source: MondoRescue/branches/stable/mindi-busybox/e2fsprogs/fsck.c@ 1770

/* vi: set sw=4 ts=4: */
/*
 * fsck --- 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.
 *
 * %Begin-Header%
 * This file may be redistributed under the terms of the GNU Public
 * License.
 * %End-Header%
 */

/* All filesystem specific hooks have been removed.
 * If filesystem cannot be determined, we will execute
 * "fsck.auto". Currently this also happens if you specify
 * UUID=xxx or LABEL=xxx as an object to check.
 * Detection code for that is also probably has to be in fsck.auto.
 *
 * In other words, this is _really_ is just a driver program which
 * spawns actual fsck.something for each filesystem to check.
 * It doesn't guess filesystem types from on-disk format.
 */

#include "libbb.h"

#define EXIT_OK          0
#define EXIT_NONDESTRUCT 1
#define EXIT_DESTRUCT    2
#define EXIT_UNCORRECTED 4
#define EXIT_ERROR       8
#define EXIT_USAGE       16
#define FSCK_CANCELED    32     /* Aborted with a signal or ^C */

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

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

#define FLAG_DONE 1
#define FLAG_PROGRESS 2
/*
 * Structure to allow exit codes to be stored
 */
struct fsck_instance {
    struct fsck_instance *next;
    int pid;
    int flags;
    int exit_status;
    time_t  start_time;
    char    *prog;
    char    *type;
    char    *device;
    char    *base_device; /* /dev/hda for /dev/hdaN etc */
};

static const char ignored_types[] ALIGN1 =
    "ignore\0"
    "iso9660\0"
    "nfs\0"
    "proc\0"
    "sw\0"
    "swap\0"
    "tmpfs\0"
    "devpts\0";

#if 0
static const char really_wanted[] ALIGN1 =
    "minix\0"
    "ext2\0"
    "ext3\0"
    "jfs\0"
    "reiserfs\0"
    "xiafs\0"
    "xfs\0";
#endif

#define BASE_MD "/dev/md"

static char **devices;
static char **args;
static int num_devices;
static int num_args;
static int verbose;

#define FS_TYPE_FLAG_NORMAL 0
#define FS_TYPE_FLAG_OPT    1
#define FS_TYPE_FLAG_NEGOPT 2
static char **fs_type_list;
static uint8_t *fs_type_flag;
static smallint fs_type_negated;

static volatile smallint cancel_requested;
static smallint doall;
static smallint noexecute;
static smallint serialize;
static smallint skip_root;
/* static smallint like_mount; */
static smallint notitle;
static smallint parallel_root;
static smallint force_all_parallel;

/* "progress indicator" code is somewhat buggy and ext[23] specific.
 * We should be filesystem agnostic. IOW: there should be a well-defined
 * API for fsck.something, NOT ad-hoc hacks in generic fsck. */
#define DO_PROGRESS_INDICATOR 0
#if DO_PROGRESS_INDICATOR
static smallint progress;
static int progress_fd;
#endif

static int num_running;
static int max_running;
static char *fstype;
static struct fs_info *filesys_info;
static struct fs_info *filesys_last;
static struct fsck_instance *instance_list;

/*
 * 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.
 */
#if ENABLE_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", NULL
};
#endif

static char *base_device(const char *device)
{
    char *str, *cp;
#if ENABLE_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' || !isdigit(cp[1])
         || cp[2] != 'd' || !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;
    }

#if ENABLE_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 void free_instance(struct fsck_instance *p)
{
    free(p->prog);
    free(p->device);
    free(p->base_device);
    free(p);
}

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 = xzalloc(sizeof(*fs));
    fs->device = xstrdup(device);
    fs->mountpt = xstrdup(mntpnt);
    fs->type = xstrdup(type);
    fs->opts = xstrdup(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 void strip_line(char *line)
{
    char *p = line + strlen(line) - 1;

    while (*line) {
        if (*p != '\n' && *p != '\r')
            break;
        *p-- = '\0';
    }
}

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

    word = *buf;
    if (*word == '\0')
        return NULL;

    word = skip_whitespace(word);
    next = skip_non_whitespace(word);
    if (*next)
        *next++ = '\0';
    *buf = next;
    return word;
}

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

    if (!word)
        return;

    for (p = q = word; *p; q++) {
        c = *p++;
        if (c != '\\') {
            *q = c;
        } else {
            *q = bb_process_escape_sequence(&p);
        }
    }
    *q = '\0';
}

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

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

    device = parse_word(&cp);
    if (!device) return 0; /* Allow blank lines */
    mntpnt = parse_word(&cp);
    type = parse_word(&cp);
    opts = parse_word(&cp);
    freq = parse_word(&cp);
    passno = parse_word(&cp);

