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lfs_inode.c revision 1.115.4.1
      1 /*	$NetBSD: lfs_inode.c,v 1.115.4.1 2008/01/02 21:58:24 bouyer 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  * 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. Neither the name of the University nor the names of its contributors
     51  *    may be used to endorse or promote products derived from this software
     52  *    without specific prior written permission.
     53  *
     54  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     55  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     56  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     57  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     58  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     59  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     60  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     61  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     62  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     63  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     64  * SUCH DAMAGE.
     65  *
     66  *	@(#)lfs_inode.c	8.9 (Berkeley) 5/8/95
     67  */
     68 
     69 #include <sys/cdefs.h>
     70 __KERNEL_RCSID(0, "$NetBSD: lfs_inode.c,v 1.115.4.1 2008/01/02 21:58:24 bouyer Exp $");
     71 
     72 #if defined(_KERNEL_OPT)
     73 #include "opt_quota.h"
     74 #endif
     75 
     76 #include <sys/param.h>
     77 #include <sys/systm.h>
     78 #include <sys/mount.h>
     79 #include <sys/malloc.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/trace.h>
     86 #include <sys/resourcevar.h>
     87 #include <sys/kauth.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 static int lfs_update_seguse(struct lfs *, struct inode *ip, long, size_t);
     98 static int lfs_indirtrunc (struct inode *, daddr_t, daddr_t,
     99 			   daddr_t, int, long *, long *, long *, size_t *);
    100 static int lfs_blkfree (struct lfs *, struct inode *, daddr_t, size_t, long *, size_t *);
    101 static int lfs_vtruncbuf(struct vnode *, daddr_t, bool, int);
    102 
    103 /* Search a block for a specific dinode. */
    104 struct ufs1_dinode *
    105 lfs_ifind(struct lfs *fs, ino_t ino, struct buf *bp)
    106 {
    107 	struct ufs1_dinode *dip = (struct ufs1_dinode *)bp->b_data;
    108 	struct ufs1_dinode *ldip, *fin;
    109 
    110 	ASSERT_NO_SEGLOCK(fs);
    111 	/*
    112 	 * Read the inode block backwards, since later versions of the
    113 	 * inode will supercede earlier ones.  Though it is unlikely, it is
    114 	 * possible that the same inode will appear in the same inode block.
    115 	 */
    116 	fin = dip + INOPB(fs);
    117 	for (ldip = fin - 1; ldip >= dip; --ldip)
    118 		if (ldip->di_inumber == ino)
    119 			return (ldip);
    120 
    121 	printf("searched %d entries\n", (int)(fin - dip));
    122 	printf("offset is 0x%x (seg %d)\n", fs->lfs_offset,
    123 	       dtosn(fs, fs->lfs_offset));
    124 	printf("block is 0x%llx (seg %lld)\n",
    125 	       (unsigned long long)dbtofsb(fs, bp->b_blkno),
    126 	       (long long)dtosn(fs, dbtofsb(fs, bp->b_blkno)));
    127 
    128 	return NULL;
    129 }
    130 
    131 int
    132 lfs_update(struct vnode *vp, const struct timespec *acc,
    133     const struct timespec *mod, int updflags)
    134 {
    135 	struct inode *ip;
    136 	struct lfs *fs = VFSTOUFS(vp->v_mount)->um_lfs;
    137 	int flags;
    138 
    139 	ASSERT_NO_SEGLOCK(fs);
    140 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    141 		return (0);
    142 	ip = VTOI(vp);
    143 
    144 	/*
    145 	 * If we are called from vinvalbuf, and the file's blocks have
    146 	 * already been scheduled for writing, but the writes have not
    147 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    148 	 * will cause a panic.	So, we must wait until any pending write
    149 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    150 	 */
    151 	mutex_enter(&vp->v_interlock);
    152 	while ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    153 	    WRITEINPROG(vp)) {
