xref: /netbsd-src/sys/ufs/lfs/lfs_alloc.c (revision 1ffa7b76c40339c17a0fb2a09fac93f287cfc046)
1 /*	$NetBSD: lfs_alloc.c,v 1.66 2003/04/02 10:39:40 fvdl 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. 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 #include <sys/cdefs.h>
74 __KERNEL_RCSID(0, "$NetBSD: lfs_alloc.c,v 1.66 2003/04/02 10:39:40 fvdl 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/kernel.h>
83 #include <sys/buf.h>
84 #include <sys/lock.h>
85 #include <sys/vnode.h>
86 #include <sys/syslog.h>
87 #include <sys/mount.h>
88 #include <sys/pool.h>
89 #include <sys/proc.h>
90 
91 #include <ufs/ufs/quota.h>
92 #include <ufs/ufs/inode.h>
93 #include <ufs/ufs/ufsmount.h>
94 #include <ufs/ufs/ufs_extern.h>
95 
96 #include <ufs/lfs/lfs.h>
97 #include <ufs/lfs/lfs_extern.h>
98 
99 extern int lfs_dirvcount;
100 extern struct lock ufs_hashlock;
101 
102 static int extend_ifile(struct lfs *, struct ucred *);
103 static int lfs_ialloc(struct lfs *, struct vnode *, ino_t, int, struct vnode **);
104 
105 /*
106  * Allocate a particular inode with a particular version number, freeing
107  * any previous versions of this inode that may have gone before.
108  * Used by the roll-forward code.
109  *
110  * XXX this function does not have appropriate locking to be used on a live fs;
111  * XXX but something similar could probably be used for an "undelete" call.
112  *
113  * Called with the Ifile inode locked.
114  */
115 int
116 lfs_rf_valloc(struct lfs *fs, ino_t ino, int version, struct proc *p,
117 	      struct vnode **vpp)
118 {
119 	IFILE *ifp;
120 	struct buf *bp, *cbp;
121 	struct vnode *vp;
122 	struct inode *ip;
123 	ino_t tino, oldnext;
124 	int error;
125 	CLEANERINFO *cip;
126 
127 	/*
128 	 * First, just try a vget. If the version number is the one we want,
129 	 * we don't have to do anything else.  If the version number is wrong,
130 	 * take appropriate action.
131 	 */
132 	error = VFS_VGET(fs->lfs_ivnode->v_mount, ino, &vp);
133 	if (error == 0) {
134 		/* printf("lfs_rf_valloc[1]: ino %d vp %p\n", ino, vp); */
135 
136 		*vpp = vp;
137 		ip = VTOI(vp);
138 		if (ip->i_gen == version)
139 			return 0;
140 		else if (ip->i_gen < version) {
141 			VOP_TRUNCATE(vp, (off_t)0, 0, NOCRED, p);
142 			ip->i_gen = ip->i_ffs1_gen = version;
143 			LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED | IN_UPDATE);
144 			return 0;
145 		} else {
146 			/* printf("ino %d: asked for version %d but got %d\n",
147 			       ino, version, ip->i_ffs1_gen); */
148 			vput(vp);
149 			*vpp = NULLVP;
150 			return EEXIST;
151 		}
152 	}
153 
154 	/*
155 	 * The inode is not in use.  Find it on the free list.
156 	 */
157 	/* If the Ifile is too short to contain this inum, extend it */
158 	while (VTOI(fs->lfs_ivnode)->i_size <= (ino /
159 		fs->lfs_ifpb + fs->lfs_cleansz + fs->lfs_segtabsz)
160 		<< fs->lfs_bshift) {
161 		extend_ifile(fs, NOCRED);
162 	}
163 
164 	LFS_IENTRY(ifp, fs, ino, bp);
165 	oldnext = ifp->if_nextfree;
166 	ifp->if_version = version;
167 	brelse(bp);
168 
169 	LFS_GET_HEADFREE(fs, cip, cbp, &ino);
170 	if (ino) {
171 		LFS_PUT_HEADFREE(fs, cip, cbp, oldnext);
172 	} else {
173 		tino = ino;
174 		while (1) {
175 			LFS_IENTRY(ifp, fs, tino, bp);
176 			if (ifp->if_nextfree == ino ||
177 			    ifp->if_nextfree == LFS_UNUSED_INUM)
178 				break;
179 			tino = ifp->if_nextfree;
180 			brelse(bp);
181 		}
182 		if (ifp->if_nextfree == LFS_UNUSED_INUM) {
183 			brelse(bp);
184 			return ENOENT;
185 		}
186 		ifp->if_nextfree = oldnext;
187 		LFS_BWRITE_LOG(bp);
188 	}
189 
190 	error = lfs_ialloc(fs, fs->lfs_ivnode, ino, version, &vp);
191 	if (error == 0) {
192 		/*
193 		 * Make it VREG so we can put blocks on it.  We will change
194 		 * this later if it turns out to be some other kind of file.
