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lfs_inode.c revision 1.115
      1 /*	$NetBSD: lfs_inode.c,v 1.115 2007/12/08 19:29:55 pooka 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 2007/12/08 19:29:55 pooka 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, int, 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 s;
    138 	int flags;
    139 
    140 	ASSERT_NO_SEGLOCK(fs);
    141 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    142 		return (0);
    143 	ip = VTOI(vp);
    144 
    145 	/*
    146 	 * If we are called from vinvalbuf, and the file's blocks have
    147 	 * already been scheduled for writing, but the writes have not
    148 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    149 	 * will cause a panic.	So, we must wait until any pending write
    150 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    151 	 */
    152 	s = splbio();
    153 	simple_lock(&vp->v_interlock);
    154 	while ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    155 	    WRITEINPROG(vp)) {
    156 		DLOG((DLOG_SEG, "lfs_update: sleeping on ino %d"
    157 		      " (in progress)\n", ip->i_number));
    158 		ltsleep(vp, (PRIBIO+1), "lfs_update", 0, &vp->v_interlock);
    159 	}
    160 	simple_unlock(&vp->v_interlock);
    161 	splx(s);
    162 	LFS_ITIMES(ip, acc, mod, NULL);
    163 	if (updflags & UPDATE_CLOSE)
    164 		flags = ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING);
    165 	else
    166 		flags = ip->i_flag & (IN_MODIFIED | IN_CLEANING);
    167 	if (flags == 0)
    168 		return (0);
    169 
    170 	/* If sync, push back the vnode and any dirty blocks it may have. */
    171 	if ((updflags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT) {
    172 		/* Avoid flushing VU_DIROP. */
    173 		simple_lock(&fs->lfs_interlock);
    174 		++fs->lfs_diropwait;
    175 		while (vp->v_uflag & VU_DIROP) {
    176 			DLOG((DLOG_DIROP, "lfs_update: sleeping on inode %d"
    177 			      " (dirops)\n", ip->i_number));
    178 			DLOG((DLOG_DIROP, "lfs_update: vflags 0x%x, iflags"
    179 			      " 0x%x\n", vp->v_uflag|vp->v_iflag|vp->v_vflag,
    180 			      ip->i_flag));
    181 			if (fs->lfs_dirops == 0)
    182 				lfs_flush_fs(fs, SEGM_SYNC);
    183 			else
    184 				ltsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    185 					0, &fs->lfs_interlock);
    186 			/* XXX KS - by falling out here, are we writing the vn
    187 			twice? */
    188 		}
    189 		--fs->lfs_diropwait;
    190 		simple_unlock(&fs->lfs_interlock);
    191 		return lfs_vflush(vp);
    192 	}
    193 	return 0;
    194 }
    195 
    196 #define	SINGLE	0	/* index of single indirect block */
    197 #define	DOUBLE	1	/* index of double indirect block */
    198 #define	TRIPLE	2	/* index of triple indirect block */
    199 /*
    200  * Truncate the inode oip to at most length size, freeing the
    201  * disk blocks.
    202  */
    203 /* VOP_BWRITE 1 + NIADDR + lfs_balloc == 2 + 2*NIADDR times */
    204 
    205 int
    206 lfs_truncate(struct vnode *ovp, off_t length, int ioflag, kauth_cred_t cred)
    207 {
    208 	daddr_t lastblock;
    209 	struct inode *oip = VTOI(ovp);
    210 	daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    211 	/* XXX ondisk32 */
    212 	int32_t newblks[NDADDR + NIADDR];
    213 	struct lfs *fs;
    214 	struct buf *bp;
    215 	int offset, size, level;
    216 	long count, rcount, blocksreleased = 0, real_released = 0;
    217 	int i, nblocks;
    218 	int aflags, error, allerror = 0;
    219 	off_t osize;
    220 	long lastseg;
    221 	size_t bc;
    222 	int obufsize, odb;
    223 	int usepc;
    224 	struct ufsmount *ump = oip->i_ump;
    225 
    226 	if (ovp->v_type == VCHR || ovp->v_type == VBLK ||
    227 	    ovp->v_type == VFIFO || ovp->v_type == VSOCK) {
    228 		KASSERT(oip->i_size == 0);
    229 		return 0;
    230 	}
    231 
    232 	if (length < 0)
    233 		return (EINVAL);
    234 
    235 	/*
    236 	 * Just return and not update modification times.
