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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_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};
1// SPDX-License-Identifier: GPL-2.0
2/*
3 * Copyright (c) 2000-2005 Silicon Graphics, Inc.
4 * All Rights Reserved.
5 */
6#include "xfs.h"
7#include "xfs_fs.h"
8#include "xfs_shared.h"
9#include "xfs_format.h"
10#include "xfs_log_format.h"
11#include "xfs_trans_resv.h"
12#include "xfs_mount.h"
13#include "xfs_inode.h"
14#include "xfs_trans.h"
15#include "xfs_inode_item.h"
16#include "xfs_bmap.h"
17#include "xfs_bmap_util.h"
18#include "xfs_dir2.h"
19#include "xfs_dir2_priv.h"
20#include "xfs_ioctl.h"
21#include "xfs_trace.h"
22#include "xfs_log.h"
23#include "xfs_icache.h"
24#include "xfs_pnfs.h"
25#include "xfs_iomap.h"
26#include "xfs_reflink.h"
27
28#include <linux/falloc.h>
29#include <linux/backing-dev.h>
30#include <linux/mman.h>
31#include <linux/fadvise.h>
32
33static const struct vm_operations_struct xfs_file_vm_ops;
34
35int
36xfs_update_prealloc_flags(
37 struct xfs_inode *ip,
38 enum xfs_prealloc_flags flags)
39{
40 struct xfs_trans *tp;
41 int error;
42
43 error = xfs_trans_alloc(ip->i_mount, &M_RES(ip->i_mount)->tr_writeid,
44 0, 0, 0, &tp);
45 if (error)
46 return error;
47
48 xfs_ilock(ip, XFS_ILOCK_EXCL);
49 xfs_trans_ijoin(tp, ip, XFS_ILOCK_EXCL);
50
51 if (!(flags & XFS_PREALLOC_INVISIBLE)) {
52 VFS_I(ip)->i_mode &= ~S_ISUID;
53 if (VFS_I(ip)->i_mode & S_IXGRP)
54 VFS_I(ip)->i_mode &= ~S_ISGID;
55 xfs_trans_ichgtime(tp, ip, XFS_ICHGTIME_MOD | XFS_ICHGTIME_CHG);
56 }
57
58 if (flags & XFS_PREALLOC_SET)
59 ip->i_d.di_flags |= XFS_DIFLAG_PREALLOC;
60 if (flags & XFS_PREALLOC_CLEAR)
61 ip->i_d.di_flags &= ~XFS_DIFLAG_PREALLOC;
62
63 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
64 if (flags & XFS_PREALLOC_SYNC)
65 xfs_trans_set_sync(tp);
66 return xfs_trans_commit(tp);
67}
68
69/*
70 * Fsync operations on directories are much simpler than on regular files,
71 * as there is no file data to flush, and thus also no need for explicit
72 * cache flush operations, and there are no non-transaction metadata updates
73 * on directories either.
74 */
75STATIC int
76xfs_dir_fsync(
77 struct file *file,
78 loff_t start,
79 loff_t end,
80 int datasync)
81{
82 struct xfs_inode *ip = XFS_I(file->f_mapping->host);
83 struct xfs_mount *mp = ip->i_mount;
84 xfs_lsn_t lsn = 0;
85
86 trace_xfs_dir_fsync(ip);
87
88 xfs_ilock(ip, XFS_ILOCK_SHARED);
89 if (xfs_ipincount(ip))
90 lsn = ip->i_itemp->ili_last_lsn;
91 xfs_iunlock(ip, XFS_ILOCK_SHARED);
92
93 if (!lsn)
94 return 0;
95 return xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, NULL);
96}
97
98STATIC int
99xfs_file_fsync(
100 struct file *file,
101 loff_t start,
102 loff_t end,
103 int datasync)
104{
105 struct inode *inode = file->f_mapping->host;
106 struct xfs_inode *ip = XFS_I(inode);
107 struct xfs_mount *mp = ip->i_mount;
108 int error = 0;
109 int log_flushed = 0;
110 xfs_lsn_t lsn = 0;
111
112 trace_xfs_file_fsync(ip);
113
114 error = file_write_and_wait_range(file, start, end);
115 if (error)
116 return error;
117
118 if (XFS_FORCED_SHUTDOWN(mp))
119 return -EIO;
120
121 xfs_iflags_clear(ip, XFS_ITRUNCATED);
122
123 /*
124 * If we have an RT and/or log subvolume we need to make sure to flush
125 * the write cache the device used for file data first. This is to
126 * ensure newly written file data make it to disk before logging the new
127 * inode size in case of an extending write.
128 */
129 if (XFS_IS_REALTIME_INODE(ip))
130 xfs_blkdev_issue_flush(mp->m_rtdev_targp);
131 else if (mp->m_logdev_targp != mp->m_ddev_targp)
132 xfs_blkdev_issue_flush(mp->m_ddev_targp);
133
134 /*
135 * All metadata updates are logged, which means that we just have to
136 * flush the log up to the latest LSN that touched the inode. If we have
137 * concurrent fsync/fdatasync() calls, we need them to all block on the
138 * log force before we clear the ili_fsync_fields field. This ensures
139 * that we don't get a racing sync operation that does not wait for the
140 * metadata to hit the journal before returning. If we race with
141 * clearing the ili_fsync_fields, then all that will happen is the log
142 * force will do nothing as the lsn will already be on disk. We can't
143 * race with setting ili_fsync_fields because that is done under
144 * XFS_ILOCK_EXCL, and that can't happen because we hold the lock shared
145 * until after the ili_fsync_fields is cleared.
