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ffs_inode.c revision 1.48
      1 /*	$NetBSD: ffs_inode.c,v 1.48 2001/11/08 05:24:52 chs 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. All advertising materials mentioning features or use of this software
     16  *    must display the following acknowledgement:
     17  *	This product includes software developed by the University of
     18  *	California, Berkeley and its contributors.
     19  * 4. Neither the name of the University nor the names of its contributors
     20  *    may be used to endorse or promote products derived from this software
     21  *    without specific prior written permission.
     22  *
     23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     33  * SUCH DAMAGE.
     34  *
     35  *	@(#)ffs_inode.c	8.13 (Berkeley) 4/21/95
     36  */
     37 
     38 #include <sys/cdefs.h>
     39 __KERNEL_RCSID(0, "$NetBSD: ffs_inode.c,v 1.48 2001/11/08 05:24:52 chs Exp $");
     40 
     41 #if defined(_KERNEL_OPT)
     42 #include "opt_ffs.h"
     43 #include "opt_quota.h"
     44 #endif
     45 
     46 #include <sys/param.h>
     47 #include <sys/systm.h>
     48 #include <sys/mount.h>
     49 #include <sys/proc.h>
     50 #include <sys/file.h>
     51 #include <sys/buf.h>
     52 #include <sys/vnode.h>
     53 #include <sys/kernel.h>
     54 #include <sys/malloc.h>
     55 #include <sys/trace.h>
     56 #include <sys/resourcevar.h>
     57 
     58 #include <ufs/ufs/quota.h>
     59 #include <ufs/ufs/inode.h>
     60 #include <ufs/ufs/ufsmount.h>
     61 #include <ufs/ufs/ufs_extern.h>
     62 #include <ufs/ufs/ufs_bswap.h>
     63 
     64 #include <ufs/ffs/fs.h>
     65 #include <ufs/ffs/ffs_extern.h>
     66 
     67 static int ffs_indirtrunc __P((struct inode *, ufs_daddr_t, ufs_daddr_t,
     68 			       ufs_daddr_t, int, long *));
     69 
     70 /*
     71  * Update the access, modified, and inode change times as specified
     72  * by the IN_ACCESS, IN_UPDATE, and IN_CHANGE flags respectively.
     73  * The IN_MODIFIED flag is used to specify that the inode needs to be
     74  * updated but that the times have already been set. The access
     75  * and modified times are taken from the second and third parameters;
     76  * the inode change time is always taken from the current time. If
     77  * UPDATE_WAIT flag is set, or UPDATE_DIROP is set and we are not doing
     78  * softupdates, then wait for the disk write of the inode to complete.
     79  */
     80 
     81 int
     82 ffs_update(v)
     83 	void *v;
     84 {
     85 	struct vop_update_args /* {
     86 		struct vnode *a_vp;
     87 		struct timespec *a_access;
     88 		struct timespec *a_modify;
     89 		int a_flags;
     90 	} */ *ap = v;
     91 	struct fs *fs;
     92 	struct buf *bp;
     93 	struct inode *ip;
     94 	int error;
     95 	struct timespec ts;
     96 	caddr_t cp;
     97 	int waitfor, flags;
     98 
     99 	if (ap->a_vp->v_mount->mnt_flag & MNT_RDONLY)
    100 		return (0);
    101 	ip = VTOI(ap->a_vp);
    102 	TIMEVAL_TO_TIMESPEC(&time, &ts);
    103 	FFS_ITIMES(ip,
    104 	    ap->a_access ? ap->a_access : &ts,
    105 	    ap->a_modify ? ap->a_modify : &ts, &ts);
    106 	flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED);
    107 	if (flags == 0)
    108 		return (0);
    109 	fs = ip->i_fs;
    110 
    111 	if ((flags & IN_MODIFIED) != 0 &&
    112 	    (ap->a_vp->v_mount->mnt_flag & MNT_ASYNC) == 0) {
    113 		waitfor = ap->a_flags & UPDATE_WAIT;
    114 		if ((ap->a_flags & UPDATE_DIROP) && !DOINGSOFTDEP(ap->a_vp))
    115 			waitfor |= UPDATE_WAIT;
    116 	} else
    117 		waitfor = 0;
    118 
    119 	/*
    120 	 * Ensure that uid and gid are correct. This is a temporary
    121 	 * fix until fsck has been changed to do the update.
