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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 */
40xfs_daddr_t
41xfs_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 */
55int
56xfs_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 */
80xfs_extnum_t
81xfs_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 */
103int
104xfs_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
151static int
152xfs_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
200static void
201xfs_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
223static inline bool
224xfs_getbmap_full(
225 struct getbmapx *bmv)
226{
227 return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
228}
229
230static bool
231xfs_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 */
255int /* error code */
256xfs_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
430out_unlock_ilock:
431 xfs_iunlock(ip, lock);
432out_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 */
443int
444xfs_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 int error = 0;
456
457 ASSERT(!xfs_need_iread_extents(ifp));
458
459 xfs_ilock(ip, XFS_ILOCK_EXCL);
460 if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
461 goto out_unlock;
462
463 while (got.br_startoff + got.br_blockcount > start_fsb) {
464 del = got;
465 xfs_trim_extent(&del, start_fsb, end_fsb - start_fsb);
466
467 /*
468 * A delete can push the cursor forward. Step back to the
469 * previous extent on non-delalloc or extents outside the
470 * target range.
471 */
472 if (!del.br_blockcount ||
473 !isnullstartblock(del.br_startblock)) {
474 if (!xfs_iext_prev_extent(ifp, &icur, &got))
475 break;
476 continue;
477 }
478
479 error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur,
480 &got, &del);
481 if (error || !xfs_iext_get_extent(ifp, &icur, &got))
482 break;
483 }
484
485out_unlock:
486 xfs_iunlock(ip, XFS_ILOCK_EXCL);
487 return error;
488}
489
490/*
491 * Test whether it is appropriate to check an inode for and free post EOF
492 * blocks. The 'force' parameter determines whether we should also consider
493 * regular files that are marked preallocated or append-only.
494 */
495bool
496xfs_can_free_eofblocks(
497 struct xfs_inode *ip,
498 bool force)
499{
500 struct xfs_bmbt_irec imap;
501 struct xfs_mount *mp = ip->i_mount;
502 xfs_fileoff_t end_fsb;
503 xfs_fileoff_t last_fsb;
504 int nimaps = 1;
505 int error;
506
507 /*
508 * Caller must either hold the exclusive io lock; or be inactivating
509 * the inode, which guarantees there are no other users of the inode.
510 */
511 if (!(VFS_I(ip)->i_state & I_FREEING))
512 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL);
513
514 /* prealloc/delalloc exists only on regular files */
515 if (!S_ISREG(VFS_I(ip)->i_mode))
516 return false;
517
518 /*
519 * Zero sized files with no cached pages and delalloc blocks will not
520 * have speculative prealloc/delalloc blocks to remove.
521 */
522 if (VFS_I(ip)->i_size == 0 &&
523 VFS_I(ip)->i_mapping->nrpages == 0 &&
524 ip->i_delayed_blks == 0)
525 return false;
526
527 /* If we haven't read in the extent list, then don't do it now. */
528 if (xfs_need_iread_extents(&ip->i_df))
529 return false;
530
531 /*
532 * Do not free real preallocated or append-only files unless the file
533 * has delalloc blocks and we are forced to remove them.
534 */
535 if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
536 if (!force || ip->i_delayed_blks == 0)
537 return false;
538
539 /*
540 * Do not try to free post-EOF blocks if EOF is beyond the end of the
541 * range supported by the page cache, because the truncation will loop
542 * forever.
543 */
544 end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
545 if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1)
546 end_fsb = xfs_rtb_roundup_rtx(mp, end_fsb);
547 last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
548 if (last_fsb <= end_fsb)
549 return false;
550
551 /*
552 * Look up the mapping for the first block past EOF. If we can't find
553 * it, there's nothing to free.
554 */
555 xfs_ilock(ip, XFS_ILOCK_SHARED);
556 error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps,
557 0);
558 xfs_iunlock(ip, XFS_ILOCK_SHARED);
559 if (error || nimaps == 0)
560 return false;
561
562 /*
563 * If there's a real mapping there or there are delayed allocation
564 * reservations, then we have post-EOF blocks to try to free.
565 */
566 return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks;
567}
568
569/*
570 * This is called to free any blocks beyond eof. The caller must hold
571 * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
572 * reference to the inode.
573 */
574int
575xfs_free_eofblocks(
576 struct xfs_inode *ip)
577{
578 struct xfs_trans *tp;
579 struct xfs_mount *mp = ip->i_mount;
580 int error;
581
582 /* Attach the dquots to the inode up front. */
583 error = xfs_qm_dqattach(ip);
584 if (error)
585 return error;
586
587 /* Wait on dio to ensure i_size has settled. */
588 inode_dio_wait(VFS_I(ip));
589
590 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
591 if (error) {
592 ASSERT(xfs_is_shutdown(mp));
593 return error;
594 }
595
596 xfs_ilock(ip, XFS_ILOCK_EXCL);
597 xfs_trans_ijoin(tp, ip, 0);
598
599 /*
600 * Do not update the on-disk file size. If we update the on-disk file
601 * size and then the system crashes before the contents of the file are
602 * flushed to disk then the files may be full of holes (ie NULL files
603 * bug).
