summaryrefslogtreecommitdiffstats
path: root/fs/xfs/libxfs/xfs_inode_fork.c
blob: 1c90ec41e9dfa9cc8a380635ebf99d7380d9fe03 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
/*
 * Copyright (c) 2000-2006 Silicon Graphics, Inc.
 * All Rights Reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License as
 * published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it would be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License
 * along with this program; if not, write the Free Software Foundation,
 * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */
#include <linux/log2.h>

#include "xfs.h"
#include "xfs_fs.h"
#include "xfs_format.h"
#include "xfs_log_format.h"
#include "xfs_trans_resv.h"
#include "xfs_mount.h"
#include "xfs_inode.h"
#include "xfs_trans.h"
#include "xfs_inode_item.h"
#include "xfs_btree.h"
#include "xfs_bmap_btree.h"
#include "xfs_bmap.h"
#include "xfs_error.h"
#include "xfs_trace.h"
#include "xfs_attr_sf.h"
#include "xfs_da_format.h"
#include "xfs_da_btree.h"
#include "xfs_dir2_priv.h"

kmem_zone_t *xfs_ifork_zone;

STATIC int xfs_iformat_local(xfs_inode_t *, xfs_dinode_t *, int, int);
STATIC int xfs_iformat_extents(xfs_inode_t *, xfs_dinode_t *, int);
STATIC int xfs_iformat_btree(xfs_inode_t *, xfs_dinode_t *, int);

static inline dev_t xfs_to_linux_dev_t(xfs_dev_t dev)
{
	return MKDEV(sysv_major(dev) & 0x1ff, sysv_minor(dev));
}

/*
 * Copy inode type and data and attr format specific information from the
 * on-disk inode to the in-core inode and fork structures.  For fifos, devices,
 * and sockets this means set i_rdev to the proper value.  For files,
 * directories, and symlinks this means to bring in the in-line data or extent
 * pointers as well as the attribute fork.  For a fork in B-tree format, only
 * the root is immediately brought in-core.  The rest will be read in later when
 * first referenced (see xfs_iread_extents()).
 */
int
xfs_iformat_fork(
	struct xfs_inode	*ip,
	struct xfs_dinode	*dip)
{
	struct inode		*inode = VFS_I(ip);
	struct xfs_attr_shortform *atp;
	int			size;
	int			error = 0;
	xfs_fsize_t             di_size;

	if (unlikely(be32_to_cpu(dip->di_nextents) +
		     be16_to_cpu(dip->di_anextents) >
		     be64_to_cpu(dip->di_nblocks))) {
		xfs_warn(ip->i_mount,
			"corrupt dinode %Lu, extent total = %d, nblocks = %Lu.",
			(unsigned long long)ip->i_ino,
			(int)(be32_to_cpu(dip->di_nextents) +
			      be16_to_cpu(dip->di_anextents)),
			(unsigned long long)
				be64_to_cpu(dip->di_nblocks));
		XFS_CORRUPTION_ERROR("xfs_iformat(1)", XFS_ERRLEVEL_LOW,
				     ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	if (unlikely(dip->di_forkoff > ip->i_mount->m_sb.sb_inodesize)) {
		xfs_warn(ip->i_mount, "corrupt dinode %Lu, forkoff = 0x%x.",
			(unsigned long long)ip->i_ino,
			dip->di_forkoff);
		XFS_CORRUPTION_ERROR("xfs_iformat(2)", XFS_ERRLEVEL_LOW,
				     ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	if (unlikely((ip->i_d.di_flags & XFS_DIFLAG_REALTIME) &&
		     !ip->i_mount->m_rtdev_targp)) {
		xfs_warn(ip->i_mount,
			"corrupt dinode %Lu, has realtime flag set.",
			ip->i_ino);
		XFS_CORRUPTION_ERROR("xfs_iformat(realtime)",
				     XFS_ERRLEVEL_LOW, ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	if (unlikely(xfs_is_reflink_inode(ip) && !S_ISREG(inode->i_mode))) {
		xfs_warn(ip->i_mount,
			"corrupt dinode %llu, wrong file type for reflink.",
			ip->i_ino);
		XFS_CORRUPTION_ERROR("xfs_iformat(reflink)",
				     XFS_ERRLEVEL_LOW, ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	if (unlikely(xfs_is_reflink_inode(ip) &&
	    (ip->i_d.di_flags & XFS_DIFLAG_REALTIME))) {
		xfs_warn(ip->i_mount,
			"corrupt dinode %llu, has reflink+realtime flag set.",
			ip->i_ino);
		XFS_CORRUPTION_ERROR("xfs_iformat(reflink)",
				     XFS_ERRLEVEL_LOW, ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	switch (inode->i_mode & S_IFMT) {
	case S_IFIFO:
	case S_IFCHR:
	case S_IFBLK:
	case S_IFSOCK:
		if (unlikely(dip->di_format != XFS_DINODE_FMT_DEV)) {
			XFS_CORRUPTION_ERROR("xfs_iformat(3)", XFS_ERRLEVEL_LOW,
					      ip->i_mount, dip);
			return -EFSCORRUPTED;
		}
		ip->i_d.di_size = 0;
		inode->i_rdev = xfs_to_linux_dev_t(xfs_dinode_get_rdev(dip));
		break;

