Loading...
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_inode.h"
14#include "xfs_trans.h"
15#include "xfs_inode_item.h"
16#include "xfs_bmap.h"
17#include "xfs_bmap_util.h"
18#include "xfs_dir2.h"
19#include "xfs_dir2_priv.h"
20#include "xfs_ioctl.h"
21#include "xfs_trace.h"
22#include "xfs_log.h"
23#include "xfs_icache.h"
24#include "xfs_pnfs.h"
25#include "xfs_iomap.h"
26#include "xfs_reflink.h"
27
28#include <linux/dax.h>
29#include <linux/falloc.h>
30#include <linux/backing-dev.h>
31#include <linux/mman.h>
32#include <linux/fadvise.h>
33#include <linux/mount.h>
34
35static const struct vm_operations_struct xfs_file_vm_ops;
36
37/*
38 * Decide if the given file range is aligned to the size of the fundamental
39 * allocation unit for the file.
40 */
41static bool
42xfs_is_falloc_aligned(
43 struct xfs_inode *ip,
44 loff_t pos,
45 long long int len)
46{
47 struct xfs_mount *mp = ip->i_mount;
48 uint64_t mask;
49
50 if (XFS_IS_REALTIME_INODE(ip)) {
51 if (!is_power_of_2(mp->m_sb.sb_rextsize)) {
52 u64 rextbytes;
53 u32 mod;
54
55 rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
56 div_u64_rem(pos, rextbytes, &mod);
57 if (mod)
58 return false;
59 div_u64_rem(len, rextbytes, &mod);
60 return mod == 0;
61 }
62 mask = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize) - 1;
63 } else {
64 mask = mp->m_sb.sb_blocksize - 1;
65 }
66
67 return !((pos | len) & mask);
68}
69
70/*
71 * Fsync operations on directories are much simpler than on regular files,
72 * as there is no file data to flush, and thus also no need for explicit
73 * cache flush operations, and there are no non-transaction metadata updates
74 * on directories either.
75 */
76STATIC int
77xfs_dir_fsync(
78 struct file *file,
79 loff_t start,
80 loff_t end,
81 int datasync)
82{
83 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
84
85 trace_xfs_dir_fsync(ip);
86 return xfs_log_force_inode(ip);
87}
88
89static xfs_csn_t
90xfs_fsync_seq(
91 struct xfs_inode *ip,
92 bool datasync)
93{
94 if (!xfs_ipincount(ip))
95 return 0;
96 if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
97 return 0;
98 return ip->i_itemp->ili_commit_seq;
99}
100
101/*
102 * All metadata updates are logged, which means that we just have to flush the
103 * log up to the latest LSN that touched the inode.
104 *
105 * If we have concurrent fsync/fdatasync() calls, we need them to all block on
106 * the log force before we clear the ili_fsync_fields field. This ensures that
107 * we don't get a racing sync operation that does not wait for the metadata to
108 * hit the journal before returning. If we race with clearing ili_fsync_fields,
109 * then all that will happen is the log force will do nothing as the lsn will
110 * already be on disk. We can't race with setting ili_fsync_fields because that
111 * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock
112 * shared until after the ili_fsync_fields is cleared.
113 */
114static int
115xfs_fsync_flush_log(
116 struct xfs_inode *ip,
117 bool datasync,
118 int *log_flushed)
119{
120 int error = 0;
121 xfs_csn_t seq;
122
123 xfs_ilock(ip, XFS_ILOCK_SHARED);
124 seq = xfs_fsync_seq(ip, datasync);
125 if (seq) {
126 error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC,
127 log_flushed);
128
129 spin_lock(&ip->i_itemp->ili_lock);
130 ip->i_itemp->ili_fsync_fields = 0;
131 spin_unlock(&ip->i_itemp->ili_lock);
132 }
133 xfs_iunlock(ip, XFS_ILOCK_SHARED);
134 return error;
135}
136
137STATIC int
138xfs_file_fsync(
139 struct file *file,
140 loff_t start,
141 loff_t end,
142 int datasync)
143{
144 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
145 struct xfs_mount *mp = ip->i_mount;
146 int error, err2;
147 int log_flushed = 0;
148
149 trace_xfs_file_fsync(ip);
150
151 error = file_write_and_wait_range(file, start, end);
152 if (error)
153 return error;
154
155 if (xfs_is_shutdown(mp))
156 return -EIO;
157
158 xfs_iflags_clear(ip, XFS_ITRUNCATED);
159
160 /*
161 * If we have an RT and/or log subvolume we need to make sure to flush
162 * the write cache the device used for file data first. This is to
163 * ensure newly written file data make it to disk before logging the new
164 * inode size in case of an extending write.
165 */
166 if (XFS_IS_REALTIME_INODE(ip))
167 error = blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
168 else if (mp->m_logdev_targp != mp->m_ddev_targp)
169 error = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
170
171 /*
172 * Any inode that has dirty modifications in the log is pinned. The
173 * racy check here for a pinned inode will not catch modifications
174 * that happen concurrently to the fsync call, but fsync semantics
175 * only require to sync previously completed I/O.
176 */
177 if (xfs_ipincount(ip)) {
178 err2 = xfs_fsync_flush_log(ip, datasync, &log_flushed);
179 if (err2 && !error)
180 error = err2;
181 }
182
183 /*
184 * If we only have a single device, and the log force about was
185 * a no-op we might have to flush the data device cache here.
186 * This can only happen for fdatasync/O_DSYNC if we were overwriting
187 * an already allocated file and thus do not have any metadata to
188 * commit.
189 */
190 if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
191 mp->m_logdev_targp == mp->m_ddev_targp) {
192 err2 = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
193 if (err2 && !error)
194 error = err2;
195 }
196
197 return error;
198}
199
200static int
201xfs_ilock_iocb(
202 struct kiocb *iocb,
203 unsigned int lock_mode)
204{
205 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
206
207 if (iocb->ki_flags & IOCB_NOWAIT) {
208 if (!xfs_ilock_nowait(ip, lock_mode))
209 return -EAGAIN;
210 } else {
211 xfs_ilock(ip, lock_mode);
212 }
213
214 return 0;
215}
216
217static int
218xfs_ilock_iocb_for_write(
219 struct kiocb *iocb,
220 unsigned int *lock_mode)
221{
222 ssize_t ret;
223 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
224
225 ret = xfs_ilock_iocb(iocb, *lock_mode);
226 if (ret)
227 return ret;
228
229 if (*lock_mode == XFS_IOLOCK_EXCL)
230 return 0;
231 if (!xfs_iflags_test(ip, XFS_IREMAPPING))
232 return 0;
233
234 xfs_iunlock(ip, *lock_mode);
235 *lock_mode = XFS_IOLOCK_EXCL;
236 return xfs_ilock_iocb(iocb, *lock_mode);
237}
238
239static unsigned int
240xfs_ilock_for_write_fault(
241 struct xfs_inode *ip)
242{
243 /* get a shared lock if no remapping in progress */
244 xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
245 if (!xfs_iflags_test(ip, XFS_IREMAPPING))
246 return XFS_MMAPLOCK_SHARED;
247
248 /* wait for remapping to complete */
249 xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
250 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
251 return XFS_MMAPLOCK_EXCL;
252}
253
254STATIC ssize_t
255xfs_file_dio_read(
256 struct kiocb *iocb,
257 struct iov_iter *to)
258{
259 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
260 ssize_t ret;
261
262 trace_xfs_file_direct_read(iocb, to);
263
264 if (!iov_iter_count(to))
265 return 0; /* skip atime */
266
267 file_accessed(iocb->ki_filp);
268
269 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
270 if (ret)
271 return ret;
272 ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0, NULL, 0);
273 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
274
275 return ret;
276}
277
278static noinline ssize_t
279xfs_file_dax_read(
280 struct kiocb *iocb,
281 struct iov_iter *to)
282{
283 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
284 ssize_t ret = 0;
285
286 trace_xfs_file_dax_read(iocb, to);
287
288 if (!iov_iter_count(to))
289 return 0; /* skip atime */
290
291 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
292 if (ret)
293 return ret;
294 ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
295 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
296
297 file_accessed(iocb->ki_filp);
298 return ret;
299}
300
301STATIC ssize_t
302xfs_file_buffered_read(
303 struct kiocb *iocb,
304 struct iov_iter *to)
305{
306 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
307 ssize_t ret;
308
309 trace_xfs_file_buffered_read(iocb, to);
310
311 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
312 if (ret)
313 return ret;
314 ret = generic_file_read_iter(iocb, to);
315 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
316
317 return ret;
318}
319
320STATIC ssize_t
321xfs_file_read_iter(
322 struct kiocb *iocb,
323 struct iov_iter *to)
324{
325 struct inode *inode = file_inode(iocb->ki_filp);
326 struct xfs_mount *mp = XFS_I(inode)->i_mount;
327 ssize_t ret = 0;
328
329 XFS_STATS_INC(mp, xs_read_calls);
330
331 if (xfs_is_shutdown(mp))
332 return -EIO;
333
334 if (IS_DAX(inode))
335 ret = xfs_file_dax_read(iocb, to);
336 else if (iocb->ki_flags & IOCB_DIRECT)
337 ret = xfs_file_dio_read(iocb, to);
338 else
339 ret = xfs_file_buffered_read(iocb, to);
340
341 if (ret > 0)
342 XFS_STATS_ADD(mp, xs_read_bytes, ret);
343 return ret;
344}
345
346STATIC ssize_t
347xfs_file_splice_read(
348 struct file *in,
349 loff_t *ppos,
350 struct pipe_inode_info *pipe,
351 size_t len,
352 unsigned int flags)
353{
354 struct inode *inode = file_inode(in);
355 struct xfs_inode *ip = XFS_I(inode);
356 struct xfs_mount *mp = ip->i_mount;
357 ssize_t ret = 0;
358
359 XFS_STATS_INC(mp, xs_read_calls);
360
361 if (xfs_is_shutdown(mp))
362 return -EIO;
363
364 trace_xfs_file_splice_read(ip, *ppos, len);
365
366 xfs_ilock(ip, XFS_IOLOCK_SHARED);
367 ret = filemap_splice_read(in, ppos, pipe, len, flags);
368 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
369 if (ret > 0)
370 XFS_STATS_ADD(mp, xs_read_bytes, ret);
371 return ret;
372}
373
374/*
375 * Common pre-write limit and setup checks.
376 *
377 * Called with the iolocked held either shared and exclusive according to
378 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
379 * if called for a direct write beyond i_size.
380 */
381STATIC ssize_t
382xfs_file_write_checks(
383 struct kiocb *iocb,
384 struct iov_iter *from,
385 unsigned int *iolock)
386{
387 struct file *file = iocb->ki_filp;
388 struct inode *inode = file->f_mapping->host;
389 struct xfs_inode *ip = XFS_I(inode);
390 ssize_t error = 0;
391 size_t count = iov_iter_count(from);
392 bool drained_dio = false;
393 loff_t isize;
394
395restart:
396 error = generic_write_checks(iocb, from);
397 if (error <= 0)
398 return error;
399
400 if (iocb->ki_flags & IOCB_NOWAIT) {
401 error = break_layout(inode, false);
402 if (error == -EWOULDBLOCK)
403 error = -EAGAIN;
404 } else {
405 error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
406 }
407
408 if (error)
409 return error;
410
411 /*
412 * For changing security info in file_remove_privs() we need i_rwsem
413 * exclusively.