    122 	 */
    123 	if (fs->fs_inodefmt < FS_44INODEFMT) {			/* XXX */
    124 		ip->i_din.ffs_din.di_ouid = ip->i_ffs_uid;	/* XXX */
    125 		ip->i_din.ffs_din.di_ogid = ip->i_ffs_gid;	/* XXX */
    126 	}							/* XXX */
    127 	error = bread(ip->i_devvp,
    128 		      fsbtodb(fs, ino_to_fsba(fs, ip->i_number)),
    129 		      (int)fs->fs_bsize, NOCRED, &bp);
    130 	if (error) {
    131 		brelse(bp);
    132 		return (error);
    133 	}
    134 	ip->i_flag &= ~(IN_MODIFIED | IN_ACCESSED);
    135 	if (DOINGSOFTDEP(ap->a_vp))
    136 		softdep_update_inodeblock(ip, bp, waitfor);
    137 	else if (ip->i_ffs_effnlink != ip->i_ffs_nlink)
    138 		panic("ffs_update: bad link cnt");
    139 	cp = (caddr_t)bp->b_data +
    140 	    (ino_to_fsbo(fs, ip->i_number) * DINODE_SIZE);
    141 #ifdef FFS_EI
    142 	if (UFS_FSNEEDSWAP(fs))
    143 		ffs_dinode_swap(&ip->i_din.ffs_din, (struct dinode *)cp);
    144 	else
    145 #endif
    146 		memcpy(cp, &ip->i_din.ffs_din, DINODE_SIZE);
    147 	if (waitfor) {
    148 		return (bwrite(bp));
    149 	} else {
    150 		bdwrite(bp);
    151 		return (0);
    152 	}
    153 }
    154 
    155 #define	SINGLE	0	/* index of single indirect block */
    156 #define	DOUBLE	1	/* index of double indirect block */
    157 #define	TRIPLE	2	/* index of triple indirect block */
    158 /*
    159  * Truncate the inode oip to at most length size, freeing the
    160  * disk blocks.
    161  */
    162 int
    163 ffs_truncate(v)
    164 	void *v;
    165 {
    166 	struct vop_truncate_args /* {
    167 		struct vnode *a_vp;
    168 		off_t a_length;
    169 		int a_flags;
    170 		struct ucred *a_cred;
    171 		struct proc *a_p;
    172 	} */ *ap = v;
    173 	struct vnode *ovp = ap->a_vp;
    174 	struct genfs_node *gp = VTOG(ovp);
    175 	ufs_daddr_t lastblock;
    176 	struct inode *oip;
    177 	ufs_daddr_t bn, lastiblock[NIADDR], indir_lbn[NIADDR];
    178 	ufs_daddr_t oldblks[NDADDR + NIADDR], newblks[NDADDR + NIADDR];
    179 	off_t length = ap->a_length;
    180 	struct fs *fs;
    181 	int offset, size, level;
    182 	long count, nblocks, blocksreleased = 0;
    183 	int i, ioflag, aflag;
    184 	int error, allerror = 0;
    185 	off_t osize;
    186 
    187 	if (length < 0)
    188 		return (EINVAL);
    189 	oip = VTOI(ovp);
    190 	if (ovp->v_type == VLNK &&
    191 	    (oip->i_ffs_size < ovp->v_mount->mnt_maxsymlinklen ||
    192 	     (ovp->v_mount->mnt_maxsymlinklen == 0 &&
    193 	      oip->i_din.ffs_din.di_blocks == 0))) {
    194 		KDASSERT(length == 0);
    195 		memset(&oip->i_ffs_shortlink, 0, (size_t)oip->i_ffs_size);
    196 		oip->i_ffs_size = 0;
    197 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    198 		return (VOP_UPDATE(ovp, NULL, NULL, UPDATE_WAIT));
    199 	}
    200 	if (oip->i_ffs_size == length) {
    201 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    202 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    203 	}
    204 #ifdef QUOTA
    205 	if ((error = getinoquota(oip)) != 0)
    206 		return (error);
    207 #endif
    208 	fs = oip->i_fs;
    209 	if (length > fs->fs_maxfilesize)
    210 		return (EFBIG);
    211 
    212 	osize = oip->i_ffs_size;
    213 	ioflag = ap->a_flags;
    214 
    215 	/*
    216 	 * Lengthen the size of the file. We must ensure that the
    217 	 * last byte of the file is allocated. Since the smallest
    218 	 * value of osize is 0, length will be at least 1.
