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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_shared.h"
21#include "xfs_format.h"
22#include "xfs_log_format.h"
23#include "xfs_trans_resv.h"
24#include "xfs_mount.h"
25#include "xfs_da_format.h"
26#include "xfs_da_btree.h"
27#include "xfs_inode.h"
28#include "xfs_trans.h"
29#include "xfs_inode_item.h"
30#include "xfs_bmap.h"
31#include "xfs_bmap_util.h"
32#include "xfs_error.h"
33#include "xfs_dir2.h"
34#include "xfs_dir2_priv.h"
35#include "xfs_ioctl.h"
36#include "xfs_trace.h"
37#include "xfs_log.h"
38#include "xfs_icache.h"
39#include "xfs_pnfs.h"
40#include "xfs_iomap.h"
41#include "xfs_reflink.h"
42
43#include <linux/dcache.h>
44#include <linux/falloc.h>
45#include <linux/pagevec.h>
46#include <linux/backing-dev.h>
47
48static const struct vm_operations_struct xfs_file_vm_ops;
49
50/*
51 * Clear the specified ranges to zero through either the pagecache or DAX.
52 * Holes and unwritten extents will be left as-is as they already are zeroed.
53 */
54int
55xfs_zero_range(
56 struct xfs_inode *ip,
57 xfs_off_t pos,
58 xfs_off_t count,
59 bool *did_zero)
60{
61 return iomap_zero_range(VFS_I(ip), pos, count, NULL, &xfs_iomap_ops);
62}
63
64int
65xfs_update_prealloc_flags(
66 struct xfs_inode *ip,
67 enum xfs_prealloc_flags flags)
68{
69 struct xfs_trans *tp;
70 int error;
71
72 error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
73 0, 0, 0, &tp);
74 if (error)
75 return error;
76
77 xfs_ilock(ip, XFS_ILOCK_EXCL);
78 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
79
80 if (!(flags & XFS_PREALLOC_INVISIBLE)) {
81 VFS_I(ip)->i_mode &= ~S_ISUID;
82 if (VFS_I(ip)->i_mode & S_IXGRP)
83 VFS_I(ip)->i_mode &= ~S_ISGID;
84 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
85 }
86
87 if (flags & XFS_PREALLOC_SET)
88 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
89 if (flags & XFS_PREALLOC_CLEAR)
90 ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
91
92 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
93 if (flags & XFS_PREALLOC_SYNC)
94 xfs_trans_set_sync(tp);
95 return xfs_trans_commit(tp);
96}
97
98/*
99 * Fsync operations on directories are much simpler than on regular files,
100 * as there is no file data to flush, and thus also no need for explicit
101 * cache flush operations, and there are no non-transaction metadata updates
102 * on directories either.
103 */
104STATIC int
105xfs_dir_fsync(
106 struct file *file,
107 loff_t start,
108 loff_t end,
109 int datasync)
110{
111 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
112 struct xfs_mount *mp = ip->i_mount;
113 xfs_lsn_t lsn = 0;
114
115 trace_xfs_dir_fsync(ip);
116
117 xfs_ilock(ip, XFS_ILOCK_SHARED);
118 if (xfs_ipincount(ip))
119 lsn = ip->i_itemp->ili_last_lsn;
120 xfs_iunlock(ip, XFS_ILOCK_SHARED);
121
122 if (!lsn)
123 return 0;
124 return _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
125}
126
127STATIC int
128xfs_file_fsync(
129 struct file *file,
130 loff_t start,
131 loff_t end,
132 int datasync)
133{
134 struct inode *inode = file->f_mapping->host;
135 struct xfs_inode *ip = XFS_I(inode);
136 struct xfs_mount *mp = ip->i_mount;
137 int error = 0;
138 int log_flushed = 0;
139 xfs_lsn_t lsn = 0;
140
141 trace_xfs_file_fsync(ip);
142
143 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
144 if (error)
145 return error;
146
147 if (XFS_FORCED_SHUTDOWN(mp))
148 return -EIO;
149
150 xfs_iflags_clear(ip, XFS_ITRUNCATED);
151
152 /*
153 * If we have an RT and/or log subvolume we need to make sure to flush
154 * the write cache the device used for file data first. This is to
155 * ensure newly written file data make it to disk before logging the new
156 * inode size in case of an extending write.
157 */
158 if (XFS_IS_REALTIME_INODE(ip))
159 xfs_blkdev_issue_flush(mp->m_rtdev_targp);
160 else if (mp->m_logdev_targp != mp->m_ddev_targp)
161 xfs_blkdev_issue_flush(mp->m_ddev_targp);
162
163 /*
164 * All metadata updates are logged, which means that we just have to
165 * flush the log up to the latest LSN that touched the inode. If we have
166 * concurrent fsync/fdatasync() calls, we need them to all block on the
167 * log force before we clear the ili_fsync_fields field. This ensures
168 * that we don't get a racing sync operation that does not wait for the
169 * metadata to hit the journal before returning. If we race with
170 * clearing the ili_fsync_fields, then all that will happen is the log
171 * force will do nothing as the lsn will already be on disk. We can't
172 * race with setting ili_fsync_fields because that is done under
173 * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared
174 * until after the ili_fsync_fields is cleared.
175 */
176 xfs_ilock(ip, XFS_ILOCK_SHARED);
177 if (xfs_ipincount(ip)) {
178 if (!datasync ||
179 (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
180 lsn = ip->i_itemp->ili_last_lsn;
181 }
182
183 if (lsn) {
184 error = _xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
185 ip->i_itemp->ili_fsync_fields = 0;
186 }
187 xfs_iunlock(ip, XFS_ILOCK_SHARED);
188
189 /*
190 * If we only have a single device, and the log force about was
191 * a no-op we might have to flush the data device cache here.
192 * This can only happen for fdatasync/O_DSYNC if we were overwriting
193 * an already allocated file and thus do not have any metadata to
194 * commit.
195 */
196 if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
197 mp->m_logdev_targp == mp->m_ddev_targp)
198 xfs_blkdev_issue_flush(mp->m_ddev_targp);
199
200 return error;
201}
202
203STATIC ssize_t
204xfs_file_dio_aio_read(
205 struct kiocb *iocb,
206 struct iov_iter *to)
207{
208 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
209 size_t count = iov_iter_count(to);
210 ssize_t ret;
211
212 trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
213
214 if (!count)
215 return 0; /* skip atime */
216
217 file_accessed(iocb->ki_filp);
218
219 xfs_ilock(ip, XFS_IOLOCK_SHARED);
220 ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
221 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
222
223 return ret;
224}
225
226static noinline ssize_t
227xfs_file_dax_read(
228 struct kiocb *iocb,
229 struct iov_iter *to)
230{
231 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
232 size_t count = iov_iter_count(to);
233 ssize_t ret = 0;
234
235 trace_xfs_file_dax_read(ip, count, iocb->ki_pos);
236
237 if (!count)
238 return 0; /* skip atime */
239
240 xfs_ilock(ip, XFS_IOLOCK_SHARED);
241 ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
242 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
243
244 file_accessed(iocb->ki_filp);
245 return ret;
246}
247
248STATIC ssize_t
249xfs_file_buffered_aio_read(
250 struct kiocb *iocb,
251 struct iov_iter *to)
252{
253 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
254 ssize_t ret;
255
256 trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
257
258 xfs_ilock(ip, XFS_IOLOCK_SHARED);
259 ret = generic_file_read_iter(iocb, to);
260 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
261
262 return ret;
263}
264
265STATIC ssize_t
266xfs_file_read_iter(
267 struct kiocb *iocb,
268 struct iov_iter *to)
269{
270 struct inode *inode = file_inode(iocb->ki_filp);
271 struct xfs_mount *mp = XFS_I(inode)->i_mount;
272 ssize_t ret = 0;
273
274 XFS_STATS_INC(mp, xs_read_calls);
275
276 if (XFS_FORCED_SHUTDOWN(mp))
277 return -EIO;
278
279 if (IS_DAX(inode))
280 ret = xfs_file_dax_read(iocb, to);
281 else if (iocb->ki_flags & IOCB_DIRECT)
282 ret = xfs_file_dio_aio_read(iocb, to);
283 else
284 ret = xfs_file_buffered_aio_read(iocb, to);
285
286 if (ret > 0)
287 XFS_STATS_ADD(mp, xs_read_bytes, ret);
288 return ret;
289}
290
291/*
292 * Zero any on disk space between the current EOF and the new, larger EOF.
293 *
294 * This handles the normal case of zeroing the remainder of the last block in
295 * the file and the unusual case of zeroing blocks out beyond the size of the
296 * file. This second case only happens with fixed size extents and when the
297 * system crashes before the inode size was updated but after blocks were
298 * allocated.
299 *
300 * Expects the iolock to be held exclusive, and will take the ilock internally.
301 */
302int /* error (positive) */
303xfs_zero_eof(
304 struct xfs_inode *ip,
305 xfs_off_t offset, /* starting I/O offset */
306 xfs_fsize_t isize, /* current inode size */
307 bool *did_zeroing)
308{
309 ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
310 ASSERT(offset > isize);
311
312 trace_xfs_zero_eof(ip, isize, offset - isize);
313 return xfs_zero_range(ip, isize, offset - isize, did_zeroing);
314}
315
316/*
317 * Common pre-write limit and setup checks.
318 *
319 * Called with the iolocked held either shared and exclusive according to
320 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
321 * if called for a direct write beyond i_size.
322 */
323STATIC ssize_t
324xfs_file_aio_write_checks(
325 struct kiocb *iocb,
326 struct iov_iter *from,
327 int *iolock)
328{
329 struct file *file = iocb->ki_filp;
330 struct inode *inode = file->f_mapping->host;
331 struct xfs_inode *ip = XFS_I(inode);
332 ssize_t error = 0;
333 size_t count = iov_iter_count(from);
334 bool drained_dio = false;
335
336restart:
337 error = generic_write_checks(iocb, from);
338 if (error <= 0)
339 return error;
340
341 error = xfs_break_layouts(inode, iolock);
342 if (error)
343 return error;
344
345 /*
346 * For changing security info in file_remove_privs() we need i_rwsem
347 * exclusively.
348 */
349 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
350 xfs_iunlock(ip, *iolock);
351 *iolock = XFS_IOLOCK_EXCL;
352 xfs_ilock(ip, *iolock);
353 goto restart;
354 }
355 /*
356 * If the offset is beyond the size of the file, we need to zero any
357 * blocks that fall between the existing EOF and the start of this
358 * write. If zeroing is needed and we are currently holding the
359 * iolock shared, we need to update it to exclusive which implies
360 * having to redo all checks before.
361 *
362 * We need to serialise against EOF updates that occur in IO
363 * completions here. We want to make sure that nobody is changing the
364 * size while we do this check until we have placed an IO barrier (i.e.
365 * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
366 * The spinlock effectively forms a memory barrier once we have the
367 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
368 * and hence be able to correctly determine if we need to run zeroing.
369 */
370 spin_lock(&ip->i_flags_lock);
371 if (iocb->ki_pos > i_size_read(inode)) {
372 bool zero = false;
373
374 spin_unlock(&ip->i_flags_lock);
375 if (!drained_dio) {
376 if (*iolock == XFS_IOLOCK_SHARED) {
377 xfs_iunlock(ip, *iolock);
378 *iolock = XFS_IOLOCK_EXCL;
379 xfs_ilock(ip, *iolock);
380 iov_iter_reexpand(from, count);
381 }
382 /*
383 * We now have an IO submission barrier in place, but
384 * AIO can do EOF updates during IO completion and hence
385 * we now need to wait for all of them to drain. Non-AIO
386 * DIO will have drained before we are given the
387 * XFS_IOLOCK_EXCL, and so for most cases this wait is a
388 * no-op.
389 */
390 inode_dio_wait(inode);
391 drained_dio = true;
392 goto restart;
393 }
394 error = xfs_zero_eof(ip, iocb->ki_pos, i_size_read(inode), &zero);
395 if (error)
396 return error;
397 } else
398 spin_unlock(&ip->i_flags_lock);
399
400 /*
401 * Updating the timestamps will grab the ilock again from
402 * xfs_fs_dirty_inode, so we have to call it after dropping the
403 * lock above. Eventually we should look into a way to avoid
404 * the pointless lock roundtrip.
405 */
406 if (likely(!(file->f_mode & FMODE_NOCMTIME))) {
407 error = file_update_time(file);
408 if (error)
409 return error;
410 }
411
412 /*
413 * If we're writing the file then make sure to clear the setuid and
414 * setgid bits if the process is not being run by root. This keeps
415 * people from modifying setuid and setgid binaries.
