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lfs_alloc.c revision 1.51
      1 /*	$NetBSD: lfs_alloc.c,v 1.51 2001/10/14 19:06:16 chs 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) 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_alloc.c	8.4 (Berkeley) 1/4/94
     71  */
     72 
     73 #if defined(_KERNEL_OPT)
     74 #include "opt_quota.h"
     75 #endif
     76 
     77 #include <sys/param.h>
     78 #include <sys/systm.h>
     79 #include <sys/kernel.h>
     80 #include <sys/buf.h>
     81 #include <sys/vnode.h>
     82 #include <sys/syslog.h>
     83 #include <sys/mount.h>
     84 #include <sys/malloc.h>
     85 #include <sys/pool.h>
     86 #include <sys/proc.h>
     87 
     88 #include <ufs/ufs/quota.h>
     89 #include <ufs/ufs/inode.h>
     90 #include <ufs/ufs/ufsmount.h>
     91 #include <ufs/ufs/ufs_extern.h>
     92 
     93 #include <ufs/lfs/lfs.h>
     94 #include <ufs/lfs/lfs_extern.h>
     95 
     96 extern int lfs_dirvcount;
     97 extern struct lock ufs_hashlock;
     98 
     99 static int extend_ifile(struct lfs *, struct ucred *);
    100 static int lfs_ialloc(struct lfs *, struct vnode *, ino_t, int, struct vnode **);
    101 
    102 /*
    103  * Allocate a particular inode with a particular version number, freeing
    104  * any previous versions of this inode that may have gone before.
    105  * Used by the roll-forward code.
    106  *
    107  * XXX this function does not have appropriate locking to be used on a live fs;
    108  * XXX but something similar could probably be used for an "undelete" call.
    109  */
    110 int
    111 lfs_rf_valloc(struct lfs *fs, ino_t ino, int version, struct proc *p,
    112 	      struct vnode **vpp)
    113 {
    114 	IFILE *ifp;
    115 	struct buf *bp, *cbp;
    116 	struct vnode *vp;
    117 	struct inode *ip;
    118 	ino_t tino, oldnext;
    119 	int error;
    120 	CLEANERINFO *cip;
    121 
    122 	/*
    123 	 * First, just try a vget. If the version number is the one we want,
    124 	 * we don't have to do anything else.  If the version number is wrong,
    125 	 * take appropriate action.
    126 	 */
    127 	error = VFS_VGET(fs->lfs_ivnode->v_mount, ino, &vp);
    128 	if (error == 0) {
    129 		/* printf("lfs_rf_valloc[1]: ino %d vp %p\n", ino, vp); */
    130 
    131 		*vpp = vp;
    132 		ip = VTOI(vp);
    133 		if (ip->i_ffs_gen == version)
    134 			return 0;
    135 		else if (ip->i_ffs_gen < version) {
    136 			VOP_TRUNCATE(vp, (off_t)0, 0, NOCRED, p);
    137 			ip->i_ffs_gen = version;
    138 			LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED | IN_UPDATE);
    139 			return 0;
    140 		} else {
    141 			/* printf("ino %d: asked for version %d but got %d\n",
    142 			       ino, version, ip->i_ffs_gen); */
    143 			vput(vp);
    144 			*vpp = NULLVP;
    145 			return EEXIST;
    146 		}
    147 	}
    148 
    149 	/*
    150 	 * The inode is not in use.  Find it on the free list.
    151 	 */
    152 	/* If the Ifile is too short to contain this inum, extend it */
    153 	while (VTOI(fs->lfs_ivnode)->i_ffs_size <= (ino /
    154 		fs->lfs_ifpb + fs->lfs_cleansz + fs->lfs_segtabsz)
    155 		<< fs->lfs_bshift) {
    156 		extend_ifile(fs, NOCRED);
    157 	}
    158 
    159 	LFS_IENTRY(ifp, fs, ino, bp);
    160 	oldnext = ifp->if_nextfree;
    161 	ifp->if_version = version;
    162 	brelse(bp);
    163 
    164 	LFS_GET_HEADFREE(fs, cip, cbp, &ino);
    165 	if (ino) {
    166 		LFS_PUT_HEADFREE(fs, cip, cbp, oldnext);
    167 	} else {
    168 		tino = ino;
    169 		while(1) {
    170 			LFS_IENTRY(ifp, fs, tino, bp);
    171 			if (ifp->if_nextfree == ino ||
    172 			    ifp->if_nextfree == LFS_UNUSED_INUM)
    173 				break;
    174 			tino = ifp->if_nextfree;
    175 			brelse(bp);
    176 		}
    177 		if (ifp->if_nextfree == LFS_UNUSED_INUM) {
    178 			brelse(bp);
    179 			return ENOENT;
    180 		}
    181 		ifp->if_nextfree = oldnext;
    182 		VOP_BWRITE(bp);
    183 	}
    184 
    185 	error = lfs_ialloc(fs, fs->lfs_ivnode, ino, version, &vp);
    186 	if (error == 0) {
    187 		/*
    188 		 * Make it VREG so we can put blocks on it.  We will change
    189 		 * this later if it turns out to be some other kind of file.
