usr/src/libexec/lfs_cleanerd/cleanerd.c

/*-
 * Copyright (c) 1992, 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *      This product includes software developed by the University of
 *      California, Berkeley and its contributors.
 * 4. 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.
 */

#ifndef lint
static char copyright[] =
"@(#) Copyright (c) 1992, 1993\n\
        The Regents of the University of California.  All rights reserved.\n";
#endif /* not lint */

#ifndef lint
static char sccsid[] = "@(#)cleanerd.c  8.1 (Berkeley) 6/4/93";
#endif /* not lint */

#include <sys/param.h>
#include <sys/mount.h>
#include <sys/time.h>

#include <ufs/ufs/dinode.h>
#include <ufs/lfs/lfs.h>

#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>

#include "clean.h"
char *special = "cleanerd";
int do_small = 0;
int do_mmap = 0;
struct cleaner_stats {
        int     blocks_read;
        int     blocks_written;
        int     segs_cleaned;
        int     segs_empty;
        int     segs_error;
} cleaner_stats;

struct seglist {
        int sl_id;      /* segment number */
        int sl_cost;    /* cleaning cost */
        char sl_empty;  /* is segment empty */
};

struct tossstruct {
        struct lfs *lfs;
        int seg;
};

/* function prototypes for system calls; not sure where they should go */
int      lfs_segwait __P((fsid_t, struct timeval *));
int      lfs_segclean __P((fsid_t, u_long));
int      lfs_bmapv __P((fsid_t, BLOCK_INFO *, int));
int      lfs_markv __P((fsid_t, BLOCK_INFO *, int));

/* function prototypes */
int      bi_tossold __P((const void *, const void *, const void *));
int      choose_segments __P((FS_INFO *, struct seglist *,
             int (*)(FS_INFO *, SEGUSE *)));
void     clean_fs __P((FS_INFO  *, int (*)(FS_INFO *, SEGUSE *)));
int      clean_loop __P((FS_INFO *));
int      clean_segment __P((FS_INFO *, int));
int      cost_benefit __P((FS_INFO *, SEGUSE *));
int      cost_compare __P((const void *, const void *));
void     sig_report __P((int));

/*
 * Cleaning Cost Functions:
 *
 * These return the cost of cleaning a segment.  The higher the cost value
 * the better it is to clean the segment, so empty segments have the highest
 * cost.  (It is probably better to think of this as a priority value
 * instead).
 *
 * This is the cost-benefit policy simulated and described in Rosenblum's
 * 1991 SOSP paper.
 */

int
cost_benefit(fsp, su)
        FS_INFO *fsp;           /* file system information */
        SEGUSE *su;
{
        struct lfs *lfsp;
        struct timeval t;
        int age;
        int live;

        gettimeofday(&t, NULL);

        live = su->su_nbytes;
        age = t.tv_sec < su->su_lastmod ? 0 : t.tv_sec - su->su_lastmod;

        lfsp = &fsp->fi_lfs;
        if (live == 0)
                return (t.tv_sec * lblkno(lfsp, seg_size(lfsp)));
        else {
                /*
                 * from lfsSegUsage.c (Mendel's code).
                 * priority calculation is done using INTEGER arithmetic.
                 * sizes are in BLOCKS (that is why we use lblkno below).
                 * age is in seconds.
                 *
                 * priority = ((seg_size - live) * age) / (seg_size + live)
                 */
#ifdef VERBOSE
                if (live < 0 || live > seg_size(lfsp)) {
                        err(0, "Bad segusage count: %d", live);
                        live = 0;
                }
#endif
                return (lblkno(lfsp, seg_size(lfsp) - live) * age)
                        / lblkno(lfsp, seg_size(lfsp) + live);
        }
}

int
main(argc, argv)
        int argc;
        char *argv[];
{
        FS_INFO *fsp;
        struct statfs *lstatfsp;        /* file system stats */
        struct timeval timeout;         /* sleep timeout */
        fsid_t fsid;
        int i, nodaemon;
        int opt, cmd_err;
        char *fs_name;                  /* name of filesystem to clean */
        extern int optind;

