Merge tag 'hyperv-fixes-signed-20211022' of git://git.kernel.org/pub/scm/linux/kernel...
[platform/kernel/linux-starfive.git] / block / fops.c
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>
17 #include <linux/fs.h>
18 #include "blk.h"
19
20 static struct inode *bdev_file_inode(struct file *file)
21 {
22         return file->f_mapping->host;
23 }
24
25 static int blkdev_get_block(struct inode *inode, sector_t iblock,
26                 struct buffer_head *bh, int create)
27 {
28         bh->b_bdev = I_BDEV(inode);
29         bh->b_blocknr = iblock;
30         set_buffer_mapped(bh);
31         return 0;
32 }
33
34 static unsigned int dio_bio_write_op(struct kiocb *iocb)
35 {
36         unsigned int op = REQ_OP_WRITE | REQ_SYNC | REQ_IDLE;
37
38         /* avoid the need for a I/O completion work item */
39         if (iocb->ki_flags & IOCB_DSYNC)
40                 op |= REQ_FUA;
41         return op;
42 }
43
44 #define DIO_INLINE_BIO_VECS 4
45
46 static void blkdev_bio_end_io_simple(struct bio *bio)
47 {
48         struct task_struct *waiter = bio->bi_private;
49
50         WRITE_ONCE(bio->bi_private, NULL);
51         blk_wake_io_task(waiter);
52 }
53
54 static ssize_t __blkdev_direct_IO_simple(struct kiocb *iocb,
55                 struct iov_iter *iter, unsigned int nr_pages)
56 {
57         struct file *file = iocb->ki_filp;
58         struct block_device *bdev = I_BDEV(bdev_file_inode(file));
59         struct bio_vec inline_vecs[DIO_INLINE_BIO_VECS], *vecs;
60         loff_t pos = iocb->ki_pos;
61         bool should_dirty = false;
62         struct bio bio;
63         ssize_t ret;
64         blk_qc_t qc;
65
66         if ((pos | iov_iter_alignment(iter)) &
67             (bdev_logical_block_size(bdev) - 1))
68                 return -EINVAL;
69
70         if (nr_pages <= DIO_INLINE_BIO_VECS)
71                 vecs = inline_vecs;
72         else {
73                 vecs = kmalloc_array(nr_pages, sizeof(struct bio_vec),
74                                      GFP_KERNEL);
75                 if (!vecs)
76                         return -ENOMEM;
77         }
78
79         bio_init(&bio, vecs, nr_pages);
80         bio_set_dev(&bio, bdev);
81         bio.bi_iter.bi_sector = pos >> 9;
82         bio.bi_write_hint = iocb->ki_hint;
83         bio.bi_private = current;
84         bio.bi_end_io = blkdev_bio_end_io_simple;
85         bio.bi_ioprio = iocb->ki_ioprio;
86
87         ret = bio_iov_iter_get_pages(&bio, iter);
88         if (unlikely(ret))
89                 goto out;
90         ret = bio.bi_iter.bi_size;
91
92         if (iov_iter_rw(iter) == READ) {
93                 bio.bi_opf = REQ_OP_READ;
94                 if (iter_is_iovec(iter))
95                         should_dirty = true;
96         } else {
97                 bio.bi_opf = dio_bio_write_op(iocb);
98                 task_io_account_write(ret);
99         }
100         if (iocb->ki_flags & IOCB_NOWAIT)
101                 bio.bi_opf |= REQ_NOWAIT;
102         if (iocb->ki_flags & IOCB_HIPRI)
103                 bio_set_polled(&bio, iocb);
104
105         qc = submit_bio(&bio);
106         for (;;) {
107                 set_current_state(TASK_UNINTERRUPTIBLE);
108                 if (!READ_ONCE(bio.bi_private))
109                         break;
110                 if (!(iocb->ki_flags & IOCB_HIPRI) ||
111                     !blk_poll(bdev_get_queue(bdev), qc, true))
112                         blk_io_schedule();
113         }
114         __set_current_state(TASK_RUNNING);
115
116         bio_release_pages(&bio, should_dirty);
117         if (unlikely(bio.bi_status))
118                 ret = blk_status_to_errno(bio.bi_status);
119
120 out:
121         if (vecs != inline_vecs)
122                 kfree(vecs);
123
124         bio_uninit(&bio);
125
126         return ret;
127 }
128
129 struct blkdev_dio {
130         union {
131                 struct kiocb            *iocb;
132                 struct task_struct      *waiter;
133         };
134         size_t                  size;
135         atomic_t                ref;
136         bool                    multi_bio : 1;
137         bool                    should_dirty : 1;
138         bool                    is_sync : 1;
139         struct bio              bio;
140 };
141
142 static struct bio_set blkdev_dio_pool;
143
144 static int blkdev_iopoll(struct kiocb *kiocb, bool wait)
145 {
146         struct block_device *bdev = I_BDEV(kiocb->ki_filp->f_mapping->host);
147         struct request_queue *q = bdev_get_queue(bdev);
148
149         return blk_poll(q, READ_ONCE(kiocb->ki_cookie), wait);
150 }
151
152 static void blkdev_bio_end_io(struct bio *bio)
153 {
154         struct blkdev_dio *dio = bio->bi_private;
155         bool should_dirty = dio->should_dirty;
156
157         if (bio->bi_status && !dio->bio.bi_status)