    154 		DLOG((DLOG_SEG, "lfs_update: sleeping on ino %d"
    155 		      " (in progress)\n", ip->i_number));
    156 		cv_wait(&vp->v_cv, &vp->v_interlock);
    157 	}
    158 	mutex_exit(&vp->v_interlock);
    159 	LFS_ITIMES(ip, acc, mod, NULL);
    160 	if (updflags & UPDATE_CLOSE)
    161 		flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING);
    162 	else
    163 		flags = ip->i_flag & (IN_MODIFIED | IN_CLEANING);
    164 	if (flags == 0)
    165 		return (0);
    166 
    167 	/* If sync, push back the vnode and any dirty blocks it may have. */
    168 	if ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT) {
    169 		/* Avoid flushing VU_DIROP. */
    170 		mutex_enter(&lfs_lock);
    171 		++fs->lfs_diropwait;
    172 		while (vp->v_uflag & VU_DIROP) {
    173 			DLOG((DLOG_DIROP, "lfs_update: sleeping on inode %d"
    174 			      " (dirops)\n", ip->i_number));
    175 			DLOG((DLOG_DIROP, "lfs_update: vflags 0x%x, iflags"
    176 			      " 0x%x\n",
    177 			      vp->v_iflag | vp->v_vflag | vp->v_uflag,
    178 			      ip->i_flag));
    179 			if (fs->lfs_dirops == 0)
    180 				lfs_flush_fs(fs, SEGM_SYNC);
    181 			else
    182 				mtsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    183 					0, &lfs_lock);
    184 			/* XXX KS - by falling out here, are we writing the vn
    185 			twice? */
    186 		}
    187 		--fs->lfs_diropwait;
    188 		mutex_exit(&lfs_lock);
    189 		return lfs_vflush(vp);
    190 	}
    191 	return 0;
    192 }
    193 
    194 #define	SINGLE	0	/* index of single indirect block */
    195 #define	DOUBLE	1	/* index of double indirect block */
    196 #define	TRIPLE	2	/* index of triple indirect block */
    197 /*
    198  * Truncate the inode oip to at most length size, freeing the
    199  * disk blocks.
    200  */
    201 /* VOP_BWRITE 1 + NIADDR + lfs_balloc == 2 + 2*NIADDR times */
    202 
    203 int
    204 lfs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
    205 {
    206 	daddr_t lastblock;
    207 	struct inode *oip = VTOI(ovp);
    208 	daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    209 	/* XXX ondisk32 */
    210 	int32_t newblks[NDADDR + NIADDR];
    211 	struct lfs *fs;
    212 	struct buf *bp;
    213 	int offset, size, level;
    214 	long count, rcount, blocksreleased = 0, real_released = 0;
    215 	int i, nblocks;
    216 	int aflags, error, allerror = 0;
    217 	off_t osize;
    218 	long lastseg;
    219 	size_t bc;
    220 	int obufsize, odb;
    221 	int usepc;
    222 	struct ufsmount *ump = oip->i_ump;
    223 
    224 	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
    225 	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
    226 		KASSERT(oip->i_size == 0);
    227 		return 0;
    228 	}
    229 
    230 	if (length < 0)
    231 		return (EINVAL);
    232 
    233 	/*
    234 	 * Just return and not update modification times.
    235 	 */
    236 	if (oip->i_size == length)
    237 		return (0);
    238 
    239 	if (ovp->v_type == VLNK &&
    240 	    (oip->i_size < ump->um_maxsymlinklen ||
    241 	     (ump->um_maxsymlinklen == 0 &&
    242 	      oip->i_ffs1_blocks == 0))) {
    243 #ifdef DIAGNOSTIC
    244 		if (length != 0)
    245 			panic("lfs_truncate: partial truncate of symlink");
    246 #endif
    247 		memset((char *)SHORTLINK(oip), 0, (u_int)oip->i_size);
    248 		oip->i_size = oip->i_ffs1_size = 0;
    249 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    250 		return (lfs_update(ovp, NULL, NULL, 0));
    251 	}
    252 	if (oip->i_size == length) {
    253 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    254 		return (lfs_update(ovp, NULL, NULL, 0));
    255 	}
    256 	fs = oip->i_lfs;
    257 	lfs_imtime(fs);
    258 	osize = oip->i_size;
    259 	usepc = (ovp->v_type == VREG && ovp != fs->lfs_ivnode);
    260 
    261 	ASSERT_NO_SEGLOCK(fs);
    262 	/*
    263 	 * Lengthen the size of the file. We must ensure that the
    264 	 * last byte of the file is allocated. Since the smallest
    265 	 * value of osize is 0, length will be at least 1.
