xref: /freebsd/sys/ufs/ffs/ffs_inode.c (revision 09e8dea79366f1e5b3a73e8a271b26e4b6bf2e6a)
1 /*
2  * Copyright (c) 1982, 1986, 1989, 1993
3  *	The Regents of the University of California.  All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  * 3. All advertising materials mentioning features or use of this software
14  *    must display the following acknowledgement:
15  *	This product includes software developed by the University of
16  *	California, Berkeley and its contributors.
17  * 4. Neither the name of the University nor the names of its contributors
18  *    may be used to endorse or promote products derived from this software
19  *    without specific prior written permission.
20  *
21  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
22  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
23  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
24  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
25  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
26  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
27  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
28  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
29  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
30  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
31  * SUCH DAMAGE.
32  *
33  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
34  * $FreeBSD$
35  */
36 
37 #include "opt_quota.h"
38 
39 #include <sys/param.h>
40 #include <sys/systm.h>
41 #include <sys/mount.h>
42 #include <sys/proc.h>
43 #include <sys/bio.h>
44 #include <sys/buf.h>
45 #include <sys/vnode.h>
46 #include <sys/malloc.h>
47 #include <sys/resourcevar.h>
48 #include <sys/vmmeter.h>
49 #include <sys/stat.h>
50 
51 #include <vm/vm.h>
52 #include <vm/vm_extern.h>
53 
54 #include <ufs/ufs/extattr.h>
55 #include <ufs/ufs/quota.h>
56 #include <ufs/ufs/ufsmount.h>
57 #include <ufs/ufs/inode.h>
58 #include <ufs/ufs/ufs_extern.h>
59 
60 #include <ufs/ffs/fs.h>
61 #include <ufs/ffs/ffs_extern.h>
62 
63 static int ffs_indirtrunc(struct inode *, ufs2_daddr_t, ufs2_daddr_t,
64 	    ufs2_daddr_t, int, ufs2_daddr_t *);
65 
66 /*
67  * Update the access, modified, and inode change times as specified by the
68  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
69  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
70  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
71  * later if not now.  If we write now, then clear both IN_MODIFIED and
72  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
73  * set, then wait for the write to complete.
74  */
75 int
76 ffs_update(vp, waitfor)
77 	struct vnode *vp;
78 	int waitfor;
79 {
80 	struct fs *fs;
81 	struct buf *bp;
82 	struct inode *ip;
83 	int error;
84 
85 	ufs_itimes(vp);
86 	ip = VTOI(vp);
87 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
88 		return (0);
89 	ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
90 	fs = ip->i_fs;
91 	if (fs->fs_ronly)
92 		return (0);
93 	/*
94 	 * Ensure that uid and gid are correct. This is a temporary
95 	 * fix until fsck has been changed to do the update.
96 	 */
97 	if (fs->fs_magic == FS_UFS1_MAGIC &&		/* XXX */
98 	    fs->fs_old_inodefmt < FS_44INODEFMT) {	/* XXX */
99 		ip->i_din1->di_ouid = ip->i_uid;	/* XXX */
100 		ip->i_din1->di_ogid = ip->i_gid;	/* XXX */
101 	}						/* XXX */
102 	error = bread(ip->i_devvp, fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
103 		(int)fs->fs_bsize, NOCRED, &bp);
104 	if (error) {
105 		brelse(bp);
106 		return (error);
107 	}
108 	if (DOINGSOFTDEP(vp))
109 		softdep_update_inodeblock(ip, bp, waitfor);
110 	else if (ip->i_effnlink != ip->i_nlink)
111 		panic("ffs_update: bad link cnt");
112 	if (ip->i_ump->um_fstype == UFS1)
113 		*((struct ufs1_dinode *)bp->b_data +
114 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din1;
115 	else
116 		*((struct ufs2_dinode *)bp->b_data +
117 		    ino_to_fsbo(fs, ip->i_number)) = *ip->i_din2;
118 	if (waitfor && !DOINGASYNC(vp)) {
119 		return (bwrite(bp));
120 	} else if (vm_page_count_severe() || buf_dirty_count_severe()) {
121 		return (bwrite(bp));
122 	} else {
123 		if (bp->b_bufsize == fs->fs_bsize)
124 			bp->b_flags |= B_CLUSTEROK;
125 		bdwrite(bp);
126 		return (0);
127 	}
128 }
129 
130 #define	SINGLE	0	/* index of single indirect block */
131 #define	DOUBLE	1	/* index of double indirect block */
132 #define	TRIPLE	2	/* index of triple indirect block */
133 /*
134  * Truncate the inode oip to at most length size, freeing the
135  * disk blocks.
