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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> | |
f278eb3d | 17 | #include <linux/fs.h> |
8581fd40 | 18 | #include <linux/module.h> |
cd82cca7 CH |
19 | #include "blk.h" |
20 | ||
fac7c6d5 | 21 | static inline struct inode *bdev_file_inode(struct file *file) |
cd82cca7 CH |
22 | { |
23 | return file->f_mapping->host; | |
24 | } | |
25 | ||
26 | static int blkdev_get_block(struct inode *inode, sector_t iblock, | |
27 | struct buffer_head *bh, int create) | |
28 | { | |
29 | bh->b_bdev = I_BDEV(inode); | |
30 | bh->b_blocknr = iblock; | |
31 | set_buffer_mapped(bh); | |
32 | return 0; | |
33 | } | |
34 | ||
35 | static unsigned int dio_bio_write_op(struct kiocb *iocb) | |
36 | { | |
37 | unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; | |
38 | ||
39 | /* avoid the need for a I/O completion work item */ | |
40 | if (iocb->ki_flags & IOCB_DSYNC) | |
41 | op |= REQ_FUA; | |
42 | return op; | |
43 | } | |
44 | ||
45 | #define DIO_INLINE_BIO_VECS 4 | |
46 | ||
cd82cca7 CH |
47 | static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, |
48 | struct iov_iter *iter, unsigned int nr_pages) | |
49 | { | |
fac7c6d5 | 50 | struct block_device *bdev = iocb->ki_filp->private_data; |
cd82cca7 CH |
51 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; |
52 | loff_t pos = iocb->ki_pos; | |
53 | bool should_dirty = false; | |
54 | struct bio bio; | |
55 | ssize_t ret; | |
cd82cca7 CH |
56 | |
57 | if ((pos | iov_iter_alignment(iter)) & | |
58 | (bdev_logical_block_size(bdev) - 1)) | |
59 | return -EINVAL; | |
60 | ||
61 | if (nr_pages <= DIO_INLINE_BIO_VECS) | |
62 | vecs = inline_vecs; | |
63 | else { | |
64 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), | |
65 | GFP_KERNEL); | |
66 | if (!vecs) | |
67 | return -ENOMEM; | |
68 | } | |
69 | ||
49add496 CH |
70 | if (iov_iter_rw(iter) == READ) { |
71 | bio_init(&bio, bdev, vecs, nr_pages, REQ_OP_READ); | |
72 | if (iter_is_iovec(iter)) | |
73 | should_dirty = true; | |
74 | } else { | |
75 | bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); | |
76 | } | |
6549a874 | 77 | bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
78 | bio.bi_ioprio = iocb->ki_ioprio; |
79 | ||
80 | ret = bio_iov_iter_get_pages(&bio, iter); | |
81 | if (unlikely(ret)) | |
82 | goto out; | |
83 | ret = bio.bi_iter.bi_size; | |
84 | ||
49add496 | 85 | if (iov_iter_rw(iter) == WRITE) |
cd82cca7 | 86 | task_io_account_write(ret); |
49add496 | 87 | |
cd82cca7 CH |
88 | if (iocb->ki_flags & IOCB_NOWAIT) |
89 | bio.bi_opf |= REQ_NOWAIT; | |
9650b453 ML |
90 | |
91 | submit_bio_wait(&bio); | |
cd82cca7 CH |
92 | |
93 | bio_release_pages(&bio, should_dirty); | |
94 | if (unlikely(bio.bi_status)) | |
95 | ret = blk_status_to_errno(bio.bi_status); | |
96 | ||
97 | out: | |
98 | if (vecs != inline_vecs) | |
99 | kfree(vecs); | |
100 | ||
101 | bio_uninit(&bio); | |
102 | ||
103 | return ret; | |
104 | } | |
105 | ||
09ce8744 | 106 | enum { |
e71aa913 PB |
107 | DIO_SHOULD_DIRTY = 1, |
108 | DIO_IS_SYNC = 2, | |
09ce8744 JA |
109 | }; |
110 | ||
cd82cca7 CH |
111 | struct blkdev_dio { |
112 | union { | |
113 | struct kiocb *iocb; | |
114 | struct task_struct *waiter; | |
115 | }; | |
116 | size_t size; | |
117 | atomic_t ref; | |
09ce8744 | 118 | unsigned int flags; |
6155631a | 119 | struct bio bio ____cacheline_aligned_in_smp; |
