Home | History | Annotate | Line # | Download | only in lfs
lfs_inode.c revision 1.39
      1 /*	$NetBSD: lfs_inode.c,v 1.39 2000/06/28 14:16:42 mrg 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 <ufs/ufs/quota.h>
     90 #include <ufs/ufs/inode.h>
     91 #include <ufs/ufs/ufsmount.h>
     92 #include <ufs/ufs/ufs_extern.h>
     93 
     94 #include <ufs/lfs/lfs.h>
     95 #include <ufs/lfs/lfs_extern.h>
     96 
     97 extern int locked_queue_count;
     98 extern long locked_queue_bytes;
     99 
    100 static int lfs_update_seguse(struct lfs *, long, size_t);
    101 static int lfs_indirtrunc (struct inode *, ufs_daddr_t, ufs_daddr_t,
    102 			   ufs_daddr_t, int, long *, long *, size_t *);
    103 static int lfs_blkfree (struct lfs *, daddr_t, size_t, long *, size_t *);
    104 static int lfs_vtruncbuf(struct vnode *, daddr_t, int, int);
    105 
    106 /* Search a block for a specific dinode. */
    107 struct dinode *
    108 lfs_ifind(fs, ino, bp)
    109 	struct lfs *fs;
    110 	ino_t ino;
    111 	struct buf *bp;
    112 {
    113 	int cnt;
    114 	struct dinode *dip = (struct dinode *)bp->b_data;
    115 	struct dinode *ldip;
    116 
    117 	for (cnt = INOPB(fs), ldip = dip + (cnt - 1); cnt--; --ldip)
    118 		if (ldip->di_inumber == ino)
    119 			return (ldip);
    120 
    121 	printf("offset is %d (seg %d)\n", fs->lfs_offset, datosn(fs,fs->lfs_offset));
    122 	printf("block is %d (seg %d)\n", bp->b_blkno, datosn(fs,bp->b_blkno));
    123 	panic("lfs_ifind: dinode %u not found", ino);
    124 	/* NOTREACHED */
    125 }
    126 
    127 int
    128 lfs_update(v)
    129 	void *v;
    130 {
    131 	struct vop_update_args /* {
    132 				  struct vnode *a_vp;
    133 				  struct timespec *a_access;
    134 				  struct timespec *a_modify;
    135 				  int a_flags;
    136 				  } */ *ap = v;
    137 	struct inode *ip;
    138 	struct vnode *vp = ap->a_vp;
    139 	int mod, oflag;
    140 	struct timespec ts;
    141 	struct lfs *fs = VFSTOUFS(vp->v_mount)->um_lfs;
    142 
    143 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    144 		return (0);
    145 	ip = VTOI(vp);
    146 
    147 	/*
    148 	 * If we are called from vinvalbuf, and the file's blocks have
    149 	 * already been scheduled for writing, but the writes have not
    150 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    151 	 * will cause a panic.  So, we must wait until any pending write
    152 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    153 	 */
    154 	while((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    155 	    WRITEINPROG(vp)) {
    156 #ifdef DEBUG_LFS
    157 		printf("lfs_update: sleeping on inode %d (in-progress)\n",
    158 		       ip->i_number);
    159 #endif
    160 		tsleep(vp, (PRIBIO+1), "lfs_update", 0);
    161 	}
    162 	mod = ip->i_flag & (IN_MODIFIED | IN_ACCESSED);
    163 	oflag = ip->i_flag;
    164 	TIMEVAL_TO_TIMESPEC(&time, &ts);
    165 	LFS_ITIMES(ip,
    166 		   ap->a_access ? ap->a_access : &ts,
    167 		   ap->a_modify ? ap->a_modify : &ts, &ts);
    168 	if (!mod && (ip->i_flag & (IN_MODIFIED | IN_ACCESSED)))
    169 		ip->i_lfs->lfs_uinodes++;
    170 	if ((ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING)) == 0) {
    171 		return (0);
    172 	}
    173 
    174 	/* If sync, push back the vnode and any dirty blocks it may have. */
    175 	if((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP))==UPDATE_WAIT) {
    176 		/* Avoid flushing VDIROP. */
    177 		++fs->lfs_diropwait;
    178 		while(vp->v_flag & VDIROP) {
    179 #ifdef DEBUG_LFS
    180 			printf("lfs_update: sleeping on inode %d (dirops)\n",
    181 			       ip->i_number);
    182 			printf("lfs_update: vflags 0x%lx, iflags 0x%x\n",
    183 				vp->v_flag, ip->i_flag);
    184 #endif
    185 			if(fs->lfs_dirops == 0)
    186 				lfs_flush_fs(fs, SEGM_SYNC);
    187 			else
    188 				tsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    189 				       0);
    190 			/* XXX KS - by falling out here, are we writing the vn
    191 			twice? */
    192 		}
    193 		--fs->lfs_diropwait;
    194 		return lfs_vflush(vp);
    195         }
    196 	return 0;
    197 }
    198 
    199 #define	SINGLE	0	/* index of single indirect block */
    200 #define	DOUBLE	1	/* index of double indirect block */
    201 #define	TRIPLE	2	/* index of triple indirect block */
    202 /*
    203  * Truncate the inode oip to at most length size, freeing the
    204  * disk blocks.
