FAILED: patch "[PATCH] fscrypt: don't set policy for a dead directory" failed to apply to 4.9-stable tree

The patch below does not apply to the 4.9-stable tree.
If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to <[email protected]>.

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 5858bdad4d0d0fc18bf29f34c3ac836e0b59441f Mon Sep 17 00:00:00 2001
From: Hongjie Fang <[email protected]>
Date: Wed, 22 May 2019 10:02:53 +0800
Subject: [PATCH] fscrypt: don't set policy for a dead directory

The directory may have been removed when entering fscrypt_ioctl_set_policy(). If so, the empty_dir() check will return error for ext4 file system.

ext4_rmdir() sets i_size = 0, then ext4_empty_dir() reports an error because 'inode->i_size < EXT4_DIR_REC_LEN(1) + EXT4_DIR_REC_LEN(2)'. If the fs is mounted with errors=panic, it will trigger a panic issue.

Add the check IS_DEADDIR() to fix this problem.

index d536889ac31b..4941fe8471ce 100644
@@ -81,6 +81,8 @@ int fscrypt_ioctl_set_policy(struct file *filp, const void __user *arg)
 	if (ret == -ENODATA) {
 		if (!S_ISDIR(inode->i_mode))
 			ret = -ENOTDIR;
+		else if (IS_DEADDIR(inode))
+			ret = -ENOENT;
 		else if (!inode->i_sb->s_cop->empty_dir(inode))
 			ret = -ENOTEMPTY;
 		else