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

[Tao Ma <tao.ma@oracle.com>]

Hi Mark,

Mark Fasheh wrote:
> 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?
http://oss.oracle.com/osswiki/OCFS2/XattrTest

btw, tristan.ye from oracle will focus on ocfs2 test in the following 
year. Thank you, tristan.

Regards,
Tao