416 */
417 if (!IS_NOSEC(inode))
418 return file_remove_privs(file);
419 return 0;
420}
421
422static int
423xfs_dio_write_end_io(
424 struct kiocb *iocb,
425 ssize_t size,
426 unsigned flags)
427{
428 struct inode *inode = file_inode(iocb->ki_filp);
429 struct xfs_inode *ip = XFS_I(inode);
430 loff_t offset = iocb->ki_pos;
431 bool update_size = false;
432 int error = 0;
433
434 trace_xfs_end_io_direct_write(ip, offset, size);
435
436 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
437 return -EIO;
438
439 if (size <= 0)
440 return size;
441
442 /*
443 * We need to update the in-core inode size here so that we don't end up
444 * with the on-disk inode size being outside the in-core inode size. We
445 * have no other method of updating EOF for AIO, so always do it here
446 * if necessary.
447 *
448 * We need to lock the test/set EOF update as we can be racing with
449 * other IO completions here to update the EOF. Failing to serialise
450 * here can result in EOF moving backwards and Bad Things Happen when
451 * that occurs.
452 */
453 spin_lock(&ip->i_flags_lock);
454 if (offset + size > i_size_read(inode)) {
455 i_size_write(inode, offset + size);
456 update_size = true;
457 }
458 spin_unlock(&ip->i_flags_lock);
459
460 if (flags & IOMAP_DIO_COW) {
461 error = xfs_reflink_end_cow(ip, offset, size);
462 if (error)
463 return error;
464 }
465
466 if (flags & IOMAP_DIO_UNWRITTEN)
467 error = xfs_iomap_write_unwritten(ip, offset, size);
468 else if (update_size)
469 error = xfs_setfilesize(ip, offset, size);
470
471 return error;
472}
473
474/*
475 * xfs_file_dio_aio_write - handle direct IO writes
476 *
477 * Lock the inode appropriately to prepare for and issue a direct IO write.
478 * By separating it from the buffered write path we remove all the tricky to
479 * follow locking changes and looping.
480 *
481 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
482 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
483 * pages are flushed out.
484 *
485 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
486 * allowing them to be done in parallel with reads and other direct IO writes.
487 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
488 * needs to do sub-block zeroing and that requires serialisation against other
489 * direct IOs to the same block. In this case we need to serialise the
490 * submission of the unaligned IOs so that we don't get racing block zeroing in
491 * the dio layer. To avoid the problem with aio, we also need to wait for
492 * outstanding IOs to complete so that unwritten extent conversion is completed
493 * before we try to map the overlapping block. This is currently implemented by
494 * hitting it with a big hammer (i.e. inode_dio_wait()).
495 *
496 * Returns with locks held indicated by @iolock and errors indicated by
497 * negative return values.
498 */
499STATIC ssize_t
500xfs_file_dio_aio_write(
501 struct kiocb *iocb,
502 struct iov_iter *from)
503{
504 struct file *file = iocb->ki_filp;
505 struct address_space *mapping = file->f_mapping;
506 struct inode *inode = mapping->host;
507 struct xfs_inode *ip = XFS_I(inode);
508 struct xfs_mount *mp = ip->i_mount;
509 ssize_t ret = 0;
510 int unaligned_io = 0;
511 int iolock;
512 size_t count = iov_iter_count(from);
513 struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
514 mp->m_rtdev_targp : mp->m_ddev_targp;
515
516 /* DIO must be aligned to device logical sector size */
517 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
518 return -EINVAL;
519
520 /*
521 * Don't take the exclusive iolock here unless the I/O is unaligned to
522 * the file system block size. We don't need to consider the EOF
523 * extension case here because xfs_file_aio_write_checks() will relock
524 * the inode as necessary for EOF zeroing cases and fill out the new
525 * inode size as appropriate.
526 */
527 if ((iocb->ki_pos & mp->m_blockmask) ||
528 ((iocb->ki_pos + count) & mp->m_blockmask)) {
529 unaligned_io = 1;
530
531 /*
532 * We can't properly handle unaligned direct I/O to reflink
533 * files yet, as we can't unshare a partial block.
534 */
535 if (xfs_is_reflink_inode(ip)) {
536 trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count);
537 return -EREMCHG;
538 }
539 iolock = XFS_IOLOCK_EXCL;
540 } else {
541 iolock = XFS_IOLOCK_SHARED;
542 }
543
544 xfs_ilock(ip, iolock);
545
546 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
547 if (ret)
548 goto out;
549 count = iov_iter_count(from);
550
551 /*
552 * If we are doing unaligned IO, wait for all other IO to drain,
553 * otherwise demote the lock if we had to take the exclusive lock
554 * for other reasons in xfs_file_aio_write_checks.
555 */
556 if (unaligned_io)
557 inode_dio_wait(inode);
558 else if (iolock == XFS_IOLOCK_EXCL) {
559 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
560 iolock = XFS_IOLOCK_SHARED;
561 }
562
563 trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
564
565 /* If this is a block-aligned directio CoW, remap immediately. */
566 if (xfs_is_reflink_inode(ip) && !unaligned_io) {
567 ret = xfs_reflink_allocate_cow_range(ip, iocb->ki_pos, count);
568 if (ret)
569 goto out;
570 }
571
572 ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, xfs_dio_write_end_io);
573out:
574 xfs_iunlock(ip, iolock);
575
576 /*
577 * No fallback to buffered IO on errors for XFS, direct IO will either
578 * complete fully or fail.
579 */
580 ASSERT(ret < 0 || ret == count);
581 return ret;
582}
583
584static noinline ssize_t
585xfs_file_dax_write(
586 struct kiocb *iocb,
587 struct iov_iter *from)
588{
589 struct inode *inode = iocb->ki_filp->f_mapping->host;
590 struct xfs_inode *ip = XFS_I(inode);
591 int iolock = XFS_IOLOCK_EXCL;
592 ssize_t ret, error = 0;
593 size_t count;
594 loff_t pos;
595
596 xfs_ilock(ip, iolock);
597 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
598 if (ret)
599 goto out;
600
601 pos = iocb->ki_pos;
602 count = iov_iter_count(from);
603
604 trace_xfs_file_dax_write(ip, count, pos);
605 ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
606 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
607 i_size_write(inode, iocb->ki_pos);
608 error = xfs_setfilesize(ip, pos, ret);
609 }
610out:
611 xfs_iunlock(ip, iolock);
612 return error ? error : ret;
613}
614
615STATIC ssize_t
616xfs_file_buffered_aio_write(
617 struct kiocb *iocb,
618 struct iov_iter *from)
619{
620 struct file *file = iocb->ki_filp;
621 struct address_space *mapping = file->f_mapping;
622 struct inode *inode = mapping->host;
623 struct xfs_inode *ip = XFS_I(inode);
624 ssize_t ret;
625 int enospc = 0;
626 int iolock;
627
628write_retry:
629 iolock = XFS_IOLOCK_EXCL;
630 xfs_ilock(ip, iolock);
631
632 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
633 if (ret)
634 goto out;
635
636 /* We can write back this queue in page reclaim */
637 current->backing_dev_info = inode_to_bdi(inode);
638
639 trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos);
640 ret = iomap_file_buffered_write(iocb, from, &xfs_iomap_ops);
641 if (likely(ret >= 0))
642 iocb->ki_pos += ret;
643
644 /*
645 * If we hit a space limit, try to free up some lingering preallocated
646 * space before returning an error. In the case of ENOSPC, first try to
647 * write back all dirty inodes to free up some of the excess reserved
648 * metadata space. This reduces the chances that the eofblocks scan
649 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
650 * also behaves as a filter to prevent too many eofblocks scans from
651 * running at the same time.
652 */
653 if (ret == -EDQUOT && !enospc) {
654 xfs_iunlock(ip, iolock);
655 enospc = xfs_inode_free_quota_eofblocks(ip);
656 if (enospc)
657 goto write_retry;
658 enospc = xfs_inode_free_quota_cowblocks(ip);
659 if (enospc)
660 goto write_retry;
661 iolock = 0;
662 } else if (ret == -ENOSPC && !enospc) {
663 struct xfs_eofblocks eofb = {0};
664
665 enospc = 1;
666 xfs_flush_inodes(ip->i_mount);
667
668 xfs_iunlock(ip, iolock);
669 eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
670 xfs_icache_free_eofblocks(ip->i_mount, &eofb);
671 goto write_retry;
672 }
673
674 current->backing_dev_info = NULL;
675out:
676 if (iolock)
677 xfs_iunlock(ip, iolock);
678 return ret;
679}
680
681STATIC ssize_t
682xfs_file_write_iter(
683 struct kiocb *iocb,
684 struct iov_iter *from)
685{
686 struct file *file = iocb->ki_filp;
687 struct address_space *mapping = file->f_mapping;
688 struct inode *inode = mapping->host;
689 struct xfs_inode *ip = XFS_I(inode);
690 ssize_t ret;
691 size_t ocount = iov_iter_count(from);
692
693 XFS_STATS_INC(ip->i_mount, xs_write_calls);
694
695 if (ocount == 0)
696 return 0;
697
698 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
699 return -EIO;
700
701 if (IS_DAX(inode))
702 ret = xfs_file_dax_write(iocb, from);
703 else if (iocb->ki_flags & IOCB_DIRECT) {
704 /*
705 * Allow a directio write to fall back to a buffered
706 * write *only* in the case that we're doing a reflink
707 * CoW. In all other directio scenarios we do not
708 * allow an operation to fall back to buffered mode.
709 */
710 ret = xfs_file_dio_aio_write(iocb, from);
711 if (ret == -EREMCHG)
712 goto buffered;
713 } else {
714buffered:
715 ret = xfs_file_buffered_aio_write(iocb, from);
716 }
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
727#define XFS_FALLOC_FL_SUPPORTED \
728 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
729 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
730 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
731
732STATIC long
733xfs_file_fallocate(
734 struct file *file,
735 int mode,
736 loff_t offset,
737 loff_t len)
738{
739 struct inode *inode = file_inode(file);
740 struct xfs_inode *ip = XFS_I(inode);
741 long error;
742 enum xfs_prealloc_flags flags = 0;
743 uint iolock = XFS_IOLOCK_EXCL;
744 loff_t new_size = 0;
745 bool do_file_insert = 0;
746
747 if (!S_ISREG(inode->i_mode))
748 return -EINVAL;
749 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
750 return -EOPNOTSUPP;
751
752 xfs_ilock(ip, iolock);
753 error = xfs_break_layouts(inode, &iolock);
754 if (error)
755 goto out_unlock;
756
757 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
758 iolock |= XFS_MMAPLOCK_EXCL;
759
760 if (mode & FALLOC_FL_PUNCH_HOLE) {
761 error = xfs_free_file_space(ip, offset, len);
762 if (error)
763 goto out_unlock;
764 } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
765 unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
766
767 if (offset & blksize_mask || len & blksize_mask) {
768 error = -EINVAL;
769 goto out_unlock;
770 }
771
772 /*
773 * There is no need to overlap collapse range with EOF,
774 * in which case it is effectively a truncate operation
775 */
776 if (offset + len >= i_size_read(inode)) {
777 error = -EINVAL;
778 goto out_unlock;
779 }
780
781 new_size = i_size_read(inode) - len;
782
783 error = xfs_collapse_file_space(ip, offset, len);
784 if (error)
785 goto out_unlock;
786 } else if (mode & FALLOC_FL_INSERT_RANGE) {
787 unsigned blksize_mask = (1 << inode->i_blkbits) - 1;
788
789 new_size = i_size_read(inode) + len;
790 if (offset & blksize_mask || len & blksize_mask) {
791 error = -EINVAL;
792 goto out_unlock;
793 }
794
795 /* check the new inode size does not wrap through zero */
796 if (new_size > inode->i_sb->s_maxbytes) {
797 error = -EFBIG;
798 goto out_unlock;
799 }
800
801 /* Offset should be less than i_size */
802 if (offset >= i_size_read(inode)) {
803 error = -EINVAL;
804 goto out_unlock;
805 }
806 do_file_insert = 1;
807 } else {
808 flags |= XFS_PREALLOC_SET;
809
810 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
811 offset + len > i_size_read(inode)) {
812 new_size = offset + len;
813 error = inode_newsize_ok(inode, new_size);
814 if (error)
815 goto out_unlock;
816 }
817
818 if (mode & FALLOC_FL_ZERO_RANGE)
819 error = xfs_zero_file_space(ip, offset, len);
820 else {
821 if (mode & FALLOC_FL_UNSHARE_RANGE) {
822 error = xfs_reflink_unshare(ip, offset, len);
823 if (error)
824 goto out_unlock;
825 }
826 error = xfs_alloc_file_space(ip, offset, len,
827 XFS_BMAPI_PREALLOC);
828 }
829 if (error)
830 goto out_unlock;
831 }
832
833 if (file->f_flags & O_DSYNC)
834 flags |= XFS_PREALLOC_SYNC;
835
836 error = xfs_update_prealloc_flags(ip, flags);
837 if (error)
838 goto out_unlock;
839
840 /* Change file size if needed */
841 if (new_size) {
842 struct iattr iattr;
843
844 iattr.ia_valid = ATTR_SIZE;
845 iattr.ia_size = new_size;
846 error = xfs_vn_setattr_size(file_dentry(file), &iattr);
847 if (error)
848 goto out_unlock;
849 }
850
851 /*
852 * Perform hole insertion now that the file size has been
853 * updated so that if we crash during the operation we don't
854 * leave shifted extents past EOF and hence losing access to
855 * the data that is contained within them.
