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cd82cca7 CH |
1 | // SPDX-License-Identifier: GPL-2.0-only |
2 | /* | |
3 | * Copyright (C) 1991, 1992 Linus Torvalds | |
4 | * Copyright (C) 2001 Andrea Arcangeli <andrea@suse.de> SuSE | |
5 | * Copyright (C) 2016 - 2020 Christoph Hellwig | |
6 | */ | |
7 | #include <linux/init.h> | |
8 | #include <linux/mm.h> | |
9 | #include <linux/blkdev.h> | |
10 | #include <linux/buffer_head.h> | |
11 | #include <linux/mpage.h> | |
12 | #include <linux/uio.h> | |
13 | #include <linux/namei.h> | |
14 | #include <linux/task_io_accounting_ops.h> | |
15 | #include <linux/falloc.h> | |
16 | #include <linux/suspend.h> | |
17 | #include "blk.h" | |
18 | ||
19 | static struct inode *bdev_file_inode(struct file *file) | |
20 | { | |
21 | return file->f_mapping->host; | |
22 | } | |
23 | ||
24 | static int blkdev_get_block(struct inode *inode, sector_t iblock, | |
25 | struct buffer_head *bh, int create) | |
26 | { | |
27 | bh->b_bdev = I_BDEV(inode); | |
28 | bh->b_blocknr = iblock; | |
29 | set_buffer_mapped(bh); | |
30 | return 0; | |
31 | } | |
32 | ||
33 | static unsigned int dio_bio_write_op(struct kiocb *iocb) | |
34 | { | |
35 | unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; | |
36 | ||
37 | /* avoid the need for a I/O completion work item */ | |
38 | if (iocb->ki_flags & IOCB_DSYNC) | |
39 | op |= REQ_FUA; | |
40 | return op; | |
41 | } | |
42 | ||
43 | #define DIO_INLINE_BIO_VECS 4 | |
44 | ||
45 | static void blkdev_bio_end_io_simple(struct bio *bio) | |
46 | { | |
47 | struct task_struct *waiter = bio->bi_private; | |
48 | ||
49 | WRITE_ONCE(bio->bi_private, NULL); | |
50 | blk_wake_io_task(waiter); | |
51 | } | |
52 | ||
53 | static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, | |
54 | struct iov_iter *iter, unsigned int nr_pages) | |
55 | { | |
56 | struct file *file = iocb->ki_filp; | |
57 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
58 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; | |
59 | loff_t pos = iocb->ki_pos; | |
60 | bool should_dirty = false; | |
61 | struct bio bio; | |
62 | ssize_t ret; | |
63 | blk_qc_t qc; | |
64 | ||
65 | if ((pos | iov_iter_alignment(iter)) & | |
66 | (bdev_logical_block_size(bdev) - 1)) | |
67 | return -EINVAL; | |
68 | ||
69 | if (nr_pages <= DIO_INLINE_BIO_VECS) | |
70 | vecs = inline_vecs; | |
71 | else { | |
72 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), | |
73 | GFP_KERNEL); | |
74 | if (!vecs) | |
75 | return -ENOMEM; | |
76 | } | |
77 | ||
78 | bio_init(&bio, vecs, nr_pages); | |
79 | bio_set_dev(&bio, bdev); | |
80 | bio.bi_iter.bi_sector = pos >> 9; | |
81 | bio.bi_write_hint = iocb->ki_hint; | |
82 | bio.bi_private = current; | |
83 | bio.bi_end_io = blkdev_bio_end_io_simple; | |
84 | bio.bi_ioprio = iocb->ki_ioprio; | |
85 | ||
86 | ret = bio_iov_iter_get_pages(&bio, iter); | |
87 | if (unlikely(ret)) | |
88 | goto out; | |
89 | ret = bio.bi_iter.bi_size; | |
90 | ||
91 | if (iov_iter_rw(iter) == READ) { | |
92 | bio.bi_opf = REQ_OP_READ; | |
93 | if (iter_is_iovec(iter)) | |
94 | should_dirty = true; | |
95 | } else { | |
96 | bio.bi_opf = dio_bio_write_op(iocb); | |
97 | task_io_account_write(ret); | |
98 | } | |
99 | if (iocb->ki_flags & IOCB_NOWAIT) | |
100 | bio.bi_opf |= REQ_NOWAIT; | |
101 | if (iocb->ki_flags & IOCB_HIPRI) | |
102 | bio_set_polled(&bio, iocb); | |
103 | ||
104 | qc = submit_bio(&bio); | |
105 | for (;;) { | |
