cmd/fs.d/df.c

	df.c revision 90a1a13596fed05f78bee9f85d396628cc310803
/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*  Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */
/*    All Rights Reserved   */


/*
 * Copyright (c) 1989, 2010, Oracle and/or its affiliates. All rights reserved.
 */


#include <dlfcn.h>
#include <stdio.h>
#include <stdarg.h>
#include <string.h>
#include <locale.h>
#include <libintl.h>
#include <stdlib.h>
#include <ftw.h>
#include <errno.h>
#include <sys/types.h>
#include <unistd.h>
#include <sys/statvfs.h>
#include <sys/stat.h>
#include <sys/param.h>
#include <sys/mnttab.h>
#include <sys/mntent.h>
#include <sys/vfstab.h>
#include <sys/wait.h>
#include <sys/mkdev.h>
#include <sys/int_limits.h>
#include <sys/zone.h>
#include <libzfs.h>

#include "fslib.h"

extern char *default_fstype(char *);

/*
 * General notice:
 * String pointers in this code may point to statically allocated memory
 * or dynamically allocated memory. Furthermore, a dynamically allocated
 * string may be pointed to by more than one pointer. This does not pose
 * a problem because malloc'ed memory is never free'd (so we don't need
 * to remember which pointers point to malloc'ed memory).
 */

/*
 * TRANSLATION_NOTE
 * Only strings passed as arguments to the TRANSLATE macro need to
 * be translated.
 */

#ifndef MNTTYPE_LOFS
#define MNTTYPE_LOFS        "lofs"
#endif

#define EQ(s1, s2)      (strcmp(s1, s2) == 0)
#define NEW(type)       xmalloc(sizeof (type))
#define CLEAR(var)      (void) memset(&(var), 0, sizeof (var))
#define MAX(a, b)       ((a) > (b) ? (a) : (b))
#define MAX3(a, b, c)       MAX(a, MAX(b, c))
#define TRANSLATE(s)        new_string(gettext(s))

#define MAX_OPTIONS     36
#define N_FSTYPES       20
#define MOUNT_TABLE_ENTRIES 40  /* initial allocation */
#define MSGBUF_SIZE     1024
#define LINEBUF_SIZE        256 /* either input or output lines */

#define BLOCK_SIZE      512 /* when reporting in terms of blocks */

#define DEVNM_CMD       "devnm"
#define FS_LIBPATH      "/usr/lib/fs/"
#define MOUNT_TAB       "/etc/mnttab"
#define VFS_TAB         "/etc/vfstab"
#define REMOTE_FS       "/etc/dfs/fstypes"

#define NUL         '\0'
#define FALSE           0
#define TRUE            1

/*
 * Formatting constants
 */
#define IBCS2_FILESYSTEM_WIDTH  15  /* Truncate to match ISC/SCO */
#define IBCS2_MOUNT_POINT_WIDTH 10  /* Truncate to match ISC/SCO */
#define FILESYSTEM_WIDTH    20
#define MOUNT_POINT_WIDTH   19
#define SPECIAL_DEVICE_WIDTH    18
#define FSTYPE_WIDTH        8
#define BLOCK_WIDTH     8
#define NFILES_WIDTH        8
#define KBYTE_WIDTH     11
#define AVAILABLE_WIDTH     10
#define SCALED_WIDTH        6
#define CAPACITY_WIDTH      9
#define BSIZE_WIDTH     6
#define FRAGSIZE_WIDTH      7
#define FSID_WIDTH      7
#define FLAG_WIDTH      8
#define NAMELEN_WIDTH       7
#define MNT_SPEC_WIDTH      MOUNT_POINT_WIDTH + SPECIAL_DEVICE_WIDTH + 2

/*
 * Flags for the errmsg() function
 */
#define ERR_NOFLAGS     0x0
#define ERR_NONAME      0x1 /* don't include the program name */
                    /* as a prefix */
#define ERR_FATAL       0x2 /* call exit after printing the */
                    /* message */
#define ERR_PERROR      0x4 /* append an errno explanation to */
                    /* the message */
#define ERR_USAGE       0x8 /* print the usage line after the */
                    /* message */

#define NUMBER_WIDTH        40

/*
 * A numbuf_t is used when converting a number to a string representation
 */
typedef char numbuf_t[ NUMBER_WIDTH ];

/*
 * We use bool_int instead of int to make clear which variables are
 * supposed to be boolean
 */
typedef int bool_int;

struct mtab_entry {
    bool_int    mte_dev_is_valid;
    dev_t       mte_dev;
    bool_int    mte_ignore; /* the "ignore" option was set */
    struct extmnttab    *mte_mount;
};


struct df_request {
    bool_int        dfr_valid;
    char            *dfr_cmd_arg;   /* what the user specified */
    struct mtab_entry   *dfr_mte;
    char            *dfr_fstype;
    int         dfr_index;  /* to make qsort stable */
};

#define DFR_MOUNT_POINT(dfrp)   (dfrp)->dfr_mte->mte_mount->mnt_mountp
#define DFR_SPECIAL(dfrp)   (dfrp)->dfr_mte->mte_mount->mnt_special
#define DFR_FSTYPE(dfrp)    (dfrp)->dfr_mte->mte_mount->mnt_fstype
#define DFR_ISMOUNTEDFS(dfrp)   ((dfrp)->dfr_mte != NULL)

#define DFRP(p)         ((struct df_request *)(p))

typedef void (*output_func)(struct df_request *, struct statvfs64 *);

struct df_output {
    output_func dfo_func;   /* function that will do the output */
    int     dfo_flags;
};

/*
 * Output flags
 */
#define DFO_NOFLAGS 0x0
#define DFO_HEADER  0x1     /* output preceded by header */
#define DFO_STATVFS 0x2     /* must do a statvfs64(2) */


static char *program_name;
static char df_options[MAX_OPTIONS] = "-";
static size_t   df_options_len = 1;
static char *o_option_arg;          /* arg to the -o option */
static char *FSType;
static char *remote_fstypes[N_FSTYPES+1];   /* allocate an extra one */
                        /* to use as a terminator */

/*
 * The following three variables support an in-memory copy of the mount table
 * to speedup searches.
 */
static struct mtab_entry    *mount_table;   /* array of mtab_entry's */
static size_t           mount_table_entries;
static size_t           mount_table_allocated_entries;

static bool_int     F_option;
static bool_int     V_option;
static bool_int     P_option;   /* Added for XCU4 compliance */
static bool_int     Z_option;
static bool_int     v_option;
static bool_int     a_option;
static bool_int     b_option;
static bool_int     e_option;
static bool_int     g_option;
static bool_int     h_option;
static bool_int     k_option;
static bool_int     l_option;
static bool_int     m_option;
static bool_int     n_option;
static bool_int     t_option;
static bool_int     o_option;

static bool_int     tty_output;
static bool_int     use_scaling;
static int      scale;

static void usage(void);
static void do_devnm(int, char **);
static void do_df(int, char **) __NORETURN;
static void parse_options(int, char **);
static char *basename(char *);

static libzfs_handle_t *(*_libzfs_init)(void);
static zfs_handle_t *(*_zfs_open)(libzfs_handle_t *, const char *, int);
static void (*_zfs_close)(zfs_handle_t *);
static uint64_t (*_zfs_prop_get_int)(zfs_handle_t *, zfs_prop_t);
static libzfs_handle_t *g_zfs;

/*
 * Dynamically check for libzfs, in case the user hasn't installed the SUNWzfs
 * packages.  A basic utility such as df shouldn't depend on optional
 * filesystems.
 */
static boolean_t
load_libzfs(void)
{
    void *hdl;

    if (_libzfs_init != NULL)
        return (g_zfs != NULL);

    if ((hdl = dlopen("libzfs.so", RTLD_LAZY)) != NULL) {
        _libzfs_init = (libzfs_handle_t *(*)(void))dlsym(hdl,
            "libzfs_init");
        _zfs_open = (zfs_handle_t *(*)())dlsym(hdl, "zfs_open");
        _zfs_close = (void (*)())dlsym(hdl, "zfs_close");
        _zfs_prop_get_int = (uint64_t (*)())
            dlsym(hdl, "zfs_prop_get_int");

        if (_libzfs_init != NULL) {
            assert(_zfs_open != NULL);
            assert(_zfs_close != NULL);
            assert(_zfs_prop_get_int != NULL);

            g_zfs = _libzfs_init();
        }
    }

    return (g_zfs != NULL);
}

int
main(int argc, char *argv[])
{
    (void) setlocale(LC_ALL, "");

