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lfs_inode.c revision 1.57
      1 /*	$NetBSD: lfs_inode.c,v 1.57 2002/05/14 20:03:54 perseant Exp $	*/
      2 
      3 /*-
      4  * Copyright (c) 1999, 2000 The NetBSD Foundation, Inc.
      5  * All rights reserved.
      6  *
      7  * This code is derived from software contributed to The NetBSD Foundation
      8  * by Konrad E. Schroder <perseant (at) hhhh.org>.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *      This product includes software developed by the NetBSD
     21  *      Foundation, Inc. and its contributors.
     22  * 4. Neither the name of The NetBSD Foundation nor the names of its
     23  *    contributors may be used to endorse or promote products derived
     24  *    from this software without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
     27  * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
     28  * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
     29  * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
     30  * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
     31  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
     32  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
     33  * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
     34  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
     35  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
     36  * POSSIBILITY OF SUCH DAMAGE.
     37  */
     38 /*
     39  * Copyright (c) 1986, 1989, 1991, 1993
     40  *	The Regents of the University of California.  All rights reserved.
     41  *
     42  * Redistribution and use in source and binary forms, with or without
     43  * modification, are permitted provided that the following conditions
     44  * are met:
     45  * 1. Redistributions of source code must retain the above copyright
     46  *    notice, this list of conditions and the following disclaimer.
     47  * 2. Redistributions in binary form must reproduce the above copyright
     48  *    notice, this list of conditions and the following disclaimer in the
     49  *    documentation and/or other materials provided with the distribution.
     50  * 3. All advertising materials mentioning features or use of this software
     51  *    must display the following acknowledgement:
     52  *	This product includes software developed by the University of
     53  *	California, Berkeley and its contributors.
     54  * 4. Neither the name of the University nor the names of its contributors
     55  *    may be used to endorse or promote products derived from this software
     56  *    without specific prior written permission.
     57  *
     58  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     59  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     60  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     61  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     62  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     63  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     64  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     65  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     66  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     67  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     68  * SUCH DAMAGE.
     69  *
     70  *	@(#)lfs_inode.c	8.9 (Berkeley) 5/8/95
     71  */
     72 
     73 #include <sys/cdefs.h>
     74 __KERNEL_RCSID(0, "$NetBSD: lfs_inode.c,v 1.57 2002/05/14 20:03:54 perseant Exp $");
     75 
     76 #if defined(_KERNEL_OPT)
     77 #include "opt_quota.h"
     78 #endif
     79 
     80 #include <sys/param.h>
     81 #include <sys/systm.h>
     82 #include <sys/mount.h>
     83 #include <sys/proc.h>
     84 #include <sys/file.h>
     85 #include <sys/buf.h>
     86 #include <sys/vnode.h>
     87 #include <sys/kernel.h>
     88 #include <sys/malloc.h>
     89 #include <sys/trace.h>
     90 #include <sys/resourcevar.h>
     91 
     92 #include <ufs/ufs/quota.h>
     93 #include <ufs/ufs/inode.h>
     94 #include <ufs/ufs/ufsmount.h>
     95 #include <ufs/ufs/ufs_extern.h>
     96 
     97 #include <ufs/lfs/lfs.h>
     98 #include <ufs/lfs/lfs_extern.h>
     99 
    100 extern int locked_queue_count;
    101 extern long locked_queue_bytes;
    102 
    103 static int lfs_update_seguse(struct lfs *, long, size_t);
    104 static int lfs_indirtrunc (struct inode *, ufs_daddr_t, ufs_daddr_t,
    105 			   ufs_daddr_t, int, long *, long *, long *, size_t *,
    106 			   struct proc *);
    107 static int lfs_blkfree (struct lfs *, daddr_t, size_t, long *, size_t *);
    108 static int lfs_vtruncbuf(struct vnode *, daddr_t, int, int);
    109 
    110 /* Search a block for a specific dinode. */
    111 struct dinode *
    112 lfs_ifind(struct lfs *fs, ino_t ino, struct buf *bp)
    113 {
    114 	struct dinode *dip = (struct dinode *)bp->b_data;
    115 	struct dinode *ldip, *fin;
    116 
    117 #ifdef LFS_IFILE_FRAG_ADDRESSING
    118 	if (fs->lfs_version == 1)
    119 		fin = dip + INOPB(fs);
    120 	else
    121 		fin = dip + INOPF(fs);
    122 #else
    123 	fin = dip + INOPB(fs);
    124 #endif
    125 
    126 	/*
    127 	 * XXX we used to go from the top down here, presumably with the
    128 	 * idea that the same inode could be written twice in the same
    129 	 * block (which is not supposed to be true).