146 */
147 xfs_ilock(ip, XFS_ILOCK_SHARED);
148 if (xfs_ipincount(ip)) {
149 if (!datasync ||
150 (ip->i_itemp->ili_fsync_fields & ~XFS_ILOG_TIMESTAMP))
151 lsn = ip->i_itemp->ili_last_lsn;
152 }
153
154 if (lsn) {
155 error = xfs_log_force_lsn(mp, lsn, XFS_LOG_SYNC, &log_flushed);
156 ip->i_itemp->ili_fsync_fields = 0;
157 }
158 xfs_iunlock(ip, XFS_ILOCK_SHARED);
159
160 /*
161 * If we only have a single device, and the log force about was
162 * a no-op we might have to flush the data device cache here.
163 * This can only happen for fdatasync/O_DSYNC if we were overwriting
164 * an already allocated file and thus do not have any metadata to
165 * commit.
166 */
167 if (!log_flushed && !XFS_IS_REALTIME_INODE(ip) &&
168 mp->m_logdev_targp == mp->m_ddev_targp)
169 xfs_blkdev_issue_flush(mp->m_ddev_targp);
170
171 return error;
172}
173
174STATIC ssize_t
175xfs_file_dio_aio_read(
176 struct kiocb *iocb,
177 struct iov_iter *to)
178{
179 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
180 size_t count = iov_iter_count(to);
181 ssize_t ret;
182
183 trace_xfs_file_direct_read(ip, count, iocb->ki_pos);
184
185 if (!count)
186 return 0; /* skip atime */
187
188 file_accessed(iocb->ki_filp);
189
190 xfs_ilock(ip, XFS_IOLOCK_SHARED);
191 ret = iomap_dio_rw(iocb, to, &xfs_iomap_ops, NULL);
192 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
193
194 return ret;
195}
196
197static noinline ssize_t
198xfs_file_dax_read(
199 struct kiocb *iocb,
200 struct iov_iter *to)
201{
202 struct xfs_inode *ip = XFS_I(iocb->ki_filp->f_mapping->host);
203 size_t count = iov_iter_count(to);
204 ssize_t ret = 0;
205
206 trace_xfs_file_dax_read(ip, count, iocb->ki_pos);
207
208 if (!count)
209 return 0; /* skip atime */
210
211 if (iocb->ki_flags & IOCB_NOWAIT) {
212 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
213 return -EAGAIN;
214 } else {
215 xfs_ilock(ip, XFS_IOLOCK_SHARED);
216 }
217
218 ret = dax_iomap_rw(iocb, to, &xfs_iomap_ops);
219 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
220
221 file_accessed(iocb->ki_filp);
222 return ret;
223}
224
225STATIC ssize_t
226xfs_file_buffered_aio_read(
227 struct kiocb *iocb,
228 struct iov_iter *to)
229{
230 struct xfs_inode *ip = XFS_I(file_inode(iocb->ki_filp));
231 ssize_t ret;
232
233 trace_xfs_file_buffered_read(ip, iov_iter_count(to), iocb->ki_pos);
234
235 if (iocb->ki_flags & IOCB_NOWAIT) {
236 if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
237 return -EAGAIN;
238 } else {
239 xfs_ilock(ip, XFS_IOLOCK_SHARED);
240 }
241 ret = generic_file_read_iter(iocb, to);
242 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
243
244 return ret;
245}
246
247STATIC ssize_t
248xfs_file_read_iter(
249 struct kiocb *iocb,
250 struct iov_iter *to)
251{
252 struct inode *inode = file_inode(iocb->ki_filp);
253 struct xfs_mount *mp = XFS_I(inode)->i_mount;
254 ssize_t ret = 0;
255
256 XFS_STATS_INC(mp, xs_read_calls);
257
258 if (XFS_FORCED_SHUTDOWN(mp))
259 return -EIO;
260
261 if (IS_DAX(inode))
262 ret = xfs_file_dax_read(iocb, to);
263 else if (iocb->ki_flags & IOCB_DIRECT)
264 ret = xfs_file_dio_aio_read(iocb, to);
265 else
266 ret = xfs_file_buffered_aio_read(iocb, to);
267
268 if (ret > 0)
269 XFS_STATS_ADD(mp, xs_read_bytes, ret);
270 return ret;
271}
272
273/*
274 * Common pre-write limit and setup checks.
275 *
276 * Called with the iolocked held either shared and exclusive according to
277 * @iolock, and returns with it held. Might upgrade the iolock to exclusive
278 * if called for a direct write beyond i_size.
279 */
280STATIC ssize_t
281xfs_file_aio_write_checks(
282 struct kiocb *iocb,
283 struct iov_iter *from,
284 int *iolock)
285{
286 struct file *file = iocb->ki_filp;
287 struct inode *inode = file->f_mapping->host;
288 struct xfs_inode *ip = XFS_I(inode);
289 ssize_t error = 0;
290 size_t count = iov_iter_count(from);
291 bool drained_dio = false;
292 loff_t isize;
293
294restart:
295 error = generic_write_checks(iocb, from);
296 if (error <= 0)
297 return error;
298
299 error = xfs_break_layouts(inode, iolock, BREAK_WRITE);
300 if (error)
301 return error;
302
303 /*
304 * For changing security info in file_remove_privs() we need i_rwsem
305 * exclusively.
306 */
307 if (*iolock == XFS_IOLOCK_SHARED && !IS_NOSEC(inode)) {
308 xfs_iunlock(ip, *iolock);
309 *iolock = XFS_IOLOCK_EXCL;
310 xfs_ilock(ip, *iolock);
311 goto restart;
312 }
313 /*
314 * If the offset is beyond the size of the file, we need to zero any
315 * blocks that fall between the existing EOF and the start of this
316 * write. If zeroing is needed and we are currently holding the
317 * iolock shared, we need to update it to exclusive which implies
318 * having to redo all checks before.
