forked from Archive/PX4-Autopilot
389 lines
13 KiB
HTML
389 lines
13 KiB
HTML
|
<html>
|
||
|
|
<head>
|
||
|
|
<title>NFS Client How-To</title>
|
||
|
|
</head>
|
||
|
|
<body background="backgd.gif">
|
||
|
|
<hr><hr>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr align="center" bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<h1><big><font color="#3c34ec"><i>NFS Client How-To</i></font></big></h1>
|
||
|
|
<p>Last Updated: June 18, 2012</p>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
<hr><hr>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<h1>Table of Contents</h1>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<center><table width ="80%">
|
||
|
|
<tr>
|
||
|
|
<td>
|
||
|
|
<table>
|
||
|
|
<tr>
|
||
|
|
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
|
||
|
|
<td>
|
||
|
|
<a href="#nfsconfiguration">Adding NFS to the NuttX Configuration</a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
<table>
|
||
|
|
<tr>
|
||
|
|
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
|
||
|
|
<td>
|
||
|
|
<a href="#mountinterface">Mount Interface</a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
<table>
|
||
|
|
<tr>
|
||
|
|
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
|
||
|
|
<td>
|
||
|
|
<a href="#nfsmount">NFS Mount Command</a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
<table>
|
||
|
|
<tr>
|
||
|
|
<td valign="top" width="22"><img height="20" width="20" src="favicon.ico"></td>
|
||
|
|
<td>
|
||
|
|
<a href="#serverconfig">Configuring the NFS server (Ubuntu)</a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table></center>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<a name="nfsconfiguration"><h1>Adding NFS to the NuttX Configuration</h1></a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
The NFS client is easily added to your configuration:
|
||
|
|
You simply need to add <code>CONFIG_NFS</code> to your <code>nuttx/.config</code> file.
|
||
|
|
There are, however, a few dependencies on other system settings:
|
||
|
|
</p>
|
||
|
|
<ol>
|
||
|
|
<li>
|
||
|
|
First, there are number of things that you must configure in order to be able to use any file system:
|
||
|
|
</li>
|
||
|
|
<ul>
|
||
|
|
<li>
|
||
|
|
<code>CONFIG_NFILE_DESCRIPTORS > 0</code>. You must include support for file descriptors.
|
||
|
|
</li>
|
||
|
|
<li>
|
||
|
|
<code>CONFIG_DISABLE_MOUNTPOINT=n</code>. You must include support for mount points in the pseudo-file system.
|
||
|
|
</li>
|
||
|
|
</ul>
|
||
|
|
<li>
|
||
|
|
And there are several dependencies on the networking configuration.
|
||
|
|
At a minimum, you need to have the following selections:
|
||
|
|
</li>
|
||
|
|
<ul>
|
||
|
|
<li>
|
||
|
|
<code>CONFIG_NET=y</code>. General networking support.
|
||
|
|
</li>
|
||
|
|
<li>
|
||
|
|
<code>CONFIG_NET_UDP=y</code>. Support for UDP.
|
||
|
|
</li>
|
||
|
|
</ul>
|
||
|
|
</ol>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<a name="mountinterface"><h1>Mount Interface</h1></a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
A low-level, C-callable interface is provided to mount a file system.
|
||
|
|
That interface is called <code>mount()</code> and is mentioned in the <a href="NuttxPortingGuide.html#NxFileSystem"><code>porting guide</code></a> and is prototyped in the header file <code>include/sys/mount.h</code>:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
int mount(const char *source, const char *target, const char *filesystemtype, unsigned long mountflags, const void *data);
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
<b>Synopsis</b>:
|
||
|
|
<code>mount()</code> attaches the filesystem specified by the <code>source</code> block device name into the root file system at the path specified by <code>target</code>.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<b>Input Paramters</b>:
|
||
|
|
<ul>
|
||
|
|
<li><code>source</code>. A null-terminated string providing the fill path to a block driver in the NuttX pseudo-file system.
|
||
|
|
<li><code>target</code>. The location in the NuttX pseudo-file system where the volume will be mounted.
|
||
|
|
<li><code>filesystemtype</code>. A string identifying the type of file system to use.
