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6#include <linux/module.h>
7#include <linux/compiler.h>
8#include <linux/fs.h>
9#include <linux/iomap.h>
10#include <linux/backing-dev.h>
11#include <linux/uio.h>
12#include <linux/task_io_accounting_ops.h>
13#include "trace.h"
14
15#include "../internal.h"
16
17
18
19
20
21#define IOMAP_DIO_WRITE_FUA (1 << 28)
22#define IOMAP_DIO_NEED_SYNC (1 << 29)
23#define IOMAP_DIO_WRITE (1 << 30)
24#define IOMAP_DIO_DIRTY (1 << 31)
25
26struct iomap_dio {
27 struct kiocb *iocb;
28 const struct iomap_dio_ops *dops;
29 loff_t i_size;
30 loff_t size;
31 atomic_t ref;
32 unsigned flags;
33 int error;
34 bool wait_for_completion;
35
36 union {
37
38 struct {
39 struct iov_iter *iter;
40 struct task_struct *waiter;
41 struct request_queue *last_queue;
42 blk_qc_t cookie;
43 } submit;
44
45
46 struct {
47 struct work_struct work;
48 } aio;
49 };
50};
51
52int iomap_dio_iopoll(struct kiocb *kiocb, bool spin)
53{
54 struct request_queue *q = READ_ONCE(kiocb->private);
55
56 if (!q)
57 return 0;
58 return blk_poll(q, READ_ONCE(kiocb->ki_cookie), spin);
59}
60EXPORT_SYMBOL_GPL(iomap_dio_iopoll);
61
62static void iomap_dio_submit_bio(const struct iomap_iter *iter,
63 struct iomap_dio *dio, struct bio *bio, loff_t pos)
64{
65 atomic_inc(&dio->ref);
66
67 if (dio->iocb->ki_flags & IOCB_HIPRI)
68 bio_set_polled(bio, dio->iocb);
69
70 dio->submit.last_queue = bdev_get_queue(iter->iomap.bdev);
71 if (dio->dops && dio->dops->submit_io)
72 dio->submit.cookie = dio->dops->submit_io(iter, bio, pos);
73 else
74 dio->submit.cookie = submit_bio(bio);
75}
76
77ssize_t iomap_dio_complete(struct iomap_dio *dio)
78{
79 const struct iomap_dio_ops *dops = dio->dops;
80 struct kiocb *iocb = dio->iocb;
81 struct inode *inode = file_inode(iocb->ki_filp);
82 loff_t offset = iocb->ki_pos;
83 ssize_t ret = dio->error;
84
85 if (dops && dops->end_io)
86 ret = dops->end_io(iocb, dio->size, ret, dio->flags);
87
88 if (likely(!ret)) {
89 ret = dio->size;
90
91 if (offset + ret > dio->i_size &&
92 !(dio->flags & IOMAP_DIO_WRITE))
93 ret = dio->i_size - offset;
94 iocb->ki_pos += ret;
95 }
96
97
98
99
100
101
102
103
104
105
106
107
108
109 if (!dio->error && dio->size &&
110 (dio->flags & IOMAP_DIO_WRITE) && inode->i_mapping->nrpages) {
111 int err;
112 err = invalidate_inode_pages2_range(inode->i_mapping,
113 offset >> PAGE_SHIFT,
114 (offset + dio->size - 1) >> PAGE_SHIFT);
115 if (err)
116 dio_warn_stale_pagecache(iocb->ki_filp);
117 }
118
119 inode_dio_end(file_inode(iocb->ki_filp));
120
121
122
123
124 if (ret > 0 && (dio->flags & IOMAP_DIO_NEED_SYNC))
125 ret = generic_write_sync(iocb, ret);
126
127 kfree(dio);
128
129 return ret;
130}
131EXPORT_SYMBOL_GPL(iomap_dio_complete);
132
133static void iomap_dio_complete_work(struct work_struct *work)
134{
135 struct iomap_dio *dio = container_of(work, struct iomap_dio, aio.work);
136 struct kiocb *iocb = dio->iocb;
137