319 *
320 * We need to serialise against EOF updates that occur in IO
321 * completions here. We want to make sure that nobody is changing the
322 * size while we do this check until we have placed an IO barrier (i.e.
323 * hold the XFS_IOLOCK_EXCL) that prevents new IO from being dispatched.
324 * The spinlock effectively forms a memory barrier once we have the
325 * XFS_IOLOCK_EXCL so we are guaranteed to see the latest EOF value
326 * and hence be able to correctly determine if we need to run zeroing.
327 */
328 spin_lock(&ip->i_flags_lock);
329 isize = i_size_read(inode);
330 if (iocb->ki_pos > isize) {
331 spin_unlock(&ip->i_flags_lock);
332 if (!drained_dio) {
333 if (*iolock == XFS_IOLOCK_SHARED) {
334 xfs_iunlock(ip, *iolock);
335 *iolock = XFS_IOLOCK_EXCL;
336 xfs_ilock(ip, *iolock);
337 iov_iter_reexpand(from, count);
338 }
339 /*
340 * We now have an IO submission barrier in place, but
341 * AIO can do EOF updates during IO completion and hence
342 * we now need to wait for all of them to drain. Non-AIO
343 * DIO will have drained before we are given the
344 * XFS_IOLOCK_EXCL, and so for most cases this wait is a
345 * no-op.
346 */
347 inode_dio_wait(inode);
348 drained_dio = true;
349 goto restart;
350 }
351
352 trace_xfs_zero_eof(ip, isize, iocb->ki_pos - isize);
353 error = iomap_zero_range(inode, isize, iocb->ki_pos - isize,
354 NULL, &xfs_iomap_ops);
355 if (error)
356 return error;
357 } else
358 spin_unlock(&ip->i_flags_lock);
359
360 /*
361 * Updating the timestamps will grab the ilock again from
362 * xfs_fs_dirty_inode, so we have to call it after dropping the
363 * lock above. Eventually we should look into a way to avoid
364 * the pointless lock roundtrip.
365 */
366 return file_modified(file);
367}
368
369static int
370xfs_dio_write_end_io(
371 struct kiocb *iocb,
372 ssize_t size,
373 int error,
374 unsigned flags)
375{
376 struct inode *inode = file_inode(iocb->ki_filp);
377 struct xfs_inode *ip = XFS_I(inode);
378 loff_t offset = iocb->ki_pos;
379 unsigned int nofs_flag;
380
381 trace_xfs_end_io_direct_write(ip, offset, size);
382
383 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
384 return -EIO;
385
386 if (error)
387 return error;
388 if (!size)
389 return 0;
390
391 /*
392 * Capture amount written on completion as we can't reliably account
393 * for it on submission.
394 */
395 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, size);
396
397 /*
398 * We can allocate memory here while doing writeback on behalf of
399 * memory reclaim. To avoid memory allocation deadlocks set the
400 * task-wide nofs context for the following operations.
401 */
402 nofs_flag = memalloc_nofs_save();
403
404 if (flags & IOMAP_DIO_COW) {
405 error = xfs_reflink_end_cow(ip, offset, size);
406 if (error)
407 goto out;
408 }
409
410 /*
411 * Unwritten conversion updates the in-core isize after extent
412 * conversion but before updating the on-disk size. Updating isize any
413 * earlier allows a racing dio read to find unwritten extents before
414 * they are converted.
415 */
416 if (flags & IOMAP_DIO_UNWRITTEN) {
417 error = xfs_iomap_write_unwritten(ip, offset, size, true);
418 goto out;
419 }
420
421 /*
422 * We need to update the in-core inode size here so that we don't end up
423 * with the on-disk inode size being outside the in-core inode size. We
424 * have no other method of updating EOF for AIO, so always do it here
425 * if necessary.
426 *
427 * We need to lock the test/set EOF update as we can be racing with
428 * other IO completions here to update the EOF. Failing to serialise
429 * here can result in EOF moving backwards and Bad Things Happen when
430 * that occurs.
431 */
432 spin_lock(&ip->i_flags_lock);
433 if (offset + size > i_size_read(inode)) {
434 i_size_write(inode, offset + size);
435 spin_unlock(&ip->i_flags_lock);
436 error = xfs_setfilesize(ip, offset, size);
437 } else {
438 spin_unlock(&ip->i_flags_lock);
439 }
440
441out:
442 memalloc_nofs_restore(nofs_flag);
443 return error;
444}
445
446static const struct iomap_dio_ops xfs_dio_write_ops = {
447 .end_io = xfs_dio_write_end_io,
448};
449
450/*
451 * xfs_file_dio_aio_write - handle direct IO writes
452 *
453 * Lock the inode appropriately to prepare for and issue a direct IO write.
454 * By separating it from the buffered write path we remove all the tricky to
455 * follow locking changes and looping.
456 *
457 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
458 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
459 * pages are flushed out.
460 *
461 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
462 * allowing them to be done in parallel with reads and other direct IO writes.
463 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
464 * needs to do sub-block zeroing and that requires serialisation against other
465 * direct IOs to the same block. In this case we need to serialise the
466 * submission of the unaligned IOs so that we don't get racing block zeroing in
467 * the dio layer. To avoid the problem with aio, we also need to wait for
468 * outstanding IOs to complete so that unwritten extent conversion is completed
469 * before we try to map the overlapping block. This is currently implemented by
470 * hitting it with a big hammer (i.e. inode_dio_wait()).
471 *
472 * Returns with locks held indicated by @iolock and errors indicated by
473 * negative return values.
