xfs_buf and buffercache/pagecache connection

[Yannis Klonatos]

Hello,

         I was looking to add a kernel hook to my system in order to 
monitor buffer-cache hit and misses. Initially I was
planning to add my modifications to the __getblk(). However, i noticed 
that XFS does not directly use the buffer-cache
for its pages but it seems to implement its own buffer.
         What I am now looking for is 1) the place where XFS checks 
whether a page exists in its buffer or not and 2)
what are the possible interactions between xfs_buf and the Linux kernel 
buffer-cache.
         I would appreciate any information regarding the above issues.

Thanks in advance,
Yannis Klonatos