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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 CH |
46 | static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb, |
47 | struct iov_iter *iter, unsigned int nr_pages) | |
48 | { | |
4e762d86 | 49 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
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 | |
37fee2e4 | 56 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
cd82cca7 CH |
57 | return -EINVAL; |
58 | ||
59 | if (nr_pages <= DIO_INLINE_BIO_VECS) | |
60 | vecs = inline_vecs; | |
61 | else { | |
62 | vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec), | |
63 | GFP_KERNEL); | |
64 | if (!vecs) | |
65 | return -ENOMEM; | |
66 | } | |
67 | ||
49add496 CH |
68 | if (iov_iter_rw(iter) == READ) { |
69 | bio_init(&bio, bdev, vecs, nr_pages, REQ_OP_READ); | |
fcb14cb1 | 70 | if (user_backed_iter(iter)) |
49add496 CH |
71 | should_dirty = true; |
72 | } else { | |
73 | bio_init(&bio, bdev, vecs, nr_pages, dio_bio_write_op(iocb)); | |
74 | } | |
6549a874 | 75 | bio.bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
76 | bio.bi_ioprio = iocb->ki_ioprio; |
77 | ||
78 | ret = bio_iov_iter_get_pages(&bio, iter); | |
79 | if (unlikely(ret)) | |
80 | goto out; | |
81 | ret = bio.bi_iter.bi_size; | |
82 | ||
49add496 | 83 | if (iov_iter_rw(iter) == WRITE) |
cd82cca7 | 84 | task_io_account_write(ret); |
49add496 | 85 | |
cd82cca7 CH |
86 | if (iocb->ki_flags & IOCB_NOWAIT) |
87 | bio.bi_opf |= REQ_NOWAIT; | |
9650b453 ML |
88 | |
89 | submit_bio_wait(&bio); | |
cd82cca7 CH |
90 | |
91 | bio_release_pages(&bio, should_dirty); | |
92 | if (unlikely(bio.bi_status)) | |
93 | ret = blk_status_to_errno(bio.bi_status); | |
94 | ||
95 | out: | |
96 | if (vecs != inline_vecs) | |
97 | kfree(vecs); | |
98 | ||
99 | bio_uninit(&bio); | |
100 | ||
101 | return ret; | |
102 | } | |
103 | ||
09ce8744 | 104 | enum { |
e71aa913 PB |
105 | DIO_SHOULD_DIRTY = 1, |
106 | DIO_IS_SYNC = 2, | |
09ce8744 JA |
107 | }; |
108 | ||
cd82cca7 CH |
109 | struct blkdev_dio { |
110 | union { | |
111 | struct kiocb *iocb; | |
112 | struct task_struct *waiter; | |
113 | }; | |
114 | size_t size; | |
115 | atomic_t ref; | |
09ce8744 | 116 | unsigned int flags; |
6155631a | 117 | struct bio bio ____cacheline_aligned_in_smp; |
cd82cca7 CH |
118 | }; |
119 | ||
120 | static struct bio_set blkdev_dio_pool; | |
121 | ||
cd82cca7 CH |
122 | static void blkdev_bio_end_io(struct bio *bio) |
123 | { | |
124 | struct blkdev_dio *dio = bio->bi_private; | |
09ce8744 | 125 | bool should_dirty = dio->flags & DIO_SHOULD_DIRTY; |
cd82cca7 CH |
126 | |
127 | if (bio->bi_status && !dio->bio.bi_status) | |
128 | dio->bio.bi_status = bio->bi_status; | |
129 | ||
e71aa913 | 130 | if (atomic_dec_and_test(&dio->ref)) { |
09ce8744 | 131 | if (!(dio->flags & DIO_IS_SYNC)) { |
cd82cca7 CH |
132 | struct kiocb *iocb = dio->iocb; |
133 | ssize_t ret; | |
134 | ||
3e08773c CH |
135 | WRITE_ONCE(iocb->private, NULL); |
136 | ||
cd82cca7 CH |
137 | if (likely(!dio->bio.bi_status)) { |
138 | ret = dio->size; | |
139 | iocb->ki_pos += ret; | |
140 | } else { | |
141 | ret = blk_status_to_errno(dio->bio.bi_status); | |
142 | } | |
143 | ||
6b19b766 | 144 | dio->iocb->ki_complete(iocb, ret); |
e71aa913 | 145 | bio_put(&dio->bio); |
cd82cca7 CH |
146 | } else { |
147 | struct task_struct *waiter = dio->waiter; | |
148 | ||
149 | WRITE_ONCE(dio->waiter, NULL); | |
150 | blk_wake_io_task(waiter); | |
151 | } | |
152 | } | |
153 | ||
154 | if (should_dirty) { | |
155 | bio_check_pages_dirty(bio); | |
156 | } else { | |
157 | bio_release_pages(bio, false); | |
158 | bio_put(bio); | |
159 | } | |
160 | } | |
161 | ||
162 | static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, | |
