xref: /netbsd-src/sys/ufs/lfs/lfs_segment.c (revision 89c5a767f8fc7a4633b2d409966e2becbb98ff92)
1 /*	$NetBSD: lfs_segment.c,v 1.40 2000/01/19 00:03:04 perseant Exp $	*/
2 
3 /*-
4  * Copyright (c) 1999 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_segment.c	8.10 (Berkeley) 6/10/95
71  */
72 
73 #define ivndebug(vp,str) printf("ino %d: %s\n",VTOI(vp)->i_number,(str))
74 
75 #include "opt_ddb.h"
76 #include <sys/param.h>
77 #include <sys/systm.h>
78 #include <sys/namei.h>
79 #include <sys/kernel.h>
80 #include <sys/resourcevar.h>
81 #include <sys/file.h>
82 #include <sys/stat.h>
83 #include <sys/buf.h>
84 #include <sys/proc.h>
85 #include <sys/conf.h>
86 #include <sys/vnode.h>
87 #include <sys/malloc.h>
88 #include <sys/mount.h>
89 
90 #include <miscfs/specfs/specdev.h>
91 #include <miscfs/fifofs/fifo.h>
92 
93 #include <ufs/ufs/quota.h>
94 #include <ufs/ufs/inode.h>
95 #include <ufs/ufs/dir.h>
96 #include <ufs/ufs/ufsmount.h>
97 #include <ufs/ufs/ufs_extern.h>
98 
99 #include <ufs/lfs/lfs.h>
100 #include <ufs/lfs/lfs_extern.h>
101 
102 extern int count_lock_queue __P((void));
103 extern struct simplelock vnode_free_list_slock;		/* XXX */
104 
105 /*
106  * Determine if it's OK to start a partial in this segment, or if we need
107  * to go on to a new segment.
108  */
109 #define	LFS_PARTIAL_FITS(fs) \
110 	((fs)->lfs_dbpseg - ((fs)->lfs_offset - (fs)->lfs_curseg) > \
111 	1 << (fs)->lfs_fsbtodb)
112 
113 void	 lfs_callback __P((struct buf *));
114 int	 lfs_gather __P((struct lfs *, struct segment *,
115 	     struct vnode *, int (*) __P((struct lfs *, struct buf *))));
116 int	 lfs_gatherblock __P((struct segment *, struct buf *, int *));
117 void	 lfs_iset __P((struct inode *, ufs_daddr_t, time_t));
118 int	 lfs_match_fake __P((struct lfs *, struct buf *));
119 int	 lfs_match_data __P((struct lfs *, struct buf *));
120 int	 lfs_match_dindir __P((struct lfs *, struct buf *));
121 int	 lfs_match_indir __P((struct lfs *, struct buf *));
122 int	 lfs_match_tindir __P((struct lfs *, struct buf *));
123 void	 lfs_newseg __P((struct lfs *));
124 void	 lfs_shellsort __P((struct buf **, ufs_daddr_t *, register int));
125 void	 lfs_supercallback __P((struct buf *));
126 void	 lfs_updatemeta __P((struct segment *));
127 int	 lfs_vref __P((struct vnode *));
128 void	 lfs_vunref __P((struct vnode *));
129 void	 lfs_writefile __P((struct lfs *, struct segment *, struct vnode *));
130 int	 lfs_writeinode __P((struct lfs *, struct segment *, struct inode *));
131 int	 lfs_writeseg __P((struct lfs *, struct segment *));
132 void	 lfs_writesuper __P((struct lfs *, daddr_t));
133 int	 lfs_writevnodes __P((struct lfs *fs, struct mount *mp,
134 	    struct segment *sp, int dirops));
135 
136 int	lfs_allclean_wakeup;		/* Cleaner wakeup address. */
137 int	lfs_writeindir = 1;             /* whether to flush indir on non-ckp */
138 int	lfs_clean_vnhead = 0;		/* Allow freeing to head of vn list */
139 int	lfs_dirvcount = 0;		/* # active dirops */
140 
141 /* Statistics Counters */
142 int lfs_dostats = 1;
143 struct lfs_stats lfs_stats;
144 
145 /* op values to lfs_writevnodes */
146 #define	VN_REG	        0
147 #define	VN_DIROP	1
148 #define	VN_EMPTY	2
149 #define VN_CLEAN        3
150 
151 #define LFS_MAX_ACTIVE          10
152 
153 /*
154  * XXX KS - Set modification time on the Ifile, so the cleaner can
155  * read the fs mod time off of it.  We don't set IN_UPDATE here,
156  * since we don't really need this to be flushed to disk (and in any
157  * case that wouldn't happen to the Ifile until we checkpoint).
158  */
159 void
160 lfs_imtime(fs)
161 	struct lfs *fs;
162 {
163 	struct timespec ts;
164 	struct inode *ip;
165 
166 	TIMEVAL_TO_TIMESPEC(&time, &ts);
167 	ip = VTOI(fs->lfs_ivnode);
168 	ip->i_ffs_mtime = ts.tv_sec;
169 	ip->i_ffs_mtimensec = ts.tv_nsec;
170 }
171 
172 /*
173  * Ifile and meta data blocks are not marked busy, so segment writes MUST be
174  * single threaded.  Currently, there are two paths into lfs_segwrite, sync()
175  * and getnewbuf().  They both mark the file system busy.  Lfs_vflush()
176  * explicitly marks the file system busy.  So lfs_segwrite is safe.  I think.
177  */
178 
179 #define SET_FLUSHING(fs,vp) (fs)->lfs_flushvp = (vp)
180 #define IS_FLUSHING(fs,vp)  ((fs)->lfs_flushvp == (vp))
181 #define CLR_FLUSHING(fs,vp) (fs)->lfs_flushvp = NULL
182 
183 int
184 lfs_vflush(vp)
185 	struct vnode *vp;
186 {
187 	struct inode *ip;
188 	struct lfs *fs;
189 	struct segment *sp;
190 	struct buf *bp, *nbp, *tbp, *tnbp;
191 	int error, s;
192 
193 	ip = VTOI(vp);
194 	fs = VFSTOUFS(vp->v_mount)->um_lfs;
195 
196 	if(ip->i_flag & IN_CLEANING) {
197 #ifdef DEBUG_LFS
198 		ivndebug(vp,"vflush/in_cleaning");
199 #endif
200 		ip->i_flag &= ~IN_CLEANING;
201 		if(ip->i_flag & IN_MODIFIED) {
202 			fs->lfs_uinodes--;
203 		} else
204 			ip->i_flag |= IN_MODIFIED;
205 		/*
206 		 * Toss any cleaning buffers that have real counterparts
207 		 * to avoid losing new data
208 		 */
209 		s = splbio();
210 		for(bp=vp->v_dirtyblkhd.lh_first; bp; bp=nbp) {
211 			nbp = bp->b_vnbufs.le_next;
212 			if(bp->b_flags & B_CALL) {
213 				for(tbp=vp->v_dirtyblkhd.lh_first; tbp;
214 				    tbp=tnbp)
215 				{
216 					tnbp = tbp->b_vnbufs.le_next;
217 					if(tbp->b_vp == bp->b_vp
218 					   && tbp->b_lblkno == bp->b_lblkno
219 					   && tbp != bp)
220 					{
221 						lfs_freebuf(bp);
222 					}
223 				}
224 			}
225 		}
226 		splx(s);
227 	}
228 
229 	/* If the node is being written, wait until that is done */
230 	if(WRITEINPROG(vp)) {
231 #ifdef DEBUG_LFS
232 		ivndebug(vp,"vflush/writeinprog");
233 #endif
234 		tsleep(vp, PRIBIO+1, "lfs_vw", 0);
235 	}
236 
237 	/* Protect against VXLOCK deadlock in vinvalbuf() */
238 	lfs_seglock(fs, SEGM_SYNC);
239 
240 	/* If we're supposed to flush a freed inode, just toss it */
241 	/* XXX - seglock, so these buffers can't be gathered, right? */
242 	if(ip->i_ffs_mode == 0) {
243 		printf("lfs_vflush: ino %d is freed, not flushing\n",
244 			ip->i_number);
245 		s = splbio();
246 		for(bp=vp->v_dirtyblkhd.lh_first; bp; bp=nbp) {
247 			nbp = bp->b_vnbufs.le_next;
248 			/* Copied from lfs_writeseg */
249 			if (bp->b_flags & B_CALL) {
250 				/* if B_CALL, it was created with newbuf */
251 				lfs_freebuf(bp);
252 			} else {
253 				bremfree(bp);
254 				bp->b_flags &= ~(B_ERROR | B_READ | B_DELWRI |
255                                          B_LOCKED | B_GATHERED);
256 				bp->b_flags |= B_DONE;
257 				reassignbuf(bp, vp);
258 				brelse(bp);
259 			}
260 		}
261 		splx(s);
262 		if(ip->i_flag & IN_CLEANING)
263 			fs->lfs_uinodes--;
