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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> |
487c607d | 18 | #include <linux/iomap.h> |
8581fd40 | 19 | #include <linux/module.h> |
cd82cca7 CH |
20 | #include "blk.h" |
21 | ||
fac7c6d5 | 22 | static inline struct inode *bdev_file_inode(struct file *file) |
cd82cca7 CH |
23 | { |
24 | return file->f_mapping->host; | |
25 | } | |
26 | ||
16458cf3 | 27 | static blk_opf_t dio_bio_write_op(struct kiocb *iocb) |
cd82cca7 | 28 | { |
16458cf3 | 29 | blk_opf_t opf = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE; |
cd82cca7 CH |
30 | |
31 | /* avoid the need for a I/O completion work item */ | |
91b94c5d | 32 | if (iocb_is_dsync(iocb)) |
16458cf3 BVA |
33 | opf |= REQ_FUA; |
34 | return opf; | |
cd82cca7 CH |
35 | } |
36 | ||
37fee2e4 KB |
37 | static bool blkdev_dio_unaligned(struct block_device *bdev, loff_t pos, |
38 | struct iov_iter *iter) | |
39 | { | |
b1a000d3 KB |
40 | return pos & (bdev_logical_block_size(bdev) - 1) || |
41 | !bdev_iter_is_aligned(bdev, iter); | |
37fee2e4 KB |
42 | } |
43 | ||
cd82cca7 CH |
44 | #define DIO_INLINE_BIO_VECS 4 |
45 | ||
cd82cca7 | 46 | static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, |
de4c7bef JG |
47 | struct iov_iter *iter, struct block_device *bdev, |
48 | unsigned int nr_pages) | |
cd82cca7 | 49 | { |
cd82cca7 CH |
50 | struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs; |
51 | loff_t pos = iocb->ki_pos; | |
52 | bool should_dirty = false; | |
53 | struct bio bio; | |
54 | ssize_t ret; | |
cd82cca7 | 55 | |
cd82cca7 CH |
56 | if (nr_pages <= DIO_INLINE_BIO_VECS) |
57 | vecs = inline_vecs; | |
58 | else { | |
59 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), | |
60 | GFP_KERNEL); | |
61 | if (!vecs) | |
62 | return -ENOMEM; | |
63 | } | |
64 | ||
49add496 CH |
65 | if (iov_iter_rw(iter) == READ) { |
66 | bio_init(&bio, bdev, vecs, nr_pages, REQ_OP_READ); | |
fcb14cb1 | 67 | if (user_backed_iter(iter)) |
49add496 CH |
68 | should_dirty = true; |
69 | } else { | |
70 | bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); | |
71 | } | |
6549a874 | 72 | bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
44981351 | 73 | bio.bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; |
cd82cca7 CH |
74 | bio.bi_ioprio = iocb->ki_ioprio; |
75 | ||
76 | ret = bio_iov_iter_get_pages(&bio, iter); | |
77 | if (unlikely(ret)) | |
78 | goto out; | |
79 | ret = bio.bi_iter.bi_size; | |
80 | ||
49add496 | 81 | if (iov_iter_rw(iter) == WRITE) |
cd82cca7 | 82 | task_io_account_write(ret); |
49add496 | 83 | |
cd82cca7 CH |
84 | if (iocb->ki_flags & IOCB_NOWAIT) |
85 | bio.bi_opf |= REQ_NOWAIT; | |
9650b453 ML |
86 | |
87 | submit_bio_wait(&bio); | |
cd82cca7 CH |
88 | |
89 | bio_release_pages(&bio, should_dirty); | |
90 | if (unlikely(bio.bi_status)) | |
91 | ret = blk_status_to_errno(bio.bi_status); | |
92 | ||
93 | out: | |
94 | if (vecs != inline_vecs) | |
95 | kfree(vecs); | |
96 | ||
97 | bio_uninit(&bio); | |
98 | ||
99 | return ret; | |
100 | } | |
101 | ||
09ce8744 | 102 | enum { |
e71aa913 PB |
103 | DIO_SHOULD_DIRTY = 1, |
104 | DIO_IS_SYNC = 2, | |
09ce8744 JA |
105 | }; |
106 | ||
cd82cca7 CH |
107 | struct blkdev_dio { |
108 | union { | |
109 | struct kiocb *iocb; | |
110 | struct task_struct *waiter; | |
111 | }; | |
112 | size_t size; | |
113 | atomic_t ref; | |
09ce8744 | 114 | unsigned int flags; |
6155631a | 115 | struct bio bio ____cacheline_aligned_in_smp; |
cd82cca7 CH |
116 | }; |
117 | ||
118 | static struct bio_set blkdev_dio_pool; | |
119 | ||
cd82cca7 CH |
120 | static void blkdev_bio_end_io(struct bio *bio) |
121 | { | |
122 | struct blkdev_dio *dio = bio->bi_private; | |
09ce8744 | 123 | bool should_dirty = dio->flags & DIO_SHOULD_DIRTY; |
