wipefs: add --lock and LOCK_BLOCK_DEVICE

[thirdparty/util-linux.git] / disk-utils / fsck.c

/*
 * 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.
 *
 * Copyright (C) 2009-2014 Karel Zak <kzak@redhat.com>
 *
 * This file may be redistributed under the terms of the GNU Public
 * License.
 */

#define _XOPEN_SOURCE 600 /* for inclusion of sa_handler in Solaris */

#include <sys/types.h>
#include <sys/wait.h>
#include <sys/stat.h>
#include <sys/file.h>
#include <fcntl.h>
#include <limits.h>
#include <stdio.h>
#include <ctype.h>
#include <string.h>
#include <time.h>
#include <stdlib.h>
#include <paths.h>
#include <unistd.h>
#include <errno.h>
#include <signal.h>
#include <dirent.h>
#include <sys/resource.h>
#include <sys/time.h>
#include <blkid.h>
#include <libmount.h>

#include "nls.h"
#include "pathnames.h"
#include "exitcodes.h"
#include "c.h"
#include "fileutils.h"
#include "monotonic.h"
#include "strutils.h"

#define XALLOC_EXIT_CODE        FSCK_EX_ERROR
#include "xalloc.h"

#define CLOSE_EXIT_CODE         FSCK_EX_ERROR
#include "closestream.h"

#ifndef DEFAULT_FSTYPE
# define DEFAULT_FSTYPE "ext2"
#endif

#define MAX_DEVICES 32
#define MAX_ARGS 32

#define FSCK_RUNTIME_DIRNAME    "/run/fsck"

static const char *ignored_types[] = {
        "ignore",
        "iso9660",
        "sw",
        NULL
};

static const char *really_wanted[] = {
        "minix",
        "ext2",
        "ext3",
        "ext4",
        "ext4dev",
        "jfs",
        "reiserfs"
};

/*
 * Internal structure for mount table entries.
 */
struct fsck_fs_data
{
        const char      *device;
        dev_t           disk;
        unsigned int    stacked:1,
                        done:1,
                        eval_device:1;
};

/*
 * Structure to allow exit codes to be stored
 */
struct fsck_instance {
        int     pid;
        int     flags;          /* FLAG_{DONE|PROGRESS} */

        int     lock;           /* flock()ed lockpath file descriptor or -1 */
        char    *lockpath;      /* /run/fsck/<diskname>.lock or NULL */

        int     exit_status;
        struct timeval start_time;
        struct timeval end_time;
        char *  prog;
        char *  type;

        struct rusage rusage;
        struct libmnt_fs *fs;
        struct fsck_instance *next;
};

#define FLAG_DONE 1
#define FLAG_PROGRESS 2

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

static int lockdisk;
static int verbose;
static int doall;
static int noexecute;
static int serialize;
static int skip_root;
static int ignore_mounted;
static int notitle;
static int parallel_root;
static int progress;
static int progress_fd;
static int force_all_parallel;
static int report_stats;
static FILE *report_stats_file;

static int num_running;
static int max_running;

static volatile int cancel_requested;
static int kill_sent;
static char *fstype;
static struct fsck_instance *instance_list;

#define FSCK_DEFAULT_PATH "/sbin"
static char *fsck_path;


/* parsed fstab and mtab */
static struct libmnt_table *fstab, *mtab;
static struct libmnt_cache *mntcache;

static int count_slaves(dev_t disk);

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;

        return (int) l;
}

/* Do we really really want to check this fs? */
static int fs_check_required(const char *type)
{
        size_t i;

        for(i = 0; i < ARRAY_SIZE(really_wanted); i++) {
                if (strcmp(type, really_wanted[i]) == 0)
                        return 1;
        }

        return 0;
}

static int is_mounted(struct libmnt_fs *fs)
{
        int rc;
        const char *src;

        src = mnt_fs_get_source(fs);
        if (!src)
                return 0;
        if (!mntcache)
                mntcache = mnt_new_cache();
        if (!mtab) {
                mtab = mnt_new_table();
                if (!mtab)
                        err(FSCK_EX_ERROR, ("failed to initialize libmount table"));
                mnt_table_set_cache(mtab, mntcache);
                mnt_table_parse_mtab(mtab, NULL);
        }

        rc = mnt_table_find_source(mtab, src, MNT_ITER_BACKWARD) ? 1 : 0;
        if (verbose) {
                if (rc)
                        printf(_("%s is mounted\n"), src);
                else
                        printf(_("%s is not mounted\n"), src);
        }
        return rc;
}

static int ignore(struct libmnt_fs *);

static struct fsck_fs_data *fs_create_data(struct libmnt_fs *fs)
{
        struct fsck_fs_data *data = mnt_fs_get_userdata(fs);

        if (!data) {
                data = xcalloc(1, sizeof(*data));
                mnt_fs_set_userdata(fs, data);
        }
        return data;
}

