NFSv4: More aggressive caching if we have a delegation.

Signed-off-by: Trond Myklebust <trond.myklebust@fys.uio.no>

fs/nfs/delegation.c

@@ -70,6 +70,8 @@ void nfs_inode_reclaim_delegation(struct inode *inode, struct rpc_cred *cred, st
 	put_rpccred(cred);
 	delegation->cred = get_rpccred(cred);
 	delegation->flags &= ~NFS_DELEGATION_NEED_RECLAIM;
+	NFS_I(inode)->delegation_state = delegation->type;
+	smp_wmb();
 }
 
 /*
@@ -96,6 +98,7 @@ int nfs_inode_set_delegation(struct inode *inode, struct rpc_cred *cred, struct
 	if (nfsi->delegation == NULL) {
 		list_add(&delegation->super_list, &clp->cl_delegations);
 		nfsi->delegation = delegation;
+		nfsi->delegation_state = delegation->type;
 		delegation = NULL;
 	} else {
 		if (memcmp(&delegation->stateid, &nfsi->delegation->stateid,
@@ -150,6 +153,7 @@ int nfs_inode_return_delegation(struct inode *inode)
 	if (delegation != NULL) {
 		list_del_init(&delegation->super_list);
 		nfsi->delegation = NULL;
+		nfsi->delegation_state = 0;
 	}
 	spin_unlock(&clp->cl_lock);
 	nfs_delegation_claim_opens(inode);
@@ -218,6 +222,7 @@ static int recall_thread(void *data)
 				sizeof(delegation->stateid.data)) == 0) {
 		list_del_init(&delegation->super_list);
 		nfsi->delegation = NULL;
+		nfsi->delegation_state = 0;
 		args->result = 0;
 	} else {
 		delegation = NULL;
@@ -302,6 +307,7 @@ void nfs_delegation_reap_unclaimed(struct nfs4_client *clp)
 			continue;
 		list_move(&delegation->super_list, &head);
 		NFS_I(delegation->inode)->delegation = NULL;
+		NFS_I(delegation->inode)->delegation_state = 0;
 	}
 	spin_unlock(&clp->cl_lock);
 	while(!list_empty(&head)) {

fs/nfs/delegation.h

@@ -8,6 +8,7 @@
 #ifndef FS_NFS_DELEGATION_H
 #define FS_NFS_DELEGATION_H
 
+#if defined(CONFIG_NFS_V4)
 /*
  * NFSv4 delegation
  */
@@ -37,4 +38,19 @@ void nfs_delegation_reap_unclaimed(struct nfs4_client *clp);
 int nfs4_proc_delegreturn(struct inode *inode, struct rpc_cred *cred, const nfs4_stateid *stateid);
 int nfs4_open_delegation_recall(struct dentry *dentry, struct nfs4_state *state);
 
+static inline int nfs_have_delegation(struct inode *inode, int flags)
+{
+	flags &= FMODE_READ|FMODE_WRITE;
+	smp_rmb();
+	if ((NFS_I(inode)->delegation_state & flags) == flags)
+		return 1;
+	return 0;
+}
+#else
+static inline int nfs_have_delegation(struct inode *inode, int flags)
+{
+	return 0;
+}
+#endif
+
 #endif

fs/nfs/dir.c

@@ -32,6 +32,8 @@
 #include <linux/smp_lock.h>
 #include <linux/namei.h>
 
+#include "delegation.h"
+
 #define NFS_PARANOIA 1
 /* #define NFS_DEBUG_VERBOSE 1 */
 
@@ -887,6 +889,8 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
 	return ret;
 no_open:
 	dput(parent);
+	if (inode != NULL && nfs_have_delegation(inode, FMODE_READ))
+		return 1;
 	return nfs_lookup_revalidate(dentry, nd);
 }
 #endif /* CONFIG_NFSV4 */

fs/nfs/file.c

@@ -31,6 +31,8 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
+#include "delegation.h"
+
 #define NFSDBG_FACILITY		NFSDBG_FILE
 
 static int nfs_file_open(struct inode *, struct file *);
@@ -127,7 +129,7 @@ nfs_file_flush(struct file *file)
 	if (!status) {
 		status = ctx->error;
 		ctx->error = 0;
-		if (!status)
+		if (!status && !nfs_have_delegation(inode, FMODE_READ))
 			__nfs_revalidate_inode(NFS_SERVER(inode), inode);
 	}
 	unlock_kernel();

fs/nfs/inode.c

@@ -39,6 +39,8 @@
 #include <asm/system.h>
 #include <asm/uaccess.h>
 
+#include "delegation.h"
+
 #define NFSDBG_FACILITY		NFSDBG_VFS
 #define NFS_PARANOIA 1
 
@@ -1017,6 +1019,30 @@ __nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
 	return status;
 }
 