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

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

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

    fs = create_fs_device(device, mntpnt, type ? type : "auto", opts,
                freq ? atoi(freq) : -1,
                passno ? atoi(passno) : -1);
    *ret_fs = fs;
    return 0;
}

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

    f = fopen_or_warn(filename, "r");
    if (f == NULL) {
        return;
    }
    while (1) {
        int r;
        char *buf = xmalloc_getline(f);
        if (!buf) break;
        r = parse_fstab_line(buf, &fs);
        free(buf);
        lineno++;
        if (r < 0) {
            bb_error_msg("WARNING: bad format "
                "on line %d of %s", lineno, filename);
            continue;
        }
        if (!fs)
            continue;
        if (fs->passno < 0)
            fs->passno = 0;
        else
            old_fstab = 0;
    }
    fclose(f);

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

    for (fs = filesys_info; fs; fs = fs->next) {
        if (strcmp(filesys, fs->device) == 0
         || (fs->mountpt && strcmp(filesys, fs->mountpt) == 0)
        )
            break;
    }

    return fs;
}

#if DO_PROGRESS_INDICATOR
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;
}
#endif


/*
 * Send a signal to all outstanding fsck child processes
 */
static void kill_all_if_cancel_requested(void)
{
    static smallint kill_sent;

    struct fsck_instance *inst;

    if (!cancel_requested || kill_sent)
        return;

    for (inst = instance_list; inst; inst = inst->next) {
        if (inst->flags & FLAG_DONE)
            continue;
        kill(inst->pid, SIGTERM);
    }
    kill_sent = 1;
}

/*
 * 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, *prev;
    pid_t pid;

    if (!instance_list)
        return NULL;

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

    inst = prev = NULL; /* for gcc */
    do {
        pid = waitpid(-1, &status, flags);
        kill_all_if_cancel_requested();
        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;
            }
            bb_perror_msg("wait");
            continue;
        }
        prev = NULL;
        inst = instance_list;
        while (inst) {
            if (inst->pid == pid)
                break;
            prev = inst;
            inst = inst->next;
        }
    } while (!inst);

    if (WIFEXITED(status))
        status = WEXITSTATUS(status);
    else if (WIFSIGNALED(status)) {
        sig = WTERMSIG(status);
        status = EXIT_UNCORRECTED;
        if (sig != SIGINT) {
            printf("Warning... %s %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 DO_PROGRESS_INDICATOR
    if (progress && (inst->flags & FLAG_PROGRESS) && !progress_active()) {
        struct fsck_instance *inst2;
        for (inst2 = instance_list; inst2; inst2 = inst2->next) {
            if (inst2->flags & FLAG_DONE)
                continue;
            if (strcmp(inst2->type, "ext2") != 0
             && strcmp(inst2->type, "ext3") != 0
            ) {
                continue;
            }
            /* ext[23], we will send USR1
             * (request to start displaying progress bar)
             *
             * 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(NULL) - 1)
                sleep(1);
            kill(inst2->pid, SIGUSR1);
            inst2->flags |= FLAG_PROGRESS;
            break;
        }
    }
#endif

 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;
}

/*
 * Execute a particular fsck program, and link it into the list of
 * child processes we are waiting for.
 */
static void execute(const char *type, const char *device, const char *mntpt,
        int interactive)
{
    char *argv[num_args + 4]; /* see count below: */
    int argc;
    int i;
    struct fsck_instance *inst;
    pid_t pid;

    inst = xzalloc(sizeof(*inst));

    argv[0] = xasprintf("fsck.%s", type); /* 1 */
    for (i = 0; i < num_args; i++)
        argv[i+1] = args[i]; /* num_args */
    argc = num_args + 1;

#if DO_PROGRESS_INDICATOR
    if (progress && !progress_active()) {
        if (strcmp(type, "ext2") == 0
         || strcmp(type, "ext3") == 0
        ) {
            argv[argc++] = xasprintf("-C%d", progress_fd); /* 1 */
            inst->flags |= FLAG_PROGRESS;
        }
    }
#endif

    argv[argc++] = xstrdup(device); /* 1 */
    argv[argc] = NULL; /* 1 */

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

    /* Fork and execute the correct program. */
    pid = -1;
    if (!noexecute) {
        pid = spawn(argv);
        if (pid < 0)
            bb_perror_msg("%s", argv[0]);
    }

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

    inst->pid = pid;
    inst->prog = argv[0];
    inst->type = xstrdup(type);
    inst->device = xstrdup(device);
    inst->base_device = base_device(device);
    inst->start_time = time(NULL);

    /* Add to the list of running fsck's.
     * (was adding to the end, but adding to the front is simpler...) */
    inst->next = instance_list;
    instance_list = inst;
}