474 */
475STATIC ssize_t
476xfs_file_dio_aio_write(
477 struct kiocb *iocb,
478 struct iov_iter *from)
479{
480 struct file *file = iocb->ki_filp;
481 struct address_space *mapping = file->f_mapping;
482 struct inode *inode = mapping->host;
483 struct xfs_inode *ip = XFS_I(inode);
484 struct xfs_mount *mp = ip->i_mount;
485 ssize_t ret = 0;
486 int unaligned_io = 0;
487 int iolock;
488 size_t count = iov_iter_count(from);
489 struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
490 mp->m_rtdev_targp : mp->m_ddev_targp;
491
492 /* DIO must be aligned to device logical sector size */
493 if ((iocb->ki_pos | count) & target->bt_logical_sectormask)
494 return -EINVAL;
495
496 /*
497 * Don't take the exclusive iolock here unless the I/O is unaligned to
498 * the file system block size. We don't need to consider the EOF
499 * extension case here because xfs_file_aio_write_checks() will relock
500 * the inode as necessary for EOF zeroing cases and fill out the new
501 * inode size as appropriate.
502 */
503 if ((iocb->ki_pos & mp->m_blockmask) ||
504 ((iocb->ki_pos + count) & mp->m_blockmask)) {
505 unaligned_io = 1;
506
507 /*
508 * We can't properly handle unaligned direct I/O to reflink
509 * files yet, as we can't unshare a partial block.
510 */
511 if (xfs_is_cow_inode(ip)) {
512 trace_xfs_reflink_bounce_dio_write(ip, iocb->ki_pos, count);
513 return -EREMCHG;
514 }
515 iolock = XFS_IOLOCK_EXCL;
516 } else {
517 iolock = XFS_IOLOCK_SHARED;
518 }
519
520 if (iocb->ki_flags & IOCB_NOWAIT) {
521 /* unaligned dio always waits, bail */
522 if (unaligned_io)
523 return -EAGAIN;
524 if (!xfs_ilock_nowait(ip, iolock))
525 return -EAGAIN;
526 } else {
527 xfs_ilock(ip, iolock);
528 }
529
530 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
531 if (ret)
532 goto out;
533 count = iov_iter_count(from);
534
535 /*
536 * If we are doing unaligned IO, we can't allow any other overlapping IO
537 * in-flight at the same time or we risk data corruption. Wait for all
538 * other IO to drain before we submit. If the IO is aligned, demote the
539 * iolock if we had to take the exclusive lock in
540 * xfs_file_aio_write_checks() for other reasons.
541 */
542 if (unaligned_io) {
543 inode_dio_wait(inode);
544 } else if (iolock == XFS_IOLOCK_EXCL) {
545 xfs_ilock_demote(ip, XFS_IOLOCK_EXCL);
546 iolock = XFS_IOLOCK_SHARED;
547 }
548
549 trace_xfs_file_direct_write(ip, count, iocb->ki_pos);
550 ret = iomap_dio_rw(iocb, from, &xfs_iomap_ops, &xfs_dio_write_ops);
551
552 /*
553 * If unaligned, this is the only IO in-flight. If it has not yet
554 * completed, wait on it before we release the iolock to prevent
555 * subsequent overlapping IO.
556 */
557 if (ret == -EIOCBQUEUED && unaligned_io)
558 inode_dio_wait(inode);
559out:
560 xfs_iunlock(ip, iolock);
561
562 /*
563 * No fallback to buffered IO on errors for XFS, direct IO will either
564 * complete fully or fail.
565 */
566 ASSERT(ret < 0 || ret == count);
567 return ret;
568}
569
570static noinline ssize_t
571xfs_file_dax_write(
572 struct kiocb *iocb,
573 struct iov_iter *from)
574{
575 struct inode *inode = iocb->ki_filp->f_mapping->host;
576 struct xfs_inode *ip = XFS_I(inode);
577 int iolock = XFS_IOLOCK_EXCL;
578 ssize_t ret, error = 0;
579 size_t count;
580 loff_t pos;
581
582 if (iocb->ki_flags & IOCB_NOWAIT) {
583 if (!xfs_ilock_nowait(ip, iolock))
584 return -EAGAIN;
585 } else {
586 xfs_ilock(ip, iolock);
587 }
588
589 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
590 if (ret)
591 goto out;
592
593 pos = iocb->ki_pos;
594 count = iov_iter_count(from);
595
596 trace_xfs_file_dax_write(ip, count, pos);
597 ret = dax_iomap_rw(iocb, from, &xfs_iomap_ops);
598 if (ret > 0 && iocb->ki_pos > i_size_read(inode)) {
599 i_size_write(inode, iocb->ki_pos);
600 error = xfs_setfilesize(ip, pos, ret);
601 }
602out:
603 xfs_iunlock(ip, iolock);
604 if (error)
605 return error;
606
607 if (ret > 0) {
608 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
609
610 /* Handle various SYNC-type writes */
611 ret = generic_write_sync(iocb, ret);
612 }
613 return ret;
614}
615
616STATIC ssize_t
617xfs_file_buffered_aio_write(
618 struct kiocb *iocb,
619 struct iov_iter *from)
620{
621 struct file *file = iocb->ki_filp;
622 struct address_space *mapping = file->f_mapping;
623 struct inode *inode = mapping->host;
624 struct xfs_inode *ip = XFS_I(inode);
625 ssize_t ret;
626 int enospc = 0;
627 int iolock;
628
629 if (iocb->ki_flags & IOCB_NOWAIT)
630 return -EOPNOTSUPP;
631
632write_retry:
633 iolock = XFS_IOLOCK_EXCL;
634 xfs_ilock(ip, iolock);
635
636 ret = xfs_file_aio_write_checks(iocb, from, &iolock);
637 if (ret)
638 goto out;
639
640 /* We can write back this queue in page reclaim */
641 current->backing_dev_info = inode_to_bdi(inode);
642
643 trace_xfs_file_buffered_write(ip, iov_iter_count(from), iocb->ki_pos);
644 ret = iomap_file_buffered_write(iocb, from, &xfs_iomap_ops);
645 if (likely(ret >= 0))
646 iocb->ki_pos += ret;
647
648 /*
649 * If we hit a space limit, try to free up some lingering preallocated
650 * space before returning an error. In the case of ENOSPC, first try to
651 * write back all dirty inodes to free up some of the excess reserved
652 * metadata space. This reduces the chances that the eofblocks scan
653 * waits on dirty mappings. Since xfs_flush_inodes() is serialized, this
654 * also behaves as a filter to prevent too many eofblocks scans from
655 * running at the same time.