cd82cca7 CH |
120 | }; |
121 | ||
122 | static struct bio_set blkdev_dio_pool; | |
123 | ||
cd82cca7 CH |
124 | static void blkdev_bio_end_io(struct bio *bio) |
125 | { | |
126 | struct blkdev_dio *dio = bio->bi_private; | |
09ce8744 | 127 | bool should_dirty = dio->flags & DIO_SHOULD_DIRTY; |
cd82cca7 CH |
128 | |
129 | if (bio->bi_status && !dio->bio.bi_status) | |
130 | dio->bio.bi_status = bio->bi_status; | |
131 | ||
e71aa913 | 132 | if (atomic_dec_and_test(&dio->ref)) { |
09ce8744 | 133 | if (!(dio->flags & DIO_IS_SYNC)) { |
cd82cca7 CH |
134 | struct kiocb *iocb = dio->iocb; |
135 | ssize_t ret; | |
136 | ||
3e08773c CH |
137 | WRITE_ONCE(iocb->private, NULL); |
138 | ||
cd82cca7 CH |
139 | if (likely(!dio->bio.bi_status)) { |
140 | ret = dio->size; | |
141 | iocb->ki_pos += ret; | |
142 | } else { | |
143 | ret = blk_status_to_errno(dio->bio.bi_status); | |
144 | } | |
145 | ||
6b19b766 | 146 | dio->iocb->ki_complete(iocb, ret); |
e71aa913 | 147 | bio_put(&dio->bio); |
cd82cca7 CH |
148 | } else { |
149 | struct task_struct *waiter = dio->waiter; | |
150 | ||
151 | WRITE_ONCE(dio->waiter, NULL); | |
152 | blk_wake_io_task(waiter); | |
153 | } | |
154 | } | |
155 | ||
156 | if (should_dirty) { | |
157 | bio_check_pages_dirty(bio); | |
158 | } else { | |
159 | bio_release_pages(bio, false); | |
160 | bio_put(bio); | |
161 | } | |
162 | } | |
163 | ||
164 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, | |
165 | unsigned int nr_pages) | |
166 | { | |
fac7c6d5 | 167 | struct block_device *bdev = iocb->ki_filp->private_data; |
cd82cca7 CH |
168 | struct blk_plug plug; |
169 | struct blkdev_dio *dio; | |
170 | struct bio *bio; | |
cd82cca7 | 171 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
b77c88c2 | 172 | unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
cd82cca7 | 173 | loff_t pos = iocb->ki_pos; |
cd82cca7 CH |
174 | int ret = 0; |
175 | ||
176 | if ((pos | iov_iter_alignment(iter)) & | |
177 | (bdev_logical_block_size(bdev) - 1)) | |
178 | return -EINVAL; | |
179 | ||
0df71650 MS |
180 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
181 | opf |= REQ_ALLOC_CACHE; | |
182 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
183 | &blkdev_dio_pool); | |
cd82cca7 | 184 | dio = container_of(bio, struct blkdev_dio, bio); |
e71aa913 PB |
185 | atomic_set(&dio->ref, 1); |
186 | /* | |
187 | * Grab an extra reference to ensure the dio structure which is embedded | |
188 | * into the first bio stays around. | |
189 | */ | |
190 | bio_get(bio); | |
191 | ||
09ce8744 JA |
192 | is_sync = is_sync_kiocb(iocb); |
193 | if (is_sync) { | |
194 | dio->flags = DIO_IS_SYNC; | |
cd82cca7 | 195 | dio->waiter = current; |
cd82cca7 | 196 | } else { |
09ce8744 | 197 | dio->flags = 0; |
cd82cca7 CH |
198 | dio->iocb = iocb; |
199 | } | |
200 | ||
201 | dio->size = 0; | |
09ce8744 JA |
202 | if (is_read && iter_is_iovec(iter)) |
203 | dio->flags |= DIO_SHOULD_DIRTY; | |
cd82cca7 | 204 | |
25d207dc | 205 | blk_start_plug(&plug); |
cd82cca7 CH |
206 | |
207 | for (;;) { | |
6549a874 | 208 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
209 | bio->bi_private = dio; |
210 | bio->bi_end_io = blkdev_bio_end_io; | |
211 | bio->bi_ioprio = iocb->ki_ioprio; | |
212 | ||
213 | ret = bio_iov_iter_get_pages(bio, iter); | |
214 | if (unlikely(ret)) { | |
215 | bio->bi_status = BLK_STS_IOERR; | |