604 */
605 error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK,
606 XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
607 if (error)
608 goto err_cancel;
609
610 error = xfs_trans_commit(tp);
611 if (error)
612 goto out_unlock;
613
614 xfs_inode_clear_eofblocks_tag(ip);
615 goto out_unlock;
616
617err_cancel:
618 /*
619 * If we get an error at this point we simply don't
620 * bother truncating the file.
621 */
622 xfs_trans_cancel(tp);
623out_unlock:
624 xfs_iunlock(ip, XFS_ILOCK_EXCL);
625 return error;
626}
627
628int
629xfs_alloc_file_space(
630 struct xfs_inode *ip,
631 xfs_off_t offset,
632 xfs_off_t len)
633{
634 xfs_mount_t *mp = ip->i_mount;
635 xfs_off_t count;
636 xfs_filblks_t allocatesize_fsb;
637 xfs_extlen_t extsz, temp;
638 xfs_fileoff_t startoffset_fsb;
639 xfs_fileoff_t endoffset_fsb;
640 int rt;
641 xfs_trans_t *tp;
642 xfs_bmbt_irec_t imaps[1], *imapp;
643 int error;
644
645 trace_xfs_alloc_file_space(ip);
646
647 if (xfs_is_shutdown(mp))
648 return -EIO;
649
650 error = xfs_qm_dqattach(ip);
651 if (error)
652 return error;
653
654 if (len <= 0)
655 return -EINVAL;
656
657 rt = XFS_IS_REALTIME_INODE(ip);
658 extsz = xfs_get_extsz_hint(ip);
659
660 count = len;
661 imapp = &imaps[0];
662 startoffset_fsb = XFS_B_TO_FSBT(mp, offset);
663 endoffset_fsb = XFS_B_TO_FSB(mp, offset + count);
664 allocatesize_fsb = endoffset_fsb - startoffset_fsb;
665
666 /*
667 * Allocate file space until done or until there is an error
668 */
669 while (allocatesize_fsb && !error) {
670 xfs_fileoff_t s, e;
671 unsigned int dblocks, rblocks, resblks;
672 int nimaps = 1;
673
674 /*
675 * Determine space reservations for data/realtime.
676 */
677 if (unlikely(extsz)) {
678 s = startoffset_fsb;
679 do_div(s, extsz);
680 s *= extsz;
681 e = startoffset_fsb + allocatesize_fsb;
682 div_u64_rem(startoffset_fsb, extsz, &temp);
683 if (temp)
684 e += temp;
685 div_u64_rem(e, extsz, &temp);
686 if (temp)
687 e += extsz - temp;
688 } else {
689 s = 0;
690 e = allocatesize_fsb;
691 }
692
693 /*
694 * The transaction reservation is limited to a 32-bit block
695 * count, hence we need to limit the number of blocks we are
696 * trying to reserve to avoid an overflow. We can't allocate
697 * more than @nimaps extents, and an extent is limited on disk
698 * to XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the
699 * limit.
700 */
701 resblks = min_t(xfs_fileoff_t, (e - s),
702 (XFS_MAX_BMBT_EXTLEN * nimaps));
703 if (unlikely(rt)) {
704 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
705 rblocks = resblks;
706 } else {
707 dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
708 rblocks = 0;
709 }
710
711 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write,
712 dblocks, rblocks, false, &tp);
713 if (error)
714 break;
715
716 error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
717 XFS_IEXT_ADD_NOSPLIT_CNT);
718 if (error == -EFBIG)
719 error = xfs_iext_count_upgrade(tp, ip,
720 XFS_IEXT_ADD_NOSPLIT_CNT);
721 if (error)
722 goto error;
723
724 error = xfs_bmapi_write(tp, ip, startoffset_fsb,
725 allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
726 &nimaps);
727 if (error)
728 goto error;
729
730 ip->i_diflags |= XFS_DIFLAG_PREALLOC;
731 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
732
733 error = xfs_trans_commit(tp);
734 xfs_iunlock(ip, XFS_ILOCK_EXCL);
735 if (error)
736 break;
737
738 /*
739 * If the allocator cannot find a single free extent large
740 * enough to cover the start block of the requested range,
741 * xfs_bmapi_write will return 0 but leave *nimaps set to 0.
742 *
743 * In that case we simply need to keep looping with the same
744 * startoffset_fsb so that one of the following allocations
745 * will eventually reach the requested range.