    205  */
    206 int
    207 lfs_truncate(v)
    208 	void *v;
    209 {
    210 	struct vop_truncate_args /* {
    211 		struct vnode *a_vp;
    212 		off_t a_length;
    213 		int a_flags;
    214 		struct ucred *a_cred;
    215 		struct proc *a_p;
    216 	} */ *ap = v;
    217 	struct vnode *ovp = ap->a_vp;
    218 	ufs_daddr_t lastblock;
    219 	struct inode *oip;
    220 	ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    221 	ufs_daddr_t newblks[NDADDR + NIADDR];
    222 	off_t length = ap->a_length;
    223 	struct lfs *fs;
    224 	struct buf *bp;
    225 	int offset, size, level;
    226 	long count, nblocks, blocksreleased = 0;
    227 	int i;
    228 	int aflags, error, allerror = 0;
    229 	off_t osize;
    230 	long lastseg;
    231 	size_t bc;
    232 
    233 	if (length < 0)
    234 		return (EINVAL);
    235 	oip = VTOI(ovp);
    236 
    237 	/*
    238 	 * Just return and not update modification times.
    239 	 */
    240 	if (oip->i_ffs_size == length)
    241 		return (0);
    242 
    243 	if (ovp->v_type == VLNK &&
    244 	    (oip->i_ffs_size < ovp->v_mount->mnt_maxsymlinklen ||
    245 	     (ovp->v_mount->mnt_maxsymlinklen == 0 &&
    246 	      oip->i_din.ffs_din.di_blocks == 0))) {
    247 #ifdef DIAGNOSTIC
    248 		if (length != 0)
    249 			panic("lfs_truncate: partial truncate of symlink");
    250 #endif
    251 		memset((char *)&oip->i_ffs_shortlink, 0, (u_int)oip->i_ffs_size);
    252 		oip->i_ffs_size = 0;
    253 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    254 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    255 	}
    256 	if (oip->i_ffs_size == length) {
    257 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    258 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    259 	}
    260 #ifdef QUOTA
    261 	if ((error = getinoquota(oip)) != 0)
    262 		return (error);
    263 #endif
    264 	fs = oip->i_lfs;
    265 	lfs_imtime(fs);
    266 	osize = oip->i_ffs_size;
    267 	ovp->v_lasta = ovp->v_clen = ovp->v_cstart = ovp->v_lastw = 0;
    268 
    269 	/*
    270 	 * Lengthen the size of the file. We must ensure that the
    271 	 * last byte of the file is allocated. Since the smallest
    272 	 * value of osize is 0, length will be at least 1.
