switch ->setxattr() to passing dentry and inode separately

smack ->d_instantiate() uses ->setxattr(), so to be able to call it before
we'd hashed the new dentry and attached it to inode, we need ->setxattr()
instances getting the inode as an explicit argument rather than obtaining
it from dentry.

Similar change for ->getxattr() had been done in commit ce23e64.  Unlike
->getxattr() (which is used by both selinux and smack instances of
->d_instantiate()) ->setxattr() is used only by smack one and unfortunately
it got missed back then.

Reported-by: Seung-Woo Kim <sw0312.kim@samsung.com>
Tested-by: Casey Schaufler <casey@schaufler-ca.com>
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
diff --git a/fs/xattr.c b/fs/xattr.c
index b16d078..4beafc4 100644
--- a/fs/xattr.c
+++ b/fs/xattr.c
@@ -100,7 +100,7 @@
 	if (issec)
 		inode->i_flags &= ~S_NOSEC;
 	if (inode->i_op->setxattr) {
-		error = inode->i_op->setxattr(dentry, name, value, size, flags);
+		error = inode->i_op->setxattr(dentry, inode, name, value, size, flags);
 		if (!error) {
 			fsnotify_xattr(dentry);
 			security_inode_post_setxattr(dentry, name, value,
@@ -745,7 +745,8 @@
  * Find the handler for the prefix and dispatch its set() operation.
  */
 int
-generic_setxattr(struct dentry *dentry, const char *name, const void *value, size_t size, int flags)
+generic_setxattr(struct dentry *dentry, struct inode *inode, const char *name,
+		 const void *value, size_t size, int flags)
 {
 	const struct xattr_handler *handler;
 
@@ -754,8 +755,7 @@
 	handler = xattr_resolve_name(dentry->d_sb->s_xattr, &name);
 	if (IS_ERR(handler))
 		return PTR_ERR(handler);
-	return handler->set(handler, dentry, d_inode(dentry), name, value,
-			    size, flags);
+	return handler->set(handler, dentry, inode, name, value, size, flags);
 }
 
 /*