/* $NetBSD: lfs_subr.c,v 1.103 2020/09/05 16:30:13 riastradh Exp $ */
/*-
* Copyright (c) 1999, 2000, 2001, 2002, 2003 The NetBSD Foundation, Inc.
* All rights reserved.
*
* This code is derived from software contributed to The NetBSD Foundation
* by Konrad E. Schroder <perseant@hhhh.org>.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*/
/*
* Copyright (c) 1991, 1993
* The Regents of the University of California. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)lfs_subr.c 8.4 (Berkeley) 5/8/95
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: lfs_subr.c,v 1.103 2020/09/05 16:30:13 riastradh Exp $");
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/malloc.h>
#include <sys/proc.h>
#include <sys/kauth.h>
#include <ufs/lfs/ulfs_inode.h>
#include <ufs/lfs/lfs.h>
#include <ufs/lfs/lfs_accessors.h>
#include <ufs/lfs/lfs_kernel.h>
#include <ufs/lfs/lfs_extern.h>
#ifdef DEBUG
const char *lfs_res_names[LFS_NB_COUNT] = {
"summary",
"superblock",
"file block",
"cluster",
"clean",
"blkiov",
};
#endif
int lfs_res_qty[LFS_NB_COUNT] = {
LFS_N_SUMMARIES,
LFS_N_SBLOCKS,
LFS_N_IBLOCKS,
LFS_N_CLUSTERS,
LFS_N_CLEAN,
LFS_N_BLKIOV,
};
void
lfs_setup_resblks(struct lfs *fs)
{
int i, j;
int maxbpp;
ASSERT_NO_SEGLOCK(fs);
fs->lfs_resblk = malloc(LFS_N_TOTAL * sizeof(res_t), M_SEGMENT,
M_WAITOK);
for (i = 0; i < LFS_N_TOTAL; i++) {
fs->lfs_resblk[i].inuse = 0;
fs->lfs_resblk[i].p = NULL;
}
for (i = 0; i < LFS_RESHASH_WIDTH; i++)
LIST_INIT(fs->lfs_reshash + i);
/*
* These types of allocations can be larger than a page,
* so we can't use the pool subsystem for them.
*/
for (i = 0, j = 0; j < LFS_N_SUMMARIES; j++, i++)
fs->lfs_resblk[i].size = lfs_sb_getsumsize(fs);
for (j = 0; j < LFS_N_SBLOCKS; j++, i++)
fs->lfs_resblk[i].size = LFS_SBPAD;
for (j = 0; j < LFS_N_IBLOCKS; j++, i++)
fs->lfs_resblk[i].size = lfs_sb_getbsize(fs);
for (j = 0; j < LFS_N_CLUSTERS; j++, i++)
fs->lfs_resblk[i].size = MAXPHYS;
for (j = 0; j < LFS_N_CLEAN; j++, i++)
fs->lfs_resblk[i].size = MAXPHYS;
for (j = 0; j < LFS_N_BLKIOV; j++, i++)
fs->lfs_resblk[i].size = LFS_MARKV_MAXBLKCNT * sizeof(BLOCK_INFO);
for (i = 0; i < LFS_N_TOTAL; i++) {
fs->lfs_resblk[i].p = malloc(fs->lfs_resblk[i].size,
M_SEGMENT, M_WAITOK);
}
/*
* Initialize pools for small types (XXX is BPP small?)
*/
pool_init(&fs->lfs_clpool, sizeof(struct lfs_cluster), 0, 0, 0,
"lfsclpl", &pool_allocator_nointr, IPL_NONE);
pool_init(&fs->lfs_segpool, sizeof(struct segment), 0, 0, 0,
"lfssegpool", &pool_allocator_nointr, IPL_NONE);
/* XXX: should this int32 be 32/64? */
maxbpp = ((lfs_sb_getsumsize(fs) - SEGSUM_SIZE(fs)) / sizeof(int32_t) + 2);
maxbpp = MIN(maxbpp, lfs_segsize(fs) / lfs_sb_getfsize(fs) + 2);
pool_init(&fs->lfs_bpppool, maxbpp * sizeof(struct buf *), 0, 0, 0,
"lfsbpppl", &pool_allocator_nointr, IPL_NONE);
}
void
lfs_free_resblks(struct lfs *fs)
{
int i;
pool_destroy(&fs->lfs_bpppool);
pool_destroy(&fs->lfs_segpool);
pool_destroy(&fs->lfs_clpool);
mutex_enter(&lfs_lock);
for (i = 0; i < LFS_N_TOTAL; i++) {
while (fs->lfs_resblk[i].inuse)
mtsleep(&fs->lfs_resblk, PRIBIO + 1, "lfs_free", 0,
&lfs_lock);
if (fs->lfs_resblk[i].p != NULL)
free(fs->lfs_resblk[i].p, M_SEGMENT);
}
free(fs->lfs_resblk, M_SEGMENT);
mutex_exit(&lfs_lock);
}
static unsigned int
lfs_mhash(void *vp)
{
return (unsigned int)(((unsigned long)vp) >> 2) % LFS_RESHASH_WIDTH;
}
/*
* Return memory of the given size for the given purpose, or use one of a
* number of spare last-resort buffers, if malloc returns NULL.
