aboutsummaryrefslogtreecommitdiff
path: root/sys/ufs/ffs/ffs_inode.c
blob: 0b4172b34300c36a59b517279548c4e064e585c6 (plain) (blame)
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
/*-
 * SPDX-License-Identifier: BSD-3-Clause
 *
 * Copyright (c) 1982, 1986, 1989, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in the
 *    documentation and/or other materials provided with the distribution.
 * 3. Neither the name of the University nor the names of its contributors
 *    may be used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
 * SUCH DAMAGE.
 *
 *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
 */

#include <sys/cdefs.h>
__FBSDID("$FreeBSD$");

#include "opt_quota.h"

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/bio.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/mount.h>
#include <sys/proc.h>
#include <sys/racct.h>
#include <sys/random.h>
#include <sys/resourcevar.h>
#include <sys/rwlock.h>
#include <sys/stat.h>
#include <sys/vmmeter.h>
#include <sys/vnode.h>

#include <vm/vm.h>
#include <vm/vm_extern.h>
#include <vm/vm_object.h>

#include <ufs/ufs/extattr.h>
#include <ufs/ufs/quota.h>
#include <ufs/ufs/ufsmount.h>
#include <ufs/ufs/inode.h>
#include <ufs/ufs/ufs_extern.h>

#include <ufs/ffs/fs.h>
#include <ufs/ffs/ffs_extern.h>

static int ffs_indirtrunc(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
	    ufs2_daddr_t, int, ufs2_daddr_t *);

static void
ffs_inode_bwrite(struct vnode *vp, struct buf *bp, int flags)
{
	if ((flags & IO_SYNC) != 0)
		bwrite(bp);
	else if (DOINGASYNC(vp))
		bdwrite(bp);
	else
		bawrite(bp);
}

/*
 * Update the access, modified, and inode change times as specified by the
 * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
 * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
 * the timestamp update).  The IN_LAZYMOD flag is set to force a write
 * later if not now.  The IN_LAZYACCESS is set instead of IN_MODIFIED if the fs
 * is currently being suspended (or is suspended) and vnode has been accessed.
 * If we write now, then clear IN_MODIFIED, IN_LAZYACCESS and IN_LAZYMOD to
 * reflect the presumably successful write, and if waitfor is set, then wait
 * for the write to complete.
 */
int
ffs_update(vp, waitfor)
	struct vnode *vp;
	int waitfor;
{
	struct fs *fs;
	struct buf *bp;
	struct inode *ip;
	daddr_t bn;
	int flags, error;

