/* vi: set sw=4 ts=4: */
/*
 * pfsck --- A generic, parallelizing front-end for the fsck program.
 * It will automatically try to run fsck programs in parallel if the
 * devices are on separate spindles.  It is based on the same ideas as
 * the generic front end for fsck by David Engel and Fred van Kempen,
 * but it has been completely rewritten from scratch to support
 * parallel execution.
 *
 * Written by Theodore Ts'o, <tytso@mit.edu>
 *
 * Miquel van Smoorenburg (miquels@drinkel.ow.org) 20-Oct-1994:
 *   o Changed -t fstype to behave like with mount when -A (all file
 *     systems) or -M (like mount) is specified.
 *   o fsck looks if it can find the fsck.type program to decide
 *     if it should ignore the fs type. This way more fsck programs
 *     can be added without changing this front-end.
 *   o -R flag skip root file system.
 *
 * Copyright (C) 1993, 1994, 1995, 1996, 1997, 1998, 1999, 2000,
 *      2001, 2002, 2003, 2004, 2005 by  Theodore Ts'o.
 *
 * Licensed under GPLv2, see file LICENSE in this source tree.
 */

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <limits.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <errno.h>
#include <paths.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>

#include "fsck.h"
#include "blkid/blkid.h"

#include "e2fsbb.h"

#include "libbb.h"

#ifndef _PATH_MNTTAB
#define _PATH_MNTTAB    "/etc/fstab"
#endif

/*
 * fsck.h
 */

#ifndef DEFAULT_FSTYPE
#define DEFAULT_FSTYPE  "ext2"
#endif

#define MAX_DEVICES 32
#define MAX_ARGS 32

/*
 * Internal structure for mount tabel entries.
 */

struct fs_info {
        char  *device;
        char  *mountpt;
        char  *type;
        char  *opts;
        int   freq;
        int   passno;
        int   flags;
        struct fs_info *next;
};

#define FLAG_DONE 1
#define FLAG_PROGRESS 2

/*
 * Structure to allow exit codes to be stored
 */
struct fsck_instance {
        int     pid;
        int     flags;
        int     exit_status;
        time_t  start_time;
        char *  prog;
        char *  type;
        char *  device;
        char *  base_device;
        struct fsck_instance *next;
};

/*
 * base_device.c
 *
 * Return the "base device" given a particular device; this is used to
 * assure that we only fsck one partition on a particular drive at any
 * one time.  Otherwise, the disk heads will be seeking all over the
 * place.  If the base device cannot be determined, return NULL.
 *
 * The base_device() function returns an allocated string which must
 * be freed.
 *
 */


#ifdef CONFIG_FEATURE_DEVFS
/*
 * Required for the uber-silly devfs /dev/ide/host1/bus2/target3/lun3
 * pathames.
 */
static const char *const devfs_hier[] = {
        "host", "bus", "target", "lun", 0
};
#endif

static char *base_device(const char *device)
{
        char *str, *cp;
#ifdef CONFIG_FEATURE_DEVFS
        const char *const *hier;
        const char *disk;
        int len;
#endif

        cp = str = xstrdup(device);

        /* Skip over /dev/; if it's not present, give up. */
        if (strncmp(cp, "/dev/", 5) != 0)
                goto errout;
        cp += 5;

        /*
         * For md devices, we treat them all as if they were all
         * on one disk, since we don't know how to parallelize them.
         */
        if (cp[0] == 'm' && cp[1] == 'd') {
                *(cp+2) = 0;
                return str;
        }

        /* Handle DAC 960 devices */
        if (strncmp(cp, "rd/", 3) == 0) {
                cp += 3;
                if (cp[0] != 'c' || cp[2] != 'd' ||
                    !isdigit(cp[1]) || !isdigit(cp[3]))
                        goto errout;
                *(cp+4) = 0;
                return str;
        }

        /* Now let's handle /dev/hd* and /dev/sd* devices.... */
        if ((cp[0] == 'h' || cp[0] == 's') && (cp[1] == 'd')) {
                cp += 2;
                /* If there's a single number after /dev/hd, skip it */
                if (isdigit(*cp))
                        cp++;
                /* What follows must be an alpha char, or give up */
                if (!isalpha(*cp))
                        goto errout;
                *(cp + 1) = 0;
                return str;
        }