*/
void *
lfs_malloc(struct lfs *fs, size_t size, int type)
{
struct lfs_res_blk *re;
void *r;
int i, start;
unsigned int h;
ASSERT_MAYBE_SEGLOCK(fs);
r = NULL;
/* If no mem allocated for this type, it just waits */
if (lfs_res_qty[type] == 0) {
r = malloc(size, M_SEGMENT, M_WAITOK);
return r;
}
/* Otherwise try a quick malloc, and if it works, great */
if ((r = malloc(size, M_SEGMENT, M_NOWAIT)) != NULL) {
return r;
}
/*
* If malloc returned NULL, we are forced to use one of our
* reserve blocks. We have on hand at least one summary block,
* at least one cluster block, at least one superblock,
* and several indirect blocks.
*/
mutex_enter(&lfs_lock);
/* skip over blocks of other types */
for (i = 0, start = 0; i < type; i++)
start += lfs_res_qty[i];
while (r == NULL) {
for (i = 0; i < lfs_res_qty[type]; i++) {
if (fs->lfs_resblk[start + i].inuse == 0) {
re = fs->lfs_resblk + start + i;
re->inuse = 1;
r = re->p;
KASSERT(re->size >= size);
h = lfs_mhash(r);
LIST_INSERT_HEAD(&fs->lfs_reshash[h], re, res);
mutex_exit(&lfs_lock);
return r;
}
}
DLOG((DLOG_MALLOC, "sleeping on %s (%d)\n",
lfs_res_names[type], lfs_res_qty[type]));
mtsleep(&fs->lfs_resblk, PVM, "lfs_malloc", 0,
&lfs_lock);
DLOG((DLOG_MALLOC, "done sleeping on %s\n",
lfs_res_names[type]));
}
/* NOTREACHED */
mutex_exit(&lfs_lock);
return r;
}
void
lfs_free(struct lfs *fs, void *p, int type)
{
unsigned int h;
res_t *re;
ASSERT_MAYBE_SEGLOCK(fs);
h = lfs_mhash(p);
mutex_enter(&lfs_lock);
LIST_FOREACH(re, &fs->lfs_reshash[h], res) {
if (re->p == p) {
KASSERT(re->inuse == 1);
LIST_REMOVE(re, res);
re->inuse = 0;
wakeup(&fs->lfs_resblk);
mutex_exit(&lfs_lock);
return;
}
}
#ifdef notyet /* XXX this assert fires */
for (int i = 0; i < LFS_N_TOTAL; i++) {
KDASSERTMSG(fs->lfs_resblk[i].p == p,
"lfs_free: inconsistent reserved block");
}
#endif
mutex_exit(&lfs_lock);
/*
* If we didn't find it, free it.
*/
free(p, M_SEGMENT);
}
/*
* lfs_seglock --
* Single thread the segment writer.