746 */
747 if (nimaps) {
748 startoffset_fsb += imapp->br_blockcount;
749 allocatesize_fsb -= imapp->br_blockcount;
750 }
751 }
752
753 return error;
754
755error:
756 xfs_trans_cancel(tp);
757 xfs_iunlock(ip, XFS_ILOCK_EXCL);
758 return error;
759}
760
761static int
762xfs_unmap_extent(
763 struct xfs_inode *ip,
764 xfs_fileoff_t startoffset_fsb,
765 xfs_filblks_t len_fsb,
766 int *done)
767{
768 struct xfs_mount *mp = ip->i_mount;
769 struct xfs_trans *tp;
770 uint resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
771 int error;
772
773 error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks, 0,
774 false, &tp);
775 if (error)
776 return error;
777
778 error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
779 XFS_IEXT_PUNCH_HOLE_CNT);
780 if (error == -EFBIG)
781 error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
782 if (error)
783 goto out_trans_cancel;
784
785 error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
786 if (error)
787 goto out_trans_cancel;
788
789 error = xfs_trans_commit(tp);
790out_unlock:
791 xfs_iunlock(ip, XFS_ILOCK_EXCL);
792 return error;
793
794out_trans_cancel:
795 xfs_trans_cancel(tp);
796 goto out_unlock;
797}
798
799/* Caller must first wait for the completion of any pending DIOs if required. */
800int
801xfs_flush_unmap_range(
802 struct xfs_inode *ip,
803 xfs_off_t offset,
804 xfs_off_t len)
805{
806 struct xfs_mount *mp = ip->i_mount;
807 struct inode *inode = VFS_I(ip);
808 xfs_off_t rounding, start, end;
809 int error;
810
811 rounding = max_t(xfs_off_t, mp->m_sb.sb_blocksize, PAGE_SIZE);
812 start = round_down(offset, rounding);
813 end = round_up(offset + len, rounding) - 1;
814
815 error = filemap_write_and_wait_range(inode->i_mapping, start, end);
816 if (error)
817 return error;
818 truncate_pagecache_range(inode, start, end);
819 return 0;
820}
821
822int
823xfs_free_file_space(
824 struct xfs_inode *ip,
825 xfs_off_t offset,
826 xfs_off_t len)
827{
828 struct xfs_mount *mp = ip->i_mount;
829 xfs_fileoff_t startoffset_fsb;
830 xfs_fileoff_t endoffset_fsb;
831 int done = 0, error;
832
833 trace_xfs_free_file_space(ip);
834
835 error = xfs_qm_dqattach(ip);
836 if (error)
837 return error;
838
839 if (len <= 0) /* if nothing being freed */
840 return 0;
841
842 startoffset_fsb = XFS_B_TO_FSB(mp, offset);
843 endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
844
845 /* We can only free complete realtime extents. */
846 if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) {
847 startoffset_fsb = xfs_rtb_roundup_rtx(mp, startoffset_fsb);
848 endoffset_fsb = xfs_rtb_rounddown_rtx(mp, endoffset_fsb);
849 }
850
851 /*
852 * Need to zero the stuff we're not freeing, on disk.
853 */
854 if (endoffset_fsb > startoffset_fsb) {
855 while (!done) {
856 error = xfs_unmap_extent(ip, startoffset_fsb,
857 endoffset_fsb - startoffset_fsb, &done);
858 if (error)
859 return error;
860 }
861 }
862
863 /*
864 * Now that we've unmap all full blocks we'll have to zero out any
865 * partial block at the beginning and/or end. xfs_zero_range is smart
866 * enough to skip any holes, including those we just created, but we
867 * must take care not to zero beyond EOF and enlarge i_size.
868 */
869 if (offset >= XFS_ISIZE(ip))
870 return 0;
871 if (offset + len > XFS_ISIZE(ip))
872 len = XFS_ISIZE(ip) - offset;
873 error = xfs_zero_range(ip, offset, len, NULL);
874 if (error)
875 return error;
876
877 /*
878 * If we zeroed right up to EOF and EOF straddles a page boundary we
879 * must make sure that the post-EOF area is also zeroed because the
880 * page could be mmap'd and xfs_zero_range doesn't do that for us.
881 * Writeback of the eof page will do this, albeit clumsily.
882 */
883 if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) {
884 error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
885 round_down(offset + len, PAGE_SIZE), LLONG_MAX);
886 }
887
888 return error;
889}
890
891static int
892xfs_prepare_shift(
893 struct xfs_inode *ip,
894 loff_t offset)
895{
896 struct xfs_mount *mp = ip->i_mount;
897 int error;
898
899 /*
900 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
901 * into the accessible region of the file.
902 */
903 if (xfs_can_free_eofblocks(ip, true)) {
904 error = xfs_free_eofblocks(ip);
905 if (error)
906 return error;
907 }
908
909 /*
910 * Shift operations must stabilize the start block offset boundary along
911 * with the full range of the operation. If we don't, a COW writeback
912 * completion could race with an insert, front merge with the start
913 * extent (after split) during the shift and corrupt the file. Start
914 * with the block just prior to the start to stabilize the boundary.
915 */
916 offset = round_down(offset, mp->m_sb.sb_blocksize);
917 if (offset)
918 offset -= mp->m_sb.sb_blocksize;
919
920 /*
921 * Writeback and invalidate cache for the remainder of the file as we're
922 * about to shift down every extent from offset to EOF.
923 */
924 error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip));
925 if (error)
926 return error;
927
928 /*
929 * Clean out anything hanging around in the cow fork now that
930 * we've flushed all the dirty data out to disk to avoid having
931 * CoW extents at the wrong offsets.
932 */
933 if (xfs_inode_has_cow_data(ip)) {
934 error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
935 true);
936 if (error)
937 return error;
938 }
939
940 return 0;
941}
942
943/*
944 * xfs_collapse_file_space()
945 * This routine frees disk space and shift extent for the given file.
946 * The first thing we do is to free data blocks in the specified range
947 * by calling xfs_free_file_space(). It would also sync dirty data
948 * and invalidate page cache over the region on which collapse range
949 * is working. And Shift extent records to the left to cover a hole.