/*
 * fs from fstab might contains real device name as well as symlink,
 * LABEL or UUID, this function returns canonicalized result.
 */
static const char *fs_get_device(struct libmnt_fs *fs)
{
        struct fsck_fs_data *data = mnt_fs_get_userdata(fs);

        if (!data || !data->eval_device) {
                const char *spec = mnt_fs_get_source(fs);

                if (!data)
                        data = fs_create_data(fs);

                data->eval_device = 1;
                data->device = mnt_resolve_spec(spec, mnt_table_get_cache(fstab));
                if (!data->device)
                        data->device = xstrdup(spec);
        }

        return data->device;
}

static dev_t fs_get_disk(struct libmnt_fs *fs, int check)
{
        struct fsck_fs_data *data;
        const char *device;
        struct stat st;

        data = mnt_fs_get_userdata(fs);
        if (data && data->disk)
                return data->disk;

        if (!check)
                return 0;

        if (mnt_fs_is_netfs(fs) || mnt_fs_is_pseudofs(fs))
                return 0;

        device = fs_get_device(fs);
        if (!device)
                return 0;

        data = fs_create_data(fs);

        if (!stat(device, &st) &&
            !blkid_devno_to_wholedisk(st.st_rdev, NULL, 0, &data->disk)) {

                if (data->disk)
                        data->stacked = count_slaves(data->disk) > 0 ? 1 : 0;
                return data->disk;
        }
        return 0;
}

static int fs_is_stacked(struct libmnt_fs *fs)
{
        struct fsck_fs_data *data = mnt_fs_get_userdata(fs);
        return data ? data->stacked : 0;
}

static int fs_is_done(struct libmnt_fs *fs)
{
        struct fsck_fs_data *data = mnt_fs_get_userdata(fs);
        return data ? data->done : 0;
}

static void fs_set_done(struct libmnt_fs *fs)
{
        struct fsck_fs_data *data = fs_create_data(fs);

        if (data)
                data->done = 1;
}

static int is_irrotational_disk(dev_t disk)
{
        char path[PATH_MAX];
        FILE *f;
        int rc, x;


        rc = snprintf(path, sizeof(path),
                        "/sys/dev/block/%d:%d/queue/rotational",
                        major(disk), minor(disk));

        if (rc < 0 || (unsigned int) rc >= sizeof(path))
                return 0;

        f = fopen(path, "r");
        if (!f)
                return 0;

        rc = fscanf(f, "%d", &x);
        if (rc != 1) {
                if (ferror(f))
                        warn(_("cannot read %s"), path);
                else
                        warnx(_("parse error: %s"), path);
        }
        fclose(f);

        return rc == 1 ? !x : 0;
}

static void lock_disk(struct fsck_instance *inst)
{
        dev_t disk = fs_get_disk(inst->fs, 1);
        char *diskpath = NULL, *diskname;

        inst->lock = -1;

        if (!disk || is_irrotational_disk(disk))
                goto done;

        diskpath = blkid_devno_to_devname(disk);
        if (!diskpath)
                goto done;

        if (access(FSCK_RUNTIME_DIRNAME, F_OK) != 0) {
                int rc = mkdir(FSCK_RUNTIME_DIRNAME,
                                    S_IWUSR|
                                    S_IRUSR|S_IRGRP|S_IROTH|
                                    S_IXUSR|S_IXGRP|S_IXOTH);
                if (rc && errno != EEXIST) {
                        warn(_("cannot create directory %s"),
                                        FSCK_RUNTIME_DIRNAME);
                        goto done;
                }
        }

        diskname = stripoff_last_component(diskpath);
        if (!diskname)
                diskname = diskpath;

        xasprintf(&inst->lockpath, FSCK_RUNTIME_DIRNAME "/%s.lock", diskname);

        if (verbose)
                printf(_("Locking disk by %s ... "), inst->lockpath);

        inst->lock = open(inst->lockpath, O_RDONLY|O_CREAT|O_CLOEXEC,
                                    S_IWUSR|S_IRUSR|S_IRGRP|S_IROTH);
        if (inst->lock >= 0) {
                int rc = -1;

