lfs_subr.c revision 1.74
1/*	$NetBSD: lfs_subr.c,v 1.74 2010/02/16 23:20:30 mlelstv 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 *
19 * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
20 * ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
21 * TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
22 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
23 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
24 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
25 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
26 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
27 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
28 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
29 * POSSIBILITY OF SUCH DAMAGE.
30 */
31/*
32 * Copyright (c) 1991, 1993
33 *	The Regents of the University of California.  All rights reserved.
34 *
35 * Redistribution and use in source and binary forms, with or without
36 * modification, are permitted provided that the following conditions
37 * are met:
38 * 1. Redistributions of source code must retain the above copyright
39 *    notice, this list of conditions and the following disclaimer.
40 * 2. Redistributions in binary form must reproduce the above copyright
41 *    notice, this list of conditions and the following disclaimer in the
42 *    documentation and/or other materials provided with the distribution.
43 * 3. Neither the name of the University nor the names of its contributors
44 *    may be used to endorse or promote products derived from this software
45 *    without specific prior written permission.
46 *
47 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
48 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
49 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
50 * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
51 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
52 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
53 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
54 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
55 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
56 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
57 * SUCH DAMAGE.
58 *
59 *	@(#)lfs_subr.c	8.4 (Berkeley) 5/8/95
60 */
61
62#include <sys/cdefs.h>
63__KERNEL_RCSID(0, "$NetBSD: lfs_subr.c,v 1.74 2010/02/16 23:20:30 mlelstv Exp $");
64
65#include <sys/param.h>
66#include <sys/systm.h>
67#include <sys/namei.h>
68#include <sys/vnode.h>
69#include <sys/buf.h>
70#include <sys/mount.h>
71#include <sys/malloc.h>
72#include <sys/proc.h>
73#include <sys/kauth.h>
74
75#include <ufs/ufs/inode.h>
76#include <ufs/lfs/lfs.h>
77#include <ufs/lfs/lfs_extern.h>
78
79#include <uvm/uvm.h>
80
81#ifdef DEBUG
82const char *lfs_res_names[LFS_NB_COUNT] = {
83	"summary",
84	"superblock",
85	"file block",
86	"cluster",
87	"clean",
88	"blkiov",
89};
90#endif
91
92int lfs_res_qty[LFS_NB_COUNT] = {
93	LFS_N_SUMMARIES,
94	LFS_N_SBLOCKS,
95	LFS_N_IBLOCKS,
96	LFS_N_CLUSTERS,
97	LFS_N_CLEAN,
98	LFS_N_BLKIOV,
99};
100
101void
102lfs_setup_resblks(struct lfs *fs)
103{
104	int i, j;
105	int maxbpp;
106
107	ASSERT_NO_SEGLOCK(fs);
108	fs->lfs_resblk = (res_t *)malloc(LFS_N_TOTAL * sizeof(res_t), M_SEGMENT,
109					  M_WAITOK);
110	for (i = 0; i < LFS_N_TOTAL; i++) {
111		fs->lfs_resblk[i].inuse = 0;
112		fs->lfs_resblk[i].p = NULL;
113	}
114	for (i = 0; i < LFS_RESHASH_WIDTH; i++)
115		LIST_INIT(fs->lfs_reshash + i);
116
117	/*
118	 * These types of allocations can be larger than a page,
119	 * so we can't use the pool subsystem for them.
120	 */
121	for (i = 0, j = 0; j < LFS_N_SUMMARIES; j++, i++)
122		fs->lfs_resblk[i].size = fs->lfs_sumsize;
123	for (j = 0; j < LFS_N_SBLOCKS; j++, i++)
124		fs->lfs_resblk[i].size = LFS_SBPAD;
125	for (j = 0; j < LFS_N_IBLOCKS; j++, i++)
126		fs->lfs_resblk[i].size = fs->lfs_bsize;
127	for (j = 0; j < LFS_N_CLUSTERS; j++, i++)
128		fs->lfs_resblk[i].size = MAXPHYS;
129	for (j = 0; j < LFS_N_CLEAN; j++, i++)
130		fs->lfs_resblk[i].size = MAXPHYS;
131	for (j = 0; j < LFS_N_BLKIOV; j++, i++)
132		fs->lfs_resblk[i].size = LFS_MARKV_MAXBLKCNT * sizeof(BLOCK_INFO);
133
134	for (i = 0; i < LFS_N_TOTAL; i++) {
135		fs->lfs_resblk[i].p = malloc(fs->lfs_resblk[i].size,
136					     M_SEGMENT, M_WAITOK);
137	}
138
139	/*
140	 * Initialize pools for small types (XXX is BPP small?)