    190 		 */
    191 		ip = VTOI(vp);
    192 		ip->i_ffs_mode = IFREG;
    193 		ip->i_ffs_nlink = 1;
    194 		ip->i_ffs_effnlink = 1;
    195 		ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
    196 		ip = VTOI(vp);
    197 
    198 		/* printf("lfs_rf_valloc: ino %d vp %p\n", ino, vp); */
    199 
    200 		/* The dirop-nature of this vnode is past */
    201 		(void)lfs_vunref(vp);
    202 		--lfs_dirvcount;
    203 		vp->v_flag &= ~VDIROP;
    204 		--fs->lfs_nadirop;
    205 		ip->i_flag &= ~IN_ADIROP;
    206 	}
    207 	*vpp = vp;
    208 	return error;
    209 }
    210 
    211 static int
    212 extend_ifile(struct lfs *fs, struct ucred *cred)
    213 {
    214 	struct vnode *vp;
    215 	struct inode *ip;
    216 	IFILE *ifp;
    217 	IFILE_V1 *ifp_v1;
    218 	struct buf *bp, *cbp;
    219 	int error;
    220 	ufs_daddr_t i, blkno, max;
    221 	ino_t oldlast;
    222 	CLEANERINFO *cip;
    223 
    224 	vp = fs->lfs_ivnode;
    225 	(void)lfs_vref(vp);
    226 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    227 	ip = VTOI(vp);
    228 	blkno = lblkno(fs, ip->i_ffs_size);
    229 	if ((error = VOP_BALLOC(vp, ip->i_ffs_size, fs->lfs_bsize, cred, 0,
    230 				&bp)) != 0) {
    231 		VOP_UNLOCK(vp, 0);
    232 		lfs_vunref(vp);
    233 		return (error);
    234 	}
    235 	ip->i_ffs_size += fs->lfs_bsize;
    236 	uvm_vnp_setsize(vp, ip->i_ffs_size);
    237 	VOP_UNLOCK(vp, 0);
    238 
    239 	i = (blkno - fs->lfs_segtabsz - fs->lfs_cleansz) *
    240 		fs->lfs_ifpb;
    241 	LFS_GET_HEADFREE(fs, cip, cbp, &oldlast);
    242 	LFS_PUT_HEADFREE(fs, cip, cbp, i);
    243 #ifdef DIAGNOSTIC
    244 	if(fs->lfs_free == LFS_UNUSED_INUM)
    245 		panic("inode 0 allocated [2]");
    246 #endif /* DIAGNOSTIC */
    247 	max = i + fs->lfs_ifpb;
    248 	/* printf("extend ifile for ino %d--%d\n", i, max); */
    249 
    250 	if(fs->lfs_version == 1) {
    251 		for (ifp_v1 = (IFILE_V1 *)bp->b_data; i < max; ++ifp_v1) {
    252 			ifp_v1->if_version = 1;
    253 			ifp_v1->if_daddr = LFS_UNUSED_DADDR;
    254 			ifp_v1->if_nextfree = ++i;
    255 		}
    256 		ifp_v1--;
    257 		ifp_v1->if_nextfree = oldlast;
    258 	} else {
    259 		for (ifp = (IFILE *)bp->b_data; i < max; ++ifp) {
    260 			ifp->if_version = 1;
    261 			ifp->if_daddr = LFS_UNUSED_DADDR;
    262 			ifp->if_nextfree = ++i;
    263 		}
    264 		ifp--;
    265 		ifp->if_nextfree = oldlast;
    266 	}
    267 
    268 	(void) VOP_BWRITE(bp); /* Ifile */
    269 	lfs_vunref(vp);
    270 
    271 	return 0;
    272 }
    273 
    274 /* Allocate a new inode. */
    275 /* ARGSUSED */
    276 /* VOP_BWRITE 2i times */
    277 int
    278 lfs_valloc(void *v)
    279 {
    280 	struct vop_valloc_args /* {
    281 				  struct vnode *a_pvp;
    282 				  int a_mode;
    283 				  struct ucred *a_cred;
    284 				  struct vnode **a_vpp;
    285 				  } */ *ap = v;
    286 	struct lfs *fs;
    287 	struct buf *bp, *cbp;
    288 	struct ifile *ifp;
    289 	ino_t new_ino;
    290 	int error;
    291 	int new_gen;
    292 	CLEANERINFO *cip;
    293 
    294 	fs = VTOI(ap->a_pvp)->i_lfs;