856 */
857 if (do_file_insert)
858 error = xfs_insert_file_space(ip, offset, len);
859
860out_unlock:
861 xfs_iunlock(ip, iolock);
862 return error;
863}
864
865STATIC int
866xfs_file_clone_range(
867 struct file *file_in,
868 loff_t pos_in,
869 struct file *file_out,
870 loff_t pos_out,
871 u64 len)
872{
873 return xfs_reflink_remap_range(file_in, pos_in, file_out, pos_out,
874 len, false);
875}
876
877STATIC ssize_t
878xfs_file_dedupe_range(
879 struct file *src_file,
880 u64 loff,
881 u64 len,
882 struct file *dst_file,
883 u64 dst_loff)
884{
885 int error;
886
887 error = xfs_reflink_remap_range(src_file, loff, dst_file, dst_loff,
888 len, true);
889 if (error)
890 return error;
891 return len;
892}
893
894STATIC int
895xfs_file_open(
896 struct inode *inode,
897 struct file *file)
898{
899 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
900 return -EFBIG;
901 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
902 return -EIO;
903 return 0;
904}
905
906STATIC int
907xfs_dir_open(
908 struct inode *inode,
909 struct file *file)
910{
911 struct xfs_inode *ip = XFS_I(inode);
912 int mode;
913 int error;
914
915 error = xfs_file_open(inode, file);
916 if (error)
917 return error;
918
919 /*
920 * If there are any blocks, read-ahead block 0 as we're almost
921 * certain to have the next operation be a read there.
922 */
923 mode = xfs_ilock_data_map_shared(ip);
924 if (ip->i_d.di_nextents > 0)
925 error = xfs_dir3_data_readahead(ip, 0, -1);
926 xfs_iunlock(ip, mode);
927 return error;
928}
929
930STATIC int
931xfs_file_release(
932 struct inode *inode,
933 struct file *filp)
934{
935 return xfs_release(XFS_I(inode));
936}
937
938STATIC int
939xfs_file_readdir(
940 struct file *file,
941 struct dir_context *ctx)
942{
943 struct inode *inode = file_inode(file);
944 xfs_inode_t *ip = XFS_I(inode);
945 size_t bufsize;
946
947 /*
948 * The Linux API doesn't pass down the total size of the buffer
949 * we read into down to the filesystem. With the filldir concept
950 * it's not needed for correct information, but the XFS dir2 leaf
951 * code wants an estimate of the buffer size to calculate it's
952 * readahead window and size the buffers used for mapping to
953 * physical blocks.
954 *
955 * Try to give it an estimate that's good enough, maybe at some
956 * point we can change the ->readdir prototype to include the
957 * buffer size. For now we use the current glibc buffer size.
958 */
959 bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
960
961 return xfs_readdir(ip, ctx, bufsize);
962}
963
964/*
965 * This type is designed to indicate the type of offset we would like
966 * to search from page cache for xfs_seek_hole_data().
967 */
968enum {
969 HOLE_OFF = 0,
970 DATA_OFF,
971};
972
973/*
974 * Lookup the desired type of offset from the given page.
975 *
976 * On success, return true and the offset argument will point to the
977 * start of the region that was found. Otherwise this function will
978 * return false and keep the offset argument unchanged.
979 */
980STATIC bool
981xfs_lookup_buffer_offset(
982 struct page *page,
983 loff_t *offset,
984 unsigned int type)
985{
986 loff_t lastoff = page_offset(page);
987 bool found = false;
988 struct buffer_head *bh, *head;
989
990 bh = head = page_buffers(page);
991 do {
992 /*
993 * Unwritten extents that have data in the page
994 * cache covering them can be identified by the
995 * BH_Unwritten state flag. Pages with multiple
996 * buffers might have a mix of holes, data and
997 * unwritten extents - any buffer with valid
998 * data in it should have BH_Uptodate flag set
999 * on it.
1000 */
1001 if (buffer_unwritten(bh) ||
1002 buffer_uptodate(bh)) {
1003 if (type == DATA_OFF)
1004 found = true;
1005 } else {
1006 if (type == HOLE_OFF)
1007 found = true;
1008 }
1009
1010 if (found) {
1011 *offset = lastoff;
1012 break;
1013 }
1014 lastoff += bh->b_size;
1015 } while ((bh = bh->b_this_page) != head);
1016
1017 return found;
1018}
1019
1020/*
1021 * This routine is called to find out and return a data or hole offset
1022 * from the page cache for unwritten extents according to the desired
1023 * type for xfs_seek_hole_data().
1024 *
1025 * The argument offset is used to tell where we start to search from the
1026 * page cache. Map is used to figure out the end points of the range to
1027 * lookup pages.
1028 *
1029 * Return true if the desired type of offset was found, and the argument
1030 * offset is filled with that address. Otherwise, return false and keep
1031 * offset unchanged.
1032 */
1033STATIC bool
1034xfs_find_get_desired_pgoff(
1035 struct inode *inode,
1036 struct xfs_bmbt_irec *map,
1037 unsigned int type,
1038 loff_t *offset)
1039{
1040 struct xfs_inode *ip = XFS_I(inode);
1041 struct xfs_mount *mp = ip->i_mount;
1042 struct pagevec pvec;
1043 pgoff_t index;
1044 pgoff_t end;
1045 loff_t endoff;
1046 loff_t startoff = *offset;
1047 loff_t lastoff = startoff;
1048 bool found = false;
1049
1050 pagevec_init(&pvec, 0);
1051
1052 index = startoff >> PAGE_SHIFT;
1053 endoff = XFS_FSB_TO_B(mp, map->br_startoff + map->br_blockcount);
1054 end = endoff >> PAGE_SHIFT;
1055 do {
1056 int want;
1057 unsigned nr_pages;
1058 unsigned int i;
1059
1060 want = min_t(pgoff_t, end - index, PAGEVEC_SIZE);
1061 nr_pages = pagevec_lookup(&pvec, inode->i_mapping, index,
1062 want);
1063 /*
1064 * No page mapped into given range. If we are searching holes
1065 * and if this is the first time we got into the loop, it means
1066 * that the given offset is landed in a hole, return it.
1067 *
1068 * If we have already stepped through some block buffers to find
1069 * holes but they all contains data. In this case, the last
1070 * offset is already updated and pointed to the end of the last
1071 * mapped page, if it does not reach the endpoint to search,
1072 * that means there should be a hole between them.
1073 */
1074 if (nr_pages == 0) {
1075 /* Data search found nothing */
1076 if (type == DATA_OFF)
1077 break;
1078
1079 ASSERT(type == HOLE_OFF);
1080 if (lastoff == startoff || lastoff < endoff) {
1081 found = true;
1082 *offset = lastoff;
1083 }
1084 break;
1085 }
1086
1087 /*
1088 * At lease we found one page. If this is the first time we
1089 * step into the loop, and if the first page index offset is
1090 * greater than the given search offset, a hole was found.
1091 */
1092 if (type == HOLE_OFF && lastoff == startoff &&
1093 lastoff < page_offset(pvec.pages[0])) {
1094 found = true;
1095 break;
1096 }
1097
1098 for (i = 0; i < nr_pages; i++) {
1099 struct page *page = pvec.pages[i];
1100 loff_t b_offset;
1101
1102 /*
1103 * At this point, the page may be truncated or
1104 * invalidated (changing page->mapping to NULL),
1105 * or even swizzled back from swapper_space to tmpfs
1106 * file mapping. However, page->index will not change
1107 * because we have a reference on the page.
1108 *
1109 * Searching done if the page index is out of range.
1110 * If the current offset is not reaches the end of
1111 * the specified search range, there should be a hole
1112 * between them.
1113 */
1114 if (page->index > end) {
1115 if (type == HOLE_OFF && lastoff < endoff) {
1116 *offset = lastoff;
1117 found = true;
1118 }
1119 goto out;
1120 }
1121
1122 lock_page(page);
1123 /*
1124 * Page truncated or invalidated(page->mapping == NULL).
1125 * We can freely skip it and proceed to check the next
1126 * page.
1127 */
1128 if (unlikely(page->mapping != inode->i_mapping)) {
1129 unlock_page(page);
1130 continue;
1131 }
1132
1133 if (!page_has_buffers(page)) {
1134 unlock_page(page);
1135 continue;
1136 }
1137
1138 found = xfs_lookup_buffer_offset(page, &b_offset, type);
1139 if (found) {
1140 /*
1141 * The found offset may be less than the start
1142 * point to search if this is the first time to
1143 * come here.
1144 */
1145 *offset = max_t(loff_t, startoff, b_offset);
1146 unlock_page(page);
1147 goto out;
1148 }
1149
1150 /*
1151 * We either searching data but nothing was found, or
1152 * searching hole but found a data buffer. In either
1153 * case, probably the next page contains the desired
1154 * things, update the last offset to it so.
1155 */
1156 lastoff = page_offset(page) + PAGE_SIZE;
1157 unlock_page(page);
1158 }
1159
1160 /*
1161 * The number of returned pages less than our desired, search
1162 * done. In this case, nothing was found for searching data,
1163 * but we found a hole behind the last offset.
1164 */
1165 if (nr_pages < want) {
1166 if (type == HOLE_OFF) {
1167 *offset = lastoff;
1168 found = true;
1169 }
1170 break;
1171 }
1172
1173 index = pvec.pages[i - 1]->index + 1;
1174 pagevec_release(&pvec);
1175 } while (index <= end);
1176
1177out:
1178 pagevec_release(&pvec);
1179 return found;
1180}
1181
1182/*
1183 * caller must lock inode with xfs_ilock_data_map_shared,
1184 * can we craft an appropriate ASSERT?
1185 *
1186 * end is because the VFS-level lseek interface is defined such that any
1187 * offset past i_size shall return -ENXIO, but we use this for quota code
1188 * which does not maintain i_size, and we want to SEEK_DATA past i_size.
1189 */
1190loff_t
1191__xfs_seek_hole_data(
1192 struct inode *inode,
1193 loff_t start,
1194 loff_t end,
1195 int whence)
1196{
1197 struct xfs_inode *ip = XFS_I(inode);
1198 struct xfs_mount *mp = ip->i_mount;
1199 loff_t uninitialized_var(offset);
1200 xfs_fileoff_t fsbno;
1201 xfs_filblks_t lastbno;
1202 int error;
1203
1204 if (start >= end) {
1205 error = -ENXIO;
1206 goto out_error;
1207 }
1208
1209 /*
1210 * Try to read extents from the first block indicated
1211 * by fsbno to the end block of the file.
1212 */
1213 fsbno = XFS_B_TO_FSBT(mp, start);
1214 lastbno = XFS_B_TO_FSB(mp, end);
1215
1216 for (;;) {
1217 struct xfs_bmbt_irec map[2];
1218 int nmap = 2;
1219 unsigned int i;
1220
1221 error = xfs_bmapi_read(ip, fsbno, lastbno - fsbno, map, &nmap,
1222 XFS_BMAPI_ENTIRE);
1223 if (error)
1224 goto out_error;
1225
1226 /* No extents at given offset, must be beyond EOF */
1227 if (nmap == 0) {
1228 error = -ENXIO;
1229 goto out_error;
1230 }
1231
1232 for (i = 0; i < nmap; i++) {
1233 offset = max_t(loff_t, start,
1234 XFS_FSB_TO_B(mp, map[i].br_startoff));
1235
1236 /* Landed in the hole we wanted? */
1237 if (whence == SEEK_HOLE &&
1238 map[i].br_startblock == HOLESTARTBLOCK)
1239 goto out;
1240
1241 /* Landed in the data extent we wanted? */
1242 if (whence == SEEK_DATA &&
1243 (map[i].br_startblock == DELAYSTARTBLOCK ||
1244 (map[i].br_state == XFS_EXT_NORM &&
1245 !isnullstartblock(map[i].br_startblock))))
1246 goto out;
1247
1248 /*
1249 * Landed in an unwritten extent, try to search
1250 * for hole or data from page cache.