|
||
|
|
<li><code>mountflags</code>. Various flags that can be used to qualify how the file system is mounted.
|
||
|
|
<li><code>data</code>. Opaque data that is passed to the file system with the mount occurs.
|
||
|
|
</ul>
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<b>Returned Values</b>
|
||
|
|
Zero is returned on success; -1 is returned on an error and <code>errno</code> is set appropriately:
|
||
|
|
<ul>
|
||
|
|
<li><code>EACCES</code>.
|
||
|
|
A component of a path was not searchable or mounting a read-onlyfilesystem was attempted without giving the <code>MS_RDONLY</code> flag.
|
||
|
|
</li>
|
||
|
|
<li><code>EBUSY</code>.
|
||
|
|
<code>source</code> is already mounted.
|
||
|
|
</li>
|
||
|
|
<li><code>EFAULT</code>.
|
||
|
|
One of the pointer arguments points outside the user address space.
|
||
|
|
</li>
|
||
|
|
<li><code>EINVAL</code>.
|
||
|
|
<code>source</code> had an invalid superblock.
|
||
|
|
</li>
|
||
|
|
<li><code>ENODEV</code>.
|
||
|
|
<code>filesystemtype</code> not configured
|
||
|
|
</li>
|
||
|
|
<li><code>ENOENT</code>.
|
||
|
|
A pathname was empty or had a nonexistent component.
|
||
|
|
</li>
|
||
|
|
<li><code>ENOMEM</code>.
|
||
|
|
Could not allocate a memory to copy filenames or data into.
|
||
|
|
</li>
|
||
|
|
<li><code>ENOTBLK</code>.
|
||
|
|
<code>source</code> is not a block device
|
||
|
|
</li>
|
||
|
|
</ul>
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
This same interface can be used to mount a remote, NFS file system using some special parameters.
|
||
|
|
The NFS mount differs from the <i>normal</i> file system mount in that: (1) there is no block driver for the NFS file system, and (2) special parameters must be passed as <code>data</code> to describe the remote NFS server.
|
||
|
|
Thus the following code snippet might represent how an NFS file system is mounted:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
#include <sys/mount.h>
|
||
|
|
#include <nuttx/fs/nfs.h>
|
||
|
|
|
||
|
|
struct nfs_args data;
|
||
|
|
char *mountpoint;
|
||
|
|
|
||
|
|
ret = mount(NULL, mountpoint, string "nfs", 0, (FAR void *)&data);
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
NOTE that: (1) the block driver paramter is <code>NULL</code>.
|
||
|
|
The <code>mount()</code> is smart enough to know that no block driver is needed with the NFS file system.
|
||
|
|
(2) The NFS file system is identified with the simple string "nfs"
|
||
|
|
(3) A reference to <code>struct nfs_args</code> is passed as an NFS-specific argument.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
The NFS-specific interface is described in the file <code>include/nuttx/fs/nfs.h</code>.
|
||
|
|
There you can see that <code>struct nfs_args</code> is defined as:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
struct nfs_args
|
||
|
|
{
|
||
|
|
uint8_t addrlen; /* Length of address */
|
||
|
|
uint8_t sotype; /* Socket type */
|
||
|
|
uint8_t flags; /* Flags, determines if following are valid: */
|
||
|
|
uint8_t timeo; /* Time value in deciseconds (with NFSMNT_TIMEO) */
|
||
|
|
uint8_t retrans; /* Times to retry send (with NFSMNT_RETRANS) */
|
||
|
|
uint16_t wsize; /* Write size in bytes (with NFSMNT_WSIZE) */
|
||
|
|
uint16_t rsize; /* Read size in bytes (with NFSMNT_RSIZE) */
|
||
|
|
uint16_t readdirsize; /* readdir size in bytes (with NFSMNT_READDIRSIZE) */
|
||
|
|
char *path; /* Server's path of the directory being mount */
|
||
|
|
struct sockaddr_storage addr; /* File server address (requires 32-bit alignment) */
|
||
|
|
};
|
||
|
|
</pre></ul>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<a name="nfsmount"><h1>NFS Mount Command</h1></a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
The <a href="NuttShell.html">NuttShell (NSH)</a> also supports a command called <code>nfsmount</code>
|
||
|
|
that can be used to mount a remote file system via the NSH command line.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<b>Command Syntax:</b>
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
nfsmount <server-address> <mount-point> <remote-path>
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
<b>Synopsis</b>.