#if !defined(TEXT_DOMAIN)       /* Should be defined by cc -D */
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);

    program_name = basename(argv[0]);

    if (EQ(program_name, DEVNM_CMD))
        do_devnm(argc, argv);

    parse_options(argc, argv);

    /*
     * The k_option implies SunOS 4.x compatibility: when the special
     * device name is too long the line will be split except when the
     * output has been redirected.
     * This is also valid for the -h option.
     */

    if (use_scaling || k_option || P_option || v_option)
        tty_output = isatty(1);

    do_df(argc - optind, &argv[optind]);
    /* NOTREACHED */
}


/*
 * Prints an error message to stderr.
 */
/* VARARGS2 */
static void
errmsg(int flags, char *fmt, ...)
{
    char buf[MSGBUF_SIZE];
    va_list ap;
    int cc;
    int offset;

    if (flags & ERR_NONAME)
        offset = 0;
    else
        offset = sprintf(buf, "%s: ", program_name);

    va_start(ap, fmt);
    cc = vsprintf(&buf[offset], gettext(fmt), ap);
    offset += cc;
    va_end(ap);

    if (flags & ERR_PERROR) {
        if (buf[offset-1] != ' ')
            (void) strcat(buf, " ");
        (void) strcat(buf, strerror(errno));
    }
    (void) fprintf(stderr, "%s\n", buf);
    if (flags & ERR_USAGE)
        usage();
    if (flags & ERR_FATAL)
        exit(1);
}


static void
usage(void)
{
    errmsg(ERR_NONAME,
        "Usage: %s [-F FSType] [-abeghklmntPVvZ]"
        " [-o FSType-specific_options]"
        " [directory | block_device | resource]", program_name);
    exit(1);
    /* NOTREACHED */
}


static char *
new_string(char *s)
{
    char *p = NULL;

    if (s) {
        p = strdup(s);
        if (p)
            return (p);
        errmsg(ERR_FATAL, "out of memory");
        /* NOTREACHED */
    }
    return (p);
}


/*
 * Allocate memory using malloc but terminate if the allocation fails
 */
static void *
xmalloc(size_t size)
{
    void *p = malloc(size);

    if (p)
        return (p);
    errmsg(ERR_FATAL, "out of memory");
    /* NOTREACHED */
    return (NULL);
}


/*
 * Allocate memory using realloc but terminate if the allocation fails
 */
static void *
xrealloc(void *ptr, size_t size)
{
    void *p = realloc(ptr, size);

    if (p)
        return (p);
    errmsg(ERR_FATAL, "out of memory");
    /* NOTREACHED */
    return (NULL);
}


/*
 * fopen the specified file for reading but terminate if the fopen fails
 */
static FILE *
xfopen(char *file)
{
    FILE *fp = fopen(file, "r");

    if (fp == NULL)
        errmsg(ERR_FATAL + ERR_PERROR, "failed to open %s:", file);
    return (fp);
}


/*
 * Read remote file system types from REMOTE_FS into the
 * remote_fstypes array.
 */
static void
init_remote_fs(void)
{
    FILE    *fp;
    char    line_buf[LINEBUF_SIZE];
    size_t  fstype_index = 0;

    if ((fp = fopen(REMOTE_FS, "r")) == NULL) {
        errmsg(ERR_NOFLAGS,
            "Warning: can't open %s, ignored", REMOTE_FS);
        return;
    }

    while (fgets(line_buf, sizeof (line_buf), fp) != NULL) {
        char buf[LINEBUF_SIZE];

        (void) sscanf(line_buf, "%s", buf);
        remote_fstypes[fstype_index++] = new_string(buf);

        if (fstype_index == N_FSTYPES)
            break;
    }
    (void) fclose(fp);
}


/*
 * Returns TRUE if fstype is a remote file system type;
 * otherwise, returns FALSE.
 */
static int
is_remote_fs(char *fstype)
{
    char **p;
    static bool_int remote_fs_initialized;

    if (! remote_fs_initialized) {
        init_remote_fs();
        remote_fs_initialized = TRUE;
    }

    for (p = remote_fstypes; *p; p++)
        if (EQ(fstype, *p))
            return (TRUE);
    return (FALSE);
}


static char *
basename(char *s)
{
    char *p = strrchr(s, '/');

    return (p ? p+1 : s);
}


/*
 * Create a new "struct extmnttab" and make sure that its fields point
 * to malloc'ed memory
 */
static struct extmnttab *
mntdup(struct extmnttab *old)
{
    struct extmnttab *new = NEW(struct extmnttab);

    new->mnt_special = new_string(old->mnt_special);
    new->mnt_mountp  = new_string(old->mnt_mountp);
    new->mnt_fstype  = new_string(old->mnt_fstype);
    new->mnt_mntopts = new_string(old->mnt_mntopts);
    new->mnt_time    = new_string(old->mnt_time);
    new->mnt_major   = old->mnt_major;
    new->mnt_minor   = old->mnt_minor;
    return (new);
}


static void
mtab_error(char *mtab_file, int status)
{
    if (status == MNT_TOOLONG)
        errmsg(ERR_NOFLAGS, "a line in %s exceeds %d characters",
            mtab_file, MNT_LINE_MAX);
    else if (status == MNT_TOOMANY)
        errmsg(ERR_NOFLAGS,
            "a line in %s has too many fields", mtab_file);
    else if (status == MNT_TOOFEW)
        errmsg(ERR_NOFLAGS,
            "a line in %s has too few fields", mtab_file);
    else
        errmsg(ERR_NOFLAGS,
            "error while reading %s: %d", mtab_file, status);
    exit(1);
    /* NOTREACHED */
}


/*
 * Read the mount table from the specified file.
 * We keep the table in memory for faster lookups.
 */
static void
mtab_read_file(void)
{
    char        *mtab_file = MOUNT_TAB;
    FILE        *fp;
    struct extmnttab    mtab;
    int     status;

    fp = xfopen(mtab_file);

    resetmnttab(fp);
    mount_table_allocated_entries = MOUNT_TABLE_ENTRIES;
    mount_table_entries = 0;
    mount_table = xmalloc(
        mount_table_allocated_entries * sizeof (struct mtab_entry));

    while ((status = getextmntent(fp, &mtab, sizeof (struct extmnttab)))
        == 0) {
        struct mtab_entry *mtep;

        if (mount_table_entries == mount_table_allocated_entries) {
            mount_table_allocated_entries += MOUNT_TABLE_ENTRIES;
            mount_table = xrealloc(mount_table,
                mount_table_allocated_entries *
                sizeof (struct mtab_entry));
        }
        mtep = &mount_table[mount_table_entries++];
        mtep->mte_mount = mntdup(&mtab);
        mtep->mte_dev_is_valid = FALSE;
        mtep->mte_ignore = (hasmntopt((struct mnttab *)&mtab,
            MNTOPT_IGNORE) != NULL);
    }

    (void) fclose(fp);

    if (status == -1)           /* reached EOF */
        return;
    mtab_error(mtab_file, status);
    /* NOTREACHED */
}


/*
 * We use this macro when we want to record the option for the purpose of
 * passing it to the FS-specific df
 */
#define SET_OPTION(opt)     opt##_option = TRUE, \
                df_options[df_options_len++] = arg

static void
parse_options(int argc, char *argv[])
{
    int arg;

    opterr = 0; /* getopt shouldn't complain about unknown options */

    while ((arg = getopt(argc, argv, "F:o:abehkVtgnlmPvZ")) != EOF) {
        if (arg == 'F') {
            if (F_option)
                errmsg(ERR_FATAL + ERR_USAGE,
                    "more than one FSType specified");
            F_option = 1;
            FSType = optarg;
        } else if (arg == 'V' && ! V_option) {
            V_option = TRUE;
        } else if (arg == 'v' && ! v_option) {
            v_option = TRUE;
        } else if (arg == 'P' && ! P_option) {
            SET_OPTION(P);
        } else if (arg == 'a' && ! a_option) {
            SET_OPTION(a);
        } else if (arg == 'b' && ! b_option) {
            SET_OPTION(b);
        } else if (arg == 'e' && ! e_option) {
            SET_OPTION(e);
        } else if (arg == 'g' && ! g_option) {
            SET_OPTION(g);
        } else if (arg == 'h') {
            use_scaling = TRUE;
            scale = 1024;
        } else if (arg == 'k' && ! k_option) {
            SET_OPTION(k);
        } else if (arg == 'l' && ! l_option) {
            SET_OPTION(l);
        } else if (arg == 'm' && ! m_option) {
            SET_OPTION(m);
        } else if (arg == 'n' && ! n_option) {
            SET_OPTION(n);
        } else if (arg == 't' && ! t_option) {
            SET_OPTION(t);
        } else if (arg == 'o') {
            if (o_option)
                errmsg(ERR_FATAL + ERR_USAGE,
                "the -o option can only be specified once");
            o_option = TRUE;
            o_option_arg = optarg;
        } else if (arg == 'Z') {
            SET_OPTION(Z);
        } else if (arg == '?') {
            errmsg(ERR_USAGE, "unknown option: %c", optopt);
        }
    }