141	 */
142	pool_init(&fs->lfs_clpool, sizeof(struct lfs_cluster), 0, 0, 0,
143		"lfsclpl", &pool_allocator_nointr, IPL_NONE);
144	pool_init(&fs->lfs_segpool, sizeof(struct segment), 0, 0, 0,
145		"lfssegpool", &pool_allocator_nointr, IPL_NONE);
146	maxbpp = ((fs->lfs_sumsize - SEGSUM_SIZE(fs)) / sizeof(int32_t) + 2);
147	maxbpp = MIN(maxbpp, segsize(fs) / fs->lfs_fsize + 2);
148	pool_init(&fs->lfs_bpppool, maxbpp * sizeof(struct buf *), 0, 0, 0,
149		"lfsbpppl", &pool_allocator_nointr, IPL_NONE);
150}
151
152void
153lfs_free_resblks(struct lfs *fs)
154{
155	int i;
156
157	pool_destroy(&fs->lfs_bpppool);
158	pool_destroy(&fs->lfs_segpool);
159	pool_destroy(&fs->lfs_clpool);
160
161	mutex_enter(&lfs_lock);
162	for (i = 0; i < LFS_N_TOTAL; i++) {
163		while (fs->lfs_resblk[i].inuse)
164			mtsleep(&fs->lfs_resblk, PRIBIO + 1, "lfs_free", 0,
165				&lfs_lock);
166		if (fs->lfs_resblk[i].p != NULL)
167			free(fs->lfs_resblk[i].p, M_SEGMENT);
168	}
169	free(fs->lfs_resblk, M_SEGMENT);
170	mutex_exit(&lfs_lock);
171}
172
173static unsigned int
174lfs_mhash(void *vp)
175{
176	return (unsigned int)(((unsigned long)vp) >> 2) % LFS_RESHASH_WIDTH;
177}
178
179/*
180 * Return memory of the given size for the given purpose, or use one of a
181 * number of spare last-resort buffers, if malloc returns NULL.
182 */
183void *
184lfs_malloc(struct lfs *fs, size_t size, int type)
185{
186	struct lfs_res_blk *re;
187	void *r;
188	int i, s, start;
189	unsigned int h;
190
191	ASSERT_MAYBE_SEGLOCK(fs);
192	r = NULL;
193
194	/* If no mem allocated for this type, it just waits */
195	if (lfs_res_qty[type] == 0) {
196		r = malloc(size, M_SEGMENT, M_WAITOK);
197		return r;
198	}
199
200	/* Otherwise try a quick malloc, and if it works, great */
201	if ((r = malloc(size, M_SEGMENT, M_NOWAIT)) != NULL) {
202		return r;
203	}
204
205	/*
206	 * If malloc returned NULL, we are forced to use one of our
207	 * reserve blocks.  We have on hand at least one summary block,
208	 * at least one cluster block, at least one superblock,
209	 * and several indirect blocks.
