xref: /openbmc/linux/fs/xfs/xfs_bmap_util.c (revision 997a5310)
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 
32 /* Kernel only BMAP related definitions and functions */
33 
34 /*
35  * Convert the given file system block to a disk block.  We have to treat it
36  * differently based on whether the file is a real time file or not, because the
37  * bmap code does.
38  */
39 xfs_daddr_t
40 xfs_fsb_to_db(struct xfs_inode *ip, xfs_fsblock_t fsb)
41 {
42 	if (XFS_IS_REALTIME_INODE(ip))
43 		return XFS_FSB_TO_BB(ip->i_mount, fsb);
44 	return XFS_FSB_TO_DADDR(ip->i_mount, fsb);
45 }
46 
47 /*
48  * Routine to zero an extent on disk allocated to the specific inode.
49  *
50  * The VFS functions take a linearised filesystem block offset, so we have to
51  * convert the sparse xfs fsb to the right format first.
52  * VFS types are real funky, too.
53  */
54 int
55 xfs_zero_extent(
56 	struct xfs_inode	*ip,
57 	xfs_fsblock_t		start_fsb,
58 	xfs_off_t		count_fsb)
59 {
60 	struct xfs_mount	*mp = ip->i_mount;
61 	struct xfs_buftarg	*target = xfs_inode_buftarg(ip);
62 	xfs_daddr_t		sector = xfs_fsb_to_db(ip, start_fsb);
63 	sector_t		block = XFS_BB_TO_FSBT(mp, sector);
64 
65 	return blkdev_issue_zeroout(target->bt_bdev,
66 		block << (mp->m_super->s_blocksize_bits - 9),
67 		count_fsb << (mp->m_super->s_blocksize_bits - 9),
68 		GFP_NOFS, 0);
69 }
70 
71 #ifdef CONFIG_XFS_RT
72 int
73 xfs_bmap_rtalloc(
74 	struct xfs_bmalloca	*ap)
75 {
76 	struct xfs_mount	*mp = ap->ip->i_mount;
77 	xfs_fileoff_t		orig_offset = ap->offset;
78 	xfs_rtblock_t		rtb;
79 	xfs_extlen_t		prod = 0;  /* product factor for allocators */
80 	xfs_extlen_t		mod = 0;   /* product factor for allocators */
81 	xfs_extlen_t		ralen = 0; /* realtime allocation length */
82 	xfs_extlen_t		align;     /* minimum allocation alignment */
83 	xfs_extlen_t		orig_length = ap->length;
84 	xfs_extlen_t		minlen = mp->m_sb.sb_rextsize;
85 	xfs_extlen_t		raminlen;
86 	bool			rtlocked = false;
87 	bool			ignore_locality = false;
88 	int			error;
89 
90 	align = xfs_get_extsz_hint(ap->ip);
91 retry:
92 	prod = align / mp->m_sb.sb_rextsize;
93 	error = xfs_bmap_extsize_align(mp, &ap->got, &ap->prev,
94 					align, 1, ap->eof, 0,
95 					ap->conv, &ap->offset, &ap->length);
96 	if (error)
97 		return error;
98 	ASSERT(ap->length);
99 	ASSERT(ap->length % mp->m_sb.sb_rextsize == 0);
100 
101 	/*
102 	 * If we shifted the file offset downward to satisfy an extent size
103 	 * hint, increase minlen by that amount so that the allocator won't
104 	 * give us an allocation that's too short to cover at least one of the
105 	 * blocks that the caller asked for.
106 	 */
107 	if (ap->offset != orig_offset)
108 		minlen += orig_offset - ap->offset;
109 
110 	/*
111 	 * If the offset & length are not perfectly aligned
112 	 * then kill prod, it will just get us in trouble.
113 	 */
114 	div_u64_rem(ap->offset, align, &mod);
115 	if (mod || ap->length % align)
116 		prod = 1;
117 	/*
118 	 * Set ralen to be the actual requested length in rtextents.
119 	 */
120 	ralen = ap->length / mp->m_sb.sb_rextsize;
121 	/*
122 	 * If the old value was close enough to XFS_BMBT_MAX_EXTLEN that
123 	 * we rounded up to it, cut it back so it's valid again.
124 	 * Note that if it's a really large request (bigger than
125 	 * XFS_BMBT_MAX_EXTLEN), we don't hear about that number, and can't
126 	 * adjust the starting point to match it.
127 	 */
128 	if (ralen * mp->m_sb.sb_rextsize >= XFS_MAX_BMBT_EXTLEN)
129 		ralen = XFS_MAX_BMBT_EXTLEN / mp->m_sb.sb_rextsize;
130 
131 	/*
132 	 * Lock out modifications to both the RT bitmap and summary inodes
133 	 */
134 	if (!rtlocked) {
135 		xfs_ilock(mp->m_rbmip, XFS_ILOCK_EXCL|XFS_ILOCK_RTBITMAP);
136 		xfs_trans_ijoin(ap->tp, mp->m_rbmip, XFS_ILOCK_EXCL);
137 		xfs_ilock(mp->m_rsumip, XFS_ILOCK_EXCL|XFS_ILOCK_RTSUM);
138 		xfs_trans_ijoin(ap->tp, mp->m_rsumip, XFS_ILOCK_EXCL);
139 		rtlocked = true;
140 	}
141 
142 	/*
143 	 * If it's an allocation to an empty file at offset 0,
144 	 * pick an extent that will space things out in the rt area.
145 	 */
146 	if (ap->eof && ap->offset == 0) {
147 		xfs_rtblock_t rtx; /* realtime extent no */
148 
149 		error = xfs_rtpick_extent(mp, ap->tp, ralen, &rtx);
150 		if (error)
151 			return error;
152 		ap->blkno = rtx * mp->m_sb.sb_rextsize;
153 	} else {
154 		ap->blkno = 0;
155 	}
156 
157 	xfs_bmap_adjacent(ap);
158 
159 	/*
160 	 * Realtime allocation, done through xfs_rtallocate_extent.
161 	 */
162 	if (ignore_locality)
163 		ap->blkno = 0;
164 	else
165 		do_div(ap->blkno, mp->m_sb.sb_rextsize);
166 	rtb = ap->blkno;
167 	ap->length = ralen;
168 	raminlen = max_t(xfs_extlen_t, 1, minlen / mp->m_sb.sb_rextsize);
169 	error = xfs_rtallocate_extent(ap->tp, ap->blkno, raminlen, ap->length,
170 			&ralen, ap->wasdel, prod, &rtb);
171 	if (error)
172 		return error;
173 
174 	if (rtb != NULLRTBLOCK) {
175 		ap->blkno = rtb * mp->m_sb.sb_rextsize;
176 		ap->length = ralen * mp->m_sb.sb_rextsize;
177 		ap->ip->i_nblocks += ap->length;
178 		xfs_trans_log_inode(ap->tp, ap->ip, XFS_ILOG_CORE);
179 		if (ap->wasdel)
180 			ap->ip->i_delayed_blks -= ap->length;
181 		/*
182 		 * Adjust the disk quota also. This was reserved
183 		 * earlier.
184 		 */
185 		xfs_trans_mod_dquot_byino(ap->tp, ap->ip,
186 			ap->wasdel ? XFS_TRANS_DQ_DELRTBCOUNT :
187 					XFS_TRANS_DQ_RTBCOUNT, ap->length);
188 		return 0;
189 	}
190 
191 	if (align > mp->m_sb.sb_rextsize) {
192 		/*
193 		 * We previously enlarged the request length to try to satisfy
194 		 * an extent size hint.  The allocator didn't return anything,
195 		 * so reset the parameters to the original values and try again
196 		 * without alignment criteria.
197 		 */
198 		ap->offset = orig_offset;
199 		ap->length = orig_length;
200 		minlen = align = mp->m_sb.sb_rextsize;
201 		goto retry;
202 	}
203 
204 	if (!ignore_locality && ap->blkno != 0) {
205 		/*
206 		 * If we can't allocate near a specific rt extent, try again
207 		 * without locality criteria.
208 		 */
209 		ignore_locality = true;
210 		goto retry;
211 	}
212 
213 	ap->blkno = NULLFSBLOCK;
214 	ap->length = 0;
215 	return 0;
216 }
217 #endif /* CONFIG_XFS_RT */
218 
219 /*
220  * Extent tree block counting routines.
221  */
222 
223 /*
224  * Count leaf blocks given a range of extent records.  Delayed allocation
225  * extents are not counted towards the totals.
226  */
227 xfs_extnum_t
228 xfs_bmap_count_leaves(
229 	struct xfs_ifork	*ifp,
230 	xfs_filblks_t		*count)
231 {
232 	struct xfs_iext_cursor	icur;
233 	struct xfs_bmbt_irec	got;
234 	xfs_extnum_t		numrecs = 0;
235 
236 	for_each_xfs_iext(ifp, &icur, &got) {
237 		if (!isnullstartblock(got.br_startblock)) {
238 			*count += got.br_blockcount;
239 			numrecs++;
240 		}
241 	}
242 
243 	return numrecs;
244 }
245 
246 /*
247  * Count fsblocks of the given fork.  Delayed allocation extents are
248  * not counted towards the totals.
