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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_bit.h"
21#include "xfs_log.h"
22#include "xfs_inum.h"
23#include "xfs_sb.h"
24#include "xfs_ag.h"
25#include "xfs_trans.h"
26#include "xfs_mount.h"
27#include "xfs_bmap_btree.h"
28#include "xfs_alloc.h"
29#include "xfs_dinode.h"
30#include "xfs_inode.h"
31#include "xfs_inode_item.h"
32#include "xfs_bmap.h"
33#include "xfs_error.h"
34#include "xfs_vnodeops.h"
35#include "xfs_da_btree.h"
36#include "xfs_ioctl.h"
37#include "xfs_trace.h"
38
39#include <linux/dcache.h>
40#include <linux/falloc.h>
41
42static const struct vm_operations_struct xfs_file_vm_ops;
43
44/*
45 * Locking primitives for read and write IO paths to ensure we consistently use
46 * and order the inode->i_mutex, ip->i_lock and ip->i_iolock.
47 */
48static inline void
49xfs_rw_ilock(
50 struct xfs_inode *ip,
51 int type)
52{
53 if (type & XFS_IOLOCK_EXCL)
54 mutex_lock(&VFS_I(ip)->i_mutex);
55 xfs_ilock(ip, type);
56}
57
58static inline void
59xfs_rw_iunlock(
60 struct xfs_inode *ip,
61 int type)
62{
63 xfs_iunlock(ip, type);
64 if (type & XFS_IOLOCK_EXCL)
65 mutex_unlock(&VFS_I(ip)->i_mutex);
66}
67
68static inline void
69xfs_rw_ilock_demote(
70 struct xfs_inode *ip,
71 int type)
72{
73 xfs_ilock_demote(ip, type);
74 if (type & XFS_IOLOCK_EXCL)
75 mutex_unlock(&VFS_I(ip)->i_mutex);
76}
77
78/*
79 * xfs_iozero
80 *
81 * xfs_iozero clears the specified range of buffer supplied,
82 * and marks all the affected blocks as valid and modified. If
83 * an affected block is not allocated, it will be allocated. If
84 * an affected block is not completely overwritten, and is not
85 * valid before the operation, it will be read from disk before
86 * being partially zeroed.
87 */
88STATIC int
89xfs_iozero(
90 struct xfs_inode *ip, /* inode */
91 loff_t pos, /* offset in file */
92 size_t count) /* size of data to zero */
93{
94 struct page *page;
95 struct address_space *mapping;
96 int status;
97
98 mapping = VFS_I(ip)->i_mapping;
99 do {
100 unsigned offset, bytes;
101 void *fsdata;
102
103 offset = (pos & (PAGE_CACHE_SIZE -1)); /* Within page */
104 bytes = PAGE_CACHE_SIZE - offset;
105 if (bytes > count)
106 bytes = count;
107
108 status = pagecache_write_begin(NULL, mapping, pos, bytes,
109 AOP_FLAG_UNINTERRUPTIBLE,
110 &page, &fsdata);
111 if (status)
112 break;
113
114 zero_user(page, offset, bytes);
115
116 status = pagecache_write_end(NULL, mapping, pos, bytes, bytes,
117 page, fsdata);
118 WARN_ON(status <= 0); /* can't return less than zero! */
119 pos += bytes;
120 count -= bytes;
121 status = 0;
122 } while (count);
123
124 return (-status);
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 struct xfs_trans *tp;
138 int error = 0;
139 int log_flushed = 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 -XFS_ERROR(EIO);
149
150 xfs_iflags_clear(ip, XFS_ITRUNCATED);
151
152 xfs_ilock(ip, XFS_IOLOCK_SHARED);
153 xfs_ioend_wait(ip);
154 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
155
156 if (mp->m_flags & XFS_MOUNT_BARRIER) {
157 /*
158 * If we have an RT and/or log subvolume we need to make sure
159 * to flush the write cache the device used for file data
160 * first. This is to ensure newly written file data make
161 * it to disk before logging the new inode size in case of
162 * an extending write.
163 */
164 if (XFS_IS_REALTIME_INODE(ip))
165 xfs_blkdev_issue_flush(mp->m_rtdev_targp);
166 else if (mp->m_logdev_targp != mp->m_ddev_targp)
167 xfs_blkdev_issue_flush(mp->m_ddev_targp);
168 }
169
170 /*
171 * We always need to make sure that the required inode state is safe on
172 * disk. The inode might be clean but we still might need to force the
173 * log because of committed transactions that haven't hit the disk yet.
174 * Likewise, there could be unflushed non-transactional changes to the
175 * inode core that have to go to disk and this requires us to issue
176 * a synchronous transaction to capture these changes correctly.