    273 	 */
    274 	if (osize < length) {
    275 		if (length > fs->lfs_maxfilesize)
    276 			return (EFBIG);
    277 		aflags = B_CLRBUF;
    278 		if (ap->a_flags & IO_SYNC)
    279 			aflags |= B_SYNC;
    280 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    281 		if (error)
    282 			return (error);
    283 		oip->i_ffs_size = length;
    284 		uvm_vnp_setsize(ovp, length);
    285 		(void) uvm_vnp_uncache(ovp);
    286 		VOP_BWRITE(bp);
    287 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    288 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    289 	}
    290 
    291 	/*
    292 	 * Make sure no writes to this inode can happen while we're
    293 	 * truncating.  Otherwise, blocks which are accounted for on the
    294 	 * inode *and* which have been created for cleaning can coexist,
    295 	 * and cause an overcounting.
    296 	 *
    297 	 * (We don't need to *hold* the seglock, though, because we already
    298 	 * hold the inode lock; draining the seglock is sufficient.)
    299 	 */
    300 	if (ovp != fs->lfs_unlockvp) {
    301 		while(fs->lfs_seglock) {
    302 			tsleep(&fs->lfs_seglock, PRIBIO+1, "lfs_truncate", 0);
    303 		}
    304 	}
    305 
    306 	/*
    307 	 * Shorten the size of the file. If the file is not being
    308 	 * truncated to a block boundary, the contents of the
    309 	 * partial block following the end of the file must be
    310 	 * zero'ed in case it ever becomes accessible again because
    311 	 * of subsequent file growth. Directories however are not
    312 	 * zero'ed as they should grow back initialized to empty.
    313 	 */
    314 	offset = blkoff(fs, length);
    315 	lastseg = -1;
    316 	bc = 0;
    317 	if (offset == 0) {
    318 		oip->i_ffs_size = length;
    319 	} else {
    320 		lbn = lblkno(fs, length);
    321 		aflags = B_CLRBUF;
    322 		if (ap->a_flags & IO_SYNC)
    323 			aflags |= B_SYNC;
    324 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    325 		if (error)
    326 			return (error);
    327 		oip->i_ffs_size = length;
    328 		size = blksize(fs, oip, lbn);
    329 		(void) uvm_vnp_uncache(ovp);
    330 		if (ovp->v_type != VDIR)
    331 			memset((char *)bp->b_data + offset, 0,
    332 			       (u_int)(size - offset));
    333 		allocbuf(bp, size);
    334 		VOP_BWRITE(bp);
    335 	}
    336 	uvm_vnp_setsize(ovp, length);
    337 	/*
    338 	 * Calculate index into inode's block list of
    339 	 * last direct and indirect blocks (if any)
    340 	 * which we want to keep.  Lastblock is -1 when
    341 	 * the file is truncated to 0.
    342 	 */
    343 	lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    344 	lastiblock[SINGLE] = lastblock - NDADDR;
    345 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    346 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    347 	nblocks = btodb(fs->lfs_bsize);
    348 	/*
    349 	 * Record changed file and block pointers before we start
    350 	 * freeing blocks.  lastiblock values are also normalized to -1
    351 	 * for calls to lfs_indirtrunc below.
    352 	 */
    353 	memcpy((caddr_t)newblks, (caddr_t)&oip->i_ffs_db[0], sizeof newblks);
    354 	for (level = TRIPLE; level >= SINGLE; level--)
    355 		if (lastiblock[level] < 0) {
    356 			newblks[NDADDR+level] = 0;
    357 			lastiblock[level] = -1;
    358 		}
    359 	for (i = NDADDR - 1; i > lastblock; i--)
    360 		newblks[i] = 0;
    361 
    362 	oip->i_ffs_size = osize;
    363 	error = lfs_vtruncbuf(ovp, lastblock + 1, 0, 0);
    364 	if (error && !allerror)
    365 		allerror = error;
    366 
    367 	/*
    368 	 * Indirect blocks first.
    369 	 */
    370 	indir_lbn[SINGLE] = -NDADDR;
    371 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    372 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    373 	for (level = TRIPLE; level >= SINGLE; level--) {
    374 		bn = oip->i_ffs_ib[level];
    375 		if (bn != 0) {
    376 			error = lfs_indirtrunc(oip, indir_lbn[level],
    377 			    bn, lastiblock[level], level, &count, &lastseg, &bc);
    378 			if (error)
    379 				allerror = error;
    380 			blocksreleased += count;
    381 			if (lastiblock[level] < 0) {
    382 				oip->i_ffs_ib[level] = 0;
    383 				lfs_blkfree(fs, bn, fs->lfs_bsize, &lastseg, &bc);
    384 				blocksreleased += nblocks;
    385 			}
    386 		}
    387 		if (lastiblock[level] >= 0)
    388 			goto done;
    389 	}
    390 
    391 	/*
    392 	 * All whole direct blocks or frags.
