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lfs_inode.c revision 1.120.18.1
      1 /*	$NetBSD: lfs_inode.c,v 1.120.18.1 2010/04/21 00:28:26 matt Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999, 2000, 2001, 2002, 2003 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  *
     19  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     20  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     21  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     22  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     23  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     24  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     25  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     26  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     27  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     28  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     29  * POSSIBILITY OF SUCH DAMAGE.
     30  */
     31 /*
     32  * Copyright (c) 1986, 1989, 1991, 1993
     33  *	The Regents of the University of California.  All rights reserved.
     34  *
     35  * Redistribution and use in source and binary forms, with or without
     36  * modification, are permitted provided that the following conditions
     37  * are met:
     38  * 1. Redistributions of source code must retain the above copyright
     39  *    notice, this list of conditions and the following disclaimer.
     40  * 2. Redistributions in binary form must reproduce the above copyright
     41  *    notice, this list of conditions and the following disclaimer in the
     42  *    documentation and/or other materials provided with the distribution.
     43  * 3. Neither the name of the University nor the names of its contributors
     44  *    may be used to endorse or promote products derived from this software
     45  *    without specific prior written permission.
     46  *
     47  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     48  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     49  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     50  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     51  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     52  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     53  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     54  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     55  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     56  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     57  * SUCH DAMAGE.
     58  *
     59  *	@(#)lfs_inode.c	8.9 (Berkeley) 5/8/95
     60  */
     61 
     62 #include <sys/cdefs.h>
     63 __KERNEL_RCSID(0, "$NetBSD: lfs_inode.c,v 1.120.18.1 2010/04/21 00:28:26 matt Exp $");
     64 
     65 #if defined(_KERNEL_OPT)
     66 #include "opt_quota.h"
     67 #endif
     68 
     69 #include <sys/param.h>
     70 #include <sys/systm.h>
     71 #include <sys/mount.h>
     72 #include <sys/malloc.h>
     73 #include <sys/proc.h>
     74 #include <sys/file.h>
     75 #include <sys/buf.h>
     76 #include <sys/vnode.h>
     77 #include <sys/kernel.h>
     78 #include <sys/trace.h>
     79 #include <sys/resourcevar.h>
     80 #include <sys/kauth.h>
     81 
     82 #include <ufs/ufs/quota.h>
     83 #include <ufs/ufs/inode.h>
     84 #include <ufs/ufs/ufsmount.h>
     85 #include <ufs/ufs/ufs_extern.h>
     86 
     87 #include <ufs/lfs/lfs.h>
     88 #include <ufs/lfs/lfs_extern.h>
     89 
     90 static int lfs_update_seguse(struct lfs *, struct inode *ip, long, size_t);
     91 static int lfs_indirtrunc (struct inode *, daddr_t, daddr_t,
     92 			   daddr_t, int, long *, long *, long *, size_t *);
     93 static int lfs_blkfree (struct lfs *, struct inode *, daddr_t, size_t, long *, size_t *);
     94 static int lfs_vtruncbuf(struct vnode *, daddr_t, bool, int);
     95 
     96 /* Search a block for a specific dinode. */
     97 struct ufs1_dinode *
     98 lfs_ifind(struct lfs *fs, ino_t ino, struct buf *bp)
     99 {
    100 	struct ufs1_dinode *dip = (struct ufs1_dinode *)bp->b_data;
    101 	struct ufs1_dinode *ldip, *fin;
    102 
    103 	ASSERT_NO_SEGLOCK(fs);
    104 	/*
    105 	 * Read the inode block backwards, since later versions of the
    106 	 * inode will supercede earlier ones.  Though it is unlikely, it is
    107 	 * possible that the same inode will appear in the same inode block.