177 *
178 * This code relies on the assumption that if the i_update_core field
179 * of the inode is clear and the inode is unpinned then it is clean
180 * and no action is required.
181 */
182 xfs_ilock(ip, XFS_ILOCK_SHARED);
183
184 /*
185 * First check if the VFS inode is marked dirty. All the dirtying
186 * of non-transactional updates no goes through mark_inode_dirty*,
187 * which allows us to distinguish beteeen pure timestamp updates
188 * and i_size updates which need to be caught for fdatasync.
189 * After that also theck for the dirty state in the XFS inode, which
190 * might gets cleared when the inode gets written out via the AIL
191 * or xfs_iflush_cluster.
192 */
193 if (((inode->i_state & I_DIRTY_DATASYNC) ||
194 ((inode->i_state & I_DIRTY_SYNC) && !datasync)) &&
195 ip->i_update_core) {
196 /*
197 * Kick off a transaction to log the inode core to get the
198 * updates. The sync transaction will also force the log.
199 */
200 xfs_iunlock(ip, XFS_ILOCK_SHARED);
201 tp = xfs_trans_alloc(mp, XFS_TRANS_FSYNC_TS);
202 error = xfs_trans_reserve(tp, 0,
203 XFS_FSYNC_TS_LOG_RES(mp), 0, 0, 0);
204 if (error) {
205 xfs_trans_cancel(tp, 0);
206 return -error;
207 }
208 xfs_ilock(ip, XFS_ILOCK_EXCL);
209
210 /*
211 * Note - it's possible that we might have pushed ourselves out
212 * of the way during trans_reserve which would flush the inode.
213 * But there's no guarantee that the inode buffer has actually
214 * gone out yet (it's delwri). Plus the buffer could be pinned
215 * anyway if it's part of an inode in another recent
216 * transaction. So we play it safe and fire off the
217 * transaction anyway.
218 */
219 xfs_trans_ijoin(tp, ip);
220 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
221 xfs_trans_set_sync(tp);
222 error = _xfs_trans_commit(tp, 0, &log_flushed);
223
224 xfs_iunlock(ip, XFS_ILOCK_EXCL);
225 } else {
226 /*
227 * Timestamps/size haven't changed since last inode flush or
228 * inode transaction commit. That means either nothing got
229 * written or a transaction committed which caught the updates.
230 * If the latter happened and the transaction hasn't hit the
231 * disk yet, the inode will be still be pinned. If it is,
232 * force the log.
233 */
234 if (xfs_ipincount(ip)) {
235 error = _xfs_log_force_lsn(mp,
236 ip->i_itemp->ili_last_lsn,
237 XFS_LOG_SYNC, &log_flushed);
238 }
239 xfs_iunlock(ip, XFS_ILOCK_SHARED);
240 }
241
242 /*
243 * If we only have a single device, and the log force about was
244 * a no-op we might have to flush the data device cache here.
245 * This can only happen for fdatasync/O_DSYNC if we were overwriting
246 * an already allocated file and thus do not have any metadata to
247 * commit.
248 */
249 if ((mp->m_flags & XFS_MOUNT_BARRIER) &&
250 mp->m_logdev_targp == mp->m_ddev_targp &&
251 !XFS_IS_REALTIME_INODE(ip) &&
252 !log_flushed)
253 xfs_blkdev_issue_flush(mp->m_ddev_targp);
254
255 return -error;
256}
257
258STATIC ssize_t
259xfs_file_aio_read(
260 struct kiocb *iocb,
261 const struct iovec *iovp,
262 unsigned long nr_segs,
263 loff_t pos)
264{
265 struct file *file = iocb->ki_filp;
266 struct inode *inode = file->f_mapping->host;
267 struct xfs_inode *ip = XFS_I(inode);
268 struct xfs_mount *mp = ip->i_mount;
269 size_t size = 0;
270 ssize_t ret = 0;
271 int ioflags = 0;
272 xfs_fsize_t n;
273 unsigned long seg;
274
275 XFS_STATS_INC(xs_read_calls);
276
277 BUG_ON(iocb->ki_pos != pos);
278
279 if (unlikely(file->f_flags & O_DIRECT))
280 ioflags |= IO_ISDIRECT;
281 if (file->f_mode & FMODE_NOCMTIME)
282 ioflags |= IO_INVIS;
283
284 /* START copy & waste from filemap.c */
285 for (seg = 0; seg < nr_segs; seg++) {
286 const struct iovec *iv = &iovp[seg];
287
288 /*
289 * If any segment has a negative length, or the cumulative
290 * length ever wraps negative then return -EINVAL.