    130 	 */
    131 	for (ldip = dip; ldip < fin; ++ldip)
    132 		if (ldip->di_inumber == ino)
    133 			return (ldip);
    134 
    135 	printf("searched %d entries\n", (int)(fin - dip));
    136 	printf("offset is 0x%x (seg %d)\n", fs->lfs_offset,
    137 	       dtosn(fs, fs->lfs_offset));
    138 	printf("block is 0x%x (seg %d)\n", dbtofsb(fs, bp->b_blkno),
    139 	       dtosn(fs, dbtofsb(fs, bp->b_blkno)));
    140 
    141 	return NULL;
    142 }
    143 
    144 int
    145 lfs_update(void *v)
    146 {
    147 	struct vop_update_args /* {
    148 				  struct vnode *a_vp;
    149 				  struct timespec *a_access;
    150 				  struct timespec *a_modify;
    151 				  int a_flags;
    152 				  } */ *ap = v;
    153 	struct inode *ip;
    154 	struct vnode *vp = ap->a_vp;
    155 	struct timespec ts;
    156 	struct lfs *fs = VFSTOUFS(vp->v_mount)->um_lfs;
    157 	int s;
    158 
    159 	if (vp->v_mount->mnt_flag & MNT_RDONLY)
    160 		return (0);
    161 	ip = VTOI(vp);
    162 
    163 	/*
    164 	 * If we are called from vinvalbuf, and the file's blocks have
    165 	 * already been scheduled for writing, but the writes have not
    166 	 * yet completed, lfs_vflush will not be called, and vinvalbuf
    167 	 * will cause a panic.  So, we must wait until any pending write
    168 	 * for our inode completes, if we are called with UPDATE_WAIT set.
    169 	 */
    170 	s = splbio();
    171 	while ((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT &&
    172 	    WRITEINPROG(vp)) {
    173 #ifdef DEBUG_LFS
    174 		printf("lfs_update: sleeping on inode %d (in-progress)\n",
    175 		       ip->i_number);
    176 #endif
    177 		tsleep(vp, (PRIBIO+1), "lfs_update", 0);
    178 	}
    179 	splx(s);
    180 	TIMEVAL_TO_TIMESPEC(&time, &ts);
    181 	LFS_ITIMES(ip,
    182 		   ap->a_access ? ap->a_access : &ts,
    183 		   ap->a_modify ? ap->a_modify : &ts, &ts);
    184 	if ((ip->i_flag & (IN_MODIFIED | IN_ACCESSED | IN_CLEANING)) == 0) {
    185 		return (0);
    186 	}
    187 
    188 	/* If sync, push back the vnode and any dirty blocks it may have. */
    189 	if ((ap->a_flags & (UPDATE_WAIT|UPDATE_DIROP)) == UPDATE_WAIT) {
    190 		/* Avoid flushing VDIROP. */
    191 		++fs->lfs_diropwait;
    192 		while (vp->v_flag & VDIROP) {
    193 #ifdef DEBUG_LFS
    194 			printf("lfs_update: sleeping on inode %d (dirops)\n",
    195 			       ip->i_number);
    196 			printf("lfs_update: vflags 0x%lx, iflags 0x%x\n",
    197 				vp->v_flag, ip->i_flag);
    198 #endif
    199 			if (fs->lfs_dirops == 0)
    200 				lfs_flush_fs(fs, SEGM_SYNC);
    201 			else
    202 				tsleep(&fs->lfs_writer, PRIBIO+1, "lfs_fsync",
    203 				       0);
    204 			/* XXX KS - by falling out here, are we writing the vn
    205 			twice? */
    206 		}
    207 		--fs->lfs_diropwait;
    208 		return lfs_vflush(vp);
    209         }
    210 	return 0;
    211 }
    212 
    213 #define	SINGLE	0	/* index of single indirect block */
    214 #define	DOUBLE	1	/* index of double indirect block */
    215 #define	TRIPLE	2	/* index of triple indirect block */
    216 /*
    217  * Truncate the inode oip to at most length size, freeing the
    218  * disk blocks.
