rebase: update go-ceph version to v0.11.0

Signed-off-by: Humble Chirammal <hchiramm@redhat.com>

vendor/github.com/ceph/go-ceph/rbd/watchers.go

@@ -0,0 +1,141 @@
+package rbd
+
+/*
+#cgo LDFLAGS: -lrbd
+#include <rbd/librbd.h>
+
+extern void imageWatchCallback(uintptr_t);
+
+// inline wrapper to cast uintptr_t to void*
+static inline int wrap_rbd_update_watch(rbd_image_t image, uint64_t *handle,
+	uintptr_t arg) {
+		return rbd_update_watch(image, handle, (void*)imageWatchCallback, (void*)arg);
+	};
+
+*/
+import "C"
+
+import (
+	"github.com/ceph/go-ceph/internal/callbacks"
+	"github.com/ceph/go-ceph/internal/retry"
+)
+
+// ImageWatcher is a representation of the rbd_image_watcher_t from librbd.h
+type ImageWatcher struct {
+	Addr   string
+	Id     int64
+	Cookie uint64
+}
+
+// ListWatchers returns the watchers on an RBD image. In case of an error, nil
+// and an error are returned.
+//
+// Note:
+//   Only supported in Ceph Mimic and newer.
+//
+// Implements:
+//   int rbd_watchers_list(rbd_image_t image,
+//                         rbd_image_watcher_t *watchers, size_t *max_watchers)
+func (image *Image) ListWatchers() ([]ImageWatcher, error) {
+	if err := image.validate(imageIsOpen); err != nil {
+		return nil, err
+	}
+
+	var (
+		err      error
+		count    C.size_t
+		watchers []C.rbd_image_watcher_t
+	)
+	retry.WithSizes(16, 4096, func(size int) retry.Hint {
+		count = C.size_t(size)
+		watchers = make([]C.rbd_image_watcher_t, count)
+		ret := C.rbd_watchers_list(image.image, &watchers[0], &count)
+		err = getErrorIfNegative(ret)
+		return retry.Size(int(count)).If(err == errRange)
+	})
+	if err != nil {
+		return nil, err
+	}
+	defer C.rbd_watchers_list_cleanup(&watchers[0], count)
+
+	imageWatchers := make([]ImageWatcher, count)
+	for i, watcher := range watchers[:count] {
+		imageWatchers[i].Addr = C.GoString(watcher.addr)
+		imageWatchers[i].Id = int64(watcher.id)
+		imageWatchers[i].Cookie = uint64(watcher.cookie)
+	}
+	return imageWatchers, nil
+}
+
+// watchCallbacks tracks the active callbacks for rbd watches
+var watchCallbacks = callbacks.New()
+
+// WatchCallback defines the function signature needed for the UpdateWatch
+// callback.
+type WatchCallback func(interface{})
+
+type watchCallbackCtx struct {
+	callback WatchCallback
+	data     interface{}
+}
+
+// Watch represents an ongoing image metadata watch.
+type Watch struct {
+	image   *Image
+	wcc     watchCallbackCtx
+	handle  C.uint64_t
+	cbIndex uintptr
+}
+
+// UpdateWatch updates the image object to watch metadata changes to the
+// image, returning a Watch object.
+//
+// Implements:
+//  int rbd_update_watch(rbd_image_t image, uint64_t *handle,
+//                       rbd_update_callback_t watch_cb, void *arg);
+func (image *Image) UpdateWatch(cb WatchCallback, data interface{}) (*Watch, error) {
+	if err := image.validate(imageIsOpen); err != nil {
+		return nil, err
+	}
+	wcc := watchCallbackCtx{
+		callback: cb,
+		data:     data,
+	}
+	w := &Watch{
+		image:   image,
+		wcc:     wcc,
+		cbIndex: watchCallbacks.Add(wcc),
+	}
+
+	ret := C.wrap_rbd_update_watch(
+		image.image,
+		&w.handle,
+		C.uintptr_t(w.cbIndex))
+	if ret != 0 {
+		return nil, getError(ret)
+	}
+	return w, nil
+}
+
+// Unwatch un-registers the image watch.
+//
+// Implements:
+//  int rbd_update_unwatch(rbd_image_t image, uint64_t handle);
+func (w *Watch) Unwatch() error {
+	if w.image == nil {
+		return ErrImageNotOpen
+	}
+	if err := w.image.validate(imageIsOpen); err != nil {
+		return err
+	}
+	ret := C.rbd_update_unwatch(w.image.image, w.handle)
+	watchCallbacks.Remove(w.cbIndex)
+	return getError(ret)
+}
+
+//export imageWatchCallback
+func imageWatchCallback(index uintptr) {
+	v := watchCallbacks.Lookup(index)
+	wcc := v.(watchCallbackCtx)
+	wcc.callback(wcc.data)
+}