163 | unsigned int nr_pages) | |
164 | { | |
4e762d86 | 165 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
cd82cca7 CH |
166 | struct blk_plug plug; |
167 | struct blkdev_dio *dio; | |
168 | struct bio *bio; | |
cd82cca7 | 169 | bool is_read = (iov_iter_rw(iter) == READ), is_sync; |
16458cf3 | 170 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
cd82cca7 | 171 | loff_t pos = iocb->ki_pos; |
cd82cca7 CH |
172 | int ret = 0; |
173 | ||
37fee2e4 | 174 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
cd82cca7 CH |
175 | return -EINVAL; |
176 | ||
0df71650 MS |
177 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
178 | opf |= REQ_ALLOC_CACHE; | |
179 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
180 | &blkdev_dio_pool); | |
cd82cca7 | 181 | dio = container_of(bio, struct blkdev_dio, bio); |
e71aa913 PB |
182 | atomic_set(&dio->ref, 1); |
183 | /* | |
184 | * Grab an extra reference to ensure the dio structure which is embedded | |
185 | * into the first bio stays around. | |
186 | */ | |
187 | bio_get(bio); | |
188 | ||
09ce8744 JA |
189 | is_sync = is_sync_kiocb(iocb); |
190 | if (is_sync) { | |
191 | dio->flags = DIO_IS_SYNC; | |
cd82cca7 | 192 | dio->waiter = current; |
cd82cca7 | 193 | } else { |
09ce8744 | 194 | dio->flags = 0; |
cd82cca7 CH |
195 | dio->iocb = iocb; |
196 | } | |
197 | ||
198 | dio->size = 0; | |
fcb14cb1 | 199 | if (is_read && user_backed_iter(iter)) |
09ce8744 | 200 | dio->flags |= DIO_SHOULD_DIRTY; |
cd82cca7 | 201 | |
25d207dc | 202 | blk_start_plug(&plug); |
cd82cca7 CH |
203 | |
204 | for (;;) { | |
6549a874 | 205 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
cd82cca7 CH |
206 | bio->bi_private = dio; |
207 | bio->bi_end_io = blkdev_bio_end_io; | |
208 | bio->bi_ioprio = iocb->ki_ioprio; | |
209 | ||
210 | ret = bio_iov_iter_get_pages(bio, iter); | |
211 | if (unlikely(ret)) { | |
212 | bio->bi_status = BLK_STS_IOERR; | |
213 | bio_endio(bio); | |
214 | break; | |
215 | } | |
67d59247 JA |
216 | if (iocb->ki_flags & IOCB_NOWAIT) { |
217 | /* | |
218 | * This is nonblocking IO, and we need to allocate | |
219 | * another bio if we have data left to map. As we | |
220 | * cannot guarantee that one of the sub bios will not | |
221 | * fail getting issued FOR NOWAIT and as error results | |
222 | * are coalesced across all of them, be safe and ask for | |
223 | * a retry of this from blocking context. | |
224 | */ | |
225 | if (unlikely(iov_iter_count(iter))) { | |
226 | bio_release_pages(bio, false); | |
227 | bio_clear_flag(bio, BIO_REFFED); | |
228 | bio_put(bio); | |
229 | blk_finish_plug(&plug); | |
230 | return -EAGAIN; | |
231 | } | |
232 | bio->bi_opf |= REQ_NOWAIT; | |
233 | } | |
cd82cca7 CH |
234 | |
235 | if (is_read) { | |
09ce8744 | 236 | if (dio->flags & DIO_SHOULD_DIRTY) |
cd82cca7 CH |
237 | bio_set_pages_dirty(bio); |
238 | } else { | |
cd82cca7 CH |
239 | task_io_account_write(bio->bi_iter.bi_size); |
240 | } | |
cd82cca7 CH |
241 | dio->size += bio->bi_iter.bi_size; |
242 | pos += bio->bi_iter.bi_size; | |
243 | ||
244 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS); | |
245 | if (!nr_pages) { | |
3e08773c | 246 | submit_bio(bio); |
cd82cca7 CH |
247 | break; |
248 | } | |
e71aa913 | 249 | atomic_inc(&dio->ref); |
cd82cca7 | 250 | submit_bio(bio); |
07888c66 | 251 | bio = bio_alloc(bdev, nr_pages, opf, GFP_KERNEL); |
cd82cca7 CH |
252 | } |
253 | ||
25d207dc | 254 | blk_finish_plug(&plug); |
cd82cca7 CH |
255 | |
256 | if (!is_sync) | |
257 | return -EIOCBQUEUED; | |
258 | ||
259 | for (;;) { | |
260 | set_current_state(TASK_UNINTERRUPTIBLE); | |
261 | if (!READ_ONCE(dio->waiter)) | |
262 | break; | |
25d207dc | 263 | blk_io_schedule(); |
cd82cca7 CH |
264 | } |
265 | __set_current_state(TASK_RUNNING); | |
