xref: /netbsd-src/sys/ufs/ext2fs/ext2fs_inode.c (revision 3816d47b2c42fcd6e549e3407f842a5b1a1d23ad)
1 /*	$NetBSD: ext2fs_inode.c,v 1.70 2009/10/19 18:41:17 bouyer Exp $	*/
2 
3 /*
4  * Copyright (c) 1982, 1986, 1989, 1993
5  *	The Regents of the University of California.  All rights reserved.
6  *
7  * Redistribution and use in source and binary forms, with or without
8  * modification, are permitted provided that the following conditions
9  * are met:
10  * 1. Redistributions of source code must retain the above copyright
11  *    notice, this list of conditions and the following disclaimer.
12  * 2. Redistributions in binary form must reproduce the above copyright
13  *    notice, this list of conditions and the following disclaimer in the
14  *    documentation and/or other materials provided with the distribution.
15  * 3. Neither the name of the University nor the names of its contributors
16  *    may be used to endorse or promote products derived from this software
17  *    without specific prior written permission.
18  *
19  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29  * SUCH DAMAGE.
30  *
31  *	@(#)ffs_inode.c	8.8 (Berkeley) 10/19/94
32  * Modified for ext2fs by Manuel Bouyer.
33  */
34 
35 /*
36  * Copyright (c) 1997 Manuel Bouyer.
37  *
38  * Redistribution and use in source and binary forms, with or without
39  * modification, are permitted provided that the following conditions
40  * are met:
41  * 1. Redistributions of source code must retain the above copyright
42  *    notice, this list of conditions and the following disclaimer.
43  * 2. Redistributions in binary form must reproduce the above copyright
44  *    notice, this list of conditions and the following disclaimer in the
45  *    documentation and/or other materials provided with the distribution.
46  *
47  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
48  * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
49  * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
50  * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
51  * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
52  * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
53  * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
54  * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
55  * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
56  * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
57  *
58  *	@(#)ffs_inode.c	8.8 (Berkeley) 10/19/94
59  * Modified for ext2fs by Manuel Bouyer.
60  */
61 
62 #include <sys/cdefs.h>
63 __KERNEL_RCSID(0, "$NetBSD: ext2fs_inode.c,v 1.70 2009/10/19 18:41:17 bouyer Exp $");
64 
65 #include <sys/param.h>
66 #include <sys/systm.h>
67 #include <sys/mount.h>
68 #include <sys/proc.h>
69 #include <sys/file.h>
70 #include <sys/buf.h>
71 #include <sys/vnode.h>
72 #include <sys/kernel.h>
73 #include <sys/malloc.h>
74 #include <sys/trace.h>
75 #include <sys/resourcevar.h>
76 #include <sys/kauth.h>
77 
78 #include <ufs/ufs/inode.h>
79 #include <ufs/ufs/ufsmount.h>
80 #include <ufs/ufs/ufs_extern.h>
81 
82 #include <ufs/ext2fs/ext2fs.h>
83 #include <ufs/ext2fs/ext2fs_extern.h>
84 
85 extern int prtactive;
86 
87 static int ext2fs_indirtrunc(struct inode *, daddr_t, daddr_t,
88 				  daddr_t, int, long *);
89 
90 /*
91  * Get the size of an inode.
92  */
93 uint64_t
94 ext2fs_size(struct inode *ip)
95 {
96 	uint64_t size = ip->i_e2fs_size;
97 
98 	if ((ip->i_e2fs_mode & IFMT) == IFREG)
99 		size |= (uint64_t)ip->i_e2fs_dacl << 32;
100 	return size;
101 }
102 
103 int
104 ext2fs_setsize(struct inode *ip, uint64_t size)
105 {
106 	if ((ip->i_e2fs_mode & IFMT) == IFREG ||
107 	    ip->i_e2fs_mode == 0) {
108 		ip->i_e2fs_dacl = size >> 32;
109 		if (size >= 0x80000000U) {
110 			struct m_ext2fs *fs = ip->i_e2fs;
111 
112 			if (fs->e2fs.e2fs_rev <= E2FS_REV0) {
113 				/* Linux automagically upgrades to REV1 here! */
114 				return EFBIG;
115 			}
116 			if (!(fs->e2fs.e2fs_features_rocompat
117 			    & EXT2F_ROCOMPAT_LARGEFILE)) {
118 				fs->e2fs.e2fs_features_rocompat |=
119 				    EXT2F_ROCOMPAT_LARGEFILE;
120 				fs->e2fs_fmod = 1;
121 			}
122 		}
123 	} else if (size >= 0x80000000U)
124 		return EFBIG;
125 
126 	ip->i_e2fs_size = size;
127 
128 	return 0;
129 }
130 
131 /*
132  * Last reference to an inode.  If necessary, write or delete it.