106 | set_current_state(TASK_UNINTERRUPTIBLE); | |
107 | if (!READ_ONCE(bio.bi_private)) | |
108 | break; | |
109 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
110 | !blk_poll(bdev_get_queue(bdev), qc, true)) | |
111 | blk_io_schedule(); | |
112 | } | |
113 | __set_current_state(TASK_RUNNING); | |
114 | ||
115 | bio_release_pages(&bio, should_dirty); | |
116 | if (unlikely(bio.bi_status)) | |
117 | ret = blk_status_to_errno(bio.bi_status); | |
118 | ||
119 | out: | |
120 | if (vecs != inline_vecs) | |
121 | kfree(vecs); | |
122 | ||
123 | bio_uninit(&bio); | |
124 | ||
125 | return ret; | |
126 | } | |
127 | ||
128 | struct blkdev_dio { | |
129 | union { | |
130 | struct kiocb *iocb; | |
131 | struct task_struct *waiter; | |
132 | }; | |
133 | size_t size; | |
134 | atomic_t ref; | |
135 | bool multi_bio : 1; | |
136 | bool should_dirty : 1; | |
137 | bool is_sync : 1; | |
138 | struct bio bio; | |
139 | }; | |
140 | ||
141 | static struct bio_set blkdev_dio_pool; | |
142 | ||
143 | static int blkdev_iopoll(struct kiocb *kiocb, bool wait) | |
144 | { | |
145 | struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host); | |
146 | struct request_queue *q = bdev_get_queue(bdev); | |
147 | ||
148 | return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait); | |
149 | } | |
150 | ||
151 | static void blkdev_bio_end_io(struct bio *bio) | |
152 | { | |
153 | struct blkdev_dio *dio = bio->bi_private; | |
154 | bool should_dirty = dio->should_dirty; | |
155 | ||
156 | if (bio->bi_status && !dio->bio.bi_status) | |
157 | dio->bio.bi_status = bio->bi_status; | |
158 | ||
159 | if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) { | |
160 | if (!dio->is_sync) { | |
161 | struct kiocb *iocb = dio->iocb; | |
162 | ssize_t ret; | |
163 | ||
164 | if (likely(!dio->bio.bi_status)) { | |
165 | ret = dio->size; | |
166 | iocb->ki_pos += ret; | |
167 | } else { | |
168 | ret = blk_status_to_errno(dio->bio.bi_status); | |
169 | } | |
170 | ||
171 | dio->iocb->ki_complete(iocb, ret, 0); | |
172 | if (dio->multi_bio) | |
173 | bio_put(&dio->bio); | |
174 | } else { | |
175 | struct task_struct *waiter = dio->waiter; | |
176 | ||
177 | WRITE_ONCE(dio->waiter, NULL); | |
178 | blk_wake_io_task(waiter); | |
179 | } | |
180 | } | |
181 | ||
182 | if (should_dirty) { | |
183 | bio_check_pages_dirty(bio); | |
184 | } else { | |
185 | bio_release_pages(bio, false); | |
186 | bio_put(bio); | |
187 | } | |
188 | } | |
189 | ||
190 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, | |
191 | unsigned int nr_pages) | |
192 | { | |
193 | struct file *file = iocb->ki_filp; | |
194 | struct inode *inode = bdev_file_inode(file); | |
195 | struct block_device *bdev = I_BDEV(inode); | |
196 | struct blk_plug plug; | |
197 | struct blkdev_dio *dio; | |
198 | struct bio *bio; | |
199 | bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0; | |
200 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; | |
201 | loff_t pos = iocb->ki_pos; | |
202 | blk_qc_t qc = BLK_QC_T_NONE; | |
203 | int ret = 0; | |
204 | ||
205 | if ((pos | iov_iter_alignment(iter)) & | |
206 | (bdev_logical_block_size(bdev) - 1)) | |
207 | return -EINVAL; | |
208 | ||
209 | bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool); | |
210 | ||
211 | dio = container_of(bio, struct blkdev_dio, bio); | |
212 | dio->is_sync = is_sync = is_sync_kiocb(iocb); | |
213 | if (dio->is_sync) { | |
214 | dio->waiter = current; | |
215 | bio_get(bio); | |
216 | } else { | |
