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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 ssize_t
218xfs_file_dio_read(
219 struct kiocb *iocb,
220 struct iov_iter *to)
221{
222 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
223 ssize_t ret;
224
225 trace_xfs_file_direct_read(iocb, to);
226
227 if (!iov_iter_count(to))
228 return 0; /* skip atime */
229
230 file_accessed(iocb->ki_filp);
231
232 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
233 if (ret)
234 return ret;
235 ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0, NULL, 0);
236 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
237
238 return ret;
239}
240
241static noinline ssize_t
242xfs_file_dax_read(
243 struct kiocb *iocb,
244 struct iov_iter *to)
245{
246 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
247 ssize_t ret = 0;
248
249 trace_xfs_file_dax_read(iocb, to);
250
251 if (!iov_iter_count(to))
252 return 0; /* skip atime */
253
254 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
255 if (ret)
256 return ret;
257 ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
258 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
259
260 file_accessed(iocb->ki_filp);
261 return ret;
262}
263
264STATIC ssize_t
265xfs_file_buffered_read(
266 struct kiocb *iocb,
267 struct iov_iter *to)
268{
269 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
270 ssize_t ret;
271
272 trace_xfs_file_buffered_read(iocb, to);
273
274 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
275 if (ret)
276 return ret;
277 ret = generic_file_read_iter(iocb, to);
278 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
279
280 return ret;
281}
282
283STATIC ssize_t
284xfs_file_read_iter(
285 struct kiocb *iocb,
286 struct iov_iter *to)
287{
288 struct inode *inode = file_inode(iocb->ki_filp);
289 struct xfs_mount *mp = XFS_I(inode)->i_mount;
290 ssize_t ret = 0;
291
292 XFS_STATS_INC(mp, xs_read_calls);
293
294 if (xfs_is_shutdown(mp))
295 return -EIO;
296
297 if (IS_DAX(inode))
298 ret = xfs_file_dax_read(iocb, to);
299 else if (iocb->ki_flags & IOCB_DIRECT)
300 ret = xfs_file_dio_read(iocb, to);
301 else
302 ret = xfs_file_buffered_read(iocb, to);
303
304 if (ret > 0)
305 XFS_STATS_ADD(mp, xs_read_bytes, ret);
306 return ret;
307}
308
309/*
310 * Common pre-write limit and setup checks.
311 *
312 * Called with the iolocked held either shared and exclusive according to
313 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
314 * if called for a direct write beyond i_size.
315 */
316STATIC ssize_t
317xfs_file_write_checks(
318 struct kiocb *iocb,
319 struct iov_iter *from,
320 unsigned int *iolock)
321{
322 struct file *file = iocb->ki_filp;
323 struct inode *inode = file->f_mapping->host;
324 struct xfs_inode *ip = XFS_I(inode);
325 ssize_t error = 0;
326 size_t count = iov_iter_count(from);
327 bool drained_dio = false;
328 loff_t isize;
329
330restart:
331 error = generic_write_checks(iocb, from);
332 if (error <= 0)
333 return error;
334
335 if (iocb->ki_flags & IOCB_NOWAIT) {
336 error = break_layout(inode, false);
337 if (error == -EWOULDBLOCK)
338 error = -EAGAIN;
339 } else {
340 error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
341 }
342
343 if (error)
344 return error;
345
346 /*
347 * For changing security info in file_remove_privs() we need i_rwsem
348 * exclusively.
349 */
350 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
351 xfs_iunlock(ip, *iolock);
352 *iolock = XFS_IOLOCK_EXCL;
353 error = xfs_ilock_iocb(iocb, *iolock);
354 if (error) {
355 *iolock = 0;
356 return error;
357 }
358 goto restart;
359 }
360
361 /*
362 * If the offset is beyond the size of the file, we need to zero any
363 * blocks that fall between the existing EOF and the start of this
364 * write. If zeroing is needed and we are currently holding the iolock
365 * shared, we need to update it to exclusive which implies having to
366 * redo all checks before.
367 *
368 * We need to serialise against EOF updates that occur in IO completions
369 * here. We want to make sure that nobody is changing the size while we
370 * do this check until we have placed an IO barrier (i.e. hold the
371 * XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The
372 * spinlock effectively forms a memory barrier once we have the
373 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and
374 * hence be able to correctly determine if we need to run zeroing.
375 *
376 * We can do an unlocked check here safely as IO completion can only
377 * extend EOF. Truncate is locked out at this point, so the EOF can
378 * not move backwards, only forwards. Hence we only need to take the
379 * slow path and spin locks when we are at or beyond the current EOF.
380 */
381 if (iocb->ki_pos <= i_size_read(inode))
382 goto out;
383
384 spin_lock(&ip->i_flags_lock);
385 isize = i_size_read(inode);
386 if (iocb->ki_pos > isize) {
387 spin_unlock(&ip->i_flags_lock);
388
389 if (iocb->ki_flags & IOCB_NOWAIT)
390 return -EAGAIN;
391
392 if (!drained_dio) {
393 if (*iolock == XFS_IOLOCK_SHARED) {
394 xfs_iunlock(ip, *iolock);
395 *iolock = XFS_IOLOCK_EXCL;
396 xfs_ilock(ip, *iolock);
397 iov_iter_reexpand(from, count);
398 }
399 /*
400 * We now have an IO submission barrier in place, but
401 * AIO can do EOF updates during IO completion and hence
402 * we now need to wait for all of them to drain. Non-AIO
403 * DIO will have drained before we are given the
404 * XFS_IOLOCK_EXCL, and so for most cases this wait is a
405 * no-op.
406 */
407 inode_dio_wait(inode);
408 drained_dio = true;
409 goto restart;
410 }
411
412 trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
413 error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL);
414 if (error)
415 return error;
416 } else
417 spin_unlock(&ip->i_flags_lock);
418
419out:
420 return kiocb_modified(iocb);
421}
422
423static int
424xfs_dio_write_end_io(
425 struct kiocb *iocb,
426 ssize_t size,
427 int error,
428 unsigned flags)
429{
430 struct inode *inode = file_inode(iocb->ki_filp);
431 struct xfs_inode *ip = XFS_I(inode);
432 loff_t offset = iocb->ki_pos;
433 unsigned int nofs_flag;
434
435 trace_xfs_end_io_direct_write(ip, offset, size);
436
437 if (xfs_is_shutdown(ip->i_mount))
438 return -EIO;
439
440 if (error)
441 return error;
442 if (!size)
443 return 0;
444
445 /*
446 * Capture amount written on completion as we can't reliably account
447 * for it on submission.
448 */
449 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
450
451 /*
452 * We can allocate memory here while doing writeback on behalf of
453 * memory reclaim. To avoid memory allocation deadlocks set the
454 * task-wide nofs context for the following operations.
455 */
456 nofs_flag = memalloc_nofs_save();
457
458 if (flags & IOMAP_DIO_COW) {
459 error = xfs_reflink_end_cow(ip, offset, size);
460 if (error)
461 goto out;
462 }
463
464 /*
465 * Unwritten conversion updates the in-core isize after extent
466 * conversion but before updating the on-disk size. Updating isize any
467 * earlier allows a racing dio read to find unwritten extents before
468 * they are converted.
469 */
470 if (flags & IOMAP_DIO_UNWRITTEN) {
471 error = xfs_iomap_write_unwritten(ip, offset, size, true);
472 goto out;
473 }
474
475 /*
476 * We need to update the in-core inode size here so that we don't end up
477 * with the on-disk inode size being outside the in-core inode size. We
478 * have no other method of updating EOF for AIO, so always do it here
479 * if necessary.
480 *
481 * We need to lock the test/set EOF update as we can be racing with
482 * other IO completions here to update the EOF. Failing to serialise
483 * here can result in EOF moving backwards and Bad Things Happen when
484 * that occurs.
485 *
486 * As IO completion only ever extends EOF, we can do an unlocked check
487 * here to avoid taking the spinlock. If we land within the current EOF,
488 * then we do not need to do an extending update at all, and we don't
489 * need to take the lock to check this. If we race with an update moving
490 * EOF, then we'll either still be beyond EOF and need to take the lock,
491 * or we'll be within EOF and we don't need to take it at all.
492 */
493 if (offset + size <= i_size_read(inode))
494 goto out;
495
496 spin_lock(&ip->i_flags_lock);
497 if (offset + size > i_size_read(inode)) {
498 i_size_write(inode, offset + size);
499 spin_unlock(&ip->i_flags_lock);
500 error = xfs_setfilesize(ip, offset, size);
501 } else {
502 spin_unlock(&ip->i_flags_lock);
503 }
504
505out:
506 memalloc_nofs_restore(nofs_flag);
507 return error;
508}
509
510static const struct iomap_dio_ops xfs_dio_write_ops = {
511 .end_io = xfs_dio_write_end_io,
512};
513
514/*
515 * Handle block aligned direct I/O writes
516 */
517static noinline ssize_t
518xfs_file_dio_write_aligned(
519 struct xfs_inode *ip,
520 struct kiocb *iocb,
521 struct iov_iter *from)
522{
523 unsigned int iolock = XFS_IOLOCK_SHARED;
524 ssize_t ret;
525
526 ret = xfs_ilock_iocb(iocb, iolock);
527 if (ret)
528 return ret;
529 ret = xfs_file_write_checks(iocb, from, &iolock);
530 if (ret)
531 goto out_unlock;
532
533 /*
534 * We don't need to hold the IOLOCK exclusively across the IO, so demote
535 * the iolock back to shared if we had to take the exclusive lock in
536 * xfs_file_write_checks() for other reasons.