    266 	 */
    267 	if (osize < length) {
    268 		if (length > ump->um_maxfilesize)
    269 			return (EFBIG);
    270 		aflags = B_CLRBUF;
    271 		if (ioflag & IO_SYNC)
    272 			aflags |= B_SYNC;
    273 		if (usepc) {
    274 			if (lblkno(fs, osize) < NDADDR &&
    275 			    lblkno(fs, osize) != lblkno(fs, length) &&
    276 			    blkroundup(fs, osize) != osize) {
    277 				off_t eob;
    278 
    279 				eob = blkroundup(fs, osize);
    280 				uvm_vnp_setwritesize(ovp, eob);
    281 				error = ufs_balloc_range(ovp, osize,
    282 				    eob - osize, cred, aflags);
    283 				if (error)
    284 					return error;
    285 				if (ioflag & IO_SYNC) {
    286 					mutex_enter(&ovp->v_interlock);
    287 					VOP_PUTPAGES(ovp,
    288 					    trunc_page(osize & fs->lfs_bmask),
    289 					    round_page(eob),
    290 					    PGO_CLEANIT | PGO_SYNCIO);
    291 				}
    292 			}
    293 			uvm_vnp_setwritesize(ovp, length);
    294 			error = ufs_balloc_range(ovp, length - 1, 1, cred,
    295 						 aflags);
    296 			if (error) {
    297 				(void) lfs_truncate(ovp, osize,
    298 						    ioflag & IO_SYNC, cred);
    299 				return error;
    300 			}
    301 			uvm_vnp_setsize(ovp, length);
    302 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    303 			KASSERT(ovp->v_size == oip->i_size);
    304 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    305 			return (lfs_update(ovp, NULL, NULL, 0));
    306 		} else {
    307 			error = lfs_reserve(fs, ovp, NULL,
    308 			    btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    309 			if (error)
    310 				return (error);
    311 			error = lfs_balloc(ovp, length - 1, 1, cred,
    312 					   aflags, &bp);
    313 			lfs_reserve(fs, ovp, NULL,
    314 			    -btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    315 			if (error)
    316 				return (error);
    317 			oip->i_ffs1_size = oip->i_size = length;
    318 			uvm_vnp_setsize(ovp, length);
    319 			(void) VOP_BWRITE(bp);
    320 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    321 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    322 			return (lfs_update(ovp, NULL, NULL, 0));
    323 		}
    324 	}
    325 
    326 	if ((error = lfs_reserve(fs, ovp, NULL,
    327 	    btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift))) != 0)
    328 		return (error);
    329 
    330 	/*
    331 	 * Shorten the size of the file. If the file is not being
    332 	 * truncated to a block boundary, the contents of the
    333 	 * partial block following the end of the file must be
    334 	 * zero'ed in case it ever becomes accessible again because
    335 	 * of subsequent file growth. Directories however are not
    336 	 * zero'ed as they should grow back initialized to empty.
    337 	 */
    338 	offset = blkoff(fs, length);
    339 	lastseg = -1;
    340 	bc = 0;
    341 
    342 	if (ovp != fs->lfs_ivnode)
    343 		lfs_seglock(fs, SEGM_PROT);
    344 	if (offset == 0) {
    345 		oip->i_size = oip->i_ffs1_size = length;
    346 	} else if (!usepc) {
    347 		lbn = lblkno(fs, length);
    348 		aflags = B_CLRBUF;
    349 		if (ioflag & IO_SYNC)
    350 			aflags |= B_SYNC;
    351 		error = lfs_balloc(ovp, length - 1, 1, cred, aflags, &bp);
    352 		if (error) {
    353 			lfs_reserve(fs, ovp, NULL,
    354 			    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    355 			goto errout;
    356 		}
    357 		obufsize = bp->b_bufsize;
    358 		odb = btofsb(fs, bp->b_bcount);
    359 		oip->i_size = oip->i_ffs1_size = length;
    360 		size = blksize(fs, oip, lbn);
    361 		if (ovp->v_type != VDIR)
    362 			memset((char *)bp->b_data + offset, 0,
    363 			       (u_int)(size - offset));
    364 		allocbuf(bp, size, 1);
    365 		if ((bp->b_cflags & BC_LOCKED) != 0 && bp->b_iodone == NULL) {
    366 			mutex_enter(&lfs_lock);
    367 			locked_queue_bytes -= obufsize - bp->b_bufsize;
    368 			mutex_exit(&lfs_lock);
    369 		}
    370 		if (bp->b_oflags & BO_DELWRI)
    371 			fs->lfs_avail += odb - btofsb(fs, size);
    372 		(void) VOP_BWRITE(bp);
    373 	} else { /* vp->v_type == VREG && length < osize && offset != 0 */
    374 		/*
    375 		 * When truncating a regular file down to a non-block-aligned
    376 		 * size, we must zero the part of last block which is past
    377 		 * the new EOF.  We must synchronously flush the zeroed pages
    378 		 * to disk since the new pages will be invalidated as soon
    379 		 * as we inform the VM system of the new, smaller size.
