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lfs_inode.c revision 1.38
      1 /*	$NetBSD: lfs_inode.c,v 1.38 2000/06/27 20:57:14 perseant Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Konrad E. Schroder <perseant (at) hhhh.org>.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *      This product includes software developed by the NetBSD
     21  *      Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 /*
     39  * Copyright (c) 1986, 1989, 1991, 1993
     40  *	The Regents of the University of California.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  *	@(#)lfs_inode.c	8.9 (Berkeley) 5/8/95
     71  */
     72 
     73 #if defined(_KERNEL) && !defined(_LKM)
     74 #include "opt_quota.h"
     75 #endif
     76 
     77 #include <sys/param.h>
     78 #include <sys/systm.h>
     79 #include <sys/mount.h>
     80 #include <sys/proc.h>
     81 #include <sys/file.h>
     82 #include <sys/buf.h>
     83 #include <sys/vnode.h>
     84 #include <sys/kernel.h>
     85 #include <sys/malloc.h>
     86 #include <sys/trace.h>
     87 #include <sys/resourcevar.h>
     88 
     89 #include <vm/vm.h>
     90 
     91 #include <ufs/ufs/quota.h>
     92 #include <ufs/ufs/inode.h>
     93 #include <ufs/ufs/ufsmount.h>
     94 #include <ufs/ufs/ufs_extern.h>
     95 
     96 #include <ufs/lfs/lfs.h>
     97 #include <ufs/lfs/lfs_extern.h>
     98 
     99 extern int locked_queue_count;
    100 extern long locked_queue_bytes;
    101 
    102 static int lfs_update_seguse(struct lfs *, long, size_t);
    103 static int lfs_indirtrunc (struct inode *, ufs_daddr_t, ufs_daddr_t,
    104 			   ufs_daddr_t, int, long *, long *, size_t *);
    105 static int lfs_blkfree (struct lfs *, daddr_t, size_t, long *, size_t *);
    106 static int lfs_vtruncbuf(struct vnode *, daddr_t, int, int);
    107 
    108 /* Search a block for a specific dinode. */
    109 struct dinode *
    110 lfs_ifind(fs, ino, bp)
    111 	struct lfs *fs;
    112 	ino_t ino;
    113 	struct buf *bp;
    114 {
    115 	int cnt;
    116 	struct dinode *dip = (struct dinode *)bp->b_data;
    117 	struct dinode *ldip;
    118 
    119 	for (cnt = INOPB(fs), ldip = dip + (cnt - 1); cnt--; --ldip)
    120 		if (ldip->di_inumber == ino)
    121 			return (ldip);
    122 
    123 	printf("offset is %d (seg %d)\n", fs->lfs_offset, datosn(fs,fs->lfs_offset));
    124 	printf("block is %d (seg %d)\n", bp->b_blkno, datosn(fs,bp->b_blkno));
    125 	panic("lfs_ifind: dinode %u not found", ino);
    126 	/* NOTREACHED */
    127 }
    128 
    129 int
    130 lfs_update(v)
    131 	void *v;
    132 {
    133 	struct vop_update_args /* {
    134 				  struct vnode *a_vp;
    135 				  struct timespec *a_access;
    136 				  struct timespec *a_modify;
    137 				  int a_flags;
    138 				  } */ *ap = v;
    139 	struct inode *ip;
    140 	struct vnode *vp = ap->a_vp;
    141 	int mod, oflag;
    142 	struct timespec ts;
    143 	struct lfs *fs = VFSTOUFS(vp->v_mount)->um_lfs;
    144 
    145 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    146 		return (0);
    147 	ip = VTOI(vp);
    148 
    149 	/*
    150 	 * If we are called from vinvalbuf, and the file's blocks have
    151 	 * already been scheduled for writing, but the writes have not
    152 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    153 	 * will cause a panic.  So, we must wait until any pending write
    154 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    155 	 */
    156 	while((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    157 	    WRITEINPROG(vp)) {
    158 #ifdef DEBUG_LFS
    159 		printf("lfs_update: sleeping on inode %d (in-progress)\n",
    160 		       ip->i_number);
    161 #endif
    162 		tsleep(vp, (PRIBIO+1), "lfs_update", 0);
    163 	}
    164 	mod = ip->i_flag & (IN_MODIFIED | IN_ACCESSED);
    165 	oflag = ip->i_flag;