217 | dio->iocb = iocb; | |
218 | } | |
219 | ||
220 | dio->size = 0; | |
221 | dio->multi_bio = false; | |
222 | dio->should_dirty = is_read && iter_is_iovec(iter); | |
223 | ||
224 | /* | |
225 | * Don't plug for HIPRI/polled IO, as those should go straight | |
226 | * to issue | |
227 | */ | |
228 | if (!is_poll) | |
229 | blk_start_plug(&plug); | |
230 | ||
231 | for (;;) { | |
232 | bio_set_dev(bio, bdev); | |
233 | bio->bi_iter.bi_sector = pos >> 9; | |
234 | bio->bi_write_hint = iocb->ki_hint; | |
235 | bio->bi_private = dio; | |
236 | bio->bi_end_io = blkdev_bio_end_io; | |
237 | bio->bi_ioprio = iocb->ki_ioprio; | |
238 | ||
239 | ret = bio_iov_iter_get_pages(bio, iter); | |
240 | if (unlikely(ret)) { | |
241 | bio->bi_status = BLK_STS_IOERR; | |
242 | bio_endio(bio); | |
243 | break; | |
244 | } | |
245 | ||
246 | if (is_read) { | |
247 | bio->bi_opf = REQ_OP_READ; | |
248 | if (dio->should_dirty) | |
249 | bio_set_pages_dirty(bio); | |
250 | } else { | |
251 | bio->bi_opf = dio_bio_write_op(iocb); | |
252 | task_io_account_write(bio->bi_iter.bi_size); | |
253 | } | |
254 | if (iocb->ki_flags & IOCB_NOWAIT) | |
255 | bio->bi_opf |= REQ_NOWAIT; | |
256 | ||
257 | dio->size += bio->bi_iter.bi_size; | |
258 | pos += bio->bi_iter.bi_size; | |
259 | ||
260 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); | |
261 | if (!nr_pages) { | |
262 | bool polled = false; | |
263 | ||
264 | if (iocb->ki_flags & IOCB_HIPRI) { | |
265 | bio_set_polled(bio, iocb); | |
266 | polled = true; | |
267 | } | |
268 | ||
269 | qc = submit_bio(bio); | |
270 | ||
271 | if (polled) | |
272 | WRITE_ONCE(iocb->ki_cookie, qc); | |
273 | break; | |
274 | } | |
275 | ||
276 | if (!dio->multi_bio) { | |
277 | /* | |
278 | * AIO needs an extra reference to ensure the dio | |
279 | * structure which is embedded into the first bio | |
280 | * stays around. | |
281 | */ | |
282 | if (!is_sync) | |
283 | bio_get(bio); | |
284 | dio->multi_bio = true; | |
285 | atomic_set(&dio->ref, 2); | |
286 | } else { | |
287 | atomic_inc(&dio->ref); | |
288 | } | |
289 | ||
290 | submit_bio(bio); | |
291 | bio = bio_alloc(GFP_KERNEL, nr_pages); | |
292 | } | |
293 | ||
294 | if (!is_poll) | |
295 | blk_finish_plug(&plug); | |
296 | ||
297 | if (!is_sync) | |
298 | return -EIOCBQUEUED; | |
299 | ||
300 | for (;;) { | |
301 | set_current_state(TASK_UNINTERRUPTIBLE); | |
302 | if (!READ_ONCE(dio->waiter)) | |
303 | break; | |
304 | ||
305 | if (!(iocb->ki_flags & IOCB_HIPRI) || | |
306 | !blk_poll(bdev_get_queue(bdev), qc, true)) | |
307 | blk_io_schedule(); | |
308 | } | |
309 | __set_current_state(TASK_RUNNING); | |
310 | ||
311 | if (!ret) | |
312 | ret = blk_status_to_errno(dio->bio.bi_status); | |
313 | if (likely(!ret)) | |
314 | ret = dio->size; | |
315 | ||
316 | bio_put(&dio->bio); | |
317 | return ret; | |
318 | } | |
319 | ||
320 | static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) | |
321 | { | |
322 | unsigned int nr_pages; | |
323 | ||
324 | if (!iov_iter_count(iter)) | |
325 | return 0; | |
326 | ||
327 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); | |
328 | if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS) | |
329 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); | |
330 | ||
331 | return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); | |
332 | } | |
333 | ||
334 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) | |
335 | { | |
336 | return block_write_full_page(page, blkdev_get_block, wbc); | |