    380 		 * We must do this before acquiring the GLOCK, since fetching
    381 		 * the pages will acquire the GLOCK internally.
    382 		 * So there is a window where another thread could see a whole
    383 		 * zeroed page past EOF, but that's life.
    384 		 */
    385 		daddr_t xlbn;
    386 		voff_t eoz;
    387 
    388 		aflags = ioflag & IO_SYNC ? B_SYNC : 0;
    389 		error = ufs_balloc_range(ovp, length - 1, 1, cred, aflags);
    390 		if (error) {
    391 			lfs_reserve(fs, ovp, NULL,
    392 				    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    393 			goto errout;
    394 		}
    395 		xlbn = lblkno(fs, length);
    396 		size = blksize(fs, oip, xlbn);
    397 		eoz = MIN(lblktosize(fs, xlbn) + size, osize);
    398 		uvm_vnp_zerorange(ovp, length, eoz - length);
    399 		if (round_page(eoz) > round_page(length)) {
    400 			mutex_enter(&ovp->v_interlock);
    401 			error = VOP_PUTPAGES(ovp, round_page(length),
    402 			    round_page(eoz),
    403 			    PGO_CLEANIT | PGO_DEACTIVATE |
    404 			    ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
    405 			if (error) {
    406 				lfs_reserve(fs, ovp, NULL,
    407 					    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    408 				goto errout;
    409 			}
    410 		}
    411 	}
    412 
    413 	genfs_node_wrlock(ovp);
    414 
    415 	oip->i_size = oip->i_ffs1_size = length;
    416 	uvm_vnp_setsize(ovp, length);
    417 	/*
    418 	 * Calculate index into inode's block list of
    419 	 * last direct and indirect blocks (if any)
    420 	 * which we want to keep.  Lastblock is -1 when
    421 	 * the file is truncated to 0.
    422 	 */
    423 	/* Avoid sign overflow - XXX assumes that off_t is a quad_t. */
    424 	if (length > QUAD_MAX - fs->lfs_bsize)
    425 		lastblock = lblkno(fs, QUAD_MAX - fs->lfs_bsize);
    426 	else
    427 		lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    428 	lastiblock[SINGLE] = lastblock - NDADDR;
    429 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    430 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    431 	nblocks = btofsb(fs, fs->lfs_bsize);
    432 	/*
    433 	 * Record changed file and block pointers before we start
    434 	 * freeing blocks.  lastiblock values are also normalized to -1
    435 	 * for calls to lfs_indirtrunc below.
    436 	 */
    437 	memcpy((void *)newblks, (void *)&oip->i_ffs1_db[0], sizeof newblks);
    438 	for (level = TRIPLE; level >= SINGLE; level--)
    439 		if (lastiblock[level] < 0) {
    440 			newblks[NDADDR+level] = 0;
    441 			lastiblock[level] = -1;
    442 		}
    443 	for (i = NDADDR - 1; i > lastblock; i--)
    444 		newblks[i] = 0;
    445 
    446 	oip->i_size = oip->i_ffs1_size = osize;
    447 	error = lfs_vtruncbuf(ovp, lastblock + 1, false, 0);
    448 	if (error && !allerror)
    449 		allerror = error;
    450 
    451 	/*
    452 	 * Indirect blocks first.
    453 	 */
    454 	indir_lbn[SINGLE] = -NDADDR;
    455 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    456 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    457 	for (level = TRIPLE; level >= SINGLE; level--) {
    458 		bn = oip->i_ffs1_ib[level];
    459 		if (bn != 0) {
    460 			error = lfs_indirtrunc(oip, indir_lbn[level],
    461 					       bn, lastiblock[level],
    462 					       level, &count, &rcount,
    463 					       &lastseg, &bc);
    464 			if (error)
    465 				allerror = error;
    466 			real_released += rcount;
    467 			blocksreleased += count;
    468 			if (lastiblock[level] < 0) {
    469 				if (oip->i_ffs1_ib[level] > 0)
    470 					real_released += nblocks;
    471 				blocksreleased += nblocks;
    472 				oip->i_ffs1_ib[level] = 0;
    473 				lfs_blkfree(fs, oip, bn, fs->lfs_bsize,
    474 					    &lastseg, &bc);
    475         			lfs_deregister_block(ovp, bn);
    476 			}
    477 		}
    478 		if (lastiblock[level] >= 0)
    479 			goto done;
    480 	}
    481 
    482 	/*
    483 	 * All whole direct blocks or frags.