195 		 */
196 		ip = VTOI(vp);
197 		ip->i_mode = ip->i_ffs1_mode = IFREG;
198 		ip->i_nlink = ip->i_ffs1_nlink = 1;
199 		ip->i_ffs_effnlink = 1;
200 		ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
201 		ip = VTOI(vp);
202 
203 		/* printf("lfs_rf_valloc: ino %d vp %p\n", ino, vp); */
204 
205 		/* The dirop-nature of this vnode is past */
206 		(void)lfs_vunref(vp);
207 		--lfs_dirvcount;
208 		vp->v_flag &= ~VDIROP;
209 		TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
210 		--fs->lfs_nadirop;
211 		ip->i_flag &= ~IN_ADIROP;
212 	}
213 	*vpp = vp;
214 	return error;
215 }
216 
217 /*
218  * Add a new block to the Ifile, to accommodate future file creations.
219  * Called with the segment lock held.
220  */
221 static int
222 extend_ifile(struct lfs *fs, struct ucred *cred)
223 {
224 	struct vnode *vp;
225 	struct inode *ip;
226 	IFILE *ifp;
227 	IFILE_V1 *ifp_v1;
228 	struct buf *bp, *cbp;
229 	int error;
230 	daddr_t i, blkno, max;
231 	ino_t oldlast;
232 	CLEANERINFO *cip;
233 
234 	vp = fs->lfs_ivnode;
235 	ip = VTOI(vp);
236 	blkno = lblkno(fs, ip->i_size);
237 	if ((error = VOP_BALLOC(vp, ip->i_size, fs->lfs_bsize, cred, 0,
238 				&bp)) != 0) {
239 		return (error);
240 	}
241 	ip->i_size += fs->lfs_bsize;
242 	ip->i_ffs1_size = ip->i_size;
243 	uvm_vnp_setsize(vp, ip->i_size);
244 
245 	i = (blkno - fs->lfs_segtabsz - fs->lfs_cleansz) *
246 		fs->lfs_ifpb;
247 	LFS_GET_HEADFREE(fs, cip, cbp, &oldlast);
248 	LFS_PUT_HEADFREE(fs, cip, cbp, i);
249 #ifdef DIAGNOSTIC
250 	if (fs->lfs_freehd == LFS_UNUSED_INUM)
251 		panic("inode 0 allocated [2]");
252 #endif /* DIAGNOSTIC */
253 	max = i + fs->lfs_ifpb;
254 	/* printf("extend_ifile: new block ino %d--%d\n", i, max - 1); */
255 
256 	if (fs->lfs_version == 1) {
257 		for (ifp_v1 = (IFILE_V1 *)bp->b_data; i < max; ++ifp_v1) {
258 			ifp_v1->if_version = 1;
259 			ifp_v1->if_daddr = LFS_UNUSED_DADDR;
260 			ifp_v1->if_nextfree = ++i;
261 		}
262 		ifp_v1--;
263 		ifp_v1->if_nextfree = oldlast;
264 	} else {
265 		for (ifp = (IFILE *)bp->b_data; i < max; ++ifp) {
266 			ifp->if_version = 1;
267 			ifp->if_daddr = LFS_UNUSED_DADDR;
268 			ifp->if_nextfree = ++i;
269 		}
270 		ifp--;
271 		ifp->if_nextfree = oldlast;
272 	}
273 	LFS_PUT_TAILFREE(fs, cip, cbp, max - 1);
274 
275 	(void) LFS_BWRITE_LOG(bp); /* Ifile */
276 
277 	return 0;
278 }
279 
280 /* Allocate a new inode. */
281 /* ARGSUSED */
282 /* VOP_BWRITE 2i times */
283 int
284 lfs_valloc(void *v)
285 {
286 	struct vop_valloc_args /* {
287 				  struct vnode *a_pvp;
288 				  int a_mode;
289 				  struct ucred *a_cred;
290 				  struct vnode **a_vpp;
291 				  } */ *ap = v;
292 	struct lfs *fs;
293 	struct buf *bp, *cbp;
294 	struct ifile *ifp;
295 	ino_t new_ino;
296 	int error;
297 	int new_gen;
298 	CLEANERINFO *cip;
299 
300 	fs = VTOI(ap->a_pvp)->i_lfs;
301 	if (fs->lfs_ronly)
302 		return EROFS;
303 	*ap->a_vpp = NULL;
304 
305 	lfs_seglock(fs, SEGM_PROT);
306 
307 	/* Get the head of the freelist. */
308 	LFS_GET_HEADFREE(fs, cip, cbp, &new_ino);
309 
310 #ifdef DIAGNOSTIC
311 	if (new_ino == LFS_UNUSED_INUM) {
312 #ifdef DEBUG
313 		lfs_dump_super(fs);
314 #endif /* DEBUG */
315 		panic("inode 0 allocated [1]");
316 	}
317 #endif /* DIAGNOSTIC */
318 #ifdef ALLOCPRINT
319 	printf("lfs_valloc: allocate inode %d\n", new_ino);
320 #endif
321 
322 	/*
323 	 * Remove the inode from the free list and write the new start
324 	 * of the free list into the superblock.
