NFS: Add helper functions for allocating filehandles and fattr structs

NFS Filehandles and struct fattr are really too large to be allocated on
the stack. This patch adds in a couple of helper functions to allocate them
dynamically instead.
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>

fs/nfs/inode.c

@@ -916,6 +916,26 @@ void nfs_fattr_init(struct nfs_fattr *fattr)
 	fattr->gencount = nfs_inc_attr_generation_counter();
 }
 
+struct nfs_fattr *nfs_alloc_fattr(void)
+{
+	struct nfs_fattr *fattr;
+
+	fattr = kmalloc(sizeof(*fattr), GFP_NOFS);
+	if (fattr != NULL)
+		nfs_fattr_init(fattr);
+	return fattr;
+}
+
+struct nfs_fh *nfs_alloc_fhandle(void)
+{
+	struct nfs_fh *fh;
+
+	fh = kmalloc(sizeof(struct nfs_fh), GFP_NOFS);
+	if (fh != NULL)
+		fh->size = 0;
+	return fh;
+}
+
 /**
  * nfs_inode_attrs_need_update - check if the inode attributes need updating
  * @inode - pointer to inode

include/linux/nfs_fs.h

@@ -356,6 +356,20 @@ extern struct nfs_open_context *nfs_find_open_context(struct inode *inode, struc
 extern u64 nfs_compat_user_ino64(u64 fileid);
 extern void nfs_fattr_init(struct nfs_fattr *fattr);
 
+extern struct nfs_fattr *nfs_alloc_fattr(void);
+
+static inline void nfs_free_fattr(const struct nfs_fattr *fattr)
+{
+	kfree(fattr);
+}
+
+extern struct nfs_fh *nfs_alloc_fhandle(void);
+
+static inline void nfs_free_fhandle(const struct nfs_fh *fh)
+{
+	kfree(fh);
+}
+
 /* linux/net/ipv4/ipconfig.c: trims ip addr off front of name, too. */
 extern __be32 root_nfs_parse_addr(char *name); /*__init*/
 extern unsigned long nfs_inc_attr_generation_counter(void);