fs.d/tmpfs/mount.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License, Version 1.0 only
 * (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
 */
#pragma ident   "%Z%%M% %I% %E% SMI"

/*
 * Copyright 2004 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <errno.h>
#include <sys/mount.h>
#include <sys/types.h>
#include <locale.h>
#include <sys/stat.h>
#include <fslib.h>
#include <stdio.h>
#include <sys/mnttab.h>
#include <poll.h>

#define MNTTYPE_TMPFS   "tmpfs"

static int  nmflg = 0;
static int  qflg = 0;

static boolean_t
in_mnttab(char *mountp)
{
    FILE *file;
    int found = B_FALSE;
    struct mnttab mntent;

    if ((file = fopen("/etc/mnttab", "r")) == NULL)
        return (B_FALSE);
    while (getmntent(file, &mntent) == 0) {
        if (mntent.mnt_mountp != NULL &&
            strcmp(mntent.mnt_mountp, mountp) == 0 &&
            mntent.mnt_fstype != NULL &&
            strcmp(mntent.mnt_fstype, MNTTYPE_TMPFS) == 0) {
            found = B_TRUE;
            break;
        }
    }
    (void) fclose(file);
    return (found);
}

int
main(int argc, char *argv[])
{
    /* mount information */
    char *special;
    char *mountp;

    int c;
    char *myname;
    char typename[64];
    extern int optind;
    extern char *optarg;
    int error = 0;
    int verbose = 0;
    int mflg = 0;
    int optcnt = 0;
    int mount_attempts = 5;

    char optbuf[MAX_MNTOPT_STR];
    int optsize = 0;
    char *saveoptbuf;

    (void) setlocale(LC_ALL, "");

#if !defined(TEXT_DOMAIN)
#define TEXT_DOMAIN "SYS_TEST"
#endif
    (void) textdomain(TEXT_DOMAIN);

    myname = strrchr(argv[0], '/');
    myname = myname ? myname + 1 : argv[0];
    (void) snprintf(typename, sizeof (typename), "%s_%s",
        MNTTYPE_TMPFS, myname);
    argv[0] = typename;
    optbuf[0] = '\0';

    while ((c = getopt(argc, argv, "?o:VmOq")) != EOF) {
        switch (c) {
        case 'V':
            verbose++;
            break;
        case '?':
            error++;
            break;
        case 'm':
            nmflg++;
            break;
        case 'O':
            mflg |= MS_OVERLAY;
            break;
        case 'o':
            (void) strncpy(optbuf, optarg, MAX_MNTOPT_STR);
            optbuf[MAX_MNTOPT_STR - 1] = '\0';
            optsize = strlen(optbuf);

            if (verbose)
                (void) fprintf(stderr, "optsize:%d optbuf:%s\n",
                    optsize, optbuf);
            break;
        case 'q':
            qflg++;
            break;
        }
    }

    if (verbose && !error) {
        char *optptr;

        (void) fprintf(stderr, "%s", typename);
        for (optcnt = 1; optcnt < argc; optcnt++) {
            optptr = argv[optcnt];
            if (optptr)
                (void) fprintf(stderr, " %s", optptr);
        }
        (void) fprintf(stderr, "\n");
    }

    if (argc - optind != 2 || error) {
        (void) fprintf(stderr,
            gettext("Usage: %s [-o size] swap mount_point\n"),
            typename);
        exit(32);
    }

    special = argv[optind++];
    mountp = argv[optind++];
    mflg |= MS_OPTIONSTR;
    mflg |= (nmflg ? MS_NOMNTTAB : 0);

    if (verbose) {
        (void) fprintf(stderr, "mount(%s, \"%s\", %d, %s",
            special, mountp, mflg, MNTTYPE_TMPFS);
        if (optsize)
            (void) fprintf(stderr, ", \"%s\", %d)\n",
                optbuf, strlen(optbuf));
        else
            (void) fprintf(stderr, ")\n");
    }
    if (optsize) {
        if ((saveoptbuf = strdup(optbuf)) == NULL) {
            (void) fprintf(stderr, gettext("%s: out of memory\n"),
                "mount");
            exit(1);
        }
    }
again:  if (mount(special, mountp, mflg, MNTTYPE_TMPFS, NULL, 0,
        optbuf, MAX_MNTOPT_STR)) {
        if (errno == EBUSY && !(mflg & MS_OVERLAY)) {
            /*
             * Because of bug 6176743, any attempt to mount
             * tmpfs filesystem could fail for reasons
             * described in that bug.  We're trying to detect
             * that situation here by checking that the filesystem
             * we're mounting is not in /etc/mnttab yet.
             * When that bug is fixed, this code can be removed.
             */
            if (!in_mnttab(mountp) && mount_attempts-- > 0) {
                (void) poll(NULL, 0, 50);
                goto again;
            }
            (void) fprintf(stderr, gettext(
                "%s: %s is already mounted or %s is busy\n"),
                myname, mountp, special);
        } else {
            perror("mount");
        }
        exit(32);
    }

    if (optsize && !qflg)
        cmp_requested_to_actual_options(saveoptbuf, optbuf,
            special, mountp);
    return (0);
}