1 // SPDX-License-Identifier: GPL-2.0
2 /*
3 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
4 * Copyright (c) 2012 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7 #include "xfs.h"
8 #include "xfs_fs.h"
9 #include "xfs_shared.h"
10 #include "xfs_format.h"
11 #include "xfs_log_format.h"
12 #include "xfs_trans_resv.h"
13 #include "xfs_bit.h"
14 #include "xfs_mount.h"
15 #include "xfs_defer.h"
16 #include "xfs_inode.h"
17 #include "xfs_btree.h"
18 #include "xfs_trans.h"
19 #include "xfs_alloc.h"
20 #include "xfs_bmap.h"
21 #include "xfs_bmap_util.h"
22 #include "xfs_bmap_btree.h"
23 #include "xfs_rtalloc.h"
24 #include "xfs_error.h"
25 #include "xfs_quota.h"
26 #include "xfs_trans_space.h"
27 #include "xfs_trace.h"
28 #include "xfs_icache.h"
29 #include "xfs_iomap.h"
30 #include "xfs_reflink.h"
31 #include "xfs_rtbitmap.h"
32
33 /* Kernel only BMAP related definitions and functions */
34
35 /*
36 * Convert the given file system block to a disk block. We have to treat it
37 * differently based on whether the file is a real time file or not, because the
38 * bmap code does.
39 */
40 xfs_daddr_t
41 xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
42 {
43 if (XFS_IS_REALTIME_INODE(ip))
44 return XFS_FSB_TO_BB(ip->i_mount, fsb);
45 return XFS_FSB_TO_DADDR(ip->i_mount, fsb);
46 }
47
48 /*
49 * Routine to zero an extent on disk allocated to the specific inode.
50 *
51 * The VFS functions take a linearised filesystem block offset, so we have to
52 * convert the sparse xfs fsb to the right format first.
53 * VFS types are real funky, too.
54 */
55 int
56 xfs_zero_extent(
57 struct xfs_inode *ip,
58 xfs_fsblock_t start_fsb,
59 xfs_off_t count_fsb)
60 {
61 struct xfs_mount *mp = ip->i_mount;
62 struct xfs_buftarg *target = xfs_inode_buftarg(ip);
63 xfs_daddr_t sector = xfs_fsb_to_db(ip, start_fsb);
64 sector_t block = XFS_BB_TO_FSBT(mp, sector);
65
66 return blkdev_issue_zeroout(target->bt_bdev,
67 block << (mp->m_super->s_blocksize_bits - 9),
68 count_fsb << (mp->m_super->s_blocksize_bits - 9),
69 GFP_KERNEL, 0);
70 }
71
72 /*
73 * Extent tree block counting routines.
74 */
75
76 /*
77 * Count leaf blocks given a range of extent records. Delayed allocation
78 * extents are not counted towards the totals.
79 */
80 xfs_extnum_t
81 xfs_bmap_count_leaves(
82 struct xfs_ifork *ifp,
83 xfs_filblks_t *count)
84 {
85 struct xfs_iext_cursor icur;
86 struct xfs_bmbt_irec got;
87 xfs_extnum_t numrecs = 0;
88
89 for_each_xfs_iext(ifp, &icur, &got) {
90 if (!isnullstartblock(got.br_startblock)) {
91 *count += got.br_blockcount;
92 numrecs++;
93 }
94 }
95
96 return numrecs;
97 }
98
99 /*
100 * Count fsblocks of the given fork. Delayed allocation extents are
101 * not counted towards the totals.
102 */
103 int
104 xfs_bmap_count_blocks(
105 struct xfs_trans *tp,
106 struct xfs_inode *ip,
107 int whichfork,
108 xfs_extnum_t *nextents,
109 xfs_filblks_t *count)
110 {
111 struct xfs_mount *mp = ip->i_mount;
112 struct xfs_ifork *ifp = xfs_ifork_ptr(ip, whichfork);
113 struct xfs_btree_cur *cur;
114 xfs_extlen_t btblocks = 0;
115 int error;
116
117 *nextents = 0;
118 *count = 0;
119
120 if (!ifp)
121 return 0;
122
123 switch (ifp->if_format) {
124 case XFS_DINODE_FMT_BTREE:
125 error = xfs_iread_extents(tp, ip, whichfork);
126 if (error)
127 return error;
128
129 cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
130 error = xfs_btree_count_blocks(cur, &btblocks);
131 xfs_btree_del_cursor(cur, error);
132 if (error)
133 return error;
134
135 /*
136 * xfs_btree_count_blocks includes the root block contained in
137 * the inode fork in @btblocks, so subtract one because we're
138 * only interested in allocated disk blocks.
139 */
140 *count += btblocks - 1;
141
142 fallthrough;
143 case XFS_DINODE_FMT_EXTENTS:
144 *nextents = xfs_bmap_count_leaves(ifp, count);
145 break;
146 }
147
148 return 0;
149 }
150
151 static int
152 xfs_getbmap_report_one(
153 struct xfs_inode *ip,
154 struct getbmapx *bmv,
155 struct kgetbmap *out,
156 int64_t bmv_end,
157 struct xfs_bmbt_irec *got)
158 {
159 struct kgetbmap *p = out + bmv->bmv_entries;
160 bool shared = false;
161 int error;
162
163 error = xfs_reflink_trim_around_shared(ip, got, &shared);
164 if (error)
165 return error;
166
167 if (isnullstartblock(got->br_startblock) ||
168 got->br_startblock == DELAYSTARTBLOCK) {
169 /*
170 * Take the flush completion as being a point-in-time snapshot
171 * where there are no delalloc extents, and if any new ones
172 * have been created racily, just skip them as being 'after'
173 * the flush and so don't get reported.
174 */
175 if (!(bmv->bmv_iflags & BMV_IF_DELALLOC))
176 return 0;
177
178 p->bmv_oflags |= BMV_OF_DELALLOC;
179 p->bmv_block = -2;
180 } else {
181 p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
182 }
183
184 if (got->br_state == XFS_EXT_UNWRITTEN &&
185 (bmv->bmv_iflags & BMV_IF_PREALLOC))
186 p->bmv_oflags |= BMV_OF_PREALLOC;
187
188 if (shared)
189 p->bmv_oflags |= BMV_OF_SHARED;
190
191 p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
192 p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
193
194 bmv->bmv_offset = p->bmv_offset + p->bmv_length;
195 bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
196 bmv->bmv_entries++;
197 return 0;
198 }
199
200 static void
201 xfs_getbmap_report_hole(
202 struct xfs_inode *ip,
203 struct getbmapx *bmv,
204 struct kgetbmap *out,
205 int64_t bmv_end,
206 xfs_fileoff_t bno,
207 xfs_fileoff_t end)
208 {
209 struct kgetbmap *p = out + bmv->bmv_entries;
210
211 if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
212 return;
213
214 p->bmv_block = -1;
215 p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
216 p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
217
218 bmv->bmv_offset = p->bmv_offset + p->bmv_length;
219 bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
220 bmv->bmv_entries++;
221 }
222
223 static inline bool
224 xfs_getbmap_full(
225 struct getbmapx *bmv)
226 {
227 return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
228 }
229
230 static bool
231 xfs_getbmap_next_rec(
232 struct xfs_bmbt_irec *rec,
233 xfs_fileoff_t total_end)
234 {
235 xfs_fileoff_t end = rec->br_startoff + rec->br_blockcount;
236
237 if (end == total_end)
238 return false;
239
240 rec->br_startoff += rec->br_blockcount;
241 if (!isnullstartblock(rec->br_startblock) &&
242 rec->br_startblock != DELAYSTARTBLOCK)
243 rec->br_startblock += rec->br_blockcount;
244 rec->br_blockcount = total_end - end;
245 return true;
246 }
247
248 /*
249 * Get inode's extents as described in bmv, and format for output.