	ASSERT_VOP_ELOCKED(vp, "ffs_update");
	ufs_itimes(vp);
	ip = VTOI(vp);
	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
		return (0);
	ip->i_flag &= ~(IN_LAZYACCESS | IN_LAZYMOD | IN_MODIFIED);
	/*
	 * The IN_SIZEMOD and IN_IBLKDATA flags indicate changes to the
	 * file size and block pointer fields in the inode. When these
	 * fields have been changed, the fsync() and fsyncdata() system 
	 * calls must write the inode to ensure their semantics that the 
	 * file is on stable store.
	 *
	 * The IN_SIZEMOD and IN_IBLKDATA flags cannot be cleared until
	 * a synchronous write of the inode is done. If they are cleared
	 * on an asynchronous write, then the inode may not yet have been
	 * written to the disk when an fsync() or fsyncdata() call is done.
	 * Absent these flags, these calls would not know that they needed
	 * to write the inode. Thus, these flags only can be cleared on
	 * synchronous writes of the inode. Since the inode will be locked
	 * for the duration of the I/O that writes it to disk, no fsync()
	 * or fsyncdata() will be able to run before the on-disk inode
	 * is complete.
	 */
	if (waitfor)
		ip->i_flag &= ~(IN_SIZEMOD | IN_IBLKDATA);
	fs = ITOFS(ip);
	if (fs->fs_ronly && ITOUMP(ip)->um_fsckpid == 0)
		return (0);
	/*
	 * If we are updating a snapshot and another process is currently
	 * writing the buffer containing the inode for this snapshot then
	 * a deadlock can occur when it tries to check the snapshot to see
	 * if that block needs to be copied. Thus when updating a snapshot
	 * we check to see if the buffer is already locked, and if it is
	 * we drop the snapshot lock until the buffer has been written
	 * and is available to us. We have to grab a reference to the
	 * snapshot vnode to prevent it from being removed while we are
	 * waiting for the buffer.
	 */
	flags = 0;
	if (IS_SNAPSHOT(ip))
		flags = GB_LOCK_NOWAIT;
loop:
	bn = fsbtodb(fs, ino_to_fsba(fs, ip->i_number));
	error = ffs_breadz(VFSTOUFS(vp->v_mount), ITODEVVP(ip), bn, bn,
	     (int) fs->fs_bsize, NULL, NULL, 0, NOCRED, flags, NULL, &bp);
	if (error != 0) {
		if (error != EBUSY)
			return (error);
		KASSERT((IS_SNAPSHOT(ip)), ("EBUSY from non-snapshot"));
		/*
		 * Wait for our inode block to become available.
		 *
		 * Hold a reference to the vnode to protect against
		 * ffs_snapgone(). Since we hold a reference, it can only
		 * get reclaimed (VIRF_DOOMED flag) in a forcible downgrade
		 * or unmount. For an unmount, the entire filesystem will be
		 * gone, so we cannot attempt to touch anything associated
		 * with it while the vnode is unlocked; all we can do is 
		 * pause briefly and try again. If when we relock the vnode
		 * we discover that it has been reclaimed, updating it is no
		 * longer necessary and we can just return an error.
		 */
		vref(vp);
		VOP_UNLOCK(vp);
		pause("ffsupd", 1);
		vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
		vrele(vp);
		if (VN_IS_DOOMED(vp))
			return (ENOENT);
		goto loop;
	}
	if (DOINGSOFTDEP(vp))
		softdep_update_inodeblock(ip, bp, waitfor);
	else if (ip->i_effnlink != ip->i_nlink)
		panic("ffs_update: bad link cnt");
	if (I_IS_UFS1(ip)) {
		*((struct ufs1_dinode *)bp->b_data +
		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
		/*
		 * XXX: FIX? The entropy here is desirable,
		 * but the harvesting may be expensive
		 */
		random_harvest_queue(&(ip->i_din1), sizeof(ip->i_din1), RANDOM_FS_ATIME);
	} else {
		ffs_update_dinode_ckhash(fs, ip->i_din2);
		*((struct ufs2_dinode *)bp->b_data +
		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
		/*
		 * XXX: FIX? The entropy here is desirable,
		 * but the harvesting may be expensive
		 */
		random_harvest_queue(&(ip->i_din2), sizeof(ip->i_din2), RANDOM_FS_ATIME);
	}
	if (waitfor) {
		error = bwrite(bp);
		if (ffs_fsfail_cleanup(VFSTOUFS(vp->v_mount), error))
			error = 0;
	} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
		bawrite(bp);
		error = 0;
	} else {
		if (bp->b_bufsize == fs->fs_bsize)
			bp->b_flags |= B_CLUSTEROK;
		bdwrite(bp);
		error = 0;
	}
	return (error);
}

#define	SINGLE	0	/* index of single indirect block */
#define	DOUBLE	1	/* index of double indirect block */
#define	TRIPLE	2	/* index of triple indirect block */
/*
 * Truncate the inode ip to at most length size, freeing the
 * disk blocks.
 */
int
ffs_truncate(vp, length, flags, cred)
	struct vnode *vp;
	off_t length;
	int flags;
	struct ucred *cred;
{
	struct inode *ip;
	ufs2_daddr_t bn, lbn, lastblock, lastiblock[UFS_NIADDR];
	ufs2_daddr_t indir_lbn[UFS_NIADDR], oldblks[UFS_NDADDR + UFS_NIADDR];
	ufs2_daddr_t newblks[UFS_NDADDR + UFS_NIADDR];
	ufs2_daddr_t count, blocksreleased = 0, datablocks, blkno;
	struct bufobj *bo;
	struct fs *fs;
	struct buf *bp;
	struct ufsmount *ump;
	int softdeptrunc, journaltrunc;
	int needextclean, extblocks;
	int offset, size, level, nblocks;
	int i, error, allerror, indiroff, waitforupdate;
	u_long key;
	off_t osize;

	ip = VTOI(vp);
	ump = VFSTOUFS(vp->v_mount);
	fs = ump->um_fs;
	bo = &vp->v_bufobj;