    219 	 */
    220 
    221 	if (osize < length) {
    222 		aflag = ioflag & IO_SYNC ? B_SYNC : 0;
    223 		if (lblkno(fs, osize) < NDADDR &&
    224 		    lblkno(fs, osize) != lblkno(fs, length) &&
    225 		    blkroundup(fs, osize) != osize) {
    226 			error = ufs_balloc_range(ovp, osize,
    227 			    blkroundup(fs, osize) - osize, ap->a_cred, aflag);
    228 			if (error) {
    229 				return error;
    230 			}
    231 			if (ioflag & IO_SYNC) {
    232 				ovp->v_size = blkroundup(fs, osize);
    233 				simple_lock(&ovp->v_interlock);
    234 				VOP_PUTPAGES(ovp, osize & ~(fs->fs_bsize - 1),
    235 				    round_page(ovp->v_size),
    236 				    PGO_CLEANIT | PGO_SYNCIO);
    237 			}
    238 		}
    239 		error = ufs_balloc_range(ovp, length - 1, 1, ap->a_cred,
    240 		    aflag);
    241 		if (error) {
    242 			(void) VOP_TRUNCATE(ovp, osize, ioflag & IO_SYNC,
    243 			    ap->a_cred, ap->a_p);
    244 			return error;
    245 		}
    246 		uvm_vnp_setsize(ovp, length);
    247 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    248 		KASSERT(ovp->v_size == oip->i_ffs_size);
    249 		return (VOP_UPDATE(ovp, NULL, NULL, 1));
    250 	}
    251 
    252 	/*
    253 	 * When truncating a regular file down to a non-block-aligned size,
    254 	 * we must zero the part of last block which is past the new EOF.
    255 	 * We must synchronously flush the zeroed pages to disk
    256 	 * since the new pages will be invalidated as soon as we
    257 	 * inform the VM system of the new, smaller size.
    258 	 * We must do this before acquiring the GLOCK, since fetching
    259 	 * the pages will acquire the GLOCK internally.
    260 	 * So there is a window where another thread could see a whole
    261 	 * zeroed page past EOF, but that's life.
    262 	 */
    263 
    264 	offset = blkoff(fs, length);
    265 	if (ovp->v_type == VREG && length < osize && offset != 0) {
    266 		voff_t eoz;
    267 
    268 		size = blksize(fs, oip, lblkno(fs, length));
    269 		eoz = MIN(lblktosize(fs, lblkno(fs, length)) + size, osize);
    270 		uvm_vnp_zerorange(ovp, length, eoz - length);
    271 		simple_lock(&ovp->v_interlock);
    272 		error = VOP_PUTPAGES(ovp, trunc_page(length), round_page(eoz),
    273 		    PGO_CLEANIT | PGO_DEACTIVATE | PGO_SYNCIO);
    274 		if (error) {
    275 			return error;
    276 		}
    277 	}
    278 
    279 	lockmgr(&gp->g_glock, LK_EXCLUSIVE, NULL);
    280 
    281 	if (DOINGSOFTDEP(ovp)) {
    282 		if (length > 0) {
    283 			/*
    284 			 * If a file is only partially truncated, then
    285 			 * we have to clean up the data structures
    286 			 * describing the allocation past the truncation
    287 			 * point. Finding and deallocating those structures
    288 			 * is a lot of work. Since partial truncation occurs
    289 			 * rarely, we solve the problem by syncing the file
    290 			 * so that it will have no data structures left.