    484 	 */
    485 	for (i = NDADDR - 1; i > lastblock; i--) {
    486 		long bsize, obsize;
    487 
    488 		bn = oip->i_ffs1_db[i];
    489 		if (bn == 0)
    490 			continue;
    491 		bsize = blksize(fs, oip, i);
    492 		if (oip->i_ffs1_db[i] > 0) {
    493 			/* Check for fragment size changes */
    494 			obsize = oip->i_lfs_fragsize[i];
    495 			real_released += btofsb(fs, obsize);
    496 			oip->i_lfs_fragsize[i] = 0;
    497 		} else
    498 			obsize = 0;
    499 		blocksreleased += btofsb(fs, bsize);
    500 		oip->i_ffs1_db[i] = 0;
    501 		lfs_blkfree(fs, oip, bn, obsize, &lastseg, &bc);
    502         	lfs_deregister_block(ovp, bn);
    503 	}
    504 	if (lastblock < 0)
    505 		goto done;
    506 
    507 	/*
    508 	 * Finally, look for a change in size of the
    509 	 * last direct block; release any frags.
    510 	 */
    511 	bn = oip->i_ffs1_db[lastblock];
    512 	if (bn != 0) {
    513 		long oldspace, newspace;
    514 #if 0
    515 		long olddspace;
    516 #endif
    517 
    518 		/*
    519 		 * Calculate amount of space we're giving
    520 		 * back as old block size minus new block size.
    521 		 */
    522 		oldspace = blksize(fs, oip, lastblock);
    523 #if 0
    524 		olddspace = oip->i_lfs_fragsize[lastblock];
    525 #endif
    526 
    527 		oip->i_size = oip->i_ffs1_size = length;
    528 		newspace = blksize(fs, oip, lastblock);
    529 		if (newspace == 0)
    530 			panic("itrunc: newspace");
    531 		if (oldspace - newspace > 0) {
    532 			blocksreleased += btofsb(fs, oldspace - newspace);
    533 		}
    534 #if 0
    535 		if (bn > 0 && olddspace - newspace > 0) {
    536 			/* No segment accounting here, just vnode */
    537 			real_released += btofsb(fs, olddspace - newspace);
    538 		}
    539 #endif
    540 	}
    541 
    542 done:
    543 	/* Finish segment accounting corrections */
    544 	lfs_update_seguse(fs, oip, lastseg, bc);
    545 #ifdef DIAGNOSTIC
    546 	for (level = SINGLE; level <= TRIPLE; level++)
    547 		if ((newblks[NDADDR + level] == 0) !=
    548 		    ((oip->i_ffs1_ib[level]) == 0)) {
    549 			panic("lfs itrunc1");
    550 		}
    551 	for (i = 0; i < NDADDR; i++)
    552 		if ((newblks[i] == 0) != (oip->i_ffs1_db[i] == 0)) {
    553 			panic("lfs itrunc2");
    554 		}
    555 	if (length == 0 &&
    556 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    557 		panic("lfs itrunc3");
    558 #endif /* DIAGNOSTIC */
    559 	/*
    560 	 * Put back the real size.
    561 	 */
    562 	oip->i_size = oip->i_ffs1_size = length;
    563 	oip->i_lfs_effnblks -= blocksreleased;
    564 	oip->i_ffs1_blocks -= real_released;
    565 	mutex_enter(&lfs_lock);
    566 	fs->lfs_bfree += blocksreleased;
    567 	mutex_exit(&lfs_lock);
    568 #ifdef DIAGNOSTIC
    569 	if (oip->i_size == 0 &&
    570 	    (oip->i_ffs1_blocks != 0 || oip->i_lfs_effnblks != 0)) {
    571 		printf("lfs_truncate: truncate to 0 but %d blks/%d effblks\n",
    572 		       oip->i_ffs1_blocks, oip->i_lfs_effnblks);
    573 		panic("lfs_truncate: persistent blocks");
    574 	}
    575 #endif
    576 
    577 	/*
    578 	 * If we truncated to zero, take us off the paging queue.
