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[netbsd-mini2440.git] / libexec / lfs_cleanerd / lfs_cleanerd.c

/* $NetBSD: lfs_cleanerd.c,v 1.21 2009/08/06 00:51:55 pooka Exp $        */

/*-
 * Copyright (c) 2005 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.
 */

/*
 * The cleaner daemon for the NetBSD Log-structured File System.
 * Only tested for use with version 2 LFSs.
 */

#include <sys/syslog.h>
#include <sys/param.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <ufs/ufs/inode.h>
#include <ufs/lfs/lfs.h>

#include <assert.h>
#include <err.h>
#include <errno.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>
#include <time.h>
#include <util.h>

#include "bufcache.h"
#include "vnode.h"
#include "lfs_user.h"
#include "fdfs.h"
#include "cleaner.h"
#include "kernelops.h"
#include "mount_lfs.h"

/*
 * Global variables.
 */
/* XXX these top few should really be fs-specific */
int use_fs_idle;        /* Use fs idle rather than cpu idle time */
int use_bytes;          /* Use bytes written rather than segments cleaned */
int load_threshold;     /* How idle is idle (CPU idle) */
int atatime;            /* How many segments (bytes) to clean at a time */

int nfss;               /* Number of filesystems monitored by this cleanerd */
struct clfs **fsp;      /* Array of extended filesystem structures */
int segwait_timeout;    /* Time to wait in lfs_segwait() */
int do_quit;            /* Quit after one cleaning loop */
int do_coalesce;        /* Coalesce filesystem */
int do_small;           /* Use small writes through markv */
char *copylog_filename; /* File to use for fs debugging analysis */
int inval_segment;      /* Segment to invalidate */
int stat_report;        /* Report statistics for this period of cycles */
int debug;              /* Turn on debugging */
struct cleaner_stats {
        double  util_tot;
        double  util_sos;
        off_t   bytes_read;
        off_t   bytes_written;
        off_t   segs_cleaned;
        off_t   segs_empty;
        off_t   segs_error;
} cleaner_stats;

extern u_int32_t cksum(void *, size_t);
extern u_int32_t lfs_sb_cksum(struct dlfs *);
extern u_int32_t lfs_cksum_part(void *, size_t, u_int32_t);
extern int ufs_getlbns(struct lfs *, struct uvnode *, daddr_t, struct indir *, int *);

/* Compat */
void pwarn(const char *unused, ...) { /* Does nothing */ };

/*
 * Log a message if debugging is turned on.
 */
void
dlog(const char *fmt, ...)
{
        va_list ap;

        if (debug == 0)
                return;

        va_start(ap, fmt);
        vsyslog(LOG_DEBUG, fmt, ap);
        va_end(ap);
}

/*
 * Remove the specified filesystem from the list, due to its having
 * become unmounted or other error condition.
 */
void
handle_error(struct clfs **cfsp, int n)
{
        syslog(LOG_NOTICE, "%s: detaching cleaner", cfsp[n]->lfs_fsmnt);
        free(cfsp[n]);
        if (n != nfss - 1)
                cfsp[n] = cfsp[nfss - 1];
        --nfss;
}

/*
 * Reinitialize a filesystem if, e.g., its size changed.
 */
int
reinit_fs(struct clfs *fs)
{
        char fsname[MNAMELEN];

        strncpy(fsname, (char *)fs->lfs_fsmnt, MNAMELEN);
        kops.ko_close(fs->clfs_ifilefd);
        kops.ko_close(fs->clfs_devfd);
        fd_reclaim(fs->clfs_devvp);
        fd_reclaim(fs->lfs_ivnode);
        free(fs->clfs_dev);
        free(fs->clfs_segtab);
        free(fs->clfs_segtabp);

        return init_fs(fs, fsname);
}

#ifdef REPAIR_ZERO_FINFO
/*
 * Use fsck's lfs routines to load the Ifile from an unmounted fs.
 * We interpret "fsname" as the name of the raw disk device.
 */
int
init_unmounted_fs(struct clfs *fs, char *fsname)
{
        struct lfs *disc_fs;
        int i;
        
        fs->clfs_dev = fsname;
        if ((fs->clfs_devfd = kops.ko_open(fs->clfs_dev, O_RDWR)) < 0) {
                syslog(LOG_ERR, "couldn't open device %s read/write",
                       fs->clfs_dev);
                return -1;
        }

        disc_fs = lfs_init(fs->clfs_devfd, 0, 0, 0, 0);

        fs->lfs_dlfs = disc_fs->lfs_dlfs; /* Structure copy */
        strncpy(fs->lfs_fsmnt, fsname, MNAMELEN);
        fs->lfs_ivnode = (struct uvnode *)disc_fs->lfs_ivnode;
        fs->clfs_devvp = fd_vget(fs->clfs_devfd, fs->lfs_fsize, fs->lfs_ssize,
                                 atatime);

        /* Allocate and clear segtab */
        fs->clfs_segtab = (struct clfs_seguse *)malloc(fs->lfs_nseg *
                                                sizeof(*fs->clfs_segtab));
        fs->clfs_segtabp = (struct clfs_seguse **)malloc(fs->lfs_nseg *
                                                sizeof(*fs->clfs_segtabp));
        for (i = 0; i < fs->lfs_nseg; i++) {
                fs->clfs_segtabp[i] = &(fs->clfs_segtab[i]);
                fs->clfs_segtab[i].flags = 0x0;
        }
        syslog(LOG_NOTICE, "%s: unmounted cleaner starting", fsname);

        return 0;
}
#endif

/*
 * Set up the file descriptors, including the Ifile descriptor.
 * If we can't get the Ifile, this is not an LFS (or the kernel is
 * too old to support the fcntl).
 * XXX Merge this and init_unmounted_fs, switching on whether
 * XXX "fsname" is a dir or a char special device.  Should
 * XXX also be able to read unmounted devices out of fstab, the way
 * XXX fsck does.
 */
int
init_fs(struct clfs *fs, char *fsname)
{
        struct statvfs sf;
        int rootfd;
        int i;

        /*
         * Get the raw device from the block device.
         * XXX this is ugly.  Is there a way to discover the raw device
         * XXX for a given mount point?
         */
        if (kops.ko_statvfs(fsname, &sf, ST_WAIT) < 0)
                return -1;
        fs->clfs_dev = malloc(strlen(sf.f_mntfromname) + 2);
        if (fs->clfs_dev == NULL) {
                syslog(LOG_ERR, "couldn't malloc device name string: %m");
                return -1;
        }
        sprintf(fs->clfs_dev, "/dev/r%s", sf.f_mntfromname + 5);
        if ((fs->clfs_devfd = kops.ko_open(fs->clfs_dev, O_RDONLY, 0)) < 0) {
                syslog(LOG_ERR, "couldn't open device %s for reading",
                        fs->clfs_dev);
                return -1;
        }