    237 	 */
    238 	if (oip->i_size == length)
    239 		return (0);
    240 
    241 	if (ovp->v_type == VLNK &&
    242 	    (oip->i_size < ump->um_maxsymlinklen ||
    243 	     (ump->um_maxsymlinklen == 0 &&
    244 	      oip->i_ffs1_blocks == 0))) {
    245 #ifdef DIAGNOSTIC
    246 		if (length != 0)
    247 			panic("lfs_truncate: partial truncate of symlink");
    248 #endif
    249 		memset((char *)SHORTLINK(oip), 0, (u_int)oip->i_size);
    250 		oip->i_size = oip->i_ffs1_size = 0;
    251 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    252 		return (lfs_update(ovp, NULL, NULL, 0));
    253 	}
    254 	if (oip->i_size == length) {
    255 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    256 		return (lfs_update(ovp, NULL, NULL, 0));
    257 	}
    258 	fs = oip->i_lfs;
    259 	lfs_imtime(fs);
    260 	osize = oip->i_size;
    261 	usepc = (ovp->v_type == VREG && ovp != fs->lfs_ivnode);
    262 
    263 	ASSERT_NO_SEGLOCK(fs);
    264 	/*
    265 	 * Lengthen the size of the file. We must ensure that the
    266 	 * last byte of the file is allocated. Since the smallest
    267 	 * value of osize is 0, length will be at least 1.
    268 	 */
    269 	if (osize < length) {
    270 		if (length > ump->um_maxfilesize)
    271 			return (EFBIG);
    272 		aflags = B_CLRBUF;
    273 		if (ioflag & IO_SYNC)
    274 			aflags |= B_SYNC;
    275 		if (usepc) {
    276 			if (lblkno(fs, osize) < NDADDR &&
    277 			    lblkno(fs, osize) != lblkno(fs, length) &&
    278 			    blkroundup(fs, osize) != osize) {
    279 				off_t eob;
    280 
    281 				eob = blkroundup(fs, osize);
    282 				uvm_vnp_setwritesize(ovp, eob);
    283 				error = ufs_balloc_range(ovp, osize,
    284 				    eob - osize, cred, aflags);
    285 				if (error)
    286 					return error;
    287 				if (ioflag & IO_SYNC) {
    288 					simple_lock(&ovp->v_interlock);
    289 					VOP_PUTPAGES(ovp,
    290 					    trunc_page(osize & fs->lfs_bmask),
    291 					    round_page(eob),
    292 					    PGO_CLEANIT | PGO_SYNCIO);
    293 				}
    294 			}
    295 			uvm_vnp_setwritesize(ovp, length);
    296 			error = ufs_balloc_range(ovp, length - 1, 1, cred,
    297 						 aflags);
    298 			if (error) {
    299 				(void) lfs_truncate(ovp, osize,
    300 						    ioflag & IO_SYNC, cred);
    301 				return error;
    302 			}
    303 			uvm_vnp_setsize(ovp, length);
    304 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    305 			KASSERT(ovp->v_size == oip->i_size);
    306 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    307 			return (lfs_update(ovp, NULL, NULL, 0));
    308 		} else {
    309 			error = lfs_reserve(fs, ovp, NULL,
    310 			    btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    311 			if (error)
    312 				return (error);
    313 			error = lfs_balloc(ovp, length - 1, 1, cred,
    314 					   aflags, &bp);
    315 			lfs_reserve(fs, ovp, NULL,
    316 			    -btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    317 			if (error)
    318 				return (error);
    319 			oip->i_ffs1_size = oip->i_size = length;
    320 			uvm_vnp_setsize(ovp, length);
    321 			(void) VOP_BWRITE(bp);
    322 			oip->i_flag |= IN_CHANGE | IN_UPDATE;
    323 			oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    324 			return (lfs_update(ovp, NULL, NULL, 0));
    325 		}
    326 	}
    327 
    328 	if ((error = lfs_reserve(fs, ovp, NULL,
    329 	    btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift))) != 0)
    330 		return (error);
    331 
    332 	/*
    333 	 * Shorten the size of the file. If the file is not being
    334 	 * truncated to a block boundary, the contents of the
    335 	 * partial block following the end of the file must be
    336 	 * zero'ed in case it ever becomes accessible again because
    337 	 * of subsequent file growth. Directories however are not
    338 	 * zero'ed as they should grow back initialized to empty.