#ifdef CONFIG_FEATURE_DEVFS
        /* Now let's handle devfs (ugh) names */
        len = 0;
        if (strncmp(cp, "ide/", 4) == 0)
                len = 4;
        if (strncmp(cp, "scsi/", 5) == 0)
                len = 5;
        if (len) {
                cp += len;
                /*
                 * Now we proceed down the expected devfs hierarchy.
                 * i.e., .../host1/bus2/target3/lun4/...
                 * If we don't find the expected token, followed by
                 * some number of digits at each level, abort.
                 */
                for (hier = devfs_hier; *hier; hier++) {
                        len = strlen(*hier);
                        if (strncmp(cp, *hier, len) != 0)
                                goto errout;
                        cp += len;
                        while (*cp != '/' && *cp != 0) {
                                if (!isdigit(*cp))
                                        goto errout;
                                cp++;
                        }
                        cp++;
                }
                *(cp - 1) = 0;
                return str;
        }

        /* Now handle devfs /dev/disc or /dev/disk names */
        disk = 0;
        if (strncmp(cp, "discs/", 6) == 0)
                disk = "disc";
        else if (strncmp(cp, "disks/", 6) == 0)
                disk = "disk";
        if (disk) {
                cp += 6;
                if (strncmp(cp, disk, 4) != 0)
                        goto errout;
                cp += 4;
                while (*cp != '/' && *cp != 0) {
                        if (!isdigit(*cp))
                                goto errout;
                        cp++;
                }
                *cp = 0;
                return str;
        }
#endif

errout:
        free(str);
        return NULL;
}


static const char *const ignored_types[] = {
        "ignore",
        "iso9660",
        "nfs",
        "proc",
        "sw",
        "swap",
        "tmpfs",
        "devpts",
        NULL
};

static const char *const really_wanted[] = {
        "minix",
        "ext2",
        "ext3",
        "jfs",
        "reiserfs",
        "xiafs",
        "xfs",
        NULL
};

#define BASE_MD "/dev/md"

/*
 * Global variables for options
 */
static char *devices[MAX_DEVICES];
static char *args[MAX_ARGS];
static int num_devices, num_args;

static int verbose;
static int doall;
static int noexecute;
static int serialize;
static int skip_root;
static int like_mount;
static int notitle;
static int parallel_root;
static int progress;
static int progress_fd;
static int force_all_parallel;
static int num_running;
static int max_running;
static volatile int cancel_requested;
static int kill_sent;
static char *fstype;
static struct fs_info *filesys_info, *filesys_last;
static struct fsck_instance *instance_list;
static char *fsck_path;
static blkid_cache cache;

static char *string_copy(const char *s)
{
        char    *ret;

        if (!s)
                return 0;
        ret = xstrdup(s);
        return ret;
}

static int string_to_int(const char *s)
{
        long l;
        char *p;

        l = strtol(s, &p, 0);
        if (*p || l == LONG_MIN || l == LONG_MAX || l < 0 || l > INT_MAX)
                return -1;
        else
                return (int) l;
}

static char *skip_over_blank(char *cp)
{
        while (*cp && isspace(*cp))
                cp++;
        return cp;
}

static char *skip_over_word(char *cp)
{
        while (*cp && !isspace(*cp))
                cp++;
        return cp;
}

static void strip_line(char *line)
{
        char    *p;

        while (*line) {
                p = line + strlen(line) - 1;
                if ((*p == '\n') || (*p == '\r'))
                        *p = 0;
                else
                        break;
        }
}

static char *parse_word(char **buf)
{
        char *word, *next;

        word = *buf;
        if (*word == 0)
                return 0;

        word = skip_over_blank(word);
        next = skip_over_word(word);
        if (*next)
                *next++ = 0;
        *buf = next;
        return word;
}

static void parse_escape(char *word)
{
        char    *q, c;
        const char *p;

        if (!word)
                return;

        strcpy_and_process_escape_sequences(word, word);
}

static void free_instance(struct fsck_instance *i)
{
        if (i->prog)
                free(i->prog);
        if (i->device)
                free(i->device);
        if (i->base_device)
                free(i->base_device);
        free(i);
}

static struct fs_info *create_fs_device(const char *device, const char *mntpnt,
                                        const char *type, const char *opts,
                                        int freq, int passno)
{
        struct fs_info *fs;

        fs = xmalloc(sizeof(struct fs_info));

        fs->device = string_copy(device);
        fs->mountpt = string_copy(mntpnt);
        fs->type = string_copy(type);
        fs->opts = string_copy(opts ? opts : "");
        fs->freq = freq;
        fs->passno = passno;
        fs->flags = 0;
        fs->next = NULL;

        if (!filesys_info)
                filesys_info = fs;
        else
                filesys_last->next = fs;
        filesys_last = fs;

        return fs;
}



static int parse_fstab_line(char *line, struct fs_info **ret_fs)
{
        char    *dev, *device, *mntpnt, *type, *opts, *freq, *passno, *cp;
        struct fs_info *fs;