cd82cca7 CH |
124 | |
125 | if (bio->bi_status && !dio->bio.bi_status) | |
126 | dio->bio.bi_status = bio->bi_status; | |
127 | ||
e71aa913 | 128 | if (atomic_dec_and_test(&dio->ref)) { |
09ce8744 | 129 | if (!(dio->flags & DIO_IS_SYNC)) { |
cd82cca7 CH |
130 | struct kiocb *iocb = dio->iocb; |
131 | ssize_t ret; | |
132 | ||
3e08773c CH |
133 | WRITE_ONCE(iocb->private, NULL); |
134 | ||
cd82cca7 CH |
135 | if (likely(!dio->bio.bi_status)) { |
136 | ret = dio->size; | |
137 | iocb->ki_pos += ret; | |
138 | } else { | |
139 | ret = blk_status_to_errno(dio->bio.bi_status); | |
140 | } | |
141 | ||
6b19b766 | 142 | dio->iocb->ki_complete(iocb, ret); |
e71aa913 | 143 | bio_put(&dio->bio); |
cd82cca7 CH |
144 | } else { |
145 | struct task_struct *waiter = dio->waiter; | |
146 | ||
147 | WRITE_ONCE(dio->waiter, NULL); | |
148 | blk_wake_io_task(waiter); | |
149 | } | |
150 | } | |
151 | ||
152 | if (should_dirty) { | |
153 | bio_check_pages_dirty(bio); | |
154 | } else { | |
155 | bio_release_pages(bio, false); | |
156 | bio_put(bio); | |
157 | } | |
158 | } | |
159 | ||
160 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, | |
de4c7bef | 161 | struct block_device *bdev, unsigned int nr_pages) |
cd82cca7 | 162 | { |
cd82cca7 CH |
163 | struct blk_plug plug; |
164 | struct blkdev_dio *dio; | |
165 | struct bio *bio; | |
cd82cca7 | 166 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
16458cf3 | 167 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
cd82cca7 | 168 | loff_t pos = iocb->ki_pos; |
cd82cca7 CH |
169 | int ret = 0; |
170 | ||
0df71650 MS |
171 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
172 | opf |= REQ_ALLOC_CACHE; | |
173 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
174 | &blkdev_dio_pool); | |
cd82cca7 | 175 | dio = container_of(bio, struct blkdev_dio, bio); |
e71aa913 PB |
176 | atomic_set(&dio->ref, 1); |
177 | /* | |
178 | * Grab an extra reference to ensure the dio structure which is embedded | |
179 | * into the first bio stays around. | |
180 | */ | |
181 | bio_get(bio); | |
182 | ||
09ce8744 JA |
183 | is_sync = is_sync_kiocb(iocb); |
184 | if (is_sync) { | |
185 | dio->flags = DIO_IS_SYNC; | |
cd82cca7 | 186 | dio->waiter = current; |
cd82cca7 | 187 | } else { |
09ce8744 | 188 | dio->flags = 0; |
cd82cca7 CH |
189 | dio->iocb = iocb; |
190 | } | |
191 | ||
192 | dio->size = 0; | |
fcb14cb1 | 193 | if (is_read && user_backed_iter(iter)) |
09ce8744 | 194 | dio->flags |= DIO_SHOULD_DIRTY; |
cd82cca7 | 195 | |
25d207dc | 196 | blk_start_plug(&plug); |
cd82cca7 CH |
197 | |
198 | for (;;) { | |
6549a874 | 199 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
44981351 | 200 | bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; |
cd82cca7 CH |
201 | bio->bi_private = dio; |
202 | bio->bi_end_io = blkdev_bio_end_io; | |
203 | bio->bi_ioprio = iocb->ki_ioprio; | |
204 | ||
205 | ret = bio_iov_iter_get_pages(bio, iter); | |
206 | if (unlikely(ret)) { | |
207 | bio->bi_status = BLK_STS_IOERR; | |
208 | bio_endio(bio); | |
209 | break; | |
210 | } | |
67d59247 JA |
211 | if (iocb->ki_flags & IOCB_NOWAIT) { |
212 | /* | |
213 | * This is nonblocking IO, and we need to allocate | |
214 | * another bio if we have data left to map. As we | |
215 | * cannot guarantee that one of the sub bios will not | |
216 | * fail getting issued FOR NOWAIT and as error results | |
217 | * are coalesced across all of them, be safe and ask for | |
218 | * a retry of this from blocking context. | |
219 | */ | |
220 | if (unlikely(iov_iter_count(iter))) { | |
221 | bio_release_pages(bio, false); | |
222 | bio_clear_flag(bio, BIO_REFFED); | |
223 | bio_put(bio); | |
224 | blk_finish_plug(&plug); | |
225 | return -EAGAIN; | |
226 | } | |
