[PATCH 18/24] NFS: Reduce the stack footprint of nfs_proc_create

[Trond Myklebust <Trond.Myklebust@netapp.com>]

Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
---
 fs/nfs/proc.c |  118 ++++++++++++++++++++++++++++++++-------------------------
 1 files changed, 66 insertions(+), 52 deletions(-)

diff --git a/fs/nfs/proc.c b/fs/nfs/proc.c
index 0288be8..aa61f2c 100644
--- a/fs/nfs/proc.c
+++ b/fs/nfs/proc.c
@@ -224,35 +224,60 @@ static int nfs_proc_readlink(struct inode *inode, struct page *page,
 	return status;
 }
 
+struct nfs_createdata {
+	struct nfs_createargs arg;
+	struct nfs_diropok res;
+	struct nfs_fh fhandle;
+	struct nfs_fattr fattr;
+};
+
+static struct nfs_createdata *nfs_alloc_createdata(struct inode *dir,
+		struct dentry *dentry, struct iattr *sattr)
+{
+	struct nfs_createdata *data;
+
+	data = kmalloc(sizeof(*data), GFP_KERNEL);
+
+	if (data != NULL) {
+		data->arg.fh = NFS_FH(dir);
+		data->arg.name = dentry->d_name.name;
+		data->arg.len = dentry->d_name.len;
+		data->arg.sattr = sattr;
+		nfs_fattr_init(&data->fattr);
+		data->fhandle.size = 0;
+		data->res.fh = &data->fhandle;
+		data->res.fattr = &data->fattr;
+	}
+	return data;
+};
+
+static void nfs_free_createdata(const struct nfs_createdata *data)
+{
+	kfree(data);
+}
+
 static int
 nfs_proc_create(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 		int flags, struct nameidata *nd)
 {
-	struct nfs_fh		fhandle;
-	struct nfs_fattr	fattr;
-	struct nfs_createargs	arg = {
-		.fh		= NFS_FH(dir),
-		.name		= dentry->d_name.name,
-		.len		= dentry->d_name.len,
-		.sattr		= sattr
-	};
-	struct nfs_diropok	res = {
-		.fh		= &fhandle,
-		.fattr		= &fattr
-	};
+	struct nfs_createdata *data;
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
-		.rpc_argp	= &arg,
-		.rpc_resp	= &res,
 	};
-	int			status;
+	int status = -ENOMEM;
 
-	nfs_fattr_init(&fattr);
 	dprintk("NFS call  create %s\n", dentry->d_name.name);
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 	nfs_mark_for_revalidate(dir);
 	if (status == 0)
-		status = nfs_instantiate(dentry, &fhandle, &fattr);
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+	nfs_free_createdata(data);
+out:
 	dprintk("NFS reply create: %d\n", status);
 	return status;
 }
@@ -264,24 +289,12 @@ static int
 nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 	       dev_t rdev)
 {
-	struct nfs_fh fhandle;
-	struct nfs_fattr fattr;
-	struct nfs_createargs	arg = {
-		.fh		= NFS_FH(dir),
-		.name		= dentry->d_name.name,
-		.len		= dentry->d_name.len,
-		.sattr		= sattr
-	};
-	struct nfs_diropok	res = {
-		.fh		= &fhandle,
-		.fattr		= &fattr
-	};
+	struct nfs_createdata *data;
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs_procedures[NFSPROC_CREATE],
-		.rpc_argp	= &arg,
-		.rpc_resp	= &res,
 	};
-	int status, mode;
+	umode_t mode;
+	int status = -ENOMEM;
 
 	dprintk("NFS call  mknod %s\n", dentry->d_name.name);
 
@@ -294,17 +307,24 @@ nfs_proc_mknod(struct inode *dir, struct dentry *dentry, struct iattr *sattr,
 		sattr->ia_size = new_encode_dev(rdev);/* get out your barf bag */
 	}
 
-	nfs_fattr_init(&fattr);
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+
 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 	nfs_mark_for_revalidate(dir);
 
 	if (status == -EINVAL && S_ISFIFO(mode)) {
 		sattr->ia_mode = mode;
-		nfs_fattr_init(&fattr);
+		nfs_fattr_init(data->res.fattr);
 		status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 	}
 	if (status == 0)
-		status = nfs_instantiate(dentry, &fhandle, &fattr);
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+	nfs_free_createdata(data);
+out:
 	dprintk("NFS reply mknod: %d\n", status);
 	return status;
 }
@@ -440,31 +460,25 @@ nfs_proc_symlink(struct inode *dir, struct dentry *dentry, struct page *page,
 static int
 nfs_proc_mkdir(struct inode *dir, struct dentry *dentry, struct iattr *sattr)
 {
-	struct nfs_fh fhandle;
-	struct nfs_fattr fattr;
-	struct nfs_createargs	arg = {
-		.fh		= NFS_FH(dir),
-		.name		= dentry->d_name.name,
-		.len		= dentry->d_name.len,
-		.sattr		= sattr
-	};
-	struct nfs_diropok	res = {
-		.fh		= &fhandle,
-		.fattr		= &fattr
-	};
+	struct nfs_createdata *data;
 	struct rpc_message msg = {
 		.rpc_proc	= &nfs_procedures[NFSPROC_MKDIR],
-		.rpc_argp	= &arg,
-		.rpc_resp	= &res,
 	};
-	int			status;
+	int status = -ENOMEM;
 
 	dprintk("NFS call  mkdir %s\n", dentry->d_name.name);
-	nfs_fattr_init(&fattr);
+	data = nfs_alloc_createdata(dir, dentry, sattr);
+	if (data == NULL)
+		goto out;
+	msg.rpc_argp = &data->arg;
+	msg.rpc_resp = &data->res;
+
 	status = rpc_call_sync(NFS_CLIENT(dir), &msg, 0);
 	nfs_mark_for_revalidate(dir);
 	if (status == 0)
-		status = nfs_instantiate(dentry, &fhandle, &fattr);
+		status = nfs_instantiate(dentry, data->res.fh, data->res.fattr);
+	nfs_free_createdata(data);
+out:
 	dprintk("NFS reply mkdir: %d\n", status);
 	return status;
 }
-- 
1.6.6.1