136  */
137 int
138 ffs_truncate(vp, length, flags, cred, td)
139 	struct vnode *vp;
140 	off_t length;
141 	int flags;
142 	struct ucred *cred;
143 	struct thread *td;
144 {
145 	struct vnode *ovp = vp;
146 	struct inode *oip;
147 	ufs2_daddr_t bn, lbn, lastblock, lastiblock[NIADDR], indir_lbn[NIADDR];
148 	ufs2_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
149 	ufs2_daddr_t count, blocksreleased = 0;
150 	struct fs *fs;
151 	struct buf *bp;
152 	int offset, size, level, nblocks;
153 	int i, aflags, error, allerror;
154 	off_t osize;
155 
156 	oip = VTOI(ovp);
157 	fs = oip->i_fs;
158 	if (length < 0)
159 		return (EINVAL);
160 	if (length > fs->fs_maxfilesize)
161 		return (EFBIG);
162 	if (ovp->v_type == VLNK &&
163 	    (oip->i_size < ovp->v_mount->mnt_maxsymlinklen ||
164 	     DIP(oip, i_blocks) == 0)) {
165 #ifdef DIAGNOSTIC
166 		if (length != 0)
167 			panic("ffs_truncate: partial truncate of symlink");
168 #endif
169 		bzero(SHORTLINK(oip), (u_int)oip->i_size);
170 		oip->i_size = 0;
171 		DIP(oip, i_size) = 0;
172 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
173 		return (UFS_UPDATE(ovp, 1));
174 	}
175 	if (oip->i_size == length) {
176 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
177 		return (UFS_UPDATE(ovp, 0));
178 	}
179 	if (fs->fs_ronly)
180 		panic("ffs_truncate: read-only filesystem");
181 #ifdef QUOTA
182 	error = getinoquota(oip);
183 	if (error)
184 		return (error);
185 #endif
186 	if ((oip->i_flags & SF_SNAPSHOT) != 0)
187 		ffs_snapremove(ovp);
188 	ovp->v_lasta = ovp->v_clen = ovp->v_cstart = ovp->v_lastw = 0;
189 	if (DOINGSOFTDEP(ovp)) {
190 		if (length > 0 || softdep_slowdown(ovp)) {
191 			/*
192 			 * If a file is only partially truncated, then
193 			 * we have to clean up the data structures
194 			 * describing the allocation past the truncation
195 			 * point. Finding and deallocating those structures
196 			 * is a lot of work. Since partial truncation occurs
197 			 * rarely, we solve the problem by syncing the file
198 			 * so that it will have no data structures left.
199 			 */
200 			if ((error = VOP_FSYNC(ovp, cred, MNT_WAIT,
201 			    td)) != 0)
202 				return (error);
203 			if (oip->i_flag & IN_SPACECOUNTED)
204 				fs->fs_pendingblocks -= DIP(oip, i_blocks);
205 		} else {
206 #ifdef QUOTA
207 			(void) chkdq(oip, -DIP(oip, i_blocks), NOCRED, 0);
208 #endif
209 			softdep_setup_freeblocks(oip, length);
210 			vinvalbuf(ovp, 0, cred, td, 0, 0);
211 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
212 			return (ffs_update(ovp, 0));
213 		}
214 	}
215 	osize = oip->i_size;
216 	/*
217 	 * Lengthen the size of the file. We must ensure that the
218 	 * last byte of the file is allocated. Since the smallest
219 	 * value of osize is 0, length will be at least 1.
220 	 */
221 	if (osize < length) {
222 		vnode_pager_setsize(ovp, length);
223 		aflags = BA_CLRBUF;
224 		if (flags & IO_SYNC)
225 			aflags |= BA_SYNC;
226 		error = UFS_BALLOC(ovp, length - 1, 1,
227 		    cred, aflags, &bp);
228 		if (error)
229 			return (error);
230 		oip->i_size = length;
231 		DIP(oip, i_size) = length;
232 		if (bp->b_bufsize == fs->fs_bsize)
233 			bp->b_flags |= B_CLUSTEROK;
234 		if (aflags & BA_SYNC)
235 			bwrite(bp);
236 		else
237 			bawrite(bp);
238 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
239 		return (UFS_UPDATE(ovp, 1));
240 	}
241 	/*
242 	 * Shorten the size of the file. If the file is not being
243 	 * truncated to a block boundary, the contents of the
244 	 * partial block following the end of the file must be
245 	 * zero'ed in case it ever becomes accessible again because
246 	 * of subsequent file growth. Directories however are not
247 	 * zero'ed as they should grow back initialized to empty.