291 */
292 size += iv->iov_len;
293 if (unlikely((ssize_t)(size|iv->iov_len) < 0))
294 return XFS_ERROR(-EINVAL);
295 }
296 /* END copy & waste from filemap.c */
297
298 if (unlikely(ioflags & IO_ISDIRECT)) {
299 xfs_buftarg_t *target =
300 XFS_IS_REALTIME_INODE(ip) ?
301 mp->m_rtdev_targp : mp->m_ddev_targp;
302 if ((iocb->ki_pos & target->bt_smask) ||
303 (size & target->bt_smask)) {
304 if (iocb->ki_pos == ip->i_size)
305 return 0;
306 return -XFS_ERROR(EINVAL);
307 }
308 }
309
310 n = XFS_MAXIOFFSET(mp) - iocb->ki_pos;
311 if (n <= 0 || size == 0)
312 return 0;
313
314 if (n < size)
315 size = n;
316
317 if (XFS_FORCED_SHUTDOWN(mp))
318 return -EIO;
319
320 if (unlikely(ioflags & IO_ISDIRECT)) {
321 xfs_rw_ilock(ip, XFS_IOLOCK_EXCL);
322
323 if (inode->i_mapping->nrpages) {
324 ret = -xfs_flushinval_pages(ip,
325 (iocb->ki_pos & PAGE_CACHE_MASK),
326 -1, FI_REMAPF_LOCKED);
327 if (ret) {
328 xfs_rw_iunlock(ip, XFS_IOLOCK_EXCL);
329 return ret;
330 }
331 }
332 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
333 } else
334 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
335
336 trace_xfs_file_read(ip, size, iocb->ki_pos, ioflags);
337
338 ret = generic_file_aio_read(iocb, iovp, nr_segs, iocb->ki_pos);
339 if (ret > 0)
340 XFS_STATS_ADD(xs_read_bytes, ret);
341
342 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
343 return ret;
344}
345
346STATIC ssize_t
347xfs_file_splice_read(
348 struct file *infilp,
349 loff_t *ppos,
350 struct pipe_inode_info *pipe,
351 size_t count,
352 unsigned int flags)
353{
354 struct xfs_inode *ip = XFS_I(infilp->f_mapping->host);
355 int ioflags = 0;
356 ssize_t ret;
357
358 XFS_STATS_INC(xs_read_calls);
359
360 if (infilp->f_mode & FMODE_NOCMTIME)
361 ioflags |= IO_INVIS;
362
363 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
364 return -EIO;
365
366 xfs_rw_ilock(ip, XFS_IOLOCK_SHARED);
367
368 trace_xfs_file_splice_read(ip, count, *ppos, ioflags);
369
370 ret = generic_file_splice_read(infilp, ppos, pipe, count, flags);
371 if (ret > 0)
372 XFS_STATS_ADD(xs_read_bytes, ret);
373
374 xfs_rw_iunlock(ip, XFS_IOLOCK_SHARED);
375 return ret;
376}
377
378STATIC void
379xfs_aio_write_isize_update(
380 struct inode *inode,
381 loff_t *ppos,
382 ssize_t bytes_written)
383{
384 struct xfs_inode *ip = XFS_I(inode);
385 xfs_fsize_t isize = i_size_read(inode);
386
387 if (bytes_written > 0)
388 XFS_STATS_ADD(xs_write_bytes, bytes_written);
389
390 if (unlikely(bytes_written < 0 && bytes_written != -EFAULT &&
391 *ppos > isize))
392 *ppos = isize;
393
394 if (*ppos > ip->i_size) {
395 xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
396 if (*ppos > ip->i_size)
397 ip->i_size = *ppos;
398 xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
399 }
400}
401
402/*
403 * If this was a direct or synchronous I/O that failed (such as ENOSPC) then
404 * part of the I/O may have been written to disk before the error occurred. In
405 * this case the on-disk file size may have been adjusted beyond the in-memory
406 * file size and now needs to be truncated back.
407 */
408STATIC void
409xfs_aio_write_newsize_update(
410 struct xfs_inode *ip)
411{
412 if (ip->i_new_size) {
413 xfs_rw_ilock(ip, XFS_ILOCK_EXCL);
414 ip->i_new_size = 0;
415 if (ip->i_d.di_size > ip->i_size)
416 ip->i_d.di_size = ip->i_size;
417 xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
418 }
419}
420
421/*
422 * xfs_file_splice_write() does not use xfs_rw_ilock() because
423 * generic_file_splice_write() takes the i_mutex itself. This, in theory,
424 * couuld cause lock inversions between the aio_write path and the splice path
425 * if someone is doing concurrent splice(2) based writes and write(2) based
426 * writes to the same inode. The only real way to fix this is to re-implement
427 * the generic code here with correct locking orders.
