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.\" $FreeBSD: src/share/man/man9/vfs_mount.9,v 1.12.22.2.4.1 2010/12/21 17:09:25 kensmith Exp $
.\"
.Dd November 26, 2004
.Dt VFS_MOUNT 9
.Os
.Sh NAME
.Nm vfs_mount
.Nd "generic file system mount function"
.Sh SYNOPSIS
.In sys/param.h
.In sys/mount.h
.Ft int
.Fo vfs_mount
.Fa "struct thread *td"
.Fa "const char *fstype"
.Fa "char *fspath"
.Fa "int fsflags"
.Fa "void *fsdata"
.Fc
.Sh DESCRIPTION
The
.Fn vfs_mount
function handles the generic portion of mounting a file system,
and calls the file system specific mount function after verifying
its parameters and setting up the structures expected by the
underlying mount code.
.Pp
.Fn vfs_mount
is called directly by the
.Xr mount 2
system call.
.Pp
Its arguments are:
.Bl -tag -width ".Fa fsflags"
.It Fa td
The thread responsible for this call.
.It Fa fstype
The type of file system being mounted.
.It Fa fspath
The path to the mount point of the file system.
.It Fa fsflags
Flags controlling the mount.
See
.Xr mount 2
for details.
.Pp
.Dv MNT_EXPORTED , MNT_NOSUID , MNT_UPDATE , MNT_RELOAD ,
.Dv MNT_FORCE , MNT_ASYNC , MNT_SYNCHRONOUS , MNT_UNION , MNT_NOATIME ,
.Dv MNT_SNAPSHOT , MNT_NOCLUSTERR , MNT_NOCLUSTERW , MNT_IGNORE ,
.Dv MNT_UNION , MNT_NOSYMFOLLOW
.It Fa fsdata
File system specific data structure.
It is in userspace
when passed to
.Fn vfs_mount
and is left untouched when passed to file system's
.Fn mount .
.El
.Sh RETURN VALUES
A 0 value is returned on success.
.Sh ERRORS
.Bl -tag -width Er
.It Bq Er ENAMETOOLONG
The fs type or the mount point path is too long or any individual
path component is too long.
.It Bq Er EPERM
Permission denied.
There are a number of reason this can occur
ranging from the user not having permission to mount a file system
to the securelevel being to high to load the
.Fa fstype
module.
.It Bq Er EINVAL
Invalid operation (ex: trying to update a non mount-point).
.It Bq Er ENOENT
The mount point does not exist (from
.Fn namei ) .
.It Bq Er ELOOP
The mount point is a muddle of links (from
.Fn namei ) .
.It Bq Er EOPNOTSUPP
The operation is not supported (ex: reloading a r/w file system).
.It Bq Er EBUSY
The mount point is busy or is not really a mount point (on update).
.It Bq Er ENOTDIR
The mount point is not a directory.
.It Bq Er ENODEV
The kernel linker was unable to load the specified
.Fa fstype
or was unable to find the specified
.Fa fstype
module.
.El
.Pp
Other errors can be returned by the file system's
.Fn mount
and
you should check the specific file system for details.
Also
this call relies on a large number of other kernel services
whose errors it returns so this list may not be exhaustive.
.Sh SEE ALSO
.Xr mount 2 ,
.Xr mount 8
.Pp
.Va vfs.usermount
.Sh AUTHORS
This manual page was written by
.An Chad David Aq davidc@acns.ab.ca .