nuttx-apps/examples/unionfs/unionfs_main.c

201 lines
6.3 KiB
C

/****************************************************************************
* examples/unionfs/unionfs_main.c
*
* Copyright (C) 2015 Gregory Nutt. All rights reserved.
* Author: Gregory Nutt <gnutt@nuttx.org>
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. 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.
* 3. Neither the name NuttX nor the names of its contributors may be
* used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
* "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
* COPYRIGHT OWNER OR CONTRIBUTORS 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.
*
****************************************************************************/
/****************************************************************************
* Included Files
****************************************************************************/
#include <nuttx/config.h>
#include <sys/types.h>
#include <sys/mount.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <stdbool.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <string.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#include <nuttx/fs/ramdisk.h>
#include <nuttx/fs/unionfs.h>
#include "romfs_atestdir.h"
#include "romfs_btestdir.h"
/****************************************************************************
* Pre-processor Definitions
****************************************************************************/
/* Configuration settings */
#ifdef CONFIG_DISABLE_MOUNTPOINT
# error "Mountpoint support is disabled"
#endif
#if CONFIG_NFILE_DESCRIPTORS < 4
# error "Not enough file descriptors"
#endif
#ifndef CONFIG_FS_ROMFS
# error "ROMFS support not enabled"
#endif
#ifndef CONFIG_FS_UNIONFS
# error "Union File System support not enabled"
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_A
# define CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_A 1
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_B
# define CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_B 2
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_SECTORSIZE
# define CONFIG_EXAMPLES_UNIONFS_SECTORSIZE 64
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_MOUNTPT
# define "/mnt/unionfs"
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_TMPA
# define "/mnt/a"
#endif
#ifndef CONFIG_EXAMPLES_UNIONFS_TMPB
# define "/mnt/b"
#endif
#define NSECTORS(b) (((b)+CONFIG_EXAMPLES_UNIONFS_SECTORSIZE-1)/CONFIG_EXAMPLES_UNIONFS_SECTORSIZE)
#define STR_RAMDEVNO(m) #m
#define MKMOUNT_DEVNAME(m) "/dev/ram" STR_RAMDEVNO(m)
#define MOUNT_DEVNAME_A MKMOUNT_DEVNAME(CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_A)
#define MOUNT_DEVNAME_B MKMOUNT_DEVNAME(CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_B)
#define SCRATCHBUFFER_SIZE 1024
/* Test directory stuff */
#define WRITABLE_MODE (S_IWOTH|S_IWGRP|S_IWUSR)
#define READABLE_MODE (S_IROTH|S_IRGRP|S_IRUSR)
#define EXECUTABLE_MODE (S_IXOTH|S_IXGRP|S_IXUSR)
#define DIRECTORY_MODE (S_IFDIR|READABLE_MODE|EXECUTABLE_MODE)
#define FILE_MODE (S_IFREG|READABLE_MODE)
/****************************************************************************
* Public Functions
****************************************************************************/
/****************************************************************************
* Name: unionfs_main
****************************************************************************/
#ifdef CONFIG_BUILD_KERNEL
int main(int argc, FAR char *argv[])
#else
int unionfs_main(int argc, char *argv[])
#endif
{
int ret;
/* Create a RAM disk for file system 1 */
ret = romdisk_register(CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_A, atestdir_img,
NSECTORS(atestdir_img_len),
CONFIG_EXAMPLES_UNIONFS_SECTORSIZE);
if (ret < 0)
{
printf("ERROR: Failed to create file system 1 RAM disk\n");
return EXIT_FAILURE;
}
/* Mount test file system 1 */
printf("Mounting ROMFS file system 1 at target=%s with source=%s\n",
CONFIG_EXAMPLES_UNIONFS_TMPA, MOUNT_DEVNAME_A);
ret = mount(MOUNT_DEVNAME_A, CONFIG_EXAMPLES_UNIONFS_TMPA, "romfs",
MS_RDONLY, NULL);
if (ret < 0)
{
printf("ERROR: File system 1 mount failed: %d\n", errno);
return EXIT_FAILURE;
}
/* Create a RAM disk for file system 2 */
ret = romdisk_register(CONFIG_EXAMPLES_UNIONFS_RAMDEVNO_B, btestdir_img,
NSECTORS(btestdir_img_len),
CONFIG_EXAMPLES_UNIONFS_SECTORSIZE);
if (ret < 0)
{
printf("ERROR: Failed to register file system 1: %d\n", ret);
return EXIT_FAILURE;
}
/* Mount test file system 2 */
printf("Mounting ROMFS file system 2 at target=%s with source=%s\n",
CONFIG_EXAMPLES_UNIONFS_TMPB, MOUNT_DEVNAME_B);
ret = mount(MOUNT_DEVNAME_B, CONFIG_EXAMPLES_UNIONFS_TMPB, "romfs",
MS_RDONLY, NULL);
if (ret < 0)
{
printf("ERROR: Failed to register file system 1: %d\n", ret);
return EXIT_FAILURE;
}
/* Now create and mount the union file system */
ret = unionfs_mount(CONFIG_EXAMPLES_UNIONFS_TMPA, NULL,
CONFIG_EXAMPLES_UNIONFS_TMPB, "offset",
CONFIG_EXAMPLES_UNIONFS_MOUNTPT);
if (ret < 0)
{
printf("ERROR: Failed to create the union file system: %d\n", ret);
return EXIT_FAILURE;
}
return EXIT_SUCCESS;
}