                /* inform users that we're waiting on the lock */
                if (verbose &&
                    (rc = flock(inst->lock, LOCK_EX | LOCK_NB)) != 0 &&
                    errno == EWOULDBLOCK)
                        printf(_("(waiting) "));

                if (rc != 0 && flock(inst->lock, LOCK_EX) != 0) {
                        close(inst->lock);                      /* failed */
                        inst->lock = -1;
                }
        }

        if (verbose)
                /* TRANSLATORS: These are followups to "Locking disk...". */
                printf("%s.\n", inst->lock >= 0 ? _("succeeded") : _("failed"));


done:
        if (inst->lock < 0) {
                free(inst->lockpath);
                inst->lockpath = NULL;
        }
        free(diskpath);
}

static void unlock_disk(struct fsck_instance *inst)
{
        if (inst->lock < 0)
                return;

        if (verbose)
                printf(_("Unlocking %s.\n"), inst->lockpath);

        close(inst->lock);                      /* unlock */

        free(inst->lockpath);

        inst->lock = -1;
        inst->lockpath = NULL;
}

static void free_instance(struct fsck_instance *i)
{
        if (lockdisk)
                unlock_disk(i);
        free(i->prog);
        free(i->lockpath);
        mnt_unref_fs(i->fs);
        free(i);
}

static struct libmnt_fs *add_dummy_fs(const char *device)
{
        struct libmnt_fs *fs = mnt_new_fs();

        if (fs && mnt_fs_set_source(fs, device) == 0 &&
                                  mnt_table_add_fs(fstab, fs) == 0) {
                mnt_unref_fs(fs);
                return fs;
        }

        mnt_unref_fs(fs);
        err(FSCK_EX_ERROR, _("failed to setup description for %s"), device);
}

static void fs_interpret_type(struct libmnt_fs *fs)
{
        const char *device;
        const char *type = mnt_fs_get_fstype(fs);

        if (type && strcmp(type, "auto") != 0)
                return;

        mnt_fs_set_fstype(fs, NULL);

        device = fs_get_device(fs);
        if (device) {
                int ambi = 0;
                char *tp;
                struct libmnt_cache *cache = mnt_table_get_cache(fstab);

                tp = mnt_get_fstype(device, &ambi, cache);
                if (!ambi)
                        mnt_fs_set_fstype(fs, tp);
                if (!cache)
                        free(tp);
        }
}

static int parser_errcb(struct libmnt_table *tb __attribute__ ((__unused__)),
                        const char *filename, int line)
{
        warnx(_("%s: parse error at line %d -- ignored"), filename, line);
        return 1;
}

/*
 * Load the filesystem database from /etc/fstab
 */
static void load_fs_info(void)
{
        const char *path;

        fstab = mnt_new_table();
        if (!fstab)
                err(FSCK_EX_ERROR, ("failed to initialize libmount table"));

        mnt_table_set_parser_errcb(fstab, parser_errcb);
        mnt_table_set_cache(fstab, mntcache);

        errno = 0;

        /*
         * Let's follow libmount defaults if $FSTAB_FILE is not specified
         */
        path = getenv("FSTAB_FILE");

        if (mnt_table_parse_fstab(fstab, path)) {
                if (!path)
                        path = mnt_get_fstab_path();

                /* don't print error when there is no fstab at all */
                if (access(path, F_OK) == 0) {
                        if (errno)
                                warn(_("%s: failed to parse fstab"), path);
                        else
                                warnx(_("%s: failed to parse fstab"), path);
                }
        }
}

/*
 * Lookup filesys in /etc/fstab and return the corresponding entry.
 * The @path has to be real path (no TAG) by mnt_resolve_spec().
 */
static struct libmnt_fs *lookup(char *path)
{
        struct libmnt_fs *fs;

        if (!path)
                return NULL;

        fs = mnt_table_find_srcpath(fstab, path, MNT_ITER_FORWARD);
        if (!fs) {
                /*
                 * Maybe mountpoint has been specified on fsck command line.
                 * Yeah, crazy feature...
                 *
                 * Note that mnt_table_find_target() may canonicalize paths in
                 * the fstab to support symlinks. This is really unwanted,
                 * because readlink() on mountpoints may trigger automounts.
                 *
                 * So, disable the cache and compare the paths as strings
                 * without care about symlinks...
                 */
                mnt_table_set_cache(fstab, NULL);
                fs = mnt_table_find_target(fstab, path, MNT_ITER_FORWARD);
                mnt_table_set_cache(fstab, mntcache);
        }
        return fs;
}