	case S_IFREG:
	case S_IFLNK:
	case S_IFDIR:
		switch (dip->di_format) {
		case XFS_DINODE_FMT_LOCAL:
			/*
			 * no local regular files yet
			 */
			if (unlikely(S_ISREG(be16_to_cpu(dip->di_mode)))) {
				xfs_warn(ip->i_mount,
			"corrupt inode %Lu (local format for regular file).",
					(unsigned long long) ip->i_ino);
				XFS_CORRUPTION_ERROR("xfs_iformat(4)",
						     XFS_ERRLEVEL_LOW,
						     ip->i_mount, dip);
				return -EFSCORRUPTED;
			}

			di_size = be64_to_cpu(dip->di_size);
			if (unlikely(di_size < 0 ||
				     di_size > XFS_DFORK_DSIZE(dip, ip->i_mount))) {
				xfs_warn(ip->i_mount,
			"corrupt inode %Lu (bad size %Ld for local inode).",
					(unsigned long long) ip->i_ino,
					(long long) di_size);
				XFS_CORRUPTION_ERROR("xfs_iformat(5)",
						     XFS_ERRLEVEL_LOW,
						     ip->i_mount, dip);
				return -EFSCORRUPTED;
			}

			size = (int)di_size;
			error = xfs_iformat_local(ip, dip, XFS_DATA_FORK, size);
			break;
		case XFS_DINODE_FMT_EXTENTS:
			error = xfs_iformat_extents(ip, dip, XFS_DATA_FORK);
			break;
		case XFS_DINODE_FMT_BTREE:
			error = xfs_iformat_btree(ip, dip, XFS_DATA_FORK);
			break;
		default:
			XFS_ERROR_REPORT("xfs_iformat(6)", XFS_ERRLEVEL_LOW,
					 ip->i_mount);
			return -EFSCORRUPTED;
		}
		break;

	default:
		XFS_ERROR_REPORT("xfs_iformat(7)", XFS_ERRLEVEL_LOW, ip->i_mount);
		return -EFSCORRUPTED;
	}
	if (error)
		return error;

	/* Check inline dir contents. */
	if (S_ISDIR(inode->i_mode) && dip->di_format == XFS_DINODE_FMT_LOCAL) {
		error = xfs_dir2_sf_verify(ip);
		if (error) {
			xfs_idestroy_fork(ip, XFS_DATA_FORK);
			return error;
		}
	}

	if (xfs_is_reflink_inode(ip)) {
		ASSERT(ip->i_cowfp == NULL);
		xfs_ifork_init_cow(ip);
	}

	if (!XFS_DFORK_Q(dip))
		return 0;

	ASSERT(ip->i_afp == NULL);
	ip->i_afp = kmem_zone_zalloc(xfs_ifork_zone, KM_SLEEP | KM_NOFS);

	switch (dip->di_aformat) {
	case XFS_DINODE_FMT_LOCAL:
		atp = (xfs_attr_shortform_t *)XFS_DFORK_APTR(dip);
		size = be16_to_cpu(atp->hdr.totsize);

		if (unlikely(size < sizeof(struct xfs_attr_sf_hdr))) {
			xfs_warn(ip->i_mount,
				"corrupt inode %Lu (bad attr fork size %Ld).",
				(unsigned long long) ip->i_ino,
				(long long) size);
			XFS_CORRUPTION_ERROR("xfs_iformat(8)",
					     XFS_ERRLEVEL_LOW,
					     ip->i_mount, dip);
			error = -EFSCORRUPTED;
			break;
		}