266 | ||
267 | if (!ret) | |
268 | ret = blk_status_to_errno(dio->bio.bi_status); | |
269 | if (likely(!ret)) | |
270 | ret = dio->size; | |
271 | ||
272 | bio_put(&dio->bio); | |
273 | return ret; | |
274 | } | |
275 | ||
54a88eb8 PB |
276 | static void blkdev_bio_end_io_async(struct bio *bio) |
277 | { | |
278 | struct blkdev_dio *dio = container_of(bio, struct blkdev_dio, bio); | |
279 | struct kiocb *iocb = dio->iocb; | |
280 | ssize_t ret; | |
281 | ||
bb49c6fa SG |
282 | WRITE_ONCE(iocb->private, NULL); |
283 | ||
54a88eb8 PB |
284 | if (likely(!bio->bi_status)) { |
285 | ret = dio->size; | |
286 | iocb->ki_pos += ret; | |
287 | } else { | |
288 | ret = blk_status_to_errno(bio->bi_status); | |
289 | } | |
290 | ||
b6773cdb | 291 | iocb->ki_complete(iocb, ret); |
54a88eb8 PB |
292 | |
293 | if (dio->flags & DIO_SHOULD_DIRTY) { | |
294 | bio_check_pages_dirty(bio); | |
295 | } else { | |
296 | bio_release_pages(bio, false); | |
297 | bio_put(bio); | |
298 | } | |
299 | } | |
300 | ||
301 | static ssize_t __blkdev_direct_IO_async(struct kiocb *iocb, | |
302 | struct iov_iter *iter, | |
303 | unsigned int nr_pages) | |
304 | { | |
4e762d86 | 305 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
b77c88c2 | 306 | bool is_read = iov_iter_rw(iter) == READ; |
16458cf3 | 307 | blk_opf_t opf = is_read ? REQ_OP_READ : dio_bio_write_op(iocb); |
54a88eb8 PB |
308 | struct blkdev_dio *dio; |
309 | struct bio *bio; | |
310 | loff_t pos = iocb->ki_pos; | |
311 | int ret = 0; | |
312 | ||
37fee2e4 | 313 | if (blkdev_dio_unaligned(bdev, pos, iter)) |
54a88eb8 PB |
314 | return -EINVAL; |
315 | ||
0df71650 MS |
316 | if (iocb->ki_flags & IOCB_ALLOC_CACHE) |
317 | opf |= REQ_ALLOC_CACHE; | |
318 | bio = bio_alloc_bioset(bdev, nr_pages, opf, GFP_KERNEL, | |
319 | &blkdev_dio_pool); | |
54a88eb8 PB |
320 | dio = container_of(bio, struct blkdev_dio, bio); |
321 | dio->flags = 0; | |
322 | dio->iocb = iocb; | |
54a88eb8 | 323 | bio->bi_iter.bi_sector = pos >> SECTOR_SHIFT; |
54a88eb8 PB |
324 | bio->bi_end_io = blkdev_bio_end_io_async; |
325 | bio->bi_ioprio = iocb->ki_ioprio; | |
326 | ||
1bb6b810 PB |
327 | if (iov_iter_is_bvec(iter)) { |
328 | /* | |
329 | * Users don't rely on the iterator being in any particular | |
330 | * state for async I/O returning -EIOCBQUEUED, hence we can | |
331 | * avoid expensive iov_iter_advance(). Bypass | |
332 | * bio_iov_iter_get_pages() and set the bvec directly. | |
333 | */ | |
334 | bio_iov_bvec_set(bio, iter); | |
335 | } else { | |
336 | ret = bio_iov_iter_get_pages(bio, iter); | |
337 | if (unlikely(ret)) { | |
75feae73 | 338 | bio_put(bio); |
1bb6b810 PB |
339 | return ret; |
340 | } | |
54a88eb8 PB |
341 | } |
342 | dio->size = bio->bi_iter.bi_size; | |
343 | ||
b77c88c2 | 344 | if (is_read) { |
fcb14cb1 | 345 | if (user_backed_iter(iter)) { |
54a88eb8 PB |
346 | dio->flags |= DIO_SHOULD_DIRTY; |
347 | bio_set_pages_dirty(bio); | |
348 | } | |
349 | } else { | |
54a88eb8 PB |
350 | task_io_account_write(bio->bi_iter.bi_size); |
351 | } | |
352 | ||
2bc05769 JA |
353 | if (iocb->ki_flags & IOCB_NOWAIT) |
354 | bio->bi_opf |= REQ_NOWAIT; | |
355 | ||
54a88eb8 | 356 | if (iocb->ki_flags & IOCB_HIPRI) { |
2bc05769 | 357 | bio->bi_opf |= REQ_POLLED; |
54a88eb8 PB |
358 | submit_bio(bio); |
359 | WRITE_ONCE(iocb->private, bio); | |
360 | } else { | |
361 | submit_bio(bio); | |
362 | } | |
363 | return -EIOCBQUEUED; | |
364 | } | |
365 | ||
cd82cca7 CH |
366 | static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter) |
367 | { | |
368 | unsigned int nr_pages; | |
369 | ||
370 | if (!iov_iter_count(iter)) | |
371 | return 0; | |
372 | ||
373 | nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1); | |
54a88eb8 PB |