    166 	TIMEVAL_TO_TIMESPEC(&time, &ts);
    167 	LFS_ITIMES(ip,
    168 		   ap->a_access ? ap->a_access : &ts,
    169 		   ap->a_modify ? ap->a_modify : &ts, &ts);
    170 	if (!mod && (ip->i_flag & (IN_MODIFIED | IN_ACCESSED)))
    171 		ip->i_lfs->lfs_uinodes++;
    172 	if ((ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING)) == 0) {
    173 		return (0);
    174 	}
    175 
    176 	/* If sync, push back the vnode and any dirty blocks it may have. */
    177 	if((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP))==UPDATE_WAIT) {
    178 		/* Avoid flushing VDIROP. */
    179 		++fs->lfs_diropwait;
    180 		while(vp->v_flag & VDIROP) {
    181 #ifdef DEBUG_LFS
    182 			printf("lfs_update: sleeping on inode %d (dirops)\n",
    183 			       ip->i_number);
    184 			printf("lfs_update: vflags 0x%lx, iflags 0x%x\n",
    185 				vp->v_flag, ip->i_flag);
    186 #endif
    187 			if(fs->lfs_dirops == 0)
    188 				lfs_flush_fs(fs, SEGM_SYNC);
    189 			else
    190 				tsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    191 				       0);
    192 			/* XXX KS - by falling out here, are we writing the vn
    193 			twice? */
    194 		}
    195 		--fs->lfs_diropwait;
    196 		return lfs_vflush(vp);
    197         }
    198 	return 0;
    199 }
    200 
    201 #define	SINGLE	0	/* index of single indirect block */
    202 #define	DOUBLE	1	/* index of double indirect block */
    203 #define	TRIPLE	2	/* index of triple indirect block */
    204 /*
    205  * Truncate the inode oip to at most length size, freeing the
    206  * disk blocks.
    207  */
    208 int
    209 lfs_truncate(v)
    210 	void *v;
    211 {
    212 	struct vop_truncate_args /* {
    213 		struct vnode *a_vp;
    214 		off_t a_length;
    215 		int a_flags;
    216 		struct ucred *a_cred;
    217 		struct proc *a_p;
    218 	} */ *ap = v;
    219 	struct vnode *ovp = ap->a_vp;
    220 	ufs_daddr_t lastblock;
    221 	struct inode *oip;
    222 	ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    223 	ufs_daddr_t newblks[NDADDR + NIADDR];
    224 	off_t length = ap->a_length;
    225 	struct lfs *fs;
    226 	struct buf *bp;
    227 	int offset, size, level;
    228 	long count, nblocks, blocksreleased = 0;
    229 	int i;
    230 	int aflags, error, allerror = 0;
    231 	off_t osize;
    232 	long lastseg;
    233 	size_t bc;
    234 
    235 	if (length < 0)
    236 		return (EINVAL);
    237 	oip = VTOI(ovp);
    238 
    239 	/*
    240 	 * Just return and not update modification times.
    241 	 */
    242 	if (oip->i_ffs_size == length)
    243 		return (0);
    244 
    245 	if (ovp->v_type == VLNK &&
    246 	    (oip->i_ffs_size < ovp->v_mount->mnt_maxsymlinklen ||
    247 	     (ovp->v_mount->mnt_maxsymlinklen == 0 &&
    248 	      oip->i_din.ffs_din.di_blocks == 0))) {
    249 #ifdef DIAGNOSTIC
    250 		if (length != 0)
    251 			panic("lfs_truncate: partial truncate of symlink");
    252 #endif
    253 		memset((char *)&oip->i_ffs_shortlink, 0, (u_int)oip->i_ffs_size);
    254 		oip->i_ffs_size = 0;
    255 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    256 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    257 	}
    258 	if (oip->i_ffs_size == length) {
    259 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    260 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    261 	}
    262 #ifdef QUOTA
    263 	if ((error = getinoquota(oip)) != 0)
    264 		return (error);
    265 #endif
    266 	fs = oip->i_lfs;
    267 	lfs_imtime(fs);
    268 	osize = oip->i_ffs_size;
    269 	ovp->v_lasta = ovp->v_clen = ovp->v_cstart = ovp->v_lastw = 0;
    270 
    271 	/*
    272 	 * Lengthen the size of the file. We must ensure that the
    273 	 * last byte of the file is allocated. Since the smallest
    274 	 * value of osize is 0, length will be at least 1.