		error = xfs_iformat_local(ip, dip, XFS_ATTR_FORK, size);
		break;
	case XFS_DINODE_FMT_EXTENTS:
		error = xfs_iformat_extents(ip, dip, XFS_ATTR_FORK);
		break;
	case XFS_DINODE_FMT_BTREE:
		error = xfs_iformat_btree(ip, dip, XFS_ATTR_FORK);
		break;
	default:
		error = -EFSCORRUPTED;
		break;
	}
	if (error) {
		kmem_zone_free(xfs_ifork_zone, ip->i_afp);
		ip->i_afp = NULL;
		if (ip->i_cowfp)
			kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
		ip->i_cowfp = NULL;
		xfs_idestroy_fork(ip, XFS_DATA_FORK);
	}
	return error;
}

void
xfs_init_local_fork(
	struct xfs_inode	*ip,
	int			whichfork,
	const void		*data,
	int			size)
{
	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
	int			mem_size = size, real_size = 0;
	bool			zero_terminate;

	/*
	 * If we are using the local fork to store a symlink body we need to
	 * zero-terminate it so that we can pass it back to the VFS directly.
	 * Overallocate the in-memory fork by one for that and add a zero
	 * to terminate it below.
	 */
	zero_terminate = S_ISLNK(VFS_I(ip)->i_mode);
	if (zero_terminate)
		mem_size++;

	if (size) {
		real_size = roundup(mem_size, 4);
		ifp->if_u1.if_data = kmem_alloc(real_size, KM_SLEEP | KM_NOFS);
		memcpy(ifp->if_u1.if_data, data, size);
		if (zero_terminate)
			ifp->if_u1.if_data[size] = '\0';
	} else {
		ifp->if_u1.if_data = NULL;
	}

	ifp->if_bytes = size;
	ifp->if_real_bytes = real_size;
	ifp->if_flags &= ~(XFS_IFEXTENTS | XFS_IFBROOT);
	ifp->if_flags |= XFS_IFINLINE;
}

/*
 * The file is in-lined in the on-disk inode.
 */
STATIC int
xfs_iformat_local(
	xfs_inode_t	*ip,
	xfs_dinode_t	*dip,
	int		whichfork,
	int		size)
{
	/*
	 * If the size is unreasonable, then something
	 * is wrong and we just bail out rather than crash in
	 * kmem_alloc() or memcpy() below.
	 */
	if (unlikely(size > XFS_DFORK_SIZE(dip, ip->i_mount, whichfork))) {
		xfs_warn(ip->i_mount,
	"corrupt inode %Lu (bad size %d for local fork, size = %d).",
			(unsigned long long) ip->i_ino, size,
			XFS_DFORK_SIZE(dip, ip->i_mount, whichfork));
		XFS_CORRUPTION_ERROR("xfs_iformat_local", XFS_ERRLEVEL_LOW,
				     ip->i_mount, dip);
		return -EFSCORRUPTED;
	}

	xfs_init_local_fork(ip, whichfork, XFS_DFORK_PTR(dip, whichfork), size);
	return 0;
}

/*
 * The file consists of a set of extents all of which fit into the on-disk
 * inode.
 */
STATIC int
xfs_iformat_extents(
	struct xfs_inode	*ip,
	struct xfs_dinode	*dip,
	int			whichfork)
{
	struct xfs_mount	*mp = ip->i_mount;
	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
	int			state = xfs_bmap_fork_to_state(whichfork);
	int			nex = XFS_DFORK_NEXTENTS(dip, whichfork);
	int			size = nex * sizeof(xfs_bmbt_rec_t);
	struct xfs_iext_cursor	icur;
	struct xfs_bmbt_rec	*dp;
	struct xfs_bmbt_irec	new;
	int			i;

	/*
	 * If the number of extents is unreasonable, then something is wrong and
	 * we just bail out rather than crash in kmem_alloc() or memcpy() below.
	 */
	if (unlikely(size < 0 || size > XFS_DFORK_SIZE(dip, mp, whichfork))) {
		xfs_warn(ip->i_mount, "corrupt inode %Lu ((a)extents = %d).",
			(unsigned long long) ip->i_ino, nex);
		XFS_CORRUPTION_ERROR("xfs_iformat_extents(1)", XFS_ERRLEVEL_LOW,
				     mp, dip);
		return -EFSCORRUPTED;
	}