/* Find fsck program for a given fs type. */
static int find_fsck(const char *type, char **progpath)
{
        char *s;
        const char *tpl;
        char *prog = NULL;
        char *p = xstrdup(fsck_path);
        int rc;

        /* 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, ":")) {
                xasprintf(&prog, tpl, s, type);
                if (access(prog, X_OK) == 0)
                        break;
                free(prog);
                prog = NULL;
        }

        free(p);
        rc = prog ? 1 : 0;

        if (progpath)
                *progpath = prog;
        else
                free(prog);

        return rc;
}

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;
}

/*
 * Process run statistics for finished fsck instances.
 *
 * If report_stats is 0, do nothing, otherwise print a selection of
 * interesting rusage statistics as well as elapsed wallclock time.
 */
static void print_stats(struct fsck_instance *inst)
{
        struct timeval delta;

        if (!inst || !report_stats || noexecute)
                return;

        timersub(&inst->end_time, &inst->start_time, &delta);

        if (report_stats_file)
                fprintf(report_stats_file, "%s %d %ld "
                                           "%ld.%06ld %ld.%06ld %ld.%06ld\n",
                        fs_get_device(inst->fs),
                        inst->exit_status,
                        inst->rusage.ru_maxrss,
                        (long)delta.tv_sec, (long)delta.tv_usec,
                        (long)inst->rusage.ru_utime.tv_sec,
                        (long)inst->rusage.ru_utime.tv_usec,
                        (long)inst->rusage.ru_stime.tv_sec,
                        (long)inst->rusage.ru_stime.tv_usec);
        else
                fprintf(stdout, "%s: status %d, rss %ld, "
                                "real %ld.%06ld, user %ld.%06ld, sys %ld.%06ld\n",
                        fs_get_device(inst->fs),
                        inst->exit_status,
                        inst->rusage.ru_maxrss,
                        (long)delta.tv_sec, (long)delta.tv_usec,
                        (long)inst->rusage.ru_utime.tv_sec,
                        (long)inst->rusage.ru_utime.tv_usec,
                        (long)inst->rusage.ru_stime.tv_sec,
                        (long)inst->rusage.ru_stime.tv_usec);
}

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

        inst = xcalloc(1, sizeof(*inst));

        argv[0] = xstrdup(progname);
        argc = 1;

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

        if (progress &&
               ((strcmp(type, "ext2") == 0) ||
                (strcmp(type, "ext3") == 0) ||
                (strcmp(type, "ext4") == 0) ||
                (strcmp(type, "ext4dev") == 0))) {

                char tmp[80];
                tmp[0] = 0;
                if (!progress_active()) {
                        snprintf(tmp, 80, "-C%d", progress_fd);
                        inst->flags |= FLAG_PROGRESS;
                } else if (progress_fd)
                        snprintf(tmp, 80, "-C%d", progress_fd * -1);
                if (tmp[0])
                        argv[argc++] = xstrdup(tmp);
        }

        argv[argc++] = xstrdup(fs_get_device(fs));
        argv[argc] = NULL;

        if (verbose || noexecute) {
                const char *tgt = mnt_fs_get_target(fs);

                if (!tgt)
                        tgt = fs_get_device(fs);
                printf("[%s (%d) -- %s] ", progpath, num_running, tgt);
                for (i=0; i < argc; i++)
                        printf("%s ", argv[i]);
                printf("\n");
        }

        mnt_ref_fs(fs);
        inst->fs = fs;
        inst->lock = -1;

        if (lockdisk)
                lock_disk(inst);

        /* Fork and execute the correct program. */
        if (noexecute)
                pid = -1;
        else if ((pid = fork()) < 0) {
                warn(_("fork failed"));
                free_instance(inst);
                return errno;
        } else if (pid == 0) {
                if (!interactive)
                        close(0);
                execv(progpath, argv);
                err(FSCK_EX_ERROR, _("%s: execute failed"), progpath);
        }

        for (i=0; i < argc; i++)
                free(argv[i]);

        inst->pid = pid;
        inst->prog = xstrdup(progname);
        inst->type = xstrdup(type);
        gettime_monotonic(&inst->start_time);
        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 = 0;
        int     sig;
        struct fsck_instance *inst, *inst2, *prev;
        pid_t   pid;
        struct rusage rusage;