414 */
415 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
416 xfs_iunlock(ip, *iolock);
417 *iolock = XFS_IOLOCK_EXCL;
418 error = xfs_ilock_iocb(iocb, *iolock);
419 if (error) {
420 *iolock = 0;
421 return error;
422 }
423 goto restart;
424 }
425
426 /*
427 * If the offset is beyond the size of the file, we need to zero any
428 * blocks that fall between the existing EOF and the start of this
429 * write. If zeroing is needed and we are currently holding the iolock
430 * shared, we need to update it to exclusive which implies having to
431 * redo all checks before.
432 *
433 * We need to serialise against EOF updates that occur in IO completions
434 * here. We want to make sure that nobody is changing the size while we
435 * do this check until we have placed an IO barrier (i.e. hold the
436 * XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The
437 * spinlock effectively forms a memory barrier once we have the
438 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and
439 * hence be able to correctly determine if we need to run zeroing.
440 *
441 * We can do an unlocked check here safely as IO completion can only
442 * extend EOF. Truncate is locked out at this point, so the EOF can
443 * not move backwards, only forwards. Hence we only need to take the
444 * slow path and spin locks when we are at or beyond the current EOF.
445 */
446 if (iocb->ki_pos <= i_size_read(inode))
447 goto out;
448
449 spin_lock(&ip->i_flags_lock);
450 isize = i_size_read(inode);
451 if (iocb->ki_pos > isize) {
452 spin_unlock(&ip->i_flags_lock);
453
454 if (iocb->ki_flags & IOCB_NOWAIT)
455 return -EAGAIN;
456
457 if (!drained_dio) {
458 if (*iolock == XFS_IOLOCK_SHARED) {
459 xfs_iunlock(ip, *iolock);
460 *iolock = XFS_IOLOCK_EXCL;
461 xfs_ilock(ip, *iolock);
462 iov_iter_reexpand(from, count);
463 }
464 /*
465 * We now have an IO submission barrier in place, but
466 * AIO can do EOF updates during IO completion and hence
467 * we now need to wait for all of them to drain. Non-AIO
468 * DIO will have drained before we are given the
469 * XFS_IOLOCK_EXCL, and so for most cases this wait is a
470 * no-op.
471 */
472 inode_dio_wait(inode);
473 drained_dio = true;
474 goto restart;
475 }
476
477 trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
478 error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL);
479 if (error)
480 return error;
481 } else
482 spin_unlock(&ip->i_flags_lock);
483
484out:
485 return kiocb_modified(iocb);
486}
487
488static int
489xfs_dio_write_end_io(
490 struct kiocb *iocb,
491 ssize_t size,
492 int error,
493 unsigned flags)
494{
495 struct inode *inode = file_inode(iocb->ki_filp);
496 struct xfs_inode *ip = XFS_I(inode);
497 loff_t offset = iocb->ki_pos;
498 unsigned int nofs_flag;
499
500 trace_xfs_end_io_direct_write(ip, offset, size);
501
502 if (xfs_is_shutdown(ip->i_mount))
503 return -EIO;
504
505 if (error)
506 return error;
507 if (!size)
508 return 0;
509
510 /*
511 * Capture amount written on completion as we can't reliably account
512 * for it on submission.
513 */
514 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
515
516 /*
517 * We can allocate memory here while doing writeback on behalf of
518 * memory reclaim. To avoid memory allocation deadlocks set the
519 * task-wide nofs context for the following operations.
520 */
521 nofs_flag = memalloc_nofs_save();
522
523 if (flags & IOMAP_DIO_COW) {
524 error = xfs_reflink_end_cow(ip, offset, size);
525 if (error)
526 goto out;
527 }
528
529 /*
530 * Unwritten conversion updates the in-core isize after extent
531 * conversion but before updating the on-disk size. Updating isize any
532 * earlier allows a racing dio read to find unwritten extents before
533 * they are converted.
534 */
535 if (flags & IOMAP_DIO_UNWRITTEN) {
536 error = xfs_iomap_write_unwritten(ip, offset, size, true);
537 goto out;
538 }
539
540 /*
541 * We need to update the in-core inode size here so that we don't end up
542 * with the on-disk inode size being outside the in-core inode size. We
543 * have no other method of updating EOF for AIO, so always do it here
544 * if necessary.
545 *
546 * We need to lock the test/set EOF update as we can be racing with
547 * other IO completions here to update the EOF. Failing to serialise
548 * here can result in EOF moving backwards and Bad Things Happen when
549 * that occurs.
550 *
551 * As IO completion only ever extends EOF, we can do an unlocked check
552 * here to avoid taking the spinlock. If we land within the current EOF,
553 * then we do not need to do an extending update at all, and we don't
554 * need to take the lock to check this. If we race with an update moving
555 * EOF, then we'll either still be beyond EOF and need to take the lock,
556 * or we'll be within EOF and we don't need to take it at all.
557 */
558 if (offset + size <= i_size_read(inode))
559 goto out;
560
561 spin_lock(&ip->i_flags_lock);
562 if (offset + size > i_size_read(inode)) {
563 i_size_write(inode, offset + size);
564 spin_unlock(&ip->i_flags_lock);
565 error = xfs_setfilesize(ip, offset, size);
566 } else {
567 spin_unlock(&ip->i_flags_lock);
568 }
569
570out:
571 memalloc_nofs_restore(nofs_flag);
572 return error;
573}
574
575static const struct iomap_dio_ops xfs_dio_write_ops = {
576 .end_io = xfs_dio_write_end_io,
577};
578
579/*
580 * Handle block aligned direct I/O writes
581 */
582static noinline ssize_t
583xfs_file_dio_write_aligned(
584 struct xfs_inode *ip,
585 struct kiocb *iocb,
586 struct iov_iter *from)
587{
588 unsigned int iolock = XFS_IOLOCK_SHARED;
589 ssize_t ret;
590
591 ret = xfs_ilock_iocb_for_write(iocb, &iolock);
592 if (ret)
593 return ret;
594 ret = xfs_file_write_checks(iocb, from, &iolock);
595 if (ret)
596 goto out_unlock;
597
598 /*
599 * We don't need to hold the IOLOCK exclusively across the IO, so demote
600 * the iolock back to shared if we had to take the exclusive lock in
601 * xfs_file_write_checks() for other reasons.
602 */
603 if (iolock == XFS_IOLOCK_EXCL) {
604 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
605 iolock = XFS_IOLOCK_SHARED;
606 }
607 trace_xfs_file_direct_write(iocb, from);
608 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
609 &xfs_dio_write_ops, 0, NULL, 0);
610out_unlock:
611 if (iolock)
612 xfs_iunlock(ip, iolock);
613 return ret;
614}
615
616/*
617 * Handle block unaligned direct I/O writes
618 *
619 * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing
620 * them to be done in parallel with reads and other direct I/O writes. However,
621 * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need
622 * to do sub-block zeroing and that requires serialisation against other direct
623 * I/O to the same block. In this case we need to serialise the submission of
624 * the unaligned I/O so that we don't get racing block zeroing in the dio layer.
625 * In the case where sub-block zeroing is not required, we can do concurrent
626 * sub-block dios to the same block successfully.
627 *
628 * Optimistically submit the I/O using the shared lock first, but use the
629 * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN
630 * if block allocation or partial block zeroing would be required. In that case
631 * we try again with the exclusive lock.
632 */
633static noinline ssize_t
634xfs_file_dio_write_unaligned(
635 struct xfs_inode *ip,
636 struct kiocb *iocb,
637 struct iov_iter *from)
638{
639 size_t isize = i_size_read(VFS_I(ip));
640 size_t count = iov_iter_count(from);
641 unsigned int iolock = XFS_IOLOCK_SHARED;
642 unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY;
643 ssize_t ret;
644
645 /*
646 * Extending writes need exclusivity because of the sub-block zeroing
647 * that the DIO code always does for partial tail blocks beyond EOF, so
648 * don't even bother trying the fast path in this case.
649 */
650 if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) {
651 if (iocb->ki_flags & IOCB_NOWAIT)
652 return -EAGAIN;
653retry_exclusive:
654 iolock = XFS_IOLOCK_EXCL;
655 flags = IOMAP_DIO_FORCE_WAIT;
656 }
657
658 ret = xfs_ilock_iocb_for_write(iocb, &iolock);
659 if (ret)
660 return ret;
661
662 /*
663 * We can't properly handle unaligned direct I/O to reflink files yet,
664 * as we can't unshare a partial block.
665 */
666 if (xfs_is_cow_inode(ip)) {
667 trace_xfs_reflink_bounce_dio_write(iocb, from);
668 ret = -ENOTBLK;
669 goto out_unlock;
670 }
671
672 ret = xfs_file_write_checks(iocb, from, &iolock);
673 if (ret)
674 goto out_unlock;
675
676 /*
677 * If we are doing exclusive unaligned I/O, this must be the only I/O
678 * in-flight. Otherwise we risk data corruption due to unwritten extent
679 * conversions from the AIO end_io handler. Wait for all other I/O to
680 * drain first.
681 */
682 if (flags & IOMAP_DIO_FORCE_WAIT)
683 inode_dio_wait(VFS_I(ip));
684
685 trace_xfs_file_direct_write(iocb, from);
686 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
687 &xfs_dio_write_ops, flags, NULL, 0);
688
689 /*
690 * Retry unaligned I/O with exclusive blocking semantics if the DIO
691 * layer rejected it for mapping or locking reasons. If we are doing
692 * nonblocking user I/O, propagate the error.
693 */
694 if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) {
695 ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY);
696 xfs_iunlock(ip, iolock);
697 goto retry_exclusive;
698 }
699
700out_unlock:
701 if (iolock)
702 xfs_iunlock(ip, iolock);
703 return ret;
704}
705
706static ssize_t
707xfs_file_dio_write(
708 struct kiocb *iocb,
709 struct iov_iter *from)
710{
711 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
712 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
713 size_t count = iov_iter_count(from);
714
715 /* direct I/O must be aligned to device logical sector size */
716 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
717 return -EINVAL;
718 if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask)
719 return xfs_file_dio_write_unaligned(ip, iocb, from);
720 return xfs_file_dio_write_aligned(ip, iocb, from);
721}
722
723static noinline ssize_t
724xfs_file_dax_write(
725 struct kiocb *iocb,
726 struct iov_iter *from)
727{
728 struct inode *inode = iocb->ki_filp->f_mapping->host;
729 struct xfs_inode *ip = XFS_I(inode);
730 unsigned int iolock = XFS_IOLOCK_EXCL;
731 ssize_t ret, error = 0;
732 loff_t pos;
733
734 ret = xfs_ilock_iocb(iocb, iolock);
735 if (ret)
736 return ret;
737 ret = xfs_file_write_checks(iocb, from, &iolock);
738 if (ret)
739 goto out;
740
741 pos = iocb->ki_pos;
742
743 trace_xfs_file_dax_write(iocb, from);
744 ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops);
745 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
746 i_size_write(inode, iocb->ki_pos);
747 error = xfs_setfilesize(ip, pos, ret);
748 }
749out:
750 if (iolock)
751 xfs_iunlock(ip, iolock);
752 if (error)
753 return error;
754
755 if (ret > 0) {
756 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
757
758 /* Handle various SYNC-type writes */
759 ret = generic_write_sync(iocb, ret);
760 }
761 return ret;
762}
763
764STATIC ssize_t
765xfs_file_buffered_write(
766 struct kiocb *iocb,
767 struct iov_iter *from)
768{
769 struct inode *inode = iocb->ki_filp->f_mapping->host;
770 struct xfs_inode *ip = XFS_I(inode);
771 ssize_t ret;
772 bool cleared_space = false;
773 unsigned int iolock;
774
775write_retry:
776 iolock = XFS_IOLOCK_EXCL;
777 ret = xfs_ilock_iocb(iocb, iolock);
778 if (ret)
779 return ret;
780
781 ret = xfs_file_write_checks(iocb, from, &iolock);
782 if (ret)
783 goto out;
784
785 trace_xfs_file_buffered_write(iocb, from);
786 ret = iomap_file_buffered_write(iocb, from,
787 &xfs_buffered_write_iomap_ops);
788
789 /*
790 * If we hit a space limit, try to free up some lingering preallocated
791 * space before returning an error. In the case of ENOSPC, first try to
792 * write back all dirty inodes to free up some of the excess reserved
793 * metadata space. This reduces the chances that the eofblocks scan
794 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
795 * also behaves as a filter to prevent too many eofblocks scans from
796 * running at the same time. Use a synchronous scan to increase the
797 * effectiveness of the scan.