158                 dio->bio.bi_status = bio->bi_status;
159
160         if (!dio->multi_bio || atomic_dec_and_test(&dio->ref)) {
161                 if (!dio->is_sync) {
162                         struct kiocb *iocb = dio->iocb;
163                         ssize_t ret;
164
165                         if (likely(!dio->bio.bi_status)) {
166                                 ret = dio->size;
167                                 iocb->ki_pos += ret;
168                         } else {
169                                 ret = blk_status_to_errno(dio->bio.bi_status);
170                         }
171
172                         dio->iocb->ki_complete(iocb, ret, 0);
173                         if (dio->multi_bio)
174                                 bio_put(&dio->bio);
175                 } else {
176                         struct task_struct *waiter = dio->waiter;
177
178                         WRITE_ONCE(dio->waiter, NULL);
179                         blk_wake_io_task(waiter);
180                 }
181         }
182
183         if (should_dirty) {
184                 bio_check_pages_dirty(bio);
185         } else {
186                 bio_release_pages(bio, false);
187                 bio_put(bio);
188         }
189 }
190
191 static ssize_t __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter,
192                 unsigned int nr_pages)
193 {
194         struct file *file = iocb->ki_filp;
195         struct inode *inode = bdev_file_inode(file);
196         struct block_device *bdev = I_BDEV(inode);
197         struct blk_plug plug;
198         struct blkdev_dio *dio;
199         struct bio *bio;
200         bool is_poll = (iocb->ki_flags & IOCB_HIPRI) != 0;
201         bool is_read = (iov_iter_rw(iter) == READ), is_sync;
202         loff_t pos = iocb->ki_pos;
203         blk_qc_t qc = BLK_QC_T_NONE;
204         int ret = 0;
205
206         if ((pos | iov_iter_alignment(iter)) &
207             (bdev_logical_block_size(bdev) - 1))
208                 return -EINVAL;
209
210         bio = bio_alloc_kiocb(iocb, nr_pages, &blkdev_dio_pool);
211
212         dio = container_of(bio, struct blkdev_dio, bio);
213         dio->is_sync = is_sync = is_sync_kiocb(iocb);
214         if (dio->is_sync) {
215                 dio->waiter = current;
216                 bio_get(bio);
217         } else {
218                 dio->iocb = iocb;
219         }
220
221         dio->size = 0;
222         dio->multi_bio = false;
223         dio->should_dirty = is_read && iter_is_iovec(iter);
224
225         /*
226          * Don't plug for HIPRI/polled IO, as those should go straight
227          * to issue
228          */
229         if (!is_poll)
230                 blk_start_plug(&plug);
231
232         for (;;) {
233                 bio_set_dev(bio, bdev);
234                 bio->bi_iter.bi_sector = pos >> 9;
235                 bio->bi_write_hint = iocb->ki_hint;
236                 bio->bi_private = dio;
237                 bio->bi_end_io = blkdev_bio_end_io;
238                 bio->bi_ioprio = iocb->ki_ioprio;
239
240                 ret = bio_iov_iter_get_pages(bio, iter);
241                 if (unlikely(ret)) {
242                         bio->bi_status = BLK_STS_IOERR;
243                         bio_endio(bio);
244                         break;
245                 }
246
247                 if (is_read) {
248                         bio->bi_opf = REQ_OP_READ;
249                         if (dio->should_dirty)
250                                 bio_set_pages_dirty(bio);
251                 } else {
252                         bio->bi_opf = dio_bio_write_op(iocb);
253                         task_io_account_write(bio->bi_iter.bi_size);
254                 }
255                 if (iocb->ki_flags & IOCB_NOWAIT)
256                         bio->bi_opf |= REQ_NOWAIT;
257
258                 dio->size += bio->bi_iter.bi_size;
259                 pos += bio->bi_iter.bi_size;
260
261                 nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS);
262                 if (!nr_pages) {
263                         bool polled = false;
264
265                         if (iocb->ki_flags & IOCB_HIPRI) {
266                                 bio_set_polled(bio, iocb);
267                                 polled = true;
268                         }
269
270                         qc = submit_bio(bio);
271
272                         if (polled)
273                                 WRITE_ONCE(iocb->ki_cookie, qc);
274                         break;
275                 }
276
277                 if (!dio->multi_bio) {
278                         /*
279                          * AIO needs an extra reference to ensure the dio
280                          * structure which is embedded into the first bio
281                          * stays around.