248 	 */
249 	offset = blkoff(fs, length);
250 	if (offset == 0) {
251 		oip->i_size = length;
252 		DIP(oip, i_size) = length;
253 	} else {
254 		lbn = lblkno(fs, length);
255 		aflags = BA_CLRBUF;
256 		if (flags & IO_SYNC)
257 			aflags |= BA_SYNC;
258 		error = UFS_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
259 		if (error) {
260 			return (error);
261 		}
262 		/*
263 		 * When we are doing soft updates and the UFS_BALLOC
264 		 * above fills in a direct block hole with a full sized
265 		 * block that will be truncated down to a fragment below,
266 		 * we must flush out the block dependency with an FSYNC
267 		 * so that we do not get a soft updates inconsistency
268 		 * when we create the fragment below.
269 		 */
270 		if (DOINGSOFTDEP(ovp) && lbn < NDADDR &&
271 		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize &&
272 		    (error = VOP_FSYNC(ovp, cred, MNT_WAIT, td)) != 0)
273 			return (error);
274 		oip->i_size = length;
275 		DIP(oip, i_size) = length;
276 		size = blksize(fs, oip, lbn);
277 		if (ovp->v_type != VDIR)
278 			bzero((char *)bp->b_data + offset,
279 			    (u_int)(size - offset));
280 		/* Kirk's code has reallocbuf(bp, size, 1) here */
281 		allocbuf(bp, size);
282 		if (bp->b_bufsize == fs->fs_bsize)
283 			bp->b_flags |= B_CLUSTEROK;
284 		if (aflags & BA_SYNC)
285 			bwrite(bp);
286 		else
287 			bawrite(bp);
288 	}
289 	/*
290 	 * Calculate index into inode's block list of
291 	 * last direct and indirect blocks (if any)
292 	 * which we want to keep.  Lastblock is -1 when
293 	 * the file is truncated to 0.
294 	 */
295 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
296 	lastiblock[SINGLE] = lastblock - NDADDR;
297 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
298 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
299 	nblocks = btodb(fs->fs_bsize);
300 	/*
301 	 * Update file and block pointers on disk before we start freeing
302 	 * blocks.  If we crash before free'ing blocks below, the blocks
303 	 * will be returned to the free list.  lastiblock values are also
304 	 * normalized to -1 for calls to ffs_indirtrunc below.
305 	 */
306 	for (level = TRIPLE; level >= SINGLE; level--) {
307 		oldblks[NDADDR + level] = DIP(oip, i_ib[level]);
308 		if (lastiblock[level] < 0) {
309 			DIP(oip, i_ib[level]) = 0;
310 			lastiblock[level] = -1;
311 		}
312 	}
313 	for (i = 0; i < NDADDR; i++) {
314 		oldblks[i] = DIP(oip, i_db[i]);
315 		if (i > lastblock)
316 			DIP(oip, i_db[i]) = 0;
317 	}
318 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
319 	allerror = UFS_UPDATE(ovp, 1);
320 
321 	/*
322 	 * Having written the new inode to disk, save its new configuration
323 	 * and put back the old block pointers long enough to process them.
324 	 * Note that we save the new block configuration so we can check it
325 	 * when we are done.
326 	 */
327 	for (i = 0; i < NDADDR; i++) {
328 		newblks[i] = DIP(oip, i_db[i]);
329 		DIP(oip, i_db[i]) = oldblks[i];
330 	}
331 	for (i = 0; i < NIADDR; i++) {
332 		newblks[NDADDR + i] = DIP(oip, i_ib[i]);
333 		DIP(oip, i_ib[i]) = oldblks[NDADDR + i];
334 	}
335 	oip->i_size = osize;
336 	DIP(oip, i_size) = osize;
337 
338 	error = vtruncbuf(ovp, cred, td, length, fs->fs_bsize);
339 	if (error && (allerror == 0))
340 		allerror = error;
341 
342 	/*
343 	 * Indirect blocks first.
