fuse_rpc.x

/*
 * Naming pattern:
 * (1) client-to-server message structs are named as <function>_arg,
 * server-to-client message structs are named as <function>_ret.
 * (2) Every server-to-client response includes a data member ret,
 * it returns 0 if RPC succeeds, otherwise it'd be assigned -errno.
 * (3) For r/w requests, a len member is included, which indicates the 
 * actual bytes completes.
 * (4) Every *_arg has a data member called ip, which is used to differentiate
 * seperate path for distinct clients. To create path at server side, it's 
 * represented as a unsigned integer.
 */

const MAX_SIZE = 4096;

/*
 * Used in operations which need to be transferred to secondary server,
 * check at 
 * (1) mkdir
 * (2) rmdir
 * (3) rename
 * (4) symlink
 * (5) link
 * (6) mknod
 * (7) utime
 * (8) truncate
 * (9) chmod
 * (10) chown
 * (11) unlink
 * (12) write
 * For these operations, path should be passed, since no fd will be opened
 * in advance.
 */
struct identity {
    int is_master;
    int is_degraded;
};

/* client asks the server to initialize rootdir */
struct init_arg {
    identity server_info;
    string ip<>;
    string rootdir<>;
};

struct init_ret {
    int ret; /* status of RPC */
};

struct getattr_arg {
    string ip<>;
    string path<>;
};

struct getattr_ret {
    int st_dev;               /* ID of device containing file */
    int st_ino;               /* inode number */
    int st_mode;              /* protection */
    int st_nlink;             /* number osf hard links */
    int st_uid;               /* user ID of owner */
    int st_gid;               /* group ID of owner */
    int st_rdev;              /* device ID (if special file) */
    unsigned long st_size;    /* total size, in bytes */
    unsigned long st_blksize; /* blocksize for file system I/O */
    unsigned long st_blocks;  /* number of 512B blocks allocated */
    long st_acc_time;         /* time of last access */
    long st_mod_time;         /* time of last modification */
    long st_chg_time;         /* time of last status change */
    int ret;                  /* status of RPC */
};

struct access_arg {
    string ip<>;
    string path<>;
    int mask;
};

struct access_ret {
    int ret; /* whether process can access file */
};

struct mkdir_arg {
    string ip<>;
    identity server_info;
    string path<>;
    int mode;
};

struct mkdir_ret {
    int ret; /* status of RPC */
};

struct rmdir_arg {
    string ip<>;
    identity server_info;
    string path<>;
};

struct rmdir_ret {
    int ret; /* status of RPC */
};

struct opendir_arg {
    string ip<>;
    string path<>;
};

struct opendir_ret {
    int fd; /* file descriptor of the directory */
    int ret; /* status of RPC */
};

struct readdir_arg {
    int fd;
};

struct readdir_ret {
    int count; /* number of struct dirent */
    opaque entries[MAX_SIZE]; /* dirent entry name */
    int ret; /* status of RPC */
};

struct releasedir_arg {
    int fd;
};

struct releasedir_ret {
    int ret; /* status of RPC */
};

struct rename_arg {
    string ip<>;
    identity server_info;
    string path<>;
    string newpath<>;
};

struct rename_ret {
    int ret; /* status of RPC */
};

struct symlink_arg {
    string ip<>;
    identity server_info;
    string path<>;
    string link<>;
};

struct symlink_ret {
    int ret; /* status of RPC */
};

struct link_arg {
    string ip<>;
    identity server_info;
    string path<>;
    string newpath<>;
};

struct link_ret {
    int ret; /* status of RPC */
};

struct readlink_arg {
    string ip<>;
    string path<>;
    unsigned int size;
};

struct readlink_ret {
    opaque buffer[MAX_SIZE]; /* file content */
    int len; /* length of the content */
    int ret; /* status of RPC */
};

struct mknod_arg {
    string ip<>;
    identity server_info;
    string path<>;
    int mode; /* protection */
    int dev; /* ID of device containing file */
};

struct mknod_ret {
    int ret; /* status of RPC */
};

struct utime_arg {
    string ip<>;
    identity server_info;
    string path<>;
    long actime; /* access time */
    long modtime; /* modification time */
};