250 * Calls formatter to fill the user's buffer until all extents
251 * are mapped, until the passed-in bmv->bmv_count slots have
252 * been filled, or until the formatter short-circuits the loop,
253 * if it is tracking filled-in extents on its own.
254 */
255 int /* error code */
256 xfs_getbmap(
257 struct xfs_inode *ip,
258 struct getbmapx *bmv, /* user bmap structure */
259 struct kgetbmap *out)
260 {
261 struct xfs_mount *mp = ip->i_mount;
262 int iflags = bmv->bmv_iflags;
263 int whichfork, lock, error = 0;
264 int64_t bmv_end, max_len;
265 xfs_fileoff_t bno, first_bno;
266 struct xfs_ifork *ifp;
267 struct xfs_bmbt_irec got, rec;
268 xfs_filblks_t len;
269 struct xfs_iext_cursor icur;
270
271 if (bmv->bmv_iflags & ~BMV_IF_VALID)
272 return -EINVAL;
273 #ifndef DEBUG
274 /* Only allow CoW fork queries if we're debugging. */
275 if (iflags & BMV_IF_COWFORK)
276 return -EINVAL;
277 #endif
278 if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
279 return -EINVAL;
280
281 if (bmv->bmv_length < -1)
282 return -EINVAL;
283 bmv->bmv_entries = 0;
284 if (bmv->bmv_length == 0)
285 return 0;
286
287 if (iflags & BMV_IF_ATTRFORK)
288 whichfork = XFS_ATTR_FORK;
289 else if (iflags & BMV_IF_COWFORK)
290 whichfork = XFS_COW_FORK;
291 else
292 whichfork = XFS_DATA_FORK;
293
294 xfs_ilock(ip, XFS_IOLOCK_SHARED);
295 switch (whichfork) {
296 case XFS_ATTR_FORK:
297 lock = xfs_ilock_attr_map_shared(ip);
298 if (!xfs_inode_has_attr_fork(ip))
299 goto out_unlock_ilock;
300
301 max_len = 1LL << 32;
302 break;
303 case XFS_COW_FORK:
304 lock = XFS_ILOCK_SHARED;
305 xfs_ilock(ip, lock);
306
307 /* No CoW fork? Just return */
308 if (!xfs_ifork_ptr(ip, whichfork))
309 goto out_unlock_ilock;
310
311 if (xfs_get_cowextsz_hint(ip))
312 max_len = mp->m_super->s_maxbytes;
313 else
314 max_len = XFS_ISIZE(ip);
315 break;
316 case XFS_DATA_FORK:
317 if (!(iflags & BMV_IF_DELALLOC) &&
318 (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_size)) {
319 error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
320 if (error)
321 goto out_unlock_iolock;
322
323 /*
324 * Even after flushing the inode, there can still be
325 * delalloc blocks on the inode beyond EOF due to
326 * speculative preallocation. These are not removed
327 * until the release function is called or the inode
328 * is inactivated. Hence we cannot assert here that
329 * ip->i_delayed_blks == 0.
330 */
331 }
332
333 if (xfs_get_extsz_hint(ip) ||
334 (ip->i_diflags &
335 (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
336 max_len = mp->m_super->s_maxbytes;
337 else
338 max_len = XFS_ISIZE(ip);
339
340 lock = xfs_ilock_data_map_shared(ip);
341 break;
342 }
343
344 ifp = xfs_ifork_ptr(ip, whichfork);
345
346 switch (ifp->if_format) {
347 case XFS_DINODE_FMT_EXTENTS:
348 case XFS_DINODE_FMT_BTREE:
349 break;
350 case XFS_DINODE_FMT_LOCAL:
351 /* Local format inode forks report no extents. */
352 goto out_unlock_ilock;
353 default:
354 error = -EINVAL;
355 goto out_unlock_ilock;
356 }
357
358 if (bmv->bmv_length == -1) {
359 max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
360 bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
361 }
362
363 bmv_end = bmv->bmv_offset + bmv->bmv_length;
364
365 first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
366 len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
367
368 error = xfs_iread_extents(NULL, ip, whichfork);
369 if (error)
370 goto out_unlock_ilock;
371
372 if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
373 /*
374 * Report a whole-file hole if the delalloc flag is set to
375 * stay compatible with the old implementation.
376 */
377 if (iflags & BMV_IF_DELALLOC)
378 xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
379 XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
380 goto out_unlock_ilock;
381 }
382
383 while (!xfs_getbmap_full(bmv)) {
384 xfs_trim_extent(&got, first_bno, len);
385
386 /*
387 * Report an entry for a hole if this extent doesn't directly
388 * follow the previous one.
389 */
390 if (got.br_startoff > bno) {
391 xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
392 got.br_startoff);
393 if (xfs_getbmap_full(bmv))
394 break;
395 }
396
397 /*
398 * In order to report shared extents accurately, we report each
399 * distinct shared / unshared part of a single bmbt record with
400 * an individual getbmapx record.
401 */
402 bno = got.br_startoff + got.br_blockcount;
403 rec = got;
404 do {
405 error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
406 &rec);
407 if (error || xfs_getbmap_full(bmv))
408 goto out_unlock_ilock;
409 } while (xfs_getbmap_next_rec(&rec, bno));
410
411 if (!xfs_iext_next_extent(ifp, &icur, &got)) {
412 xfs_fileoff_t end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
413
414 if (bmv->bmv_entries > 0)
415 out[bmv->bmv_entries - 1].bmv_oflags |=
416 BMV_OF_LAST;
417
418 if (whichfork != XFS_ATTR_FORK && bno < end &&
419 !xfs_getbmap_full(bmv)) {
420 xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
421 bno, end);
422 }
423 break;
424 }
425
426 if (bno >= first_bno + len)
427 break;
428 }
429
430 out_unlock_ilock:
431 xfs_iunlock(ip, lock);
432 out_unlock_iolock:
433 xfs_iunlock(ip, XFS_IOLOCK_SHARED);
434 return error;
435 }
436
437 /*
438 * Dead simple method of punching delalyed allocation blocks from a range in
439 * the inode. This will always punch out both the start and end blocks, even
440 * if the ranges only partially overlap them, so it is up to the caller to
441 * ensure that partial blocks are not passed in.