249  */
250 int
251 xfs_bmap_count_blocks(
252 	struct xfs_trans	*tp,
253 	struct xfs_inode	*ip,
254 	int			whichfork,
255 	xfs_extnum_t		*nextents,
256 	xfs_filblks_t		*count)
257 {
258 	struct xfs_mount	*mp = ip->i_mount;
259 	struct xfs_ifork	*ifp = xfs_ifork_ptr(ip, whichfork);
260 	struct xfs_btree_cur	*cur;
261 	xfs_extlen_t		btblocks = 0;
262 	int			error;
263 
264 	*nextents = 0;
265 	*count = 0;
266 
267 	if (!ifp)
268 		return 0;
269 
270 	switch (ifp->if_format) {
271 	case XFS_DINODE_FMT_BTREE:
272 		error = xfs_iread_extents(tp, ip, whichfork);
273 		if (error)
274 			return error;
275 
276 		cur = xfs_bmbt_init_cursor(mp, tp, ip, whichfork);
277 		error = xfs_btree_count_blocks(cur, &btblocks);
278 		xfs_btree_del_cursor(cur, error);
279 		if (error)
280 			return error;
281 
282 		/*
283 		 * xfs_btree_count_blocks includes the root block contained in
284 		 * the inode fork in @btblocks, so subtract one because we're
285 		 * only interested in allocated disk blocks.
286 		 */
287 		*count += btblocks - 1;
288 
289 		fallthrough;
290 	case XFS_DINODE_FMT_EXTENTS:
291 		*nextents = xfs_bmap_count_leaves(ifp, count);
292 		break;
293 	}
294 
295 	return 0;
296 }
297 
298 static int
299 xfs_getbmap_report_one(
300 	struct xfs_inode	*ip,
301 	struct getbmapx		*bmv,
302 	struct kgetbmap		*out,
303 	int64_t			bmv_end,
304 	struct xfs_bmbt_irec	*got)
305 {
306 	struct kgetbmap		*p = out + bmv->bmv_entries;
307 	bool			shared = false;
308 	int			error;
309 
310 	error = xfs_reflink_trim_around_shared(ip, got, &shared);
311 	if (error)
312 		return error;
313 
314 	if (isnullstartblock(got->br_startblock) ||
315 	    got->br_startblock == DELAYSTARTBLOCK) {
316 		/*
317 		 * Take the flush completion as being a point-in-time snapshot
318 		 * where there are no delalloc extents, and if any new ones
319 		 * have been created racily, just skip them as being 'after'
320 		 * the flush and so don't get reported.
321 		 */
322 		if (!(bmv->bmv_iflags & BMV_IF_DELALLOC))
323 			return 0;
324 
325 		p->bmv_oflags |= BMV_OF_DELALLOC;
326 		p->bmv_block = -2;
327 	} else {
328 		p->bmv_block = xfs_fsb_to_db(ip, got->br_startblock);
329 	}
330 
331 	if (got->br_state == XFS_EXT_UNWRITTEN &&
332 	    (bmv->bmv_iflags & BMV_IF_PREALLOC))
333 		p->bmv_oflags |= BMV_OF_PREALLOC;
334 
335 	if (shared)
336 		p->bmv_oflags |= BMV_OF_SHARED;
337 
338 	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, got->br_startoff);
339 	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, got->br_blockcount);
340 
341 	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
342 	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
343 	bmv->bmv_entries++;
344 	return 0;
345 }
346 
347 static void
348 xfs_getbmap_report_hole(
349 	struct xfs_inode	*ip,
350 	struct getbmapx		*bmv,
351 	struct kgetbmap		*out,
352 	int64_t			bmv_end,
353 	xfs_fileoff_t		bno,
354 	xfs_fileoff_t		end)
355 {
356 	struct kgetbmap		*p = out + bmv->bmv_entries;
357 
358 	if (bmv->bmv_iflags & BMV_IF_NO_HOLES)
359 		return;
360 
361 	p->bmv_block = -1;
362 	p->bmv_offset = XFS_FSB_TO_BB(ip->i_mount, bno);
363 	p->bmv_length = XFS_FSB_TO_BB(ip->i_mount, end - bno);
364 
365 	bmv->bmv_offset = p->bmv_offset + p->bmv_length;
366 	bmv->bmv_length = max(0LL, bmv_end - bmv->bmv_offset);
367 	bmv->bmv_entries++;
368 }
369 
370 static inline bool
371 xfs_getbmap_full(
372 	struct getbmapx		*bmv)
373 {
374 	return bmv->bmv_length == 0 || bmv->bmv_entries >= bmv->bmv_count - 1;
375 }
376 
377 static bool
378 xfs_getbmap_next_rec(
379 	struct xfs_bmbt_irec	*rec,
380 	xfs_fileoff_t		total_end)
381 {
382 	xfs_fileoff_t		end = rec->br_startoff + rec->br_blockcount;
383 
384 	if (end == total_end)
385 		return false;
386 
387 	rec->br_startoff += rec->br_blockcount;
388 	if (!isnullstartblock(rec->br_startblock) &&
389 	    rec->br_startblock != DELAYSTARTBLOCK)
390 		rec->br_startblock += rec->br_blockcount;
391 	rec->br_blockcount = total_end - end;
392 	return true;
393 }
394 
395 /*
396  * Get inode's extents as described in bmv, and format for output.
397  * Calls formatter to fill the user's buffer until all extents
398  * are mapped, until the passed-in bmv->bmv_count slots have
399  * been filled, or until the formatter short-circuits the loop,
400  * if it is tracking filled-in extents on its own.
401  */
402 int						/* error code */
403 xfs_getbmap(
404 	struct xfs_inode	*ip,
405 	struct getbmapx		*bmv,		/* user bmap structure */
406 	struct kgetbmap		*out)
407 {
408 	struct xfs_mount	*mp = ip->i_mount;
409 	int			iflags = bmv->bmv_iflags;
410 	int			whichfork, lock, error = 0;
411 	int64_t			bmv_end, max_len;
412 	xfs_fileoff_t		bno, first_bno;
413 	struct xfs_ifork	*ifp;
414 	struct xfs_bmbt_irec	got, rec;
415 	xfs_filblks_t		len;
416 	struct xfs_iext_cursor	icur;
417 
418 	if (bmv->bmv_iflags & ~BMV_IF_VALID)
419 		return -EINVAL;
420 #ifndef DEBUG
421 	/* Only allow CoW fork queries if we're debugging. */
422 	if (iflags & BMV_IF_COWFORK)
423 		return -EINVAL;
424 #endif
425 	if ((iflags & BMV_IF_ATTRFORK) && (iflags & BMV_IF_COWFORK))
426 		return -EINVAL;
427 
428 	if (bmv->bmv_length < -1)
429 		return -EINVAL;
430 	bmv->bmv_entries = 0;
431 	if (bmv->bmv_length == 0)
432 		return 0;
433 
434 	if (iflags & BMV_IF_ATTRFORK)
435 		whichfork = XFS_ATTR_FORK;
436 	else if (iflags & BMV_IF_COWFORK)
437 		whichfork = XFS_COW_FORK;
438 	else
439 		whichfork = XFS_DATA_FORK;
440 
441 	xfs_ilock(ip, XFS_IOLOCK_SHARED);
442 	switch (whichfork) {
443 	case XFS_ATTR_FORK:
444 		lock = xfs_ilock_attr_map_shared(ip);
445 		if (!xfs_inode_has_attr_fork(ip))
446 			goto out_unlock_ilock;
447 
448 		max_len = 1LL << 32;
449 		break;
450 	case XFS_COW_FORK:
451 		lock = XFS_ILOCK_SHARED;
452 		xfs_ilock(ip, lock);
453 
454 		/* No CoW fork? Just return */
455 		if (!xfs_ifork_ptr(ip, whichfork))
456 			goto out_unlock_ilock;
457 
458 		if (xfs_get_cowextsz_hint(ip))
459 			max_len = mp->m_super->s_maxbytes;
460 		else
461 			max_len = XFS_ISIZE(ip);
462 		break;
463 	case XFS_DATA_FORK:
464 		if (!(iflags & BMV_IF_DELALLOC) &&
465 		    (ip->i_delayed_blks || XFS_ISIZE(ip) > ip->i_disk_size)) {
466 			error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
467 			if (error)
468 				goto out_unlock_iolock;
469 
470 			/*
471 			 * Even after flushing the inode, there can still be
472 			 * delalloc blocks on the inode beyond EOF due to
473 			 * speculative preallocation.  These are not removed
474 			 * until the release function is called or the inode
475 			 * is inactivated.  Hence we cannot assert here that
476 			 * ip->i_delayed_blks == 0.