        cmd_err = nodaemon = 0;
        while ((opt = getopt(argc, argv, "smd")) != EOF) {
                switch (opt) {
                        case 's':       /* small writes */
                                do_small = 1;
                                break;
                        case 'm':
                                do_mmap = 1;
                                break;
                        case 'd':
                                nodaemon = 1;
                                break;
                        default:
                                ++cmd_err;
                }
        }
        argc -= optind;
        argv += optind;
        if (cmd_err || (argc != 1))
                err(1, "usage: lfs_cleanerd [-smd] fs_name");

        fs_name = argv[0];

        signal (SIGINT, sig_report);
        signal (SIGUSR1, sig_report);
        signal (SIGUSR2, sig_report);
        if (fs_getmntinfo(&lstatfsp, fs_name, MOUNT_LFS) == 0) {
                /* didn't find the filesystem */
                err(1, "lfs_cleanerd: filesystem %s isn't an LFS!", fs_name);
        }

        if (!nodaemon)  /* should we become a daemon, chdir to / & close fd's */
                if (daemon(0, 0) == -1)
                        err(1, "lfs_cleanerd: couldn't become a daemon!");

        timeout.tv_sec = 5*60; /* five minutes */
        timeout.tv_usec = 0;
        fsid.val[0] = 0;
        fsid.val[1] = 0;

        for (fsp = get_fs_info(lstatfsp, do_mmap); ;
            reread_fs_info(fsp, do_mmap)) {
                /*
                 * clean the filesystem, and, if it needed cleaning
                 * (i.e. it returned nonzero) try it again
                 * to make sure that some nasty process hasn't just
                 * filled the disk system up.
                 */
                if (clean_loop(fsp))
                        continue;

#ifdef VERBOSE
                (void)printf("Cleaner going to sleep.\n");
#endif
                if (lfs_segwait(fsid, &timeout) < 0)
                        err(0, "lfs_segwait: returned error\n");
#ifdef VERBOSE
                (void)printf("Cleaner waking up.\n");
#endif
        }
}

/* return the number of segments cleaned */
int
clean_loop(fsp)
        FS_INFO *fsp;   /* file system information */
{
        double loadavg[MAXLOADS];
        time_t  now;
        u_long max_free_segs;

        /*
         * Compute the maximum possible number of free segments, given the
         * number of free blocks.
         */
        max_free_segs = fsp->fi_statfsp->f_bfree / fsp->fi_lfs.lfs_ssize;

        /*
         * We will clean if there are not enough free blocks or total clean
         * space is less than BUSY_LIM % of possible clean space.
         */
        now = time((time_t *)NULL);
        if (fsp->fi_cip->clean < max_free_segs &&
            (fsp->fi_cip->clean <= MIN_SEGS(&fsp->fi_lfs) ||
            fsp->fi_cip->clean < max_free_segs * BUSY_LIM)) {
                printf("Cleaner Running  at %s (%d of %d segments available)\n",
                    ctime(&now), fsp->fi_cip->clean, max_free_segs);
                clean_fs(fsp, cost_benefit);
                return (1);
        } else {
                /*
                 * We will also clean if the system is reasonably idle and
                 * the total clean space is less then IDLE_LIM % of possible
                 * clean space.
                 */
                if (getloadavg(loadavg, MAXLOADS) == -1) {
                        perror("getloadavg: failed\n");
                        return (-1);
                }
                if (loadavg[ONE_MIN] == 0.0 && loadavg[FIVE_MIN] &&
                    fsp->fi_cip->clean < max_free_segs * IDLE_LIM) {
                        clean_fs(fsp, cost_benefit);
                        printf("Cleaner Running  at %s (system idle)\n",
                            ctime(&now));
                        return (1);
                }
        }
        printf("Cleaner Not Running at %s\n", ctime(&now));
        return (0);
}


