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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 | ||
cd82cca7 CH |
413 | static int blkdev_writepage(struct page *page, struct writeback_control *wbc) |
414 | { | |
415 | return block_write_full_page(page, blkdev_get_block, wbc); | |
416 | } | |
417 | ||
2c69e205 | 418 | static int blkdev_read_folio(struct file *file, struct folio *folio) |
cd82cca7 | 419 | { |
2c69e205 | 420 | return block_read_full_folio(folio, blkdev_get_block); |
cd82cca7 CH |
421 | } |
422 | ||
423 | static void blkdev_readahead(struct readahead_control *rac) | |
424 | { | |
425 | mpage_readahead(rac, blkdev_get_block); | |
426 | } | |
427 | ||
428 | static int blkdev_write_begin(struct file *file, struct address_space *mapping, | |
9d6b0cd7 | 429 | loff_t pos, unsigned len, struct page **pagep, void **fsdata) |
cd82cca7 | 430 | { |
b3992d1e | 431 | return block_write_begin(mapping, pos, len, pagep, blkdev_get_block); |
cd82cca7 CH |
432 | } |
433 | ||
434 | static int blkdev_write_end(struct file *file, struct address_space *mapping, | |
435 | loff_t pos, unsigned len, unsigned copied, struct page *page, | |
436 | void *fsdata) | |
437 | { | |
438 | int ret; | |
439 | ret = block_write_end(file, mapping, pos, len, copied, page, fsdata); | |
440 | ||
441 | unlock_page(page); | |
442 | put_page(page); | |
443 | ||
444 | return ret; | |
445 | } | |
446 | ||
cd82cca7 | 447 | const struct address_space_operations def_blk_aops = { |
e621900a | 448 | .dirty_folio = block_dirty_folio, |
7ba13abb | 449 | .invalidate_folio = block_invalidate_folio, |
2c69e205 | 450 | .read_folio = blkdev_read_folio, |
cd82cca7 CH |
451 | .readahead = blkdev_readahead, |
452 | .writepage = blkdev_writepage, | |
453 | .write_begin = blkdev_write_begin, | |
454 | .write_end = blkdev_write_end, | |
67235182 | 455 | .migrate_folio = buffer_migrate_folio_norefs, |
cd82cca7 CH |
456 | .is_dirty_writeback = buffer_check_dirty_writeback, |
457 | }; | |
925c86a1 CH |
458 | #else /* CONFIG_BUFFER_HEAD */ |
459 | static int blkdev_read_folio(struct file *file, struct folio *folio) | |
460 | { | |
461 | return iomap_read_folio(folio, &blkdev_iomap_ops); | |
462 | } | |
463 | ||
464 | static void blkdev_readahead(struct readahead_control *rac) | |
465 | { | |
466 | iomap_readahead(rac, &blkdev_iomap_ops); | |
467 | } | |
468 | ||
469 | static int blkdev_map_blocks(struct iomap_writepage_ctx *wpc, | |
470 | struct inode *inode, loff_t offset) | |
471 | { | |
472 | loff_t isize = i_size_read(inode); | |
473 | ||
474 | if (WARN_ON_ONCE(offset >= isize)) | |
475 | return -EIO; | |
476 | if (offset >= wpc->iomap.offset && | |
477 | offset < wpc->iomap.offset + wpc->iomap.length) | |
478 | return 0; | |
479 | return blkdev_iomap_begin(inode, offset, isize - offset, | |
480 | IOMAP_WRITE, &wpc->iomap, NULL); | |
481 | } | |
482 | ||
483 | static const struct iomap_writeback_ops blkdev_writeback_ops = { | |
484 | .map_blocks = blkdev_map_blocks, | |
485 | }; | |
486 | ||
487 | static int blkdev_writepages(struct address_space *mapping, | |
488 | struct writeback_control *wbc) | |
489 | { | |
490 | struct iomap_writepage_ctx wpc = { }; | |
491 | ||
492 | return iomap_writepages(mapping, wbc, &wpc, &blkdev_writeback_ops); | |
493 | } | |
494 | ||
