NFSv4: Clean up nfs4_open_revalidate

Remove references to 'struct nameidata' from the low-level open_revalidate
code, and replace them with a struct nfs_open_context which will be
correctly initialised upon success.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/dir.c

@@ -1169,6 +1169,7 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
 	struct dentry *parent = NULL;
 	struct inode *inode = dentry->d_inode;
 	struct inode *dir;
+	struct nfs_open_context *ctx;
 	int openflags, ret = 0;
 
 	if (!is_atomic_open(nd) || d_mountpoint(dentry))
@@ -1194,12 +1195,20 @@ static int nfs_open_revalidate(struct dentry *dentry, struct nameidata *nd)
 	/* We can't create new files, or truncate existing ones here */
 	openflags &= ~(O_CREAT|O_EXCL|O_TRUNC);
 
+	ctx = nameidata_to_nfs_open_context(dentry, nd);
+	ret = PTR_ERR(ctx);
+	if (IS_ERR(ctx))
+		goto out;
 	/*
 	 * Note: we're not holding inode->i_mutex and so may be racing with
 	 * operations that change the directory. We therefore save the
 	 * change attribute *before* we do the RPC call.
 	 */
-	ret = nfs4_open_revalidate(dir, dentry, openflags, nd);
+	ret = nfs4_open_revalidate(dir, ctx, openflags);
+	if (ret == 1)
+		nfs_intent_set_file(nd, ctx);
+	else
+		put_nfs_open_context(ctx);
 out:
 	dput(parent);
 	if (!ret)

fs/nfs/nfs4_fs.h

@@ -243,7 +243,7 @@ extern int nfs4_init_clientid(struct nfs_client *, struct rpc_cred *);
 extern int nfs41_init_clientid(struct nfs_client *, struct rpc_cred *);
 extern int nfs4_do_close(struct path *path, struct nfs4_state *state, gfp_t gfp_mask, int wait);
 extern struct inode *nfs4_atomic_open(struct inode *, struct nfs_open_context *, int, struct iattr *);
-extern int nfs4_open_revalidate(struct inode *, struct dentry *, int, struct nameidata *);
+extern int nfs4_open_revalidate(struct inode *, struct nfs_open_context *, int);
 extern int nfs4_server_capabilities(struct nfs_server *server, struct nfs_fh *fhandle);
 extern int nfs4_proc_fs_locations(struct inode *dir, const struct qstr *name,
 		struct nfs4_fs_locations *fs_locations, struct page *page);

fs/nfs/nfs4proc.c

@@ -2038,21 +2038,11 @@ nfs4_atomic_open(struct inode *dir, struct nfs_open_context *ctx, int open_flags
 }
 
 int
-nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, struct nameidata *nd)
+nfs4_open_revalidate(struct inode *dir, struct nfs_open_context *ctx, int openflags)
 {
-	struct path path = {
-		.mnt = nd->path.mnt,
-		.dentry = dentry,
-	};
-	struct rpc_cred *cred;
 	struct nfs4_state *state;
-	fmode_t fmode = openflags & (FMODE_READ | FMODE_WRITE);
 
-	cred = rpc_lookup_cred();
-	if (IS_ERR(cred))
-		return PTR_ERR(cred);
-	state = nfs4_do_open(dir, &path, fmode, openflags, NULL, cred);
-	put_rpccred(cred);
+	state = nfs4_do_open(dir, &ctx->path, ctx->mode, openflags, NULL, ctx->cred);
 	if (IS_ERR(state)) {
 		switch (PTR_ERR(state)) {
 			case -EPERM:
@@ -2065,14 +2055,13 @@ nfs4_open_revalidate(struct inode *dir, struct dentry *dentry, int openflags, st
 				goto out_drop;
 		}
 	}
-	if (state->inode == dentry->d_inode) {
-		nfs_set_verifier(dentry, nfs_save_change_attribute(dir));
-		nfs4_intent_set_file(nd, &path, state, fmode);
+	ctx->state = state;
+	if (state->inode == ctx->path.dentry->d_inode) {
+		nfs_set_verifier(ctx->path.dentry, nfs_save_change_attribute(dir));
 		return 1;
 	}
-	nfs4_close_sync(&path, state, fmode);
 out_drop:
-	d_drop(dentry);
+	d_drop(ctx->path.dentry);
 	return 0;
 }