337 | } | |
338 | ||
339 | static int blkdev_readpage(struct file * file, struct page * page) | |
340 | { | |
341 | return block_read_full_page(page, blkdev_get_block); | |
342 | } | |
343 | ||
344 | static void blkdev_readahead(struct readahead_control *rac) | |
345 | { | |
346 | mpage_readahead(rac, blkdev_get_block); | |
347 | } | |
348 | ||
349 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
350 | loff_t pos, unsigned len, unsigned flags, struct page **pagep, | |
351 | void **fsdata) | |
352 | { | |
353 | return block_write_begin(mapping, pos, len, flags, pagep, | |
354 | blkdev_get_block); | |
355 | } | |
356 | ||
357 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
358 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
359 | void *fsdata) | |
360 | { | |
361 | int ret; | |
362 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
363 | ||
364 | unlock_page(page); | |
365 | put_page(page); | |
366 | ||
367 | return ret; | |
368 | } | |
369 | ||
370 | static int blkdev_writepages(struct address_space *mapping, | |
371 | struct writeback_control *wbc) | |
372 | { | |
373 | return generic_writepages(mapping, wbc); | |
374 | } | |
375 | ||
376 | const struct address_space_operations def_blk_aops = { | |
377 | .set_page_dirty = __set_page_dirty_buffers, | |
378 | .readpage = blkdev_readpage, | |
379 | .readahead = blkdev_readahead, | |
380 | .writepage = blkdev_writepage, | |
381 | .write_begin = blkdev_write_begin, | |
382 | .write_end = blkdev_write_end, | |
383 | .writepages = blkdev_writepages, | |
384 | .direct_IO = blkdev_direct_IO, | |
385 | .migratepage = buffer_migrate_page_norefs, | |
386 | .is_dirty_writeback = buffer_check_dirty_writeback, | |
387 | }; | |
388 | ||
389 | /* | |
390 | * for a block special file file_inode(file)->i_size is zero | |
391 | * so we compute the size by hand (just as in block_read/write above) | |
392 | */ | |
393 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
394 | { | |
395 | struct inode *bd_inode = bdev_file_inode(file); | |
396 | loff_t retval; | |
397 | ||
398 | inode_lock(bd_inode); | |
399 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
400 | inode_unlock(bd_inode); | |
401 | return retval; | |
402 | } | |
403 | ||
404 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
405 | int datasync) | |
406 | { | |
407 | struct inode *bd_inode = bdev_file_inode(filp); | |
408 | struct block_device *bdev = I_BDEV(bd_inode); | |
409 | int error; | |
410 | ||
411 | error = file_write_and_wait_range(filp, start, end); | |
412 | if (error) | |
413 | return error; | |
414 | ||
415 | /* | |
416 | * There is no need to serialise calls to blkdev_issue_flush with | |
417 | * i_mutex and doing so causes performance issues with concurrent | |
418 | * O_SYNC writers to a block device. | |
419 | */ | |
420 | error = blkdev_issue_flush(bdev); | |
421 | if (error == -EOPNOTSUPP) | |
422 | error = 0; | |
423 | ||
424 | return error; | |
425 | } | |
426 | ||
427 | static int blkdev_open(struct inode *inode, struct file *filp) | |
428 | { | |
429 | struct block_device *bdev; | |
430 | ||
431 | /* | |
432 | * Preserve backwards compatibility and allow large file access | |
433 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
434 | * binary needs it. We might want to drop this workaround | |
435 | * during an unstable branch. | |
436 | */ | |
437 | filp->f_flags |= O_LARGEFILE; | |
