xref: /netbsd-src/sys/ufs/lfs/lfs_alloc.c (revision 3b01aba77a7a698587faaae455bbfe740923c1f5)
1 /*	$NetBSD: lfs_alloc.c,v 1.48 2001/07/13 20:30:23 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@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 
87 #include <ufs/ufs/quota.h>
88 #include <ufs/ufs/inode.h>
89 #include <ufs/ufs/ufsmount.h>
90 #include <ufs/ufs/ufs_extern.h>
91 
92 #include <ufs/lfs/lfs.h>
93 #include <ufs/lfs/lfs_extern.h>
94 
95 extern int lfs_dirvcount;
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, struct vnode **);
100 
101 /*
102  * Allocate a particular inode with a particular version number, freeing
103  * any previous versions of this inode that may have gone before.
104  * Used by the roll-forward code.
105  *
106  * XXX this function does not have appropriate locking to be used on a live fs;
107  * XXX but something similar could probably be used for an "undelete" call.
108  */
109 int
110 lfs_rf_valloc(struct lfs *fs, ino_t ino, int version, struct proc *p,
111 	      struct vnode **vpp)
112 {
113 	IFILE *ifp;
114 	struct buf *bp, *cbp;
115 	struct vnode *vp;
116 	struct inode *ip;
117 	ino_t tino, oldnext;
118 	int error;
119 	CLEANERINFO *cip;
120 
121 	/*
122 	 * First, just try a vget. If the version number is the one we want,
123 	 * we don't have to do anything else.  If the version number is wrong,
124 	 * take appropriate action.
125 	 */
126 	error = VFS_VGET(fs->lfs_ivnode->v_mount, ino, &vp);
127 	if (error == 0) {
128 		/* printf("lfs_rf_valloc[1]: ino %d vp %p\n", ino, vp); */
129 
130 		*vpp = vp;
131 		ip = VTOI(vp);
132 		if (ip->i_ffs_gen == version)
133 			return 0;
134 		else if (ip->i_ffs_gen < version) {
135 			VOP_TRUNCATE(vp, (off_t)0, 0, NOCRED, p);
136 			ip->i_ffs_gen = version;
137 			LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED | IN_UPDATE);
138 			return 0;
139 		} else {
140 			/* printf("ino %d: asked for version %d but got %d\n",
141 			       ino, version, ip->i_ffs_gen); */
142 			vput(vp);
143 			*vpp = NULLVP;
144 			return EEXIST;
145 		}
146 	}
147 
148 	/*
149 	 * The inode is not in use.  Find it on the free list.
150 	 */
151 	/* If the Ifile is too short to contain this inum, extend it */
152 	while (VTOI(fs->lfs_ivnode)->i_ffs_size <= (ino /
153 		fs->lfs_ifpb + fs->lfs_cleansz + fs->lfs_segtabsz)
154 		<< fs->lfs_bshift) {
155 		extend_ifile(fs, NOCRED);
156 	}
157 
158 	LFS_IENTRY(ifp, fs, ino, bp);
159 	oldnext = ifp->if_nextfree;
160 	ifp->if_version = version;
161 	brelse(bp);
162 
163 	LFS_GET_HEADFREE(fs, cip, cbp, &ino);
164 	if (ino) {
165 		LFS_PUT_HEADFREE(fs, cip, cbp, oldnext);
166 	} else {
167 		tino = ino;
168 		while(1) {
169 			LFS_IENTRY(ifp, fs, tino, bp);
170 			if (ifp->if_nextfree == ino ||
171 			    ifp->if_nextfree == LFS_UNUSED_INUM)
172 				break;
173 			tino = ifp->if_nextfree;
174 			brelse(bp);
175 		}
176 		if (ifp->if_nextfree == LFS_UNUSED_INUM) {
177 			brelse(bp);
178 			return ENOENT;
179 		}
180 		ifp->if_nextfree = oldnext;
181 		VOP_BWRITE(bp);
182 	}
183 
184 	error = lfs_ialloc(fs, fs->lfs_ivnode, ino, version, &vp);
185 	if (error == 0) {
186 		/*
187 		 * Make it VREG so we can put blocks on it.  We will change
188 		 * this later if it turns out to be some other kind of file.