210	 */
211
212	mutex_enter(&lfs_lock);
213	/* skip over blocks of other types */
214	for (i = 0, start = 0; i < type; i++)
215		start += lfs_res_qty[i];
216	while (r == NULL) {
217		for (i = 0; i < lfs_res_qty[type]; i++) {
218			if (fs->lfs_resblk[start + i].inuse == 0) {
219				re = fs->lfs_resblk + start + i;
220				re->inuse = 1;
221				r = re->p;
222				KASSERT(re->size >= size);
223				h = lfs_mhash(r);
224				s = splbio();
225				LIST_INSERT_HEAD(&fs->lfs_reshash[h], re, res);
226				splx(s);
227				mutex_exit(&lfs_lock);
228				return r;
229			}
230		}
231		DLOG((DLOG_MALLOC, "sleeping on %s (%d)\n",
232		      lfs_res_names[type], lfs_res_qty[type]));
233		mtsleep(&fs->lfs_resblk, PVM, "lfs_malloc", 0,
234			&lfs_lock);
235		DLOG((DLOG_MALLOC, "done sleeping on %s\n",
236		      lfs_res_names[type]));
237	}
238	/* NOTREACHED */
239	mutex_exit(&lfs_lock);
240	return r;
241}
242
243void
244lfs_free(struct lfs *fs, void *p, int type)
245{
246	int s;
247	unsigned int h;
248	res_t *re;
249#ifdef DEBUG
250	int i;
251#endif
252
253	ASSERT_MAYBE_SEGLOCK(fs);
254	h = lfs_mhash(p);
255	mutex_enter(&lfs_lock);
256	s = splbio();
257	LIST_FOREACH(re, &fs->lfs_reshash[h], res) {
258		if (re->p == p) {
259			KASSERT(re->inuse == 1);
260			LIST_REMOVE(re, res);
261			re->inuse = 0;
262			wakeup(&fs->lfs_resblk);
263			splx(s);
264			mutex_exit(&lfs_lock);
265			return;
266		}
267	}
268#ifdef DEBUG
269	for (i = 0; i < LFS_N_TOTAL; i++) {
270		if (fs->lfs_resblk[i].p == p)
271			panic("lfs_free: inconsistent reserved block");
272	}
273#endif
274	splx(s);
275	mutex_exit(&lfs_lock);
276
277	/*
278	 * If we didn't find it, free it.
279	 */
280	free(p, M_SEGMENT);
281}
282
283/*
284 * lfs_seglock --
285 *	Single thread the segment writer.
286 */
287int
288lfs_seglock(struct lfs *fs, unsigned long flags)
289{
290	struct segment *sp;
291
292	mutex_enter(&lfs_lock);
293	if (fs->lfs_seglock) {
294		if (fs->lfs_lockpid == curproc->p_pid &&
295		    fs->lfs_locklwp == curlwp->l_lid) {
296			++fs->lfs_seglock;
297			fs->lfs_sp->seg_flags |= flags;
298			mutex_exit(&lfs_lock);
299			return 0;
300		} else if (flags & SEGM_PAGEDAEMON) {
301			mutex_exit(&lfs_lock);
302			return EWOULDBLOCK;
303		} else {
304			while (fs->lfs_seglock) {
305				(void)mtsleep(&fs->lfs_seglock, PRIBIO + 1,
306					"lfs_seglock", 0, &lfs_lock);
307			}
308		}
309	}
310
311	fs->lfs_seglock = 1;
312	fs->lfs_lockpid = curproc->p_pid;
313	fs->lfs_locklwp = curlwp->l_lid;
314	mutex_exit(&lfs_lock);
315	fs->lfs_cleanind = 0;
316
317#ifdef DEBUG
318	LFS_ENTER_LOG("seglock", __FILE__, __LINE__, 0, flags, curproc->p_pid);
319#endif
320	/* Drain fragment size changes out */
321	rw_enter(&fs->lfs_fraglock, RW_WRITER);
322
323	sp = fs->lfs_sp = pool_get(&fs->lfs_segpool, PR_WAITOK);
324	sp->bpp = pool_get(&fs->lfs_bpppool, PR_WAITOK);
325	sp->seg_flags = flags;
326	sp->vp = NULL;
327	sp->seg_iocount = 0;
328	(void) lfs_initseg(fs);
329
330	/*
331	 * Keep a cumulative count of the outstanding I/O operations.  If the
332	 * disk drive catches up with us it could go to zero before we finish,
333	 * so we artificially increment it by one until we've scheduled all of
334	 * the writes we intend to do.