438 | filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; | |
439 | ||
440 | if (filp->f_flags & O_NDELAY) | |
441 | filp->f_mode |= FMODE_NDELAY; | |
442 | if (filp->f_flags & O_EXCL) | |
443 | filp->f_mode |= FMODE_EXCL; | |
444 | if ((filp->f_flags & O_ACCMODE) == 3) | |
445 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
446 | ||
447 | bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); | |
448 | if (IS_ERR(bdev)) | |
449 | return PTR_ERR(bdev); | |
450 | filp->f_mapping = bdev->bd_inode->i_mapping; | |
451 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); | |
452 | return 0; | |
453 | } | |
454 | ||
455 | static int blkdev_close(struct inode *inode, struct file *filp) | |
456 | { | |
457 | struct block_device *bdev = I_BDEV(bdev_file_inode(filp)); | |
458 | ||
459 | blkdev_put(bdev, filp->f_mode); | |
460 | return 0; | |
461 | } | |
462 | ||
463 | static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg) | |
464 | { | |
465 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
466 | fmode_t mode = file->f_mode; | |
467 | ||
468 | /* | |
469 | * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have | |
470 | * to updated it before every ioctl. | |
471 | */ | |
472 | if (file->f_flags & O_NDELAY) | |
473 | mode |= FMODE_NDELAY; | |
474 | else | |
475 | mode &= ~FMODE_NDELAY; | |
476 | ||
477 | return blkdev_ioctl(bdev, mode, cmd, arg); | |
478 | } | |
479 | ||
480 | /* | |
481 | * Write data to the block device. Only intended for the block device itself | |
482 | * and the raw driver which basically is a fake block device. | |
483 | * | |
484 | * Does not take i_mutex for the write and thus is not for general purpose | |
485 | * use. | |
486 | */ | |
487 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
488 | { | |
489 | struct file *file = iocb->ki_filp; | |
490 | struct inode *bd_inode = bdev_file_inode(file); | |
491 | loff_t size = i_size_read(bd_inode); | |
492 | struct blk_plug plug; | |
493 | size_t shorted = 0; | |
494 | ssize_t ret; | |
495 | ||
496 | if (bdev_read_only(I_BDEV(bd_inode))) | |
497 | return -EPERM; | |
498 | ||
499 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
500 | return -ETXTBSY; | |
501 | ||
502 | if (!iov_iter_count(from)) | |
503 | return 0; | |
504 | ||
505 | if (iocb->ki_pos >= size) | |
506 | return -ENOSPC; | |
507 | ||
508 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
509 | return -EOPNOTSUPP; | |
510 | ||
511 | size -= iocb->ki_pos; | |
512 | if (iov_iter_count(from) > size) { | |
513 | shorted = iov_iter_count(from) - size; | |
514 | iov_iter_truncate(from, size); | |
515 | } | |
516 | ||
517 | blk_start_plug(&plug); | |
518 | ret = __generic_file_write_iter(iocb, from); | |
519 | if (ret > 0) | |
520 | ret = generic_write_sync(iocb, ret); | |
521 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
522 | blk_finish_plug(&plug); | |
523 | return ret; | |
524 | } | |
525 | ||
526 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
527 | { | |
528 | struct file *file = iocb->ki_filp; | |
529 | struct inode *bd_inode = bdev_file_inode(file); | |
530 | loff_t size = i_size_read(bd_inode); | |
531 | loff_t pos = iocb->ki_pos; | |
532 | size_t shorted = 0; | |
533 | ssize_t ret; | |
534 | ||
535 | if (pos >= size) | |
536 | return 0; | |
537 | ||
538 | size -= pos; | |
539 | if (iov_iter_count(to) > size) { | |
540 | shorted = iov_iter_count(to) - size; | |
541 | iov_iter_truncate(to, size); | |
542 | } | |
543 | ||