798 */
799 if (ret == -EDQUOT && !cleared_space) {
800 xfs_iunlock(ip, iolock);
801 xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC);
802 cleared_space = true;
803 goto write_retry;
804 } else if (ret == -ENOSPC && !cleared_space) {
805 struct xfs_icwalk icw = {0};
806
807 cleared_space = true;
808 xfs_flush_inodes(ip->i_mount);
809
810 xfs_iunlock(ip, iolock);
811 icw.icw_flags = XFS_ICWALK_FLAG_SYNC;
812 xfs_blockgc_free_space(ip->i_mount, &icw);
813 goto write_retry;
814 }
815
816out:
817 if (iolock)
818 xfs_iunlock(ip, iolock);
819
820 if (ret > 0) {
821 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
822 /* Handle various SYNC-type writes */
823 ret = generic_write_sync(iocb, ret);
824 }
825 return ret;
826}
827
828STATIC ssize_t
829xfs_file_write_iter(
830 struct kiocb *iocb,
831 struct iov_iter *from)
832{
833 struct inode *inode = iocb->ki_filp->f_mapping->host;
834 struct xfs_inode *ip = XFS_I(inode);
835 ssize_t ret;
836 size_t ocount = iov_iter_count(from);
837
838 XFS_STATS_INC(ip->i_mount, xs_write_calls);
839
840 if (ocount == 0)
841 return 0;
842
843 if (xfs_is_shutdown(ip->i_mount))
844 return -EIO;
845
846 if (IS_DAX(inode))
847 return xfs_file_dax_write(iocb, from);
848
849 if (iocb->ki_flags & IOCB_DIRECT) {
850 /*
851 * Allow a directio write to fall back to a buffered
852 * write *only* in the case that we're doing a reflink
853 * CoW. In all other directio scenarios we do not
854 * allow an operation to fall back to buffered mode.
855 */
856 ret = xfs_file_dio_write(iocb, from);
857 if (ret != -ENOTBLK)
858 return ret;
859 }
860
861 return xfs_file_buffered_write(iocb, from);
862}
863
864static void
865xfs_wait_dax_page(
866 struct inode *inode)
867{
868 struct xfs_inode *ip = XFS_I(inode);
869
870 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
871 schedule();
872 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
873}
874
875int
876xfs_break_dax_layouts(
877 struct inode *inode,
878 bool *retry)
879{
880 struct page *page;
881
882 xfs_assert_ilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL);
883
884 page = dax_layout_busy_page(inode->i_mapping);
885 if (!page)
886 return 0;
887
888 *retry = true;
889 return ___wait_var_event(&page->_refcount,
890 atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
891 0, 0, xfs_wait_dax_page(inode));
892}
893
894int
895xfs_break_layouts(
896 struct inode *inode,
897 uint *iolock,
898 enum layout_break_reason reason)
899{
900 bool retry;
901 int error;
902
903 xfs_assert_ilocked(XFS_I(inode), XFS_IOLOCK_SHARED | XFS_IOLOCK_EXCL);
904
905 do {
906 retry = false;
907 switch (reason) {
908 case BREAK_UNMAP:
909 error = xfs_break_dax_layouts(inode, &retry);
910 if (error || retry)
911 break;
912 fallthrough;
913 case BREAK_WRITE:
914 error = xfs_break_leased_layouts(inode, iolock, &retry);
915 break;
916 default:
917 WARN_ON_ONCE(1);
918 error = -EINVAL;
919 }
920 } while (error == 0 && retry);
921
922 return error;
923}
924
925/* Does this file, inode, or mount want synchronous writes? */
926static inline bool xfs_file_sync_writes(struct file *filp)
927{
928 struct xfs_inode *ip = XFS_I(file_inode(filp));
929
930 if (xfs_has_wsync(ip->i_mount))
931 return true;
932 if (filp->f_flags & (__O_SYNC | O_DSYNC))
933 return true;
934 if (IS_SYNC(file_inode(filp)))
935 return true;
936
937 return false;
938}
939
940#define XFS_FALLOC_FL_SUPPORTED \
941 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
942 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
943 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
944
945STATIC long
946xfs_file_fallocate(
947 struct file *file,
948 int mode,
949 loff_t offset,
950 loff_t len)
951{
952 struct inode *inode = file_inode(file);
953 struct xfs_inode *ip = XFS_I(inode);
954 long error;
955 uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
956 loff_t new_size = 0;
957 bool do_file_insert = false;
958
959 if (!S_ISREG(inode->i_mode))
960 return -EINVAL;
961 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
962 return -EOPNOTSUPP;
963
964 xfs_ilock(ip, iolock);
965 error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
966 if (error)
967 goto out_unlock;
968
969 /*
970 * Must wait for all AIO to complete before we continue as AIO can
971 * change the file size on completion without holding any locks we
972 * currently hold. We must do this first because AIO can update both
973 * the on disk and in memory inode sizes, and the operations that follow
974 * require the in-memory size to be fully up-to-date.
975 */
976 inode_dio_wait(inode);
977
978 /*
979 * Now AIO and DIO has drained we flush and (if necessary) invalidate
980 * the cached range over the first operation we are about to run.
981 *
982 * We care about zero and collapse here because they both run a hole
983 * punch over the range first. Because that can zero data, and the range
984 * of invalidation for the shift operations is much larger, we still do
985 * the required flush for collapse in xfs_prepare_shift().
986 *
987 * Insert has the same range requirements as collapse, and we extend the
988 * file first which can zero data. Hence insert has the same
989 * flush/invalidate requirements as collapse and so they are both
990 * handled at the right time by xfs_prepare_shift().
991 */
992 if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE |
993 FALLOC_FL_COLLAPSE_RANGE)) {
994 error = xfs_flush_unmap_range(ip, offset, len);
995 if (error)
996 goto out_unlock;
997 }
998
999 error = file_modified(file);
1000 if (error)
1001 goto out_unlock;
1002
1003 if (mode & FALLOC_FL_PUNCH_HOLE) {
1004 error = xfs_free_file_space(ip, offset, len);
1005 if (error)
1006 goto out_unlock;
1007 } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
1008 if (!xfs_is_falloc_aligned(ip, offset, len)) {
1009 error = -EINVAL;
1010 goto out_unlock;
1011 }
1012
1013 /*
1014 * There is no need to overlap collapse range with EOF,
1015 * in which case it is effectively a truncate operation
1016 */
1017 if (offset + len >= i_size_read(inode)) {
1018 error = -EINVAL;
1019 goto out_unlock;
1020 }
1021
1022 new_size = i_size_read(inode) - len;
1023
1024 error = xfs_collapse_file_space(ip, offset, len);
1025 if (error)
1026 goto out_unlock;
1027 } else if (mode & FALLOC_FL_INSERT_RANGE) {
1028 loff_t isize = i_size_read(inode);
1029
1030 if (!xfs_is_falloc_aligned(ip, offset, len)) {
1031 error = -EINVAL;
1032 goto out_unlock;
1033 }
1034
1035 /*
1036 * New inode size must not exceed ->s_maxbytes, accounting for
1037 * possible signed overflow.
1038 */
1039 if (inode->i_sb->s_maxbytes - isize < len) {
1040 error = -EFBIG;
1041 goto out_unlock;
1042 }
1043 new_size = isize + len;
1044
1045 /* Offset should be less than i_size */
1046 if (offset >= isize) {
1047 error = -EINVAL;
1048 goto out_unlock;
1049 }
1050 do_file_insert = true;
1051 } else {
1052 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
1053 offset + len > i_size_read(inode)) {
1054 new_size = offset + len;
1055 error = inode_newsize_ok(inode, new_size);
1056 if (error)
1057 goto out_unlock;
1058 }
1059
1060 if (mode & FALLOC_FL_ZERO_RANGE) {
1061 /*
1062 * Punch a hole and prealloc the range. We use a hole
1063 * punch rather than unwritten extent conversion for two
1064 * reasons:
1065 *
1066 * 1.) Hole punch handles partial block zeroing for us.
1067 * 2.) If prealloc returns ENOSPC, the file range is
1068 * still zero-valued by virtue of the hole punch.
1069 */
1070 unsigned int blksize = i_blocksize(inode);
1071
1072 trace_xfs_zero_file_space(ip);
1073
1074 error = xfs_free_file_space(ip, offset, len);
1075 if (error)
1076 goto out_unlock;
1077
1078 len = round_up(offset + len, blksize) -
1079 round_down(offset, blksize);
1080 offset = round_down(offset, blksize);
1081 } else if (mode & FALLOC_FL_UNSHARE_RANGE) {
1082 error = xfs_reflink_unshare(ip, offset, len);
1083 if (error)
1084 goto out_unlock;
1085 } else {
1086 /*
1087 * If always_cow mode we can't use preallocations and
1088 * thus should not create them.
1089 */
1090 if (xfs_is_always_cow_inode(ip)) {
1091 error = -EOPNOTSUPP;
1092 goto out_unlock;
1093 }
1094 }
1095
1096 if (!xfs_is_always_cow_inode(ip)) {
1097 error = xfs_alloc_file_space(ip, offset, len);
1098 if (error)
1099 goto out_unlock;
1100 }
1101 }
1102
1103 /* Change file size if needed */
1104 if (new_size) {
1105 struct iattr iattr;
1106
1107 iattr.ia_valid = ATTR_SIZE;
1108 iattr.ia_size = new_size;
1109 error = xfs_vn_setattr_size(file_mnt_idmap(file),
1110 file_dentry(file), &iattr);
1111 if (error)
1112 goto out_unlock;
1113 }
1114
1115 /*
1116 * Perform hole insertion now that the file size has been
1117 * updated so that if we crash during the operation we don't
1118 * leave shifted extents past EOF and hence losing access to
1119 * the data that is contained within them.