    339 	 */
    340 	offset = blkoff(fs, length);
    341 	lastseg = -1;
    342 	bc = 0;
    343 
    344 	if (ovp != fs->lfs_ivnode)
    345 		lfs_seglock(fs, SEGM_PROT);
    346 	if (offset == 0) {
    347 		oip->i_size = oip->i_ffs1_size = length;
    348 	} else if (!usepc) {
    349 		lbn = lblkno(fs, length);
    350 		aflags = B_CLRBUF;
    351 		if (ioflag & IO_SYNC)
    352 			aflags |= B_SYNC;
    353 		error = lfs_balloc(ovp, length - 1, 1, cred, aflags, &bp);
    354 		if (error) {
    355 			lfs_reserve(fs, ovp, NULL,
    356 			    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    357 			goto errout;
    358 		}
    359 		obufsize = bp->b_bufsize;
    360 		odb = btofsb(fs, bp->b_bcount);
    361 		oip->i_size = oip->i_ffs1_size = length;
    362 		size = blksize(fs, oip, lbn);
    363 		if (ovp->v_type != VDIR)
    364 			memset((char *)bp->b_data + offset, 0,
    365 			       (u_int)(size - offset));
    366 		allocbuf(bp, size, 1);
    367 		if ((bp->b_flags & (B_LOCKED | B_CALL)) == B_LOCKED) {
    368 			simple_lock(&lfs_subsys_lock);
    369 			locked_queue_bytes -= obufsize - bp->b_bufsize;
    370 			simple_unlock(&lfs_subsys_lock);
    371 		}
    372 		if (bp->b_flags & B_DELWRI)
    373 			fs->lfs_avail += odb - btofsb(fs, size);
    374 		(void) VOP_BWRITE(bp);
    375 	} else { /* vp->v_type == VREG && length < osize && offset != 0 */
    376 		/*
    377 		 * When truncating a regular file down to a non-block-aligned
    378 		 * size, we must zero the part of last block which is past
    379 		 * the new EOF.  We must synchronously flush the zeroed pages
    380 		 * to disk since the new pages will be invalidated as soon
    381 		 * as we inform the VM system of the new, smaller size.
    382 		 * We must do this before acquiring the GLOCK, since fetching
    383 		 * the pages will acquire the GLOCK internally.
    384 		 * So there is a window where another thread could see a whole
    385 		 * zeroed page past EOF, but that's life.
    386 		 */
    387 		daddr_t xlbn;
    388 		voff_t eoz;
    389 
    390 		aflags = ioflag & IO_SYNC ? B_SYNC : 0;
    391 		error = ufs_balloc_range(ovp, length - 1, 1, cred, aflags);
    392 		if (error) {
    393 			lfs_reserve(fs, ovp, NULL,
    394 				    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    395 			goto errout;
    396 		}
    397 		xlbn = lblkno(fs, length);
    398 		size = blksize(fs, oip, xlbn);
    399 		eoz = MIN(lblktosize(fs, xlbn) + size, osize);
    400 		uvm_vnp_zerorange(ovp, length, eoz - length);
    401 		if (round_page(eoz) > round_page(length)) {
    402 			simple_lock(&ovp->v_interlock);
    403 			error = VOP_PUTPAGES(ovp, round_page(length),
    404 			    round_page(eoz),
    405 			    PGO_CLEANIT | PGO_DEACTIVATE |
    406 			    ((ioflag & IO_SYNC) ? PGO_SYNCIO : 0));
    407 			if (error) {
    408 				lfs_reserve(fs, ovp, NULL,
    409 					    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    410 				goto errout;
    411 			}
    412 		}
    413 	}
    414 
    415 	genfs_node_wrlock(ovp);
    416 
    417 	oip->i_size = oip->i_ffs1_size = length;
    418 	uvm_vnp_setsize(ovp, length);
    419 	/*
    420 	 * Calculate index into inode's block list of
    421 	 * last direct and indirect blocks (if any)
    422 	 * which we want to keep.  Lastblock is -1 when
    423 	 * the file is truncated to 0.