|
||
|
|
The <code>nfsmount</code> command mounts a network file system in the NuttX pseudo filesystem.
|
||
|
|
The <code>nfsmount</code> will use NFSv3 UDP protocol to mount the remote file system.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<b>Command Line Arguments</b>.
|
||
|
|
The <code>nfsmount</code> takes three arguments:
|
||
|
|
</p>
|
||
|
|
<ol>
|
||
|
|
<li>
|
||
|
|
The <code><server-address></code> is the IP address of the server exporting the file system you wish to mount.
|
||
|
|
This implementation of NFS for the NuttX RTOS is only for a local area network, so the server and client must be in the same network.
|
||
|
|
</li>
|
||
|
|
<li>
|
||
|
|
The <code><mount-point ></code> is the location in the NuttX pseudo filesystem where the mounted volume will appear.
|
||
|
|
This mount point can only reside in the NuttX pseudo filesystem.
|
||
|
|
By convention, this mount point is a subdirectory under <code>/mnt</code>.
|
||
|
|
The mount command will create whatever pseudo directories that may be needed to complete the full path (but the full path must not already exist).
|
||
|
|
</li>
|
||
|
|
<li>
|
||
|
|
The <code><remote-path></code> is the file system <code>/</code> directory being exported from server.
|
||
|
|
This <code>/</code> directory must have been configured for exportation on the server before when the NFS server was set up.
|
||
|
|
</li>
|
||
|
|
</ol>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
After the volume has been mounted in the NuttX pseudo filesystem, it may be access in the same way as other objects in the file system.
|
||
|
|
</p>
|
||
|
|
<p>
|
||
|
|
<b>Example</b>.
|
||
|
|
Suppose the the NFS server has been configured to export the directory <code>/export/shared</code>.
|
||
|
|
The the following command would mount that file system (assuming that the target also has privileges to mount the file system).
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
NuttShell (NSH)
|
||
|
|
nsh> ls /mnt
|
||
|
|
/mnt:
|
||
|
|
nsh: ls: no such directory: /mnt
|
||
|
|
nsh> nfsmount 10.0.0.1 /mnt/nfs /export/shared
|
||
|
|
nsh> ls -l /mnt/nfs
|
||
|
|
/mnt/nfs:
|
||
|
|
drwxrwxrwx 4096 ..
|
||
|
|
drwxrwxrwx 4096 testdir/
|
||
|
|
-rw-rw-rw- 6 ctest.txt
|
||
|
|
-rw-r--r-- 15 btest.txt
|
||
|
|
drwxrwxrwx 4096 .
|
||
|
|
nsh> echo "This is a test" >/mnt/nfs/testdir/testfile.txt
|
||
|
|
nsh> ls -l /mnt/nfs/testdir
|
||
|
|
/mnt/nfs/testdir:
|
||
|
|
-rw-rw-rw- 21 another.txt
|
||
|
|
drwxrwxrwx 4096 ..
|
||
|
|
drwxrwxrwx 4096 .
|
||
|
|
-rw-rw-rw- 16 testfile.txt
|
||
|
|
nsh> cat /mnt/nfs/testdir/testfile.txt
|
||
|
|
This is a test
|
||
|
|
</pre></ul>
|
||
|
|
|
||
|
|
<table width ="100%">
|
||
|
|
<tr bgcolor="#e4e4e4">
|
||
|
|
<td>
|
||
|
|
<a name="serverconfig"><h1>Configuring the NFS server (Ubuntu)</h1></a>
|
||
|
|
</td>
|
||
|
|
</tr>
|
||
|
|
</table>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
Setting up the server will be done in two steps:
|
||
|
|
First, setting up the configuration file for NFS, and then starting the NFS services.
|
||
|
|
But first, you need to install the nfs server on Ubuntu with the these two commands:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo apt-get install nfs-common</FONT>
|
||
|
|
# sudo apt-get install nfs-kernel-server</FONT>
|
||
|
|
</pre></ul>
|
||
|
|
|
||
|
|
<p>
|
||
|
|
After that, we need to make or choose the directory we want to export from the NFS server.
|
||
|
|
In our case, we are going to make a new directory called <code>/export</code>.