	ASSERT_VOP_LOCKED(vp, "ffs_truncate");

	if (length < 0)
		return (EINVAL);
	if (length > fs->fs_maxfilesize)
		return (EFBIG);
#ifdef QUOTA
	error = getinoquota(ip);
	if (error)
		return (error);
#endif
	/*
	 * Historically clients did not have to specify which data
	 * they were truncating. So, if not specified, we assume
	 * traditional behavior, e.g., just the normal data.
	 */
	if ((flags & (IO_EXT | IO_NORMAL)) == 0)
		flags |= IO_NORMAL;
	if (!DOINGSOFTDEP(vp) && !DOINGASYNC(vp))
		flags |= IO_SYNC;
	waitforupdate = (flags & IO_SYNC) != 0 || !DOINGASYNC(vp);
	/*
	 * If we are truncating the extended-attributes, and cannot
	 * do it with soft updates, then do it slowly here. If we are
	 * truncating both the extended attributes and the file contents
	 * (e.g., the file is being unlinked), then pick it off with
	 * soft updates below.
	 */
	allerror = 0;
	needextclean = 0;
	softdeptrunc = 0;
	journaltrunc = DOINGSUJ(vp);
	journaltrunc = 0;	/* XXX temp patch until bug found */
	if (journaltrunc == 0 && DOINGSOFTDEP(vp) && length == 0)
		softdeptrunc = !softdep_slowdown(vp);
	extblocks = 0;
	datablocks = DIP(ip, i_blocks);
	if (fs->fs_magic == FS_UFS2_MAGIC && ip->i_din2->di_extsize > 0) {
		extblocks = btodb(fragroundup(fs, ip->i_din2->di_extsize));
		datablocks -= extblocks;
	}
	if ((flags & IO_EXT) && extblocks > 0) {
		if (length != 0)
			panic("ffs_truncate: partial trunc of extdata");
		if (softdeptrunc || journaltrunc) {
			if ((flags & IO_NORMAL) == 0)
				goto extclean;
			needextclean = 1;
		} else {
			if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
				return (error);
#ifdef QUOTA
			(void) chkdq(ip, -extblocks, NOCRED, FORCE);
#endif
			vinvalbuf(vp, V_ALT, 0, 0);
			vn_pages_remove(vp,
			    OFF_TO_IDX(lblktosize(fs, -extblocks)), 0);
			osize = ip->i_din2->di_extsize;
			ip->i_din2->di_blocks -= extblocks;
			ip->i_din2->di_extsize = 0;
			for (i = 0; i < UFS_NXADDR; i++) {
				oldblks[i] = ip->i_din2->di_extb[i];
				ip->i_din2->di_extb[i] = 0;
			}
			UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
			if ((error = ffs_update(vp, waitforupdate)))
				return (error);
			for (i = 0; i < UFS_NXADDR; i++) {
				if (oldblks[i] == 0)
					continue;
				ffs_blkfree(ump, fs, ITODEVVP(ip), oldblks[i],
				    sblksize(fs, osize, i), ip->i_number,
				    vp->v_type, NULL, SINGLETON_KEY);
			}
		}
	}
	if ((flags & IO_NORMAL) == 0)
		return (0);
	if (vp->v_type == VLNK &&
	    (ip->i_size < vp->v_mount->mnt_maxsymlinklen ||
	     datablocks == 0)) {
#ifdef INVARIANTS
		if (length != 0)
			panic("ffs_truncate: partial truncate of symlink");
#endif
		bzero(SHORTLINK(ip), (u_int)ip->i_size);
		ip->i_size = 0;
		DIP_SET(ip, i_size, 0);
		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
		if (needextclean)
			goto extclean;
		return (ffs_update(vp, waitforupdate));
	}
	if (ip->i_size == length) {
		UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
		if (needextclean)
			goto extclean;
		return (ffs_update(vp, 0));
	}
	if (fs->fs_ronly)
		panic("ffs_truncate: read-only filesystem");
	if (IS_SNAPSHOT(ip))
		ffs_snapremove(vp);
	vp->v_lasta = vp->v_clen = vp->v_cstart = vp->v_lastw = 0;
	osize = ip->i_size;
	/*
	 * Lengthen the size of the file. We must ensure that the
	 * last byte of the file is allocated. Since the smallest
	 * value of osize is 0, length will be at least 1.
	 */
	if (osize < length) {
		vnode_pager_setsize(vp, length);
		flags |= BA_CLRBUF;
		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