        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;
        }

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

        do {
                pid = wait4(-1, &status, flags, &rusage);
                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) {
                                warnx(_("wait: no more child process?!?"));
                                return NULL;
                        }
                        warn(_("waitpid failed"));
                        continue;
                }
                for (prev = NULL, 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 = FSCK_EX_UNCORRECTED;
                } else {
                        warnx(_("Warning... %s for device %s exited "
                               "with signal %d."),
                               inst->prog, fs_get_device(inst->fs), sig);
                        status = FSCK_EX_ERROR;
                }
        } else {
                warnx(_("%s %s: status is %x, should never happen."),
                       inst->prog, fs_get_device(inst->fs), status);
                status = FSCK_EX_ERROR;
        }

        inst->exit_status = status;
        inst->flags |= FLAG_DONE;
        gettime_monotonic(&inst->end_time);
        memcpy(&inst->rusage, &rusage, sizeof(struct rusage));

        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") != 0 &&
                            strcmp(inst2->type, "ext3") &&
                            strcmp(inst2->type, "ext4") != 0 &&
                            strcmp(inst2->type, "ext4dev") != 0)
                                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.tv_sec < time(NULL) + 2) {
                                if (fork() == 0) {
                                        sleep(1);
                                        kill(inst2->pid, SIGUSR1);
                                        exit(FSCK_EX_OK);
                                }
                        } else
                                kill(inst2->pid, SIGUSR1);
                        inst2->flags |= FLAG_PROGRESS;
                        break;
                }
        }
ret_inst:
        if (prev)
                prev->next = inst->next;
        else
                instance_list = inst->next;

        print_stats(inst);

        if (verbose > 1)
                printf(_("Finished with %s (exit status %d)\n"),
                       fs_get_device(inst->fs), 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 int fsck_device(struct libmnt_fs *fs, int interactive)
{
        char *progname, *progpath;
        const char *type;
        int retval;

        fs_interpret_type(fs);

        type = mnt_fs_get_fstype(fs);

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

        xasprintf(&progname, "fsck.%s", type);

        if (!find_fsck(progname, &progpath)) {
                free(progname);
                if (fs_check_required(type)) {
                        retval = ENOENT;
                        goto err;
                }
                return 0;
        }

        num_running++;
        retval = execute(progname, progpath, type, fs, interactive);
        free(progname);
        free(progpath);
        if (retval) {
                num_running--;
                goto err;
        }
        return 0;
err:
        warnx(_("error %d (%m) while executing fsck.%s for %s"),
                        retval, type, fs_get_device(fs));
        return FSCK_EX_ERROR;
}


/*
 * Deal with the fsck -t argument.
 */
static 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 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 = xcalloc(num, sizeof(char *));
        cmp->type = xcalloc(num, sizeof(int));
        cmp->negate = 0;

        if (!fs_type)
                return;

        list = xstrdup(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)) {
                                errx(FSCK_EX_USAGE,
                                        _("Either all or none of the filesystem types passed to -t must be prefixed\n"
                                          "with 'no' or '!'."));
                        }
                }

                cmp->list[num++] = xstrdup(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(const char *opt, const char *optlist)
{
        char    *list, *s;

        if (!optlist)
                return 0;
        list = xstrdup(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 libmnt_fs *fs, struct fs_type_compile *cmp)
{
        int n, ret = 0, checked_type = 0;
        char *cp;

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

        for (n=0; (cp = cmp->list[n]); n++) {
                switch (cmp->type[n]) {
                case FS_TYPE_NORMAL:
                {
                        const char *type = mnt_fs_get_fstype(fs);

                        checked_type++;
                        if (type && strcmp(cp, type) == 0)
                                ret = 1;
                        break;
                }
                case FS_TYPE_NEGOPT:
                        if (opt_in_list(cp, mnt_fs_get_options(fs)))
                                return 0;
                        break;
                case FS_TYPE_OPT:
                        if (!opt_in_list(cp, mnt_fs_get_options(fs)))
                                return 0;
                        break;
                }
        }
        if (checked_type == 0)
                return 1;
        return (cmp->negate ? !ret : ret);
}

/*
 * Check if a device exists
 */
static int device_exists(const char *device)
{
        struct stat st;

        if (stat(device, &st) == -1)
                return 0;
        if (!S_ISBLK(st.st_mode))
                return 0;
        return 1;
}

static int fs_ignored_type(struct libmnt_fs *fs)
{
        const char **ip, *type;

        if (mnt_fs_is_netfs(fs) || mnt_fs_is_pseudofs(fs) || mnt_fs_is_swaparea(fs))
                return 1;

        type = mnt_fs_get_fstype(fs);

        for(ip = ignored_types; type && *ip; ip++) {
                if (strcmp(type, *ip) == 0)
                        return 1;
        }

        return 0;
}

/* Check if we should ignore this filesystem. */
static int ignore(struct libmnt_fs *fs)
{
        const char *type;