    424 	 */
    425 	/* Avoid sign overflow - XXX assumes that off_t is a quad_t. */
    426 	if (length > QUAD_MAX - fs->lfs_bsize)
    427 		lastblock = lblkno(fs, QUAD_MAX - fs->lfs_bsize);
    428 	else
    429 		lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    430 	lastiblock[SINGLE] = lastblock - NDADDR;
    431 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    432 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    433 	nblocks = btofsb(fs, fs->lfs_bsize);
    434 	/*
    435 	 * Record changed file and block pointers before we start
    436 	 * freeing blocks.  lastiblock values are also normalized to -1
    437 	 * for calls to lfs_indirtrunc below.
    438 	 */
    439 	memcpy((void *)newblks, (void *)&oip->i_ffs1_db[0], sizeof newblks);
    440 	for (level = TRIPLE; level >= SINGLE; level--)
    441 		if (lastiblock[level] < 0) {
    442 			newblks[NDADDR+level] = 0;
    443 			lastiblock[level] = -1;
    444 		}
    445 	for (i = NDADDR - 1; i > lastblock; i--)
    446 		newblks[i] = 0;
    447 
    448 	oip->i_size = oip->i_ffs1_size = osize;
    449 	error = lfs_vtruncbuf(ovp, lastblock + 1, 0, 0);
    450 	if (error && !allerror)
    451 		allerror = error;
    452 
    453 	/*
    454 	 * Indirect blocks first.
    455 	 */
    456 	indir_lbn[SINGLE] = -NDADDR;
    457 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    458 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    459 	for (level = TRIPLE; level >= SINGLE; level--) {
    460 		bn = oip->i_ffs1_ib[level];
    461 		if (bn != 0) {
    462 			error = lfs_indirtrunc(oip, indir_lbn[level],
    463 					       bn, lastiblock[level],
    464 					       level, &count, &rcount,
    465 					       &lastseg, &bc);
    466 			if (error)
    467 				allerror = error;
    468 			real_released += rcount;
    469 			blocksreleased += count;
    470 			if (lastiblock[level] < 0) {
    471 				if (oip->i_ffs1_ib[level] > 0)
    472 					real_released += nblocks;
    473 				blocksreleased += nblocks;
    474 				oip->i_ffs1_ib[level] = 0;
    475 				lfs_blkfree(fs, oip, bn, fs->lfs_bsize,
    476 					    &lastseg, &bc);
    477         			lfs_deregister_block(ovp, bn);
    478 			}
    479 		}
    480 		if (lastiblock[level] >= 0)
    481 			goto done;
    482 	}
    483 
    484 	/*
    485 	 * All whole direct blocks or frags.