    275 	 */
    276 	if (osize < length) {
    277 		if (length > fs->lfs_maxfilesize)
    278 			return (EFBIG);
    279 		aflags = B_CLRBUF;
    280 		if (ap->a_flags & IO_SYNC)
    281 			aflags |= B_SYNC;
    282 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    283 		if (error)
    284 			return (error);
    285 		oip->i_ffs_size = length;
    286 		uvm_vnp_setsize(ovp, length);
    287 		(void) uvm_vnp_uncache(ovp);
    288 		VOP_BWRITE(bp);
    289 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    290 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    291 	}
    292 
    293 	/*
    294 	 * Make sure no writes to this inode can happen while we're
    295 	 * truncating.  Otherwise, blocks which are accounted for on the
    296 	 * inode *and* which have been created for cleaning can coexist,
    297 	 * and cause an overcounting.
    298 	 *
    299 	 * (We don't need to *hold* the seglock, though, because we already
    300 	 * hold the inode lock; draining the seglock is sufficient.)
    301 	 */
    302 	if (ovp != fs->lfs_unlockvp) {
    303 		while(fs->lfs_seglock) {
    304 			tsleep(&fs->lfs_seglock, PRIBIO+1, "lfs_truncate", 0);
    305 		}
    306 	}
    307 
    308 	/*
    309 	 * Shorten the size of the file. If the file is not being
    310 	 * truncated to a block boundary, the contents of the
    311 	 * partial block following the end of the file must be
    312 	 * zero'ed in case it ever becomes accessible again because
    313 	 * of subsequent file growth. Directories however are not
    314 	 * zero'ed as they should grow back initialized to empty.
    315 	 */
    316 	offset = blkoff(fs, length);
    317 	lastseg = -1;
    318 	bc = 0;
    319 	if (offset == 0) {
    320 		oip->i_ffs_size = length;
    321 	} else {
    322 		lbn = lblkno(fs, length);
    323 		aflags = B_CLRBUF;
    324 		if (ap->a_flags & IO_SYNC)
    325 			aflags |= B_SYNC;
    326 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    327 		if (error)
    328 			return (error);
    329 		oip->i_ffs_size = length;
    330 		size = blksize(fs, oip, lbn);
    331 		(void) uvm_vnp_uncache(ovp);
    332 		if (ovp->v_type != VDIR)
    333 			memset((char *)bp->b_data + offset, 0,
    334 			       (u_int)(size - offset));
    335 		allocbuf(bp, size);
    336 		VOP_BWRITE(bp);
    337 	}
    338 	uvm_vnp_setsize(ovp, length);
    339 	/*
    340 	 * Calculate index into inode's block list of
    341 	 * last direct and indirect blocks (if any)
    342 	 * which we want to keep.  Lastblock is -1 when
    343 	 * the file is truncated to 0.
    344 	 */
    345 	lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    346 	lastiblock[SINGLE] = lastblock - NDADDR;
    347 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    348 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    349 	nblocks = btodb(fs->lfs_bsize);
    350 	/*
    351 	 * Record changed file and block pointers before we start
    352 	 * freeing blocks.  lastiblock values are also normalized to -1
    353 	 * for calls to lfs_indirtrunc below.
    354 	 */
    355 	memcpy((caddr_t)newblks, (caddr_t)&oip->i_ffs_db[0], sizeof newblks);
    356 	for (level = TRIPLE; level >= SINGLE; level--)
    357 		if (lastiblock[level] < 0) {
    358 			newblks[NDADDR+level] = 0;
    359 			lastiblock[level] = -1;
    360 		}
    361 	for (i = NDADDR - 1; i > lastblock; i--)
    362 		newblks[i] = 0;
    363 
    364 	oip->i_ffs_size = osize;
    365 	error = lfs_vtruncbuf(ovp, lastblock + 1, 0, 0);
    366 	if (error && !allerror)
    367 		allerror = error;
    368 
    369 	/*
    370 	 * Indirect blocks first.