264 		if(ip->i_flag & IN_MODIFIED)
265 			fs->lfs_uinodes--;
266 		ip->i_flag &= ~(IN_MODIFIED|IN_UPDATE|IN_ACCESS|IN_CHANGE|IN_CLEANING);
267 		printf("lfs_vflush: done not flushing ino %d\n",
268 			ip->i_number);
269 		lfs_segunlock(fs);
270 		return 0;
271 	}
272 
273 	SET_FLUSHING(fs,vp);
274 	if (fs->lfs_nactive > LFS_MAX_ACTIVE) {
275 		error = lfs_segwrite(vp->v_mount, SEGM_SYNC|SEGM_CKP);
276 		CLR_FLUSHING(fs,vp);
277 		lfs_segunlock(fs);
278 		return error;
279 	}
280 	sp = fs->lfs_sp;
281 
282 	if (vp->v_dirtyblkhd.lh_first == NULL) {
283 		lfs_writevnodes(fs, vp->v_mount, sp, VN_EMPTY);
284 	} else if((ip->i_flag & IN_CLEANING) && (fs->lfs_sp->seg_flags & SEGM_CLEAN)) {
285 #ifdef DEBUG_LFS
286 		ivndebug(vp,"vflush/clean");
287 #endif
288 		lfs_writevnodes(fs, vp->v_mount, sp, VN_CLEAN);
289 	}
290 	else if(lfs_dostats) {
291 		if(vp->v_dirtyblkhd.lh_first || (VTOI(vp)->i_flag & (IN_MODIFIED|IN_UPDATE|IN_ACCESS|IN_CHANGE|IN_CLEANING)))
292 			++lfs_stats.vflush_invoked;
293 #ifdef DEBUG_LFS
294 		ivndebug(vp,"vflush");
295 #endif
296 	}
297 
298 #ifdef DIAGNOSTIC
299 	/* XXX KS This actually can happen right now, though it shouldn't(?) */
300 	if(vp->v_flag & VDIROP) {
301 		printf("lfs_vflush: flushing VDIROP, this shouldn\'t be\n");
302 		/* panic("VDIROP being flushed...this can\'t happen"); */
303 	}
304 	if(vp->v_usecount<0) {
305 		printf("usecount=%ld\n",vp->v_usecount);
306 		panic("lfs_vflush: usecount<0");
307 	}
308 #endif
309 
310 	do {
311 		do {
312 			if (vp->v_dirtyblkhd.lh_first != NULL)
313 				lfs_writefile(fs, sp, vp);
314 		} while (lfs_writeinode(fs, sp, ip));
315 	} while (lfs_writeseg(fs, sp) && ip->i_number == LFS_IFILE_INUM);
316 
317 	if(lfs_dostats) {
318 		++lfs_stats.nwrites;
319 		if (sp->seg_flags & SEGM_SYNC)
320 			++lfs_stats.nsync_writes;
321 		if (sp->seg_flags & SEGM_CKP)
322 			++lfs_stats.ncheckpoints;
323 	}
324 	lfs_segunlock(fs);
325 
326 	CLR_FLUSHING(fs,vp);
327 	return (0);
328 }
329 
330 #ifdef DEBUG_LFS_VERBOSE
331 # define vndebug(vp,str) if(VTOI(vp)->i_flag & IN_CLEANING) printf("not writing ino %d because %s (op %d)\n",VTOI(vp)->i_number,(str),op)
332 #else
333 # define vndebug(vp,str)
334 #endif
335 
336 int
337 lfs_writevnodes(fs, mp, sp, op)
338 	struct lfs *fs;
339 	struct mount *mp;
340 	struct segment *sp;
341 	int op;
342 {
343 	struct inode *ip;
344 	struct vnode *vp;
345 	int inodes_written=0, only_cleaning;
346 
347 #ifndef LFS_NO_BACKVP_HACK
348 	/* BEGIN HACK */
349 #define	VN_OFFSET	(((caddr_t)&vp->v_mntvnodes.le_next) - (caddr_t)vp)
350 #define	BACK_VP(VP)	((struct vnode *)(((caddr_t)VP->v_mntvnodes.le_prev) - VN_OFFSET))
351 #define	BEG_OF_VLIST	((struct vnode *)(((caddr_t)&mp->mnt_vnodelist.lh_first) - VN_OFFSET))
352 
353 	/* Find last vnode. */
354  loop:	for (vp = mp->mnt_vnodelist.lh_first;
355 	     vp && vp->v_mntvnodes.le_next != NULL;
356 	     vp = vp->v_mntvnodes.le_next);
357 	for (; vp && vp != BEG_OF_VLIST; vp = BACK_VP(vp)) {
358 #else
359 	loop:
360 	for (vp = mp->mnt_vnodelist.lh_first;
361 	     vp != NULL;
362 	     vp = vp->v_mntvnodes.le_next) {
363 #endif
364 		/*
365 		 * If the vnode that we are about to sync is no longer
366 		 * associated with this mount point, start over.
367 		 */
368 		if (vp->v_mount != mp)
369 			goto loop;
370 
371 		ip = VTOI(vp);
372 		if ((op == VN_DIROP && !(vp->v_flag & VDIROP)) ||
373 		    (op != VN_DIROP && op != VN_CLEAN && (vp->v_flag & VDIROP))) {
374 			vndebug(vp,"dirop");
375 			continue;
376 		}
377 
378 		if (op == VN_EMPTY && vp->v_dirtyblkhd.lh_first) {
379 			vndebug(vp,"empty");
380 			continue;
381 		}
382 
383 		if (vp->v_type == VNON) {
384 			continue;
385 		}
386 
387 		if(op == VN_CLEAN && ip->i_number != LFS_IFILE_INUM
388 		   && vp != fs->lfs_flushvp
389 		   && !(ip->i_flag & IN_CLEANING)) {
390 			vndebug(vp,"cleaning");
391 			continue;
392 		}
393 
394 		if (lfs_vref(vp)) {
395 			vndebug(vp,"vref");
396 			continue;
397 		}
398 
399 #if 0 /* XXX KS - if we skip the ifile, things could go badly for us. */
400 		if(WRITEINPROG(vp)) {
401 			lfs_vunref(vp);
402 #ifdef DEBUG_LFS
403 			ivndebug(vp,"writevnodes/writeinprog");
404 #endif
405 			continue;
406 		}
407 #endif
408 		only_cleaning = 0;
409 		/*
410 		 * Write the inode/file if dirty and it's not the
411 		 * the IFILE.
412 		 */
413 		if ((ip->i_flag &
414 		     (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE | IN_CLEANING) ||
415 		     vp->v_dirtyblkhd.lh_first != NULL))
416 		{
417 			only_cleaning = ((ip->i_flag & (IN_ACCESS|IN_CHANGE|IN_MODIFIED|IN_UPDATE|IN_CLEANING))==IN_CLEANING);
418 
419 			if(ip->i_number != LFS_IFILE_INUM
420 			   && vp->v_dirtyblkhd.lh_first != NULL)
421 			{
422 				lfs_writefile(fs, sp, vp);
423 			}
424 			if(vp->v_dirtyblkhd.lh_first != NULL) {
425 				if(WRITEINPROG(vp)) {
426 #ifdef DEBUG_LFS
427 					ivndebug(vp,"writevnodes/write2");
428 #endif
429 				} else if(!(ip->i_flag & (IN_ACCESS|IN_CHANGE|IN_MODIFIED|IN_UPDATE|IN_CLEANING))) {
430 #ifdef DEBUG_LFS
431 					printf("<%d>",ip->i_number);
432 #endif
433 					ip->i_flag |= IN_MODIFIED;
434 					++fs->lfs_uinodes;
435 				}
436 			}
437 			(void) lfs_writeinode(fs, sp, ip);
438 			inodes_written++;
439 		}
440 
441 		if(lfs_clean_vnhead && only_cleaning)
442 			lfs_vunref_head(vp);
443 		else
444 			lfs_vunref(vp);
445 	}
446 	return inodes_written;
447 }
448 
449 int
450 lfs_segwrite(mp, flags)
451 	struct mount *mp;
452 	int flags;			/* Do a checkpoint. */
453 {
454 	struct buf *bp;
455 	struct inode *ip;
456 	struct lfs *fs;
457 	struct segment *sp;
458 	struct vnode *vp;
459 	SEGUSE *segusep;
460 	ufs_daddr_t ibno;
461 	int do_ckp, error, i;
462 	int writer_set = 0;
463 	int need_unlock = 0;
464 
465 	fs = VFSTOUFS(mp)->um_lfs;
466 
467 	lfs_imtime(fs);
468 
469 	/*
470 	 * If we are not the cleaner, and we have fewer than MIN_FREE_SEGS
471 	 * clean segments, wait until cleaner writes.
472 	 */
473 	if(!(flags & SEGM_CLEAN)
474 	   && (!fs->lfs_seglock || !(fs->lfs_sp->seg_flags & SEGM_CLEAN)))
475 	{
476 		do {
477 			if (fs->lfs_nclean <= MIN_FREE_SEGS
478 			    || fs->lfs_avail <= 0)
479 			{
480 				wakeup(&lfs_allclean_wakeup);
481 				wakeup(&fs->lfs_nextseg);
482 				error = tsleep(&fs->lfs_avail, PRIBIO + 1,
483 					       "lfs_avail", 0);
484 				if (error) {
485 					return (error);
486 				}
487 			}
488 		} while (fs->lfs_nclean <= MIN_FREE_SEGS || fs->lfs_avail <= 0);
489 	}
490 
491 	/*
492 	 * Allocate a segment structure and enough space to hold pointers to
493 	 * the maximum possible number of buffers which can be described in a
494 	 * single summary block.
