xref: /dragonfly/sys/vfs/ufs/ffs_inode.c (revision c8860c9a)
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. Neither the name of the University nor the names of its contributors
14  *    may be used to endorse or promote products derived from this software
15  *    without specific prior written permission.
16  *
17  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
18  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
19  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
20  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
21  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
22  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
23  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
24  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
25  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
26  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
27  * SUCH DAMAGE.
28  *
29  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
30  * $FreeBSD: src/sys/ufs/ffs/ffs_inode.c,v 1.56.2.5 2002/02/05 18:35:03 dillon Exp $
31  */
32 
33 #include "opt_quota.h"
34 
35 #include <sys/param.h>
36 #include <sys/systm.h>
37 #include <sys/mount.h>
38 #include <sys/proc.h>
39 #include <sys/buf.h>
40 #include <sys/vnode.h>
41 #include <sys/kernel.h>
42 #include <sys/malloc.h>
43 #include <sys/resourcevar.h>
44 #include <sys/vmmeter.h>
45 
46 #include <vm/vm.h>
47 #include <vm/vm_extern.h>
48 
49 #include "quota.h"
50 #include "ufsmount.h"
51 #include "inode.h"
52 #include "ufs_extern.h"
53 
54 #include "fs.h"
55 #include "ffs_extern.h"
56 
57 #include <vm/vm_page2.h>
58 #include <sys/buf2.h>
59 
60 static int ffs_indirtrunc (struct inode *, ufs_daddr_t, ufs_daddr_t,
61 	    ufs_daddr_t, int, long *);
62 
63 /*
64  * Update the access, modified, and inode change times as specified by the
65  * IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.  Write the inode
66  * to disk if the IN_MODIFIED flag is set (it may be set initially, or by
67  * the timestamp update).  The IN_LAZYMOD flag is set to force a write
68  * later if not now.  If we write now, then clear both IN_MODIFIED and
69  * IN_LAZYMOD to reflect the presumably successful write, and if waitfor is
70  * set, then wait for the write to complete.
71  */
72 int
73 ffs_update(struct vnode *vp, int waitfor)
74 {
75 	struct fs *fs;
76 	struct buf *bp;
77 	struct inode *ip;
78 	int error;
79 
80 	ufs_itimes(vp);
81 	ip = VTOI(vp);
82 	if ((ip->i_flag & IN_MODIFIED) == 0 && waitfor == 0)
83 		return (0);
84 	ip->i_flag &= ~(IN_LAZYMOD | IN_MODIFIED);
85 	fs = ip->i_fs;
86 	if (fs->fs_ronly)
87 		return (0);
88 
89 	/*
90 	 * The vnode type is usually set to VBAD if an unrecoverable I/O
91 	 * error has occured (such as when reading the inode).  Clear the
92 	 * modified bits but do not write anything out in this case.
93 	 */
94 	if (vp->v_type == VBAD)
95 		return (0);
96 	/*
97 	 * Ensure that uid and gid are correct. This is a temporary
98 	 * fix until fsck has been changed to do the update.
99 	 */
100 	if (fs->fs_inodefmt < FS_44INODEFMT) {		/* XXX */
101 		ip->i_din.di_ouid = ip->i_uid;		/* XXX */
102 		ip->i_din.di_ogid = ip->i_gid;		/* XXX */
103 	}						/* XXX */
104 	error = bread(ip->i_devvp,
105 		      fsbtodoff(fs, ino_to_fsba(fs, ip->i_number)),
106 		      (int)fs->fs_bsize, &bp);
107 	if (error) {
108 		brelse(bp);
109 		return (error);
110 	}
111 	if (DOINGSOFTDEP(vp))
112 		softdep_update_inodeblock(ip, bp, waitfor);
113 	else if (ip->i_effnlink != ip->i_nlink)
114 		panic("ffs_update: bad link cnt");
115 	*((struct ufs1_dinode *)bp->b_data +
116 	    ino_to_fsbo(fs, ip->i_number)) = ip->i_din;
117 	if (waitfor && !DOINGASYNC(vp)) {
118 		return (bwrite(bp));
119 	} else if (vm_paging_severe() || buf_dirty_count_severe()) {
120 		return (bwrite(bp));
121 	} else {
122 		if (bp->b_bufsize == fs->fs_bsize)
123 			bp->b_flags |= B_CLUSTEROK;
124 		bdwrite(bp);
125 		return (0);
126 	}
127 }
128 
129 #define	SINGLE	0	/* index of single indirect block */
130 #define	DOUBLE	1	/* index of double indirect block */
131 #define	TRIPLE	2	/* index of triple indirect block */
132 /*
133  * Truncate the inode oip to at most length size, freeing the
134  * disk blocks.