    393 	 */
    394 	for (i = NDADDR - 1; i > lastblock; i--) {
    395 		long bsize;
    396 
    397 		bn = oip->i_ffs_db[i];
    398 		if (bn == 0)
    399 			continue;
    400 		oip->i_ffs_db[i] = 0;
    401 		bsize = blksize(fs, oip, i);
    402 		lfs_blkfree(fs, bn, bsize, &lastseg, &bc);
    403 		blocksreleased += btodb(bsize);
    404 	}
    405 	if (lastblock < 0)
    406 		goto done;
    407 
    408 	/*
    409 	 * Finally, look for a change in size of the
    410 	 * last direct block; release any frags.
    411 	 */
    412 	bn = oip->i_ffs_db[lastblock];
    413 	if (bn != 0) {
    414 		long oldspace, newspace;
    415 
    416 		/*
    417 		 * Calculate amount of space we're giving
    418 		 * back as old block size minus new block size.
    419 		 */
    420 		oldspace = blksize(fs, oip, lastblock);
    421 		oip->i_ffs_size = length;
    422 		newspace = blksize(fs, oip, lastblock);
    423 		if (newspace == 0)
    424 			panic("itrunc: newspace");
    425 		if (oldspace - newspace > 0) {
    426 			lfs_blkfree(fs, bn, oldspace - newspace, &lastseg, &bc);
    427 			blocksreleased += btodb(oldspace - newspace);
    428 		}
    429 	}
    430 
    431 done:
    432 	/* Finish segment accounting corrections */
    433 	lfs_update_seguse(fs, lastseg, bc);
    434 #ifdef DIAGNOSTIC
    435 	for (level = SINGLE; level <= TRIPLE; level++)
    436 		if (newblks[NDADDR + level] != oip->i_ffs_ib[level])
    437 			panic("lfs itrunc1");
    438 	for (i = 0; i < NDADDR; i++)
    439 		if (newblks[i] != oip->i_ffs_db[i])
    440 			panic("lfs itrunc2");
    441 	if (length == 0 &&
    442 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    443 		panic("lfs itrunc3");
    444 #endif /* DIAGNOSTIC */
    445 	/*
    446 	 * Put back the real size.
    447 	 */
    448 	oip->i_ffs_size = length;
    449 	oip->i_ffs_blocks -= blocksreleased;
    450 	fs->lfs_bfree += blocksreleased;
    451 #ifdef DIAGNOSTIC
    452 	if (oip->i_ffs_size == 0 && oip->i_ffs_blocks > 0) {
    453 		printf("lfs_tuncate: truncate to 0 but %d blocks on inode\n",
    454 		       oip->i_ffs_blocks);
    455 		panic("lfs_truncate: persistent blocks\n");
    456 	}
    457 #endif
    458 	if (oip->i_ffs_blocks < 0) {
    459 #ifdef DIAGNOSTIC
    460 		panic("lfs_truncate: negative block count\n");
    461 #endif
    462 		oip->i_ffs_blocks = 0;
    463 	}
    464 	oip->i_flag |= IN_CHANGE;
    465 #ifdef QUOTA
    466 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    467 #endif
    468 	return (allerror);
    469 }
    470 
    471 /* Update segment usage information when removing a block. */
    472 static int
    473 lfs_blkfree(struct lfs *fs, daddr_t daddr, size_t bsize, long *lastseg,
    474 	    size_t *num)
    475 {
    476 	long seg;
    477 	int error = 0;
    478 
    479 	bsize = fragroundup(fs, bsize);
    480 	if (daddr > 0) {
    481 		if (*lastseg != (seg = datosn(fs, daddr))) {
    482 			error = lfs_update_seguse(fs, *lastseg, *num);
    483 			*num = bsize;
    484 			*lastseg = seg;
    485 		} else
    486 			*num += bsize;
    487 	}
    488 	return error;
    489 }
    490 
    491 /* Finish the accounting updates for a segment. */
    492 static int
    493 lfs_update_seguse(struct lfs *fs, long lastseg, size_t num)
    494 {
    495 	SEGUSE *sup;
    496 	struct buf *bp;
    497 
    498 	if (lastseg < 0 || num == 0)
    499 		return 0;
    500 
    501 
    502 	LFS_SEGENTRY(sup, fs, lastseg, bp);
    503 	if (num > sup->su_nbytes) {
    504 		printf("lfs_truncate: segment %ld short by %ld\n",
    505 		       lastseg, (long)num - sup->su_nbytes);
    506 		panic("lfs_truncate: negative bytes");
    507 		sup->su_nbytes = num;
    508 	}
    509 	sup->su_nbytes -= num;
    510 	return (VOP_BWRITE(bp));
    511 }
    512 
    513 /*
    514  * Release blocks associated with the inode ip and stored in the indirect
    515  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    516  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    517  * and recursive calls to indirtrunc must be used to cleanse other indirect
    518  * blocks.