189 		 */
190 		ip = VTOI(vp);
191 		ip->i_ffs_mode = IFREG;
192 		ip->i_ffs_nlink = 1;
193 		ip->i_ffs_effnlink = 1;
194 		ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
195 		ip = VTOI(vp);
196 
197 		/* printf("lfs_rf_valloc: ino %d vp %p\n", ino, vp); */
198 
199 		/* The dirop-nature of this vnode is past */
200 		(void)lfs_vunref(vp);
201 		--lfs_dirvcount;
202 		vp->v_flag &= ~VDIROP;
203 		--fs->lfs_nadirop;
204 		ip->i_flag &= ~IN_ADIROP;
205 	}
206 	*vpp = vp;
207 	return error;
208 }
209 
210 static int
211 extend_ifile(struct lfs *fs, struct ucred *cred)
212 {
213 	struct vnode *vp;
214 	struct inode *ip;
215 	IFILE *ifp;
216 	IFILE_V1 *ifp_v1;
217 	struct buf *bp, *cbp;
218 	int error;
219 	ufs_daddr_t i, blkno, max;
220 	ino_t oldlast;
221 	CLEANERINFO *cip;
222 
223 	vp = fs->lfs_ivnode;
224 	(void)lfs_vref(vp);
225 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
226 	ip = VTOI(vp);
227 	blkno = lblkno(fs, ip->i_ffs_size);
228 	if ((error = VOP_BALLOC(vp, ip->i_ffs_size, fs->lfs_bsize, cred, 0,
229 				&bp)) != 0) {
230 		VOP_UNLOCK(vp, 0);
231 		lfs_vunref(vp);
232 		return (error);
233 	}
234 	ip->i_ffs_size += fs->lfs_bsize;
235 	uvm_vnp_setsize(vp, ip->i_ffs_size);
236 	VOP_UNLOCK(vp, 0);
237 
238 	i = (blkno - fs->lfs_segtabsz - fs->lfs_cleansz) *
239 		fs->lfs_ifpb;
240 	LFS_GET_HEADFREE(fs, cip, cbp, &oldlast);
241 	LFS_PUT_HEADFREE(fs, cip, cbp, i);
242 #ifdef DIAGNOSTIC
243 	if(fs->lfs_free == LFS_UNUSED_INUM)
244 		panic("inode 0 allocated [2]");
245 #endif /* DIAGNOSTIC */
246 	max = i + fs->lfs_ifpb;
247 	/* printf("extend ifile for ino %d--%d\n", i, max); */
248 
249 	if(fs->lfs_version == 1) {
250 		for (ifp_v1 = (IFILE_V1 *)bp->b_data; i < max; ++ifp_v1) {
251 			ifp_v1->if_version = 1;
252 			ifp_v1->if_daddr = LFS_UNUSED_DADDR;
253 			ifp_v1->if_nextfree = ++i;
254 		}
255 		ifp_v1--;
256 		ifp_v1->if_nextfree = oldlast;
257 	} else {
258 		for (ifp = (IFILE *)bp->b_data; i < max; ++ifp) {
259 			ifp->if_version = 1;
260 			ifp->if_daddr = LFS_UNUSED_DADDR;
261 			ifp->if_nextfree = ++i;
262 		}
263 		ifp--;
264 		ifp->if_nextfree = oldlast;
265 	}
266 
267 	(void) VOP_BWRITE(bp); /* Ifile */
268 	lfs_vunref(vp);
269 
270 	return 0;
271 }
272 
273 /* Allocate a new inode. */
274 /* ARGSUSED */
275 /* VOP_BWRITE 2i times */
276 int
277 lfs_valloc(void *v)
278 {
279 	struct vop_valloc_args /* {
280 				  struct vnode *a_pvp;
281 				  int a_mode;
282 				  struct ucred *a_cred;
283 				  struct vnode **a_vpp;
284 				  } */ *ap = v;
285 	struct lfs *fs;
286 	struct buf *bp, *cbp;
287 	struct ifile *ifp;
288 	ino_t new_ino;
289 	int error;
290 	int new_gen;
291 	CLEANERINFO *cip;
292 
293 	fs = VTOI(ap->a_pvp)->i_lfs;
294 	if (fs->lfs_ronly)
295 		return EROFS;
296 	*ap->a_vpp = NULL;
297 
298 	if (fs->lfs_version == 1) {
299 		/*
300 		 * Use lfs_seglock here, instead of fs->lfs_freelock, to
301 		 * ensure that the free list is not changed in between
302 		 * the time that the ifile blocks are written to disk
303 		 * and the time that the superblock is written to disk.