        /* Find the Ifile and open it */
        if ((rootfd = kops.ko_open(fsname, O_RDONLY, 0)) < 0)
                return -2;
        if (kops.ko_fcntl(rootfd, LFCNIFILEFH, &fs->clfs_ifilefh) < 0)
                return -3;
        if ((fs->clfs_ifilefd = kops.ko_fhopen(&fs->clfs_ifilefh,
            sizeof(fs->clfs_ifilefh), O_RDONLY)) < 0)
                return -4;
        kops.ko_close(rootfd);

        /* Load in the superblock */
        if (kops.ko_pread(fs->clfs_devfd, &(fs->lfs_dlfs), sizeof(struct dlfs),
                  LFS_LABELPAD) < 0)
                return -1;

        /* If this is not a version 2 filesystem, complain and exit */
        if (fs->lfs_version != 2) {
                syslog(LOG_ERR, "%s: not a version 2 LFS", fsname);
                return -1;
        }

        /* Assume fsname is the mounted name */
        strncpy((char *)fs->lfs_fsmnt, fsname, MNAMELEN);

        /* Set up vnodes for Ifile and raw device */
        fs->lfs_ivnode = fd_vget(fs->clfs_ifilefd, fs->lfs_bsize, 0, 0);
        fs->clfs_devvp = fd_vget(fs->clfs_devfd, fs->lfs_fsize, fs->lfs_ssize,
                                 atatime);

        /* Allocate and clear segtab */
        fs->clfs_segtab = (struct clfs_seguse *)malloc(fs->lfs_nseg *
                                                sizeof(*fs->clfs_segtab));
        fs->clfs_segtabp = (struct clfs_seguse **)malloc(fs->lfs_nseg *
                                                sizeof(*fs->clfs_segtabp));
        if (fs->clfs_segtab == NULL || fs->clfs_segtabp == NULL) {
                syslog(LOG_ERR, "%s: couldn't malloc segment table: %m",
                        fs->clfs_dev);
                return -1;
        }

        for (i = 0; i < fs->lfs_nseg; i++) {
                fs->clfs_segtabp[i] = &(fs->clfs_segtab[i]);
                fs->clfs_segtab[i].flags = 0x0;
        }

        syslog(LOG_NOTICE, "%s: attaching cleaner", fsname);
        return 0;
}

/*
 * Invalidate all the currently held Ifile blocks so they will be
 * reread when we clean.  Check the size while we're at it, and
 * resize the buffer cache if necessary.
 */
void
reload_ifile(struct clfs *fs)
{
        struct ubuf *bp;
        struct stat st;
        int ohashmax;
        extern int hashmax;

        while ((bp = LIST_FIRST(&fs->lfs_ivnode->v_dirtyblkhd)) != NULL) {
                bremfree(bp);
                buf_destroy(bp);
        }
        while ((bp = LIST_FIRST(&fs->lfs_ivnode->v_cleanblkhd)) != NULL) {
                bremfree(bp);
                buf_destroy(bp);
        }

        /* If Ifile is larger than buffer cache, rehash */
        fstat(fs->clfs_ifilefd, &st);
        if (st.st_size / fs->lfs_bsize > hashmax) {
                ohashmax = hashmax;
                bufrehash(st.st_size / fs->lfs_bsize);
                dlog("%s: resized buffer hash from %d to %d",
                     fs->lfs_fsmnt, ohashmax, hashmax);
        }
}

/*
 * Get IFILE entry for the given inode, store in ifpp.  The buffer
 * which contains that data is returned in bpp, and must be brelse()d
 * by the caller.
 */
void
lfs_ientry(IFILE **ifpp, struct clfs *fs, ino_t ino, struct ubuf **bpp)
{
        int error;

        error = bread(fs->lfs_ivnode, ino / fs->lfs_ifpb + fs->lfs_cleansz +
                      fs->lfs_segtabsz, fs->lfs_bsize, NOCRED, 0, bpp);
        if (error)
                syslog(LOG_ERR, "%s: ientry failed for ino %d",
                        fs->lfs_fsmnt, (int)ino);
        *ifpp = (IFILE *)(*bpp)->b_data + ino % fs->lfs_ifpb;
        return;
}

#ifdef TEST_PATTERN
/*
 * Check ROOTINO for file data.  The assumption is that we are running
 * the "twofiles" test with the rest of the filesystem empty.  Files
 * created by "twofiles" match the test pattern, but ROOTINO and the
 * executable itself (assumed to be inode 3) should not match.
 */
static void
check_test_pattern(BLOCK_INFO *bip)
{
        int j;
        unsigned char *cp = bip->bi_bp;

        /* Check inode sanity */
        if (bip->bi_lbn == LFS_UNUSED_LBN) {
                assert(((struct ufs1_dinode *)bip->bi_bp)->di_inumber ==
                        bip->bi_inode);
        }

        /* These can have the test pattern and it's all good */
        if (bip->bi_inode > 3)
                return;

        for (j = 0; j < bip->bi_size; j++) {
                if (cp[j] != (j & 0xff))
                        break;
        }
        assert(j < bip->bi_size);
}
#endif /* TEST_PATTERN */

/*
 * Parse the partial segment at daddr, adding its information to
 * bip.  Return the address of the next partial segment to read.
 */
int32_t
parse_pseg(struct clfs *fs, daddr_t daddr, BLOCK_INFO **bipp, int *bic)
{
        SEGSUM *ssp;
        IFILE *ifp;
        BLOCK_INFO *bip, *nbip;
        int32_t *iaddrp, idaddr, odaddr;
        FINFO *fip;
        struct ubuf *ifbp;
        struct ufs1_dinode *dip;
        u_int32_t ck, vers;
        int fic, inoc, obic;
        int i;
        char *cp;

        odaddr = daddr;
        obic = *bic;
        bip = *bipp;

        /*
         * Retrieve the segment header, set up the SEGSUM pointer
         * as well as the first FINFO and inode address pointer.
         */
        cp = fd_ptrget(fs->clfs_devvp, daddr);
        ssp = (SEGSUM *)cp;
        iaddrp = ((int32_t *)(cp + fs->lfs_ibsize)) - 1;
        fip = (FINFO *)(cp + sizeof(SEGSUM));

        /*
         * Check segment header magic and checksum
         */
        if (ssp->ss_magic != SS_MAGIC) {
                syslog(LOG_WARNING, "%s: sumsum magic number bad at 0x%x:"
                       " read 0x%x, expected 0x%x", fs->lfs_fsmnt,
                       (int32_t)daddr, ssp->ss_magic, SS_MAGIC);
                return 0x0;
        }
        ck = cksum(&ssp->ss_datasum, fs->lfs_sumsize - sizeof(ssp->ss_sumsum));
        if (ck != ssp->ss_sumsum) {
                syslog(LOG_WARNING, "%s: sumsum checksum mismatch at 0x%x:"
                       " read 0x%x, computed 0x%x", fs->lfs_fsmnt,
                       (int32_t)daddr, ssp->ss_sumsum, ck);
                return 0x0;
        }

