Sophie: nfs-utils-1:1.1.5-2mdv2009.1 x86

nfs-utils-1.1.5-2mdv2009.1.x86_64.rpm

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<H2><A NAME="SECTION00033000000000000000">
File Handle in Kernel-Space NFS Server</A>
</H2>

<P>
To make the file handle from the NFS server in the Linux kernel to
work with other NFS client implementations, we have to remove
dentry from file handle. The direct result is the file handle
for the same file remains unchanged across machine reboot. Rebooting
Linux NFS server no longer cause the NFS clients to get the stale NFS
file handle.

<P>
However, deleting and creating the
same pathname may still lead to the same file handle. To solve
it, a generation counter is added to the file handle:

<P>

<UL><LI>A system wide generation counter is initialized with a
  	random number during machine boot.

<P>

<LI>When a new inode is created, it is assigned with the
  	current generation counter and the generation counter
	is incremented.

<P>

<LI>When a freed inode is written to the disk, its generation
  	counter is incremented.

</UL>

<P>
Since we removed the dependency on pathname in the file handle,
rename and hard links within the same directory won't cause change
in the file handle.
However, since the parent directory inode is still the part of the
file handle, move a file or hard link a file from one directory to
a different directory within the same
file system will result in the file handle change. So far we haven't
got any report which shows it is a real problem yet.

<P>
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<ADDRESS>
<I>H.J. Lu</I>
<BR><I>1999-08-15</I>
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