xref: /netbsd-src/sys/ufs/lfs/lfs_alloc.c (revision aaf4ece63a859a04e37cf3a7229b5fab0157cc06)
1 /*	$NetBSD: lfs_alloc.c,v 1.86 2005/12/11 12:25:26 christos 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@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. 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_alloc.c	8.4 (Berkeley) 1/4/94
67  */
68 
69 #include <sys/cdefs.h>
70 __KERNEL_RCSID(0, "$NetBSD: lfs_alloc.c,v 1.86 2005/12/11 12:25:26 christos 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/kernel.h>
79 #include <sys/buf.h>
80 #include <sys/lock.h>
81 #include <sys/vnode.h>
82 #include <sys/syslog.h>
83 #include <sys/mount.h>
84 #include <sys/pool.h>
85 #include <sys/proc.h>
86 #include <sys/tree.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 struct lock ufs_hashlock;
97 
98 static int extend_ifile(struct lfs *, struct ucred *);
99 static int lfs_ialloc(struct lfs *, struct vnode *, ino_t, int,
100     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  * Called with the Ifile inode locked.
111  */
112 int
113 lfs_rf_valloc(struct lfs *fs, ino_t ino, int vers, struct lwp *l,
114 	      struct vnode **vpp)
115 {
116 	IFILE *ifp;
117 	struct buf *bp, *cbp;
118 	struct vnode *vp;
119 	struct inode *ip;
120 	ino_t tino, oldnext;
121 	int error;
122 	CLEANERINFO *cip;
123 
124 	ASSERT_SEGLOCK(fs); /* XXX it doesn't, really */
125 
126 	/*
127 	 * First, just try a vget. If the version number is the one we want,
128 	 * we don't have to do anything else.  If the version number is wrong,
129 	 * take appropriate action.
130 	 */
131 	error = VFS_VGET(fs->lfs_ivnode->v_mount, ino, &vp);
132 	if (error == 0) {
133 		DLOG((DLOG_RF, "lfs_rf_valloc[1]: ino %d vp %p\n", ino, vp));
134 
135 		*vpp = vp;
136 		ip = VTOI(vp);
137 		if (ip->i_gen == vers)
138 			return 0;
139 		else if (ip->i_gen < vers) {
140 			lfs_truncate(vp, (off_t)0, 0, NOCRED, l);
141 			ip->i_gen = ip->i_ffs1_gen = vers;
142 			LFS_SET_UINO(ip, IN_CHANGE | IN_UPDATE);
143 			return 0;
144 		} else {
145 			DLOG((DLOG_RF, "ino %d: sought version %d, got %d\n",
146 			       ino, vers, ip->i_ffs1_gen));
147 			vput(vp);
148 			*vpp = NULLVP;
149 			return EEXIST;
150 		}
151 	}
152 
153 	/*
154 	 * The inode is not in use.  Find it on the free list.
155 	 */
156 	/* If the Ifile is too short to contain this inum, extend it */
157 	while (VTOI(fs->lfs_ivnode)->i_size <= (ino /
158 		fs->lfs_ifpb + fs->lfs_cleansz + fs->lfs_segtabsz)
159 		<< fs->lfs_bshift) {
160 		extend_ifile(fs, NOCRED);
161 	}
162 
163 	LFS_IENTRY(ifp, fs, ino, bp);
164 	oldnext = ifp->if_nextfree;
165 	ifp->if_version = vers;
166 	brelse(bp);
167 
168 	LFS_GET_HEADFREE(fs, cip, cbp, &ino);
169 	if (ino) {
170 		LFS_PUT_HEADFREE(fs, cip, cbp, oldnext);
171 	} else {
172 		tino = ino;
173 		while (1) {
174 			LFS_IENTRY(ifp, fs, tino, bp);
175 			if (ifp->if_nextfree == ino ||
176 			    ifp->if_nextfree == LFS_UNUSED_INUM)
177 				break;
178 			tino = ifp->if_nextfree;
179 			brelse(bp);
180 		}
181 		if (ifp->if_nextfree == LFS_UNUSED_INUM) {
182 			brelse(bp);
183 			return ENOENT;
184 		}
185 		ifp->if_nextfree = oldnext;
186 		LFS_BWRITE_LOG(bp);
187 	}
188 
189 	error = lfs_ialloc(fs, fs->lfs_ivnode, ino, vers, &vp);
190 	if (error == 0) {
191 		/*
192 		 * Make it VREG so we can put blocks on it.  We will change
193 		 * this later if it turns out to be some other kind of file.