495 | const struct address_space_operations def_blk_aops = { | |
496 | .dirty_folio = filemap_dirty_folio, | |
497 | .release_folio = iomap_release_folio, | |
498 | .invalidate_folio = iomap_invalidate_folio, | |
499 | .read_folio = blkdev_read_folio, | |
500 | .readahead = blkdev_readahead, | |
501 | .writepages = blkdev_writepages, | |
502 | .is_partially_uptodate = iomap_is_partially_uptodate, | |
503 | .error_remove_page = generic_error_remove_page, | |
504 | .migrate_folio = filemap_migrate_folio, | |
505 | }; | |
506 | #endif /* CONFIG_BUFFER_HEAD */ | |
cd82cca7 CH |
507 | |
508 | /* | |
509 | * for a block special file file_inode(file)->i_size is zero | |
510 | * so we compute the size by hand (just as in block_read/write above) | |
511 | */ | |
512 | static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence) | |
513 | { | |
514 | struct inode *bd_inode = bdev_file_inode(file); | |
515 | loff_t retval; | |
516 | ||
517 | inode_lock(bd_inode); | |
518 | retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode)); | |
519 | inode_unlock(bd_inode); | |
520 | return retval; | |
521 | } | |
522 | ||
523 | static int blkdev_fsync(struct file *filp, loff_t start, loff_t end, | |
524 | int datasync) | |
525 | { | |
4e762d86 | 526 | struct block_device *bdev = I_BDEV(filp->f_mapping->host); |
cd82cca7 CH |
527 | int error; |
528 | ||
529 | error = file_write_and_wait_range(filp, start, end); | |
530 | if (error) | |
531 | return error; | |
532 | ||
533 | /* | |
534 | * There is no need to serialise calls to blkdev_issue_flush with | |
535 | * i_mutex and doing so causes performance issues with concurrent | |
536 | * O_SYNC writers to a block device. | |
537 | */ | |
538 | error = blkdev_issue_flush(bdev); | |
539 | if (error == -EOPNOTSUPP) | |
540 | error = 0; | |
541 | ||
542 | return error; | |
543 | } | |
544 | ||
05bdb996 CH |
545 | blk_mode_t file_to_blk_mode(struct file *file) |
546 | { | |
547 | blk_mode_t mode = 0; | |
548 | ||
549 | if (file->f_mode & FMODE_READ) | |
550 | mode |= BLK_OPEN_READ; | |
551 | if (file->f_mode & FMODE_WRITE) | |
552 | mode |= BLK_OPEN_WRITE; | |
ee3249a8 | 553 | if (file->private_data) |
05bdb996 CH |
554 | mode |= BLK_OPEN_EXCL; |
555 | if (file->f_flags & O_NDELAY) | |
556 | mode |= BLK_OPEN_NDELAY; | |
557 | ||
558 | /* | |
559 | * If all bits in O_ACCMODE set (aka O_RDWR | O_WRONLY), the floppy | |
560 | * driver has historically allowed ioctls as if the file was opened for | |
561 | * writing, but does not allow and actual reads or writes. | |
562 | */ | |
563 | if ((file->f_flags & O_ACCMODE) == (O_RDWR | O_WRONLY)) | |
564 | mode |= BLK_OPEN_WRITE_IOCTL; | |
565 | ||
566 | return mode; | |
567 | } | |
568 | ||
cd82cca7 CH |
569 | static int blkdev_open(struct inode *inode, struct file *filp) |
570 | { | |
571 | struct block_device *bdev; | |
572 | ||
573 | /* | |
574 | * Preserve backwards compatibility and allow large file access | |
575 | * even if userspace doesn't ask for it explicitly. Some mkfs | |
576 | * binary needs it. We might want to drop this workaround | |
577 | * during an unstable branch. | |
578 | */ | |
579 | filp->f_flags |= O_LARGEFILE; | |
a05f7bd9 | 580 | filp->f_mode |= FMODE_BUF_RASYNC | FMODE_CAN_ODIRECT; |
cd82cca7 | 581 | |
ee3249a8 CH |
582 | /* |
