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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 | ||
16458cf3 | 35 | static blk_opf_t dio_bio_write_op(struct kiocb *iocb) |
cd82cca7 | 36 | { |
16458cf3 | 37 | blk_opf_t opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; |
cd82cca7 CH |
38 | |
39 | /* avoid the need for a I/O completion work item */ | |
91b94c5d | 40 | if (iocb_is_dsync(iocb)) |
16458cf3 BVA |
41 | opf |= REQ_FUA; |
42 | return opf; | |
cd82cca7 CH |
43 | } |
44 | ||
37fee2e4 KB |
45 | static bool blkdev_dio_unaligned(struct block_device *bdev, loff_t pos, |
46 | struct iov_iter *iter) | |
47 | { | |
b1a000d3 KB |
48 | return pos & (bdev_logical_block_size(bdev) - 1) || |
49 | !bdev_iter_is_aligned(bdev, iter); | |
37fee2e4 KB |
50 | } |
51 | ||
cd82cca7 CH |
52 | #define DIO_INLINE_BIO_VECS 4 |
53 | ||
cd82cca7 CH |
54 | static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, |
55 | struct iov_iter *iter, unsigned int nr_pages) | |
56 | { | |
fac7c6d5 | 57 | struct block_device *bdev = iocb->ki_filp->private_data; |
cd82cca7 CH |
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; | |
cd82cca7 | 63 | |
37fee2e4 | 64 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
cd82cca7 CH |
65 | return -EINVAL; |
66 | ||
67 | if (nr_pages <= DIO_INLINE_BIO_VECS) | |
68 | vecs = inline_vecs; | |
69 | else { | |
70 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), | |
71 | GFP_KERNEL); | |
72 | if (!vecs) | |
73 | return -ENOMEM; | |
74 | } | |
75 | ||
49add496 CH |
76 | if (iov_iter_rw(iter) == READ) { |
77 | bio_init(&bio, bdev, vecs, nr_pages, REQ_OP_READ); | |
fcb14cb1 | 78 | if (user_backed_iter(iter)) |
49add496 CH |
79 | should_dirty = true; |
80 | } else { | |
81 | bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); | |
82 | } | |
6549a874 | 83 | bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
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 | ||
49add496 | 91 | if (iov_iter_rw(iter) == WRITE) |
cd82cca7 | 92 | task_io_account_write(ret); |
49add496 | 93 | |
cd82cca7 CH |
94 | if (iocb->ki_flags & IOCB_NOWAIT) |
95 | bio.bi_opf |= REQ_NOWAIT; | |
9650b453 ML |
96 | |
97 | submit_bio_wait(&bio); | |
cd82cca7 CH |
98 | |
99 | bio_release_pages(&bio, should_dirty); | |
100 | if (unlikely(bio.bi_status)) | |
101 | ret = blk_status_to_errno(bio.bi_status); | |
102 | ||
103 | out: | |
104 | if (vecs != inline_vecs) | |
105 | kfree(vecs); | |
106 | ||
107 | bio_uninit(&bio); | |
108 | ||
109 | return ret; | |
110 | } | |
111 | ||
09ce8744 | 112 | enum { |
e71aa913 PB |
113 | DIO_SHOULD_DIRTY = 1, |
114 | DIO_IS_SYNC = 2, | |
09ce8744 JA |
115 | }; |
116 | ||
cd82cca7 CH |
117 | struct blkdev_dio { |
118 | union { | |
119 | struct kiocb *iocb; | |
120 | struct task_struct *waiter; | |
121 | }; | |
122 | size_t size; | |
123 | atomic_t ref; | |
09ce8744 | 124 | unsigned int flags; |
6155631a | 125 | struct bio bio ____cacheline_aligned_in_smp; |
cd82cca7 CH |
126 | }; |
127 | ||
128 | static struct bio_set blkdev_dio_pool; | |
129 | ||
cd82cca7 CH |
130 | static void blkdev_bio_end_io(struct bio *bio) |
131 | { | |
132 | struct blkdev_dio *dio = bio->bi_private; | |
09ce8744 | 133 | bool should_dirty = dio->flags & DIO_SHOULD_DIRTY; |
cd82cca7 CH |
134 | |