428 */
429STATIC ssize_t
430xfs_file_splice_write(
431 struct pipe_inode_info *pipe,
432 struct file *outfilp,
433 loff_t *ppos,
434 size_t count,
435 unsigned int flags)
436{
437 struct inode *inode = outfilp->f_mapping->host;
438 struct xfs_inode *ip = XFS_I(inode);
439 xfs_fsize_t new_size;
440 int ioflags = 0;
441 ssize_t ret;
442
443 XFS_STATS_INC(xs_write_calls);
444
445 if (outfilp->f_mode & FMODE_NOCMTIME)
446 ioflags |= IO_INVIS;
447
448 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
449 return -EIO;
450
451 xfs_ilock(ip, XFS_IOLOCK_EXCL);
452
453 new_size = *ppos + count;
454
455 xfs_ilock(ip, XFS_ILOCK_EXCL);
456 if (new_size > ip->i_size)
457 ip->i_new_size = new_size;
458 xfs_iunlock(ip, XFS_ILOCK_EXCL);
459
460 trace_xfs_file_splice_write(ip, count, *ppos, ioflags);
461
462 ret = generic_file_splice_write(pipe, outfilp, ppos, count, flags);
463
464 xfs_aio_write_isize_update(inode, ppos, ret);
465 xfs_aio_write_newsize_update(ip);
466 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
467 return ret;
468}
469
470/*
471 * This routine is called to handle zeroing any space in the last
472 * block of the file that is beyond the EOF. We do this since the
473 * size is being increased without writing anything to that block
474 * and we don't want anyone to read the garbage on the disk.
475 */
476STATIC int /* error (positive) */
477xfs_zero_last_block(
478 xfs_inode_t *ip,
479 xfs_fsize_t offset,
480 xfs_fsize_t isize)
481{
482 xfs_fileoff_t last_fsb;
483 xfs_mount_t *mp = ip->i_mount;
484 int nimaps;
485 int zero_offset;
486 int zero_len;
487 int error = 0;
488 xfs_bmbt_irec_t imap;
489
490 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL));
491
492 zero_offset = XFS_B_FSB_OFFSET(mp, isize);
493 if (zero_offset == 0) {
494 /*
495 * There are no extra bytes in the last block on disk to
496 * zero, so return.
497 */
498 return 0;
499 }
500
501 last_fsb = XFS_B_TO_FSBT(mp, isize);
502 nimaps = 1;
503 error = xfs_bmapi(NULL, ip, last_fsb, 1, 0, NULL, 0, &imap,
504 &nimaps, NULL);
505 if (error) {
506 return error;
507 }
508 ASSERT(nimaps > 0);
509 /*
510 * If the block underlying isize is just a hole, then there
511 * is nothing to zero.
512 */
513 if (imap.br_startblock == HOLESTARTBLOCK) {
514 return 0;
515 }
516 /*
517 * Zero the part of the last block beyond the EOF, and write it
518 * out sync. We need to drop the ilock while we do this so we
519 * don't deadlock when the buffer cache calls back to us.
520 */
521 xfs_iunlock(ip, XFS_ILOCK_EXCL);
522
523 zero_len = mp->m_sb.sb_blocksize - zero_offset;
524 if (isize + zero_len > offset)
525 zero_len = offset - isize;
526 error = xfs_iozero(ip, isize, zero_len);
527
528 xfs_ilock(ip, XFS_ILOCK_EXCL);
529 ASSERT(error >= 0);
530 return error;
531}
532
533/*
534 * Zero any on disk space between the current EOF and the new,
535 * larger EOF. This handles the normal case of zeroing the remainder
536 * of the last block in the file and the unusual case of zeroing blocks
537 * out beyond the size of the file. This second case only happens
538 * with fixed size extents and when the system crashes before the inode
539 * size was updated but after blocks were allocated. If fill is set,
540 * then any holes in the range are filled and zeroed. If not, the holes
541 * are left alone as holes.
542 */
543
544int /* error (positive) */
545xfs_zero_eof(
546 xfs_inode_t *ip,
547 xfs_off_t offset, /* starting I/O offset */
548 xfs_fsize_t isize) /* current inode size */
549{
550 xfs_mount_t *mp = ip->i_mount;
551 xfs_fileoff_t start_zero_fsb;
552 xfs_fileoff_t end_zero_fsb;
553 xfs_fileoff_t zero_count_fsb;
554 xfs_fileoff_t last_fsb;
555 xfs_fileoff_t zero_off;
556 xfs_fsize_t zero_len;
557 int nimaps;
558 int error = 0;
559 xfs_bmbt_irec_t imap;
560
561 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
562 ASSERT(offset > isize);
563
564 /*
565 * First handle zeroing the block on which isize resides.
566 * We only zero a part of that block so it is handled specially.