282                          */
283                         if (!is_sync)
284                                 bio_get(bio);
285                         dio->multi_bio = true;
286                         atomic_set(&dio->ref, 2);
287                 } else {
288                         atomic_inc(&dio->ref);
289                 }
290
291                 submit_bio(bio);
292                 bio = bio_alloc(GFP_KERNEL, nr_pages);
293         }
294
295         if (!is_poll)
296                 blk_finish_plug(&plug);
297
298         if (!is_sync)
299                 return -EIOCBQUEUED;
300
301         for (;;) {
302                 set_current_state(TASK_UNINTERRUPTIBLE);
303                 if (!READ_ONCE(dio->waiter))
304                         break;
305
306                 if (!(iocb->ki_flags & IOCB_HIPRI) ||
307                     !blk_poll(bdev_get_queue(bdev), qc, true))
308                         blk_io_schedule();
309         }
310         __set_current_state(TASK_RUNNING);
311
312         if (!ret)
313                 ret = blk_status_to_errno(dio->bio.bi_status);
314         if (likely(!ret))
315                 ret = dio->size;
316
317         bio_put(&dio->bio);
318         return ret;
319 }
320
321 static ssize_t blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter)
322 {
323         unsigned int nr_pages;
324
325         if (!iov_iter_count(iter))
326                 return 0;
327
328         nr_pages = bio_iov_vecs_to_alloc(iter, BIO_MAX_VECS + 1);
329         if (is_sync_kiocb(iocb) && nr_pages <= BIO_MAX_VECS)
330                 return __blkdev_direct_IO_simple(iocb, iter, nr_pages);
331
332         return __blkdev_direct_IO(iocb, iter, bio_max_segs(nr_pages));
333 }
334
335 static int blkdev_writepage(struct page *page, struct writeback_control *wbc)
336 {
337         return block_write_full_page(page, blkdev_get_block, wbc);
338 }
339
340 static int blkdev_readpage(struct file * file, struct page * page)
341 {
342         return block_read_full_page(page, blkdev_get_block);
343 }
344
345 static void blkdev_readahead(struct readahead_control *rac)
346 {
347         mpage_readahead(rac, blkdev_get_block);
348 }
349
350 static int blkdev_write_begin(struct file *file, struct address_space *mapping,
351                 loff_t pos, unsigned len, unsigned flags, struct page **pagep,
352                 void **fsdata)
353 {
354         return block_write_begin(mapping, pos, len, flags, pagep,
355                                  blkdev_get_block);
356 }
357
358 static int blkdev_write_end(struct file *file, struct address_space *mapping,
359                 loff_t pos, unsigned len, unsigned copied, struct page *page,
360                 void *fsdata)
361 {
362         int ret;
363         ret = block_write_end(file, mapping, pos, len, copied, page, fsdata);
364
365         unlock_page(page);
366         put_page(page);
367
368         return ret;
369 }
370
371 static int blkdev_writepages(struct address_space *mapping,
372                              struct writeback_control *wbc)
373 {
374         return generic_writepages(mapping, wbc);
375 }
376
377 const struct address_space_operations def_blk_aops = {
378         .set_page_dirty = __set_page_dirty_buffers,
379         .readpage       = blkdev_readpage,
380         .readahead      = blkdev_readahead,
381         .writepage      = blkdev_writepage,
382         .write_begin    = blkdev_write_begin,
383         .write_end      = blkdev_write_end,
384         .writepages     = blkdev_writepages,
385         .direct_IO      = blkdev_direct_IO,
386         .migratepage    = buffer_migrate_page_norefs,
387         .is_dirty_writeback = buffer_check_dirty_writeback,
388 };
389
390 /*
391  * for a block special file file_inode(file)->i_size is zero
392  * so we compute the size by hand (just as in block_read/write above)
393  */
394 static loff_t blkdev_llseek(struct file *file, loff_t offset, int whence)
395 {
396         struct inode *bd_inode = bdev_file_inode(file);
397         loff_t retval;
398
399         inode_lock(bd_inode);
400         retval = fixed_size_llseek(file, offset, whence, i_size_read(bd_inode));
401         inode_unlock(bd_inode);
402         return retval;
403 }
404
405 static int blkdev_fsync(struct file *filp, loff_t start, loff_t end,
406                 int datasync)
407 {
408         struct inode *bd_inode = bdev_file_inode(filp);
409         struct block_device *bdev = I_BDEV(bd_inode);
410         int error;
411
412         error = file_write_and_wait_range(filp, start, end);
413         if (error)
414                 return error;
415
416         /*
417          * There is no need to serialise calls to blkdev_issue_flush with
418          * i_mutex and doing so causes performance issues with concurrent
419          * O_SYNC writers to a block device.