    291 			 */
    292 			if ((error = VOP_FSYNC(ovp, ap->a_cred, FSYNC_WAIT,
    293 			    0, 0, ap->a_p)) != 0) {
    294 				lockmgr(&gp->g_glock, LK_RELEASE, NULL);
    295 				return (error);
    296 			}
    297 		} else {
    298 			uvm_vnp_setsize(ovp, length);
    299 #ifdef QUOTA
    300  			(void) chkdq(oip, -oip->i_ffs_blocks, NOCRED, 0);
    301 #endif
    302 			softdep_setup_freeblocks(oip, length);
    303 			(void) vinvalbuf(ovp, 0, ap->a_cred, ap->a_p, 0, 0);
    304 			lockmgr(&gp->g_glock, LK_RELEASE, NULL);
    305 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    306 			return (VOP_UPDATE(ovp, NULL, NULL, 0));
    307 		}
    308 	}
    309 
    310 	/*
    311 	 * Reduce the size of the file.
    312 	 */
    313 	oip->i_ffs_size = length;
    314 	uvm_vnp_setsize(ovp, length);
    315 	/*
    316 	 * Calculate index into inode's block list of
    317 	 * last direct and indirect blocks (if any)
    318 	 * which we want to keep.  Lastblock is -1 when
    319 	 * the file is truncated to 0.
    320 	 */
    321 	lastblock = lblkno(fs, length + fs->fs_bsize - 1) - 1;
    322 	lastiblock[SINGLE] = lastblock - NDADDR;
    323 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    324 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    325 	nblocks = btodb(fs->fs_bsize);
    326 	/*
    327 	 * Update file and block pointers on disk before we start freeing
    328 	 * blocks.  If we crash before free'ing blocks below, the blocks
    329 	 * will be returned to the free list.  lastiblock values are also
    330 	 * normalized to -1 for calls to ffs_indirtrunc below.
    331 	 */
    332 	memcpy((caddr_t)oldblks, (caddr_t)&oip->i_ffs_db[0], sizeof oldblks);
    333 	for (level = TRIPLE; level >= SINGLE; level--)
    334 		if (lastiblock[level] < 0) {
    335 			oip->i_ffs_ib[level] = 0;
    336 			lastiblock[level] = -1;
    337 		}
    338 	for (i = NDADDR - 1; i > lastblock; i--)
    339 		oip->i_ffs_db[i] = 0;
    340 	oip->i_flag |= IN_CHANGE | IN_UPDATE;
    341 	error = VOP_UPDATE(ovp, NULL, NULL, UPDATE_WAIT);
    342 	if (error && !allerror)
    343 		allerror = error;
    344 
    345 	/*
    346 	 * Having written the new inode to disk, save its new configuration
    347 	 * and put back the old block pointers long enough to process them.
    348 	 * Note that we save the new block configuration so we can check it
    349 	 * when we are done.
    350 	 */
    351 	memcpy((caddr_t)newblks, (caddr_t)&oip->i_ffs_db[0], sizeof newblks);
    352 	memcpy((caddr_t)&oip->i_ffs_db[0], (caddr_t)oldblks, sizeof oldblks);
    353 	oip->i_ffs_size = osize;
    354 	error = vtruncbuf(ovp, lastblock + 1, 0, 0);
    355 	if (error && !allerror)
    356 		allerror = error;
    357 
    358 	/*
    359 	 * Indirect blocks first.