950 * RETURNS:
951 * 0 on success
952 * errno on error
953 *
954 */
955int
956xfs_collapse_file_space(
957 struct xfs_inode *ip,
958 xfs_off_t offset,
959 xfs_off_t len)
960{
961 struct xfs_mount *mp = ip->i_mount;
962 struct xfs_trans *tp;
963 int error;
964 xfs_fileoff_t next_fsb = XFS_B_TO_FSB(mp, offset + len);
965 xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
966 bool done = false;
967
968 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
969
970 trace_xfs_collapse_file_space(ip);
971
972 error = xfs_free_file_space(ip, offset, len);
973 if (error)
974 return error;
975
976 error = xfs_prepare_shift(ip, offset);
977 if (error)
978 return error;
979
980 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
981 if (error)
982 return error;
983
984 xfs_ilock(ip, XFS_ILOCK_EXCL);
985 xfs_trans_ijoin(tp, ip, 0);
986
987 while (!done) {
988 error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
989 &done);
990 if (error)
991 goto out_trans_cancel;
992 if (done)
993 break;
994
995 /* finish any deferred frees and roll the transaction */
996 error = xfs_defer_finish(&tp);
997 if (error)
998 goto out_trans_cancel;
999 }
1000
1001 error = xfs_trans_commit(tp);
1002 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1003 return error;
1004
1005out_trans_cancel:
1006 xfs_trans_cancel(tp);
1007 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1008 return error;
1009}
1010
1011/*
1012 * xfs_insert_file_space()
1013 * This routine create hole space by shifting extents for the given file.
1014 * The first thing we do is to sync dirty data and invalidate page cache
1015 * over the region on which insert range is working. And split an extent
1016 * to two extents at given offset by calling xfs_bmap_split_extent.
1017 * And shift all extent records which are laying between [offset,
1018 * last allocated extent] to the right to reserve hole range.
1019 * RETURNS:
1020 * 0 on success
1021 * errno on error
1022 */
1023int
1024xfs_insert_file_space(
1025 struct xfs_inode *ip,
1026 loff_t offset,
1027 loff_t len)
1028{
1029 struct xfs_mount *mp = ip->i_mount;
1030 struct xfs_trans *tp;
1031 int error;
1032 xfs_fileoff_t stop_fsb = XFS_B_TO_FSB(mp, offset);
1033 xfs_fileoff_t next_fsb = NULLFSBLOCK;
1034 xfs_fileoff_t shift_fsb = XFS_B_TO_FSB(mp, len);
1035 bool done = false;
1036
1037 xfs_assert_ilocked(ip, XFS_IOLOCK_EXCL | XFS_MMAPLOCK_EXCL);
1038
1039 trace_xfs_insert_file_space(ip);
1040
1041 error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
1042 if (error)
1043 return error;
1044
1045 error = xfs_prepare_shift(ip, offset);
1046 if (error)
1047 return error;
1048
1049 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write,
1050 XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp);
1051 if (error)
1052 return error;
1053
1054 xfs_ilock(ip, XFS_ILOCK_EXCL);
1055 xfs_trans_ijoin(tp, ip, 0);
1056
1057 error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
1058 XFS_IEXT_PUNCH_HOLE_CNT);
1059 if (error == -EFBIG)
1060 error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
1061 if (error)
1062 goto out_trans_cancel;
1063
1064 /*
1065 * The extent shifting code works on extent granularity. So, if stop_fsb
1066 * is not the starting block of extent, we need to split the extent at
1067 * stop_fsb.
1068 */
1069 error = xfs_bmap_split_extent(tp, ip, stop_fsb);
1070 if (error)
1071 goto out_trans_cancel;
1072
1073 do {
1074 error = xfs_defer_finish(&tp);
1075 if (error)
1076 goto out_trans_cancel;
1077
1078 error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
1079 &done, stop_fsb);
1080 if (error)
1081 goto out_trans_cancel;
1082 } while (!done);
1083
1084 error = xfs_trans_commit(tp);
1085 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1086 return error;
1087
1088out_trans_cancel:
1089 xfs_trans_cancel(tp);
1090 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1091 return error;
1092}
1093
1094/*
1095 * We need to check that the format of the data fork in the temporary inode is
1096 * valid for the target inode before doing the swap. This is not a problem with
1097 * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
1098 * data fork depending on the space the attribute fork is taking so we can get
1099 * invalid formats on the target inode.
1100 *
1101 * E.g. target has space for 7 extents in extent format, temp inode only has
1102 * space for 6. If we defragment down to 7 extents, then the tmp format is a
1103 * btree, but when swapped it needs to be in extent format. Hence we can't just
1104 * blindly swap data forks on attr2 filesystems.
1105 *
1106 * Note that we check the swap in both directions so that we don't end up with
1107 * a corrupt temporary inode, either.
1108 *
1109 * Note that fixing the way xfs_fsr sets up the attribute fork in the source
1110 * inode will prevent this situation from occurring, so all we do here is
1111 * reject and log the attempt. basically we are putting the responsibility on
1112 * userspace to get this right.