420          */
421         error = blkdev_issue_flush(bdev);
422         if (error == -EOPNOTSUPP)
423                 error = 0;
424
425         return error;
426 }
427
428 static int blkdev_open(struct inode *inode, struct file *filp)
429 {
430         struct block_device *bdev;
431
432         /*
433          * Preserve backwards compatibility and allow large file access
434          * even if userspace doesn't ask for it explicitly. Some mkfs
435          * binary needs it. We might want to drop this workaround
436          * during an unstable branch.
437          */
438         filp->f_flags |= O_LARGEFILE;
439         filp->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
440
441         if (filp->f_flags & O_NDELAY)
442                 filp->f_mode |= FMODE_NDELAY;
443         if (filp->f_flags & O_EXCL)
444                 filp->f_mode |= FMODE_EXCL;
445         if ((filp->f_flags & O_ACCMODE) == 3)
446                 filp->f_mode |= FMODE_WRITE_IOCTL;
447
448         bdev = blkdev_get_by_dev(inode->i_rdev, filp->f_mode, filp);
449         if (IS_ERR(bdev))
450                 return PTR_ERR(bdev);
451         filp->f_mapping = bdev->bd_inode->i_mapping;
452         filp->f_wb_err = filemap_sample_wb_err(filp->f_mapping);
453         return 0;
454 }
455
456 static int blkdev_close(struct inode *inode, struct file *filp)
457 {
458         struct block_device *bdev = I_BDEV(bdev_file_inode(filp));
459
460         blkdev_put(bdev, filp->f_mode);
461         return 0;
462 }
463
464 static long block_ioctl(struct file *file, unsigned cmd, unsigned long arg)
465 {
466         struct block_device *bdev = I_BDEV(bdev_file_inode(file));
467         fmode_t mode = file->f_mode;
468
469         /*
470          * O_NDELAY can be altered using fcntl(.., F_SETFL, ..), so we have
471          * to updated it before every ioctl.
472          */
473         if (file->f_flags & O_NDELAY)
474                 mode |= FMODE_NDELAY;
475         else
476                 mode &= ~FMODE_NDELAY;
477
478         return blkdev_ioctl(bdev, mode, cmd, arg);
479 }
480
481 /*
482  * Write data to the block device.  Only intended for the block device itself
483  * and the raw driver which basically is a fake block device.
484  *
485  * Does not take i_mutex for the write and thus is not for general purpose
486  * use.