    371 	 */
    372 	indir_lbn[SINGLE] = -NDADDR;
    373 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    374 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    375 	for (level = TRIPLE; level >= SINGLE; level--) {
    376 		bn = oip->i_ffs_ib[level];
    377 		if (bn != 0) {
    378 			error = lfs_indirtrunc(oip, indir_lbn[level],
    379 			    bn, lastiblock[level], level, &count, &lastseg, &bc);
    380 			if (error)
    381 				allerror = error;
    382 			blocksreleased += count;
    383 			if (lastiblock[level] < 0) {
    384 				oip->i_ffs_ib[level] = 0;
    385 				lfs_blkfree(fs, bn, fs->lfs_bsize, &lastseg, &bc);
    386 				blocksreleased += nblocks;
    387 			}
    388 		}
    389 		if (lastiblock[level] >= 0)
    390 			goto done;
    391 	}
    392 
    393 	/*
    394 	 * All whole direct blocks or frags.
    395 	 */
    396 	for (i = NDADDR - 1; i > lastblock; i--) {
    397 		long bsize;
    398 
    399 		bn = oip->i_ffs_db[i];
    400 		if (bn == 0)
    401 			continue;
    402 		oip->i_ffs_db[i] = 0;
    403 		bsize = blksize(fs, oip, i);
    404 		lfs_blkfree(fs, bn, bsize, &lastseg, &bc);
    405 		blocksreleased += btodb(bsize);
    406 	}
    407 	if (lastblock < 0)
    408 		goto done;
    409 
    410 	/*
    411 	 * Finally, look for a change in size of the
    412 	 * last direct block; release any frags.
    413 	 */
    414 	bn = oip->i_ffs_db[lastblock];
    415 	if (bn != 0) {
    416 		long oldspace, newspace;
    417 
    418 		/*
    419 		 * Calculate amount of space we're giving
    420 		 * back as old block size minus new block size.
    421 		 */
    422 		oldspace = blksize(fs, oip, lastblock);
    423 		oip->i_ffs_size = length;
    424 		newspace = blksize(fs, oip, lastblock);
    425 		if (newspace == 0)
    426 			panic("itrunc: newspace");
    427 		if (oldspace - newspace > 0) {
    428 			lfs_blkfree(fs, bn, oldspace - newspace, &lastseg, &bc);
    429 			blocksreleased += btodb(oldspace - newspace);
    430 		}
    431 	}
    432 
    433 done:
    434 	/* Finish segment accounting corrections */
    435 	lfs_update_seguse(fs, lastseg, bc);
    436 #ifdef DIAGNOSTIC
    437 	for (level = SINGLE; level <= TRIPLE; level++)
    438 		if (newblks[NDADDR + level] != oip->i_ffs_ib[level])
    439 			panic("lfs itrunc1");
    440 	for (i = 0; i < NDADDR; i++)
    441 		if (newblks[i] != oip->i_ffs_db[i])
    442 			panic("lfs itrunc2");
    443 	if (length == 0 &&
    444 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    445 		panic("lfs itrunc3");
    446 #endif /* DIAGNOSTIC */
    447 	/*
    448 	 * Put back the real size.