135 | if (bio->bi_status && !dio->bio.bi_status) | |
136 | dio->bio.bi_status = bio->bi_status; | |
137 | ||
e71aa913 | 138 | if (atomic_dec_and_test(&dio->ref)) { |
09ce8744 | 139 | if (!(dio->flags & DIO_IS_SYNC)) { |
cd82cca7 CH |
140 | struct kiocb *iocb = dio->iocb; |
141 | ssize_t ret; | |
142 | ||
3e08773c CH |
143 | WRITE_ONCE(iocb->private, NULL); |
144 | ||
cd82cca7 CH |
145 | if (likely(!dio->bio.bi_status)) { |
146 | ret = dio->size; | |
147 | iocb->ki_pos += ret; | |
148 | } else { | |
149 | ret = blk_status_to_errno(dio->bio.bi_status); | |
150 | } | |
151 | ||
6b19b766 | 152 | dio->iocb->ki_complete(iocb, ret); |
e71aa913 | 153 | bio_put(&dio->bio); |
cd82cca7 CH |
154 | } else { |
155 | struct task_struct *waiter = dio->waiter; | |
156 | ||
157 | WRITE_ONCE(dio->waiter, NULL); | |
158 | blk_wake_io_task(waiter); | |
159 | } | |
160 | } | |
161 | ||
162 | if (should_dirty) { | |
163 | bio_check_pages_dirty(bio); | |
164 | } else { | |
165 | bio_release_pages(bio, false); | |
166 | bio_put(bio); | |
167 | } | |
168 | } | |
169 | ||
170 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, | |
171 | unsigned int nr_pages) | |
172 | { | |
fac7c6d5 | 173 | struct block_device *bdev = iocb->ki_filp->private_data; |
cd82cca7 CH |
174 | struct blk_plug plug; |
175 | struct blkdev_dio *dio; | |
176 | struct bio *bio; | |
cd82cca7 | 177 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
16458cf3 | 178 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
cd82cca7 | 179 | loff_t pos = iocb->ki_pos; |
cd82cca7 CH |
180 | int ret = 0; |
181 | ||
37fee2e4 | 182 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
cd82cca7 CH |
183 | return -EINVAL; |
184 | ||
0df71650 MS |
185 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
186 | opf |= REQ_ALLOC_CACHE; | |
187 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
188 | &blkdev_dio_pool); | |
cd82cca7 | 189 | dio = container_of(bio, struct blkdev_dio, bio); |
e71aa913 PB |
190 | atomic_set(&dio->ref, 1); |
191 | /* | |
192 | * Grab an extra reference to ensure the dio structure which is embedded | |
193 | * into the first bio stays around. | |
194 | */ | |
195 | bio_get(bio); | |
196 | ||
09ce8744 JA |
197 | is_sync = is_sync_kiocb(iocb); |
198 | if (is_sync) { | |
199 | dio->flags = DIO_IS_SYNC; | |
cd82cca7 | 200 | dio->waiter = current; |
cd82cca7 | 201 | } else { |
09ce8744 | 202 | dio->flags = 0; |
cd82cca7 CH |
203 | dio->iocb = iocb; |
204 | } | |
205 | ||
206 | dio->size = 0; | |
fcb14cb1 | 207 | if (is_read && user_backed_iter(iter)) |
09ce8744 | 208 | dio->flags |= DIO_SHOULD_DIRTY; |
cd82cca7 | 209 | |
25d207dc | 210 | blk_start_plug(&plug); |
cd82cca7 CH |
211 | |
212 | for (;;) { | |
6549a874 | 213 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
214 | bio->bi_private = dio; |
215 | bio->bi_end_io = blkdev_bio_end_io; | |
216 | bio->bi_ioprio = iocb->ki_ioprio; | |
217 | ||
218 | ret = bio_iov_iter_get_pages(bio, iter); | |
219 | if (unlikely(ret)) { | |
220 | bio->bi_status = BLK_STS_IOERR; | |
221 | bio_endio(bio); | |
222 | break; | |
223 | } | |
224 | ||
225 | if (is_read) { | |
09ce8744 | 226 | if (dio->flags & DIO_SHOULD_DIRTY) |
cd82cca7 CH |
227 | bio_set_pages_dirty(bio); |
228 | } else { | |
cd82cca7 CH |