656 */
657 if (ret == -EDQUOT && !enospc) {
658 xfs_iunlock(ip, iolock);
659 enospc = xfs_inode_free_quota_eofblocks(ip);
660 if (enospc)
661 goto write_retry;
662 enospc = xfs_inode_free_quota_cowblocks(ip);
663 if (enospc)
664 goto write_retry;
665 iolock = 0;
666 } else if (ret == -ENOSPC && !enospc) {
667 struct xfs_eofblocks eofb = {0};
668
669 enospc = 1;
670 xfs_flush_inodes(ip->i_mount);
671
672 xfs_iunlock(ip, iolock);
673 eofb.eof_flags = XFS_EOF_FLAGS_SYNC;
674 xfs_icache_free_eofblocks(ip->i_mount, &eofb);
675 xfs_icache_free_cowblocks(ip->i_mount, &eofb);
676 goto write_retry;
677 }
678
679 current->backing_dev_info = NULL;
680out:
681 if (iolock)
682 xfs_iunlock(ip, iolock);
683
684 if (ret > 0) {
685 XFS_STATS_ADD(ip->i_mount, xs_write_bytes, ret);
686 /* Handle various SYNC-type writes */
687 ret = generic_write_sync(iocb, ret);
688 }
689 return ret;
690}
691
692STATIC ssize_t
693xfs_file_write_iter(
694 struct kiocb *iocb,
695 struct iov_iter *from)
696{
697 struct file *file = iocb->ki_filp;
698 struct address_space *mapping = file->f_mapping;
699 struct inode *inode = mapping->host;
700 struct xfs_inode *ip = XFS_I(inode);
701 ssize_t ret;
702 size_t ocount = iov_iter_count(from);
703
704 XFS_STATS_INC(ip->i_mount, xs_write_calls);
705
706 if (ocount == 0)
707 return 0;
708
709 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
710 return -EIO;
711
712 if (IS_DAX(inode))
713 return xfs_file_dax_write(iocb, from);
714
715 if (iocb->ki_flags & IOCB_DIRECT) {
716 /*
717 * Allow a directio write to fall back to a buffered
718 * write *only* in the case that we're doing a reflink
719 * CoW. In all other directio scenarios we do not
720 * allow an operation to fall back to buffered mode.
721 */
722 ret = xfs_file_dio_aio_write(iocb, from);
723 if (ret != -EREMCHG)
724 return ret;
725 }
726
727 return xfs_file_buffered_aio_write(iocb, from);
728}
729
730static void
731xfs_wait_dax_page(
732 struct inode *inode)
733{
734 struct xfs_inode *ip = XFS_I(inode);
735
736 xfs_iunlock(ip, XFS_MMAPLOCK_EXCL);
737 schedule();
738 xfs_ilock(ip, XFS_MMAPLOCK_EXCL);
739}
740
741static int
742xfs_break_dax_layouts(
743 struct inode *inode,
744 bool *retry)
745{
746 struct page *page;
747
748 ASSERT(xfs_isilocked(XFS_I(inode), XFS_MMAPLOCK_EXCL));
749
750 page = dax_layout_busy_page(inode->i_mapping);
751 if (!page)
752 return 0;
753
754 *retry = true;
755 return ___wait_var_event(&page->_refcount,
756 atomic_read(&page->_refcount) == 1, TASK_INTERRUPTIBLE,
757 0, 0, xfs_wait_dax_page(inode));
758}
759
760int
761xfs_break_layouts(
762 struct inode *inode,
763 uint *iolock,
764 enum layout_break_reason reason)
765{
766 bool retry;
767 int error;
768
769 ASSERT(xfs_isilocked(XFS_I(inode), XFS_IOLOCK_SHARED|XFS_IOLOCK_EXCL));
770
771 do {
772 retry = false;
773 switch (reason) {
774 case BREAK_UNMAP:
775 error = xfs_break_dax_layouts(inode, &retry);
776 if (error || retry)
777 break;
778 /* fall through */
779 case BREAK_WRITE:
780 error = xfs_break_leased_layouts(inode, iolock, &retry);
781 break;
782 default:
783 WARN_ON_ONCE(1);
784 error = -EINVAL;
785 }
786 } while (error == 0 && retry);
787
788 return error;
789}
790
791#define XFS_FALLOC_FL_SUPPORTED \
792 (FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE | \
793 FALLOC_FL_COLLAPSE_RANGE | FALLOC_FL_ZERO_RANGE | \
794 FALLOC_FL_INSERT_RANGE | FALLOC_FL_UNSHARE_RANGE)
795
796STATIC long
797xfs_file_fallocate(
798 struct file *file,
799 int mode,
800 loff_t offset,
801 loff_t len)