325 	 */
326 	LFS_IENTRY(ifp, fs, new_ino, bp);
327 	if (ifp->if_daddr != LFS_UNUSED_DADDR)
328 		panic("lfs_valloc: inuse inode %d on the free list", new_ino);
329 	LFS_PUT_HEADFREE(fs, cip, cbp, ifp->if_nextfree);
330 	/* printf("lfs_valloc: headfree %d -> %d\n", new_ino, ifp->if_nextfree); */
331 
332 	new_gen = ifp->if_version; /* version was updated by vfree */
333 	brelse(bp);
334 
335 	/* Extend IFILE so that the next lfs_valloc will succeed. */
336 	if (fs->lfs_freehd == LFS_UNUSED_INUM) {
337 		if ((error = extend_ifile(fs, ap->a_cred)) != 0) {
338 			LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
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 	lfs_segunlock(fs);
349 
350 	return lfs_ialloc(fs, ap->a_pvp, new_ino, new_gen, ap->a_vpp);
351 }
352 
353 /*
354  * Finish allocating a new inode, given an inode and generation number.
355  */
356 static int
357 lfs_ialloc(struct lfs *fs, struct vnode *pvp, ino_t new_ino, int new_gen,
358 	   struct vnode **vpp)
359 {
360 	struct inode *ip;
361 	struct vnode *vp;
362 	IFILE *ifp;
363 	struct buf *bp, *cbp;
364 	int error;
365 	CLEANERINFO *cip;
366 
367 	error = getnewvnode(VT_LFS, pvp->v_mount, lfs_vnodeop_p, &vp);
368 	/* printf("lfs_ialloc: ino %d vp %p error %d\n", new_ino, vp, error);*/
369 	if (error)
370 		goto errout;
371 
372 	lockmgr(&ufs_hashlock, LK_EXCLUSIVE, 0);
373 	/* Create an inode to associate with the vnode. */
374 	lfs_vcreate(pvp->v_mount, new_ino, vp);
375 
376 	ip = VTOI(vp);
377 	LFS_SET_UINO(ip, IN_CHANGE | IN_MODIFIED);
378 	/* on-disk structure has been zeroed out by lfs_vcreate */
379 	ip->i_din.ffs1_din->di_inumber = new_ino;
380 
381 	/* Set a new generation number for this inode. */
382 	if (new_gen) {
383 		ip->i_gen = new_gen;
384 		ip->i_ffs1_gen = new_gen;
385 	}
386 
387 	/* Insert into the inode hash table. */
388 	ufs_ihashins(ip);
389 	lockmgr(&ufs_hashlock, LK_RELEASE, 0);
390 
391 	ufs_vinit(vp->v_mount, lfs_specop_p, lfs_fifoop_p, &vp);
392 	ip = VTOI(vp);
393 	/* printf("lfs_ialloc[2]: ino %d vp %p\n", new_ino, vp);*/
394 
395 	memset(ip->i_lfs_fragsize, 0, NDADDR * sizeof(*ip->i_lfs_fragsize));
396 
397 	uvm_vnp_setsize(vp, 0);
398 	*vpp = vp;
399 	if (!(vp->v_flag & VDIROP)) {
400 		(void)lfs_vref(vp);
401 		++lfs_dirvcount;
402 		TAILQ_INSERT_TAIL(&fs->lfs_dchainhd, ip, i_lfs_dchain);
403 	}
404 	vp->v_flag |= VDIROP;
405 
406 	if (!(ip->i_flag & IN_ADIROP))
407 		++fs->lfs_nadirop;
408 	ip->i_flag |= IN_ADIROP;
409 	genfs_node_init(vp, &lfs_genfsops);
410 	VREF(ip->i_devvp);
411 	/* Set superblock modified bit and increment file count. */
412 	fs->lfs_fmod = 1;
413 	++fs->lfs_nfiles;
414 	return (0);
415 
416     errout:
417 	/*
418 	 * Put the new inum back on the free list.