    449 	 */
    450 	oip->i_ffs_size = length;
    451 	oip->i_ffs_blocks -= blocksreleased;
    452 	fs->lfs_bfree += blocksreleased;
    453 #ifdef DIAGNOSTIC
    454 	if (oip->i_ffs_size == 0 && oip->i_ffs_blocks > 0) {
    455 		printf("lfs_tuncate: truncate to 0 but %d blocks on inode\n",
    456 		       oip->i_ffs_blocks);
    457 		panic("lfs_truncate: persistent blocks\n");
    458 	}
    459 #endif
    460 	if (oip->i_ffs_blocks < 0) {
    461 #ifdef DIAGNOSTIC
    462 		panic("lfs_truncate: negative block count\n");
    463 #endif
    464 		oip->i_ffs_blocks = 0;
    465 	}
    466 	oip->i_flag |= IN_CHANGE;
    467 #ifdef QUOTA
    468 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    469 #endif
    470 	return (allerror);
    471 }
    472 
    473 /* Update segment usage information when removing a block. */
    474 static int
    475 lfs_blkfree(struct lfs *fs, daddr_t daddr, size_t bsize, long *lastseg,
    476 	    size_t *num)
    477 {
    478 	long seg;
    479 	int error = 0;
    480 
    481 	bsize = fragroundup(fs, bsize);
    482 	if (daddr > 0) {
    483 		if (*lastseg != (seg = datosn(fs, daddr))) {
    484 			error = lfs_update_seguse(fs, *lastseg, *num);
    485 			*num = bsize;
    486 			*lastseg = seg;
    487 		} else
    488 			*num += bsize;
    489 	}
    490 	return error;
    491 }
    492 
    493 /* Finish the accounting updates for a segment. */
    494 static int
    495 lfs_update_seguse(struct lfs *fs, long lastseg, size_t num)
    496 {
    497 	SEGUSE *sup;
    498 	struct buf *bp;
    499 
    500 	if (lastseg < 0 || num == 0)
    501 		return 0;
    502 
    503 
    504 	LFS_SEGENTRY(sup, fs, lastseg, bp);
    505 	if (num > sup->su_nbytes) {
    506 		printf("lfs_truncate: segment %ld short by %ld\n",
    507 		       lastseg, (long)num - sup->su_nbytes);
    508 		panic("lfs_truncate: negative bytes");
    509 		sup->su_nbytes = num;
    510 	}
    511 	sup->su_nbytes -= num;
    512 	return (VOP_BWRITE(bp));
    513 }
    514 
    515 /*
    516  * Release blocks associated with the inode ip and stored in the indirect
    517  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    518  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    519  * and recursive calls to indirtrunc must be used to cleanse other indirect
    520  * blocks.
    521  *
    522  * NB: triple indirect blocks are untested.
    523  */
    524 static int
    525 lfs_indirtrunc(struct inode *ip, ufs_daddr_t lbn, daddr_t dbn,
    526 	       ufs_daddr_t lastbn, int level, long *countp,
    527 	       long *lastsegp, size_t *bcp)
    528 {
    529 	int i;
    530 	struct buf *bp;
    531 	struct lfs *fs = ip->i_lfs;
    532 	ufs_daddr_t *bap;
    533 	struct vnode *vp;
    534 	ufs_daddr_t *copy = NULL, nb, nlbn, last;
    535 	long blkcount, factor;
    536 	int nblocks, blocksreleased = 0;
    537 	int error = 0, allerror = 0;
    538 
    539 	/*
    540 	 * Calculate index in current block of last
    541 	 * block to be kept.  -1 indicates the entire
    542 	 * block so we need not calculate the index.
    543 	 */
    544 	factor = 1;
    545 	for (i = SINGLE; i < level; i++)
    546 		factor *= NINDIR(fs);
    547 	last = lastbn;
    548 	if (lastbn > 0)
    549 		last /= factor;
    550 	nblocks = btodb(fs->lfs_bsize);
    551 	/*
    552 	 * Get buffer of block pointers, zero those entries corresponding
    553 	 * to blocks to be free'd, and update on disk copy first.  Since
    554 	 * double(triple) indirect before single(double) indirect, calls
    555 	 * to bmap on these blocks will fail.  However, we already have
    556 	 * the on disk address, so we have to set the b_blkno field
    557 	 * explicitly instead of letting bread do everything for us.
    558 	 */
    559 	vp = ITOV(ip);
    560 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    561 	if (bp->b_flags & (B_DONE | B_DELWRI)) {
    562 		/* Braces must be here in case trace evaluates to nothing. */
    563 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    564 	} else {
    565 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    566 		curproc->p_stats->p_ru.ru_inblock++;	/* pay for read */
    567 		bp->b_flags |= B_READ;
    568 		if (bp->b_bcount > bp->b_bufsize)
    569 			panic("lfs_indirtrunc: bad buffer size");
    570 		bp->b_blkno = dbn;
    571 		VOP_STRATEGY(bp);
    572 		error = biowait(bp);
    573 	}
    574 	if (error) {
    575 		brelse(bp);
    576 		*countp = 0;
    577 		return (error);
    578 	}
    579 
    580 	bap = (ufs_daddr_t *)bp->b_data;
    581 	if (lastbn >= 0) {
    582 		MALLOC(copy, ufs_daddr_t *, fs->lfs_bsize, M_TEMP, M_WAITOK);
    583 		memcpy((caddr_t)copy, (caddr_t)bap, (u_int)fs->lfs_bsize);
    584 		memset((caddr_t)&bap[last + 1], 0,
    585 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
    586 		error = VOP_BWRITE(bp);
    587 		if (error)
    588 			allerror = error;
    589 		bap = copy;
    590 	}
    591 
    592 	/*
    593 	 * Recursively free totally unused blocks.