138 iocb->ki_complete(iocb, iomap_dio_complete(dio), 0);
139}
140
141
142
143
144
145
146static inline void iomap_dio_set_error(struct iomap_dio *dio, int ret)
147{
148 cmpxchg(&dio->error, 0, ret);
149}
150
151static void iomap_dio_bio_end_io(struct bio *bio)
152{
153 struct iomap_dio *dio = bio->bi_private;
154 bool should_dirty = (dio->flags & IOMAP_DIO_DIRTY);
155
156 if (bio->bi_status)
157 iomap_dio_set_error(dio, blk_status_to_errno(bio->bi_status));
158
159 if (atomic_dec_and_test(&dio->ref)) {
160 if (dio->wait_for_completion) {
161 struct task_struct *waiter = dio->submit.waiter;
162 WRITE_ONCE(dio->submit.waiter, NULL);
163 blk_wake_io_task(waiter);
164 } else if (dio->flags & IOMAP_DIO_WRITE) {
165 struct inode *inode = file_inode(dio->iocb->ki_filp);
166
167 INIT_WORK(&dio->aio.work, iomap_dio_complete_work);
168 queue_work(inode->i_sb->s_dio_done_wq, &dio->aio.work);
169 } else {
170 iomap_dio_complete_work(&dio->aio.work);
171 }
172 }
173
174 if (should_dirty) {
175 bio_check_pages_dirty(bio);
176 } else {
177 bio_release_pages(bio, false);
178 bio_put(bio);
179 }
180}
181
182static void iomap_dio_zero(const struct iomap_iter *iter, struct iomap_dio *dio,
183 loff_t pos, unsigned len)
184{
185 struct page *page = ZERO_PAGE(0);
186 int flags = REQ_SYNC | REQ_IDLE;
187 struct bio *bio;
188
189 bio = bio_alloc(GFP_KERNEL, 1);
190 bio_set_dev(bio, iter->iomap.bdev);
191 bio->bi_iter.bi_sector = iomap_sector(&iter->iomap, pos);
192 bio->bi_private = dio;
193 bio->bi_end_io = iomap_dio_bio_end_io;
194
195 get_page(page);
196 __bio_add_page(bio, page, len, 0);
197 bio_set_op_attrs(bio, REQ_OP_WRITE, flags);
198 iomap_dio_submit_bio(iter, dio, bio, pos);
199}
200
201
202
203
204
205
206static inline unsigned int iomap_dio_bio_opflags(struct iomap_dio *dio,
207 const struct iomap *iomap, bool use_fua)
208{
209 unsigned int opflags = REQ_SYNC | REQ_IDLE;
210
211 if (!(dio->flags & IOMAP_DIO_WRITE)) {
212 WARN_ON_ONCE(iomap->flags & IOMAP_F_ZONE_APPEND);
213 return REQ_OP_READ;
214 }
215
216 if (iomap->flags & IOMAP_F_ZONE_APPEND)
217 opflags |= REQ_OP_ZONE_APPEND;
218 else
219 opflags |= REQ_OP_WRITE;
220
221 if (use_fua)
222 opflags |= REQ_FUA;
223 else
224 dio->flags &= ~IOMAP_DIO_WRITE_FUA;
225
226 return opflags;
227}
228
229static loff_t iomap_dio_bio_iter(const struct iomap_iter *iter,
230 struct iomap_dio *dio)
231{
232 const struct iomap *iomap = &iter->iomap;
233 struct inode *inode = iter->inode;
234 unsigned int blkbits = blksize_bits(bdev_logical_block_size(iomap->bdev));
235 unsigned int fs_block_size = i_blocksize(inode), pad;
236 unsigned int align = iov_iter_alignment(dio->submit.iter);
237 loff_t length = iomap_length(iter);
238 loff_t pos = iter->pos;
239 unsigned int bio_opf;
240 struct bio *bio;
241 bool need_zeroout = false;
242 bool use_fua = false;
243 int nr_pages, ret = 0;
244 size_t copied = 0;
245 size_t orig_count;
246
247 if ((pos | length | align) & ((1 << blkbits) - 1))
248 return -EINVAL;