495 	 */
496 	do_ckp = (flags & SEGM_CKP) || fs->lfs_nactive > LFS_MAX_ACTIVE;
497 	lfs_seglock(fs, flags | (do_ckp ? SEGM_CKP : 0));
498 	sp = fs->lfs_sp;
499 
500 	/*
501 	 * If lfs_flushvp is non-NULL, we are called from lfs_vflush,
502 	 * in which case we have to flush *all* buffers off of this vnode.
503 	 * We don't care about other nodes, but write any non-dirop nodes
504 	 * anyway in anticipation of another getnewvnode().
505 	 *
506 	 * If we're cleaning we only write cleaning and ifile blocks, and
507 	 * no dirops, since otherwise we'd risk corruption in a crash.
508 	 */
509 	if(sp->seg_flags & SEGM_CLEAN)
510 		lfs_writevnodes(fs, mp, sp, VN_CLEAN);
511 	else {
512 		lfs_writevnodes(fs, mp, sp, VN_REG);
513 		if(!fs->lfs_dirops || !fs->lfs_flushvp) {
514 			while(fs->lfs_dirops)
515 				if((error = tsleep(&fs->lfs_writer, PRIBIO + 1,
516 						"lfs writer", 0)))
517 				{
518 					free(sp->bpp, M_SEGMENT);
519 					free(sp, M_SEGMENT);
520 					return (error);
521 				}
522 			fs->lfs_writer++;
523 			writer_set=1;
524 			lfs_writevnodes(fs, mp, sp, VN_DIROP);
525 			((SEGSUM *)(sp->segsum))->ss_flags &= ~(SS_CONT);
526 		}
527 	}
528 
529 	/*
530 	 * If we are doing a checkpoint, mark everything since the
531 	 * last checkpoint as no longer ACTIVE.
532 	 */
533 	if (do_ckp) {
534 		for (ibno = fs->lfs_cleansz + fs->lfs_segtabsz;
535 		     --ibno >= fs->lfs_cleansz; ) {
536 			if (bread(fs->lfs_ivnode, ibno, fs->lfs_bsize, NOCRED, &bp))
537 
538 				panic("lfs_segwrite: ifile read");
539 			segusep = (SEGUSE *)bp->b_data;
540 			for (i = fs->lfs_sepb; i--; segusep++)
541 				segusep->su_flags &= ~SEGUSE_ACTIVE;
542 
543 			/* But the current segment is still ACTIVE */
544 			if (fs->lfs_curseg/fs->lfs_sepb==(ibno-fs->lfs_cleansz))
545 				((SEGUSE *)(bp->b_data))[fs->lfs_curseg%fs->lfs_sepb].su_flags |= SEGUSE_ACTIVE;
546 			error = VOP_BWRITE(bp);
547 		}
548 	}
549 
550 	if (do_ckp || fs->lfs_doifile) {
551 	redo:
552 		vp = fs->lfs_ivnode;
553 		/*
554 		 * Depending on the circumstances of our calling, the ifile
555 		 * inode might be locked.  If it is, and if it is locked by
556 		 * us, we should VREF instead of vget here.
557 		 */
558 		need_unlock = 0;
559 		if(VOP_ISLOCKED(vp)
560 		   && vp->v_lock.lk_lockholder == curproc->p_pid) {
561 			VREF(vp);
562 		} else {
563 			while (vget(vp, LK_EXCLUSIVE))
564 				continue;
565 			need_unlock = 1;
566 		}
567 		ip = VTOI(vp);
568 		if (vp->v_dirtyblkhd.lh_first != NULL)
569 			lfs_writefile(fs, sp, vp);
570 		(void)lfs_writeinode(fs, sp, ip);
571 
572 		/* Only vput if we used vget() above. */
573 		if(need_unlock)
574 			vput(vp);
575 		else
576 			vrele(vp);
577 
578 		if (lfs_writeseg(fs, sp) && do_ckp)
579 			goto redo;
580 	} else {
581 		(void) lfs_writeseg(fs, sp);
582 	}
583 
584 	/*
585 	 * If the I/O count is non-zero, sleep until it reaches zero.
586 	 * At the moment, the user's process hangs around so we can
587 	 * sleep.
588 	 */
589 	fs->lfs_doifile = 0;
590 	if(writer_set && --fs->lfs_writer==0)
591 		wakeup(&fs->lfs_dirops);
592 
593 	if(lfs_dostats) {
594 		++lfs_stats.nwrites;
595 		if (sp->seg_flags & SEGM_SYNC)
596 			++lfs_stats.nsync_writes;
597 		if (sp->seg_flags & SEGM_CKP)
598 			++lfs_stats.ncheckpoints;
599 	}
600 	lfs_segunlock(fs);
601 	return (0);
602 }
603 
604 /*
605  * Write the dirty blocks associated with a vnode.
606  */
607 void
608 lfs_writefile(fs, sp, vp)
609 	struct lfs *fs;
610 	struct segment *sp;
611 	struct vnode *vp;
612 {
613 	struct buf *bp;
614 	struct finfo *fip;
615 	IFILE *ifp;
616 
617 
618 	if (sp->seg_bytes_left < fs->lfs_bsize ||
619 	    sp->sum_bytes_left < sizeof(struct finfo))
620 		(void) lfs_writeseg(fs, sp);
621 
622 	sp->sum_bytes_left -= sizeof(struct finfo) - sizeof(ufs_daddr_t);
623 	++((SEGSUM *)(sp->segsum))->ss_nfinfo;
624 
625 	if(vp->v_flag & VDIROP)
626 		((SEGSUM *)(sp->segsum))->ss_flags |= (SS_DIROP|SS_CONT);
627 
628 	fip = sp->fip;
629 	fip->fi_nblocks = 0;
630 	fip->fi_ino = VTOI(vp)->i_number;
631 	LFS_IENTRY(ifp, fs, fip->fi_ino, bp);
632 	fip->fi_version = ifp->if_version;
633 	brelse(bp);
634 
635 	if(sp->seg_flags & SEGM_CLEAN)
636 	{
637 		lfs_gather(fs, sp, vp, lfs_match_fake);
638 		/*
639 		 * For a file being flushed, we need to write *all* blocks.
640 		 * This means writing the cleaning blocks first, and then
641 		 * immediately following with any non-cleaning blocks.
642 		 * The same is true of the Ifile since checkpoints assume
643 		 * that all valid Ifile blocks are written.
644 		 */
645 	   	if(IS_FLUSHING(fs,vp) || VTOI(vp)->i_number == LFS_IFILE_INUM)
646 			lfs_gather(fs, sp, vp, lfs_match_data);
647 	} else
648 		lfs_gather(fs, sp, vp, lfs_match_data);
649 
650 	/*
651 	 * It may not be necessary to write the meta-data blocks at this point,
652 	 * as the roll-forward recovery code should be able to reconstruct the
653 	 * list.
654 	 *
655 	 * We have to write them anyway, though, under two conditions: (1) the
656 	 * vnode is being flushed (for reuse by vinvalbuf); or (2) we are
657 	 * checkpointing.