    108 	 */
    109 	fin = dip + INOPB(fs);
    110 	for (ldip = fin - 1; ldip >= dip; --ldip)
    111 		if (ldip->di_inumber == ino)
    112 			return (ldip);
    113 
    114 	printf("searched %d entries\n", (int)(fin - dip));
    115 	printf("offset is 0x%x (seg %d)\n", fs->lfs_offset,
    116 	       dtosn(fs, fs->lfs_offset));
    117 	printf("block is 0x%llx (seg %lld)\n",
    118 	       (unsigned long long)dbtofsb(fs, bp->b_blkno),
    119 	       (long long)dtosn(fs, dbtofsb(fs, bp->b_blkno)));
    120 
    121 	return NULL;
    122 }
    123 
    124 int
    125 lfs_update(struct vnode *vp, const struct timespec *acc,
    126     const struct timespec *mod, int updflags)
    127 {
    128 	struct inode *ip;
    129 	struct lfs *fs = VFSTOUFS(vp->v_mount)->um_lfs;
    130 	int flags;
    131 
    132 	ASSERT_NO_SEGLOCK(fs);
    133 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    134 		return (0);
    135 	ip = VTOI(vp);
    136 
    137 	/*
    138 	 * If we are called from vinvalbuf, and the file's blocks have
    139 	 * already been scheduled for writing, but the writes have not
    140 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    141 	 * will cause a panic.	So, we must wait until any pending write
    142 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    143 	 */
    144 	mutex_enter(&vp->v_interlock);
    145 	while ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    146 	    WRITEINPROG(vp)) {
    147 		DLOG((DLOG_SEG, "lfs_update: sleeping on ino %d"
    148 		      " (in progress)\n", ip->i_number));
    149 		cv_wait(&vp->v_cv, &vp->v_interlock);
    150 	}
    151 	mutex_exit(&vp->v_interlock);
    152 	LFS_ITIMES(ip, acc, mod, NULL);
    153 	if (updflags & UPDATE_CLOSE)
    154 		flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING);
    155 	else
    156 		flags = ip->i_flag & (IN_MODIFIED | IN_CLEANING);
    157 	if (flags == 0)
    158 		return (0);
    159 
    160 	/* If sync, push back the vnode and any dirty blocks it may have. */
    161 	if ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT) {
    162 		/* Avoid flushing VU_DIROP. */
    163 		mutex_enter(&lfs_lock);
    164 		++fs->lfs_diropwait;
    165 		while (vp->v_uflag & VU_DIROP) {
    166 			DLOG((DLOG_DIROP, "lfs_update: sleeping on inode %d"
    167 			      " (dirops)\n", ip->i_number));
    168 			DLOG((DLOG_DIROP, "lfs_update: vflags 0x%x, iflags"
    169 			      " 0x%x\n",
    170 			      vp->v_iflag | vp->v_vflag | vp->v_uflag,
    171 			      ip->i_flag));
    172 			if (fs->lfs_dirops == 0)
    173 				lfs_flush_fs(fs, SEGM_SYNC);
    174 			else
    175 				mtsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    176 					0, &lfs_lock);
    177 			/* XXX KS - by falling out here, are we writing the vn
    178 			twice? */
    179 		}
    180 		--fs->lfs_diropwait;
    181 		mutex_exit(&lfs_lock);
    182 		return lfs_vflush(vp);
    183 	}
    184 	return 0;
    185 }
    186 
    187 #define	SINGLE	0	/* index of single indirect block */
    188 #define	DOUBLE	1	/* index of double indirect block */
    189 #define	TRIPLE	2	/* index of triple indirect block */
    190 /*
    191  * Truncate the inode oip to at most length size, freeing the
    192  * disk blocks.
    193  */
    194 /* VOP_BWRITE 1 + NIADDR + lfs_balloc == 2 + 2*NIADDR times */
    195 
    196 int
    197 lfs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
    198 {
    199 	daddr_t lastblock;
    200 	struct inode *oip = VTOI(ovp);
    201 	daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    202 	/* XXX ondisk32 */
    203 	int32_t newblks[NDADDR + NIADDR];
    204 	struct lfs *fs;
    205 	struct buf *bp;
    206 	int offset, size, level;
    207 	long count, rcount, blocksreleased = 0, real_released = 0;
    208 	int i, nblocks;
    209 	int aflags, error, allerror = 0;
    210 	off_t osize;
    211 	long lastseg;
    212 	size_t bc;
    213 	int obufsize, odb;
    214 	int usepc;
    215 	struct ufsmount *ump = oip->i_ump;
    216 
    217 	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
    218 	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
    219 		KASSERT(oip->i_size == 0);
    220 		return 0;
    221 	}
    222 
    223 	if (length < 0)
    224 		return (EINVAL);
    225 
    226 	/*
    227 	 * Just return and not update modification times.