216 | bio_endio(bio); | |
217 | break; | |
218 | } | |
219 | ||
220 | if (is_read) { | |
09ce8744 | 221 | if (dio->flags & DIO_SHOULD_DIRTY) |
cd82cca7 CH |
222 | bio_set_pages_dirty(bio); |
223 | } else { | |
cd82cca7 CH |
224 | task_io_account_write(bio->bi_iter.bi_size); |
225 | } | |
226 | if (iocb->ki_flags & IOCB_NOWAIT) | |
227 | bio->bi_opf |= REQ_NOWAIT; | |
228 | ||
229 | dio->size += bio->bi_iter.bi_size; | |
230 | pos += bio->bi_iter.bi_size; | |
231 | ||
232 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); | |
233 | if (!nr_pages) { | |
3e08773c | 234 | submit_bio(bio); |
cd82cca7 CH |
235 | break; |
236 | } | |
e71aa913 | 237 | atomic_inc(&dio->ref); |
cd82cca7 | 238 | submit_bio(bio); |
07888c66 | 239 | bio = bio_alloc(bdev, nr_pages, opf, GFP_KERNEL); |
cd82cca7 CH |
240 | } |
241 | ||
25d207dc | 242 | blk_finish_plug(&plug); |
cd82cca7 CH |
243 | |
244 | if (!is_sync) | |
245 | return -EIOCBQUEUED; | |
246 | ||
247 | for (;;) { | |
248 | set_current_state(TASK_UNINTERRUPTIBLE); | |
249 | if (!READ_ONCE(dio->waiter)) | |
250 | break; | |
25d207dc | 251 | blk_io_schedule(); |
cd82cca7 CH |
252 | } |
253 | __set_current_state(TASK_RUNNING); | |
254 | ||
255 | if (!ret) | |
256 | ret = blk_status_to_errno(dio->bio.bi_status); | |
257 | if (likely(!ret)) | |
258 | ret = dio->size; | |
259 | ||
260 | bio_put(&dio->bio); | |
261 | return ret; | |
262 | } | |
263 | ||
54a88eb8 PB |
264 | static void blkdev_bio_end_io_async(struct bio *bio) |
265 | { | |
266 | struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio); | |
267 | struct kiocb *iocb = dio->iocb; | |
268 | ssize_t ret; | |
269 | ||
bb49c6fa SG |
270 | WRITE_ONCE(iocb->private, NULL); |
271 | ||
54a88eb8 PB |
272 | if (likely(!bio->bi_status)) { |
273 | ret = dio->size; | |
274 | iocb->ki_pos += ret; | |
275 | } else { | |
276 | ret = blk_status_to_errno(bio->bi_status); | |
277 | } | |
278 | ||
b6773cdb | 279 | iocb->ki_complete(iocb, ret); |
54a88eb8 PB |
280 | |
281 | if (dio->flags & DIO_SHOULD_DIRTY) { | |
282 | bio_check_pages_dirty(bio); | |
283 | } else { | |
284 | bio_release_pages(bio, false); | |
285 | bio_put(bio); | |
286 | } | |
287 | } | |
288 | ||
289 | static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, | |
290 | struct iov_iter *iter, | |
291 | unsigned int nr_pages) | |
292 | { | |
293 | struct block_device *bdev = iocb->ki_filp->private_data; | |
b77c88c2 CH |
294 | bool is_read = iov_iter_rw(iter) == READ; |
295 | unsigned int opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); | |
54a88eb8 PB |
296 | struct blkdev_dio *dio; |
297 | struct bio *bio; | |
298 | loff_t pos = iocb->ki_pos; | |
299 | int ret = 0; | |
300 | ||
301 | if ((pos | iov_iter_alignment(iter)) & | |
302 | (bdev_logical_block_size(bdev) - 1)) | |
303 | return -EINVAL; | |
304 | ||
0df71650 MS |
305 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
306 | opf |= REQ_ALLOC_CACHE; | |
307 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
308 | &blkdev_dio_pool); | |
54a88eb8 PB |
309 | dio = container_of(bio, struct blkdev_dio, bio); |
310 | dio->flags = 0; | |
311 | dio->iocb = iocb; | |
54a88eb8 | 312 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
54a88eb8 PB |
313 | bio->bi_end_io = blkdev_bio_end_io_async; |
314 | bio->bi_ioprio = iocb->ki_ioprio; | |
315 | ||
1bb6b810 PB |
316 | if (iov_iter_is_bvec(iter)) { |