        *ret_fs = 0;
        strip_line(line);
        if ((cp = strchr(line, '#')))
                *cp = 0;        /* Ignore everything after the comment char */
        cp = line;

        device = parse_word(&cp);
        mntpnt = parse_word(&cp);
        type = parse_word(&cp);
        opts = parse_word(&cp);
        freq = parse_word(&cp);
        passno = parse_word(&cp);

        if (!device)
                return 0;       /* Allow blank lines */

        if (!mntpnt || !type)
                return -1;

        parse_escape(device);
        parse_escape(mntpnt);
        parse_escape(type);
        parse_escape(opts);
        parse_escape(freq);
        parse_escape(passno);

        dev = blkid_get_devname(cache, device, NULL);
        if (dev)
                device = dev;

        if (strchr(type, ','))
                type = 0;

        fs = create_fs_device(device, mntpnt, type ? type : "auto", opts,
                              freq ? atoi(freq) : -1,
                              passno ? atoi(passno) : -1);
        if (dev)
                free(dev);

        if (!fs)
                return -1;
        *ret_fs = fs;
        return 0;
}

static void interpret_type(struct fs_info *fs)
{
        char    *t;

        if (strcmp(fs->type, "auto") != 0)
                return;
        t = blkid_get_tag_value(cache, "TYPE", fs->device);
        if (t) {
                free(fs->type);
                fs->type = t;
        }
}

/*
 * Load the filesystem database from /etc/fstab
 */
static void load_fs_info(const char *filename)
{
        FILE    *f;
        char    buf[1024];
        int     lineno = 0;
        int     old_fstab = 1;
        struct fs_info *fs;

        if ((f = fopen_or_warn(filename, "r")) == NULL) {
                return;
        }
        while (!feof(f)) {
                lineno++;
                if (!fgets(buf, sizeof(buf), f))
                        break;
                buf[sizeof(buf)-1] = 0;
                if (parse_fstab_line(buf, &fs) < 0) {
                        bb_error_msg("WARNING: bad format "
                                "on line %d of %s\n", lineno, filename);
                        continue;
                }
                if (!fs)
                        continue;
                if (fs->passno < 0)
                        fs->passno = 0;
                else
                        old_fstab = 0;
        }

        fclose(f);

        if (old_fstab) {
                fputs("\007\007\007"
                "WARNING: Your /etc/fstab does not contain the fsck passno\n"
                "       field.  I will kludge around things for you, but you\n"
                "       should fix your /etc/fstab file as soon as you can.\n\n", stderr);

                for (fs = filesys_info; fs; fs = fs->next) {
                        fs->passno = 1;
                }
        }
}

/* Lookup filesys in /etc/fstab and return the corresponding entry. */
static struct fs_info *lookup(char *filesys)
{
        struct fs_info *fs;

        /* No filesys name given. */
        if (filesys == NULL)
                return NULL;

        for (fs = filesys_info; fs; fs = fs->next) {
                if (!strcmp(filesys, fs->device) ||
                    (fs->mountpt && !strcmp(filesys, fs->mountpt)))
                        break;
        }

        return fs;
}

/* Find fsck program for a given fs type. */
static char *find_fsck(char *type)
{
        char *s;
        const char *tpl;
        char *p = string_copy(fsck_path);
        struct stat st;

        /* Are we looking for a program or just a type? */
        tpl = (strncmp(type, "fsck.", 5) ? "%s/fsck.%s" : "%s/%s");

        for (s = strtok(p, ":"); s; s = strtok(NULL, ":")) {
                s = xasprintf(tpl, s, type);
                if (stat(s, &st) == 0) break;
                free(s);
        }
        free(p);
        return s;
}

static int progress_active(void)
{
        struct fsck_instance *inst;

        for (inst = instance_list; inst; inst = inst->next) {
                if (inst->flags & FLAG_DONE)
                        continue;
                if (inst->flags & FLAG_PROGRESS)
                        return 1;
        }
        return 0;
}