567 */
568 error = xfs_zero_last_block(ip, offset, isize);
569 if (error) {
570 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
571 return error;
572 }
573
574 /*
575 * Calculate the range between the new size and the old
576 * where blocks needing to be zeroed may exist. To get the
577 * block where the last byte in the file currently resides,
578 * we need to subtract one from the size and truncate back
579 * to a block boundary. We subtract 1 in case the size is
580 * exactly on a block boundary.
581 */
582 last_fsb = isize ? XFS_B_TO_FSBT(mp, isize - 1) : (xfs_fileoff_t)-1;
583 start_zero_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)isize);
584 end_zero_fsb = XFS_B_TO_FSBT(mp, offset - 1);
585 ASSERT((xfs_sfiloff_t)last_fsb < (xfs_sfiloff_t)start_zero_fsb);
586 if (last_fsb == end_zero_fsb) {
587 /*
588 * The size was only incremented on its last block.
589 * We took care of that above, so just return.
590 */
591 return 0;
592 }
593
594 ASSERT(start_zero_fsb <= end_zero_fsb);
595 while (start_zero_fsb <= end_zero_fsb) {
596 nimaps = 1;
597 zero_count_fsb = end_zero_fsb - start_zero_fsb + 1;
598 error = xfs_bmapi(NULL, ip, start_zero_fsb, zero_count_fsb,
599 0, NULL, 0, &imap, &nimaps, NULL);
600 if (error) {
601 ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL|XFS_IOLOCK_EXCL));
602 return error;
603 }
604 ASSERT(nimaps > 0);
605
606 if (imap.br_state == XFS_EXT_UNWRITTEN ||
607 imap.br_startblock == HOLESTARTBLOCK) {
608 /*
609 * This loop handles initializing pages that were
610 * partially initialized by the code below this
611 * loop. It basically zeroes the part of the page
612 * that sits on a hole and sets the page as P_HOLE
613 * and calls remapf if it is a mapped file.
614 */
615 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
616 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
617 continue;
618 }
619
620 /*
621 * There are blocks we need to zero.
622 * Drop the inode lock while we're doing the I/O.
623 * We'll still have the iolock to protect us.
624 */
625 xfs_iunlock(ip, XFS_ILOCK_EXCL);
626
627 zero_off = XFS_FSB_TO_B(mp, start_zero_fsb);
628 zero_len = XFS_FSB_TO_B(mp, imap.br_blockcount);
629
630 if ((zero_off + zero_len) > offset)
631 zero_len = offset - zero_off;
632
633 error = xfs_iozero(ip, zero_off, zero_len);
634 if (error) {
635 goto out_lock;
636 }
637
638 start_zero_fsb = imap.br_startoff + imap.br_blockcount;
639 ASSERT(start_zero_fsb <= (end_zero_fsb + 1));
640
641 xfs_ilock(ip, XFS_ILOCK_EXCL);
642 }
643
644 return 0;
645
646out_lock:
647 xfs_ilock(ip, XFS_ILOCK_EXCL);
648 ASSERT(error >= 0);
649 return error;
650}
651
652/*
653 * Common pre-write limit and setup checks.
654 *
655 * Returns with iolock held according to @iolock.
656 */
657STATIC ssize_t
658xfs_file_aio_write_checks(
659 struct file *file,
660 loff_t *pos,
661 size_t *count,
662 int *iolock)
663{
664 struct inode *inode = file->f_mapping->host;
665 struct xfs_inode *ip = XFS_I(inode);
666 xfs_fsize_t new_size;
667 int error = 0;
668
669 error = generic_write_checks(file, pos, count, S_ISBLK(inode->i_mode));
670 if (error) {
671 xfs_rw_iunlock(ip, XFS_ILOCK_EXCL | *iolock);
672 *iolock = 0;
673 return error;
674 }
675
676 new_size = *pos + *count;
677 if (new_size > ip->i_size)
678 ip->i_new_size = new_size;
679
680 if (likely(!(file->f_mode & FMODE_NOCMTIME)))
681 file_update_time(file);
682
683 /*
684 * If the offset is beyond the size of the file, we need to zero any
685 * blocks that fall between the existing EOF and the start of this
686 * write.
687 */
688 if (*pos > ip->i_size)
689 error = -xfs_zero_eof(ip, *pos, ip->i_size);
690
691 xfs_rw_iunlock(ip, XFS_ILOCK_EXCL);
692 if (error)
693 return error;
694
695 /*
696 * If we're writing the file then make sure to clear the setuid and
697 * setgid bits if the process is not being run by root. This keeps
698 * people from modifying setuid and setgid binaries.
699 */
700 return file_remove_suid(file);
701
702}
703
704/*
705 * xfs_file_dio_aio_write - handle direct IO writes
706 *
707 * Lock the inode appropriately to prepare for and issue a direct IO write.