442 */
443 void
444 xfs_bmap_punch_delalloc_range(
445 struct xfs_inode *ip,
446 xfs_off_t start_byte,
447 xfs_off_t end_byte)
448 {
449 struct xfs_mount *mp = ip->i_mount;
450 struct xfs_ifork *ifp = &ip->i_df;
451 xfs_fileoff_t start_fsb = XFS_B_TO_FSBT(mp, start_byte);
452 xfs_fileoff_t end_fsb = XFS_B_TO_FSB(mp, end_byte);
453 struct xfs_bmbt_irec got, del;
454 struct xfs_iext_cursor icur;
455
456 ASSERT(!xfs_need_iread_extents(ifp));
457
458 xfs_ilock(ip, XFS_ILOCK_EXCL);
459 if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
460 goto out_unlock;
461
462 while (got.br_startoff + got.br_blockcount > start_fsb) {
463 del = got;
464 xfs_trim_extent(&del, start_fsb, end_fsb - start_fsb);
465
466 /*
467 * A delete can push the cursor forward. Step back to the
468 * previous extent on non-delalloc or extents outside the
469 * target range.
470 */
471 if (!del.br_blockcount ||
472 !isnullstartblock(del.br_startblock)) {
473 if (!xfs_iext_prev_extent(ifp, &icur, &got))
474 break;
475 continue;
476 }
477
478 xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur, &got, &del);
479 if (!xfs_iext_get_extent(ifp, &icur, &got))
480 break;
481 }
482
483 out_unlock:
484 xfs_iunlock(ip, XFS_ILOCK_EXCL);
485 }
486
487 /*
488 * Test whether it is appropriate to check an inode for and free post EOF
489 * blocks.
490 */
491 bool
492 xfs_can_free_eofblocks(
493 struct xfs_inode *ip)
494 {
495 struct xfs_bmbt_irec imap;
496 struct xfs_mount *mp = ip->i_mount;
497 xfs_fileoff_t end_fsb;
498 xfs_fileoff_t last_fsb;
499 int nimaps = 1;
500 int error;
501
502 /*
503 * Caller must either hold the exclusive io lock; or be inactivating
504 * the inode, which guarantees there are no other users of the inode.
505 */
506 if (!(VFS_I(ip)->i_state & I_FREEING))
507 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL);
508
509 /* prealloc/delalloc exists only on regular files */
510 if (!S_ISREG(VFS_I(ip)->i_mode))
511 return false;
512
513 /*
514 * Zero sized files with no cached pages and delalloc blocks will not
515 * have speculative prealloc/delalloc blocks to remove.
516 */
517 if (VFS_I(ip)->i_size == 0 &&
518 VFS_I(ip)->i_mapping->nrpages == 0 &&
519 ip->i_delayed_blks == 0)
520 return false;
521
522 /* If we haven't read in the extent list, then don't do it now. */
523 if (xfs_need_iread_extents(&ip->i_df))
524 return false;
525
526 /*
527 * Only free real extents for inodes with persistent preallocations or
528 * the append-only flag.
529 */
530 if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
531 if (ip->i_delayed_blks == 0)
532 return false;
533
534 /*
535 * Do not try to free post-EOF blocks if EOF is beyond the end of the
536 * range supported by the page cache, because the truncation will loop
537 * forever.
538 */
539 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
540 if (xfs_inode_has_bigrtalloc(ip))
541 end_fsb = xfs_rtb_roundup_rtx(mp, end_fsb);
542 last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
543 if (last_fsb <= end_fsb)
544 return false;
545
546 /*
547 * Look up the mapping for the first block past EOF. If we can't find
548 * it, there's nothing to free.
549 */
550 xfs_ilock(ip, XFS_ILOCK_SHARED);
551 error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps,
552 0);
553 xfs_iunlock(ip, XFS_ILOCK_SHARED);
554 if (error || nimaps == 0)
555 return false;
556
557 /*
558 * If there's a real mapping there or there are delayed allocation
559 * reservations, then we have post-EOF blocks to try to free.
560 */
561 return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks;
562 }
563
564 /*
565 * This is called to free any blocks beyond eof. The caller must hold
566 * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
567 * reference to the inode.
568 */
569 int
570 xfs_free_eofblocks(
571 struct xfs_inode *ip)
572 {
573 struct xfs_trans *tp;
574 struct xfs_mount *mp = ip->i_mount;
575 int error;
576
577 /* Attach the dquots to the inode up front. */
578 error = xfs_qm_dqattach(ip);
579 if (error)
580 return error;
581
582 /* Wait on dio to ensure i_size has settled. */
583 inode_dio_wait(VFS_I(ip));
584
585 /*
586 * For preallocated files only free delayed allocations.
587 *
588 * Note that this means we also leave speculative preallocations in
589 * place for preallocated files.
590 */
591 if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)) {
592 if (ip->i_delayed_blks) {
593 xfs_bmap_punch_delalloc_range(ip,
594 round_up(XFS_ISIZE(ip), mp->m_sb.sb_blocksize),
595 LLONG_MAX);
596 }
597 xfs_inode_clear_eofblocks_tag(ip);
598 return 0;
599 }
600
601 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
602 if (error) {
603 ASSERT(xfs_is_shutdown(mp));
604 return error;
605 }
606
607 xfs_ilock(ip, XFS_ILOCK_EXCL);
608 xfs_trans_ijoin(tp, ip, 0);
609
610 /*
611 * Do not update the on-disk file size. If we update the on-disk file
612 * size and then the system crashes before the contents of the file are
613 * flushed to disk then the files may be full of holes (ie NULL files
614 * bug).
615 */
616 error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK,
617 XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
618 if (error)
619 goto err_cancel;
620
621 error = xfs_trans_commit(tp);
622 if (error)
623 goto out_unlock;
624
625 xfs_inode_clear_eofblocks_tag(ip);
626 goto out_unlock;
627
628 err_cancel:
629 /*
630 * If we get an error at this point we simply don't
631 * bother truncating the file.