374 | if (likely(nr_pages <= BIO_MAX_VECS)) { |
375 | if (is_sync_kiocb(iocb)) | |
376 | return __blkdev_direct_IO_simple(iocb, iter, nr_pages); | |
377 | return __blkdev_direct_IO_async(iocb, iter, nr_pages); | |
378 | } | |
cd82cca7 CH |
379 | return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages)); |
380 | } | |
381 | ||
487c607d CH |
382 | static int blkdev_iomap_begin(struct inode *inode, loff_t offset, loff_t length, |
383 | unsigned int flags, struct iomap *iomap, struct iomap *srcmap) | |
384 | { | |
385 | struct block_device *bdev = I_BDEV(inode); | |
386 | loff_t isize = i_size_read(inode); | |
387 | ||
388 | iomap->bdev = bdev; | |
389 | iomap->offset = ALIGN_DOWN(offset, bdev_logical_block_size(bdev)); | |
390 | if (iomap->offset >= isize) | |
391 | return -EIO; | |
392 | iomap->type = IOMAP_MAPPED; | |
393 | iomap->addr = iomap->offset; | |
394 | iomap->length = isize - iomap->offset; | |
925c86a1 | 395 | iomap->flags |= IOMAP_F_BUFFER_HEAD; /* noop for !CONFIG_BUFFER_HEAD */ |
487c607d CH |
396 | return 0; |
397 | } | |
398 | ||
399 | static const struct iomap_ops blkdev_iomap_ops = { | |
400 | .iomap_begin = blkdev_iomap_begin, | |
401 | }; | |
402 | ||
925c86a1 CH |
403 | #ifdef CONFIG_BUFFER_HEAD |
404 | static int blkdev_get_block(struct inode *inode, sector_t iblock, | |
405 | struct buffer_head *bh, int create) | |
406 | { | |
407 | bh->b_bdev = I_BDEV(inode); | |
408 | bh->b_blocknr = iblock; | |
409 | set_buffer_mapped(bh); | |
410 | return 0; | |
411 | } | |
412 | ||
17bf23a9 MWO |
413 | /* |
414 | * We cannot call mpage_writepages() as it does not take the buffer lock. | |
415 | * We must use block_write_full_folio() directly which holds the buffer | |
416 | * lock. The buffer lock provides the synchronisation with writeback | |
417 | * that filesystems rely on when they use the blockdev's mapping. | |
418 | */ | |
419 | static int blkdev_writepages(struct address_space *mapping, | |
420 | struct writeback_control *wbc) | |
cd82cca7 | 421 | { |
17bf23a9 MWO |
422 | struct blk_plug plug; |
423 | int err; | |
424 | ||
425 | blk_start_plug(&plug); | |
426 | err = write_cache_pages(mapping, wbc, block_write_full_folio, | |
427 | blkdev_get_block); | |
428 | blk_finish_plug(&plug); | |
429 | ||
430 | return err; | |
cd82cca7 CH |
431 | } |
432 | ||
2c69e205 | 433 | static int blkdev_read_folio(struct file *file, struct folio *folio) |
cd82cca7 | 434 | { |
2c69e205 | 435 | return block_read_full_folio(folio, blkdev_get_block); |
cd82cca7 CH |
436 | } |
437 | ||
438 | static void blkdev_readahead(struct readahead_control *rac) | |
439 | { | |
440 | mpage_readahead(rac, blkdev_get_block); | |
441 | } | |
442 | ||
443 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
9d6b0cd7 | 444 | loff_t pos, unsigned len, struct page **pagep, void **fsdata) |
cd82cca7 | 445 | { |
b3992d1e | 446 | return block_write_begin(mapping, pos, len, pagep, blkdev_get_block); |
cd82cca7 CH |
447 | } |
448 | ||
449 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
450 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
451 | void *fsdata) | |
452 | { | |
453 | int ret; | |
454 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
455 | ||
456 | unlock_page(page); | |
457 | put_page(page); | |
458 | ||
459 | return ret; | |
460 | } | |
461 | ||
cd82cca7 | 462 | const struct address_space_operations def_blk_aops = { |
e621900a | 463 | .dirty_folio = block_dirty_folio, |
7ba13abb | 464 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 465 | .read_folio = blkdev_read_folio, |
cd82cca7 | 466 | .readahead = blkdev_readahead, |
17bf23a9 | 467 | .writepages = blkdev_writepages, |
cd82cca7 CH |
468 | .write_begin = blkdev_write_begin, |
469 | .write_end = blkdev_write_end, | |