1113 */
1114static int
1115xfs_swap_extents_check_format(
1116 struct xfs_inode *ip, /* target inode */
1117 struct xfs_inode *tip) /* tmp inode */
1118{
1119 struct xfs_ifork *ifp = &ip->i_df;
1120 struct xfs_ifork *tifp = &tip->i_df;
1121
1122 /* User/group/project quota ids must match if quotas are enforced. */
1123 if (XFS_IS_QUOTA_ON(ip->i_mount) &&
1124 (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) ||
1125 !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) ||
1126 ip->i_projid != tip->i_projid))
1127 return -EINVAL;
1128
1129 /* Should never get a local format */
1130 if (ifp->if_format == XFS_DINODE_FMT_LOCAL ||
1131 tifp->if_format == XFS_DINODE_FMT_LOCAL)
1132 return -EINVAL;
1133
1134 /*
1135 * if the target inode has less extents that then temporary inode then
1136 * why did userspace call us?
1137 */
1138 if (ifp->if_nextents < tifp->if_nextents)
1139 return -EINVAL;
1140
1141 /*
1142 * If we have to use the (expensive) rmap swap method, we can
1143 * handle any number of extents and any format.
1144 */
1145 if (xfs_has_rmapbt(ip->i_mount))
1146 return 0;
1147
1148 /*
1149 * if the target inode is in extent form and the temp inode is in btree
1150 * form then we will end up with the target inode in the wrong format
1151 * as we already know there are less extents in the temp inode.
1152 */
1153 if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1154 tifp->if_format == XFS_DINODE_FMT_BTREE)
1155 return -EINVAL;
1156
1157 /* Check temp in extent form to max in target */
1158 if (tifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1159 tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1160 return -EINVAL;
1161
1162 /* Check target in extent form to max in temp */
1163 if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1164 ifp->if_nextents > XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1165 return -EINVAL;
1166
1167 /*
1168 * If we are in a btree format, check that the temp root block will fit
1169 * in the target and that it has enough extents to be in btree format
1170 * in the target.
1171 *
1172 * Note that we have to be careful to allow btree->extent conversions
1173 * (a common defrag case) which will occur when the temp inode is in
1174 * extent format...
1175 */
1176 if (tifp->if_format == XFS_DINODE_FMT_BTREE) {
1177 if (xfs_inode_has_attr_fork(ip) &&
1178 XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip))
1179 return -EINVAL;
1180 if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1181 return -EINVAL;
1182 }
1183
1184 /* Reciprocal target->temp btree format checks */
1185 if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
1186 if (xfs_inode_has_attr_fork(tip) &&
1187 XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip))
1188 return -EINVAL;
1189 if (ifp->if_nextents <= XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1190 return -EINVAL;
1191 }
1192
1193 return 0;
1194}
1195
1196static int
1197xfs_swap_extent_flush(
1198 struct xfs_inode *ip)
1199{
1200 int error;
1201
1202 error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
1203 if (error)
1204 return error;
1205 truncate_pagecache_range(VFS_I(ip), 0, -1);
1206
1207 /* Verify O_DIRECT for ftmp */
1208 if (VFS_I(ip)->i_mapping->nrpages)
1209 return -EINVAL;
1210 return 0;
1211}
1212
1213/*
1214 * Move extents from one file to another, when rmap is enabled.
1215 */
1216STATIC int
1217xfs_swap_extent_rmap(
1218 struct xfs_trans **tpp,
1219 struct xfs_inode *ip,
1220 struct xfs_inode *tip)
1221{
1222 struct xfs_trans *tp = *tpp;
1223 struct xfs_bmbt_irec irec;
1224 struct xfs_bmbt_irec uirec;
1225 struct xfs_bmbt_irec tirec;
1226 xfs_fileoff_t offset_fsb;
1227 xfs_fileoff_t end_fsb;
1228 xfs_filblks_t count_fsb;
1229 int error;
1230 xfs_filblks_t ilen;
1231 xfs_filblks_t rlen;
1232 int nimaps;
1233 uint64_t tip_flags2;
1234
1235 /*
1236 * If the source file has shared blocks, we must flag the donor
1237 * file as having shared blocks so that we get the shared-block
1238 * rmap functions when we go to fix up the rmaps. The flags
1239 * will be switch for reals later.