304 		 */
305 		lfs_seglock(fs, SEGM_PROT);
306 	} else {
307 		lockmgr(&fs->lfs_freelock, LK_EXCLUSIVE, 0);
308 	}
309 
310 	/* Get the head of the freelist. */
311 	LFS_GET_HEADFREE(fs, cip, cbp, &new_ino);
312 
313 #ifdef DIAGNOSTIC
314 	if(new_ino == LFS_UNUSED_INUM) {
315 #ifdef DEBUG
316 		lfs_dump_super(fs);
317 #endif /* DEBUG */
318 		panic("inode 0 allocated [1]");
319 	}
320 #endif /* DIAGNOSTIC */
321 #ifdef ALLOCPRINT
322 	printf("lfs_valloc: allocate inode %d\n", new_ino);
323 #endif
324 
325 	/*
326 	 * Remove the inode from the free list and write the new start
327 	 * of the free list into the superblock.
328 	 */
329 	LFS_IENTRY(ifp, fs, new_ino, bp);
330 	if (ifp->if_daddr != LFS_UNUSED_DADDR)
331 		panic("lfs_valloc: inuse inode %d on the free list", new_ino);
332 	LFS_PUT_HEADFREE(fs, cip, cbp, ifp->if_nextfree);
333 
334 	new_gen = ifp->if_version; /* version was updated by vfree */
335 	brelse(bp);
336 
337 	/* Extend IFILE so that the next lfs_valloc will succeed. */
338 	if (fs->lfs_free == LFS_UNUSED_INUM) {
339 		if ((error = extend_ifile(fs, ap->a_cred)) != 0) {
340 			LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
341 			if (fs->lfs_version == 1)
342 				lfs_segunlock(fs);
343 			else
344 				lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
345 			return error;
346 		}
347 	}
348 #ifdef DIAGNOSTIC
349 	if(fs->lfs_free == LFS_UNUSED_INUM)
350 		panic("inode 0 allocated [3]");
351 #endif /* DIAGNOSTIC */
352 
353 	if (fs->lfs_version == 1)
354 		lfs_segunlock(fs);
355 	else
356 		lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
357 
358 	return lfs_ialloc(fs, ap->a_pvp, new_ino, new_gen, ap->a_vpp);
359 }
360 
361 static int
362 lfs_ialloc(struct lfs *fs, struct vnode *pvp, ino_t new_ino, int new_gen,
363 	   struct vnode **vpp)
364 {
365 	struct inode *ip;
366 	struct vnode *vp;
367 	IFILE *ifp;
368 	struct buf *bp, *cbp;
369 	int error;
370 	CLEANERINFO *cip;
371 
372 	error = getnewvnode(VT_LFS, pvp->v_mount, lfs_vnodeop_p, &vp);
373 	/* printf("lfs_ialloc: ino %d vp %p error %d\n", new_ino, vp, error);*/
374 	if (error)
375 		goto errout;
376 
377 	lockmgr(&ufs_hashlock, LK_EXCLUSIVE, 0);
378 	/* Create an inode to associate with the vnode. */
379 	lfs_vcreate(pvp->v_mount, new_ino, vp);
380 
381 	ip = VTOI(vp);
382 	LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED);
383 	/* Zero out the direct and indirect block addresses. */
384 	bzero(&ip->i_din, sizeof(ip->i_din));
385 	ip->i_din.ffs_din.di_inumber = new_ino;
386 
387 	/* Set a new generation number for this inode. */
388 	if (new_gen)
389 		ip->i_ffs_gen = new_gen;
