NFS: Check size by inode_newsize_ok in nfs_setattr

Set rlimit for NFS's files is useless right now.
For local process's rlimit, it should be checked by nfs client.

The same, CIFS also call inode_change_ok checking rlimit at its client
in cifs_setattr_nounix() and cifs_setattr_unix().

v3, fix bad using of error

Signed-off-by: Kinglong Mee <kinglongmee@gmail.com>
Signed-off-by: Trond Myklebust <trond.myklebust@primarydata.com>

fs/nfs/inode.c

@@ -504,7 +504,7 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
 {
 	struct inode *inode = d_inode(dentry);
 	struct nfs_fattr *fattr;
-	int error = -ENOMEM;
+	int error = 0;
 
 	nfs_inc_stats(inode, NFSIOS_VFSSETATTR);
 
@@ -513,15 +513,14 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
 		attr->ia_valid &= ~ATTR_MODE;
 
 	if (attr->ia_valid & ATTR_SIZE) {
-		loff_t i_size;
-
 		BUG_ON(!S_ISREG(inode->i_mode));
 
-		i_size = i_size_read(inode);
-		if (attr->ia_size == i_size)
+		error = inode_newsize_ok(inode, attr->ia_size);
+		if (error)
+			return error;
+
+		if (attr->ia_size == i_size_read(inode))
 			attr->ia_valid &= ~ATTR_SIZE;
-		else if (attr->ia_size < i_size && IS_SWAPFILE(inode))
-			return -ETXTBSY;
 	}
 
 	/* Optimization: if the end result is no change, don't RPC */
@@ -536,8 +535,11 @@ nfs_setattr(struct dentry *dentry, struct iattr *attr)
 		nfs_sync_inode(inode);
 
 	fattr = nfs_alloc_fattr();
-	if (fattr == NULL)
+	if (fattr == NULL) {
+		error = -ENOMEM;
 		goto out;
+	}
+
 	/*
 	 * Return any delegations if we're going to change ACLs
 	 */