1251 */
1252 if (map[i].br_state == XFS_EXT_UNWRITTEN) {
1253 if (xfs_find_get_desired_pgoff(inode, &map[i],
1254 whence == SEEK_HOLE ? HOLE_OFF : DATA_OFF,
1255 &offset))
1256 goto out;
1257 }
1258 }
1259
1260 /*
1261 * We only received one extent out of the two requested. This
1262 * means we've hit EOF and didn't find what we are looking for.
1263 */
1264 if (nmap == 1) {
1265 /*
1266 * If we were looking for a hole, set offset to
1267 * the end of the file (i.e., there is an implicit
1268 * hole at the end of any file).
1269 */
1270 if (whence == SEEK_HOLE) {
1271 offset = end;
1272 break;
1273 }
1274 /*
1275 * If we were looking for data, it's nowhere to be found
1276 */
1277 ASSERT(whence == SEEK_DATA);
1278 error = -ENXIO;
1279 goto out_error;
1280 }
1281
1282 ASSERT(i > 1);
1283
1284 /*
1285 * Nothing was found, proceed to the next round of search
1286 * if the next reading offset is not at or beyond EOF.
1287 */
1288 fsbno = map[i - 1].br_startoff + map[i - 1].br_blockcount;
1289 start = XFS_FSB_TO_B(mp, fsbno);
1290 if (start >= end) {
1291 if (whence == SEEK_HOLE) {
1292 offset = end;
1293 break;
1294 }
1295 ASSERT(whence == SEEK_DATA);
1296 error = -ENXIO;
1297 goto out_error;
1298 }
1299 }
1300
1301out:
1302 /*
1303 * If at this point we have found the hole we wanted, the returned
1304 * offset may be bigger than the file size as it may be aligned to
1305 * page boundary for unwritten extents. We need to deal with this
1306 * situation in particular.
1307 */
1308 if (whence == SEEK_HOLE)
1309 offset = min_t(loff_t, offset, end);
1310
1311 return offset;
1312
1313out_error:
1314 return error;
1315}
1316
1317STATIC loff_t
1318xfs_seek_hole_data(
1319 struct file *file,
1320 loff_t start,
1321 int whence)
1322{
1323 struct inode *inode = file->f_mapping->host;
1324 struct xfs_inode *ip = XFS_I(inode);
1325 struct xfs_mount *mp = ip->i_mount;
1326 uint lock;
1327 loff_t offset, end;
1328 int error = 0;
1329
1330 if (XFS_FORCED_SHUTDOWN(mp))
1331 return -EIO;
1332
1333 lock = xfs_ilock_data_map_shared(ip);
1334
1335 end = i_size_read(inode);
1336 offset = __xfs_seek_hole_data(inode, start, end, whence);
1337 if (offset < 0) {
1338 error = offset;
1339 goto out_unlock;
1340 }
1341
1342 offset = vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1343
1344out_unlock:
1345 xfs_iunlock(ip, lock);
1346
1347 if (error)
1348 return error;
1349 return offset;
1350}
1351
1352STATIC loff_t
1353xfs_file_llseek(
1354 struct file *file,
1355 loff_t offset,
1356 int whence)
1357{
1358 switch (whence) {
1359 case SEEK_END:
1360 case SEEK_CUR:
1361 case SEEK_SET:
1362 return generic_file_llseek(file, offset, whence);
1363 case SEEK_HOLE:
1364 case SEEK_DATA:
1365 return xfs_seek_hole_data(file, offset, whence);
1366 default:
1367 return -EINVAL;
1368 }
1369}
1370
1371/*
1372 * Locking for serialisation of IO during page faults. This results in a lock
1373 * ordering of:
1374 *
1375 * mmap_sem (MM)
1376 * sb_start_pagefault(vfs, freeze)
1377 * i_mmaplock (XFS - truncate serialisation)
1378 * page_lock (MM)
1379 * i_lock (XFS - extent map serialisation)
1380 */
1381
1382/*
1383 * mmap()d file has taken write protection fault and is being made writable. We
1384 * can set the page state up correctly for a writable page, which means we can
1385 * do correct delalloc accounting (ENOSPC checking!) and unwritten extent
1386 * mapping.
1387 */
1388STATIC int
1389xfs_filemap_page_mkwrite(
1390 struct vm_area_struct *vma,
1391 struct vm_fault *vmf)
1392{
1393 struct inode *inode = file_inode(vma->vm_file);
1394 int ret;
1395
1396 trace_xfs_filemap_page_mkwrite(XFS_I(inode));
1397
1398 sb_start_pagefault(inode->i_sb);
1399 file_update_time(vma->vm_file);
1400 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1401
1402 if (IS_DAX(inode)) {
1403 ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops);
1404 } else {
1405 ret = iomap_page_mkwrite(vma, vmf, &xfs_iomap_ops);
1406 ret = block_page_mkwrite_return(ret);
1407 }
1408
1409 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1410 sb_end_pagefault(inode->i_sb);
1411
1412 return ret;
1413}
1414
1415STATIC int
1416xfs_filemap_fault(
1417 struct vm_area_struct *vma,
1418 struct vm_fault *vmf)
1419{
1420 struct inode *inode = file_inode(vma->vm_file);
1421 int ret;
1422
1423 trace_xfs_filemap_fault(XFS_I(inode));
1424
1425 /* DAX can shortcut the normal fault path on write faults! */
1426 if ((vmf->flags & FAULT_FLAG_WRITE) && IS_DAX(inode))
1427 return xfs_filemap_page_mkwrite(vma, vmf);
1428
1429 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1430 if (IS_DAX(inode))
1431 ret = dax_iomap_fault(vma, vmf, &xfs_iomap_ops);
1432 else
1433 ret = filemap_fault(vma, vmf);
1434 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1435
1436 return ret;
1437}
1438
1439/*
1440 * Similar to xfs_filemap_fault(), the DAX fault path can call into here on
1441 * both read and write faults. Hence we need to handle both cases. There is no
1442 * ->pmd_mkwrite callout for huge pages, so we have a single function here to
1443 * handle both cases here. @flags carries the information on the type of fault
1444 * occuring.
1445 */
1446STATIC int
1447xfs_filemap_pmd_fault(
1448 struct vm_area_struct *vma,
1449 unsigned long addr,
1450 pmd_t *pmd,
1451 unsigned int flags)
1452{
1453 struct inode *inode = file_inode(vma->vm_file);
1454 struct xfs_inode *ip = XFS_I(inode);
1455 int ret;
1456
1457 if (!IS_DAX(inode))
1458 return VM_FAULT_FALLBACK;
1459
1460 trace_xfs_filemap_pmd_fault(ip);
1461
1462 if (flags & FAULT_FLAG_WRITE) {
1463 sb_start_pagefault(inode->i_sb);
1464 file_update_time(vma->vm_file);
1465 }
1466
1467 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1468 ret = dax_iomap_pmd_fault(vma, addr, pmd, flags, &xfs_iomap_ops);
1469 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1470
1471 if (flags & FAULT_FLAG_WRITE)
1472 sb_end_pagefault(inode->i_sb);
1473
1474 return ret;
1475}
1476
1477/*
1478 * pfn_mkwrite was originally inteneded to ensure we capture time stamp
1479 * updates on write faults. In reality, it's need to serialise against
1480 * truncate similar to page_mkwrite. Hence we cycle the XFS_MMAPLOCK_SHARED
1481 * to ensure we serialise the fault barrier in place.
1482 */
1483static int
1484xfs_filemap_pfn_mkwrite(
1485 struct vm_area_struct *vma,
1486 struct vm_fault *vmf)
1487{
1488
1489 struct inode *inode = file_inode(vma->vm_file);
1490 struct xfs_inode *ip = XFS_I(inode);
1491 int ret = VM_FAULT_NOPAGE;
1492 loff_t size;
1493
1494 trace_xfs_filemap_pfn_mkwrite(ip);
1495
1496 sb_start_pagefault(inode->i_sb);
1497 file_update_time(vma->vm_file);
1498
1499 /* check if the faulting page hasn't raced with truncate */
1500 xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
1501 size = (i_size_read(inode) + PAGE_SIZE - 1) >> PAGE_SHIFT;
1502 if (vmf->pgoff >= size)
1503 ret = VM_FAULT_SIGBUS;
1504 else if (IS_DAX(inode))
1505 ret = dax_pfn_mkwrite(vma, vmf);
1506 xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
1507 sb_end_pagefault(inode->i_sb);
1508 return ret;
1509
1510}
1511
1512static const struct vm_operations_struct xfs_file_vm_ops = {
1513 .fault = xfs_filemap_fault,
1514 .pmd_fault = xfs_filemap_pmd_fault,
1515 .map_pages = filemap_map_pages,
1516 .page_mkwrite = xfs_filemap_page_mkwrite,
1517 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1518};
1519
1520STATIC int
1521xfs_file_mmap(
1522 struct file *filp,
1523 struct vm_area_struct *vma)
1524{
1525 file_accessed(filp);
1526 vma->vm_ops = &xfs_file_vm_ops;
1527 if (IS_DAX(file_inode(filp)))
1528 vma->vm_flags |= VM_MIXEDMAP | VM_HUGEPAGE;
1529 return 0;
1530}
1531
1532const struct file_operations xfs_file_operations = {
1533 .llseek = xfs_file_llseek,
1534 .read_iter = xfs_file_read_iter,
1535 .write_iter = xfs_file_write_iter,
1536 .splice_read = generic_file_splice_read,
1537 .splice_write = iter_file_splice_write,
1538 .unlocked_ioctl = xfs_file_ioctl,
1539#ifdef CONFIG_COMPAT
1540 .compat_ioctl = xfs_file_compat_ioctl,
1541#endif
1542 .mmap = xfs_file_mmap,
1543 .open = xfs_file_open,
1544 .release = xfs_file_release,
1545 .fsync = xfs_file_fsync,
1546 .get_unmapped_area = thp_get_unmapped_area,
1547 .fallocate = xfs_file_fallocate,
1548 .clone_file_range = xfs_file_clone_range,
1549 .dedupe_file_range = xfs_file_dedupe_range,
1550};
1551
1552const struct file_operations xfs_dir_file_operations = {
1553 .open = xfs_dir_open,
1554 .read = generic_read_dir,
1555 .iterate_shared = xfs_file_readdir,
1556 .llseek = generic_file_llseek,
1557 .unlocked_ioctl = xfs_file_ioctl,
1558#ifdef CONFIG_COMPAT
1559 .compat_ioctl = xfs_file_compat_ioctl,
1560#endif
1561 .fsync = xfs_dir_fsync,
1562};
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#include "xfs_file.h"
28
29#include <linux/dax.h>
30#include <linux/falloc.h>
31#include <linux/backing-dev.h>
32#include <linux/mman.h>
33#include <linux/fadvise.h>
34#include <linux/mount.h>
35
36static const struct vm_operations_struct xfs_file_vm_ops;
37
38/*
39 * Decide if the given file range is aligned to the size of the fundamental
40 * allocation unit for the file.
41 */
42bool
43xfs_is_falloc_aligned(
44 struct xfs_inode *ip,
45 loff_t pos,
46 long long int len)
47{
48 unsigned int alloc_unit = xfs_inode_alloc_unitsize(ip);
49
50 if (!is_power_of_2(alloc_unit))
51 return isaligned_64(pos, alloc_unit) &&
52 isaligned_64(len, alloc_unit);
53
54 return !((pos | len) & (alloc_unit - 1));
55}
56
57/*
58 * Fsync operations on directories are much simpler than on regular files,
59 * as there is no file data to flush, and thus also no need for explicit
60 * cache flush operations, and there are no non-transaction metadata updates
61 * on directories either.
62 */
63STATIC int
64xfs_dir_fsync(
65 struct file *file,
66 loff_t start,
67 loff_t end,
68 int datasync)
69{
70 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
71
72 trace_xfs_dir_fsync(ip);
73 return xfs_log_force_inode(ip);
74}
75
76static xfs_csn_t
77xfs_fsync_seq(
78 struct xfs_inode *ip,
79 bool datasync)
80{
81 if (!xfs_ipincount(ip))
82 return 0;
83 if (datasync && !(ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
84 return 0;
85 return ip->i_itemp->ili_commit_seq;
86}
87
88/*
89 * All metadata updates are logged, which means that we just have to flush the
90 * log up to the latest LSN that touched the inode.