658 	 */
659 	if(lfs_writeindir
660 	   || IS_FLUSHING(fs,vp)
661 	   || (sp->seg_flags & SEGM_CKP))
662 	{
663 		lfs_gather(fs, sp, vp, lfs_match_indir);
664 		lfs_gather(fs, sp, vp, lfs_match_dindir);
665 		lfs_gather(fs, sp, vp, lfs_match_tindir);
666 	}
667 	fip = sp->fip;
668 	if (fip->fi_nblocks != 0) {
669 		sp->fip = (FINFO*)((caddr_t)fip + sizeof(struct finfo) +
670 				   sizeof(ufs_daddr_t) * (fip->fi_nblocks-1));
671 		sp->start_lbp = &sp->fip->fi_blocks[0];
672 	} else {
673 		sp->sum_bytes_left += sizeof(FINFO) - sizeof(ufs_daddr_t);
674 		--((SEGSUM *)(sp->segsum))->ss_nfinfo;
675 	}
676 }
677 
678 int
679 lfs_writeinode(fs, sp, ip)
680 	struct lfs *fs;
681 	struct segment *sp;
682 	struct inode *ip;
683 {
684 	struct buf *bp, *ibp;
685 	IFILE *ifp;
686 	SEGUSE *sup;
687 	ufs_daddr_t daddr;
688 	ino_t ino;
689 	int error, i, ndx;
690 	int redo_ifile = 0;
691 	struct timespec ts;
692 	int gotblk=0;
693 
694 	if (!(ip->i_flag & (IN_ACCESS | IN_CHANGE | IN_MODIFIED | IN_UPDATE | IN_CLEANING)))
695 		return(0);
696 
697 	/* Allocate a new inode block if necessary. */
698 	if ((ip->i_number != LFS_IFILE_INUM || sp->idp==NULL) && sp->ibp == NULL) {
699 		/* Allocate a new segment if necessary. */
700 		if (sp->seg_bytes_left < fs->lfs_bsize ||
701 		    sp->sum_bytes_left < sizeof(ufs_daddr_t))
702 			(void) lfs_writeseg(fs, sp);
703 
704 		/* Get next inode block. */
705 		daddr = fs->lfs_offset;
706 		fs->lfs_offset += fsbtodb(fs, 1);
707 		sp->ibp = *sp->cbpp++ =
708 			getblk(VTOI(fs->lfs_ivnode)->i_devvp, daddr, fs->lfs_bsize, 0, 0);
709 		gotblk++;
710 
711 		/* Zero out inode numbers */
712 		for (i = 0; i < INOPB(fs); ++i)
713 			((struct dinode *)sp->ibp->b_data)[i].di_inumber = 0;
714 
715 		++sp->start_bpp;
716 		fs->lfs_avail -= fsbtodb(fs, 1);
717 		/* Set remaining space counters. */
718 		sp->seg_bytes_left -= fs->lfs_bsize;
719 		sp->sum_bytes_left -= sizeof(ufs_daddr_t);
720 		ndx = LFS_SUMMARY_SIZE / sizeof(ufs_daddr_t) -
721 			sp->ninodes / INOPB(fs) - 1;
722 		((ufs_daddr_t *)(sp->segsum))[ndx] = daddr;
723 	}
724 
725 	/* Update the inode times and copy the inode onto the inode page. */
726 	if (ip->i_flag & (IN_CLEANING|IN_MODIFIED))
727 		--fs->lfs_uinodes;
728 	TIMEVAL_TO_TIMESPEC(&time, &ts);
729 	LFS_ITIMES(ip, &ts, &ts, &ts);
730 
731 	if(ip->i_flag & IN_CLEANING)
732 		ip->i_flag &= ~IN_CLEANING;
733 	else
734 		ip->i_flag &= ~(IN_ACCESS|IN_CHANGE|IN_MODIFIED|IN_UPDATE);
735 
736 	/*
737 	 * If this is the Ifile, and we've already written the Ifile in this
738 	 * partial segment, just overwrite it (it's not on disk yet) and
739 	 * continue.
740 	 *
741 	 * XXX we know that the bp that we get the second time around has
742 	 * already been gathered.
743 	 */
744 	if(ip->i_number == LFS_IFILE_INUM && sp->idp) {
745 		*(sp->idp) = ip->i_din.ffs_din;
746 		return 0;
747 	}
748 
749 	bp = sp->ibp;
750 	((struct dinode *)bp->b_data)[sp->ninodes % INOPB(fs)] =
751 		ip->i_din.ffs_din;
752 
753 	if(ip->i_number == LFS_IFILE_INUM) /* We know sp->idp == NULL */
754 		sp->idp = ((struct dinode *)bp->b_data)+(sp->ninodes % INOPB(fs));
755 	if(gotblk) {
756 		bp->b_flags |= B_LOCKED;
757 		brelse(bp);
758 	}
759 
760 	/* Increment inode count in segment summary block. */
761 	++((SEGSUM *)(sp->segsum))->ss_ninos;
762 
763 	/* If this page is full, set flag to allocate a new page. */
764 	if (++sp->ninodes % INOPB(fs) == 0)
765 		sp->ibp = NULL;
766 
767 	/*
768 	 * If updating the ifile, update the super-block.  Update the disk
769 	 * address and access times for this inode in the ifile.
770 	 */
771 	ino = ip->i_number;
772 	if (ino == LFS_IFILE_INUM) {
773 		daddr = fs->lfs_idaddr;
774 		fs->lfs_idaddr = bp->b_blkno;
775 	} else {
776 		LFS_IENTRY(ifp, fs, ino, ibp);
777 		daddr = ifp->if_daddr;
778 		ifp->if_daddr = bp->b_blkno;
779 #ifdef LFS_DEBUG_NEXTFREE
780 		if(ino > 3 && ifp->if_nextfree) {
781 			vprint("lfs_writeinode",ITOV(ip));
782 			printf("lfs_writeinode: updating free ino %d\n",
783 				ip->i_number);
784 		}
785 #endif
786 		error = VOP_BWRITE(ibp);
787 	}
788 
789 	/*
790 	 * No need to update segment usage if there was no former inode address
791 	 * or if the last inode address is in the current partial segment.
792 	 */
793 	if (daddr != LFS_UNUSED_DADDR &&
794 	    !(daddr >= fs->lfs_lastpseg && daddr <= bp->b_blkno)) {
795 		LFS_SEGENTRY(sup, fs, datosn(fs, daddr), bp);
796 #ifdef DIAGNOSTIC
797 		if (sup->su_nbytes < DINODE_SIZE) {
798 			/* XXX -- Change to a panic. */
799 			printf("lfs_writeinode: negative bytes (segment %d short by %d)\n",
800 			       datosn(fs, daddr), (int)DINODE_SIZE - sup->su_nbytes);
801 			panic("lfs_writeinode: negative bytes");
802 			sup->su_nbytes = DINODE_SIZE;
803 		}
804 #endif
805 		sup->su_nbytes -= DINODE_SIZE;
806 		redo_ifile =
807 			(ino == LFS_IFILE_INUM && !(bp->b_flags & B_GATHERED));
808 		error = VOP_BWRITE(bp);
809 	}
810 	return (redo_ifile);
811 }
812 
813 int
814 lfs_gatherblock(sp, bp, sptr)
815 	struct segment *sp;
816 	struct buf *bp;
817 	int *sptr;
818 {
819 	struct lfs *fs;
820 	int version;
821 
822 	/*
823 	 * If full, finish this segment.  We may be doing I/O, so
824 	 * release and reacquire the splbio().
825 	 */
826 #ifdef DIAGNOSTIC
827 	if (sp->vp == NULL)
828 		panic ("lfs_gatherblock: Null vp in segment");
829 #endif
830 	fs = sp->fs;
831 	if (sp->sum_bytes_left < sizeof(ufs_daddr_t) ||
832 	    sp->seg_bytes_left < bp->b_bcount) {
833 		if (sptr)
834 			splx(*sptr);
835 		lfs_updatemeta(sp);
836 
837 		version = sp->fip->fi_version;
838 		(void) lfs_writeseg(fs, sp);
839 
840 		sp->fip->fi_version = version;
841 		sp->fip->fi_ino = VTOI(sp->vp)->i_number;
842 		/* Add the current file to the segment summary. */
843 		++((SEGSUM *)(sp->segsum))->ss_nfinfo;
844 		sp->sum_bytes_left -=
845 			sizeof(struct finfo) - sizeof(ufs_daddr_t);
846 
847 		if (sptr)
848 			*sptr = splbio();
849 		return(1);
850 	}
851 
852 #ifdef DEBUG
853 	if(bp->b_flags & B_GATHERED) {
854 		printf("lfs_gatherblock: already gathered! Ino %d, lbn %d\n",
855 		       sp->fip->fi_ino, bp->b_lblkno);
856 		return(0);
857 	}
858 #endif
859 	/* Insert into the buffer list, update the FINFO block. */
860 	bp->b_flags |= B_GATHERED;
861 	*sp->cbpp++ = bp;
862 	sp->fip->fi_blocks[sp->fip->fi_nblocks++] = bp->b_lblkno;
863 
864 	sp->sum_bytes_left -= sizeof(ufs_daddr_t);
865 	sp->seg_bytes_left -= bp->b_bcount;
866 	return(0);
867 }
868 
869 int
870 lfs_gather(fs, sp, vp, match)
871 	struct lfs *fs;
872 	struct segment *sp;
873 	struct vnode *vp;
874 	int (*match) __P((struct lfs *, struct buf *));
875 {
876 	struct buf *bp;
877 	int s, count=0;
878 
879 	sp->vp = vp;
880 	s = splbio();
881 
882 #ifndef LFS_NO_BACKBUF_HACK
883 loop:	for (bp = vp->v_dirtyblkhd.lh_first; bp; bp = bp->b_vnbufs.le_next) {
884 #else /* LFS_NO_BACKBUF_HACK */
885 /* This is a hack to see if ordering the blocks in LFS makes a difference. */
886 # define	BUF_OFFSET	(((void *)&bp->b_vnbufs.le_next) - (void *)bp)
887 # define	BACK_BUF(BP)	((struct buf *)(((void *)BP->b_vnbufs.le_prev) - BUF_OFFSET))
888 # define	BEG_OF_LIST	((struct buf *)(((void *)&vp->v_dirtyblkhd.lh_first) - BUF_OFFSET))
889 /* Find last buffer. */
890 loop:	for (bp = vp->v_dirtyblkhd.lh_first; bp && bp->b_vnbufs.le_next != NULL;
891 	    bp = bp->b_vnbufs.le_next);
892 	for (; bp && bp != BEG_OF_LIST; bp = BACK_BUF(bp)) {
893 #endif /* LFS_NO_BACKBUF_HACK */
894 		if ((bp->b_flags & (B_BUSY|B_GATHERED)) || !match(fs, bp))
895 			continue;
896 		if(vp->v_type == VBLK) {
897 			/* For block devices, just write the blocks. */
898 			/* XXX Do we really need to even do this? */
899 #ifdef DEBUG_LFS
900 			if(count==0)
901 				printf("BLK(");
902 			printf(".");
903 #endif
904 			/* Get the block before bwrite, so we don't corrupt the free list */
905 			bp->b_flags |= B_BUSY;
906 			bremfree(bp);
907 			bwrite(bp);
908 		} else {
909 #ifdef DIAGNOSTIC
910 			if (!(bp->b_flags & B_DELWRI))
911 				panic("lfs_gather: bp not B_DELWRI");
912 			if (!(bp->b_flags & B_LOCKED)) {
913 				printf("lfs_gather: lbn %d blk %d not B_LOCKED\n", bp->b_lblkno, bp->b_blkno);
914 				VOP_PRINT(bp->b_vp);
915 				panic("lfs_gather: bp not B_LOCKED");
916 			}
917 #endif
918 			if (lfs_gatherblock(sp, bp, &s)) {
919 				goto loop;
920 			}
921 		}
922 		count++;
923 	}
924 	splx(s);
925 #ifdef DEBUG_LFS
926 	if(vp->v_type == VBLK && count)
927 		printf(")\n");
928 #endif
929 	lfs_updatemeta(sp);
930 	sp->vp = NULL;
931 	return count;
932 }
933 
934 /*
935  * Update the metadata that points to the blocks listed in the FINFO
936  * array.