537 */
538 if (iolock == XFS_IOLOCK_EXCL) {
539 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
540 iolock = XFS_IOLOCK_SHARED;
541 }
542 trace_xfs_file_direct_write(iocb, from);
543 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
544 &xfs_dio_write_ops, 0, NULL, 0);
545out_unlock:
546 if (iolock)
547 xfs_iunlock(ip, iolock);
548 return ret;
549}
550
551/*
552 * Handle block unaligned direct I/O writes
553 *
554 * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing
555 * them to be done in parallel with reads and other direct I/O writes. However,
556 * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need
557 * to do sub-block zeroing and that requires serialisation against other direct
558 * I/O to the same block. In this case we need to serialise the submission of
559 * the unaligned I/O so that we don't get racing block zeroing in the dio layer.
560 * In the case where sub-block zeroing is not required, we can do concurrent
561 * sub-block dios to the same block successfully.
562 *
563 * Optimistically submit the I/O using the shared lock first, but use the
564 * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN
565 * if block allocation or partial block zeroing would be required. In that case
566 * we try again with the exclusive lock.
567 */
568static noinline ssize_t
569xfs_file_dio_write_unaligned(
570 struct xfs_inode *ip,
571 struct kiocb *iocb,
572 struct iov_iter *from)
573{
574 size_t isize = i_size_read(VFS_I(ip));
575 size_t count = iov_iter_count(from);
576 unsigned int iolock = XFS_IOLOCK_SHARED;
577 unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY;
578 ssize_t ret;
579
580 /*
581 * Extending writes need exclusivity because of the sub-block zeroing
582 * that the DIO code always does for partial tail blocks beyond EOF, so
583 * don't even bother trying the fast path in this case.
584 */
585 if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) {
586 if (iocb->ki_flags & IOCB_NOWAIT)
587 return -EAGAIN;
588retry_exclusive:
589 iolock = XFS_IOLOCK_EXCL;
590 flags = IOMAP_DIO_FORCE_WAIT;
591 }
592
593 ret = xfs_ilock_iocb(iocb, iolock);
594 if (ret)
595 return ret;
596
597 /*
598 * We can't properly handle unaligned direct I/O to reflink files yet,
599 * as we can't unshare a partial block.
600 */
601 if (xfs_is_cow_inode(ip)) {
602 trace_xfs_reflink_bounce_dio_write(iocb, from);
603 ret = -ENOTBLK;
604 goto out_unlock;
605 }
606
607 ret = xfs_file_write_checks(iocb, from, &iolock);
608 if (ret)
609 goto out_unlock;
610
611 /*
612 * If we are doing exclusive unaligned I/O, this must be the only I/O
613 * in-flight. Otherwise we risk data corruption due to unwritten extent
614 * conversions from the AIO end_io handler. Wait for all other I/O to
615 * drain first.
616 */
617 if (flags & IOMAP_DIO_FORCE_WAIT)
618 inode_dio_wait(VFS_I(ip));
619
620 trace_xfs_file_direct_write(iocb, from);
621 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
622 &xfs_dio_write_ops, flags, NULL, 0);
623
624 /*
625 * Retry unaligned I/O with exclusive blocking semantics if the DIO
626 * layer rejected it for mapping or locking reasons. If we are doing
627 * nonblocking user I/O, propagate the error.
628 */
629 if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) {
630 ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY);
631 xfs_iunlock(ip, iolock);
632 goto retry_exclusive;
633 }
634
635out_unlock:
636 if (iolock)
637 xfs_iunlock(ip, iolock);
638 return ret;
639}
640
641static ssize_t
642xfs_file_dio_write(
643 struct kiocb *iocb,
644 struct iov_iter *from)
645{
646 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
647 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
648 size_t count = iov_iter_count(from);
649
650 /* direct I/O must be aligned to device logical sector size */
651 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
652 return -EINVAL;
653 if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask)
654 return xfs_file_dio_write_unaligned(ip, iocb, from);
655 return xfs_file_dio_write_aligned(ip, iocb, from);
656}
657
658static noinline ssize_t
659xfs_file_dax_write(
660 struct kiocb *iocb,
661 struct iov_iter *from)
662{
663 struct inode *inode = iocb->ki_filp->f_mapping->host;
664 struct xfs_inode *ip = XFS_I(inode);
665 unsigned int iolock = XFS_IOLOCK_EXCL;
666 ssize_t ret, error = 0;
667 loff_t pos;
668
669 ret = xfs_ilock_iocb(iocb, iolock);
670 if (ret)
671 return ret;
672 ret = xfs_file_write_checks(iocb, from, &iolock);
673 if (ret)
674 goto out;
675
676 pos = iocb->ki_pos;
677
678 trace_xfs_file_dax_write(iocb, from);
679 ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops);
680 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
681 i_size_write(inode, iocb->ki_pos);
682 error = xfs_setfilesize(ip, pos, ret);
683 }
684out:
685 if (iolock)
686 xfs_iunlock(ip, iolock);
687 if (error)
688 return error;
689
690 if (ret > 0) {
691 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
692
693 /* Handle various SYNC-type writes */
694 ret = generic_write_sync(iocb, ret);
695 }
696 return ret;
697}
698
699STATIC ssize_t
700xfs_file_buffered_write(
701 struct kiocb *iocb,
702 struct iov_iter *from)
703{
704 struct inode *inode = iocb->ki_filp->f_mapping->host;
705 struct xfs_inode *ip = XFS_I(inode);
706 ssize_t ret;
707 bool cleared_space = false;
708 unsigned int iolock;
709
710write_retry:
711 iolock = XFS_IOLOCK_EXCL;
712 ret = xfs_ilock_iocb(iocb, iolock);
713 if (ret)
714 return ret;
715
716 ret = xfs_file_write_checks(iocb, from, &iolock);
717 if (ret)
718 goto out;
719
720 /* We can write back this queue in page reclaim */
721 current->backing_dev_info = inode_to_bdi(inode);
722
723 trace_xfs_file_buffered_write(iocb, from);
724 ret = iomap_file_buffered_write(iocb, from,
725 &xfs_buffered_write_iomap_ops);
726 if (likely(ret >= 0))
727 iocb->ki_pos += ret;
728
729 /*
730 * If we hit a space limit, try to free up some lingering preallocated
731 * space before returning an error. In the case of ENOSPC, first try to
732 * write back all dirty inodes to free up some of the excess reserved
733 * metadata space. This reduces the chances that the eofblocks scan
734 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
735 * also behaves as a filter to prevent too many eofblocks scans from
736 * running at the same time. Use a synchronous scan to increase the
737 * effectiveness of the scan.
738 */
739 if (ret == -EDQUOT && !cleared_space) {
740 xfs_iunlock(ip, iolock);
741 xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC);
742 cleared_space = true;
743 goto write_retry;
744 } else if (ret == -ENOSPC && !cleared_space) {
745 struct xfs_icwalk icw = {0};
746
747 cleared_space = true;
748 xfs_flush_inodes(ip->i_mount);
749
750 xfs_iunlock(ip, iolock);
751 icw.icw_flags = XFS_ICWALK_FLAG_SYNC;
752 xfs_blockgc_free_space(ip->i_mount, &icw);
753 goto write_retry;
754 }
755
756 current->backing_dev_info = NULL;
757out:
758 if (iolock)
759 xfs_iunlock(ip, iolock);
760
761 if (ret > 0) {
762 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
763 /* Handle various SYNC-type writes */
764 ret = generic_write_sync(iocb, ret);
765 }
766 return ret;
767}
768
769STATIC ssize_t
770xfs_file_write_iter(
771 struct kiocb *iocb,
772 struct iov_iter *from)
773{
774 struct inode *inode = iocb->ki_filp->f_mapping->host;
775 struct xfs_inode *ip = XFS_I(inode);
776 ssize_t ret;
777 size_t ocount = iov_iter_count(from);
778
779 XFS_STATS_INC(ip->i_mount, xs_write_calls);
780
781 if (ocount == 0)
782 return 0;
783
784 if (xfs_is_shutdown(ip->i_mount))
785 return -EIO;
786
787 if (IS_DAX(inode))
788 return xfs_file_dax_write(iocb, from);
789
790 if (iocb->ki_flags & IOCB_DIRECT) {
791 /*
792 * Allow a directio write to fall back to a buffered
793 * write *only* in the case that we're doing a reflink
794 * CoW. In all other directio scenarios we do not
795 * allow an operation to fall back to buffered mode.