/*
 * Execute a particular fsck program, and link it into the list of
 * child processes we are waiting for.
 */
static int execute(const char *type, const char *device, const char *mntpt,
                   int interactive)
{
        char *s, *argv[80];
        char *prog;
        int  argc, i;
        struct fsck_instance *inst, *p;
        pid_t   pid;

        inst = xzalloc(sizeof(struct fsck_instance));

        prog = xasprintf("fsck.%s", type);
        argv[0] = prog;
        argc = 1;

        for (i=0; i <num_args; i++)
                argv[argc++] = string_copy(args[i]);

        if (progress && !progress_active()) {
                if ((strcmp(type, "ext2") == 0) ||
                    (strcmp(type, "ext3") == 0)) {
                        char tmp[80];
                        snprintf(tmp, 80, "-C%d", progress_fd);
                        argv[argc++] = string_copy(tmp);
                        inst->flags |= FLAG_PROGRESS;
                }
        }

        argv[argc++] = string_copy(device);
        argv[argc] = 0;

        s = find_fsck(prog);
        if (s == NULL) {
                bb_error_msg("%s: not found", prog);
                return ENOENT;
        }

        if (verbose || noexecute) {
                printf("[%s (%d) -- %s] ", s, num_running,
                       mntpt ? mntpt : device);
                for (i=0; i < argc; i++)
                        printf("%s ", argv[i]);
                bb_putchar('\n');
        }

        /* Fork and execute the correct program. */
        if (noexecute)
                pid = -1;
        else if ((pid = fork()) < 0) {
                perror("vfork"+1);
                return errno;
        } else if (pid == 0) {
                if (!interactive)
                        close(0);
                (void) execv(s, argv);
                bb_simple_perror_msg_and_die(argv[0]);
        }

        for (i = 1; i < argc; i++)
                free(argv[i]);

        free(s);
        inst->pid = pid;
        inst->prog = prog;
        inst->type = string_copy(type);
        inst->device = string_copy(device);
        inst->base_device = base_device(device);
        inst->start_time = time(0);
        inst->next = NULL;

        /*
         * Find the end of the list, so we add the instance on at the end.
         */
        for (p = instance_list; p && p->next; p = p->next);

        if (p)
                p->next = inst;
        else
                instance_list = inst;

        return 0;
}

/*
 * Send a signal to all outstanding fsck child processes
 */
static int kill_all(int signum)
{
        struct fsck_instance *inst;
        int     n = 0;

        for (inst = instance_list; inst; inst = inst->next) {
                if (inst->flags & FLAG_DONE)
                        continue;
                kill(inst->pid, signum);
                n++;
        }
        return n;
}

/*
 * Wait for one child process to exit; when it does, unlink it from
 * the list of executing child processes, and return it.
 */
static struct fsck_instance *wait_one(int flags)
{
        int     status;
        int     sig;
        struct fsck_instance *inst, *inst2, *prev;
        pid_t   pid;

        if (!instance_list)
                return NULL;

        if (noexecute) {
                inst = instance_list;
                prev = 0;
#ifdef RANDOM_DEBUG
                while (inst->next && (random() & 1)) {
                        prev = inst;
                        inst = inst->next;
                }
#endif
                inst->exit_status = 0;
                goto ret_inst;
        }

        /*
         * gcc -Wall fails saving throw against stupidity
         * (inst and prev are thought to be uninitialized variables)
         */
        inst = prev = NULL;

        do {
                pid = waitpid(-1, &status, flags);
                if (cancel_requested && !kill_sent) {
                        kill_all(SIGTERM);
                        kill_sent++;
                }
                if ((pid == 0) && (flags & WNOHANG))
                        return NULL;
                if (pid < 0) {
                        if ((errno == EINTR) || (errno == EAGAIN))
                                continue;
                        if (errno == ECHILD) {
                                bb_error_msg("wait: no more child process?!?");
                                return NULL;
                        }
                        perror("wait");
                        continue;
                }
                for (prev = 0, inst = instance_list;
                     inst;
                     prev = inst, inst = inst->next) {
                        if (inst->pid == pid)
                                break;
                }
        } while (!inst);