227 | bio->bi_opf |= REQ_NOWAIT; | |
228 | } | |
cd82cca7 CH |
229 | |
230 | if (is_read) { | |
09ce8744 | 231 | if (dio->flags & DIO_SHOULD_DIRTY) |
cd82cca7 CH |
232 | bio_set_pages_dirty(bio); |
233 | } else { | |
cd82cca7 CH |
234 | task_io_account_write(bio->bi_iter.bi_size); |
235 | } | |
cd82cca7 CH |
236 | dio->size += bio->bi_iter.bi_size; |
237 | pos += bio->bi_iter.bi_size; | |
238 | ||
239 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); | |
240 | if (!nr_pages) { | |
3e08773c | 241 | submit_bio(bio); |
cd82cca7 CH |
242 | break; |
243 | } | |
e71aa913 | 244 | atomic_inc(&dio->ref); |
cd82cca7 | 245 | submit_bio(bio); |
07888c66 | 246 | bio = bio_alloc(bdev, nr_pages, opf, GFP_KERNEL); |
cd82cca7 CH |
247 | } |
248 | ||
25d207dc | 249 | blk_finish_plug(&plug); |
cd82cca7 CH |
250 | |
251 | if (!is_sync) | |
252 | return -EIOCBQUEUED; | |
253 | ||
254 | for (;;) { | |
255 | set_current_state(TASK_UNINTERRUPTIBLE); | |
256 | if (!READ_ONCE(dio->waiter)) | |
257 | break; | |
25d207dc | 258 | blk_io_schedule(); |
cd82cca7 CH |
259 | } |
260 | __set_current_state(TASK_RUNNING); | |
261 | ||
262 | if (!ret) | |
263 | ret = blk_status_to_errno(dio->bio.bi_status); | |
264 | if (likely(!ret)) | |
265 | ret = dio->size; | |
266 | ||
267 | bio_put(&dio->bio); | |
268 | return ret; | |
269 | } | |
270 | ||
54a88eb8 PB |
271 | static void blkdev_bio_end_io_async(struct bio *bio) |
272 | { | |
273 | struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio); | |
274 | struct kiocb *iocb = dio->iocb; | |
275 | ssize_t ret; | |
276 | ||
bb49c6fa SG |
277 | WRITE_ONCE(iocb->private, NULL); |
278 | ||
54a88eb8 PB |
279 | if (likely(!bio->bi_status)) { |
280 | ret = dio->size; | |
281 | iocb->ki_pos += ret; | |
282 | } else { | |
283 | ret = blk_status_to_errno(bio->bi_status); | |
284 | } | |
285 | ||
b6773cdb | 286 | iocb->ki_complete(iocb, ret); |
54a88eb8 PB |
287 | |
288 | if (dio->flags & DIO_SHOULD_DIRTY) { | |
289 | bio_check_pages_dirty(bio); | |
290 | } else { | |
291 | bio_release_pages(bio, false); | |
292 | bio_put(bio); | |
293 | } | |
294 | } | |
295 | ||
296 | static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, | |
297 | struct iov_iter *iter, | |
de4c7bef | 298 | struct block_device *bdev, |
54a88eb8 PB |
299 | unsigned int nr_pages) |
300 | { | |
b77c88c2 | 301 | bool is_read = iov_iter_rw(iter) == READ; |
16458cf3 | 302 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
54a88eb8 PB |
303 | struct blkdev_dio *dio; |
304 | struct bio *bio; | |
305 | loff_t pos = iocb->ki_pos; | |
306 | int ret = 0; | |
307 | ||
0df71650 MS |
308 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
309 | opf |= REQ_ALLOC_CACHE; | |
310 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
311 | &blkdev_dio_pool); | |
54a88eb8 PB |
312 | dio = container_of(bio, struct blkdev_dio, bio); |
313 | dio->flags = 0; | |
314 | dio->iocb = iocb; | |
54a88eb8 | 315 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
44981351 | 316 | bio->bi_write_hint = file_inode(iocb->ki_filp)->i_write_hint; |
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 | ||
2bc05769 JA |
346 | if (iocb->ki_flags & IOCB_NOWAIT) |
347 | bio->bi_opf |= REQ_NOWAIT; | |
348 | ||
54a88eb8 | 349 | if (iocb->ki_flags & IOCB_HIPRI) { |
2bc05769 | 350 | bio->bi_opf |= REQ_POLLED; |
54a88eb8 PB |
351 | submit_bio(bio); |
352 | WRITE_ONCE(iocb->private, bio); | |
353 | } else { | |
354 | submit_bio(bio); | |
355 | } | |
356 | return -EIOCBQUEUED; | |
357 | } | |
358 | ||
cd82cca7 CH |
359 | static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
360 | { | |
de4c7bef | 361 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
cd82cca7 CH |
362 | unsigned int nr_pages; |
363 | ||
364 | if (!iov_iter_count(iter)) | |