477 			 */
478 		}
479 
480 		if (xfs_get_extsz_hint(ip) ||
481 		    (ip->i_diflags &
482 		     (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND)))
483 			max_len = mp->m_super->s_maxbytes;
484 		else
485 			max_len = XFS_ISIZE(ip);
486 
487 		lock = xfs_ilock_data_map_shared(ip);
488 		break;
489 	}
490 
491 	ifp = xfs_ifork_ptr(ip, whichfork);
492 
493 	switch (ifp->if_format) {
494 	case XFS_DINODE_FMT_EXTENTS:
495 	case XFS_DINODE_FMT_BTREE:
496 		break;
497 	case XFS_DINODE_FMT_LOCAL:
498 		/* Local format inode forks report no extents. */
499 		goto out_unlock_ilock;
500 	default:
501 		error = -EINVAL;
502 		goto out_unlock_ilock;
503 	}
504 
505 	if (bmv->bmv_length == -1) {
506 		max_len = XFS_FSB_TO_BB(mp, XFS_B_TO_FSB(mp, max_len));
507 		bmv->bmv_length = max(0LL, max_len - bmv->bmv_offset);
508 	}
509 
510 	bmv_end = bmv->bmv_offset + bmv->bmv_length;
511 
512 	first_bno = bno = XFS_BB_TO_FSBT(mp, bmv->bmv_offset);
513 	len = XFS_BB_TO_FSB(mp, bmv->bmv_length);
514 
515 	error = xfs_iread_extents(NULL, ip, whichfork);
516 	if (error)
517 		goto out_unlock_ilock;
518 
519 	if (!xfs_iext_lookup_extent(ip, ifp, bno, &icur, &got)) {
520 		/*
521 		 * Report a whole-file hole if the delalloc flag is set to
522 		 * stay compatible with the old implementation.
523 		 */
524 		if (iflags & BMV_IF_DELALLOC)
525 			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
526 					XFS_B_TO_FSB(mp, XFS_ISIZE(ip)));
527 		goto out_unlock_ilock;
528 	}
529 
530 	while (!xfs_getbmap_full(bmv)) {
531 		xfs_trim_extent(&got, first_bno, len);
532 
533 		/*
534 		 * Report an entry for a hole if this extent doesn't directly
535 		 * follow the previous one.
536 		 */
537 		if (got.br_startoff > bno) {
538 			xfs_getbmap_report_hole(ip, bmv, out, bmv_end, bno,
539 					got.br_startoff);
540 			if (xfs_getbmap_full(bmv))
541 				break;
542 		}
543 
544 		/*
545 		 * In order to report shared extents accurately, we report each
546 		 * distinct shared / unshared part of a single bmbt record with
547 		 * an individual getbmapx record.
548 		 */
549 		bno = got.br_startoff + got.br_blockcount;
550 		rec = got;
551 		do {
552 			error = xfs_getbmap_report_one(ip, bmv, out, bmv_end,
553 					&rec);
554 			if (error || xfs_getbmap_full(bmv))
555 				goto out_unlock_ilock;
556 		} while (xfs_getbmap_next_rec(&rec, bno));
557 
558 		if (!xfs_iext_next_extent(ifp, &icur, &got)) {
559 			xfs_fileoff_t	end = XFS_B_TO_FSB(mp, XFS_ISIZE(ip));
560 
561 			if (bmv->bmv_entries > 0)
562 				out[bmv->bmv_entries - 1].bmv_oflags |=
563 								BMV_OF_LAST;
564 
565 			if (whichfork != XFS_ATTR_FORK && bno < end &&
566 			    !xfs_getbmap_full(bmv)) {
567 				xfs_getbmap_report_hole(ip, bmv, out, bmv_end,
568 						bno, end);
569 			}
570 			break;
571 		}
572 
573 		if (bno >= first_bno + len)
574 			break;
575 	}
576 
577 out_unlock_ilock:
578 	xfs_iunlock(ip, lock);
579 out_unlock_iolock:
580 	xfs_iunlock(ip, XFS_IOLOCK_SHARED);
581 	return error;
582 }
583 
584 /*
585  * Dead simple method of punching delalyed allocation blocks from a range in
586  * the inode.  This will always punch out both the start and end blocks, even
587  * if the ranges only partially overlap them, so it is up to the caller to
588  * ensure that partial blocks are not passed in.
589  */
590 int
591 xfs_bmap_punch_delalloc_range(
592 	struct xfs_inode	*ip,
593 	xfs_off_t		start_byte,
594 	xfs_off_t		end_byte)
595 {
596 	struct xfs_mount	*mp = ip->i_mount;
597 	struct xfs_ifork	*ifp = &ip->i_df;
598 	xfs_fileoff_t		start_fsb = XFS_B_TO_FSBT(mp, start_byte);
599 	xfs_fileoff_t		end_fsb = XFS_B_TO_FSB(mp, end_byte);
600 	struct xfs_bmbt_irec	got, del;
601 	struct xfs_iext_cursor	icur;
602 	int			error = 0;
603 
604 	ASSERT(!xfs_need_iread_extents(ifp));
605 
606 	xfs_ilock(ip, XFS_ILOCK_EXCL);
607 	if (!xfs_iext_lookup_extent_before(ip, ifp, &end_fsb, &icur, &got))
608 		goto out_unlock;
609 
610 	while (got.br_startoff + got.br_blockcount > start_fsb) {
611 		del = got;
612 		xfs_trim_extent(&del, start_fsb, end_fsb - start_fsb);
613 
614 		/*
615 		 * A delete can push the cursor forward. Step back to the
616 		 * previous extent on non-delalloc or extents outside the
617 		 * target range.
618 		 */
619 		if (!del.br_blockcount ||
620 		    !isnullstartblock(del.br_startblock)) {
621 			if (!xfs_iext_prev_extent(ifp, &icur, &got))
622 				break;
623 			continue;
624 		}
625 
626 		error = xfs_bmap_del_extent_delay(ip, XFS_DATA_FORK, &icur,
627 						  &got, &del);
628 		if (error || !xfs_iext_get_extent(ifp, &icur, &got))
629 			break;
630 	}
631 
632 out_unlock:
633 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
634 	return error;
635 }
636 
637 /*
638  * Test whether it is appropriate to check an inode for and free post EOF
639  * blocks. The 'force' parameter determines whether we should also consider
640  * regular files that are marked preallocated or append-only.
641  */
642 bool
643 xfs_can_free_eofblocks(
644 	struct xfs_inode	*ip,
645 	bool			force)
646 {
647 	struct xfs_bmbt_irec	imap;
648 	struct xfs_mount	*mp = ip->i_mount;
649 	xfs_fileoff_t		end_fsb;
650 	xfs_fileoff_t		last_fsb;
651 	int			nimaps = 1;
652 	int			error;
653 
654 	/*
655 	 * Caller must either hold the exclusive io lock; or be inactivating
656 	 * the inode, which guarantees there are no other users of the inode.
657 	 */
658 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL) ||
659 	       (VFS_I(ip)->i_state & I_FREEING));
660 
661 	/* prealloc/delalloc exists only on regular files */
662 	if (!S_ISREG(VFS_I(ip)->i_mode))
663 		return false;
664 
665 	/*
666 	 * Zero sized files with no cached pages and delalloc blocks will not
667 	 * have speculative prealloc/delalloc blocks to remove.
668 	 */
669 	if (VFS_I(ip)->i_size == 0 &&
670 	    VFS_I(ip)->i_mapping->nrpages == 0 &&
671 	    ip->i_delayed_blks == 0)
672 		return false;
673 
674 	/* If we haven't read in the extent list, then don't do it now. */
675 	if (xfs_need_iread_extents(&ip->i_df))
676 		return false;
677 
678 	/*
679 	 * Do not free real preallocated or append-only files unless the file
680 	 * has delalloc blocks and we are forced to remove them.
681 	 */
682 	if (ip->i_diflags & (XFS_DIFLAG_PREALLOC | XFS_DIFLAG_APPEND))
683 		if (!force || ip->i_delayed_blks == 0)
684 			return false;
685 
686 	/*
687 	 * Do not try to free post-EOF blocks if EOF is beyond the end of the
688 	 * range supported by the page cache, because the truncation will loop
689 	 * forever.
690 	 */
691 	end_fsb = XFS_B_TO_FSB(mp, (xfs_ufsize_t)XFS_ISIZE(ip));
692 	if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1)
693 		end_fsb = roundup_64(end_fsb, mp->m_sb.sb_rextsize);
694 	last_fsb = XFS_B_TO_FSB(mp, mp->m_super->s_maxbytes);
695 	if (last_fsb <= end_fsb)
696 		return false;
697 
698 	/*
699 	 * Look up the mapping for the first block past EOF.  If we can't find
700 	 * it, there's nothing to free.
701 	 */
702 	xfs_ilock(ip, XFS_ILOCK_SHARED);
703 	error = xfs_bmapi_read(ip, end_fsb, last_fsb - end_fsb, &imap, &nimaps,
704 			0);
705 	xfs_iunlock(ip, XFS_ILOCK_SHARED);
706 	if (error || nimaps == 0)
707 		return false;
708 
709 	/*
710 	 * If there's a real mapping there or there are delayed allocation
711 	 * reservations, then we have post-EOF blocks to try to free.
712 	 */
713 	return imap.br_startblock != HOLESTARTBLOCK || ip->i_delayed_blks;
714 }
715 
716 /*
717  * This is called to free any blocks beyond eof. The caller must hold
718  * IOLOCK_EXCL unless we are in the inode reclaim path and have the only
719  * reference to the inode.