        if (WIFEXITED(status))
                status = WEXITSTATUS(status);
        else if (WIFSIGNALED(status)) {
                sig = WTERMSIG(status);
                if (sig == SIGINT) {
                        status = EXIT_UNCORRECTED;
                } else {
                        printf("Warning... %s for device %s exited "
                               "with signal %d.\n",
                               inst->prog, inst->device, sig);
                        status = EXIT_ERROR;
                }
        } else {
                printf("%s %s: status is %x, should never happen.\n",
                       inst->prog, inst->device, status);
                status = EXIT_ERROR;
        }
        inst->exit_status = status;
        if (progress && (inst->flags & FLAG_PROGRESS) &&
            !progress_active()) {
                for (inst2 = instance_list; inst2; inst2 = inst2->next) {
                        if (inst2->flags & FLAG_DONE)
                                continue;
                        if (strcmp(inst2->type, "ext2") &&
                            strcmp(inst2->type, "ext3"))
                                continue;
                        /*
                         * If we've just started the fsck, wait a tiny
                         * bit before sending the kill, to give it
                         * time to set up the signal handler
                         */
                        if (inst2->start_time < time(0)+2) {
                                if (fork() == 0) {
                                        sleep(1);
                                        kill(inst2->pid, SIGUSR1);
                                        exit(0);
                                }
                        } else
                                kill(inst2->pid, SIGUSR1);
                        inst2->flags |= FLAG_PROGRESS;
                        break;
                }
        }
ret_inst:
        if (prev)
                prev->next = inst->next;
        else
                instance_list = inst->next;
        if (verbose > 1)
                printf("Finished with %s (exit status %d)\n",
                       inst->device, inst->exit_status);
        num_running--;
        return inst;
}

#define FLAG_WAIT_ALL           0
#define FLAG_WAIT_ATLEAST_ONE   1
/*
 * Wait until all executing child processes have exited; return the
 * logical OR of all of their exit code values.
 */
static int wait_many(int flags)
{
        struct fsck_instance *inst;
        int     global_status = 0;
        int     wait_flags = 0;

        while ((inst = wait_one(wait_flags))) {
                global_status |= inst->exit_status;
                free_instance(inst);
#ifdef RANDOM_DEBUG
                if (noexecute && (flags & WNOHANG) && !(random() % 3))
                        break;
#endif
                if (flags & FLAG_WAIT_ATLEAST_ONE)
                        wait_flags = WNOHANG;
        }
        return global_status;
}

/*
 * Run the fsck program on a particular device
 *
 * If the type is specified using -t, and it isn't prefixed with "no"
 * (as in "noext2") and only one filesystem type is specified, then
 * use that type regardless of what is specified in /etc/fstab.
 *
 * If the type isn't specified by the user, then use either the type
 * specified in /etc/fstab, or DEFAULT_FSTYPE.
 */
static void fsck_device(struct fs_info *fs, int interactive)
{
        const char *type;
        int retval;

        interpret_type(fs);

        if (strcmp(fs->type, "auto") != 0)
                type = fs->type;
        else if (fstype && strncmp(fstype, "no", 2) &&
            strncmp(fstype, "opts=", 5) && strncmp(fstype, "loop", 4) &&
            !strchr(fstype, ','))
                type = fstype;
        else
                type = DEFAULT_FSTYPE;

        num_running++;
        retval = execute(type, fs->device, fs->mountpt, interactive);
        if (retval) {
                bb_error_msg("error %d while executing fsck.%s for %s",
                                                retval, type, fs->device);
                num_running--;
        }
}


/*
 * Deal with the fsck -t argument.
 */
struct fs_type_compile {
        char **list;
        int *type;
        int  negate;
} fs_type_compiled;

#define FS_TYPE_NORMAL  0
#define FS_TYPE_OPT     1
#define FS_TYPE_NEGOPT  2

static const char fs_type_syntax_error[] =
"Either all or none of the filesystem types passed to -t must be prefixed\n"
   "with 'no' or '!'.";

static void compile_fs_type(char *fs_type, struct fs_type_compile *cmp)
{
        char    *cp, *list, *s;
        int     num = 2;
        int     negate, first_negate = 1;

        if (fs_type) {
                for (cp=fs_type; *cp; cp++) {
                        if (*cp == ',')
                                num++;
                }
        }

        cmp->list = xzalloc(num * sizeof(char *));
        cmp->type = xzalloc(num * sizeof(int));
        cmp->negate = 0;

        if (!fs_type)
                return;

        list = string_copy(fs_type);
        num = 0;
        s = strtok(list, ",");
        while (s) {
                negate = 0;
                if (strncmp(s, "no", 2) == 0) {
                        s += 2;
                        negate = 1;
                } else if (*s == '!') {
                        s++;
                        negate = 1;
                }
                if (strcmp(s, "loop") == 0)
                        /* loop is really short-hand for opts=loop */
                        goto loop_special_case;
                else if (strncmp(s, "opts=", 5) == 0) {
                        s += 5;
                loop_special_case:
                        cmp->type[num] = negate ? FS_TYPE_NEGOPT : FS_TYPE_OPT;
                } else {
                        if (first_negate) {
                                cmp->negate = negate;
                                first_negate = 0;
                        }
                        if ((negate && !cmp->negate) ||
                            (!negate && cmp->negate)) {
                                bb_error_msg_and_die("%s", fs_type_syntax_error);
                        }
                }
                cmp->list[num++] = string_copy(s);
                s = strtok(NULL, ",");
        }
        free(list);
}