365 | return 0; | |
366 | ||
de4c7bef JG |
367 | if (blkdev_dio_unaligned(bdev, iocb->ki_pos, iter)) |
368 | return -EINVAL; | |
369 | ||
cd82cca7 | 370 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); |
54a88eb8 PB |
371 | if (likely(nr_pages <= BIO_MAX_VECS)) { |
372 | if (is_sync_kiocb(iocb)) | |
de4c7bef JG |
373 | return __blkdev_direct_IO_simple(iocb, iter, bdev, |
374 | nr_pages); | |
375 | return __blkdev_direct_IO_async(iocb, iter, bdev, nr_pages); | |
54a88eb8 | 376 | } |
de4c7bef | 377 | return __blkdev_direct_IO(iocb, iter, bdev, bio_max_segs(nr_pages)); |
cd82cca7 CH |
378 | } |
379 | ||
487c607d CH |
380 | static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, |
381 | unsigned int flags, struct iomap *iomap, struct iomap *srcmap) | |
382 | { | |
383 | struct block_device *bdev = I_BDEV(inode); | |
384 | loff_t isize = i_size_read(inode); | |
385 | ||
386 | iomap->bdev = bdev; | |
387 | iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev)); | |
0c12028a | 388 | if (offset >= isize) |
487c607d CH |
389 | return -EIO; |
390 | iomap->type = IOMAP_MAPPED; | |
391 | iomap->addr = iomap->offset; | |
392 | iomap->length = isize - iomap->offset; | |
925c86a1 | 393 | iomap->flags |= IOMAP_F_BUFFER_HEAD; /* noop for !CONFIG_BUFFER_HEAD */ |
487c607d CH |
394 | return 0; |
395 | } | |
396 | ||
397 | static const struct iomap_ops blkdev_iomap_ops = { | |
398 | .iomap_begin = blkdev_iomap_begin, | |
399 | }; | |
400 | ||
925c86a1 CH |
401 | #ifdef CONFIG_BUFFER_HEAD |
402 | static int blkdev_get_block(struct inode *inode, sector_t iblock, | |
403 | struct buffer_head *bh, int create) | |
404 | { | |
405 | bh->b_bdev = I_BDEV(inode); | |
406 | bh->b_blocknr = iblock; | |
407 | set_buffer_mapped(bh); | |
408 | return 0; | |
409 | } | |
410 | ||
17bf23a9 MWO |
411 | /* |
412 | * We cannot call mpage_writepages() as it does not take the buffer lock. | |
413 | * We must use block_write_full_folio() directly which holds the buffer | |
414 | * lock. The buffer lock provides the synchronisation with writeback | |
415 | * that filesystems rely on when they use the blockdev's mapping. | |
416 | */ | |
417 | static int blkdev_writepages(struct address_space *mapping, | |
418 | struct writeback_control *wbc) | |
cd82cca7 | 419 | { |
17bf23a9 MWO |
420 | struct blk_plug plug; |
421 | int err; | |
422 | ||
423 | blk_start_plug(&plug); | |
424 | err = write_cache_pages(mapping, wbc, block_write_full_folio, | |
425 | blkdev_get_block); | |
426 | blk_finish_plug(&plug); | |
427 | ||
428 | return err; | |
cd82cca7 CH |
429 | } |
430 | ||
2c69e205 | 431 | static int blkdev_read_folio(struct file *file, struct folio *folio) |
cd82cca7 | 432 | { |
2c69e205 | 433 | return block_read_full_folio(folio, blkdev_get_block); |
cd82cca7 CH |
434 | } |
435 | ||
436 | static void blkdev_readahead(struct readahead_control *rac) | |
437 | { | |
438 | mpage_readahead(rac, blkdev_get_block); | |
439 | } | |
440 | ||
441 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
9d6b0cd7 | 442 | loff_t pos, unsigned len, struct page **pagep, void **fsdata) |
cd82cca7 | 443 | { |
b3992d1e | 444 | return block_write_begin(mapping, pos, len, pagep, blkdev_get_block); |
cd82cca7 CH |
445 | } |
446 | ||
447 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
448 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
449 | void *fsdata) | |
450 | { | |
451 | int ret; | |
452 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
453 | ||
454 | unlock_page(page); | |
455 | put_page(page); | |
456 | ||
457 | return ret; | |
458 | } | |
459 | ||
cd82cca7 | 460 | const struct address_space_operations def_blk_aops = { |
e621900a | 461 | .dirty_folio = block_dirty_folio, |