    /*
     * Option sanity checks
     */
    if (g_option && o_option)
        errmsg(ERR_FATAL, "-o and -g options are incompatible");
    if (l_option && o_option)
        errmsg(ERR_FATAL, "-o and -l options are incompatible");
    if (n_option && o_option)
        errmsg(ERR_FATAL, "-o and -n options are incompatible");
    if (use_scaling && o_option)
        errmsg(ERR_FATAL, "-o and -h options are incompatible");
}


/*
 * Check if the user-specified argument is a resource name.
 * A resource name is whatever is placed in the mnt_special field of
 * struct mnttab. In the case of NFS, a resource name has the form
 * hostname:pathname
 * We try to find an exact match between the user-specified argument
 * and the mnt_special field of a mount table entry.
 * We also use the heuristic of removing the basename from the user-specified
 * argument and repeating the test until we get a match. This works
 * fine for NFS but may fail for other remote file system types. However,
 * it is guaranteed that the function will not fail if the user specifies
 * the exact resource name.
 * If successful, this function sets the 'dfr_mte' field of '*dfrp'
 */
static void
resource_mount_entry(struct df_request *dfrp)
{
    char *name;

    /*
     * We need our own copy since we will modify the string
     */
    name = new_string(dfrp->dfr_cmd_arg);

    for (;;) {
        char *p;
        int i;

        /*
         * Compare against all known mount points.
         * We start from the most recent mount, which is at the
         * end of the array.
         */
        for (i = mount_table_entries - 1; i >= 0; i--) {
            struct mtab_entry *mtep = &mount_table[i];

            if (EQ(name, mtep->mte_mount->mnt_special)) {
                dfrp->dfr_mte = mtep;
                break;
            }
        }

        /*
         * Remove the last component of the pathname.
         * If there is no such component, this is not a resource name.
         */
        p = strrchr(name, '/');
        if (p == NULL)
            break;
        *p = NUL;
    }
}


/*
 * Try to match the command line argument which is a block special device
 * with the special device of one of the mounted file systems.
 * If one is found, set the appropriate field of 'dfrp' to the mount
 * table entry.
 */
static void
bdev_mount_entry(struct df_request *dfrp)
{
    int i;
    char *special = dfrp->dfr_cmd_arg;

    /*
     * Compare against all known mount points.
     * We start from the most recent mount, which is at the
     * end of the array.
     */
    for (i = mount_table_entries - 1; i >= 0; i--) {
        struct mtab_entry *mtep = &mount_table[i];

        if (EQ(special, mtep->mte_mount->mnt_special)) {
            dfrp->dfr_mte = mtep;
            break;
        }
    }
}

static struct mtab_entry *
devid_matches(int i, dev_t devno)
{
    struct mtab_entry   *mtep = &mount_table[i];
    struct extmnttab    *mtp = mtep->mte_mount;
    /* int  len = strlen(mtp->mnt_mountp); */

    if (EQ(mtp->mnt_fstype, MNTTYPE_SWAP))
        return (NULL);
    /*
     * check if device numbers match. If there is a cached device number
     * in the mtab_entry, use it, otherwise get the device number
     * either from the mnttab entry or by stat'ing the mount point.
     */
    if (! mtep->mte_dev_is_valid) {
        struct stat64 st;
        dev_t dev = NODEV;

        dev = makedev(mtp->mnt_major, mtp->mnt_minor);
        if (dev == 0)
            dev = NODEV;
        if (dev == NODEV) {
            if (stat64(mtp->mnt_mountp, &st) == -1) {
                return (NULL);
            } else {
                dev = st.st_dev;
            }
        }
        mtep->mte_dev = dev;
        mtep->mte_dev_is_valid = TRUE;
    }
    if (mtep->mte_dev == devno) {
        return (mtep);
    }
    return (NULL);
}

/*
 * Find the mount point under which the user-specified path resides
 * and set the 'dfr_mte' field of '*dfrp' to point to the mount table entry.
 */
static void
path_mount_entry(struct df_request *dfrp, dev_t devno)
{
    char            dirpath[MAXPATHLEN];
    char            *dir = dfrp->dfr_cmd_arg;
    struct mtab_entry   *match, *tmatch;
    int i;

    /*
     * Expand the given path to get a canonical version (i.e. an absolute
     * path without symbolic links).
     */
    if (realpath(dir, dirpath) == NULL) {
        errmsg(ERR_PERROR, "cannot canonicalize %s:", dir);
        return;
    }
    /*
     * If the mnt point is lofs, search from the top of entries from
     * /etc/mnttab and return the entry that best matches the pathname.
     * For non-lofs mount points, return the first entry from the bottom
     * of the entries in /etc/mnttab that matches on the devid field
     */
    match = NULL;
    if (dfrp->dfr_fstype && EQ(dfrp->dfr_fstype, MNTTYPE_LOFS)) {
        struct extmnttab *entryp;
        char *path, *mountp;
        char p, m;
        int score;
        int best_score = 0;
        int best_index = -1;

        for (i = 0; i < mount_table_entries; i++) {
            entryp = mount_table[i].mte_mount;

            if (!EQ(entryp->mnt_fstype, MNTTYPE_LOFS))
                continue;

            path = dirpath;
            mountp = entryp->mnt_mountp;
            score = 0;
            /*
             * Count the number of matching characters
             * until either path or mountpoint is exhausted
             */
            while ((p = *path++) == (m = *mountp++)) {
                score++;

                if (p == '\0' || m == '\0')
                    break;
            }

            /* Both exhausted so we have a match */
            if (p == '\0' && m == '\0') {
                best_index = i;
                break;
            }

            /*
             * We have exhausted the mountpoint and the current
             * character in the path is a '/' hence the full path
             * traverses this mountpoint.
             * Record this as the best candidate so far.
             */
            if (p == '/' && m == '\0') {
                if (score > best_score) {
                    best_index = i;
                    best_score = score;
                }
            }
        }

        if (best_index > -1)
            match = &mount_table[best_index];
    } else {
        for (i = mount_table_entries - 1; i >= 0; i--) {
            if (tmatch = devid_matches(i, devno)) {
                /*
                 * If executing in a zone, there might be lofs
                 * mounts for which the real mount point is
                 * invisible; accept the "best fit" for this
                 * devid.
                 */
                match = tmatch;
                if (!EQ(match->mte_mount->mnt_fstype,
                    MNTTYPE_LOFS)) {
                    break;
                }
            }
        }
    }
    if (! match) {
        errmsg(ERR_NOFLAGS,
            "Could not find mount point for %s", dir);
        return;
    }
    dfrp->dfr_mte = match;
}

/*
 * Execute a single FS-specific df command for all given requests
 * Return 0 if successful, 1 otherwise.
 */
static int
run_fs_specific_df(struct df_request request_list[], int entries)
{
    int i;
    int argv_index;
    char    **argv;
    size_t  size;
    pid_t   pid;
    int status;
    char    cmd_path[MAXPATHLEN];
    char    *fstype;

    if (entries == 0)
        return (0);

    fstype = request_list[0].dfr_fstype;

    if (F_option && ! EQ(FSType, fstype))
        return (0);

    (void) sprintf(cmd_path, "%s%s/df", FS_LIBPATH, fstype);
    /*
     * Argv entries:
     *      1 for the path
     *      2 for -o <options>
     *      1 for the generic options that we propagate
     *      1 for the terminating NULL pointer
     *      n for the number of user-specified arguments
     */
    size = (5 + entries) * sizeof (char *);
    argv = xmalloc(size);
    (void) memset(argv, 0, size);

    argv[0] = cmd_path;
    argv_index = 1;
    if (o_option) {
        argv[argv_index++] = "-o";
        argv[argv_index++] = o_option_arg;
    }