317 | /* | |
318 | * Users don't rely on the iterator being in any particular | |
319 | * state for async I/O returning -EIOCBQUEUED, hence we can | |
320 | * avoid expensive iov_iter_advance(). Bypass | |
321 | * bio_iov_iter_get_pages() and set the bvec directly. | |
322 | */ | |
323 | bio_iov_bvec_set(bio, iter); | |
324 | } else { | |
325 | ret = bio_iov_iter_get_pages(bio, iter); | |
326 | if (unlikely(ret)) { | |
75feae73 | 327 | bio_put(bio); |
1bb6b810 PB |
328 | return ret; |
329 | } | |
54a88eb8 PB |
330 | } |
331 | dio->size = bio->bi_iter.bi_size; | |
332 | ||
b77c88c2 | 333 | if (is_read) { |
54a88eb8 PB |
334 | if (iter_is_iovec(iter)) { |
335 | dio->flags |= DIO_SHOULD_DIRTY; | |
336 | bio_set_pages_dirty(bio); | |
337 | } | |
338 | } else { | |
54a88eb8 PB |
339 | task_io_account_write(bio->bi_iter.bi_size); |
340 | } | |
341 | ||
54a88eb8 | 342 | if (iocb->ki_flags & IOCB_HIPRI) { |
842e39b0 | 343 | bio->bi_opf |= REQ_POLLED | REQ_NOWAIT; |
54a88eb8 PB |
344 | submit_bio(bio); |
345 | WRITE_ONCE(iocb->private, bio); | |
346 | } else { | |
842e39b0 PB |
347 | if (iocb->ki_flags & IOCB_NOWAIT) |
348 | bio->bi_opf |= REQ_NOWAIT; | |
54a88eb8 PB |
349 | submit_bio(bio); |
350 | } | |
351 | return -EIOCBQUEUED; | |
352 | } | |
353 | ||
cd82cca7 CH |
354 | static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
355 | { | |
356 | unsigned int nr_pages; | |
357 | ||
358 | if (!iov_iter_count(iter)) | |
359 | return 0; | |
360 | ||
361 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); | |
54a88eb8 PB |
362 | if (likely(nr_pages <= BIO_MAX_VECS)) { |
363 | if (is_sync_kiocb(iocb)) | |
364 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); | |
365 | return __blkdev_direct_IO_async(iocb, iter, nr_pages); | |
366 | } | |
cd82cca7 CH |
367 | return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); |
368 | } | |
369 | ||
370 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) | |
371 | { | |
372 | return block_write_full_page(page, blkdev_get_block, wbc); | |
373 | } | |
374 | ||
2c69e205 | 375 | static int blkdev_read_folio(struct file *file, struct folio *folio) |
cd82cca7 | 376 | { |
2c69e205 | 377 | return block_read_full_folio(folio, blkdev_get_block); |
cd82cca7 CH |
378 | } |
379 | ||
380 | static void blkdev_readahead(struct readahead_control *rac) | |
381 | { | |
382 | mpage_readahead(rac, blkdev_get_block); | |
383 | } | |
384 | ||
385 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
9d6b0cd7 | 386 | loff_t pos, unsigned len, struct page **pagep, void **fsdata) |
cd82cca7 | 387 | { |
b3992d1e | 388 | return block_write_begin(mapping, pos, len, pagep, blkdev_get_block); |
cd82cca7 CH |
389 | } |
390 | ||
391 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
392 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
393 | void *fsdata) | |
394 | { | |
395 | int ret; | |
396 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
397 | ||
398 | unlock_page(page); | |
399 | put_page(page); | |
400 | ||
401 | return ret; | |
402 | } | |
403 | ||
404 | static int blkdev_writepages(struct address_space *mapping, | |
405 | struct writeback_control *wbc) | |
406 | { | |
407 | return generic_writepages(mapping, wbc); | |
408 | } | |
409 | ||
410 | const struct address_space_operations def_blk_aops = { | |
e621900a | 411 | .dirty_folio = block_dirty_folio, |