133  */
134 int
135 ext2fs_inactive(void *v)
136 {
137 	struct vop_inactive_args /* {
138 		struct vnode *a_vp;
139 		bool *a_recycle;
140 	} */ *ap = v;
141 	struct vnode *vp = ap->a_vp;
142 	struct inode *ip = VTOI(vp);
143 	int error = 0;
144 
145 	if (prtactive && vp->v_usecount != 0)
146 		vprint("ext2fs_inactive: pushing active", vp);
147 	/* Get rid of inodes related to stale file handles. */
148 	if (ip->i_e2fs_mode == 0 || ip->i_e2fs_dtime != 0)
149 		goto out;
150 
151 	error = 0;
152 	if (ip->i_e2fs_nlink == 0 && (vp->v_mount->mnt_flag & MNT_RDONLY) == 0) {
153 		/* Defer final inode free and update to reclaim.*/
154 		if (ext2fs_size(ip) != 0) {
155 			error = ext2fs_truncate(vp, (off_t)0, 0, NOCRED);
156 		}
157 		ip->i_e2fs_dtime = time_second;
158 		ip->i_flag |= IN_CHANGE | IN_UPDATE;
159 		mutex_enter(&vp->v_interlock);
160 		vp->v_iflag |= VI_FREEING;
161 		mutex_exit(&vp->v_interlock);
162 		ext2fs_vfree(vp, ip->i_number, ip->i_e2fs_mode);
163 	}
164 	if (ip->i_flag & (IN_CHANGE | IN_UPDATE | IN_MODIFIED)) {
165 		ext2fs_update(vp, NULL, NULL, 0);
166 	}
167 out:
168 	/*
169 	 * If we are done with the inode, reclaim it
170 	 * so that it can be reused immediately.
171 	 */
172 	*ap->a_recycle = (ip->i_e2fs_dtime != 0);
173 	VOP_UNLOCK(vp, 0);
174 	return (error);
175 }
176 
177 
178 /*
179  * Update the access, modified, and inode change times as specified by the
180  * IACCESS, IUPDATE, and ICHANGE flags respectively. The IMODIFIED flag is
181  * used to specify that the inode needs to be updated but that the times have
182  * already been set. The access and modified times are taken from the second
183  * and third parameters; the inode change time is always taken from the current
184  * time. If UPDATE_WAIT or UPDATE_DIROP is set, then wait for the disk
185  * write of the inode to complete.
186  */
187 int
188 ext2fs_update(struct vnode *vp, const struct timespec *acc,
189     const struct timespec *mod, int updflags)
190 {
191 	struct m_ext2fs *fs;
192 	struct buf *bp;
193 	struct inode *ip;
194 	int error;
195 	void *cp;
196 	int flags;
197 
198 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
199 		return (0);
200 	ip = VTOI(vp);
201 	EXT2FS_ITIMES(ip, acc, mod, NULL);
202 	if (updflags & UPDATE_CLOSE)
203 		flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED);
204 	else
205 		flags = ip->i_flag & IN_MODIFIED;
206 	if (flags == 0)
207 		return (0);
208 	fs = ip->i_e2fs;
209 
210 	error = bread(ip->i_devvp,
211 			  fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
212 			  (int)fs->e2fs_bsize, NOCRED, B_MODIFY, &bp);
213 	if (error) {
214 		brelse(bp, 0);
215 		return (error);
216 	}
217 	ip->i_flag &= ~(IN_MODIFIED | IN_ACCESSED);
218 	cp = (char *)bp->b_data +
219 	    (ino_to_fsbo(fs, ip->i_number) * EXT2_DINODE_SIZE(fs));
220 	e2fs_isave(ip->i_din.e2fs_din, (struct ext2fs_dinode *)cp);
221 	if ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) != 0 &&
222 	    (flags & IN_MODIFIED) != 0 &&
223 	    (vp->v_mount->mnt_flag & MNT_ASYNC) == 0)
224 		return (bwrite(bp));
225 	else {
226 		bdwrite(bp);
227 		return (0);
228 	}
229 }
230 
231 #define	SINGLE	0	/* index of single indirect block */
232 #define	DOUBLE	1	/* index of double indirect block */
233 #define	TRIPLE	2	/* index of triple indirect block */
234 /*
235  * Truncate the inode oip to at most length size, freeing the
236  * disk blocks.