937  */
938 void
939 lfs_updatemeta(sp)
940 	struct segment *sp;
941 {
942 	SEGUSE *sup;
943 	struct buf *bp;
944 	struct lfs *fs;
945 	struct vnode *vp;
946 	struct indir a[NIADDR + 2], *ap;
947 	struct inode *ip;
948 	ufs_daddr_t daddr, lbn, off;
949 	int error, i, nblocks, num;
950 
951 	vp = sp->vp;
952 	nblocks = &sp->fip->fi_blocks[sp->fip->fi_nblocks] - sp->start_lbp;
953 	if (nblocks < 0)
954 		panic("This is a bad thing\n");
955 	if (vp == NULL || nblocks == 0)
956 		return;
957 
958 	/* Sort the blocks. */
959 	/*
960 	 * XXX KS - We have to sort even if the blocks come from the
961 	 * cleaner, because there might be other pending blocks on the
962 	 * same inode...and if we don't sort, and there are fragments
963 	 * present, blocks may be written in the wrong place.
964 	 */
965 	/* if (!(sp->seg_flags & SEGM_CLEAN)) */
966 	lfs_shellsort(sp->start_bpp, sp->start_lbp, nblocks);
967 
968 	/*
969 	 * Record the length of the last block in case it's a fragment.
970 	 * If there are indirect blocks present, they sort last.  An
971 	 * indirect block will be lfs_bsize and its presence indicates
972 	 * that you cannot have fragments.
973 	 */
974 	sp->fip->fi_lastlength = sp->start_bpp[nblocks - 1]->b_bcount;
975 
976 	/*
977 	 * Assign disk addresses, and update references to the logical
978 	 * block and the segment usage information.
979 	 */
980 	fs = sp->fs;
981 	for (i = nblocks; i--; ++sp->start_bpp) {
982 		lbn = *sp->start_lbp++;
983 
984 		(*sp->start_bpp)->b_blkno = off = fs->lfs_offset;
985 		if((*sp->start_bpp)->b_blkno == (*sp->start_bpp)->b_lblkno) {
986 			printf("lfs_updatemeta: ino %d blk %d has same lbn and daddr\n", VTOI(vp)->i_number, off);
987 		}
988 		fs->lfs_offset +=
989 			fragstodb(fs, numfrags(fs, (*sp->start_bpp)->b_bcount));
990 		error = ufs_bmaparray(vp, lbn, &daddr, a, &num, NULL);
991 		if (error)
992 			panic("lfs_updatemeta: ufs_bmaparray %d", error);
993 		ip = VTOI(vp);
994 		switch (num) {
995 		case 0:
996 			ip->i_ffs_db[lbn] = off;
997 			break;
998 		case 1:
999 			ip->i_ffs_ib[a[0].in_off] = off;
1000 			break;
1001 		default:
1002 			ap = &a[num - 1];
1003 			if (bread(vp, ap->in_lbn, fs->lfs_bsize, NOCRED, &bp))
1004 				panic("lfs_updatemeta: bread bno %d",
1005 				      ap->in_lbn);
1006 			/*
1007 			 * Bread may create a new (indirect) block which needs
1008 			 * to get counted for the inode.
1009 			 */
1010 			if (/* bp->b_blkno == -1 && */
1011 			    !(bp->b_flags & (B_DELWRI|B_DONE))) {
1012 				ip->i_ffs_blocks += fsbtodb(fs, 1);
1013 				fs->lfs_bfree -= fragstodb(fs, fs->lfs_frag);
1014 			}
1015 			((ufs_daddr_t *)bp->b_data)[ap->in_off] = off;
1016 			VOP_BWRITE(bp);
1017 		}
1018 		/* Update segment usage information. */
1019 		if (daddr != UNASSIGNED && !(daddr >= fs->lfs_lastpseg && daddr <= off)) {
1020 			LFS_SEGENTRY(sup, fs, datosn(fs, daddr), bp);
1021 #ifdef DIAGNOSTIC
1022 			if (sup->su_nbytes < (*sp->start_bpp)->b_bcount) {
1023 				/* XXX -- Change to a panic. */
1024 				printf("lfs_updatemeta: negative bytes (segment %d short by %ld)\n",
1025 				       datosn(fs, daddr), (*sp->start_bpp)->b_bcount - sup->su_nbytes);
1026 				printf("lfs_updatemeta: ino %d, lbn %d, addr = %x\n",
1027 				       VTOI(sp->vp)->i_number, (*sp->start_bpp)->b_lblkno, daddr);
1028 				panic("lfs_updatemeta: negative bytes");
1029 				sup->su_nbytes = (*sp->start_bpp)->b_bcount;
1030 			}
1031 #endif
1032 			sup->su_nbytes -= (*sp->start_bpp)->b_bcount;
1033 			error = VOP_BWRITE(bp);
1034 		}
1035 	}
1036 }
1037 
1038 /*
1039  * Start a new segment.
1040  */
1041 int
1042 lfs_initseg(fs)
1043 	struct lfs *fs;
1044 {
1045 	struct segment *sp;
1046 	SEGUSE *sup;
1047 	SEGSUM *ssp;
1048 	struct buf *bp;
1049 	int repeat;
1050 
1051 	sp = fs->lfs_sp;
1052 
1053 	repeat = 0;
1054 	/* Advance to the next segment. */
1055 	if (!LFS_PARTIAL_FITS(fs)) {
1056 		/* Wake up any cleaning procs waiting on this file system. */
1057 		wakeup(&lfs_allclean_wakeup);
1058 		wakeup(&fs->lfs_nextseg);
1059 		lfs_newseg(fs);
1060 		repeat = 1;
1061 		fs->lfs_offset = fs->lfs_curseg;
1062 		sp->seg_number = datosn(fs, fs->lfs_curseg);
1063 		sp->seg_bytes_left = fs->lfs_dbpseg * DEV_BSIZE;
1064 		/*
1065 		 * If the segment contains a superblock, update the offset
1066 		 * and summary address to skip over it.
1067 		 */
1068 		LFS_SEGENTRY(sup, fs, sp->seg_number, bp);
1069 		if (sup->su_flags & SEGUSE_SUPERBLOCK) {
1070 			fs->lfs_offset += LFS_SBPAD / DEV_BSIZE;
1071 			sp->seg_bytes_left -= LFS_SBPAD;
1072 		}
1073 		brelse(bp);
1074 	} else {
1075 		sp->seg_number = datosn(fs, fs->lfs_curseg);
1076 		sp->seg_bytes_left = (fs->lfs_dbpseg -
1077 				      (fs->lfs_offset - fs->lfs_curseg)) * DEV_BSIZE;
1078 	}
1079 	fs->lfs_lastpseg = fs->lfs_offset;
1080 
1081 	sp->fs = fs;
1082 	sp->ibp = NULL;
1083 	sp->idp = NULL;
1084 	sp->ninodes = 0;
1085 
1086 	/* Get a new buffer for SEGSUM and enter it into the buffer list. */
1087 	sp->cbpp = sp->bpp;
1088 	*sp->cbpp = lfs_newbuf(VTOI(fs->lfs_ivnode)->i_devvp,
1089 			       fs->lfs_offset, LFS_SUMMARY_SIZE);
1090 	sp->segsum = (*sp->cbpp)->b_data;
1091 	bzero(sp->segsum, LFS_SUMMARY_SIZE);
1092 	sp->start_bpp = ++sp->cbpp;
1093 	fs->lfs_offset += LFS_SUMMARY_SIZE / DEV_BSIZE;
1094 
1095 	/* Set point to SEGSUM, initialize it. */
1096 	ssp = sp->segsum;
1097 	ssp->ss_next = fs->lfs_nextseg;
1098 	ssp->ss_nfinfo = ssp->ss_ninos = 0;
1099 	ssp->ss_magic = SS_MAGIC;
1100 
1101 	/* Set pointer to first FINFO, initialize it. */
1102 	sp->fip = (struct finfo *)((caddr_t)sp->segsum + sizeof(SEGSUM));
1103 	sp->fip->fi_nblocks = 0;
1104 	sp->start_lbp = &sp->fip->fi_blocks[0];
1105 	sp->fip->fi_lastlength = 0;
1106 
1107 	sp->seg_bytes_left -= LFS_SUMMARY_SIZE;
1108 	sp->sum_bytes_left = LFS_SUMMARY_SIZE - sizeof(SEGSUM);
1109 
1110 	return(repeat);
1111 }
1112 
1113 /*
1114  * Return the next segment to write.