/*
 * This function returns true if a particular option appears in a
 * comma-delimited options list
 */
static int opt_in_list(char *opt, char *optlist)
{
        char    *list, *s;

        if (!optlist)
                return 0;
        list = string_copy(optlist);

        s = strtok(list, ",");
        while (s) {
                if (strcmp(s, opt) == 0) {
                        free(list);
                        return 1;
                }
                s = strtok(NULL, ",");
        }
        free(list);
        return 0;
}

/* See if the filesystem matches the criteria given by the -t option */
static int fs_match(struct fs_info *fs, struct fs_type_compile *cmp)
{
        int n, ret = 0, checked_type = 0;
        char *cp;

        if (cmp->list == 0 || cmp->list[0] == 0)
                return 1;

        for (n=0; (cp = cmp->list[n]); n++) {
                switch (cmp->type[n]) {
                case FS_TYPE_NORMAL:
                        checked_type++;
                        if (strcmp(cp, fs->type) == 0) {
                                ret = 1;
                        }
                        break;
                case FS_TYPE_NEGOPT:
                        if (opt_in_list(cp, fs->opts))
                                return 0;
                        break;
                case FS_TYPE_OPT:
                        if (!opt_in_list(cp, fs->opts))
                                return 0;
                        break;
                }
        }
        if (checked_type == 0)
                return 1;
        return (cmp->negate ? !ret : ret);
}

/* Check if we should ignore this filesystem. */
static int ignore(struct fs_info *fs)
{
        int wanted;
        char *s;

        /*
         * If the pass number is 0, ignore it.
         */
        if (fs->passno == 0)
                return 1;

        interpret_type(fs);

        /*
         * If a specific fstype is specified, and it doesn't match,
         * ignore it.
         */
        if (!fs_match(fs, &fs_type_compiled)) return 1;

        /* Are we ignoring this type? */
        if (index_in_str_array(ignored_types, fs->type) >= 0)
                return 1;

        /* Do we really really want to check this fs? */
        wanted = index_in_str_array(really_wanted, fs->type) >= 0;

        /* See if the <fsck.fs> program is available. */
        s = find_fsck(fs->type);
        if (s == NULL) {
                if (wanted)
                        bb_error_msg("can't check %s: fsck.%s not found",
                                fs->device, fs->type);
                return 1;
        }
        free(s);

        /* We can and want to check this file system type. */
        return 0;
}

/*
 * Returns TRUE if a partition on the same disk is already being
 * checked.
 */
static int device_already_active(char *device)
{
        struct fsck_instance *inst;
        char *base;

        if (force_all_parallel)
                return 0;

#ifdef BASE_MD
        /* Don't check a soft raid disk with any other disk */
        if (instance_list &&
            (!strncmp(instance_list->device, BASE_MD, sizeof(BASE_MD)-1) ||
             !strncmp(device, BASE_MD, sizeof(BASE_MD)-1)))
                return 1;
#endif

        base = base_device(device);
        /*
         * If we don't know the base device, assume that the device is
         * already active if there are any fsck instances running.
         */
        if (!base)
                return (instance_list != 0);
        for (inst = instance_list; inst; inst = inst->next) {
                if (!inst->base_device || !strcmp(base, inst->base_device)) {
                        free(base);
                        return 1;
                }
        }
        free(base);
        return 0;
}

/* Check all file systems, using the /etc/fstab table. */
static int check_all(void)
{
        struct fs_info *fs = NULL;
        int status = EXIT_OK;
        int not_done_yet = 1;
        int passno = 1;
        int pass_done;

        if (verbose)
                fputs("Checking all file systems.\n", stdout);

        /*
         * Do an initial scan over the filesystem; mark filesystems
         * which should be ignored as done, and resolve any "auto"
         * filesystem types (done as a side-effect of calling ignore()).
         */
        for (fs = filesys_info; fs; fs = fs->next) {
                if (ignore(fs))
                        fs->flags |= FLAG_DONE;
        }