    295 	if (fs->lfs_ronly)
    296 		return EROFS;
    297 	*ap->a_vpp = NULL;
    298 
    299 	if (fs->lfs_version == 1) {
    300 		/*
    301 		 * Use lfs_seglock here, instead of fs->lfs_freelock, to
    302 		 * ensure that the free list is not changed in between
    303 		 * the time that the ifile blocks are written to disk
    304 		 * and the time that the superblock is written to disk.
    305 		 */
    306 		lfs_seglock(fs, SEGM_PROT);
    307 	} else {
    308 		lockmgr(&fs->lfs_freelock, LK_EXCLUSIVE, 0);
    309 	}
    310 
    311 	/* Get the head of the freelist. */
    312 	LFS_GET_HEADFREE(fs, cip, cbp, &new_ino);
    313 
    314 #ifdef DIAGNOSTIC
    315 	if(new_ino == LFS_UNUSED_INUM) {
    316 #ifdef DEBUG
    317 		lfs_dump_super(fs);
    318 #endif /* DEBUG */
    319 		panic("inode 0 allocated [1]");
    320 	}
    321 #endif /* DIAGNOSTIC */
    322 #ifdef ALLOCPRINT
    323 	printf("lfs_valloc: allocate inode %d\n", new_ino);
    324 #endif
    325 
    326 	/*
    327 	 * Remove the inode from the free list and write the new start
    328 	 * of the free list into the superblock.
    329 	 */
    330 	LFS_IENTRY(ifp, fs, new_ino, bp);
    331 	if (ifp->if_daddr != LFS_UNUSED_DADDR)
    332 		panic("lfs_valloc: inuse inode %d on the free list", new_ino);
    333 	LFS_PUT_HEADFREE(fs, cip, cbp, ifp->if_nextfree);
    334 
    335 	new_gen = ifp->if_version; /* version was updated by vfree */
    336 	brelse(bp);
    337 
    338 	/* Extend IFILE so that the next lfs_valloc will succeed. */
    339 	if (fs->lfs_free == LFS_UNUSED_INUM) {
    340 		if ((error = extend_ifile(fs, ap->a_cred)) != 0) {
    341 			LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
    342 			if (fs->lfs_version == 1)
    343 				lfs_segunlock(fs);
    344 			else
    345 				lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
    346 			return error;
    347 		}
    348 	}
    349 #ifdef DIAGNOSTIC
    350 	if(fs->lfs_free == LFS_UNUSED_INUM)
    351 		panic("inode 0 allocated [3]");
    352 #endif /* DIAGNOSTIC */
    353 
    354 	if (fs->lfs_version == 1)
    355 		lfs_segunlock(fs);
    356 	else
    357 		lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
    358 
    359 	return lfs_ialloc(fs, ap->a_pvp, new_ino, new_gen, ap->a_vpp);
    360 }
    361 
    362 static int
    363 lfs_ialloc(struct lfs *fs, struct vnode *pvp, ino_t new_ino, int new_gen,
    364 	   struct vnode **vpp)
    365 {
    366 	struct inode *ip;
    367 	struct vnode *vp;
    368 	IFILE *ifp;
    369 	struct buf *bp, *cbp;
    370 	int error;
    371 	CLEANERINFO *cip;
    372 
    373 	error = getnewvnode(VT_LFS, pvp->v_mount, lfs_vnodeop_p, &vp);
    374 	/* printf("lfs_ialloc: ino %d vp %p error %d\n", new_ino, vp, error);*/
    375 	if (error)
    376 		goto errout;
    377 
    378 	lockmgr(&ufs_hashlock, LK_EXCLUSIVE, 0);
    379 	/* Create an inode to associate with the vnode. */
    380 	lfs_vcreate(pvp->v_mount, new_ino, vp);
    381 
    382 	ip = VTOI(vp);
    383 	LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED);