*/
int
lfs_seglock(struct lfs *fs, unsigned long flags)
{
struct segment *sp;
mutex_enter(&lfs_lock);
if (fs->lfs_seglock) {
if (fs->lfs_lockpid == curproc->p_pid &&
fs->lfs_locklwp == curlwp->l_lid) {
++fs->lfs_seglock;
fs->lfs_sp->seg_flags |= flags;
mutex_exit(&lfs_lock);
return 0;
} else if (flags & SEGM_PAGEDAEMON) {
mutex_exit(&lfs_lock);
return EWOULDBLOCK;
} else {
while (fs->lfs_seglock) {
(void)mtsleep(&fs->lfs_seglock, PRIBIO + 1,
"lfs_seglock", 0, &lfs_lock);
}
}
}
fs->lfs_seglock = 1;
fs->lfs_lockpid = curproc->p_pid;
fs->lfs_locklwp = curlwp->l_lid;
mutex_exit(&lfs_lock);
fs->lfs_cleanind = 0;
LFS_ENTER_LOG("seglock", __FILE__, __LINE__, 0, flags, curproc->p_pid);
/* Drain fragment size changes out */
rw_enter(&fs->lfs_fraglock, RW_WRITER);
sp = fs->lfs_sp = pool_get(&fs->lfs_segpool, PR_WAITOK);
sp->bpp = pool_get(&fs->lfs_bpppool, PR_WAITOK);
sp->seg_flags = flags;
sp->vp = NULL;
sp->seg_iocount = 0;
(void) lfs_initseg(fs);
/*
* Keep a cumulative count of the outstanding I/O operations. If the
* disk drive catches up with us it could go to zero before we finish,
* so we artificially increment it by one until we've scheduled all of
* the writes we intend to do.
*/
mutex_enter(&lfs_lock);
++fs->lfs_iocount;
fs->lfs_startseg = lfs_sb_getcurseg(fs);
mutex_exit(&lfs_lock);
return 0;
}
static void lfs_unmark_dirop(struct lfs *);
static void
lfs_unmark_dirop(struct lfs *fs)
{
struct inode *ip, *marker;
struct vnode *vp;
int doit;
ASSERT_NO_SEGLOCK(fs);
mutex_enter(&lfs_lock);
doit = !(fs->lfs_flags & LFS_UNDIROP);
if (doit)
fs->lfs_flags |= LFS_UNDIROP;
mutex_exit(&lfs_lock);
if (!doit)
return;
marker = pool_get(&lfs_inode_pool, PR_WAITOK);
KASSERT(fs != NULL);
memset(marker, 0, sizeof(*marker));
marker->inode_ext.lfs = pool_get(&lfs_inoext_pool, PR_WAITOK);
memset(marker->inode_ext.lfs, 0, sizeof(*marker->inode_ext.lfs));
marker->i_state |= IN_MARKER;
mutex_enter(&lfs_lock);
TAILQ_INSERT_HEAD(&fs->lfs_dchainhd, marker, i_lfs_dchain);
while ((ip = TAILQ_NEXT(marker, i_lfs_dchain)) != NULL) {
TAILQ_REMOVE(&fs->lfs_dchainhd, marker, i_lfs_dchain);
TAILQ_INSERT_AFTER(&fs->lfs_dchainhd, ip, marker,
i_lfs_dchain);
if (ip->i_state & IN_MARKER)
continue;
vp = ITOV(ip);
if ((ip->i_state & (IN_ADIROP | IN_CDIROP)) == IN_CDIROP) {
--lfs_dirvcount;
--fs->lfs_dirvcount;
vp->v_uflag &= ~VU_DIROP;
TAILQ_REMOVE(&fs->lfs_dchainhd, ip, i_lfs_dchain);
wakeup(&lfs_dirvcount);
fs->lfs_unlockvp = vp;
mutex_exit(&lfs_lock);
vrele(vp);
mutex_enter(&lfs_lock);
fs->lfs_unlockvp = NULL;
ip->i_state &= ~IN_CDIROP;
}
}
TAILQ_REMOVE(&fs->lfs_dchainhd, marker, i_lfs_dchain);
fs->lfs_flags &= ~LFS_UNDIROP;
wakeup(&fs->lfs_flags);
mutex_exit(&lfs_lock);
pool_put(&lfs_inoext_pool, marker->inode_ext.lfs);
pool_put(&lfs_inode_pool, marker);
}
static void
lfs_auto_segclean(struct lfs *fs)
{
int i, error, waited;
ASSERT_SEGLOCK(fs);
/*
* Now that we've swapped lfs_activesb, but while we still
* hold the segment lock, run through the segment list marking
* the empty ones clean.
* XXX - do we really need to do them all at once?
