NFSv4: Simplify the NFSv4 OPEN compound

Get rid of the post-op GETATTR on the directory in order to reduce
the amount of processing done on the server.

The cost is that if we later need to stat() the directory, then we
know that the ctime and mtime are likely to be invalid.

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
index 2e0fbff..f01c3d1 100644
--- a/fs/nfs/nfs4proc.c
+++ b/fs/nfs/nfs4proc.c
@@ -788,7 +788,6 @@
 	struct nfs4_string owner_name;
 	struct nfs4_string group_name;
 	struct nfs_fattr f_attr;
-	struct nfs_fattr dir_attr;
 	struct dentry *dir;
 	struct dentry *dentry;
 	struct nfs4_state_owner *owner;
@@ -804,12 +803,10 @@
 static void nfs4_init_opendata_res(struct nfs4_opendata *p)
 {
 	p->o_res.f_attr = &p->f_attr;
-	p->o_res.dir_attr = &p->dir_attr;
 	p->o_res.seqid = p->o_arg.seqid;
 	p->c_res.seqid = p->c_arg.seqid;
 	p->o_res.server = p->o_arg.server;
 	nfs_fattr_init(&p->f_attr);
-	nfs_fattr_init(&p->dir_attr);
 	nfs_fattr_init_names(&p->f_attr, &p->owner_name, &p->group_name);
 }
 
@@ -843,7 +840,6 @@
 	p->o_arg.name = &dentry->d_name;
 	p->o_arg.server = server;
 	p->o_arg.bitmask = server->attr_bitmask;
-	p->o_arg.dir_bitmask = server->cache_consistency_bitmask;
 	p->o_arg.claim = NFS4_OPEN_CLAIM_NULL;
 	if (attrs != NULL && attrs->ia_valid != 0) {
 		__be32 verf[2];
@@ -1611,8 +1607,6 @@
 
 	nfs_fattr_map_and_free_names(NFS_SERVER(dir), &data->f_attr);
 
-	nfs_refresh_inode(dir, o_res->dir_attr);
-
 	if (o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
 		status = _nfs4_proc_open_confirm(data);
 		if (status != 0)
@@ -1645,11 +1639,8 @@
 
 	nfs_fattr_map_and_free_names(server, &data->f_attr);
 
-	if (o_arg->open_flags & O_CREAT) {
+	if (o_arg->open_flags & O_CREAT)
 		update_changeattr(dir, &o_res->cinfo);
-		nfs_post_op_update_inode(dir, o_res->dir_attr);
-	} else
-		nfs_refresh_inode(dir, o_res->dir_attr);
 	if ((o_res->rflags & NFS4_OPEN_RESULT_LOCKTYPE_POSIX) == 0)
 		server->caps &= ~NFS_CAP_POSIX_LOCK;
 	if(o_res->rflags & NFS4_OPEN_RESULT_CONFIRM) {
diff --git a/fs/nfs/nfs4xdr.c b/fs/nfs/nfs4xdr.c
index ac7a3b0..6e878dc 100644
--- a/fs/nfs/nfs4xdr.c
+++ b/fs/nfs/nfs4xdr.c
@@ -431,20 +431,14 @@
 #define NFS4_enc_open_sz        (compound_encode_hdr_maxsz + \
 				encode_sequence_maxsz + \
 				encode_putfh_maxsz + \
-				encode_savefh_maxsz + \
 				encode_open_maxsz + \
 				encode_getfh_maxsz + \
-				encode_getattr_maxsz + \
-				encode_restorefh_maxsz + \
 				encode_getattr_maxsz)
 #define NFS4_dec_open_sz        (compound_decode_hdr_maxsz + \
 				decode_sequence_maxsz + \
 				decode_putfh_maxsz + \
-				decode_savefh_maxsz + \
 				decode_open_maxsz + \
 				decode_getfh_maxsz + \
-				decode_getattr_maxsz + \
-				decode_restorefh_maxsz + \
 				decode_getattr_maxsz)
 #define NFS4_enc_open_confirm_sz \
 				(compound_encode_hdr_maxsz + \
@@ -2191,12 +2185,9 @@
 	encode_compound_hdr(xdr, req, &hdr);
 	encode_sequence(xdr, &args->seq_args, &hdr);
 	encode_putfh(xdr, args->fh, &hdr);
-	encode_savefh(xdr, &hdr);
 	encode_open(xdr, args, &hdr);
 	encode_getfh(xdr, &hdr);
 	encode_getfattr(xdr, args->bitmask, &hdr);
-	encode_restorefh(xdr, &hdr);
-	encode_getfattr(xdr, args->dir_bitmask, &hdr);
 	encode_nops(&hdr);
 }
 
@@ -6075,19 +6066,12 @@
 	status = decode_putfh(xdr);
 	if (status)
 		goto out;
-	status = decode_savefh(xdr);
-	if (status)
-		goto out;
 	status = decode_open(xdr, res);
 	if (status)
 		goto out;
 	if (decode_getfh(xdr, &res->fh) != 0)
 		goto out;
-	if (decode_getfattr(xdr, res->f_attr, res->server) != 0)
-		goto out;
-	if (decode_restorefh(xdr) != 0)
-		goto out;
-	decode_getfattr(xdr, res->dir_attr, res->server);
+	decode_getfattr(xdr, res->f_attr, res->server);
 out:
 	return status;
 }
diff --git a/include/linux/nfs_xdr.h b/include/linux/nfs_xdr.h
index bc36808..92a929f 100644
--- a/include/linux/nfs_xdr.h
+++ b/include/linux/nfs_xdr.h
@@ -338,7 +338,6 @@
 	const struct qstr *	name;
 	const struct nfs_server *server;	 /* Needed for ID mapping */
 	const u32 *		bitmask;
-	const u32 *		dir_bitmask;
 	__u32			claim;
 	struct nfs4_sequence_args	seq_args;
 };
@@ -349,7 +348,6 @@
 	struct nfs4_change_info	cinfo;
 	__u32                   rflags;
 	struct nfs_fattr *      f_attr;
-	struct nfs_fattr *      dir_attr;
 	struct nfs_seqid *	seqid;
 	const struct nfs_server *server;
 	fmode_t			delegation_type;