Avoid misclassifying local EC as distributed when .dat stat errors occur; also standardize unload-before-remove.

weed/storage/disk_location_ec.go

@@ -13,7 +13,6 @@ import (
 	"github.com/seaweedfs/seaweedfs/weed/glog"
 	"github.com/seaweedfs/seaweedfs/weed/storage/erasure_coding"
 	"github.com/seaweedfs/seaweedfs/weed/storage/needle"
-	"github.com/seaweedfs/seaweedfs/weed/util"
 )
 
 var (
@@ -224,7 +223,15 @@ func (l *DiskLocation) loadAllEcShards() (err error) {
 				prevCollection = ""
 			}
 
-			datExists := util.FileExists(datFileName)
+			// Determine .dat presence robustly; unexpected errors are treated as "exists"
+			datExists := false
+			if _, err := os.Stat(datFileName); err == nil {
+				datExists = true
+			} else if !os.IsNotExist(err) {
+				glog.Warningf("Failed to stat .dat file %s: %v", datFileName, err)
+				// Safer to assume local .dat exists to avoid misclassifying as distributed EC
+				datExists = true
+			}
 
 			// Validate EC volume if .dat file exists (incomplete EC encoding scenario)
 			// This checks shard count, shard size consistency, and expected size vs .dat file
@@ -232,8 +239,6 @@ func (l *DiskLocation) loadAllEcShards() (err error) {
 			if datExists && !l.validateEcVolume(collection, volumeId) {
 				glog.Warningf("Incomplete or invalid EC volume %d: .dat exists but validation failed, cleaning up EC files...", volumeId)
 				l.removeEcVolumeFiles(collection, volumeId)
-				// Clean up any in-memory state. This does not delete files (already deleted by removeEcVolumeFiles).
-				l.unloadEcVolume(volumeId)
 				reset()
 				continue
 			}
@@ -243,12 +248,14 @@ func (l *DiskLocation) loadAllEcShards() (err error) {
 				// If .dat is gone, log error but don't clean up (may be waiting for shards from other servers)
 				if datExists {
 					glog.Warningf("Failed to load EC shards for volume %d and .dat exists: %v, cleaning up EC files to use .dat...", volumeId, err)
+					// Unload first to release FDs, then remove files
+					l.unloadEcVolume(volumeId)
 					l.removeEcVolumeFiles(collection, volumeId)
 				} else {
 					glog.Warningf("Failed to load EC shards for volume %d: %v (this may be normal for distributed EC volumes)", volumeId, err)
+					// Clean up any partially loaded in-memory state. This does not delete files.
+					l.unloadEcVolume(volumeId)
 				}
-				// Clean up any partially loaded in-memory state. This does not delete files.
-				l.unloadEcVolume(volumeId)
 				reset()
 				continue
 			}
@@ -311,17 +318,25 @@ func (l *DiskLocation) checkOrphanedShards(shards []string, collection string, v
 	if len(shards) == 0 || volumeId == 0 {
 		return false
 	}
-
+	
 	// Check if .dat file exists (incomplete encoding, not distributed EC)
-	// If .dat file exists, this is not a distributed EC volume, so cleanup the orphaned shards
+	// Use os.Stat for robust error handling; unexpected errors treated as "exists"
 	baseFileName := erasure_coding.EcShardFileName(collection, l.Directory, int(volumeId))
 	datFileName := baseFileName + ".dat"
-	if util.FileExists(datFileName) {
+	
+	datExists := false
+	if _, err := os.Stat(datFileName); err == nil {
+		datExists = true
+	} else if !os.IsNotExist(err) {
+		glog.Warningf("Failed to stat .dat file %s: %v", datFileName, err)
+		// Safer to assume local .dat exists to avoid misclassifying as distributed EC
+		datExists = true
+	}
+	
+	if datExists {
 		glog.Warningf("Found %d EC shards without .ecx file for volume %d (incomplete encoding interrupted before .ecx creation), cleaning up...",
 			len(shards), volumeId)
 		l.removeEcVolumeFiles(collection, volumeId)
-		// Clean up any in-memory state. This does not delete files (already deleted by removeEcVolumeFiles).
-		l.unloadEcVolume(volumeId)
 		return true
 	}
 	return false