    579 	 */
    580 	mutex_enter(&lfs_lock);
    581 	if (oip->i_size == 0 && oip->i_flags & IN_PAGING) {
    582 		oip->i_flags &= ~IN_PAGING;
    583 		TAILQ_REMOVE(&fs->lfs_pchainhd, oip, i_lfs_pchain);
    584 	}
    585 	mutex_exit(&lfs_lock);
    586 
    587 	oip->i_flag |= IN_CHANGE;
    588 #ifdef QUOTA
    589 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    590 #endif
    591 	lfs_reserve(fs, ovp, NULL,
    592 	    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    593 	genfs_node_unlock(ovp);
    594   errout:
    595 	oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    596 	if (ovp != fs->lfs_ivnode)
    597 		lfs_segunlock(fs);
    598 	return (allerror ? allerror : error);
    599 }
    600 
    601 /* Update segment and avail usage information when removing a block. */
    602 static int
    603 lfs_blkfree(struct lfs *fs, struct inode *ip, daddr_t daddr,
    604 	    size_t bsize, long *lastseg, size_t *num)
    605 {
    606 	long seg;
    607 	int error = 0;
    608 
    609 	ASSERT_SEGLOCK(fs);
    610 	bsize = fragroundup(fs, bsize);
    611 	if (daddr > 0) {
    612 		if (*lastseg != (seg = dtosn(fs, daddr))) {
    613 			error = lfs_update_seguse(fs, ip, *lastseg, *num);
    614 			*num = bsize;
    615 			*lastseg = seg;
    616 		} else
    617 			*num += bsize;
    618 	}
    619 
    620 	return error;
    621 }
    622 
    623 /* Finish the accounting updates for a segment. */
    624 static int
    625 lfs_update_seguse(struct lfs *fs, struct inode *ip, long lastseg, size_t num)
    626 {
    627 	struct segdelta *sd;
    628 	struct vnode *vp;
    629 
    630 	ASSERT_SEGLOCK(fs);
    631 	if (lastseg < 0 || num == 0)
    632 		return 0;
    633 
    634 	vp = ITOV(ip);
    635 	LIST_FOREACH(sd, &ip->i_lfs_segdhd, list)
    636 		if (sd->segnum == lastseg)
    637 			break;
    638 	if (sd == NULL) {
    639 		sd = malloc(sizeof(*sd), M_SEGMENT, M_WAITOK);
    640 		sd->segnum = lastseg;
    641 		sd->num = 0;
    642 		LIST_INSERT_HEAD(&ip->i_lfs_segdhd, sd, list);
    643 	}
    644 	sd->num += num;
    645 
    646 	return 0;
    647 }
    648 
    649 static void
    650 lfs_finalize_seguse(struct lfs *fs, void *v)
    651 {
    652 	SEGUSE *sup;
    653 	struct buf *bp;
    654 	struct segdelta *sd;
    655 	LIST_HEAD(, segdelta) *hd = v;
    656 
    657 	ASSERT_SEGLOCK(fs);
    658 	while((sd = LIST_FIRST(hd)) != NULL) {
    659 		LIST_REMOVE(sd, list);
    660 		LFS_SEGENTRY(sup, fs, sd->segnum, bp);
    661 		if (sd->num > sup->su_nbytes) {
    662 			printf("lfs_finalize_seguse: segment %ld short by %ld\n",
    663 				sd->segnum, (long)(sd->num - sup->su_nbytes));
    664 			panic("lfs_finalize_seguse: negative bytes");
    665 			sup->su_nbytes = sd->num;
    666 		}
    667 		sup->su_nbytes -= sd->num;
    668 		LFS_WRITESEGENTRY(sup, fs, sd->segnum, bp);
    669 		free(sd, M_SEGMENT);
    670 	}
    671 }
    672 
    673 /* Finish the accounting updates for a segment. */
    674 void
    675 lfs_finalize_ino_seguse(struct lfs *fs, struct inode *ip)
    676 {
    677 	ASSERT_SEGLOCK(fs);
    678 	lfs_finalize_seguse(fs, &ip->i_lfs_segdhd);
    679 }
    680 
    681 /* Finish the accounting updates for a segment. */
    682 void
    683 lfs_finalize_fs_seguse(struct lfs *fs)
    684 {
    685 	ASSERT_SEGLOCK(fs);
    686 	lfs_finalize_seguse(fs, &fs->lfs_segdhd);
    687 }
    688 
    689 /*
    690  * Release blocks associated with the inode ip and stored in the indirect
    691  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    692  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    693  * and recursive calls to indirtrunc must be used to cleanse other indirect
    694  * blocks.