632 */
633 xfs_trans_cancel(tp);
634 out_unlock:
635 xfs_iunlock(ip, XFS_ILOCK_EXCL);
636 return error;
637 }
638
639 int
640 xfs_alloc_file_space(
641 struct xfs_inode *ip,
642 xfs_off_t offset,
643 xfs_off_t len)
644 {
645 xfs_mount_t *mp = ip->i_mount;
646 xfs_off_t count;
647 xfs_filblks_t allocatesize_fsb;
648 xfs_extlen_t extsz, temp;
649 xfs_fileoff_t startoffset_fsb;
650 xfs_fileoff_t endoffset_fsb;
651 int rt;
652 xfs_trans_t *tp;
653 xfs_bmbt_irec_t imaps[1], *imapp;
654 int error;
655
656 trace_xfs_alloc_file_space(ip);
657
658 if (xfs_is_shutdown(mp))
659 return -EIO;
660
661 error = xfs_qm_dqattach(ip);
662 if (error)
663 return error;
664
665 if (len <= 0)
666 return -EINVAL;
667
668 rt = XFS_IS_REALTIME_INODE(ip);
669 extsz = xfs_get_extsz_hint(ip);
670
671 count = len;
672 imapp = &imaps[0];
673 startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
674 endoffset_fsb = XFS_B_TO_FSB(mp, offset + count);
675 allocatesize_fsb = endoffset_fsb - startoffset_fsb;
676
677 /*
678 * Allocate file space until done or until there is an error
679 */
680 while (allocatesize_fsb && !error) {
681 xfs_fileoff_t s, e;
682 unsigned int dblocks, rblocks, resblks;
683 int nimaps = 1;
684
685 /*
686 * Determine space reservations for data/realtime.
687 */
688 if (unlikely(extsz)) {
689 s = startoffset_fsb;
690 do_div(s, extsz);
691 s *= extsz;
692 e = startoffset_fsb + allocatesize_fsb;
693 div_u64_rem(startoffset_fsb, extsz, &temp);
694 if (temp)
695 e += temp;
696 div_u64_rem(e, extsz, &temp);
697 if (temp)
698 e += extsz - temp;
699 } else {
700 s = 0;
701 e = allocatesize_fsb;
702 }
703
704 /*
705 * The transaction reservation is limited to a 32-bit block
706 * count, hence we need to limit the number of blocks we are
707 * trying to reserve to avoid an overflow. We can't allocate
708 * more than @nimaps extents, and an extent is limited on disk
709 * to XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the
710 * limit.
711 */
712 resblks = min_t(xfs_fileoff_t, (e - s),
713 (XFS_MAX_BMBT_EXTLEN * nimaps));
714 if (unlikely(rt)) {
715 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
716 rblocks = resblks;
717 } else {
718 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
719 rblocks = 0;
720 }
721
722 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write,
723 dblocks, rblocks, false, &tp);
724 if (error)
725 break;
726
727 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
728 XFS_IEXT_ADD_NOSPLIT_CNT);
729 if (error)
730 goto error;
731
732 /*
733 * If the allocator cannot find a single free extent large
734 * enough to cover the start block of the requested range,
735 * xfs_bmapi_write will return -ENOSR.
736 *
737 * In that case we simply need to keep looping with the same
738 * startoffset_fsb so that one of the following allocations
739 * will eventually reach the requested range.
740 */
741 error = xfs_bmapi_write(tp, ip, startoffset_fsb,
742 allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
743 &nimaps);
744 if (error) {
745 if (error != -ENOSR)
746 goto error;
747 error = 0;
748 } else {
749 startoffset_fsb += imapp->br_blockcount;
750 allocatesize_fsb -= imapp->br_blockcount;
751 }
752
753 ip->i_diflags |= XFS_DIFLAG_PREALLOC;
754 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
755
756 error = xfs_trans_commit(tp);
757 xfs_iunlock(ip, XFS_ILOCK_EXCL);
758 }
759
760 return error;
761
762 error:
763 xfs_trans_cancel(tp);
764 xfs_iunlock(ip, XFS_ILOCK_EXCL);
765 return error;
766 }
767
768 static int
769 xfs_unmap_extent(
770 struct xfs_inode *ip,
771 xfs_fileoff_t startoffset_fsb,
772 xfs_filblks_t len_fsb,
773 int *done)
774 {
775 struct xfs_mount *mp = ip->i_mount;
776 struct xfs_trans *tp;
777 uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
778 int error;
779
780 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks, 0,
781 false, &tp);
782 if (error)
783 return error;
784
785 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
786 XFS_IEXT_PUNCH_HOLE_CNT);
787 if (error)
788 goto out_trans_cancel;
789
790 error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
791 if (error)
792 goto out_trans_cancel;
793
794 error = xfs_trans_commit(tp);
795 out_unlock:
796 xfs_iunlock(ip, XFS_ILOCK_EXCL);
797 return error;
798
799 out_trans_cancel:
800 xfs_trans_cancel(tp);
801 goto out_unlock;
802 }
803
804 /* Caller must first wait for the completion of any pending DIOs if required. */
805 int
806 xfs_flush_unmap_range(
807 struct xfs_inode *ip,
808 xfs_off_t offset,
809 xfs_off_t len)
810 {
811 struct inode *inode = VFS_I(ip);
812 xfs_off_t rounding, start, end;
813 int error;
814
815 /*
816 * Make sure we extend the flush out to extent alignment
817 * boundaries so any extent range overlapping the start/end
818 * of the modification we are about to do is clean and idle.
819 */
820 rounding = max_t(xfs_off_t, xfs_inode_alloc_unitsize(ip), PAGE_SIZE);
821 start = rounddown_64(offset, rounding);
822 end = roundup_64(offset + len, rounding) - 1;
823
824 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
825 if (error)
826 return error;
827 truncate_pagecache_range(inode, start, end);
828 return 0;
829 }
830
831 int
832 xfs_free_file_space(
833 struct xfs_inode *ip,
834 xfs_off_t offset,
835 xfs_off_t len)
836 {
837 struct xfs_mount *mp = ip->i_mount;
838 xfs_fileoff_t startoffset_fsb;
839 xfs_fileoff_t endoffset_fsb;
840 int done = 0, error;
841
842 trace_xfs_free_file_space(ip);
843
844 error = xfs_qm_dqattach(ip);
845 if (error)
846 return error;
847
848 if (len <= 0) /* if nothing being freed */
849 return 0;
850
851 startoffset_fsb = XFS_B_TO_FSB(mp, offset);
852 endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
853
854 /* We can only free complete realtime extents. */
855 if (xfs_inode_has_bigrtalloc(ip)) {
856 startoffset_fsb = xfs_rtb_roundup_rtx(mp, startoffset_fsb);
857 endoffset_fsb = xfs_rtb_rounddown_rtx(mp, endoffset_fsb);
858 }
859
860 /*
861 * Need to zero the stuff we're not freeing, on disk.
862 */
863 if (endoffset_fsb > startoffset_fsb) {
864 while (!done) {
865 error = xfs_unmap_extent(ip, startoffset_fsb,
866 endoffset_fsb - startoffset_fsb, &done);
867 if (error)
868 return error;
869 }
870 }
871
872 /*
873 * Now that we've unmap all full blocks we'll have to zero out any
874 * partial block at the beginning and/or end. xfs_zero_range is smart
875 * enough to skip any holes, including those we just created, but we
876 * must take care not to zero beyond EOF and enlarge i_size.