335	 */
336	mutex_enter(&lfs_lock);
337	++fs->lfs_iocount;
338	mutex_exit(&lfs_lock);
339	return 0;
340}
341
342static void lfs_unmark_dirop(struct lfs *);
343
344static void
345lfs_unmark_dirop(struct lfs *fs)
346{
347	struct inode *ip, *nip;
348	struct vnode *vp;
349	int doit;
350
351	ASSERT_NO_SEGLOCK(fs);
352	mutex_enter(&lfs_lock);
353	doit = !(fs->lfs_flags & LFS_UNDIROP);
354	if (doit)
355		fs->lfs_flags |= LFS_UNDIROP;
356	if (!doit) {
357		mutex_exit(&lfs_lock);
358		return;
359	}
360
361	for (ip = TAILQ_FIRST(&fs->lfs_dchainhd); ip != NULL; ip = nip) {
362		nip = TAILQ_NEXT(ip, i_lfs_dchain);
363		vp = ITOV(ip);
364		if (VOP_ISLOCKED(vp) == LK_EXCLOTHER)
365			continue;
366		if ((VTOI(vp)->i_flag & (IN_ADIROP | IN_ALLMOD)) == 0) {
367			--lfs_dirvcount;
368			--fs->lfs_dirvcount;
369			vp->v_uflag &= ~VU_DIROP;
370			TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
371			wakeup(&lfs_dirvcount);
372			fs->lfs_unlockvp = vp;
373			mutex_exit(&lfs_lock);
374			vrele(vp);
375			mutex_enter(&lfs_lock);
376			fs->lfs_unlockvp = NULL;
377		}
378	}
379
380	fs->lfs_flags &= ~LFS_UNDIROP;
381	wakeup(&fs->lfs_flags);
382	mutex_exit(&lfs_lock);
383}
384
385static void
386lfs_auto_segclean(struct lfs *fs)
387{
388	int i, error, s, waited;
389
390	ASSERT_SEGLOCK(fs);
391	/*
392	 * Now that we've swapped lfs_activesb, but while we still
393	 * hold the segment lock, run through the segment list marking
394	 * the empty ones clean.
395	 * XXX - do we really need to do them all at once?
396	 */
397	waited = 0;
398	for (i = 0; i < fs->lfs_nseg; i++) {
399		if ((fs->lfs_suflags[0][i] &
400		     (SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) ==
401		    (SEGUSE_DIRTY | SEGUSE_EMPTY) &&
402		    (fs->lfs_suflags[1][i] &
403		     (SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) ==
404		    (SEGUSE_DIRTY | SEGUSE_EMPTY)) {
405
406			/* Make sure the sb is written before we clean */
407			mutex_enter(&lfs_lock);
408			s = splbio();
409			while (waited == 0 && fs->lfs_sbactive)
410				mtsleep(&fs->lfs_sbactive, PRIBIO+1, "lfs asb",
411					0, &lfs_lock);
412			splx(s);
413			mutex_exit(&lfs_lock);
414			waited = 1;
415
416			if ((error = lfs_do_segclean(fs, i)) != 0) {
417				DLOG((DLOG_CLEAN, "lfs_auto_segclean: lfs_do_segclean returned %d for seg %d\n", error, i));
418			}
419		}
420		fs->lfs_suflags[1 - fs->lfs_activesb][i] =
421			fs->lfs_suflags[fs->lfs_activesb][i];
422	}
423}
424
425/*
426 * lfs_segunlock --
427 *	Single thread the segment writer.
428 */
429void
430lfs_segunlock(struct lfs *fs)
431{
432	struct segment *sp;
433	unsigned long sync, ckp;
434	struct buf *bp;
435	int do_unmark_dirop = 0;
436
437	sp = fs->lfs_sp;
438
439	mutex_enter(&lfs_lock);
440	KASSERT(LFS_SEGLOCK_HELD(fs));
441	if (fs->lfs_seglock == 1) {
442		if ((sp->seg_flags & (SEGM_PROT | SEGM_CLEAN)) == 0 &&
443		    LFS_STARVED_FOR_SEGS(fs) == 0)
444			do_unmark_dirop = 1;
445		mutex_exit(&lfs_lock);
446		sync = sp->seg_flags & SEGM_SYNC;
447		ckp = sp->seg_flags & SEGM_CKP;
448
449		/* We should have a segment summary, and nothing else */
450		KASSERT(sp->cbpp == sp->bpp + 1);
451
452		/* Free allocated segment summary */
453		fs->lfs_offset -= btofsb(fs, fs->lfs_sumsize);
454		bp = *sp->bpp;
455		lfs_freebuf(fs, bp);
456
457		pool_put(&fs->lfs_bpppool, sp->bpp);
458		sp->bpp = NULL;
459
460		/*
461		 * If we're not sync, we're done with sp, get rid of it.