194 		 */
195 		ip = VTOI(vp);
196 		ip->i_mode = ip->i_ffs1_mode = IFREG;
197 		ip->i_nlink = ip->i_ffs1_nlink = 1;
198 		ip->i_ffs_effnlink = 1;
199 		ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
200 		ip = VTOI(vp);
201 
202 		DLOG((DLOG_RF, "lfs_rf_valloc: ino %d vp %p\n", ino, vp));
203 
204 		/* The dirop-nature of this vnode is past */
205 		lfs_unmark_vnode(vp);
206 		(void)lfs_vunref(vp);
207 		vp->v_flag &= ~VDIROP;
208 		simple_lock(&fs->lfs_interlock);
209 		simple_lock(&lfs_subsys_lock);
210 		--lfs_dirvcount;
211 		simple_unlock(&lfs_subsys_lock);
212 		TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
213 		simple_unlock(&fs->lfs_interlock);
214 	}
215 	*vpp = vp;
216 	return error;
217 }
218 
219 /*
220  * Add a new block to the Ifile, to accommodate future file creations.
221  * Called with the segment lock held.
222  */
223 static int
224 extend_ifile(struct lfs *fs, struct ucred *cred)
225 {
226 	struct vnode *vp;
227 	struct inode *ip;
228 	IFILE *ifp;
229 	IFILE_V1 *ifp_v1;
230 	struct buf *bp, *cbp;
231 	int error;
232 	daddr_t i, blkno, xmax;
233 	ino_t oldlast;
234 	CLEANERINFO *cip;
235 
236 	ASSERT_SEGLOCK(fs);
237 
238 	vp = fs->lfs_ivnode;
239 	ip = VTOI(vp);
240 	blkno = lblkno(fs, ip->i_size);
241 	if ((error = lfs_balloc(vp, ip->i_size, fs->lfs_bsize, cred, 0,
242 				&bp)) != 0) {
243 		return (error);
244 	}
245 	ip->i_size += fs->lfs_bsize;
246 	ip->i_ffs1_size = ip->i_size;
247 	uvm_vnp_setsize(vp, ip->i_size);
248 
249 	i = (blkno - fs->lfs_segtabsz - fs->lfs_cleansz) *
250 		fs->lfs_ifpb;
251 	LFS_GET_HEADFREE(fs, cip, cbp, &oldlast);
252 	LFS_PUT_HEADFREE(fs, cip, cbp, i);
253 #ifdef DIAGNOSTIC
254 	if (fs->lfs_freehd == LFS_UNUSED_INUM)
255 		panic("inode 0 allocated [2]");
256 #endif /* DIAGNOSTIC */
257 	xmax = i + fs->lfs_ifpb;
258 
259 	if (fs->lfs_version == 1) {
260 		for (ifp_v1 = (IFILE_V1 *)bp->b_data; i < xmax; ++ifp_v1) {
261 			ifp_v1->if_version = 1;
262 			ifp_v1->if_daddr = LFS_UNUSED_DADDR;
263 			ifp_v1->if_nextfree = ++i;
264 		}
265 		ifp_v1--;
266 		ifp_v1->if_nextfree = oldlast;
267 	} else {
268 		for (ifp = (IFILE *)bp->b_data; i < xmax; ++ifp) {
269 			ifp->if_version = 1;
270 			ifp->if_daddr = LFS_UNUSED_DADDR;
271 			ifp->if_nextfree = ++i;
272 		}
273 		ifp--;
274 		ifp->if_nextfree = oldlast;
275 	}
276 	LFS_PUT_TAILFREE(fs, cip, cbp, xmax - 1);
277 