    519  *
    520  * NB: triple indirect blocks are untested.
    521  */
    522 static int
    523 lfs_indirtrunc(struct inode *ip, ufs_daddr_t lbn, daddr_t dbn,
    524 	       ufs_daddr_t lastbn, int level, long *countp,
    525 	       long *lastsegp, size_t *bcp)
    526 {
    527 	int i;
    528 	struct buf *bp;
    529 	struct lfs *fs = ip->i_lfs;
    530 	ufs_daddr_t *bap;
    531 	struct vnode *vp;
    532 	ufs_daddr_t *copy = NULL, nb, nlbn, last;
    533 	long blkcount, factor;
    534 	int nblocks, blocksreleased = 0;
    535 	int error = 0, allerror = 0;
    536 
    537 	/*
    538 	 * Calculate index in current block of last
    539 	 * block to be kept.  -1 indicates the entire
    540 	 * block so we need not calculate the index.
    541 	 */
    542 	factor = 1;
    543 	for (i = SINGLE; i < level; i++)
    544 		factor *= NINDIR(fs);
    545 	last = lastbn;
    546 	if (lastbn > 0)
    547 		last /= factor;
    548 	nblocks = btodb(fs->lfs_bsize);
    549 	/*
    550 	 * Get buffer of block pointers, zero those entries corresponding
    551 	 * to blocks to be free'd, and update on disk copy first.  Since
    552 	 * double(triple) indirect before single(double) indirect, calls
    553 	 * to bmap on these blocks will fail.  However, we already have
    554 	 * the on disk address, so we have to set the b_blkno field
    555 	 * explicitly instead of letting bread do everything for us.
    556 	 */
    557 	vp = ITOV(ip);
    558 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    559 	if (bp->b_flags & (B_DONE | B_DELWRI)) {
    560 		/* Braces must be here in case trace evaluates to nothing. */
    561 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    562 	} else {
    563 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    564 		curproc->p_stats->p_ru.ru_inblock++;	/* pay for read */
    565 		bp->b_flags |= B_READ;
    566 		if (bp->b_bcount > bp->b_bufsize)
    567 			panic("lfs_indirtrunc: bad buffer size");
    568 		bp->b_blkno = dbn;
    569 		VOP_STRATEGY(bp);
    570 		error = biowait(bp);
    571 	}
    572 	if (error) {
    573 		brelse(bp);
    574 		*countp = 0;
    575 		return (error);
    576 	}
    577 
    578 	bap = (ufs_daddr_t *)bp->b_data;
    579 	if (lastbn >= 0) {
    580 		MALLOC(copy, ufs_daddr_t *, fs->lfs_bsize, M_TEMP, M_WAITOK);
    581 		memcpy((caddr_t)copy, (caddr_t)bap, (u_int)fs->lfs_bsize);
    582 		memset((caddr_t)&bap[last + 1], 0,
    583 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
    584 		error = VOP_BWRITE(bp);
    585 		if (error)
    586 			allerror = error;
    587 		bap = copy;
    588 	}
    589 
    590 	/*
    591 	 * Recursively free totally unused blocks.