    486 	 */
    487 	for (i = NDADDR - 1; i > lastblock; i--) {
    488 		long bsize, obsize;
    489 
    490 		bn = oip->i_ffs1_db[i];
    491 		if (bn == 0)
    492 			continue;
    493 		bsize = blksize(fs, oip, i);
    494 		if (oip->i_ffs1_db[i] > 0) {
    495 			/* Check for fragment size changes */
    496 			obsize = oip->i_lfs_fragsize[i];
    497 			real_released += btofsb(fs, obsize);
    498 			oip->i_lfs_fragsize[i] = 0;
    499 		} else
    500 			obsize = 0;
    501 		blocksreleased += btofsb(fs, bsize);
    502 		oip->i_ffs1_db[i] = 0;
    503 		lfs_blkfree(fs, oip, bn, obsize, &lastseg, &bc);
    504         	lfs_deregister_block(ovp, bn);
    505 	}
    506 	if (lastblock < 0)
    507 		goto done;
    508 
    509 	/*
    510 	 * Finally, look for a change in size of the
    511 	 * last direct block; release any frags.
    512 	 */
    513 	bn = oip->i_ffs1_db[lastblock];
    514 	if (bn != 0) {
    515 		long oldspace, newspace;
    516 #if 0
    517 		long olddspace;
    518 #endif
    519 
    520 		/*
    521 		 * Calculate amount of space we're giving
    522 		 * back as old block size minus new block size.
    523 		 */
    524 		oldspace = blksize(fs, oip, lastblock);
    525 #if 0
    526 		olddspace = oip->i_lfs_fragsize[lastblock];
    527 #endif
    528 
    529 		oip->i_size = oip->i_ffs1_size = length;
    530 		newspace = blksize(fs, oip, lastblock);
    531 		if (newspace == 0)
    532 			panic("itrunc: newspace");
    533 		if (oldspace - newspace > 0) {
    534 			blocksreleased += btofsb(fs, oldspace - newspace);
    535 		}
    536 #if 0
    537 		if (bn > 0 && olddspace - newspace > 0) {
    538 			/* No segment accounting here, just vnode */
    539 			real_released += btofsb(fs, olddspace - newspace);
    540 		}
    541 #endif
    542 	}
    543 
    544 done:
    545 	/* Finish segment accounting corrections */
    546 	lfs_update_seguse(fs, oip, lastseg, bc);
    547 #ifdef DIAGNOSTIC
    548 	for (level = SINGLE; level <= TRIPLE; level++)
    549 		if ((newblks[NDADDR + level] == 0) !=
    550 		    ((oip->i_ffs1_ib[level]) == 0)) {
    551 			panic("lfs itrunc1");
    552 		}
    553 	for (i = 0; i < NDADDR; i++)
    554 		if ((newblks[i] == 0) != (oip->i_ffs1_db[i] == 0)) {
    555 			panic("lfs itrunc2");
    556 		}
    557 	if (length == 0 &&
    558 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    559 		panic("lfs itrunc3");
    560 #endif /* DIAGNOSTIC */
    561 	/*
    562 	 * Put back the real size.
    563 	 */
    564 	oip->i_size = oip->i_ffs1_size = length;
    565 	oip->i_lfs_effnblks -= blocksreleased;
    566 	oip->i_ffs1_blocks -= real_released;
    567 	simple_lock(&fs->lfs_interlock);
    568 	fs->lfs_bfree += blocksreleased;
    569 	simple_unlock(&fs->lfs_interlock);
    570 #ifdef DIAGNOSTIC
    571 	if (oip->i_size == 0 &&
    572 	    (oip->i_ffs1_blocks != 0 || oip->i_lfs_effnblks != 0)) {
    573 		printf("lfs_truncate: truncate to 0 but %d blks/%d effblks\n",
    574 		       oip->i_ffs1_blocks, oip->i_lfs_effnblks);
    575 		panic("lfs_truncate: persistent blocks");
    576 	}
    577 #endif
    578 
    579 	/*
    580 	 * If we truncated to zero, take us off the paging queue.