*/
waited = 0;
for (i = 0; i < lfs_sb_getnseg(fs); i++) {
if ((fs->lfs_suflags[0][i] &
(SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) ==
(SEGUSE_DIRTY | SEGUSE_EMPTY) &&
(fs->lfs_suflags[1][i] &
(SEGUSE_ACTIVE | SEGUSE_DIRTY | SEGUSE_EMPTY)) ==
(SEGUSE_DIRTY | SEGUSE_EMPTY)) {
/* Make sure the sb is written before we clean */
mutex_enter(&lfs_lock);
while (waited == 0 && fs->lfs_sbactive)
mtsleep(&fs->lfs_sbactive, PRIBIO+1, "lfs asb",
0, &lfs_lock);
mutex_exit(&lfs_lock);
waited = 1;
if ((error = lfs_do_segclean(fs, i)) != 0) {
DLOG((DLOG_CLEAN, "lfs_auto_segclean: lfs_do_segclean returned %d for seg %d\n", error, i));
}
}
fs->lfs_suflags[1 - fs->lfs_activesb][i] =
fs->lfs_suflags[fs->lfs_activesb][i];
}
}
/*
* lfs_segunlock --
* Single thread the segment writer.
*/
void
lfs_segunlock(struct lfs *fs)
{
struct segment *sp;
unsigned long sync, ckp;
struct buf *bp;
int do_unmark_dirop = 0;
sp = fs->lfs_sp;
mutex_enter(&lfs_lock);
if (!LFS_SEGLOCK_HELD(fs))
panic("lfs seglock not held");
if (fs->lfs_seglock == 1) {
if ((sp->seg_flags & (SEGM_PROT | SEGM_CLEAN)) == 0)
do_unmark_dirop = 1;
mutex_exit(&lfs_lock);
sync = sp->seg_flags & SEGM_SYNC;
ckp = sp->seg_flags & SEGM_CKP;
/* We should have a segment summary, and nothing else */
KASSERT(sp->cbpp == sp->bpp + 1);
/* Free allocated segment summary */
lfs_sb_suboffset(fs, lfs_btofsb(fs, lfs_sb_getsumsize(fs)));
bp = *sp->bpp;
lfs_freebuf(fs, bp);
pool_put(&fs->lfs_bpppool, sp->bpp);
sp->bpp = NULL;
/*
* If we're not sync, we're done with sp, get rid of it.
* Otherwise, we keep a local copy around but free
* fs->lfs_sp so another process can use it (we have to
* wait but they don't have to wait for us).
*/
if (!sync)
pool_put(&fs->lfs_segpool, sp);
fs->lfs_sp = NULL;
/*
* If the I/O count is non-zero, sleep until it reaches zero.
* At the moment, the user's process hangs around so we can
* sleep.
*/
mutex_enter(&lfs_lock);
if (--fs->lfs_iocount <= 1)
wakeup(&fs->lfs_iocount);
mutex_exit(&lfs_lock);
/*
* If we're not checkpointing, we don't have to block
* other processes to wait for a synchronous write
* to complete.
*/
if (!ckp) {
LFS_ENTER_LOG("segunlock_std", __FILE__, __LINE__, 0, 0, curproc->p_pid);
mutex_enter(&lfs_lock);
--fs->lfs_seglock;
fs->lfs_lockpid = 0;
fs->lfs_locklwp = 0;
mutex_exit(&lfs_lock);
wakeup(&fs->lfs_seglock);
}
/*
* We let checkpoints happen asynchronously. That means
* that during recovery, we have to roll forward between
* the two segments described by the first and second
* superblocks to make sure that the checkpoint described
* by a superblock completed.
*/
mutex_enter(&lfs_lock);
while (ckp && sync && fs->lfs_iocount) {
(void)mtsleep(&fs->lfs_iocount, PRIBIO + 1,
"lfs_iocount", 0, &lfs_lock);
DLOG((DLOG_SEG, "sleeping on iocount %x == %d\n", fs, fs->lfs_iocount));
}
while (sync && sp->seg_iocount) {
(void)mtsleep(&sp->seg_iocount, PRIBIO + 1,
"seg_iocount", 0, &lfs_lock);
DLOG((DLOG_SEG, "sleeping on iocount %x == %d\n", sp, sp->seg_iocount));
}
mutex_exit(&lfs_lock);
if (sync)
pool_put(&fs->lfs_segpool, sp);
if (ckp) {
fs->lfs_nactive = 0;
/* If we *know* everything's on disk, write both sbs */
/* XXX should wait for this one */
if (sync)
lfs_writesuper(fs, lfs_sb_getsboff(fs, fs->lfs_activesb));
lfs_writesuper(fs, lfs_sb_getsboff(fs, 1 - fs->lfs_activesb));
if (!(fs->lfs_ivnode->v_mount->mnt_iflag & IMNT_UNMOUNT)) {
lfs_auto_segclean(fs);
/* If sync, we can clean the remainder too */
if (sync)
lfs_auto_segclean(fs);
}
fs->lfs_activesb = 1 - fs->lfs_activesb;
LFS_ENTER_LOG("segunlock_ckp", __FILE__, __LINE__, 0, 0, curproc->p_pid);
mutex_enter(&lfs_lock);
--fs->lfs_seglock;
fs->lfs_lockpid = 0;
fs->lfs_locklwp = 0;
mutex_exit(&lfs_lock);
wakeup(&fs->lfs_seglock);
}
/* Reenable fragment size changes */
rw_exit(&fs->lfs_fraglock);
if (do_unmark_dirop)
lfs_unmark_dirop(fs);
} else {
--fs->lfs_seglock;
KASSERT(fs->lfs_seglock != 0);
mutex_exit(&lfs_lock);
}
}
/*
* Drain dirops and start writer.