1115  */
1116 void
1117 lfs_newseg(fs)
1118 	struct lfs *fs;
1119 {
1120 	CLEANERINFO *cip;
1121 	SEGUSE *sup;
1122 	struct buf *bp;
1123 	int curseg, isdirty, sn;
1124 
1125 	LFS_SEGENTRY(sup, fs, datosn(fs, fs->lfs_nextseg), bp);
1126 	sup->su_flags |= SEGUSE_DIRTY | SEGUSE_ACTIVE;
1127 	sup->su_nbytes = 0;
1128 	sup->su_nsums = 0;
1129 	sup->su_ninos = 0;
1130 	(void) VOP_BWRITE(bp);
1131 
1132 	LFS_CLEANERINFO(cip, fs, bp);
1133 	--cip->clean;
1134 	++cip->dirty;
1135 	fs->lfs_nclean = cip->clean;
1136 	(void) VOP_BWRITE(bp);
1137 
1138 	fs->lfs_lastseg = fs->lfs_curseg;
1139 	fs->lfs_curseg = fs->lfs_nextseg;
1140 	for (sn = curseg = datosn(fs, fs->lfs_curseg);;) {
1141 		sn = (sn + 1) % fs->lfs_nseg;
1142 		if (sn == curseg)
1143 			panic("lfs_nextseg: no clean segments");
1144 		LFS_SEGENTRY(sup, fs, sn, bp);
1145 		isdirty = sup->su_flags & SEGUSE_DIRTY;
1146 		brelse(bp);
1147 		if (!isdirty)
1148 			break;
1149 	}
1150 
1151 	++fs->lfs_nactive;
1152 	fs->lfs_nextseg = sntoda(fs, sn);
1153 	if(lfs_dostats) {
1154 		++lfs_stats.segsused;
1155 	}
1156 }
1157 
1158 int
1159 lfs_writeseg(fs, sp)
1160 	struct lfs *fs;
1161 	struct segment *sp;
1162 {
1163 	extern int locked_queue_count;
1164 	extern long locked_queue_bytes;
1165 	struct buf **bpp, *bp, *cbp;
1166 	SEGUSE *sup;
1167 	SEGSUM *ssp;
1168 	dev_t i_dev;
1169 	u_long *datap, *dp;
1170 	int do_again, i, nblocks, s;
1171 #ifdef LFS_TRACK_IOS
1172 	int j;
1173 #endif
1174 	int (*strategy)__P((void *));
1175 	struct vop_strategy_args vop_strategy_a;
1176 	u_short ninos;
1177 	struct vnode *devvp;
1178 	char *p;
1179 	struct vnode *vn;
1180 	struct inode *ip;
1181 #if defined(DEBUG) && defined(LFS_PROPELLER)
1182 	static int propeller;
1183 	char propstring[4] = "-\\|/";
1184 
1185 	printf("%c\b",propstring[propeller++]);
1186 	if(propeller==4)
1187 		propeller = 0;
1188 #endif
1189 
1190 	/*
1191 	 * If there are no buffers other than the segment summary to write
1192 	 * and it is not a checkpoint, don't do anything.  On a checkpoint,
1193 	 * even if there aren't any buffers, you need to write the superblock.
1194 	 */
1195 	if ((nblocks = sp->cbpp - sp->bpp) == 1)
1196 		return (0);
1197 
1198 #ifdef DEBUG_LFS
1199 	lfs_check_bpp(fs,sp,__FILE__,__LINE__);
1200 #endif
1201 	i_dev = VTOI(fs->lfs_ivnode)->i_dev;
1202 	devvp = VTOI(fs->lfs_ivnode)->i_devvp;
1203 
1204 	/* Update the segment usage information. */
1205 	LFS_SEGENTRY(sup, fs, sp->seg_number, bp);
1206 
1207 	/* Loop through all blocks, except the segment summary. */
1208 	for (bpp = sp->bpp; ++bpp < sp->cbpp; ) {
1209 		if((*bpp)->b_vp != devvp)
1210 			sup->su_nbytes += (*bpp)->b_bcount;
1211 	}
1212 
1213 	ssp = (SEGSUM *)sp->segsum;
1214 
1215 	ninos = (ssp->ss_ninos + INOPB(fs) - 1) / INOPB(fs);
1216 	sup->su_nbytes += ssp->ss_ninos * DINODE_SIZE;
1217 	/* sup->su_nbytes += LFS_SUMMARY_SIZE; */
1218 	sup->su_lastmod = time.tv_sec;
1219 	sup->su_ninos += ninos;
1220 	++sup->su_nsums;
1221 
1222 	do_again = !(bp->b_flags & B_GATHERED);
1223 	(void)VOP_BWRITE(bp);
1224 	/*
1225 	 * Compute checksum across data and then across summary; the first
1226 	 * block (the summary block) is skipped.  Set the create time here
1227 	 * so that it's guaranteed to be later than the inode mod times.
1228 	 *
1229 	 * XXX
1230 	 * Fix this to do it inline, instead of malloc/copy.
1231 	 */
1232 	datap = dp = malloc(nblocks * sizeof(u_long), M_SEGMENT, M_WAITOK);
1233 	for (bpp = sp->bpp, i = nblocks - 1; i--;) {
1234 		if (((*++bpp)->b_flags & (B_CALL|B_INVAL)) == (B_CALL|B_INVAL)) {
1235 			if (copyin((*bpp)->b_saveaddr, dp++, sizeof(u_long)))
1236 				panic("lfs_writeseg: copyin failed [1]: ino %d blk %d", VTOI((*bpp)->b_vp)->i_number, (*bpp)->b_lblkno);
1237 		} else {
1238 			if( !((*bpp)->b_flags & B_CALL) ) {
1239 				/*
1240 				 * Before we record data for a checksm,
1241 				 * make sure the data won't change in between
1242 				 * the checksum calculation and the write,
1243 				 * by marking the buffer B_BUSY.  It will
1244 				 * be freed later by brelse().
1245 				 */
1246 			again:
1247 				s = splbio();
1248 				if((*bpp)->b_flags & B_BUSY) {
1249 #ifdef DEBUG
1250 					printf("lfs_writeseg: avoiding potential data summary corruption for ino %d, lbn %d\n",
1251 					       VTOI((*bpp)->b_vp)->i_number,
1252 					       bp->b_lblkno);
1253 #endif
1254 					(*bpp)->b_flags |= B_WANTED;
1255 					tsleep((*bpp), (PRIBIO + 1),
1256 					       "lfs_writeseg", 0);
1257 					splx(s);
1258 					goto again;
1259 				}
1260 				(*bpp)->b_flags |= B_BUSY;
1261 				splx(s);
1262 			}
1263 			*dp++ = ((u_long *)(*bpp)->b_data)[0];
1264 		}
1265 	}
1266 	ssp->ss_create = time.tv_sec;
1267 	ssp->ss_datasum = cksum(datap, (nblocks - 1) * sizeof(u_long));
1268 	ssp->ss_sumsum =
1269 	    cksum(&ssp->ss_datasum, LFS_SUMMARY_SIZE - sizeof(ssp->ss_sumsum));
1270 	free(datap, M_SEGMENT);
1271 #ifdef DIAGNOSTIC
1272 	if (fs->lfs_bfree < fsbtodb(fs, ninos) + LFS_SUMMARY_SIZE / DEV_BSIZE)
1273 		panic("lfs_writeseg: No diskspace for summary");
1274 #endif
1275 	fs->lfs_bfree -= (fsbtodb(fs, ninos) + LFS_SUMMARY_SIZE / DEV_BSIZE);
1276 
1277 	strategy = devvp->v_op[VOFFSET(vop_strategy)];
1278 
1279 	/*
1280 	 * When we simply write the blocks we lose a rotation for every block
1281 	 * written.  To avoid this problem, we allocate memory in chunks, copy
1282 	 * the buffers into the chunk and write the chunk.  CHUNKSIZE is the
1283 	 * largest size I/O devices can handle.
1284 	 * When the data is copied to the chunk, turn off the the B_LOCKED bit
1285 	 * and brelse the buffer (which will move them to the LRU list).  Add
1286 	 * the B_CALL flag to the buffer header so we can count I/O's for the
1287 	 * checkpoints and so we can release the allocated memory.
1288 	 *
1289 	 * XXX
1290 	 * This should be removed if the new virtual memory system allows us to
1291 	 * easily make the buffers contiguous in kernel memory and if that's
1292 	 * fast enough.