583 | * Use the file private data to store the holder for exclusive openes. | |
584 | * file_to_blk_mode relies on it being present to set BLK_OPEN_EXCL. | |
585 | */ | |
cd82cca7 | 586 | if (filp->f_flags & O_EXCL) |
ee3249a8 | 587 | filp->private_data = filp; |
cd82cca7 | 588 | |
05bdb996 | 589 | bdev = blkdev_get_by_dev(inode->i_rdev, file_to_blk_mode(filp), |
ee3249a8 | 590 | filp->private_data, NULL); |
cd82cca7 CH |
591 | if (IS_ERR(bdev)) |
592 | return PTR_ERR(bdev); | |
fac7c6d5 | 593 | |
e9833d87 JA |
594 | if (bdev_nowait(bdev)) |
595 | filp->f_mode |= FMODE_NOWAIT; | |
596 | ||
cd82cca7 CH |
597 | filp->f_mapping = bdev->bd_inode->i_mapping; |
598 | filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping); | |
599 | return 0; | |
600 | } | |
601 | ||
7ee34cbc | 602 | static int blkdev_release(struct inode *inode, struct file *filp) |
cd82cca7 | 603 | { |
ee3249a8 | 604 | blkdev_put(I_BDEV(filp->f_mapping->host), filp->private_data); |
cd82cca7 CH |
605 | return 0; |
606 | } | |
607 | ||
727cfe97 CH |
608 | static ssize_t |
609 | blkdev_direct_write(struct kiocb *iocb, struct iov_iter *from) | |
610 | { | |
611 | size_t count = iov_iter_count(from); | |
612 | ssize_t written; | |
613 | ||
614 | written = kiocb_invalidate_pages(iocb, count); | |
615 | if (written) { | |
616 | if (written == -EBUSY) | |
617 | return 0; | |
618 | return written; | |
619 | } | |
620 | ||
621 | written = blkdev_direct_IO(iocb, from); | |
622 | if (written > 0) { | |
623 | kiocb_invalidate_post_direct_write(iocb, count); | |
624 | iocb->ki_pos += written; | |
625 | count -= written; | |
626 | } | |
627 | if (written != -EIOCBQUEUED) | |
628 | iov_iter_revert(from, count - iov_iter_count(from)); | |
629 | return written; | |
630 | } | |
631 | ||
487c607d CH |
632 | static ssize_t blkdev_buffered_write(struct kiocb *iocb, struct iov_iter *from) |
633 | { | |
634 | return iomap_file_buffered_write(iocb, from, &blkdev_iomap_ops); | |
635 | } | |
636 | ||
cd82cca7 CH |
637 | /* |
638 | * Write data to the block device. Only intended for the block device itself | |
639 | * and the raw driver which basically is a fake block device. | |
640 | * | |
641 | * Does not take i_mutex for the write and thus is not for general purpose | |
642 | * use. | |
643 | */ | |
644 | static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from) | |
645 | { | |
727cfe97 CH |
646 | struct file *file = iocb->ki_filp; |
647 | struct block_device *bdev = I_BDEV(file->f_mapping->host); | |
fac7c6d5 | 648 | struct inode *bd_inode = bdev->bd_inode; |
138c1a38 | 649 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
650 | size_t shorted = 0; |
651 | ssize_t ret; | |
652 | ||
fac7c6d5 | 653 | if (bdev_read_only(bdev)) |
cd82cca7 CH |
654 | return -EPERM; |
655 | ||
656 | if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev)) | |
657 | return -ETXTBSY; | |
658 | ||
659 | if (!iov_iter_count(from)) | |
660 | return 0; | |
661 | ||
662 | if (iocb->ki_pos >= size) | |
663 | return -ENOSPC; | |
664 | ||
665 | if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT) | |
666 | return -EOPNOTSUPP; | |
667 | ||
668 | size -= iocb->ki_pos; | |
669 | if (iov_iter_count(from) > size) { | |
670 | shorted = iov_iter_count(from) - size; | |
671 | iov_iter_truncate(from, size); | |