void
clean_fs(fsp, cost_func)
        FS_INFO *fsp;   /* file system information */
        int (*cost_func) __P((FS_INFO *, SEGUSE *));
{
        struct seglist *segs, *sp;
        int i;

        if ((segs = malloc(fsp->fi_lfs.lfs_nseg * sizeof(struct seglist)))
            == NULL) {
                err(0, "malloc failed");
                return;
        }
        i = choose_segments(fsp, segs, cost_func);
#ifdef VERBOSE
        printf("clean_fs: found %d segments to clean in file system %s\n",
                i, fsp->fi_statfsp->f_mntonname);
        fflush(stdout);
#endif
        if (i)
                for (i = MIN(i, NUM_TO_CLEAN(fsp)), sp = segs; i-- ; ++sp) {
                        if (clean_segment(fsp, sp->sl_id) < 0)
                                perror("clean_segment failed");
                        else if (lfs_segclean (fsp->fi_statfsp->f_fsid,
                            sp->sl_id) < 0)
                                perror("lfs_segclean failed");
                        printf("Completed cleaning segment %d\n", sp->sl_id);
                }
        free(segs);
}

/*
 * Segment with the highest priority get sorted to the beginning of the
 * list.  This sort assumes that empty segments always have a higher
 * cost/benefit than any utilized segment.
 */
int
cost_compare(a, b)
        const void *a;
        const void *b;
{
        return (((struct seglist *)b)->sl_cost -
            ((struct seglist *)a)->sl_cost);
}


/*
 * Returns the number of segments to be cleaned with the elements of seglist
 * filled in.
 */
int
choose_segments(fsp, seglist, cost_func)
        FS_INFO *fsp;
        struct seglist *seglist;
        int (*cost_func) __P((FS_INFO *, SEGUSE *));
{
        struct lfs *lfsp;
        struct seglist *sp;
        SEGUSE *sup;
        int i, nsegs;

        lfsp = &fsp->fi_lfs;

#ifdef VERBOSE
        (void) printf("Entering choose_segments\n");
#endif
        dump_super(lfsp);
        dump_cleaner_info(fsp->fi_cip);

        for (sp = seglist, i = 0; i < lfsp->lfs_nseg; ++i) {
                sup = SEGUSE_ENTRY(lfsp, fsp->fi_segusep, i);
                 PRINT_SEGUSE(sup, i);
                if (!(sup->su_flags & SEGUSE_DIRTY) ||
                    sup->su_flags & SEGUSE_ACTIVE)
                        continue;
#ifdef VERBOSE
                (void) printf("\tchoosing segment %d\n", i);
#endif
                sp->sl_cost = (*cost_func)(fsp, sup);
                sp->sl_id = i;
                sp->sl_empty = sup->su_nbytes ? 0 : 1;
                ++sp;
        }
        nsegs = sp - seglist;
        qsort(seglist, nsegs, sizeof(struct seglist), cost_compare);
#ifdef VERBOSE
        (void)printf("Returning %d segments\n", nsegs);
#endif
        return (nsegs);
}


int
clean_segment(fsp, id)
        FS_INFO *fsp;   /* file system information */
        int id;         /* segment number */
{
        BLOCK_INFO *block_array, *bp;
        SEGUSE *sp;
        struct lfs *lfsp;
        struct tossstruct t;
        caddr_t seg_buf;
        int num_blocks, maxblocks, clean_blocks;

        lfsp = &fsp->fi_lfs;
        sp = SEGUSE_ENTRY(lfsp, fsp->fi_segusep, id);

#ifdef VERBOSE
        (void) printf("cleaning segment %d: contains %lu bytes\n", id,
            sp->su_nbytes);
        fflush(stdout);
#endif
        /* XXX could add debugging to verify that segment is really empty */
        if (sp->su_nbytes == sp->su_nsums * LFS_SUMMARY_SIZE) {
                ++cleaner_stats.segs_empty;
                return (0);
        }

