From 9627e342c8c9e9fcb39748338a09f3bf02c3256f Mon Sep 17 00:00:00 2001
From: anand76 <anand76@devvm1373.frc2.facebook.com>
Date: Mon, 16 Nov 2020 18:41:43 -0800
Subject: [PATCH] Use default FileSystem in GenerateUniqueId (#7672)

Summary:
Use ```FileSystem::Default``` to read ```/proc/sys/kernel/uuid```, so it works for ```Envs``` with remote ```FileSystem``` as well.

Pull Request resolved: https://github.com/facebook/rocksdb/pull/7672

Reviewed By: riversand963

Differential Revision: D24998702

Pulled By: anand1976

fbshipit-source-id: fa95c1d70f0e4ed17561201f047aa055046d06c3
---
 env/env_posix.cc | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/env/env_posix.cc b/env/env_posix.cc
index 78d5e251b..f7efbae80 100644
--- a/env/env_posix.cc
+++ b/env/env_posix.cc
@@ -463,11 +463,12 @@ void PosixEnv::WaitForJoin() {
 
 std::string Env::GenerateUniqueId() {
   std::string uuid_file = "/proc/sys/kernel/random/uuid";
+  std::shared_ptr<FileSystem> fs = FileSystem::Default();
 
-  Status s = FileExists(uuid_file);
+  Status s = fs->FileExists(uuid_file, IOOptions(), nullptr);
   if (s.ok()) {
     std::string uuid;
-    s = ReadFileToString(this, uuid_file, &uuid);
+    s = ReadFileToString(fs.get(), uuid_file, &uuid);
     if (s.ok()) {
       return uuid;
     }