        /* Initialize data sum */
        ck = 0;

        /* Point daddr at next block after segment summary */
        ++daddr;

        /*
         * Loop over file info and inode pointers.  We always move daddr
         * forward here because we are also computing the data checksum
         * as we go.
         */
        fic = inoc = 0;
        while (fic < ssp->ss_nfinfo || inoc < ssp->ss_ninos) {
                /*
                 * We must have either a file block or an inode block.
                 * If we don't have either one, it's an error.
                 */
                if (fic >= ssp->ss_nfinfo && *iaddrp != daddr) {
                        syslog(LOG_WARNING, "%s: bad pseg at %x (seg %d)",
                               fs->lfs_fsmnt, odaddr, dtosn(fs, odaddr));
                        *bipp = bip;
                        return 0x0;
                }

                /*
                 * Note each inode from the inode blocks
                 */
                if (inoc < ssp->ss_ninos && *iaddrp == daddr) {
                        cp = fd_ptrget(fs->clfs_devvp, daddr);
                        ck = lfs_cksum_part(cp, sizeof(u_int32_t), ck);
                        dip = (struct ufs1_dinode *)cp;
                        for (i = 0; i < fs->lfs_inopb; i++) {
                                if (dip[i].di_inumber == 0)
                                        break;

                                /*
                                 * Check currency before adding it
                                 */
#ifndef REPAIR_ZERO_FINFO
                                lfs_ientry(&ifp, fs, dip[i].di_inumber, &ifbp);
                                idaddr = ifp->if_daddr;
                                brelse(ifbp, 0);
                                if (idaddr != daddr)
#endif
                                        continue;

                                /*
                                 * A current inode.  Add it.
                                 */
                                ++*bic;
                                nbip = (BLOCK_INFO *)realloc(bip, *bic *
                                                             sizeof(*bip));
                                if (nbip)
                                        bip = nbip;
                                else {
                                        --*bic;
                                        *bipp = bip;
                                        return 0x0;
                                }
                                bip[*bic - 1].bi_inode = dip[i].di_inumber;
                                bip[*bic - 1].bi_lbn = LFS_UNUSED_LBN;
                                bip[*bic - 1].bi_daddr = daddr;
                                bip[*bic - 1].bi_segcreate = ssp->ss_create;
                                bip[*bic - 1].bi_version = dip[i].di_gen;
                                bip[*bic - 1].bi_bp = &(dip[i]);
                                bip[*bic - 1].bi_size = DINODE1_SIZE;
                        }
                        inoc += i;
                        daddr += btofsb(fs, fs->lfs_ibsize);
                        --iaddrp;
                        continue;
                }

                /*
                 * Note each file block from the finfo blocks
                 */
                if (fic >= ssp->ss_nfinfo)
                        continue;

                /* Count this finfo, whether or not we use it */
                ++fic;

                /*
                 * If this finfo has nblocks==0, it was written wrong.
                 * Kernels with this problem always wrote this zero-sized
                 * finfo last, so just ignore it.
                 */
                if (fip->fi_nblocks == 0) {
#ifdef REPAIR_ZERO_FINFO
                        struct ubuf *nbp;
                        SEGSUM *nssp;

                        syslog(LOG_WARNING, "fixing short FINFO at %x (seg %d)",
                               odaddr, dtosn(fs, odaddr));
                        bread(fs->clfs_devvp, odaddr, fs->lfs_fsize,
                            NOCRED, 0, &nbp);
                        nssp = (SEGSUM *)nbp->b_data;
                        --nssp->ss_nfinfo;
                        nssp->ss_sumsum = cksum(&nssp->ss_datasum,
                                fs->lfs_sumsize - sizeof(nssp->ss_sumsum));
                        bwrite(nbp);
#endif
                        syslog(LOG_WARNING, "zero-length FINFO at %x (seg %d)",
                               odaddr, dtosn(fs, odaddr));
                        continue;
                }

                /*
                 * Check currency before adding blocks
                 */
#ifdef REPAIR_ZERO_FINFO
                vers = -1;
#else
                lfs_ientry(&ifp, fs, fip->fi_ino, &ifbp);
                vers = ifp->if_version;
                brelse(ifbp, 0);
#endif
                if (vers != fip->fi_version) {
                        size_t size;

                        /* Read all the blocks from the data summary */
                        for (i = 0; i < fip->fi_nblocks; i++) {
                                size = (i == fip->fi_nblocks - 1) ?
                                        fip->fi_lastlength : fs->lfs_bsize;
                                cp = fd_ptrget(fs->clfs_devvp, daddr);
                                ck = lfs_cksum_part(cp, sizeof(u_int32_t), ck);
                                daddr += btofsb(fs, size);
                        }
                        fip = (FINFO *)(fip->fi_blocks + fip->fi_nblocks);
                        continue;
                }

                /* Add all the blocks from the finfos (current or not) */
                nbip = (BLOCK_INFO *)realloc(bip, (*bic + fip->fi_nblocks) *
                                             sizeof(*bip));
                if (nbip)
                        bip = nbip;
                else {
                        *bipp = bip;
                        return 0x0;
                }

                for (i = 0; i < fip->fi_nblocks; i++) {
                        bip[*bic + i].bi_inode = fip->fi_ino;
                        bip[*bic + i].bi_lbn = fip->fi_blocks[i];
                        bip[*bic + i].bi_daddr = daddr;
                        bip[*bic + i].bi_segcreate = ssp->ss_create;
                        bip[*bic + i].bi_version = fip->fi_version;
                        bip[*bic + i].bi_size = (i == fip->fi_nblocks - 1) ?
                                fip->fi_lastlength : fs->lfs_bsize;
                        cp = fd_ptrget(fs->clfs_devvp, daddr);
                        ck = lfs_cksum_part(cp, sizeof(u_int32_t), ck);
                        bip[*bic + i].bi_bp = cp;
                        daddr += btofsb(fs, bip[*bic + i].bi_size);

#ifdef TEST_PATTERN
                        check_test_pattern(bip + *bic + i); /* XXXDEBUG */
#endif
                }
                *bic += fip->fi_nblocks;
                fip = (FINFO *)(fip->fi_blocks + fip->fi_nblocks);
        }

#ifndef REPAIR_ZERO_FINFO
        if (ssp->ss_datasum != ck) {
                syslog(LOG_WARNING, "%s: data checksum bad at 0x%x:"
                       " read 0x%x, computed 0x%x", fs->lfs_fsmnt, odaddr,
                       ssp->ss_datasum, ck);
                *bic = obic;
                return 0x0;
        }
#endif