91 *
92 * If we have concurrent fsync/fdatasync() calls, we need them to all block on
93 * the log force before we clear the ili_fsync_fields field. This ensures that
94 * we don't get a racing sync operation that does not wait for the metadata to
95 * hit the journal before returning. If we race with clearing ili_fsync_fields,
96 * then all that will happen is the log force will do nothing as the lsn will
97 * already be on disk. We can't race with setting ili_fsync_fields because that
98 * is done under XFS_ILOCK_EXCL, and that can't happen because we hold the lock
99 * shared until after the ili_fsync_fields is cleared.
100 */
101static int
102xfs_fsync_flush_log(
103 struct xfs_inode *ip,
104 bool datasync,
105 int *log_flushed)
106{
107 int error = 0;
108 xfs_csn_t seq;
109
110 xfs_ilock(ip, XFS_ILOCK_SHARED);
111 seq = xfs_fsync_seq(ip, datasync);
112 if (seq) {
113 error = xfs_log_force_seq(ip->i_mount, seq, XFS_LOG_SYNC,
114 log_flushed);
115
116 spin_lock(&ip->i_itemp->ili_lock);
117 ip->i_itemp->ili_fsync_fields = 0;
118 spin_unlock(&ip->i_itemp->ili_lock);
119 }
120 xfs_iunlock(ip, XFS_ILOCK_SHARED);
121 return error;
122}
123
124STATIC int
125xfs_file_fsync(
126 struct file *file,
127 loff_t start,
128 loff_t end,
129 int datasync)
130{
131 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
132 struct xfs_mount *mp = ip->i_mount;
133 int error, err2;
134 int log_flushed = 0;
135
136 trace_xfs_file_fsync(ip);
137
138 error = file_write_and_wait_range(file, start, end);
139 if (error)
140 return error;
141
142 if (xfs_is_shutdown(mp))
143 return -EIO;
144
145 xfs_iflags_clear(ip, XFS_ITRUNCATED);
146
147 /*
148 * If we have an RT and/or log subvolume we need to make sure to flush
149 * the write cache the device used for file data first. This is to
150 * ensure newly written file data make it to disk before logging the new
151 * inode size in case of an extending write.
152 */
153 if (XFS_IS_REALTIME_INODE(ip))
154 error = blkdev_issue_flush(mp->m_rtdev_targp->bt_bdev);
155 else if (mp->m_logdev_targp != mp->m_ddev_targp)
156 error = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
157
158 /*
159 * Any inode that has dirty modifications in the log is pinned. The
160 * racy check here for a pinned inode will not catch modifications
161 * that happen concurrently to the fsync call, but fsync semantics
162 * only require to sync previously completed I/O.
163 */
164 if (xfs_ipincount(ip)) {
165 err2 = xfs_fsync_flush_log(ip, datasync, &log_flushed);
166 if (err2 && !error)
167 error = err2;
168 }
169
170 /*
171 * If we only have a single device, and the log force about was
172 * a no-op we might have to flush the data device cache here.
173 * This can only happen for fdatasync/O_DSYNC if we were overwriting
174 * an already allocated file and thus do not have any metadata to
175 * commit.
176 */
177 if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
178 mp->m_logdev_targp == mp->m_ddev_targp) {
179 err2 = blkdev_issue_flush(mp->m_ddev_targp->bt_bdev);
180 if (err2 && !error)
181 error = err2;
182 }
183
184 return error;
185}
186
187static int
188xfs_ilock_iocb(
189 struct kiocb *iocb,
190 unsigned int lock_mode)
191{
192 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
193
194 if (iocb->ki_flags & IOCB_NOWAIT) {
195 if (!xfs_ilock_nowait(ip, lock_mode))
196 return -EAGAIN;
197 } else {
198 xfs_ilock(ip, lock_mode);
199 }
200
201 return 0;
202}
203
204static int
205xfs_ilock_iocb_for_write(
206 struct kiocb *iocb,
207 unsigned int *lock_mode)
208{
209 ssize_t ret;
210 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
211
212 ret = xfs_ilock_iocb(iocb, *lock_mode);
213 if (ret)
214 return ret;
215
216 /*
217 * If a reflink remap is in progress we always need to take the iolock
218 * exclusively to wait for it to finish.
219 */
220 if (*lock_mode == XFS_IOLOCK_SHARED &&
221 xfs_iflags_test(ip, XFS_IREMAPPING)) {
222 xfs_iunlock(ip, *lock_mode);
223 *lock_mode = XFS_IOLOCK_EXCL;
224 return xfs_ilock_iocb(iocb, *lock_mode);
225 }
226
227 return 0;
228}
229
230STATIC ssize_t
231xfs_file_dio_read(
232 struct kiocb *iocb,
233 struct iov_iter *to)
234{
235 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
236 ssize_t ret;
237
238 trace_xfs_file_direct_read(iocb, to);
239
240 if (!iov_iter_count(to))
241 return 0; /* skip atime */
242
243 file_accessed(iocb->ki_filp);
244
245 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
246 if (ret)
247 return ret;
248 ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL, 0, NULL, 0);
249 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
250
251 return ret;
252}
253
254static noinline ssize_t
255xfs_file_dax_read(
256 struct kiocb *iocb,
257 struct iov_iter *to)
258{
259 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
260 ssize_t ret = 0;
261
262 trace_xfs_file_dax_read(iocb, to);
263
264 if (!iov_iter_count(to))
265 return 0; /* skip atime */
266
267 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
268 if (ret)
269 return ret;
270 ret = dax_iomap_rw(iocb, to, &xfs_read_iomap_ops);
271 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
272
273 file_accessed(iocb->ki_filp);
274 return ret;
275}
276
277STATIC ssize_t
278xfs_file_buffered_read(
279 struct kiocb *iocb,
280 struct iov_iter *to)
281{
282 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
283 ssize_t ret;
284
285 trace_xfs_file_buffered_read(iocb, to);
286
287 ret = xfs_ilock_iocb(iocb, XFS_IOLOCK_SHARED);
288 if (ret)
289 return ret;
290 ret = generic_file_read_iter(iocb, to);
291 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
292
293 return ret;
294}
295
296STATIC ssize_t
297xfs_file_read_iter(
298 struct kiocb *iocb,
299 struct iov_iter *to)
300{
301 struct inode *inode = file_inode(iocb->ki_filp);
302 struct xfs_mount *mp = XFS_I(inode)->i_mount;
303 ssize_t ret = 0;
304
305 XFS_STATS_INC(mp, xs_read_calls);
306
307 if (xfs_is_shutdown(mp))
308 return -EIO;
309
310 if (IS_DAX(inode))
311 ret = xfs_file_dax_read(iocb, to);
312 else if (iocb->ki_flags & IOCB_DIRECT)
313 ret = xfs_file_dio_read(iocb, to);
314 else
315 ret = xfs_file_buffered_read(iocb, to);
316
317 if (ret > 0)
318 XFS_STATS_ADD(mp, xs_read_bytes, ret);
319 return ret;
320}
321
322STATIC ssize_t
323xfs_file_splice_read(
324 struct file *in,
325 loff_t *ppos,
326 struct pipe_inode_info *pipe,
327 size_t len,
328 unsigned int flags)
329{
330 struct inode *inode = file_inode(in);
331 struct xfs_inode *ip = XFS_I(inode);
332 struct xfs_mount *mp = ip->i_mount;
333 ssize_t ret = 0;
334
335 XFS_STATS_INC(mp, xs_read_calls);
336
337 if (xfs_is_shutdown(mp))
338 return -EIO;
339
340 trace_xfs_file_splice_read(ip, *ppos, len);
341
342 xfs_ilock(ip, XFS_IOLOCK_SHARED);
343 ret = filemap_splice_read(in, ppos, pipe, len, flags);
344 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
345 if (ret > 0)
346 XFS_STATS_ADD(mp, xs_read_bytes, ret);
347 return ret;
348}
349
350/*
351 * Take care of zeroing post-EOF blocks when they might exist.
352 *
353 * Returns 0 if successfully, a negative error for a failure, or 1 if this
354 * function dropped the iolock and reacquired it exclusively and the caller
355 * needs to restart the write sanity checks.
356 */
357static ssize_t
358xfs_file_write_zero_eof(
359 struct kiocb *iocb,
360 struct iov_iter *from,
361 unsigned int *iolock,
362 size_t count,
363 bool *drained_dio)
364{
365 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
366 loff_t isize;
367 int error;
368
369 /*
370 * We need to serialise against EOF updates that occur in IO completions
371 * here. We want to make sure that nobody is changing the size while
372 * we do this check until we have placed an IO barrier (i.e. hold
373 * XFS_IOLOCK_EXCL) that prevents new IO from being dispatched. The
374 * spinlock effectively forms a memory barrier once we have
375 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value and
376 * hence be able to correctly determine if we need to run zeroing.
377 */
378 spin_lock(&ip->i_flags_lock);
379 isize = i_size_read(VFS_I(ip));
380 if (iocb->ki_pos <= isize) {
381 spin_unlock(&ip->i_flags_lock);
382 return 0;
383 }
384 spin_unlock(&ip->i_flags_lock);
385
386 if (iocb->ki_flags & IOCB_NOWAIT)
387 return -EAGAIN;
388
389 if (!*drained_dio) {
390 /*
391 * If zeroing is needed and we are currently holding the iolock
392 * shared, we need to update it to exclusive which implies
393 * having to redo all checks before.
394 */
395 if (*iolock == XFS_IOLOCK_SHARED) {
396 xfs_iunlock(ip, *iolock);
397 *iolock = XFS_IOLOCK_EXCL;
398 xfs_ilock(ip, *iolock);
399 iov_iter_reexpand(from, count);
400 }
401
402 /*
403 * We now have an IO submission barrier in place, but AIO can do
404 * EOF updates during IO completion and hence we now need to
405 * wait for all of them to drain. Non-AIO DIO will have drained
406 * before we are given the XFS_IOLOCK_EXCL, and so for most
407 * cases this wait is a no-op.
408 */
409 inode_dio_wait(VFS_I(ip));
410 *drained_dio = true;
411 return 1;
412 }
413
414 trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
415
416 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
417 error = xfs_zero_range(ip, isize, iocb->ki_pos - isize, NULL);
418 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
419
420 return error;
421}
422
423/*
424 * Common pre-write limit and setup checks.
425 *
426 * Called with the iolock held either shared and exclusive according to
427 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
428 * if called for a direct write beyond i_size.
429 */
430STATIC ssize_t
431xfs_file_write_checks(
432 struct kiocb *iocb,
433 struct iov_iter *from,
434 unsigned int *iolock)
435{
436 struct inode *inode = iocb->ki_filp->f_mapping->host;
437 size_t count = iov_iter_count(from);
438 bool drained_dio = false;
439 ssize_t error;
440
441restart:
442 error = generic_write_checks(iocb, from);
443 if (error <= 0)
444 return error;
445
446 if (iocb->ki_flags & IOCB_NOWAIT) {
447 error = break_layout(inode, false);
448 if (error == -EWOULDBLOCK)
449 error = -EAGAIN;
450 } else {
451 error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
452 }
453
454 if (error)
455 return error;
456
457 /*
458 * For changing security info in file_remove_privs() we need i_rwsem
459 * exclusively.
460 */
461 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
462 xfs_iunlock(XFS_I(inode), *iolock);
463 *iolock = XFS_IOLOCK_EXCL;
464 error = xfs_ilock_iocb(iocb, *iolock);
465 if (error) {
466 *iolock = 0;
467 return error;
468 }
469 goto restart;
470 }
471
472 /*
473 * If the offset is beyond the size of the file, we need to zero all
474 * blocks that fall between the existing EOF and the start of this
475 * write.
476 *
477 * We can do an unlocked check for i_size here safely as I/O completion
478 * can only extend EOF. Truncate is locked out at this point, so the
479 * EOF can not move backwards, only forwards. Hence we only need to take
480 * the slow path when we are at or beyond the current EOF.
481 */
482 if (iocb->ki_pos > i_size_read(inode)) {
483 error = xfs_file_write_zero_eof(iocb, from, iolock, count,
484 &drained_dio);
485 if (error == 1)
486 goto restart;
487 if (error)
488 return error;
489 }
490
491 return kiocb_modified(iocb);
492}
493
494static int
495xfs_dio_write_end_io(
496 struct kiocb *iocb,
497 ssize_t size,
498 int error,
499 unsigned flags)
500{
501 struct inode *inode = file_inode(iocb->ki_filp);
502 struct xfs_inode *ip = XFS_I(inode);
503 loff_t offset = iocb->ki_pos;
504 unsigned int nofs_flag;
505
506 trace_xfs_end_io_direct_write(ip, offset, size);
507
508 if (xfs_is_shutdown(ip->i_mount))
509 return -EIO;
510
511 if (error)
512 return error;
513 if (!size)
514 return 0;
515
516 /*
517 * Capture amount written on completion as we can't reliably account
518 * for it on submission.