877 */
878 if (offset >= XFS_ISIZE(ip))
879 return 0;
880 if (offset + len > XFS_ISIZE(ip))
881 len = XFS_ISIZE(ip) - offset;
882 error = xfs_zero_range(ip, offset, len, NULL);
883 if (error)
884 return error;
885
886 /*
887 * If we zeroed right up to EOF and EOF straddles a page boundary we
888 * must make sure that the post-EOF area is also zeroed because the
889 * page could be mmap'd and xfs_zero_range doesn't do that for us.
890 * Writeback of the eof page will do this, albeit clumsily.
891 */
892 if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) {
893 error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
894 round_down(offset + len, PAGE_SIZE), LLONG_MAX);
895 }
896
897 return error;
898 }
899
900 static int
901 xfs_prepare_shift(
902 struct xfs_inode *ip,
903 loff_t offset)
904 {
905 unsigned int rounding;
906 int error;
907
908 /*
909 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
910 * into the accessible region of the file.
911 */
912 if (xfs_can_free_eofblocks(ip)) {
913 error = xfs_free_eofblocks(ip);
914 if (error)
915 return error;
916 }
917
918 /*
919 * Shift operations must stabilize the start block offset boundary along
920 * with the full range of the operation. If we don't, a COW writeback
921 * completion could race with an insert, front merge with the start
922 * extent (after split) during the shift and corrupt the file. Start
923 * with the allocation unit just prior to the start to stabilize the
924 * boundary.
925 */
926 rounding = xfs_inode_alloc_unitsize(ip);
927 offset = rounddown_64(offset, rounding);
928 if (offset)
929 offset -= rounding;
930
931 /*
932 * Writeback and invalidate cache for the remainder of the file as we're
933 * about to shift down every extent from offset to EOF.
934 */
935 error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip));
936 if (error)
937 return error;
938
939 /*
940 * Clean out anything hanging around in the cow fork now that
941 * we've flushed all the dirty data out to disk to avoid having
942 * CoW extents at the wrong offsets.
943 */
944 if (xfs_inode_has_cow_data(ip)) {
945 error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
946 true);
947 if (error)
948 return error;
949 }
950
951 return 0;
952 }
953
954 /*
955 * xfs_collapse_file_space()
956 * This routine frees disk space and shift extent for the given file.
957 * The first thing we do is to free data blocks in the specified range
958 * by calling xfs_free_file_space(). It would also sync dirty data
959 * and invalidate page cache over the region on which collapse range
960 * is working. And Shift extent records to the left to cover a hole.
961 * RETURNS:
962 * 0 on success
963 * errno on error
964 *
965 */
966 int
967 xfs_collapse_file_space(
968 struct xfs_inode *ip,
969 xfs_off_t offset,
970 xfs_off_t len)
971 {
972 struct xfs_mount *mp = ip->i_mount;
973 struct xfs_trans *tp;
974 int error;
975 xfs_fileoff_t next_fsb = XFS_B_TO_FSB(mp, offset + len);
976 xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
977 bool done = false;
978
979 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
980
981 trace_xfs_collapse_file_space(ip);
982
983 error = xfs_free_file_space(ip, offset, len);
984 if (error)
985 return error;
986
987 error = xfs_prepare_shift(ip, offset);
988 if (error)
989 return error;
990
991 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
992 if (error)
993 return error;
994
995 xfs_ilock(ip, XFS_ILOCK_EXCL);
996 xfs_trans_ijoin(tp, ip, 0);
997
998 while (!done) {
999 error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
1000 &done);
1001 if (error)
1002 goto out_trans_cancel;
1003 if (done)
1004 break;
1005
1006 /* finish any deferred frees and roll the transaction */
1007 error = xfs_defer_finish(&tp);
1008 if (error)
1009 goto out_trans_cancel;
1010 }
1011
1012 error = xfs_trans_commit(tp);
1013 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1014 return error;
1015
1016 out_trans_cancel:
1017 xfs_trans_cancel(tp);
1018 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1019 return error;
1020 }
1021
1022 /*
1023 * xfs_insert_file_space()
1024 * This routine create hole space by shifting extents for the given file.
1025 * The first thing we do is to sync dirty data and invalidate page cache
1026 * over the region on which insert range is working. And split an extent
1027 * to two extents at given offset by calling xfs_bmap_split_extent.
1028 * And shift all extent records which are laying between [offset,
1029 * last allocated extent] to the right to reserve hole range.
1030 * RETURNS:
1031 * 0 on success
1032 * errno on error
1033 */
1034 int
1035 xfs_insert_file_space(
1036 struct xfs_inode *ip,
1037 loff_t offset,
1038 loff_t len)
1039 {
1040 struct xfs_mount *mp = ip->i_mount;
1041 struct xfs_trans *tp;
1042 int error;
1043 xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, offset);
1044 xfs_fileoff_t next_fsb = NULLFSBLOCK;
1045 xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
1046 bool done = false;
1047
1048 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
1049
1050 trace_xfs_insert_file_space(ip);
1051
1052 error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
1053 if (error)
1054 return error;
1055
1056 error = xfs_prepare_shift(ip, offset);
1057 if (error)
1058 return error;
1059
1060 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write,
1061 XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp);
1062 if (error)
1063 return error;
1064
1065 xfs_ilock(ip, XFS_ILOCK_EXCL);
1066 xfs_trans_ijoin(tp, ip, 0);
1067
1068 error = xfs_iext_count_extend(tp, ip, XFS_DATA_FORK,
1069 XFS_IEXT_PUNCH_HOLE_CNT);
1070 if (error)
1071 goto out_trans_cancel;
1072
1073 /*
1074 * The extent shifting code works on extent granularity. So, if stop_fsb
1075 * is not the starting block of extent, we need to split the extent at
1076 * stop_fsb.
1077 */
1078 error = xfs_bmap_split_extent(tp, ip, stop_fsb);
1079 if (error)
1080 goto out_trans_cancel;
1081
1082 do {
1083 error = xfs_defer_finish(&tp);
1084 if (error)
1085 goto out_trans_cancel;
1086
1087 error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
1088 &done, stop_fsb);
1089 if (error)
1090 goto out_trans_cancel;
1091 } while (!done);
1092
1093 error = xfs_trans_commit(tp);
1094 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1095 return error;
1096
1097 out_trans_cancel:
1098 xfs_trans_cancel(tp);
1099 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1100 return error;
1101 }
1102
1103 /*
1104 * We need to check that the format of the data fork in the temporary inode is
1105 * valid for the target inode before doing the swap. This is not a problem with
1106 * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
1107 * data fork depending on the space the attribute fork is taking so we can get
1108 * invalid formats on the target inode.
1109 *
1110 * E.g. target has space for 7 extents in extent format, temp inode only has
1111 * space for 6. If we defragment down to 7 extents, then the tmp format is a
1112 * btree, but when swapped it needs to be in extent format. Hence we can't just
1113 * blindly swap data forks on attr2 filesystems.
1114 *
1115 * Note that we check the swap in both directions so that we don't end up with
1116 * a corrupt temporary inode, either.