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

        /*
         * If this is a bind mount, ignore it.
         */
        if (opt_in_list("bind", mnt_fs_get_options(fs))) {
                warnx(_("%s: skipping bad line in /etc/fstab: "
                        "bind mount with nonzero fsck pass number"),
                        mnt_fs_get_target(fs));
                return 1;
        }

        /*
         * ignore devices that don't exist and have the "nofail" mount option
         */
        if (!device_exists(fs_get_device(fs))) {
                if (opt_in_list("nofail", mnt_fs_get_options(fs))) {
                        if (verbose)
                                printf(_("%s: skipping nonexistent device\n"),
                                                        fs_get_device(fs));
                        return 1;
                }
                if (verbose)
                        printf(_("%s: nonexistent device (\"nofail\" fstab "
                                 "option may be used to skip this device)\n"),
                                fs_get_device(fs));
        }

        fs_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;

        type = mnt_fs_get_fstype(fs);
        if (!type) {
                if (verbose)
                        printf(_("%s: skipping unknown filesystem type\n"),
                                fs_get_device(fs));
                return 1;
        }

        /* Are we ignoring this type? */
        if (fs_ignored_type(fs))
                return 1;



        /* See if the <fsck.fs> program is available. */
        if (!find_fsck(type, NULL)) {
                if (fs_check_required(type))
                        warnx(_("cannot check %s: fsck.%s not found"),
                                fs_get_device(fs), type);
                return 1;
        }

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

static int count_slaves(dev_t disk)
{
        DIR *dir;
        struct dirent *dp;
        char dirname[PATH_MAX];
        int count = 0;

        snprintf(dirname, sizeof(dirname),
                        "/sys/dev/block/%u:%u/slaves/",
                        major(disk), minor(disk));

        if (!(dir = opendir(dirname)))
                return -1;

        while ((dp = readdir(dir)) != NULL) {
#ifdef _DIRENT_HAVE_D_TYPE
                if (dp->d_type != DT_UNKNOWN && dp->d_type != DT_LNK)
                        continue;
#endif
                if (dp->d_name[0] == '.' &&
                    ((dp->d_name[1] == 0) ||
                     ((dp->d_name[1] == '.') && (dp->d_name[2] == 0))))
                        continue;

                count++;
        }

        closedir(dir);
        return count;
}

/*
 * Returns TRUE if a partition on the same disk is already being
 * checked.
 */
static int disk_already_active(struct libmnt_fs *fs)
{
        struct fsck_instance *inst;
        dev_t disk;

        if (force_all_parallel)
                return 0;

        if (instance_list && fs_is_stacked(instance_list->fs))
                /* any instance for a stacked device is already running */
                return 1;

        disk = fs_get_disk(fs, 1);

        /*
         * If we don't know the base device, assume that the device is
         * already active if there are any fsck instances running.
         *
         * Don't check a stacked device with any other disk too.
         */
        if (!disk || fs_is_stacked(fs))
                return (instance_list != NULL);

        for (inst = instance_list; inst; inst = inst->next) {
                dev_t idisk = fs_get_disk(inst->fs, 0);

                if (!idisk || disk == idisk)
                        return 1;
        }

        return 0;
}

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

        struct libmnt_fs *fs;
        struct libmnt_iter *itr = mnt_new_iter(MNT_ITER_FORWARD);

        if (!itr)
                err(FSCK_EX_ERROR, _("failed to allocate iterator"));

        /*
         * 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()).
         */
        while (mnt_table_next_fs(fstab, itr, &fs) == 0) {
                if (ignore(fs)) {
                        fs_set_done(fs);
                        continue;
                }
        }

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

        /*
         * Find and check the root filesystem.
         */
        if (!parallel_root) {
                fs = mnt_table_find_target(fstab, "/", MNT_ITER_FORWARD);
                if (fs) {
                        if (!skip_root &&
                            !fs_is_done(fs) &&
                            !(ignore_mounted && is_mounted(fs))) {
                                status |= fsck_device(fs, 1);
                                status |= wait_many(FLAG_WAIT_ALL);
                                if (status > FSCK_EX_NONDESTRUCT) {
                                        mnt_free_iter(itr);
                                        return status;
                                }
                        }
                        fs_set_done(fs);
                }
        }