519 */
520 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
521
522 /*
523 * We can allocate memory here while doing writeback on behalf of
524 * memory reclaim. To avoid memory allocation deadlocks set the
525 * task-wide nofs context for the following operations.
526 */
527 nofs_flag = memalloc_nofs_save();
528
529 if (flags & IOMAP_DIO_COW) {
530 error = xfs_reflink_end_cow(ip, offset, size);
531 if (error)
532 goto out;
533 }
534
535 /*
536 * Unwritten conversion updates the in-core isize after extent
537 * conversion but before updating the on-disk size. Updating isize any
538 * earlier allows a racing dio read to find unwritten extents before
539 * they are converted.
540 */
541 if (flags & IOMAP_DIO_UNWRITTEN) {
542 error = xfs_iomap_write_unwritten(ip, offset, size, true);
543 goto out;
544 }
545
546 /*
547 * We need to update the in-core inode size here so that we don't end up
548 * with the on-disk inode size being outside the in-core inode size. We
549 * have no other method of updating EOF for AIO, so always do it here
550 * if necessary.
551 *
552 * We need to lock the test/set EOF update as we can be racing with
553 * other IO completions here to update the EOF. Failing to serialise
554 * here can result in EOF moving backwards and Bad Things Happen when
555 * that occurs.
556 *
557 * As IO completion only ever extends EOF, we can do an unlocked check
558 * here to avoid taking the spinlock. If we land within the current EOF,
559 * then we do not need to do an extending update at all, and we don't
560 * need to take the lock to check this. If we race with an update moving
561 * EOF, then we'll either still be beyond EOF and need to take the lock,
562 * or we'll be within EOF and we don't need to take it at all.
563 */
564 if (offset + size <= i_size_read(inode))
565 goto out;
566
567 spin_lock(&ip->i_flags_lock);
568 if (offset + size > i_size_read(inode)) {
569 i_size_write(inode, offset + size);
570 spin_unlock(&ip->i_flags_lock);
571 error = xfs_setfilesize(ip, offset, size);
572 } else {
573 spin_unlock(&ip->i_flags_lock);
574 }
575
576out:
577 memalloc_nofs_restore(nofs_flag);
578 return error;
579}
580
581static const struct iomap_dio_ops xfs_dio_write_ops = {
582 .end_io = xfs_dio_write_end_io,
583};
584
585/*
586 * Handle block aligned direct I/O writes
587 */
588static noinline ssize_t
589xfs_file_dio_write_aligned(
590 struct xfs_inode *ip,
591 struct kiocb *iocb,
592 struct iov_iter *from)
593{
594 unsigned int iolock = XFS_IOLOCK_SHARED;
595 ssize_t ret;
596
597 ret = xfs_ilock_iocb_for_write(iocb, &iolock);
598 if (ret)
599 return ret;
600 ret = xfs_file_write_checks(iocb, from, &iolock);
601 if (ret)
602 goto out_unlock;
603
604 /*
605 * We don't need to hold the IOLOCK exclusively across the IO, so demote
606 * the iolock back to shared if we had to take the exclusive lock in
607 * xfs_file_write_checks() for other reasons.
608 */
609 if (iolock == XFS_IOLOCK_EXCL) {
610 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
611 iolock = XFS_IOLOCK_SHARED;
612 }
613 trace_xfs_file_direct_write(iocb, from);
614 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
615 &xfs_dio_write_ops, 0, NULL, 0);
616out_unlock:
617 if (iolock)
618 xfs_iunlock(ip, iolock);
619 return ret;
620}
621
622/*
623 * Handle block unaligned direct I/O writes
624 *
625 * In most cases direct I/O writes will be done holding IOLOCK_SHARED, allowing
626 * them to be done in parallel with reads and other direct I/O writes. However,
627 * if the I/O is not aligned to filesystem blocks, the direct I/O layer may need
628 * to do sub-block zeroing and that requires serialisation against other direct
629 * I/O to the same block. In this case we need to serialise the submission of
630 * the unaligned I/O so that we don't get racing block zeroing in the dio layer.
631 * In the case where sub-block zeroing is not required, we can do concurrent
632 * sub-block dios to the same block successfully.
633 *
634 * Optimistically submit the I/O using the shared lock first, but use the
635 * IOMAP_DIO_OVERWRITE_ONLY flag to tell the lower layers to return -EAGAIN
636 * if block allocation or partial block zeroing would be required. In that case
637 * we try again with the exclusive lock.
638 */
639static noinline ssize_t
640xfs_file_dio_write_unaligned(
641 struct xfs_inode *ip,
642 struct kiocb *iocb,
643 struct iov_iter *from)
644{
645 size_t isize = i_size_read(VFS_I(ip));
646 size_t count = iov_iter_count(from);
647 unsigned int iolock = XFS_IOLOCK_SHARED;
648 unsigned int flags = IOMAP_DIO_OVERWRITE_ONLY;
649 ssize_t ret;
650
651 /*
652 * Extending writes need exclusivity because of the sub-block zeroing
653 * that the DIO code always does for partial tail blocks beyond EOF, so
654 * don't even bother trying the fast path in this case.
655 */
656 if (iocb->ki_pos > isize || iocb->ki_pos + count >= isize) {
657 if (iocb->ki_flags & IOCB_NOWAIT)
658 return -EAGAIN;
659retry_exclusive:
660 iolock = XFS_IOLOCK_EXCL;
661 flags = IOMAP_DIO_FORCE_WAIT;
662 }
663
664 ret = xfs_ilock_iocb_for_write(iocb, &iolock);
665 if (ret)
666 return ret;
667
668 /*
669 * We can't properly handle unaligned direct I/O to reflink files yet,
670 * as we can't unshare a partial block.
671 */
672 if (xfs_is_cow_inode(ip)) {
673 trace_xfs_reflink_bounce_dio_write(iocb, from);
674 ret = -ENOTBLK;
675 goto out_unlock;
676 }
677
678 ret = xfs_file_write_checks(iocb, from, &iolock);
679 if (ret)
680 goto out_unlock;
681
682 /*
683 * If we are doing exclusive unaligned I/O, this must be the only I/O
684 * in-flight. Otherwise we risk data corruption due to unwritten extent
685 * conversions from the AIO end_io handler. Wait for all other I/O to
686 * drain first.
687 */
688 if (flags & IOMAP_DIO_FORCE_WAIT)
689 inode_dio_wait(VFS_I(ip));
690
691 trace_xfs_file_direct_write(iocb, from);
692 ret = iomap_dio_rw(iocb, from, &xfs_direct_write_iomap_ops,
693 &xfs_dio_write_ops, flags, NULL, 0);
694
695 /*
696 * Retry unaligned I/O with exclusive blocking semantics if the DIO
697 * layer rejected it for mapping or locking reasons. If we are doing
698 * nonblocking user I/O, propagate the error.
699 */
700 if (ret == -EAGAIN && !(iocb->ki_flags & IOCB_NOWAIT)) {
701 ASSERT(flags & IOMAP_DIO_OVERWRITE_ONLY);
702 xfs_iunlock(ip, iolock);
703 goto retry_exclusive;
704 }
705
706out_unlock:
707 if (iolock)
708 xfs_iunlock(ip, iolock);
709 return ret;
710}
711
712static ssize_t
713xfs_file_dio_write(
714 struct kiocb *iocb,
715 struct iov_iter *from)
716{
717 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
718 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
719 size_t count = iov_iter_count(from);
720
721 /* direct I/O must be aligned to device logical sector size */
722 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
723 return -EINVAL;
724 if ((iocb->ki_pos | count) & ip->i_mount->m_blockmask)
725 return xfs_file_dio_write_unaligned(ip, iocb, from);
726 return xfs_file_dio_write_aligned(ip, iocb, from);
727}
728
729static noinline ssize_t
730xfs_file_dax_write(
731 struct kiocb *iocb,
732 struct iov_iter *from)
733{
734 struct inode *inode = iocb->ki_filp->f_mapping->host;
735 struct xfs_inode *ip = XFS_I(inode);
736 unsigned int iolock = XFS_IOLOCK_EXCL;
737 ssize_t ret, error = 0;
738 loff_t pos;
739
740 ret = xfs_ilock_iocb(iocb, iolock);
741 if (ret)
742 return ret;
743 ret = xfs_file_write_checks(iocb, from, &iolock);
744 if (ret)
745 goto out;
746
747 pos = iocb->ki_pos;
748
749 trace_xfs_file_dax_write(iocb, from);
750 ret = dax_iomap_rw(iocb, from, &xfs_dax_write_iomap_ops);
751 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
752 i_size_write(inode, iocb->ki_pos);
753 error = xfs_setfilesize(ip, pos, ret);
754 }
755out:
756 if (iolock)
757 xfs_iunlock(ip, iolock);
758 if (error)
759 return error;
760
761 if (ret > 0) {
762 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
763
764 /* Handle various SYNC-type writes */
765 ret = generic_write_sync(iocb, ret);
766 }
767 return ret;
768}
769
770STATIC ssize_t
771xfs_file_buffered_write(
772 struct kiocb *iocb,
773 struct iov_iter *from)
774{
775 struct inode *inode = iocb->ki_filp->f_mapping->host;
776 struct xfs_inode *ip = XFS_I(inode);
777 ssize_t ret;
778 bool cleared_space = false;
779 unsigned int iolock;
780
781write_retry:
782 iolock = XFS_IOLOCK_EXCL;
783 ret = xfs_ilock_iocb(iocb, iolock);
784 if (ret)
785 return ret;
786
787 ret = xfs_file_write_checks(iocb, from, &iolock);
788 if (ret)
789 goto out;
790
791 trace_xfs_file_buffered_write(iocb, from);
792 ret = iomap_file_buffered_write(iocb, from,
793 &xfs_buffered_write_iomap_ops, NULL);
794
795 /*
796 * If we hit a space limit, try to free up some lingering preallocated
797 * space before returning an error. In the case of ENOSPC, first try to
798 * write back all dirty inodes to free up some of the excess reserved
799 * metadata space. This reduces the chances that the eofblocks scan
800 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
801 * also behaves as a filter to prevent too many eofblocks scans from
802 * running at the same time. Use a synchronous scan to increase the
803 * effectiveness of the scan.
804 */
805 if (ret == -EDQUOT && !cleared_space) {
806 xfs_iunlock(ip, iolock);
807 xfs_blockgc_free_quota(ip, XFS_ICWALK_FLAG_SYNC);
808 cleared_space = true;
809 goto write_retry;
810 } else if (ret == -ENOSPC && !cleared_space) {
811 struct xfs_icwalk icw = {0};
812
813 cleared_space = true;
814 xfs_flush_inodes(ip->i_mount);
815
816 xfs_iunlock(ip, iolock);
817 icw.icw_flags = XFS_ICWALK_FLAG_SYNC;
818 xfs_blockgc_free_space(ip->i_mount, &icw);
819 goto write_retry;
820 }
821
822out:
823 if (iolock)
824 xfs_iunlock(ip, iolock);
825
826 if (ret > 0) {
827 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
828 /* Handle various SYNC-type writes */
829 ret = generic_write_sync(iocb, ret);
830 }
831 return ret;
832}
833
834STATIC ssize_t
835xfs_file_write_iter(
836 struct kiocb *iocb,
837 struct iov_iter *from)
838{
839 struct inode *inode = iocb->ki_filp->f_mapping->host;
840 struct xfs_inode *ip = XFS_I(inode);
841 ssize_t ret;
842 size_t ocount = iov_iter_count(from);
843
844 XFS_STATS_INC(ip->i_mount, xs_write_calls);
845
846 if (ocount == 0)
847 return 0;
848
849 if (xfs_is_shutdown(ip->i_mount))
850 return -EIO;
851
852 if (IS_DAX(inode))
853 return xfs_file_dax_write(iocb, from);
854
855 if (iocb->ki_flags & IOCB_ATOMIC) {
856 /*
857 * Currently only atomic writing of a single FS block is
858 * supported. It would be possible to atomic write smaller than
859 * a FS block, but there is no requirement to support this.
860 * Note that iomap also does not support this yet.
861 */
862 if (ocount != ip->i_mount->m_sb.sb_blocksize)
863 return -EINVAL;
864 ret = generic_atomic_write_valid(iocb, from);
865 if (ret)
866 return ret;
867 }
868
869 if (iocb->ki_flags & IOCB_DIRECT) {
870 /*
871 * Allow a directio write to fall back to a buffered
872 * write *only* in the case that we're doing a reflink
873 * CoW. In all other directio scenarios we do not
874 * allow an operation to fall back to buffered mode.
