From cbf38af7051a57d3a80ec797c2af13eb5cc1b9d1 Mon Sep 17 00:00:00 2001
From: Deepak Ojha <dojha@cohesity.com>
Date: Fri, 5 Feb 2021 12:39:05 -0800
Subject: [PATCH] Wal recovery failure with encryption due to zero bytes WAL
 size. (#7924)

Summary:
Fixes issue https://github.com/facebook/rocksdb/issues/7410

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7924

Reviewed By: jay-zhuang

Differential Revision: D26216805

Pulled By: ajkr

fbshipit-source-id: 5720635ee06003269bfaf8c8616b3671974b08a8
---
 env/env_encryption.cc | 11 ++++++++++-
 1 file changed, 10 insertions(+), 1 deletion(-)

diff --git a/env/env_encryption.cc b/env/env_encryption.cc
index ca2542abb..8eec392ae 100644
--- a/env/env_encryption.cc
+++ b/env/env_encryption.cc
@@ -646,6 +646,15 @@ class EncryptedEnvImpl : public EnvWrapper {
     if (!status.ok()) {
       return status;
     }
+    uint64_t file_size;
+    status = EnvWrapper::GetFileSize(fname, &file_size);
+    if (!status.ok()) {
+      return status;
+    }
+    if (!file_size) {
+      *result = std::move(underlying);
+      return status;
+    }
     // Create cipher stream
     std::unique_ptr<BlockAccessCipherStream> stream;
     size_t prefix_length;
@@ -830,7 +839,7 @@ class EncryptedEnvImpl : public EnvWrapper {
   virtual Status GetFileSize(const std::string& fname,
                              uint64_t* file_size) override {
     auto status = EnvWrapper::GetFileSize(fname, file_size);
-    if (!status.ok()) {
+    if (!status.ok() || !(*file_size)) {
       return status;
     }
     EncryptionProvider* provider;