    /*
     * Check if we need to propagate any generic options
     */
    if (df_options_len > 1)
        argv[argv_index++] = df_options;

    /*
     * If there is a user-specified path, we pass that to the
     * FS-specific df. Otherwise, we are guaranteed to have a mount
     * point, since a request without a user path implies that
     * we are reporting only on mounted file systems.
     */
    for (i = 0; i < entries; i++) {
        struct df_request *dfrp = &request_list[i];

        argv[argv_index++] = (dfrp->dfr_cmd_arg == NULL)
            ? DFR_MOUNT_POINT(dfrp)
            : dfrp->dfr_cmd_arg;
    }

    if (V_option) {
        for (i = 0; i < argv_index-1; i++)
            (void) printf("%s ", argv[i]);
        (void) printf("%s\n", argv[i]);
        return (0);
    }

    pid = fork();

    if (pid == -1) {
        errmsg(ERR_PERROR, "cannot fork process:");
        return (1);
    } else if (pid == 0) {
        (void) execv(cmd_path, argv);
        if (errno == ENOENT)
            errmsg(ERR_NOFLAGS,
                "operation not applicable for FSType %s",
                fstype);
        else
            errmsg(ERR_PERROR, "cannot execute %s:", cmd_path);
        exit(2);
    }

    /*
     * Reap the child
     */
    for (;;) {
        pid_t wpid = waitpid(pid, &status, 0);

        if (wpid == -1)
            if (errno == EINTR)
                continue;
            else {
                errmsg(ERR_PERROR, "waitpid error:");
                return (1);
            }
        else
            break;
    }

    return ((WIFEXITED(status) && WEXITSTATUS(status) == 0) ? 0 : 1);
}


/*
 * Remove from the request list all requests that do not apply.
 * Notice that the subsequent processing of the requests depends on
 * the sanity checking performed by this function.
 */
static int
prune_list(struct df_request request_list[],
        size_t n_requests,
        size_t *valid_requests)
{
    size_t  i;
    size_t  n_valid = 0;
    int errors = 0;

    for (i = 0; i < n_requests; i++) {
        struct df_request *dfrp = &request_list[i];

        /*
         * Skip file systems that are not mounted if either the
         * -l or -n options were specified. If none of these options
         * are present, the appropriate FS-specific df will be invoked.
         */
        if (! DFR_ISMOUNTEDFS(dfrp)) {
            if (l_option || n_option) {
                errmsg(ERR_NOFLAGS,
                    "%s option incompatible with unmounted "
                    "special device (%s)",
                    l_option ? "-l" : "-n", dfrp->dfr_cmd_arg);
                dfrp->dfr_valid = FALSE;
                errors++;
            }
            else
                n_valid++;
            continue;
        }

        /*
         * Check for inconsistency between the argument of -F and
         * the actual file system type.
         * If there is an inconsistency and the user specified a
         * path, this is an error since we are asked to interpret
         * the path using the wrong file system type. If there is
         * no path associated with this request, we quietly ignore it.
         */
        if (F_option && ! EQ(dfrp->dfr_fstype, FSType)) {
            dfrp->dfr_valid = FALSE;
            if (dfrp->dfr_cmd_arg != NULL) {
                errmsg(ERR_NOFLAGS,
                "Warning: %s mounted as a %s file system",
                    dfrp->dfr_cmd_arg, dfrp->dfr_fstype);
                errors++;
            }
            continue;
        }

        /*
         * Skip remote file systems if the -l option is present
         */
        if (l_option && is_remote_fs(dfrp->dfr_fstype)) {
            if (dfrp->dfr_cmd_arg != NULL) {
                errmsg(ERR_NOFLAGS,
                    "Warning: %s is not a local file system",
                    dfrp->dfr_cmd_arg);
                errors++;
            }
            dfrp->dfr_valid = FALSE;
            continue;
        }

        /*
         * Skip file systems mounted as "ignore" unless the -a option
         * is present, or the user explicitly specified them on
         * the command line.
         */
        if (dfrp->dfr_mte->mte_ignore &&
            ! (a_option || dfrp->dfr_cmd_arg)) {
            dfrp->dfr_valid = FALSE;
            continue;
        }

        n_valid++;
    }
    *valid_requests = n_valid;
    return (errors);
}


/*
 * Print the appropriate header for the requested output format.
 * Options are checked in order of their precedence.
 */
static void
print_header(void)
{
    if (use_scaling) { /* this comes from the -h option */
        int arg = 'h';

        (void) printf("%-*s %*s %*s %*s %-*s %s\n",
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            SCALED_WIDTH, TRANSLATE("Size"),
            SCALED_WIDTH, TRANSLATE("Used"),
            AVAILABLE_WIDTH, TRANSLATE("Available"),
            CAPACITY_WIDTH, TRANSLATE("Capacity"),
            TRANSLATE("Mounted on"));
        SET_OPTION(h);
        return;
    }
    if (k_option) {
        int arg = 'h';

        (void) printf(gettext("%-*s %*s %*s %*s %-*s %s\n"),
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            KBYTE_WIDTH, TRANSLATE("1024-blocks"),
            KBYTE_WIDTH, TRANSLATE("Used"),
            KBYTE_WIDTH, TRANSLATE("Available"),
            CAPACITY_WIDTH, TRANSLATE("Capacity"),
            TRANSLATE("Mounted on"));
        SET_OPTION(h);
        return;
    }
    if (m_option) {
        int arg = 'h';

        (void) printf(gettext("%-*s %*s %*s %*s %-*s %s\n"),
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            KBYTE_WIDTH, TRANSLATE("1M-blocks"),
            KBYTE_WIDTH, TRANSLATE("Used"),
            KBYTE_WIDTH, TRANSLATE("Available"),
            CAPACITY_WIDTH, TRANSLATE("Capacity"),
            TRANSLATE("Mounted on"));
        SET_OPTION(h);
        return;
    }
    /* Added for XCU4 compliance */
    if (P_option) {
        int arg = 'h';

        (void) printf(gettext("%-*s %*s %*s %*s %-*s %s\n"),
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            KBYTE_WIDTH, TRANSLATE("512-blocks"),
            KBYTE_WIDTH, TRANSLATE("Used"),
            KBYTE_WIDTH, TRANSLATE("Available"),
            CAPACITY_WIDTH, TRANSLATE("Capacity"),
            TRANSLATE("Mounted on"));

        SET_OPTION(h);
        return;
    }
    /* End XCU4 */
    if (v_option) {
        (void) printf("%-*s %-*s %*s %*s %*s %-*s\n",
            IBCS2_MOUNT_POINT_WIDTH, TRANSLATE("Mount Dir"),
            IBCS2_FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            BLOCK_WIDTH, TRANSLATE("blocks"),
            BLOCK_WIDTH, TRANSLATE("used"),
            BLOCK_WIDTH, TRANSLATE("free"),
            CAPACITY_WIDTH, TRANSLATE(" %used"));
        return;
    }
    if (e_option) {
        (void) printf(gettext("%-*s %*s\n"),
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            BLOCK_WIDTH, TRANSLATE("ifree"));
        return;
    }
    if (b_option) {
        (void) printf(gettext("%-*s %*s\n"),
            FILESYSTEM_WIDTH, TRANSLATE("Filesystem"),
            BLOCK_WIDTH, TRANSLATE("avail"));
        return;
    }
}


/*
 * Convert an unsigned long long to a string representation and place the
 * result in the caller-supplied buffer.
 * The given number is in units of "unit_from" size, but the
 * converted number will be in units of "unit_to" size. The unit sizes
 * must be powers of 2.
 * The value "(unsigned long long)-1" is a special case and is always
 * converted to "-1".
 * Returns a pointer to the caller-supplied buffer.
 */
static char *
number_to_string(
            char *buf,      /* put the result here */
            unsigned long long number, /* convert this number */
            int unit_from,      /* from units of this size */
            int unit_to)        /* to units of this size */
{
    if ((long long)number == (long long)-1)
        (void) strcpy(buf, "-1");
    else {
        if (unit_from == unit_to)
            (void) sprintf(buf, "%llu", number);
        else if (unit_from < unit_to)
            (void) sprintf(buf, "%llu",
                number / (unsigned long long)(unit_to / unit_from));
        else
            (void) sprintf(buf, "%llu",
                number * (unsigned long long)(unit_from / unit_to));
    }
    return (buf);
}