237  */
238 int
239 ext2fs_truncate(struct vnode *ovp, off_t length, int ioflag,
240     kauth_cred_t cred)
241 {
242 	daddr_t lastblock;
243 	struct inode *oip = VTOI(ovp);
244 	daddr_t bn, lastiblock[NIADDR], indir_lbn[NIADDR];
245 	/* XXX ondisk32 */
246 	int32_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
247 	struct m_ext2fs *fs;
248 	int offset, size, level;
249 	long count, blocksreleased = 0;
250 	int i, nblocks;
251 	int error, allerror = 0;
252 	off_t osize;
253 	int sync;
254 	struct ufsmount *ump = oip->i_ump;
255 
256 	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
257 	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
258 		return 0;
259 	}
260 
261 	if (length < 0)
262 		return (EINVAL);
263 
264 	if (ovp->v_type == VLNK &&
265 	    (ext2fs_size(oip) < ump->um_maxsymlinklen ||
266 	     (ump->um_maxsymlinklen == 0 && oip->i_e2fs_nblock == 0))) {
267 		KDASSERT(length == 0);
268 		memset((char *)&oip->i_din.e2fs_din->e2di_shortlink, 0,
269 			(u_int)ext2fs_size(oip));
270 		(void)ext2fs_setsize(oip, 0);
271 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
272 		return (ext2fs_update(ovp, NULL, NULL, 0));
273 	}
274 	if (ext2fs_size(oip) == length) {
275 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
276 		return (ext2fs_update(ovp, NULL, NULL, 0));
277 	}
278 	fs = oip->i_e2fs;
279 	if (length > ump->um_maxfilesize)
280 		return (EFBIG);
281 
282 	osize = ext2fs_size(oip);
283 
284 	/*
285 	 * Lengthen the size of the file. We must ensure that the
286 	 * last byte of the file is allocated. Since the smallest
287 	 * value of osize is 0, length will be at least 1.
288 	 */
289 	if (osize < length) {
290 		uvm_vnp_setwritesize(ovp, length);
291 		error = ufs_balloc_range(ovp, length - 1, 1, cred,
292 		    ioflag & IO_SYNC ? B_SYNC : 0);
293 		if (error) {
294 			(void) ext2fs_truncate(ovp, osize, ioflag & IO_SYNC,
295 			    cred);
296 			return (error);
297 		}
298 		uvm_vnp_setsize(ovp, length);
299 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
300 		KASSERT(error  || ovp->v_size == ext2fs_size(oip));
301 		return (ext2fs_update(ovp, NULL, NULL, 0));
302 	}
303 	/*
304 	 * Shorten the size of the file. If the file is not being
305 	 * truncated to a block boundry, the contents of the
306 	 * partial block following the end of the file must be
307 	 * zero'ed in case it ever become accessible again because
308 	 * of subsequent file growth.
309 	 */
310 	offset = blkoff(fs, length);
311 	if (offset != 0) {
312 		size = fs->e2fs_bsize;
313 
314 		/* XXXUBC we should handle more than just VREG */
315 		uvm_vnp_zerorange(ovp, length, size - offset);
316 	}
317 	(void)ext2fs_setsize(oip, length);
318 	uvm_vnp_setsize(ovp, length);
319 	/*
320 	 * Calculate index into inode's block list of
321 	 * last direct and indirect blocks (if any)
322 	 * which we want to keep.  Lastblock is -1 when
323 	 * the file is truncated to 0.
324 	 */
325 	lastblock = lblkno(fs, length + fs->e2fs_bsize - 1) - 1;
326 	lastiblock[SINGLE] = lastblock - NDADDR;
327 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
328 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
329 	nblocks = btodb(fs->e2fs_bsize);
330 	/*
331 	 * Update file and block pointers on disk before we start freeing
332 	 * blocks.  If we crash before free'ing blocks below, the blocks
333 	 * will be returned to the free list.  lastiblock values are also
334 	 * normalized to -1 for calls to ext2fs_indirtrunc below.