67235182 | 470 | .migrate_folio = buffer_migrate_folio_norefs, |
cd82cca7 CH |
471 | .is_dirty_writeback = buffer_check_dirty_writeback, |
472 | }; | |
925c86a1 CH |
473 | #else /* CONFIG_BUFFER_HEAD */ |
474 | static int blkdev_read_folio(struct file *file, struct folio *folio) | |
475 | { | |
476 | return iomap_read_folio(folio, &blkdev_iomap_ops); | |
477 | } | |
478 | ||
479 | static void blkdev_readahead(struct readahead_control *rac) | |
480 | { | |
481 | iomap_readahead(rac, &blkdev_iomap_ops); | |
482 | } | |
483 | ||
484 | static int blkdev_map_blocks(struct iomap_writepage_ctx *wpc, | |
485 | struct inode *inode, loff_t offset) | |
486 | { | |
487 | loff_t isize = i_size_read(inode); | |
488 | ||
489 | if (WARN_ON_ONCE(offset >= isize)) | |
490 | return -EIO; | |
491 | if (offset >= wpc->iomap.offset && | |
492 | offset < wpc->iomap.offset + wpc->iomap.length) | |
493 | return 0; | |
494 | return blkdev_iomap_begin(inode, offset, isize - offset, | |
495 | IOMAP_WRITE, &wpc->iomap, NULL); | |
496 | } | |
497 | ||
498 | static const struct iomap_writeback_ops blkdev_writeback_ops = { | |
499 | .map_blocks = blkdev_map_blocks, | |
500 | }; | |
501 | ||
502 | static int blkdev_writepages(struct address_space *mapping, | |
503 | struct writeback_control *wbc) | |
504 | { | |
505 | struct iomap_writepage_ctx wpc = { }; | |
506 | ||
507 | return iomap_writepages(mapping, wbc, &wpc, &blkdev_writeback_ops); | |
508 | } | |
509 | ||
510 | const struct address_space_operations def_blk_aops = { | |
511 | .dirty_folio = filemap_dirty_folio, | |
512 | .release_folio = iomap_release_folio, | |
513 | .invalidate_folio = iomap_invalidate_folio, | |
514 | .read_folio = blkdev_read_folio, | |
515 | .readahead = blkdev_readahead, | |
516 | .writepages = blkdev_writepages, | |
517 | .is_partially_uptodate = iomap_is_partially_uptodate, | |
af7628d6 | 518 | .error_remove_folio = generic_error_remove_folio, |
925c86a1 CH |
519 | .migrate_folio = filemap_migrate_folio, |
520 | }; | |
521 | #endif /* CONFIG_BUFFER_HEAD */ | |
cd82cca7 CH |
522 | |
523 | /* | |
524 | * for a block special file file_inode(file)->i_size is zero | |
525 | * so we compute the size by hand (just as in block_read/write above) | |
526 | */ | |
527 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
528 | { | |
529 | struct inode *bd_inode = bdev_file_inode(file); | |
530 | loff_t retval; | |
531 | ||
532 | inode_lock(bd_inode); | |
533 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
534 | inode_unlock(bd_inode); | |
535 | return retval; | |
536 | } | |
537 | ||
538 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
539 | int datasync) | |
540 | { | |
4e762d86 | 541 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
cd82cca7 CH |
542 | int error; |
543 | ||
544 | error = file_write_and_wait_range(filp, start, end); | |
545 | if (error) | |
546 | return error; | |
547 | ||
548 | /* | |
549 | * There is no need to serialise calls to blkdev_issue_flush with | |
550 | * i_mutex and doing so causes performance issues with concurrent | |
551 | * O_SYNC writers to a block device. | |
552 | */ | |
553 | error = blkdev_issue_flush(bdev); | |
554 | if (error == -EOPNOTSUPP) | |
555 | error = 0; | |
556 | ||
557 | return error; | |
558 | } | |
559 | ||
841dd789 JK |
560 | /** |
561 | * file_to_blk_mode - get block open flags from file flags | |
562 | * @file: file whose open flags should be converted | |
563 | * | |
564 | * Look at file open flags and generate corresponding block open flags from | |
565 | * them. The function works both for file just being open (e.g. during ->open | |
566 | * callback) and for file that is already open. This is actually non-trivial | |
567 | * (see comment in the function). | |
568 | */ | |