/*
 * Convert an unsigned long long to a string representation and place the
 * result in the caller-supplied buffer.
 * The given number is in units of "unit_from" size,
 * this will first be converted to a number in 1024 or 1000 byte size,
 * depending on the scaling factor.
 * Then the number is scaled down until it is small enough to be in a good
 * human readable format i.e. in the range 0 thru scale-1.
 * If it's smaller than 10 there's room enough to provide one decimal place.
 * The value "(unsigned long long)-1" is a special case and is always
 * converted to "-1".
 * Returns a pointer to the caller-supplied buffer.
 */
static char *
number_to_scaled_string(
            numbuf_t buf,       /* put the result here */
            unsigned long long number, /* convert this number */
            int unit_from,
            int scale)
{
    unsigned long long save = 0;
    char *M = "KMGTPE"; /* Measurement: kilo, mega, giga, tera, peta, exa */
    char *uom = M;    /* unit of measurement, initially 'K' (=M[0]) */

    if ((long long)number == (long long)-1) {
        (void) strcpy(buf, "-1");
        return (buf);
    }

    /*
     * Convert number from unit_from to given scale (1024 or 1000).
     * This means multiply number by unit_from and divide by scale.
     *
     * Would like to multiply by unit_from and then divide by scale,
     * but if the first multiplication would overflow, then need to
     * divide by scale and then multiply by unit_from.
     */
    if (number > (UINT64_MAX / (unsigned long long)unit_from)) {
        number = (number / (unsigned long long)scale) *
            (unsigned long long)unit_from;
    } else {
        number = (number * (unsigned long long)unit_from) /
            (unsigned long long)scale;
    }

    /*
     * Now we have number as a count of scale units.
     * Stop scaling when we reached exa bytes, then something is
     * probably wrong with our number.
     */

    while ((number >= scale) && (*uom != 'E')) {
        uom++; /* next unit of measurement */
        save = number;
        number = (number + (scale / 2)) / scale;
    }
    /* check if we should output a decimal place after the point */
    if (save && ((save / scale) < 10)) {
        /* sprintf() will round for us */
        float fnum = (float)save / scale;
        (void) sprintf(buf, "%2.1f%c", fnum, *uom);
    } else {
        (void) sprintf(buf, "%4llu%c", number, *uom);
    }
    return (buf);
}

/*
 * The statvfs() implementation allows us to return only two values, the total
 * number of blocks and the number of blocks free.  The equation 'used = total -
 * free' will not work for ZFS filesystems, due to the nature of pooled storage.
 * We choose to return values in the statvfs structure that will produce correct
 * results for 'used' and 'available', but not 'total'.  This function will open
 * the underlying ZFS dataset if necessary and get the real value.
 */
static void
adjust_total_blocks(struct df_request *dfrp, fsblkcnt64_t *total,
    uint64_t blocksize)
{
    char *dataset, *slash;
    boolean_t first = TRUE;
    uint64_t quota = 0;

    if (strcmp(DFR_FSTYPE(dfrp), MNTTYPE_ZFS) != 0 || !load_libzfs())
        return;

    /*
     * We want to get the total size for this filesystem as bounded by any
     * quotas. In order to do this, we start at the current filesystem and
     * work upwards looking for the smallest quota.  When we reach the
     * pool itself, the quota is the amount used plus the amount
     * available.
     */
    if ((dataset = strdup(DFR_SPECIAL(dfrp))) == NULL)
        return;

    slash = dataset + strlen(dataset);
    while (slash != NULL) {
        zfs_handle_t *zhp;
        uint64_t this_quota;

        *slash = '\0';

        zhp = _zfs_open(g_zfs, dataset, ZFS_TYPE_DATASET);
        if (zhp == NULL)
            break;

        /* true at first iteration of loop */
        if (first) {
            quota = _zfs_prop_get_int(zhp, ZFS_PROP_REFQUOTA);
            if (quota == 0)
                quota = UINT64_MAX;
            first = FALSE;
        }

        this_quota = _zfs_prop_get_int(zhp, ZFS_PROP_QUOTA);
        if (this_quota && this_quota < quota)
            quota = this_quota;

        /* true at last iteration of loop */
        if ((slash = strrchr(dataset, '/')) == NULL) {
            uint64_t size;

            size = _zfs_prop_get_int(zhp, ZFS_PROP_USED) +
                _zfs_prop_get_int(zhp, ZFS_PROP_AVAILABLE);
            if (size < quota)
                quota = size;
        }

        _zfs_close(zhp);
    }

    /*
     * Modify total only if we managed to get some stats from libzfs.
     */
    if (quota != 0)
        *total = quota / blocksize;
    free(dataset);
}

/*
 * The output will appear properly columnized regardless of the names of
 * the various fields
 */
static void
g_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    fsblkcnt64_t    available_blocks    = fsp->f_bavail;
    fsblkcnt64_t    total_blocks = fsp->f_blocks;
    numbuf_t    total_blocks_buf;
    numbuf_t    total_files_buf;
    numbuf_t    free_blocks_buf;
    numbuf_t    available_blocks_buf;
    numbuf_t    free_files_buf;
    numbuf_t    fname_buf;
    char        *temp_buf;

#define DEFINE_STR_LEN(var)         \
    static char *var##_str;         \
    static size_t var##_len

#define SET_STR_LEN(name, var)\
    if (! var##_str) {\
        var##_str = TRANSLATE(name); \
        var##_len = strlen(var##_str); \
    }

    DEFINE_STR_LEN(block_size);
    DEFINE_STR_LEN(frag_size);
    DEFINE_STR_LEN(total_blocks);
    DEFINE_STR_LEN(free_blocks);
    DEFINE_STR_LEN(available);
    DEFINE_STR_LEN(total_files);
    DEFINE_STR_LEN(free_files);
    DEFINE_STR_LEN(fstype);
    DEFINE_STR_LEN(fsys_id);
    DEFINE_STR_LEN(fname);
    DEFINE_STR_LEN(flag);

    /*
     * TRANSLATION_NOTE
     * The first argument of each of the following macro invocations is a
     * string that needs to be translated.
     */
    SET_STR_LEN("block size", block_size);
    SET_STR_LEN("frag size", frag_size);
    SET_STR_LEN("total blocks", total_blocks);
    SET_STR_LEN("free blocks", free_blocks);
    SET_STR_LEN("available", available);
    SET_STR_LEN("total files", total_files);
    SET_STR_LEN("free files", free_files);
    SET_STR_LEN("fstype", fstype);
    SET_STR_LEN("filesys id", fsys_id);
    SET_STR_LEN("filename length", fname);
    SET_STR_LEN("flag", flag);

#define NCOL1_WIDTH (int)MAX3(BLOCK_WIDTH, NFILES_WIDTH, FSTYPE_WIDTH)
#define NCOL2_WIDTH (int)MAX3(BLOCK_WIDTH, FSID_WIDTH, FLAG_WIDTH) + 2
#define NCOL3_WIDTH (int)MAX3(BSIZE_WIDTH, BLOCK_WIDTH, NAMELEN_WIDTH)
#define NCOL4_WIDTH (int)MAX(FRAGSIZE_WIDTH, NFILES_WIDTH)

#define SCOL1_WIDTH (int)MAX3(total_blocks_len, free_files_len, fstype_len)
#define SCOL2_WIDTH (int)MAX3(free_blocks_len, fsys_id_len, flag_len)
#define SCOL3_WIDTH (int)MAX3(block_size_len, available_len, fname_len)
#define SCOL4_WIDTH (int)MAX(frag_size_len, total_files_len)

    temp_buf = xmalloc(
        MAX(MOUNT_POINT_WIDTH, strlen(DFR_MOUNT_POINT(dfrp)))
        + MAX(SPECIAL_DEVICE_WIDTH, strlen(DFR_SPECIAL(dfrp)))
        + 20); /* plus slop - nulls & formatting */
    (void) sprintf(temp_buf, "%-*s(%-*s):",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        SPECIAL_DEVICE_WIDTH, DFR_SPECIAL(dfrp));

    (void) printf("%-*s %*lu %-*s %*lu %-*s\n",
        NCOL1_WIDTH + 1 + SCOL1_WIDTH + 1 + NCOL2_WIDTH + 1 +  SCOL2_WIDTH,
        temp_buf,
        NCOL3_WIDTH, fsp->f_bsize, SCOL3_WIDTH, block_size_str,
        NCOL4_WIDTH, fsp->f_frsize, SCOL4_WIDTH, frag_size_str);
    free(temp_buf);