7ba13abb | 462 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 463 | .read_folio = blkdev_read_folio, |
cd82cca7 | 464 | .readahead = blkdev_readahead, |
17bf23a9 | 465 | .writepages = blkdev_writepages, |
cd82cca7 CH |
466 | .write_begin = blkdev_write_begin, |
467 | .write_end = blkdev_write_end, | |
67235182 | 468 | .migrate_folio = buffer_migrate_folio_norefs, |
cd82cca7 CH |
469 | .is_dirty_writeback = buffer_check_dirty_writeback, |
470 | }; | |
925c86a1 CH |
471 | #else /* CONFIG_BUFFER_HEAD */ |
472 | static int blkdev_read_folio(struct file *file, struct folio *folio) | |
473 | { | |
474 | return iomap_read_folio(folio, &blkdev_iomap_ops); | |
475 | } | |
476 | ||
477 | static void blkdev_readahead(struct readahead_control *rac) | |
478 | { | |
479 | iomap_readahead(rac, &blkdev_iomap_ops); | |
480 | } | |
481 | ||
482 | static int blkdev_map_blocks(struct iomap_writepage_ctx *wpc, | |
19871b5c | 483 | struct inode *inode, loff_t offset, unsigned int len) |
925c86a1 CH |
484 | { |
485 | loff_t isize = i_size_read(inode); | |
486 | ||
487 | if (WARN_ON_ONCE(offset >= isize)) | |
488 | return -EIO; | |
489 | if (offset >= wpc->iomap.offset && | |
490 | offset < wpc->iomap.offset + wpc->iomap.length) | |
491 | return 0; | |
492 | return blkdev_iomap_begin(inode, offset, isize - offset, | |
493 | IOMAP_WRITE, &wpc->iomap, NULL); | |
494 | } | |
495 | ||
496 | static const struct iomap_writeback_ops blkdev_writeback_ops = { | |
497 | .map_blocks = blkdev_map_blocks, | |
498 | }; | |
499 | ||
500 | static int blkdev_writepages(struct address_space *mapping, | |
501 | struct writeback_control *wbc) | |
502 | { | |
503 | struct iomap_writepage_ctx wpc = { }; | |
504 | ||
505 | return iomap_writepages(mapping, wbc, &wpc, &blkdev_writeback_ops); | |
506 | } | |
507 | ||
508 | const struct address_space_operations def_blk_aops = { | |
509 | .dirty_folio = filemap_dirty_folio, | |
510 | .release_folio = iomap_release_folio, | |
511 | .invalidate_folio = iomap_invalidate_folio, | |
512 | .read_folio = blkdev_read_folio, | |
513 | .readahead = blkdev_readahead, | |
514 | .writepages = blkdev_writepages, | |
515 | .is_partially_uptodate = iomap_is_partially_uptodate, | |
af7628d6 | 516 | .error_remove_folio = generic_error_remove_folio, |
925c86a1 CH |
517 | .migrate_folio = filemap_migrate_folio, |
518 | }; | |
519 | #endif /* CONFIG_BUFFER_HEAD */ | |
cd82cca7 CH |
520 | |
521 | /* | |
522 | * for a block special file file_inode(file)->i_size is zero | |
523 | * so we compute the size by hand (just as in block_read/write above) | |
524 | */ | |
525 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
526 | { | |
527 | struct inode *bd_inode = bdev_file_inode(file); | |
528 | loff_t retval; | |
529 | ||
530 | inode_lock(bd_inode); | |
531 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
532 | inode_unlock(bd_inode); | |
533 | return retval; | |
534 | } | |
535 | ||
536 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
537 | int datasync) | |
538 | { | |
4e762d86 | 539 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
cd82cca7 CH |
540 | int error; |
541 | ||
542 | error = file_write_and_wait_range(filp, start, end); | |
543 | if (error) | |
544 | return error; | |
545 | ||
546 | /* | |
547 | * There is no need to serialise calls to blkdev_issue_flush with | |
548 | * i_mutex and doing so causes performance issues with concurrent | |
549 | * O_SYNC writers to a block device. | |
550 | */ | |
551 | error = blkdev_issue_flush(bdev); | |
552 | if (error == -EOPNOTSUPP) | |
553 | error = 0; | |
554 | ||
555 | return error; | |
556 | } | |
557 | ||
841dd789 JK |
558 | /** |
559 | * file_to_blk_mode - get block open flags from file flags | |
560 | * @file: file whose open flags should be converted | |