249
250 if (iomap->type == IOMAP_UNWRITTEN) {
251 dio->flags |= IOMAP_DIO_UNWRITTEN;
252 need_zeroout = true;
253 }
254
255 if (iomap->flags & IOMAP_F_SHARED)
256 dio->flags |= IOMAP_DIO_COW;
257
258 if (iomap->flags & IOMAP_F_NEW) {
259 need_zeroout = true;
260 } else if (iomap->type == IOMAP_MAPPED) {
261
262
263
264
265
266
267
268 if (!(iomap->flags & (IOMAP_F_SHARED|IOMAP_F_DIRTY)) &&
269 (dio->flags & IOMAP_DIO_WRITE_FUA) &&
270 blk_queue_fua(bdev_get_queue(iomap->bdev)))
271 use_fua = true;
272 }
273
274
275
276
277
278
279 orig_count = iov_iter_count(dio->submit.iter);
280 iov_iter_truncate(dio->submit.iter, length);
281
282 if (!iov_iter_count(dio->submit.iter))
283 goto out;
284
285 if (need_zeroout) {
286
287 pad = pos & (fs_block_size - 1);
288 if (pad)
289 iomap_dio_zero(iter, dio, pos - pad, pad);
290 }
291
292
293
294
295
296
297 bio_opf = iomap_dio_bio_opflags(dio, iomap, use_fua);
298
299 nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter, BIO_MAX_VECS);
300 do {
301 size_t n;
302 if (dio->error) {
303 iov_iter_revert(dio->submit.iter, copied);
304 copied = ret = 0;
305 goto out;
306 }
307
308 bio = bio_alloc(GFP_KERNEL, nr_pages);
309 bio_set_dev(bio, iomap->bdev);
310 bio->bi_iter.bi_sector = iomap_sector(iomap, pos);
311 bio->bi_write_hint = dio->iocb->ki_hint;
312 bio->bi_ioprio = dio->iocb->ki_ioprio;
313 bio->bi_private = dio;
314 bio->bi_end_io = iomap_dio_bio_end_io;
315 bio->bi_opf = bio_opf;
316
317 ret = bio_iov_iter_get_pages(bio, dio->submit.iter);
318 if (unlikely(ret)) {
319
320
321
322
323
324
325 bio_put(bio);
326 goto zero_tail;
327 }
328
329 n = bio->bi_iter.bi_size;
330 if (dio->flags & IOMAP_DIO_WRITE) {
331 task_io_account_write(n);
332 } else {
333 if (dio->flags & IOMAP_DIO_DIRTY)
334 bio_set_pages_dirty(bio);
335 }
336
337 dio->size += n;
338 copied += n;
339
340 nr_pages = bio_iov_vecs_to_alloc(dio->submit.iter,
341 BIO_MAX_VECS);
342 iomap_dio_submit_bio(iter, dio, bio, pos);
343 pos += n;
344 } while (nr_pages);
345
346
347
348
349
350
351
352zero_tail:
353 if (need_zeroout ||
354 ((dio->flags & IOMAP_DIO_WRITE) && pos >= i_size_read(inode))) {
355
356 pad = pos & (fs_block_size - 1);
357 if (pad)
358 iomap_dio_zero(iter, dio, pos, fs_block_size - pad);
359 }
360out:
361
362 iov_iter_reexpand(dio->submit.iter, orig_count - copied);
363 if (copied)
364 return copied;
365 return ret;
366}
367
368static loff_t iomap_dio_hole_iter(const struct iomap_iter *iter,
369 struct iomap_dio *dio)
370{
371 loff_t length = iov_iter_zero(iomap_length(iter), dio->submit.iter);
372
373 dio->size += length;
374 return length;
375}
376
377static loff_t iomap_dio_inline_iter(const struct iomap_iter *iomi,
378 struct iomap_dio *dio)
379{
380 const struct iomap *iomap = &iomi->iomap;
381 struct iov_iter *iter = dio->submit.iter;
382 void *inline_data = iomap_inline_data(iomap, iomi->pos);
383 loff_t length = iomap_length(iomi);
384 loff_t pos = iomi->pos;
385 size_t copied;