    219  */
    220 /* VOP_BWRITE 1 + NIADDR + VOP_BALLOC == 2 + 2*NIADDR times */
    221 int
    222 lfs_truncate(void *v)
    223 {
    224 	struct vop_truncate_args /* {
    225 		struct vnode *a_vp;
    226 		off_t a_length;
    227 		int a_flags;
    228 		struct ucred *a_cred;
    229 		struct proc *a_p;
    230 	} */ *ap = v;
    231 	struct vnode *ovp = ap->a_vp;
    232 	ufs_daddr_t lastblock;
    233 	struct inode *oip;
    234 	ufs_daddr_t bn, lbn, lastiblock[NIADDR], indir_lbn[NIADDR];
    235 	ufs_daddr_t newblks[NDADDR + NIADDR];
    236 	off_t length = ap->a_length;
    237 	struct lfs *fs;
    238 	struct buf *bp;
    239 	int offset, size, level;
    240 	long count, rcount, nblocks, blocksreleased = 0, real_released = 0;
    241 	int i;
    242 	int aflags, error, allerror = 0;
    243 	off_t osize;
    244 	long lastseg;
    245 	size_t bc;
    246 	int obufsize, odb;
    247 
    248 	if (length < 0)
    249 		return (EINVAL);
    250 	oip = VTOI(ovp);
    251 
    252 	/*
    253 	 * Just return and not update modification times.
    254 	 */
    255 	if (oip->i_ffs_size == length)
    256 		return (0);
    257 
    258 	if (ovp->v_type == VLNK &&
    259 	    (oip->i_ffs_size < ovp->v_mount->mnt_maxsymlinklen ||
    260 	     (ovp->v_mount->mnt_maxsymlinklen == 0 &&
    261 	      oip->i_din.ffs_din.di_blocks == 0))) {
    262 #ifdef DIAGNOSTIC
    263 		if (length != 0)
    264 			panic("lfs_truncate: partial truncate of symlink");
    265 #endif
    266 		memset((char *)&oip->i_ffs_shortlink, 0, (u_int)oip->i_ffs_size);
    267 		oip->i_ffs_size = 0;
    268 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    269 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    270 	}
    271 	if (oip->i_ffs_size == length) {
    272 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    273 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    274 	}
    275 #ifdef QUOTA
    276 	if ((error = getinoquota(oip)) != 0)
    277 		return (error);
    278 #endif
    279 	fs = oip->i_lfs;
    280 	lfs_imtime(fs);
    281 	osize = oip->i_ffs_size;
    282 
    283 	/*
    284 	 * Lengthen the size of the file. We must ensure that the
    285 	 * last byte of the file is allocated. Since the smallest
    286 	 * value of osize is 0, length will be at least 1.
    287 	 */
    288 	if (osize < length) {
    289 		if (length > fs->lfs_maxfilesize)
    290 			return (EFBIG);
    291 		aflags = B_CLRBUF;
    292 		if (ap->a_flags & IO_SYNC)
    293 			aflags |= B_SYNC;
    294 		error = lfs_reserve(fs, ovp, btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    295 		if (error)
    296 			return (error);
    297 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    298 		lfs_reserve(fs, ovp, -btofsb(fs, (NIADDR + 2) << fs->lfs_bshift));
    299 		if (error)
    300 			return (error);
    301 		oip->i_ffs_size = length;
    302 		uvm_vnp_setsize(ovp, length);
    303 		(void) VOP_BWRITE(bp);
    304 		oip->i_flag |= IN_CHANGE | IN_UPDATE;
    305 		return (VOP_UPDATE(ovp, NULL, NULL, 0));
    306 	}
    307 
    308 	if ((error = lfs_reserve(fs, ovp, btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift))) != 0)
    309 		return (error);
    310 	/*
    311 	 * Make sure no writes to this inode can happen while we're
    312 	 * truncating.  Otherwise, blocks which are accounted for on the
    313 	 * inode *and* which have been created for cleaning can coexist,
    314 	 * and cause an overcounting.