135  */
136 int
137 ffs_truncate(struct vnode *vp, off_t length, int flags, struct ucred *cred)
138 {
139 	struct vnode *ovp = vp;
140 	ufs_daddr_t lastblock;
141 	struct inode *oip;
142 	ufs_daddr_t bn, lbn, lastiblock[UFS_NIADDR], indir_lbn[UFS_NIADDR];
143 	ufs_daddr_t oldblks[UFS_NDADDR + UFS_NIADDR];
144 	ufs_daddr_t newblks[UFS_NDADDR + UFS_NIADDR];
145 	struct fs *fs;
146 	struct buf *bp;
147 	int offset, size, level;
148 	long count, nblocks, blocksreleased = 0;
149 	int i;
150 	int aflags, error, allerror;
151 	off_t osize;
152 
153 	oip = VTOI(ovp);
154 	fs = oip->i_fs;
155 	if (length < 0)
156 		return (EINVAL);
157 	if (length > fs->fs_maxfilesize)
158 		return (EFBIG);
159 	if (ovp->v_type == VLNK &&
160 	    (oip->i_size < ovp->v_mount->mnt_maxsymlinklen || oip->i_din.di_blocks == 0)) {
161 #ifdef DIAGNOSTIC
162 		if (length != 0)
163 			panic("ffs_truncate: partial truncate of symlink");
164 #endif /* DIAGNOSTIC */
165 		bzero((char *)&oip->i_shortlink, (uint)oip->i_size);
166 		oip->i_size = 0;
167 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
168 		return (ffs_update(ovp, 1));
169 	}
170 	if (oip->i_size == length) {
171 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
172 		return (ffs_update(ovp, 0));
173 	}
174 	if (fs->fs_ronly)
175 		panic("ffs_truncate: read-only filesystem");
176 #ifdef QUOTA
177 	error = ufs_getinoquota(oip);
178 	if (error)
179 		return (error);
180 #endif
181 	if (DOINGSOFTDEP(ovp)) {
182 		if (length > 0 || softdep_slowdown(ovp)) {
183 			/*
184 			 * If a file is only partially truncated, then
185 			 * we have to clean up the data structures
186 			 * describing the allocation past the truncation
187 			 * point. Finding and deallocating those structures
188 			 * is a lot of work. Since partial truncation occurs
189 			 * rarely, we solve the problem by syncing the file
190 			 * so that it will have no data structures left.
191 			 */
192 			if ((error = VOP_FSYNC(ovp, MNT_WAIT, 0)) != 0)
193 				return (error);
194 		} else {
195 #ifdef QUOTA
196 			(void) ufs_chkdq(oip, -oip->i_blocks, NOCRED, 0);
197 #endif
198 			softdep_setup_freeblocks(oip, length);
199 			vinvalbuf(ovp, 0, 0, 0);
200 			nvnode_pager_setsize(ovp, 0, fs->fs_bsize, 0);
201 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
202 			return (ffs_update(ovp, 0));
203 		}
204 	}
205 	osize = oip->i_size;
206 
207 	/*
208 	 * Lengthen the size of the file. We must ensure that the
209 	 * last byte of the file is allocated. Since the smallest
210 	 * value of osize is 0, length will be at least 1.
211 	 *
212 	 * nvextendbuf() only breads the old buffer.  The blocksize
213 	 * of the new buffer must be specified so it knows how large
214 	 * to make the VM object.
215 	 */
216 	if (osize < length) {
217 		nvextendbuf(vp, osize, length,
218 			    blkoffsize(fs, oip, osize),	/* oblksize */
219 			    blkoffresize(fs, length),	/* nblksize */
220 			    blkoff(fs, osize),
221 			    blkoff(fs, length),
222 			    0);
223 
224 		aflags = B_CLRBUF;
225 		if (flags & IO_SYNC)
226 			aflags |= B_SYNC;
227 		/* BALLOC will reallocate the fragment at the old EOF */
228 		error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
229 		if (error)
230 			return (error);
231 		oip->i_size = length;
232 		if (bp->b_bufsize == fs->fs_bsize)
233 			bp->b_flags |= B_CLUSTEROK;
234 		if (aflags & B_SYNC)
235 			bwrite(bp);
236 		else
237 			bawrite(bp);
238 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
239 		return (ffs_update(ovp, 1));
240 	}
241 
242 	/*
243 	 * Shorten the size of the file.