386
387 if (WARN_ON_ONCE(!iomap_inline_data_valid(iomap)))
388 return -EIO;
389
390 if (dio->flags & IOMAP_DIO_WRITE) {
391 loff_t size = iomi->inode->i_size;
392
393 if (pos > size)
394 memset(iomap_inline_data(iomap, size), 0, pos - size);
395 copied = copy_from_iter(inline_data, length, iter);
396 if (copied) {
397 if (pos + copied > size)
398 i_size_write(iomi->inode, pos + copied);
399 mark_inode_dirty(iomi->inode);
400 }
401 } else {
402 copied = copy_to_iter(inline_data, length, iter);
403 }
404 dio->size += copied;
405 return copied;
406}
407
408static loff_t iomap_dio_iter(const struct iomap_iter *iter,
409 struct iomap_dio *dio)
410{
411 switch (iter->iomap.type) {
412 case IOMAP_HOLE:
413 if (WARN_ON_ONCE(dio->flags & IOMAP_DIO_WRITE))
414 return -EIO;
415 return iomap_dio_hole_iter(iter, dio);
416 case IOMAP_UNWRITTEN:
417 if (!(dio->flags & IOMAP_DIO_WRITE))
418 return iomap_dio_hole_iter(iter, dio);
419 return iomap_dio_bio_iter(iter, dio);
420 case IOMAP_MAPPED:
421 return iomap_dio_bio_iter(iter, dio);
422 case IOMAP_INLINE:
423 return iomap_dio_inline_iter(iter, dio);
424 case IOMAP_DELALLOC:
425
426
427
428
429
430
431 pr_warn_ratelimited("Direct I/O collision with buffered writes! File: %pD4 Comm: %.20s\n",
432 dio->iocb->ki_filp, current->comm);
433 return -EIO;
434 default:
435 WARN_ON_ONCE(1);
436 return -EIO;
437 }
438}
439
440
441
442
443
444
445
446
447
448
449
450
451
452struct iomap_dio *
453__iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
454 const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
455 unsigned int dio_flags)
456{
457 struct address_space *mapping = iocb->ki_filp->f_mapping;
458 struct inode *inode = file_inode(iocb->ki_filp);
459 struct iomap_iter iomi = {
460 .inode = inode,
461 .pos = iocb->ki_pos,
462 .len = iov_iter_count(iter),
463 .flags = IOMAP_DIRECT,
464 };
465 loff_t end = iomi.pos + iomi.len - 1, ret = 0;
466 bool wait_for_completion =
467 is_sync_kiocb(iocb) || (dio_flags & IOMAP_DIO_FORCE_WAIT);
468 struct blk_plug plug;
469 struct iomap_dio *dio;
470
471 if (!iomi.len)
472 return NULL;
473
474 dio = kmalloc(sizeof(*dio), GFP_KERNEL);
475 if (!dio)
476 return ERR_PTR(-ENOMEM);
477
478 dio->iocb = iocb;
479 atomic_set(&dio->ref, 1);
480 dio->size = 0;
481 dio->i_size = i_size_read(inode);
482 dio->dops = dops;
483 dio->error = 0;
484 dio->flags = 0;
485
486 dio->submit.iter = iter;
487 dio->submit.waiter = current;
488 dio->submit.cookie = BLK_QC_T_NONE;
489 dio->submit.last_queue = NULL;
490
491 if (iov_iter_rw(iter) == READ) {
492 if (iomi.pos >= dio->i_size)
493 goto out_free_dio;
494
495 if (iocb->ki_flags & IOCB_NOWAIT) {
496 if (filemap_range_needs_writeback(mapping, iomi.pos,
497 end)) {
498 ret = -EAGAIN;
499 goto out_free_dio;
500 }
501 iomi.flags |= IOMAP_NOWAIT;
502 }
503
504 if (iter_is_iovec(iter))
505 dio->flags |= IOMAP_DIO_DIRTY;
506 } else {
507 iomi.flags |= IOMAP_WRITE;
508 dio->flags |= IOMAP_DIO_WRITE;