	ifp->if_real_bytes = 0;
	ifp->if_bytes = 0;
	ifp->if_u1.if_root = NULL;
	ifp->if_height = 0;
	if (size) {
		dp = (xfs_bmbt_rec_t *) XFS_DFORK_PTR(dip, whichfork);

		xfs_iext_first(ifp, &icur);
		for (i = 0; i < nex; i++, dp++) {
			xfs_bmbt_disk_get_all(dp, &new);
			if (!xfs_bmbt_validate_extent(mp, whichfork, &new)) {
				XFS_ERROR_REPORT("xfs_iformat_extents(2)",
						 XFS_ERRLEVEL_LOW, mp);
				return -EFSCORRUPTED;
			}

			xfs_iext_insert(ip, &icur, &new, state);
			trace_xfs_read_extent(ip, &icur, state, _THIS_IP_);
			xfs_iext_next(ifp, &icur);
		}
	}
	ifp->if_flags |= XFS_IFEXTENTS;
	return 0;
}

/*
 * The file has too many extents to fit into
 * the inode, so they are in B-tree format.
 * Allocate a buffer for the root of the B-tree
 * and copy the root into it.  The i_extents
 * field will remain NULL until all of the
 * extents are read in (when they are needed).
 */
STATIC int
xfs_iformat_btree(
	xfs_inode_t		*ip,
	xfs_dinode_t		*dip,
	int			whichfork)
{
	struct xfs_mount	*mp = ip->i_mount;
	xfs_bmdr_block_t	*dfp;
	xfs_ifork_t		*ifp;
	/* REFERENCED */
	int			nrecs;
	int			size;
	int			level;

	ifp = XFS_IFORK_PTR(ip, whichfork);
	dfp = (xfs_bmdr_block_t *)XFS_DFORK_PTR(dip, whichfork);
	size = XFS_BMAP_BROOT_SPACE(mp, dfp);
	nrecs = be16_to_cpu(dfp->bb_numrecs);
	level = be16_to_cpu(dfp->bb_level);

	/*
	 * blow out if -- fork has less extents than can fit in
	 * fork (fork shouldn't be a btree format), root btree
	 * block has more records than can fit into the fork,
	 * or the number of extents is greater than the number of
	 * blocks.
	 */
	if (unlikely(XFS_IFORK_NEXTENTS(ip, whichfork) <=
					XFS_IFORK_MAXEXT(ip, whichfork) ||
		     XFS_BMDR_SPACE_CALC(nrecs) >
					XFS_DFORK_SIZE(dip, mp, whichfork) ||
		     XFS_IFORK_NEXTENTS(ip, whichfork) > ip->i_d.di_nblocks) ||
		     level == 0 || level > XFS_BTREE_MAXLEVELS) {
		xfs_warn(mp, "corrupt inode %Lu (btree).",
					(unsigned long long) ip->i_ino);
		XFS_CORRUPTION_ERROR("xfs_iformat_btree", XFS_ERRLEVEL_LOW,
					 mp, dip);
		return -EFSCORRUPTED;
	}

	ifp->if_broot_bytes = size;
	ifp->if_broot = kmem_alloc(size, KM_SLEEP | KM_NOFS);
	ASSERT(ifp->if_broot != NULL);
	/*
	 * Copy and convert from the on-disk structure
	 * to the in-memory structure.
	 */
	xfs_bmdr_to_bmbt(ip, dfp, XFS_DFORK_SIZE(dip, ip->i_mount, whichfork),
			 ifp->if_broot, size);
	ifp->if_flags &= ~XFS_IFEXTENTS;
	ifp->if_flags |= XFS_IFBROOT;

	ifp->if_real_bytes = 0;
	ifp->if_bytes = 0;
	ifp->if_u1.if_root = NULL;
	ifp->if_height = 0;
	return 0;
}

/*
 * Reallocate the space for if_broot based on the number of records
 * being added or deleted as indicated in rec_diff.  Move the records
 * and pointers in if_broot to fit the new size.  When shrinking this
 * will eliminate holes between the records and pointers created by
 * the caller.  When growing this will create holes to be filled in
 * by the caller.
 *
 * The caller must not request to add more records than would fit in
 * the on-disk inode root.  If the if_broot is currently NULL, then
 * if we are adding records, one will be allocated.  The caller must also
 * not request that the number of records go below zero, although
 * it can go to zero.
 *
 * ip -- the inode whose if_broot area is changing
 * ext_diff -- the change in the number of records, positive or negative,
 *	 requested for the if_broot array.
 */
void
xfs_iroot_realloc(
	xfs_inode_t		*ip,
	int			rec_diff,
	int			whichfork)
{
	struct xfs_mount	*mp = ip->i_mount;
	int			cur_max;
	xfs_ifork_t		*ifp;
	struct xfs_btree_block	*new_broot;
	int			new_max;
	size_t			new_size;
	char			*np;
	char			*op;