720  */
721 int
722 xfs_free_eofblocks(
723 	struct xfs_inode	*ip)
724 {
725 	struct xfs_trans	*tp;
726 	struct xfs_mount	*mp = ip->i_mount;
727 	int			error;
728 
729 	/* Attach the dquots to the inode up front. */
730 	error = xfs_qm_dqattach(ip);
731 	if (error)
732 		return error;
733 
734 	/* Wait on dio to ensure i_size has settled. */
735 	inode_dio_wait(VFS_I(ip));
736 
737 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_itruncate, 0, 0, 0, &tp);
738 	if (error) {
739 		ASSERT(xfs_is_shutdown(mp));
740 		return error;
741 	}
742 
743 	xfs_ilock(ip, XFS_ILOCK_EXCL);
744 	xfs_trans_ijoin(tp, ip, 0);
745 
746 	/*
747 	 * Do not update the on-disk file size.  If we update the on-disk file
748 	 * size and then the system crashes before the contents of the file are
749 	 * flushed to disk then the files may be full of holes (ie NULL files
750 	 * bug).
751 	 */
752 	error = xfs_itruncate_extents_flags(&tp, ip, XFS_DATA_FORK,
753 				XFS_ISIZE(ip), XFS_BMAPI_NODISCARD);
754 	if (error)
755 		goto err_cancel;
756 
757 	error = xfs_trans_commit(tp);
758 	if (error)
759 		goto out_unlock;
760 
761 	xfs_inode_clear_eofblocks_tag(ip);
762 	goto out_unlock;
763 
764 err_cancel:
765 	/*
766 	 * If we get an error at this point we simply don't
767 	 * bother truncating the file.
768 	 */
769 	xfs_trans_cancel(tp);
770 out_unlock:
771 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
772 	return error;
773 }
774 
775 int
776 xfs_alloc_file_space(
777 	struct xfs_inode	*ip,
778 	xfs_off_t		offset,
779 	xfs_off_t		len)
780 {
781 	xfs_mount_t		*mp = ip->i_mount;
782 	xfs_off_t		count;
783 	xfs_filblks_t		allocatesize_fsb;
784 	xfs_extlen_t		extsz, temp;
785 	xfs_fileoff_t		startoffset_fsb;
786 	xfs_fileoff_t		endoffset_fsb;
787 	int			rt;
788 	xfs_trans_t		*tp;
789 	xfs_bmbt_irec_t		imaps[1], *imapp;
790 	int			error;
791 
792 	trace_xfs_alloc_file_space(ip);
793 
794 	if (xfs_is_shutdown(mp))
795 		return -EIO;
796 
797 	error = xfs_qm_dqattach(ip);
798 	if (error)
799 		return error;
800 
801 	if (len <= 0)
802 		return -EINVAL;
803 
804 	rt = XFS_IS_REALTIME_INODE(ip);
805 	extsz = xfs_get_extsz_hint(ip);
806 
807 	count = len;
808 	imapp = &imaps[0];
809 	startoffset_fsb	= XFS_B_TO_FSBT(mp, offset);
810 	endoffset_fsb = XFS_B_TO_FSB(mp, offset + count);
811 	allocatesize_fsb = endoffset_fsb - startoffset_fsb;
812 
813 	/*
814 	 * Allocate file space until done or until there is an error
815 	 */
816 	while (allocatesize_fsb && !error) {
817 		xfs_fileoff_t	s, e;
818 		unsigned int	dblocks, rblocks, resblks;
819 		int		nimaps = 1;
820 
821 		/*
822 		 * Determine space reservations for data/realtime.
823 		 */
824 		if (unlikely(extsz)) {
825 			s = startoffset_fsb;
826 			do_div(s, extsz);
827 			s *= extsz;
828 			e = startoffset_fsb + allocatesize_fsb;
829 			div_u64_rem(startoffset_fsb, extsz, &temp);
830 			if (temp)
831 				e += temp;
832 			div_u64_rem(e, extsz, &temp);
833 			if (temp)
834 				e += extsz - temp;
835 		} else {
836 			s = 0;
837 			e = allocatesize_fsb;
838 		}
839 
840 		/*
841 		 * The transaction reservation is limited to a 32-bit block
842 		 * count, hence we need to limit the number of blocks we are
843 		 * trying to reserve to avoid an overflow. We can't allocate
844 		 * more than @nimaps extents, and an extent is limited on disk
845 		 * to XFS_BMBT_MAX_EXTLEN (21 bits), so use that to enforce the
846 		 * limit.
847 		 */
848 		resblks = min_t(xfs_fileoff_t, (e - s),
849 				(XFS_MAX_BMBT_EXTLEN * nimaps));
850 		if (unlikely(rt)) {
851 			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
852 			rblocks = resblks;
853 		} else {
854 			dblocks = XFS_DIOSTRAT_SPACE_RES(mp, resblks);
855 			rblocks = 0;
856 		}
857 
858 		error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write,
859 				dblocks, rblocks, false, &tp);
860 		if (error)
861 			break;
862 
863 		error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
864 				XFS_IEXT_ADD_NOSPLIT_CNT);
865 		if (error == -EFBIG)
866 			error = xfs_iext_count_upgrade(tp, ip,
867 					XFS_IEXT_ADD_NOSPLIT_CNT);
868 		if (error)
869 			goto error;
870 
871 		error = xfs_bmapi_write(tp, ip, startoffset_fsb,
872 				allocatesize_fsb, XFS_BMAPI_PREALLOC, 0, imapp,
873 				&nimaps);
874 		if (error)
875 			goto error;
876 
877 		ip->i_diflags |= XFS_DIFLAG_PREALLOC;
878 		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
879 
880 		error = xfs_trans_commit(tp);
881 		xfs_iunlock(ip, XFS_ILOCK_EXCL);
882 		if (error)
883 			break;
884 
885 		/*
886 		 * If the allocator cannot find a single free extent large
887 		 * enough to cover the start block of the requested range,
888 		 * xfs_bmapi_write will return 0 but leave *nimaps set to 0.
889 		 *
890 		 * In that case we simply need to keep looping with the same
891 		 * startoffset_fsb so that one of the following allocations
892 		 * will eventually reach the requested range.
893 		 */
894 		if (nimaps) {
895 			startoffset_fsb += imapp->br_blockcount;
896 			allocatesize_fsb -= imapp->br_blockcount;
897 		}
898 	}
899 
900 	return error;
901 
902 error:
903 	xfs_trans_cancel(tp);
904 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
905 	return error;
906 }
907 
908 static int
909 xfs_unmap_extent(
910 	struct xfs_inode	*ip,
911 	xfs_fileoff_t		startoffset_fsb,
912 	xfs_filblks_t		len_fsb,
913 	int			*done)
914 {
915 	struct xfs_mount	*mp = ip->i_mount;
916 	struct xfs_trans	*tp;
917 	uint			resblks = XFS_DIOSTRAT_SPACE_RES(mp, 0);
918 	int			error;
919 
920 	error = xfs_trans_alloc_inode(ip, &M_RES(mp)->tr_write, resblks, 0,
921 			false, &tp);
922 	if (error)
923 		return error;
924 
925 	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
926 			XFS_IEXT_PUNCH_HOLE_CNT);
927 	if (error == -EFBIG)
928 		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
929 	if (error)
930 		goto out_trans_cancel;
931 
932 	error = xfs_bunmapi(tp, ip, startoffset_fsb, len_fsb, 0, 2, done);
933 	if (error)
934 		goto out_trans_cancel;
935 
936 	error = xfs_trans_commit(tp);
937 out_unlock:
938 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
939 	return error;
940 
941 out_trans_cancel:
942 	xfs_trans_cancel(tp);
943 	goto out_unlock;
944 }
945 
946 /* Caller must first wait for the completion of any pending DIOs if required. */
947 int
948 xfs_flush_unmap_range(
949 	struct xfs_inode	*ip,
950 	xfs_off_t		offset,
951 	xfs_off_t		len)
952 {
953 	struct xfs_mount	*mp = ip->i_mount;
954 	struct inode		*inode = VFS_I(ip);
955 	xfs_off_t		rounding, start, end;
956 	int			error;
957 
958 	rounding = max_t(xfs_off_t, mp->m_sb.sb_blocksize, PAGE_SIZE);
959 	start = round_down(offset, rounding);
960 	end = round_up(offset + len, rounding) - 1;
961 
962 	error = filemap_write_and_wait_range(inode->i_mapping, start, end);
963 	if (error)
964 		return error;
965 	truncate_pagecache_range(inode, start, end);
966 	return 0;
967 }
968 
969 int
970 xfs_free_file_space(
971 	struct xfs_inode	*ip,
972 	xfs_off_t		offset,
973 	xfs_off_t		len)
974 {
975 	struct xfs_mount	*mp = ip->i_mount;
976 	xfs_fileoff_t		startoffset_fsb;
977 	xfs_fileoff_t		endoffset_fsb;
978 	int			done = 0, error;
979 
980 	trace_xfs_free_file_space(ip);
981 
982 	error = xfs_qm_dqattach(ip);
983 	if (error)
984 		return error;
985 
986 	if (len <= 0)	/* if nothing being freed */
987 		return 0;
988 
989 	startoffset_fsb = XFS_B_TO_FSB(mp, offset);
990 	endoffset_fsb = XFS_B_TO_FSBT(mp, offset + len);
991 
992 	/* We can only free complete realtime extents. */
993 	if (XFS_IS_REALTIME_INODE(ip) && mp->m_sb.sb_rextsize > 1) {
994 		startoffset_fsb = roundup_64(startoffset_fsb,
995 					     mp->m_sb.sb_rextsize);
996 		endoffset_fsb = rounddown_64(endoffset_fsb,
997 					     mp->m_sb.sb_rextsize);
998 	}
999 
1000 	/*
1001 	 * Need to zero the stuff we're not freeing, on disk.