672 | } | |
673 | ||
727cfe97 CH |
674 | ret = file_update_time(file); |
675 | if (ret) | |
676 | return ret; | |
677 | ||
678 | if (iocb->ki_flags & IOCB_DIRECT) { | |
679 | ret = blkdev_direct_write(iocb, from); | |
680 | if (ret >= 0 && iov_iter_count(from)) | |
681 | ret = direct_write_fallback(iocb, from, ret, | |
487c607d | 682 | blkdev_buffered_write(iocb, from)); |
727cfe97 | 683 | } else { |
487c607d | 684 | ret = blkdev_buffered_write(iocb, from); |
727cfe97 CH |
685 | } |
686 | ||
cd82cca7 CH |
687 | if (ret > 0) |
688 | ret = generic_write_sync(iocb, ret); | |
689 | iov_iter_reexpand(from, iov_iter_count(from) + shorted); | |
cd82cca7 CH |
690 | return ret; |
691 | } | |
692 | ||
693 | static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to) | |
694 | { | |
4e762d86 | 695 | struct block_device *bdev = I_BDEV(iocb->ki_filp->f_mapping->host); |
138c1a38 | 696 | loff_t size = bdev_nr_bytes(bdev); |
cd82cca7 CH |
697 | loff_t pos = iocb->ki_pos; |
698 | size_t shorted = 0; | |
ceaa7625 | 699 | ssize_t ret = 0; |
3e1f941d | 700 | size_t count; |
cd82cca7 | 701 | |
3e1f941d | 702 | if (unlikely(pos + iov_iter_count(to) > size)) { |
6450fe1f PB |
703 | if (pos >= size) |
704 | return 0; | |
705 | size -= pos; | |
3e1f941d ID |
706 | shorted = iov_iter_count(to) - size; |
707 | iov_iter_truncate(to, size); | |
cd82cca7 CH |
708 | } |
709 | ||
3e1f941d ID |
710 | count = iov_iter_count(to); |
711 | if (!count) | |
712 | goto reexpand; /* skip atime */ | |
713 | ||
ceaa7625 | 714 | if (iocb->ki_flags & IOCB_DIRECT) { |
3c435a0f CH |
715 | ret = kiocb_write_and_wait(iocb, count); |
716 | if (ret < 0) | |
717 | goto reexpand; | |
ceaa7625 JA |
718 | file_accessed(iocb->ki_filp); |
719 | ||
720 | ret = blkdev_direct_IO(iocb, to); | |
721 | if (ret >= 0) { | |
722 | iocb->ki_pos += ret; | |
723 | count -= ret; | |
724 | } | |
3e1f941d | 725 | iov_iter_revert(to, count - iov_iter_count(to)); |
ceaa7625 | 726 | if (ret < 0 || !count) |
3e1f941d | 727 | goto reexpand; |
ceaa7625 JA |
728 | } |
729 | ||
730 | ret = filemap_read(iocb, to, ret); | |
6450fe1f | 731 | |
3e1f941d | 732 | reexpand: |
6450fe1f PB |
733 | if (unlikely(shorted)) |
734 | iov_iter_reexpand(to, iov_iter_count(to) + shorted); | |
cd82cca7 CH |
735 | return ret; |
736 | } | |
737 | ||
738 | #define BLKDEV_FALLOC_FL_SUPPORTED \ | |
739 | (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \ | |
740 | FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE) | |
741 | ||
742 | static long blkdev_fallocate(struct file *file, int mode, loff_t start, | |
743 | loff_t len) | |
744 | { | |
f278eb3d ML |
745 | struct inode *inode = bdev_file_inode(file); |
746 | struct block_device *bdev = I_BDEV(inode); | |
cd82cca7 CH |
747 | loff_t end = start + len - 1; |
748 | loff_t isize; | |
749 | int error; | |
750 | ||
751 | /* Fail if we don't recognize the flags. */ | |
752 | if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED) | |
753 | return -EOPNOTSUPP; | |
754 | ||
755 | /* Don't go off the end of the device. */ | |
2a93ad8f | 756 | isize = bdev_nr_bytes(bdev); |
cd82cca7 CH |
757 | if (start >= isize) |
758 | return -EINVAL; | |
759 | if (end >= isize) { | |
760 | if (mode & FALLOC_FL_KEEP_SIZE) { | |
761 | len = isize - start; | |
762 | end = start + len - 1; | |