1117 *
1118 * Note that fixing the way xfs_fsr sets up the attribute fork in the source
1119 * inode will prevent this situation from occurring, so all we do here is
1120 * reject and log the attempt. basically we are putting the responsibility on
1121 * userspace to get this right.
1122 */
1123 static int
1124 xfs_swap_extents_check_format(
1125 struct xfs_inode *ip, /* target inode */
1126 struct xfs_inode *tip) /* tmp inode */
1127 {
1128 struct xfs_ifork *ifp = &ip->i_df;
1129 struct xfs_ifork *tifp = &tip->i_df;
1130
1131 /* User/group/project quota ids must match if quotas are enforced. */
1132 if (XFS_IS_QUOTA_ON(ip->i_mount) &&
1133 (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) ||
1134 !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) ||
1135 ip->i_projid != tip->i_projid))
1136 return -EINVAL;
1137
1138 /* Should never get a local format */
1139 if (ifp->if_format == XFS_DINODE_FMT_LOCAL ||
1140 tifp->if_format == XFS_DINODE_FMT_LOCAL)
1141 return -EINVAL;
1142
1143 /*
1144 * if the target inode has less extents that then temporary inode then
1145 * why did userspace call us?
1146 */
1147 if (ifp->if_nextents < tifp->if_nextents)
1148 return -EINVAL;
1149
1150 /*
1151 * If we have to use the (expensive) rmap swap method, we can
1152 * handle any number of extents and any format.
1153 */
1154 if (xfs_has_rmapbt(ip->i_mount))
1155 return 0;
1156
1157 /*
1158 * if the target inode is in extent form and the temp inode is in btree
1159 * form then we will end up with the target inode in the wrong format
1160 * as we already know there are less extents in the temp inode.
1161 */
1162 if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1163 tifp->if_format == XFS_DINODE_FMT_BTREE)
1164 return -EINVAL;
1165
1166 /* Check temp in extent form to max in target */
1167 if (tifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1168 tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1169 return -EINVAL;
1170
1171 /* Check target in extent form to max in temp */
1172 if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1173 ifp->if_nextents > XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1174 return -EINVAL;
1175
1176 /*
1177 * If we are in a btree format, check that the temp root block will fit
1178 * in the target and that it has enough extents to be in btree format
1179 * in the target.
1180 *
1181 * Note that we have to be careful to allow btree->extent conversions
1182 * (a common defrag case) which will occur when the temp inode is in
1183 * extent format...
1184 */
1185 if (tifp->if_format == XFS_DINODE_FMT_BTREE) {
1186 if (xfs_inode_has_attr_fork(ip) &&
1187 XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip))
1188 return -EINVAL;
1189 if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1190 return -EINVAL;
1191 }
1192
1193 /* Reciprocal target->temp btree format checks */
1194 if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
1195 if (xfs_inode_has_attr_fork(tip) &&
1196 XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip))
1197 return -EINVAL;
1198 if (ifp->if_nextents <= XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1199 return -EINVAL;
1200 }
1201
1202 return 0;
1203 }
1204
1205 static int
1206 xfs_swap_extent_flush(
1207 struct xfs_inode *ip)
1208 {
1209 int error;
1210
1211 error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
1212 if (error)
1213 return error;
1214 truncate_pagecache_range(VFS_I(ip), 0, -1);
1215
1216 /* Verify O_DIRECT for ftmp */
1217 if (VFS_I(ip)->i_mapping->nrpages)
1218 return -EINVAL;
1219 return 0;
1220 }
1221
1222 /*
1223 * Move extents from one file to another, when rmap is enabled.
1224 */
1225 STATIC int
1226 xfs_swap_extent_rmap(
1227 struct xfs_trans **tpp,
1228 struct xfs_inode *ip,
1229 struct xfs_inode *tip)
1230 {
1231 struct xfs_trans *tp = *tpp;
1232 struct xfs_bmbt_irec irec;
1233 struct xfs_bmbt_irec uirec;
1234 struct xfs_bmbt_irec tirec;
1235 xfs_fileoff_t offset_fsb;
1236 xfs_fileoff_t end_fsb;
1237 xfs_filblks_t count_fsb;
1238 int error;
1239 xfs_filblks_t ilen;
1240 xfs_filblks_t rlen;
1241 int nimaps;
1242 uint64_t tip_flags2;
1243
1244 /*
1245 * If the source file has shared blocks, we must flag the donor
1246 * file as having shared blocks so that we get the shared-block
1247 * rmap functions when we go to fix up the rmaps. The flags
1248 * will be switch for reals later.
1249 */
1250 tip_flags2 = tip->i_diflags2;
1251 if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK)
1252 tip->i_diflags2 |= XFS_DIFLAG2_REFLINK;
1253
1254 offset_fsb = 0;
1255 end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
1256 count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
1257
1258 while (count_fsb) {
1259 /* Read extent from the donor file */
1260 nimaps = 1;
1261 error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
1262 &nimaps, 0);
1263 if (error)
1264 goto out;
1265 ASSERT(nimaps == 1);
1266 ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
1267
1268 trace_xfs_swap_extent_rmap_remap(tip, &tirec);
1269 ilen = tirec.br_blockcount;
1270
1271 /* Unmap the old blocks in the source file. */
1272 while (tirec.br_blockcount) {
1273 ASSERT(tp->t_highest_agno == NULLAGNUMBER);
1274 trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
1275
1276 /* Read extent from the source file */
1277 nimaps = 1;
1278 error = xfs_bmapi_read(ip, tirec.br_startoff,
1279 tirec.br_blockcount, &irec,
1280 &nimaps, 0);
1281 if (error)
1282 goto out;
1283 ASSERT(nimaps == 1);
1284 ASSERT(tirec.br_startoff == irec.br_startoff);
1285 trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
1286
1287 /* Trim the extent. */
1288 uirec = tirec;
1289 uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
1290 tirec.br_blockcount,
1291 irec.br_blockcount);
1292 trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
1293
1294 if (xfs_bmap_is_real_extent(&uirec)) {
1295 error = xfs_iext_count_extend(tp, ip,
1296 XFS_DATA_FORK,
1297 XFS_IEXT_SWAP_RMAP_CNT);
1298 if (error)
1299 goto out;
1300 }
1301
1302 if (xfs_bmap_is_real_extent(&irec)) {
1303 error = xfs_iext_count_extend(tp, tip,
1304 XFS_DATA_FORK,
1305 XFS_IEXT_SWAP_RMAP_CNT);
1306 if (error)
1307 goto out;
1308 }
1309