708 * By separating it from the buffered write path we remove all the tricky to
709 * follow locking changes and looping.
710 *
711 * If there are cached pages or we're extending the file, we need IOLOCK_EXCL
712 * until we're sure the bytes at the new EOF have been zeroed and/or the cached
713 * pages are flushed out.
714 *
715 * In most cases the direct IO writes will be done holding IOLOCK_SHARED
716 * allowing them to be done in parallel with reads and other direct IO writes.
717 * However, if the IO is not aligned to filesystem blocks, the direct IO layer
718 * needs to do sub-block zeroing and that requires serialisation against other
719 * direct IOs to the same block. In this case we need to serialise the
720 * submission of the unaligned IOs so that we don't get racing block zeroing in
721 * the dio layer. To avoid the problem with aio, we also need to wait for
722 * outstanding IOs to complete so that unwritten extent conversion is completed
723 * before we try to map the overlapping block. This is currently implemented by
724 * hitting it with a big hammer (i.e. xfs_ioend_wait()).
725 *
726 * Returns with locks held indicated by @iolock and errors indicated by
727 * negative return values.
728 */
729STATIC ssize_t
730xfs_file_dio_aio_write(
731 struct kiocb *iocb,
732 const struct iovec *iovp,
733 unsigned long nr_segs,
734 loff_t pos,
735 size_t ocount,
736 int *iolock)
737{
738 struct file *file = iocb->ki_filp;
739 struct address_space *mapping = file->f_mapping;
740 struct inode *inode = mapping->host;
741 struct xfs_inode *ip = XFS_I(inode);
742 struct xfs_mount *mp = ip->i_mount;
743 ssize_t ret = 0;
744 size_t count = ocount;
745 int unaligned_io = 0;
746 struct xfs_buftarg *target = XFS_IS_REALTIME_INODE(ip) ?
747 mp->m_rtdev_targp : mp->m_ddev_targp;
748
749 *iolock = 0;
750 if ((pos & target->bt_smask) || (count & target->bt_smask))
751 return -XFS_ERROR(EINVAL);
752
753 if ((pos & mp->m_blockmask) || ((pos + count) & mp->m_blockmask))
754 unaligned_io = 1;
755
756 if (unaligned_io || mapping->nrpages || pos > ip->i_size)
757 *iolock = XFS_IOLOCK_EXCL;
758 else
759 *iolock = XFS_IOLOCK_SHARED;
760 xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
761
762 ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
763 if (ret)
764 return ret;
765
766 if (mapping->nrpages) {
767 WARN_ON(*iolock != XFS_IOLOCK_EXCL);
768 ret = -xfs_flushinval_pages(ip, (pos & PAGE_CACHE_MASK), -1,
769 FI_REMAPF_LOCKED);
770 if (ret)
771 return ret;
772 }
773
774 /*
775 * If we are doing unaligned IO, wait for all other IO to drain,
776 * otherwise demote the lock if we had to flush cached pages
777 */
778 if (unaligned_io)
779 xfs_ioend_wait(ip);
780 else if (*iolock == XFS_IOLOCK_EXCL) {
781 xfs_rw_ilock_demote(ip, XFS_IOLOCK_EXCL);
782 *iolock = XFS_IOLOCK_SHARED;
783 }
784
785 trace_xfs_file_direct_write(ip, count, iocb->ki_pos, 0);
786 ret = generic_file_direct_write(iocb, iovp,
787 &nr_segs, pos, &iocb->ki_pos, count, ocount);
788
789 /* No fallback to buffered IO on errors for XFS. */
790 ASSERT(ret < 0 || ret == count);
791 return ret;
792}
793
794STATIC ssize_t
795xfs_file_buffered_aio_write(
796 struct kiocb *iocb,
797 const struct iovec *iovp,
798 unsigned long nr_segs,
799 loff_t pos,
800 size_t ocount,
801 int *iolock)
802{
803 struct file *file = iocb->ki_filp;
804 struct address_space *mapping = file->f_mapping;
805 struct inode *inode = mapping->host;
806 struct xfs_inode *ip = XFS_I(inode);
807 ssize_t ret;
808 int enospc = 0;
809 size_t count = ocount;
810
811 *iolock = XFS_IOLOCK_EXCL;
812 xfs_rw_ilock(ip, XFS_ILOCK_EXCL | *iolock);
813
814 ret = xfs_file_aio_write_checks(file, &pos, &count, iolock);
815 if (ret)
816 return ret;
817
818 /* We can write back this queue in page reclaim */
819 current->backing_dev_info = mapping->backing_dev_info;
820
821write_retry:
822 trace_xfs_file_buffered_write(ip, count, iocb->ki_pos, 0);