544 | ret = generic_file_read_iter(iocb, to); | |
545 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
546 | return ret; | |
547 | } | |
548 | ||
549 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
550 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
551 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
552 | ||
553 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
554 | loff_t len) | |
555 | { | |
556 | struct block_device *bdev = I_BDEV(bdev_file_inode(file)); | |
557 | loff_t end = start + len - 1; | |
558 | loff_t isize; | |
559 | int error; | |
560 | ||
561 | /* Fail if we don't recognize the flags. */ | |
562 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
563 | return -EOPNOTSUPP; | |
564 | ||
565 | /* Don't go off the end of the device. */ | |
566 | isize = i_size_read(bdev->bd_inode); | |
567 | if (start >= isize) | |
568 | return -EINVAL; | |
569 | if (end >= isize) { | |
570 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
571 | len = isize - start; | |
572 | end = start + len - 1; | |
573 | } else | |
574 | return -EINVAL; | |
575 | } | |
576 | ||
577 | /* | |
578 | * Don't allow IO that isn't aligned to logical block size. | |
579 | */ | |
580 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
581 | return -EINVAL; | |
582 | ||
583 | /* Invalidate the page cache, including dirty pages. */ | |
584 | error = truncate_bdev_range(bdev, file->f_mode, start, end); | |
585 | if (error) | |
586 | return error; | |
587 | ||
588 | switch (mode) { | |
589 | case FALLOC_FL_ZERO_RANGE: | |
590 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
591 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, | |
592 | GFP_KERNEL, BLKDEV_ZERO_NOUNMAP); | |
593 | break; | |
594 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
595 | error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9, | |
596 | GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK); | |
597 | break; | |
598 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
599 | error = blkdev_issue_discard(bdev, start >> 9, len >> 9, | |
600 | GFP_KERNEL, 0); | |
601 | break; | |
602 | default: | |
603 | return -EOPNOTSUPP; | |
604 | } | |
605 | if (error) | |
606 | return error; | |
607 | ||
608 | /* | |
609 | * Invalidate the page cache again; if someone wandered in and dirtied | |
610 | * a page, we just discard it - userspace has no way of knowing whether | |
611 | * the write happened before or after discard completing... | |
612 | */ | |
613 | return truncate_bdev_range(bdev, file->f_mode, start, end); | |
614 | } | |
615 | ||
616 | const struct file_operations def_blk_fops = { | |
617 | .open = blkdev_open, | |
618 | .release = blkdev_close, | |
619 | .llseek = blkdev_llseek, | |
620 | .read_iter = blkdev_read_iter, | |
621 | .write_iter = blkdev_write_iter, | |
622 | .iopoll = blkdev_iopoll, | |
623 | .mmap = generic_file_mmap, | |
624 | .fsync = blkdev_fsync, | |
625 | .unlocked_ioctl = block_ioctl, | |
626 | #ifdef CONFIG_COMPAT | |
627 | .compat_ioctl = compat_blkdev_ioctl, | |
628 | #endif | |
629 | .splice_read = generic_file_splice_read, | |
630 | .splice_write = iter_file_splice_write, | |
631 | .fallocate = blkdev_fallocate, | |
632 | }; | |
633 | ||
634 | static __init int blkdev_init(void) | |
635 | { | |
636 | return bioset_init(&blkdev_dio_pool, 4, | |
637 | offsetof(struct blkdev_dio, bio), | |
638 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
639 | } | |
640 | module_init(blkdev_init); |