1310 /* Remove the mapping from the donor file. */
1311 xfs_bmap_unmap_extent(tp, tip, XFS_DATA_FORK, &uirec);
1312
1313 /* Remove the mapping from the source file. */
1314 xfs_bmap_unmap_extent(tp, ip, XFS_DATA_FORK, &irec);
1315
1316 /* Map the donor file's blocks into the source file. */
1317 xfs_bmap_map_extent(tp, ip, XFS_DATA_FORK, &uirec);
1318
1319 /* Map the source file's blocks into the donor file. */
1320 xfs_bmap_map_extent(tp, tip, XFS_DATA_FORK, &irec);
1321
1322 error = xfs_defer_finish(tpp);
1323 tp = *tpp;
1324 if (error)
1325 goto out;
1326
1327 tirec.br_startoff += rlen;
1328 if (tirec.br_startblock != HOLESTARTBLOCK &&
1329 tirec.br_startblock != DELAYSTARTBLOCK)
1330 tirec.br_startblock += rlen;
1331 tirec.br_blockcount -= rlen;
1332 }
1333
1334 /* Roll on... */
1335 count_fsb -= ilen;
1336 offset_fsb += ilen;
1337 }
1338
1339 tip->i_diflags2 = tip_flags2;
1340 return 0;
1341
1342 out:
1343 trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
1344 tip->i_diflags2 = tip_flags2;
1345 return error;
1346 }
1347
1348 /* Swap the extents of two files by swapping data forks. */
1349 STATIC int
1350 xfs_swap_extent_forks(
1351 struct xfs_trans *tp,
1352 struct xfs_inode *ip,
1353 struct xfs_inode *tip,
1354 int *src_log_flags,
1355 int *target_log_flags)
1356 {
1357 xfs_filblks_t aforkblks = 0;
1358 xfs_filblks_t taforkblks = 0;
1359 xfs_extnum_t junk;
1360 uint64_t tmp;
1361 int error;
1362
1363 /*
1364 * Count the number of extended attribute blocks
1365 */
1366 if (xfs_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 &&
1367 ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1368 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk,
1369 &aforkblks);
1370 if (error)
1371 return error;
1372 }
1373 if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 &&
1374 tip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1375 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK, &junk,
1376 &taforkblks);
1377 if (error)
1378 return error;
1379 }
1380
1381 /*
1382 * Btree format (v3) inodes have the inode number stamped in the bmbt
1383 * block headers. We can't start changing the bmbt blocks until the
1384 * inode owner change is logged so recovery does the right thing in the
1385 * event of a crash. Set the owner change log flags now and leave the
1386 * bmbt scan as the last step.
1387 */
1388 if (xfs_has_v3inodes(ip->i_mount)) {
1389 if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1390 (*target_log_flags) |= XFS_ILOG_DOWNER;
1391 if (tip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1392 (*src_log_flags) |= XFS_ILOG_DOWNER;
1393 }
1394
1395 /*
1396 * Swap the data forks of the inodes
1397 */
1398 swap(ip->i_df, tip->i_df);
1399
1400 /*
1401 * Fix the on-disk inode values
1402 */
1403 tmp = (uint64_t)ip->i_nblocks;
1404 ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks;
1405 tip->i_nblocks = tmp + taforkblks - aforkblks;
1406
1407 /*
1408 * The extents in the source inode could still contain speculative
1409 * preallocation beyond EOF (e.g. the file is open but not modified
1410 * while defrag is in progress). In that case, we need to copy over the
1411 * number of delalloc blocks the data fork in the source inode is
1412 * tracking beyond EOF so that when the fork is truncated away when the
1413 * temporary inode is unlinked we don't underrun the i_delayed_blks
1414 * counter on that inode.
1415 */
1416 ASSERT(tip->i_delayed_blks == 0);
1417 tip->i_delayed_blks = ip->i_delayed_blks;
1418 ip->i_delayed_blks = 0;
1419
1420 switch (ip->i_df.if_format) {
1421 case XFS_DINODE_FMT_EXTENTS:
1422 (*src_log_flags) |= XFS_ILOG_DEXT;
1423 break;
1424 case XFS_DINODE_FMT_BTREE:
1425 ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1426 (*src_log_flags & XFS_ILOG_DOWNER));
1427 (*src_log_flags) |= XFS_ILOG_DBROOT;
1428 break;
1429 }
1430
1431 switch (tip->i_df.if_format) {
1432 case XFS_DINODE_FMT_EXTENTS:
1433 (*target_log_flags) |= XFS_ILOG_DEXT;
1434 break;
1435 case XFS_DINODE_FMT_BTREE:
1436 (*target_log_flags) |= XFS_ILOG_DBROOT;
1437 ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1438 (*target_log_flags & XFS_ILOG_DOWNER));
1439 break;
1440 }
1441
1442 return 0;
1443 }
1444
1445 /*
1446 * Fix up the owners of the bmbt blocks to refer to the current inode. The
1447 * change owner scan attempts to order all modified buffers in the current
1448 * transaction. In the event of ordered buffer failure, the offending buffer is
1449 * physically logged as a fallback and the scan returns -EAGAIN. We must roll
1450 * the transaction in this case to replenish the fallback log reservation and
1451 * restart the scan. This process repeats until the scan completes.
1452 */
1453 static int
1454 xfs_swap_change_owner(
1455 struct xfs_trans **tpp,
1456 struct xfs_inode *ip,
1457 struct xfs_inode *tmpip)
1458 {
1459 int error;
1460 struct xfs_trans *tp = *tpp;
1461
1462 do {
1463 error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
1464 NULL);
1465 /* success or fatal error */
1466 if (error != -EAGAIN)
1467 break;
1468
1469 error = xfs_trans_roll(tpp);
1470 if (error)
1471 break;
1472 tp = *tpp;
1473
1474 /*
1475 * Redirty both inodes so they can relog and keep the log tail
1476 * moving forward.
1477 */
1478 xfs_trans_ijoin(tp, ip, 0);
1479 xfs_trans_ijoin(tp, tmpip, 0);
1480 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1481 xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
1482 } while (true);
1483
1484 return error;
1485 }
1486
1487 int
1488 xfs_swap_extents(
1489 struct xfs_inode *ip, /* target inode */
1490 struct xfs_inode *tip, /* tmp inode */
1491 struct xfs_swapext *sxp)
1492 {
1493 struct xfs_mount *mp = ip->i_mount;
1494 struct xfs_trans *tp;
1495 struct xfs_bstat *sbp = &sxp->sx_stat;
1496 int src_log_flags, target_log_flags;
1497 int error = 0;
1498 uint64_t f;
1499 int resblks = 0;
1500 unsigned int flags = 0;
1501 struct timespec64 ctime, mtime;
1502
1503 /*
1504 * Lock the inodes against other IO, page faults and truncate to
1505 * begin with. Then we can ensure the inodes are flushed and have no
1506 * page cache safely. Once we have done this we can take the ilocks and
1507 * do the rest of the checks.