05bdb996 CH |
569 | blk_mode_t file_to_blk_mode(struct file *file) |
570 | { | |
571 | blk_mode_t mode = 0; | |
841dd789 | 572 | struct bdev_handle *handle = file->private_data; |
05bdb996 CH |
573 | |
574 | if (file->f_mode & FMODE_READ) | |
575 | mode |= BLK_OPEN_READ; | |
576 | if (file->f_mode & FMODE_WRITE) | |
577 | mode |= BLK_OPEN_WRITE; | |
841dd789 JK |
578 | /* |
579 | * do_dentry_open() clears O_EXCL from f_flags, use handle->mode to | |
580 | * determine whether the open was exclusive for already open files. | |
581 | */ | |
582 | if (handle) | |
583 | mode |= handle->mode & BLK_OPEN_EXCL; | |
584 | else if (file->f_flags & O_EXCL) | |
05bdb996 CH |
585 | mode |= BLK_OPEN_EXCL; |
586 | if (file->f_flags & O_NDELAY) | |
587 | mode |= BLK_OPEN_NDELAY; | |
588 | ||
589 | /* | |
590 | * If all bits in O_ACCMODE set (aka O_RDWR | O_WRONLY), the floppy | |
591 | * driver has historically allowed ioctls as if the file was opened for | |
592 | * writing, but does not allow and actual reads or writes. | |
593 | */ | |
594 | if ((file->f_flags & O_ACCMODE) == (O_RDWR | O_WRONLY)) | |
595 | mode |= BLK_OPEN_WRITE_IOCTL; | |
596 | ||
597 | return mode; | |
598 | } | |
599 | ||
cd82cca7 CH |
600 | static int blkdev_open(struct inode *inode, struct file *filp) |
601 | { | |
841dd789 JK |
602 | struct bdev_handle *handle; |
603 | blk_mode_t mode; | |
cd82cca7 CH |
604 | |
605 | /* | |
606 | * Preserve backwards compatibility and allow large file access | |
607 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
608 | * binary needs it. We might want to drop this workaround | |
609 | * during an unstable branch. | |
610 | */ | |
611 | filp->f_flags |= O_LARGEFILE; | |
a05f7bd9 | 612 | filp->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT; |
cd82cca7 | 613 | |
841dd789 JK |
614 | mode = file_to_blk_mode(filp); |
615 | handle = bdev_open_by_dev(inode->i_rdev, mode, | |
616 | mode & BLK_OPEN_EXCL ? filp : NULL, NULL); | |
617 | if (IS_ERR(handle)) | |
618 | return PTR_ERR(handle); | |
fac7c6d5 | 619 | |
841dd789 | 620 | if (bdev_nowait(handle->bdev)) |
e9833d87 JA |
621 | filp->f_mode |= FMODE_NOWAIT; |
622 | ||
841dd789 | 623 | filp->f_mapping = handle->bdev->bd_inode->i_mapping; |
cd82cca7 | 624 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); |
841dd789 | 625 | filp->private_data = handle; |
cd82cca7 CH |
626 | return 0; |
627 | } | |
628 | ||
7ee34cbc | 629 | static int blkdev_release(struct inode *inode, struct file *filp) |
cd82cca7 | 630 | { |
841dd789 | 631 | bdev_release(filp->private_data); |
cd82cca7 CH |
632 | return 0; |
633 | } | |
634 | ||
727cfe97 CH |
635 | static ssize_t |
636 | blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) | |
637 | { | |
638 | size_t count = iov_iter_count(from); | |
639 | ssize_t written; | |
640 | ||
641 | written = kiocb_invalidate_pages(iocb, count); | |
642 | if (written) { | |
643 | if (written == -EBUSY) | |
644 | return 0; | |
645 | return written; | |
646 | } | |
647 | ||
648 | written = blkdev_direct_IO(iocb, from); | |
649 | if (written > 0) { | |
650 | kiocb_invalidate_post_direct_write(iocb, count); | |
651 | iocb->ki_pos += written; | |
652 | count -= written; | |
653 | } | |
654 | if (written != -EIOCBQUEUED) | |
655 | iov_iter_revert(from, count - iov_iter_count(from)); | |
656 | return written; | |
657 | } | |
658 | ||
487c607d CH |
659 | static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) |
660 | { | |
661 | return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); | |
662 | } | |
663 | ||
cd82cca7 CH |
664 | /* |
665 | * Write data to the block device. Only intended for the block device itself | |
666 | * and the raw driver which basically is a fake block device. | |
667 | * | |