7ba13abb | 412 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 413 | .read_folio = blkdev_read_folio, |
cd82cca7 CH |
414 | .readahead = blkdev_readahead, |
415 | .writepage = blkdev_writepage, | |
416 | .write_begin = blkdev_write_begin, | |
417 | .write_end = blkdev_write_end, | |
418 | .writepages = blkdev_writepages, | |
419 | .direct_IO = blkdev_direct_IO, | |
67235182 | 420 | .migrate_folio = buffer_migrate_folio_norefs, |
cd82cca7 CH |
421 | .is_dirty_writeback = buffer_check_dirty_writeback, |
422 | }; | |
423 | ||
424 | /* | |
425 | * for a block special file file_inode(file)->i_size is zero | |
426 | * so we compute the size by hand (just as in block_read/write above) | |
427 | */ | |
428 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
429 | { | |
430 | struct inode *bd_inode = bdev_file_inode(file); | |
431 | loff_t retval; | |
432 | ||
433 | inode_lock(bd_inode); | |
434 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
435 | inode_unlock(bd_inode); | |
436 | return retval; | |
437 | } | |
438 | ||
439 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
440 | int datasync) | |
441 | { | |
fac7c6d5 | 442 | struct block_device *bdev = filp->private_data; |
cd82cca7 CH |
443 | int error; |
444 | ||
445 | error = file_write_and_wait_range(filp, start, end); | |
446 | if (error) | |
447 | return error; | |
448 | ||
449 | /* | |
450 | * There is no need to serialise calls to blkdev_issue_flush with | |
451 | * i_mutex and doing so causes performance issues with concurrent | |
452 | * O_SYNC writers to a block device. | |
453 | */ | |
454 | error = blkdev_issue_flush(bdev); | |
455 | if (error == -EOPNOTSUPP) | |
456 | error = 0; | |
457 | ||
458 | return error; | |
459 | } | |
460 | ||
461 | static int blkdev_open(struct inode *inode, struct file *filp) | |
462 | { | |
463 | struct block_device *bdev; | |
464 | ||
465 | /* | |
466 | * Preserve backwards compatibility and allow large file access | |
467 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
468 | * binary needs it. We might want to drop this workaround | |
469 | * during an unstable branch. | |
470 | */ | |
471 | filp->f_flags |= O_LARGEFILE; | |
472 | filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; | |
473 | ||
474 | if (filp->f_flags & O_NDELAY) | |
475 | filp->f_mode |= FMODE_NDELAY; | |
476 | if (filp->f_flags & O_EXCL) | |
477 | filp->f_mode |= FMODE_EXCL; | |
478 | if ((filp->f_flags & O_ACCMODE) == 3) | |
479 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
480 | ||
481 | bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); | |
482 | if (IS_ERR(bdev)) | |
483 | return PTR_ERR(bdev); | |
fac7c6d5 PB |
484 | |
485 | filp->private_data = bdev; | |
cd82cca7 CH |
486 | filp->f_mapping = bdev->bd_inode->i_mapping; |
487 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); | |
488 | return 0; | |
489 | } | |
490 | ||
491 | static int blkdev_close(struct inode *inode, struct file *filp) | |
492 | { | |
fac7c6d5 | 493 | struct block_device *bdev = filp->private_data; |
cd82cca7 CH |
494 | |
495 | blkdev_put(bdev, filp->f_mode); | |
496 | return 0; | |
497 | } | |
498 | ||
cd82cca7 CH |
499 | /* |
500 | * Write data to the block device. Only intended for the block device itself | |
501 | * and the raw driver which basically is a fake block device. | |
502 | * | |
503 | * Does not take i_mutex for the write and thus is not for general purpose | |