1240 */
1241 tip_flags2 = tip->i_diflags2;
1242 if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK)
1243 tip->i_diflags2 |= XFS_DIFLAG2_REFLINK;
1244
1245 offset_fsb = 0;
1246 end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
1247 count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
1248
1249 while (count_fsb) {
1250 /* Read extent from the donor file */
1251 nimaps = 1;
1252 error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
1253 &nimaps, 0);
1254 if (error)
1255 goto out;
1256 ASSERT(nimaps == 1);
1257 ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
1258
1259 trace_xfs_swap_extent_rmap_remap(tip, &tirec);
1260 ilen = tirec.br_blockcount;
1261
1262 /* Unmap the old blocks in the source file. */
1263 while (tirec.br_blockcount) {
1264 ASSERT(tp->t_highest_agno == NULLAGNUMBER);
1265 trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
1266
1267 /* Read extent from the source file */
1268 nimaps = 1;
1269 error = xfs_bmapi_read(ip, tirec.br_startoff,
1270 tirec.br_blockcount, &irec,
1271 &nimaps, 0);
1272 if (error)
1273 goto out;
1274 ASSERT(nimaps == 1);
1275 ASSERT(tirec.br_startoff == irec.br_startoff);
1276 trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
1277
1278 /* Trim the extent. */
1279 uirec = tirec;
1280 uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
1281 tirec.br_blockcount,
1282 irec.br_blockcount);
1283 trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
1284
1285 if (xfs_bmap_is_real_extent(&uirec)) {
1286 error = xfs_iext_count_may_overflow(ip,
1287 XFS_DATA_FORK,
1288 XFS_IEXT_SWAP_RMAP_CNT);
1289 if (error == -EFBIG)
1290 error = xfs_iext_count_upgrade(tp, ip,
1291 XFS_IEXT_SWAP_RMAP_CNT);
1292 if (error)
1293 goto out;
1294 }
1295
1296 if (xfs_bmap_is_real_extent(&irec)) {
1297 error = xfs_iext_count_may_overflow(tip,
1298 XFS_DATA_FORK,
1299 XFS_IEXT_SWAP_RMAP_CNT);
1300 if (error == -EFBIG)
1301 error = xfs_iext_count_upgrade(tp, ip,
1302 XFS_IEXT_SWAP_RMAP_CNT);
1303 if (error)
1304 goto out;
1305 }
1306
1307 /* Remove the mapping from the donor file. */
1308 xfs_bmap_unmap_extent(tp, tip, XFS_DATA_FORK, &uirec);
1309
1310 /* Remove the mapping from the source file. */
1311 xfs_bmap_unmap_extent(tp, ip, XFS_DATA_FORK, &irec);
1312
1313 /* Map the donor file's blocks into the source file. */
1314 xfs_bmap_map_extent(tp, ip, XFS_DATA_FORK, &uirec);
1315
1316 /* Map the source file's blocks into the donor file. */
1317 xfs_bmap_map_extent(tp, tip, XFS_DATA_FORK, &irec);
1318
1319 error = xfs_defer_finish(tpp);
1320 tp = *tpp;
1321 if (error)
1322 goto out;
1323
1324 tirec.br_startoff += rlen;
1325 if (tirec.br_startblock != HOLESTARTBLOCK &&
1326 tirec.br_startblock != DELAYSTARTBLOCK)
1327 tirec.br_startblock += rlen;
1328 tirec.br_blockcount -= rlen;
1329 }
1330
1331 /* Roll on... */
1332 count_fsb -= ilen;
1333 offset_fsb += ilen;
1334 }
1335
1336 tip->i_diflags2 = tip_flags2;
1337 return 0;
1338
1339out:
1340 trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
1341 tip->i_diflags2 = tip_flags2;
1342 return error;
1343}
1344
1345/* Swap the extents of two files by swapping data forks. */
1346STATIC int
1347xfs_swap_extent_forks(
1348 struct xfs_trans *tp,
1349 struct xfs_inode *ip,
1350 struct xfs_inode *tip,
1351 int *src_log_flags,
1352 int *target_log_flags)
1353{
1354 xfs_filblks_t aforkblks = 0;
1355 xfs_filblks_t taforkblks = 0;
1356 xfs_extnum_t junk;
1357 uint64_t tmp;
1358 int error;
1359
1360 /*
1361 * Count the number of extended attribute blocks
1362 */
1363 if (xfs_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 &&
1364 ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1365 error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk,
1366 &aforkblks);
1367 if (error)
1368 return error;
1369 }
1370 if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 &&
1371 tip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1372 error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK, &junk,
1373 &taforkblks);
1374 if (error)
1375 return error;
1376 }
1377
1378 /*
1379 * Btree format (v3) inodes have the inode number stamped in the bmbt
1380 * block headers. We can't start changing the bmbt blocks until the
1381 * inode owner change is logged so recovery does the right thing in the
1382 * event of a crash. Set the owner change log flags now and leave the
1383 * bmbt scan as the last step.
1384 */
1385 if (xfs_has_v3inodes(ip->i_mount)) {
1386 if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1387 (*target_log_flags) |= XFS_ILOG_DOWNER;
1388 if (tip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1389 (*src_log_flags) |= XFS_ILOG_DOWNER;
1390 }
1391
1392 /*
1393 * Swap the data forks of the inodes
1394 */
1395 swap(ip->i_df, tip->i_df);
1396
1397 /*
1398 * Fix the on-disk inode values
1399 */
1400 tmp = (uint64_t)ip->i_nblocks;
1401 ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks;
1402 tip->i_nblocks = tmp + taforkblks - aforkblks;
1403
1404 /*
1405 * The extents in the source inode could still contain speculative
1406 * preallocation beyond EOF (e.g. the file is open but not modified
1407 * while defrag is in progress). In that case, we need to copy over the
1408 * number of delalloc blocks the data fork in the source inode is
1409 * tracking beyond EOF so that when the fork is truncated away when the
1410 * temporary inode is unlinked we don't underrun the i_delayed_blks
1411 * counter on that inode.
