NFSv4: Add {get,set,list}xattr methods for nfs4

 Add {get,set,list}xattr methods for nfs4.  The new methods are no-ops, to be
 used by subsequent ACL patch.

 Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
 Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 dir.c      |    3 +++
 file.c     |   14 ++++++++++++++
 inode.c    |   31 ++++++++++++++++++++++++++++++-
 nfs4_fs.h  |    7 +++++++
 nfs4proc.c |    2 +-
 5 files changed, 55 insertions(+), 2 deletions(-)

Index: linux-2.6.11/fs/nfs/dir.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/dir.c
+++ linux-2.6.11/fs/nfs/dir.c
@@ -91,6 +91,9 @@ struct inode_operations nfs4_dir_inode_o
 	.permission	= nfs_permission,
 	.getattr	= nfs_getattr,
 	.setattr	= nfs_setattr,
+	.getxattr       = nfs4_getxattr,
+	.setxattr       = nfs4_setxattr,
+	.listxattr      = nfs4_listxattr,
 };
 
 #endif /* CONFIG_NFS_V4 */
Index: linux-2.6.11/fs/nfs/file.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/file.c
+++ linux-2.6.11/fs/nfs/file.c
@@ -31,6 +31,7 @@
 #include <asm/uaccess.h>
 #include <asm/system.h>
 
+#include "nfs4_fs.h"
 #include "delegation.h"
 
 #define NFSDBG_FACILITY		NFSDBG_FILE
@@ -70,6 +71,19 @@ struct inode_operations nfs_file_inode_o
 	.setattr	= nfs_setattr,
 };
 
+#ifdef CONFIG_NFS_V4
+
+struct inode_operations nfs4_file_inode_operations = {
+	.permission	= nfs_permission,
+	.getattr	= nfs_getattr,
+	.setattr	= nfs_setattr,
+	.getxattr	= nfs4_getxattr,
+	.setxattr	= nfs4_setxattr,
+	.listxattr	= nfs4_listxattr,
+};
+
+#endif /* CONFIG_NFS_V4 */
+
 /* Hack for future NFS swap support */
 #ifndef IS_SWAPFILE
 # define IS_SWAPFILE(inode)	(0)
Index: linux-2.6.11/fs/nfs/inode.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/inode.c
+++ linux-2.6.11/fs/nfs/inode.c
@@ -1496,8 +1496,37 @@ static struct file_system_type nfs_fs_ty
 
 #ifdef CONFIG_NFS_V4
 
-static void nfs4_clear_inode(struct inode *);
+int
+nfs4_setxattr(struct dentry *dentry, const char *key, const void *buf,
+		size_t buflen, int flags)
+{
+	return -EOPNOTSUPP;
+}
+
+/* The getxattr man page suggests returning -ENODATA for unknown attributes,
+ * and that's what we'll do for e.g. user attributes that haven't been set.
+ * But we'll follow ext2/ext3's lead by returning -EOPNOTSUPP for unsupported
+ * attributes in kernel-managed attribute namespaces. */
+ssize_t
+nfs4_getxattr(struct dentry *dentry, const char *key, void *buf,
+		size_t buflen)
+{
+	return -EOPNOTSUPP;
+}
 
+ssize_t
+nfs4_listxattr(struct dentry *dentry, char *buf, size_t buflen)
+{
+	ssize_t len = 0;
+
+	if (buf && buflen < len)
+		return -ERANGE;
+	if (buf)
+		memcpy(buf, "", 0);
+	return 0;
+}
+
+static void nfs4_clear_inode(struct inode *);
 
 static struct super_operations nfs4_sops = { 
 	.alloc_inode	= nfs_alloc_inode,
Index: linux-2.6.11/fs/nfs/nfs4proc.c
===================================================================
--- linux-2.6.11.orig/fs/nfs/nfs4proc.c
+++ linux-2.6.11/fs/nfs/nfs4proc.c
@@ -2746,7 +2746,7 @@ struct nfs_rpc_ops	nfs_v4_clientops = {
 	.version	= 4,			/* protocol version */
 	.dentry_ops	= &nfs4_dentry_operations,
 	.dir_inode_ops	= &nfs4_dir_inode_operations,
-	.file_inode_ops	= &nfs_file_inode_operations,
+	.file_inode_ops	= &nfs4_file_inode_operations,
 	.getroot	= nfs4_proc_get_root,
 	.getattr	= nfs4_proc_getattr,
 	.setattr	= nfs4_proc_setattr,
Index: linux-2.6.11/fs/nfs/nfs4_fs.h
===================================================================
--- linux-2.6.11.orig/fs/nfs/nfs4_fs.h
+++ linux-2.6.11/fs/nfs/nfs4_fs.h
@@ -176,6 +176,13 @@ struct nfs4_state_recovery_ops {
 
 extern struct dentry_operations nfs4_dentry_operations;
 extern struct inode_operations nfs4_dir_inode_operations;
+extern struct inode_operations nfs4_file_inode_operations;
+
+/* inode.c */
+extern ssize_t nfs4_getxattr(struct dentry *, const char *, void *, size_t);
+extern int nfs4_setxattr(struct dentry *, const char *, const void *, size_t, int);
+extern ssize_t nfs4_listxattr(struct dentry *, char *, size_t);
+
 
 /* nfs4proc.c */
 extern int nfs4_map_errors(int err);