	/*
	 * Handle the degenerate case quietly.
	 */
	if (rec_diff == 0) {
		return;
	}

	ifp = XFS_IFORK_PTR(ip, whichfork);
	if (rec_diff > 0) {
		/*
		 * If there wasn't any memory allocated before, just
		 * allocate it now and get out.
		 */
		if (ifp->if_broot_bytes == 0) {
			new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, rec_diff);
			ifp->if_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
			ifp->if_broot_bytes = (int)new_size;
			return;
		}

		/*
		 * If there is already an existing if_broot, then we need
		 * to realloc() it and shift the pointers to their new
		 * location.  The records don't change location because
		 * they are kept butted up against the btree block header.
		 */
		cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
		new_max = cur_max + rec_diff;
		new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
		ifp->if_broot = kmem_realloc(ifp->if_broot, new_size,
				KM_SLEEP | KM_NOFS);
		op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
						     ifp->if_broot_bytes);
		np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
						     (int)new_size);
		ifp->if_broot_bytes = (int)new_size;
		ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
			XFS_IFORK_SIZE(ip, whichfork));
		memmove(np, op, cur_max * (uint)sizeof(xfs_fsblock_t));
		return;
	}

	/*
	 * rec_diff is less than 0.  In this case, we are shrinking the
	 * if_broot buffer.  It must already exist.  If we go to zero
	 * records, just get rid of the root and clear the status bit.
	 */
	ASSERT((ifp->if_broot != NULL) && (ifp->if_broot_bytes > 0));
	cur_max = xfs_bmbt_maxrecs(mp, ifp->if_broot_bytes, 0);
	new_max = cur_max + rec_diff;
	ASSERT(new_max >= 0);
	if (new_max > 0)
		new_size = XFS_BMAP_BROOT_SPACE_CALC(mp, new_max);
	else
		new_size = 0;
	if (new_size > 0) {
		new_broot = kmem_alloc(new_size, KM_SLEEP | KM_NOFS);
		/*
		 * First copy over the btree block header.
		 */
		memcpy(new_broot, ifp->if_broot,
			XFS_BMBT_BLOCK_LEN(ip->i_mount));
	} else {
		new_broot = NULL;
		ifp->if_flags &= ~XFS_IFBROOT;
	}

	/*
	 * Only copy the records and pointers if there are any.
	 */
	if (new_max > 0) {
		/*
		 * First copy the records.
		 */
		op = (char *)XFS_BMBT_REC_ADDR(mp, ifp->if_broot, 1);
		np = (char *)XFS_BMBT_REC_ADDR(mp, new_broot, 1);
		memcpy(np, op, new_max * (uint)sizeof(xfs_bmbt_rec_t));

		/*
		 * Then copy the pointers.
		 */
		op = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, ifp->if_broot, 1,
						     ifp->if_broot_bytes);
		np = (char *)XFS_BMAP_BROOT_PTR_ADDR(mp, new_broot, 1,
						     (int)new_size);
		memcpy(np, op, new_max * (uint)sizeof(xfs_fsblock_t));
	}
	kmem_free(ifp->if_broot);
	ifp->if_broot = new_broot;
	ifp->if_broot_bytes = (int)new_size;
	if (ifp->if_broot)
		ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
			XFS_IFORK_SIZE(ip, whichfork));
	return;
}


/*
 * This is called when the amount of space needed for if_data
 * is increased or decreased.  The change in size is indicated by
 * the number of bytes that need to be added or deleted in the
 * byte_diff parameter.
 *
 * If the amount of space needed has decreased below the size of the
 * inline buffer, then switch to using the inline buffer.  Otherwise,
 * use kmem_realloc() or kmem_alloc() to adjust the size of the buffer
 * to what is needed.
 *
 * ip -- the inode whose if_data area is changing
 * byte_diff -- the change in the number of bytes, positive or negative,
 *	 requested for the if_data array.
 */
void
xfs_idata_realloc(
	xfs_inode_t	*ip,
	int		byte_diff,
	int		whichfork)
{
	xfs_ifork_t	*ifp;
	int		new_size;
	int		real_size;