244 	 *
245 	 * NOTE: The block size specified in nvtruncbuf() is the blocksize
246 	 *	 of the buffer containing length prior to any reallocation
247 	 *	 of the block.
248 	 */
249 	allerror = nvtruncbuf(ovp, length, blkoffsize(fs, oip, length),
250 			      blkoff(fs, length), 0);
251 	offset = blkoff(fs, length);
252 	if (offset == 0) {
253 		oip->i_size = length;
254 	} else {
255 		lbn = lblkno(fs, length);
256 		aflags = B_CLRBUF;
257 		if (flags & IO_SYNC)
258 			aflags |= B_SYNC;
259 		error = VOP_BALLOC(ovp, length - 1, 1, cred, aflags, &bp);
260 		if (error)
261 			return (error);
262 
263 		/*
264 		 * When we are doing soft updates and the UFS_BALLOC
265 		 * above fills in a direct block hole with a full sized
266 		 * block that will be truncated down to a fragment below,
267 		 * we must flush out the block dependency with an FSYNC
268 		 * so that we do not get a soft updates inconsistency
269 		 * when we create the fragment below.
270 		 *
271 		 * nvtruncbuf() may have re-dirtied the underlying block
272 		 * as part of its truncation zeroing code.  To avoid a
273 		 * 'locking against myself' panic in the second fsync we
274 		 * can simply undirty the bp since the redirtying was
275 		 * related to areas of the buffer that we are going to
276 		 * throw away anyway, and we will b*write() the remainder
277 		 * anyway down below.
278 		 */
279 		if (DOINGSOFTDEP(ovp) && lbn < UFS_NDADDR &&
280 		    fragroundup(fs, blkoff(fs, length)) < fs->fs_bsize) {
281 			bundirty(bp);
282 			error = VOP_FSYNC(ovp, MNT_WAIT, 0);
283 			if (error) {
284 				bdwrite(bp);
285 				return (error);
286 			}
287 		}
288 		oip->i_size = length;
289 		size = blksize(fs, oip, lbn);
290 #if 0
291 		/* remove - nvtruncbuf deals with this */
292 		if (ovp->v_type != VDIR)
293 			bzero((char *)bp->b_data + offset,
294 			    (uint)(size - offset));
295 #endif
296 		/* Kirk's code has reallocbuf(bp, size, 1) here */
297 		allocbuf(bp, size);
298 		if (bp->b_bufsize == fs->fs_bsize)
299 			bp->b_flags |= B_CLUSTEROK;
300 		if (aflags & B_SYNC)
301 			bwrite(bp);
302 		else
303 			bawrite(bp);
304 	}
305 	/*
306 	 * Calculate index into inode's block list of
307 	 * last direct and indirect blocks (if any)
308 	 * which we want to keep.  Lastblock is -1 when
309 	 * the file is truncated to 0.
310 	 */
311 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
312 	lastiblock[SINGLE] = lastblock - UFS_NDADDR;
313 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
314 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
315 	nblocks = btodb(fs->fs_bsize);
316 
317 	/*
318 	 * Update file and block pointers on disk before we start freeing
319 	 * blocks.  If we crash before free'ing blocks below, the blocks
320 	 * will be returned to the free list.  lastiblock values are also
321 	 * normalized to -1 for calls to ffs_indirtrunc below.
322 	 */
323 	for (level = TRIPLE; level >= SINGLE; level--) {
324 		oldblks[UFS_NDADDR + level] = oip->i_ib[level];
325 		if (lastiblock[level] < 0) {
326 			oip->i_ib[level] = 0;
327 			lastiblock[level] = -1;
328 		}
329 	}
330 	for (i = 0; i < UFS_NDADDR; i++) {
331 		oldblks[i] = oip->i_db[i];
332 		if (i > lastblock)
333 			oip->i_db[i] = 0;
334 	}
335 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
336 	error = ffs_update(ovp, 1);
337 	if (error && allerror == 0)
338 		allerror = error;
339 
340 	/*
341 	 * Having written the new inode to disk, save its new configuration
342 	 * and put back the old block pointers long enough to process them.
343 	 * Note that we save the new block configuration so we can check it
344 	 * when we are done.