419 	 */
420 	lfs_seglock(fs, SEGM_PROT);
421 	LFS_IENTRY(ifp, fs, new_ino, bp);
422 	ifp->if_daddr = LFS_UNUSED_DADDR;
423 	LFS_GET_HEADFREE(fs, cip, cbp, &(ifp->if_nextfree));
424 	LFS_PUT_HEADFREE(fs, cip, cbp, new_ino);
425 	(void) LFS_BWRITE_LOG(bp); /* Ifile */
426 	lfs_segunlock(fs);
427 
428 	*vpp = NULLVP;
429 	return (error);
430 }
431 
432 /* Create a new vnode/inode pair and initialize what fields we can. */
433 void
434 lfs_vcreate(struct mount *mp, ino_t ino, struct vnode *vp)
435 {
436 	struct inode *ip;
437 	struct ufs1_dinode *dp;
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 	memset(ip, 0, sizeof(*ip));
449 	dp = pool_get(&lfs_dinode_pool, PR_WAITOK);
450 	memset(dp, 0, sizeof(*dp));
451 	ip->inode_ext.lfs = pool_get(&lfs_inoext_pool, PR_WAITOK);
452 	vp->v_data = ip;
453 	ip->i_din.ffs1_din = dp;
454 	ip->i_ump = ump;
455 	ip->i_vnode = vp;
456 	ip->i_devvp = ump->um_devvp;
457 	ip->i_dev = ump->um_dev;
458 	ip->i_number = dp->di_inumber = ino;
459 	ip->i_lfs = ump->um_lfs;
460 	ip->i_lfs_effnblks = 0;
461 #ifdef QUOTA
462 	for (i = 0; i < MAXQUOTAS; i++)
463 		ip->i_dquot[i] = NODQUOT;
464 #endif
465 #ifdef DEBUG_LFS_VNLOCK
466 	if (ino == LFS_IFILE_INUM)
467 		vp->v_vnlock->lk_wmesg = "inlock";
468 #endif
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 	daddr_t old_iaddr;
490 	ino_t ino, otail;
491 	extern int lfs_dirvcount;
492 	int s;
493 
494 	/* Get the inode number and file system. */
495 	vp = ap->a_pvp;
496 	ip = VTOI(vp);
497 	fs = ip->i_lfs;
498 	ino = ip->i_number;
499 
500 	/* Drain of pending writes */
501 	s = splbio();
502 	if (fs->lfs_version > 1 && WRITEINPROG(vp))
503 		tsleep(vp, (PRIBIO+1), "lfs_vfree", 0);
504 	splx(s);
505 
506 	lfs_seglock(fs, SEGM_PROT);
507 
508 	if (vp->v_flag & VDIROP) {
509 		--lfs_dirvcount;
510 		vp->v_flag &= ~VDIROP;
511 		TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
512 		wakeup(&lfs_dirvcount);
513 		lfs_vunref(vp);
514 	}
515 	lfs_unmark_vnode(vp);
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) LFS_BWRITE_LOG(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) LFS_BWRITE_LOG(bp); /* Ifile */
541 		LFS_GET_TAILFREE(fs, cip, cbp, &otail);
542 		LFS_IENTRY(ifp, fs, otail, bp);
543 		ifp->if_nextfree = ino;
544 		LFS_BWRITE_LOG(bp);
545 		LFS_PUT_TAILFREE(fs, cip, cbp, ino);
546 		/* printf("lfs_vfree: tailfree %d -> %d\n", otail, ino); */
547 	}
548 #ifdef DIAGNOSTIC
549 	if (ino == LFS_UNUSED_INUM) {
550 		panic("inode 0 freed");
551 	}
552 #endif /* DIAGNOSTIC */
553 	if (old_iaddr != LFS_UNUSED_DADDR) {
554 		LFS_SEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp);
555 #ifdef DIAGNOSTIC
556 		if (sup->su_nbytes < sizeof (struct ufs1_dinode)) {
557 			printf("lfs_vfree: negative byte count"
558 			       " (segment %" PRIu32 " short by %d)\n",
559 			       dtosn(fs, old_iaddr),
560 			       (int)sizeof (struct ufs1_dinode) -
561 				    sup->su_nbytes);
562 			panic("lfs_vfree: negative byte count");
563 			sup->su_nbytes = sizeof (struct ufs1_dinode);
564 		}
565 #endif
566 		sup->su_nbytes -= sizeof (struct ufs1_dinode);
567 		LFS_WRITESEGENTRY(sup, fs, dtosn(fs, old_iaddr), bp); /* Ifile */
568 	}
569 
570 	/* Set superblock modified bit and decrement file count. */
571 	fs->lfs_fmod = 1;
572 	--fs->lfs_nfiles;
573 
574 	lfs_segunlock(fs);
575 
576 	return (0);
577 }
578