509
510 if (iocb->ki_flags & IOCB_NOWAIT) {
511 if (filemap_range_has_page(mapping, iomi.pos, end)) {
512 ret = -EAGAIN;
513 goto out_free_dio;
514 }
515 iomi.flags |= IOMAP_NOWAIT;
516 }
517
518
519 if (iocb->ki_flags & IOCB_DSYNC)
520 dio->flags |= IOMAP_DIO_NEED_SYNC;
521
522
523
524
525
526
527
528 if ((iocb->ki_flags & (IOCB_DSYNC | IOCB_SYNC)) == IOCB_DSYNC)
529 dio->flags |= IOMAP_DIO_WRITE_FUA;
530 }
531
532 if (dio_flags & IOMAP_DIO_OVERWRITE_ONLY) {
533 ret = -EAGAIN;
534 if (iomi.pos >= dio->i_size ||
535 iomi.pos + iomi.len > dio->i_size)
536 goto out_free_dio;
537 iomi.flags |= IOMAP_OVERWRITE_ONLY;
538 }
539
540 ret = filemap_write_and_wait_range(mapping, iomi.pos, end);
541 if (ret)
542 goto out_free_dio;
543
544 if (iov_iter_rw(iter) == WRITE) {
545
546
547
548
549
550 if (invalidate_inode_pages2_range(mapping,
551 iomi.pos >> PAGE_SHIFT, end >> PAGE_SHIFT)) {
552 trace_iomap_dio_invalidate_fail(inode, iomi.pos,
553 iomi.len);
554 ret = -ENOTBLK;
555 goto out_free_dio;
556 }
557
558 if (!wait_for_completion && !inode->i_sb->s_dio_done_wq) {
559 ret = sb_init_dio_done_wq(inode->i_sb);
560 if (ret < 0)
561 goto out_free_dio;
562 }
563 }
564
565 inode_dio_begin(inode);
566
567 blk_start_plug(&plug);
568 while ((ret = iomap_iter(&iomi, ops)) > 0)
569 iomi.processed = iomap_dio_iter(&iomi, dio);
570 blk_finish_plug(&plug);
571
572
573
574
575
576
577 if (iov_iter_rw(iter) == READ && iomi.pos >= dio->i_size)
578 iov_iter_revert(iter, iomi.pos - dio->i_size);
579
580
581 if (ret == -ENOTBLK) {
582 wait_for_completion = true;
583 ret = 0;
584 }
585 if (ret < 0)
586 iomap_dio_set_error(dio, ret);
587
588
589
590
591
592 if (dio->flags & IOMAP_DIO_WRITE_FUA)
593 dio->flags &= ~IOMAP_DIO_NEED_SYNC;
594
595 WRITE_ONCE(iocb->ki_cookie, dio->submit.cookie);
596 WRITE_ONCE(iocb->private, dio->submit.last_queue);
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613 dio->wait_for_completion = wait_for_completion;
614 if (!atomic_dec_and_test(&dio->ref)) {
615 if (!wait_for_completion)
616 return ERR_PTR(-EIOCBQUEUED);
617
618 for (;;) {
619 set_current_state(TASK_UNINTERRUPTIBLE);
620 if (!READ_ONCE(dio->submit.waiter))
621 break;
622
623 if (!(iocb->ki_flags & IOCB_HIPRI) ||
624 !dio->submit.last_queue ||
625 !blk_poll(dio->submit.last_queue,
626 dio->submit.cookie, true))
627 blk_io_schedule();
628 }
629 __set_current_state(TASK_RUNNING);
630 }
631
632 return dio;
633
634out_free_dio:
635 kfree(dio);
636 if (ret)
637 return ERR_PTR(ret);
638 return NULL;
639}
640EXPORT_SYMBOL_GPL(__iomap_dio_rw);
641
642ssize_t
643iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
644 const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
645 unsigned int dio_flags)
646{
647 struct iomap_dio *dio;
648
649 dio = __iomap_dio_rw(iocb, iter, ops, dops, dio_flags);
650 if (IS_ERR_OR_NULL(dio))
651 return PTR_ERR_OR_ZERO(dio);
652 return iomap_dio_complete(dio);
653}
654EXPORT_SYMBOL_GPL(iomap_dio_rw);
655