875 */
876 ret = xfs_file_dio_write(iocb, from);
877 if (ret != -ENOTBLK)
878 return ret;
879 }
880
881 return xfs_file_buffered_write(iocb, from);
882}
883
884/* Does this file, inode, or mount want synchronous writes? */
885static inline bool xfs_file_sync_writes(struct file *filp)
886{
887 struct xfs_inode *ip = XFS_I(file_inode(filp));
888
889 if (xfs_has_wsync(ip->i_mount))
890 return true;
891 if (filp->f_flags & (__O_SYNC | O_DSYNC))
892 return true;
893 if (IS_SYNC(file_inode(filp)))
894 return true;
895
896 return false;
897}
898
899static int
900xfs_falloc_newsize(
901 struct file *file,
902 int mode,
903 loff_t offset,
904 loff_t len,
905 loff_t *new_size)
906{
907 struct inode *inode = file_inode(file);
908
909 if ((mode & FALLOC_FL_KEEP_SIZE) || offset + len <= i_size_read(inode))
910 return 0;
911 *new_size = offset + len;
912 return inode_newsize_ok(inode, *new_size);
913}
914
915static int
916xfs_falloc_setsize(
917 struct file *file,
918 loff_t new_size)
919{
920 struct iattr iattr = {
921 .ia_valid = ATTR_SIZE,
922 .ia_size = new_size,
923 };
924
925 if (!new_size)
926 return 0;
927 return xfs_vn_setattr_size(file_mnt_idmap(file), file_dentry(file),
928 &iattr);
929}
930
931static int
932xfs_falloc_collapse_range(
933 struct file *file,
934 loff_t offset,
935 loff_t len)
936{
937 struct inode *inode = file_inode(file);
938 loff_t new_size = i_size_read(inode) - len;
939 int error;
940
941 if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
942 return -EINVAL;
943
944 /*
945 * There is no need to overlap collapse range with EOF, in which case it
946 * is effectively a truncate operation
947 */
948 if (offset + len >= i_size_read(inode))
949 return -EINVAL;
950
951 error = xfs_collapse_file_space(XFS_I(inode), offset, len);
952 if (error)
953 return error;
954 return xfs_falloc_setsize(file, new_size);
955}
956
957static int
958xfs_falloc_insert_range(
959 struct file *file,
960 loff_t offset,
961 loff_t len)
962{
963 struct inode *inode = file_inode(file);
964 loff_t isize = i_size_read(inode);
965 int error;
966
967 if (!xfs_is_falloc_aligned(XFS_I(inode), offset, len))
968 return -EINVAL;
969
970 /*
971 * New inode size must not exceed ->s_maxbytes, accounting for
972 * possible signed overflow.
973 */
974 if (inode->i_sb->s_maxbytes - isize < len)
975 return -EFBIG;
976
977 /* Offset should be less than i_size */
978 if (offset >= isize)
979 return -EINVAL;
980
981 error = xfs_falloc_setsize(file, isize + len);
982 if (error)
983 return error;
984
985 /*
986 * Perform hole insertion now that the file size has been updated so
987 * that if we crash during the operation we don't leave shifted extents
988 * past EOF and hence losing access to the data that is contained within
989 * them.
990 */
991 return xfs_insert_file_space(XFS_I(inode), offset, len);
992}
993
994/*
995 * Punch a hole and prealloc the range. We use a hole punch rather than
996 * unwritten extent conversion for two reasons:
997 *
998 * 1.) Hole punch handles partial block zeroing for us.
999 * 2.) If prealloc returns ENOSPC, the file range is still zero-valued by
1000 * virtue of the hole punch.
1001 */
1002static int
1003xfs_falloc_zero_range(
1004 struct file *file,
1005 int mode,
1006 loff_t offset,
1007 loff_t len)
1008{
1009 struct inode *inode = file_inode(file);
1010 unsigned int blksize = i_blocksize(inode);
1011 loff_t new_size = 0;
1012 int error;
1013
1014 trace_xfs_zero_file_space(XFS_I(inode));
1015
1016 error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
1017 if (error)
1018 return error;
1019
1020 error = xfs_free_file_space(XFS_I(inode), offset, len);
1021 if (error)
1022 return error;
1023
1024 len = round_up(offset + len, blksize) - round_down(offset, blksize);
1025 offset = round_down(offset, blksize);
1026 error = xfs_alloc_file_space(XFS_I(inode), offset, len);
1027 if (error)
1028 return error;
1029 return xfs_falloc_setsize(file, new_size);
1030}
1031
1032static int
1033xfs_falloc_unshare_range(
1034 struct file *file,
1035 int mode,
1036 loff_t offset,
1037 loff_t len)
1038{
1039 struct inode *inode = file_inode(file);
1040 loff_t new_size = 0;
1041 int error;
1042
1043 error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
1044 if (error)
1045 return error;
1046
1047 error = xfs_reflink_unshare(XFS_I(inode), offset, len);
1048 if (error)
1049 return error;
1050
1051 error = xfs_alloc_file_space(XFS_I(inode), offset, len);
1052 if (error)
1053 return error;
1054 return xfs_falloc_setsize(file, new_size);
1055}
1056
1057static int
1058xfs_falloc_allocate_range(
1059 struct file *file,
1060 int mode,
1061 loff_t offset,
1062 loff_t len)
1063{
1064 struct inode *inode = file_inode(file);
1065 loff_t new_size = 0;
1066 int error;
1067
1068 /*
1069 * If always_cow mode we can't use preallocations and thus should not
1070 * create them.
1071 */
1072 if (xfs_is_always_cow_inode(XFS_I(inode)))
1073 return -EOPNOTSUPP;
1074
1075 error = xfs_falloc_newsize(file, mode, offset, len, &new_size);
1076 if (error)
1077 return error;
1078
1079 error = xfs_alloc_file_space(XFS_I(inode), offset, len);
1080 if (error)
1081 return error;
1082 return xfs_falloc_setsize(file, new_size);
1083}
1084
1085#define XFS_FALLOC_FL_SUPPORTED \
1086 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
1087 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
1088 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
1089
1090STATIC long
1091xfs_file_fallocate(
1092 struct file *file,
1093 int mode,
1094 loff_t offset,
1095 loff_t len)
1096{
1097 struct inode *inode = file_inode(file);
1098 struct xfs_inode *ip = XFS_I(inode);
1099 long error;
1100 uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
1101
1102 if (!S_ISREG(inode->i_mode))
1103 return -EINVAL;
1104 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
1105 return -EOPNOTSUPP;
1106
1107 xfs_ilock(ip, iolock);
1108 error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
1109 if (error)
1110 goto out_unlock;
1111
1112 /*
1113 * Must wait for all AIO to complete before we continue as AIO can
1114 * change the file size on completion without holding any locks we
1115 * currently hold. We must do this first because AIO can update both
1116 * the on disk and in memory inode sizes, and the operations that follow
1117 * require the in-memory size to be fully up-to-date.
1118 */
1119 inode_dio_wait(inode);
1120
1121 error = file_modified(file);
1122 if (error)
1123 goto out_unlock;
1124
1125 switch (mode & FALLOC_FL_MODE_MASK) {
1126 case FALLOC_FL_PUNCH_HOLE:
1127 error = xfs_free_file_space(ip, offset, len);
1128 break;
1129 case FALLOC_FL_COLLAPSE_RANGE:
1130 error = xfs_falloc_collapse_range(file, offset, len);
1131 break;
1132 case FALLOC_FL_INSERT_RANGE:
1133 error = xfs_falloc_insert_range(file, offset, len);
1134 break;
1135 case FALLOC_FL_ZERO_RANGE:
1136 error = xfs_falloc_zero_range(file, mode, offset, len);
1137 break;
1138 case FALLOC_FL_UNSHARE_RANGE:
1139 error = xfs_falloc_unshare_range(file, mode, offset, len);
1140 break;
1141 case FALLOC_FL_ALLOCATE_RANGE:
1142 error = xfs_falloc_allocate_range(file, mode, offset, len);
1143 break;
1144 default:
1145 error = -EOPNOTSUPP;
1146 break;
1147 }
1148
1149 if (!error && xfs_file_sync_writes(file))
1150 error = xfs_log_force_inode(ip);
1151
1152out_unlock:
1153 xfs_iunlock(ip, iolock);
1154 return error;
1155}
1156
1157STATIC int
1158xfs_file_fadvise(
1159 struct file *file,
1160 loff_t start,
1161 loff_t end,
1162 int advice)
1163{
1164 struct xfs_inode *ip = XFS_I(file_inode(file));
1165 int ret;
1166 int lockflags = 0;
1167
1168 /*
1169 * Operations creating pages in page cache need protection from hole
1170 * punching and similar ops
1171 */
1172 if (advice == POSIX_FADV_WILLNEED) {
1173 lockflags = XFS_IOLOCK_SHARED;
1174 xfs_ilock(ip, lockflags);
1175 }
1176 ret = generic_fadvise(file, start, end, advice);
1177 if (lockflags)
1178 xfs_iunlock(ip, lockflags);
1179 return ret;
1180}
1181
1182STATIC loff_t
1183xfs_file_remap_range(
1184 struct file *file_in,
1185 loff_t pos_in,
1186 struct file *file_out,
1187 loff_t pos_out,
1188 loff_t len,
1189 unsigned int remap_flags)
1190{
1191 struct inode *inode_in = file_inode(file_in);
1192 struct xfs_inode *src = XFS_I(inode_in);
1193 struct inode *inode_out = file_inode(file_out);
1194 struct xfs_inode *dest = XFS_I(inode_out);
1195 struct xfs_mount *mp = src->i_mount;
1196 loff_t remapped = 0;
1197 xfs_extlen_t cowextsize;
1198 int ret;
1199
1200 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
1201 return -EINVAL;
1202
1203 if (!xfs_has_reflink(mp))
1204 return -EOPNOTSUPP;
1205
1206 if (xfs_is_shutdown(mp))
1207 return -EIO;
1208
1209 /* Prepare and then clone file data. */
1210 ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
1211 &len, remap_flags);
1212 if (ret || len == 0)
1213 return ret;
1214
1215 trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
1216
1217 ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
1218 &remapped);
1219 if (ret)
1220 goto out_unlock;
1221
1222 /*
1223 * Carry the cowextsize hint from src to dest if we're sharing the
1224 * entire source file to the entire destination file, the source file
1225 * has a cowextsize hint, and the destination file does not.
1226 */
1227 cowextsize = 0;
1228 if (pos_in == 0 && len == i_size_read(inode_in) &&
1229 (src->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE) &&
1230 pos_out == 0 && len >= i_size_read(inode_out) &&
1231 !(dest->i_diflags2 & XFS_DIFLAG2_COWEXTSIZE))
1232 cowextsize = src->i_cowextsize;
1233
1234 ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
1235 remap_flags);
1236 if (ret)
1237 goto out_unlock;
1238
1239 if (xfs_file_sync_writes(file_in) || xfs_file_sync_writes(file_out))
1240 xfs_log_force_inode(dest);
1241out_unlock:
1242 xfs_iunlock2_remapping(src, dest);
1243 if (ret)
1244 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
1245 /*
1246 * If the caller did not set CAN_SHORTEN, then it is not prepared to
1247 * handle partial results -- either the whole remap succeeds, or we
1248 * must say why it did not. In this case, any error should be returned
1249 * to the caller.
1250 */
1251 if (ret && remapped < len && !(remap_flags & REMAP_FILE_CAN_SHORTEN))
1252 return ret;
1253 return remapped > 0 ? remapped : ret;
1254}
1255
1256STATIC int
1257xfs_file_open(
1258 struct inode *inode,
1259 struct file *file)
1260{
1261 if (xfs_is_shutdown(XFS_M(inode->i_sb)))
1262 return -EIO;
1263 file->f_mode |= FMODE_NOWAIT | FMODE_CAN_ODIRECT;
1264 if (xfs_inode_can_atomicwrite(XFS_I(inode)))
1265 file->f_mode |= FMODE_CAN_ATOMIC_WRITE;
1266 return generic_file_open(inode, file);
1267}
1268
1269STATIC int
1270xfs_dir_open(
1271 struct inode *inode,
1272 struct file *file)
1273{
1274 struct xfs_inode *ip = XFS_I(inode);
1275 unsigned int mode;
1276 int error;
1277
1278 if (xfs_is_shutdown(ip->i_mount))
1279 return -EIO;
1280 error = generic_file_open(inode, file);
1281 if (error)
1282 return error;
1283
1284 /*
1285 * If there are any blocks, read-ahead block 0 as we're almost
1286 * certain to have the next operation be a read there.
1287 */
1288 mode = xfs_ilock_data_map_shared(ip);
1289 if (ip->i_df.if_nextents > 0)
1290 error = xfs_dir3_data_readahead(ip, 0, 0);
1291 xfs_iunlock(ip, mode);
1292 return error;
1293}
1294
1295/*
1296 * Don't bother propagating errors. We're just doing cleanup, and the caller
1297 * ignores the return value anyway.
