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.Dd September 5, 2013
.Dt DIRFS 5
.Os
.Sh NAME
.Nm dirfs
.Nd "pseudo-filesystem for vkernel"
.Sh SYNOPSIS
To compile this driver into the vkernel,
place the following line in your
vkernel configuration file:
.Bd -ragged -offset indent
.Cd "options DIRFS"
.Ed
.Pp
Actually this driver does not provide a loadable module.
.Pp
In
.Xr fstab 5 :
.Bd -literal -compact
/usr/src     /mnt dirfs rw 0 0
.Ed
.Sh DESCRIPTION
.Nm
was born from the idea of providing an easy way for
.Xr vkernel 7
to access host's directories without any sort of configuration as it would be
needed by NFS for example.
.Pp
It runs directly in the vkernel's
.Xr VFS 9
code, as any other regular filesystem but it uses syscalls to retrieve the
information needed for every operation requested.
.Pp
It should be noted that when the vkernel is run by a regular user, the
operations
.Nm
can perform on the mounted host directory are bound to the permissions of
the aforementioned user.
.Pp
Multiple
.Nm
mounts are allowed.
.Sh EXAMPLES
To mount a
.Nm
memory file system:
.Pp
.Dl "mount -t dirfs /usr/src /mnt"
.Sh SEE ALSO
.Xr fstab 5 ,
.Xr mount_dirfs 8
.Sh HISTORY
The
.Nm
driver first appeared in
.Dx 3.5 .
.Sh AUTHORS
.An -nosplit
The
.Nm
vkernel implementation was written from the scratch by
.An Antonio Huete Jimenez Aq Mt tuxillo@quantumachine.net
.Pp
Numerous fixes and pointers by
.An Matthew Dillon Aq Mt dillon@apollo.backplane.com
.Pp
This manual page was written by
.An Antonio Huete Jimenez Aq Mt tuxillo@quantumachine.net
.Sh BUGS
Currently there is no locking on file descriptors between the host
and the vkernel.
This means that there might be problems with concurrent accesses to the same
file.
.Pp
There is no support for hardlinks in
.Nm
yet.