		if (error) {
			vnode_pager_setsize(vp, osize);
			return (error);
		}
		ip->i_size = length;
		DIP_SET(ip, i_size, length);
		if (bp->b_bufsize == fs->fs_bsize)
			bp->b_flags |= B_CLUSTEROK;
		ffs_inode_bwrite(vp, bp, flags);
		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
		return (ffs_update(vp, waitforupdate));
	}
	/*
	 * Lookup block number for a given offset. Zero length files
	 * have no blocks, so return a blkno of -1.
	 */
	lbn = lblkno(fs, length - 1);
	if (length == 0) {
		blkno = -1;
	} else if (lbn < UFS_NDADDR) {
		blkno = DIP(ip, i_db[lbn]);
	} else {
		error = UFS_BALLOC(vp, lblktosize(fs, (off_t)lbn), fs->fs_bsize,
		    cred, BA_METAONLY, &bp);
		if (error)
			return (error);
		indiroff = (lbn - UFS_NDADDR) % NINDIR(fs);
		if (I_IS_UFS1(ip))
			blkno = ((ufs1_daddr_t *)(bp->b_data))[indiroff];
		else
			blkno = ((ufs2_daddr_t *)(bp->b_data))[indiroff];
		/*
		 * If the block number is non-zero, then the indirect block
		 * must have been previously allocated and need not be written.
		 * If the block number is zero, then we may have allocated
		 * the indirect block and hence need to write it out.
		 */
		if (blkno != 0)
			brelse(bp);
		else if (flags & IO_SYNC)
			bwrite(bp);
		else
			bdwrite(bp);
	}
	/*
	 * If the block number at the new end of the file is zero,
	 * then we must allocate it to ensure that the last block of 
	 * the file is allocated. Soft updates does not handle this
	 * case, so here we have to clean up the soft updates data
	 * structures describing the allocation past the truncation
	 * point. Finding and deallocating those structures is a lot of
	 * work. Since partial truncation with a hole at the end occurs
	 * rarely, we solve the problem by syncing the file so that it
	 * will have no soft updates data structures left.
	 */
	if (blkno == 0 && (error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
		return (error);
	if (blkno != 0 && DOINGSOFTDEP(vp)) {
		if (softdeptrunc == 0 && journaltrunc == 0) {
			/*
			 * If soft updates cannot handle this truncation,
			 * clean up soft dependency data structures and
			 * fall through to the synchronous truncation.
			 */
			if ((error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
				return (error);
		} else {
			flags = IO_NORMAL | (needextclean ? IO_EXT: 0);
			if (journaltrunc)
				softdep_journal_freeblocks(ip, cred, length,
				    flags);
			else
				softdep_setup_freeblocks(ip, length, flags);
			ASSERT_VOP_LOCKED(vp, "ffs_truncate1");
			if (journaltrunc == 0) {
				UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
				error = ffs_update(vp, 0);
			}
			return (error);
		}
	}
	/*
	 * Shorten the size of the file. If the last block of the
	 * shortened file is unallocated, we must allocate it.
	 * Additionally, if the file is not being truncated to a
	 * block boundary, the contents of the partial block
	 * following the end of the file must be zero'ed in
	 * case it ever becomes accessible again because of
	 * subsequent file growth. Directories however are not
	 * zero'ed as they should grow back initialized to empty.
	 */
	offset = blkoff(fs, length);
	if (blkno != 0 && offset == 0) {
		ip->i_size = length;
		DIP_SET(ip, i_size, length);
		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
	} else {
		lbn = lblkno(fs, length);
		flags |= BA_CLRBUF;
		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
		if (error)
			return (error);
		ffs_inode_bwrite(vp, bp, flags);