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo mkdir /export
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
It is important that <code>/export</code> directory allow access to everyone (777 permissions) as we will be accessing the NFS share from the client with no authentication.
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo chmod 777 /export
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
When all this is done, we will need to edit the configuration file to set up an NFS server: <code>/etc/exports</code>.
|
||
|
|
This file contains a list of entries;
|
||
|
|
each entry indicates a volume that is shared and how it is shared.
|
||
|
|
For more information for a complete description of all the setup options for this file you can check in the man pages (<code>man export</code>).</p>
|
||
|
|
An entry in <code>/etc/exports</code> will typically look like this:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
directory machine1(option11,option12)
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
So for our example we export <coce>/export</code> to the client 10.0.0.2 add the entry:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
/export 10.0.0.2(rw)
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
In our case we are using all the default options except for the <code>ro</code> that we replaced with <code>rw</code> so that our client will have read and write access to the directory that we are exporting.
|
||
|
|
</p>
|
||
|
|
</p>
|
||
|
|
After we do all the require configurations, we are ready to start the server with the next command:
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo /etc/init.d/nfs-kernel-server start
|
||
|
|
</pre></ul>
|
||
|
|
</p>
|
||
|
|
Note: If you later decide to add more NFS exports to the /etc/exports file, you will need to either restart NFS daemon
|
||
|
|
or run command exportfs.
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo /etc/init.d/nfs-kernel-server start
|
||
|
|
</pre></ul>
|
||
|
|
<p>Or</p>
|
||
|
|
<ul><pre>
|
||
|
|
# exportfs -ra
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
Now we can check if the export directory and our mount point is properly set up.
|
||
|
|
</p>
|
||
|
|
<ul><pre>
|
||
|
|
# sudo showmount -e
|
||
|
|
# sudo showmount -a
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
And also we can verify if NFS is running in the system with:
|
||
|
|
</p>
|
||
|
|
<P STYLE="margin-left: 0.49in; margin-bottom: 0in; line-height: 100%">
|
||
|
|
<ul><pre>
|
||
|
|
# rpcinfo –p</FONT>
|
||
|
|
program vers proto port
|
||
|
|
100000 2 tcp 111 portmapper
|
||
|
|
100000 2 udp 111 portmapper
|
||
|
|
100011 1 udp 749 rquotad
|
||
|
|
100011 2 udp 749 rquotad
|
||
|
|
100005 1 udp 759 mountd
|
||
|
|
100005 1 tcp 761 mountd
|
||
|
|
100005 2 udp 764 mountd
|
||
|
|
100005 2 tcp 766 mountd
|
||
|
|
100005 3 udp 769 mountd
|
||
|
|
100005 3 tcp 771 mountd
|
||
|
|
100003 2 udp 2049 nfs
|
||
|
|
100003 3 udp 2049 nfs
|
||
|
|
300019 1 tcp 830 amd
|
||
|
|
300019 1 udp 831 amd
|
||
|
|
100024 1 udp 944 status
|
||
|
|
100024 1 tcp 946 status
|
||
|
|
100021 1 udp 1042 nlockmgr
|
||
|
|
100021 3 udp 1042 nlockmgr
|
||
|
|
100021 4 udp 1042 nlockmgr
|
||
|
|
100021 1 tcp 1629 nlockmgr
|
||
|
|
100021 3 tcp 1629 nlockmgr
|
||
|
|
100021 4 tcp 1629 nlockmgr
|
||
|
|
</pre></ul>
|
||
|
|
<p>
|
||
|
|
Now your NFS sever is sharing <code>/export</code> directory to be accessed.
|
||
|
|
</p>
|
||
|
|
|
||
|
|
</body>
|
||
|
|
</html>
|