561 | * | |
562 | * Look at file open flags and generate corresponding block open flags from | |
563 | * them. The function works both for file just being open (e.g. during ->open | |
564 | * callback) and for file that is already open. This is actually non-trivial | |
565 | * (see comment in the function). | |
566 | */ | |
05bdb996 CH |
567 | blk_mode_t file_to_blk_mode(struct file *file) |
568 | { | |
569 | blk_mode_t mode = 0; | |
570 | ||
571 | if (file->f_mode & FMODE_READ) | |
572 | mode |= BLK_OPEN_READ; | |
573 | if (file->f_mode & FMODE_WRITE) | |
574 | mode |= BLK_OPEN_WRITE; | |
841dd789 | 575 | /* |
ab838b3f CB |
576 | * do_dentry_open() clears O_EXCL from f_flags, use file->private_data |
577 | * to determine whether the open was exclusive for already open files. | |
841dd789 | 578 | */ |
ab838b3f CB |
579 | if (file->private_data) |
580 | mode |= BLK_OPEN_EXCL; | |
841dd789 | 581 | else if (file->f_flags & O_EXCL) |
05bdb996 CH |
582 | mode |= BLK_OPEN_EXCL; |
583 | if (file->f_flags & O_NDELAY) | |
584 | mode |= BLK_OPEN_NDELAY; | |
585 | ||
586 | /* | |
587 | * If all bits in O_ACCMODE set (aka O_RDWR | O_WRONLY), the floppy | |
588 | * driver has historically allowed ioctls as if the file was opened for | |
589 | * writing, but does not allow and actual reads or writes. | |
590 | */ | |
591 | if ((file->f_flags & O_ACCMODE) == (O_RDWR | O_WRONLY)) | |
592 | mode |= BLK_OPEN_WRITE_IOCTL; | |
593 | ||
594 | return mode; | |
595 | } | |
596 | ||
cd82cca7 CH |
597 | static int blkdev_open(struct inode *inode, struct file *filp) |
598 | { | |
a56aefca | 599 | struct block_device *bdev; |
841dd789 | 600 | blk_mode_t mode; |
a56aefca | 601 | int ret; |
cd82cca7 | 602 | |
841dd789 | 603 | mode = file_to_blk_mode(filp); |
ab838b3f CB |
604 | /* Use the file as the holder. */ |
605 | if (mode & BLK_OPEN_EXCL) | |
606 | filp->private_data = filp; | |
607 | ret = bdev_permission(inode->i_rdev, mode, filp->private_data); | |
a56aefca CB |
608 | if (ret) |
609 | return ret; | |
610 | ||
611 | bdev = blkdev_get_no_open(inode->i_rdev); | |
612 | if (!bdev) | |
613 | return -ENXIO; | |
614 | ||
ab838b3f | 615 | ret = bdev_open(bdev, mode, filp->private_data, NULL, filp); |
a56aefca CB |
616 | if (ret) |
617 | blkdev_put_no_open(bdev); | |
618 | return ret; | |
cd82cca7 CH |
619 | } |
620 | ||
7ee34cbc | 621 | static int blkdev_release(struct inode *inode, struct file *filp) |
cd82cca7 | 622 | { |
ab838b3f | 623 | bdev_release(filp); |
cd82cca7 CH |
624 | return 0; |
625 | } | |
626 | ||
727cfe97 CH |
627 | static ssize_t |
628 | blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) | |
629 | { | |
630 | size_t count = iov_iter_count(from); | |
631 | ssize_t written; | |
632 | ||
633 | written = kiocb_invalidate_pages(iocb, count); | |
634 | if (written) { | |
635 | if (written == -EBUSY) | |
636 | return 0; | |
637 | return written; | |
638 | } | |
639 | ||
640 | written = blkdev_direct_IO(iocb, from); | |
641 | if (written > 0) { | |
642 | kiocb_invalidate_post_direct_write(iocb, count); | |
643 | iocb->ki_pos += written; | |
644 | count -= written; | |
645 | } | |
646 | if (written != -EIOCBQUEUED) | |
647 | iov_iter_revert(from, count - iov_iter_count(from)); | |
648 | return written; | |
649 | } | |
650 | ||
487c607d CH |
651 | static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) |
652 | { | |
653 | return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); | |
654 | } | |
655 | ||
cd82cca7 CH |
656 | /* |
657 | * Write data to the block device. Only intended for the block device itself | |
658 | * and the raw driver which basically is a fake block device. | |
659 | * | |
660 | * Does not take i_mutex for the write and thus is not for general purpose | |