390 
391 	/* Insert into the inode hash table. */
392 	ufs_ihashins(ip);
393 	lockmgr(&ufs_hashlock, LK_RELEASE, 0);
394 
395 	error = ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
396 	ip = VTOI(vp);
397 	if (error) {
398 		vput(vp);
399 		goto errout;
400 	}
401 	/* printf("lfs_ialloc[2]: ino %d vp %p\n", new_ino, vp);*/
402 
403 	*vpp = vp;
404 #if 1
405 	if(!(vp->v_flag & VDIROP)) {
406 		(void)lfs_vref(vp);
407 		++lfs_dirvcount;
408 	}
409 	vp->v_flag |= VDIROP;
410 
411 	if(!(ip->i_flag & IN_ADIROP))
412 		++fs->lfs_nadirop;
413 	ip->i_flag |= IN_ADIROP;
414 #endif
415 	VREF(ip->i_devvp);
416 	/* Set superblock modified bit and increment file count. */
417 	fs->lfs_fmod = 1;
418 	++fs->lfs_nfiles;
419 	return (0);
420 
421     errout:
422 	/*
423 	 * Put the new inum back on the free list.
424 	 */
425 	LFS_IENTRY(ifp, fs, new_ino, bp);
426 	ifp->if_daddr = LFS_UNUSED_DADDR;
427 	LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
428 	LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
429 	(void) VOP_BWRITE(bp); /* Ifile */
430 
431 	*vpp = NULLVP;
432 	return (error);
433 }
434 
435 /* Create a new vnode/inode pair and initialize what fields we can. */
436 void
437 lfs_vcreate(struct mount *mp, ino_t ino, struct vnode *vp)
438 {
439 	struct inode *ip;
440 	struct ufsmount *ump;
441 #ifdef QUOTA
442 	int i;
443 #endif
444 
445 	/* Get a pointer to the private mount structure. */
446 	ump = VFSTOUFS(mp);
447 
448 	/* Initialize the inode. */
449 	ip = pool_get(&lfs_inode_pool, PR_WAITOK);
450 	vp->v_data = ip;
451 	ip->i_vnode = vp;
452 	ip->i_devvp = ump->um_devvp;
453 	ip->i_dev = ump->um_dev;
454 	ip->i_number = ip->i_din.ffs_din.di_inumber = ino;
455 	ip->i_lfs = ump->um_lfs;
456 #ifdef QUOTA
457 	for (i = 0; i < MAXQUOTAS; i++)
458 		ip->i_dquot[i] = NODQUOT;
459 #endif
460 	ip->i_lockf = 0;
461 	ip->i_diroff = 0;
462 	ip->i_ffs_mode = 0;
463 	ip->i_ffs_size = 0;
464 	ip->i_ffs_blocks = 0;
465 	ip->i_lfs_effnblks = 0;
466 	ip->i_flag = 0;
467 	/* Why was IN_MODIFIED ever set here? */
468 	/* LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED); */
469 }
470 
471 /* Free an inode. */
472 /* ARGUSED */
473 /* VOP_BWRITE 2i times */
474 int
475 lfs_vfree(void *v)
476 {
477 	struct vop_vfree_args /* {
478 				 struct vnode *a_pvp;
479 				 ino_t a_ino;
480 				 int a_mode;
481 				 } */ *ap = v;
482 	SEGUSE *sup;
483 	CLEANERINFO *cip;
484 	struct buf *cbp, *bp;
485 	struct ifile *ifp;
486 	struct inode *ip;
487 	struct vnode *vp;
488 	struct lfs *fs;
489 	ufs_daddr_t old_iaddr;
490 	ino_t ino, otail;
491 	extern int lfs_dirvcount;
492 