		/*
		 * When we are doing soft updates and the UFS_BALLOC
		 * above fills in a direct block hole with a full sized
		 * block that will be truncated down to a fragment below,
		 * we must flush out the block dependency with an FSYNC
		 * so that we do not get a soft updates inconsistency
		 * when we create the fragment below.
		 */
		if (DOINGSOFTDEP(vp) && lbn < UFS_NDADDR &&
		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
		    (error = ffs_syncvnode(vp, MNT_WAIT, 0)) != 0)
			return (error);

		error = UFS_BALLOC(vp, length - 1, 1, cred, flags, &bp);
		if (error)
			return (error);
		ip->i_size = length;
		DIP_SET(ip, i_size, length);
		size = blksize(fs, ip, lbn);
		if (vp->v_type != VDIR && offset != 0)
			bzero((char *)bp->b_data + offset,
			    (u_int)(size - offset));
		/* Kirk's code has reallocbuf(bp, size, 1) here */
		allocbuf(bp, size);
		if (bp->b_bufsize == fs->fs_bsize)
			bp->b_flags |= B_CLUSTEROK;
		ffs_inode_bwrite(vp, bp, flags);
		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
	}
	/*
	 * Calculate index into inode's block list of
	 * last direct and indirect blocks (if any)
	 * which we want to keep.  Lastblock is -1 when
	 * the file is truncated to 0.
	 */
	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
	lastiblock[SINGLE] = lastblock - UFS_NDADDR;
	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
	nblocks = btodb(fs->fs_bsize);
	/*
	 * Update file and block pointers on disk before we start freeing
	 * blocks.  If we crash before free'ing blocks below, the blocks
	 * will be returned to the free list.  lastiblock values are also
	 * normalized to -1 for calls to ffs_indirtrunc below.
	 */
	for (level = TRIPLE; level >= SINGLE; level--) {
		oldblks[UFS_NDADDR + level] = DIP(ip, i_ib[level]);
		if (lastiblock[level] < 0) {
			DIP_SET(ip, i_ib[level], 0);
			lastiblock[level] = -1;
		}
	}
	for (i = 0; i < UFS_NDADDR; i++) {
		oldblks[i] = DIP(ip, i_db[i]);
		if (i > lastblock)
			DIP_SET(ip, i_db[i], 0);
	}
	UFS_INODE_SET_FLAG(ip, IN_CHANGE | IN_UPDATE);
	allerror = ffs_update(vp, waitforupdate);

	/*
	 * Having written the new inode to disk, save its new configuration
	 * and put back the old block pointers long enough to process them.
	 * Note that we save the new block configuration so we can check it
	 * when we are done.
	 */
	for (i = 0; i < UFS_NDADDR; i++) {
		newblks[i] = DIP(ip, i_db[i]);
		DIP_SET(ip, i_db[i], oldblks[i]);
	}
	for (i = 0; i < UFS_NIADDR; i++) {
		newblks[UFS_NDADDR + i] = DIP(ip, i_ib[i]);
		DIP_SET(ip, i_ib[i], oldblks[UFS_NDADDR + i]);
	}
	ip->i_size = osize;
	DIP_SET(ip, i_size, osize);
	UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);

	error = vtruncbuf(vp, length, fs->fs_bsize);
	if (error && (allerror == 0))
		allerror = error;

	/*
	 * Indirect blocks first.
	 */
	indir_lbn[SINGLE] = -UFS_NDADDR;
	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
	for (level = TRIPLE; level >= SINGLE; level--) {
		bn = DIP(ip, i_ib[level]);
		if (bn != 0) {
			error = ffs_indirtrunc(ip, indir_lbn[level],
			    fsbtodb(fs, bn), lastiblock[level], level, &count);
			if (error)
				allerror = error;
			blocksreleased += count;
			if (lastiblock[level] < 0) {
				DIP_SET(ip, i_ib[level], 0);
				ffs_blkfree(ump, fs, ump->um_devvp, bn,
				    fs->fs_bsize, ip->i_number,
				    vp->v_type, NULL, SINGLETON_KEY);
				blocksreleased += nblocks;
			}
		}
		if (lastiblock[level] >= 0)
			goto done;
	}