668 | * Does not take i_mutex for the write and thus is not for general purpose | |
669 | * use. | |
670 | */ | |
671 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
672 | { | |
727cfe97 CH |
673 | struct file *file = iocb->ki_filp; |
674 | struct block_device *bdev = I_BDEV(file->f_mapping->host); | |
fac7c6d5 | 675 | struct inode *bd_inode = bdev->bd_inode; |
138c1a38 | 676 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
677 | size_t shorted = 0; |
678 | ssize_t ret; | |
679 | ||
fac7c6d5 | 680 | if (bdev_read_only(bdev)) |
cd82cca7 CH |
681 | return -EPERM; |
682 | ||
683 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
684 | return -ETXTBSY; | |
685 | ||
686 | if (!iov_iter_count(from)) | |
687 | return 0; | |
688 | ||
689 | if (iocb->ki_pos >= size) | |
690 | return -ENOSPC; | |
691 | ||
692 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
693 | return -EOPNOTSUPP; | |
694 | ||
695 | size -= iocb->ki_pos; | |
696 | if (iov_iter_count(from) > size) { | |
697 | shorted = iov_iter_count(from) - size; | |
698 | iov_iter_truncate(from, size); | |
699 | } | |
700 | ||
727cfe97 CH |
701 | ret = file_update_time(file); |
702 | if (ret) | |
703 | return ret; | |
704 | ||
705 | if (iocb->ki_flags & IOCB_DIRECT) { | |
706 | ret = blkdev_direct_write(iocb, from); | |
707 | if (ret >= 0 && iov_iter_count(from)) | |
708 | ret = direct_write_fallback(iocb, from, ret, | |
487c607d | 709 | blkdev_buffered_write(iocb, from)); |
727cfe97 | 710 | } else { |
487c607d | 711 | ret = blkdev_buffered_write(iocb, from); |
727cfe97 CH |
712 | } |
713 | ||
cd82cca7 CH |
714 | if (ret > 0) |
715 | ret = generic_write_sync(iocb, ret); | |
716 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
cd82cca7 CH |
717 | return ret; |
718 | } | |
719 | ||
720 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
721 | { | |
4e762d86 | 722 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
138c1a38 | 723 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
724 | loff_t pos = iocb->ki_pos; |
725 | size_t shorted = 0; | |
ceaa7625 | 726 | ssize_t ret = 0; |
3e1f941d | 727 | size_t count; |
cd82cca7 | 728 | |
3e1f941d | 729 | if (unlikely(pos + iov_iter_count(to) > size)) { |
6450fe1f PB |
730 | if (pos >= size) |
731 | return 0; | |
732 | size -= pos; | |
3e1f941d ID |
733 | shorted = iov_iter_count(to) - size; |
734 | iov_iter_truncate(to, size); | |
cd82cca7 CH |
735 | } |
736 | ||
3e1f941d ID |
737 | count = iov_iter_count(to); |
738 | if (!count) | |
739 | goto reexpand; /* skip atime */ | |
740 | ||
ceaa7625 | 741 | if (iocb->ki_flags & IOCB_DIRECT) { |
3c435a0f CH |
742 | ret = kiocb_write_and_wait(iocb, count); |
743 | if (ret < 0) | |
744 | goto reexpand; | |
ceaa7625 JA |
745 | file_accessed(iocb->ki_filp); |
746 | ||
747 | ret = blkdev_direct_IO(iocb, to); | |
748 | if (ret >= 0) { | |
749 | iocb->ki_pos += ret; | |
750 | count -= ret; | |
751 | } | |
3e1f941d | 752 | iov_iter_revert(to, count - iov_iter_count(to)); |
ceaa7625 | 753 | if (ret < 0 || !count) |
3e1f941d | 754 | goto reexpand; |
ceaa7625 JA |
755 | } |
756 | ||
757 | ret = filemap_read(iocb, to, ret); | |
6450fe1f | 758 | |
3e1f941d | 759 | reexpand: |
6450fe1f PB |
760 | if (unlikely(shorted)) |
761 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
cd82cca7 CH |
762 | return ret; |
763 | } | |
764 | ||
765 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
766 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
767 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
768 | ||
769 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
770 | loff_t len) | |
771 | { | |
f278eb3d ML |
772 | struct inode *inode = bdev_file_inode(file); |
773 | struct block_device *bdev = I_BDEV(inode); | |
cd82cca7 CH |
774 | loff_t end = start + len - 1; |