796 */
797 ret = xfs_file_dio_write(iocb, from);
798 if (ret != -ENOTBLK)
799 return ret;
800 }
801
802 return xfs_file_buffered_write(iocb, from);
803}
804
805static void
806xfs_wait_dax_page(
807 struct inode *inode)
808{
809 struct xfs_inode *ip = XFS_I(inode);
810
811 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
812 schedule();
813 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
814}
815
816int
817xfs_break_dax_layouts(
818 struct inode *inode,
819 bool *retry)
820{
821 struct page *page;
822
823 ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));
824
825 page = dax_layout_busy_page(inode->i_mapping);
826 if (!page)
827 return 0;
828
829 *retry = true;
830 return ___wait_var_event(&page->_refcount,
831 atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
832 0, 0, xfs_wait_dax_page(inode));
833}
834
835int
836xfs_break_layouts(
837 struct inode *inode,
838 uint *iolock,
839 enum layout_break_reason reason)
840{
841 bool retry;
842 int error;
843
844 ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
845
846 do {
847 retry = false;
848 switch (reason) {
849 case BREAK_UNMAP:
850 error = xfs_break_dax_layouts(inode, &retry);
851 if (error || retry)
852 break;
853 fallthrough;
854 case BREAK_WRITE:
855 error = xfs_break_leased_layouts(inode, iolock, &retry);
856 break;
857 default:
858 WARN_ON_ONCE(1);
859 error = -EINVAL;
860 }
861 } while (error == 0 && retry);
862
863 return error;
864}
865
866/* Does this file, inode, or mount want synchronous writes? */
867static inline bool xfs_file_sync_writes(struct file *filp)
868{
869 struct xfs_inode *ip = XFS_I(file_inode(filp));
870
871 if (xfs_has_wsync(ip->i_mount))
872 return true;
873 if (filp->f_flags & (__O_SYNC | O_DSYNC))
874 return true;
875 if (IS_SYNC(file_inode(filp)))
876 return true;
877
878 return false;
879}
880
881#define XFS_FALLOC_FL_SUPPORTED \
882 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
883 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
884 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
885
886STATIC long
887xfs_file_fallocate(
888 struct file *file,
889 int mode,
890 loff_t offset,
891 loff_t len)
892{
893 struct inode *inode = file_inode(file);
894 struct xfs_inode *ip = XFS_I(inode);
895 long error;
896 uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
897 loff_t new_size = 0;
898 bool do_file_insert = false;
899
900 if (!S_ISREG(inode->i_mode))
901 return -EINVAL;
902 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
903 return -EOPNOTSUPP;
904
905 xfs_ilock(ip, iolock);
906 error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
907 if (error)
908 goto out_unlock;
909
910 /*
911 * Must wait for all AIO to complete before we continue as AIO can
912 * change the file size on completion without holding any locks we
913 * currently hold. We must do this first because AIO can update both
914 * the on disk and in memory inode sizes, and the operations that follow
915 * require the in-memory size to be fully up-to-date.
916 */
917 inode_dio_wait(inode);
918
919 /*
920 * Now AIO and DIO has drained we flush and (if necessary) invalidate
921 * the cached range over the first operation we are about to run.
922 *
923 * We care about zero and collapse here because they both run a hole
924 * punch over the range first. Because that can zero data, and the range
925 * of invalidation for the shift operations is much larger, we still do
926 * the required flush for collapse in xfs_prepare_shift().
927 *
928 * Insert has the same range requirements as collapse, and we extend the
929 * file first which can zero data. Hence insert has the same
930 * flush/invalidate requirements as collapse and so they are both
931 * handled at the right time by xfs_prepare_shift().
932 */
933 if (mode & (FALLOC_FL_PUNCH_HOLE | FALLOC_FL_ZERO_RANGE |
934 FALLOC_FL_COLLAPSE_RANGE)) {
935 error = xfs_flush_unmap_range(ip, offset, len);
936 if (error)
937 goto out_unlock;
938 }
939
940 error = file_modified(file);
941 if (error)
942 goto out_unlock;
943
944 if (mode & FALLOC_FL_PUNCH_HOLE) {
945 error = xfs_free_file_space(ip, offset, len);
946 if (error)
947 goto out_unlock;
948 } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
949 if (!xfs_is_falloc_aligned(ip, offset, len)) {
950 error = -EINVAL;
951 goto out_unlock;
952 }
953
954 /*
955 * There is no need to overlap collapse range with EOF,
956 * in which case it is effectively a truncate operation
957 */
958 if (offset + len >= i_size_read(inode)) {
959 error = -EINVAL;
960 goto out_unlock;
961 }
962
963 new_size = i_size_read(inode) - len;
964
965 error = xfs_collapse_file_space(ip, offset, len);
966 if (error)
967 goto out_unlock;
968 } else if (mode & FALLOC_FL_INSERT_RANGE) {
969 loff_t isize = i_size_read(inode);
970
971 if (!xfs_is_falloc_aligned(ip, offset, len)) {
972 error = -EINVAL;
973 goto out_unlock;
974 }
975
976 /*
977 * New inode size must not exceed ->s_maxbytes, accounting for
978 * possible signed overflow.
979 */
980 if (inode->i_sb->s_maxbytes - isize < len) {
981 error = -EFBIG;
982 goto out_unlock;
983 }
984 new_size = isize + len;
985
986 /* Offset should be less than i_size */
987 if (offset >= isize) {
988 error = -EINVAL;
989 goto out_unlock;
990 }
991 do_file_insert = true;
992 } else {
993 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
994 offset + len > i_size_read(inode)) {
995 new_size = offset + len;
996 error = inode_newsize_ok(inode, new_size);
997 if (error)
998 goto out_unlock;
999 }
1000
1001 if (mode & FALLOC_FL_ZERO_RANGE) {
1002 /*
1003 * Punch a hole and prealloc the range. We use a hole
1004 * punch rather than unwritten extent conversion for two
1005 * reasons:
1006 *
1007 * 1.) Hole punch handles partial block zeroing for us.
1008 * 2.) If prealloc returns ENOSPC, the file range is
1009 * still zero-valued by virtue of the hole punch.
1010 */
1011 unsigned int blksize = i_blocksize(inode);
1012
1013 trace_xfs_zero_file_space(ip);
1014
1015 error = xfs_free_file_space(ip, offset, len);
1016 if (error)
1017 goto out_unlock;
1018
1019 len = round_up(offset + len, blksize) -
1020 round_down(offset, blksize);
1021 offset = round_down(offset, blksize);
1022 } else if (mode & FALLOC_FL_UNSHARE_RANGE) {
1023 error = xfs_reflink_unshare(ip, offset, len);
1024 if (error)
1025 goto out_unlock;
1026 } else {
1027 /*
1028 * If always_cow mode we can't use preallocations and
1029 * thus should not create them.
1030 */
1031 if (xfs_is_always_cow_inode(ip)) {
1032 error = -EOPNOTSUPP;
1033 goto out_unlock;
1034 }
1035 }
1036
1037 if (!xfs_is_always_cow_inode(ip)) {
1038 error = xfs_alloc_file_space(ip, offset, len);
1039 if (error)
1040 goto out_unlock;
1041 }
1042 }
1043
1044 /* Change file size if needed */
1045 if (new_size) {
1046 struct iattr iattr;
1047
1048 iattr.ia_valid = ATTR_SIZE;
1049 iattr.ia_size = new_size;
1050 error = xfs_vn_setattr_size(file_mnt_user_ns(file),
1051 file_dentry(file), &iattr);
1052 if (error)
1053 goto out_unlock;
1054 }
1055
1056 /*
1057 * Perform hole insertion now that the file size has been
1058 * updated so that if we crash during the operation we don't
1059 * leave shifted extents past EOF and hence losing access to
1060 * the data that is contained within them.
1061 */
1062 if (do_file_insert) {
1063 error = xfs_insert_file_space(ip, offset, len);
1064 if (error)
1065 goto out_unlock;
1066 }
1067
1068 if (xfs_file_sync_writes(file))
1069 error = xfs_log_force_inode(ip);
1070
1071out_unlock:
1072 xfs_iunlock(ip, iolock);
1073 return error;
1074}
1075
1076STATIC int
1077xfs_file_fadvise(
1078 struct file *file,
1079 loff_t start,
1080 loff_t end,
1081 int advice)
1082{
1083 struct xfs_inode *ip = XFS_I(file_inode(file));
1084 int ret;
1085 int lockflags = 0;
1086
1087 /*
1088 * Operations creating pages in page cache need protection from hole
1089 * punching and similar ops
1090 */
1091 if (advice == POSIX_FADV_WILLNEED) {
1092 lockflags = XFS_IOLOCK_SHARED;
1093 xfs_ilock(ip, lockflags);
1094 }
1095 ret = generic_fadvise(file, start, end, advice);
1096 if (lockflags)
1097 xfs_iunlock(ip, lockflags);
1098 return ret;
1099}
1100
1101STATIC loff_t
1102xfs_file_remap_range(
1103 struct file *file_in,
1104 loff_t pos_in,
1105 struct file *file_out,
1106 loff_t pos_out,
1107 loff_t len,
1108 unsigned int remap_flags)
1109{
1110 struct inode *inode_in = file_inode(file_in);
1111 struct xfs_inode *src = XFS_I(inode_in);
1112 struct inode *inode_out = file_inode(file_out);
1113 struct xfs_inode *dest = XFS_I(inode_out);
1114 struct xfs_mount *mp = src->i_mount;
1115 loff_t remapped = 0;
1116 xfs_extlen_t cowextsize;
1117 int ret;
1118
1119 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
1120 return -EINVAL;
1121
1122 if (!xfs_has_reflink(mp))
1123 return -EOPNOTSUPP;
1124
1125 if (xfs_is_shutdown(mp))
1126 return -EIO;
1127
1128 /* Prepare and then clone file data. */
1129 ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
1130 &len, remap_flags);
1131 if (ret || len == 0)
1132 return ret;
1133
1134 trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
1135
1136 ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
1137 &remapped);
1138 if (ret)
1139 goto out_unlock;
1140
1141 /*
1142 * Carry the cowextsize hint from src to dest if we're sharing the
1143 * entire source file to the entire destination file, the source file
1144 * has a cowextsize hint, and the destination file does not.