278 	(void) LFS_BWRITE_LOG(bp); /* Ifile */
279 
280 	return 0;
281 }
282 
283 /* Allocate a new inode. */
284 /* ARGSUSED */
285 /* VOP_BWRITE 2i times */
286 int
287 lfs_valloc(struct vnode *pvp, int mode, struct ucred *cred, struct vnode **vpp)
288 {
289 	struct lfs *fs;
290 	struct buf *bp, *cbp;
291 	struct ifile *ifp;
292 	ino_t new_ino;
293 	int error;
294 	int new_gen;
295 	CLEANERINFO *cip;
296 
297 	fs = VTOI(pvp)->i_lfs;
298 	if (fs->lfs_ronly)
299 		return EROFS;
300 
301 	ASSERT_NO_SEGLOCK(fs);
302 
303 	lfs_seglock(fs, SEGM_PROT);
304 	vn_lock(fs->lfs_ivnode, LK_EXCLUSIVE);
305 
306 	/* Get the head of the freelist. */
307 	LFS_GET_HEADFREE(fs, cip, cbp, &new_ino);
308 
309 #ifdef DIAGNOSTIC
310 	if (new_ino == LFS_UNUSED_INUM) {
311 #ifdef DEBUG
312 		lfs_dump_super(fs);
313 #endif /* DEBUG */
314 		panic("inode 0 allocated [1]");
315 	}
316 #endif /* DIAGNOSTIC */
317 	DLOG((DLOG_ALLOC, "lfs_valloc: allocate inode %d\n", new_ino));
318 
319 	/*
320 	 * Remove the inode from the free list and write the new start
321 	 * of the free list into the superblock.
322 	 */
323 	LFS_IENTRY(ifp, fs, new_ino, bp);
324 	if (ifp->if_daddr != LFS_UNUSED_DADDR)
325 		panic("lfs_valloc: inuse inode %llu on the free list",
326 		    (unsigned long long)new_ino);
327 	LFS_PUT_HEADFREE(fs, cip, cbp, ifp->if_nextfree);
328 	DLOG((DLOG_ALLOC, "lfs_valloc: headfree %d -> %d\n", new_ino,
329 	      ifp->if_nextfree));
330 
331 	new_gen = ifp->if_version; /* version was updated by vfree */
332 	brelse(bp);
333 
334 	/* Extend IFILE so that the next lfs_valloc will succeed. */
335 	if (fs->lfs_freehd == LFS_UNUSED_INUM) {
336 		if ((error = extend_ifile(fs, cred)) != 0) {
337 			LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
338 			VOP_UNLOCK(fs->lfs_ivnode, 0);
339 			lfs_segunlock(fs);
340 			return error;
341 		}
342 	}
343 #ifdef DIAGNOSTIC
344 	if (fs->lfs_freehd == LFS_UNUSED_INUM)
345 		panic("inode 0 allocated [3]");
346 #endif /* DIAGNOSTIC */
347 
348 	/* Set superblock modified bit and increment file count. */
349 	simple_lock(&fs->lfs_interlock);
350 	fs->lfs_fmod = 1;
351 	simple_unlock(&fs->lfs_interlock);
352 	++fs->lfs_nfiles;
353 
354 	VOP_UNLOCK(fs->lfs_ivnode, 0);
355 	lfs_segunlock(fs);
356 
357 	return lfs_ialloc(fs, pvp, new_ino, new_gen, vpp);
358 }
359 
360 /*
361  * Finish allocating a new inode, given an inode and generation number.