1412 */
1413 ASSERT(tip->i_delayed_blks == 0);
1414 tip->i_delayed_blks = ip->i_delayed_blks;
1415 ip->i_delayed_blks = 0;
1416
1417 switch (ip->i_df.if_format) {
1418 case XFS_DINODE_FMT_EXTENTS:
1419 (*src_log_flags) |= XFS_ILOG_DEXT;
1420 break;
1421 case XFS_DINODE_FMT_BTREE:
1422 ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1423 (*src_log_flags & XFS_ILOG_DOWNER));
1424 (*src_log_flags) |= XFS_ILOG_DBROOT;
1425 break;
1426 }
1427
1428 switch (tip->i_df.if_format) {
1429 case XFS_DINODE_FMT_EXTENTS:
1430 (*target_log_flags) |= XFS_ILOG_DEXT;
1431 break;
1432 case XFS_DINODE_FMT_BTREE:
1433 (*target_log_flags) |= XFS_ILOG_DBROOT;
1434 ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1435 (*target_log_flags & XFS_ILOG_DOWNER));
1436 break;
1437 }
1438
1439 return 0;
1440}
1441
1442/*
1443 * Fix up the owners of the bmbt blocks to refer to the current inode. The
1444 * change owner scan attempts to order all modified buffers in the current
1445 * transaction. In the event of ordered buffer failure, the offending buffer is
1446 * physically logged as a fallback and the scan returns -EAGAIN. We must roll
1447 * the transaction in this case to replenish the fallback log reservation and
1448 * restart the scan. This process repeats until the scan completes.
1449 */
1450static int
1451xfs_swap_change_owner(
1452 struct xfs_trans **tpp,
1453 struct xfs_inode *ip,
1454 struct xfs_inode *tmpip)
1455{
1456 int error;
1457 struct xfs_trans *tp = *tpp;
1458
1459 do {
1460 error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
1461 NULL);
1462 /* success or fatal error */
1463 if (error != -EAGAIN)
1464 break;
1465
1466 error = xfs_trans_roll(tpp);
1467 if (error)
1468 break;
1469 tp = *tpp;
1470
1471 /*
1472 * Redirty both inodes so they can relog and keep the log tail
1473 * moving forward.
1474 */
1475 xfs_trans_ijoin(tp, ip, 0);
1476 xfs_trans_ijoin(tp, tmpip, 0);
1477 xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1478 xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
1479 } while (true);
1480
1481 return error;
1482}
1483
1484int
1485xfs_swap_extents(
1486 struct xfs_inode *ip, /* target inode */
1487 struct xfs_inode *tip, /* tmp inode */
1488 struct xfs_swapext *sxp)
1489{
1490 struct xfs_mount *mp = ip->i_mount;
1491 struct xfs_trans *tp;
1492 struct xfs_bstat *sbp = &sxp->sx_stat;
1493 int src_log_flags, target_log_flags;
1494 int error = 0;
1495 uint64_t f;
1496 int resblks = 0;
1497 unsigned int flags = 0;
1498 struct timespec64 ctime, mtime;
1499
1500 /*
1501 * Lock the inodes against other IO, page faults and truncate to
1502 * begin with. Then we can ensure the inodes are flushed and have no
1503 * page cache safely. Once we have done this we can take the ilocks and
1504 * do the rest of the checks.
1505 */
1506 lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1507 filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
1508 VFS_I(tip)->i_mapping);
1509
1510 /* Verify that both files have the same format */
1511 if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
1512 error = -EINVAL;
1513 goto out_unlock;
1514 }
1515
1516 /* Verify both files are either real-time or non-realtime */
1517 if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
1518 error = -EINVAL;
1519 goto out_unlock;
1520 }
1521
1522 error = xfs_qm_dqattach(ip);
1523 if (error)
1524 goto out_unlock;
1525
1526 error = xfs_qm_dqattach(tip);
1527 if (error)
1528 goto out_unlock;
1529
1530 error = xfs_swap_extent_flush(ip);
1531 if (error)
1532 goto out_unlock;
1533 error = xfs_swap_extent_flush(tip);
1534 if (error)
1535 goto out_unlock;
1536
1537 if (xfs_inode_has_cow_data(tip)) {
1538 error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true);
1539 if (error)
1540 goto out_unlock;
1541 }
1542
1543 /*
1544 * Extent "swapping" with rmap requires a permanent reservation and
1545 * a block reservation because it's really just a remap operation
1546 * performed with log redo items!
1547 */
1548 if (xfs_has_rmapbt(mp)) {
1549 int w = XFS_DATA_FORK;
1550 uint32_t ipnext = ip->i_df.if_nextents;
1551 uint32_t tipnext = tip->i_df.if_nextents;
1552
1553 /*
1554 * Conceptually this shouldn't affect the shape of either bmbt,
1555 * but since we atomically move extents one by one, we reserve
1556 * enough space to rebuild both trees.
1557 */
1558 resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w);
1559 resblks += XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w);
1560
1561 /*
1562 * If either inode straddles a bmapbt block allocation boundary,
1563 * the rmapbt algorithm triggers repeated allocs and frees as
1564 * extents are remapped. This can exhaust the block reservation
1565 * prematurely and cause shutdown. Return freed blocks to the
1566 * transaction reservation to counter this behavior.
1567 */
1568 flags |= XFS_TRANS_RES_FDBLKS;
1569 }
1570 error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags,
1571 &tp);
1572 if (error)
1573 goto out_unlock;
1574
1575 /*
1576 * Lock and join the inodes to the tansaction so that transaction commit
1577 * or cancel will unlock the inodes from this point onwards.
