Merge pull request #1159 from ceph/wip-rbd-rm-watchers

Reviewed-by: Josh Durgin <josh.durgin@inktank.com>

src/librbd/internal.cc

@@ -1353,15 +1353,31 @@ namespace librbd {
     if (r < 0) {
       ldout(cct, 2) << "error opening image: " << cpp_strerror(-r) << dendl;
     } else {
+      string header_oid = ictx->header_oid;
+      old_format = ictx->old_format;
+      unknown_format = false;
+      id = ictx->id;
+
       if (ictx->snaps.size()) {
 	lderr(cct) << "image has snapshots - not removing" << dendl;
 	close_image(ictx);
 	return -ENOTEMPTY;
       }
-      string header_oid = ictx->header_oid;
-      old_format = ictx->old_format;
-      unknown_format = false;
-      id = ictx->id;
+
+      std::list<obj_watch_t> watchers;
+      r = io_ctx.list_watchers(header_oid, &watchers);
+      if (r < 0) {
+        lderr(cct) << "error listing watchers" << dendl;
+        close_image(ictx);
+        return r;
+      }
+      if (watchers.size() > 1) {
+        lderr(cct) << "image has watchers - not removing" << dendl;
+        close_image(ictx);
+        return -EBUSY;
+      }
+      assert(watchers.size() == 1);
+
       ictx->md_lock.get_read();
       trim_image(ictx, 0, prog_ctx);
       ictx->md_lock.put_read();
@@ -1375,6 +1391,7 @@ namespace librbd {
 				   parent_info.spec, id);
       if (r < 0 && r != -ENOENT) {
 	lderr(cct) << "error removing child from children list" << dendl;
+        close_image(ictx);
 	return r;
       }
       close_image(ictx);

src/pybind/cephfs.py

@@ -115,6 +115,21 @@ class cephfs_stat(Structure):
                 ('__unused2', c_long),
                 ('__unused3', c_long) ]
 
+def load_libcephfs():
+    """
+    Load the libcephfs shared library.
+    """
+    libcephfs_path = find_library('cephfs')
+    if libcephfs_path:
+        return CDLL(libcephfs_path)
+
+    # try harder, find_library() doesn't search LD_LIBRARY_PATH
+    # in addition, it doesn't seem work on centos 6.4 (see e46d2ca067b5)
+    try:
+        return CDLL('libcephfs.so.1')
+    except OSError:
+        raise EnvironmentError("Unable to find libcephfs")
+
 class LibCephFS(object):
     """libcephfs python wrapper"""
     def require_state(self, *args):
@@ -125,10 +140,7 @@ def require_state(self, *args):
                                   "CephFS object in state %s." % (self.state))
 
     def __init__(self, conf=None, conffile=None):
-        libcephfs_path = find_library('cephfs')
-        if not libcephfs_path:
-            raise EnvironmentError("Unable to find libcephfs")
-        self.libcephfs = CDLL(libcephfs_path)
+        self.libcephfs = load_libcephfs()
         self.cluster = c_void_p()
 
         if conffile is not None and not isinstance(conffile, str):

src/pybind/rbd.py

@@ -122,9 +122,15 @@ def load_librbd():
     Load the librbd shared library.
     """
     librbd_path = find_library('rbd')
-    if not librbd_path:
+    if librbd_path:
+        return CDLL(librbd_path)
+
+    # try harder, find_library() doesn't search LD_LIBRARY_PATH
+    # in addition, it doesn't seem work on centos 6.4 (see e46d2ca067b5)
+    try:
+        return CDLL('librbd.so.1')
+    except OSError:
         raise EnvironmentError("Unable to find librbd")
-    return CDLL(librbd_path)
 
 class RBD(object):
     """

src/test/pybind/test_rbd.py

@@ -363,7 +363,11 @@ def test_remove_with_snap(self):
         self.image.remove_snap('snap1')
 
     def test_remove_with_watcher(self):
+        data = rand_data(256)
+        self.image.write(data, 0)
         assert_raises(ImageBusy, remove_image)
+        read = self.image.read(0, 256)
+        eq(read, data)
 
     def test_rollback_to_snap(self):
         self.image.write('\0' * 256, 0)

src/test/run-rbd-tests

@@ -24,8 +24,7 @@ run_cli_tests() {
 run_api_tests() {
     recreate_pool rbd
     # skip many_snaps since it takes several minutes
-    # skip remove_with_watcher until #2533 is fixed
-    nosetests -v test_rbd -e '.*many_snaps' -e '.*remove_with_watcher'
+    nosetests -v test_rbd -e '.*many_snaps'
     # ceph_test_librbd creates its own pools
     ceph_test_librbd
 }