From 1d0fde434fac309d32a490eeea9d03507d23cad9 Mon Sep 17 00:00:00 2001
From: Sherman Beus <sherman.beus@pnnl.gov>
Date: Fri, 29 Mar 2024 11:51:45 -0700
Subject: [PATCH] Removes previous addition of an "io lock" due to the
 potential for a deadlock (actually happened) and no straight-forward work
 around. Worst case scenario is that the pruneTree function removes a
 directory just as another bit of logic was going to write to it and there's
 an error. STS is pretty fault tolerant, so the request would just be tried
 again anyway. Seems fine without that additional locking.

---
 stage/local.go | 24 ++----------------------
 1 file changed, 2 insertions(+), 22 deletions(-)

diff --git a/stage/local.go b/stage/local.go
index e21bdd3..4edba30 100644
--- a/stage/local.go
+++ b/stage/local.go
@@ -102,12 +102,6 @@ type Stage struct {
 	cacheTime  time.Time
 	cacheTimes []time.Time
 
-	// Every normal file I/O function does a read lock, so write locking
-	// it will block the stage area from interacting with the file system.
-	// This is useful for when we want to clean up the stage and target
-	// areas.
-	ioLock sync.RWMutex
-
 	pathLock  sync.RWMutex
 	pathLocks map[string]*sync.RWMutex
 	readyLock sync.RWMutex
@@ -181,8 +175,6 @@ func (s *Stage) pathToName(path, stripExt string) (name string) {
 // Scan walks the stage area tree looking for companion files and returns any
 // found in the form of a JSON-encoded byte array
 func (s *Stage) Scan(version string) (jsonBytes []byte, err error) {
-	s.ioLock.RLock()
-	defer s.ioLock.RUnlock()
 	var name string
 	var lock *sync.RWMutex
 	var partials []*sts.Partial
@@ -216,8 +208,6 @@ func (s *Stage) Scan(version string) (jsonBytes []byte, err error) {
 }
 
 func (s *Stage) initStageFile(path string, size int64) error {
-	s.ioLock.RLock()
-	defer s.ioLock.RUnlock()
 	var err error
 	info, err := os.Stat(path + partExt)
 	if err == nil && info.Size() == size {
@@ -266,9 +256,6 @@ func (s *Stage) Prepare(parts []sts.Binned) {
 
 // Receive reads a single file part with file metadata and reader
 func (s *Stage) Receive(file *sts.Partial, reader io.Reader) (err error) {
-	s.ioLock.RLock()
-	defer s.ioLock.RUnlock()
-
 	if len(file.Parts) != 1 {
 		err = fmt.Errorf(
 			"can only receive a single part for a single reader (%d given)",
@@ -460,8 +447,6 @@ func (s *Stage) setCanReceive(value bool) {
 // files in the stage area that should be completed from the previous server
 // run
 func (s *Stage) Recover() {
-	s.ioLock.Lock()
-	defer s.ioLock.Unlock()
 	s.setCanReceive(false)
 	defer s.setCanReceive(true)
 	s.logInfo("Beginning stage recovery")
@@ -602,9 +587,8 @@ func (s *Stage) scheduleClean(minAge time.Duration) {
 }
 
 func (s *Stage) pruneTree(dir string, minAge time.Duration) {
-	s.ioLock.Lock()
-	defer s.ioLock.Unlock()
-	s.logDebug("Pruning empty directories ...")
+	s.logInfo("Pruning empty directories ...")
+	defer s.logInfo("Pruning complete")
 	var dirs []string
 	err := filepath.Walk(dir,
 		func(path string, info os.FileInfo, err error) error {
@@ -798,8 +782,6 @@ func (s *Stage) processHandler() {
 }
 
 func (s *Stage) process(file *finalFile) {
-	s.ioLock.RLock()
-	defer s.ioLock.RUnlock()
 
 	s.logDebug("Validating:", file.name)
 
@@ -978,8 +960,6 @@ func (s *Stage) finalize(file *finalFile) {
 }
 
 func (s *Stage) putFileAway(file *finalFile) (targetPath string, err error) {
-	s.ioLock.RLock()
-	defer s.ioLock.RUnlock()
 
 	// Better to log the file twice rather than receive it twice.  If we log
 	// after putting the file away, it's possible that a crash could occur