    581 	 */
    582 	simple_lock(&fs->lfs_interlock);
    583 	if (oip->i_size == 0 && oip->i_flags & IN_PAGING) {
    584 		oip->i_flags &= ~IN_PAGING;
    585 		TAILQ_REMOVE(&fs->lfs_pchainhd, oip, i_lfs_pchain);
    586 	}
    587 	simple_unlock(&fs->lfs_interlock);
    588 
    589 	oip->i_flag |= IN_CHANGE;
    590 #ifdef QUOTA
    591 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    592 #endif
    593 	lfs_reserve(fs, ovp, NULL,
    594 	    -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    595 	genfs_node_unlock(ovp);
    596   errout:
    597 	oip->i_lfs_hiblk = lblkno(fs, oip->i_size + fs->lfs_bsize - 1) - 1;
    598 	if (ovp != fs->lfs_ivnode)
    599 		lfs_segunlock(fs);
    600 	return (allerror ? allerror : error);
    601 }
    602 
    603 /* Update segment and avail usage information when removing a block. */
    604 static int
    605 lfs_blkfree(struct lfs *fs, struct inode *ip, daddr_t daddr,
    606 	    size_t bsize, long *lastseg, size_t *num)
    607 {
    608 	long seg;
    609 	int error = 0;
    610 
    611 	ASSERT_SEGLOCK(fs);
    612 	bsize = fragroundup(fs, bsize);
    613 	if (daddr > 0) {
    614 		if (*lastseg != (seg = dtosn(fs, daddr))) {
    615 			error = lfs_update_seguse(fs, ip, *lastseg, *num);
    616 			*num = bsize;
    617 			*lastseg = seg;
    618 		} else
    619 			*num += bsize;
    620 	}
    621 
    622 	return error;
    623 }
    624 
    625 /* Finish the accounting updates for a segment. */
    626 static int
    627 lfs_update_seguse(struct lfs *fs, struct inode *ip, long lastseg, size_t num)
    628 {
    629 	struct segdelta *sd;
    630 	struct vnode *vp;
    631 
    632 	ASSERT_SEGLOCK(fs);
    633 	if (lastseg < 0 || num == 0)
    634 		return 0;
    635 
    636 	vp = ITOV(ip);
    637 	LIST_FOREACH(sd, &ip->i_lfs_segdhd, list)
    638 		if (sd->segnum == lastseg)
    639 			break;
    640 	if (sd == NULL) {
    641 		sd = malloc(sizeof(*sd), M_SEGMENT, M_WAITOK);
    642 		sd->segnum = lastseg;
    643 		sd->num = 0;
    644 		LIST_INSERT_HEAD(&ip->i_lfs_segdhd, sd, list);
    645 	}
    646 	sd->num += num;
    647 
    648 	return 0;
    649 }
    650 
    651 static void
    652 lfs_finalize_seguse(struct lfs *fs, void *v)
    653 {
    654 	SEGUSE *sup;
    655 	struct buf *bp;
    656 	struct segdelta *sd;
    657 	LIST_HEAD(, segdelta) *hd = v;
    658 
    659 	ASSERT_SEGLOCK(fs);
    660 	while((sd = LIST_FIRST(hd)) != NULL) {
    661 		LIST_REMOVE(sd, list);
    662 		LFS_SEGENTRY(sup, fs, sd->segnum, bp);
    663 		if (sd->num > sup->su_nbytes) {
    664 			printf("lfs_finalize_seguse: segment %ld short by %ld\n",
    665 				sd->segnum, (long)(sd->num - sup->su_nbytes));
    666 			panic("lfs_finalize_seguse: negative bytes");
    667 			sup->su_nbytes = sd->num;
    668 		}
    669 		sup->su_nbytes -= sd->num;
    670 		LFS_WRITESEGENTRY(sup, fs, sd->segnum, bp);
    671 		free(sd, M_SEGMENT);
    672 	}
    673 }
    674 
    675 /* Finish the accounting updates for a segment. */
    676 void
    677 lfs_finalize_ino_seguse(struct lfs *fs, struct inode *ip)
    678 {
    679 	ASSERT_SEGLOCK(fs);
    680 	lfs_finalize_seguse(fs, &ip->i_lfs_segdhd);
    681 }
    682 
    683 /* Finish the accounting updates for a segment. */
    684 void
    685 lfs_finalize_fs_seguse(struct lfs *fs)
    686 {
    687 	ASSERT_SEGLOCK(fs);
    688 	lfs_finalize_seguse(fs, &fs->lfs_segdhd);
    689 }
    690 
    691 /*
    692  * Release blocks associated with the inode ip and stored in the indirect
    693  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    694  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    695  * and recursive calls to indirtrunc must be used to cleanse other indirect
    696  * blocks.