1578 */
1579 xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
1580 xfs_trans_ijoin(tp, ip, 0);
1581 xfs_trans_ijoin(tp, tip, 0);
1582
1583
1584 /* Verify all data are being swapped */
1585 if (sxp->sx_offset != 0 ||
1586 sxp->sx_length != ip->i_disk_size ||
1587 sxp->sx_length != tip->i_disk_size) {
1588 error = -EFAULT;
1589 goto out_trans_cancel;
1590 }
1591
1592 trace_xfs_swap_extent_before(ip, 0);
1593 trace_xfs_swap_extent_before(tip, 1);
1594
1595 /* check inode formats now that data is flushed */
1596 error = xfs_swap_extents_check_format(ip, tip);
1597 if (error) {
1598 xfs_notice(mp,
1599 "%s: inode 0x%llx format is incompatible for exchanging.",
1600 __func__, ip->i_ino);
1601 goto out_trans_cancel;
1602 }
1603
1604 /*
1605 * Compare the current change & modify times with that
1606 * passed in. If they differ, we abort this swap.
1607 * This is the mechanism used to ensure the calling
1608 * process that the file was not changed out from
1609 * under it.
1610 */
1611 ctime = inode_get_ctime(VFS_I(ip));
1612 mtime = inode_get_mtime(VFS_I(ip));
1613 if ((sbp->bs_ctime.tv_sec != ctime.tv_sec) ||
1614 (sbp->bs_ctime.tv_nsec != ctime.tv_nsec) ||
1615 (sbp->bs_mtime.tv_sec != mtime.tv_sec) ||
1616 (sbp->bs_mtime.tv_nsec != mtime.tv_nsec)) {
1617 error = -EBUSY;
1618 goto out_trans_cancel;
1619 }
1620
1621 /*
1622 * Note the trickiness in setting the log flags - we set the owner log
1623 * flag on the opposite inode (i.e. the inode we are setting the new
1624 * owner to be) because once we swap the forks and log that, log
1625 * recovery is going to see the fork as owned by the swapped inode,
1626 * not the pre-swapped inodes.
1627 */
1628 src_log_flags = XFS_ILOG_CORE;
1629 target_log_flags = XFS_ILOG_CORE;
1630
1631 if (xfs_has_rmapbt(mp))
1632 error = xfs_swap_extent_rmap(&tp, ip, tip);
1633 else
1634 error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
1635 &target_log_flags);
1636 if (error)
1637 goto out_trans_cancel;
1638
1639 /* Do we have to swap reflink flags? */
1640 if ((ip->i_diflags2 & XFS_DIFLAG2_REFLINK) ^
1641 (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) {
1642 f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1643 ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1644 ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1645 tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1646 tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK;
1647 }
1648
1649 /* Swap the cow forks. */
1650 if (xfs_has_reflink(mp)) {
1651 ASSERT(!ip->i_cowfp ||
1652 ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1653 ASSERT(!tip->i_cowfp ||
1654 tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1655
1656 swap(ip->i_cowfp, tip->i_cowfp);
1657
1658 if (ip->i_cowfp && ip->i_cowfp->if_bytes)
1659 xfs_inode_set_cowblocks_tag(ip);
1660 else
1661 xfs_inode_clear_cowblocks_tag(ip);
1662 if (tip->i_cowfp && tip->i_cowfp->if_bytes)
1663 xfs_inode_set_cowblocks_tag(tip);
1664 else
1665 xfs_inode_clear_cowblocks_tag(tip);
1666 }
1667
1668 xfs_trans_log_inode(tp, ip, src_log_flags);
1669 xfs_trans_log_inode(tp, tip, target_log_flags);
1670
1671 /*
1672 * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
1673 * have inode number owner values in the bmbt blocks that still refer to
1674 * the old inode. Scan each bmbt to fix up the owner values with the
1675 * inode number of the current inode.
1676 */
1677 if (src_log_flags & XFS_ILOG_DOWNER) {
1678 error = xfs_swap_change_owner(&tp, ip, tip);
1679 if (error)
1680 goto out_trans_cancel;
1681 }
1682 if (target_log_flags & XFS_ILOG_DOWNER) {
1683 error = xfs_swap_change_owner(&tp, tip, ip);
1684 if (error)
1685 goto out_trans_cancel;
1686 }
1687
1688 /*
1689 * If this is a synchronous mount, make sure that the
1690 * transaction goes to disk before returning to the user.
1691 */
1692 if (xfs_has_wsync(mp))
1693 xfs_trans_set_sync(tp);
1694
1695 error = xfs_trans_commit(tp);
1696
1697 trace_xfs_swap_extent_after(ip, 0);
1698 trace_xfs_swap_extent_after(tip, 1);
1699
1700out_unlock_ilock:
1701 xfs_iunlock(ip, XFS_ILOCK_EXCL);
1702 xfs_iunlock(tip, XFS_ILOCK_EXCL);
1703out_unlock:
1704 filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
1705 VFS_I(tip)->i_mapping);
1706 unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1707 return error;
1708
1709out_trans_cancel:
1710 xfs_trans_cancel(tp);
1711 goto out_unlock_ilock;
1712}