1002 	 */
1003 	if (endoffset_fsb > startoffset_fsb) {
1004 		while (!done) {
1005 			error = xfs_unmap_extent(ip, startoffset_fsb,
1006 					endoffset_fsb - startoffset_fsb, &done);
1007 			if (error)
1008 				return error;
1009 		}
1010 	}
1011 
1012 	/*
1013 	 * Now that we've unmap all full blocks we'll have to zero out any
1014 	 * partial block at the beginning and/or end.  xfs_zero_range is smart
1015 	 * enough to skip any holes, including those we just created, but we
1016 	 * must take care not to zero beyond EOF and enlarge i_size.
1017 	 */
1018 	if (offset >= XFS_ISIZE(ip))
1019 		return 0;
1020 	if (offset + len > XFS_ISIZE(ip))
1021 		len = XFS_ISIZE(ip) - offset;
1022 	error = xfs_zero_range(ip, offset, len, NULL);
1023 	if (error)
1024 		return error;
1025 
1026 	/*
1027 	 * If we zeroed right up to EOF and EOF straddles a page boundary we
1028 	 * must make sure that the post-EOF area is also zeroed because the
1029 	 * page could be mmap'd and xfs_zero_range doesn't do that for us.
1030 	 * Writeback of the eof page will do this, albeit clumsily.
1031 	 */
1032 	if (offset + len >= XFS_ISIZE(ip) && offset_in_page(offset + len) > 0) {
1033 		error = filemap_write_and_wait_range(VFS_I(ip)->i_mapping,
1034 				round_down(offset + len, PAGE_SIZE), LLONG_MAX);
1035 	}
1036 
1037 	return error;
1038 }
1039 
1040 static int
1041 xfs_prepare_shift(
1042 	struct xfs_inode	*ip,
1043 	loff_t			offset)
1044 {
1045 	struct xfs_mount	*mp = ip->i_mount;
1046 	int			error;
1047 
1048 	/*
1049 	 * Trim eofblocks to avoid shifting uninitialized post-eof preallocation
1050 	 * into the accessible region of the file.
1051 	 */
1052 	if (xfs_can_free_eofblocks(ip, true)) {
1053 		error = xfs_free_eofblocks(ip);
1054 		if (error)
1055 			return error;
1056 	}
1057 
1058 	/*
1059 	 * Shift operations must stabilize the start block offset boundary along
1060 	 * with the full range of the operation. If we don't, a COW writeback
1061 	 * completion could race with an insert, front merge with the start
1062 	 * extent (after split) during the shift and corrupt the file. Start
1063 	 * with the block just prior to the start to stabilize the boundary.
1064 	 */
1065 	offset = round_down(offset, mp->m_sb.sb_blocksize);
1066 	if (offset)
1067 		offset -= mp->m_sb.sb_blocksize;
1068 
1069 	/*
1070 	 * Writeback and invalidate cache for the remainder of the file as we're
1071 	 * about to shift down every extent from offset to EOF.
1072 	 */
1073 	error = xfs_flush_unmap_range(ip, offset, XFS_ISIZE(ip));
1074 	if (error)
1075 		return error;
1076 
1077 	/*
1078 	 * Clean out anything hanging around in the cow fork now that
1079 	 * we've flushed all the dirty data out to disk to avoid having
1080 	 * CoW extents at the wrong offsets.
1081 	 */
1082 	if (xfs_inode_has_cow_data(ip)) {
1083 		error = xfs_reflink_cancel_cow_range(ip, offset, NULLFILEOFF,
1084 				true);
1085 		if (error)
1086 			return error;
1087 	}
1088 
1089 	return 0;
1090 }
1091 
1092 /*
1093  * xfs_collapse_file_space()
1094  *	This routine frees disk space and shift extent for the given file.
1095  *	The first thing we do is to free data blocks in the specified range
1096  *	by calling xfs_free_file_space(). It would also sync dirty data
1097  *	and invalidate page cache over the region on which collapse range
1098  *	is working. And Shift extent records to the left to cover a hole.
1099  * RETURNS:
1100  *	0 on success
1101  *	errno on error
1102  *
1103  */
1104 int
1105 xfs_collapse_file_space(
1106 	struct xfs_inode	*ip,
1107 	xfs_off_t		offset,
1108 	xfs_off_t		len)
1109 {
1110 	struct xfs_mount	*mp = ip->i_mount;
1111 	struct xfs_trans	*tp;
1112 	int			error;
1113 	xfs_fileoff_t		next_fsb = XFS_B_TO_FSB(mp, offset + len);
1114 	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
1115 	bool			done = false;
1116 
1117 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1118 	ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
1119 
1120 	trace_xfs_collapse_file_space(ip);
1121 
1122 	error = xfs_free_file_space(ip, offset, len);
1123 	if (error)
1124 		return error;
1125 
1126 	error = xfs_prepare_shift(ip, offset);
1127 	if (error)
1128 		return error;
1129 
1130 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, 0, 0, 0, &tp);
1131 	if (error)
1132 		return error;
1133 
1134 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1135 	xfs_trans_ijoin(tp, ip, 0);
1136 
1137 	while (!done) {
1138 		error = xfs_bmap_collapse_extents(tp, ip, &next_fsb, shift_fsb,
1139 				&done);
1140 		if (error)
1141 			goto out_trans_cancel;
1142 		if (done)
1143 			break;
1144 
1145 		/* finish any deferred frees and roll the transaction */
1146 		error = xfs_defer_finish(&tp);
1147 		if (error)
1148 			goto out_trans_cancel;
1149 	}
1150 
1151 	error = xfs_trans_commit(tp);
1152 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1153 	return error;
1154 
1155 out_trans_cancel:
1156 	xfs_trans_cancel(tp);
1157 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1158 	return error;
1159 }
1160 
1161 /*
1162  * xfs_insert_file_space()
1163  *	This routine create hole space by shifting extents for the given file.
1164  *	The first thing we do is to sync dirty data and invalidate page cache
1165  *	over the region on which insert range is working. And split an extent
1166  *	to two extents at given offset by calling xfs_bmap_split_extent.
1167  *	And shift all extent records which are laying between [offset,
1168  *	last allocated extent] to the right to reserve hole range.
1169  * RETURNS:
1170  *	0 on success
1171  *	errno on error
1172  */
1173 int
1174 xfs_insert_file_space(
1175 	struct xfs_inode	*ip,
1176 	loff_t			offset,
1177 	loff_t			len)
1178 {
1179 	struct xfs_mount	*mp = ip->i_mount;
1180 	struct xfs_trans	*tp;
1181 	int			error;
1182 	xfs_fileoff_t		stop_fsb = XFS_B_TO_FSB(mp, offset);
1183 	xfs_fileoff_t		next_fsb = NULLFSBLOCK;
1184 	xfs_fileoff_t		shift_fsb = XFS_B_TO_FSB(mp, len);
1185 	bool			done = false;
1186 
1187 	ASSERT(xfs_isilocked(ip, XFS_IOLOCK_EXCL));
1188 	ASSERT(xfs_isilocked(ip, XFS_MMAPLOCK_EXCL));
1189 
1190 	trace_xfs_insert_file_space(ip);
1191 
1192 	error = xfs_bmap_can_insert_extents(ip, stop_fsb, shift_fsb);
1193 	if (error)
1194 		return error;
1195 
1196 	error = xfs_prepare_shift(ip, offset);
1197 	if (error)
1198 		return error;
1199 
1200 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write,
1201 			XFS_DIOSTRAT_SPACE_RES(mp, 0), 0, 0, &tp);
1202 	if (error)
1203 		return error;
1204 
1205 	xfs_ilock(ip, XFS_ILOCK_EXCL);
1206 	xfs_trans_ijoin(tp, ip, 0);
1207 
1208 	error = xfs_iext_count_may_overflow(ip, XFS_DATA_FORK,
1209 			XFS_IEXT_PUNCH_HOLE_CNT);
1210 	if (error == -EFBIG)
1211 		error = xfs_iext_count_upgrade(tp, ip, XFS_IEXT_PUNCH_HOLE_CNT);
1212 	if (error)
1213 		goto out_trans_cancel;
1214 
1215 	/*
1216 	 * The extent shifting code works on extent granularity. So, if stop_fsb
1217 	 * is not the starting block of extent, we need to split the extent at
1218 	 * stop_fsb.