	if (byte_diff == 0) {
		return;
	}

	ifp = XFS_IFORK_PTR(ip, whichfork);
	new_size = (int)ifp->if_bytes + byte_diff;
	ASSERT(new_size >= 0);

	if (new_size == 0) {
		kmem_free(ifp->if_u1.if_data);
		ifp->if_u1.if_data = NULL;
		real_size = 0;
	} else {
		/*
		 * Stuck with malloc/realloc.
		 * For inline data, the underlying buffer must be
		 * a multiple of 4 bytes in size so that it can be
		 * logged and stay on word boundaries.  We enforce
		 * that here.
		 */
		real_size = roundup(new_size, 4);
		if (ifp->if_u1.if_data == NULL) {
			ASSERT(ifp->if_real_bytes == 0);
			ifp->if_u1.if_data = kmem_alloc(real_size,
							KM_SLEEP | KM_NOFS);
		} else {
			/*
			 * Only do the realloc if the underlying size
			 * is really changing.
			 */
			if (ifp->if_real_bytes != real_size) {
				ifp->if_u1.if_data =
					kmem_realloc(ifp->if_u1.if_data,
							real_size,
							KM_SLEEP | KM_NOFS);
			}
		}
	}
	ifp->if_real_bytes = real_size;
	ifp->if_bytes = new_size;
	ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
}

void
xfs_idestroy_fork(
	xfs_inode_t	*ip,
	int		whichfork)
{
	xfs_ifork_t	*ifp;

	ifp = XFS_IFORK_PTR(ip, whichfork);
	if (ifp->if_broot != NULL) {
		kmem_free(ifp->if_broot);
		ifp->if_broot = NULL;
	}

	/*
	 * If the format is local, then we can't have an extents
	 * array so just look for an inline data array.  If we're
	 * not local then we may or may not have an extents list,
	 * so check and free it up if we do.
	 */
	if (XFS_IFORK_FORMAT(ip, whichfork) == XFS_DINODE_FMT_LOCAL) {
		if (ifp->if_u1.if_data != NULL) {
			ASSERT(ifp->if_real_bytes != 0);
			kmem_free(ifp->if_u1.if_data);
			ifp->if_u1.if_data = NULL;
			ifp->if_real_bytes = 0;
		}
	} else if ((ifp->if_flags & XFS_IFEXTENTS) && ifp->if_height) {
		xfs_iext_destroy(ifp);
	}

	ASSERT(ifp->if_real_bytes == 0);

	if (whichfork == XFS_ATTR_FORK) {
		kmem_zone_free(xfs_ifork_zone, ip->i_afp);
		ip->i_afp = NULL;
	} else if (whichfork == XFS_COW_FORK) {
		kmem_zone_free(xfs_ifork_zone, ip->i_cowfp);
		ip->i_cowfp = NULL;
	}
}

/*
 * Convert in-core extents to on-disk form
 *
 * In the case of the data fork, the in-core and on-disk fork sizes can be
 * different due to delayed allocation extents. We only copy on-disk extents
 * here, so callers must always use the physical fork size to determine the
 * size of the buffer passed to this routine.  We will return the size actually
 * used.
 */
int
xfs_iextents_copy(
	struct xfs_inode	*ip,
	struct xfs_bmbt_rec	*dp,
	int			whichfork)
{
	int			state = xfs_bmap_fork_to_state(whichfork);
	struct xfs_ifork	*ifp = XFS_IFORK_PTR(ip, whichfork);
	struct xfs_iext_cursor	icur;
	struct xfs_bmbt_irec	rec;
	int			copied = 0;

	ASSERT(xfs_isilocked(ip, XFS_ILOCK_EXCL | XFS_ILOCK_SHARED));
	ASSERT(ifp->if_bytes > 0);

	for_each_xfs_iext(ifp, &icur, &rec) {
		if (isnullstartblock(rec.br_startblock))
			continue;
		ASSERT(xfs_bmbt_validate_extent(ip->i_mount, whichfork, &rec));
		xfs_bmbt_disk_set_all(dp, &rec);
		trace_xfs_write_extent(ip, &icur, state, _RET_IP_);
		copied += sizeof(struct xfs_bmbt_rec);
		dp++;
	}