229 | task_io_account_write(bio->bi_iter.bi_size); |
230 | } | |
231 | if (iocb->ki_flags & IOCB_NOWAIT) | |
232 | bio->bi_opf |= REQ_NOWAIT; | |
233 | ||
234 | dio->size += bio->bi_iter.bi_size; | |
235 | pos += bio->bi_iter.bi_size; | |
236 | ||
237 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); | |
238 | if (!nr_pages) { | |
3e08773c | 239 | submit_bio(bio); |
cd82cca7 CH |
240 | break; |
241 | } | |
e71aa913 | 242 | atomic_inc(&dio->ref); |
cd82cca7 | 243 | submit_bio(bio); |
07888c66 | 244 | bio = bio_alloc(bdev, nr_pages, opf, GFP_KERNEL); |
cd82cca7 CH |
245 | } |
246 | ||
25d207dc | 247 | blk_finish_plug(&plug); |
cd82cca7 CH |
248 | |
249 | if (!is_sync) | |
250 | return -EIOCBQUEUED; | |
251 | ||
252 | for (;;) { | |
253 | set_current_state(TASK_UNINTERRUPTIBLE); | |
254 | if (!READ_ONCE(dio->waiter)) | |
255 | break; | |
25d207dc | 256 | blk_io_schedule(); |
cd82cca7 CH |
257 | } |
258 | __set_current_state(TASK_RUNNING); | |
259 | ||
260 | if (!ret) | |
261 | ret = blk_status_to_errno(dio->bio.bi_status); | |
262 | if (likely(!ret)) | |
263 | ret = dio->size; | |
264 | ||
265 | bio_put(&dio->bio); | |
266 | return ret; | |
267 | } | |
268 | ||
54a88eb8 PB |
269 | static void blkdev_bio_end_io_async(struct bio *bio) |
270 | { | |
271 | struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio); | |
272 | struct kiocb *iocb = dio->iocb; | |
273 | ssize_t ret; | |
274 | ||
bb49c6fa SG |
275 | WRITE_ONCE(iocb->private, NULL); |
276 | ||
54a88eb8 PB |
277 | if (likely(!bio->bi_status)) { |
278 | ret = dio->size; | |
279 | iocb->ki_pos += ret; | |
280 | } else { | |
281 | ret = blk_status_to_errno(bio->bi_status); | |
282 | } | |
283 | ||
b6773cdb | 284 | iocb->ki_complete(iocb, ret); |
54a88eb8 PB |
285 | |
286 | if (dio->flags & DIO_SHOULD_DIRTY) { | |
287 | bio_check_pages_dirty(bio); | |
288 | } else { | |
289 | bio_release_pages(bio, false); | |
290 | bio_put(bio); | |
291 | } | |
292 | } | |
293 | ||
294 | static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, | |
295 | struct iov_iter *iter, | |
296 | unsigned int nr_pages) | |
297 | { | |
298 | struct block_device *bdev = iocb->ki_filp->private_data; | |
b77c88c2 | 299 | bool is_read = iov_iter_rw(iter) == READ; |
16458cf3 | 300 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
54a88eb8 PB |
301 | struct blkdev_dio *dio; |
302 | struct bio *bio; | |
303 | loff_t pos = iocb->ki_pos; | |
304 | int ret = 0; | |
305 | ||
37fee2e4 | 306 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
54a88eb8 PB |
307 | return -EINVAL; |
308 | ||
0df71650 MS |
309 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
310 | opf |= REQ_ALLOC_CACHE; | |
311 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
312 | &blkdev_dio_pool); | |
54a88eb8 PB |
313 | dio = container_of(bio, struct blkdev_dio, bio); |
314 | dio->flags = 0; | |
315 | dio->iocb = iocb; | |
54a88eb8 | 316 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
54a88eb8 PB |
317 | bio->bi_end_io = blkdev_bio_end_io_async; |
318 | bio->bi_ioprio = iocb->ki_ioprio; | |
319 | ||
1bb6b810 PB |
320 | if (iov_iter_is_bvec(iter)) { |
321 | /* | |
322 | * Users don't rely on the iterator being in any particular | |
323 | * state for async I/O returning -EIOCBQUEUED, hence we can | |
324 | * avoid expensive iov_iter_advance(). Bypass | |