        *bipp = bip;
        return daddr;
}

static void
log_segment_read(struct clfs *fs, int sn)
{
        FILE *fp;
        char *cp;
        
        /*
         * Write the segment read, and its contents, into a log file in
         * the current directory.  We don't need to log the location of
         * the segment, since that can be inferred from the segments up
         * to this point (ss_nextseg field of the previously written segment).
         *
         * We can use this info later to reconstruct the filesystem at any
         * given point in time for analysis, by replaying the log forward
         * indexed by the segment serial numbers; but it is not suitable
         * for everyday use since the copylog will be simply enormous.
         */
        cp = fd_ptrget(fs->clfs_devvp, sntod(fs, sn));

        fp = fopen(copylog_filename, "ab");
        if (fp != NULL) {
                if (fwrite(cp, (size_t)fs->lfs_ssize, 1, fp) != 1) {
                        perror("writing segment to copy log");
                }
        }
        fclose(fp);
}

/*
 * Read a segment to populate the BLOCK_INFO structures.
 * Return the number of partial segments read and parsed.
 */
int
load_segment(struct clfs *fs, int sn, BLOCK_INFO **bipp, int *bic)
{
        int32_t daddr;
        int i, npseg;

        daddr = sntod(fs, sn);
        if (daddr < btofsb(fs, LFS_LABELPAD))
                daddr = btofsb(fs, LFS_LABELPAD);
        for (i = 0; i < LFS_MAXNUMSB; i++) {
                if (fs->lfs_sboffs[i] == daddr) {
                        daddr += btofsb(fs, LFS_SBPAD);
                        break;
                }
        }

        /* Preload the segment buffer */
        if (fd_preload(fs->clfs_devvp, sntod(fs, sn)) < 0)
                return -1;

        if (copylog_filename)
                log_segment_read(fs, sn);

        /* Note bytes read for stats */
        cleaner_stats.segs_cleaned++;
        cleaner_stats.bytes_read += fs->lfs_ssize;
        ++fs->clfs_nactive;

        npseg = 0;
        while(dtosn(fs, daddr) == sn &&
              dtosn(fs, daddr + btofsb(fs, fs->lfs_bsize)) == sn) {
                daddr = parse_pseg(fs, daddr, bipp, bic);
                if (daddr == 0x0) {
                        ++cleaner_stats.segs_error;
                        break;
                }
                ++npseg;
        }

        return npseg;
}

void
calc_cb(struct clfs *fs, int sn, struct clfs_seguse *t)
{
        time_t now;
        int64_t age, benefit, cost;

        time(&now);
        age = (now < t->lastmod ? 0 : now - t->lastmod);

        /* Under no circumstances clean active or already-clean segments */
        if ((t->flags & SEGUSE_ACTIVE) || !(t->flags & SEGUSE_DIRTY)) {
                t->priority = 0;
                return;
        }

        /*
         * If the segment is empty, there is no reason to clean it.
         * Clear its error condition, if any, since we are never going to
         * try to parse this one.
         */
        if (t->nbytes == 0) {
                t->flags &= ~SEGUSE_ERROR; /* Strip error once empty */
                t->priority = 0;
                return;
        }

        if (t->flags & SEGUSE_ERROR) {  /* No good if not already empty */
                /* No benefit */
                t->priority = 0;
                return;
        }

        if (t->nbytes > fs->lfs_ssize) {
                /* Another type of error */
                syslog(LOG_WARNING, "segment %d: bad seguse count %d",
                       sn, t->nbytes);
                t->flags |= SEGUSE_ERROR;
                t->priority = 0;
                return;
        }

        /*
         * The non-degenerate case.  Use Rosenblum's cost-benefit algorithm.
         * Calculate the benefit from cleaning this segment (one segment,
         * minus fragmentation, dirty blocks and a segment summary block)
         * and weigh that against the cost (bytes read plus bytes written).
         * We count the summary headers as "dirty" to avoid cleaning very
         * old and very full segments.
         */
        benefit = (int64_t)fs->lfs_ssize - t->nbytes -
                  (t->nsums + 1) * fs->lfs_fsize;
        if (fs->lfs_bsize > fs->lfs_fsize) /* fragmentation */
                benefit -= (fs->lfs_bsize / 2);
        if (benefit <= 0) {
                t->priority = 0;
                return;
        }

        cost = fs->lfs_ssize + t->nbytes;
        t->priority = (256 * benefit * age) / cost;

        return;
}

/*
 * Comparator for BLOCK_INFO structures.  Anything not in one of the segments
 * we're looking at sorts higher; after that we sort first by inode number
 * and then by block number (unsigned, i.e., negative sorts higher) *but*
 * sort inodes before data blocks.
 */
static int
bi_comparator(const void *va, const void *vb)
{
        const BLOCK_INFO *a, *b;

        a = (const BLOCK_INFO *)va;
        b = (const BLOCK_INFO *)vb;

        /* Check for out-of-place block */
        if (a->bi_segcreate == a->bi_daddr &&
            b->bi_segcreate != b->bi_daddr)
                return -1;
        if (a->bi_segcreate != a->bi_daddr &&
            b->bi_segcreate == b->bi_daddr)
                return 1;
        if (a->bi_size <= 0 && b->bi_size > 0)
                return 1;
        if (b->bi_size <= 0 && a->bi_size > 0)
                return -1;

        /* Check inode number */
        if (a->bi_inode != b->bi_inode)
                return a->bi_inode - b->bi_inode;

        /* Check lbn */
        if (a->bi_lbn == LFS_UNUSED_LBN) /* Inodes sort lower than blocks */
                return -1;
        if (b->bi_lbn == LFS_UNUSED_LBN)
                return 1;
        if ((u_int32_t)a->bi_lbn > (u_int32_t)b->bi_lbn)
                return 1;
        else
                return -1;

        return 0;
}

/*
 * Comparator for sort_segments: cost-benefit equation.
 */
static int
cb_comparator(const void *va, const void *vb)
{
        const struct clfs_seguse *a, *b;

        a = *(const struct clfs_seguse * const *)va;
        b = *(const struct clfs_seguse * const *)vb;
        return a->priority > b->priority ? -1 : 1;
}

void
toss_old_blocks(struct clfs *fs, BLOCK_INFO **bipp, int *bic, int *sizep)
{
        int i, r;
        BLOCK_INFO *bip = *bipp;
        struct lfs_fcntl_markv /* {
                BLOCK_INFO *blkiov;
                int blkcnt;
        } */ lim;

        if (bic == 0 || bip == NULL)
                return;

        /*
         * Kludge: Store the disk address in segcreate so we know which
         * ones to toss.
         */
        for (i = 0; i < *bic; i++)
                bip[i].bi_segcreate = bip[i].bi_daddr;