823 ret = generic_file_buffered_write(iocb, iovp, nr_segs,
824 pos, &iocb->ki_pos, count, ret);
825 /*
826 * if we just got an ENOSPC, flush the inode now we aren't holding any
827 * page locks and retry *once*
828 */
829 if (ret == -ENOSPC && !enospc) {
830 ret = -xfs_flush_pages(ip, 0, -1, 0, FI_NONE);
831 if (ret)
832 return ret;
833 enospc = 1;
834 goto write_retry;
835 }
836 current->backing_dev_info = NULL;
837 return ret;
838}
839
840STATIC ssize_t
841xfs_file_aio_write(
842 struct kiocb *iocb,
843 const struct iovec *iovp,
844 unsigned long nr_segs,
845 loff_t pos)
846{
847 struct file *file = iocb->ki_filp;
848 struct address_space *mapping = file->f_mapping;
849 struct inode *inode = mapping->host;
850 struct xfs_inode *ip = XFS_I(inode);
851 ssize_t ret;
852 int iolock;
853 size_t ocount = 0;
854
855 XFS_STATS_INC(xs_write_calls);
856
857 BUG_ON(iocb->ki_pos != pos);
858
859 ret = generic_segment_checks(iovp, &nr_segs, &ocount, VERIFY_READ);
860 if (ret)
861 return ret;
862
863 if (ocount == 0)
864 return 0;
865
866 xfs_wait_for_freeze(ip->i_mount, SB_FREEZE_WRITE);
867
868 if (XFS_FORCED_SHUTDOWN(ip->i_mount))
869 return -EIO;
870
871 if (unlikely(file->f_flags & O_DIRECT))
872 ret = xfs_file_dio_aio_write(iocb, iovp, nr_segs, pos,
873 ocount, &iolock);
874 else
875 ret = xfs_file_buffered_aio_write(iocb, iovp, nr_segs, pos,
876 ocount, &iolock);
877
878 xfs_aio_write_isize_update(inode, &iocb->ki_pos, ret);
879
880 if (ret <= 0)
881 goto out_unlock;
882
883 /* Handle various SYNC-type writes */
884 if ((file->f_flags & O_DSYNC) || IS_SYNC(inode)) {
885 loff_t end = pos + ret - 1;
886 int error;
887
888 xfs_rw_iunlock(ip, iolock);
889 error = xfs_file_fsync(file, pos, end,
890 (file->f_flags & __O_SYNC) ? 0 : 1);
891 xfs_rw_ilock(ip, iolock);
892 if (error)
893 ret = error;
894 }
895
896out_unlock:
897 xfs_aio_write_newsize_update(ip);
898 xfs_rw_iunlock(ip, iolock);
899 return ret;
900}
901
902STATIC long
903xfs_file_fallocate(
904 struct file *file,
905 int mode,
906 loff_t offset,
907 loff_t len)
908{
909 struct inode *inode = file->f_path.dentry->d_inode;
910 long error;
911 loff_t new_size = 0;
912 xfs_flock64_t bf;
913 xfs_inode_t *ip = XFS_I(inode);
914 int cmd = XFS_IOC_RESVSP;
915 int attr_flags = XFS_ATTR_NOLOCK;
916
917 if (mode & ~(FALLOC_FL_KEEP_SIZE | FALLOC_FL_PUNCH_HOLE))
918 return -EOPNOTSUPP;
919
920 bf.l_whence = 0;
921 bf.l_start = offset;
922 bf.l_len = len;
923
924 xfs_ilock(ip, XFS_IOLOCK_EXCL);
925
926 if (mode & FALLOC_FL_PUNCH_HOLE)
927 cmd = XFS_IOC_UNRESVSP;
928
929 /* check the new inode size is valid before allocating */
930 if (!(mode & FALLOC_FL_KEEP_SIZE) &&
931 offset + len > i_size_read(inode)) {
932 new_size = offset + len;
933 error = inode_newsize_ok(inode, new_size);
934 if (error)
935 goto out_unlock;
936 }
937
938 if (file->f_flags & O_DSYNC)
939 attr_flags |= XFS_ATTR_SYNC;
940
941 error = -xfs_change_file_space(ip, cmd, &bf, 0, attr_flags);
942 if (error)
943 goto out_unlock;
944
945 /* Change file size if needed */
946 if (new_size) {
947 struct iattr iattr;
948
949 iattr.ia_valid = ATTR_SIZE;
950 iattr.ia_size = new_size;
951 error = -xfs_setattr_size(ip, &iattr, XFS_ATTR_NOLOCK);
952 }
953
954out_unlock:
955 xfs_iunlock(ip, XFS_IOLOCK_EXCL);
956 return error;
957}
958
959
960STATIC int
961xfs_file_open(
962 struct inode *inode,
963 struct file *file)
964{
965 if (!(file->f_flags & O_LARGEFILE) && i_size_read(inode) > MAX_NON_LFS)
966 return -EFBIG;
967 if (XFS_FORCED_SHUTDOWN(XFS_M(inode->i_sb)))
968 return -EIO;
969 return 0;
970}
971
972STATIC int
973xfs_dir_open(
974 struct inode *inode,
975 struct file *file)
976{
977 struct xfs_inode *ip = XFS_I(inode);
978 int mode;
979 int error;
980
981 error = xfs_file_open(inode, file);
982 if (error)
983 return error;
984
985 /*
986 * If there are any blocks, read-ahead block 0 as we're almost
987 * certain to have the next operation be a read there.