325 | * bio_iov_iter_get_pages() and set the bvec directly. | |
326 | */ | |
327 | bio_iov_bvec_set(bio, iter); | |
328 | } else { | |
329 | ret = bio_iov_iter_get_pages(bio, iter); | |
330 | if (unlikely(ret)) { | |
75feae73 | 331 | bio_put(bio); |
1bb6b810 PB |
332 | return ret; |
333 | } | |
54a88eb8 PB |
334 | } |
335 | dio->size = bio->bi_iter.bi_size; | |
336 | ||
b77c88c2 | 337 | if (is_read) { |
fcb14cb1 | 338 | if (user_backed_iter(iter)) { |
54a88eb8 PB |
339 | dio->flags |= DIO_SHOULD_DIRTY; |
340 | bio_set_pages_dirty(bio); | |
341 | } | |
342 | } else { | |
54a88eb8 PB |
343 | task_io_account_write(bio->bi_iter.bi_size); |
344 | } | |
345 | ||
54a88eb8 | 346 | if (iocb->ki_flags & IOCB_HIPRI) { |
842e39b0 | 347 | bio->bi_opf |= REQ_POLLED | REQ_NOWAIT; |
54a88eb8 PB |
348 | submit_bio(bio); |
349 | WRITE_ONCE(iocb->private, bio); | |
350 | } else { | |
842e39b0 PB |
351 | if (iocb->ki_flags & IOCB_NOWAIT) |
352 | bio->bi_opf |= REQ_NOWAIT; | |
54a88eb8 PB |
353 | submit_bio(bio); |
354 | } | |
355 | return -EIOCBQUEUED; | |
356 | } | |
357 | ||
cd82cca7 CH |
358 | static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
359 | { | |
360 | unsigned int nr_pages; | |
361 | ||
362 | if (!iov_iter_count(iter)) | |
363 | return 0; | |
364 | ||
365 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); | |
54a88eb8 PB |
366 | if (likely(nr_pages <= BIO_MAX_VECS)) { |
367 | if (is_sync_kiocb(iocb)) | |
368 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); | |
369 | return __blkdev_direct_IO_async(iocb, iter, nr_pages); | |
370 | } | |
cd82cca7 CH |
371 | return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); |
372 | } | |
373 | ||
374 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) | |
375 | { | |
376 | return block_write_full_page(page, blkdev_get_block, wbc); | |
377 | } | |
378 | ||
2c69e205 | 379 | static int blkdev_read_folio(struct file *file, struct folio *folio) |
cd82cca7 | 380 | { |
2c69e205 | 381 | return block_read_full_folio(folio, blkdev_get_block); |
cd82cca7 CH |
382 | } |
383 | ||
384 | static void blkdev_readahead(struct readahead_control *rac) | |
385 | { | |
386 | mpage_readahead(rac, blkdev_get_block); | |
387 | } | |
388 | ||
389 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
9d6b0cd7 | 390 | loff_t pos, unsigned len, struct page **pagep, void **fsdata) |
cd82cca7 | 391 | { |
b3992d1e | 392 | return block_write_begin(mapping, pos, len, pagep, blkdev_get_block); |
cd82cca7 CH |
393 | } |
394 | ||
395 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
396 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
397 | void *fsdata) | |
398 | { | |
399 | int ret; | |
400 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
401 | ||
402 | unlock_page(page); | |
403 | put_page(page); | |
404 | ||
405 | return ret; | |
406 | } | |
407 | ||
cd82cca7 | 408 | const struct address_space_operations def_blk_aops = { |
e621900a | 409 | .dirty_folio = block_dirty_folio, |
7ba13abb | 410 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 411 | .read_folio = blkdev_read_folio, |
cd82cca7 CH |
412 | .readahead = blkdev_readahead, |
413 | .writepage = blkdev_writepage, | |
414 | .write_begin = blkdev_write_begin, | |
415 | .write_end = blkdev_write_end, | |