    697  *
    698  * NB: triple indirect blocks are untested.
    699  */
    700 static int
    701 lfs_indirtrunc(struct inode *ip, daddr_t lbn, daddr_t dbn,
    702 	       daddr_t lastbn, int level, long *countp,
    703 	       long *rcountp, long *lastsegp, size_t *bcp)
    704 {
    705 	int i;
    706 	struct buf *bp;
    707 	struct lfs *fs = ip->i_lfs;
    708 	int32_t *bap;	/* XXX ondisk32 */
    709 	struct vnode *vp;
    710 	daddr_t nb, nlbn, last;
    711 	int32_t *copy = NULL;	/* XXX ondisk32 */
    712 	long blkcount, rblkcount, factor;
    713 	int nblocks, blocksreleased = 0, real_released = 0;
    714 	int error = 0, allerror = 0;
    715 
    716 	ASSERT_SEGLOCK(fs);
    717 	/*
    718 	 * Calculate index in current block of last
    719 	 * block to be kept.  -1 indicates the entire
    720 	 * block so we need not calculate the index.
    721 	 */
    722 	factor = 1;
    723 	for (i = SINGLE; i < level; i++)
    724 		factor *= NINDIR(fs);
    725 	last = lastbn;
    726 	if (lastbn > 0)
    727 		last /= factor;
    728 	nblocks = btofsb(fs, fs->lfs_bsize);
    729 	/*
    730 	 * Get buffer of block pointers, zero those entries corresponding
    731 	 * to blocks to be free'd, and update on disk copy first.  Since
    732 	 * double(triple) indirect before single(double) indirect, calls
    733 	 * to bmap on these blocks will fail.  However, we already have
    734 	 * the on disk address, so we have to set the b_blkno field
    735 	 * explicitly instead of letting bread do everything for us.
    736 	 */
    737 	vp = ITOV(ip);
    738 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    739 	if (bp->b_flags & (B_DONE | B_DELWRI)) {
    740 		/* Braces must be here in case trace evaluates to nothing. */
    741 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    742 	} else {
    743 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    744 		curlwp->l_proc->p_stats->p_ru.ru_inblock++; /* pay for read */
    745 		bp->b_flags |= B_READ;
    746 		if (bp->b_bcount > bp->b_bufsize)
    747 			panic("lfs_indirtrunc: bad buffer size");
    748 		bp->b_blkno = fsbtodb(fs, dbn);
    749 		VOP_STRATEGY(vp, bp);
    750 		error = biowait(bp);
    751 	}
    752 	if (error) {
    753 		brelse(bp, 0);
    754 		*countp = *rcountp = 0;
    755 		return (error);
    756 	}
    757 
    758 	bap = (int32_t *)bp->b_data;	/* XXX ondisk32 */
    759 	if (lastbn >= 0) {
    760 		copy = (int32_t *)lfs_malloc(fs, fs->lfs_bsize, LFS_NB_IBLOCK);
    761 		memcpy((void *)copy, (void *)bap, (u_int)fs->lfs_bsize);
    762 		memset((void *)&bap[last + 1], 0,
    763 		/* XXX ondisk32 */
    764 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (int32_t));
    765 		error = VOP_BWRITE(bp);
    766 		if (error)
    767 			allerror = error;
    768 		bap = copy;
    769 	}
    770 
    771 	/*
    772 	 * Recursively free totally unused blocks.