    315 	 *
    316 	 * (We don't need to *hold* the seglock, though, because we already
    317 	 * hold the inode lock; draining the seglock is sufficient.)
    318 	 */
    319 #ifdef LFS_AGGRESSIVE_SEGLOCK
    320 	lfs_seglock(fs, SEGM_PROT);
    321 #else
    322 	if (ovp != fs->lfs_unlockvp) {
    323 		while (fs->lfs_seglock) {
    324 			tsleep(&fs->lfs_seglock, PRIBIO+1, "lfs_truncate", 0);
    325 		}
    326 	}
    327 #endif
    328 
    329 	/*
    330 	 * Shorten the size of the file. If the file is not being
    331 	 * truncated to a block boundary, the contents of the
    332 	 * partial block following the end of the file must be
    333 	 * zero'ed in case it ever becomes accessible again because
    334 	 * of subsequent file growth. Directories however are not
    335 	 * zero'ed as they should grow back initialized to empty.
    336 	 */
    337 	offset = blkoff(fs, length);
    338 	lastseg = -1;
    339 	bc = 0;
    340 	if (offset == 0) {
    341 		oip->i_ffs_size = length;
    342 	} else {
    343 		lbn = lblkno(fs, length);
    344 		aflags = B_CLRBUF;
    345 		if (ap->a_flags & IO_SYNC)
    346 			aflags |= B_SYNC;
    347 		error = VOP_BALLOC(ovp, length - 1, 1, ap->a_cred, aflags, &bp);
    348 		if (error) {
    349 			lfs_reserve(fs, ovp, -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    350 #ifdef LFS_AGGRESSIVE_SEGLOCK
    351 			lfs_segunlock(fs);
    352 #endif
    353 			return (error);
    354 		}
    355 		obufsize = bp->b_bufsize;
    356 		odb = btofsb(fs, bp->b_bcount);
    357 		oip->i_ffs_size = length;
    358 		size = blksize(fs, oip, lbn);
    359 		if (ovp->v_type != VDIR)
    360 			memset((char *)bp->b_data + offset, 0,
    361 			       (u_int)(size - offset));
    362 		allocbuf(bp, size);
    363 		if ((bp->b_flags & (B_LOCKED | B_CALL)) == B_LOCKED)
    364 			locked_queue_bytes -= obufsize - bp->b_bufsize;
    365 		if (bp->b_flags & B_DELWRI)
    366 			fs->lfs_avail += odb - btofsb(fs, size);
    367 		(void) VOP_BWRITE(bp);
    368 	}
    369 	uvm_vnp_setsize(ovp, length);
    370 	/*
    371 	 * Calculate index into inode's block list of
    372 	 * last direct and indirect blocks (if any)
    373 	 * which we want to keep.  Lastblock is -1 when
    374 	 * the file is truncated to 0.
    375 	 */
    376 	lastblock = lblkno(fs, length + fs->lfs_bsize - 1) - 1;
    377 	lastiblock[SINGLE] = lastblock - NDADDR;
    378 	lastiblock[DOUBLE] = lastiblock[SINGLE] - NINDIR(fs);
    379 	lastiblock[TRIPLE] = lastiblock[DOUBLE] - NINDIR(fs) * NINDIR(fs);
    380 	nblocks = btofsb(fs, fs->lfs_bsize);
    381 	/*
    382 	 * Record changed file and block pointers before we start
    383 	 * freeing blocks.  lastiblock values are also normalized to -1
    384 	 * for calls to lfs_indirtrunc below.