struct utime_ret {
    int ret; /* status of RPC */
};

struct truncate_arg {
    string ip<>;
    identity server_info;
    string path<>;
    int newsize;
};

struct truncate_ret {
    int ret; /* status of RPC */
};

struct chmod_arg {
    string ip<>;
    identity server_info;
    string path<>;
    int mode;
};

struct chmod_ret {
    int ret; /* status of RPC */
};

struct chown_arg {
    string ip<>;
    identity server_info;
    string path<>;
    unsigned int uid;
    unsigned int gid;
};

struct chown_ret {
    int ret; /* status of RPC */
};

struct unlink_arg {
    string ip<>;
    identity server_info;
    string path<>;
};

struct unlink_ret {
    int ret; /* status of RPC */
};

struct open_arg {
    string ip<>;
    string path<>;
    int flags;
};

struct open_ret {
    int fd; /* file descriptor of file */
    int ret; /* status of RPC */
};

struct release_arg {
    string ip<>;
    int fd;
};

struct release_ret {
    int ret; /* status of RPC */
};

struct read_arg {
    string ip<>;
    int fd;
    unsigned int size;
    unsigned int offset;
};

struct read_ret {
    opaque buffer[MAX_SIZE]; /* file content */
    int len; /* length of the content */
    int ret; /* status of RPC */
};

struct write_arg {
    string ip<>;
    identity server_info;
    int fd;
    string path<>;
    unsigned int size;
    unsigned int offset;
    opaque buffer[MAX_SIZE]; /* write-in content */
};

struct write_ret {
    int len; /* length of the content */
    int ret; /* status of RPC */
};

struct statfs_arg {
    string path<>;
};

struct statfs_ret {
    unsigned long f_bsize;   /* Filesystem block size */
    unsigned long f_frsize;  /* Fragment size */
    unsigned long f_blocks;  /* Size of fs in f_frsize units */
    unsigned long f_bfree;   /* Number of free blocks */
    unsigned long f_bavail;  /* Number of free blocks for unprivileged users */
    unsigned long f_files;   /* Number of inodes */
    unsigned long f_ffree;   /* Number of free inodes */
    unsigned long f_favail;  /* Number of free inodes for unprivileged users */
    unsigned long f_fsid;    /* Filesystem ID */
    unsigned long f_flag;    /* Mount flags */
    unsigned long f_namemax; /* Maximum filename length */
    int ret;                 /* status of syscall and RPC */
};
               
program COMPUTE{
    version COMPUTE_VERS {
        init_ret INIT_ROOTDIR(init_arg) = 0;
        getattr_ret BB_GETATTR(getattr_arg) = 1;
        access_ret BB_ACCESS(access_arg) = 2;
        mkdir_ret BB_MKDIR(mkdir_arg) = 3;
        rmdir_ret BB_RMDIR(rmdir_arg) = 4;
        opendir_ret BB_OPENDIR(opendir_arg) = 5;
        readdir_ret BB_READDIR(readdir_arg) = 6;
        releasedir_ret BB_RELEASEDIR(releasedir_arg) = 7;
        rename_ret BB_RENAME(rename_arg) = 8;
        symlink_ret BB_SYMLINK(symlink_arg) = 9;
        link_ret BB_LINK(link_arg) = 10;
        readlink_ret BB_READLINK(readlink_arg) = 11;
        mknod_ret BB_MKNOD(mknod_arg) = 12;
        truncate_ret BB_TRUNCATE(truncate_arg) = 13;
        unlink_ret BB_UNLINK(unlink_arg) = 14;
        utime_ret BB_UTIME(utime_arg) = 15;
        chmod_ret BB_CHMOD(chmod_arg) = 16;
        chown_ret BB_CHOWN(chown_arg) = 17;
        open_ret BB_OPEN(open_arg) = 18;
        release_ret BB_RELEASE(release_arg) = 19;
        read_ret BB_READ(read_arg) = 20;
        write_ret BB_WRITE(write_arg) = 21;
        statfs_ret BB_STATFS(statfs_arg) = 22;
    } = 6;
} = 456123789;