    228 	 */
    229 	if (oip->i_size == length) {
    230 		/* still do a uvm_vnp_setsize() as writesize may be larger */
    231 		uvm_vnp_setsize(ovp, length);
    232 		return (0);
    233 	}
    234 
    235 	if (ovp->v_type == VLNK &&
    236 	    (oip->i_size < ump->um_maxsymlinklen ||
    237 	     (ump->um_maxsymlinklen == 0 &&
    238 	      oip->i_ffs1_blocks == 0))) {
    239 #ifdef DIAGNOSTIC
    240 		if (length != 0)
    241 			panic("lfs_truncate: partial truncate of symlink");
    242 #endif
    243 		memset((char *)SHORTLINK(oip), 0, (u_int)oip->i_size);
    244 		oip->i_size = oip->i_ffs1_size = 0;
    245 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    246 		return (lfs_update(ovp, NULL, NULL, 0));
    247 	}
    248 	if (oip->i_size == length) {
    249 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    250 		return (lfs_update(ovp, NULL, NULL, 0));
    251 	}
    252 	fs = oip->i_lfs;
    253 	lfs_imtime(fs);
    254 	osize = oip->i_size;
    255 	usepc = (ovp->v_type == VREG && ovp != fs->lfs_ivnode);
    256 
    257 	ASSERT_NO_SEGLOCK(fs);
    258 	/*
    259 	 * Lengthen the size of the file. We must ensure that the
    260 	 * last byte of the file is allocated. Since the smallest
    261 	 * value of osize is 0, length will be at least 1.
    262 	 */
    263 	if (osize < length) {
    264 		if (length > ump->um_maxfilesize)
    265 			return (EFBIG);
    266 		aflags = B_CLRBUF;
    267 		if (ioflag & IO_SYNC)
    268 			aflags |= B_SYNC;
    269 		if (usepc) {
    270 			if (lblkno(fs, osize) < NDADDR &&
    271 			    lblkno(fs, osize) != lblkno(fs, length) &&
    272 			    blkroundup(fs, osize) != osize) {
    273 				off_t eob;
    274 
    275 				eob = blkroundup(fs, osize);
    276 				uvm_vnp_setwritesize(ovp, eob);
    277 				error = ufs_balloc_range(ovp, osize,
    278 				    eob - osize, cred, aflags);
    279 				if (error)
    280 					return error;
    281 				if (ioflag & IO_SYNC) {
    282 					mutex_enter(&ovp->v_interlock);
    283 					VOP_PUTPAGES(ovp,
    284 					    trunc_page(osize & fs->lfs_bmask),
    285 					    round_page(eob),
    286 					    PGO_CLEANIT | PGO_SYNCIO);
    287 				}
    288 			}
    289 			uvm_vnp_setwritesize(ovp, length);
    290 			error = ufs_balloc_range(ovp, length - 1, 1, cred,
    291 						 aflags);
    292 			if (error) {
    293 				(void) lfs_truncate(ovp, osize,
    294 						    ioflag & IO_SYNC, cred);
    295 				return error;
    296 			}
    297 			uvm_vnp_setsize(ovp, length);
    298 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    299 			KASSERT(ovp->v_size == oip->i_size);
    300 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    301 			return (lfs_update(ovp, NULL, NULL, 0));
    302 		} else {
    303 			error = lfs_reserve(fs, ovp, NULL,
    304 			    btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    305 			if (error)
    306 				return (error);
    307 			error = lfs_balloc(ovp, length - 1, 1, cred,
    308 					   aflags, &bp);
    309 			lfs_reserve(fs, ovp, NULL,
    310 			    -btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    311 			if (error)
    312 				return (error);
    313 			oip->i_ffs1_size = oip->i_size = length;
    314 			uvm_vnp_setsize(ovp, length);
    315 			(void) VOP_BWRITE(bp);
    316 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    317 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    318 			return (lfs_update(ovp, NULL, NULL, 0));
    319 		}
    320 	}
    321 
    322 	if ((error = lfs_reserve(fs, ovp, NULL,
    323 	    btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift))) != 0)
    324 		return (error);
    325 
    326 	/*
    327 	 * Shorten the size of the file. If the file is not being
    328 	 * truncated to a block boundary, the contents of the
    329 	 * partial block following the end of the file must be
    330 	 * zero'ed in case it ever becomes accessible again because
    331 	 * of subsequent file growth. Directories however are not
    332 	 * zero'ed as they should grow back initialized to empty.