1298 */
1299STATIC int
1300xfs_file_release(
1301 struct inode *inode,
1302 struct file *file)
1303{
1304 struct xfs_inode *ip = XFS_I(inode);
1305 struct xfs_mount *mp = ip->i_mount;
1306
1307 /*
1308 * If this is a read-only mount or the file system has been shut down,
1309 * don't generate I/O.
1310 */
1311 if (xfs_is_readonly(mp) || xfs_is_shutdown(mp))
1312 return 0;
1313
1314 /*
1315 * If we previously truncated this file and removed old data in the
1316 * process, we want to initiate "early" writeout on the last close.
1317 * This is an attempt to combat the notorious NULL files problem which
1318 * is particularly noticeable from a truncate down, buffered (re-)write
1319 * (delalloc), followed by a crash. What we are effectively doing here
1320 * is significantly reducing the time window where we'd otherwise be
1321 * exposed to that problem.
1322 */
1323 if (xfs_iflags_test_and_clear(ip, XFS_ITRUNCATED)) {
1324 xfs_iflags_clear(ip, XFS_EOFBLOCKS_RELEASED);
1325 if (ip->i_delayed_blks > 0)
1326 filemap_flush(inode->i_mapping);
1327 }
1328
1329 /*
1330 * XFS aggressively preallocates post-EOF space to generate contiguous
1331 * allocations for writers that append to the end of the file.
1332 *
1333 * To support workloads that close and reopen the file frequently, these
1334 * preallocations usually persist after a close unless it is the first
1335 * close for the inode. This is a tradeoff to generate tightly packed
1336 * data layouts for unpacking tarballs or similar archives that write
1337 * one file after another without going back to it while keeping the
1338 * preallocation for files that have recurring open/write/close cycles.
1339 *
1340 * This heuristic is skipped for inodes with the append-only flag as
1341 * that flag is rather pointless for inodes written only once.
1342 *
1343 * There is no point in freeing blocks here for open but unlinked files
1344 * as they will be taken care of by the inactivation path soon.
1345 *
1346 * When releasing a read-only context, don't flush data or trim post-EOF
1347 * blocks. This avoids open/read/close workloads from removing EOF
1348 * blocks that other writers depend upon to reduce fragmentation.
1349 *
1350 * If we can't get the iolock just skip truncating the blocks past EOF
1351 * because we could deadlock with the mmap_lock otherwise. We'll get
1352 * another chance to drop them once the last reference to the inode is
1353 * dropped, so we'll never leak blocks permanently.
1354 */
1355 if (inode->i_nlink &&
1356 (file->f_mode & FMODE_WRITE) &&
1357 !(ip->i_diflags & XFS_DIFLAG_APPEND) &&
1358 !xfs_iflags_test(ip, XFS_EOFBLOCKS_RELEASED) &&
1359 xfs_ilock_nowait(ip, XFS_IOLOCK_EXCL)) {
1360 if (xfs_can_free_eofblocks(ip) &&
1361 !xfs_iflags_test_and_set(ip, XFS_EOFBLOCKS_RELEASED))
1362 xfs_free_eofblocks(ip);
1363 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
1364 }
1365
1366 return 0;
1367}
1368
1369STATIC int
1370xfs_file_readdir(
1371 struct file *file,
1372 struct dir_context *ctx)
1373{
1374 struct inode *inode = file_inode(file);
1375 xfs_inode_t *ip = XFS_I(inode);
1376 size_t bufsize;
1377
1378 /*
1379 * The Linux API doesn't pass down the total size of the buffer
1380 * we read into down to the filesystem. With the filldir concept
1381 * it's not needed for correct information, but the XFS dir2 leaf
1382 * code wants an estimate of the buffer size to calculate it's
1383 * readahead window and size the buffers used for mapping to
1384 * physical blocks.
1385 *
1386 * Try to give it an estimate that's good enough, maybe at some
1387 * point we can change the ->readdir prototype to include the
1388 * buffer size. For now we use the current glibc buffer size.
1389 */
1390 bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_disk_size);
1391
1392 return xfs_readdir(NULL, ip, ctx, bufsize);
1393}
1394
1395STATIC loff_t
1396xfs_file_llseek(
1397 struct file *file,
1398 loff_t offset,
1399 int whence)
1400{
1401 struct inode *inode = file->f_mapping->host;
1402
1403 if (xfs_is_shutdown(XFS_I(inode)->i_mount))
1404 return -EIO;
1405
1406 switch (whence) {
1407 default:
1408 return generic_file_llseek(file, offset, whence);
1409 case SEEK_HOLE:
1410 offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
1411 break;
1412 case SEEK_DATA:
1413 offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
1414 break;
1415 }
1416
1417 if (offset < 0)
1418 return offset;
1419 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1420}
1421
1422static inline vm_fault_t
1423xfs_dax_fault_locked(
1424 struct vm_fault *vmf,
1425 unsigned int order,
1426 bool write_fault)
1427{
1428 vm_fault_t ret;
1429 pfn_t pfn;
1430
1431 if (!IS_ENABLED(CONFIG_FS_DAX)) {
1432 ASSERT(0);
1433 return VM_FAULT_SIGBUS;
1434 }
1435 ret = dax_iomap_fault(vmf, order, &pfn, NULL,
1436 (write_fault && !vmf->cow_page) ?
1437 &xfs_dax_write_iomap_ops :
1438 &xfs_read_iomap_ops);
1439 if (ret & VM_FAULT_NEEDDSYNC)
1440 ret = dax_finish_sync_fault(vmf, order, pfn);
1441 return ret;
1442}
1443
1444static vm_fault_t
1445xfs_dax_read_fault(
1446 struct vm_fault *vmf,
1447 unsigned int order)
1448{
1449 struct xfs_inode *ip = XFS_I(file_inode(vmf->vma->vm_file));
1450 vm_fault_t ret;
1451
1452 trace_xfs_read_fault(ip, order);
1453
1454 xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
1455 ret = xfs_dax_fault_locked(vmf, order, false);
1456 xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
1457
1458 return ret;
1459}
1460
1461/*
1462 * Locking for serialisation of IO during page faults. This results in a lock
1463 * ordering of:
1464 *
1465 * mmap_lock (MM)
1466 * sb_start_pagefault(vfs, freeze)
1467 * invalidate_lock (vfs/XFS_MMAPLOCK - truncate serialisation)
1468 * page_lock (MM)
1469 * i_lock (XFS - extent map serialisation)
1470 */
1471static vm_fault_t
1472xfs_write_fault(
1473 struct vm_fault *vmf,
1474 unsigned int order)
1475{
1476 struct inode *inode = file_inode(vmf->vma->vm_file);
1477 struct xfs_inode *ip = XFS_I(inode);
1478 unsigned int lock_mode = XFS_MMAPLOCK_SHARED;
1479 vm_fault_t ret;
1480
1481 trace_xfs_write_fault(ip, order);
1482
1483 sb_start_pagefault(inode->i_sb);
1484 file_update_time(vmf->vma->vm_file);
1485
1486 /*
1487 * Normally we only need the shared mmaplock, but if a reflink remap is
1488 * in progress we take the exclusive lock to wait for the remap to
1489 * finish before taking a write fault.
1490 */
1491 xfs_ilock(ip, XFS_MMAPLOCK_SHARED);
1492 if (xfs_iflags_test(ip, XFS_IREMAPPING)) {
1493 xfs_iunlock(ip, XFS_MMAPLOCK_SHARED);
1494 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
1495 lock_mode = XFS_MMAPLOCK_EXCL;
1496 }
1497
1498 if (IS_DAX(inode))
1499 ret = xfs_dax_fault_locked(vmf, order, true);
1500 else
1501 ret = iomap_page_mkwrite(vmf, &xfs_buffered_write_iomap_ops);
1502 xfs_iunlock(ip, lock_mode);
1503
1504 sb_end_pagefault(inode->i_sb);
1505 return ret;
1506}
1507
1508static inline bool
1509xfs_is_write_fault(
1510 struct vm_fault *vmf)
1511{
1512 return (vmf->flags & FAULT_FLAG_WRITE) &&
1513 (vmf->vma->vm_flags & VM_SHARED);
1514}
1515
1516static vm_fault_t
1517xfs_filemap_fault(
1518 struct vm_fault *vmf)
1519{
1520 struct inode *inode = file_inode(vmf->vma->vm_file);
1521
1522 /* DAX can shortcut the normal fault path on write faults! */
1523 if (IS_DAX(inode)) {
1524 if (xfs_is_write_fault(vmf))
1525 return xfs_write_fault(vmf, 0);
1526 return xfs_dax_read_fault(vmf, 0);
1527 }
1528
1529 trace_xfs_read_fault(XFS_I(inode), 0);
1530 return filemap_fault(vmf);
1531}
1532
1533static vm_fault_t
1534xfs_filemap_huge_fault(
1535 struct vm_fault *vmf,
1536 unsigned int order)
1537{
1538 if (!IS_DAX(file_inode(vmf->vma->vm_file)))
1539 return VM_FAULT_FALLBACK;
1540
1541 /* DAX can shortcut the normal fault path on write faults! */
1542 if (xfs_is_write_fault(vmf))
1543 return xfs_write_fault(vmf, order);
1544 return xfs_dax_read_fault(vmf, order);
1545}
1546
1547static vm_fault_t
1548xfs_filemap_page_mkwrite(
1549 struct vm_fault *vmf)
1550{
1551 return xfs_write_fault(vmf, 0);
1552}
1553
1554/*
1555 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
1556 * on write faults. In reality, it needs to serialise against truncate and
1557 * prepare memory for writing so handle is as standard write fault.
1558 */
1559static vm_fault_t
1560xfs_filemap_pfn_mkwrite(
1561 struct vm_fault *vmf)
1562{
1563 return xfs_write_fault(vmf, 0);
1564}
1565
1566static const struct vm_operations_struct xfs_file_vm_ops = {
1567 .fault = xfs_filemap_fault,
1568 .huge_fault = xfs_filemap_huge_fault,
1569 .map_pages = filemap_map_pages,
1570 .page_mkwrite = xfs_filemap_page_mkwrite,
1571 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1572};
1573
1574STATIC int
1575xfs_file_mmap(
1576 struct file *file,
1577 struct vm_area_struct *vma)
1578{
1579 struct inode *inode = file_inode(file);
1580 struct xfs_buftarg *target = xfs_inode_buftarg(XFS_I(inode));
1581
1582 /*
1583 * We don't support synchronous mappings for non-DAX files and
1584 * for DAX files if underneath dax_device is not synchronous.
1585 */
1586 if (!daxdev_mapping_supported(vma, target->bt_daxdev))
1587 return -EOPNOTSUPP;
1588
1589 file_accessed(file);
1590 vma->vm_ops = &xfs_file_vm_ops;
1591 if (IS_DAX(inode))
1592 vm_flags_set(vma, VM_HUGEPAGE);
1593 return 0;
1594}
1595
1596const struct file_operations xfs_file_operations = {
1597 .llseek = xfs_file_llseek,
1598 .read_iter = xfs_file_read_iter,
1599 .write_iter = xfs_file_write_iter,
1600 .splice_read = xfs_file_splice_read,
1601 .splice_write = iter_file_splice_write,
1602 .iopoll = iocb_bio_iopoll,
1603 .unlocked_ioctl = xfs_file_ioctl,
1604#ifdef CONFIG_COMPAT
1605 .compat_ioctl = xfs_file_compat_ioctl,
1606#endif
1607 .mmap = xfs_file_mmap,
1608 .open = xfs_file_open,
1609 .release = xfs_file_release,
1610 .fsync = xfs_file_fsync,
1611 .get_unmapped_area = thp_get_unmapped_area,
1612 .fallocate = xfs_file_fallocate,
1613 .fadvise = xfs_file_fadvise,
1614 .remap_file_range = xfs_file_remap_range,
1615 .fop_flags = FOP_MMAP_SYNC | FOP_BUFFER_RASYNC |
1616 FOP_BUFFER_WASYNC | FOP_DIO_PARALLEL_WRITE,
1617};
1618
1619const struct file_operations xfs_dir_file_operations = {
1620 .open = xfs_dir_open,
1621 .read = generic_read_dir,
1622 .iterate_shared = xfs_file_readdir,
1623 .llseek = generic_file_llseek,
1624 .unlocked_ioctl = xfs_file_ioctl,
1625#ifdef CONFIG_COMPAT
1626 .compat_ioctl = xfs_file_compat_ioctl,
1627#endif
1628 .fsync = xfs_dir_fsync,
1629};