487  */
488 static ssize_t blkdev_write_iter(struct kiocb *iocb, struct iov_iter *from)
489 {
490         struct file *file = iocb->ki_filp;
491         struct inode *bd_inode = bdev_file_inode(file);
492         loff_t size = i_size_read(bd_inode);
493         struct blk_plug plug;
494         size_t shorted = 0;
495         ssize_t ret;
496
497         if (bdev_read_only(I_BDEV(bd_inode)))
498                 return -EPERM;
499
500         if (IS_SWAPFILE(bd_inode) && !is_hibernate_resume_dev(bd_inode->i_rdev))
501                 return -ETXTBSY;
502
503         if (!iov_iter_count(from))
504                 return 0;
505
506         if (iocb->ki_pos >= size)
507                 return -ENOSPC;
508
509         if ((iocb->ki_flags & (IOCB_NOWAIT | IOCB_DIRECT)) == IOCB_NOWAIT)
510                 return -EOPNOTSUPP;
511
512         size -= iocb->ki_pos;
513         if (iov_iter_count(from) > size) {
514                 shorted = iov_iter_count(from) - size;
515                 iov_iter_truncate(from, size);
516         }
517
518         blk_start_plug(&plug);
519         ret = __generic_file_write_iter(iocb, from);
520         if (ret > 0)
521                 ret = generic_write_sync(iocb, ret);
522         iov_iter_reexpand(from, iov_iter_count(from) + shorted);
523         blk_finish_plug(&plug);
524         return ret;
525 }
526
527 static ssize_t blkdev_read_iter(struct kiocb *iocb, struct iov_iter *to)
528 {
529         struct file *file = iocb->ki_filp;
530         struct inode *bd_inode = bdev_file_inode(file);
531         loff_t size = i_size_read(bd_inode);
532         loff_t pos = iocb->ki_pos;
533         size_t shorted = 0;
534         ssize_t ret;
535
536         if (pos >= size)
537                 return 0;
538
539         size -= pos;
540         if (iov_iter_count(to) > size) {
541                 shorted = iov_iter_count(to) - size;
542                 iov_iter_truncate(to, size);
543         }
544
545         ret = generic_file_read_iter(iocb, to);
546         iov_iter_reexpand(to, iov_iter_count(to) + shorted);
547         return ret;
548 }
549
550 #define BLKDEV_FALLOC_FL_SUPPORTED                                      \
551                 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE |           \
552                  FALLOC_FL_ZERO_RANGE | FALLOC_FL_NO_HIDE_STALE)
553
554 static long blkdev_fallocate(struct file *file, int mode, loff_t start,
555                              loff_t len)
556 {
557         struct inode *inode = bdev_file_inode(file);
558         struct block_device *bdev = I_BDEV(inode);
559         loff_t end = start + len - 1;
560         loff_t isize;
561         int error;
562
563         /* Fail if we don't recognize the flags. */
564         if (mode & ~BLKDEV_FALLOC_FL_SUPPORTED)
565                 return -EOPNOTSUPP;
566
567         /* Don't go off the end of the device. */
568         isize = i_size_read(bdev->bd_inode);
569         if (start >= isize)
570                 return -EINVAL;
571         if (end >= isize) {
572                 if (mode & FALLOC_FL_KEEP_SIZE) {
573                         len = isize - start;
574                         end = start + len - 1;
575                 } else
576                         return -EINVAL;
577         }
578
579         /*
580          * Don't allow IO that isn't aligned to logical block size.
581          */
582         if ((start | len) & (bdev_logical_block_size(bdev) - 1))
583                 return -EINVAL;
584
585         filemap_invalidate_lock(inode->i_mapping);
586
587         /* Invalidate the page cache, including dirty pages. */
588         error = truncate_bdev_range(bdev, file->f_mode, start, end);
589         if (error)
590                 goto fail;
591
592         switch (mode) {
593         case FALLOC_FL_ZERO_RANGE:
594         case FALLOC_FL_ZERO_RANGE | FALLOC_FL_KEEP_SIZE:
595                 error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
596                                             GFP_KERNEL, BLKDEV_ZERO_NOUNMAP);
597                 break;
598         case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE:
599                 error = blkdev_issue_zeroout(bdev, start >> 9, len >> 9,
600                                              GFP_KERNEL, BLKDEV_ZERO_NOFALLBACK);
601                 break;
602         case FALLOC_FL_PUNCH_HOLE | FALLOC_FL_KEEP_SIZE | FALLOC_FL_NO_HIDE_STALE:
603                 error = blkdev_issue_discard(bdev, start >> 9, len >> 9,
604                                              GFP_KERNEL, 0);
605                 break;
606         default:
607                 error = -EOPNOTSUPP;
608         }
609
610  fail:
611         filemap_invalidate_unlock(inode->i_mapping);
612         return error;
613 }
614
615 const struct file_operations def_blk_fops = {
616         .open           = blkdev_open,
617         .release        = blkdev_close,
618         .llseek         = blkdev_llseek,
619         .read_iter      = blkdev_read_iter,
620         .write_iter     = blkdev_write_iter,
621         .iopoll         = blkdev_iopoll,
622         .mmap           = generic_file_mmap,
623         .fsync          = blkdev_fsync,
624         .unlocked_ioctl = block_ioctl,
625 #ifdef CONFIG_COMPAT
626         .compat_ioctl   = compat_blkdev_ioctl,
627 #endif
628         .splice_read    = generic_file_splice_read,
629         .splice_write   = iter_file_splice_write,
630         .fallocate      = blkdev_fallocate,
631 };
632
633 static __init int blkdev_init(void)
634 {
635         return bioset_init(&blkdev_dio_pool, 4,
636                                 offsetof(struct blkdev_dio, bio),
637                                 BIOSET_NEED_BVECS|BIOSET_PERCPU_CACHE);
638 }
639 module_init(blkdev_init);