1120 */
1121 if (do_file_insert) {
1122 error = xfs_insert_file_space(ip, offset, len);
1123 if (error)
1124 goto out_unlock;
1125 }
1126
1127 if (xfs_file_sync_writes(file))
1128 error = xfs_log_force_inode(ip);
1129
1130out_unlock:
1131 xfs_iunlock(ip, iolock);
1132 return error;
1133}
1134
1135STATIC int
1136xfs_file_fadvise(
1137 struct file *file,
1138 loff_t start,
1139 loff_t end,
1140 int advice)
1141{
1142 struct xfs_inode *ip = XFS_I(file_inode(file));
1143 int ret;
1144 int lockflags = 0;
1145
1146 /*
1147 * Operations creating pages in page cache need protection from hole
1148 * punching and similar ops
1149 */
1150 if (advice == POSIX_FADV_WILLNEED) {
1151 lockflags = XFS_IOLOCK_SHARED;
1152 xfs_ilock(ip, lockflags);
1153 }
1154 ret = generic_fadvise(file, start, end, advice);
1155 if (lockflags)
1156 xfs_iunlock(ip, lockflags);
1157 return ret;
1158}
1159
1160STATIC loff_t
1161xfs_file_remap_range(
1162 struct file *file_in,
1163 loff_t pos_in,
1164 struct file *file_out,
1165 loff_t pos_out,
1166 loff_t len,
1167 unsigned int remap_flags)
1168{
1169 struct inode *inode_in = file_inode(file_in);
1170 struct xfs_inode *src = XFS_I(inode_in);
1171 struct inode *inode_out = file_inode(file_out);
1172 struct xfs_inode *dest = XFS_I(inode_out);
1173 struct xfs_mount *mp = src->i_mount;
1174 loff_t remapped = 0;
1175 xfs_extlen_t cowextsize;
1176 int ret;
1177
1178 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
1179 return -EINVAL;
1180
1181 if (!xfs_has_reflink(mp))
1182 return -EOPNOTSUPP;
1183
1184 if (xfs_is_shutdown(mp))
1185 return -EIO;
1186
1187 /* Prepare and then clone file data. */
1188 ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
1189 &len, remap_flags);
1190 if (ret || len == 0)
1191 return ret;
1192
1193 trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
1194
1195 ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
1196 &remapped);
1197 if (ret)
1198 goto out_unlock;
1199
1200 /*
1201 * Carry the cowextsize hint from src to dest if we're sharing the
1202 * entire source file to the entire destination file, the source file
1203 * has a cowextsize hint, and the destination file does not.
1204 */
1205 cowextsize = 0;
1206 if (pos_in == 0 && len == i_size_read(inode_in) &&
1207 (src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
1208 pos_out == 0 && len >= i_size_read(inode_out) &&
1209 !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE))
1210 cowextsize = src->i_cowextsize;
1211
1212 ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
1213 remap_flags);
1214 if (ret)
1215 goto out_unlock;
1216
1217 if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
1218 xfs_log_force_inode(dest);
1219out_unlock:
1220 xfs_iunlock2_remapping(src, dest);
1221 if (ret)
1222 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
1223 return remapped > 0 ? remapped : ret;
1224}
1225
1226STATIC int
1227xfs_file_open(
1228 struct inode *inode,
1229 struct file *file)
1230{
1231 if (xfs_is_shutdown(XFS_M(inode->i_sb)))
1232 return -EIO;
1233 file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC |
1234 FMODE_DIO_PARALLEL_WRITE | FMODE_CAN_ODIRECT;
1235 return generic_file_open(inode, file);
1236}
1237
1238STATIC int
1239xfs_dir_open(
1240 struct inode *inode,
1241 struct file *file)
1242{
1243 struct xfs_inode *ip = XFS_I(inode);
1244 unsigned int mode;
1245 int error;
1246
1247 error = xfs_file_open(inode, file);
1248 if (error)
1249 return error;
1250
1251 /*
1252 * If there are any blocks, read-ahead block 0 as we're almost
1253 * certain to have the next operation be a read there.
1254 */
1255 mode = xfs_ilock_data_map_shared(ip);
1256 if (ip->i_df.if_nextents > 0)
1257 error = xfs_dir3_data_readahead(ip, 0, 0);
1258 xfs_iunlock(ip, mode);
1259 return error;
1260}
1261
1262STATIC int
1263xfs_file_release(
1264 struct inode *inode,
1265 struct file *filp)
1266{
1267 return xfs_release(XFS_I(inode));
1268}
1269
1270STATIC int
1271xfs_file_readdir(
1272 struct file *file,
1273 struct dir_context *ctx)
1274{
1275 struct inode *inode = file_inode(file);
1276 xfs_inode_t *ip = XFS_I(inode);
1277 size_t bufsize;
1278
1279 /*
1280 * The Linux API doesn't pass down the total size of the buffer
1281 * we read into down to the filesystem. With the filldir concept
1282 * it's not needed for correct information, but the XFS dir2 leaf
1283 * code wants an estimate of the buffer size to calculate it's
1284 * readahead window and size the buffers used for mapping to
1285 * physical blocks.
1286 *
1287 * Try to give it an estimate that's good enough, maybe at some
1288 * point we can change the ->readdir prototype to include the
1289 * buffer size. For now we use the current glibc buffer size.
1290 */
1291 bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_disk_size);
1292
1293 return xfs_readdir(NULL, ip, ctx, bufsize);
1294}
1295
1296STATIC loff_t
1297xfs_file_llseek(
1298 struct file *file,
1299 loff_t offset,
1300 int whence)
1301{
1302 struct inode *inode = file->f_mapping->host;
1303
1304 if (xfs_is_shutdown(XFS_I(inode)->i_mount))
1305 return -EIO;
1306
1307 switch (whence) {
1308 default:
1309 return generic_file_llseek(file, offset, whence);
1310 case SEEK_HOLE:
1311 offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
1312 break;
1313 case SEEK_DATA:
1314 offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
1315 break;
1316 }
1317
1318 if (offset < 0)
1319 return offset;
1320 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1321}
1322
1323#ifdef CONFIG_FS_DAX
1324static inline vm_fault_t
1325xfs_dax_fault(
1326 struct vm_fault *vmf,
1327 unsigned int order,
1328 bool write_fault,
1329 pfn_t *pfn)
1330{
1331 return dax_iomap_fault(vmf, order, pfn, NULL,
1332 (write_fault && !vmf->cow_page) ?
1333 &xfs_dax_write_iomap_ops :
1334 &xfs_read_iomap_ops);
1335}
1336#else
1337static inline vm_fault_t
1338xfs_dax_fault(
1339 struct vm_fault *vmf,
1340 unsigned int order,
1341 bool write_fault,
1342 pfn_t *pfn)
1343{
1344 ASSERT(0);
1345 return VM_FAULT_SIGBUS;
1346}
1347#endif
1348
1349/*
1350 * Locking for serialisation of IO during page faults. This results in a lock
1351 * ordering of:
1352 *
1353 * mmap_lock (MM)
1354 * sb_start_pagefault(vfs, freeze)
1355 * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation)
1356 * page_lock (MM)
1357 * i_lock (XFS - extent map serialisation)
1358 */
1359static vm_fault_t
1360__xfs_filemap_fault(
1361 struct vm_fault *vmf,
1362 unsigned int order,
1363 bool write_fault)
1364{
1365 struct inode *inode = file_inode(vmf->vma->vm_file);
1366 struct xfs_inode *ip = XFS_I(inode);
1367 vm_fault_t ret;
1368 unsigned int lock_mode = 0;
1369
1370 trace_xfs_filemap_fault(ip, order, write_fault);
1371
1372 if (write_fault) {
1373 sb_start_pagefault(inode->i_sb);
1374 file_update_time(vmf->vma->vm_file);
1375 }
1376
1377 if (IS_DAX(inode) || write_fault)
1378 lock_mode = xfs_ilock_for_write_fault(XFS_I(inode));
1379
1380 if (IS_DAX(inode)) {
1381 pfn_t pfn;
1382
1383 ret = xfs_dax_fault(vmf, order, write_fault, &pfn);
1384 if (ret & VM_FAULT_NEEDDSYNC)
1385 ret = dax_finish_sync_fault(vmf, order, pfn);
1386 } else if (write_fault) {
1387 ret = iomap_page_mkwrite(vmf, &xfs_page_mkwrite_iomap_ops);
1388 } else {
1389 ret = filemap_fault(vmf);
1390 }
1391
1392 if (lock_mode)
1393 xfs_iunlock(XFS_I(inode), lock_mode);
1394
1395 if (write_fault)
1396 sb_end_pagefault(inode->i_sb);
1397 return ret;
1398}
1399
1400static inline bool
1401xfs_is_write_fault(
1402 struct vm_fault *vmf)
1403{
1404 return (vmf->flags & FAULT_FLAG_WRITE) &&
1405 (vmf->vma->vm_flags & VM_SHARED);
1406}
1407
1408static vm_fault_t
1409xfs_filemap_fault(
1410 struct vm_fault *vmf)
1411{
1412 /* DAX can shortcut the normal fault path on write faults! */
1413 return __xfs_filemap_fault(vmf, 0,
1414 IS_DAX(file_inode(vmf->vma->vm_file)) &&
1415 xfs_is_write_fault(vmf));
1416}
1417
1418static vm_fault_t
1419xfs_filemap_huge_fault(
1420 struct vm_fault *vmf,
1421 unsigned int order)
1422{
1423 if (!IS_DAX(file_inode(vmf->vma->vm_file)))
1424 return VM_FAULT_FALLBACK;
1425
1426 /* DAX can shortcut the normal fault path on write faults! */
1427 return __xfs_filemap_fault(vmf, order,
1428 xfs_is_write_fault(vmf));
1429}
1430
1431static vm_fault_t
1432xfs_filemap_page_mkwrite(
1433 struct vm_fault *vmf)
1434{
1435 return __xfs_filemap_fault(vmf, 0, true);
1436}
1437
1438/*
1439 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
1440 * on write faults. In reality, it needs to serialise against truncate and
1441 * prepare memory for writing so handle is as standard write fault.
1442 */
1443static vm_fault_t
1444xfs_filemap_pfn_mkwrite(
1445 struct vm_fault *vmf)
1446{
1447
1448 return __xfs_filemap_fault(vmf, 0, true);
1449}
1450
1451static const struct vm_operations_struct xfs_file_vm_ops = {
1452 .fault = xfs_filemap_fault,
1453 .huge_fault = xfs_filemap_huge_fault,
1454 .map_pages = filemap_map_pages,
1455 .page_mkwrite = xfs_filemap_page_mkwrite,
1456 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1457};
1458
1459STATIC int
1460xfs_file_mmap(
1461 struct file *file,
1462 struct vm_area_struct *vma)
1463{
1464 struct inode *inode = file_inode(file);
1465 struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode));
1466
1467 /*
1468 * We don't support synchronous mappings for non-DAX files and
1469 * for DAX files if underneath dax_device is not synchronous.