        /*
         * This is for the bone-headed user who enters the root
         * filesystem twice.  Skip root will skip all root entries.
         */
        if (skip_root) {
                mnt_reset_iter(itr, MNT_ITER_FORWARD);

                while(mnt_table_next_fs(fstab, itr, &fs) == 0) {
                        const char *tgt = mnt_fs_get_target(fs);

                        if (tgt && strcmp(tgt, "/") == 0)
                                fs_set_done(fs);
                }
        }

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

                mnt_reset_iter(itr, MNT_ITER_FORWARD);

                while(mnt_table_next_fs(fstab, itr, &fs) == 0) {

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

                        /*
                         * 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);
        mnt_free_iter(itr);
        return status;
}

static void __attribute__((__noreturn__)) usage(void)
{
        FILE *out = stdout;
        fputs(USAGE_HEADER, out);
        fprintf(out, _(" %s [options] -- [fs-options] [<filesystem> ...]\n"),
                         program_invocation_short_name);

        fputs(USAGE_SEPARATOR, out);
        fputs(_("Check and repair a Linux filesystem.\n"), out);

        fputs(USAGE_OPTIONS, out);
        fputs(_(" -A         check all filesystems\n"), out);
        fputs(_(" -C [<fd>]  display progress bar; file descriptor is for GUIs\n"), out);
        fputs(_(" -l         lock the device to guarantee exclusive access\n"), out);
        fputs(_(" -M         do not check mounted filesystems\n"), out);
        fputs(_(" -N         do not execute, just show what would be done\n"), out);
        fputs(_(" -P         check filesystems in parallel, including root\n"), out);
        fputs(_(" -R         skip root filesystem; useful only with '-A'\n"), out);
        fputs(_(" -r [<fd>]  report statistics for each device checked;\n"
                "            file descriptor is for GUIs\n"), out);
        fputs(_(" -s         serialize the checking operations\n"), out);
        fputs(_(" -T         do not show the title on startup\n"), out);
        fputs(_(" -t <type>  specify filesystem types to be checked;\n"
                "            <type> is allowed to be a comma-separated list\n"), out);
        fputs(_(" -V         explain what is being done\n"), out);

        fputs(USAGE_SEPARATOR, out);
        printf( " -?, --help     %s\n", USAGE_OPTSTR_HELP);
        printf( "     --version  %s\n", USAGE_OPTSTR_VERSION);
        fputs(USAGE_SEPARATOR, out);
        fputs(_("See the specific fsck.* commands for available fs-options."), out);
        printf(USAGE_MAN_TAIL("fsck(8)"));
        exit(FSCK_EX_OK);
}

static void signal_cancel(int sig __attribute__((__unused__)))
{
        cancel_requested++;
}

static void parse_argv(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;
        int     report_stats_fd = -1;

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

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

        for (i=1; i < argc; i++) {
                arg = argv[i];
                if (!arg)
                        continue;

                /* the only two longopts to satisfy UL standards */
                if (!opts_for_fsck && !strcmp(arg, "--help"))
                        usage();
                if (!opts_for_fsck && !strcmp(arg, "--version"))
                        print_version(FSCK_EX_OK);

                if ((arg[0] == '/' && !opts_for_fsck) || strchr(arg, '=')) {
                        if (num_devices >= MAX_DEVICES)
                                errx(FSCK_EX_ERROR, _("too many devices"));

                        dev = mnt_resolve_spec(arg, mntcache);