    592 	 */
    593 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    594 	    i--, nlbn += factor) {
    595 		nb = bap[i];
    596 		if (nb == 0)
    597 			continue;
    598 		if (level > SINGLE) {
    599 			error = lfs_indirtrunc(ip, nlbn, nb,
    600 					       (ufs_daddr_t)-1, level - 1,
    601 					       &blkcount, lastsegp, bcp);
    602 			if (error)
    603 				allerror = error;
    604 			blocksreleased += blkcount;
    605 		}
    606 		lfs_blkfree(fs, nb, fs->lfs_bsize, lastsegp, bcp);
    607 		blocksreleased += nblocks;
    608 	}
    609 
    610 	/*
    611 	 * Recursively free last partial block.
    612 	 */
    613 	if (level > SINGLE && lastbn >= 0) {
    614 		last = lastbn % factor;
    615 		nb = bap[i];
    616 		if (nb != 0) {
    617 			error = lfs_indirtrunc(ip, nlbn, nb,
    618 					       last, level - 1, &blkcount,
    619 					       lastsegp, bcp);
    620 			if (error)
    621 				allerror = error;
    622 			blocksreleased += blkcount;
    623 		}
    624 	}
    625 
    626 	if (copy != NULL) {
    627 		FREE(copy, M_TEMP);
    628 	} else {
    629 		bp->b_flags |= B_INVAL;
    630 		brelse(bp);
    631 	}
    632 
    633 	*countp = blocksreleased;
    634 	return (allerror);
    635 }
    636 
    637 /*
    638  * Destroy any in core blocks past the truncation length.
    639  * Inlined from vtruncbuf, so that lfs_avail could be updated.
    640  */
    641 static int
    642 lfs_vtruncbuf(vp, lbn, slpflag, slptimeo)
    643 	struct vnode *vp;
    644 	daddr_t lbn;
    645 	int slpflag, slptimeo;
    646 {
    647 	struct buf *bp, *nbp;
    648 	int s, error;
    649 	struct lfs *fs;
    650 
    651 	fs = VTOI(vp)->i_lfs;
    652 	s = splbio();
    653 
    654 restart:
    655 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    656 		nbp = LIST_NEXT(bp, b_vnbufs);
    657 		if (bp->b_lblkno < lbn)
    658 			continue;
    659 		if (bp->b_flags & B_BUSY) {
    660 			bp->b_flags |= B_WANTED;
    661 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    662 			    "lfs_vtruncbuf", slptimeo);
    663 			if (error) {
    664 				splx(s);
    665 				return (error);
    666 			}
    667 			goto restart;
    668 		}
    669 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    670 		if (bp->b_flags & B_DELWRI)
    671 			fs->lfs_avail += bp->b_bcount;
    672 		if (bp->b_flags & B_LOCKED) {
    673 			bp->b_flags &= ~B_LOCKED;
    674 			--locked_queue_count;
    675 			locked_queue_bytes -= bp->b_bcount;
    676 		}
    677 		brelse(bp);
    678 	}
    679 
    680 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    681 		nbp = LIST_NEXT(bp, b_vnbufs);
    682 		if (bp->b_lblkno < lbn)
    683 			continue;
    684 		if (bp->b_flags & B_BUSY) {
    685 			bp->b_flags |= B_WANTED;
    686 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    687 			    "lfs_vtruncbuf", slptimeo);
    688 			if (error) {
    689 				splx(s);
    690 				return (error);
    691 			}
    692 			goto restart;
    693 		}
    694 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    695 		if (bp->b_flags & B_DELWRI)
    696 			fs->lfs_avail += bp->b_bcount;
    697 		if (bp->b_flags & B_LOCKED) {
    698 			bp->b_flags &= ~B_LOCKED;
    699 			--locked_queue_count;
    700 			locked_queue_bytes -= bp->b_bcount;
    701 		}
    702 		brelse(bp);
    703 	}
    704 
    705 	splx(s);
    706 
    707 	return (0);
    708 }
    709 
    710