1470 */
1471 if (!daxdev_mapping_supported(vma, target->bt_daxdev))
1472 return -EOPNOTSUPP;
1473
1474 file_accessed(file);
1475 vma->vm_ops = &xfs_file_vm_ops;
1476 if (IS_DAX(inode))
1477 vm_flags_set(vma, VM_HUGEPAGE);
1478 return 0;
1479}
1480
1481const struct file_operations xfs_file_operations = {
1482 .llseek = xfs_file_llseek,
1483 .read_iter = xfs_file_read_iter,
1484 .write_iter = xfs_file_write_iter,
1485 .splice_read = xfs_file_splice_read,
1486 .splice_write = iter_file_splice_write,
1487 .iopoll = iocb_bio_iopoll,
1488 .unlocked_ioctl = xfs_file_ioctl,
1489#ifdef CONFIG_COMPAT
1490 .compat_ioctl = xfs_file_compat_ioctl,
1491#endif
1492 .mmap = xfs_file_mmap,
1493 .mmap_supported_flags = MAP_SYNC,
1494 .open = xfs_file_open,
1495 .release = xfs_file_release,
1496 .fsync = xfs_file_fsync,
1497 .get_unmapped_area = thp_get_unmapped_area,
1498 .fallocate = xfs_file_fallocate,
1499 .fadvise = xfs_file_fadvise,
1500 .remap_file_range = xfs_file_remap_range,
1501};
1502
1503const struct file_operations xfs_dir_file_operations = {
1504 .open = xfs_dir_open,
1505 .read = generic_read_dir,
1506 .iterate_shared = xfs_file_readdir,
1507 .llseek = generic_file_llseek,
1508 .unlocked_ioctl = xfs_file_ioctl,
1509#ifdef CONFIG_COMPAT
1510 .compat_ioctl = xfs_file_compat_ioctl,
1511#endif
1512 .fsync = xfs_dir_fsync,
1513};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_inode.h"
14#include "xfs_trans.h"
15#include "xfs_inode_item.h"
16#include "xfs_bmap.h"
17#include "xfs_bmap_util.h"
18#include "xfs_dir2.h"
19#include "xfs_dir2_priv.h"
20#include "xfs_ioctl.h"
21#include "xfs_trace.h"
22#include "xfs_log.h"
23#include "xfs_icache.h"
24#include "xfs_pnfs.h"
25#include "xfs_iomap.h"
26#include "xfs_reflink.h"
27
28#include <linux/falloc.h>
29#include <linux/backing-dev.h>
30#include <linux/mman.h>
31#include <linux/fadvise.h>
32#include <linux/mount.h>
33
34static const struct vm_operations_struct xfs_file_vm_ops;
35
36/*
37 * Decide if the given file range is aligned to the size of the fundamental
38 * allocation unit for the file.
39 */
40static bool
41xfs_is_falloc_aligned(
42 struct xfs_inode *ip,
43 loff_t pos,
44 long long int len)
45{
46 struct xfs_mount *mp = ip->i_mount;
47 uint64_t mask;
48
49 if (XFS_IS_REALTIME_INODE(ip)) {
50 if (!is_power_of_2(mp->m_sb.sb_rextsize)) {
51 u64 rextbytes;
52 u32 mod;
53
54 rextbytes = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize);
55 div_u64_rem(pos, rextbytes, &mod);
56 if (mod)
57 return false;
58 div_u64_rem(len, rextbytes, &mod);
59 return mod == 0;
60 }
61 mask = XFS_FSB_TO_B(mp, mp->m_sb.sb_rextsize) - 1;
62 } else {
63 mask = mp->m_sb.sb_blocksize - 1;
64 }
65
66 return !((pos | len) & mask);
67}
68
69int
70xfs_update_prealloc_flags(
71 struct xfs_inode *ip,
72 enum xfs_prealloc_flags flags)
73{
74 struct xfs_trans *tp;
75 int error;
76
77 error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
78 0, 0, 0, &tp);
79 if (error)
80 return error;
81
82 xfs_ilock(ip, XFS_ILOCK_EXCL);
83 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
84
85 if (!(flags & XFS_PREALLOC_INVISIBLE)) {
86 VFS_I(ip)->i_mode &= ~S_ISUID;
87 if (VFS_I(ip)->i_mode & S_IXGRP)
88 VFS_I(ip)->i_mode &= ~S_ISGID;
89 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
90 }
91
92 if (flags & XFS_PREALLOC_SET)
93 ip->i_diflags |= XFS_DIFLAG_PREALLOC;
94 if (flags & XFS_PREALLOC_CLEAR)
95 ip->i_diflags &= ~XFS_DIFLAG_PREALLOC;
96
97 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
98 if (flags & XFS_PREALLOC_SYNC)
99 xfs_trans_set_sync(tp);
100 return xfs_trans_commit(tp);
101}
102
103/*
104 * Fsync operations on directories are much simpler than on regular files,
105 * as there is no file data to flush, and thus also no need for explicit
106 * cache flush operations, and there are no non-transaction metadata updates
107 * on directories either.
108 */
109STATIC int
110xfs_dir_fsync(
111 struct file *file,
112 loff_t start,
113 loff_t end,
114 int datasync)
115{
116 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
117
118 trace_xfs_dir_fsync(ip);
119 return xfs_log_force_inode(ip);
120}
121
122static xfs_csn_t
123xfs_fsync_seq(
124 struct xfs_inode *ip,
125 bool datasync)
126{
127 if (!xfs_ipincount(ip))
128 return 0;
129 if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
130 return 0;
131 return ip->i_itemp->ili_commit_seq;
132}
133
134/*
135 * All metadata updates are logged, which means that we just have to flush the
136 * log up to the latest LSN that touched the inode.
137 *
138 * If we have concurrent fsync/fdatasync() calls, we need them to all block on
139 * the log force before we clear the ili_fsync_fields field. This ensures that
140 * we don't get a racing sync operation that does not wait for the metadata to
141 * hit the journal before returning. If we race with clearing ili_fsync_fields,
142 * then all that will happen is the log force will do nothing as the lsn will
143 * already be on disk. We can't race with setting ili_fsync_fields because that
144 * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock
145 * shared until after the ili_fsync_fields is cleared.
146 */
147static int
148xfs_fsync_flush_log(
149 struct xfs_inode *ip,
150 bool datasync,
151 int *log_flushed)
152{
153 int error = 0;
154 xfs_csn_t seq;
155
156 xfs_ilock(ip, XFS_ILOCK_SHARED);
157 seq = xfs_fsync_seq(ip, datasync);
158 if (seq) {
159 error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC,
160 log_flushed);
161
162 spin_lock(&ip->i_itemp->ili_lock);
163 ip->i_itemp->ili_fsync_fields = 0;
164 spin_unlock(&ip->i_itemp->ili_lock);
165 }
166 xfs_iunlock(ip, XFS_ILOCK_SHARED);
167 return error;
168}
169
170STATIC int
171xfs_file_fsync(
172 struct file *file,
173 loff_t start,
174 loff_t end,
175 int datasync)
176{
177 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
178 struct xfs_mount *mp = ip->i_mount;
179 int error = 0;
180 int log_flushed = 0;
181
182 trace_xfs_file_fsync(ip);
183
184 error = file_write_and_wait_range(file, start, end);
185 if (error)
186 return error;
187
188 if (XFS_FORCED_SHUTDOWN(mp))
189 return -EIO;
190
191 xfs_iflags_clear(ip, XFS_ITRUNCATED);
192
193 /*
194 * If we have an RT and/or log subvolume we need to make sure to flush
195 * the write cache the device used for file data first. This is to
196 * ensure newly written file data make it to disk before logging the new
197 * inode size in case of an extending write.
198 */
199 if (XFS_IS_REALTIME_INODE(ip))
200 blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
201 else if (mp->m_logdev_targp != mp->m_ddev_targp)
202 blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
203
204 /*
205 * Any inode that has dirty modifications in the log is pinned. The
206 * racy check here for a pinned inode while not catch modifications
207 * that happen concurrently to the fsync call, but fsync semantics
208 * only require to sync previously completed I/O.
209 */
210 if (xfs_ipincount(ip))
211 error = xfs_fsync_flush_log(ip, datasync, &log_flushed);
212
213 /*
214 * If we only have a single device, and the log force about was
215 * a no-op we might have to flush the data device cache here.
216 * This can only happen for fdatasync/O_DSYNC if we were overwriting
217 * an already allocated file and thus do not have any metadata to
218 * commit.
219 */
220 if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
221 mp->m_logdev_targp == mp->m_ddev_targp)
222 blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
223
224 return error;
225}
226
227static int
228xfs_ilock_iocb(
229 struct kiocb *iocb,
230 unsigned int lock_mode)
231{
232 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
233
234 if (iocb->ki_flags & IOCB_NOWAIT) {
235 if (!xfs_ilock_nowait(ip, lock_mode))
236 return -EAGAIN;
237 } else {
238 xfs_ilock(ip, lock_mode);
239 }
240
241 return 0;
242}
243
244STATIC ssize_t
245xfs_file_dio_read(
246 struct kiocb *iocb,
247 struct iov_iter *to)
248{
249 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
250 ssize_t ret;
251
252 trace_xfs_file_direct_read(iocb, to);
253
254 if (!iov_iter_count(to))
255 return 0; /* skip atime */
256
257 file_accessed(iocb->ki_filp);
258
259 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
260 if (ret)
261 return ret;
262 ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0);
263 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
264
265 return ret;
266}
267
268static noinline ssize_t
269xfs_file_dax_read(
270 struct kiocb *iocb,
271 struct iov_iter *to)
272{
273 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
274 ssize_t ret = 0;
275
276 trace_xfs_file_dax_read(iocb, to);
277
278 if (!iov_iter_count(to))
279 return 0; /* skip atime */
280
281 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
282 if (ret)
283 return ret;
284 ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
285 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
286
287 file_accessed(iocb->ki_filp);
288 return ret;
289}
290
291STATIC ssize_t
292xfs_file_buffered_read(
293 struct kiocb *iocb,
294 struct iov_iter *to)
295{
296 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
297 ssize_t ret;
298
299 trace_xfs_file_buffered_read(iocb, to);
300
301 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
302 if (ret)
303 return ret;
304 ret = generic_file_read_iter(iocb, to);
305 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
306
307 return ret;
308}
309
310STATIC ssize_t
311xfs_file_read_iter(
312 struct kiocb *iocb,
313 struct iov_iter *to)
314{
315 struct inode *inode = file_inode(iocb->ki_filp);
316 struct xfs_mount *mp = XFS_I(inode)->i_mount;
317 ssize_t ret = 0;
318
319 XFS_STATS_INC(mp, xs_read_calls);
320
321 if (XFS_FORCED_SHUTDOWN(mp))
322 return -EIO;
323
324 if (IS_DAX(inode))
325 ret = xfs_file_dax_read(iocb, to);
326 else if (iocb->ki_flags & IOCB_DIRECT)
327 ret = xfs_file_dio_read(iocb, to);
328 else
329 ret = xfs_file_buffered_read(iocb, to);
330
331 if (ret > 0)
332 XFS_STATS_ADD(mp, xs_read_bytes, ret);
333 return ret;
334}
335
336/*
337 * Common pre-write limit and setup checks.
338 *
339 * Called with the iolocked held either shared and exclusive according to
340 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
341 * if called for a direct write beyond i_size.
342 */
343STATIC ssize_t
344xfs_file_write_checks(
345 struct kiocb *iocb,
346 struct iov_iter *from,
347 int *iolock)
348{
349 struct file *file = iocb->ki_filp;
350 struct inode *inode = file->f_mapping->host;
351 struct xfs_inode *ip = XFS_I(inode);
352 ssize_t error = 0;
353 size_t count = iov_iter_count(from);
354 bool drained_dio = false;
355 loff_t isize;
356
357restart:
358 error = generic_write_checks(iocb, from);
359 if (error <= 0)
360 return error;
361
362 if (iocb->ki_flags & IOCB_NOWAIT) {
363 error = break_layout(inode, false);
364 if (error == -EWOULDBLOCK)
365 error = -EAGAIN;
366 } else {
367 error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
368 }
369
370 if (error)
371 return error;
372
373 /*
374 * For changing security info in file_remove_privs() we need i_rwsem
375 * exclusively.
376 */
377 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
378 xfs_iunlock(ip, *iolock);
379 *iolock = XFS_IOLOCK_EXCL;
380 error = xfs_ilock_iocb(iocb, *iolock);
381 if (error) {
382 *iolock = 0;
383 return error;
384 }
385 goto restart;
386 }
387
388 /*
389 * If the offset is beyond the size of the file, we need to zero any
390 * blocks that fall between the existing EOF and the start of this
391 * write. If zeroing is needed and we are currently holding the iolock
392 * shared, we need to update it to exclusive which implies having to
393 * redo all checks before.