    333 	 */
    334 	offset = blkoff(fs, length);
    335 	lastseg = -1;
    336 	bc = 0;
    337 
    338 	if (ovp != fs->lfs_ivnode)
    339 		lfs_seglock(fs, SEGM_PROT);
    340 	if (offset == 0) {
    341 		oip->i_size = oip->i_ffs1_size = length;
    342 	} else if (!usepc) {
    343 		lbn = lblkno(fs, length);
    344 		aflags = B_CLRBUF;
    345 		if (ioflag & IO_SYNC)
    346 			aflags |= B_SYNC;
    347 		error = lfs_balloc(ovp, length - 1, 1, cred, aflags, &bp);
    348 		if (error) {
    349 			lfs_reserve(fs, ovp, NULL,
    350 			    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    351 			goto errout;
    352 		}
    353 		obufsize = bp->b_bufsize;
    354 		odb = btofsb(fs, bp->b_bcount);
    355 		oip->i_size = oip->i_ffs1_size = length;
    356 		size = blksize(fs, oip, lbn);
    357 		if (ovp->v_type != VDIR)
    358 			memset((char *)bp->b_data + offset, 0,
    359 			       (u_int)(size - offset));
    360 		allocbuf(bp, size, 1);
    361 		if ((bp->b_flags & B_LOCKED) != 0 && bp->b_iodone == NULL) {
    362 			mutex_enter(&lfs_lock);
    363 			locked_queue_bytes -= obufsize - bp->b_bufsize;
    364 			mutex_exit(&lfs_lock);
    365 		}
    366 		if (bp->b_oflags & BO_DELWRI)
    367 			fs->lfs_avail += odb - btofsb(fs, size);
    368 		(void) VOP_BWRITE(bp);
    369 	} else { /* vp->v_type == VREG && length < osize && offset != 0 */
    370 		/*
    371 		 * When truncating a regular file down to a non-block-aligned
    372 		 * size, we must zero the part of last block which is past
    373 		 * the new EOF.  We must synchronously flush the zeroed pages
    374 		 * to disk since the new pages will be invalidated as soon
    375 		 * as we inform the VM system of the new, smaller size.
    376 		 * We must do this before acquiring the GLOCK, since fetching
    377 		 * the pages will acquire the GLOCK internally.
    378 		 * So there is a window where another thread could see a whole
    379 		 * zeroed page past EOF, but that's life.
    380 		 */
    381 		daddr_t xlbn;
    382 		voff_t eoz;
    383 
    384 		aflags = ioflag & IO_SYNC ? B_SYNC : 0;
    385 		error = ufs_balloc_range(ovp, length - 1, 1, cred, aflags);
    386 		if (error) {
    387 			lfs_reserve(fs, ovp, NULL,
    388 				    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    389 			goto errout;
    390 		}
    391 		xlbn = lblkno(fs, length);
    392 		size = blksize(fs, oip, xlbn);
    393 		eoz = MIN(lblktosize(fs, xlbn) + size, osize);
    394 		uvm_vnp_zerorange(ovp, length, eoz - length);
    395 		if (round_page(eoz) > round_page(length)) {
    396 			mutex_enter(&ovp->v_interlock);
    397 			error = VOP_PUTPAGES(ovp, round_page(length),
    398 			    round_page(eoz),
    399 			    PGO_CLEANIT | PGO_DEACTIVATE |
    400 			    ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
    401 			if (error) {
    402 				lfs_reserve(fs, ovp, NULL,
    403 					    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    404 				goto errout;
    405 			}
    406 		}
    407 	}
    408 
    409 	genfs_node_wrlock(ovp);
    410 
    411 	oip->i_size = oip->i_ffs1_size = length;
    412 	uvm_vnp_setsize(ovp, length);
    413 	/*
    414 	 * Calculate index into inode's block list of
    415 	 * last direct and indirect blocks (if any)
    416 	 * which we want to keep.  Lastblock is -1 when
    417 	 * the file is truncated to 0.
    418 	 */
    419 	/* Avoid sign overflow - XXX assumes that off_t is a quad_t. */
    420 	if (length > QUAD_MAX - fs->lfs_bsize)
    421 		lastblock = lblkno(fs, QUAD_MAX - fs->lfs_bsize);
    422 	else
    423 		lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    424 	lastiblock[SINGLE] = lastblock - NDADDR;
    425 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    426 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    427 	nblocks = btofsb(fs, fs->lfs_bsize);
    428 	/*
    429 	 * Record changed file and block pointers before we start
    430 	 * freeing blocks.  lastiblock values are also normalized to -1
    431 	 * for calls to lfs_indirtrunc below.
    432 	 */
    433 	memcpy((void *)newblks, (void *)&oip->i_ffs1_db[0], sizeof newblks);
    434 	for (level = TRIPLE; level >= SINGLE; level--)
    435 		if (lastiblock[level] < 0) {
    436 			newblks[NDADDR+level] = 0;
    437 			lastiblock[level] = -1;
    438 		}
    439 	for (i = NDADDR - 1; i > lastblock; i--)
    440 		newblks[i] = 0;
    441 
    442 	oip->i_size = oip->i_ffs1_size = osize;
    443 	error = lfs_vtruncbuf(ovp, lastblock + 1, false, 0);
    444 	if (error && !allerror)
    445 		allerror = error;
    446 
    447 	/*
    448 	 * Indirect blocks first.