        /* Sort the blocks */
        heapsort(bip, *bic, sizeof(BLOCK_INFO), bi_comparator);

        /* Use bmapv to locate the blocks */
        lim.blkiov = bip;
        lim.blkcnt = *bic;
        if ((r = kops.ko_fcntl(fs->clfs_ifilefd, LFCNBMAPV, &lim)) < 0) {
                syslog(LOG_WARNING, "%s: bmapv returned %d (%m)",
                       fs->lfs_fsmnt, r);
                return;
        }

        /* Toss blocks not in this segment */
        heapsort(bip, *bic, sizeof(BLOCK_INFO), bi_comparator);

        /* Get rid of stale blocks */
        if (sizep)
                *sizep = 0;
        for (i = 0; i < *bic; i++) {
                if (bip[i].bi_segcreate != bip[i].bi_daddr)
                        break;
                if (sizep)
                        *sizep += bip[i].bi_size;
        }
        *bic = i; /* XXX realloc bip? */
        *bipp = bip;

        return;
}

/*
 * Clean a segment and mark it invalid.
 */
int
invalidate_segment(struct clfs *fs, int sn)
{
        BLOCK_INFO *bip;
        int i, r, bic;
        off_t nb;
        double util;
        struct lfs_fcntl_markv /* {
                BLOCK_INFO *blkiov;
                int blkcnt;
        } */ lim;

        dlog("%s: inval seg %d", fs->lfs_fsmnt, sn);

        bip = NULL;
        bic = 0;
        fs->clfs_nactive = 0;
        if (load_segment(fs, sn, &bip, &bic) <= 0)
                return -1;
        toss_old_blocks(fs, &bip, &bic, NULL);

        /* Record statistics */
        for (i = nb = 0; i < bic; i++)
                nb += bip[i].bi_size;
        util = ((double)nb) / (fs->clfs_nactive * fs->lfs_ssize);
        cleaner_stats.util_tot += util;
        cleaner_stats.util_sos += util * util;
        cleaner_stats.bytes_written += nb;

        /*
         * Use markv to move the blocks.
         */
        lim.blkiov = bip;
        lim.blkcnt = bic;
        if ((r = kops.ko_fcntl(fs->clfs_ifilefd, LFCNMARKV, &lim)) < 0) {
                syslog(LOG_WARNING, "%s: markv returned %d (%m) "
                       "for seg %d", fs->lfs_fsmnt, r, sn);
                return r;
        }

        /*
         * Finally call invalidate to invalidate the segment.
         */
        if ((r = kops.ko_fcntl(fs->clfs_ifilefd, LFCNINVAL, &sn)) < 0) {
                syslog(LOG_WARNING, "%s: inval returned %d (%m) "
                       "for seg %d", fs->lfs_fsmnt, r, sn);
                return r;
        }

        return 0;
}

/*
 * Check to see if the given ino/lbn pair is represented in the BLOCK_INFO
 * array we are sending to the kernel, or if the kernel will have to add it.
 * The kernel will only add each such pair once, though, so keep track of
 * previous requests in a separate "extra" BLOCK_INFO array.  Returns 1
 * if the block needs to be added, 0 if it is already represented.
 */
static int
check_or_add(ino_t ino, int32_t lbn, BLOCK_INFO *bip, int bic, BLOCK_INFO **ebipp, int *ebicp)
{
        BLOCK_INFO *t, *ebip = *ebipp;
        int ebic = *ebicp;
        int k;

        for (k = 0; k < bic; k++) {
                if (bip[k].bi_inode != ino)
                        break;
                if (bip[k].bi_lbn == lbn) {
                        return 0;
                }
        }

        /* Look on the list of extra blocks, too */
        for (k = 0; k < ebic; k++) {
                if (ebip[k].bi_inode == ino && ebip[k].bi_lbn == lbn) {
                        return 0;
                }
        }

        ++ebic;
        t = realloc(ebip, ebic * sizeof(BLOCK_INFO));
        if (t == NULL)
                return 1; /* Note *ebipc is not updated */

        ebip = t;
        ebip[ebic - 1].bi_inode = ino;
        ebip[ebic - 1].bi_lbn = lbn;

        *ebipp = ebip;
        *ebicp = ebic;
        return 1;
}

/*
 * Look for indirect blocks we will have to write which are not
 * contained in this collection of blocks.  This constitutes
 * a hidden cleaning cost, since we are unaware of it until we
 * have already read the segments.  Return the total cost, and fill
 * in *ifc with the part of that cost due to rewriting the Ifile.
 */
static off_t
check_hidden_cost(struct clfs *fs, BLOCK_INFO *bip, int bic, off_t *ifc)
{
        int start;
        struct indir in[NIADDR + 1];
        int num;
        int i, j, ebic;
        BLOCK_INFO *ebip;
        int32_t lbn;

        start = 0;
        ebip = NULL;
        ebic = 0;
        for (i = 0; i < bic; i++) {
                if (i == 0 || bip[i].bi_inode != bip[start].bi_inode) {
                        start = i;
                        /*
                         * Look for IFILE blocks, unless this is the Ifile.
                         */
                        if (bip[i].bi_inode != fs->lfs_ifile) {
                                lbn = fs->lfs_cleansz + bip[i].bi_inode /
                                                        fs->lfs_ifpb;
                                *ifc += check_or_add(fs->lfs_ifile, lbn,
                                                     bip, bic, &ebip, &ebic);
                        }
                }
                if (bip[i].bi_lbn == LFS_UNUSED_LBN)
                        continue;
                if (bip[i].bi_lbn < NDADDR)
                        continue;

                ufs_getlbns((struct lfs *)fs, NULL, (daddr_t)bip[i].bi_lbn, in, &num);
                for (j = 0; j < num; j++) {
                        check_or_add(bip[i].bi_inode, in[j].in_lbn,
                                     bip + start, bic - start, &ebip, &ebic);
                }
        }
        return ebic;
}

/*
 * Select segments to clean, add blocks from these segments to a cleaning
 * list, and send this list through lfs_markv() to move them to new
 * locations on disk.
 */
int
clean_fs(struct clfs *fs, CLEANERINFO *cip)
{
        int i, j, ngood, sn, bic, r, npos;
        int bytes, totbytes;
        struct ubuf *bp;
        SEGUSE *sup;
        static BLOCK_INFO *bip;
        struct lfs_fcntl_markv /* {
                BLOCK_INFO *blkiov;
                int blkcnt;
        } */ lim;
        int mc;
        BLOCK_INFO *mbip;
        int inc;
        off_t nb;
        off_t goal;
        off_t extra, if_extra;
        double util;