        /*
         * Find and check the root filesystem.
         */
        if (!parallel_root) {
                for (fs = filesys_info; fs; fs = fs->next) {
                        if (LONE_CHAR(fs->mountpt, '/'))
                                break;
                }
                if (fs) {
                        if (!skip_root && !ignore(fs)) {
                                fsck_device(fs, 1);
                                status |= wait_many(FLAG_WAIT_ALL);
                                if (status > EXIT_NONDESTRUCT)
                                        return status;
                        }
                        fs->flags |= FLAG_DONE;
                }
        }
        /*
         * This is for the bone-headed user who enters the root
         * filesystem twice.  Skip root will skep all root entries.
         */
        if (skip_root)
                for (fs = filesys_info; fs; fs = fs->next)
                        if (LONE_CHAR(fs->mountpt, '/'))
                                fs->flags |= FLAG_DONE;

        while (not_done_yet) {
                not_done_yet = 0;
                pass_done = 1;

                for (fs = filesys_info; fs; fs = fs->next) {
                        if (cancel_requested)
                                break;
                        if (fs->flags & FLAG_DONE)
                                continue;
                        /*
                         * If the filesystem's pass number is higher
                         * than the current pass number, then we don't
                         * do it yet.
                         */
                        if (fs->passno > passno) {
                                not_done_yet++;
                                continue;
                        }
                        /*
                         * If a filesystem on a particular device has
                         * already been spawned, then we need to defer
                         * this to another pass.
                         */
                        if (device_already_active(fs->device)) {
                                pass_done = 0;
                                continue;
                        }
                        /*
                         * Spawn off the fsck process
                         */
                        fsck_device(fs, serialize);
                        fs->flags |= FLAG_DONE;

                        /*
                         * Only do one filesystem at a time, or if we
                         * have a limit on the number of fsck's extant
                         * at one time, apply that limit.
                         */
                        if (serialize ||
                            (max_running && (num_running >= max_running))) {
                                pass_done = 0;
                                break;
                        }
                }
                if (cancel_requested)
                        break;
                if (verbose > 1)
                        printf("--waiting-- (pass %d)\n", passno);
                status |= wait_many(pass_done ? FLAG_WAIT_ALL :
                                    FLAG_WAIT_ATLEAST_ONE);
                if (pass_done) {
                        if (verbose > 1)
                                printf("----------------------------------\n");
                        passno++;
                } else
                        not_done_yet++;
        }
        if (cancel_requested && !kill_sent) {
                kill_all(SIGTERM);
                kill_sent++;
        }
        status |= wait_many(FLAG_WAIT_ATLEAST_ONE);
        return status;
}

static void signal_cancel(int sig FSCK_ATTR((unused)))
{
        cancel_requested++;
}

static void PRS(int argc, char **argv)
{
        int     i, j;
        char    *arg, *dev, *tmp = NULL;
        char    options[128];
        int     opt = 0;
        int     opts_for_fsck = 0;
        struct sigaction        sa;

        /*
         * Set up signal action
         */
        memset(&sa, 0, sizeof(struct sigaction));
        sa.sa_handler = signal_cancel;
        sigaction(SIGINT, &sa, 0);
        sigaction(SIGTERM, &sa, 0);

        num_devices = 0;
        num_args = 0;
        instance_list = 0;

