nfsservctl - syscall interface to kernel nfs daemon

#include <linux/nfsd/syscall.h>
long nfsservctl(int cmd, struct nfsctl_arg *argp,
 union nfsctl_res *resp);

Note: Since Linux 3.1, this system call no longer exists. It has been replaced by a set of files in the nfsd filesystem; see nfsd(7).

/*
 * These are the commands understood by nfsctl().
 */
#define NFSCTL_SVC        0  /* This is a server process. */
#define NFSCTL_ADDCLIENT  1  /* Add an NFS client. */
#define NFSCTL_DELCLIENT  2  /* Remove an NFS client. */
#define NFSCTL_EXPORT     3  /* Export a filesystem. */
#define NFSCTL_UNEXPORT   4  /* Unexport a filesystem. */
#define NFSCTL_UGIDUPDATE 5  /* Update a client's UID/GID map
                                (only in Linux 2.4.x and earlier). */
#define NFSCTL_GETFH      6  /* Get a file handle (used by mountd(8))
                                (only in Linux 2.4.x and earlier). */
struct nfsctl_arg {
    int                       ca_version;     /* safeguard */
    union {
        struct nfsctl_svc     u_svc;
        struct nfsctl_client  u_client;
        struct nfsctl_export  u_export;
        struct nfsctl_uidmap  u_umap;
        struct nfsctl_fhparm  u_getfh;
        unsigned int          u_debug;
    } u;
}
union nfsctl_res {
        struct knfs_fh          cr_getfh;
        unsigned int            cr_debug;
};

On success, zero is returned. On error, -1 is returned, and errno is set to indicate the error.

nfsd(7)