Add more error handling and logging.

Bugfix: return zero for free and avail so libfuse knows cloud storage is responding.

component/file_cache/file_cache.go

@@ -386,12 +386,15 @@ func (fc *FileCache) StatFs() (*common.Statfs_t, bool, error) {
 		return fc.NextComponent().StatFs()
 	}
 
+	log.Trace("FileCache::StatFs")
+
 	// cache_size = f_blocks * f_frsize/1024
 	// cache_size - used = f_frsize * f_bavail/1024
 	// cache_size - used = vfs.f_bfree * vfs.f_frsize / 1024
 	// if cache size is set to 0 then we have the root mount usage
 	maxCacheSize := fc.maxCacheSize * MB
 	if maxCacheSize == 0 {
+		log.Err("FileCache::StatFs : Not responding to StatFs because max cache size is zero")
 		return nil, false, nil
 	}
 	usage, _ := common.GetUsage(fc.tmpPath)
@@ -400,6 +403,7 @@ func (fc *FileCache) StatFs() (*common.Statfs_t, bool, error) {
 	// how much space is available on the underlying file system?
 	availableOnCacheFS, err := fc.getAvailableSize()
 	if err != nil {
+		log.Err("FileCache::StatFs : Not responding to StatFs because getAvailableSize failed. Here's why: %v", err)
 		return nil, false, err
 	}
 
@@ -416,6 +420,7 @@ func (fc *FileCache) StatFs() (*common.Statfs_t, bool, error) {
 		Namemax: 255,
 	}
 
+	log.Debug("FileCache::StatFs : responding with free=%d avail=%d blocks=%d (bsize=%d)", stat.Bfree, stat.Bavail, stat.Blocks, stat.Bsize)
 	return &stat, true, nil
 }
 

component/s3storage/client.go

@@ -1131,29 +1131,29 @@ func (cl *Client) combineSmallBlocks(name string, blockList []*common.Block) ([]
 	return newBlockList, nil
 }
 
-func (cl *Client) GetUsedSize() uint64 {
+func (cl *Client) GetUsedSize() (uint64, error) {
 	headBucketOutput, err := cl.headBucket()
 	if err != nil {
-		return 0
+		return 0, err
 	}
 
 	response, ok := middleware.GetRawResponse(headBucketOutput.ResultMetadata).(*smithyHttp.Response)
 	if !ok || response == nil {
-		return 0
+		return 0, fmt.Errorf("Failed GetRawResponse from HeadBucketOutput")
 	}
 
 	headerValue, ok := response.Header["X-Rstor-Size"]
 	if !ok {
 		headerValue, ok = response.Header["X-Lyve-Size"]
 	}
 	if !ok || len(headerValue) == 0 {
-		return 0
+		return 0, fmt.Errorf("HeadBucket response has no size header (is the endpoint not Lyve Cloud?)")
 	}
 
 	bucketSizeBytes, err := strconv.ParseUint(headerValue[0], 10, 64)
 	if err != nil {
-		return 0
+		return 0, err
 	}
 
-	return bucketSizeBytes
+	return bucketSizeBytes, nil
 }

component/s3storage/connection.go

@@ -112,5 +112,5 @@ type S3Connection interface {
 	StageAndCommit(name string, bol *common.BlockOffsetList) error
 
 	NewCredentialKey(_, _ string) error
-	GetUsedSize() uint64
+	GetUsedSize() (uint64, error)
 }

component/s3storage/s3storage.go

@@ -479,23 +479,33 @@ func (s3 *S3Storage) FlushFile(options internal.FlushFileOptions) error {
 const blockSize = 4096
 
 func (s3 *S3Storage) StatFs() (*common.Statfs_t, bool, error) {
+	log.Trace("S3Storage::StatFs")
 	// cache_size = f_blocks * f_frsize/1024
 	// cache_size - used = f_frsize * f_bavail/1024
 	// cache_size - used = vfs.f_bfree * vfs.f_frsize / 1024
 	// if cache size is set to 0 then we have the root mount usage
-	sizeUsed := s3.storage.GetUsedSize()
+	sizeUsed, err := s3.storage.GetUsedSize()
+	if err != nil {
+		// TODO: will returning EIO break any applications that depend on StatFs?
+		return nil, false, err
+	}
 
 	stat := common.Statfs_t{
-		Blocks:  sizeUsed / blockSize,
-		Bavail:  sizeUsed / blockSize,
-		Bfree:   sizeUsed / blockSize,
+		Blocks: sizeUsed / blockSize,
+		// there is no set capacity limit in cloud storage
+		// so we use zero for free and avail
+		// this zero value is used in the libfuse component to recognize that cloud storage responded
+		Bavail:  0,
+		Bfree:   0,
 		Bsize:   blockSize,
 		Ffree:   1e9,
 		Files:   1e9,
 		Frsize:  blockSize,
 		Namemax: 255,
 	}
 
+	log.Debug("S3Storage::StatFs : responding with free=%d avail=%d blocks=%d (bsize=%d)", stat.Bfree, stat.Bavail, stat.Blocks, stat.Bsize)
+
 	return &stat, true, nil
 }