/*
 * 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 "auto".
 */
static void fsck_device(struct fs_info *fs, int interactive)
{
    const char *type;

    if (strcmp(fs->type, "auto") != 0) {
        type = fs->type;
        if (verbose > 2)
            bb_info_msg("using filesystem type '%s' %s",
                    type, "from fstab");
    } else if (fstype
     && (fstype[0] != 'n' || fstype[1] != 'o') /* != "no" */
     && strncmp(fstype, "opts=", 5) != 0
     && strncmp(fstype, "loop", 4) != 0
     && !strchr(fstype, ',')
    ) {
        type = fstype;
        if (verbose > 2)
            bb_info_msg("using filesystem type '%s' %s",
                    type, "from -t");
    } else {
        type = "auto";
        if (verbose > 2)
            bb_info_msg("using filesystem type '%s' %s",
                    type, "(default)");
    }

    num_running++;
    execute(type, fs->device, fs->mountpt, interactive);
}

/*
 * 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 != NULL);

    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;
}

/*
 * 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 *s;
    int len;

    if (!optlist)
        return 0;

    len = strlen(opt);
    s = optlist - 1;
    while (1) {
        s = strstr(s + 1, opt);
        if (!s)
            return 0;
        /* neither "opt.." nor "xxx,opt.."? */
        if (s != optlist && s[-1] != ',')
            continue;
        /* neither "..opt" nor "..opt,xxx"? */
        if (s[len] != '\0' && s[len] != ',')
            continue;
        return 1;
    }
}

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

    if (!fs_type_list)
        return 1;

    ret = 0;
    checked_type = 0;
    n = 0;
    while (1) {
        cp = fs_type_list[n];
        if (!cp)
            break;
        switch (fs_type_flag[n]) {
        case FS_TYPE_FLAG_NORMAL:
            checked_type++;
            if (strcmp(cp, fs->type) == 0)
                ret = 1;
            break;
        case FS_TYPE_FLAG_NEGOPT:
            if (opt_in_list(cp, fs->opts))
                return 0;
            break;
        case FS_TYPE_FLAG_OPT:
            if (!opt_in_list(cp, fs->opts))
                return 0;
            break;
        }
        n++;
    }
    if (checked_type == 0)
        return 1;

    return (fs_type_negated ? !ret : ret);
}

/* Check if we should ignore this filesystem. */
static int ignore(struct fs_info *fs)
{
    /*
     * If the pass number is 0, ignore it.
     */
    if (fs->passno == 0)
        return 1;

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

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

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

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

    if (verbose)
        puts("Checking all filesystems");

    /*
     * 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 skip all root entries.
     */
    if (skip_root)
        for (fs = filesys_info; fs; fs = fs->next)
            if (LONE_CHAR(fs->mountpt, '/'))
                fs->flags |= FLAG_DONE;

    not_done_yet = 1;
    passno = 1;
    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 = 1;
                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)
                puts("----------------------------------");
            passno++;
        } else
            not_done_yet = 1;
    }
    kill_all_if_cancel_requested();
    status |= wait_many(FLAG_WAIT_ATLEAST_ONE);
    return status;
}

/*
 * Deal with the fsck -t argument.
 * Huh, for mount "-t novfat,nfs" means "neither vfat nor nfs"!
 * Why here we require "-t novfat,nonfs" ??
 */
static void compile_fs_type(char *fs_type)
{
    char *s;
    int num = 2;
    smallint negate;

    if (fs_type) {
        s = fs_type;
        while ((s = strchr(s, ','))) {
            num++;
            s++;
        }
    }

    fs_type_list = xzalloc(num * sizeof(fs_type_list[0]));
    fs_type_flag = xzalloc(num * sizeof(fs_type_flag[0]));
    fs_type_negated = -1; /* not yet known is it negated or not */

    if (!fs_type)
        return;

    num = 0;
    s = fs_type;
    while (1) {
        char *comma;

        negate = 0;
        if (s[0] == 'n' && s[1] == 'o') { /* "no.." */
            s += 2;
            negate = 1;
        } else if (s[0] == '!') {
            s++;
            negate = 1;
        }

        if (strcmp(s, "loop") == 0)
            /* loop is really short-hand for opts=loop */
            goto loop_special_case;
        if (strncmp(s, "opts=", 5) == 0) {
            s += 5;
 loop_special_case:
            fs_type_flag[num] = negate ? FS_TYPE_FLAG_NEGOPT : FS_TYPE_FLAG_OPT;
        } else {
            if (fs_type_negated == -1)
                fs_type_negated = negate;
            if (fs_type_negated != negate)
                bb_error_msg_and_die(
"either all or none of the filesystem types passed to -t must be prefixed "
"with 'no' or '!'");
        }
        comma = strchr(s, ',');
        fs_type_list[num++] = comma ? xstrndup(s, comma-s) : xstrdup(s);
        if (!comma)
            break;
        s = comma + 1;
    }
}

static void parse_args(int argc, char **argv)
{
    int i, j;
    char *arg, *tmp;
    char *options = NULL;
    int optpos = 0;
    int opts_for_fsck = 0;