1219 	 */
1220 	error = xfs_bmap_split_extent(tp, ip, stop_fsb);
1221 	if (error)
1222 		goto out_trans_cancel;
1223 
1224 	do {
1225 		error = xfs_defer_finish(&tp);
1226 		if (error)
1227 			goto out_trans_cancel;
1228 
1229 		error = xfs_bmap_insert_extents(tp, ip, &next_fsb, shift_fsb,
1230 				&done, stop_fsb);
1231 		if (error)
1232 			goto out_trans_cancel;
1233 	} while (!done);
1234 
1235 	error = xfs_trans_commit(tp);
1236 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1237 	return error;
1238 
1239 out_trans_cancel:
1240 	xfs_trans_cancel(tp);
1241 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1242 	return error;
1243 }
1244 
1245 /*
1246  * We need to check that the format of the data fork in the temporary inode is
1247  * valid for the target inode before doing the swap. This is not a problem with
1248  * attr1 because of the fixed fork offset, but attr2 has a dynamically sized
1249  * data fork depending on the space the attribute fork is taking so we can get
1250  * invalid formats on the target inode.
1251  *
1252  * E.g. target has space for 7 extents in extent format, temp inode only has
1253  * space for 6.  If we defragment down to 7 extents, then the tmp format is a
1254  * btree, but when swapped it needs to be in extent format. Hence we can't just
1255  * blindly swap data forks on attr2 filesystems.
1256  *
1257  * Note that we check the swap in both directions so that we don't end up with
1258  * a corrupt temporary inode, either.
1259  *
1260  * Note that fixing the way xfs_fsr sets up the attribute fork in the source
1261  * inode will prevent this situation from occurring, so all we do here is
1262  * reject and log the attempt. basically we are putting the responsibility on
1263  * userspace to get this right.
1264  */
1265 static int
1266 xfs_swap_extents_check_format(
1267 	struct xfs_inode	*ip,	/* target inode */
1268 	struct xfs_inode	*tip)	/* tmp inode */
1269 {
1270 	struct xfs_ifork	*ifp = &ip->i_df;
1271 	struct xfs_ifork	*tifp = &tip->i_df;
1272 
1273 	/* User/group/project quota ids must match if quotas are enforced. */
1274 	if (XFS_IS_QUOTA_ON(ip->i_mount) &&
1275 	    (!uid_eq(VFS_I(ip)->i_uid, VFS_I(tip)->i_uid) ||
1276 	     !gid_eq(VFS_I(ip)->i_gid, VFS_I(tip)->i_gid) ||
1277 	     ip->i_projid != tip->i_projid))
1278 		return -EINVAL;
1279 
1280 	/* Should never get a local format */
1281 	if (ifp->if_format == XFS_DINODE_FMT_LOCAL ||
1282 	    tifp->if_format == XFS_DINODE_FMT_LOCAL)
1283 		return -EINVAL;
1284 
1285 	/*
1286 	 * if the target inode has less extents that then temporary inode then
1287 	 * why did userspace call us?
1288 	 */
1289 	if (ifp->if_nextents < tifp->if_nextents)
1290 		return -EINVAL;
1291 
1292 	/*
1293 	 * If we have to use the (expensive) rmap swap method, we can
1294 	 * handle any number of extents and any format.
1295 	 */
1296 	if (xfs_has_rmapbt(ip->i_mount))
1297 		return 0;
1298 
1299 	/*
1300 	 * if the target inode is in extent form and the temp inode is in btree
1301 	 * form then we will end up with the target inode in the wrong format
1302 	 * as we already know there are less extents in the temp inode.
1303 	 */
1304 	if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1305 	    tifp->if_format == XFS_DINODE_FMT_BTREE)
1306 		return -EINVAL;
1307 
1308 	/* Check temp in extent form to max in target */
1309 	if (tifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1310 	    tifp->if_nextents > XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1311 		return -EINVAL;
1312 
1313 	/* Check target in extent form to max in temp */
1314 	if (ifp->if_format == XFS_DINODE_FMT_EXTENTS &&
1315 	    ifp->if_nextents > XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1316 		return -EINVAL;
1317 
1318 	/*
1319 	 * If we are in a btree format, check that the temp root block will fit
1320 	 * in the target and that it has enough extents to be in btree format
1321 	 * in the target.
1322 	 *
1323 	 * Note that we have to be careful to allow btree->extent conversions
1324 	 * (a common defrag case) which will occur when the temp inode is in
1325 	 * extent format...
1326 	 */
1327 	if (tifp->if_format == XFS_DINODE_FMT_BTREE) {
1328 		if (xfs_inode_has_attr_fork(ip) &&
1329 		    XFS_BMAP_BMDR_SPACE(tifp->if_broot) > xfs_inode_fork_boff(ip))
1330 			return -EINVAL;
1331 		if (tifp->if_nextents <= XFS_IFORK_MAXEXT(ip, XFS_DATA_FORK))
1332 			return -EINVAL;
1333 	}
1334 
1335 	/* Reciprocal target->temp btree format checks */
1336 	if (ifp->if_format == XFS_DINODE_FMT_BTREE) {
1337 		if (xfs_inode_has_attr_fork(tip) &&
1338 		    XFS_BMAP_BMDR_SPACE(ip->i_df.if_broot) > xfs_inode_fork_boff(tip))
1339 			return -EINVAL;
1340 		if (ifp->if_nextents <= XFS_IFORK_MAXEXT(tip, XFS_DATA_FORK))
1341 			return -EINVAL;
1342 	}
1343 
1344 	return 0;
1345 }
1346 
1347 static int
1348 xfs_swap_extent_flush(
1349 	struct xfs_inode	*ip)
1350 {
1351 	int	error;
1352 
1353 	error = filemap_write_and_wait(VFS_I(ip)->i_mapping);
1354 	if (error)
1355 		return error;
1356 	truncate_pagecache_range(VFS_I(ip), 0, -1);
1357 
1358 	/* Verify O_DIRECT for ftmp */
1359 	if (VFS_I(ip)->i_mapping->nrpages)
1360 		return -EINVAL;
1361 	return 0;
1362 }
1363 
1364 /*
1365  * Move extents from one file to another, when rmap is enabled.
1366  */
1367 STATIC int
1368 xfs_swap_extent_rmap(
1369 	struct xfs_trans		**tpp,
1370 	struct xfs_inode		*ip,
1371 	struct xfs_inode		*tip)
1372 {
1373 	struct xfs_trans		*tp = *tpp;
1374 	struct xfs_bmbt_irec		irec;
1375 	struct xfs_bmbt_irec		uirec;
1376 	struct xfs_bmbt_irec		tirec;
1377 	xfs_fileoff_t			offset_fsb;
1378 	xfs_fileoff_t			end_fsb;
1379 	xfs_filblks_t			count_fsb;
1380 	int				error;
1381 	xfs_filblks_t			ilen;
1382 	xfs_filblks_t			rlen;
1383 	int				nimaps;
1384 	uint64_t			tip_flags2;
1385 
1386 	/*
1387 	 * If the source file has shared blocks, we must flag the donor
1388 	 * file as having shared blocks so that we get the shared-block
1389 	 * rmap functions when we go to fix up the rmaps.  The flags
1390 	 * will be switch for reals later.