    594 	 */
    595 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    596 	    i--, nlbn += factor) {
    597 		nb = bap[i];
    598 		if (nb == 0)
    599 			continue;
    600 		if (level > SINGLE) {
    601 			error = lfs_indirtrunc(ip, nlbn, nb,
    602 					       (ufs_daddr_t)-1, level - 1,
    603 					       &blkcount, lastsegp, bcp);
    604 			if (error)
    605 				allerror = error;
    606 			blocksreleased += blkcount;
    607 		}
    608 		lfs_blkfree(fs, nb, fs->lfs_bsize, lastsegp, bcp);
    609 		blocksreleased += nblocks;
    610 	}
    611 
    612 	/*
    613 	 * Recursively free last partial block.
    614 	 */
    615 	if (level > SINGLE && lastbn >= 0) {
    616 		last = lastbn % factor;
    617 		nb = bap[i];
    618 		if (nb != 0) {
    619 			error = lfs_indirtrunc(ip, nlbn, nb,
    620 					       last, level - 1, &blkcount,
    621 					       lastsegp, bcp);
    622 			if (error)
    623 				allerror = error;
    624 			blocksreleased += blkcount;
    625 		}
    626 	}
    627 
    628 	if (copy != NULL) {
    629 		FREE(copy, M_TEMP);
    630 	} else {
    631 		bp->b_flags |= B_INVAL;
    632 		brelse(bp);
    633 	}
    634 
    635 	*countp = blocksreleased;
    636 	return (allerror);
    637 }
    638 
    639 /*
    640  * Destroy any in core blocks past the truncation length.
    641  * Inlined from vtruncbuf, so that lfs_avail could be updated.
    642  */
    643 static int
    644 lfs_vtruncbuf(vp, lbn, slpflag, slptimeo)
    645 	struct vnode *vp;
    646 	daddr_t lbn;
    647 	int slpflag, slptimeo;
    648 {
    649 	struct buf *bp, *nbp;
    650 	int s, error;
    651 	struct lfs *fs;
    652 
    653 	fs = VTOI(vp)->i_lfs;
    654 	s = splbio();
    655 
    656 restart:
    657 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    658 		nbp = LIST_NEXT(bp, b_vnbufs);
    659 		if (bp->b_lblkno < lbn)
    660 			continue;
    661 		if (bp->b_flags & B_BUSY) {
    662 			bp->b_flags |= B_WANTED;
    663 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    664 			    "lfs_vtruncbuf", slptimeo);
    665 			if (error) {
    666 				splx(s);
    667 				return (error);
    668 			}
    669 			goto restart;
    670 		}
    671 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    672 		if (bp->b_flags & B_DELWRI)
    673 			fs->lfs_avail += bp->b_bcount;
    674 		if (bp->b_flags & B_LOCKED) {
    675 			bp->b_flags &= ~B_LOCKED;
    676 			--locked_queue_count;
    677 			locked_queue_bytes -= bp->b_bcount;
    678 		}
    679 		brelse(bp);
    680 	}
    681 
    682 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    683 		nbp = LIST_NEXT(bp, b_vnbufs);
    684 		if (bp->b_lblkno < lbn)
    685 			continue;
    686 		if (bp->b_flags & B_BUSY) {
    687 			bp->b_flags |= B_WANTED;
    688 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    689 			    "lfs_vtruncbuf", slptimeo);
    690 			if (error) {
    691 				splx(s);
    692 				return (error);
    693 			}
    694 			goto restart;
    695 		}
    696 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    697 		if (bp->b_flags & B_DELWRI)
    698 			fs->lfs_avail += bp->b_bcount;
    699 		if (bp->b_flags & B_LOCKED) {
    700 			bp->b_flags &= ~B_LOCKED;
    701 			--locked_queue_count;
    702 			locked_queue_bytes -= bp->b_bcount;
    703 		}
    704 		brelse(bp);
    705 	}
    706 
    707 	splx(s);
    708 
    709 	return (0);
    710 }
    711 
    712