    384 	/* Zero out the direct and indirect block addresses. */
    385 	bzero(&ip->i_din, sizeof(ip->i_din));
    386 	ip->i_din.ffs_din.di_inumber = new_ino;
    387 
    388 	/* Set a new generation number for this inode. */
    389 	if (new_gen)
    390 		ip->i_ffs_gen = new_gen;
    391 
    392 	/* Insert into the inode hash table. */
    393 	ufs_ihashins(ip);
    394 	lockmgr(&ufs_hashlock, LK_RELEASE, 0);
    395 
    396 	ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
    397 	ip = VTOI(vp);
    398 	/* printf("lfs_ialloc[2]: ino %d vp %p\n", new_ino, vp);*/
    399 
    400 	uvm_vnp_setsize(vp, 0);
    401 	*vpp = vp;
    402 #if 1
    403 	if(!(vp->v_flag & VDIROP)) {
    404 		(void)lfs_vref(vp);
    405 		++lfs_dirvcount;
    406 	}
    407 	vp->v_flag |= VDIROP;
    408 
    409 	if(!(ip->i_flag & IN_ADIROP))
    410 		++fs->lfs_nadirop;
    411 	ip->i_flag |= IN_ADIROP;
    412 #endif
    413 	VREF(ip->i_devvp);
    414 	/* Set superblock modified bit and increment file count. */
    415 	fs->lfs_fmod = 1;
    416 	++fs->lfs_nfiles;
    417 	return (0);
    418 
    419     errout:
    420 	/*
    421 	 * Put the new inum back on the free list.
    422 	 */
    423 	LFS_IENTRY(ifp, fs, new_ino, bp);
    424 	ifp->if_daddr = LFS_UNUSED_DADDR;
    425 	LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
    426 	LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
    427 	(void) VOP_BWRITE(bp); /* Ifile */
    428 
    429 	*vpp = NULLVP;
    430 	return (error);
    431 }
    432 
    433 /* Create a new vnode/inode pair and initialize what fields we can. */
    434 void
    435 lfs_vcreate(struct mount *mp, ino_t ino, struct vnode *vp)
    436 {
    437 	struct inode *ip;
    438 	struct ufsmount *ump;
    439 #ifdef QUOTA
    440 	int i;
    441 #endif
    442 
    443 	/* Get a pointer to the private mount structure. */
    444 	ump = VFSTOUFS(mp);
    445 
    446 	/* Initialize the inode. */
    447 	ip = pool_get(&lfs_inode_pool, PR_WAITOK);
    448 	vp->v_data = ip;
    449 	ip->i_vnode = vp;
    450 	ip->i_devvp = ump->um_devvp;
    451 	ip->i_dev = ump->um_dev;
    452 	ip->i_number = ip->i_din.ffs_din.di_inumber = ino;
    453 	ip->i_lfs = ump->um_lfs;
    454 #ifdef QUOTA
    455 	for (i = 0; i < MAXQUOTAS; i++)
    456 		ip->i_dquot[i] = NODQUOT;
    457 #endif
    458 	ip->i_lockf = 0;
    459 	ip->i_diroff = 0;
    460 	ip->i_ffs_mode = 0;
    461 	ip->i_ffs_size = 0;
    462 	ip->i_ffs_blocks = 0;
    463 	ip->i_lfs_effnblks = 0;
    464 	ip->i_flag = 0;
    465 	/* Why was IN_MODIFIED ever set here? */
    466 	/* LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED); */
    467 }
    468 
    469 /* Free an inode. */
    470 /* ARGUSED */
    471 /* VOP_BWRITE 2i times */
    472 int
    473 lfs_vfree(void *v)
    474 {
    475 	struct vop_vfree_args /* {
    476 				 struct vnode *a_pvp;
    477 				 ino_t a_ino;
    478 				 int a_mode;
    479 				 } */ *ap = v;
    480 	SEGUSE *sup;
    481 	CLEANERINFO *cip;
    482 	struct buf *cbp, *bp;
    483 	struct ifile *ifp;
    484 	struct inode *ip;
    485 	struct vnode *vp;