988 */
989 mode = xfs_ilock_map_shared(ip);
990 if (ip->i_d.di_nextents > 0)
991 xfs_da_reada_buf(NULL, ip, 0, XFS_DATA_FORK);
992 xfs_iunlock(ip, mode);
993 return 0;
994}
995
996STATIC int
997xfs_file_release(
998 struct inode *inode,
999 struct file *filp)
1000{
1001 return -xfs_release(XFS_I(inode));
1002}
1003
1004STATIC int
1005xfs_file_readdir(
1006 struct file *filp,
1007 void *dirent,
1008 filldir_t filldir)
1009{
1010 struct inode *inode = filp->f_path.dentry->d_inode;
1011 xfs_inode_t *ip = XFS_I(inode);
1012 int error;
1013 size_t bufsize;
1014
1015 /*
1016 * The Linux API doesn't pass down the total size of the buffer
1017 * we read into down to the filesystem. With the filldir concept
1018 * it's not needed for correct information, but the XFS dir2 leaf
1019 * code wants an estimate of the buffer size to calculate it's
1020 * readahead window and size the buffers used for mapping to
1021 * physical blocks.
1022 *
1023 * Try to give it an estimate that's good enough, maybe at some
1024 * point we can change the ->readdir prototype to include the
1025 * buffer size. For now we use the current glibc buffer size.
1026 */
1027 bufsize = (size_t)min_t(loff_t, 32768, ip->i_d.di_size);
1028
1029 error = xfs_readdir(ip, dirent, bufsize,
1030 (xfs_off_t *)&filp->f_pos, filldir);
1031 if (error)
1032 return -error;
1033 return 0;
1034}
1035
1036STATIC int
1037xfs_file_mmap(
1038 struct file *filp,
1039 struct vm_area_struct *vma)
1040{
1041 vma->vm_ops = &xfs_file_vm_ops;
1042 vma->vm_flags |= VM_CAN_NONLINEAR;
1043
1044 file_accessed(filp);
1045 return 0;
1046}
1047
1048/*
1049 * mmap()d file has taken write protection fault and is being made
1050 * writable. We can set the page state up correctly for a writable
1051 * page, which means we can do correct delalloc accounting (ENOSPC
1052 * checking!) and unwritten extent mapping.
1053 */
1054STATIC int
1055xfs_vm_page_mkwrite(
1056 struct vm_area_struct *vma,
1057 struct vm_fault *vmf)
1058{
1059 return block_page_mkwrite(vma, vmf, xfs_get_blocks);
1060}
1061
1062const struct file_operations xfs_file_operations = {
1063 .llseek = generic_file_llseek,
1064 .read = do_sync_read,
1065 .write = do_sync_write,
1066 .aio_read = xfs_file_aio_read,
1067 .aio_write = xfs_file_aio_write,
1068 .splice_read = xfs_file_splice_read,
1069 .splice_write = xfs_file_splice_write,
1070 .unlocked_ioctl = xfs_file_ioctl,
1071#ifdef CONFIG_COMPAT
1072 .compat_ioctl = xfs_file_compat_ioctl,
1073#endif
1074 .mmap = xfs_file_mmap,
1075 .open = xfs_file_open,
1076 .release = xfs_file_release,
1077 .fsync = xfs_file_fsync,
1078 .fallocate = xfs_file_fallocate,
1079};
1080
1081const struct file_operations xfs_dir_file_operations = {
1082 .open = xfs_dir_open,
1083 .read = generic_read_dir,
1084 .readdir = xfs_file_readdir,
1085 .llseek = generic_file_llseek,
1086 .unlocked_ioctl = xfs_file_ioctl,
1087#ifdef CONFIG_COMPAT
1088 .compat_ioctl = xfs_file_compat_ioctl,
1089#endif
1090 .fsync = xfs_file_fsync,
1091};
1092
1093static const struct vm_operations_struct xfs_file_vm_ops = {
1094 .fault = filemap_fault,
1095 .page_mkwrite = xfs_vm_page_mkwrite,
1096};
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};