bsd/man/man2/nfsclnt.2

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  23 .Dd January 9, 2007
  24 .Dt NFSCLNT 2
  25 .Os
  26 .Sh NAME
  27 .Nm nfsclnt
  28 .Nd NFS client services
  29 .Sh SYNOPSIS
  30 .Fd #include <unistd.h>
  31 .Fd #include <nfs/nfs.h>
  32 .Ft int
  33 .Fn nfsclnt "int flags" "void *argstructp"
  34 .Sh DESCRIPTION
  35 The
  36 .Fn nfsclnt
  37 function is used by the NFS client daemons to pass information into and out
  38 of the kernel.
  39 The
  40 .Fa flags
  41 argument consists of several bits that show what action is to be taken
  42 once in the kernel and the
  43 .Fa argstructp
  44 points to any corresponding data that the action may require.
  45 .Pp
  46 .Xr rpc.lockd 8
  47 calls
  48 .Fn nfsclnt
  49 with the flag
  50 .Dv NFSCLNT_LOCKDANS
  51 and a pointer to a
  52 .Bd -literal
  53 struct lockd_ans {
  54         int             la_version;             /* lockd_ans version */
  55         int             la_errno;               /* return status */
  56         u_int64_t       la_xid;                 /* unique message transaction ID */
  57         int             la_flags;               /* answer flags */
  58         pid_t           la_pid;                 /* pid of lock requester/owner */
  59         off_t           la_start;               /* lock starting offset */
  60         off_t           la_len;                 /* lock length */
  61         int             la_fh_len;              /* The file handle length. */
  62         u_int8_t        la_fh[NFSV3_MAX_FH_SIZE];/* The file handle. */
  63 };
  64 .Ed
  65 .sp
  66 to pass the response to an NFS file locking request back
  67 into the kernel.
  68 .Sh RETURN VALUES
  69 Upon successful completion, a value of 0 is returned.  Otherwise, -1
  70 is returned and the global variable
  71 .Va errno
  72 is set to specify the error.
  73 .Sh ERRORS
  74 .Bl -tag -width Er
  75 .It Bq Er EPERM
  76 The caller is not the super-user.
  77 .It Bq Er EINVAL
  78 The action specified by the
  79 .Fa flags
  80 argument was not valid.
  81 .It Bq EFAULT
  82 .Fa argstructp
  83 points to an invalid address.
  84 .It Bq EPIPE
  85 The response doesn't match any currently-outstanding lock request.
  86 .El
  87 .Sh SEE ALSO
  88 .Xr rpc.lockd 8
  89 .Sh BUGS
  90 The
  91 .Nm nfsclnt
  92 system call is designed specifically for the
  93 .Tn NFS
  94 client daemons and as such is specific to their requirements.  Several
  95 fields of the argument structures are assumed to be valid, such that
  96 .Nm nfsclnt
  97 must be used with extreme care.