362  */
363 static int
364 lfs_ialloc(struct lfs *fs, struct vnode *pvp, ino_t new_ino, int new_gen,
365 	   struct vnode **vpp)
366 {
367 	struct inode *ip;
368 	struct vnode *vp;
369 
370 	ASSERT_NO_SEGLOCK(fs);
371 
372 	vp = *vpp;
373 	lockmgr(&ufs_hashlock, LK_EXCLUSIVE, 0);
374 	/* Create an inode to associate with the vnode. */
375 	lfs_vcreate(pvp->v_mount, new_ino, vp);
376 
377 	ip = VTOI(vp);
378 	LFS_SET_UINO(ip, IN_CHANGE);
379 	/* on-disk structure has been zeroed out by lfs_vcreate */
380 	ip->i_din.ffs1_din->di_inumber = new_ino;
381 
382 	/* Note no blocks yet */
383 	ip->i_lfs_hiblk = -1;
384 
385 	/* Set a new generation number for this inode. */
386 	if (new_gen) {
387 		ip->i_gen = new_gen;
388 		ip->i_ffs1_gen = new_gen;
389 	}
390 
391 	/* Insert into the inode hash table. */
392 	ufs_ihashins(ip);
393 	lockmgr(&ufs_hashlock, LK_RELEASE, 0);
394 
395 	ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, vpp);
396 	vp = *vpp;
397 	ip = VTOI(vp);
398 
399 	memset(ip->i_lfs_fragsize, 0, NDADDR * sizeof(*ip->i_lfs_fragsize));
400 
401 	uvm_vnp_setsize(vp, 0);
402 	lfs_mark_vnode(vp);
403 	genfs_node_init(vp, &lfs_genfsops);
404 	VREF(ip->i_devvp);
405 	return (0);
406 }
407 
408 /* Create a new vnode/inode pair and initialize what fields we can. */
409 void
410 lfs_vcreate(struct mount *mp, ino_t ino, struct vnode *vp)
411 {
412 	struct inode *ip;
413 	struct ufs1_dinode *dp;
414 	struct ufsmount *ump;
415 #ifdef QUOTA
416 	int i;
417 #endif
418 
419 	/* Get a pointer to the private mount structure. */
420 	ump = VFSTOUFS(mp);
421 
422 	ASSERT_NO_SEGLOCK(ump->um_lfs);
423 
424 	/* Initialize the inode. */
425 	ip = pool_get(&lfs_inode_pool, PR_WAITOK);
426 	memset(ip, 0, sizeof(*ip));
427 	dp = pool_get(&lfs_dinode_pool, PR_WAITOK);
428 	memset(dp, 0, sizeof(*dp));
429 	ip->inode_ext.lfs = pool_get(&lfs_inoext_pool, PR_WAITOK);
430 	memset(ip->inode_ext.lfs, 0, sizeof(*ip->inode_ext.lfs));
431 	vp->v_data = ip;
432 	ip->i_din.ffs1_din = dp;
433 	ip->i_ump = ump;
434 	ip->i_vnode = vp;
435 	ip->i_devvp = ump->um_devvp;
436 	ip->i_dev = ump->um_dev;
437 	ip->i_number = dp->di_inumber = ino;
438 	ip->i_lfs = ump->um_lfs;
439 	ip->i_lfs_effnblks = 0;
440 	SPLAY_INIT(&ip->i_lfs_lbtree);
441 	ip->i_lfs_nbtree = 0;
442 #ifdef QUOTA
443 	for (i = 0; i < MAXQUOTAS; i++)
444 		ip->i_dquot[i] = NODQUOT;
445 #endif
446 #ifdef DEBUG
447 	if (ino == LFS_IFILE_INUM)
448 		vp->v_vnlock->lk_wmesg = "inlock";
449 #endif
450 }
451 
452 /* Free an inode. */
453 /* ARGUSED */
454 /* VOP_BWRITE 2i times */
455 int
456 lfs_vfree(struct vnode *vp, ino_t ino, int mode)
457 {
458 	SEGUSE *sup;
459 	CLEANERINFO *cip;
460 	struct buf *cbp, *bp;
461 	struct ifile *ifp;
462 	struct inode *ip;
463 	struct lfs *fs;
464 	daddr_t old_iaddr;
465 	ino_t otail;
466 	int s;
467 
468 	/* Get the inode number and file system. */
469 	ip = VTOI(vp);
470 	fs = ip->i_lfs;
471 	ino = ip->i_number;
472 
473 	ASSERT_NO_SEGLOCK(fs);
474 