    385 	 */
    386 	memcpy((caddr_t)newblks, (caddr_t)&oip->i_ffs_db[0], sizeof newblks);
    387 	for (level = TRIPLE; level >= SINGLE; level--)
    388 		if (lastiblock[level] < 0) {
    389 			newblks[NDADDR+level] = 0;
    390 			lastiblock[level] = -1;
    391 		}
    392 	for (i = NDADDR - 1; i > lastblock; i--)
    393 		newblks[i] = 0;
    394 
    395 	oip->i_ffs_size = osize;
    396 	error = lfs_vtruncbuf(ovp, lastblock + 1, 0, 0);
    397 	if (error && !allerror)
    398 		allerror = error;
    399 
    400 	/*
    401 	 * Indirect blocks first.
    402 	 */
    403 	indir_lbn[SINGLE] = -NDADDR;
    404 	indir_lbn[DOUBLE] = indir_lbn[SINGLE] - NINDIR(fs) - 1;
    405 	indir_lbn[TRIPLE] = indir_lbn[DOUBLE] - NINDIR(fs) * NINDIR(fs) - 1;
    406 	for (level = TRIPLE; level >= SINGLE; level--) {
    407 		bn = oip->i_ffs_ib[level];
    408 		if (bn != 0) {
    409 			error = lfs_indirtrunc(oip, indir_lbn[level],
    410 					       bn, lastiblock[level],
    411 					       level, &count, &rcount,
    412 					       &lastseg, &bc, ap->a_p);
    413 			if (error)
    414 				allerror = error;
    415 			real_released += rcount;
    416 			blocksreleased += count;
    417 			if (lastiblock[level] < 0) {
    418 				if (oip->i_ffs_ib[level] > 0)
    419 					real_released += nblocks;
    420 				blocksreleased += nblocks;
    421 				oip->i_ffs_ib[level] = 0;
    422 				lfs_blkfree(fs, bn, fs->lfs_bsize, &lastseg, &bc);
    423 			}
    424 		}
    425 		if (lastiblock[level] >= 0)
    426 			goto done;
    427 	}
    428 
    429 	/*
    430 	 * All whole direct blocks or frags.
    431 	 */
    432 	for (i = NDADDR - 1; i > lastblock; i--) {
    433 		long bsize;
    434 
    435 		bn = oip->i_ffs_db[i];
    436 		if (bn == 0)
    437 			continue;
    438 		bsize = blksize(fs, oip, i);
    439 		if (oip->i_ffs_db[i] > 0)
    440 			real_released += btofsb(fs, bsize);
    441 		blocksreleased += btofsb(fs, bsize);
    442 		oip->i_ffs_db[i] = 0;
    443 		lfs_blkfree(fs, bn, bsize, &lastseg, &bc);
    444 	}
    445 	if (lastblock < 0)
    446 		goto done;
    447 
    448 	/*
    449 	 * Finally, look for a change in size of the
    450 	 * last direct block; release any frags.
    451 	 */
    452 	bn = oip->i_ffs_db[lastblock];
    453 	if (bn != 0) {
    454 		long oldspace, newspace;
    455 
    456 		/*
    457 		 * Calculate amount of space we're giving
    458 		 * back as old block size minus new block size.