    695  *
    696  * NB: triple indirect blocks are untested.
    697  */
    698 static int
    699 lfs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
    700 	       daddr_t lastbn, int level, long *countp,
    701 	       long *rcountp, long *lastsegp, size_t *bcp)
    702 {
    703 	int i;
    704 	struct buf *bp;
    705 	struct lfs *fs = ip->i_lfs;
    706 	int32_t *bap;	/* XXX ondisk32 */
    707 	struct vnode *vp;
    708 	daddr_t nb, nlbn, last;
    709 	int32_t *copy = NULL;	/* XXX ondisk32 */
    710 	long blkcount, rblkcount, factor;
    711 	int nblocks, blocksreleased = 0, real_released = 0;
    712 	int error = 0, allerror = 0;
    713 
    714 	ASSERT_SEGLOCK(fs);
    715 	/*
    716 	 * Calculate index in current block of last
    717 	 * block to be kept.  -1 indicates the entire
    718 	 * block so we need not calculate the index.
    719 	 */
    720 	factor = 1;
    721 	for (i = SINGLE; i < level; i++)
    722 		factor *= NINDIR(fs);
    723 	last = lastbn;
    724 	if (lastbn > 0)
    725 		last /= factor;
    726 	nblocks = btofsb(fs, fs->lfs_bsize);
    727 	/*
    728 	 * Get buffer of block pointers, zero those entries corresponding
    729 	 * to blocks to be free'd, and update on disk copy first.  Since
    730 	 * double(triple) indirect before single(double) indirect, calls
    731 	 * to bmap on these blocks will fail.  However, we already have
    732 	 * the on disk address, so we have to set the b_blkno field
    733 	 * explicitly instead of letting bread do everything for us.
    734 	 */
    735 	vp = ITOV(ip);
    736 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    737 	if (bp->b_oflags & (BO_DONE | BO_DELWRI)) {
    738 		/* Braces must be here in case trace evaluates to nothing. */
    739 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    740 	} else {
    741 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    742 		curlwp->l_proc->p_stats->p_ru.ru_inblock++; /* pay for read */
    743 		bp->b_flags |= B_READ;
    744 		if (bp->b_bcount > bp->b_bufsize)
    745 			panic("lfs_indirtrunc: bad buffer size");
    746 		bp->b_blkno = fsbtodb(fs, dbn);
    747 		VOP_STRATEGY(vp, bp);
    748 		error = biowait(bp);
    749 	}
    750 	if (error) {
    751 		brelse(bp, 0);
    752 		*countp = *rcountp = 0;
    753 		return (error);
    754 	}
    755 
    756 	bap = (int32_t *)bp->b_data;	/* XXX ondisk32 */
    757 	if (lastbn >= 0) {
    758 		copy = (int32_t *)lfs_malloc(fs, fs->lfs_bsize, LFS_NB_IBLOCK);
    759 		memcpy((void *)copy, (void *)bap, (u_int)fs->lfs_bsize);
    760 		memset((void *)&bap[last + 1], 0,
    761 		/* XXX ondisk32 */
    762 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (int32_t));
    763 		error = VOP_BWRITE(bp);
    764 		if (error)
    765 			allerror = error;
    766 		bap = copy;
    767 	}
    768 
    769 	/*
    770 	 * Recursively free totally unused blocks.
    771 	 */
    772 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    773 	    i--, nlbn += factor) {
    774 		nb = bap[i];
    775 		if (nb == 0)
    776 			continue;
    777 		if (level > SINGLE) {
    778 			error = lfs_indirtrunc(ip, nlbn, nb,
    779 					       (daddr_t)-1, level - 1,
    780 					       &blkcount, &rblkcount,
    781 					       lastsegp, bcp);
    782 			if (error)
    783 				allerror = error;
    784 			blocksreleased += blkcount;
    785 			real_released += rblkcount;
    786 		}
    787 		lfs_blkfree(fs, ip, nb, fs->lfs_bsize, lastsegp, bcp);
    788 		if (bap[i] > 0)
    789 			real_released += nblocks;
    790 		blocksreleased += nblocks;
    791 	}
    792 
    793 	/*
    794 	 * Recursively free last partial block.