+int nfs_attribute_timeout(struct inode *inode)
+{
+	struct nfs_inode *nfsi = NFS_I(inode);
+
+	if (nfs_have_delegation(inode, FMODE_READ))
+		return 0;
+	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
+}
+
+/**
+ * nfs_revalidate_inode - Revalidate the inode attributes
+ * @server - pointer to nfs_server struct
+ * @inode - pointer to inode struct
+ *
+ * Updates inode attribute information by retrieving the data from the server.
+ */
+int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
+{
+	if (!(NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
+			&& !nfs_attribute_timeout(inode))
+		return NFS_STALE(inode) ? -ESTALE : 0;
+	return __nfs_revalidate_inode(server, inode);
+}
+
 /**
  * nfs_begin_data_update
  * @inode - pointer to inode
@@ -1038,11 +1064,13 @@ void nfs_end_data_update(struct inode *inode)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 
-	/* Mark the attribute cache for revalidation */
-	nfsi->flags |= NFS_INO_INVALID_ATTR;
-	/* Directories and symlinks: invalidate page cache too */
-	if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		nfsi->flags |= NFS_INO_INVALID_DATA;
+	if (!nfs_have_delegation(inode, FMODE_READ)) {
+		/* Mark the attribute cache for revalidation */
+		nfsi->flags |= NFS_INO_INVALID_ATTR;
+		/* Directories and symlinks: invalidate page cache too */
+		if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
+			nfsi->flags |= NFS_INO_INVALID_DATA;
+	}
 	nfsi->cache_change_attribute ++;
 	atomic_dec(&nfsi->data_updates);
 }
@@ -1083,6 +1111,10 @@ int nfs_refresh_inode(struct inode *inode, struct nfs_fattr *fattr)
 	loff_t cur_size, new_isize;
 	int data_unstable;
 
+	/* Do we hold a delegation? */
+	if (nfs_have_delegation(inode, FMODE_READ))
+		return 0;
+
 	/* Are we in the process of updating data on the server? */
 	data_unstable = nfs_caches_unstable(inode);
 
@@ -1280,7 +1312,8 @@ static int nfs_update_inode(struct inode *inode, struct nfs_fattr *fattr, unsign
 	if (!(S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode)
 				|| S_ISLNK(inode->i_mode)))
 		invalid &= ~NFS_INO_INVALID_DATA;
-	nfsi->flags |= invalid;
+	if (!nfs_have_delegation(inode, FMODE_READ))
+		nfsi->flags |= invalid;
 
 	return 0;
  out_changed:
@@ -1437,8 +1470,6 @@ static struct file_system_type nfs_fs_type = {
 
 #ifdef CONFIG_NFS_V4
 
-#include "delegation.h"
-
 static void nfs4_clear_inode(struct inode *);
 
 
@@ -1767,6 +1798,7 @@ static struct file_system_type nfs4_fs_type = {
 	do { \
 		INIT_LIST_HEAD(&(nfsi)->open_states); \
 		nfsi->delegation = NULL; \
+		nfsi->delegation_state = 0; \
 		init_rwsem(&nfsi->rwsem); \
 	} while(0)
 #define register_nfs4fs() register_filesystem(&nfs4_fs_type)

fs/nfs/write.c

@@ -63,6 +63,8 @@
 #include <linux/smp_lock.h>
 #include <linux/mempool.h>
 
+#include "delegation.h"
+
 #define NFSDBG_FACILITY		NFSDBG_PAGECACHE
 
 #define MIN_POOL_WRITE		(32)
@@ -382,8 +384,7 @@ int nfs_writepages(struct address_space *mapping, struct writeback_control *wbc)
 /*
  * Insert a write request into an inode
  */
-static inline int
-nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
+static int nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 {
 	struct nfs_inode *nfsi = NFS_I(inode);
 	int error;
@@ -395,6 +396,8 @@ nfs_inode_add_request(struct inode *inode, struct nfs_page *req)
 	if (!nfsi->npages) {
 		igrab(inode);
 		nfs_begin_data_update(inode);
+		if (nfs_have_delegation(inode, FMODE_WRITE))
+			nfsi->change_attr++;
 	}
 	nfsi->npages++;
 	atomic_inc(&req->wb_count);

include/linux/nfs_fs.h

@@ -185,6 +185,7 @@ struct nfs_inode {
         /* NFSv4 state */
 	struct list_head	open_states;
 	struct nfs_delegation	*delegation;
+	int			 delegation_state;
 	struct rw_semaphore	rwsem;
 #endif /* CONFIG_NFS_V4*/
 
@@ -294,6 +295,8 @@ extern int nfs_access_get_cached(struct inode *, struct rpc_cred *, struct nfs_a
 extern void nfs_access_add_cache(struct inode *, struct nfs_access_entry *);
 extern int nfs_open(struct inode *, struct file *);
 extern int nfs_release(struct inode *, struct file *);
+extern int nfs_attribute_timeout(struct inode *inode);
+extern int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode);
 extern int __nfs_revalidate_inode(struct nfs_server *, struct inode *);
 extern int nfs_setattr(struct dentry *, struct iattr *);
 extern void nfs_begin_attr_update(struct inode *);
@@ -446,28 +449,6 @@ extern int  nfsroot_mount(struct sockaddr_in *, char *, struct nfs_fh *,
  * inline functions
  */
 
-static inline int nfs_attribute_timeout(struct inode *inode)
-{
-	struct nfs_inode *nfsi = NFS_I(inode);
-
-	return time_after(jiffies, nfsi->read_cache_jiffies+nfsi->attrtimeo);
-}
-
-/**
- * nfs_revalidate_inode - Revalidate the inode attributes
- * @server - pointer to nfs_server struct
- * @inode - pointer to inode struct
- *
- * Updates inode attribute information by retrieving the data from the server.
- */
-static inline int nfs_revalidate_inode(struct nfs_server *server, struct inode *inode)
-{
-	if (!(NFS_FLAGS(inode) & (NFS_INO_INVALID_ATTR|NFS_INO_INVALID_DATA))
-			&& !nfs_attribute_timeout(inode))
-		return NFS_STALE(inode) ? -ESTALE : 0;
-	return __nfs_revalidate_inode(server, inode);
-}
-
 static inline loff_t
 nfs_size_to_loff_t(__u64 size)
 {