From cb671ea1ca409c4dc436925f726230f5b77fb528 Mon Sep 17 00:00:00 2001
From: phantomape <cxucheng@outlook.com>
Date: Sun, 29 Mar 2020 21:54:47 -0700
Subject: [PATCH] env: Add clearerr() before repeating an interrupted file read
 (#6609)

Summary:
This change updates PosixSequentialFile::Read to call clearerr()
before fread()ing again after an EINTR is returned on a previous
fread.

The original fix is from https://github.com/cockroachdb/rocksdb/commit/bd8f1ebb91bbf0e668d24faef273042cc1fe52de.
Fixing https://github.com/facebook/rocksdb/issues/6509

Signed-off-by: phantomape <cxucheng@outlook.com>
Pull Request resolved: https://github.com/facebook/rocksdb/pull/6609

Reviewed By: zhichao-cao

Differential Revision: D20731482

Pulled By: riversand963

fbshipit-source-id: 7f1f3a1449077d5560f45c465a78d08633740ba0
---
 env/io_posix.cc | 1 +
 1 file changed, 1 insertion(+)

diff --git a/env/io_posix.cc b/env/io_posix.cc
index b44dbd717..e2dc47ae4 100644
--- a/env/io_posix.cc
+++ b/env/io_posix.cc
@@ -234,6 +234,7 @@ IOStatus PosixSequentialFile::Read(size_t n, const IOOptions& /*opts*/,
   IOStatus s;
   size_t r = 0;
   do {
+    clearerr(file_);
     r = fread_unlocked(scratch, 1, n, file_);
   } while (r == 0 && ferror(file_) && errno == EINTR);
   *result = Slice(scratch, r);