	ASSERT(copied > 0);
	ASSERT(copied <= ifp->if_bytes);
	return copied;
}

/*
 * Each of the following cases stores data into the same region
 * of the on-disk inode, so only one of them can be valid at
 * any given time. While it is possible to have conflicting formats
 * and log flags, e.g. having XFS_ILOG_?DATA set when the fork is
 * in EXTENTS format, this can only happen when the fork has
 * changed formats after being modified but before being flushed.
 * In these cases, the format always takes precedence, because the
 * format indicates the current state of the fork.
 */
void
xfs_iflush_fork(
	xfs_inode_t		*ip,
	xfs_dinode_t		*dip,
	xfs_inode_log_item_t	*iip,
	int			whichfork)
{
	char			*cp;
	xfs_ifork_t		*ifp;
	xfs_mount_t		*mp;
	static const short	brootflag[2] =
		{ XFS_ILOG_DBROOT, XFS_ILOG_ABROOT };
	static const short	dataflag[2] =
		{ XFS_ILOG_DDATA, XFS_ILOG_ADATA };
	static const short	extflag[2] =
		{ XFS_ILOG_DEXT, XFS_ILOG_AEXT };

	if (!iip)
		return;
	ifp = XFS_IFORK_PTR(ip, whichfork);
	/*
	 * This can happen if we gave up in iformat in an error path,
	 * for the attribute fork.
	 */
	if (!ifp) {
		ASSERT(whichfork == XFS_ATTR_FORK);
		return;
	}
	cp = XFS_DFORK_PTR(dip, whichfork);
	mp = ip->i_mount;
	switch (XFS_IFORK_FORMAT(ip, whichfork)) {
	case XFS_DINODE_FMT_LOCAL:
		if ((iip->ili_fields & dataflag[whichfork]) &&
		    (ifp->if_bytes > 0)) {
			ASSERT(ifp->if_u1.if_data != NULL);
			ASSERT(ifp->if_bytes <= XFS_IFORK_SIZE(ip, whichfork));
			memcpy(cp, ifp->if_u1.if_data, ifp->if_bytes);
		}
		break;

	case XFS_DINODE_FMT_EXTENTS:
		ASSERT((ifp->if_flags & XFS_IFEXTENTS) ||
		       !(iip->ili_fields & extflag[whichfork]));
		if ((iip->ili_fields & extflag[whichfork]) &&
		    (ifp->if_bytes > 0)) {
			ASSERT(XFS_IFORK_NEXTENTS(ip, whichfork) > 0);
			(void)xfs_iextents_copy(ip, (xfs_bmbt_rec_t *)cp,
				whichfork);
		}
		break;

	case XFS_DINODE_FMT_BTREE:
		if ((iip->ili_fields & brootflag[whichfork]) &&
		    (ifp->if_broot_bytes > 0)) {
			ASSERT(ifp->if_broot != NULL);
			ASSERT(XFS_BMAP_BMDR_SPACE(ifp->if_broot) <=
			        XFS_IFORK_SIZE(ip, whichfork));
			xfs_bmbt_to_bmdr(mp, ifp->if_broot, ifp->if_broot_bytes,
				(xfs_bmdr_block_t *)cp,
				XFS_DFORK_SIZE(dip, mp, whichfork));
		}
		break;

	case XFS_DINODE_FMT_DEV:
		if (iip->ili_fields & XFS_ILOG_DEV) {
			ASSERT(whichfork == XFS_DATA_FORK);
			xfs_dinode_put_rdev(dip, sysv_encode_dev(VFS_I(ip)->i_rdev));
		}
		break;

	default:
		ASSERT(0);
		break;
	}
}

/* Convert bmap state flags to an inode fork. */
struct xfs_ifork *
xfs_iext_state_to_fork(
	struct xfs_inode	*ip,
	int			state)
{
	if (state & BMAP_COWFORK)
		return ip->i_cowfp;
	else if (state & BMAP_ATTRFORK)
		return ip->i_afp;
	return &ip->i_df;
}

/*
 * Initialize an inode's copy-on-write fork.
 */
void
xfs_ifork_init_cow(
	struct xfs_inode	*ip)
{
	if (ip->i_cowfp)
		return;

	ip->i_cowfp = kmem_zone_zalloc(xfs_ifork_zone,
				       KM_SLEEP | KM_NOFS);
	ip->i_cowfp->if_flags = XFS_IFEXTENTS;
	ip->i_cformat = XFS_DINODE_FMT_EXTENTS;
	ip->i_cnextents = 0;
}