1145 */
1146 cowextsize = 0;
1147 if (pos_in == 0 && len == i_size_read(inode_in) &&
1148 (src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
1149 pos_out == 0 && len >= i_size_read(inode_out) &&
1150 !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE))
1151 cowextsize = src->i_cowextsize;
1152
1153 ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
1154 remap_flags);
1155 if (ret)
1156 goto out_unlock;
1157
1158 if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
1159 xfs_log_force_inode(dest);
1160out_unlock:
1161 xfs_iunlock2_io_mmap(src, dest);
1162 if (ret)
1163 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
1164 return remapped > 0 ? remapped : ret;
1165}
1166
1167STATIC int
1168xfs_file_open(
1169 struct inode *inode,
1170 struct file *file)
1171{
1172 if (xfs_is_shutdown(XFS_M(inode->i_sb)))
1173 return -EIO;
1174 file->f_mode |= FMODE_NOWAIT | FMODE_BUF_RASYNC | FMODE_BUF_WASYNC;
1175 return generic_file_open(inode, file);
1176}
1177
1178STATIC int
1179xfs_dir_open(
1180 struct inode *inode,
1181 struct file *file)
1182{
1183 struct xfs_inode *ip = XFS_I(inode);
1184 unsigned int mode;
1185 int error;
1186
1187 error = xfs_file_open(inode, file);
1188 if (error)
1189 return error;
1190
1191 /*
1192 * If there are any blocks, read-ahead block 0 as we're almost
1193 * certain to have the next operation be a read there.
1194 */
1195 mode = xfs_ilock_data_map_shared(ip);
1196 if (ip->i_df.if_nextents > 0)
1197 error = xfs_dir3_data_readahead(ip, 0, 0);
1198 xfs_iunlock(ip, mode);
1199 return error;
1200}
1201
1202STATIC int
1203xfs_file_release(
1204 struct inode *inode,
1205 struct file *filp)
1206{
1207 return xfs_release(XFS_I(inode));
1208}
1209
1210STATIC int
1211xfs_file_readdir(
1212 struct file *file,
1213 struct dir_context *ctx)
1214{
1215 struct inode *inode = file_inode(file);
1216 xfs_inode_t *ip = XFS_I(inode);
1217 size_t bufsize;
1218
1219 /*
1220 * The Linux API doesn't pass down the total size of the buffer
1221 * we read into down to the filesystem. With the filldir concept
1222 * it's not needed for correct information, but the XFS dir2 leaf
1223 * code wants an estimate of the buffer size to calculate it's
1224 * readahead window and size the buffers used for mapping to
1225 * physical blocks.
1226 *
1227 * Try to give it an estimate that's good enough, maybe at some
1228 * point we can change the ->readdir prototype to include the
1229 * buffer size. For now we use the current glibc buffer size.
1230 */
1231 bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_disk_size);
1232
1233 return xfs_readdir(NULL, ip, ctx, bufsize);
1234}
1235
1236STATIC loff_t
1237xfs_file_llseek(
1238 struct file *file,
1239 loff_t offset,
1240 int whence)
1241{
1242 struct inode *inode = file->f_mapping->host;
1243
1244 if (xfs_is_shutdown(XFS_I(inode)->i_mount))
1245 return -EIO;
1246
1247 switch (whence) {
1248 default:
1249 return generic_file_llseek(file, offset, whence);
1250 case SEEK_HOLE:
1251 offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
1252 break;
1253 case SEEK_DATA:
1254 offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
1255 break;
1256 }
1257
1258 if (offset < 0)
1259 return offset;
1260 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1261}
1262
1263#ifdef CONFIG_FS_DAX
1264static inline vm_fault_t
1265xfs_dax_fault(
1266 struct vm_fault *vmf,
1267 enum page_entry_size pe_size,
1268 bool write_fault,
1269 pfn_t *pfn)
1270{
1271 return dax_iomap_fault(vmf, pe_size, pfn, NULL,
1272 (write_fault && !vmf->cow_page) ?
1273 &xfs_dax_write_iomap_ops :
1274 &xfs_read_iomap_ops);
1275}
1276#else
1277static inline vm_fault_t
1278xfs_dax_fault(
1279 struct vm_fault *vmf,
1280 enum page_entry_size pe_size,
1281 bool write_fault,
1282 pfn_t *pfn)
1283{
1284 ASSERT(0);
1285 return VM_FAULT_SIGBUS;
1286}
1287#endif
1288
1289/*
1290 * Locking for serialisation of IO during page faults. This results in a lock
1291 * ordering of:
1292 *
1293 * mmap_lock (MM)
1294 * sb_start_pagefault(vfs, freeze)
1295 * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation)
1296 * page_lock (MM)
1297 * i_lock (XFS - extent map serialisation)
1298 */
1299static vm_fault_t
1300__xfs_filemap_fault(
1301 struct vm_fault *vmf,
1302 enum page_entry_size pe_size,
1303 bool write_fault)
1304{
1305 struct inode *inode = file_inode(vmf->vma->vm_file);
1306 struct xfs_inode *ip = XFS_I(inode);
1307 vm_fault_t ret;
1308
1309 trace_xfs_filemap_fault(ip, pe_size, write_fault);
1310
1311 if (write_fault) {
1312 sb_start_pagefault(inode->i_sb);
1313 file_update_time(vmf->vma->vm_file);
1314 }
1315
1316 if (IS_DAX(inode)) {
1317 pfn_t pfn;
1318
1319 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1320 ret = xfs_dax_fault(vmf, pe_size, write_fault, &pfn);
1321 if (ret & VM_FAULT_NEEDDSYNC)
1322 ret = dax_finish_sync_fault(vmf, pe_size, pfn);
1323 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1324 } else {
1325 if (write_fault) {
1326 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1327 ret = iomap_page_mkwrite(vmf,
1328 &xfs_page_mkwrite_iomap_ops);
1329 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1330 } else {
1331 ret = filemap_fault(vmf);
1332 }
1333 }
1334
1335 if (write_fault)
1336 sb_end_pagefault(inode->i_sb);
1337 return ret;
1338}
1339
1340static inline bool
1341xfs_is_write_fault(
1342 struct vm_fault *vmf)
1343{
1344 return (vmf->flags & FAULT_FLAG_WRITE) &&
1345 (vmf->vma->vm_flags & VM_SHARED);
1346}
1347
1348static vm_fault_t
1349xfs_filemap_fault(
1350 struct vm_fault *vmf)
1351{
1352 /* DAX can shortcut the normal fault path on write faults! */
1353 return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
1354 IS_DAX(file_inode(vmf->vma->vm_file)) &&
1355 xfs_is_write_fault(vmf));
1356}
1357
1358static vm_fault_t
1359xfs_filemap_huge_fault(
1360 struct vm_fault *vmf,
1361 enum page_entry_size pe_size)
1362{
1363 if (!IS_DAX(file_inode(vmf->vma->vm_file)))
1364 return VM_FAULT_FALLBACK;
1365
1366 /* DAX can shortcut the normal fault path on write faults! */
1367 return __xfs_filemap_fault(vmf, pe_size,
1368 xfs_is_write_fault(vmf));
1369}
1370
1371static vm_fault_t
1372xfs_filemap_page_mkwrite(
1373 struct vm_fault *vmf)
1374{
1375 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1376}
1377
1378/*
1379 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
1380 * on write faults. In reality, it needs to serialise against truncate and
1381 * prepare memory for writing so handle is as standard write fault.
1382 */
1383static vm_fault_t
1384xfs_filemap_pfn_mkwrite(
1385 struct vm_fault *vmf)
1386{
1387
1388 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1389}
1390
1391static vm_fault_t
1392xfs_filemap_map_pages(
1393 struct vm_fault *vmf,
1394 pgoff_t start_pgoff,
1395 pgoff_t end_pgoff)
1396{
1397 struct inode *inode = file_inode(vmf->vma->vm_file);
1398 vm_fault_t ret;
1399
1400 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1401 ret = filemap_map_pages(vmf, start_pgoff, end_pgoff);
1402 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1403 return ret;
1404}
1405
1406static const struct vm_operations_struct xfs_file_vm_ops = {
1407 .fault = xfs_filemap_fault,
1408 .huge_fault = xfs_filemap_huge_fault,
1409 .map_pages = xfs_filemap_map_pages,
1410 .page_mkwrite = xfs_filemap_page_mkwrite,
1411 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1412};
1413
1414STATIC int
1415xfs_file_mmap(
1416 struct file *file,
1417 struct vm_area_struct *vma)
1418{
1419 struct inode *inode = file_inode(file);
1420 struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode));
1421
1422 /*
1423 * We don't support synchronous mappings for non-DAX files and
1424 * for DAX files if underneath dax_device is not synchronous.
