V10/man/man2/fmount.2

.TH FMOUNT 2
.CT 2 sa comm_proc
.SH NAME
fmount, funmount \- mount or remove file system
.SH SYNOPSIS
.nf
.B int fmount(type, fildes, name, flag)
.B char *name;
.sp
.B int funmount(name)
.B char *name;
.fi
.SH DESCRIPTION
.I Fmount
mounts a file system of the named
.I type
described by the file descriptor
.I fildes
on pathname
.IR name .
Henceforth,
references to
.I name
(the mount point)
will refer to the root file
on the newly mounted file system.
.PP
.I Name
must already exist.
Its old contents are inaccessible while the
file system is mounted.
.PP
The meaning of
.I flag
varies with the file system type.
.PP
Allowed types are
.TP
.B 0
Regular (block device) file system.
.I Fildes
must be a block special file.
If
.I flag
is nonzero,
the file system may not be written on;
this must be used with physically write-protected media
or errors will occur when access times are updated,
even if no explicit write is attempted.
.TP
.B 2
Process file system,
.IR proc (4).
.I Fildes
is ignored.
.TP
.B 3
Mounted stream.
.I Fildes
must refer to a stream;
future calls to
.IR open (2)
on
.I name
will reopen that stream.
The mount is undone
if the other end of the stream
is closed or hung up.
.TP
.B 4
Stream (network) file system.
.I Fildes
is a stream
connected to a file system server,
.IR netfs (8).
.PP
Types 5 and 6
are used internally
to close off errors
and for pipes;
these types may not be mounted.
.PP
.I Funmount
removes knowledge of the file system
mounted at
.IR name .
The mount point
reverts to its previous interpretation.
.PP
The userid owning
.I name
may mount or unmount file systems
of type 3 or 4.
For other types,
these calls are restricted to the super-user.
.SH SEE ALSO
.IR mount (8),
.IR netfs (8),
.IR proc (4),
.IR stream (4)
.SH DIAGNOSTICS
.BR EBADF ,
.BR EBUSY ,
.BR EINVAL ,
.BR EIO ,
.BR ENODEV
.SH BUGS
Although
.I fildes
for type 2 file systems is ignored,
it must be a valid file descriptor.