802{
803 struct inode *inode = file_inode(file);
804 struct xfs_inode *ip = XFS_I(inode);
805 long error;
806 enum xfs_prealloc_flags flags = 0;
807 uint iolock = XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL;
808 loff_t new_size = 0;
809 bool do_file_insert = false;
810
811 if (!S_ISREG(inode->i_mode))
812 return -EINVAL;
813 if (mode & ~XFS_FALLOC_FL_SUPPORTED)
814 return -EOPNOTSUPP;
815
816 xfs_ilock(ip, iolock);
817 error = xfs_break_layouts(inode, &iolock, BREAK_UNMAP);
818 if (error)
819 goto out_unlock;
820
821 if (mode & FALLOC_FL_PUNCH_HOLE) {
822 error = xfs_free_file_space(ip, offset, len);
823 if (error)
824 goto out_unlock;
825 } else if (mode & FALLOC_FL_COLLAPSE_RANGE) {
826 unsigned int blksize_mask = i_blocksize(inode) - 1;
827
828 if (offset & blksize_mask || len & blksize_mask) {
829 error = -EINVAL;
830 goto out_unlock;
831 }
832
833 /*
834 * There is no need to overlap collapse range with EOF,
835 * in which case it is effectively a truncate operation
836 */
837 if (offset + len >= i_size_read(inode)) {
838 error = -EINVAL;
839 goto out_unlock;
840 }
841
842 new_size = i_size_read(inode) - len;
843
844 error = xfs_collapse_file_space(ip, offset, len);
845 if (error)
846 goto out_unlock;
847 } else if (mode & FALLOC_FL_INSERT_RANGE) {
848 unsigned int blksize_mask = i_blocksize(inode) - 1;
849 loff_t isize = i_size_read(inode);
850
851 if (offset & blksize_mask || len & blksize_mask) {
852 error = -EINVAL;
853 goto out_unlock;
854 }
855
856 /*
857 * New inode size must not exceed ->s_maxbytes, accounting for
858 * possible signed overflow.
859 */
860 if (inode->i_sb->s_maxbytes - isize < len) {
861 error = -EFBIG;
862 goto out_unlock;
863 }
864 new_size = isize + len;
865
866 /* Offset should be less than i_size */
867 if (offset >= isize) {
868 error = -EINVAL;
869 goto out_unlock;
870 }
871 do_file_insert = true;
872 } else {
873 flags |= XFS_PREALLOC_SET;
874
875 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
876 offset + len > i_size_read(inode)) {
877 new_size = offset + len;
878 error = inode_newsize_ok(inode, new_size);
879 if (error)
880 goto out_unlock;
881 }
882
883 if (mode & FALLOC_FL_ZERO_RANGE) {
884 error = xfs_zero_file_space(ip, offset, len);
885 } else if (mode & FALLOC_FL_UNSHARE_RANGE) {
886 error = xfs_reflink_unshare(ip, offset, len);
887 if (error)
888 goto out_unlock;
889
890 if (!xfs_is_always_cow_inode(ip)) {
891 error = xfs_alloc_file_space(ip, offset, len,
892 XFS_BMAPI_PREALLOC);
893 }
894 } else {
895 /*
896 * If always_cow mode we can't use preallocations and
897 * thus should not create them.
898 */
899 if (xfs_is_always_cow_inode(ip)) {
900 error = -EOPNOTSUPP;
901 goto out_unlock;
902 }
903
904 error = xfs_alloc_file_space(ip, offset, len,
905 XFS_BMAPI_PREALLOC);
906 }
907 if (error)
908 goto out_unlock;
909 }
910
911 if (file->f_flags & O_DSYNC)
912 flags |= XFS_PREALLOC_SYNC;
913
914 error = xfs_update_prealloc_flags(ip, flags);
915 if (error)
916 goto out_unlock;
917
918 /* Change file size if needed */
919 if (new_size) {
920 struct iattr iattr;
921
922 iattr.ia_valid = ATTR_SIZE;
923 iattr.ia_size = new_size;
924 error = xfs_vn_setattr_size(file_dentry(file), &iattr);
925 if (error)
926 goto out_unlock;
927 }
928
929 /*
930 * Perform hole insertion now that the file size has been
931 * updated so that if we crash during the operation we don't
932 * leave shifted extents past EOF and hence losing access to
933 * the data that is contained within them.