1425 */
1426 if (!daxdev_mapping_supported(vma, target->bt_daxdev))
1427 return -EOPNOTSUPP;
1428
1429 file_accessed(file);
1430 vma->vm_ops = &xfs_file_vm_ops;
1431 if (IS_DAX(inode))
1432 vma->vm_flags |= VM_HUGEPAGE;
1433 return 0;
1434}
1435
1436const struct file_operations xfs_file_operations = {
1437 .llseek = xfs_file_llseek,
1438 .read_iter = xfs_file_read_iter,
1439 .write_iter = xfs_file_write_iter,
1440 .splice_read = generic_file_splice_read,
1441 .splice_write = iter_file_splice_write,
1442 .iopoll = iocb_bio_iopoll,
1443 .unlocked_ioctl = xfs_file_ioctl,
1444#ifdef CONFIG_COMPAT
1445 .compat_ioctl = xfs_file_compat_ioctl,
1446#endif
1447 .mmap = xfs_file_mmap,
1448 .mmap_supported_flags = MAP_SYNC,
1449 .open = xfs_file_open,
1450 .release = xfs_file_release,
1451 .fsync = xfs_file_fsync,
1452 .get_unmapped_area = thp_get_unmapped_area,
1453 .fallocate = xfs_file_fallocate,
1454 .fadvise = xfs_file_fadvise,
1455 .remap_file_range = xfs_file_remap_range,
1456};
1457
1458const struct file_operations xfs_dir_file_operations = {
1459 .open = xfs_dir_open,
1460 .read = generic_read_dir,
1461 .iterate_shared = xfs_file_readdir,
1462 .llseek = generic_file_llseek,
1463 .unlocked_ioctl = xfs_file_ioctl,
1464#ifdef CONFIG_COMPAT
1465 .compat_ioctl = xfs_file_compat_ioctl,
1466#endif
1467 .fsync = xfs_dir_fsync,
1468};
1/*
2 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
3 * All Rights Reserved.
4 *
5 * This program is free software; you can redistribute it and/or
6 * modify it under the terms of the GNU General Public License as
7 * published by the Free Software Foundation.
8 *
9 * This program is distributed in the hope that it would be useful,
10 * but WITHOUT ANY WARRANTY; without even the implied warranty of
11 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 * GNU General Public License for more details.
13 *
14 * You should have received a copy of the GNU General Public License
15 * along with this program; if not, write the Free Software Foundation,
16 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17 */
18#include "xfs.h"
19#include "xfs_fs.h"
20#include "xfs_log.h"
21#include "xfs_sb.h"
22#include "xfs_ag.h"
23#include "xfs_trans.h"
24#include "xfs_mount.h"
25#include "xfs_bmap_btree.h"
26#include "xfs_alloc.h"
27#include "xfs_dinode.h"
28#include "xfs_inode.h"
29#include "xfs_inode_item.h"
30#include "xfs_bmap.h"
31#include "xfs_error.h"
32#include "xfs_vnodeops.h"
33#include "xfs_da_btree.h"
34#include "xfs_ioctl.h"
35#include "xfs_trace.h"
36
37#include <linux/dcache.h>
38#include <linux/falloc.h>
39
40static const struct vm_operations_struct xfs_file_vm_ops;
41
42/*
43 * Locking primitives for read and write IO paths to ensure we consistently use
44 * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
45 */
46static inline void
47xfs_rw_ilock(
48 struct xfs_inode *ip,
49 int type)
50{
51 if (type & XFS_IOLOCK_EXCL)
52 mutex_lock(&VFS_I(ip)->i_mutex);
53 xfs_ilock(ip, type);
54}
55
56static inline void
57xfs_rw_iunlock(
58 struct xfs_inode *ip,
59 int type)
60{
61 xfs_iunlock(ip, type);
62 if (type & XFS_IOLOCK_EXCL)
63 mutex_unlock(&VFS_I(ip)->i_mutex);
64}
65
66static inline void
67xfs_rw_ilock_demote(
68 struct xfs_inode *ip,
69 int type)
70{
71 xfs_ilock_demote(ip, type);
72 if (type & XFS_IOLOCK_EXCL)
73 mutex_unlock(&VFS_I(ip)->i_mutex);
74}
75
76/*
77 * xfs_iozero
78 *
79 * xfs_iozero clears the specified range of buffer supplied,
80 * and marks all the affected blocks as valid and modified. If
81 * an affected block is not allocated, it will be allocated. If
82 * an affected block is not completely overwritten, and is not
83 * valid before the operation, it will be read from disk before
84 * being partially zeroed.
85 */
86STATIC int
87xfs_iozero(
88 struct xfs_inode *ip, /* inode */
89 loff_t pos, /* offset in file */
90 size_t count) /* size of data to zero */
91{
92 struct page *page;
93 struct address_space *mapping;
94 int status;
95
96 mapping = VFS_I(ip)->i_mapping;
97 do {
98 unsigned offset, bytes;
99 void *fsdata;
100
101 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
102 bytes = PAGE_CACHE_SIZE - offset;
103 if (bytes > count)
104 bytes = count;
105
106 status = pagecache_write_begin(NULL, mapping, pos, bytes,
107 AOP_FLAG_UNINTERRUPTIBLE,
108 &page, &fsdata);
109 if (status)
110 break;
111
112 zero_user(page, offset, bytes);
113
114 status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
115 page, fsdata);
116 WARN_ON(status <= 0); /* can't return less than zero! */
117 pos += bytes;
118 count -= bytes;
119 status = 0;
120 } while (count);
121
122 return (-status);
123}
124
125/*
126 * Fsync operations on directories are much simpler than on regular files,
127 * as there is no file data to flush, and thus also no need for explicit
128 * cache flush operations, and there are no non-transaction metadata updates
129 * on directories either.
130 */
131STATIC int
132xfs_dir_fsync(
133 struct file *file,
134 loff_t start,
135 loff_t end,
136 int datasync)
137{
138 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
139 struct xfs_mount *mp = ip->i_mount;
140 xfs_lsn_t lsn = 0;
141
142 trace_xfs_dir_fsync(ip);
143
144 xfs_ilock(ip, XFS_ILOCK_SHARED);
145 if (xfs_ipincount(ip))
146 lsn = ip->i_itemp->ili_last_lsn;
147 xfs_iunlock(ip, XFS_ILOCK_SHARED);
148
149 if (!lsn)
150 return 0;
151 return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
152}
153
154STATIC int
155xfs_file_fsync(
156 struct file *file,
157 loff_t start,
158 loff_t end,
159 int datasync)
160{
161 struct inode *inode = file->f_mapping->host;
162 struct xfs_inode *ip = XFS_I(inode);
163 struct xfs_mount *mp = ip->i_mount;
164 int error = 0;
165 int log_flushed = 0;
166 xfs_lsn_t lsn = 0;
167
168 trace_xfs_file_fsync(ip);
169
170 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
171 if (error)
172 return error;
173
174 if (XFS_FORCED_SHUTDOWN(mp))
175 return -XFS_ERROR(EIO);
176
177 xfs_iflags_clear(ip, XFS_ITRUNCATED);
178
179 if (mp->m_flags & XFS_MOUNT_BARRIER) {
180 /*
181 * If we have an RT and/or log subvolume we need to make sure
182 * to flush the write cache the device used for file data
183 * first. This is to ensure newly written file data make
184 * it to disk before logging the new inode size in case of
185 * an extending write.
186 */
187 if (XFS_IS_REALTIME_INODE(ip))
188 xfs_blkdev_issue_flush(mp->m_rtdev_targp);
189 else if (mp->m_logdev_targp != mp->m_ddev_targp)
190 xfs_blkdev_issue_flush(mp->m_ddev_targp);
191 }
192
193 /*
194 * All metadata updates are logged, which means that we just have
195 * to flush the log up to the latest LSN that touched the inode.
196 */
197 xfs_ilock(ip, XFS_ILOCK_SHARED);
198 if (xfs_ipincount(ip)) {
199 if (!datasync ||
200 (ip->i_itemp->ili_fields & ~XFS_ILOG_TIMESTAMP))
201 lsn = ip->i_itemp->ili_last_lsn;
202 }
203 xfs_iunlock(ip, XFS_ILOCK_SHARED);
204
205 if (lsn)
206 error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
207
208 /*
209 * If we only have a single device, and the log force about was
210 * a no-op we might have to flush the data device cache here.
211 * This can only happen for fdatasync/O_DSYNC if we were overwriting
212 * an already allocated file and thus do not have any metadata to
213 * commit.
214 */
215 if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
216 mp->m_logdev_targp == mp->m_ddev_targp &&
217 !XFS_IS_REALTIME_INODE(ip) &&
218 !log_flushed)
219 xfs_blkdev_issue_flush(mp->m_ddev_targp);
220
221 return -error;
222}
223
224STATIC ssize_t
225xfs_file_aio_read(
226 struct kiocb *iocb,
227 const struct iovec *iovp,
228 unsigned long nr_segs,
229 loff_t pos)
230{
231 struct file *file = iocb->ki_filp;
232 struct inode *inode = file->f_mapping->host;
233 struct xfs_inode *ip = XFS_I(inode);
234 struct xfs_mount *mp = ip->i_mount;
235 size_t size = 0;
236 ssize_t ret = 0;
237 int ioflags = 0;
238 xfs_fsize_t n;
239 unsigned long seg;
240
241 XFS_STATS_INC(xs_read_calls);
242
243 BUG_ON(iocb->ki_pos != pos);
244
245 if (unlikely(file->f_flags & O_DIRECT))
246 ioflags |= IO_ISDIRECT;
247 if (file->f_mode & FMODE_NOCMTIME)
248 ioflags |= IO_INVIS;
249
250 /* START copy & waste from filemap.c */
251 for (seg = 0; seg < nr_segs; seg++) {
252 const struct iovec *iv = &iovp[seg];
253
254 /*
255 * If any segment has a negative length, or the cumulative
256 * length ever wraps negative then return -EINVAL.
