Ocfs2 devel - Aug 2009 - Why do we read the blocks in __ocfs2_xxattr_set_value_outside()?

In __ocfs2_xattr_set_value_outside(), we walk each block of the
xattr value and read it before we copy the new data on top and dirty it.
Why are we reading the block from disk if we're just overwriting it?
Would't "sb_getblk(); ocfs2_set_buffer_uptodate()" work better?

Joel

-- 

"This is the end, beautiful friend.
 This is the end, my only friend the end
 Of our elaborate plans, the end
 Of everything that stands, the end
 No safety or surprise, the end
 I'll never look into your eyes again."

Joel Becker
Principal Software Developer
Oracle
E-mail: joel.becker at oracle.com
Phone: (650) 506-8127

Joel Becker wrote:
> 	In __ocfs2_xattr_set_value_outside(), we walk each block of the
> xattr value and read it before we copy the new data on top and dirty it.
> Why are we reading the block from disk if we're just overwriting it?
> Would't "sb_getblk(); ocfs2_set_buffer_uptodate()" work
better?
You made it. yeah, we can do like it.

I remembered that when I first try sb_getblk, I used 
ocfs2_set_new_buffer_uptodate and get a BUG_ON(sorry for it, at the time 
I wrote this piece of code, I don't know much about ocfs2 buffer cache :( ).

Regards,
Tao