345 	 */
346 	for (i = 0; i < UFS_NDADDR; i++) {
347 		newblks[i] = oip->i_db[i];
348 		oip->i_db[i] = oldblks[i];
349 	}
350 	for (i = 0; i < UFS_NIADDR; i++) {
351 		newblks[UFS_NDADDR + i] = oip->i_ib[i];
352 		oip->i_ib[i] = oldblks[UFS_NDADDR + i];
353 	}
354 	oip->i_size = osize;
355 
356 	if (error && allerror == 0)
357 		allerror = error;
358 
359 	/*
360 	 * Indirect blocks first.
361 	 */
362 	indir_lbn[SINGLE] = -UFS_NDADDR;
363 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
364 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
365 	for (level = TRIPLE; level >= SINGLE; level--) {
366 		bn = oip->i_ib[level];
367 		if (bn != 0) {
368 			error = ffs_indirtrunc(oip, indir_lbn[level],
369 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
370 			if (error)
371 				allerror = error;
372 			blocksreleased += count;
373 			if (lastiblock[level] < 0) {
374 				oip->i_ib[level] = 0;
375 				ffs_blkfree(oip, bn, fs->fs_bsize);
376 				blocksreleased += nblocks;
377 			}
378 		}
379 		if (lastiblock[level] >= 0)
380 			goto done;
381 	}
382 
383 	/*
384 	 * All whole direct blocks or frags.
385 	 */
386 	for (i = UFS_NDADDR - 1; i > lastblock; i--) {
387 		long bsize;
388 
389 		bn = oip->i_db[i];
390 		if (bn == 0)
391 			continue;
392 		oip->i_db[i] = 0;
393 		bsize = blksize(fs, oip, i);
394 		ffs_blkfree(oip, bn, bsize);
395 		blocksreleased += btodb(bsize);
396 	}
397 	if (lastblock < 0)
398 		goto done;
399 
400 	/*
401 	 * Finally, look for a change in size of the
402 	 * last direct block; release any frags.
403 	 */
404 	bn = oip->i_db[lastblock];
405 	if (bn != 0) {
406 		long oldspace, newspace;
407 
408 		/*
409 		 * Calculate amount of space we're giving
410 		 * back as old block size minus new block size.
411 		 */
412 		oldspace = blksize(fs, oip, lastblock);
413 		oip->i_size = length;
414 		newspace = blksize(fs, oip, lastblock);
415 		if (newspace == 0)
416 			panic("ffs_truncate: newspace");
417 		if (oldspace - newspace > 0) {
418 			/*
419 			 * Block number of space to be free'd is
420 			 * the old block # plus the number of frags
421 			 * required for the storage we're keeping.
422 			 */
423 			bn += numfrags(fs, newspace);
424 			ffs_blkfree(oip, bn, oldspace - newspace);
425 			blocksreleased += btodb(oldspace - newspace);
426 		}
427 	}
428 done:
429 #ifdef DIAGNOSTIC
430 	for (level = SINGLE; level <= TRIPLE; level++)
431 		if (newblks[UFS_NDADDR + level] != oip->i_ib[level])
432 			panic("ffs_truncate1");
433 	for (i = 0; i < UFS_NDADDR; i++)
434 		if (newblks[i] != oip->i_db[i])
435 			panic("ffs_truncate2");
436 	if (length == 0 && !RB_EMPTY(&ovp->v_rbdirty_tree))
437 		panic("ffs_truncate3");
438 #endif /* DIAGNOSTIC */
439 	/*
440 	 * Put back the real size.
441 	 */
442 	oip->i_size = length;
443 	oip->i_blocks -= blocksreleased;
444 
445 	if (oip->i_blocks < 0)			/* sanity */
446 		oip->i_blocks = 0;
447 	oip->i_flag |= IN_CHANGE;
448 #ifdef QUOTA
449 	(void) ufs_chkdq(oip, -blocksreleased, NOCRED, 0);
450 #endif
451 	return (allerror);
452 }
453 
454 /*
455  * Release blocks associated with the inode ip and stored in the indirect
456  * block bn.  Blocks are free'd in LIFO order up to (but not including)
457  * lastbn.  If level is greater than SINGLE, the block is an indirect block
458  * and recursive calls to indirtrunc must be used to cleanse other indirect
459  * blocks.
460  *
461  * NB: triple indirect blocks are untested.
462  */
463 static int
464 ffs_indirtrunc(struct inode *ip, ufs_daddr_t lbn, ufs_daddr_t dbn,
465 	       ufs_daddr_t lastbn, int level, long *countp)
466 {
467 	int i;
468 	struct buf *bp;
469 	struct fs *fs = ip->i_fs;
470 	ufs_daddr_t *bap;
471 	struct vnode *vp;
472 	ufs_daddr_t *copy = NULL, nb, nlbn, last;
473 	long blkcount, factor;
474 	int nblocks, blocksreleased = 0;
475 	int error = 0, allerror = 0;
476 
477 	/*
478 	 * Calculate index in current block of last
479 	 * block to be kept.  -1 indicates the entire
480 	 * block so we need not calculate the index.
