patch !1727 and #625

ais/tgtdaecp.go

@@ -1403,6 +1403,9 @@ func (t *targetrunner) commitCopyRenameLB(bckFrom, bckTo *cluster.Bck, msgInt *a
 		waiter.Add(1)
 		go xact.Run(waiter, msgInt.GlobRebID)
 		waiter.Wait()
+
+		time.Sleep(200 * time.Millisecond) // FIXME: !1727
+
 	case cmn.ActCopyBucket:
 		var xact *mirror.XactBckCopy
 		xact, err = xaction.Registry.RenewBckCopy(t, bckFrom, bckTo, cmn.ActCommit)

cli/resources/object.md

@@ -1,12 +1,10 @@
-## Object
-
-The CLI allows users to interact with objects in the AIS cluster.
+## Operations on objects
 
 ### GET
 
 `ais get BUCKET_NAME/OBJECT_NAME OUT_FILE`
 
-Gets the object from the bucket.
+GET object from bucket.
 
 | Flag | Type | Description | Default |
 | --- | --- | --- | --- |
@@ -221,14 +219,27 @@ Deletes an object or list/range of objects from the bucket.
 <a name="ft3">3</a> Options `--list,--range` and argument(s) `OBJECT_NAME` are mutually exclusive. List and range deletions expect only a bucket name; if one or more
 `OBJECT_NAME`s are given, a separate `DELETE` request is sent for each object.
 
-#### More Examples
+#### Examples
 
-| Command | Description |
-| --- | --- |
-| `ais rm object mybucket/myobj` | Deletes object `myobj` from bucket `mybucket` |
-| `ais rm object aisbck/obj1 cloudbck/obj2` | Deletes two objects (`obj1`, `obj2`) from different buckets (`aisbck`, `cloudbck`) |
-| `ais rm object mybucket/ --list "obj1,obj2,obj3"` | Deletes a list of objects (`obj1`, `obj2`, `obj3`) from bucket `mybucket` |
-| `ais rm object mybucket/ --range "1:3" --prefix "test-" --regex "\\d\\d\\d"` | Deletes objects in range `001-003`, with prefix `test-`, matching `[0-9][0-9][0-9]` regex, from bucket `mybucket` |
+1) Delete object `myobj` from bucket `mybucket`
+```sh
+$ ais rm object mybucket/myobj
+```
+
+2) Delete objects (`obj1`, `obj2`) from buckets (`aisbck`, `cloudbck`) respectively
+```sh
+$ ais rm object aisbck/obj1 cloudbck/obj2
+```
+
+3) Delete a list of objects (`obj1`, `obj2`, `obj3`) from bucket `mybucket`
+```sh
+$ ais rm object mybucket/ --list "obj1,obj2,obj3"
+```
+
+4) Delete all objects in range `001-003`, with prefix `test-`, matching `[0-9][0-9][0-9]` regex, from bucket `mybucket`
+```sh
+$ ais rm object mybucket/ --range "1:3" --prefix "test-" --regex "\\d\\d\\d"
+```
 
 ### Evict
 
@@ -295,9 +306,10 @@ Renames object from an ais bucket.
 
 #### Examples
 
-| Command | Description |
-| --- | --- |
-| `ais rename object mybucket/obj obj1` | Renames object `obj` from bucket `mybucket` to `obj1` |
+1) Rename object `obj1` as `obj2`
+```sh
+ais rename object mybucket/obj1 obj2
+```
 
 ### Compose
 

cmn/common.go

@@ -811,19 +811,38 @@ func RemoveFile(path string) error {
 	return nil
 }
 
-func IsDirEmpty(dir string) ([]string, bool, error) {
+func IsDirEmpty(dir string, ignoreEmptySubdirs ...bool) ([]string, bool /* is empty */, error) {
 	var names []string
 	f, err := os.Open(dir)
 	if err != nil {
 		return nil, false, err
 	}
 	defer f.Close()
 
-	names, err = f.Readdirnames(2)
+	names, err = f.Readdirnames(3)
 	if err == io.EOF {
 		return nil, true, nil
 	}
-	return names, false, err
+	if err != nil {
+		return names, false, err
+	}
+	if len(names) == 0 {
+		return names, true, nil
+	}
+	if len(names) > 1 {
+		return names, false, nil
+	}
+	if len(ignoreEmptySubdirs) == 0 || !ignoreEmptySubdirs[0] {
+		return names, false, nil
+	}
+	// FIXME: #625
+	subdir := filepath.Join(dir, names[0])
+	if finfo, erc := os.Stat(subdir); erc == nil {
+		if finfo.IsDir() {
+			return IsDirEmpty(subdir)
+		}
+	}
+	return names, false, nil
 }
 
 // computes xxhash if requested

fs/mountfs.go

@@ -653,7 +653,8 @@ func (mi *MountpathInfo) createBckDirs(bck cmn.Bck) (num int, err error) {
 	for contentType := range CSM.RegisteredContentTypes {
 		dir := mi.MakePathCT(bck, contentType)
 		if err := Access(dir); err == nil {
-			if names, empty, errEmpty := cmn.IsDirEmpty(dir); errEmpty != nil {
+			// FIXME: ignore empty subdirs #625
+			if names, empty, errEmpty := cmn.IsDirEmpty(dir, true /*ignore empty subdirs*/); errEmpty != nil {
 				return num, errEmpty
 			} else if !empty {
 				return num, fmt.Errorf("bucket %s: directory %s already exists and is not empty (%v...)",