661 | * use. | |
662 | */ | |
663 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
664 | { | |
727cfe97 | 665 | struct file *file = iocb->ki_filp; |
39c3b4e7 AV |
666 | struct inode *bd_inode = bdev_file_inode(file); |
667 | struct block_device *bdev = I_BDEV(bd_inode); | |
138c1a38 | 668 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
669 | size_t shorted = 0; |
670 | ssize_t ret; | |
671 | ||
fac7c6d5 | 672 | if (bdev_read_only(bdev)) |
cd82cca7 CH |
673 | return -EPERM; |
674 | ||
675 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
676 | return -ETXTBSY; | |
677 | ||
678 | if (!iov_iter_count(from)) | |
679 | return 0; | |
680 | ||
681 | if (iocb->ki_pos >= size) | |
682 | return -ENOSPC; | |
683 | ||
684 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
685 | return -EOPNOTSUPP; | |
686 | ||
687 | size -= iocb->ki_pos; | |
688 | if (iov_iter_count(from) > size) { | |
689 | shorted = iov_iter_count(from) - size; | |
690 | iov_iter_truncate(from, size); | |
691 | } | |
692 | ||
727cfe97 CH |
693 | ret = file_update_time(file); |
694 | if (ret) | |
695 | return ret; | |
696 | ||
697 | if (iocb->ki_flags & IOCB_DIRECT) { | |
698 | ret = blkdev_direct_write(iocb, from); | |
699 | if (ret >= 0 && iov_iter_count(from)) | |
700 | ret = direct_write_fallback(iocb, from, ret, | |
487c607d | 701 | blkdev_buffered_write(iocb, from)); |
727cfe97 | 702 | } else { |
487c607d | 703 | ret = blkdev_buffered_write(iocb, from); |
727cfe97 CH |
704 | } |
705 | ||
cd82cca7 CH |
706 | if (ret > 0) |
707 | ret = generic_write_sync(iocb, ret); | |
708 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
cd82cca7 CH |
709 | return ret; |
710 | } | |
711 | ||
712 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
713 | { | |
4e762d86 | 714 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
138c1a38 | 715 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
716 | loff_t pos = iocb->ki_pos; |
717 | size_t shorted = 0; | |
ceaa7625 | 718 | ssize_t ret = 0; |
3e1f941d | 719 | size_t count; |
cd82cca7 | 720 | |
3e1f941d | 721 | if (unlikely(pos + iov_iter_count(to) > size)) { |
6450fe1f PB |
722 | if (pos >= size) |
723 | return 0; | |
724 | size -= pos; | |
3e1f941d ID |
725 | shorted = iov_iter_count(to) - size; |
726 | iov_iter_truncate(to, size); | |
cd82cca7 CH |
727 | } |
728 | ||
3e1f941d ID |
729 | count = iov_iter_count(to); |
730 | if (!count) | |
731 | goto reexpand; /* skip atime */ | |
732 | ||
ceaa7625 | 733 | if (iocb->ki_flags & IOCB_DIRECT) { |
3c435a0f CH |
734 | ret = kiocb_write_and_wait(iocb, count); |
735 | if (ret < 0) | |
736 | goto reexpand; | |
ceaa7625 JA |
737 | file_accessed(iocb->ki_filp); |
738 | ||
739 | ret = blkdev_direct_IO(iocb, to); | |
740 | if (ret >= 0) { | |
741 | iocb->ki_pos += ret; | |
742 | count -= ret; | |
743 | } | |
3e1f941d | 744 | iov_iter_revert(to, count - iov_iter_count(to)); |
ceaa7625 | 745 | if (ret < 0 || !count) |
3e1f941d | 746 | goto reexpand; |
ceaa7625 JA |
747 | } |
748 | ||
749 | ret = filemap_read(iocb, to, ret); | |
6450fe1f | 750 | |
3e1f941d | 751 | reexpand: |
6450fe1f PB |
752 | if (unlikely(shorted)) |
753 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
cd82cca7 CH |
754 | return ret; |
755 | } | |
756 | ||
757 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
758 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
759 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
760 | ||
761 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
762 | loff_t len) | |
763 | { | |
f278eb3d ML |
764 | struct inode *inode = bdev_file_inode(file); |
765 | struct block_device *bdev = I_BDEV(inode); | |
cd82cca7 CH |
766 | loff_t end = start + len - 1; |
767 | loff_t isize; | |
768 | int error; | |
769 | ||