475 	/* Drain of pending writes */
476 	simple_lock(&vp->v_interlock);
477 	s = splbio();
478 	if (fs->lfs_version > 1 && WRITEINPROG(vp))
479 		ltsleep(vp, (PRIBIO+1), "lfs_vfree", 0, &vp->v_interlock);
480 	splx(s);
481 	simple_unlock(&vp->v_interlock);
482 
483 	lfs_seglock(fs, SEGM_PROT);
484 	vn_lock(fs->lfs_ivnode, LK_EXCLUSIVE);
485 
486 	lfs_unmark_vnode(vp);
487 	if (vp->v_flag & VDIROP) {
488 		vp->v_flag &= ~VDIROP;
489 		simple_lock(&fs->lfs_interlock);
490 		simple_lock(&lfs_subsys_lock);
491 		--lfs_dirvcount;
492 		simple_unlock(&lfs_subsys_lock);
493 		TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
494 		simple_unlock(&fs->lfs_interlock);
495 		wakeup(&lfs_dirvcount);
496 		lfs_vunref(vp);
497 	}
498 
499 	LFS_CLR_UINO(ip, IN_ACCESSED|IN_CLEANING|IN_MODIFIED);
500 	ip->i_flag &= ~IN_ALLMOD;
501 
502 	/*
503 	 * Set the ifile's inode entry to unused, increment its version number
504 	 * and link it onto the free chain.
505 	 */
506 	LFS_IENTRY(ifp, fs, ino, bp);
507 	old_iaddr = ifp->if_daddr;
508 	ifp->if_daddr = LFS_UNUSED_DADDR;
509 	++ifp->if_version;
510 	if (fs->lfs_version == 1) {
511 		LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
512 		LFS_PUT_HEADFREE(fs, cip, cbp, ino);
513 		(void) LFS_BWRITE_LOG(bp); /* Ifile */
514 	} else {
515 		ifp->if_nextfree = LFS_UNUSED_INUM;
516 		/*
517 		 * XXX Writing the freed node here means that it might not
518 		 * XXX make it into the free list in the event of a crash
519 		 * XXX (the ifile could be written before the rest of this
520 		 * XXX completes).
521 		 */
522 		(void) LFS_BWRITE_LOG(bp); /* Ifile */
523 		LFS_GET_TAILFREE(fs, cip, cbp, &otail);
524 		LFS_IENTRY(ifp, fs, otail, bp);
525 		ifp->if_nextfree = ino;
526 		LFS_BWRITE_LOG(bp);
527 		LFS_PUT_TAILFREE(fs, cip, cbp, ino);
528 		DLOG((DLOG_ALLOC, "lfs_vfree: tailfree %d -> %d\n", otail,
529 		      ino));
530 	}
531 #ifdef DIAGNOSTIC
532 	if (ino == LFS_UNUSED_INUM) {
533 		panic("inode 0 freed");
534 	}
535 #endif /* DIAGNOSTIC */
536 	if (old_iaddr != LFS_UNUSED_DADDR) {
537 		LFS_SEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp);
538 #ifdef DIAGNOSTIC
539 		if (sup->su_nbytes < sizeof (struct ufs1_dinode)) {
540 			printf("lfs_vfree: negative byte count"
541 			       " (segment %" PRIu32 " short by %d)\n",
542 			       dtosn(fs, old_iaddr),
543 			       (int)sizeof (struct ufs1_dinode) -
544 				    sup->su_nbytes);
545 			panic("lfs_vfree: negative byte count");
546 			sup->su_nbytes = sizeof (struct ufs1_dinode);
547 		}
548 #endif
549 		sup->su_nbytes -= sizeof (struct ufs1_dinode);
550 		LFS_WRITESEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp); /* Ifile */
551 	}
552 
553 	/* Set superblock modified bit and decrement file count. */
554 	simple_lock(&fs->lfs_interlock);
555 	fs->lfs_fmod = 1;
556 	simple_unlock(&fs->lfs_interlock);
557 	--fs->lfs_nfiles;
558 
559 	VOP_UNLOCK(fs->lfs_ivnode, 0);
560 	lfs_segunlock(fs);
561 
562 	return (0);
563 }
564