                        if (!dev && strchr(arg, '=')) {
                                /*
                                 * Check to see if we failed because
                                 * /proc/partitions isn't found.
                                 */
                                if (access(_PATH_PROC_PARTITIONS, R_OK) < 0) {
                                        warn(_("cannot open %s"),
                                                _PATH_PROC_PARTITIONS);
                                        errx(FSCK_EX_ERROR, _("Is /proc mounted?"));
                                }
                                /*
                                 * Check to see if this is because
                                 * we're not running as root
                                 */
                                if (geteuid())
                                        errx(FSCK_EX_ERROR,
                                                _("must be root to scan for matching filesystems: %s"),
                                                arg);
                                else
                                        errx(FSCK_EX_ERROR,
                                                _("couldn't find matching filesystem: %s"),
                                                arg);
                        }
                        devices[num_devices++] = dev ? dev : xstrdup(arg);
                        continue;
                }
                if (arg[0] != '-' || opts_for_fsck) {
                        if (num_args >= MAX_ARGS)
                                errx(FSCK_EX_ERROR, _("too many arguments"));
                        args[num_args++] = xstrdup(arg);
                        continue;
                }
                for (j=1; arg[j]; j++) {
                        if (opts_for_fsck) {
                                options[++opt] = arg[j];
                                continue;
                        }
                        switch (arg[j]) {
                        case 'A':
                                doall = 1;
                                break;
                        case 'C':
                                progress = 1;
                                if (arg[j+1]) {                                 /* -C<fd> */
                                        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] != '-') {   /* -C <fd> */
                                        progress_fd = string_to_int(argv[i+1]);
                                        if (progress_fd < 0)
                                                progress_fd = 0;
                                        else {
                                                ++i;
                                                goto next_arg;
                                        }
                                }
                                break;
                        case 'l':
                                lockdisk = 1;
                                break;
                        case 'V':
                                verbose++;
                                break;
                        case 'N':
                                noexecute = 1;
                                break;
                        case 'R':
                                skip_root = 1;
                                break;
                        case 'T':
                                notitle = 1;
                                break;
                        case 'M':
                                ignore_mounted = 1;
                                break;
                        case 'P':
                                parallel_root = 1;
                                break;
                        case 'r':
                                report_stats = 1;
                                if (arg[j+1]) {                                 /* -r<fd> */
                                        report_stats_fd = strtou32_or_err(arg+j+1, _("invalid argument of -r"));
                                        goto next_arg;
                                } else if (i+1 < argc && *argv[i+1] >= '0' && *argv[i+1] <= '9') {      /* -r <fd> */
                                        report_stats_fd = strtou32_or_err(argv[i+1], _("invalid argument of -r"));
                                        ++i;
                                        goto next_arg;
                                }
                                break;
                        case 's':
                                serialize = 1;
                                break;
                        case 't':
                                tmp = NULL;
                                if (fstype)
                                        errx(FSCK_EX_USAGE,
                                                _("option '%s' may be specified only once"), "-t");
                                if (arg[j+1])
                                        tmp = arg+j+1;
                                else if ((i+1) < argc)
                                        tmp = argv[++i];
                                else
                                        errx(FSCK_EX_USAGE,
                                                _("option '%s' requires an argument"), "-t");
                                fstype = xstrdup(tmp);
                                compile_fs_type(fstype, &fs_type_compiled);
                                goto next_arg;
                        case '-':
                                opts_for_fsck++;
                                break;
                        case '?':
                                usage();
                                break;
                        default:
                                options[++opt] = arg[j];
                                break;
                        }
                }
        next_arg:
                if (opt) {
                        options[0] = '-';
                        options[++opt] = '\0';
                        if (num_args >= MAX_ARGS)
                                errx(FSCK_EX_ERROR, _("too many arguments"));
                        args[num_args++] = xstrdup(options);
                        opt = 0;
                }
        }

        /* Validate the report stats file descriptor to avoid disasters */
        if (report_stats_fd >= 0) {
                report_stats_file = fdopen(report_stats_fd, "w");
                if (!report_stats_file)
                        err(FSCK_EX_ERROR,
                                _("invalid argument of -r: %d"),
                                report_stats_fd);
        }

        if (getenv("FSCK_FORCE_ALL_PARALLEL"))
                force_all_parallel++;
        if ((tmp = getenv("FSCK_MAX_INST")))
            max_running = atoi(tmp);
}

int main(int argc, char *argv[])
{
        int i, status = 0;
        int interactive = 0;
        struct libmnt_fs *fs;
        const char *path = getenv("PATH");

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

        setlocale(LC_MESSAGES, "");
        setlocale(LC_CTYPE, "");
        bindtextdomain(PACKAGE, LOCALEDIR);
        textdomain(PACKAGE);
        close_stdout_atexit();

        strutils_set_exitcode(FSCK_EX_USAGE);
        mnt_init_debug(0);              /* init libmount debug mask */
        mntcache = mnt_new_cache();     /* no fatal error if failed */

        parse_argv(argc, argv);

        if (!notitle)
                printf(UTIL_LINUX_VERSION);

        load_fs_info();

        fsck_path = xstrdup(path && *path ? path : FSCK_DEFAULT_PATH);

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

        if (lockdisk && (doall || num_devices > 1)) {
                warnx(_("the -l option can be used with one "
                                  "device only -- ignore"));
                lockdisk = 0;
        }

        /* 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 = add_dummy_fs(devices[i]);
                else if (fs_ignored_type(fs))
                        continue;
                if (ignore_mounted && is_mounted(fs))
                        continue;
                status |= 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);
        free(fsck_path);
        mnt_unref_cache(mntcache);
        mnt_unref_table(fstab);
        mnt_unref_table(mtab);
        return status;
}