394 *
395 * We need to serialise against EOF updates that occur in IO completions
396 * here. We want to make sure that nobody is changing the size while we
397 * do this check until we have placed an IO barrier (i.e. hold the
398 * XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The
399 * spinlock effectively forms a memory barrier once we have the
400 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and
401 * hence be able to correctly determine if we need to run zeroing.
402 *
403 * We can do an unlocked check here safely as IO completion can only
404 * extend EOF. Truncate is locked out at this point, so the EOF can
405 * not move backwards, only forwards. Hence we only need to take the
406 * slow path and spin locks when we are at or beyond the current EOF.
407 */
408 if (iocb->ki_pos <= i_size_read(inode))
409 goto out;
410
411 spin_lock(&ip->i_flags_lock);
412 isize = i_size_read(inode);
413 if (iocb->ki_pos > isize) {
414 spin_unlock(&ip->i_flags_lock);
415
416 if (iocb->ki_flags & IOCB_NOWAIT)
417 return -EAGAIN;
418
419 if (!drained_dio) {
420 if (*iolock == XFS_IOLOCK_SHARED) {
421 xfs_iunlock(ip, *iolock);
422 *iolock = XFS_IOLOCK_EXCL;
423 xfs_ilock(ip, *iolock);
424 iov_iter_reexpand(from, count);
425 }
426 /*
427 * We now have an IO submission barrier in place, but
428 * AIO can do EOF updates during IO completion and hence
429 * we now need to wait for all of them to drain. Non-AIO
430 * DIO will have drained before we are given the
431 * XFS_IOLOCK_EXCL, and so for most cases this wait is a
432 * no-op.
433 */
434 inode_dio_wait(inode);
435 drained_dio = true;
436 goto restart;
437 }
438
439 trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
440 error = iomap_zero_range(inode, isize, iocb->ki_pos - isize,
441 NULL, &xfs_buffered_write_iomap_ops);
442 if (error)
443 return error;
444 } else
445 spin_unlock(&ip->i_flags_lock);
446
447out:
448 return file_modified(file);
449}
450
451static int
452xfs_dio_write_end_io(
453 struct kiocb *iocb,
454 ssize_t size,
455 int error,
456 unsigned flags)
457{
458 struct inode *inode = file_inode(iocb->ki_filp);
459 struct xfs_inode *ip = XFS_I(inode);
460 loff_t offset = iocb->ki_pos;
461 unsigned int nofs_flag;
462
463 trace_xfs_end_io_direct_write(ip, offset, size);
464
465 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
466 return -EIO;
467
468 if (error)
469 return error;
470 if (!size)
471 return 0;
472
473 /*
474 * Capture amount written on completion as we can't reliably account
475 * for it on submission.
476 */
477 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
478
479 /*
480 * We can allocate memory here while doing writeback on behalf of
481 * memory reclaim. To avoid memory allocation deadlocks set the
482 * task-wide nofs context for the following operations.
483 */
484 nofs_flag = memalloc_nofs_save();
485
486 if (flags & IOMAP_DIO_COW) {
487 error = xfs_reflink_end_cow(ip, offset, size);
488 if (error)
489 goto out;
490 }
491
492 /*
493 * Unwritten conversion updates the in-core isize after extent
494 * conversion but before updating the on-disk size. Updating isize any
495 * earlier allows a racing dio read to find unwritten extents before
496 * they are converted.
497 */
498 if (flags & IOMAP_DIO_UNWRITTEN) {
499 error = xfs_iomap_write_unwritten(ip, offset, size, true);
500 goto out;
501 }
502
503 /*
504 * We need to update the in-core inode size here so that we don't end up
505 * with the on-disk inode size being outside the in-core inode size. We
506 * have no other method of updating EOF for AIO, so always do it here
507 * if necessary.
508 *
509 * We need to lock the test/set EOF update as we can be racing with
510 * other IO completions here to update the EOF. Failing to serialise
511 * here can result in EOF moving backwards and Bad Things Happen when
512 * that occurs.
513 *
514 * As IO completion only ever extends EOF, we can do an unlocked check
515 * here to avoid taking the spinlock. If we land within the current EOF,
516 * then we do not need to do an extending update at all, and we don't
517 * need to take the lock to check this. If we race with an update moving
518 * EOF, then we'll either still be beyond EOF and need to take the lock,
519 * or we'll be within EOF and we don't need to take it at all.
520 */
521 if (offset + size <= i_size_read(inode))
522 goto out;
523
524 spin_lock(&ip->i_flags_lock);
525 if (offset + size > i_size_read(inode)) {
526 i_size_write(inode, offset + size);
527 spin_unlock(&ip->i_flags_lock);
528 error = xfs_setfilesize(ip, offset, size);
529 } else {
530 spin_unlock(&ip->i_flags_lock);
531 }
532
533out:
534 memalloc_nofs_restore(nofs_flag);
535 return error;
536}
537
538static const struct iomap_dio_ops xfs_dio_write_ops = {
539 .end_io = xfs_dio_write_end_io,
540};
541
542/*
543 * Handle block aligned direct I/O writes
544 */
545static noinline ssize_t
546xfs_file_dio_write_aligned(
547 struct xfs_inode *ip,
548 struct kiocb *iocb,
549 struct iov_iter *from)
550{
551 int iolock = XFS_IOLOCK_SHARED;
552 ssize_t ret;
553
554 ret = xfs_ilock_iocb(iocb, iolock);
555 if (ret)
556 return ret;
557 ret = xfs_file_write_checks(iocb, from, &iolock);
558 if (ret)
559 goto out_unlock;
560
561 /*
562 * We don't need to hold the IOLOCK exclusively across the IO, so demote
563 * the iolock back to shared if we had to take the exclusive lock in
564 * xfs_file_write_checks() for other reasons.
565 */
566 if (iolock == XFS_IOLOCK_EXCL) {
567 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
568 iolock = XFS_IOLOCK_SHARED;
569 }
570 trace_xfs_file_direct_write(iocb, from);
571 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
572 &xfs_dio_write_ops, 0);
573out_unlock:
574 if (iolock)
575 xfs_iunlock(ip, iolock);
576 return ret;
577}
578
579/*
580 * Handle block unaligned direct I/O writes
581 *
582 * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing
583 * them to be done in parallel with reads and other direct I/O writes. However,
584 * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need
585 * to do sub-block zeroing and that requires serialisation against other direct
586 * I/O to the same block. In this case we need to serialise the submission of
587 * the unaligned I/O so that we don't get racing block zeroing in the dio layer.
588 * In the case where sub-block zeroing is not required, we can do concurrent
589 * sub-block dios to the same block successfully.
590 *
591 * Optimistically submit the I/O using the shared lock first, but use the
592 * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN
593 * if block allocation or partial block zeroing would be required. In that case
594 * we try again with the exclusive lock.
595 */
596static noinline ssize_t
597xfs_file_dio_write_unaligned(
598 struct xfs_inode *ip,
599 struct kiocb *iocb,
600 struct iov_iter *from)
601{
602 size_t isize = i_size_read(VFS_I(ip));
603 size_t count = iov_iter_count(from);
604 int iolock = XFS_IOLOCK_SHARED;
605 unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY;
606 ssize_t ret;
607
608 /*
609 * Extending writes need exclusivity because of the sub-block zeroing
610 * that the DIO code always does for partial tail blocks beyond EOF, so
611 * don't even bother trying the fast path in this case.
612 */
613 if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) {
614retry_exclusive:
615 if (iocb->ki_flags & IOCB_NOWAIT)
616 return -EAGAIN;
617 iolock = XFS_IOLOCK_EXCL;
618 flags = IOMAP_DIO_FORCE_WAIT;
619 }
620
621 ret = xfs_ilock_iocb(iocb, iolock);
622 if (ret)
623 return ret;
624
625 /*
626 * We can't properly handle unaligned direct I/O to reflink files yet,
627 * as we can't unshare a partial block.
628 */
629 if (xfs_is_cow_inode(ip)) {
630 trace_xfs_reflink_bounce_dio_write(iocb, from);
631 ret = -ENOTBLK;
632 goto out_unlock;
633 }
634
635 ret = xfs_file_write_checks(iocb, from, &iolock);
636 if (ret)
637 goto out_unlock;
638
639 /*
640 * If we are doing exclusive unaligned I/O, this must be the only I/O
641 * in-flight. Otherwise we risk data corruption due to unwritten extent
642 * conversions from the AIO end_io handler. Wait for all other I/O to
643 * drain first.
644 */
645 if (flags & IOMAP_DIO_FORCE_WAIT)
646 inode_dio_wait(VFS_I(ip));
647
648 trace_xfs_file_direct_write(iocb, from);
649 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
650 &xfs_dio_write_ops, flags);
651
652 /*
653 * Retry unaligned I/O with exclusive blocking semantics if the DIO
654 * layer rejected it for mapping or locking reasons. If we are doing
655 * nonblocking user I/O, propagate the error.
656 */
657 if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) {
658 ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY);
659 xfs_iunlock(ip, iolock);
660 goto retry_exclusive;
661 }
662
663out_unlock:
664 if (iolock)
665 xfs_iunlock(ip, iolock);
666 return ret;
667}
668
669static ssize_t
670xfs_file_dio_write(
671 struct kiocb *iocb,
672 struct iov_iter *from)
673{
674 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
675 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
676 size_t count = iov_iter_count(from);
677
678 /* direct I/O must be aligned to device logical sector size */
679 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
680 return -EINVAL;
681 if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask)
682 return xfs_file_dio_write_unaligned(ip, iocb, from);
683 return xfs_file_dio_write_aligned(ip, iocb, from);
684}
685
686static noinline ssize_t
687xfs_file_dax_write(
688 struct kiocb *iocb,
689 struct iov_iter *from)
690{
691 struct inode *inode = iocb->ki_filp->f_mapping->host;
692 struct xfs_inode *ip = XFS_I(inode);
693 int iolock = XFS_IOLOCK_EXCL;
694 ssize_t ret, error = 0;
695 loff_t pos;
696
697 ret = xfs_ilock_iocb(iocb, iolock);
698 if (ret)
699 return ret;
700 ret = xfs_file_write_checks(iocb, from, &iolock);
701 if (ret)
702 goto out;
703
704 pos = iocb->ki_pos;
705
706 trace_xfs_file_dax_write(iocb, from);
707 ret = dax_iomap_rw(iocb, from, &xfs_direct_write_iomap_ops);
708 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
709 i_size_write(inode, iocb->ki_pos);
710 error = xfs_setfilesize(ip, pos, ret);
711 }
712out:
713 if (iolock)
714 xfs_iunlock(ip, iolock);
715 if (error)
716 return error;
717
718 if (ret > 0) {
719 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
720
721 /* Handle various SYNC-type writes */
722 ret = generic_write_sync(iocb, ret);
723 }
724 return ret;
725}
726
727STATIC ssize_t
728xfs_file_buffered_write(
729 struct kiocb *iocb,
730 struct iov_iter *from)
731{
732 struct file *file = iocb->ki_filp;
733 struct address_space *mapping = file->f_mapping;
734 struct inode *inode = mapping->host;
735 struct xfs_inode *ip = XFS_I(inode);
736 ssize_t ret;
737 bool cleared_space = false;
738 int iolock;
739
740 if (iocb->ki_flags & IOCB_NOWAIT)
741 return -EOPNOTSUPP;
742
743write_retry:
744 iolock = XFS_IOLOCK_EXCL;
745 xfs_ilock(ip, iolock);
746
747 ret = xfs_file_write_checks(iocb, from, &iolock);
748 if (ret)
749 goto out;
750
751 /* We can write back this queue in page reclaim */
752 current->backing_dev_info = inode_to_bdi(inode);
753
754 trace_xfs_file_buffered_write(iocb, from);
755 ret = iomap_file_buffered_write(iocb, from,
756 &xfs_buffered_write_iomap_ops);
757 if (likely(ret >= 0))
758 iocb->ki_pos += ret;
759
760 /*
761 * If we hit a space limit, try to free up some lingering preallocated
762 * space before returning an error. In the case of ENOSPC, first try to
763 * write back all dirty inodes to free up some of the excess reserved
764 * metadata space. This reduces the chances that the eofblocks scan
765 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
766 * also behaves as a filter to prevent too many eofblocks scans from
767 * running at the same time. Use a synchronous scan to increase the
768 * effectiveness of the scan.