        for (i=1; i < argc; i++) {
                arg = argv[i];
                if (!arg)
                        continue;
                if ((arg[0] == '/' && !opts_for_fsck) || strchr(arg, '=')) {
                        if (num_devices >= MAX_DEVICES) {
                                bb_error_msg_and_die("too many devices");
                        }
                        dev = blkid_get_devname(cache, arg, NULL);
                        if (!dev && strchr(arg, '=')) {
                                /*
                                 * Check to see if we failed because
                                 * /proc/partitions isn't found.
                                 */
                                if (access("/proc/partitions", R_OK) < 0) {
                                        bb_perror_msg_and_die("can't open /proc/partitions "
                                                        "(is /proc mounted?)");
                                }
                                /*
                                 * Check to see if this is because
                                 * we're not running as root
                                 */
                                if (geteuid())
                                        bb_error_msg_and_die(
                "must be root to scan for matching filesystems: %s\n", arg);
                                else
                                        bb_error_msg_and_die(
                "can't find matching filesystem: %s", arg);
                        }
                        devices[num_devices++] = dev ? dev : string_copy(arg);
                        continue;
                }
                if (arg[0] != '-' || opts_for_fsck) {
                        if (num_args >= MAX_ARGS) {
                                bb_error_msg_and_die("too many arguments");
                        }
                        args[num_args++] = string_copy(arg);
                        continue;
                }
                for (j=1; arg[j]; j++) {
                        if (opts_for_fsck) {
                                options[++opt] = arg[j];
                                continue;
                        }
                        switch (arg[j]) {
                        case 'A':
                                doall++;
                                break;
                        case 'C':
                                progress++;
                                if (arg[j+1]) {
                                        progress_fd = string_to_int(arg+j+1);
                                        if (progress_fd < 0)
                                                progress_fd = 0;
                                        else
                                                goto next_arg;
                                } else if ((i+1) < argc
                                 && argv[i+1][0] != '-') {
                                        progress_fd = string_to_int(argv[i]);
                                        if (progress_fd < 0)
                                                progress_fd = 0;
                                        else {
                                                goto next_arg;
                                                i++;
                                        }
                                }
                                break;
                        case 'V':
                                verbose++;
                                break;
                        case 'N':
                                noexecute++;
                                break;
                        case 'R':
                                skip_root++;
                                break;
                        case 'T':
                                notitle++;
                                break;
                        case 'M':
                                like_mount++;
                                break;
                        case 'P':
                                parallel_root++;
                                break;
                        case 's':
                                serialize++;
                                break;
                        case 't':
                                tmp = 0;
                                if (fstype)
                                        bb_show_usage();
                                if (arg[j+1])
                                        tmp = arg+j+1;
                                else if ((i+1) < argc)
                                        tmp = argv[++i];
                                else
                                        bb_show_usage();
                                fstype = string_copy(tmp);
                                compile_fs_type(fstype, &fs_type_compiled);
                                goto next_arg;
                        case '-':
                                opts_for_fsck++;
                                break;
                        case '?':
                                bb_show_usage();
                                break;
                        default:
                                options[++opt] = arg[j];
                                break;
                        }
                }
        next_arg:
                if (opt) {
                        options[0] = '-';
                        options[++opt] = '\0';
                        if (num_args >= MAX_ARGS) {
                                bb_error_msg("too many arguments");
                        }
                        args[num_args++] = string_copy(options);
                        opt = 0;
                }
        }
        if (getenv("FSCK_FORCE_ALL_PARALLEL"))
                force_all_parallel++;
        if ((tmp = getenv("FSCK_MAX_INST")))
            max_running = atoi(tmp);
}

int fsck_main(int argc, char **argv) MAIN_EXTERNALLY_VISIBLE;
int fsck_main(int argc, char **argv)
{
        int i, status = 0;
        int interactive = 0;
        const char *fstab;
        struct fs_info *fs;

        setvbuf(stdout, NULL, _IONBF, BUFSIZ);
        setvbuf(stderr, NULL, _IONBF, BUFSIZ);

        blkid_get_cache(&cache, NULL);
        PRS(argc, argv);

        if (!notitle)
                printf("fsck %s (%s)\n", E2FSPROGS_VERSION, E2FSPROGS_DATE);

        fstab = getenv("FSTAB_FILE");
        if (!fstab)
                fstab = _PATH_MNTTAB;
        load_fs_info(fstab);

        fsck_path = e2fs_set_sbin_path();

        if ((num_devices == 1) || (serialize))
                interactive = 1;

        /* If -A was specified ("check all"), do that! */
        if (doall)
                return check_all();

        if (num_devices == 0) {
                serialize++;
                interactive++;
                return check_all();
        }
        for (i = 0; i < num_devices; i++) {
                if (cancel_requested) {
                        if (!kill_sent) {
                                kill_all(SIGTERM);
                                kill_sent++;
                        }
                        break;
                }
                fs = lookup(devices[i]);
                if (!fs) {
                        fs = create_fs_device(devices[i], 0, "auto",
                                              0, -1, -1);
                        if (!fs)
                                continue;
                }
                fsck_device(fs, interactive);
                if (serialize ||
                    (max_running && (num_running >= max_running))) {
                        struct fsck_instance *inst;

                        inst = wait_one(0);
                        if (inst) {
                                status |= inst->exit_status;
                                free_instance(inst);
                        }
                        if (verbose > 1)
                                printf("----------------------------------\n");
                }
        }
        status |= wait_many(FLAG_WAIT_ALL);
        blkid_put_cache(cache);
        return status;
}