NFS: Add a new ACCESS rpc call cache to the linux nfs client

The current access cache only allows one entry at a time to be cached for each
inode. Add a per-inode red-black tree in order to allow more than one to
be cached at a time.

Should significantly cut down the time spent in path traversal for shared
directories such as ${PATH}, /usr/share, etc.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

1 files changed, 4 insertions, 9 deletions

diff --git a/fs/nfs/inode.c b/fs/nfs/inode.c
index d349fb2245da..b94ab060bb1e 100644
--- a/fs/nfs/inode.c
+++ b/fs/nfs/inode.c
@@ -76,19 +76,14 @@ int nfs_write_inode(struct inode *inode, int sync)
 
 void nfs_clear_inode(struct inode *inode)
 {
-        struct nfs_inode *nfsi = NFS_I(inode);
-        struct rpc_cred *cred;
-
         /*
          * The following should never happen...
          */
         BUG_ON(nfs_have_writebacks(inode));
-        BUG_ON (!list_empty(&nfsi->open_files));
+        BUG_ON(!list_empty(&NFS_I(inode)->open_files));
+        BUG_ON(atomic_read(&NFS_I(inode)->data_updates) != 0);
         nfs_zap_acl_cache(inode);
-        cred = nfsi->cache_access.cred;
-        if (cred)
-                put_rpccred(cred);
-        BUG_ON(atomic_read(&nfsi->data_updates) != 0);
+        nfs_access_zap_cache(inode);
 }
 
 /**
@@ -290,7 +285,7 @@ nfs_fhget(struct super_block *sb, struct nfs_fh *fh, struct nfs_fattr *fattr)
                 nfsi->attrtimeo = NFS_MINATTRTIMEO(inode);
                 nfsi->attrtimeo_timestamp = jiffies;
                 memset(nfsi->cookieverf, 0, sizeof(nfsi->cookieverf));
-                nfsi->cache_access.cred = NULL;
+                nfsi->access_cache = RB_ROOT;
 
                 unlock_new_inode(inode);
         } else