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/ecryptfs/inode.c b/fs/ecryptfs/inode.c
index 318b046..9d153b6 100644
--- a/fs/ecryptfs/inode.c
+++ b/fs/ecryptfs/inode.c
@@ -1001,7 +1001,8 @@
 }
 
 int
-ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
+ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
+		  const char *name, const void *value,
 		  size_t size, int flags)
 {
 	int rc = 0;
@@ -1014,8 +1015,8 @@
 	}
 
 	rc = vfs_setxattr(lower_dentry, name, value, size, flags);
-	if (!rc && d_really_is_positive(dentry))
-		fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
+	if (!rc && inode)
+		fsstack_copy_attr_all(inode, d_inode(lower_dentry));
 out:
 	return rc;
 }