    /*
     * Adjust available_blocks value -  it can be less than 0 on
     * a 4.x file system. Reset it to 0 in order to avoid printing
     * negative numbers.
     */
    if ((long long)available_blocks < (long long)0)
        available_blocks = (fsblkcnt64_t)0;

    adjust_total_blocks(dfrp, &total_blocks, fsp->f_frsize);

    (void) printf("%*s %-*s %*s %-*s %*s %-*s %*s %-*s\n",
        NCOL1_WIDTH, number_to_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, 512),
        SCOL1_WIDTH, total_blocks_str,
        NCOL2_WIDTH, number_to_string(free_blocks_buf,
        fsp->f_bfree, fsp->f_frsize, 512),
        SCOL2_WIDTH, free_blocks_str,
        NCOL3_WIDTH, number_to_string(available_blocks_buf,
        available_blocks, fsp->f_frsize, 512),
        SCOL3_WIDTH, available_str,
        NCOL4_WIDTH, number_to_string(total_files_buf,
        fsp->f_files, 1, 1),
        SCOL4_WIDTH, total_files_str);

    (void) printf("%*s %-*s %*lu %-*s %s\n",
        NCOL1_WIDTH, number_to_string(free_files_buf,
        fsp->f_ffree, 1, 1),
        SCOL1_WIDTH, free_files_str,
        NCOL2_WIDTH, fsp->f_fsid, SCOL2_WIDTH, fsys_id_str,
        fsp->f_fstr);

    (void) printf("%*s %-*s %#*.*lx %-*s %*s %-*s\n\n",
        NCOL1_WIDTH, fsp->f_basetype, SCOL1_WIDTH, fstype_str,
        NCOL2_WIDTH, NCOL2_WIDTH-2, fsp->f_flag, SCOL2_WIDTH, flag_str,
        NCOL3_WIDTH, number_to_string(fname_buf,
        (unsigned long long)fsp->f_namemax, 1, 1),
        SCOL3_WIDTH, fname_str);
}


static void
k_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    fsblkcnt64_t total_blocks       = fsp->f_blocks;
    fsblkcnt64_t    free_blocks     = fsp->f_bfree;
    fsblkcnt64_t    available_blocks    = fsp->f_bavail;
    fsblkcnt64_t    used_blocks;
    char        *file_system        = DFR_SPECIAL(dfrp);
    numbuf_t    total_blocks_buf;
    numbuf_t    used_blocks_buf;
    numbuf_t    available_blocks_buf;
    char        capacity_buf[LINEBUF_SIZE];

    /*
     * If the free block count is -1, don't trust anything but the total
     * number of blocks.
     */
    if (free_blocks == (fsblkcnt64_t)-1) {
        used_blocks = (fsblkcnt64_t)-1;
        (void) strcpy(capacity_buf, "  100%");
    } else {
        fsblkcnt64_t reserved_blocks = free_blocks - available_blocks;

        used_blocks = total_blocks - free_blocks;

        /*
         * The capacity estimation is bogus when available_blocks is 0
         * and the super-user has allocated more space. The reason
         * is that reserved_blocks is inaccurate in that case, because
         * when the super-user allocates space, free_blocks is updated
         * but available_blocks is not (since it can't drop below 0).
         *
         * XCU4 and POSIX.2 require that any fractional result of the
         * capacity estimation be rounded to the next highest integer,
         * hence the addition of 0.5.
         */
        (void) sprintf(capacity_buf, "%5.0f%%",
            (total_blocks == 0) ? 0.0 :
            ((double)used_blocks /
            (double)(total_blocks - reserved_blocks))
            * 100.0 + 0.5);
    }

    /*
     * The available_blocks can be less than 0 on a 4.x file system.
     * Reset it to 0 in order to avoid printing negative numbers.
     */
    if ((long long)available_blocks < (long long)0)
        available_blocks = (fsblkcnt64_t)0;
    /*
     * Print long special device names (usually NFS mounts) in a line
     * by themselves when the output is directed to a terminal.
     */
    if (tty_output && strlen(file_system) > (size_t)FILESYSTEM_WIDTH) {
        (void) printf("%s\n", file_system);
        file_system = "";
    }

    adjust_total_blocks(dfrp, &total_blocks, fsp->f_frsize);

    if (use_scaling) { /* comes from the -h option */
    (void) printf("%-*s %*s %*s %*s %-*s %-s\n",
        FILESYSTEM_WIDTH, file_system,
        SCALED_WIDTH, number_to_scaled_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, scale),
        SCALED_WIDTH, number_to_scaled_string(used_blocks_buf,
        used_blocks, fsp->f_frsize, scale),
        AVAILABLE_WIDTH, number_to_scaled_string(available_blocks_buf,
        available_blocks, fsp->f_frsize, scale),
        CAPACITY_WIDTH, capacity_buf,
        DFR_MOUNT_POINT(dfrp));
        return;
    }

    if (v_option) {
    (void) printf("%-*.*s %-*.*s %*lld %*lld %*lld %-.*s\n",
        IBCS2_MOUNT_POINT_WIDTH, IBCS2_MOUNT_POINT_WIDTH,
        DFR_MOUNT_POINT(dfrp),
        IBCS2_FILESYSTEM_WIDTH, IBCS2_FILESYSTEM_WIDTH, file_system,
        BLOCK_WIDTH, total_blocks,
        BLOCK_WIDTH, used_blocks,
        BLOCK_WIDTH, available_blocks,
        CAPACITY_WIDTH, capacity_buf);
        return;
    }

    if (P_option && !k_option && !m_option) {
    (void) printf("%-*s %*s %*s %*s %-*s %-s\n",
        FILESYSTEM_WIDTH, file_system,
        KBYTE_WIDTH, number_to_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, 512),
        KBYTE_WIDTH, number_to_string(used_blocks_buf,
        used_blocks, fsp->f_frsize, 512),
        KBYTE_WIDTH, number_to_string(available_blocks_buf,
        available_blocks, fsp->f_frsize, 512),
        CAPACITY_WIDTH, capacity_buf,
        DFR_MOUNT_POINT(dfrp));
    } else if (m_option) {
    (void) printf("%-*s %*s %*s %*s %-*s %-s\n",
        FILESYSTEM_WIDTH, file_system,
        KBYTE_WIDTH, number_to_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, 1024*1024),
        KBYTE_WIDTH, number_to_string(used_blocks_buf,
        used_blocks, fsp->f_frsize, 1024*1024),
        KBYTE_WIDTH, number_to_string(available_blocks_buf,
        available_blocks, fsp->f_frsize, 1024*1024),
        CAPACITY_WIDTH, capacity_buf,
        DFR_MOUNT_POINT(dfrp));
    } else {
    (void) printf("%-*s %*s %*s %*s %-*s %-s\n",
        FILESYSTEM_WIDTH, file_system,
        KBYTE_WIDTH, number_to_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, 1024),
        KBYTE_WIDTH, number_to_string(used_blocks_buf,
        used_blocks, fsp->f_frsize, 1024),
        KBYTE_WIDTH, number_to_string(available_blocks_buf,
        available_blocks, fsp->f_frsize, 1024),
        CAPACITY_WIDTH, capacity_buf,
        DFR_MOUNT_POINT(dfrp));
    }
}

/*
 * The following is for internationalization support.
 */
static bool_int strings_initialized;
static char     *files_str;
static char *blocks_str;
static char *total_str;
static char *kilobytes_str;

static void
strings_init(void)
{
    total_str = TRANSLATE("total");
    files_str = TRANSLATE("files");
    blocks_str = TRANSLATE("blocks");
    kilobytes_str = TRANSLATE("kilobytes");
    strings_initialized = TRUE;
}

#define STRINGS_INIT()      if (!strings_initialized) strings_init()


static void
t_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    fsblkcnt64_t    total_blocks = fsp->f_blocks;
    numbuf_t    total_blocks_buf;
    numbuf_t    total_files_buf;
    numbuf_t    free_blocks_buf;
    numbuf_t    free_files_buf;

    STRINGS_INIT();

    adjust_total_blocks(dfrp, &total_blocks, fsp->f_frsize);