        /* Read the segment table into our private structure */
        npos = 0;
        for (i = 0; i < fs->lfs_nseg; i+= fs->lfs_sepb) {
                bread(fs->lfs_ivnode, fs->lfs_cleansz + i / fs->lfs_sepb,
                      fs->lfs_bsize, NOCRED, 0, &bp);
                for (j = 0; j < fs->lfs_sepb && i + j < fs->lfs_nseg; j++) {
                        sup = ((SEGUSE *)bp->b_data) + j;
                        fs->clfs_segtab[i + j].nbytes  = sup->su_nbytes;
                        fs->clfs_segtab[i + j].nsums = sup->su_nsums;
                        fs->clfs_segtab[i + j].lastmod = sup->su_lastmod;
                        /* Keep error status but renew other flags */
                        fs->clfs_segtab[i + j].flags  &= SEGUSE_ERROR;
                        fs->clfs_segtab[i + j].flags  |= sup->su_flags;

                        /* Compute cost-benefit coefficient */
                        calc_cb(fs, i + j, fs->clfs_segtab + i + j);
                        if (fs->clfs_segtab[i + j].priority > 0)
                                ++npos;
                }
                brelse(bp, 0);
        }

        /* Sort segments based on cleanliness, fulness, and condition */
        heapsort(fs->clfs_segtabp, fs->lfs_nseg, sizeof(struct clfs_seguse *),
                 cb_comparator);

        /* If no segment is cleanable, just return */
        if (fs->clfs_segtabp[0]->priority == 0) {
                dlog("%s: no segment cleanable", fs->lfs_fsmnt);
                return 0;
        }

        /* Load some segments' blocks into bip */
        bic = 0;
        fs->clfs_nactive = 0;
        ngood = 0;
        if (use_bytes) {
                /* Set attainable goal */
                goal = fs->lfs_ssize * atatime;
                if (goal > (cip->clean - 1) * fs->lfs_ssize / 2)
                        goal = MAX((cip->clean - 1) * fs->lfs_ssize,
                                   fs->lfs_ssize) / 2;

                dlog("%s: cleaning with goal %" PRId64
                     " bytes (%d segs clean, %d cleanable)",
                     fs->lfs_fsmnt, goal, cip->clean, npos);
                syslog(LOG_INFO, "%s: cleaning with goal %" PRId64
                       " bytes (%d segs clean, %d cleanable)",
                       fs->lfs_fsmnt, goal, cip->clean, npos);
                totbytes = 0;
                for (i = 0; i < fs->lfs_nseg && totbytes < goal; i++) {
                        if (fs->clfs_segtabp[i]->priority == 0)
                                break;
                        /* Upper bound on number of segments at once */
                        if (ngood * fs->lfs_ssize > 4 * goal)
                                break;
                        sn = (fs->clfs_segtabp[i] - fs->clfs_segtab);
                        dlog("%s: add seg %d prio %" PRIu64
                             " containing %ld bytes",
                             fs->lfs_fsmnt, sn, fs->clfs_segtabp[i]->priority,
                             fs->clfs_segtabp[i]->nbytes);
                        if ((r = load_segment(fs, sn, &bip, &bic)) > 0) {
                                ++ngood;
                                toss_old_blocks(fs, &bip, &bic, &bytes);
                                totbytes += bytes;
                        } else if (r == 0)
                                fd_release(fs->clfs_devvp);
                        else
                                break;
                }
        } else {
                /* Set attainable goal */
                goal = atatime;
                if (goal > cip->clean - 1)
                        goal = MAX(cip->clean - 1, 1);

                dlog("%s: cleaning with goal %d segments (%d clean, %d cleanable)",
                       fs->lfs_fsmnt, (int)goal, cip->clean, npos);
                for (i = 0; i < fs->lfs_nseg && ngood < goal; i++) {
                        if (fs->clfs_segtabp[i]->priority == 0)
                                break;
                        sn = (fs->clfs_segtabp[i] - fs->clfs_segtab);
                        dlog("%s: add seg %d prio %" PRIu64,
                             fs->lfs_fsmnt, sn, fs->clfs_segtabp[i]->priority);
                        if ((r = load_segment(fs, sn, &bip, &bic)) > 0)
                                ++ngood;
                        else if (r == 0)
                                fd_release(fs->clfs_devvp);
                        else
                                break;
                }
                toss_old_blocks(fs, &bip, &bic, NULL);
        }

        /* If there is nothing to do, try again later. */
        if (bic == 0) {
                dlog("%s: no blocks to clean in %d cleanable segments",
                       fs->lfs_fsmnt, (int)ngood);
                fd_release_all(fs->clfs_devvp);
                return 0;
        }

        /* Record statistics */
        for (i = nb = 0; i < bic; i++)
                nb += bip[i].bi_size;
        util = ((double)nb) / (fs->clfs_nactive * fs->lfs_ssize);
        cleaner_stats.util_tot += util;
        cleaner_stats.util_sos += util * util;
        cleaner_stats.bytes_written += nb;

        /*
         * Check out our blocks to see if there are hidden cleaning costs.
         * If there are, we might be cleaning ourselves deeper into a hole
         * rather than doing anything useful.
         * XXX do something about this.
         */
        if_extra = 0;
        extra = fs->lfs_bsize * (off_t)check_hidden_cost(fs, bip, bic, &if_extra);
        if_extra *= fs->lfs_bsize;

        /*
         * Use markv to move the blocks.
         */
        if (do_small) 
                inc = MAXPHYS / fs->lfs_bsize - 1;
        else
                inc = LFS_MARKV_MAXBLKCNT / 2;
        for (mc = 0, mbip = bip; mc < bic; mc += inc, mbip += inc) {
                lim.blkiov = mbip;
                lim.blkcnt = (bic - mc > inc ? inc : bic - mc);
#ifdef TEST_PATTERN
                dlog("checking blocks %d-%d", mc, mc + lim.blkcnt - 1);
                for (i = 0; i < lim.blkcnt; i++) {
                        check_test_pattern(mbip + i);
                }
#endif /* TEST_PATTERN */
                dlog("sending blocks %d-%d", mc, mc + lim.blkcnt - 1);
                if ((r = kops.ko_fcntl(fs->clfs_ifilefd, LFCNMARKV, &lim))<0) {
                        syslog(LOG_WARNING, "%s: markv returned %d (%m)",
                               fs->lfs_fsmnt, r);
                        if (errno != EAGAIN && errno != ESHUTDOWN) {
                                fd_release_all(fs->clfs_devvp);
                                return r;
                        }
                }
        }

        /*
         * Report progress (or lack thereof)
         */
        syslog(LOG_INFO, "%s: wrote %" PRId64 " dirty + %"
               PRId64 " supporting indirect + %"
               PRId64 " supporting Ifile = %"
               PRId64 " bytes to clean %d segs (%" PRId64 "%% recovery)",
               fs->lfs_fsmnt, (int64_t)nb, (int64_t)(extra - if_extra),
               (int64_t)if_extra, (int64_t)(nb + extra), ngood,
               (ngood ? (int64_t)(100 - (100 * (nb + extra)) /
                                         (ngood * fs->lfs_ssize)) :
                (int64_t)0));
        if (nb + extra >= ngood * fs->lfs_ssize)
                syslog(LOG_WARNING, "%s: cleaner not making forward progress",
                       fs->lfs_fsmnt);

