[Ocfs2-devel] [PATCH 1/1] ocfs2: Add extended attribute support v3

[Mark Fasheh]

On Tue, Aug 05, 2008 at 10:39:39AM +0800, Tao Ma wrote:
> >>>Or are you trying to protect xattr against itself? If that's the case, 
> >>>you
> >>>could push this lock up to the top and take it around entire operations.
> >>Actually I am trying to protect xattr read/write by this semaphore,
> >>since we found a bug about it.
> >>http://oss.oracle.com/bugzilla/show_bug.cgi?id=990
> >>
> >>So I need change comment about xattr semaphore.
> >>/* protects extended attribute change on this inode */
> >
> >You could, or how about we just take i_mutex at the top of our xattr
> >operations for now? If we need the extra performance that more complicated
> >locking gives us, we can add this later.
> We can't use i_mutex because of the performance issue. And actually 
> xattr_sem is done by me at the very beginning and I think it should be 
> included in Tiger's patch, so asked him to merge it to his patch. ;)
> I originally used i_mutex in get and list to protect xattr, but as 
> tristan tested the patch, he told me that the performance is very bad 
> compared with ext3, so I looked at how ext3 implemented it and there 
> comes out the usage of xattr_sem.

Ok, if that's the case then we can certainly keep xattr_sem. I'm curious
though - what tests are we talking about here?
	--Mark

--
Mark Fasheh