1293 	 */
1294 
1295 #define CHUNKSIZE MAXPHYS
1296 
1297 	if(devvp==NULL)
1298 		panic("devvp is NULL");
1299 	for (bpp = sp->bpp,i = nblocks; i;) {
1300 		cbp = lfs_newbuf(devvp, (*bpp)->b_blkno, CHUNKSIZE);
1301 		cbp->b_dev = i_dev;
1302 		cbp->b_flags |= B_ASYNC | B_BUSY;
1303 		cbp->b_bcount = 0;
1304 
1305 #ifdef DIAGNOSTIC
1306 		if(datosn(fs,(*bpp)->b_blkno + ((*bpp)->b_bcount - 1)/DEV_BSIZE) != datosn(fs,cbp->b_blkno)) {
1307 			panic("lfs_writeseg: Segment overwrite");
1308 		}
1309 #endif
1310 
1311 		s = splbio();
1312 		if(fs->lfs_iocount >= LFS_THROTTLE) {
1313 			tsleep(&fs->lfs_iocount, PRIBIO+1, "lfs throttle", 0);
1314 		}
1315 		++fs->lfs_iocount;
1316 #ifdef LFS_TRACK_IOS
1317 		for(j=0;j<LFS_THROTTLE;j++) {
1318 			if(fs->lfs_pending[j]==LFS_UNUSED_DADDR) {
1319 				fs->lfs_pending[j] = cbp->b_blkno;
1320 				break;
1321 			}
1322 		}
1323 #endif /* LFS_TRACK_IOS */
1324 		for (p = cbp->b_data; i && cbp->b_bcount < CHUNKSIZE; i--) {
1325 			bp = *bpp;
1326 
1327 			if (bp->b_bcount > (CHUNKSIZE - cbp->b_bcount))
1328 				break;
1329 
1330 			/*
1331 			 * Fake buffers from the cleaner are marked as B_INVAL.
1332 			 * We need to copy the data from user space rather than
1333 			 * from the buffer indicated.
1334 			 * XXX == what do I do on an error?
1335 			 */
1336 			if ((bp->b_flags & (B_CALL|B_INVAL)) == (B_CALL|B_INVAL)) {
1337 				if (copyin(bp->b_saveaddr, p, bp->b_bcount))
1338 					panic("lfs_writeseg: copyin failed [2]");
1339 			} else
1340 				bcopy(bp->b_data, p, bp->b_bcount);
1341 			p += bp->b_bcount;
1342 			cbp->b_bcount += bp->b_bcount;
1343 			if (bp->b_flags & B_LOCKED) {
1344 				--locked_queue_count;
1345 				locked_queue_bytes -= bp->b_bufsize;
1346 			}
1347 			bp->b_flags &= ~(B_ERROR | B_READ | B_DELWRI |
1348 					 B_LOCKED | B_GATHERED);
1349 			vn = bp->b_vp;
1350 			if (bp->b_flags & B_CALL) {
1351 				/* if B_CALL, it was created with newbuf */
1352 				lfs_freebuf(bp);
1353 			} else {
1354 				bremfree(bp);
1355 				bp->b_flags |= B_DONE;
1356 				if(vn)
1357 					reassignbuf(bp, vn);
1358 				brelse(bp);
1359 			}
1360 			if(bp->b_flags & B_NEEDCOMMIT) { /* XXX */
1361 				bp->b_flags &= ~B_NEEDCOMMIT;
1362 				wakeup(bp);
1363 			}
1364 
1365 			bpp++;
1366 
1367 			/*
1368 			 * If this is the last block for this vnode, but
1369 			 * there are other blocks on its dirty list,
1370 			 * set IN_MODIFIED/IN_CLEANING depending on what
1371 			 * sort of block.  Only do this for our mount point,
1372 			 * not for, e.g., inode blocks that are attached to
1373 			 * the devvp.
1374 			 */
1375 			if(i>1 && vn && *bpp && (*bpp)->b_vp != vn
1376 			   && (*bpp)->b_vp && (bp=vn->v_dirtyblkhd.lh_first)!=NULL &&
1377 			   vn->v_mount == fs->lfs_ivnode->v_mount)
1378 			{
1379 				ip = VTOI(vn);
1380 #ifdef DEBUG_LFS
1381 				printf("lfs_writeseg: marking ino %d\n",ip->i_number);
1382 #endif
1383 		       		if(!(ip->i_flag & (IN_CLEANING|IN_MODIFIED))) {
1384 					fs->lfs_uinodes++;
1385 					if(bp->b_flags & B_CALL)
1386 						ip->i_flag |= IN_CLEANING;
1387 					else
1388 						ip->i_flag |= IN_MODIFIED;
1389 				}
1390 			}
1391 			/* if(vn->v_dirtyblkhd.lh_first == NULL) */
1392 				wakeup(vn);
1393 		}
1394 		++cbp->b_vp->v_numoutput;
1395 		splx(s);
1396 		/*
1397 		 * XXXX This is a gross and disgusting hack.  Since these
1398 		 * buffers are physically addressed, they hang off the
1399 		 * device vnode (devvp).  As a result, they have no way
1400 		 * of getting to the LFS superblock or lfs structure to
1401 		 * keep track of the number of I/O's pending.  So, I am
1402 		 * going to stuff the fs into the saveaddr field of
1403 		 * the buffer (yuk).
1404 		 */
1405 		cbp->b_saveaddr = (caddr_t)fs;
1406 		vop_strategy_a.a_desc = VDESC(vop_strategy);
1407 		vop_strategy_a.a_bp = cbp;
1408 		(strategy)(&vop_strategy_a);
1409 	}
1410 	/*
1411 	 * XXX
1412 	 * Vinvalbuf can move locked buffers off the locked queue
1413 	 * and we have no way of knowing about this.  So, after
1414 	 * doing a big write, we recalculate how many buffers are
1415 	 * really still left on the locked queue.
1416 	 */
1417 	lfs_countlocked(&locked_queue_count,&locked_queue_bytes);
1418 	wakeup(&locked_queue_count);
1419 	if(lfs_dostats) {
1420 		++lfs_stats.psegwrites;
1421 		lfs_stats.blocktot += nblocks - 1;
1422 		if (fs->lfs_sp->seg_flags & SEGM_SYNC)
1423 			++lfs_stats.psyncwrites;
1424 		if (fs->lfs_sp->seg_flags & SEGM_CLEAN) {
1425 			++lfs_stats.pcleanwrites;
1426 			lfs_stats.cleanblocks += nblocks - 1;
1427 		}
1428 	}
1429 	return (lfs_initseg(fs) || do_again);
1430 }
1431 
1432 void
1433 lfs_writesuper(fs, daddr)
1434 	struct lfs *fs;
1435 	daddr_t daddr;
1436 {
1437 	struct buf *bp;
1438 	dev_t i_dev;
1439 	int (*strategy) __P((void *));
1440 	int s;
1441 	struct vop_strategy_args vop_strategy_a;
1442 
1443 #ifdef LFS_CANNOT_ROLLFW
1444 	/*
1445 	 * If we can write one superblock while another is in
1446 	 * progress, we risk not having a complete checkpoint if we crash.
1447 	 * So, block here if a superblock write is in progress.
1448 	 */
1449 	s = splbio();
1450 	while(fs->lfs_sbactive) {
1451 		tsleep(&fs->lfs_sbactive, PRIBIO+1, "lfs sb", 0);
1452 	}
1453 	fs->lfs_sbactive = daddr;
1454 	splx(s);
1455 #endif
1456 	i_dev = VTOI(fs->lfs_ivnode)->i_dev;
1457 	strategy = VTOI(fs->lfs_ivnode)->i_devvp->v_op[VOFFSET(vop_strategy)];
1458 
1459 	/* Set timestamp of this version of the superblock */
1460 	fs->lfs_tstamp = time.tv_sec;
1461 
1462 	/* Checksum the superblock and copy it into a buffer. */
1463 	fs->lfs_cksum = lfs_sb_cksum(&(fs->lfs_dlfs));
1464 	bp = lfs_newbuf(VTOI(fs->lfs_ivnode)->i_devvp, daddr, LFS_SBPAD);
1465 	*(struct dlfs *)bp->b_data = fs->lfs_dlfs;
1466 
1467 	bp->b_dev = i_dev;
1468 	bp->b_flags |= B_BUSY | B_CALL | B_ASYNC;
1469 	bp->b_flags &= ~(B_DONE | B_ERROR | B_READ | B_DELWRI);
1470 	bp->b_iodone = lfs_supercallback;
1471 	/* XXX KS - same nasty hack as above */
1472 	bp->b_saveaddr = (caddr_t)fs;
1473 
1474 	vop_strategy_a.a_desc = VDESC(vop_strategy);
1475 	vop_strategy_a.a_bp = bp;
1476 	s = splbio();
1477 	++bp->b_vp->v_numoutput;
1478 	splx(s);
1479 	(strategy)(&vop_strategy_a);
1480 }
1481 
1482 /*
1483  * Logical block number match routines used when traversing the dirty block
1484  * chain.