    449 	 */
    450 	indir_lbn[SINGLE] = -NDADDR;
    451 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    452 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    453 	for (level = TRIPLE; level >= SINGLE; level--) {
    454 		bn = oip->i_ffs1_ib[level];
    455 		if (bn != 0) {
    456 			error = lfs_indirtrunc(oip, indir_lbn[level],
    457 					       bn, lastiblock[level],
    458 					       level, &count, &rcount,
    459 					       &lastseg, &bc);
    460 			if (error)
    461 				allerror = error;
    462 			real_released += rcount;
    463 			blocksreleased += count;
    464 			if (lastiblock[level] < 0) {
    465 				if (oip->i_ffs1_ib[level] > 0)
    466 					real_released += nblocks;
    467 				blocksreleased += nblocks;
    468 				oip->i_ffs1_ib[level] = 0;
    469 				lfs_blkfree(fs, oip, bn, fs->lfs_bsize,
    470 					    &lastseg, &bc);
    471         			lfs_deregister_block(ovp, bn);
    472 			}
    473 		}
    474 		if (lastiblock[level] >= 0)
    475 			goto done;
    476 	}
    477 
    478 	/*
    479 	 * All whole direct blocks or frags.
    480 	 */
    481 	for (i = NDADDR - 1; i > lastblock; i--) {
    482 		long bsize, obsize;
    483 
    484 		bn = oip->i_ffs1_db[i];
    485 		if (bn == 0)
    486 			continue;
    487 		bsize = blksize(fs, oip, i);
    488 		if (oip->i_ffs1_db[i] > 0) {
    489 			/* Check for fragment size changes */
    490 			obsize = oip->i_lfs_fragsize[i];
    491 			real_released += btofsb(fs, obsize);
    492 			oip->i_lfs_fragsize[i] = 0;
    493 		} else
    494 			obsize = 0;
    495 		blocksreleased += btofsb(fs, bsize);
    496 		oip->i_ffs1_db[i] = 0;
    497 		lfs_blkfree(fs, oip, bn, obsize, &lastseg, &bc);
    498         	lfs_deregister_block(ovp, bn);
    499 	}
    500 	if (lastblock < 0)
    501 		goto done;
    502 
    503 	/*
    504 	 * Finally, look for a change in size of the
    505 	 * last direct block; release any frags.
    506 	 */
    507 	bn = oip->i_ffs1_db[lastblock];
    508 	if (bn != 0) {
    509 		long oldspace, newspace;
    510 #if 0
    511 		long olddspace;
    512 #endif
    513 
    514 		/*
    515 		 * Calculate amount of space we're giving
    516 		 * back as old block size minus new block size.
    517 		 */
    518 		oldspace = blksize(fs, oip, lastblock);
    519 #if 0
    520 		olddspace = oip->i_lfs_fragsize[lastblock];
    521 #endif
    522 
    523 		oip->i_size = oip->i_ffs1_size = length;
    524 		newspace = blksize(fs, oip, lastblock);
    525 		if (newspace == 0)
    526 			panic("itrunc: newspace");
    527 		if (oldspace - newspace > 0) {
    528 			blocksreleased += btofsb(fs, oldspace - newspace);
    529 		}
    530 #if 0
    531 		if (bn > 0 && olddspace - newspace > 0) {
    532 			/* No segment accounting here, just vnode */
    533 			real_released += btofsb(fs, olddspace - newspace);
    534 		}
    535 #endif
    536 	}
    537 
    538 done:
    539 	/* Finish segment accounting corrections */
    540 	lfs_update_seguse(fs, oip, lastseg, bc);
    541 #ifdef DIAGNOSTIC
    542 	for (level = SINGLE; level <= TRIPLE; level++)
    543 		if ((newblks[NDADDR + level] == 0) !=
    544 		    ((oip->i_ffs1_ib[level]) == 0)) {
    545 			panic("lfs itrunc1");
    546 		}
    547 	for (i = 0; i < NDADDR; i++)
    548 		if ((newblks[i] == 0) != (oip->i_ffs1_db[i] == 0)) {
    549 			panic("lfs itrunc2");
    550 		}
    551 	if (length == 0 &&
    552 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    553 		panic("lfs itrunc3");
    554 #endif /* DIAGNOSTIC */
    555 	/*
    556 	 * Put back the real size.