        /*
         * Finally call reclaim to prompt cleaning of the segments.
         */
        kops.ko_fcntl(fs->clfs_ifilefd, LFCNRECLAIM, NULL);

        fd_release_all(fs->clfs_devvp);
        return 0;
}

/*
 * Read the cleanerinfo block and apply cleaning policy to determine whether
 * the given filesystem needs to be cleaned.  Returns 1 if it does, 0 if it
 * does not, or -1 on error.
 */
int
needs_cleaning(struct clfs *fs, CLEANERINFO *cip)
{
        struct ubuf *bp;
        struct stat st;
        daddr_t fsb_per_seg, max_free_segs;
        time_t now;
        double loadavg;

        /* If this fs is "on hold", don't clean it. */
        if (fs->clfs_onhold)
                return 0;

        /*
         * Read the cleanerinfo block from the Ifile.  We don't want
         * the cached information, so invalidate the buffer before
         * handing it back.
         */
        if (bread(fs->lfs_ivnode, 0, fs->lfs_bsize, NOCRED, 0, &bp)) {
                syslog(LOG_ERR, "%s: can't read inode", fs->lfs_fsmnt);
                return -1;
        }
        *cip = *(CLEANERINFO *)bp->b_data; /* Structure copy */
        brelse(bp, B_INVAL);
        cleaner_stats.bytes_read += fs->lfs_bsize;

        /*
         * If the number of segments changed under us, reinit.
         * We don't have to start over from scratch, however,
         * since we don't hold any buffers.
         */
        if (fs->lfs_nseg != cip->clean + cip->dirty) {
                if (reinit_fs(fs) < 0) {
                        /* The normal case for unmount */
                        syslog(LOG_NOTICE, "%s: filesystem unmounted", fs->lfs_fsmnt);
                        return -1;
                }
                syslog(LOG_NOTICE, "%s: nsegs changed", fs->lfs_fsmnt);
        }

        /* Compute theoretical "free segments" maximum based on usage */
        fsb_per_seg = segtod(fs, 1);
        max_free_segs = MAX(cip->bfree, 0) / fsb_per_seg + fs->lfs_minfreeseg;

        dlog("%s: bfree = %d, avail = %d, clean = %d/%d",
             fs->lfs_fsmnt, cip->bfree, cip->avail, cip->clean, fs->lfs_nseg);

        /* If the writer is waiting on us, clean it */
        if (cip->clean <= fs->lfs_minfreeseg ||
            (cip->flags & LFS_CLEANER_MUST_CLEAN))
                return 1;

        /* If there are enough segments, don't clean it */
        if (cip->bfree - cip->avail <= fsb_per_seg &&
            cip->avail > fsb_per_seg)
                return 0;

        /* If we are in dire straits, clean it */
        if (cip->bfree - cip->avail > fsb_per_seg &&
            cip->avail <= fsb_per_seg)
                return 1;

        /* If under busy threshold, clean regardless of load */
        if (cip->clean < max_free_segs * BUSY_LIM)
                return 1;

        /* Check busy status; clean if idle and under idle limit */
        if (use_fs_idle) {
                /* Filesystem idle */
                time(&now);
                if (fstat(fs->clfs_ifilefd, &st) < 0) {
                        syslog(LOG_ERR, "%s: failed to stat ifile",
                               fs->lfs_fsmnt);
                        return -1;
                }
                if (now - st.st_mtime > segwait_timeout &&
                    cip->clean < max_free_segs * IDLE_LIM)
                        return 1;
        } else {
                /* CPU idle - use one-minute load avg */
                if (getloadavg(&loadavg, 1) == -1) {
                        syslog(LOG_ERR, "%s: failed to get load avg",
                               fs->lfs_fsmnt);
                        return -1;
                }
                if (loadavg < load_threshold &&
                    cip->clean < max_free_segs * IDLE_LIM)
                        return 1;
        }

        return 0;
}

/*
 * Report statistics.  If the signal was SIGUSR2, clear the statistics too.
 * If the signal was SIGINT, exit.
 */
static void
sig_report(int sig)
{
        double avg = 0.0, stddev;

        avg = cleaner_stats.util_tot / MAX(cleaner_stats.segs_cleaned, 1.0);
        stddev = cleaner_stats.util_sos / MAX(cleaner_stats.segs_cleaned -
                                              avg * avg, 1.0);
        syslog(LOG_INFO, "bytes read:        %" PRId64, cleaner_stats.bytes_read);
        syslog(LOG_INFO, "bytes written:     %" PRId64, cleaner_stats.bytes_written);
        syslog(LOG_INFO, "segments cleaned:  %" PRId64, cleaner_stats.segs_cleaned);
#if 0
        /* "Empty segments" is meaningless, since the kernel handles those */
        syslog(LOG_INFO, "empty segments:    %" PRId64, cleaner_stats.segs_empty);
#endif
        syslog(LOG_INFO, "error segments:    %" PRId64, cleaner_stats.segs_error);
        syslog(LOG_INFO, "utilization total: %g", cleaner_stats.util_tot);
        syslog(LOG_INFO, "utilization sos:   %g", cleaner_stats.util_sos);
        syslog(LOG_INFO, "utilization avg:   %4.2f", avg);
        syslog(LOG_INFO, "utilization sdev:  %9.6f", stddev);

        if (debug)
                bufstats();

        if (sig == SIGUSR2)
                memset(&cleaner_stats, 0, sizeof(cleaner_stats));
        if (sig == SIGINT)
                exit(0);
}

static void
sig_exit(int sig)
{
        exit(0);
}

static void
usage(void)
{
        errx(1, "usage: lfs_cleanerd [-bcdfmqs] [-i segnum] [-l load] "
             "[-n nsegs] [-r report_freq] [-t timeout] fs_name ...");
}

#ifndef LFS_CLEANER_AS_LIB
/*
 * Main.
 */
int
main(int argc, char **argv)
{

        return lfs_cleaner_main(argc, argv);
}
#endif

int
lfs_cleaner_main(int argc, char **argv)
{
        int i, opt, error, r, loopcount, nodetach;
        struct timeval tv;
        CLEANERINFO ci;
#ifndef USE_CLIENT_SERVER
        char *cp, *pidname;
#endif

        /*
         * Set up defaults
         */
        atatime  = 1;
        segwait_timeout = 300; /* Five minutes */
        load_threshold  = 0.2;
        stat_report     = 0;
        inval_segment   = -1;
        copylog_filename = NULL;
        nodetach        = 0;

