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, 1 deletions

diff --git a/include/linux/nfs_fs.h b/include/linux/nfs_fs.h
index 6c2066caeaab..cc013ed2e52e 100644
--- a/include/linux/nfs_fs.h
+++ b/include/linux/nfs_fs.h
@@ -42,6 +42,7 @@
 #include <linux/in.h>
 #include <linux/mm.h>
 #include <linux/pagemap.h>
+#include <linux/rbtree.h>
 #include <linux/rwsem.h>
 #include <linux/wait.h>
 
@@ -69,6 +70,7 @@
  * NFSv3/v4 Access mode cache entry
  */
 struct nfs_access_entry {
+        struct rb_node          rb_node;
         unsigned long           jiffies;
         struct rpc_cred *       cred;
         int                     mask;
@@ -145,7 +147,7 @@ struct nfs_inode {
          */
         atomic_t                data_updates;
 
-        struct nfs_access_entry cache_access;
+        struct rb_root          access_cache;
 #ifdef CONFIG_NFS_V3_ACL
         struct posix_acl        *acl_access;
         struct posix_acl        *acl_default;
@@ -297,6 +299,7 @@ extern int nfs_getattr(struct vfsmount *, struct dentry *, struct kstat *);
 extern int nfs_permission(struct inode *, int, struct nameidata *);
 extern int nfs_access_get_cached(struct inode *, struct rpc_cred *, struct nfs_access_entry *);
 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
+extern void nfs_access_zap_cache(struct inode *inode);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
 extern int nfs_attribute_timeout(struct inode *inode);