769 */
770 if (ret == -EDQUOT && !cleared_space) {
771 xfs_iunlock(ip, iolock);
772 xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC);
773 cleared_space = true;
774 goto write_retry;
775 } else if (ret == -ENOSPC && !cleared_space) {
776 struct xfs_icwalk icw = {0};
777
778 cleared_space = true;
779 xfs_flush_inodes(ip->i_mount);
780
781 xfs_iunlock(ip, iolock);
782 icw.icw_flags = XFS_ICWALK_FLAG_SYNC;
783 xfs_blockgc_free_space(ip->i_mount, &icw);
784 goto write_retry;
785 }
786
787 current->backing_dev_info = NULL;
788out:
789 if (iolock)
790 xfs_iunlock(ip, iolock);
791
792 if (ret > 0) {
793 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
794 /* Handle various SYNC-type writes */
795 ret = generic_write_sync(iocb, ret);
796 }
797 return ret;
798}
799
800STATIC ssize_t
801xfs_file_write_iter(
802 struct kiocb *iocb,
803 struct iov_iter *from)
804{
805 struct file *file = iocb->ki_filp;
806 struct address_space *mapping = file->f_mapping;
807 struct inode *inode = mapping->host;
808 struct xfs_inode *ip = XFS_I(inode);
809 ssize_t ret;
810 size_t ocount = iov_iter_count(from);
811
812 XFS_STATS_INC(ip->i_mount, xs_write_calls);
813
814 if (ocount == 0)
815 return 0;
816
817 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
818 return -EIO;
819
820 if (IS_DAX(inode))
821 return xfs_file_dax_write(iocb, from);
822
823 if (iocb->ki_flags & IOCB_DIRECT) {
824 /*
825 * Allow a directio write to fall back to a buffered
826 * write *only* in the case that we're doing a reflink
827 * CoW. In all other directio scenarios we do not
828 * allow an operation to fall back to buffered mode.
829 */
830 ret = xfs_file_dio_write(iocb, from);
831 if (ret != -ENOTBLK)
832 return ret;
833 }
834
835 return xfs_file_buffered_write(iocb, from);
836}
837
838static void
839xfs_wait_dax_page(
840 struct inode *inode)
841{
842 struct xfs_inode *ip = XFS_I(inode);
843
844 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
845 schedule();
846 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
847}
848
849static int
850xfs_break_dax_layouts(
851 struct inode *inode,
852 bool *retry)
853{
854 struct page *page;
855
856 ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));
857
858 page = dax_layout_busy_page(inode->i_mapping);
859 if (!page)
860 return 0;
861
862 *retry = true;
863 return ___wait_var_event(&page->_refcount,
864 atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
865 0, 0, xfs_wait_dax_page(inode));
866}
867
868int
869xfs_break_layouts(
870 struct inode *inode,
871 uint *iolock,
872 enum layout_break_reason reason)
873{
874 bool retry;
875 int error;
876
877 ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
878
879 do {
880 retry = false;
881 switch (reason) {
882 case BREAK_UNMAP:
883 error = xfs_break_dax_layouts(inode, &retry);
884 if (error || retry)
885 break;
886 fallthrough;
887 case BREAK_WRITE:
888 error = xfs_break_leased_layouts(inode, iolock, &retry);
889 break;
890 default:
891 WARN_ON_ONCE(1);
892 error = -EINVAL;
893 }
894 } while (error == 0 && retry);
895
896 return error;
897}
898
899#define XFS_FALLOC_FL_SUPPORTED \
900 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
901 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
902 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
903
904STATIC long
905xfs_file_fallocate(
906 struct file *file,
907 int mode,
908 loff_t offset,
909 loff_t len)
910{
911 struct inode *inode = file_inode(file);
912 struct xfs_inode *ip = XFS_I(inode);
913 long error;
914 enum xfs_prealloc_flags flags = 0;
915 uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
916 loff_t new_size = 0;
917 bool do_file_insert = false;
918
919 if (!S_ISREG(inode->i_mode))
920 return -EINVAL;
921 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
922 return -EOPNOTSUPP;
923
924 xfs_ilock(ip, iolock);
925 error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
926 if (error)
927 goto out_unlock;
928
929 /*
930 * Must wait for all AIO to complete before we continue as AIO can
931 * change the file size on completion without holding any locks we
932 * currently hold. We must do this first because AIO can update both
933 * the on disk and in memory inode sizes, and the operations that follow
934 * require the in-memory size to be fully up-to-date.
935 */
936 inode_dio_wait(inode);
937
938 /*
939 * Now AIO and DIO has drained we flush and (if necessary) invalidate
940 * the cached range over the first operation we are about to run.
941 *
942 * We care about zero and collapse here because they both run a hole
943 * punch over the range first. Because that can zero data, and the range
944 * of invalidation for the shift operations is much larger, we still do
945 * the required flush for collapse in xfs_prepare_shift().
946 *
947 * Insert has the same range requirements as collapse, and we extend the
948 * file first which can zero data. Hence insert has the same
949 * flush/invalidate requirements as collapse and so they are both
950 * handled at the right time by xfs_prepare_shift().
951 */
952 if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE |
953 FALLOC_FL_COLLAPSE_RANGE)) {
954 error = xfs_flush_unmap_range(ip, offset, len);
955 if (error)
956 goto out_unlock;
957 }
958
959 if (mode & FALLOC_FL_PUNCH_HOLE) {
960 error = xfs_free_file_space(ip, offset, len);
961 if (error)
962 goto out_unlock;
963 } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
964 if (!xfs_is_falloc_aligned(ip, offset, len)) {
965 error = -EINVAL;
966 goto out_unlock;
967 }
968
969 /*
970 * There is no need to overlap collapse range with EOF,
971 * in which case it is effectively a truncate operation
972 */
973 if (offset + len >= i_size_read(inode)) {
974 error = -EINVAL;
975 goto out_unlock;
976 }
977
978 new_size = i_size_read(inode) - len;
979
980 error = xfs_collapse_file_space(ip, offset, len);
981 if (error)
982 goto out_unlock;
983 } else if (mode & FALLOC_FL_INSERT_RANGE) {
984 loff_t isize = i_size_read(inode);
985
986 if (!xfs_is_falloc_aligned(ip, offset, len)) {
987 error = -EINVAL;
988 goto out_unlock;
989 }
990
991 /*
992 * New inode size must not exceed ->s_maxbytes, accounting for
993 * possible signed overflow.
994 */
995 if (inode->i_sb->s_maxbytes - isize < len) {
996 error = -EFBIG;
997 goto out_unlock;
998 }
999 new_size = isize + len;
1000
1001 /* Offset should be less than i_size */
1002 if (offset >= isize) {
1003 error = -EINVAL;
1004 goto out_unlock;
1005 }
1006 do_file_insert = true;
1007 } else {
1008 flags |= XFS_PREALLOC_SET;
1009
1010 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
1011 offset + len > i_size_read(inode)) {
1012 new_size = offset + len;
1013 error = inode_newsize_ok(inode, new_size);
1014 if (error)
1015 goto out_unlock;
1016 }
1017
1018 if (mode & FALLOC_FL_ZERO_RANGE) {
1019 /*
1020 * Punch a hole and prealloc the range. We use a hole
1021 * punch rather than unwritten extent conversion for two
1022 * reasons:
1023 *
1024 * 1.) Hole punch handles partial block zeroing for us.
1025 * 2.) If prealloc returns ENOSPC, the file range is
1026 * still zero-valued by virtue of the hole punch.
1027 */
1028 unsigned int blksize = i_blocksize(inode);
1029
1030 trace_xfs_zero_file_space(ip);
1031
1032 error = xfs_free_file_space(ip, offset, len);
1033 if (error)
1034 goto out_unlock;
1035
1036 len = round_up(offset + len, blksize) -
1037 round_down(offset, blksize);
1038 offset = round_down(offset, blksize);
1039 } else if (mode & FALLOC_FL_UNSHARE_RANGE) {
1040 error = xfs_reflink_unshare(ip, offset, len);
1041 if (error)
1042 goto out_unlock;
1043 } else {
1044 /*
1045 * If always_cow mode we can't use preallocations and
1046 * thus should not create them.
1047 */
1048 if (xfs_is_always_cow_inode(ip)) {
1049 error = -EOPNOTSUPP;
1050 goto out_unlock;
1051 }
1052 }
1053
1054 if (!xfs_is_always_cow_inode(ip)) {
1055 error = xfs_alloc_file_space(ip, offset, len,
1056 XFS_BMAPI_PREALLOC);
1057 if (error)
1058 goto out_unlock;
1059 }
1060 }
1061
1062 if (file->f_flags & O_DSYNC)
1063 flags |= XFS_PREALLOC_SYNC;
1064
1065 error = xfs_update_prealloc_flags(ip, flags);
1066 if (error)
1067 goto out_unlock;
1068
1069 /* Change file size if needed */
1070 if (new_size) {
1071 struct iattr iattr;
1072
1073 iattr.ia_valid = ATTR_SIZE;
1074 iattr.ia_size = new_size;
1075 error = xfs_vn_setattr_size(file_mnt_user_ns(file),
1076 file_dentry(file), &iattr);
1077 if (error)
1078 goto out_unlock;
1079 }
1080
1081 /*
1082 * Perform hole insertion now that the file size has been
1083 * updated so that if we crash during the operation we don't
1084 * leave shifted extents past EOF and hence losing access to
1085 * the data that is contained within them.