335 	 */
336 	memcpy((void *)oldblks, (void *)&oip->i_e2fs_blocks[0], sizeof oldblks);
337 	sync = 0;
338 	for (level = TRIPLE; level >= SINGLE; level--) {
339 		if (lastiblock[level] < 0 && oldblks[NDADDR + level] != 0) {
340 			sync = 1;
341 			oip->i_e2fs_blocks[NDADDR + level] = 0;
342 			lastiblock[level] = -1;
343 		}
344 	}
345 	for (i = 0; i < NDADDR; i++) {
346 		if (i > lastblock && oldblks[i] != 0) {
347 			sync = 1;
348 			oip->i_e2fs_blocks[i] = 0;
349 		}
350 	}
351 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
352 	if (sync) {
353 		error = ext2fs_update(ovp, NULL, NULL, UPDATE_WAIT);
354 		if (error && !allerror)
355 			allerror = error;
356 	}
357 
358 	/*
359 	 * Having written the new inode to disk, save its new configuration
360 	 * and put back the old block pointers long enough to process them.
361 	 * Note that we save the new block configuration so we can check it
362 	 * when we are done.
363 	 */
364 	memcpy((void *)newblks, (void *)&oip->i_e2fs_blocks[0], sizeof newblks);
365 	memcpy((void *)&oip->i_e2fs_blocks[0], (void *)oldblks, sizeof oldblks);
366 
367 	(void)ext2fs_setsize(oip, osize);
368 	error = vtruncbuf(ovp, lastblock + 1, 0, 0);
369 	if (error && !allerror)
370 		allerror = error;
371 
372 	/*
373 	 * Indirect blocks first.
374 	 */
375 	indir_lbn[SINGLE] = -NDADDR;
376 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) -1;
377 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
378 	for (level = TRIPLE; level >= SINGLE; level--) {
379 		/* XXX ondisk32 */
380 		bn = fs2h32(oip->i_e2fs_blocks[NDADDR + level]);
381 		if (bn != 0) {
382 			error = ext2fs_indirtrunc(oip, indir_lbn[level],
383 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
384 			if (error)
385 				allerror = error;
386 			blocksreleased += count;
387 			if (lastiblock[level] < 0) {
388 				oip->i_e2fs_blocks[NDADDR + level] = 0;
389 				ext2fs_blkfree(oip, bn);
390 				blocksreleased += nblocks;
391 			}
392 		}
393 		if (lastiblock[level] >= 0)
394 			goto done;
395 	}
396 
397 	/*
398 	 * All whole direct blocks or frags.
399 	 */
400 	for (i = NDADDR - 1; i > lastblock; i--) {
401 		/* XXX ondisk32 */
402 		bn = fs2h32(oip->i_e2fs_blocks[i]);
403 		if (bn == 0)
404 			continue;
405 		oip->i_e2fs_blocks[i] = 0;
406 		ext2fs_blkfree(oip, bn);
407 		blocksreleased += btodb(fs->e2fs_bsize);
408 	}
409 
410 done:
411 #ifdef DIAGNOSTIC
412 	for (level = SINGLE; level <= TRIPLE; level++)
413 		if (newblks[NDADDR + level] !=
414 		    oip->i_e2fs_blocks[NDADDR + level])
415 			panic("ext2fs_truncate1");
416 	for (i = 0; i < NDADDR; i++)
417 		if (newblks[i] != oip->i_e2fs_blocks[i])
418 			panic("ext2fs_truncate2");
419 	if (length == 0 &&
420 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) ||
421 	     !LIST_EMPTY(&ovp->v_dirtyblkhd)))
422 		panic("ext2fs_truncate3");
423 #endif /* DIAGNOSTIC */
424 	/*
425 	 * Put back the real size.
426 	 */
427 	(void)ext2fs_setsize(oip, length);
428 	oip->i_e2fs_nblock -= blocksreleased;
429 	oip->i_flag |= IN_CHANGE;
430 	KASSERT(ovp->v_type != VREG || ovp->v_size == ext2fs_size(oip));
431 	return (allerror);
432 }
433 
434 /*
435  * Release blocks associated with the inode ip and stored in the indirect
436  * block bn.  Blocks are free'd in LIFO order up to (but not including)
437  * lastbn.  If level is greater than SINGLE, the block is an indirect block
438  * and recursive calls to indirtrunc must be used to cleanse other indirect
439  * blocks.
440  *
441  * NB: triple indirect blocks are untested.