    486 	struct lfs *fs;
    487 	ufs_daddr_t old_iaddr;
    488 	ino_t ino, otail;
    489 	extern int lfs_dirvcount;
    490 
    491 	/* Get the inode number and file system. */
    492 	vp = ap->a_pvp;
    493 	ip = VTOI(vp);
    494 	fs = ip->i_lfs;
    495 	ino = ip->i_number;
    496 
    497 	/* Drain of pending writes */
    498 	if (fs->lfs_version > 1 && WRITEINPROG(vp))
    499 		tsleep(vp, (PRIBIO+1), "lfs_vfree", 0);
    500 
    501 	if (fs->lfs_version == 1)
    502 		lfs_seglock(fs, SEGM_PROT);
    503 	else
    504 		lockmgr(&fs->lfs_freelock, LK_EXCLUSIVE, 0);
    505 
    506 	if(vp->v_flag & VDIROP) {
    507 		--lfs_dirvcount;
    508 		vp->v_flag &= ~VDIROP;
    509 		wakeup(&lfs_dirvcount);
    510 		lfs_vunref(vp);
    511 	}
    512 	if (ip->i_flag & IN_ADIROP) {
    513 		--fs->lfs_nadirop;
    514 		ip->i_flag &= ~IN_ADIROP;
    515 	}
    516 
    517 	LFS_CLR_UINO(ip, IN_ACCESSED|IN_CLEANING|IN_MODIFIED);
    518 	ip->i_flag &= ~IN_ALLMOD;
    519 
    520 	/*
    521 	 * Set the ifile's inode entry to unused, increment its version number
    522 	 * and link it onto the free chain.
    523 	 */
    524 	LFS_IENTRY(ifp, fs, ino, bp);
    525 	old_iaddr = ifp->if_daddr;
    526 	ifp->if_daddr = LFS_UNUSED_DADDR;
    527 	++ifp->if_version;
    528 	if (fs->lfs_version == 1) {
    529 		LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
    530 		LFS_PUT_HEADFREE(fs, cip, cbp, ino);
    531 		(void) VOP_BWRITE(bp); /* Ifile */
    532 	} else {
    533 		ifp->if_nextfree = LFS_UNUSED_INUM;
    534 		/*
    535 		 * XXX Writing the freed node here means that it might not
    536 		 * XXX make it into the free list in the event of a crash
    537 		 * XXX (the ifile could be written before the rest of this
    538 		 * XXX completes).
    539 		 */
    540 		(void) VOP_BWRITE(bp); /* Ifile */
    541 		LFS_GET_TAILFREE(fs, cip, cbp, &otail);
    542 		LFS_IENTRY(ifp, fs, otail, bp);
    543 		ifp->if_nextfree = ino;
    544 		VOP_BWRITE(bp);
    545 		LFS_PUT_TAILFREE(fs, cip, cbp, ino);
    546 	}
    547 #ifdef DIAGNOSTIC
    548 	if(ino == LFS_UNUSED_INUM) {
    549 		panic("inode 0 freed");
    550 	}
    551 #endif /* DIAGNOSTIC */
    552 	if (old_iaddr != LFS_UNUSED_DADDR) {
    553 		LFS_SEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp);
    554 #ifdef DIAGNOSTIC
    555 		if (sup->su_nbytes < DINODE_SIZE) {
    556 			printf("lfs_vfree: negative byte count"
    557 			       " (segment %d short by %d)\n",
    558 			       dtosn(fs, old_iaddr),
    559 			       (int)DINODE_SIZE - sup->su_nbytes);
    560 			panic("lfs_vfree: negative byte count");
    561 			sup->su_nbytes = DINODE_SIZE;
    562 		}
    563 #endif
    564 		sup->su_nbytes -= DINODE_SIZE;
    565 		(void) VOP_BWRITE(bp); /* Ifile */
    566 	}
    567 
    568 	/* Set superblock modified bit and decrement file count. */
    569 	fs->lfs_fmod = 1;
    570 	--fs->lfs_nfiles;
    571 
    572 	if (fs->lfs_version == 1)
    573 		lfs_segunlock(fs);
    574 	else
    575 		lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
    576 	return (0);
    577 }
    578