770 | /* Fail if we don't recognize the flags. */ | |
771 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
772 | return -EOPNOTSUPP; | |
773 | ||
774 | /* Don't go off the end of the device. */ | |
2a93ad8f | 775 | isize = bdev_nr_bytes(bdev); |
cd82cca7 CH |
776 | if (start >= isize) |
777 | return -EINVAL; | |
778 | if (end >= isize) { | |
779 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
780 | len = isize - start; | |
781 | end = start + len - 1; | |
782 | } else | |
783 | return -EINVAL; | |
784 | } | |
785 | ||
786 | /* | |
787 | * Don't allow IO that isn't aligned to logical block size. | |
788 | */ | |
789 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
790 | return -EINVAL; | |
791 | ||
f278eb3d ML |
792 | filemap_invalidate_lock(inode->i_mapping); |
793 | ||
1364a3c3 SK |
794 | /* |
795 | * Invalidate the page cache, including dirty pages, for valid | |
796 | * de-allocate mode calls to fallocate(). | |
797 | */ | |
cd82cca7 CH |
798 | switch (mode) { |
799 | case FALLOC_FL_ZERO_RANGE: | |
800 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
801 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
802 | if (error) | |
803 | goto fail; | |
804 | ||
6549a874 PB |
805 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
806 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
807 | BLKDEV_ZERO_NOUNMAP); | |
cd82cca7 CH |
808 | break; |
809 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
810 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
811 | if (error) | |
812 | goto fail; | |
813 | ||
6549a874 PB |
814 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
815 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
816 | BLKDEV_ZERO_NOFALLBACK); | |
cd82cca7 CH |
817 | break; |
818 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
1364a3c3 SK |
819 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
820 | if (error) | |
821 | goto fail; | |
822 | ||
6549a874 | 823 | error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
44abff2c | 824 | len >> SECTOR_SHIFT, GFP_KERNEL); |
cd82cca7 CH |
825 | break; |
826 | default: | |
f278eb3d | 827 | error = -EOPNOTSUPP; |
cd82cca7 | 828 | } |
cd82cca7 | 829 | |
f278eb3d ML |
830 | fail: |
831 | filemap_invalidate_unlock(inode->i_mapping); | |
832 | return error; | |
cd82cca7 CH |
833 | } |
834 | ||
69baa3a6 LP |
835 | static int blkdev_mmap(struct file *file, struct vm_area_struct *vma) |
836 | { | |
837 | struct inode *bd_inode = bdev_file_inode(file); | |
838 | ||
839 | if (bdev_read_only(I_BDEV(bd_inode))) | |
840 | return generic_file_readonly_mmap(file, vma); | |
841 | ||
842 | return generic_file_mmap(file, vma); | |
843 | } | |
844 | ||
cd82cca7 CH |
845 | const struct file_operations def_blk_fops = { |
846 | .open = blkdev_open, | |
7ee34cbc | 847 | .release = blkdev_release, |
cd82cca7 CH |
848 | .llseek = blkdev_llseek, |
849 | .read_iter = blkdev_read_iter, | |
850 | .write_iter = blkdev_write_iter, | |
3e08773c | 851 | .iopoll = iocb_bio_iopoll, |
69baa3a6 | 852 | .mmap = blkdev_mmap, |
cd82cca7 | 853 | .fsync = blkdev_fsync, |
8a709512 | 854 | .unlocked_ioctl = blkdev_ioctl, |
cd82cca7 CH |
855 | #ifdef CONFIG_COMPAT |
856 | .compat_ioctl = compat_blkdev_ioctl, | |
857 | #endif | |
2cb1e089 | 858 | .splice_read = filemap_splice_read, |
cd82cca7 CH |
859 | .splice_write = iter_file_splice_write, |
860 | .fallocate = blkdev_fallocate, | |
210a03c9 | 861 | .fop_flags = FOP_BUFFER_RASYNC, |
cd82cca7 CH |
862 | }; |
863 | ||
864 | static __init int blkdev_init(void) | |
865 | { | |
866 | return bioset_init(&blkdev_dio_pool, 4, | |
867 | offsetof(struct blkdev_dio, bio), | |
868 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
869 | } | |
870 | module_init(blkdev_init); |