    459 		 */
    460 		oldspace = blksize(fs, oip, lastblock);
    461 		oip->i_ffs_size = length;
    462 		newspace = blksize(fs, oip, lastblock);
    463 		if (newspace == 0)
    464 			panic("itrunc: newspace");
    465 		if (oldspace - newspace > 0) {
    466 			lfs_blkfree(fs, bn, oldspace - newspace, &lastseg, &bc);
    467 			if (bn > 0)
    468 				real_released += btofsb(fs, oldspace - newspace);
    469 			blocksreleased += btofsb(fs, oldspace - newspace);
    470 		}
    471 	}
    472 
    473 done:
    474 	/* Finish segment accounting corrections */
    475 	lfs_update_seguse(fs, lastseg, bc);
    476 #ifdef DIAGNOSTIC
    477 	for (level = SINGLE; level <= TRIPLE; level++)
    478 		if (newblks[NDADDR + level] != oip->i_ffs_ib[level])
    479 			panic("lfs itrunc1");
    480 	for (i = 0; i < NDADDR; i++)
    481 		if (newblks[i] != oip->i_ffs_db[i])
    482 			panic("lfs itrunc2");
    483 	if (length == 0 &&
    484 	    (!LIST_EMPTY(&ovp->v_cleanblkhd) || !LIST_EMPTY(&ovp->v_dirtyblkhd)))
    485 		panic("lfs itrunc3");
    486 #endif /* DIAGNOSTIC */
    487 	/*
    488 	 * Put back the real size.
    489 	 */
    490 	oip->i_ffs_size = length;
    491 	oip->i_lfs_effnblks -= blocksreleased;
    492 	oip->i_ffs_blocks -= real_released;
    493 	fs->lfs_bfree += blocksreleased;
    494 #ifdef DIAGNOSTIC
    495 	if (oip->i_ffs_size == 0 && oip->i_ffs_blocks != 0) {
    496 		printf("lfs_truncate: truncate to 0 but %d blocks on inode\n",
    497 		       oip->i_ffs_blocks);
    498 		panic("lfs_truncate: persistent blocks\n");
    499 	}
    500 #endif
    501 	oip->i_flag |= IN_CHANGE;
    502 #ifdef QUOTA
    503 	(void) chkdq(oip, -blocksreleased, NOCRED, 0);
    504 #endif
    505 	lfs_reserve(fs, ovp, -btofsb(fs, (2 * NIADDR + 3) << fs->lfs_bshift));
    506 #ifdef LFS_AGGRESSIVE_SEGLOCK
    507 	lfs_segunlock(fs);
    508 #endif
    509 	return (allerror);
    510 }
    511 
    512 /* Update segment usage information when removing a block. */
    513 static int
    514 lfs_blkfree(struct lfs *fs, daddr_t daddr, size_t bsize, long *lastseg,
    515 	    size_t *num)
    516 {
    517 	long seg;
    518 	int error = 0;
    519 
    520 	bsize = fragroundup(fs, bsize);
    521 	if (daddr > 0) {
    522 		if (*lastseg != (seg = dtosn(fs, daddr))) {
    523 			error = lfs_update_seguse(fs, *lastseg, *num);
    524 			*num = bsize;
    525 			*lastseg = seg;
    526 		} else
    527 			*num += bsize;
    528 	}
    529 	return error;
    530 }
    531 
    532 /* Finish the accounting updates for a segment. */
    533 static int
    534 lfs_update_seguse(struct lfs *fs, long lastseg, size_t num)
    535 {
    536 	SEGUSE *sup;
    537 	struct buf *bp;
    538 	int error;
    539 
    540 	if (lastseg < 0 || num == 0)
    541 		return 0;
    542 
    543 	LFS_SEGENTRY(sup, fs, lastseg, bp);
    544 	if (num > sup->su_nbytes) {
    545 		printf("lfs_truncate: segment %ld short by %ld\n",
    546 		       lastseg, (long)num - sup->su_nbytes);
    547 		panic("lfs_truncate: negative bytes");
    548 		sup->su_nbytes = num;
    549 	}
    550 	sup->su_nbytes -= num;
    551 	error = LFS_BWRITE_LOG(bp); /* Ifile */
    552 	return error;
    553 }
    554 
    555 /*
    556  * Release blocks associated with the inode ip and stored in the indirect
    557  * block bn.  Blocks are free'd in LIFO order up to (but not including)
    558  * lastbn.  If level is greater than SINGLE, the block is an indirect block
    559  * and recursive calls to indirtrunc must be used to cleanse other indirect
    560  * blocks.
    561  *
    562  * NB: triple indirect blocks are untested.