934 */
935 if (do_file_insert)
936 error = xfs_insert_file_space(ip, offset, len);
937
938out_unlock:
939 xfs_iunlock(ip, iolock);
940 return error;
941}
942
943STATIC int
944xfs_file_fadvise(
945 struct file *file,
946 loff_t start,
947 loff_t end,
948 int advice)
949{
950 struct xfs_inode *ip = XFS_I(file_inode(file));
951 int ret;
952 int lockflags = 0;
953
954 /*
955 * Operations creating pages in page cache need protection from hole
956 * punching and similar ops
957 */
958 if (advice == POSIX_FADV_WILLNEED) {
959 lockflags = XFS_IOLOCK_SHARED;
960 xfs_ilock(ip, lockflags);
961 }
962 ret = generic_fadvise(file, start, end, advice);
963 if (lockflags)
964 xfs_iunlock(ip, lockflags);
965 return ret;
966}
967
968STATIC loff_t
969xfs_file_remap_range(
970 struct file *file_in,
971 loff_t pos_in,
972 struct file *file_out,
973 loff_t pos_out,
974 loff_t len,
975 unsigned int remap_flags)
976{
977 struct inode *inode_in = file_inode(file_in);
978 struct xfs_inode *src = XFS_I(inode_in);
979 struct inode *inode_out = file_inode(file_out);
980 struct xfs_inode *dest = XFS_I(inode_out);
981 struct xfs_mount *mp = src->i_mount;
982 loff_t remapped = 0;
983 xfs_extlen_t cowextsize;
984 int ret;
985
986 if (remap_flags & ~(REMAP_FILE_DEDUP | REMAP_FILE_ADVISORY))
987 return -EINVAL;
988
989 if (!xfs_sb_version_hasreflink(&mp->m_sb))
990 return -EOPNOTSUPP;
991
992 if (XFS_FORCED_SHUTDOWN(mp))
993 return -EIO;
994
995 /* Prepare and then clone file data. */
996 ret = xfs_reflink_remap_prep(file_in, pos_in, file_out, pos_out,
997 &len, remap_flags);
998 if (ret < 0 || len == 0)
999 return ret;
1000
1001 trace_xfs_reflink_remap_range(src, pos_in, len, dest, pos_out);
1002
1003 ret = xfs_reflink_remap_blocks(src, pos_in, dest, pos_out, len,
1004 &remapped);
1005 if (ret)
1006 goto out_unlock;
1007
1008 /*
1009 * Carry the cowextsize hint from src to dest if we're sharing the
1010 * entire source file to the entire destination file, the source file
1011 * has a cowextsize hint, and the destination file does not.
1012 */
1013 cowextsize = 0;
1014 if (pos_in == 0 && len == i_size_read(inode_in) &&
1015 (src->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE) &&
1016 pos_out == 0 && len >= i_size_read(inode_out) &&
1017 !(dest->i_d.di_flags2 & XFS_DIFLAG2_COWEXTSIZE))
1018 cowextsize = src->i_d.di_cowextsize;
1019
1020 ret = xfs_reflink_update_dest(dest, pos_out + len, cowextsize,
1021 remap_flags);
1022
1023out_unlock:
1024 xfs_reflink_remap_unlock(file_in, file_out);
1025 if (ret)
1026 trace_xfs_reflink_remap_range_error(dest, ret, _RET_IP_);
1027 return remapped > 0 ? remapped : ret;
1028}
1029
1030STATIC int
1031xfs_file_open(
1032 struct inode *inode,
1033 struct file *file)
1034{
1035 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
1036 return -EFBIG;
1037 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
1038 return -EIO;
1039 file->f_mode |= FMODE_NOWAIT;
1040 return 0;
1041}
1042
1043STATIC int
1044xfs_dir_open(
1045 struct inode *inode,
1046 struct file *file)
1047{
1048 struct xfs_inode *ip = XFS_I(inode);
1049 int mode;
1050 int error;
1051
1052 error = xfs_file_open(inode, file);
1053 if (error)
1054 return error;
1055
1056 /*
1057 * If there are any blocks, read-ahead block 0 as we're almost
1058 * certain to have the next operation be a read there.
1059 */
1060 mode = xfs_ilock_data_map_shared(ip);
1061 if (ip->i_d.di_nextents > 0)
1062 error = xfs_dir3_data_readahead(ip, 0, -1);
1063 xfs_iunlock(ip, mode);
1064 return error;
1065}
1066
1067STATIC int
1068xfs_file_release(
1069 struct inode *inode,
1070 struct file *filp)
1071{
1072 return xfs_release(XFS_I(inode));
1073}
1074
1075STATIC int
1076xfs_file_readdir(
1077 struct file *file,
1078 struct dir_context *ctx)
1079{
1080 struct inode *inode = file_inode(file);
1081 xfs_inode_t *ip = XFS_I(inode);
1082 size_t bufsize;
1083
1084 /*
1085 * The Linux API doesn't pass down the total size of the buffer
1086 * we read into down to the filesystem. With the filldir concept
1087 * it's not needed for correct information, but the XFS dir2 leaf
1088 * code wants an estimate of the buffer size to calculate it's
1089 * readahead window and size the buffers used for mapping to
1090 * physical blocks.
1091 *
1092 * Try to give it an estimate that's good enough, maybe at some
1093 * point we can change the ->readdir prototype to include the
1094 * buffer size. For now we use the current glibc buffer size.