	/*
	 * All whole direct blocks or frags.
	 */
	key = ffs_blkrelease_start(ump, ump->um_devvp, ip->i_number);
	for (i = UFS_NDADDR - 1; i > lastblock; i--) {
		long bsize;

		bn = DIP(ip, i_db[i]);
		if (bn == 0)
			continue;
		DIP_SET(ip, i_db[i], 0);
		bsize = blksize(fs, ip, i);
		ffs_blkfree(ump, fs, ump->um_devvp, bn, bsize, ip->i_number,
		    vp->v_type, NULL, key);
		blocksreleased += btodb(bsize);
	}
	ffs_blkrelease_finish(ump, key);
	if (lastblock < 0)
		goto done;

	/*
	 * Finally, look for a change in size of the
	 * last direct block; release any frags.
	 */
	bn = DIP(ip, i_db[lastblock]);
	if (bn != 0) {
		long oldspace, newspace;

		/*
		 * Calculate amount of space we're giving
		 * back as old block size minus new block size.
		 */
		oldspace = blksize(fs, ip, lastblock);
		ip->i_size = length;
		DIP_SET(ip, i_size, length);
		UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE | IN_UPDATE);
		newspace = blksize(fs, ip, lastblock);
		if (newspace == 0)
			panic("ffs_truncate: newspace");
		if (oldspace - newspace > 0) {
			/*
			 * Block number of space to be free'd is
			 * the old block # plus the number of frags
			 * required for the storage we're keeping.
			 */
			bn += numfrags(fs, newspace);
			ffs_blkfree(ump, fs, ump->um_devvp, bn,
			   oldspace - newspace, ip->i_number, vp->v_type,
			   NULL, SINGLETON_KEY);
			blocksreleased += btodb(oldspace - newspace);
		}
	}
done:
#ifdef INVARIANTS
	for (level = SINGLE; level <= TRIPLE; level++)
		if (newblks[UFS_NDADDR + level] != DIP(ip, i_ib[level]))
			panic("ffs_truncate1: level %d newblks %jd != i_ib %jd",
			    level, (intmax_t)newblks[UFS_NDADDR + level],
			    (intmax_t)DIP(ip, i_ib[level]));
	for (i = 0; i < UFS_NDADDR; i++)
		if (newblks[i] != DIP(ip, i_db[i]))
			panic("ffs_truncate2: blkno %d newblks %jd != i_db %jd",
			    i, (intmax_t)newblks[UFS_NDADDR + level],
			    (intmax_t)DIP(ip, i_ib[level]));
	BO_LOCK(bo);
	if (length == 0 &&
	    (fs->fs_magic != FS_UFS2_MAGIC || ip->i_din2->di_extsize == 0) &&
	    (bo->bo_dirty.bv_cnt > 0 || bo->bo_clean.bv_cnt > 0))
		panic("ffs_truncate3: vp = %p, buffers: dirty = %d, clean = %d",
			vp, bo->bo_dirty.bv_cnt, bo->bo_clean.bv_cnt);
	BO_UNLOCK(bo);
#endif /* INVARIANTS */
	/*
	 * Put back the real size.
	 */
	ip->i_size = length;
	DIP_SET(ip, i_size, length);
	if (DIP(ip, i_blocks) >= blocksreleased)
		DIP_SET(ip, i_blocks, DIP(ip, i_blocks) - blocksreleased);
	else	/* sanity */
		DIP_SET(ip, i_blocks, 0);
	UFS_INODE_SET_FLAG(ip, IN_SIZEMOD | IN_CHANGE);
#ifdef QUOTA
	(void) chkdq(ip, -blocksreleased, NOCRED, FORCE);
#endif
	return (allerror);

extclean:
	if (journaltrunc)
		softdep_journal_freeblocks(ip, cred, length, IO_EXT);
	else
		softdep_setup_freeblocks(ip, length, IO_EXT);
	return (ffs_update(vp, waitforupdate));
}