1391 	 */
1392 	tip_flags2 = tip->i_diflags2;
1393 	if (ip->i_diflags2 & XFS_DIFLAG2_REFLINK)
1394 		tip->i_diflags2 |= XFS_DIFLAG2_REFLINK;
1395 
1396 	offset_fsb = 0;
1397 	end_fsb = XFS_B_TO_FSB(ip->i_mount, i_size_read(VFS_I(ip)));
1398 	count_fsb = (xfs_filblks_t)(end_fsb - offset_fsb);
1399 
1400 	while (count_fsb) {
1401 		/* Read extent from the donor file */
1402 		nimaps = 1;
1403 		error = xfs_bmapi_read(tip, offset_fsb, count_fsb, &tirec,
1404 				&nimaps, 0);
1405 		if (error)
1406 			goto out;
1407 		ASSERT(nimaps == 1);
1408 		ASSERT(tirec.br_startblock != DELAYSTARTBLOCK);
1409 
1410 		trace_xfs_swap_extent_rmap_remap(tip, &tirec);
1411 		ilen = tirec.br_blockcount;
1412 
1413 		/* Unmap the old blocks in the source file. */
1414 		while (tirec.br_blockcount) {
1415 			ASSERT(tp->t_highest_agno == NULLAGNUMBER);
1416 			trace_xfs_swap_extent_rmap_remap_piece(tip, &tirec);
1417 
1418 			/* Read extent from the source file */
1419 			nimaps = 1;
1420 			error = xfs_bmapi_read(ip, tirec.br_startoff,
1421 					tirec.br_blockcount, &irec,
1422 					&nimaps, 0);
1423 			if (error)
1424 				goto out;
1425 			ASSERT(nimaps == 1);
1426 			ASSERT(tirec.br_startoff == irec.br_startoff);
1427 			trace_xfs_swap_extent_rmap_remap_piece(ip, &irec);
1428 
1429 			/* Trim the extent. */
1430 			uirec = tirec;
1431 			uirec.br_blockcount = rlen = min_t(xfs_filblks_t,
1432 					tirec.br_blockcount,
1433 					irec.br_blockcount);
1434 			trace_xfs_swap_extent_rmap_remap_piece(tip, &uirec);
1435 
1436 			if (xfs_bmap_is_real_extent(&uirec)) {
1437 				error = xfs_iext_count_may_overflow(ip,
1438 						XFS_DATA_FORK,
1439 						XFS_IEXT_SWAP_RMAP_CNT);
1440 				if (error == -EFBIG)
1441 					error = xfs_iext_count_upgrade(tp, ip,
1442 							XFS_IEXT_SWAP_RMAP_CNT);
1443 				if (error)
1444 					goto out;
1445 			}
1446 
1447 			if (xfs_bmap_is_real_extent(&irec)) {
1448 				error = xfs_iext_count_may_overflow(tip,
1449 						XFS_DATA_FORK,
1450 						XFS_IEXT_SWAP_RMAP_CNT);
1451 				if (error == -EFBIG)
1452 					error = xfs_iext_count_upgrade(tp, ip,
1453 							XFS_IEXT_SWAP_RMAP_CNT);
1454 				if (error)
1455 					goto out;
1456 			}
1457 
1458 			/* Remove the mapping from the donor file. */
1459 			xfs_bmap_unmap_extent(tp, tip, &uirec);
1460 
1461 			/* Remove the mapping from the source file. */
1462 			xfs_bmap_unmap_extent(tp, ip, &irec);
1463 
1464 			/* Map the donor file's blocks into the source file. */
1465 			xfs_bmap_map_extent(tp, ip, &uirec);
1466 
1467 			/* Map the source file's blocks into the donor file. */
1468 			xfs_bmap_map_extent(tp, tip, &irec);
1469 
1470 			error = xfs_defer_finish(tpp);
1471 			tp = *tpp;
1472 			if (error)
1473 				goto out;
1474 
1475 			tirec.br_startoff += rlen;
1476 			if (tirec.br_startblock != HOLESTARTBLOCK &&
1477 			    tirec.br_startblock != DELAYSTARTBLOCK)
1478 				tirec.br_startblock += rlen;
1479 			tirec.br_blockcount -= rlen;
1480 		}
1481 
1482 		/* Roll on... */
1483 		count_fsb -= ilen;
1484 		offset_fsb += ilen;
1485 	}
1486 
1487 	tip->i_diflags2 = tip_flags2;
1488 	return 0;
1489 
1490 out:
1491 	trace_xfs_swap_extent_rmap_error(ip, error, _RET_IP_);
1492 	tip->i_diflags2 = tip_flags2;
1493 	return error;
1494 }
1495 
1496 /* Swap the extents of two files by swapping data forks. */
1497 STATIC int
1498 xfs_swap_extent_forks(
1499 	struct xfs_trans	*tp,
1500 	struct xfs_inode	*ip,
1501 	struct xfs_inode	*tip,
1502 	int			*src_log_flags,
1503 	int			*target_log_flags)
1504 {
1505 	xfs_filblks_t		aforkblks = 0;
1506 	xfs_filblks_t		taforkblks = 0;
1507 	xfs_extnum_t		junk;
1508 	uint64_t		tmp;
1509 	int			error;
1510 
1511 	/*
1512 	 * Count the number of extended attribute blocks
1513 	 */
1514 	if (xfs_inode_has_attr_fork(ip) && ip->i_af.if_nextents > 0 &&
1515 	    ip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1516 		error = xfs_bmap_count_blocks(tp, ip, XFS_ATTR_FORK, &junk,
1517 				&aforkblks);
1518 		if (error)
1519 			return error;
1520 	}
1521 	if (xfs_inode_has_attr_fork(tip) && tip->i_af.if_nextents > 0 &&
1522 	    tip->i_af.if_format != XFS_DINODE_FMT_LOCAL) {
1523 		error = xfs_bmap_count_blocks(tp, tip, XFS_ATTR_FORK, &junk,
1524 				&taforkblks);
1525 		if (error)
1526 			return error;
1527 	}
1528 
1529 	/*
1530 	 * Btree format (v3) inodes have the inode number stamped in the bmbt
1531 	 * block headers. We can't start changing the bmbt blocks until the
1532 	 * inode owner change is logged so recovery does the right thing in the
1533 	 * event of a crash. Set the owner change log flags now and leave the
1534 	 * bmbt scan as the last step.
1535 	 */
1536 	if (xfs_has_v3inodes(ip->i_mount)) {
1537 		if (ip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1538 			(*target_log_flags) |= XFS_ILOG_DOWNER;
1539 		if (tip->i_df.if_format == XFS_DINODE_FMT_BTREE)
1540 			(*src_log_flags) |= XFS_ILOG_DOWNER;
1541 	}
1542 
1543 	/*
1544 	 * Swap the data forks of the inodes
1545 	 */
1546 	swap(ip->i_df, tip->i_df);
1547 
1548 	/*
1549 	 * Fix the on-disk inode values
1550 	 */
1551 	tmp = (uint64_t)ip->i_nblocks;
1552 	ip->i_nblocks = tip->i_nblocks - taforkblks + aforkblks;
1553 	tip->i_nblocks = tmp + taforkblks - aforkblks;
1554 
1555 	/*
1556 	 * The extents in the source inode could still contain speculative
1557 	 * preallocation beyond EOF (e.g. the file is open but not modified
1558 	 * while defrag is in progress). In that case, we need to copy over the
1559 	 * number of delalloc blocks the data fork in the source inode is
1560 	 * tracking beyond EOF so that when the fork is truncated away when the
1561 	 * temporary inode is unlinked we don't underrun the i_delayed_blks
1562 	 * counter on that inode.
1563 	 */
1564 	ASSERT(tip->i_delayed_blks == 0);
1565 	tip->i_delayed_blks = ip->i_delayed_blks;
1566 	ip->i_delayed_blks = 0;
1567 
1568 	switch (ip->i_df.if_format) {
1569 	case XFS_DINODE_FMT_EXTENTS:
1570 		(*src_log_flags) |= XFS_ILOG_DEXT;
1571 		break;
1572 	case XFS_DINODE_FMT_BTREE:
1573 		ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1574 		       (*src_log_flags & XFS_ILOG_DOWNER));
1575 		(*src_log_flags) |= XFS_ILOG_DBROOT;
1576 		break;
1577 	}
1578 
1579 	switch (tip->i_df.if_format) {
1580 	case XFS_DINODE_FMT_EXTENTS:
1581 		(*target_log_flags) |= XFS_ILOG_DEXT;
1582 		break;
1583 	case XFS_DINODE_FMT_BTREE:
1584 		(*target_log_flags) |= XFS_ILOG_DBROOT;
1585 		ASSERT(!xfs_has_v3inodes(ip->i_mount) ||
1586 		       (*target_log_flags & XFS_ILOG_DOWNER));
1587 		break;
1588 	}
1589 
1590 	return 0;
1591 }
1592 
1593 /*
1594  * Fix up the owners of the bmbt blocks to refer to the current inode. The
1595  * change owner scan attempts to order all modified buffers in the current
1596  * transaction. In the event of ordered buffer failure, the offending buffer is
1597  * physically logged as a fallback and the scan returns -EAGAIN. We must roll
1598  * the transaction in this case to replenish the fallback log reservation and
1599  * restart the scan. This process repeats until the scan completes.
1600  */
1601 static int
1602 xfs_swap_change_owner(
1603 	struct xfs_trans	**tpp,
1604 	struct xfs_inode	*ip,
1605 	struct xfs_inode	*tmpip)
1606 {
1607 	int			error;
1608 	struct xfs_trans	*tp = *tpp;
1609 
1610 	do {
1611 		error = xfs_bmbt_change_owner(tp, ip, XFS_DATA_FORK, ip->i_ino,
1612 					      NULL);
1613 		/* success or fatal error */
1614 		if (error != -EAGAIN)
1615 			break;
1616 
1617 		error = xfs_trans_roll(tpp);
1618 		if (error)
1619 			break;
1620 		tp = *tpp;
1621 
1622 		/*
1623 		 * Redirty both inodes so they can relog and keep the log tail
1624 		 * moving forward.
1625 		 */
1626 		xfs_trans_ijoin(tp, ip, 0);
1627 		xfs_trans_ijoin(tp, tmpip, 0);
1628 		xfs_trans_log_inode(tp, ip, XFS_ILOG_CORE);
1629 		xfs_trans_log_inode(tp, tmpip, XFS_ILOG_CORE);
1630 	} while (true);
1631 
1632 	return error;
1633 }
1634 
1635 int
1636 xfs_swap_extents(
1637 	struct xfs_inode	*ip,	/* target inode */
1638 	struct xfs_inode	*tip,	/* tmp inode */
1639 	struct xfs_swapext	*sxp)
1640 {
1641 	struct xfs_mount	*mp = ip->i_mount;
1642 	struct xfs_trans	*tp;
1643 	struct xfs_bstat	*sbp = &sxp->sx_stat;
1644 	int			src_log_flags, target_log_flags;
1645 	int			error = 0;
1646 	uint64_t		f;
1647 	int			resblks = 0;
1648 	unsigned int		flags = 0;
1649 	struct timespec64	ctime;
1650 
1651 	/*
1652 	 * Lock the inodes against other IO, page faults and truncate to
1653 	 * begin with.  Then we can ensure the inodes are flushed and have no
1654 	 * page cache safely. Once we have done this we can take the ilocks and
1655 	 * do the rest of the checks.