        /*
         * Parse command-line arguments
         */
        while ((opt = getopt(argc, argv, "bC:cdDfi:l:mn:qr:st:")) != -1) {
                switch (opt) {
                    case 'b':   /* Use bytes written, not segments read */
                            use_bytes = 1;
                            break;
                    case 'C':   /* copy log */
                            copylog_filename = optarg;
                            break;
                    case 'c':   /* Coalesce files */
                            do_coalesce++;
                            break;
                    case 'd':   /* Debug mode. */
                            nodetach++;
                            debug++;
                            break;
                    case 'D':   /* stay-on-foreground */
                            nodetach++;
                            break;
                    case 'f':   /* Use fs idle time rather than cpu idle */
                            use_fs_idle = 1;
                            break;
                    case 'i':   /* Invalidate this segment */
                            inval_segment = atoi(optarg);
                            break;
                    case 'l':   /* Load below which to clean */
                            load_threshold = atof(optarg);
                            break;
                    case 'm':   /* [compat only] */
                            break;
                    case 'n':   /* How many segs to clean at once */
                            atatime = atoi(optarg);
                            break;
                    case 'q':   /* Quit after one run */
                            do_quit = 1;
                            break;
                    case 'r':   /* Report every stat_report segments */
                            stat_report = atoi(optarg);
                            break;
                    case 's':   /* Small writes */
                            do_small = 1;
                            break;
                    case 't':   /* timeout */
                            segwait_timeout = atoi(optarg);
                            break;
                    default:
                            usage();
                            /* NOTREACHED */
                }
        }
        argc -= optind;
        argv += optind;

        if (argc < 1)
                usage();
        if (inval_segment >= 0 && argc != 1) {
                errx(1, "lfs_cleanerd: may only specify one filesystem when "
                     "using -i flag");
        }

        if (do_coalesce) {
                errx(1, "lfs_cleanerd: -c disabled due to reports of file "
                     "corruption; you may re-enable it by rebuilding the "
                     "cleaner");
        }

        /*
         * Set up daemon mode or foreground mode
         */
        if (nodetach) {
                openlog("lfs_cleanerd", LOG_NDELAY | LOG_PID | LOG_PERROR,
                        LOG_DAEMON);
                signal(SIGINT, sig_report);
        } else {
                if (daemon(0, 0) == -1)
                        err(1, "lfs_cleanerd: couldn't become a daemon!");
                openlog("lfs_cleanerd", LOG_NDELAY | LOG_PID, LOG_DAEMON);
                signal(SIGINT, sig_exit);
        }

        /*
         * Look for an already-running master daemon.  If there is one,
         * send it our filesystems to add to its list and exit.
         * If there is none, become the master.
         */
#ifdef USE_CLIENT_SERVER
        try_to_become_master(argc, argv);
#else
        /* XXX think about this */
        asprintf(&pidname, "lfs_cleanerd:m:%s", argv[0]);
        if (pidname == NULL) {
                syslog(LOG_ERR, "malloc failed: %m");
                exit(1);
        }
        for (cp = pidname; cp != NULL; cp = strchr(cp, '/'))
                *cp = '|';
        pidfile(pidname);
#endif

        /*
         * Signals mean daemon should report its statistics
         */
        memset(&cleaner_stats, 0, sizeof(cleaner_stats));
        signal(SIGUSR1, sig_report);
        signal(SIGUSR2, sig_report);

        /*
         * Start up buffer cache.  We only use this for the Ifile,
         * and we will resize it if necessary, so it can start small.
         */
        bufinit(4);

#ifdef REPAIR_ZERO_FINFO
        {
                BLOCK_INFO *bip = NULL;
                int bic = 0;

                nfss = 1;
                fsp = (struct clfs **)malloc(sizeof(*fsp));
                fsp[0] = (struct clfs *)calloc(1, sizeof(**fsp));

                if (init_unmounted_fs(fsp[0], argv[0]) < 0) {
                        err(1, "init_unmounted_fs");
                }
                dlog("Filesystem has %d segments", fsp[0]->lfs_nseg);
                for (i = 0; i < fsp[0]->lfs_nseg; i++) {
                        load_segment(fsp[0], i, &bip, &bic);
                        bic = 0;
                }
                exit(0);
        }
#endif

        /*
         * Initialize cleaning structures, open devices, etc.
         */
        nfss = argc;
        fsp = (struct clfs **)malloc(nfss * sizeof(*fsp));
        if (fsp == NULL) {
                syslog(LOG_ERR, "couldn't allocate fs table: %m");
                exit(1);
        }
        for (i = 0; i < nfss; i++) {
                fsp[i] = (struct clfs *)calloc(1, sizeof(**fsp));
                if ((r = init_fs(fsp[i], argv[i])) < 0) {
                        syslog(LOG_ERR, "%s: couldn't init: error code %d",
                               argv[i], r);
                        handle_error(fsp, i);
                        --i; /* Do the new #i over again */
                }
        }

        /*
         * If asked to coalesce, do so and exit.
         */
        if (do_coalesce) {
                for (i = 0; i < nfss; i++)
                        clean_all_inodes(fsp[i]);
                exit(0);
        }

        /*
         * If asked to invalidate a segment, do that and exit.
         */
        if (inval_segment >= 0) {
                invalidate_segment(fsp[0], inval_segment);
                exit(0);
        }

        /*
         * Main cleaning loop.
         */
        loopcount = 0;
        while (nfss > 0) {
                int cleaned_one;
                do {
#ifdef USE_CLIENT_SERVER
                        check_control_socket();
#endif
                        cleaned_one = 0;
                        for (i = 0; i < nfss; i++) {
                                if ((error = needs_cleaning(fsp[i], &ci)) < 0) {
                                        handle_error(fsp, i);
                                        continue;
                                }
                                if (error == 0) /* No need to clean */
                                        continue;
                                
                                reload_ifile(fsp[i]);
                                if (clean_fs(fsp[i], &ci) < 0) {
                                        handle_error(fsp, i);
                                        continue;
                                }
                                ++cleaned_one;
                        }
                        ++loopcount;
                        if (stat_report && loopcount % stat_report == 0)
                                sig_report(0);
                        if (do_quit)
                                exit(0);
                } while(cleaned_one);
                tv.tv_sec = segwait_timeout;
                tv.tv_usec = 0;
                /* XXX: why couldn't others work if fsp socket is shutdown? */
                error = kops.ko_fcntl(fsp[0]->clfs_ifilefd,LFCNSEGWAITALL,&tv);
                if (error) {
                        if (errno == ESHUTDOWN) {
                                for (i = 0; i < nfss; i++) {
                                        handle_error(fsp, i);
                                        assert(nfss == 0);
                                }
                        } else
                                err(1, "LFCNSEGWAITALL");
                }
        }

        /* NOTREACHED */
        return 0;
}