    360 	 */
    361 	indir_lbn[SINGLE] = -NDADDR;
    362 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    363 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    364 	for (level = TRIPLE; level >= SINGLE; level--) {
    365 		bn = ufs_rw32(oip->i_ffs_ib[level], UFS_FSNEEDSWAP(fs));
    366 		if (bn != 0) {
    367 			error = ffs_indirtrunc(oip, indir_lbn[level],
    368 			    fsbtodb(fs, bn), lastiblock[level], level, &count);
    369 			if (error)
    370 				allerror = error;
    371 			blocksreleased += count;
    372 			if (lastiblock[level] < 0) {
    373 				oip->i_ffs_ib[level] = 0;
    374 				ffs_blkfree(oip, bn, fs->fs_bsize);
    375 				blocksreleased += nblocks;
    376 			}
    377 		}
    378 		if (lastiblock[level] >= 0)
    379 			goto done;
    380 	}
    381 
    382 	/*
    383 	 * All whole direct blocks or frags.
    384 	 */
    385 	for (i = NDADDR - 1; i > lastblock; i--) {
    386 		long bsize;
    387 
    388 		bn = ufs_rw32(oip->i_ffs_db[i], UFS_FSNEEDSWAP(fs));
    389 		if (bn == 0)
    390 			continue;
    391 		oip->i_ffs_db[i] = 0;
    392 		bsize = blksize(fs, oip, i);
    393 		ffs_blkfree(oip, bn, bsize);
    394 		blocksreleased += btodb(bsize);
    395 	}
    396 	if (lastblock < 0)
    397 		goto done;
    398 
    399 	/*
    400 	 * Finally, look for a change in size of the
    401 	 * last direct block; release any frags.
    402 	 */
    403 	bn = ufs_rw32(oip->i_ffs_db[lastblock], UFS_FSNEEDSWAP(fs));
    404 	if (bn != 0) {
    405 		long oldspace, newspace;
    406 
    407 		/*
    408 		 * Calculate amount of space we're giving
    409 		 * back as old block size minus new block size.
    410 		 */
    411 		oldspace = blksize(fs, oip, lastblock);
    412 		oip->i_ffs_size = length;
    413 		newspace = blksize(fs, oip, lastblock);
    414 		if (newspace == 0)
    415 			panic("itrunc: newspace");
    416 		if (oldspace - newspace > 0) {
    417 			/*
    418 			 * Block number of space to be free'd is
    419 			 * the old block # plus the number of frags
    420 			 * required for the storage we're keeping.
    421 			 */
    422 			bn += numfrags(fs, newspace);
    423 			ffs_blkfree(oip, bn, oldspace - newspace);
    424 			blocksreleased += btodb(oldspace - newspace);
    425 		}
    426 	}
    427 
    428 done:
    429 #ifdef DIAGNOSTIC
    430 	for (level = SINGLE; level <= TRIPLE; level++)
    431 		if (newblks[NDADDR + level] != oip->i_ffs_ib[level])
    432 			panic("itrunc1");
    433 	for (i = 0; i < NDADDR; i++)
    434 		if (newblks[i] != oip->i_ffs_db[i])
    435 			panic("itrunc2");
    436 	if (length == 0 &&
    437 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    438 		panic("itrunc3");
    439 #endif /* DIAGNOSTIC */
    440 	/*
    441 	 * Put back the real size.
    442 	 */
    443 	oip->i_ffs_size = length;
    444 	oip->i_ffs_blocks -= blocksreleased;
    445 	lockmgr(&gp->g_glock, LK_RELEASE, NULL);
    446 	oip->i_flag |= IN_CHANGE;
    447 #ifdef QUOTA
    448 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    449 #endif
    450 	KASSERT(ovp->v_type != VREG || ovp->v_size == oip->i_ffs_size);
    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(ip, lbn, dbn, lastbn, level, countp)
    465 	struct inode *ip;
    466 	ufs_daddr_t lbn, lastbn;
    467 	ufs_daddr_t dbn;
    468 	int level;
    469 	long *countp;
    470 {
    471 	int i;
    472 	struct buf *bp;
    473 	struct fs *fs = ip->i_fs;
    474 	ufs_daddr_t *bap;
    475 	struct vnode *vp;
    476 	ufs_daddr_t *copy = NULL, nb, nlbn, last;
    477 	long blkcount, factor;
    478 	int nblocks, blocksreleased = 0;
    479 	int error = 0, allerror = 0;
    480 
    481 	/*
    482 	 * Calculate index in current block of last
    483 	 * block to be kept.  -1 indicates the entire
    484 	 * block so we need not calculate the index.
