fusexmp_fh.c

linux下的用户文件系统fuse-2.5.2

/*
    FUSE: Filesystem in Userspace
    Copyright (C) 2001-2006  Miklos Szeredi <[e-mail]>

    This program can be distributed under the terms of the GNU GPL.
    See the file COPYING.
*/

#include <config.h>

#define _GNU_SOURCE

#include <fuse.h>
#include <stdio.h>
#include <string.h>
#include <unistd.h>
#include <fcntl.h>
#include <dirent.h>
#include <errno.h>
#ifdef HAVE_SETXATTR
#include <sys/xattr.h>
#endif

static int xmp_getattr(const char *path, struct stat *stbuf)
{
    int res;

    res = lstat(path, stbuf);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_fgetattr(const char *path, struct stat *stbuf,
                        struct fuse_file_info *fi)
{
    int res;

    (void) path;

    res = fstat(fi->fh, stbuf);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_access(const char *path, int mask)
{
    int res;

    res = access(path, mask);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_readlink(const char *path, char *buf, size_t size)
{
    int res;

    res = readlink(path, buf, size - 1);
    if (res == -1)
        return -errno;

    buf[res] = '\0';
    return 0;
}

static int xmp_opendir(const char *path, struct fuse_file_info *fi)
{
    DIR *dp = opendir(path);
    if (dp == NULL)
        return -errno;

    fi->fh = (unsigned long) dp;
    return 0;
}

static inline DIR *get_dirp(struct fuse_file_info *fi)
{
    return (DIR *) (uintptr_t) fi->fh;
}

static int xmp_readdir(const char *path, void *buf, fuse_fill_dir_t filler,
                       off_t offset, struct fuse_file_info *fi)
{
    DIR *dp = get_dirp(fi);
    struct dirent *de;

    (void) path;
    seekdir(dp, offset);
    while ((de = readdir(dp)) != NULL) {
        struct stat st;
        memset(&st, 0, sizeof(st));
        st.st_ino = de->d_ino;
        st.st_mode = de->d_type << 12;
        if (filler(buf, de->d_name, &st, telldir(dp)))
            break;
    }

    return 0;
}

static int xmp_releasedir(const char *path, struct fuse_file_info *fi)
{
    DIR *dp = get_dirp(fi);
    (void) path;
    closedir(dp);
    return 0;
}

static int xmp_mknod(const char *path, mode_t mode, dev_t rdev)
{
    int res;

    if (S_ISFIFO(mode))
        res = mkfifo(path, mode);
    else
        res = mknod(path, mode, rdev);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_mkdir(const char *path, mode_t mode)
{
    int res;

    res = mkdir(path, mode);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_unlink(const char *path)
{
    int res;

    res = unlink(path);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_rmdir(const char *path)
{
    int res;

    res = rmdir(path);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_symlink(const char *from, const char *to)
{
    int res;

    res = symlink(from, to);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_rename(const char *from, const char *to)
{
    int res;

    res = rename(from, to);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_link(const char *from, const char *to)
{
    int res;

    res = link(from, to);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_chmod(const char *path, mode_t mode)
{
    int res;

    res = chmod(path, mode);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_chown(const char *path, uid_t uid, gid_t gid)
{
    int res;

    res = lchown(path, uid, gid);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_truncate(const char *path, off_t size)
{
    int res;

    res = truncate(path, size);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_ftruncate(const char *path, off_t size,
                         struct fuse_file_info *fi)
{
    int res;

    (void) path;

    res = ftruncate(fi->fh, size);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_utime(const char *path, struct utimbuf *buf)
{
    int res;

    res = utime(path, buf);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_create(const char *path, mode_t mode, struct fuse_file_info *fi)
{
    int fd;

    fd = open(path, fi->flags, mode);
    if (fd == -1)
        return -errno;

    fi->fh = fd;
    return 0;
}

static int xmp_open(const char *path, struct fuse_file_info *fi)
{
    int fd;

    fd = open(path, fi->flags);
    if (fd == -1)
        return -errno;

    fi->fh = fd;
    return 0;
}

static int xmp_read(const char *path, char *buf, size_t size, off_t offset,
                    struct fuse_file_info *fi)
{
    int res;

    (void) path;
    res = pread(fi->fh, buf, size, offset);
    if (res == -1)
        res = -errno;

    return res;
}

static int xmp_write(const char *path, const char *buf, size_t size,
                     off_t offset, struct fuse_file_info *fi)
{
    int res;

    (void) path;
    res = pwrite(fi->fh, buf, size, offset);
    if (res == -1)
        res = -errno;

    return res;
}

static int xmp_statfs(const char *path, struct statvfs *stbuf)
{
    int res;

    res = statvfs(path, stbuf);
    if (res == -1)
        return -errno;

    return 0;
}

static int xmp_release(const char *path, struct fuse_file_info *fi)
{
    (void) path;
    close(fi->fh);

    return 0;
}

static int xmp_fsync(const char *path, int isdatasync,
                     struct fuse_file_info *fi)
{
    int res;
    (void) path;

#ifndef HAVE_FDATASYNC
    (void) isdatasync;
#else
    if (isdatasync)
        res = fdatasync(fi->fh);
    else
#endif
        res = fsync(fi->fh);
    if (res == -1)
        return -errno;

    return 0;
}

#ifdef HAVE_SETXATTR
/* xattr operations are optional and can safely be left unimplemented */
static int xmp_setxattr(const char *path, const char *name, const char *value,
                        size_t size, int flags)
{
    int res = lsetxattr(path, name, value, size, flags);
    if (res == -1)
        return -errno;
    return 0;
}

static int xmp_getxattr(const char *path, const char *name, char *value,
                    size_t size)
{
    int res = lgetxattr(path, name, value, size);
    if (res == -1)
        return -errno;
    return res;
}

static int xmp_listxattr(const char *path, char *list, size_t size)
{
    int res = llistxattr(path, list, size);
    if (res == -1)
        return -errno;
    return res;
}

static int xmp_removexattr(const char *path, const char *name)
{
    int res = lremovexattr(path, name);
    if (res == -1)
        return -errno;
    return 0;
}
#endif /* HAVE_SETXATTR */

static struct fuse_operations xmp_oper = {
    .getattr	= xmp_getattr,
    .fgetattr	= xmp_fgetattr,
    .access	= xmp_access,
    .readlink	= xmp_readlink,
    .opendir	= xmp_opendir,
    .readdir	= xmp_readdir,
    .releasedir	= xmp_releasedir,
    .mknod	= xmp_mknod,
    .mkdir	= xmp_mkdir,
    .symlink	= xmp_symlink,
    .unlink	= xmp_unlink,
    .rmdir	= xmp_rmdir,
    .rename	= xmp_rename,
    .link	= xmp_link,
    .chmod	= xmp_chmod,
    .chown	= xmp_chown,
    .truncate	= xmp_truncate,
    .ftruncate	= xmp_ftruncate,
    .utime	= xmp_utime,
    .create	= xmp_create,
    .open	= xmp_open,
    .read	= xmp_read,
    .write	= xmp_write,
    .statfs	= xmp_statfs,
    .release	= xmp_release,
    .fsync	= xmp_fsync,
#ifdef HAVE_SETXATTR
    .setxattr	= xmp_setxattr,
    .getxattr	= xmp_getxattr,
    .listxattr	= xmp_listxattr,
    .removexattr= xmp_removexattr,
#endif
};

int main(int argc, char *argv[])
{
    umask(0);
    return fuse_main(argc, argv, &xmp_oper);
}