/*
 * Release blocks associated with the inode ip and stored in the indirect
 * block bn.  Blocks are free'd in LIFO order up to (but not including)
 * lastbn.  If level is greater than SINGLE, the block is an indirect block
 * and recursive calls to indirtrunc must be used to cleanse other indirect
 * blocks.
 */
static int
ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
	struct inode *ip;
	ufs2_daddr_t lbn, lastbn;
	ufs2_daddr_t dbn;
	int level;
	ufs2_daddr_t *countp;
{
	struct buf *bp;
	struct fs *fs;
	struct ufsmount *ump;
	struct vnode *vp;
	caddr_t copy = NULL;
	u_long key;
	int i, nblocks, error = 0, allerror = 0;
	ufs2_daddr_t nb, nlbn, last;
	ufs2_daddr_t blkcount, factor, blocksreleased = 0;
	ufs1_daddr_t *bap1 = NULL;
	ufs2_daddr_t *bap2 = NULL;
#define BAP(ip, i) (I_IS_UFS1(ip) ? bap1[i] : bap2[i])

	fs = ITOFS(ip);
	ump = ITOUMP(ip);

	/*
	 * Calculate index in current block of last
	 * block to be kept.  -1 indicates the entire
	 * block so we need not calculate the index.
	 */
	factor = lbn_offset(fs, level);
	last = lastbn;
	if (lastbn > 0)
		last /= factor;
	nblocks = btodb(fs->fs_bsize);
	/*
	 * Get buffer of block pointers, zero those entries corresponding
	 * to blocks to be free'd, and update on disk copy first.  Since
	 * double(triple) indirect before single(double) indirect, calls
	 * to VOP_BMAP() on these blocks will fail.  However, we already
	 * have the on-disk address, so we just pass it to bread() instead
	 * of having bread() attempt to calculate it using VOP_BMAP().
	 */
	vp = ITOV(ip);
	error = ffs_breadz(ump, vp, lbn, dbn, (int)fs->fs_bsize, NULL, NULL, 0,
	    NOCRED, 0, NULL, &bp);
	if (error) {
		*countp = 0;
		return (error);
	}

	if (I_IS_UFS1(ip))
		bap1 = (ufs1_daddr_t *)bp->b_data;
	else
		bap2 = (ufs2_daddr_t *)bp->b_data;
	if (lastbn != -1) {
		copy = malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
		bcopy((caddr_t)bp->b_data, copy, (u_int)fs->fs_bsize);
		for (i = last + 1; i < NINDIR(fs); i++)
			if (I_IS_UFS1(ip))
				bap1[i] = 0;
			else
				bap2[i] = 0;
		if (DOINGASYNC(vp)) {
			bdwrite(bp);
		} else {
			error = bwrite(bp);
			if (error)
				allerror = error;
		}
		if (I_IS_UFS1(ip))
			bap1 = (ufs1_daddr_t *)copy;
		else
			bap2 = (ufs2_daddr_t *)copy;
	}

	/*
	 * Recursively free totally unused blocks.
	 */
	key = ffs_blkrelease_start(ump, ITODEVVP(ip), ip->i_number);
	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
	    i--, nlbn += factor) {
		nb = BAP(ip, i);
		if (nb == 0)
			continue;
		if (level > SINGLE) {
			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
			    (ufs2_daddr_t)-1, level - 1, &blkcount)) != 0)
				allerror = error;
			blocksreleased += blkcount;
		}
		ffs_blkfree(ump, fs, ITODEVVP(ip), nb, fs->fs_bsize,
		    ip->i_number, vp->v_type, NULL, key);
		blocksreleased += nblocks;
	}
	ffs_blkrelease_finish(ump, key);

	/*
	 * Recursively free last partial block.
	 */
	if (level > SINGLE && lastbn >= 0) {
		last = lastbn % factor;
		nb = BAP(ip, i);
		if (nb != 0) {
			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
			    last, level - 1, &blkcount);
			if (error)
				allerror = error;
			blocksreleased += blkcount;
		}
	}
	if (copy != NULL) {
		free(copy, M_TEMP);
	} else {
		bp->b_flags |= B_INVAL | B_NOCACHE;
		brelse(bp);
	}

	*countp = blocksreleased;
	return (allerror);
}

int
ffs_rdonly(struct inode *ip)
{

	return (ITOFS(ip)->fs_ronly != 0);
}