    557 	 */
    558 	oip->i_size = oip->i_ffs1_size = length;
    559 	oip->i_lfs_effnblks -= blocksreleased;
    560 	oip->i_ffs1_blocks -= real_released;
    561 	mutex_enter(&lfs_lock);
    562 	fs->lfs_bfree += blocksreleased;
    563 	mutex_exit(&lfs_lock);
    564 #ifdef DIAGNOSTIC
    565 	if (oip->i_size == 0 &&
    566 	    (oip->i_ffs1_blocks != 0 || oip->i_lfs_effnblks != 0)) {
    567 		printf("lfs_truncate: truncate to 0 but %d blks/%d effblks\n",
    568 		       oip->i_ffs1_blocks, oip->i_lfs_effnblks);
    569 		panic("lfs_truncate: persistent blocks");
    570 	}
    571 #endif
    572 
    573 	/*
    574 	 * If we truncated to zero, take us off the paging queue.
    575 	 */
    576 	mutex_enter(&lfs_lock);
    577 	if (oip->i_size == 0 && oip->i_flags & IN_PAGING) {
    578 		oip->i_flags &= ~IN_PAGING;
    579 		TAILQ_REMOVE(&fs->lfs_pchainhd, oip, i_lfs_pchain);
    580 	}
    581 	mutex_exit(&lfs_lock);
    582 
    583 	oip->i_flag |= IN_CHANGE;
    584 #ifdef QUOTA
    585 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    586 #endif
    587 	lfs_reserve(fs, ovp, NULL,
    588 	    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    589 	genfs_node_unlock(ovp);
    590   errout:
    591 	oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    592 	if (ovp != fs->lfs_ivnode)
    593 		lfs_segunlock(fs);
    594 	return (allerror ? allerror : error);
    595 }
    596 
    597 /* Update segment and avail usage information when removing a block. */
    598 static int
    599 lfs_blkfree(struct lfs *fs, struct inode *ip, daddr_t daddr,
    600 	    size_t bsize, long *lastseg, size_t *num)
    601 {
    602 	long seg;
    603 	int error = 0;
    604 
    605 	ASSERT_SEGLOCK(fs);
    606 	bsize = fragroundup(fs, bsize);
    607 	if (daddr > 0) {
    608 		if (*lastseg != (seg = dtosn(fs, daddr))) {
    609 			error = lfs_update_seguse(fs, ip, *lastseg, *num);
    610 			*num = bsize;
    611 			*lastseg = seg;
    612 		} else
    613 			*num += bsize;
    614 	}
    615 
    616 	return error;
    617 }
    618 
    619 /* Finish the accounting updates for a segment. */
    620 static int
    621 lfs_update_seguse(struct lfs *fs, struct inode *ip, long lastseg, size_t num)
    622 {
    623 	struct segdelta *sd;
    624 	struct vnode *vp;
    625 
    626 	ASSERT_SEGLOCK(fs);
    627 	if (lastseg < 0 || num == 0)
    628 		return 0;
    629 
    630 	vp = ITOV(ip);
    631 	LIST_FOREACH(sd, &ip->i_lfs_segdhd, list)
    632 		if (sd->segnum == lastseg)
    633 			break;
    634 	if (sd == NULL) {
    635 		sd = malloc(sizeof(*sd), M_SEGMENT, M_WAITOK);
    636 		sd->segnum = lastseg;
    637 		sd->num = 0;
    638 		LIST_INSERT_HEAD(&ip->i_lfs_segdhd, sd, list);
    639 	}
    640 	sd->num += num;
    641 
    642 	return 0;
    643 }
    644 
    645 static void
    646 lfs_finalize_seguse(struct lfs *fs, void *v)
    647 {
    648 	SEGUSE *sup;
    649 	struct buf *bp;
    650 	struct segdelta *sd;
    651 	LIST_HEAD(, segdelta) *hd = v;
    652 
    653 	ASSERT_SEGLOCK(fs);
    654 	while((sd = LIST_FIRST(hd)) != NULL) {
    655 		LIST_REMOVE(sd, list);
    656 		LFS_SEGENTRY(sup, fs, sd->segnum, bp);
    657 		if (sd->num > sup->su_nbytes) {
    658 			printf("lfs_finalize_seguse: segment %ld short by %ld\n",
    659 				sd->segnum, (long)(sd->num - sup->su_nbytes));
    660 			panic("lfs_finalize_seguse: negative bytes");
    661 			sup->su_nbytes = sd->num;
    662 		}
    663 		sup->su_nbytes -= sd->num;
    664 		LFS_WRITESEGENTRY(sup, fs, sd->segnum, bp);
    665 		free(sd, M_SEGMENT);
    666 	}
    667 }
    668 
    669 /* Finish the accounting updates for a segment. */
    670 void
    671 lfs_finalize_ino_seguse(struct lfs *fs, struct inode *ip)
    672 {
    673 	ASSERT_SEGLOCK(fs);
    674 	lfs_finalize_seguse(fs, &ip->i_lfs_segdhd);
    675 }
    676 
    677 /* Finish the accounting updates for a segment. */
    678 void
    679 lfs_finalize_fs_seguse(struct lfs *fs)
    680 {
    681 	ASSERT_SEGLOCK(fs);
    682 	lfs_finalize_seguse(fs, &fs->lfs_segdhd);
    683 }
    684 
    685 /*
    686  * Release blocks associated with the inode ip and stored in the indirect
    687  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    688  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    689  * and recursive calls to indirtrunc must be used to cleanse other indirect
    690  * blocks.