257 */
258 size += iv->iov_len;
259 if (unlikely((ssize_t)(size|iv->iov_len) < 0))
260 return XFS_ERROR(-EINVAL);
261 }
262 /* END copy & waste from filemap.c */
263
264 if (unlikely(ioflags & IO_ISDIRECT)) {
265 xfs_buftarg_t *target =
266 XFS_IS_REALTIME_INODE(ip) ?
267 mp->m_rtdev_targp : mp->m_ddev_targp;
268 if ((iocb->ki_pos & target->bt_smask) ||
269 (size & target->bt_smask)) {
270 if (iocb->ki_pos == i_size_read(inode))
271 return 0;
272 return -XFS_ERROR(EINVAL);
273 }
274 }
275
276 n = XFS_MAXIOFFSET(mp) - iocb->ki_pos;
277 if (n <= 0 || size == 0)
278 return 0;
279
280 if (n < size)
281 size = n;
282
283 if (XFS_FORCED_SHUTDOWN(mp))
284 return -EIO;
285
286 /*
287 * Locking is a bit tricky here. If we take an exclusive lock
288 * for direct IO, we effectively serialise all new concurrent
289 * read IO to this file and block it behind IO that is currently in
290 * progress because IO in progress holds the IO lock shared. We only
291 * need to hold the lock exclusive to blow away the page cache, so
292 * only take lock exclusively if the page cache needs invalidation.
293 * This allows the normal direct IO case of no page cache pages to
294 * proceeed concurrently without serialisation.
295 */
296 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
297 if ((ioflags & IO_ISDIRECT) && inode->i_mapping->nrpages) {
298 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
299 xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
300
301 if (inode->i_mapping->nrpages) {
302 ret = -xfs_flushinval_pages(ip,
303 (iocb->ki_pos & PAGE_CACHE_MASK),
304 -1, FI_REMAPF_LOCKED);
305 if (ret) {
306 xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
307 return ret;
308 }
309 }
310 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
311 }
312
313 trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
314
315 ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos);
316 if (ret > 0)
317 XFS_STATS_ADD(xs_read_bytes, ret);
318
319 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
320 return ret;
321}
322
323STATIC ssize_t
324xfs_file_splice_read(
325 struct file *infilp,
326 loff_t *ppos,
327 struct pipe_inode_info *pipe,
328 size_t count,
329 unsigned int flags)
330{
331 struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
332 int ioflags = 0;
333 ssize_t ret;
334
335 XFS_STATS_INC(xs_read_calls);
336
337 if (infilp->f_mode & FMODE_NOCMTIME)
338 ioflags |= IO_INVIS;
339
340 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
341 return -EIO;
342
343 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
344
345 trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
346
347 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
348 if (ret > 0)
349 XFS_STATS_ADD(xs_read_bytes, ret);
350
351 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
352 return ret;
353}
354
355/*
356 * xfs_file_splice_write() does not use xfs_rw_ilock() because
357 * generic_file_splice_write() takes the i_mutex itself. This, in theory,
358 * couuld cause lock inversions between the aio_write path and the splice path
359 * if someone is doing concurrent splice(2) based writes and write(2) based
360 * writes to the same inode. The only real way to fix this is to re-implement
361 * the generic code here with correct locking orders.
362 */
363STATIC ssize_t
364xfs_file_splice_write(
365 struct pipe_inode_info *pipe,
366 struct file *outfilp,
367 loff_t *ppos,
368 size_t count,
369 unsigned int flags)
370{
371 struct inode *inode = outfilp->f_mapping->host;
372 struct xfs_inode *ip = XFS_I(inode);
373 int ioflags = 0;
374 ssize_t ret;
375
376 XFS_STATS_INC(xs_write_calls);
377
378 if (outfilp->f_mode & FMODE_NOCMTIME)
379 ioflags |= IO_INVIS;
380
381 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
382 return -EIO;
383
384 xfs_ilock(ip, XFS_IOLOCK_EXCL);
385
386 trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
387
388 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
389 if (ret > 0)
390 XFS_STATS_ADD(xs_write_bytes, ret);
391
392 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
393 return ret;
394}
395
396/*
397 * This routine is called to handle zeroing any space in the last block of the
398 * file that is beyond the EOF. We do this since the size is being increased
399 * without writing anything to that block and we don't want to read the
400 * garbage on the disk.
401 */
402STATIC int /* error (positive) */
403xfs_zero_last_block(
404 struct xfs_inode *ip,
405 xfs_fsize_t offset,
406 xfs_fsize_t isize)
407{
408 struct xfs_mount *mp = ip->i_mount;
409 xfs_fileoff_t last_fsb = XFS_B_TO_FSBT(mp, isize);
410 int zero_offset = XFS_B_FSB_OFFSET(mp, isize);
411 int zero_len;
412 int nimaps = 1;
413 int error = 0;
414 struct xfs_bmbt_irec imap;
415
416 xfs_ilock(ip, XFS_ILOCK_EXCL);
417 error = xfs_bmapi_read(ip, last_fsb, 1, &imap, &nimaps, 0);
418 xfs_iunlock(ip, XFS_ILOCK_EXCL);
419 if (error)
420 return error;
421
422 ASSERT(nimaps > 0);
423
424 /*
425 * If the block underlying isize is just a hole, then there
426 * is nothing to zero.
427 */
428 if (imap.br_startblock == HOLESTARTBLOCK)
429 return 0;
430
431 zero_len = mp->m_sb.sb_blocksize - zero_offset;
432 if (isize + zero_len > offset)
433 zero_len = offset - isize;
434 return xfs_iozero(ip, isize, zero_len);
435}
436
437/*
438 * Zero any on disk space between the current EOF and the new, larger EOF.
439 *
440 * This handles the normal case of zeroing the remainder of the last block in
441 * the file and the unusual case of zeroing blocks out beyond the size of the
442 * file. This second case only happens with fixed size extents and when the
443 * system crashes before the inode size was updated but after blocks were
444 * allocated.
445 *
446 * Expects the iolock to be held exclusive, and will take the ilock internally.
447 */
448int /* error (positive) */
449xfs_zero_eof(
450 struct xfs_inode *ip,
451 xfs_off_t offset, /* starting I/O offset */
452 xfs_fsize_t isize) /* current inode size */
453{
454 struct xfs_mount *mp = ip->i_mount;
455 xfs_fileoff_t start_zero_fsb;
456 xfs_fileoff_t end_zero_fsb;
457 xfs_fileoff_t zero_count_fsb;
458 xfs_fileoff_t last_fsb;
459 xfs_fileoff_t zero_off;
460 xfs_fsize_t zero_len;
461 int nimaps;
462 int error = 0;
463 struct xfs_bmbt_irec imap;
464
465 ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
466 ASSERT(offset > isize);
467
468 /*
469 * First handle zeroing the block on which isize resides.
470 *
471 * We only zero a part of that block so it is handled specially.
472 */
473 if (XFS_B_FSB_OFFSET(mp, isize) != 0) {
474 error = xfs_zero_last_block(ip, offset, isize);
475 if (error)
476 return error;
477 }
478
479 /*
480 * Calculate the range between the new size and the old where blocks
481 * needing to be zeroed may exist.
482 *
483 * To get the block where the last byte in the file currently resides,
484 * we need to subtract one from the size and truncate back to a block
485 * boundary. We subtract 1 in case the size is exactly on a block
486 * boundary.
487 */
488 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
489 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
490 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
491 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
492 if (last_fsb == end_zero_fsb) {
493 /*
494 * The size was only incremented on its last block.
495 * We took care of that above, so just return.
496 */
497 return 0;
498 }
499
500 ASSERT(start_zero_fsb <= end_zero_fsb);
501 while (start_zero_fsb <= end_zero_fsb) {
502 nimaps = 1;
503 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
504
505 xfs_ilock(ip, XFS_ILOCK_EXCL);
506 error = xfs_bmapi_read(ip, start_zero_fsb, zero_count_fsb,
507 &imap, &nimaps, 0);
508 xfs_iunlock(ip, XFS_ILOCK_EXCL);
509 if (error)
510 return error;
511
512 ASSERT(nimaps > 0);
513
514 if (imap.br_state == XFS_EXT_UNWRITTEN ||
515 imap.br_startblock == HOLESTARTBLOCK) {
516 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
517 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
518 continue;
519 }
520
521 /*
522 * There are blocks we need to zero.
523 */
524 zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
525 zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
526
527 if ((zero_off + zero_len) > offset)
528 zero_len = offset - zero_off;
529
530 error = xfs_iozero(ip, zero_off, zero_len);
531 if (error)
532 return error;
533
534 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
535 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
536 }
537
538 return 0;
539}
540
541/*
542 * Common pre-write limit and setup checks.