*
* No simple_locks are held when we enter and none are held when we return.
*/
void
lfs_writer_enter(struct lfs *fs, const char *wmesg)
{
int error __diagused;
ASSERT_NO_SEGLOCK(fs);
mutex_enter(&lfs_lock);
/* disallow dirops during flush */
fs->lfs_writer++;
while (fs->lfs_dirops > 0) {
++fs->lfs_diropwait;
error = mtsleep(&fs->lfs_writer, PRIBIO+1, wmesg, 0,
&lfs_lock);
KASSERT(error == 0);
--fs->lfs_diropwait;
}
mutex_exit(&lfs_lock);
}
int
lfs_writer_tryenter(struct lfs *fs)
{
int writer_set;
ASSERT_MAYBE_SEGLOCK(fs);
mutex_enter(&lfs_lock);
writer_set = (fs->lfs_dirops == 0);
if (writer_set)
fs->lfs_writer++;
mutex_exit(&lfs_lock);
return writer_set;
}
void
lfs_writer_leave(struct lfs *fs)
{
bool dowakeup;
ASSERT_MAYBE_SEGLOCK(fs);
mutex_enter(&lfs_lock);
dowakeup = !(--fs->lfs_writer);
if (dowakeup)
cv_broadcast(&fs->lfs_diropscv);
mutex_exit(&lfs_lock);
}
/*
* Unlock, wait for the cleaner, then relock to where we were before.
* To be used only at a fairly high level, to address a paucity of free
* segments propagated back from lfs_gop_write().
*/
void
lfs_segunlock_relock(struct lfs *fs)
{
int n = fs->lfs_seglock;
u_int16_t seg_flags;
CLEANERINFO *cip;
struct buf *bp;
if (n == 0)
return;
/* Write anything we've already gathered to disk */
lfs_writeseg(fs, fs->lfs_sp);
/* Tell cleaner */
LFS_CLEANERINFO(cip, fs, bp);
lfs_ci_setflags(fs, cip,
lfs_ci_getflags(fs, cip) | LFS_CLEANER_MUST_CLEAN);
LFS_SYNC_CLEANERINFO(cip, fs, bp, 1);
/* Save segment flags for later */
seg_flags = fs->lfs_sp->seg_flags;
fs->lfs_sp->seg_flags |= SEGM_PROT; /* Don't unmark dirop nodes */
while(fs->lfs_seglock)
lfs_segunlock(fs);
/* Wait for the cleaner */
lfs_wakeup_cleaner(fs);
mutex_enter(&lfs_lock);
while (LFS_STARVED_FOR_SEGS(fs))
mtsleep(&fs->lfs_availsleep, PRIBIO, "relock", 0,
&lfs_lock);
mutex_exit(&lfs_lock);
/* Put the segment lock back the way it was. */
while(n--)
lfs_seglock(fs, seg_flags);
/* Cleaner can relax now */
LFS_CLEANERINFO(cip, fs, bp);
lfs_ci_setflags(fs, cip,
lfs_ci_getflags(fs, cip) & ~LFS_CLEANER_MUST_CLEAN);
LFS_SYNC_CLEANERINFO(cip, fs, bp, 1);
return;
}
/*
* Wake up the cleaner, provided that nowrap is not set.
*/
void
lfs_wakeup_cleaner(struct lfs *fs)
{
if (fs->lfs_nowrap > 0)
return;
cv_broadcast(&fs->lfs_nextsegsleep);
cv_broadcast(&lfs_allclean_wakeup);
}