cd82cca7 | 416 | .direct_IO = blkdev_direct_IO, |
67235182 | 417 | .migrate_folio = buffer_migrate_folio_norefs, |
cd82cca7 CH |
418 | .is_dirty_writeback = buffer_check_dirty_writeback, |
419 | }; | |
420 | ||
421 | /* | |
422 | * for a block special file file_inode(file)->i_size is zero | |
423 | * so we compute the size by hand (just as in block_read/write above) | |
424 | */ | |
425 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
426 | { | |
427 | struct inode *bd_inode = bdev_file_inode(file); | |
428 | loff_t retval; | |
429 | ||
430 | inode_lock(bd_inode); | |
431 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
432 | inode_unlock(bd_inode); | |
433 | return retval; | |
434 | } | |
435 | ||
436 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
437 | int datasync) | |
438 | { | |
fac7c6d5 | 439 | struct block_device *bdev = filp->private_data; |
cd82cca7 CH |
440 | int error; |
441 | ||
442 | error = file_write_and_wait_range(filp, start, end); | |
443 | if (error) | |
444 | return error; | |
445 | ||
446 | /* | |
447 | * There is no need to serialise calls to blkdev_issue_flush with | |
448 | * i_mutex and doing so causes performance issues with concurrent | |
449 | * O_SYNC writers to a block device. | |
450 | */ | |
451 | error = blkdev_issue_flush(bdev); | |
452 | if (error == -EOPNOTSUPP) | |
453 | error = 0; | |
454 | ||
455 | return error; | |
456 | } | |
457 | ||
458 | static int blkdev_open(struct inode *inode, struct file *filp) | |
459 | { | |
460 | struct block_device *bdev; | |
461 | ||
462 | /* | |
463 | * Preserve backwards compatibility and allow large file access | |
464 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
465 | * binary needs it. We might want to drop this workaround | |
466 | * during an unstable branch. | |
467 | */ | |
468 | filp->f_flags |= O_LARGEFILE; | |
469 | filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC; | |
470 | ||
471 | if (filp->f_flags & O_NDELAY) | |
472 | filp->f_mode |= FMODE_NDELAY; | |
473 | if (filp->f_flags & O_EXCL) | |
474 | filp->f_mode |= FMODE_EXCL; | |
475 | if ((filp->f_flags & O_ACCMODE) == 3) | |
476 | filp->f_mode |= FMODE_WRITE_IOCTL; | |
477 | ||
478 | bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp); | |
479 | if (IS_ERR(bdev)) | |
480 | return PTR_ERR(bdev); | |
fac7c6d5 PB |
481 | |
482 | filp->private_data = bdev; | |
cd82cca7 CH |
483 | filp->f_mapping = bdev->bd_inode->i_mapping; |
484 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); | |
485 | return 0; | |
486 | } | |
487 | ||
488 | static int blkdev_close(struct inode *inode, struct file *filp) | |
489 | { | |
fac7c6d5 | 490 | struct block_device *bdev = filp->private_data; |
cd82cca7 CH |
491 | |
492 | blkdev_put(bdev, filp->f_mode); | |
493 | return 0; | |
494 | } | |
495 | ||
cd82cca7 CH |
496 | /* |
497 | * Write data to the block device. Only intended for the block device itself | |
498 | * and the raw driver which basically is a fake block device. | |
499 | * | |
500 | * Does not take i_mutex for the write and thus is not for general purpose | |
501 | * use. | |
502 | */ | |
503 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
504 | { | |
fac7c6d5 PB |
505 | struct block_device *bdev = iocb->ki_filp->private_data; |