543 *
544 * Called with the iolocked held either shared and exclusive according to
545 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
546 * if called for a direct write beyond i_size.
547 */
548STATIC ssize_t
549xfs_file_aio_write_checks(
550 struct file *file,
551 loff_t *pos,
552 size_t *count,
553 int *iolock)
554{
555 struct inode *inode = file->f_mapping->host;
556 struct xfs_inode *ip = XFS_I(inode);
557 int error = 0;
558
559restart:
560 error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
561 if (error)
562 return error;
563
564 /*
565 * If the offset is beyond the size of the file, we need to zero any
566 * blocks that fall between the existing EOF and the start of this
567 * write. If zeroing is needed and we are currently holding the
568 * iolock shared, we need to update it to exclusive which implies
569 * having to redo all checks before.
570 */
571 if (*pos > i_size_read(inode)) {
572 if (*iolock == XFS_IOLOCK_SHARED) {
573 xfs_rw_iunlock(ip, *iolock);
574 *iolock = XFS_IOLOCK_EXCL;
575 xfs_rw_ilock(ip, *iolock);
576 goto restart;
577 }
578 error = -xfs_zero_eof(ip, *pos, i_size_read(inode));
579 if (error)
580 return error;
581 }
582
583 /*
584 * Updating the timestamps will grab the ilock again from
585 * xfs_fs_dirty_inode, so we have to call it after dropping the
586 * lock above. Eventually we should look into a way to avoid
587 * the pointless lock roundtrip.
588 */
589 if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
590 error = file_update_time(file);
591 if (error)
592 return error;
593 }
594
595 /*
596 * If we're writing the file then make sure to clear the setuid and
597 * setgid bits if the process is not being run by root. This keeps
598 * people from modifying setuid and setgid binaries.
599 */
600 return file_remove_suid(file);
601}
602
603/*
604 * xfs_file_dio_aio_write - handle direct IO writes
605 *
606 * Lock the inode appropriately to prepare for and issue a direct IO write.
607 * By separating it from the buffered write path we remove all the tricky to
608 * follow locking changes and looping.
609 *
610 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
611 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
612 * pages are flushed out.
613 *
614 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
615 * allowing them to be done in parallel with reads and other direct IO writes.
616 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
617 * needs to do sub-block zeroing and that requires serialisation against other
618 * direct IOs to the same block. In this case we need to serialise the
619 * submission of the unaligned IOs so that we don't get racing block zeroing in
620 * the dio layer. To avoid the problem with aio, we also need to wait for
621 * outstanding IOs to complete so that unwritten extent conversion is completed
622 * before we try to map the overlapping block. This is currently implemented by
623 * hitting it with a big hammer (i.e. inode_dio_wait()).
624 *
625 * Returns with locks held indicated by @iolock and errors indicated by
626 * negative return values.
627 */
628STATIC ssize_t
629xfs_file_dio_aio_write(
630 struct kiocb *iocb,
631 const struct iovec *iovp,
632 unsigned long nr_segs,
633 loff_t pos,
634 size_t ocount)
635{
636 struct file *file = iocb->ki_filp;
637 struct address_space *mapping = file->f_mapping;
638 struct inode *inode = mapping->host;
639 struct xfs_inode *ip = XFS_I(inode);
640 struct xfs_mount *mp = ip->i_mount;
641 ssize_t ret = 0;
642 size_t count = ocount;
643 int unaligned_io = 0;
644 int iolock;
645 struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
646 mp->m_rtdev_targp : mp->m_ddev_targp;
647
648 if ((pos & target->bt_smask) || (count & target->bt_smask))
649 return -XFS_ERROR(EINVAL);
650
651 if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
652 unaligned_io = 1;
653
654 /*
655 * We don't need to take an exclusive lock unless there page cache needs
656 * to be invalidated or unaligned IO is being executed. We don't need to
657 * consider the EOF extension case here because
658 * xfs_file_aio_write_checks() will relock the inode as necessary for
659 * EOF zeroing cases and fill out the new inode size as appropriate.
660 */
661 if (unaligned_io || mapping->nrpages)
662 iolock = XFS_IOLOCK_EXCL;
663 else
664 iolock = XFS_IOLOCK_SHARED;
665 xfs_rw_ilock(ip, iolock);
666
667 /*
668 * Recheck if there are cached pages that need invalidate after we got
669 * the iolock to protect against other threads adding new pages while
670 * we were waiting for the iolock.
671 */
672 if (mapping->nrpages && iolock == XFS_IOLOCK_SHARED) {
673 xfs_rw_iunlock(ip, iolock);
674 iolock = XFS_IOLOCK_EXCL;
675 xfs_rw_ilock(ip, iolock);
676 }
677
678 ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
679 if (ret)
680 goto out;
681
682 if (mapping->nrpages) {
683 ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
684 FI_REMAPF_LOCKED);
685 if (ret)
686 goto out;
687 }
688
689 /*
690 * If we are doing unaligned IO, wait for all other IO to drain,
691 * otherwise demote the lock if we had to flush cached pages
692 */
693 if (unaligned_io)
694 inode_dio_wait(inode);
695 else if (iolock == XFS_IOLOCK_EXCL) {
696 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
697 iolock = XFS_IOLOCK_SHARED;
698 }
699
700 trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
701 ret = generic_file_direct_write(iocb, iovp,
702 &nr_segs, pos, &iocb->ki_pos, count, ocount);
703
704out:
705 xfs_rw_iunlock(ip, iolock);
706
707 /* No fallback to buffered IO on errors for XFS. */
708 ASSERT(ret < 0 || ret == count);
709 return ret;
710}
711
712STATIC ssize_t
713xfs_file_buffered_aio_write(
714 struct kiocb *iocb,
715 const struct iovec *iovp,
716 unsigned long nr_segs,
717 loff_t pos,
718 size_t ocount)
719{
720 struct file *file = iocb->ki_filp;
721 struct address_space *mapping = file->f_mapping;
722 struct inode *inode = mapping->host;
723 struct xfs_inode *ip = XFS_I(inode);
724 ssize_t ret;
725 int enospc = 0;
726 int iolock = XFS_IOLOCK_EXCL;
727 size_t count = ocount;
728
729 xfs_rw_ilock(ip, iolock);
730
731 ret = xfs_file_aio_write_checks(file, &pos, &count, &iolock);
732 if (ret)
733 goto out;
734
735 /* We can write back this queue in page reclaim */
736 current->backing_dev_info = mapping->backing_dev_info;
737
738write_retry:
739 trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
740 ret = generic_file_buffered_write(iocb, iovp, nr_segs,
741 pos, &iocb->ki_pos, count, ret);
742 /*
743 * if we just got an ENOSPC, flush the inode now we aren't holding any
744 * page locks and retry *once*
745 */
746 if (ret == -ENOSPC && !enospc) {
747 enospc = 1;
748 ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
749 if (!ret)
750 goto write_retry;
751 }
752
753 current->backing_dev_info = NULL;
754out:
755 xfs_rw_iunlock(ip, iolock);
756 return ret;
757}
758
759STATIC ssize_t
760xfs_file_aio_write(
761 struct kiocb *iocb,
762 const struct iovec *iovp,
763 unsigned long nr_segs,
764 loff_t pos)
765{
766 struct file *file = iocb->ki_filp;
767 struct address_space *mapping = file->f_mapping;
768 struct inode *inode = mapping->host;
769 struct xfs_inode *ip = XFS_I(inode);
770 ssize_t ret;
771 size_t ocount = 0;
772
773 XFS_STATS_INC(xs_write_calls);
774
775 BUG_ON(iocb->ki_pos != pos);
776
777 ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
778 if (ret)
779 return ret;
780
781 if (ocount == 0)
782 return 0;
783
784 xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
785
786 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
787 return -EIO;
788
789 if (unlikely(file->f_flags & O_DIRECT))
790 ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos, ocount);
791 else
792 ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
793 ocount);
794
795 if (ret > 0) {
796 ssize_t err;
797
798 XFS_STATS_ADD(xs_write_bytes, ret);
799
800 /* Handle various SYNC-type writes */
801 err = generic_write_sync(file, pos, ret);
802 if (err < 0)
803 ret = err;
804 }
805
806 return ret;
807}
808
809STATIC long
810xfs_file_fallocate(
811 struct file *file,
812 int mode,
813 loff_t offset,
814 loff_t len)
815{
816 struct inode *inode = file->f_path.dentry->d_inode;
817 long error;
818 loff_t new_size = 0;
819 xfs_flock64_t bf;
820 xfs_inode_t *ip = XFS_I(inode);
821 int cmd = XFS_IOC_RESVSP;
822 int attr_flags = XFS_ATTR_NOLOCK;
823
824 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
825 return -EOPNOTSUPP;
826
827 bf.l_whence = 0;
828 bf.l_start = offset;
829 bf.l_len = len;
830
831 xfs_ilock(ip, XFS_IOLOCK_EXCL);
832
833 if (mode & FALLOC_FL_PUNCH_HOLE)
834 cmd = XFS_IOC_UNRESVSP;
835
836 /* check the new inode size is valid before allocating */
837 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
838 offset + len > i_size_read(inode)) {
839 new_size = offset + len;
840 error = inode_newsize_ok(inode, new_size);
841 if (error)
842 goto out_unlock;
843 }
844
845 if (file->f_flags & O_DSYNC)
846 attr_flags |= XFS_ATTR_SYNC;
847
848 error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags);
849 if (error)
850 goto out_unlock;
851
852 /* Change file size if needed */
853 if (new_size) {
854 struct iattr iattr;
855
856 iattr.ia_valid = ATTR_SIZE;
857 iattr.ia_size = new_size;
858 error = -xfs_setattr_size(ip, &iattr, XFS_ATTR_NOLOCK);
859 }
860
861out_unlock:
862 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
863 return error;
864}
865
866
867STATIC int
868xfs_file_open(
869 struct inode *inode,
870 struct file *file)
871{
872 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
873 return -EFBIG;
874 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
875 return -EIO;
876 return 0;
877}
878
879STATIC int
880xfs_dir_open(
881 struct inode *inode,
882 struct file *file)
883{
884 struct xfs_inode *ip = XFS_I(inode);
885 int mode;
886 int error;
887
888 error = xfs_file_open(inode, file);
889 if (error)
890 return error;
891
892 /*
893 * If there are any blocks, read-ahead block 0 as we're almost
894 * certain to have the next operation be a read there.