    485 	 */
    486 	factor = 1;
    487 	for (i = SINGLE; i < level; i++)
    488 		factor *= NINDIR(fs);
    489 	last = lastbn;
    490 	if (lastbn > 0)
    491 		last /= factor;
    492 	nblocks = btodb(fs->fs_bsize);
    493 	/*
    494 	 * Get buffer of block pointers, zero those entries corresponding
    495 	 * to blocks to be free'd, and update on disk copy first.  Since
    496 	 * double(triple) indirect before single(double) indirect, calls
    497 	 * to bmap on these blocks will fail.  However, we already have
    498 	 * the on disk address, so we have to set the b_blkno field
    499 	 * explicitly instead of letting bread do everything for us.
    500 	 */
    501 	vp = ITOV(ip);
    502 	bp = getblk(vp, lbn, (int)fs->fs_bsize, 0, 0);
    503 	if (bp->b_flags & (B_DONE | B_DELWRI)) {
    504 		/* Braces must be here in case trace evaluates to nothing. */
    505 		trace(TR_BREADHIT, pack(vp, fs->fs_bsize), lbn);
    506 	} else {
    507 		trace(TR_BREADMISS, pack(vp, fs->fs_bsize), lbn);
    508 		curproc->p_stats->p_ru.ru_inblock++;	/* pay for read */
    509 		bp->b_flags |= B_READ;
    510 		if (bp->b_bcount > bp->b_bufsize)
    511 			panic("ffs_indirtrunc: bad buffer size");
    512 		bp->b_blkno = dbn;
    513 		VOP_STRATEGY(bp);
    514 		error = biowait(bp);
    515 	}
    516 	if (error) {
    517 		brelse(bp);
    518 		*countp = 0;
    519 		return (error);
    520 	}
    521 
    522 	bap = (ufs_daddr_t *)bp->b_data;
    523 	if (lastbn >= 0) {
    524 		copy = (ufs_daddr_t *) malloc(fs->fs_bsize, M_TEMP, M_WAITOK);
    525 		memcpy((caddr_t)copy, (caddr_t)bap, (u_int)fs->fs_bsize);
    526 		memset((caddr_t)&bap[last + 1], 0,
    527 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
    528 		error = bwrite(bp);
    529 		if (error)
    530 			allerror = error;
    531 		bap = copy;
    532 	}
    533 
    534 	/*
    535 	 * Recursively free totally unused blocks.
    536 	 */
    537 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    538 	    i--, nlbn += factor) {
    539 		nb = ufs_rw32(bap[i], UFS_FSNEEDSWAP(fs));
    540 		if (nb == 0)
    541 			continue;
    542 		if (level > SINGLE) {
    543 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
    544 					       (ufs_daddr_t)-1, level - 1,
    545 					       &blkcount);
    546 			if (error)
    547 				allerror = error;
    548 			blocksreleased += blkcount;
    549 		}
    550 		ffs_blkfree(ip, nb, fs->fs_bsize);
    551 		blocksreleased += nblocks;
    552 	}
    553 
    554 	/*
    555 	 * Recursively free last partial block.
    556 	 */
    557 	if (level > SINGLE && lastbn >= 0) {
    558 		last = lastbn % factor;
    559 		nb = ufs_rw32(bap[i], UFS_FSNEEDSWAP(fs));
    560 		if (nb != 0) {
    561 			error = ffs_indirtrunc(ip, nlbn, fsbtodb(fs, nb),
    562 					       last, level - 1, &blkcount);
    563 			if (error)
    564 				allerror = error;
    565 			blocksreleased += blkcount;
    566 		}
    567 	}
    568 
    569 	if (copy != NULL) {
    570 		FREE(copy, M_TEMP);
    571 	} else {
    572 		bp->b_flags |= B_INVAL;
    573 		brelse(bp);
    574 	}
    575 
    576 	*countp = blocksreleased;
    577 	return (allerror);
    578 }
    579