775 | loff_t isize; | |
776 | int error; | |
777 | ||
778 | /* Fail if we don't recognize the flags. */ | |
779 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
780 | return -EOPNOTSUPP; | |
781 | ||
782 | /* Don't go off the end of the device. */ | |
2a93ad8f | 783 | isize = bdev_nr_bytes(bdev); |
cd82cca7 CH |
784 | if (start >= isize) |
785 | return -EINVAL; | |
786 | if (end >= isize) { | |
787 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
788 | len = isize - start; | |
789 | end = start + len - 1; | |
790 | } else | |
791 | return -EINVAL; | |
792 | } | |
793 | ||
794 | /* | |
795 | * Don't allow IO that isn't aligned to logical block size. | |
796 | */ | |
797 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
798 | return -EINVAL; | |
799 | ||
f278eb3d ML |
800 | filemap_invalidate_lock(inode->i_mapping); |
801 | ||
1364a3c3 SK |
802 | /* |
803 | * Invalidate the page cache, including dirty pages, for valid | |
804 | * de-allocate mode calls to fallocate(). | |
805 | */ | |
cd82cca7 CH |
806 | switch (mode) { |
807 | case FALLOC_FL_ZERO_RANGE: | |
808 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
809 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
810 | if (error) | |
811 | goto fail; | |
812 | ||
6549a874 PB |
813 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
814 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
815 | BLKDEV_ZERO_NOUNMAP); | |
cd82cca7 CH |
816 | break; |
817 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
818 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
819 | if (error) | |
820 | goto fail; | |
821 | ||
6549a874 PB |
822 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
823 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
824 | BLKDEV_ZERO_NOFALLBACK); | |
cd82cca7 CH |
825 | break; |
826 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
1364a3c3 SK |
827 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
828 | if (error) | |
829 | goto fail; | |
830 | ||
6549a874 | 831 | error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
44abff2c | 832 | len >> SECTOR_SHIFT, GFP_KERNEL); |
cd82cca7 CH |
833 | break; |
834 | default: | |
f278eb3d | 835 | error = -EOPNOTSUPP; |
cd82cca7 | 836 | } |
cd82cca7 | 837 | |
f278eb3d ML |
838 | fail: |
839 | filemap_invalidate_unlock(inode->i_mapping); | |
840 | return error; | |
cd82cca7 CH |
841 | } |
842 | ||
69baa3a6 LP |
843 | static int blkdev_mmap(struct file *file, struct vm_area_struct *vma) |
844 | { | |
845 | struct inode *bd_inode = bdev_file_inode(file); | |
846 | ||
847 | if (bdev_read_only(I_BDEV(bd_inode))) | |
848 | return generic_file_readonly_mmap(file, vma); | |
849 | ||
850 | return generic_file_mmap(file, vma); | |
851 | } | |
852 | ||
cd82cca7 CH |
853 | const struct file_operations def_blk_fops = { |
854 | .open = blkdev_open, | |
7ee34cbc | 855 | .release = blkdev_release, |
cd82cca7 CH |
856 | .llseek = blkdev_llseek, |
857 | .read_iter = blkdev_read_iter, | |
858 | .write_iter = blkdev_write_iter, | |
3e08773c | 859 | .iopoll = iocb_bio_iopoll, |
69baa3a6 | 860 | .mmap = blkdev_mmap, |
cd82cca7 | 861 | .fsync = blkdev_fsync, |
8a709512 | 862 | .unlocked_ioctl = blkdev_ioctl, |
cd82cca7 CH |
863 | #ifdef CONFIG_COMPAT |
864 | .compat_ioctl = compat_blkdev_ioctl, | |
865 | #endif | |
2cb1e089 | 866 | .splice_read = filemap_splice_read, |
cd82cca7 CH |
867 | .splice_write = iter_file_splice_write, |
868 | .fallocate = blkdev_fallocate, | |
869 | }; | |
870 | ||
871 | static __init int blkdev_init(void) | |
872 | { | |
873 | return bioset_init(&blkdev_dio_pool, 4, | |
874 | offsetof(struct blkdev_dio, bio), | |
875 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
876 | } | |
877 | module_init(blkdev_init); |