462		 * Otherwise, we keep a local copy around but free
463		 * fs->lfs_sp so another process can use it (we have to
464		 * wait but they don't have to wait for us).
465		 */
466		if (!sync)
467			pool_put(&fs->lfs_segpool, sp);
468		fs->lfs_sp = NULL;
469
470		/*
471		 * If the I/O count is non-zero, sleep until it reaches zero.
472		 * At the moment, the user's process hangs around so we can
473		 * sleep.
474		 */
475		mutex_enter(&lfs_lock);
476		if (--fs->lfs_iocount == 0) {
477			LFS_DEBUG_COUNTLOCKED("lfs_segunlock");
478		}
479		if (fs->lfs_iocount <= 1)
480			wakeup(&fs->lfs_iocount);
481		mutex_exit(&lfs_lock);
482		/*
483		 * If we're not checkpointing, we don't have to block
484		 * other processes to wait for a synchronous write
485		 * to complete.
486		 */
487		if (!ckp) {
488#ifdef DEBUG
489			LFS_ENTER_LOG("segunlock_std", __FILE__, __LINE__, 0, 0, curproc->p_pid);
490#endif
491			mutex_enter(&lfs_lock);
492			--fs->lfs_seglock;
493			fs->lfs_lockpid = 0;
494			fs->lfs_locklwp = 0;
495			mutex_exit(&lfs_lock);
496			wakeup(&fs->lfs_seglock);
497		}
498		/*
499		 * We let checkpoints happen asynchronously.  That means
500		 * that during recovery, we have to roll forward between
501		 * the two segments described by the first and second
502		 * superblocks to make sure that the checkpoint described
503		 * by a superblock completed.
504		 */
505		mutex_enter(&lfs_lock);
506		while (ckp && sync && fs->lfs_iocount) {
507			(void)mtsleep(&fs->lfs_iocount, PRIBIO + 1,
508				      "lfs_iocount", 0, &lfs_lock);
509			DLOG((DLOG_SEG, "sleeping on iocount %x == %d\n", fs, fs->lfs_iocount));
510		}
511		while (sync && sp->seg_iocount) {
512			(void)mtsleep(&sp->seg_iocount, PRIBIO + 1,
513				     "seg_iocount", 0, &lfs_lock);
514			DLOG((DLOG_SEG, "sleeping on iocount %x == %d\n", sp, sp->seg_iocount));
515		}
516		mutex_exit(&lfs_lock);
517		if (sync)
518			pool_put(&fs->lfs_segpool, sp);
519
520		if (ckp) {
521			fs->lfs_nactive = 0;
522			/* If we *know* everything's on disk, write both sbs */
523			/* XXX should wait for this one	 */
524			if (sync)
525				lfs_writesuper(fs, fs->lfs_sboffs[fs->lfs_activesb]);
526			lfs_writesuper(fs, fs->lfs_sboffs[1 - fs->lfs_activesb]);
527			if (!(fs->lfs_ivnode->v_mount->mnt_iflag & IMNT_UNMOUNT)) {
528				lfs_auto_segclean(fs);
529				/* If sync, we can clean the remainder too */
530				if (sync)
531					lfs_auto_segclean(fs);
532			}
533			fs->lfs_activesb = 1 - fs->lfs_activesb;
534#ifdef DEBUG
535			LFS_ENTER_LOG("segunlock_ckp", __FILE__, __LINE__, 0, 0, curproc->p_pid);
536#endif
537			mutex_enter(&lfs_lock);
538			--fs->lfs_seglock;
539			fs->lfs_lockpid = 0;
540			fs->lfs_locklwp = 0;
541			mutex_exit(&lfs_lock);
542			wakeup(&fs->lfs_seglock);
543		}
544		/* Reenable fragment size changes */
545		rw_exit(&fs->lfs_fraglock);
546		if (do_unmark_dirop)
547			lfs_unmark_dirop(fs);
548	} else if (fs->lfs_seglock == 0) {
549		mutex_exit(&lfs_lock);
550		panic ("Seglock not held");
551	} else {
552		--fs->lfs_seglock;
553		mutex_exit(&lfs_lock);
554	}
555}
556
557/*
558 * Drain dirops and start writer.