442  */
443 static int
444 ext2fs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn, daddr_t lastbn,
445 		int level, long *countp)
446 {
447 	int i;
448 	struct buf *bp;
449 	struct m_ext2fs *fs = ip->i_e2fs;
450 	int32_t *bap;	/* XXX ondisk32 */
451 	struct vnode *vp;
452 	daddr_t nb, nlbn, last;
453 	int32_t *copy = NULL;	/* XXX ondisk32 */
454 	long blkcount, factor;
455 	int nblocks, blocksreleased = 0;
456 	int error = 0, allerror = 0;
457 
458 	/*
459 	 * Calculate index in current block of last
460 	 * block to be kept.  -1 indicates the entire
461 	 * block so we need not calculate the index.
462 	 */
463 	factor = 1;
464 	for (i = SINGLE; i < level; i++)
465 		factor *= NINDIR(fs);
466 	last = lastbn;
467 	if (lastbn > 0)
468 		last /= factor;
469 	nblocks = btodb(fs->e2fs_bsize);
470 	/*
471 	 * Get buffer of block pointers, zero those entries corresponding
472 	 * to blocks to be free'd, and update on disk copy first.  Since
473 	 * double(triple) indirect before single(double) indirect, calls
474 	 * to bmap on these blocks will fail.  However, we already have
475 	 * the on disk address, so we have to set the b_blkno field
476 	 * explicitly instead of letting bread do everything for us.
477 	 */
478 	vp = ITOV(ip);
479 	bp = getblk(vp, lbn, (int)fs->e2fs_bsize, 0, 0);
480 	if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
481 		/* Braces must be here in case trace evaluates to nothing. */
482 		trace(TR_BREADHIT, pack(vp, fs->e2fs_bsize), lbn);
483 	} else {
484 		trace(TR_BREADMISS, pack(vp, fs->e2fs_bsize), lbn);
485 		curlwp->l_ru.ru_inblock++;	/* pay for read */
486 		bp->b_flags |= B_READ;
487 		if (bp->b_bcount > bp->b_bufsize)
488 			panic("ext2fs_indirtrunc: bad buffer size");
489 		bp->b_blkno = dbn;
490 		VOP_STRATEGY(vp, bp);
491 		error = biowait(bp);
492 	}
493 	if (error) {
494 		brelse(bp, 0);
495 		*countp = 0;
496 		return (error);
497 	}
498 
499 	bap = (int32_t *)bp->b_data;	/* XXX ondisk32 */
500 	if (lastbn >= 0) {
501 		/* XXX ondisk32 */
502 		copy = malloc(fs->e2fs_bsize, M_TEMP, M_WAITOK);
503 		memcpy((void *)copy, (void *)bap, (u_int)fs->e2fs_bsize);
504 		memset((void *)&bap[last + 1], 0,
505 			(u_int)(NINDIR(fs) - (last + 1)) * sizeof (uint32_t));
506 		error = bwrite(bp);
507 		if (error)
508 			allerror = error;
509 		bap = copy;
510 	}
511 
512 	/*
513 	 * Recursively free totally unused blocks.
514 	 */
515 	for (i = NINDIR(fs) - 1,
516 		nlbn = lbn + 1 - i * factor; i > last;
517 		i--, nlbn += factor) {
518 		/* XXX ondisk32 */
519 		nb = fs2h32(bap[i]);
520 		if (nb == 0)
521 			continue;
522 		if (level > SINGLE) {
523 			error = ext2fs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
524 						   (daddr_t)-1, level - 1,
525 						   &blkcount);
526 			if (error)
527 				allerror = error;
528 			blocksreleased += blkcount;
529 		}
530 		ext2fs_blkfree(ip, nb);
531 		blocksreleased += nblocks;
532 	}
533 
534 	/*
535 	 * Recursively free last partial block.
536 	 */
537 	if (level > SINGLE && lastbn >= 0) {
538 		last = lastbn % factor;
539 		/* XXX ondisk32 */
540 		nb = fs2h32(bap[i]);
541 		if (nb != 0) {
542 			error = ext2fs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
543 						   last, level - 1, &blkcount);
544 			if (error)
545 				allerror = error;
546 			blocksreleased += blkcount;
547 		}
548 	}
549 
550 	if (copy != NULL) {
551 		free(copy, M_TEMP);
552 	} else {
553 		brelse(bp, BC_INVAL);
554 	}
555 
556 	*countp = blocksreleased;
557 	return (allerror);
558 }
559