup_bdev); |
1da177e4 | 1873 | |
93b270f7 | 1874 | int __invalidate_device(struct block_device *bdev, bool kill_dirty) |
b71e8a4c DH |
1875 | { |
1876 | struct super_block *sb = get_super(bdev); | |
1877 | int res = 0; | |
1878 | ||
1879 | if (sb) { | |
1880 | /* | |
1881 | * no need to lock the super, get_super holds the | |
1882 | * read mutex so the filesystem cannot go away | |
1883 | * under us (->put_super runs with the write lock | |
1884 | * hold). | |
1885 | */ | |
1886 | shrink_dcache_sb(sb); | |
93b270f7 | 1887 | res = invalidate_inodes(sb, kill_dirty); |
b71e8a4c DH |
1888 | drop_super(sb); |
1889 | } | |
f98393a6 | 1890 | invalidate_bdev(bdev); |
b71e8a4c DH |
1891 | return res; |
1892 | } | |
1893 | EXPORT_SYMBOL(__invalidate_device); | |
5c0d6b60 JK |
1894 | |
1895 | void iterate_bdevs(void (*func)(struct block_device *, void *), void *arg) | |
1896 | { | |
1897 | struct inode *inode, *old_inode = NULL; | |
1898 | ||
74278da9 | 1899 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1900 | list_for_each_entry(inode, &blockdev_superblock->s_inodes, i_sb_list) { |
1901 | struct address_space *mapping = inode->i_mapping; | |
af309226 | 1902 | struct block_device *bdev; |
5c0d6b60 JK |
1903 | |
1904 | spin_lock(&inode->i_lock); | |
1905 | if (inode->i_state & (I_FREEING|I_WILL_FREE|I_NEW) || | |
1906 | mapping->nrpages == 0) { | |
1907 | spin_unlock(&inode->i_lock); | |
1908 | continue; | |
1909 | } | |
1910 | __iget(inode); | |
1911 | spin_unlock(&inode->i_lock); | |
74278da9 | 1912 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1913 | /* |
1914 | * We hold a reference to 'inode' so it couldn't have been | |
1915 | * removed from s_inodes list while we dropped the | |
74278da9 | 1916 | * s_inode_list_lock We cannot iput the inode now as we can |
5c0d6b60 | 1917 | * be holding the last reference and we cannot iput it under |
74278da9 | 1918 | * s_inode_list_lock. So we keep the reference and iput it |
5c0d6b60 JK |
1919 | * later. |
1920 | */ | |
1921 | iput(old_inode); | |
1922 | old_inode = inode; | |
af309226 | 1923 | bdev = I_BDEV(inode); |
5c0d6b60 | 1924 | |
af309226 RV |
1925 | mutex_lock(&bdev->bd_mutex); |
1926 | if (bdev->bd_openers) | |
1927 | func(bdev, arg); | |
1928 | mutex_unlock(&bdev->bd_mutex); | |
5c0d6b60 | 1929 | |
74278da9 | 1930 | spin_lock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 | 1931 | } |
74278da9 | 1932 | spin_unlock(&blockdev_superblock->s_inode_list_lock); |
5c0d6b60 JK |
1933 | iput(old_inode); |
1934 | } |