344 	 */
345 	indir_lbn[SINGLE] = -NDADDR;
346 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
347 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
348 	for (level = TRIPLE; level >= SINGLE; level--) {
349 		bn = DIP(oip, i_ib[level]);
350 		if (bn != 0) {
351 			error = ffs_indirtrunc(oip, indir_lbn[level],
352 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
353 			if (error)
354 				allerror = error;
355 			blocksreleased += count;
356 			if (lastiblock[level] < 0) {
357 				DIP(oip, i_ib[level]) = 0;
358 				ffs_blkfree(fs, oip->i_devvp, bn, fs->fs_bsize,
359 				    oip->i_number);
360 				blocksreleased += nblocks;
361 			}
362 		}
363 		if (lastiblock[level] >= 0)
364 			goto done;
365 	}
366 
367 	/*
368 	 * All whole direct blocks or frags.
369 	 */
370 	for (i = NDADDR - 1; i > lastblock; i--) {
371 		long bsize;
372 
373 		bn = DIP(oip, i_db[i]);
374 		if (bn == 0)
375 			continue;
376 		DIP(oip, i_db[i]) = 0;
377 		bsize = blksize(fs, oip, i);
378 		ffs_blkfree(fs, oip->i_devvp, bn, bsize, oip->i_number);
379 		blocksreleased += btodb(bsize);
380 	}
381 	if (lastblock < 0)
382 		goto done;
383 
384 	/*
385 	 * Finally, look for a change in size of the
386 	 * last direct block; release any frags.
387 	 */
388 	bn = DIP(oip, i_db[lastblock]);
389 	if (bn != 0) {
390 		long oldspace, newspace;
391 
392 		/*
393 		 * Calculate amount of space we're giving
394 		 * back as old block size minus new block size.
395 		 */
396 		oldspace = blksize(fs, oip, lastblock);
397 		oip->i_size = length;
398 		DIP(oip, i_size) = length;
399 		newspace = blksize(fs, oip, lastblock);
400 		if (newspace == 0)
401 			panic("ffs_truncate: newspace");
402 		if (oldspace - newspace > 0) {
403 			/*
404 			 * Block number of space to be free'd is
405 			 * the old block # plus the number of frags
406 			 * required for the storage we're keeping.
407 			 */
408 			bn += numfrags(fs, newspace);
409 			ffs_blkfree(fs, oip->i_devvp, bn, oldspace - newspace,
410 			    oip->i_number);
411 			blocksreleased += btodb(oldspace - newspace);
412 		}
413 	}
414 done:
415 #ifdef DIAGNOSTIC
416 	for (level = SINGLE; level <= TRIPLE; level++)
417 		if (newblks[NDADDR + level] != DIP(oip, i_ib[level]))
418 			panic("ffs_truncate1");
419 	for (i = 0; i < NDADDR; i++)
420 		if (newblks[i] != DIP(oip, i_db[i]))
421 			panic("ffs_truncate2");
422 	if (length == 0 &&
423 	    (!TAILQ_EMPTY(&ovp->v_dirtyblkhd) ||
424 	     !TAILQ_EMPTY(&ovp->v_cleanblkhd)))
425 		panic("ffs_truncate3");
426 #endif /* DIAGNOSTIC */
427 	/*
428 	 * Put back the real size.
429 	 */
430 	oip->i_size = length;
431 	DIP(oip, i_size) = length;
432 	DIP(oip, i_blocks) -= blocksreleased;
433 
434 	if (DIP(oip, i_blocks) < 0)			/* sanity */
435 		DIP(oip, i_blocks) = 0;
436 	oip->i_flag |= IN_CHANGE;
437 #ifdef QUOTA
438 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
439 #endif
440 	return (allerror);
441 }
442 
443 /*
444  * Release blocks associated with the inode ip and stored in the indirect
445  * block bn.  Blocks are free'd in LIFO order up to (but not including)
446  * lastbn.  If level is greater than SINGLE, the block is an indirect block
447  * and recursive calls to indirtrunc must be used to cleanse other indirect
448  * blocks.