493 	/* Get the inode number and file system. */
494 	vp = ap->a_pvp;
495 	ip = VTOI(vp);
496 	fs = ip->i_lfs;
497 	ino = ip->i_number;
498 
499 	/* Drain of pending writes */
500 	if (fs->lfs_version > 1 && WRITEINPROG(vp))
501 		tsleep(vp, (PRIBIO+1), "lfs_vfree", 0);
502 
503 	if (fs->lfs_version == 1)
504 		lfs_seglock(fs, SEGM_PROT);
505 	else
506 		lockmgr(&fs->lfs_freelock, LK_EXCLUSIVE, 0);
507 
508 	if(vp->v_flag & VDIROP) {
509 		--lfs_dirvcount;
510 		vp->v_flag &= ~VDIROP;
511 		wakeup(&lfs_dirvcount);
512 		lfs_vunref(vp);
513 	}
514 	if (ip->i_flag & IN_ADIROP) {
515 		--fs->lfs_nadirop;
516 		ip->i_flag &= ~IN_ADIROP;
517 	}
518 
519 	LFS_CLR_UINO(ip, IN_ACCESSED|IN_CLEANING|IN_MODIFIED);
520 	ip->i_flag &= ~IN_ALLMOD;
521 
522 	/*
523 	 * Set the ifile's inode entry to unused, increment its version number
524 	 * and link it onto the free chain.
525 	 */
526 	LFS_IENTRY(ifp, fs, ino, bp);
527 	old_iaddr = ifp->if_daddr;
528 	ifp->if_daddr = LFS_UNUSED_DADDR;
529 	++ifp->if_version;
530 	if (fs->lfs_version == 1) {
531 		LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
532 		LFS_PUT_HEADFREE(fs, cip, cbp, ino);
533 		(void) VOP_BWRITE(bp); /* Ifile */
534 	} else {
535 		ifp->if_nextfree = LFS_UNUSED_INUM;
536 		/*
537 		 * XXX Writing the freed node here means that it might not
538 		 * XXX make it into the free list in the event of a crash
539 		 * XXX (the ifile could be written before the rest of this
540 		 * XXX completes).
541 		 */
542 		(void) VOP_BWRITE(bp); /* Ifile */
543 		LFS_GET_TAILFREE(fs, cip, cbp, &otail);
544 		LFS_IENTRY(ifp, fs, otail, bp);
545 		ifp->if_nextfree = ino;
546 		VOP_BWRITE(bp);
547 		LFS_PUT_TAILFREE(fs, cip, cbp, ino);
548 	}
549 #ifdef DIAGNOSTIC
550 	if(ino == LFS_UNUSED_INUM) {
551 		panic("inode 0 freed");
552 	}
553 #endif /* DIAGNOSTIC */
554 	if (old_iaddr != LFS_UNUSED_DADDR) {
555 		LFS_SEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp);
556 #ifdef DIAGNOSTIC
557 		if (sup->su_nbytes < DINODE_SIZE) {
558 			printf("lfs_vfree: negative byte count"
559 			       " (segment %d short by %d)\n",
560 			       dtosn(fs, old_iaddr),
561 			       (int)DINODE_SIZE - sup->su_nbytes);
562 			panic("lfs_vfree: negative byte count");
563 			sup->su_nbytes = DINODE_SIZE;
564 		}
565 #endif
566 		sup->su_nbytes -= DINODE_SIZE;
567 		(void) VOP_BWRITE(bp); /* Ifile */
568 	}
569 
570 	/* Set superblock modified bit and decrement file count. */
571 	fs->lfs_fmod = 1;
572 	--fs->lfs_nfiles;
573 
574 	if (fs->lfs_version == 1)
575 		lfs_segunlock(fs);
576 	else
577 		lockmgr(&fs->lfs_freelock, LK_RELEASE, 0);
578 	return (0);
579 }
580