1656 	 */
1657 	lock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1658 	filemap_invalidate_lock_two(VFS_I(ip)->i_mapping,
1659 				    VFS_I(tip)->i_mapping);
1660 
1661 	/* Verify that both files have the same format */
1662 	if ((VFS_I(ip)->i_mode & S_IFMT) != (VFS_I(tip)->i_mode & S_IFMT)) {
1663 		error = -EINVAL;
1664 		goto out_unlock;
1665 	}
1666 
1667 	/* Verify both files are either real-time or non-realtime */
1668 	if (XFS_IS_REALTIME_INODE(ip) != XFS_IS_REALTIME_INODE(tip)) {
1669 		error = -EINVAL;
1670 		goto out_unlock;
1671 	}
1672 
1673 	error = xfs_qm_dqattach(ip);
1674 	if (error)
1675 		goto out_unlock;
1676 
1677 	error = xfs_qm_dqattach(tip);
1678 	if (error)
1679 		goto out_unlock;
1680 
1681 	error = xfs_swap_extent_flush(ip);
1682 	if (error)
1683 		goto out_unlock;
1684 	error = xfs_swap_extent_flush(tip);
1685 	if (error)
1686 		goto out_unlock;
1687 
1688 	if (xfs_inode_has_cow_data(tip)) {
1689 		error = xfs_reflink_cancel_cow_range(tip, 0, NULLFILEOFF, true);
1690 		if (error)
1691 			goto out_unlock;
1692 	}
1693 
1694 	/*
1695 	 * Extent "swapping" with rmap requires a permanent reservation and
1696 	 * a block reservation because it's really just a remap operation
1697 	 * performed with log redo items!
1698 	 */
1699 	if (xfs_has_rmapbt(mp)) {
1700 		int		w = XFS_DATA_FORK;
1701 		uint32_t	ipnext = ip->i_df.if_nextents;
1702 		uint32_t	tipnext	= tip->i_df.if_nextents;
1703 
1704 		/*
1705 		 * Conceptually this shouldn't affect the shape of either bmbt,
1706 		 * but since we atomically move extents one by one, we reserve
1707 		 * enough space to rebuild both trees.
1708 		 */
1709 		resblks = XFS_SWAP_RMAP_SPACE_RES(mp, ipnext, w);
1710 		resblks +=  XFS_SWAP_RMAP_SPACE_RES(mp, tipnext, w);
1711 
1712 		/*
1713 		 * If either inode straddles a bmapbt block allocation boundary,
1714 		 * the rmapbt algorithm triggers repeated allocs and frees as
1715 		 * extents are remapped. This can exhaust the block reservation
1716 		 * prematurely and cause shutdown. Return freed blocks to the
1717 		 * transaction reservation to counter this behavior.
1718 		 */
1719 		flags |= XFS_TRANS_RES_FDBLKS;
1720 	}
1721 	error = xfs_trans_alloc(mp, &M_RES(mp)->tr_write, resblks, 0, flags,
1722 				&tp);
1723 	if (error)
1724 		goto out_unlock;
1725 
1726 	/*
1727 	 * Lock and join the inodes to the tansaction so that transaction commit
1728 	 * or cancel will unlock the inodes from this point onwards.
1729 	 */
1730 	xfs_lock_two_inodes(ip, XFS_ILOCK_EXCL, tip, XFS_ILOCK_EXCL);
1731 	xfs_trans_ijoin(tp, ip, 0);
1732 	xfs_trans_ijoin(tp, tip, 0);
1733 
1734 
1735 	/* Verify all data are being swapped */
1736 	if (sxp->sx_offset != 0 ||
1737 	    sxp->sx_length != ip->i_disk_size ||
1738 	    sxp->sx_length != tip->i_disk_size) {
1739 		error = -EFAULT;
1740 		goto out_trans_cancel;
1741 	}
1742 
1743 	trace_xfs_swap_extent_before(ip, 0);
1744 	trace_xfs_swap_extent_before(tip, 1);
1745 
1746 	/* check inode formats now that data is flushed */
1747 	error = xfs_swap_extents_check_format(ip, tip);
1748 	if (error) {
1749 		xfs_notice(mp,
1750 		    "%s: inode 0x%llx format is incompatible for exchanging.",
1751 				__func__, ip->i_ino);
1752 		goto out_trans_cancel;
1753 	}
1754 
1755 	/*
1756 	 * Compare the current change & modify times with that
1757 	 * passed in.  If they differ, we abort this swap.
1758 	 * This is the mechanism used to ensure the calling
1759 	 * process that the file was not changed out from
1760 	 * under it.
1761 	 */
1762 	ctime = inode_get_ctime(VFS_I(ip));
1763 	if ((sbp->bs_ctime.tv_sec != ctime.tv_sec) ||
1764 	    (sbp->bs_ctime.tv_nsec != ctime.tv_nsec) ||
1765 	    (sbp->bs_mtime.tv_sec != VFS_I(ip)->i_mtime.tv_sec) ||
1766 	    (sbp->bs_mtime.tv_nsec != VFS_I(ip)->i_mtime.tv_nsec)) {
1767 		error = -EBUSY;
1768 		goto out_trans_cancel;
1769 	}
1770 
1771 	/*
1772 	 * Note the trickiness in setting the log flags - we set the owner log
1773 	 * flag on the opposite inode (i.e. the inode we are setting the new
1774 	 * owner to be) because once we swap the forks and log that, log
1775 	 * recovery is going to see the fork as owned by the swapped inode,
1776 	 * not the pre-swapped inodes.
1777 	 */
1778 	src_log_flags = XFS_ILOG_CORE;
1779 	target_log_flags = XFS_ILOG_CORE;
1780 
1781 	if (xfs_has_rmapbt(mp))
1782 		error = xfs_swap_extent_rmap(&tp, ip, tip);
1783 	else
1784 		error = xfs_swap_extent_forks(tp, ip, tip, &src_log_flags,
1785 				&target_log_flags);
1786 	if (error)
1787 		goto out_trans_cancel;
1788 
1789 	/* Do we have to swap reflink flags? */
1790 	if ((ip->i_diflags2 & XFS_DIFLAG2_REFLINK) ^
1791 	    (tip->i_diflags2 & XFS_DIFLAG2_REFLINK)) {
1792 		f = ip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1793 		ip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1794 		ip->i_diflags2 |= tip->i_diflags2 & XFS_DIFLAG2_REFLINK;
1795 		tip->i_diflags2 &= ~XFS_DIFLAG2_REFLINK;
1796 		tip->i_diflags2 |= f & XFS_DIFLAG2_REFLINK;
1797 	}
1798 
1799 	/* Swap the cow forks. */
1800 	if (xfs_has_reflink(mp)) {
1801 		ASSERT(!ip->i_cowfp ||
1802 		       ip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1803 		ASSERT(!tip->i_cowfp ||
1804 		       tip->i_cowfp->if_format == XFS_DINODE_FMT_EXTENTS);
1805 
1806 		swap(ip->i_cowfp, tip->i_cowfp);
1807 
1808 		if (ip->i_cowfp && ip->i_cowfp->if_bytes)
1809 			xfs_inode_set_cowblocks_tag(ip);
1810 		else
1811 			xfs_inode_clear_cowblocks_tag(ip);
1812 		if (tip->i_cowfp && tip->i_cowfp->if_bytes)
1813 			xfs_inode_set_cowblocks_tag(tip);
1814 		else
1815 			xfs_inode_clear_cowblocks_tag(tip);
1816 	}
1817 
1818 	xfs_trans_log_inode(tp, ip,  src_log_flags);
1819 	xfs_trans_log_inode(tp, tip, target_log_flags);
1820 
1821 	/*
1822 	 * The extent forks have been swapped, but crc=1,rmapbt=0 filesystems
1823 	 * have inode number owner values in the bmbt blocks that still refer to
1824 	 * the old inode. Scan each bmbt to fix up the owner values with the
1825 	 * inode number of the current inode.
1826 	 */
1827 	if (src_log_flags & XFS_ILOG_DOWNER) {
1828 		error = xfs_swap_change_owner(&tp, ip, tip);
1829 		if (error)
1830 			goto out_trans_cancel;
1831 	}
1832 	if (target_log_flags & XFS_ILOG_DOWNER) {
1833 		error = xfs_swap_change_owner(&tp, tip, ip);
1834 		if (error)
1835 			goto out_trans_cancel;
1836 	}
1837 
1838 	/*
1839 	 * If this is a synchronous mount, make sure that the
1840 	 * transaction goes to disk before returning to the user.
1841 	 */
1842 	if (xfs_has_wsync(mp))
1843 		xfs_trans_set_sync(tp);
1844 
1845 	error = xfs_trans_commit(tp);
1846 
1847 	trace_xfs_swap_extent_after(ip, 0);
1848 	trace_xfs_swap_extent_after(tip, 1);
1849 
1850 out_unlock_ilock:
1851 	xfs_iunlock(ip, XFS_ILOCK_EXCL);
1852 	xfs_iunlock(tip, XFS_ILOCK_EXCL);
1853 out_unlock:
1854 	filemap_invalidate_unlock_two(VFS_I(ip)->i_mapping,
1855 				      VFS_I(tip)->i_mapping);
1856 	unlock_two_nondirectories(VFS_I(ip), VFS_I(tip));
1857 	return error;
1858 
1859 out_trans_cancel:
1860 	xfs_trans_cancel(tp);
1861 	goto out_unlock_ilock;
1862 }
1863