559 *
560 * No simple_locks are held when we enter and none are held when we return.
561 */
562int
563lfs_writer_enter(struct lfs *fs, const char *wmesg)
564{
565	int error = 0;
566
567	ASSERT_MAYBE_SEGLOCK(fs);
568	mutex_enter(&lfs_lock);
569
570	/* disallow dirops during flush */
571	fs->lfs_writer++;
572
573	while (fs->lfs_dirops > 0) {
574		++fs->lfs_diropwait;
575		error = mtsleep(&fs->lfs_writer, PRIBIO+1, wmesg, 0,
576				&lfs_lock);
577		--fs->lfs_diropwait;
578	}
579
580	if (error)
581		fs->lfs_writer--;
582
583	mutex_exit(&lfs_lock);
584
585	return error;
586}
587
588void
589lfs_writer_leave(struct lfs *fs)
590{
591	bool dowakeup;
592
593	ASSERT_MAYBE_SEGLOCK(fs);
594	mutex_enter(&lfs_lock);
595	dowakeup = !(--fs->lfs_writer);
596	mutex_exit(&lfs_lock);
597	if (dowakeup)
598		wakeup(&fs->lfs_dirops);
599}
600
601/*
602 * Unlock, wait for the cleaner, then relock to where we were before.
603 * To be used only at a fairly high level, to address a paucity of free
604 * segments propagated back from lfs_gop_write().
605 */
606void
607lfs_segunlock_relock(struct lfs *fs)
608{
609	int n = fs->lfs_seglock;
610	u_int16_t seg_flags;
611	CLEANERINFO *cip;
612	struct buf *bp;
613
614	if (n == 0)
615		return;
616
617	/* Write anything we've already gathered to disk */
618	lfs_writeseg(fs, fs->lfs_sp);
619
620	/* Tell cleaner */
621	LFS_CLEANERINFO(cip, fs, bp);
622	cip->flags |= LFS_CLEANER_MUST_CLEAN;
623	LFS_SYNC_CLEANERINFO(cip, fs, bp, 1);
624
625	/* Save segment flags for later */
626	seg_flags = fs->lfs_sp->seg_flags;
627
628	fs->lfs_sp->seg_flags |= SEGM_PROT; /* Don't unmark dirop nodes */
629	while(fs->lfs_seglock)
630		lfs_segunlock(fs);
631
632	/* Wait for the cleaner */
633	lfs_wakeup_cleaner(fs);
634	mutex_enter(&lfs_lock);
635	while (LFS_STARVED_FOR_SEGS(fs))
636		mtsleep(&fs->lfs_avail, PRIBIO, "relock", 0,
637			&lfs_lock);
638	mutex_exit(&lfs_lock);
639
640	/* Put the segment lock back the way it was. */
641	while(n--)
642		lfs_seglock(fs, seg_flags);
643
644	/* Cleaner can relax now */
645	LFS_CLEANERINFO(cip, fs, bp);
646	cip->flags &= ~LFS_CLEANER_MUST_CLEAN;
647	LFS_SYNC_CLEANERINFO(cip, fs, bp, 1);
648
649	return;
650}
651
652/*
653 * Wake up the cleaner, provided that nowrap is not set.
654 */
655void
656lfs_wakeup_cleaner(struct lfs *fs)
657{
658	if (fs->lfs_nowrap > 0)
659		return;
660
661	wakeup(&fs->lfs_nextseg);
662	wakeup(&lfs_allclean_wakeup);
663}
664