    795 	 */
    796 	if (level > SINGLE && lastbn >= 0) {
    797 		last = lastbn % factor;
    798 		nb = bap[i];
    799 		if (nb != 0) {
    800 			error = lfs_indirtrunc(ip, nlbn, nb,
    801 					       last, level - 1, &blkcount,
    802 					       &rblkcount, lastsegp, bcp);
    803 			if (error)
    804 				allerror = error;
    805 			real_released += rblkcount;
    806 			blocksreleased += blkcount;
    807 		}
    808 	}
    809 
    810 	if (copy != NULL) {
    811 		lfs_free(fs, copy, LFS_NB_IBLOCK);
    812 	} else {
    813 		mutex_enter(&bufcache_lock);
    814 		if (bp->b_oflags & BO_DELWRI) {
    815 			LFS_UNLOCK_BUF(bp);
    816 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    817 			wakeup(&fs->lfs_avail);
    818 		}
    819 		brelsel(bp, BC_INVAL);
    820 		mutex_exit(&bufcache_lock);
    821 	}
    822 
    823 	*countp = blocksreleased;
    824 	*rcountp = real_released;
    825 	return (allerror);
    826 }
    827 
    828 /*
    829  * Destroy any in core blocks past the truncation length.
    830  * Inlined from vtruncbuf, so that lfs_avail could be updated.
    831  * We take the seglock to prevent cleaning from occurring while we are
    832  * invalidating blocks.
    833  */
    834 static int
    835 lfs_vtruncbuf(struct vnode *vp, daddr_t lbn, bool catch, int slptimeo)
    836 {
    837 	struct buf *bp, *nbp;
    838 	int error;
    839 	struct lfs *fs;
    840 	voff_t off;
    841 
    842 	off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
    843 	mutex_enter(&vp->v_interlock);
    844 	error = VOP_PUTPAGES(vp, off, 0, PGO_FREE | PGO_SYNCIO);
    845 	if (error)
    846 		return error;
    847 
    848 	fs = VTOI(vp)->i_lfs;
    849 
    850 	ASSERT_SEGLOCK(fs);
    851 
    852 	mutex_enter(&bufcache_lock);
    853 restart:
    854 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    855 		nbp = LIST_NEXT(bp, b_vnbufs);
    856 		if (bp->b_lblkno < lbn)
    857 			continue;
    858 		error = bbusy(bp, catch, slptimeo);
    859 		if (error == EPASSTHROUGH)
    860 			goto restart;
    861 		if (error != 0) {
    862 			mutex_exit(&bufcache_lock);
    863 			return (error);
    864 		}
    865 		mutex_enter(bp->b_objlock);
    866 		if (bp->b_oflags & BO_DELWRI) {
    867 			bp->b_oflags &= ~BO_DELWRI;
    868 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    869 			wakeup(&fs->lfs_avail);
    870 		}
    871 		mutex_exit(bp->b_objlock);
    872 		LFS_UNLOCK_BUF(bp);
    873 		brelsel(bp, BC_INVAL | BC_VFLUSH);
    874 	}
    875 
    876 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    877 		nbp = LIST_NEXT(bp, b_vnbufs);
    878 		if (bp->b_lblkno < lbn)
    879 			continue;
    880 		error = bbusy(bp, catch, slptimeo);
    881 		if (error == EPASSTHROUGH)
    882 			goto restart;
    883 		if (error != 0) {
    884 			mutex_exit(&bufcache_lock);
    885 			return (error);
    886 		}
    887 		mutex_enter(bp->b_objlock);
    888 		if (bp->b_oflags & BO_DELWRI) {
    889 			bp->b_oflags &= ~BO_DELWRI;
    890 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    891 			wakeup(&fs->lfs_avail);
    892 		}
    893 		mutex_exit(bp->b_objlock);
    894 		LFS_UNLOCK_BUF(bp);
    895 		brelsel(bp, BC_INVAL | BC_VFLUSH);
    896 	}
    897 	mutex_exit(&bufcache_lock);
    898 
    899 	return (0);
    900 }
    901 
    902