449  */
450 static int
451 ffs_indirtrunc(ip, lbn, dbn, lastbn, level, countp)
452 	struct inode *ip;
453 	ufs2_daddr_t lbn, lastbn;
454 	ufs2_daddr_t dbn;
455 	int level;
456 	ufs2_daddr_t *countp;
457 {
458 	struct buf *bp;
459 	struct fs *fs = ip->i_fs;
460 	struct vnode *vp;
461 	caddr_t copy = NULL;
462 	int i, nblocks, error = 0, allerror = 0;
463 	ufs2_daddr_t nb, nlbn, last;
464 	ufs2_daddr_t blkcount, factor, blocksreleased = 0;
465 	ufs1_daddr_t *bap1 = NULL;
466 	ufs2_daddr_t *bap2 = NULL;
467 #	define BAP(ip, i) (((ip)->i_ump->um_fstype == UFS1) ? bap1[i] : bap2[i])
468 
469 	/*
470 	 * Calculate index in current block of last
471 	 * block to be kept.  -1 indicates the entire
472 	 * block so we need not calculate the index.
473 	 */
474 	factor = 1;
475 	for (i = SINGLE; i < level; i++)
476 		factor *= NINDIR(fs);
477 	last = lastbn;
478 	if (lastbn > 0)
479 		last /= factor;
480 	nblocks = btodb(fs->fs_bsize);
481 	/*
482 	 * Get buffer of block pointers, zero those entries corresponding
483 	 * to blocks to be free'd, and update on disk copy first.  Since
484 	 * double(triple) indirect before single(double) indirect, calls
485 	 * to bmap on these blocks will fail.  However, we already have
486 	 * the on disk address, so we have to set the b_blkno field
487 	 * explicitly instead of letting bread do everything for us.
488 	 */
489 	vp = ITOV(ip);
490 	bp = getblk(vp, lbn, (int)fs->fs_bsize, 0, 0);
491 	if ((bp->b_flags & B_CACHE) == 0) {
492 		curproc->p_stats->p_ru.ru_inblock++;	/* pay for read */
493 		bp->b_iocmd = BIO_READ;
494 		bp->b_flags &= ~B_INVAL;
495 		bp->b_ioflags &= ~BIO_ERROR;
496 		if (bp->b_bcount > bp->b_bufsize)
497 			panic("ffs_indirtrunc: bad buffer size");
498 		bp->b_blkno = dbn;
499 		vfs_busy_pages(bp, 0);
500 		BUF_STRATEGY(bp);
501 		error = bufwait(bp);
502 	}
503 	if (error) {
504 		brelse(bp);
505 		*countp = 0;
506 		return (error);
507 	}
508 
509 	if (ip->i_ump->um_fstype == UFS1)
510 		bap1 = (ufs1_daddr_t *)bp->b_data;
511 	else
512 		bap2 = (ufs2_daddr_t *)bp->b_data;
513 	if (lastbn != -1) {
514 		MALLOC(copy, caddr_t, fs->fs_bsize, M_TEMP, M_WAITOK);
515 		bcopy((caddr_t)bp->b_data, copy, (u_int)fs->fs_bsize);
516 		for (i = last + 1; i < NINDIR(fs); i++)
517 			BAP(ip, i) = 0;
518 		if (DOINGASYNC(vp)) {
519 			bawrite(bp);
520 		} else {
521 			error = bwrite(bp);
522 			if (error)
523 				allerror = error;
524 		}
525 		if (ip->i_ump->um_fstype == UFS1)
526 			bap1 = (ufs1_daddr_t *)copy;
527 		else
528 			bap2 = (ufs2_daddr_t *)copy;
529 	}
530 
531 	/*
532 	 * Recursively free totally unused blocks.
533 	 */
534 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
535 	    i--, nlbn += factor) {
536 		nb = BAP(ip, i);
537 		if (nb == 0)
538 			continue;
539 		if (level > SINGLE) {
540 			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
541 			    (ufs2_daddr_t)-1, level - 1, &blkcount)) != 0)
542 				allerror = error;
543 			blocksreleased += blkcount;
544 		}
545 		ffs_blkfree(fs, ip->i_devvp, nb, fs->fs_bsize, ip->i_number);
546 		blocksreleased += nblocks;
547 	}
548 
549 	/*
550 	 * Recursively free last partial block.
551 	 */
552 	if (level > SINGLE && lastbn >= 0) {
553 		last = lastbn % factor;
554 		nb = BAP(ip, i);
555 		if (nb != 0) {
556 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
557 			    last, level - 1, &blkcount);
558 			if (error)
559 				allerror = error;
560 			blocksreleased += blkcount;
561 		}
562 	}
563 	if (copy != NULL) {
564 		FREE(copy, M_TEMP);
565 	} else {
566 		bp->b_flags |= B_INVAL | B_NOCACHE;
567 		brelse(bp);
568 	}
569 
570 	*countp = blocksreleased;
571 	return (allerror);
572 }
573