    691  *
    692  * NB: triple indirect blocks are untested.
    693  */
    694 static int
    695 lfs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
    696 	       daddr_t lastbn, int level, long *countp,
    697 	       long *rcountp, long *lastsegp, size_t *bcp)
    698 {
    699 	int i;
    700 	struct buf *bp;
    701 	struct lfs *fs = ip->i_lfs;
    702 	int32_t *bap;	/* XXX ondisk32 */
    703 	struct vnode *vp;
    704 	daddr_t nb, nlbn, last;
    705 	int32_t *copy = NULL;	/* XXX ondisk32 */
    706 	long blkcount, rblkcount, factor;
    707 	int nblocks, blocksreleased = 0, real_released = 0;
    708 	int error = 0, allerror = 0;
    709 
    710 	ASSERT_SEGLOCK(fs);
    711 	/*
    712 	 * Calculate index in current block of last
    713 	 * block to be kept.  -1 indicates the entire
    714 	 * block so we need not calculate the index.
    715 	 */
    716 	factor = 1;
    717 	for (i = SINGLE; i < level; i++)
    718 		factor *= NINDIR(fs);
    719 	last = lastbn;
    720 	if (lastbn > 0)
    721 		last /= factor;
    722 	nblocks = btofsb(fs, fs->lfs_bsize);
    723 	/*
    724 	 * Get buffer of block pointers, zero those entries corresponding
    725 	 * to blocks to be free'd, and update on disk copy first.  Since
    726 	 * double(triple) indirect before single(double) indirect, calls
    727 	 * to bmap on these blocks will fail.  However, we already have
    728 	 * the on disk address, so we have to set the b_blkno field
    729 	 * explicitly instead of letting bread do everything for us.
    730 	 */
    731 	vp = ITOV(ip);
    732 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    733 	if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
    734 		/* Braces must be here in case trace evaluates to nothing. */
    735 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    736 	} else {
    737 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    738 		curlwp->l_ru.ru_inblock++; /* pay for read */
    739 		bp->b_flags |= B_READ;
    740 		if (bp->b_bcount > bp->b_bufsize)
    741 			panic("lfs_indirtrunc: bad buffer size");
    742 		bp->b_blkno = fsbtodb(fs, dbn);
    743 		VOP_STRATEGY(vp, bp);
    744 		error = biowait(bp);
    745 	}
    746 	if (error) {
    747 		brelse(bp, 0);
    748 		*countp = *rcountp = 0;
    749 		return (error);
    750 	}
    751 
    752 	bap = (int32_t *)bp->b_data;	/* XXX ondisk32 */
    753 	if (lastbn >= 0) {
    754 		copy = (int32_t *)lfs_malloc(fs, fs->lfs_bsize, LFS_NB_IBLOCK);
    755 		memcpy((void *)copy, (void *)bap, (u_int)fs->lfs_bsize);
    756 		memset((void *)&bap[last + 1], 0,
    757 		/* XXX ondisk32 */
    758 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (int32_t));
    759 		error = VOP_BWRITE(bp);
    760 		if (error)
    761 			allerror = error;
    762 		bap = copy;
    763 	}
    764 
    765 	/*
    766 	 * Recursively free totally unused blocks.
