source: mainline/uspace/srv/fs/minixfs/mfs_super.c@ 9e3dc95

/*
 * Copyright (c) 2011 Maurizio Lombardi
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * - Redistributions of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * - Redistributions in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * - The name of the author may not be used to endorse or promote products
 *   derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */

/** @addtogroup fs
 * @{
 */

#include <libfs.h>
#include <stdlib.h>
#include <libblock.h>
#include <errno.h>
#include <str.h>
#include "mfs_super.h"
#include "mfs_utils.h"
#include "../../vfs/vfs.h"

static bool check_magic_number(int16_t magic, bool *native, mfs_version_t *version);

void mfs_mounted(ipc_callid_t rid, ipc_call_t *request)
{
        devmap_handle_t devmap_handle = (devmap_handle_t) IPC_GET_ARG1(*request);
        enum cache_mode cmode;  
        struct mfs_superblock *sp;
        bool native;
        mfs_version_t version;

        /* Accept the mount options */
        char *opts;
        int rc = async_data_write_accept((void **) &opts, true, 0, 0, 0, NULL);
        
        if (rc != EOK) {
                async_answer_0(rid, rc);
                return;
        }

        /* Check for option enabling write through. */
        if (str_cmp(opts, "wtcache") == 0)
                cmode = CACHE_MODE_WT;
        else
                cmode = CACHE_MODE_WB;

        free(opts);

        /* initialize libblock */
        rc = block_init(devmap_handle, MFS_SUPER_BLOCK_SIZE);
        if (rc != EOK) {
                async_answer_0(rid, rc);
                return;
        }

        /* prepare the superblock */
        rc = block_bb_read(devmap_handle, MFS_SUPER_BLOCK);
        if (rc != EOK) {
                block_fini(devmap_handle);
                async_answer_0(rid, rc);
                return;
        }

        /* get the buffer with the superblock */
        sp = block_bb_get(devmap_handle);

        if (!check_magic_number(sp->s_magic, &native, &version)) {
                /*Magic number is invalid!*/
                block_fini(devmap_handle);
                async_answer_0(rid, ENOTSUP);
                return;
        }
}

static bool check_magic_number(int16_t magic, bool *native, mfs_version_t *version)
{
        *native = true;

repeat_check:

        switch (*native ? magic : conv16(false, magic)) {
        case MFS_MAGIC_V1:
                *version = MFS_VERSION_V1;
                return true;
        case MFS_MAGIC_V2:
                *version = MFS_VERSION_V2;
                return true;
        case MFS_MAGIC_V3:
                *version = MFS_VERSION_V3;
                return true;
        default:
                ;
        }

        if (*native) {
                *native = false;
                goto repeat_check;
        } else {
                return false;
        }

        /*Should never happens*/
        return false;
}


/**
 * @}
 */