FAILED: patch "[PATCH] f2fs: report correct st_size for encrypted symlinks" failed to apply to 4.19-stable tree

The patch below does not apply to the 4.19-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 461b43a8f92e68e96c4424b31e15f2b35f1bbfa9 Mon Sep 17 00:00:00 2001
From: Eric Biggers <[email protected]>
Date: Thu, 1 Jul 2021 23:53:48 -0700
Subject: [PATCH] f2fs: report correct st_size for encrypted symlinks

The stat() family of syscalls report the wrong size for encrypted symlinks, which has caused breakage in several userspace programs.

Fix this by calling fscrypt_symlink_getattr() after f2fs_getattr() for encrypted symlinks. This function computes the correct size by reading and decrypting the symlink target (if it's not already cached).

For more details, see the commit which added fscrypt_symlink_getattr().

index e149c8c66a71..9c528e583c9d 100644
@@ -1323,9 +1323,19 @@ static const char *f2fs_encrypted_get_link(struct dentry *dentry,
 	return target;
 }
 
+static int f2fs_encrypted_symlink_getattr(struct user_namespace *mnt_userns,
+					  const struct path *path,
+					  struct kstat *stat, u32 request_mask,
+					  unsigned int query_flags)
+{
+	f2fs_getattr(mnt_userns, path, stat, request_mask, query_flags);
+
+	return fscrypt_symlink_getattr(path, stat);
+}
+
 const struct inode_operations f2fs_encrypted_symlink_inode_operations = {
 	.get_link	= f2fs_encrypted_get_link,
-	.getattr	= f2fs_getattr,
+	.getattr	= f2fs_encrypted_symlink_getattr,
 	.setattr	= f2fs_setattr,
 	.listxattr	= f2fs_listxattr,
 };