    563  */
    564 static int
    565 lfs_indirtrunc(struct inode *ip, ufs_daddr_t lbn, daddr_t dbn,
    566 	       ufs_daddr_t lastbn, int level, long *countp,
    567 	       long *rcountp, long *lastsegp, size_t *bcp, struct proc *p)
    568 {
    569 	int i;
    570 	struct buf *bp;
    571 	struct lfs *fs = ip->i_lfs;
    572 	ufs_daddr_t *bap;
    573 	struct vnode *vp;
    574 	ufs_daddr_t *copy = NULL, nb, nlbn, last;
    575 	long blkcount, rblkcount, factor;
    576 	int nblocks, blocksreleased = 0, real_released = 0;
    577 	int error = 0, allerror = 0;
    578 
    579 	/*
    580 	 * Calculate index in current block of last
    581 	 * block to be kept.  -1 indicates the entire
    582 	 * block so we need not calculate the index.
    583 	 */
    584 	factor = 1;
    585 	for (i = SINGLE; i < level; i++)
    586 		factor *= NINDIR(fs);
    587 	last = lastbn;
    588 	if (lastbn > 0)
    589 		last /= factor;
    590 	nblocks = btofsb(fs, fs->lfs_bsize);
    591 	/*
    592 	 * Get buffer of block pointers, zero those entries corresponding
    593 	 * to blocks to be free'd, and update on disk copy first.  Since
    594 	 * double(triple) indirect before single(double) indirect, calls
    595 	 * to bmap on these blocks will fail.  However, we already have
    596 	 * the on disk address, so we have to set the b_blkno field
    597 	 * explicitly instead of letting bread do everything for us.
    598 	 */
    599 	vp = ITOV(ip);
    600 	bp = getblk(vp, lbn, (int)fs->lfs_bsize, 0, 0);
    601 	if (bp->b_flags & (B_DONE | B_DELWRI)) {
    602 		/* Braces must be here in case trace evaluates to nothing. */
    603 		trace(TR_BREADHIT, pack(vp, fs->lfs_bsize), lbn);
    604 	} else {
    605 		trace(TR_BREADMISS, pack(vp, fs->lfs_bsize), lbn);
    606 		p->p_stats->p_ru.ru_inblock++;	/* pay for read */
    607 		bp->b_flags |= B_READ;
    608 		if (bp->b_bcount > bp->b_bufsize)
    609 			panic("lfs_indirtrunc: bad buffer size");
    610 		bp->b_blkno = fsbtodb(fs, dbn);
    611 		VOP_STRATEGY(bp);
    612 		error = biowait(bp);
    613 	}
    614 	if (error) {
    615 		brelse(bp);
    616 		*countp = *rcountp = 0;
    617 		return (error);
    618 	}
    619 
    620 	bap = (ufs_daddr_t *)bp->b_data;
    621 	if (lastbn >= 0) {
    622 		MALLOC(copy, ufs_daddr_t *, fs->lfs_bsize, M_TEMP, M_WAITOK);
    623 		memcpy((caddr_t)copy, (caddr_t)bap, (u_int)fs->lfs_bsize);
    624 		memset((caddr_t)&bap[last + 1], 0,
    625 		  (u_int)(NINDIR(fs) - (last + 1)) * sizeof (ufs_daddr_t));
    626 		error = VOP_BWRITE(bp);
    627 		if (error)
    628 			allerror = error;
    629 		bap = copy;
    630 	}
    631 
    632 	/*
    633 	 * Recursively free totally unused blocks.
    634 	 */
    635 	for (i = NINDIR(fs) - 1, nlbn = lbn + 1 - i * factor; i > last;
    636 	    i--, nlbn += factor) {
    637 		nb = bap[i];
    638 		if (nb == 0)
    639 			continue;
    640 		if (level > SINGLE) {
    641 			error = lfs_indirtrunc(ip, nlbn, nb,
    642 					       (ufs_daddr_t)-1, level - 1,
    643 					       &blkcount, &rblkcount,
    644 					       lastsegp, bcp, p);
    645 			if (error)
    646 				allerror = error;
    647 			blocksreleased += blkcount;
    648 			real_released += rblkcount;
    649 		}
    650 		lfs_blkfree(fs, nb, fs->lfs_bsize, lastsegp, bcp);
    651 		if (bap[i] > 0)
    652 			real_released += nblocks;
    653 		blocksreleased += nblocks;
    654 	}
    655 
    656 	/*
    657 	 * Recursively free last partial block.