1485  */
1486 int
1487 lfs_match_fake(fs, bp)
1488 	struct lfs *fs;
1489 	struct buf *bp;
1490 {
1491 	return (bp->b_flags & B_CALL);
1492 }
1493 
1494 int
1495 lfs_match_data(fs, bp)
1496 	struct lfs *fs;
1497 	struct buf *bp;
1498 {
1499 	return (bp->b_lblkno >= 0);
1500 }
1501 
1502 int
1503 lfs_match_indir(fs, bp)
1504 	struct lfs *fs;
1505 	struct buf *bp;
1506 {
1507 	int lbn;
1508 
1509 	lbn = bp->b_lblkno;
1510 	return (lbn < 0 && (-lbn - NDADDR) % NINDIR(fs) == 0);
1511 }
1512 
1513 int
1514 lfs_match_dindir(fs, bp)
1515 	struct lfs *fs;
1516 	struct buf *bp;
1517 {
1518 	int lbn;
1519 
1520 	lbn = bp->b_lblkno;
1521 	return (lbn < 0 && (-lbn - NDADDR) % NINDIR(fs) == 1);
1522 }
1523 
1524 int
1525 lfs_match_tindir(fs, bp)
1526 	struct lfs *fs;
1527 	struct buf *bp;
1528 {
1529 	int lbn;
1530 
1531 	lbn = bp->b_lblkno;
1532 	return (lbn < 0 && (-lbn - NDADDR) % NINDIR(fs) == 2);
1533 }
1534 
1535 /*
1536  * XXX - The only buffers that are going to hit these functions are the
1537  * segment write blocks, or the segment summaries, or the superblocks.
1538  *
1539  * All of the above are created by lfs_newbuf, and so do not need to be
1540  * released via brelse.
1541  */
1542 void
1543 lfs_callback(bp)
1544 	struct buf *bp;
1545 {
1546 	struct lfs *fs;
1547 #ifdef LFS_TRACK_IOS
1548 	int j;
1549 #endif
1550 
1551 	fs = (struct lfs *)bp->b_saveaddr;
1552 #ifdef DIAGNOSTIC
1553 	if (fs->lfs_iocount == 0)
1554 		panic("lfs_callback: zero iocount\n");
1555 #endif
1556 	if (--fs->lfs_iocount < LFS_THROTTLE)
1557 		wakeup(&fs->lfs_iocount);
1558 #ifdef LFS_TRACK_IOS
1559 	for(j=0;j<LFS_THROTTLE;j++) {
1560 		if(fs->lfs_pending[j]==bp->b_blkno) {
1561 			fs->lfs_pending[j] = LFS_UNUSED_DADDR;
1562 			wakeup(&(fs->lfs_pending[j]));
1563 			break;
1564 		}
1565 	}
1566 #endif /* LFS_TRACK_IOS */
1567 
1568 	lfs_freebuf(bp);
1569 }
1570 
1571 void
1572 lfs_supercallback(bp)
1573 	struct buf *bp;
1574 {
1575 #ifdef LFS_CANNOT_ROLLFW
1576 	struct lfs *fs;
1577 
1578 	fs = (struct lfs *)bp->b_saveaddr;
1579 	fs->lfs_sbactive=NULL;
1580 	wakeup(&fs->lfs_sbactive);
1581 #endif
1582 	lfs_freebuf(bp);
1583 }
1584 
1585 /*
1586  * Shellsort (diminishing increment sort) from Data Structures and
1587  * Algorithms, Aho, Hopcraft and Ullman, 1983 Edition, page 290;
1588  * see also Knuth Vol. 3, page 84.  The increments are selected from
1589  * formula (8), page 95.  Roughly O(N^3/2).
1590  */
1591 /*
1592  * This is our own private copy of shellsort because we want to sort
1593  * two parallel arrays (the array of buffer pointers and the array of
1594  * logical block numbers) simultaneously.  Note that we cast the array
1595  * of logical block numbers to a unsigned in this routine so that the
1596  * negative block numbers (meta data blocks) sort AFTER the data blocks.
1597  */
1598 
1599 void
1600 lfs_shellsort(bp_array, lb_array, nmemb)
1601 	struct buf **bp_array;
1602 	ufs_daddr_t *lb_array;
1603 	register int nmemb;
1604 {
1605 	static int __rsshell_increments[] = { 4, 1, 0 };
1606 	register int incr, *incrp, t1, t2;
1607 	struct buf *bp_temp;
1608 	u_long lb_temp;
1609 
1610 	for (incrp = __rsshell_increments; (incr = *incrp++) != 0;)
1611 		for (t1 = incr; t1 < nmemb; ++t1)
1612 			for (t2 = t1 - incr; t2 >= 0;)
1613 				if (lb_array[t2] > lb_array[t2 + incr]) {
1614 					lb_temp = lb_array[t2];
1615 					lb_array[t2] = lb_array[t2 + incr];
1616 					lb_array[t2 + incr] = lb_temp;
1617 					bp_temp = bp_array[t2];
1618 					bp_array[t2] = bp_array[t2 + incr];
1619 					bp_array[t2 + incr] = bp_temp;
1620 					t2 -= incr;
1621 				} else
1622 					break;
1623 }
1624 
1625 /*
1626  * Check VXLOCK.  Return 1 if the vnode is locked.  Otherwise, vget it.
1627  */
1628 int
1629 lfs_vref(vp)
1630 	register struct vnode *vp;
1631 {
1632 	/*
1633 	 * If we return 1 here during a flush, we risk vinvalbuf() not
1634 	 * being able to flush all of the pages from this vnode, which
1635 	 * will cause it to panic.  So, return 0 if a flush is in progress.
1636 	 */
1637 	if (vp->v_flag & VXLOCK) {
1638 		if(IS_FLUSHING(VTOI(vp)->i_lfs,vp)) {
1639 			return 0;
1640 		}
1641 		return(1);
1642 	}
1643 	return (vget(vp, 0));
1644 }
1645 
1646 /*
1647  * This is vrele except that we do not want to VOP_INACTIVE this vnode. We
1648  * inline vrele here to avoid the vn_lock and VOP_INACTIVE call at the end.
1649  */
1650 void
1651 lfs_vunref(vp)
1652 	register struct vnode *vp;
1653 {
1654 	/*
1655 	 * Analogous to lfs_vref, if the node is flushing, fake it.
1656 	 */
1657 	if((vp->v_flag & VXLOCK) && IS_FLUSHING(VTOI(vp)->i_lfs,vp)) {
1658 		return;
1659 	}
1660 
1661 	simple_lock(&vp->v_interlock);
1662 #ifdef DIAGNOSTIC
1663 	if(vp->v_usecount<=0) {
1664 		printf("lfs_vunref: flags are 0x%lx\n", vp->v_flag);
1665 		printf("lfs_vunref: usecount = %ld\n", vp->v_usecount);
1666 		panic("lfs_vunref: v_usecount<0");
1667 	}
1668 #endif
1669 	vp->v_usecount--;
1670 	if (vp->v_usecount > 0) {
1671 		simple_unlock(&vp->v_interlock);
1672 		return;
1673 	}
1674 #ifdef DIAGNOSTIC
1675 	if(VOP_ISLOCKED(vp))
1676 		panic("lfs_vunref: vnode locked");
1677 #endif
1678 	/*
1679 	 * insert at tail of LRU list
1680 	 */
1681 	simple_lock(&vnode_free_list_slock);
1682 	if (vp->v_holdcnt > 0)
1683 		TAILQ_INSERT_TAIL(&vnode_hold_list, vp, v_freelist);
1684 	else
1685 		TAILQ_INSERT_TAIL(&vnode_free_list, vp, v_freelist);
1686 	simple_unlock(&vnode_free_list_slock);
1687 	simple_unlock(&vp->v_interlock);
1688 }
1689 
1690 /*
1691  * We use this when we have vnodes that were loaded in solely for cleaning.
1692  * There is no reason to believe that these vnodes will be referenced again
1693  * soon, since the cleaning process is unrelated to normal filesystem
1694  * activity.  Putting cleaned vnodes at the tail of the list has the effect
1695  * of flushing the vnode LRU.  So, put vnodes that were loaded only for
1696  * cleaning at the head of the list, instead.
1697  */
1698 void
1699 lfs_vunref_head(vp)
1700 	register struct vnode *vp;
1701 {
1702 	simple_lock(&vp->v_interlock);
1703 #ifdef DIAGNOSTIC
1704 	if(vp->v_usecount==0) {
1705 		panic("lfs_vunref: v_usecount<0");
1706 	}
1707 #endif
1708 	vp->v_usecount--;
1709 	if (vp->v_usecount > 0) {
1710 		simple_unlock(&vp->v_interlock);
1711 		return;
1712 	}
1713 #ifdef DIAGNOSTIC
1714 	if(VOP_ISLOCKED(vp))
1715 		panic("lfs_vunref_head: vnode locked");
1716 #endif
1717 	/*
1718 	 * insert at head of LRU list
1719 	 */
1720 	simple_lock(&vnode_free_list_slock);
1721 	TAILQ_INSERT_HEAD(&vnode_free_list, vp, v_freelist);
1722 	simple_unlock(&vnode_free_list_slock);
1723 	simple_unlock(&vp->v_interlock);
1724 }
1725 
1726