481 	 */
482 	factor = 1;
483 	for (i = SINGLE; i < level; i++)
484 		factor *= NINDIR(fs);
485 	last = lastbn;
486 	if (lastbn > 0)
487 		last /= factor;
488 	nblocks = btodb(fs->fs_bsize);
489 	/*
490 	 * Get buffer of block pointers, zero those entries corresponding
491 	 * to blocks to be free'd, and update on disk copy first.  Since
492 	 * double(triple) indirect before single(double) indirect, calls
493 	 * to bmap on these blocks will fail.  However, we already have
494 	 * the on disk address, so we have to set the bio_offset field
495 	 * explicitly instead of letting bread do everything for us.
496 	 */
497 	vp = ITOV(ip);
498 	bp = getblk(vp, lblktodoff(fs, lbn), (int)fs->fs_bsize, 0, 0);
499 	if ((bp->b_flags & B_CACHE) == 0) {
500 		bp->b_flags &= ~(B_ERROR|B_INVAL);
501 		bp->b_cmd = BUF_CMD_READ;
502 		if (bp->b_bcount > bp->b_bufsize)
503 			panic("ffs_indirtrunc: bad buffer size");
504 		/*
505 		 * BIO is bio2 which chains back to bio1.  We wait
506 		 * on bio1.
507 		 */
508 		bp->b_bio2.bio_offset = dbtodoff(fs, dbn);
509 		bp->b_bio1.bio_done = biodone_sync;
510 		bp->b_bio1.bio_flags |= BIO_SYNC;
511 		vfs_busy_pages(vp, bp);
512 		/*
513 		 * Access the block device layer using the device vnode
514 		 * and the translated block number (bio2) instead of the
515 		 * file vnode (vp) and logical block number (bio1).
516 		 *
517 		 * Even though we are bypassing the vnode layer, we still
518 		 * want the vnode state to indicate that an I/O on its behalf
519 		 * is in progress.
520 		 */
521 		bio_start_transaction(&bp->b_bio1, &vp->v_track_read);
522 		vn_strategy(ip->i_devvp, &bp->b_bio2);
523 		error = biowait(&bp->b_bio1, "biord");
524 	}
525 	if (error) {
526 		brelse(bp);
527 		*countp = 0;
528 		return (error);
529 	}
530 
531 	bap = (ufs_daddr_t *)bp->b_data;
532 	if (lastbn != -1) {
533 		copy = kmalloc(fs->fs_bsize, M_TEMP, M_WAITOK);
534 		bcopy((caddr_t)bap, (caddr_t)copy, (uint)fs->fs_bsize);
535 		bzero((caddr_t)&bap[last + 1],
536 		    (uint)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
537 		if (DOINGASYNC(vp)) {
538 			bawrite(bp);
539 		} else {
540 			error = bwrite(bp);
541 			if (error)
542 				allerror = error;
543 		}
544 		bap = copy;
545 	}
546 
547 	/*
548 	 * Recursively free totally unused blocks.
549 	 */
550 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
551 	    i--, nlbn += factor) {
552 		nb = bap[i];
553 		if (nb == 0)
554 			continue;
555 		if (level > SINGLE) {
556 			if ((error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
557 			    (ufs_daddr_t)-1, level - 1, &blkcount)) != 0)
558 				allerror = error;
559 			blocksreleased += blkcount;
560 		}
561 		ffs_blkfree(ip, nb, fs->fs_bsize);
562 		blocksreleased += nblocks;
563 	}
564 
565 	/*
566 	 * Recursively free last partial block.
567 	 */
568 	if (level > SINGLE && lastbn >= 0) {
569 		last = lastbn % factor;
570 		nb = bap[i];
571 		if (nb != 0) {
572 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
573 			    last, level - 1, &blkcount);
574 			if (error)
575 				allerror = error;
576 			blocksreleased += blkcount;
577 		}
578 	}
579 	if (copy != NULL) {
580 		kfree(copy, M_TEMP);
581 	} else {
582 		bp->b_flags |= B_INVAL | B_NOCACHE;
583 		brelse(bp);
584 	}
585 
586 	*countp = blocksreleased;
587 	return (allerror);
588 }
589