tree 7a5ad7481b160e1d40cdc95626bfdb5e8577c88e
parent a78ef704a8dd430225955f0709b22d4a6ba21deb
author Sage Weil <sage@newdream.net> 1319821362 -0700
committer Christoph Hellwig <hch@serles.lst.de> 1320234823 +0100

vfs: add d_prune dentry operation

This adds a d_prune dentry operation that is called by the VFS prior to
pruning (i.e. unhashing and killing) a hashed dentry from the dcache.
Wrap dentry_lru_del() and use the new _prune() helper in the cases where we
are about to unhash and kill the dentry.

This will be used by Ceph to maintain a flag indicating whether the
complete contents of a directory are contained in the dcache, allowing it
to satisfy lookups and readdir without addition server communication.

Renumber a few DCACHE_* #defines to group DCACHE_OP_PRUNE with the other
DCACHE_OP_ bits.

Signed-off-by: Sage Weil <sage@newdream.net>
Signed-off-by: Christoph Hellwig <hch@lst.de>