763 | } else | |
764 | return -EINVAL; | |
765 | } | |
766 | ||
767 | /* | |
768 | * Don't allow IO that isn't aligned to logical block size. | |
769 | */ | |
770 | if ((start | len) & (bdev_logical_block_size(bdev) - 1)) | |
771 | return -EINVAL; | |
772 | ||
f278eb3d ML |
773 | filemap_invalidate_lock(inode->i_mapping); |
774 | ||
1364a3c3 SK |
775 | /* |
776 | * Invalidate the page cache, including dirty pages, for valid | |
777 | * de-allocate mode calls to fallocate(). | |
778 | */ | |
cd82cca7 CH |
779 | switch (mode) { |
780 | case FALLOC_FL_ZERO_RANGE: | |
781 | case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
782 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
783 | if (error) | |
784 | goto fail; | |
785 | ||
6549a874 PB |
786 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
787 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
788 | BLKDEV_ZERO_NOUNMAP); | |
cd82cca7 CH |
789 | break; |
790 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE: | |
1364a3c3 SK |
791 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
792 | if (error) | |
793 | goto fail; | |
794 | ||
6549a874 PB |
795 | error = blkdev_issue_zeroout(bdev, start >> SECTOR_SHIFT, |
796 | len >> SECTOR_SHIFT, GFP_KERNEL, | |
797 | BLKDEV_ZERO_NOFALLBACK); | |
cd82cca7 CH |
798 | break; |
799 | case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE: | |
1364a3c3 SK |
800 | error = truncate_bdev_range(bdev, file_to_blk_mode(file), start, end); |
801 | if (error) | |
802 | goto fail; | |
803 | ||
6549a874 | 804 | error = blkdev_issue_discard(bdev, start >> SECTOR_SHIFT, |
44abff2c | 805 | len >> SECTOR_SHIFT, GFP_KERNEL); |
cd82cca7 CH |
806 | break; |
807 | default: | |
f278eb3d | 808 | error = -EOPNOTSUPP; |
cd82cca7 | 809 | } |
cd82cca7 | 810 | |
f278eb3d ML |
811 | fail: |
812 | filemap_invalidate_unlock(inode->i_mapping); | |
813 | return error; | |
cd82cca7 CH |
814 | } |
815 | ||
69baa3a6 LP |
816 | static int blkdev_mmap(struct file *file, struct vm_area_struct *vma) |
817 | { | |
818 | struct inode *bd_inode = bdev_file_inode(file); | |
819 | ||
820 | if (bdev_read_only(I_BDEV(bd_inode))) | |
821 | return generic_file_readonly_mmap(file, vma); | |
822 | ||
823 | return generic_file_mmap(file, vma); | |
824 | } | |
825 | ||
cd82cca7 CH |
826 | const struct file_operations def_blk_fops = { |
827 | .open = blkdev_open, | |
7ee34cbc | 828 | .release = blkdev_release, |
cd82cca7 CH |
829 | .llseek = blkdev_llseek, |
830 | .read_iter = blkdev_read_iter, | |
831 | .write_iter = blkdev_write_iter, | |
3e08773c | 832 | .iopoll = iocb_bio_iopoll, |
69baa3a6 | 833 | .mmap = blkdev_mmap, |
cd82cca7 | 834 | .fsync = blkdev_fsync, |
8a709512 | 835 | .unlocked_ioctl = blkdev_ioctl, |
cd82cca7 CH |
836 | #ifdef CONFIG_COMPAT |
837 | .compat_ioctl = compat_blkdev_ioctl, | |
838 | #endif | |
2cb1e089 | 839 | .splice_read = filemap_splice_read, |
cd82cca7 CH |
840 | .splice_write = iter_file_splice_write, |
841 | .fallocate = blkdev_fallocate, | |
842 | }; | |
843 | ||
844 | static __init int blkdev_init(void) | |
845 | { | |
846 | return bioset_init(&blkdev_dio_pool, 4, | |
847 | offsetof(struct blkdev_dio, bio), | |
848 | BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE); | |
849 | } | |
850 | module_init(blkdev_init); |