1095 */
1096 bufsize = (size_t)min_t(loff_t, XFS_READDIR_BUFSIZE, ip->i_d.di_size);
1097
1098 return xfs_readdir(NULL, ip, ctx, bufsize);
1099}
1100
1101STATIC loff_t
1102xfs_file_llseek(
1103 struct file *file,
1104 loff_t offset,
1105 int whence)
1106{
1107 struct inode *inode = file->f_mapping->host;
1108
1109 if (XFS_FORCED_SHUTDOWN(XFS_I(inode)->i_mount))
1110 return -EIO;
1111
1112 switch (whence) {
1113 default:
1114 return generic_file_llseek(file, offset, whence);
1115 case SEEK_HOLE:
1116 offset = iomap_seek_hole(inode, offset, &xfs_seek_iomap_ops);
1117 break;
1118 case SEEK_DATA:
1119 offset = iomap_seek_data(inode, offset, &xfs_seek_iomap_ops);
1120 break;
1121 }
1122
1123 if (offset < 0)
1124 return offset;
1125 return vfs_setpos(file, offset, inode->i_sb->s_maxbytes);
1126}
1127
1128/*
1129 * Locking for serialisation of IO during page faults. This results in a lock
1130 * ordering of:
1131 *
1132 * mmap_sem (MM)
1133 * sb_start_pagefault(vfs, freeze)
1134 * i_mmaplock (XFS - truncate serialisation)
1135 * page_lock (MM)
1136 * i_lock (XFS - extent map serialisation)
1137 */
1138static vm_fault_t
1139__xfs_filemap_fault(
1140 struct vm_fault *vmf,
1141 enum page_entry_size pe_size,
1142 bool write_fault)
1143{
1144 struct inode *inode = file_inode(vmf->vma->vm_file);
1145 struct xfs_inode *ip = XFS_I(inode);
1146 vm_fault_t ret;
1147
1148 trace_xfs_filemap_fault(ip, pe_size, write_fault);
1149
1150 if (write_fault) {
1151 sb_start_pagefault(inode->i_sb);
1152 file_update_time(vmf->vma->vm_file);
1153 }
1154
1155 xfs_ilock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1156 if (IS_DAX(inode)) {
1157 pfn_t pfn;
1158
1159 ret = dax_iomap_fault(vmf, pe_size, &pfn, NULL, &xfs_iomap_ops);
1160 if (ret & VM_FAULT_NEEDDSYNC)
1161 ret = dax_finish_sync_fault(vmf, pe_size, pfn);
1162 } else {
1163 if (write_fault)
1164 ret = iomap_page_mkwrite(vmf, &xfs_iomap_ops);
1165 else
1166 ret = filemap_fault(vmf);
1167 }
1168 xfs_iunlock(XFS_I(inode), XFS_MMAPLOCK_SHARED);
1169
1170 if (write_fault)
1171 sb_end_pagefault(inode->i_sb);
1172 return ret;
1173}
1174
1175static vm_fault_t
1176xfs_filemap_fault(
1177 struct vm_fault *vmf)
1178{
1179 /* DAX can shortcut the normal fault path on write faults! */
1180 return __xfs_filemap_fault(vmf, PE_SIZE_PTE,
1181 IS_DAX(file_inode(vmf->vma->vm_file)) &&
1182 (vmf->flags & FAULT_FLAG_WRITE));
1183}
1184
1185static vm_fault_t
1186xfs_filemap_huge_fault(
1187 struct vm_fault *vmf,
1188 enum page_entry_size pe_size)
1189{
1190 if (!IS_DAX(file_inode(vmf->vma->vm_file)))
1191 return VM_FAULT_FALLBACK;
1192
1193 /* DAX can shortcut the normal fault path on write faults! */
1194 return __xfs_filemap_fault(vmf, pe_size,
1195 (vmf->flags & FAULT_FLAG_WRITE));
1196}
1197
1198static vm_fault_t
1199xfs_filemap_page_mkwrite(
1200 struct vm_fault *vmf)
1201{
1202 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1203}
1204
1205/*
1206 * pfn_mkwrite was originally intended to ensure we capture time stamp updates
1207 * on write faults. In reality, it needs to serialise against truncate and
1208 * prepare memory for writing so handle is as standard write fault.
1209 */
1210static vm_fault_t
1211xfs_filemap_pfn_mkwrite(
1212 struct vm_fault *vmf)
1213{
1214
1215 return __xfs_filemap_fault(vmf, PE_SIZE_PTE, true);
1216}
1217
1218static const struct vm_operations_struct xfs_file_vm_ops = {
1219 .fault = xfs_filemap_fault,
1220 .huge_fault = xfs_filemap_huge_fault,
1221 .map_pages = filemap_map_pages,
1222 .page_mkwrite = xfs_filemap_page_mkwrite,
1223 .pfn_mkwrite = xfs_filemap_pfn_mkwrite,
1224};
1225
1226STATIC int
1227xfs_file_mmap(
1228 struct file *filp,
1229 struct vm_area_struct *vma)
1230{
1231 struct dax_device *dax_dev;
1232
1233 dax_dev = xfs_find_daxdev_for_inode(file_inode(filp));
1234 /*
1235 * We don't support synchronous mappings for non-DAX files and
1236 * for DAX files if underneath dax_device is not synchronous.
1237 */
1238 if (!daxdev_mapping_supported(vma, dax_dev))
1239 return -EOPNOTSUPP;
1240
1241 file_accessed(filp);
1242 vma->vm_ops = &xfs_file_vm_ops;
1243 if (IS_DAX(file_inode(filp)))
1244 vma->vm_flags |= VM_HUGEPAGE;
1245 return 0;
1246}
1247
1248const struct file_operations xfs_file_operations = {
1249 .llseek = xfs_file_llseek,
1250 .read_iter = xfs_file_read_iter,
1251 .write_iter = xfs_file_write_iter,
1252 .splice_read = generic_file_splice_read,
1253 .splice_write = iter_file_splice_write,
1254 .iopoll = iomap_dio_iopoll,
1255 .unlocked_ioctl = xfs_file_ioctl,
1256#ifdef CONFIG_COMPAT
1257 .compat_ioctl = xfs_file_compat_ioctl,
1258#endif
1259 .mmap = xfs_file_mmap,
1260 .mmap_supported_flags = MAP_SYNC,
1261 .open = xfs_file_open,
1262 .release = xfs_file_release,
1263 .fsync = xfs_file_fsync,
1264 .get_unmapped_area = thp_get_unmapped_area,
1265 .fallocate = xfs_file_fallocate,
1266 .fadvise = xfs_file_fadvise,
1267 .remap_file_range = xfs_file_remap_range,
1268};
1269
1270const struct file_operations xfs_dir_file_operations = {
1271 .open = xfs_dir_open,
1272 .read = generic_read_dir,
1273 .iterate_shared = xfs_file_readdir,
1274 .llseek = generic_file_llseek,
1275 .unlocked_ioctl = xfs_file_ioctl,
1276#ifdef CONFIG_COMPAT
1277 .compat_ioctl = xfs_file_compat_ioctl,
1278#endif
1279 .fsync = xfs_dir_fsync,
1280};