895 */
896 mode = xfs_ilock_map_shared(ip);
897 if (ip->i_d.di_nextents > 0)
898 xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
899 xfs_iunlock(ip, mode);
900 return 0;
901}
902
903STATIC int
904xfs_file_release(
905 struct inode *inode,
906 struct file *filp)
907{
908 return -xfs_release(XFS_I(inode));
909}
910
911STATIC int
912xfs_file_readdir(
913 struct file *filp,
914 void *dirent,
915 filldir_t filldir)
916{
917 struct inode *inode = filp->f_path.dentry->d_inode;
918 xfs_inode_t *ip = XFS_I(inode);
919 int error;
920 size_t bufsize;
921
922 /*
923 * The Linux API doesn't pass down the total size of the buffer
924 * we read into down to the filesystem. With the filldir concept
925 * it's not needed for correct information, but the XFS dir2 leaf
926 * code wants an estimate of the buffer size to calculate it's
927 * readahead window and size the buffers used for mapping to
928 * physical blocks.
929 *
930 * Try to give it an estimate that's good enough, maybe at some
931 * point we can change the ->readdir prototype to include the
932 * buffer size. For now we use the current glibc buffer size.
933 */
934 bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
935
936 error = xfs_readdir(ip, dirent, bufsize,
937 (xfs_off_t *)&filp->f_pos, filldir);
938 if (error)
939 return -error;
940 return 0;
941}
942
943STATIC int
944xfs_file_mmap(
945 struct file *filp,
946 struct vm_area_struct *vma)
947{
948 vma->vm_ops = &xfs_file_vm_ops;
949 vma->vm_flags |= VM_CAN_NONLINEAR;
950
951 file_accessed(filp);
952 return 0;
953}
954
955/*
956 * mmap()d file has taken write protection fault and is being made
957 * writable. We can set the page state up correctly for a writable
958 * page, which means we can do correct delalloc accounting (ENOSPC
959 * checking!) and unwritten extent mapping.
960 */
961STATIC int
962xfs_vm_page_mkwrite(
963 struct vm_area_struct *vma,
964 struct vm_fault *vmf)
965{
966 return block_page_mkwrite(vma, vmf, xfs_get_blocks);
967}
968
969STATIC loff_t
970xfs_seek_data(
971 struct file *file,
972 loff_t start,
973 u32 type)
974{
975 struct inode *inode = file->f_mapping->host;
976 struct xfs_inode *ip = XFS_I(inode);
977 struct xfs_mount *mp = ip->i_mount;
978 struct xfs_bmbt_irec map[2];
979 int nmap = 2;
980 loff_t uninitialized_var(offset);
981 xfs_fsize_t isize;
982 xfs_fileoff_t fsbno;
983 xfs_filblks_t end;
984 uint lock;
985 int error;
986
987 lock = xfs_ilock_map_shared(ip);
988
989 isize = i_size_read(inode);
990 if (start >= isize) {
991 error = ENXIO;
992 goto out_unlock;
993 }
994
995 fsbno = XFS_B_TO_FSBT(mp, start);
996
997 /*
998 * Try to read extents from the first block indicated
999 * by fsbno to the end block of the file.
1000 */
1001 end = XFS_B_TO_FSB(mp, isize);
1002
1003 error = xfs_bmapi_read(ip, fsbno, end - fsbno, map, &nmap,
1004 XFS_BMAPI_ENTIRE);
1005 if (error)
1006 goto out_unlock;
1007
1008 /*
1009 * Treat unwritten extent as data extent since it might
1010 * contains dirty data in page cache.
1011 */
1012 if (map[0].br_startblock != HOLESTARTBLOCK) {
1013 offset = max_t(loff_t, start,
1014 XFS_FSB_TO_B(mp, map[0].br_startoff));
1015 } else {
1016 if (nmap == 1) {
1017 error = ENXIO;
1018 goto out_unlock;
1019 }
1020
1021 offset = max_t(loff_t, start,
1022 XFS_FSB_TO_B(mp, map[1].br_startoff));
1023 }
1024
1025 if (offset != file->f_pos)
1026 file->f_pos = offset;
1027
1028out_unlock:
1029 xfs_iunlock_map_shared(ip, lock);
1030
1031 if (error)
1032 return -error;
1033 return offset;
1034}
1035
1036STATIC loff_t
1037xfs_seek_hole(
1038 struct file *file,
1039 loff_t start,
1040 u32 type)
1041{
1042 struct inode *inode = file->f_mapping->host;
1043 struct xfs_inode *ip = XFS_I(inode);
1044 struct xfs_mount *mp = ip->i_mount;
1045 loff_t uninitialized_var(offset);
1046 loff_t holeoff;
1047 xfs_fsize_t isize;
1048 xfs_fileoff_t fsbno;
1049 uint lock;
1050 int error;
1051
1052 if (XFS_FORCED_SHUTDOWN(mp))
1053 return -XFS_ERROR(EIO);
1054
1055 lock = xfs_ilock_map_shared(ip);
1056
1057 isize = i_size_read(inode);
1058 if (start >= isize) {
1059 error = ENXIO;
1060 goto out_unlock;
1061 }
1062
1063 fsbno = XFS_B_TO_FSBT(mp, start);
1064 error = xfs_bmap_first_unused(NULL, ip, 1, &fsbno, XFS_DATA_FORK);
1065 if (error)
1066 goto out_unlock;
1067
1068 holeoff = XFS_FSB_TO_B(mp, fsbno);
1069 if (holeoff <= start)
1070 offset = start;
1071 else {
1072 /*
1073 * xfs_bmap_first_unused() could return a value bigger than
1074 * isize if there are no more holes past the supplied offset.
1075 */
1076 offset = min_t(loff_t, holeoff, isize);
1077 }
1078
1079 if (offset != file->f_pos)
1080 file->f_pos = offset;
1081
1082out_unlock:
1083 xfs_iunlock_map_shared(ip, lock);
1084
1085 if (error)
1086 return -error;
1087 return offset;
1088}
1089
1090STATIC loff_t
1091xfs_file_llseek(
1092 struct file *file,
1093 loff_t offset,
1094 int origin)
1095{
1096 switch (origin) {
1097 case SEEK_END:
1098 case SEEK_CUR:
1099 case SEEK_SET:
1100 return generic_file_llseek(file, offset, origin);
1101 case SEEK_DATA:
1102 return xfs_seek_data(file, offset, origin);
1103 case SEEK_HOLE:
1104 return xfs_seek_hole(file, offset, origin);
1105 default:
1106 return -EINVAL;
1107 }
1108}
1109
1110const struct file_operations xfs_file_operations = {
1111 .llseek = xfs_file_llseek,
1112 .read = do_sync_read,
1113 .write = do_sync_write,
1114 .aio_read = xfs_file_aio_read,
1115 .aio_write = xfs_file_aio_write,
1116 .splice_read = xfs_file_splice_read,
1117 .splice_write = xfs_file_splice_write,
1118 .unlocked_ioctl = xfs_file_ioctl,
1119#ifdef CONFIG_COMPAT
1120 .compat_ioctl = xfs_file_compat_ioctl,
1121#endif
1122 .mmap = xfs_file_mmap,
1123 .open = xfs_file_open,
1124 .release = xfs_file_release,
1125 .fsync = xfs_file_fsync,
1126 .fallocate = xfs_file_fallocate,
1127};
1128
1129const struct file_operations xfs_dir_file_operations = {
1130 .open = xfs_dir_open,
1131 .read = generic_read_dir,
1132 .readdir = xfs_file_readdir,
1133 .llseek = generic_file_llseek,
1134 .unlocked_ioctl = xfs_file_ioctl,
1135#ifdef CONFIG_COMPAT
1136 .compat_ioctl = xfs_file_compat_ioctl,
1137#endif
1138 .fsync = xfs_dir_fsync,
1139};
1140
1141static const struct vm_operations_struct xfs_file_vm_ops = {
1142 .fault = filemap_fault,
1143 .page_mkwrite = xfs_vm_page_mkwrite,
1144};