        /* map the segment into a buffer */
        if (mmap_segment(fsp, id, &seg_buf, do_mmap) < 0) {
                err(0, "mmap_segment failed");
                ++cleaner_stats.segs_error;
                return (-1);
        }
        /* get a list of blocks that are contained by the segment */
        if (lfs_segmapv(fsp, id, seg_buf, &block_array, &num_blocks) < 0) {
                err(0, "clean_segment: lfs_segmapv failed");
                ++cleaner_stats.segs_error;
                return (-1);
        }
        cleaner_stats.blocks_read += fsp->fi_lfs.lfs_ssize;

#ifdef VERBOSE
        (void) printf("lfs_segmapv returned %d blocks\n", num_blocks);
        fflush (stdout);
#endif

        /* get the current disk address of blocks contained by the segment */
        if (lfs_bmapv(fsp->fi_statfsp->f_fsid, block_array, num_blocks) < 0) {
                perror("clean_segment: lfs_bmapv failed\n");
                ++cleaner_stats.segs_error;
                return -1;
        }

        /* Now toss any blocks not in the current segment */
        t.lfs = lfsp;
        t.seg = id;
        toss(block_array, &num_blocks, sizeof(BLOCK_INFO), bi_tossold, &t);

        /* Check if last element should be tossed */
        if (num_blocks && bi_tossold(&t, block_array + num_blocks - 1, NULL))
                --num_blocks;

#ifdef VERBOSE
        {
                BLOCK_INFO *_bip;
                u_long *lp;
                int i;

                (void) printf("after bmapv still have %d blocks\n", num_blocks);
                fflush (stdout);
                if (num_blocks)
                        printf("BLOCK INFOS\n");
                for (_bip = block_array, i=0; i < num_blocks; ++_bip, ++i) {
                        PRINT_BINFO(_bip);
                        lp = (u_long *)_bip->bi_bp;
                }
        }
#endif
        cleaner_stats.blocks_written += num_blocks;
        if (do_small)
                maxblocks = MAXPHYS / fsp->fi_lfs.lfs_bsize - 1;
        else
                maxblocks = num_blocks;

        for (bp = block_array; num_blocks > 0; bp += clean_blocks) {
                clean_blocks = maxblocks < num_blocks ? maxblocks : num_blocks;
                if (lfs_markv(fsp->fi_statfsp->f_fsid, bp, clean_blocks) < 0 ) {
                        err(0, "clean_segment: lfs_markv failed");
                        ++cleaner_stats.segs_error;
                        return (-1);
                }
                num_blocks -= clean_blocks;
        }

        free(block_array);
        munmap_segment (fsp, seg_buf, do_mmap);
        ++cleaner_stats.segs_cleaned;
        return (0);
}


int
bi_tossold(client, a, b)
        const void *client;
        const void *a;
        const void *b;
{
        const struct tossstruct *t;

        t = (struct tossstruct *)client;

        return (((BLOCK_INFO *)a)->bi_daddr == LFS_UNUSED_DADDR ||
            datosn(t->lfs, ((BLOCK_INFO *)a)->bi_daddr) != t->seg);
}

void
sig_report(sig)
        int sig;
{
        printf ("lfs_cleanerd:\t%s%d\n\t\t%s%d\n\t\t%s%d\n\t\t%s%d\n\t\t%s%d\n",
                "blocks_read    ", cleaner_stats.blocks_read,
                "blocks_written ", cleaner_stats.blocks_written,
                "segs_cleaned   ", cleaner_stats.segs_cleaned,
                "segs_empty     ", cleaner_stats.segs_empty,
                "seg_error      ", cleaner_stats.segs_error);
        if (sig == SIGUSR2) {
                cleaner_stats.blocks_read = 0;
                cleaner_stats.blocks_written = 0;
                cleaner_stats.segs_cleaned = 0;
                cleaner_stats.segs_empty = 0;
                cleaner_stats.segs_error = 0;
        }
        if (sig == SIGINT)
                exit(0);
}