[Ocfs2-devel] [PATCH 1/1] Ocfs2: Stop tracking a negative dentry after dentry_iput().

[Joel Becker <Joel.Becker@oracle.com>]

On Mon, Nov 15, 2010 at 09:39:09PM +0800, Tristan Ye wrote:
> I suddenly hit the problem during 2.6.37-rc1 regression test, which was
> introduced by commit '5e98d492406818e6a94c0ba54c61f59d40cefa4a'(Track
> negative entries v3), following scenario reproduces the issue easily:
> 
> Node A			Node B
> ================	============
> $touch 	testfile	
> 			$ls testfile
> $rm -rf testfile
> $touch 	testfile	
> 			$ls testfile
> 			ls: cannot access testfile: No such file or directory
> 
> This patch stops tracking the dentry which was negativated by a inode deletion,
> so as to force the revaliation in next lookup, in case we'll touch the inode
> again in the same node.
> 
> It didn't hurt the performance of multiple lookup for none-existed files anyway,
> while regresses a bit in the first try after a file deletion.

	I'm going to take this fix for now, because it is clearing the
problem.  However, it looks like the original code _should_ work.  If we
have created a file, the directory's generation should have been
updated.  Thus, the pgen shouldn't match the generation set when the old
inode was deleted.  Right?

Joel


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Joel Becker
Senior Development Manager
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127