    767 	 */
    768 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    769 	    i--, nlbn += factor) {
    770 		nb = bap[i];
    771 		if (nb == 0)
    772 			continue;
    773 		if (level > SINGLE) {
    774 			error = lfs_indirtrunc(ip, nlbn, nb,
    775 					       (daddr_t)-1, level - 1,
    776 					       &blkcount, &rblkcount,
    777 					       lastsegp, bcp);
    778 			if (error)
    779 				allerror = error;
    780 			blocksreleased += blkcount;
    781 			real_released += rblkcount;
    782 		}
    783 		lfs_blkfree(fs, ip, nb, fs->lfs_bsize, lastsegp, bcp);
    784 		if (bap[i] > 0)
    785 			real_released += nblocks;
    786 		blocksreleased += nblocks;
    787 	}
    788 
    789 	/*
    790 	 * Recursively free last partial block.
    791 	 */
    792 	if (level > SINGLE && lastbn >= 0) {
    793 		last = lastbn % factor;
    794 		nb = bap[i];
    795 		if (nb != 0) {
    796 			error = lfs_indirtrunc(ip, nlbn, nb,
    797 					       last, level - 1, &blkcount,
    798 					       &rblkcount, lastsegp, bcp);
    799 			if (error)
    800 				allerror = error;
    801 			real_released += rblkcount;
    802 			blocksreleased += blkcount;
    803 		}
    804 	}
    805 
    806 	if (copy != NULL) {
    807 		lfs_free(fs, copy, LFS_NB_IBLOCK);
    808 	} else {
    809 		mutex_enter(&bufcache_lock);
    810 		if (bp->b_oflags & BO_DELWRI) {
    811 			LFS_UNLOCK_BUF(bp);
    812 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    813 			wakeup(&fs->lfs_avail);
    814 		}
    815 		brelsel(bp, BC_INVAL);
    816 		mutex_exit(&bufcache_lock);
    817 	}
    818 
    819 	*countp = blocksreleased;
    820 	*rcountp = real_released;
    821 	return (allerror);
    822 }
    823 
    824 /*
    825  * Destroy any in core blocks past the truncation length.
    826  * Inlined from vtruncbuf, so that lfs_avail could be updated.
    827  * We take the seglock to prevent cleaning from occurring while we are
    828  * invalidating blocks.
    829  */
    830 static int
    831 lfs_vtruncbuf(struct vnode *vp, daddr_t lbn, bool catch, int slptimeo)
    832 {
    833 	struct buf *bp, *nbp;
    834 	int error;
    835 	struct lfs *fs;
    836 	voff_t off;
    837 
    838 	off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
    839 	mutex_enter(&vp->v_interlock);
    840 	error = VOP_PUTPAGES(vp, off, 0, PGO_FREE | PGO_SYNCIO);
    841 	if (error)
    842 		return error;
    843 
    844 	fs = VTOI(vp)->i_lfs;
    845 
    846 	ASSERT_SEGLOCK(fs);
    847 
    848 	mutex_enter(&bufcache_lock);
    849 restart:
    850 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    851 		nbp = LIST_NEXT(bp, b_vnbufs);
    852 		if (bp->b_lblkno < lbn)
    853 			continue;
    854 		error = bbusy(bp, catch, slptimeo, NULL);
    855 		if (error == EPASSTHROUGH)
    856 			goto restart;
    857 		if (error != 0) {
    858 			mutex_exit(&bufcache_lock);
    859 			return (error);
    860 		}
    861 		mutex_enter(bp->b_objlock);
    862 		if (bp->b_oflags & BO_DELWRI) {
    863 			bp->b_oflags &= ~BO_DELWRI;
    864 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    865 			wakeup(&fs->lfs_avail);
    866 		}
    867 		mutex_exit(bp->b_objlock);
    868 		LFS_UNLOCK_BUF(bp);
    869 		brelsel(bp, BC_INVAL | BC_VFLUSH);
    870 	}
    871 
    872 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    873 		nbp = LIST_NEXT(bp, b_vnbufs);
    874 		if (bp->b_lblkno < lbn)
    875 			continue;
    876 		error = bbusy(bp, catch, slptimeo, NULL);
    877 		if (error == EPASSTHROUGH)
    878 			goto restart;
    879 		if (error != 0) {
    880 			mutex_exit(&bufcache_lock);
    881 			return (error);
    882 		}
    883 		mutex_enter(bp->b_objlock);
    884 		if (bp->b_oflags & BO_DELWRI) {
    885 			bp->b_oflags &= ~BO_DELWRI;
    886 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    887 			wakeup(&fs->lfs_avail);
    888 		}
    889 		mutex_exit(bp->b_objlock);
    890 		LFS_UNLOCK_BUF(bp);
    891 		brelsel(bp, BC_INVAL | BC_VFLUSH);
    892 	}
    893 	mutex_exit(&bufcache_lock);
    894 
    895 	return (0);
    896 }
    897 
    898