    (void) printf("%-*s(%-*s): %*s %s %*s %s\n",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        SPECIAL_DEVICE_WIDTH, DFR_SPECIAL(dfrp),
        BLOCK_WIDTH, number_to_string(free_blocks_buf,
        fsp->f_bfree, fsp->f_frsize, 512),
        blocks_str,
        NFILES_WIDTH, number_to_string(free_files_buf,
        fsp->f_ffree, 1, 1),
        files_str);
    /*
     * The total column used to use the same space as the mnt pt & special
     * dev fields. However, this doesn't work with massive special dev
     * fields * (eg > 500 chars) causing an enormous amount of white space
     * before the total column (see bug 4100411). So the code was
     * simplified to set the total column at the usual gap.
     * This had the side effect of fixing a bug where the previously
     * used static buffer was overflowed by the same massive special dev.
     */
    (void) printf("%*s: %*s %s %*s %s\n",
        MNT_SPEC_WIDTH, total_str,
        BLOCK_WIDTH, number_to_string(total_blocks_buf,
        total_blocks, fsp->f_frsize, 512),
        blocks_str,
        NFILES_WIDTH, number_to_string(total_files_buf,
        fsp->f_files, 1, 1),
        files_str);
}


static void
eb_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    numbuf_t free_files_buf;
    numbuf_t free_kbytes_buf;

    STRINGS_INIT();

    (void) printf("%-*s(%-*s): %*s %s\n",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        SPECIAL_DEVICE_WIDTH, DFR_SPECIAL(dfrp),
        MAX(KBYTE_WIDTH, NFILES_WIDTH),
        number_to_string(free_kbytes_buf,
        fsp->f_bfree, fsp->f_frsize, 1024),
        kilobytes_str);
    (void) printf("%-*s(%-*s): %*s %s\n",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        SPECIAL_DEVICE_WIDTH, DFR_SPECIAL(dfrp),
        MAX(NFILES_WIDTH, NFILES_WIDTH),
        number_to_string(free_files_buf, fsp->f_ffree, 1, 1),
        files_str);
}


static void
e_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    numbuf_t free_files_buf;

    (void) printf("%-*s %*s\n",
        FILESYSTEM_WIDTH, DFR_SPECIAL(dfrp),
        NFILES_WIDTH,
        number_to_string(free_files_buf, fsp->f_ffree, 1, 1));
}


static void
b_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    numbuf_t free_blocks_buf;

    (void) printf("%-*s %*s\n",
        FILESYSTEM_WIDTH, DFR_SPECIAL(dfrp),
        BLOCK_WIDTH, number_to_string(free_blocks_buf,
        fsp->f_bfree, fsp->f_frsize, 1024));
}


/* ARGSUSED */
static void
n_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    (void) printf("%-*s: %-*s\n",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        FSTYPE_WIDTH, dfrp->dfr_fstype);
}


static void
default_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    numbuf_t free_blocks_buf;
    numbuf_t free_files_buf;

    STRINGS_INIT();

    (void) printf("%-*s(%-*s):%*s %s %*s %s\n",
        MOUNT_POINT_WIDTH, DFR_MOUNT_POINT(dfrp),
        SPECIAL_DEVICE_WIDTH, DFR_SPECIAL(dfrp),
        BLOCK_WIDTH, number_to_string(free_blocks_buf,
        fsp->f_bfree, fsp->f_frsize, 512),
        blocks_str,
        NFILES_WIDTH, number_to_string(free_files_buf,
        fsp->f_ffree, 1, 1),
        files_str);
}


/* ARGSUSED */
static void
V_output(struct df_request *dfrp, struct statvfs64 *fsp)
{
    char temp_buf[LINEBUF_SIZE];

    if (df_options_len > 1)
        (void) strcat(strcpy(temp_buf, df_options), " ");
    else
        temp_buf[0] = NUL;

    (void) printf("%s -F %s %s%s\n",
        program_name, dfrp->dfr_fstype, temp_buf,
        dfrp->dfr_cmd_arg ? dfrp->dfr_cmd_arg: DFR_SPECIAL(dfrp));
}


/*
 * This function is used to sort the array of df_requests according to fstype
 */
static int
df_reqcomp(const void *p1, const void *p2)
{
    int v = strcmp(DFRP(p1)->dfr_fstype, DFRP(p2)->dfr_fstype);

    if (v != 0)
        return (v);
    else
        return (DFRP(p1)->dfr_index - DFRP(p2)->dfr_index);
}


static void
vfs_error(char *file, int status)
{
    if (status == VFS_TOOLONG)
        errmsg(ERR_NOFLAGS, "a line in %s exceeds %d characters",
            file, MNT_LINE_MAX);
    else if (status == VFS_TOOMANY)
        errmsg(ERR_NOFLAGS, "a line in %s has too many fields", file);
    else if (status == VFS_TOOFEW)
        errmsg(ERR_NOFLAGS, "a line in %s has too few fields", file);
    else
        errmsg(ERR_NOFLAGS, "error while reading %s: %d", file, status);
}


/*
 * Try to determine the fstype for the specified block device.
 * Return in order of decreasing preference:
 *  file system type from vfstab
 *  file system type as specified by -F option
 *  default file system type
 */
static char *
find_fstype(char *special)
{
    struct vfstab   vtab;
    FILE        *fp;
    int     status;
    char        *vfstab_file = VFS_TAB;

    fp = xfopen(vfstab_file);
    status = getvfsspec(fp, &vtab, special);
    (void) fclose(fp);
    if (status > 0)
        vfs_error(vfstab_file, status);

    if (status == 0) {
        if (F_option && ! EQ(FSType, vtab.vfs_fstype))
            errmsg(ERR_NOFLAGS,
            "warning: %s is of type %s", special, vtab.vfs_fstype);
        return (new_string(vtab.vfs_fstype));
    }
    else
        return (F_option ? FSType : default_fstype(special));
}

/*
 * When this function returns, the following fields are filled for all
 * valid entries in the requests[] array:
 *      dfr_mte     (if the file system is mounted)
 *      dfr_fstype
 *      dfr_index
 *
 * The function returns the number of errors that occurred while building
 * the request list.
 */
static int
create_request_list(
            int argc,
            char *argv[],
            struct df_request *requests_p[],
            size_t *request_count)
{
    struct df_request   *requests;
    struct df_request   *dfrp;
    size_t          size;
    size_t          i;
    size_t          request_index = 0;
    size_t          max_requests;
    int         errors = 0;

    /*
     * If no args, use the mounted file systems, otherwise use the
     * user-specified arguments.
     */
    if (argc == 0) {
        mtab_read_file();
        max_requests = mount_table_entries;
    } else
        max_requests = argc;

    size = max_requests * sizeof (struct df_request);
    requests = xmalloc(size);
    (void) memset(requests, 0, size);

    if (argc == 0) {
        /*
         * If -Z wasn't specified, we skip mounts in other
         * zones.  This obviously is a noop in a non-global
         * zone.
         */
        boolean_t showall = (getzoneid() != GLOBAL_ZONEID) || Z_option;
        struct zone_summary *zsp;

        if (!showall) {
            zsp = fs_get_zone_summaries();
            if (zsp == NULL)
                errmsg(ERR_FATAL,
                    "unable to retrieve list of zones");
        }

        for (i = 0; i < mount_table_entries; i++) {
            struct extmnttab *mtp = mount_table[i].mte_mount;

            if (EQ(mtp->mnt_fstype, MNTTYPE_SWAP))
                continue;

            if (!showall) {
                if (fs_mount_in_other_zone(zsp,
                    mtp->mnt_mountp))
                    continue;
            }
            dfrp = &requests[request_index++];
            dfrp->dfr_mte       = &mount_table[i];
            dfrp->dfr_fstype    = mtp->mnt_fstype;
            dfrp->dfr_index     = i;
            dfrp->dfr_valid     = TRUE;
        }
    } else {
        struct stat64 *arg_stat; /* array of stat structures    */
        bool_int *valid_stat;   /* which structures are valid   */

        arg_stat = xmalloc(argc * sizeof (struct stat64));
        valid_stat = xmalloc(argc * sizeof (bool_int));

