From 0f0758aeced1a65ebb7d1070ea6c031d79484205 Mon Sep 17 00:00:00 2001
From: Frank Wessels <fwessels@xs4all.nl>
Date: Wed, 31 May 2017 09:22:53 -0700
Subject: [PATCH] Load IO error count for posix atomically (#4448)

* Load error count atomically in order to check for maximum allowed number of IO errors.

* Remove unused (previously atomic) network IO error count
---
 cmd/posix.go              | 26 +++++++++++++-------------
 cmd/storage-rpc-client.go |  1 -
 2 files changed, 13 insertions(+), 14 deletions(-)

diff --git a/cmd/posix.go b/cmd/posix.go
index fb7b025c9..024e8aacd 100644
--- a/cmd/posix.go
+++ b/cmd/posix.go
@@ -251,7 +251,7 @@ func (s *posix) MakeVol(volume string) (err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
@@ -285,7 +285,7 @@ func (s *posix) ListVols() (volsInfo []VolInfo, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return nil, errFaultyDisk
 	}
 
@@ -349,7 +349,7 @@ func (s *posix) StatVol(volume string) (volInfo VolInfo, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return VolInfo{}, errFaultyDisk
 	}
 
@@ -388,7 +388,7 @@ func (s *posix) DeleteVol(volume string) (err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
@@ -422,7 +422,7 @@ func (s *posix) ListDir(volume, dirPath string) (entries []string, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return nil, errFaultyDisk
 	}
 
@@ -459,7 +459,7 @@ func (s *posix) ReadAll(volume, path string) (buf []byte, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return nil, errFaultyDisk
 	}
 
@@ -544,7 +544,7 @@ func (s *posix) ReadFileWithVerify(volume, path string, offset int64, buf []byte
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return 0, errFaultyDisk
 	}
 
@@ -664,7 +664,7 @@ func (s *posix) createFile(volume, path string) (f *os.File, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return nil, errFaultyDisk
 	}
 
@@ -737,7 +737,7 @@ func (s *posix) PrepareFile(volume, path string, fileSize int64) (err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
@@ -784,7 +784,7 @@ func (s *posix) AppendFile(volume, path string, buf []byte) (err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
@@ -815,7 +815,7 @@ func (s *posix) StatFile(volume, path string) (file FileInfo, err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return FileInfo{}, errFaultyDisk
 	}
 
@@ -911,7 +911,7 @@ func (s *posix) DeleteFile(volume, path string) (err error) {
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
@@ -951,7 +951,7 @@ func (s *posix) RenameFile(srcVolume, srcPath, dstVolume, dstPath string) (err e
 		}
 	}()
 
-	if s.ioErrCount > maxAllowedIOError {
+	if atomic.LoadInt32(&s.ioErrCount) > maxAllowedIOError {
 		return errFaultyDisk
 	}
 
diff --git a/cmd/storage-rpc-client.go b/cmd/storage-rpc-client.go
index 14dab823c..ee31587b1 100644
--- a/cmd/storage-rpc-client.go
+++ b/cmd/storage-rpc-client.go
@@ -28,7 +28,6 @@ import (
 )
 
 type networkStorage struct {
-	networkIOErrCount int32 // ref: https://golang.org/pkg/sync/atomic/#pkg-note-BUG
 	rpcClient         *AuthRPCClient
 }