504 | * use. | |
505 | */ | |
506 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
507 | { | |
fac7c6d5 PB |
508 | struct block_device *bdev = iocb->ki_filp->private_data; |
509 | struct inode *bd_inode = bdev->bd_inode; | |
138c1a38 | 510 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
511 | struct blk_plug plug; |
512 | size_t shorted = 0; | |
513 | ssize_t ret; | |
514 | ||
fac7c6d5 | 515 | if (bdev_read_only(bdev)) |
cd82cca7 CH |
516 | return -EPERM; |
517 | ||
518 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
519 | return -ETXTBSY; | |
520 | ||
521 | if (!iov_iter_count(from)) | |
522 | return 0; | |
523 | ||
524 | if (iocb->ki_pos >= size) | |
525 | return -ENOSPC; | |
526 | ||
527 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
528 | return -EOPNOTSUPP; | |
529 | ||
530 | size -= iocb->ki_pos; | |
531 | if (iov_iter_count(from) > size) { | |
532 | shorted = iov_iter_count(from) - size; | |
533 | iov_iter_truncate(from, size); | |
534 | } | |
535 | ||
536 | blk_start_plug(&plug); | |
537 | ret = __generic_file_write_iter(iocb, from); | |
538 | if (ret > 0) | |
539 | ret = generic_write_sync(iocb, ret); | |
540 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
541 | blk_finish_plug(&plug); | |
542 | return ret; | |
543 | } | |
544 | ||
545 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
546 | { | |
fac7c6d5 | 547 | struct block_device *bdev = iocb->ki_filp->private_data; |
138c1a38 | 548 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
549 | loff_t pos = iocb->ki_pos; |
550 | size_t shorted = 0; | |
ceaa7625 | 551 | ssize_t ret = 0; |
3e1f941d | 552 | size_t count; |
cd82cca7 | 553 | |
3e1f941d | 554 | if (unlikely(pos + iov_iter_count(to) > size)) { |
6450fe1f PB |
555 | if (pos >= size) |
556 | return 0; | |
557 | size -= pos; | |
3e1f941d ID |
558 | shorted = iov_iter_count(to) - size; |
559 | iov_iter_truncate(to, size); | |
cd82cca7 CH |
560 | } |
561 | ||
3e1f941d ID |
562 | count = iov_iter_count(to); |
563 | if (!count) | |
564 | goto reexpand; /* skip atime */ | |
565 | ||
ceaa7625 JA |
566 | if (iocb->ki_flags & IOCB_DIRECT) { |
567 | struct address_space *mapping = iocb->ki_filp->f_mapping; | |
568 | ||
569 | if (iocb->ki_flags & IOCB_NOWAIT) { | |
3e1f941d ID |
570 | if (filemap_range_needs_writeback(mapping, pos, |
571 | pos + count - 1)) { | |
572 | ret = -EAGAIN; | |
573 | goto reexpand; | |
574 | } | |
ceaa7625 | 575 | } else { |
3e1f941d ID |
576 | ret = filemap_write_and_wait_range(mapping, pos, |
577 | pos + count - 1); | |
ceaa7625 | 578 | if (ret < 0) |
3e1f941d | 579 | goto reexpand; |
ceaa7625 JA |
580 | } |
581 | ||
582 | file_accessed(iocb->ki_filp); | |
583 | ||
584 | ret = blkdev_direct_IO(iocb, to); | |
585 | if (ret >= 0) { | |
586 | iocb->ki_pos += ret; | |
587 | count -= ret; | |
588 | } | |
3e1f941d | 589 | iov_iter_revert(to, count - iov_iter_count(to)); |
ceaa7625 | 590 | if (ret < 0 || !count) |
3e1f941d | 591 | goto reexpand; |
ceaa7625 JA |
592 | } |
593 | ||
594 | ret = filemap_read(iocb, to, ret); | |
6450fe1f | 595 | |
3e1f941d | 596 | reexpand: |
6450fe1f PB |
597 | if (unlikely(shorted)) |
598 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
cd82cca7 CH |
599 | return ret; |
600 | } | |
601 | ||
602 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
603 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