    658 	 */
    659 	if (level > SINGLE && lastbn >= 0) {
    660 		last = lastbn % factor;
    661 		nb = bap[i];
    662 		if (nb != 0) {
    663 			error = lfs_indirtrunc(ip, nlbn, nb,
    664 					       last, level - 1, &blkcount,
    665 					       &rblkcount, lastsegp, bcp, p);
    666 			if (error)
    667 				allerror = error;
    668 			real_released += rblkcount;
    669 			blocksreleased += blkcount;
    670 		}
    671 	}
    672 
    673 	if (copy != NULL) {
    674 		FREE(copy, M_TEMP);
    675 	} else {
    676 		if (bp->b_flags & B_DELWRI) {
    677 			LFS_UNLOCK_BUF(bp);
    678 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    679 			wakeup(&fs->lfs_avail);
    680 		}
    681 		bp->b_flags |= B_INVAL;
    682 		brelse(bp);
    683 	}
    684 
    685 	*countp = blocksreleased;
    686 	*rcountp = real_released;
    687 	return (allerror);
    688 }
    689 
    690 /*
    691  * Destroy any in core blocks past the truncation length.
    692  * Inlined from vtruncbuf, so that lfs_avail could be updated.
    693  */
    694 static int
    695 lfs_vtruncbuf(struct vnode *vp, daddr_t lbn, int slpflag, int slptimeo)
    696 {
    697 	struct buf *bp, *nbp;
    698 	int s, error;
    699 	struct lfs *fs;
    700 
    701 	fs = VTOI(vp)->i_lfs;
    702 	s = splbio();
    703 
    704 restart:
    705 	for (bp = LIST_FIRST(&vp->v_cleanblkhd); bp; bp = nbp) {
    706 		nbp = LIST_NEXT(bp, b_vnbufs);
    707 		if (bp->b_lblkno < lbn)
    708 			continue;
    709 		if (bp->b_flags & B_BUSY) {
    710 			bp->b_flags |= B_WANTED;
    711 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    712 			    "lfs_vtruncbuf", slptimeo);
    713 			if (error) {
    714 				splx(s);
    715 				return (error);
    716 			}
    717 			goto restart;
    718 		}
    719 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    720 		if (bp->b_flags & B_DELWRI) {
    721 			bp->b_flags &= ~B_DELWRI;
    722 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    723 			wakeup(&fs->lfs_avail);
    724 		}
    725 		LFS_UNLOCK_BUF(bp);
    726 		brelse(bp);
    727 	}
    728 
    729 	for (bp = LIST_FIRST(&vp->v_dirtyblkhd); bp; bp = nbp) {
    730 		nbp = LIST_NEXT(bp, b_vnbufs);
    731 		if (bp->b_lblkno < lbn)
    732 			continue;
    733 		if (bp->b_flags & B_BUSY) {
    734 			bp->b_flags |= B_WANTED;
    735 			error = tsleep((caddr_t)bp, slpflag | (PRIBIO + 1),
    736 			    "lfs_vtruncbuf", slptimeo);
    737 			if (error) {
    738 				splx(s);
    739 				return (error);
    740 			}
    741 			goto restart;
    742 		}
    743 		bp->b_flags |= B_BUSY | B_INVAL | B_VFLUSH;
    744 		if (bp->b_flags & B_DELWRI) {
    745 			bp->b_flags &= ~B_DELWRI;
    746 			fs->lfs_avail += btofsb(fs, bp->b_bcount);
    747 			wakeup(&fs->lfs_avail);
    748 		}
    749 		LFS_UNLOCK_BUF(bp);
    750 		brelse(bp);
    751 	}
    752 
    753 	splx(s);
    754 
    755 	return (0);
    756 }
    757 
    758