    773 	 */
    774 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    775 	    i--, nlbn += factor) {
    776 		nb = bap[i];
    777 		if (nb == 0)
    778 			continue;
    779 		if (level > SINGLE) {
    780 			error = lfs_indirtrunc(ip, nlbn, nb,
    781 					       (daddr_t)-1, level - 1,
    782 					       &blkcount, &rblkcount,
    783 					       lastsegp, bcp);
    784 			if (error)
    785 				allerror = error;
    786 			blocksreleased += blkcount;
    787 			real_released += rblkcount;
    788 		}
    789 		lfs_blkfree(fs, ip, nb, fs->lfs_bsize, lastsegp, bcp);
    790 		if (bap[i] > 0)
    791 			real_released += nblocks;
    792 		blocksreleased += nblocks;
    793 	}
    794 
    795 	/*
    796 	 * Recursively free last partial block.
    797 	 */
    798 	if (level > SINGLE && lastbn >= 0) {
    799 		last = lastbn % factor;
    800 		nb = bap[i];
    801 		if (nb != 0) {
    802 			error = lfs_indirtrunc(ip, nlbn, nb,
    803 					       last, level - 1, &blkcount,
    804 					       &rblkcount, lastsegp, bcp);
    805 			if (error)
    806 				allerror = error;
    807 			real_released += rblkcount;
    808 			blocksreleased += blkcount;
    809 		}
    810 	}
    811 
    812 	if (copy != NULL) {
    813 		lfs_free(fs, copy, LFS_NB_IBLOCK);
    814 	} else {
    815 		if (bp->b_flags & B_DELWRI) {
    816 			LFS_UNLOCK_BUF(bp);
    817 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    818 			wakeup(&fs->lfs_avail);
    819 		}
    820 		brelse(bp, BC_INVAL);
    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, int slpflag, int slptimeo)
    836 {
    837 	struct buf *bp, *nbp;
    838 	int s, error;
    839 	struct lfs *fs;
    840 	voff_t off;
    841 
    842 	off = round_page((voff_t)lbn << vp->v_mount->mnt_fs_bshift);
    843 	simple_lock(&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 	s = splbio();
    850 
    851 	ASSERT_SEGLOCK(fs);
    852 restart:
    853 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    854 		nbp = LIST_NEXT(bp, b_vnbufs);
    855 		if (bp->b_lblkno < lbn)
    856 			continue;
    857 		simple_lock(&bp->b_interlock);
    858 		if (bp->b_flags & B_BUSY) {
    859 			bp->b_flags |= B_WANTED;
    860 			error = ltsleep(bp, slpflag | (PRIBIO + 1) | PNORELOCK,
    861 			    "lfs_vtruncbuf", slptimeo, &bp->b_interlock);
    862 			if (error) {
    863 				splx(s);
    864 				return (error);
    865 			}
    866 			goto restart;
    867 		}
    868 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    869 		if (bp->b_flags & B_DELWRI) {
    870 			bp->b_flags &= ~B_DELWRI;
    871 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    872 			wakeup(&fs->lfs_avail);
    873 		}
    874 		LFS_UNLOCK_BUF(bp);
    875 		simple_unlock(&bp->b_interlock);
    876 		brelse(bp, 0);
    877 	}
    878 
    879 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    880 		nbp = LIST_NEXT(bp, b_vnbufs);
    881 		if (bp->b_lblkno < lbn)
    882 			continue;
    883 		simple_lock(&bp->b_interlock);
    884 		if (bp->b_flags & B_BUSY) {
    885 			bp->b_flags |= B_WANTED;
    886 			error = ltsleep(bp, slpflag | (PRIBIO + 1) | PNORELOCK,
    887 			    "lfs_vtruncbuf", slptimeo, &bp->b_interlock);
    888 			if (error) {
    889 				splx(s);
    890 				return (error);
    891 			}
    892 			goto restart;
    893 		}
    894 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    895 		if (bp->b_flags & B_DELWRI) {
    896 			bp->b_flags &= ~B_DELWRI;
    897 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    898 			wakeup(&fs->lfs_avail);
    899 		}
    900 		LFS_UNLOCK_BUF(bp);
    901 		simple_unlock(&bp->b_interlock);
    902 		brelse(bp, 0);
    903 	}
    904 
    905 	splx(s);
    906 
    907 	return (0);
    908 }
    909 
    910