1508 */
1509 lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1510 filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
1511 VFS_I(tip)->i_mapping);
1512
1513 /* Verify that both files have the same format */
1514 if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
1515 error = -EINVAL;
1516 goto out_unlock;
1517 }
1518
1519 /* Verify both files are either real-time or non-realtime */
1520 if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
1521 error = -EINVAL;
1522 goto out_unlock;
1523 }
1524
1525 error = xfs_qm_dqattach(ip);
1526 if (error)
1527 goto out_unlock;
1528
1529 error = xfs_qm_dqattach(tip);
1530 if (error)
1531 goto out_unlock;
1532
1533 error = xfs_swap_extent_flush(ip);
1534 if (error)
1535 goto out_unlock;
1536 error = xfs_swap_extent_flush(tip);
1537 if (error)
1538 goto out_unlock;
1539
1540 if (xfs_inode_has_cow_data(tip)) {
1541 error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true);
1542 if (error)
1543 goto out_unlock;
1544 }
1545
1546 /*
1547 * Extent "swapping" with rmap requires a permanent reservation and
1548 * a block reservation because it's really just a remap operation
1549 * performed with log redo items!
1550 */
1551 if (xfs_has_rmapbt(mp)) {
1552 int w = XFS_DATA_FORK;
1553 uint32_t ipnext = ip->i_df.if_nextents;
1554 uint32_t tipnext = tip->i_df.if_nextents;
1555
1556 /*
1557 * Conceptually this shouldn't affect the shape of either bmbt,
1558 * but since we atomically move extents one by one, we reserve
1559 * enough space to rebuild both trees.
1560 */
1561 resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w);
1562 resblks += XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w);
1563
1564 /*
1565 * If either inode straddles a bmapbt block allocation boundary,
1566 * the rmapbt algorithm triggers repeated allocs and frees as
1567 * extents are remapped. This can exhaust the block reservation
1568 * prematurely and cause shutdown. Return freed blocks to the
1569 * transaction reservation to counter this behavior.
1570 */
1571 flags |= XFS_TRANS_RES_FDBLKS;
1572 }
1573 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags,
1574 &tp);
1575 if (error)
1576 goto out_unlock;
1577
1578 /*
1579 * Lock and join the inodes to the tansaction so that transaction commit
1580 * or cancel will unlock the inodes from this point onwards.
1581 */
1582 xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
1583 xfs_trans_ijoin(tp, ip, 0);
1584 xfs_trans_ijoin(tp, tip, 0);
1585
1586
1587 /* Verify all data are being swapped */
1588 if (sxp->sx_offset != 0 ||
1589 sxp->sx_length != ip->i_disk_size ||
1590 sxp->sx_length != tip->i_disk_size) {
1591 error = -EFAULT;
1592 goto out_trans_cancel;
1593 }
1594
1595 trace_xfs_swap_extent_before(ip, 0);
1596 trace_xfs_swap_extent_before(tip, 1);
1597
1598 /* check inode formats now that data is flushed */
1599 error = xfs_swap_extents_check_format(ip, tip);
1600 if (error) {
1601 xfs_notice(mp,
1602 "%s: inode 0x%llx format is incompatible for exchanging.",
1603 __func__, ip->i_ino);
1604 goto out_trans_cancel;
1605 }
1606
1607 /*
1608 * Compare the current change & modify times with that
1609 * passed in. If they differ, we abort this swap.
1610 * This is the mechanism used to ensure the calling
1611 * process that the file was not changed out from
1612 * under it.
1613 */
1614 ctime = inode_get_ctime(VFS_I(ip));
1615 mtime = inode_get_mtime(VFS_I(ip));
1616 if ((sbp->bs_ctime.tv_sec != ctime.tv_sec) ||
1617 (sbp->bs_ctime.tv_nsec != ctime.tv_nsec) ||
1618 (sbp->bs_mtime.tv_sec != mtime.tv_sec) ||
1619 (sbp->bs_mtime.tv_nsec != mtime.tv_nsec)) {
1620 error = -EBUSY;
1621 goto out_trans_cancel;
1622 }
1623
1624 /*
1625 * Note the trickiness in setting the log flags - we set the owner log
1626 * flag on the opposite inode (i.e. the inode we are setting the new
1627 * owner to be) because once we swap the forks and log that, log
1628 * recovery is going to see the fork as owned by the swapped inode,
1629 * not the pre-swapped inodes.
1630 */
1631 src_log_flags = XFS_ILOG_CORE;
1632 target_log_flags = XFS_ILOG_CORE;
1633
1634 if (xfs_has_rmapbt(mp))
1635 error = xfs_swap_extent_rmap(&tp, ip, tip);
1636 else
1637 error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
1638 &target_log_flags);
1639 if (error)
1640 goto out_trans_cancel;
1641
1642 /* Do we have to swap reflink flags? */
1643 if ((ip->i_diflags2 & XFS_DIFLAG2_REFLINK) ^
1644 (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) {
1645 f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1646 ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1647 ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1648 tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1649 tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK;
1650 }
1651
1652 /* Swap the cow forks. */
1653 if (xfs_has_reflink(mp)) {
1654 ASSERT(!ip->i_cowfp ||
1655 ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1656 ASSERT(!tip->i_cowfp ||
1657 tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1658
1659 swap(ip->i_cowfp, tip->i_cowfp);
1660
1661 if (ip->i_cowfp && ip->i_cowfp->if_bytes)
1662 xfs_inode_set_cowblocks_tag(ip);
1663 else
1664 xfs_inode_clear_cowblocks_tag(ip);
1665 if (tip->i_cowfp && tip->i_cowfp->if_bytes)
1666 xfs_inode_set_cowblocks_tag(tip);
1667 else
1668 xfs_inode_clear_cowblocks_tag(tip);
1669 }
1670
1671 xfs_trans_log_inode(tp, ip, src_log_flags);
1672 xfs_trans_log_inode(tp, tip, target_log_flags);
1673
1674 /*
1675 * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
1676 * have inode number owner values in the bmbt blocks that still refer to
1677 * the old inode. Scan each bmbt to fix up the owner values with the
1678 * inode number of the current inode.
1679 */
1680 if (src_log_flags & XFS_ILOG_DOWNER) {
1681 error = xfs_swap_change_owner(&tp, ip, tip);
1682 if (error)
1683 goto out_trans_cancel;
1684 }
1685 if (target_log_flags & XFS_ILOG_DOWNER) {
1686 error = xfs_swap_change_owner(&tp, tip, ip);
1687 if (error)
1688 goto out_trans_cancel;
1689 }
1690
1691 /*
1692 * If this is a synchronous mount, make sure that the
1693 * transaction goes to disk before returning to the user.
1694 */
1695 if (xfs_has_wsync(mp))
1696 xfs_trans_set_sync(tp);
1697
1698 error = xfs_trans_commit(tp);
1699
1700 trace_xfs_swap_extent_after(ip, 0);
1701 trace_xfs_swap_extent_after(tip, 1);
1702
1703 out_unlock_ilock:
1704 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1705 xfs_iunlock(tip, XFS_ILOCK_EXCL);
1706 out_unlock:
1707 filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
1708 VFS_I(tip)->i_mapping);
1709 unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1710 return error;
1711
1712 out_trans_cancel:
1713 xfs_trans_cancel(tp);
1714 goto out_unlock_ilock;
1715 }
1716
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