506 | struct inode *bd_inode = bdev->bd_inode; | |
138c1a38 | 507 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
508 | struct blk_plug plug; |
509 | size_t shorted = 0; | |
510 | ssize_t ret; | |
511 | ||
fac7c6d5 | 512 | if (bdev_read_only(bdev)) |
cd82cca7 CH |
513 | return -EPERM; |
514 | ||
515 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
516 | return -ETXTBSY; | |
517 | ||
518 | if (!iov_iter_count(from)) | |
519 | return 0; | |
520 | ||
521 | if (iocb->ki_pos >= size) | |
522 | return -ENOSPC; | |
523 | ||
524 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
525 | return -EOPNOTSUPP; | |
526 | ||
527 | size -= iocb->ki_pos; | |
528 | if (iov_iter_count(from) > size) { | |
529 | shorted = iov_iter_count(from) - size; | |
530 | iov_iter_truncate(from, size); | |
531 | } | |
532 | ||
533 | blk_start_plug(&plug); | |
534 | ret = __generic_file_write_iter(iocb, from); | |
535 | if (ret > 0) | |
536 | ret = generic_write_sync(iocb, ret); | |
537 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
538 | blk_finish_plug(&plug); | |
539 | return ret; | |
540 | } | |
541 | ||
542 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
543 | { | |
fac7c6d5 | 544 | struct block_device *bdev = iocb->ki_filp->private_data; |
138c1a38 | 545 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
546 | loff_t pos = iocb->ki_pos; |
547 | size_t shorted = 0; | |
ceaa7625 | 548 | ssize_t ret = 0; |
3e1f941d | 549 | size_t count; |
cd82cca7 | 550 | |
3e1f941d | 551 | if (unlikely(pos + iov_iter_count(to) > size)) { |
6450fe1f PB |
552 | if (pos >= size) |
553 | return 0; | |
554 | size -= pos; | |
3e1f941d ID |
555 | shorted = iov_iter_count(to) - size; |
556 | iov_iter_truncate(to, size); | |
cd82cca7 CH |
557 | } |
558 | ||
3e1f941d ID |
559 | count = iov_iter_count(to); |
560 | if (!count) | |
561 | goto reexpand; /* skip atime */ | |
562 | ||
ceaa7625 JA |
563 | if (iocb->ki_flags & IOCB_DIRECT) { |
564 | struct address_space *mapping = iocb->ki_filp->f_mapping; | |
565 | ||
566 | if (iocb->ki_flags & IOCB_NOWAIT) { | |
3e1f941d ID |
567 | if (filemap_range_needs_writeback(mapping, pos, |
568 | pos + count - 1)) { | |
569 | ret = -EAGAIN; | |
570 | goto reexpand; | |
571 | } | |
ceaa7625 | 572 | } else { |
3e1f941d ID |
573 | ret = filemap_write_and_wait_range(mapping, pos, |
574 | pos + count - 1); | |
ceaa7625 | 575 | if (ret < 0) |
3e1f941d | 576 | goto reexpand; |
ceaa7625 JA |
577 | } |
578 | ||
579 | file_accessed(iocb->ki_filp); | |
580 | ||
581 | ret = blkdev_direct_IO(iocb, to); | |
582 | if (ret >= 0) { | |
583 | iocb->ki_pos += ret; | |
584 | count -= ret; | |
585 | } | |
3e1f941d | 586 | iov_iter_revert(to, count - iov_iter_count(to)); |
ceaa7625 | 587 | if (ret < 0 || !count) |
3e1f941d | 588 | goto reexpand; |
ceaa7625 JA |
589 | } |
590 | ||
591 | ret = filemap_read(iocb, to, ret); | |
6450fe1f | 592 | |
3e1f941d | 593 | reexpand: |
6450fe1f PB |
594 | if (unlikely(shorted)) |
595 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
cd82cca7 CH |
596 | return ret; |
597 | } | |
598 | ||
599 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
600 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
601 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
602 | ||