604 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
605 | ||
606 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
607 | loff_t len) | |
608 | { | |
f278eb3d ML |
609 | struct inode *inode = bdev_file_inode(file); |
610 | struct block_device *bdev = I_BDEV(inode); | |
cd82cca7 CH |
611 | loff_t end = start + len - 1; |
612 | loff_t isize; | |
613 | int error; | |
614 | ||
615 | /* Fail if we don't recognize the flags. */ | |
616 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
617 | return -EOPNOTSUPP; | |
618 | ||
619 | /* Don't go off the end of the device. */ | |
2a93ad8f | 620 | isize = bdev_nr_bytes(bdev); |
cd82cca7 CH |
621 | if (start >= isize) |
622 | return -EINVAL; | |
623 | if (end >= isize) { | |
624 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
625 | len = isize - start; | |
626 | end = start + len - 1; | |
627 | } else | |
628 | return -EINVAL; | |
629 | } | |
630 | ||
631 | /* | |
632 | * Don't allow IO that isn't aligned to logical block size. | |
633 | */ | |
634 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
635 | return -EINVAL; | |
636 | ||
f278eb3d ML |
637 | filemap_invalidate_lock(inode->i_mapping); |
638 | ||
cd82cca7 CH |
639 | /* Invalidate the page cache, including dirty pages. */ |
640 | error = truncate_bdev_range(bdev, file->f_mode, start, end); | |
641 | if (error) | |
f278eb3d | 642 | goto fail; |
cd82cca7 CH |
643 | |
644 | switch (mode) { | |
645 | case FALLOC_FL_ZERO_RANGE: | |
646 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
6549a874 PB |
647 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
648 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
649 | BLKDEV_ZERO_NOUNMAP); | |
cd82cca7 CH |
650 | break; |
651 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
6549a874 PB |
652 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
653 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
654 | BLKDEV_ZERO_NOFALLBACK); | |
cd82cca7 CH |
655 | break; |
656 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
6549a874 | 657 | error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
44abff2c | 658 | len >> SECTOR_SHIFT, GFP_KERNEL); |
cd82cca7 CH |
659 | break; |
660 | default: | |
f278eb3d | 661 | error = -EOPNOTSUPP; |
cd82cca7 | 662 | } |
cd82cca7 | 663 | |
f278eb3d ML |
664 | fail: |
665 | filemap_invalidate_unlock(inode->i_mapping); | |
666 | return error; | |
cd82cca7 CH |
667 | } |
668 | ||
669 | const struct file_operations def_blk_fops = { | |
670 | .open = blkdev_open, | |
671 | .release = blkdev_close, | |
672 | .llseek = blkdev_llseek, | |
673 | .read_iter = blkdev_read_iter, | |
674 | .write_iter = blkdev_write_iter, | |
3e08773c | 675 | .iopoll = iocb_bio_iopoll, |
cd82cca7 CH |
676 | .mmap = generic_file_mmap, |
677 | .fsync = blkdev_fsync, | |
8a709512 | 678 | .unlocked_ioctl = blkdev_ioctl, |
cd82cca7 CH |
679 | #ifdef CONFIG_COMPAT |
680 | .compat_ioctl = compat_blkdev_ioctl, | |
681 | #endif | |
682 | .splice_read = generic_file_splice_read, | |
683 | .splice_write = iter_file_splice_write, | |
684 | .fallocate = blkdev_fallocate, | |
685 | }; | |
686 | ||
687 | static __init int blkdev_init(void) | |
688 | { | |
689 | return bioset_init(&blkdev_dio_pool, 4, | |
690 | offsetof(struct blkdev_dio, bio), | |
691 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
692 | } | |
693 | module_init(blkdev_init); |