    /* in bss, so already zeroed
    num_devices = 0;
    num_args = 0;
    instance_list = NULL;
    */

/* TODO: getopt32 */
    for (i = 1; i < argc; i++) {
        arg = argv[i];

        /* "/dev/blk" or "/path" or "UUID=xxx" or "LABEL=xxx" */
        if ((arg[0] == '/' && !opts_for_fsck) || strchr(arg, '=')) {
// FIXME: must check that arg is a blkdev, or resolve
// "/path", "UUID=xxx" or "LABEL=xxx" into block device name
// ("UUID=xxx"/"LABEL=xxx" can probably shifted to fsck.auto duties)
            devices = xrealloc(devices, (num_devices+1) * sizeof(devices[0]));
            devices[num_devices++] = xstrdup(arg);
            continue;
        }

        if (arg[0] != '-' || opts_for_fsck) {
            args = xrealloc(args, (num_args+1) * sizeof(args[0]));
            args[num_args++] = xstrdup(arg);
            continue;
        }

        for (j = 1; arg[j]; j++) {
            if (opts_for_fsck) {
                optpos++;
                /* one extra for '\0' */
                options = xrealloc(options, optpos + 2);
                options[optpos] = arg[j];
                continue;
            }
            switch (arg[j]) {
            case 'A':
                doall = 1;
                break;
#if DO_PROGRESS_INDICATOR
            case 'C':
                progress = 1;
                if (arg[++j]) { /* -Cn */
                    progress_fd = xatoi_u(&arg[j]);
                    goto next_arg;
                }
                /* -C n */
                progress_fd = xatoi_u(argv[++i]);
                goto next_arg;
#endif
            case 'V':
                verbose++;
                break;
            case 'N':
                noexecute = 1;
                break;
            case 'R':
                skip_root = 1;
                break;
            case 'T':
                notitle = 1;
                break;
/*          case 'M':
                like_mount = 1;
                break; */
            case 'P':
                parallel_root = 1;
                break;
            case 's':
                serialize = 1;
                break;
            case 't':
                if (fstype)
                    bb_show_usage();
                if (arg[++j])
                    tmp = &arg[j];
                else if (++i < argc)
                    tmp = argv[i];
                else
                    bb_show_usage();
                fstype = xstrdup(tmp);
                compile_fs_type(fstype);
                goto next_arg;
            case '-':
                opts_for_fsck++;
                break;
            case '?':
                bb_show_usage();
                break;
            default:
                optpos++;
                /* one extra for '\0' */
                options = xrealloc(options, optpos + 2);
                options[optpos] = arg[j];
                break;
            }
        }
 next_arg:
        if (optpos) {
            options[0] = '-';
            options[optpos + 1] = '\0';
            args = xrealloc(args, (num_args+1) * sizeof(args[0]));
            args[num_args++] = options;
            optpos = 0;
            options = NULL;
        }
    }
    if (getenv("FSCK_FORCE_ALL_PARALLEL"))
        force_all_parallel = 1;
    tmp = getenv("FSCK_MAX_INST");
    if (tmp)
        max_running = xatoi(tmp);
}

static void signal_cancel(int sig ATTRIBUTE_UNUSED)
{
    cancel_requested = 1;
}

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

    memset(&sa, 0, sizeof(sa));
    sa.sa_handler = signal_cancel;
    sigaction(SIGINT, &sa, 0);
    sigaction(SIGTERM, &sa, 0);

    setbuf(stdout, NULL);

    parse_args(argc, argv);

    if (!notitle)
        puts("fsck (busybox "BB_VER", "BB_BT")");

    /* Even plain "fsck /dev/hda1" needs fstab to get fs type,
     * so we are scanning it anyway */
    fstab = getenv("FSTAB_FILE");
    if (!fstab)
        fstab = "/etc/fstab";
    load_fs_info(fstab);

    interactive = (num_devices == 1) | serialize;

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

    if (num_devices == 0) {
        serialize = 1;
        interactive = 1;
        return check_all();
    }

    for (i = 0; i < num_devices; i++) {
        if (cancel_requested) {
            kill_all_if_cancel_requested();
            break;
        }

        fs = lookup(devices[i]);
        if (!fs)
            fs = create_fs_device(devices[i], 0, "auto", 0, -1, -1);
        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)
                puts("----------------------------------");
        }
    }
    status |= wait_many(FLAG_WAIT_ALL);
    return status;
}