From f98f115ac2d70245f1089188a9c972783001439a Mon Sep 17 00:00:00 2001
From: Klaus Post <klauspost@gmail.com>
Date: Wed, 15 Sep 2021 09:24:41 -0700
Subject: [PATCH] fs: Fix non-progressing scanner (#13218)

Scanner would keep doing the same cycle in FS mode leading to missed updates.

Add a few sanity checks and handle errors better.
---
 cmd/data-scanner.go | 17 +++++++++++------
 cmd/fs-v1.go        |  9 ++++++++-
 2 files changed, 19 insertions(+), 7 deletions(-)

diff --git a/cmd/data-scanner.go b/cmd/data-scanner.go
index 820383e2b..8b785da27 100644
--- a/cmd/data-scanner.go
+++ b/cmd/data-scanner.go
@@ -405,11 +405,11 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 		err := readDirFn(path.Join(f.root, folder.name), func(entName string, typ os.FileMode) error {
 			// Parse
 			entName = pathClean(path.Join(folder.name, entName))
-			if entName == "" {
+			if entName == "" || entName == folder.name {
 				if f.dataUsageScannerDebug {
-					console.Debugf(scannerLogPrefix+" no bucket (%s,%s)\n", f.root, entName)
+					console.Debugf(scannerLogPrefix+" no entity (%s,%s)\n", f.root, entName)
 				}
-				return errDoneForNow
+				return nil
 			}
 			bucket, prefix := path2BucketObjectWithBasePath(f.root, entName)
 			if bucket == "" {
@@ -435,7 +435,9 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 			if typ&os.ModeDir != 0 {
 				h := hashPath(entName)
 				_, exists := f.oldCache.Cache[h.Key()]
-
+				if h == thisHash {
+					return nil
+				}
 				this := cachedFolder{name: entName, parent: &thisHash, objectHealProbDiv: folder.objectHealProbDiv}
 				delete(abandonedChildren, h.Key()) // h.Key() already accounted for.
 				if exists {
@@ -468,11 +470,14 @@ func (f *folderScanner) scanFolder(ctx context.Context, folder cachedFolder, int
 			item.heal = item.heal && f.healObjectSelect > 0
 
 			sz, err := f.getSize(item)
-			if err == errSkipFile {
+			if err != nil {
 				wait() // wait to proceed to next entry.
-
+				if err != errSkipFile && f.dataUsageScannerDebug {
+					console.Debugf(scannerLogPrefix+" getSize \"%v/%v\" returned err: %v\n", bucket, item.objectPath(), err)
+				}
 				return nil
 			}
+
 			// successfully read means we have a valid object.
 			foundObjects = true
 			// Remove filename i.e is the meta file to construct object name
diff --git a/cmd/fs-v1.go b/cmd/fs-v1.go
index 58bf69d12..1cda0e1e0 100644
--- a/cmd/fs-v1.go
+++ b/cmd/fs-v1.go
@@ -258,6 +258,12 @@ func (fs *FSObjects) NSScanner(ctx context.Context, bf *bloomFilter, updates cha
 		updates <- totalCache.dui(dataUsageRoot, buckets)
 		return nil
 	}
+	for i, b := range buckets {
+		if isReservedOrInvalidBucket(b.Name, false) {
+			// Delete bucket...
+			buckets = append(buckets[:i], buckets[i+1:]...)
+		}
+	}
 
 	totalCache.Info.BloomFilter = bf.bytes()
 
@@ -282,6 +288,7 @@ func (fs *FSObjects) NSScanner(ctx context.Context, bf *bloomFilter, updates cha
 			bCache.Info.Name = b.Name
 		}
 		bCache.Info.BloomFilter = totalCache.Info.BloomFilter
+		bCache.Info.NextCycle = wantCycle
 		upds := make(chan dataUsageEntry, 1)
 		var wg sync.WaitGroup
 		wg.Add(1)
@@ -290,7 +297,7 @@ func (fs *FSObjects) NSScanner(ctx context.Context, bf *bloomFilter, updates cha
 			for update := range upds {
 				totalCache.replace(b.Name, dataUsageRoot, update)
 				if intDataUpdateTracker.debug {
-					logger.Info(color.Green("NSScanner:")+" Got update:", len(totalCache.Cache))
+					logger.Info(color.Green("NSScanner:")+" Got update: %v", len(totalCache.Cache))
 				}
 				cloned := totalCache.clone()
 				updates <- cloned.dui(dataUsageRoot, buckets)