Make the scan debounce delay configurable. Disable for integration tests

pkg/storage/fs/posix/options/options.go

@@ -29,6 +29,8 @@ type Options struct {
 
 	UseSpaceGroups bool `mapstructure:"use_space_groups"`
 
+	ScanDebounceDelay int `mapstructure:"scan_debounce_delay"`
+
 	WatchFS                 bool   `mapstructure:"watch_fs"`
 	WatchType               string `mapstructure:"watch_type"`
 	WatchPath               string `mapstructure:"watch_path"`

pkg/storage/fs/posix/tree/assimilation.go

@@ -78,6 +78,11 @@ func NewScanDebouncer(d time.Duration, f func(item scanItem)) *ScanDebouncer {
 
 // Debounce restarts the debounce timer for the given space
 func (d *ScanDebouncer) Debounce(item scanItem) {
+	if d.after == 0 {
+		d.f(item)
+		return
+	}
+
 	d.mutex.Lock()
 	defer d.mutex.Unlock()
 

pkg/storage/fs/posix/tree/tree.go

@@ -114,7 +114,7 @@ func New(lu node.PathLookup, bs Blobstore, um usermapper.Mapper, trashbin *trash
 		idCache:    cache,
 		propagator: propagator.New(lu, &o.Options),
 		scanQueue:  scanQueue,
-		scanDebouncer: NewScanDebouncer(1000*time.Millisecond, func(item scanItem) {
+		scanDebouncer: NewScanDebouncer(time.Duration(o.ScanDebounceDelay)*time.Millisecond, func(item scanItem) {
 			scanQueue <- item
 		}),
 		es:  es,

tests/oc-integration-tests/drone/storage-users-posixfs.toml

@@ -26,6 +26,7 @@ treetime_accounting = true
 treesize_accounting = true
 personalspacepath_template = "users/{{.User.Username}}"
 generalspacepath_template = "projects/{{.SpaceId}}"
+watch_fs = true
 
 [grpc.services.storageprovider.drivers.posix.filemetadatacache]
 cache_store = "noop"
@@ -48,6 +49,7 @@ root = "/drone/src/tmp/reva/data"
 permissionssvc = "localhost:10000"
 treetime_accounting = true
 treesize_accounting = true
+scan_debounce_delay = 0
 
 [http.services.dataprovider.drivers.posix.idcache]
 cache_store = "redis"