        /*
         * Obtain stat64 information for each argument before
         * constructing the list of mounted file systems. By
         * touching all these places we force the automounter
         * to establish any mounts required to access the arguments,
         * so that the corresponding mount table entries will exist
         * when we look for them.
         * It is still possible that the automounter may timeout
         * mounts between the time we read the mount table and the
         * time we process the request. Even in that case, when
         * we issue the statvfs64(2) for the mount point, the file
         * system will be mounted again. The only problem will
         * occur if the automounter maps change in the meantime
         * and the mount point is eliminated.
         */
        for (i = 0; i < argc; i++)
            valid_stat[i] = (stat64(argv[i], &arg_stat[i]) == 0);

        mtab_read_file();

        for (i = 0; i < argc; i++) {
            char *arg = argv[i];

            dfrp = &requests[request_index];

            dfrp->dfr_index = request_index;
            dfrp->dfr_cmd_arg = arg;

            if (valid_stat[i]) {
                dfrp->dfr_fstype = arg_stat[i].st_fstype;
                if (S_ISBLK(arg_stat[i].st_mode)) {
                    bdev_mount_entry(dfrp);
                    dfrp->dfr_valid = TRUE;
                } else if (S_ISDIR(arg_stat[i].st_mode) ||
                    S_ISREG(arg_stat[i].st_mode) ||
                    S_ISFIFO(arg_stat[i].st_mode)) {
                    path_mount_entry(dfrp,
                        arg_stat[i].st_dev);
                    if (! DFR_ISMOUNTEDFS(dfrp)) {
                        errors++;
                        continue;
                    }
                    dfrp->dfr_valid = TRUE;
                }
            } else {
                resource_mount_entry(dfrp);
                dfrp->dfr_valid = DFR_ISMOUNTEDFS(dfrp);
            }

            /*
             * If we haven't managed to verify that the request
             * is valid, we must have gotten a bad argument.
             */
            if (!dfrp->dfr_valid) {
                errmsg(ERR_NOFLAGS,
                    "(%-10s) not a block device, directory or "
                    "mounted resource", arg);
                errors++;
                continue;
            }

            /*
             * Determine the file system type.
             */
            if (DFR_ISMOUNTEDFS(dfrp))
                dfrp->dfr_fstype =
                    dfrp->dfr_mte->mte_mount->mnt_fstype;
            else
                dfrp->dfr_fstype =
                    find_fstype(dfrp->dfr_cmd_arg);

            request_index++;
        }
    }
    *requests_p = requests;
    *request_count = request_index;
    return (errors);
}


/*
 * Select the appropriate function and flags to use for output.
 * Notice that using both -e and -b options produces a different form of
 * output than either of those two options alone; this is the behavior of
 * the SVR4 df.
 */
static struct df_output *
select_output(void)
{
    static struct df_output dfo;

    /*
     * The order of checking options follows the option precedence
     * rules as they are listed in the man page.
     */
    if (use_scaling) { /* comes from the -h option */
        dfo.dfo_func = k_output;
        dfo.dfo_flags = DFO_HEADER + DFO_STATVFS;
    } else if (V_option) {
        dfo.dfo_func = V_output;
        dfo.dfo_flags = DFO_NOFLAGS;
    } else if (g_option) {
        dfo.dfo_func = g_output;
        dfo.dfo_flags = DFO_STATVFS;
    } else if (k_option || m_option || P_option || v_option) {
        dfo.dfo_func = k_output;
        dfo.dfo_flags = DFO_HEADER + DFO_STATVFS;
    } else if (t_option) {
        dfo.dfo_func = t_output;
        dfo.dfo_flags = DFO_STATVFS;
    } else if (b_option && e_option) {
        dfo.dfo_func = eb_output;
        dfo.dfo_flags = DFO_STATVFS;
    } else if (b_option) {
        dfo.dfo_func = b_output;
        dfo.dfo_flags = DFO_HEADER + DFO_STATVFS;
    } else if (e_option) {
        dfo.dfo_func = e_output;
        dfo.dfo_flags = DFO_HEADER + DFO_STATVFS;
    } else if (n_option) {
        dfo.dfo_func = n_output;
        dfo.dfo_flags = DFO_NOFLAGS;
    } else {
        dfo.dfo_func = default_output;
        dfo.dfo_flags = DFO_STATVFS;
    }
    return (&dfo);
}


/*
 * The (argc,argv) pair contains all the non-option arguments
 */
static void
do_df(int argc, char *argv[])
{
    size_t          i;
    struct df_request   *requests;      /* array of requests */
    size_t          n_requests;
    struct df_request   *dfrp;
    int         errors;

    errors = create_request_list(argc, argv, &requests, &n_requests);

    if (n_requests == 0)
        exit(errors);

    /*
     * If we are going to run the FSType-specific df command,
     * rearrange the requests so that we can issue a single command
     * per file system type.
     */
    if (o_option) {
        size_t j;

        /*
         * qsort is not a stable sorting method (i.e. requests of
         * the same file system type may be swapped, and hence appear
         * in the output in a different order from the one in which
         * they were listed in the command line). In order to force
         * stability, we use the dfr_index field which is unique
         * for each request.
         */
        qsort(requests,
            n_requests, sizeof (struct df_request), df_reqcomp);
        for (i = 0; i < n_requests; i = j) {
            char *fstype = requests[i].dfr_fstype;

            for (j = i+1; j < n_requests; j++)
                if (! EQ(fstype, requests[j].dfr_fstype))
                    break;

            /*
             * At this point, requests in the range [i,j) are
             * of the same type.
             *
             * If the -F option was used, and the user specified
             * arguments, the filesystem types must match
             *
             * XXX: the alternative of doing this check here is to
             *  invoke prune_list, but then we have to
             *  modify this code to ignore invalid requests.
             */
            if (F_option && ! EQ(fstype, FSType)) {
                size_t k;

                for (k = i; k < j; k++) {
                    dfrp = &requests[k];
                    if (dfrp->dfr_cmd_arg != NULL) {
                        errmsg(ERR_NOFLAGS,
                            "Warning: %s mounted as a "
                            "%s file system",
                            dfrp->dfr_cmd_arg,
                            dfrp->dfr_fstype);
                        errors++;
                    }
                }
            } else
                errors += run_fs_specific_df(&requests[i], j-i);
        }
    } else {
        size_t valid_requests;

        /*
         * We have to prune the request list to avoid printing a header
         * if there are no valid requests
         */
        errors += prune_list(requests, n_requests, &valid_requests);

        if (valid_requests) {
            struct df_output *dfop = select_output();

            /* indicates if we already printed out a header line */
            int printed_header = 0;

            for (i = 0; i < n_requests; i++) {
                dfrp = &requests[i];
                if (! dfrp->dfr_valid)
                    continue;

                /*
                 * If we don't have a mount point,
                 * this must be a block device.
                 */
                if (DFR_ISMOUNTEDFS(dfrp)) {
                    struct statvfs64 stvfs;

                    if ((dfop->dfo_flags & DFO_STATVFS) &&
                        statvfs64(DFR_MOUNT_POINT(dfrp),
                        &stvfs) == -1) {
                        errmsg(ERR_PERROR,
                            "cannot statvfs %s:",
                            DFR_MOUNT_POINT(dfrp));
                        errors++;
                        continue;
                    }
                    if ((!printed_header) &&
                        (dfop->dfo_flags & DFO_HEADER)) {
                        print_header();
                        printed_header = 1;
                    }

                    (*dfop->dfo_func)(dfrp, &stvfs);
                } else {
                    /*
                     *  -h option only works for
                     *  mounted filesystems
                     */
                    if (use_scaling) {
                        errmsg(ERR_NOFLAGS,
        "-h option incompatible with unmounted special device (%s)",
                            dfrp->dfr_cmd_arg);
                        errors++;
                        continue;
                    }
                    errors += run_fs_specific_df(dfrp, 1);
                }
            }
        }
    }
    exit(errors);
}


/*
 * The rest of this file implements the devnm command
 */

static char *
find_dev_name(char *file, dev_t dev)
{
    struct df_request dfreq;

    dfreq.dfr_cmd_arg = file;
    dfreq.dfr_fstype = 0;
    dfreq.dfr_mte = NULL;
    path_mount_entry(&dfreq, dev);
    return (DFR_ISMOUNTEDFS(&dfreq) ? DFR_SPECIAL(&dfreq) : NULL);
}


static void
do_devnm(int argc, char *argv[])
{
    int arg;
    int errors = 0;
    char *dev_name;

    if (argc == 1)
        errmsg(ERR_NONAME, "Usage: %s name ...", DEVNM_CMD);

    mtab_read_file();

    for (arg = 1; arg < argc; arg++) {
        char *file = argv[arg];
        struct stat64 st;

        if (stat64(file, &st) == -1) {
            errmsg(ERR_PERROR, "%s: ", file);
            errors++;
            continue;
        }

        if (! is_remote_fs(st.st_fstype) &&
            ! EQ(st.st_fstype, MNTTYPE_TMPFS) &&
            (dev_name = find_dev_name(file, st.st_dev)))
            (void) printf("%s %s\n", dev_name, file);
        else
            errmsg(ERR_NOFLAGS,
                "%s not found", file);
    }
    exit(errors);
    /* NOTREACHED */
}