603 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
604 | loff_t len) | |
605 | { | |
f278eb3d ML |
606 | struct inode *inode = bdev_file_inode(file); |
607 | struct block_device *bdev = I_BDEV(inode); | |
cd82cca7 CH |
608 | loff_t end = start + len - 1; |
609 | loff_t isize; | |
610 | int error; | |
611 | ||
612 | /* Fail if we don't recognize the flags. */ | |
613 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
614 | return -EOPNOTSUPP; | |
615 | ||
616 | /* Don't go off the end of the device. */ | |
2a93ad8f | 617 | isize = bdev_nr_bytes(bdev); |
cd82cca7 CH |
618 | if (start >= isize) |
619 | return -EINVAL; | |
620 | if (end >= isize) { | |
621 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
622 | len = isize - start; | |
623 | end = start + len - 1; | |
624 | } else | |
625 | return -EINVAL; | |
626 | } | |
627 | ||
628 | /* | |
629 | * Don't allow IO that isn't aligned to logical block size. | |
630 | */ | |
631 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
632 | return -EINVAL; | |
633 | ||
f278eb3d ML |
634 | filemap_invalidate_lock(inode->i_mapping); |
635 | ||
cd82cca7 CH |
636 | /* Invalidate the page cache, including dirty pages. */ |
637 | error = truncate_bdev_range(bdev, file->f_mode, start, end); | |
638 | if (error) | |
f278eb3d | 639 | goto fail; |
cd82cca7 CH |
640 | |
641 | switch (mode) { | |
642 | case FALLOC_FL_ZERO_RANGE: | |
643 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
6549a874 PB |
644 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
645 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
646 | BLKDEV_ZERO_NOUNMAP); | |
cd82cca7 CH |
647 | break; |
648 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
6549a874 PB |
649 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
650 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
651 | BLKDEV_ZERO_NOFALLBACK); | |
cd82cca7 CH |
652 | break; |
653 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
6549a874 | 654 | error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
44abff2c | 655 | len >> SECTOR_SHIFT, GFP_KERNEL); |
cd82cca7 CH |
656 | break; |
657 | default: | |
f278eb3d | 658 | error = -EOPNOTSUPP; |
cd82cca7 | 659 | } |
cd82cca7 | 660 | |
f278eb3d ML |
661 | fail: |
662 | filemap_invalidate_unlock(inode->i_mapping); | |
663 | return error; | |
cd82cca7 CH |
664 | } |
665 | ||
666 | const struct file_operations def_blk_fops = { | |
667 | .open = blkdev_open, | |
668 | .release = blkdev_close, | |
669 | .llseek = blkdev_llseek, | |
670 | .read_iter = blkdev_read_iter, | |
671 | .write_iter = blkdev_write_iter, | |
3e08773c | 672 | .iopoll = iocb_bio_iopoll, |
cd82cca7 CH |
673 | .mmap = generic_file_mmap, |
674 | .fsync = blkdev_fsync, | |
8a709512 | 675 | .unlocked_ioctl = blkdev_ioctl, |
cd82cca7 CH |
676 | #ifdef CONFIG_COMPAT |
677 | .compat_ioctl = compat_blkdev_ioctl, | |
678 | #endif | |
679 | .splice_read = generic_file_splice_read, | |
680 | .splice_write = iter_file_splice_write, | |
681 | .fallocate = blkdev_fallocate, | |
682 | }; | |
683 | ||
684 | static __init int blkdev_init(void) | |
685 | { | |
686 | return bioset_init(&blkdev_dio_pool, 4, | |
687 | offsetof(struct blkdev_dio, bio), | |
688 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
689 | } | |
690 | module_init(blkdev_init); |