1086 */
1087 if (do_file_insert)
1088 error = xfs_insert_file_space(ip, offset, len);
1089
1090out_unlock:
1091 xfs_iunlock(ip, iolock);
1092 return error;
1093}
1094
1095STATIC int
1096xfs_file_fadvise(
1097 struct file *file,
1098 loff_t start,
1099 loff_t end,
1100 int advice)
1101{
1102 struct xfs_inode *ip = XFS_I(file_inode(file));
1103 int ret;
1104 int lockflags = 0;
1105
1106 /*
1107 * Operations creating pages in page cache need protection from hole
1108 * punching and similar ops
1109 */
1110 if (advice == POSIX_FADV_WILLNEED) {
1111 lockflags = XFS_IOLOCK_SHARED;
1112 xfs_ilock(ip, lockflags);
1113 }
1114 ret = generic_fadvise(file, start, end, advice);
1115 if (lockflags)
1116 xfs_iunlock(ip, lockflags);
1117 return ret;
1118}
1119
1120/* Does this file, inode, or mount want synchronous writes? */
1121static inline bool xfs_file_sync_writes(struct file *filp)
1122{
1123 struct xfs_inode *ip = XFS_I(file_inode(filp));
1124
1125 if (ip->i_mount->m_flags & XFS_MOUNT_WSYNC)
1126 return true;
1127 if (filp->f_flags & (__O_SYNC | O_DSYNC))
1128 return true;
1129 if (IS_SYNC(file_inode(filp)))
1130 return true;
1131
1132 return false;
1133}
1134
1135STATIC loff_t
1136xfs_file_remap_range(
1137 struct file *file_in,
1138 loff_t pos_in,
1139 struct file *file_out,
1140 loff_t pos_out,
1141 loff_t len,
1142 unsigned int remap_flags)
1143{
1144 struct inode *inode_in = file_inode(file_in);
1145 struct xfs_inode *src = XFS_I(inode_in);
1146 struct inode *inode_out = file_inode(file_out);
1147 struct xfs_inode *dest = XFS_I(inode_out);
1148 struct xfs_mount *mp = src->i_mount;
1149 loff_t remapped = 0;
1150 xfs_extlen_t cowextsize;
1151 int ret;
1152
1153 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
1154 return -EINVAL;
1155
1156 if (!xfs_sb_version_hasreflink(&mp->m_sb))
1157 return -EOPNOTSUPP;
1158
1159 if (XFS_FORCED_SHUTDOWN(mp))
1160 return -EIO;
1161
1162 /* Prepare and then clone file data. */
1163 ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
1164 &len, remap_flags);
1165 if (ret || len == 0)
1166 return ret;
1167
1168 trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
1169
1170 ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
1171 &remapped);
1172 if (ret)
1173 goto out_unlock;
1174
1175 /*
1176 * Carry the cowextsize hint from src to dest if we're sharing the
1177 * entire source file to the entire destination file, the source file
1178 * has a cowextsize hint, and the destination file does not.
1179 */
1180 cowextsize = 0;
1181 if (pos_in == 0 && len == i_size_read(inode_in) &&
1182 (src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
1183 pos_out == 0 && len >= i_size_read(inode_out) &&
1184 !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE))
1185 cowextsize = src->i_cowextsize;
1186
1187 ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
1188 remap_flags);
1189 if (ret)
1190 goto out_unlock;
1191
1192 if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
1193 xfs_log_force_inode(dest);
1194out_unlock:
1195 xfs_iunlock2_io_mmap(src, dest);
1196 if (ret)
1197 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
1198 return remapped > 0 ? remapped : ret;
1199}
1200
1201STATIC int
1202xfs_file_open(
1203 struct inode *inode,
1204 struct file *file)
1205{
1206 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1207 return -EFBIG;
1208 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
1209 return -EIO;
1210 file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC;
1211 return 0;
1212}
1213
1214STATIC int
1215xfs_dir_open(
1216 struct inode *inode,
1217 struct file *file)
1218{
1219 struct xfs_inode *ip = XFS_I(inode);
1220 int mode;
1221 int error;
1222
1223 error = xfs_file_open(inode, file);
1224 if (error)
1225 return error;
1226
1227 /*
1228 * If there are any blocks, read-ahead block 0 as we're almost
1229 * certain to have the next operation be a read there.
1230 */
1231 mode = xfs_ilock_data_map_shared(ip);
1232 if (ip->i_df.if_nextents > 0)
1233 error = xfs_dir3_data_readahead(ip, 0, 0);
1234 xfs_iunlock(ip, mode);
1235 return error;
1236}
1237
1238STATIC int
1239xfs_file_release(
1240 struct inode *inode,
1241 struct file *filp)
1242{
1243 return xfs_release(XFS_I(inode));
1244}
1245
1246STATIC int
1247xfs_file_readdir(
1248 struct file *file,
1249 struct dir_context *ctx)
1250{
1251 struct inode *inode = file_inode(file);
1252 xfs_inode_t *ip = XFS_I(inode);
1253 size_t bufsize;
1254
1255 /*
1256 * The Linux API doesn't pass down the total size of the buffer
1257 * we read into down to the filesystem. With the filldir concept
1258 * it's not needed for correct information, but the XFS dir2 leaf
1259 * code wants an estimate of the buffer size to calculate it's
1260 * readahead window and size the buffers used for mapping to
1261 * physical blocks.
1262 *
1263 * Try to give it an estimate that's good enough, maybe at some
1264 * point we can change the ->readdir prototype to include the
1265 * buffer size. For now we use the current glibc buffer size.
1266 */
1267 bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_disk_size);
1268
1269 return xfs_readdir(NULL, ip, ctx, bufsize);
1270}
1271
1272STATIC loff_t
1273xfs_file_llseek(
1274 struct file *file,
1275 loff_t offset,
1276 int whence)
1277{
1278 struct inode *inode = file->f_mapping->host;
1279
1280 if (XFS_FORCED_SHUTDOWN(XFS_I(inode)->i_mount))
1281 return -EIO;
1282
1283 switch (whence) {
1284 default:
1285 return generic_file_llseek(file, offset, whence);
1286 case SEEK_HOLE:
1287 offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
1288 break;
1289 case SEEK_DATA:
1290 offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
1291 break;
1292 }
1293
1294 if (offset < 0)
1295 return offset;
1296 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1297}
1298
1299/*
1300 * Locking for serialisation of IO during page faults. This results in a lock
1301 * ordering of:
1302 *
1303 * mmap_lock (MM)
1304 * sb_start_pagefault(vfs, freeze)
1305 * i_mmaplock (XFS - truncate serialisation)
1306 * page_lock (MM)
1307 * i_lock (XFS - extent map serialisation)
1308 */
1309static vm_fault_t
1310__xfs_filemap_fault(
1311 struct vm_fault *vmf,
1312 enum page_entry_size pe_size,
1313 bool write_fault)
1314{
1315 struct inode *inode = file_inode(vmf->vma->vm_file);
1316 struct xfs_inode *ip = XFS_I(inode);
1317 vm_fault_t ret;
1318
1319 trace_xfs_filemap_fault(ip, pe_size, write_fault);
1320
1321 if (write_fault) {
1322 sb_start_pagefault(inode->i_sb);
1323 file_update_time(vmf->vma->vm_file);
1324 }
1325
1326 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1327 if (IS_DAX(inode)) {
1328 pfn_t pfn;
1329
1330 ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL,
1331 (write_fault && !vmf->cow_page) ?
1332 &xfs_direct_write_iomap_ops :
1333 &xfs_read_iomap_ops);
1334 if (ret & VM_FAULT_NEEDDSYNC)
1335 ret = dax_finish_sync_fault(vmf, pe_size, pfn);
1336 } else {
1337 if (write_fault)
1338 ret = iomap_page_mkwrite(vmf,
1339 &xfs_buffered_write_iomap_ops);
1340 else
1341 ret = filemap_fault(vmf);
1342 }
1343 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1344
1345 if (write_fault)
1346 sb_end_pagefault(inode->i_sb);
1347 return ret;
1348}
1349
1350static inline bool
1351xfs_is_write_fault(
1352 struct vm_fault *vmf)
1353{
1354 return (vmf->flags & FAULT_FLAG_WRITE) &&
1355 (vmf->vma->vm_flags & VM_SHARED);
1356}
1357
1358static vm_fault_t
1359xfs_filemap_fault(
1360 struct vm_fault *vmf)
1361{
1362 /* DAX can shortcut the normal fault path on write faults! */
1363 return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
1364 IS_DAX(file_inode(vmf->vma->vm_file)) &&
1365 xfs_is_write_fault(vmf));
1366}
1367
1368static vm_fault_t
1369xfs_filemap_huge_fault(
1370 struct vm_fault *vmf,
1371 enum page_entry_size pe_size)
1372{
1373 if (!IS_DAX(file_inode(vmf->vma->vm_file)))
1374 return VM_FAULT_FALLBACK;
1375
1376 /* DAX can shortcut the normal fault path on write faults! */
1377 return __xfs_filemap_fault(vmf, pe_size,
1378 xfs_is_write_fault(vmf));
1379}
1380
1381static vm_fault_t
1382xfs_filemap_page_mkwrite(
1383 struct vm_fault *vmf)
1384{
1385 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1386}
1387
1388/*
1389 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
1390 * on write faults. In reality, it needs to serialise against truncate and
1391 * prepare memory for writing so handle is as standard write fault.
1392 */
1393static vm_fault_t
1394xfs_filemap_pfn_mkwrite(
1395 struct vm_fault *vmf)
1396{
1397
1398 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1399}
1400
1401static vm_fault_t
1402xfs_filemap_map_pages(
1403 struct vm_fault *vmf,
1404 pgoff_t start_pgoff,
1405 pgoff_t end_pgoff)
1406{
1407 struct inode *inode = file_inode(vmf->vma->vm_file);
1408 vm_fault_t ret;
1409
1410 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1411 ret = filemap_map_pages(vmf, start_pgoff, end_pgoff);
1412 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1413 return ret;
1414}
1415
1416static const struct vm_operations_struct xfs_file_vm_ops = {
1417 .fault = xfs_filemap_fault,
1418 .huge_fault = xfs_filemap_huge_fault,
1419 .map_pages = xfs_filemap_map_pages,
1420 .page_mkwrite = xfs_filemap_page_mkwrite,
1421 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1422};
1423
1424STATIC int
1425xfs_file_mmap(
1426 struct file *file,
1427 struct vm_area_struct *vma)
1428{
1429 struct inode *inode = file_inode(file);
1430 struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode));
1431
1432 /*
1433 * We don't support synchronous mappings for non-DAX files and
1434 * for DAX files if underneath dax_device is not synchronous.
1435 */
1436 if (!daxdev_mapping_supported(vma, target->bt_daxdev))
1437 return -EOPNOTSUPP;
1438
1439 file_accessed(file);
1440 vma->vm_ops = &xfs_file_vm_ops;
1441 if (IS_DAX(inode))
1442 vma->vm_flags |= VM_HUGEPAGE;
1443 return 0;
1444}
1445
1446const struct file_operations xfs_file_operations = {
1447 .llseek = xfs_file_llseek,
1448 .read_iter = xfs_file_read_iter,
1449 .write_iter = xfs_file_write_iter,
1450 .splice_read = generic_file_splice_read,
1451 .splice_write = iter_file_splice_write,
1452 .iopoll = iomap_dio_iopoll,
1453 .unlocked_ioctl = xfs_file_ioctl,
1454#ifdef CONFIG_COMPAT
1455 .compat_ioctl = xfs_file_compat_ioctl,
1456#endif
1457 .mmap = xfs_file_mmap,
1458 .mmap_supported_flags = MAP_SYNC,
1459 .open = xfs_file_open,
1460 .release = xfs_file_release,
1461 .fsync = xfs_file_fsync,
1462 .get_unmapped_area = thp_get_unmapped_area,
1463 .fallocate = xfs_file_fallocate,
1464 .fadvise = xfs_file_fadvise,
1465 .remap_file_range = xfs_file_remap_range,
1466};
1467
1468const struct file_operations xfs_dir_file_operations = {
1469 .open = xfs_dir_open,
1470 .read = generic_read_dir,
1471 .iterate_shared = xfs_file_readdir,
1472 .llseek = generic_file_llseek,
1473 .unlocked_ioctl = xfs_file_ioctl,
1474#ifdef CONFIG_COMPAT
1475 .compat_ioctl = xfs_file_compat_ioctl,
1476#endif
1477 .fsync = xfs_dir_fsync,
1478};