rbd: rename image-cache invalidate command

Rename command image-cache to persistent-cache. Refactoring the code
of invalidate command.

[ idryomov: error message, incorporate doc and help.t hunks, drop
  do_persistent_cache_invalidate() ]

Signed-off-by: Yin Congmin <congmin.yin@intel.com>
Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

doc/rbd/rbd-persistent-write-log-cache.rst

@@ -99,20 +99,20 @@ For example::
                 hit_bytes: 192 MiB / 66%
                 miss_bytes: 97 MiB
 
-Discard Cache
--------------
+Invalidate Cache
+----------------
 
-To discard a cache file with ``rbd``, specify the ``image-cache invalidate``
-option, the pool name and the image name.  ::
+To invalidate (discard) a cache file with ``rbd``, specify the
+``persistent-cache invalidate`` command, the pool name and the image name.  ::
 
-        rbd image-cache invalidate {pool-name}/{image-name}
+        rbd persistent-cache invalidate {pool-name}/{image-name}
 
-The command removes the cache metadata of the corresponding image, disable
+The command removes the cache metadata of the corresponding image, disables
 the cache feature and deletes the local cache file if it exists.
 
 For example::
 
-        $ rbd image-cache invalidate rbd/foo
+        $ rbd persistent-cache invalidate rbd/foo
 
 .. _section: ../../rados/configuration/ceph-conf/#configuration-sections
 .. _commands: ../../man/8/rbd#commands

src/test/cli/rbd/help.t

@@ -56,7 +56,6 @@
       group snap remove (... rm)        Remove a snapshot from a group.
       group snap rename                 Rename group's snapshot.
       group snap rollback               Rollback group to snapshot.
-      image-cache invalidate            Discard existing / dirty image cache
       image-meta get                    Image metadata get the value associated
                                         with the key.
       image-meta list (image-meta ls)   Image metadata list keys with values.
@@ -125,6 +124,8 @@
       object-map rebuild                Rebuild an invalid object map.
       perf image iostat                 Display image IO statistics.
       perf image iotop                  Display a top-like IO monitor.
+      persistent-cache invalidate       Invalidate (discard) existing / dirty
+                                        persistent cache.
       pool init                         Initialize pool for use by RBD.
       pool stats                        Display pool statistics.
       remove (rm)                       Delete an image.
@@ -1107,23 +1108,6 @@
     --group arg          group name
     --snap arg           snapshot name
   
-  rbd help image-cache invalidate
-  usage: rbd image-cache invalidate [--pool <pool>] [--namespace <namespace>] 
-                                    [--image <image>] [--image-id <image-id>] 
-                                    <image-spec> 
-  
-  Discard existing / dirty image cache
-  
-  Positional arguments
-    <image-spec>         image specification
-                         (example: [<pool-name>/[<namespace>/]]<image-name>)
-  
-  Optional arguments
-    -p [ --pool ] arg    pool name
-    --namespace arg      namespace name
-    --image arg          image name
-    --image-id arg       image id
-  
   rbd help image-meta get
   usage: rbd image-meta get [--pool <pool>] [--namespace <namespace>] 
                             [--image <image>] 
@@ -2124,6 +2108,25 @@
     -p [ --pool ] arg    pool name
     --namespace arg      namespace name
   
+  rbd help persistent-cache invalidate
+  usage: rbd persistent-cache invalidate
+                                        [--pool <pool>] 
+                                        [--namespace <namespace>] 
+                                        [--image <image>] [--image-id <image-id>] 
+                                        <image-spec> 
+  
+  Invalidate (discard) existing / dirty persistent cache.
+  
+  Positional arguments
+    <image-spec>         image specification
+                         (example: [<pool-name>/[<namespace>/]]<image-name>)
+  
+  Optional arguments
+    -p [ --pool ] arg    pool name
+    --namespace arg      namespace name
+    --image arg          image name
+    --image-id arg       image id
+  
   rbd help pool init
   usage: rbd pool init [--pool <pool>] [--force] 
                        <pool-name> 

src/tools/rbd/CMakeLists.txt

@@ -26,7 +26,6 @@ set(rbd_srcs
   action/Flatten.cc
   action/Ggate.cc
   action/Group.cc
-  action/ImageCache.cc
   action/ImageMeta.cc
   action/Import.cc
   action/Info.cc
@@ -43,6 +42,7 @@ set(rbd_srcs
   action/Nbd.cc
   action/ObjectMap.cc
   action/Perf.cc
+  action/PersistentCache.cc
   action/Pool.cc
   action/Remove.cc
   action/Rename.cc

src/tools/rbd/action/PersistentCache.cc

@@ -14,27 +14,27 @@
 
 namespace rbd {
 namespace action {
-namespace image_cache {
+namespace persistent_cache {
 
 namespace at = argument_types;
 namespace po = boost::program_options;
 
-void get_arguments(po::options_description *positional,
-                   po::options_description *options) {
-  at::add_image_spec_options(positional, options,
-				at::ARGUMENT_MODIFIER_NONE);
+void get_arguments_invalidate(po::options_description *positional,
+                              po::options_description *options) {
+  at::add_image_spec_options(positional, options, at::ARGUMENT_MODIFIER_NONE);
   at::add_image_id_option(options);
 }
 
-int execute_discard(const po::variables_map &vm,
-                    const std::vector<std::string> &ceph_global_init_args) {
+int execute_invalidate(const po::variables_map &vm,
+                       const std::vector<std::string> &ceph_global_init_args) {
   size_t arg_index = 0;
   std::string pool_name;
   std::string namespace_name;
   std::string image_name;
+  std::string snap_name;
   int r = utils::get_pool_image_snapshot_names(
     vm, at::ARGUMENT_MODIFIER_NONE, &arg_index, &pool_name, &namespace_name,
-    &image_name, nullptr, true, utils::SNAPSHOT_PRESENCE_NONE,
+    &image_name, &snap_name, true, utils::SNAPSHOT_PRESENCE_NONE,
     utils::SPEC_VALIDATION_NONE);
   if (r < 0) {
     return r;
@@ -43,29 +43,27 @@ int execute_discard(const po::variables_map &vm,
   librados::Rados rados;
   librados::IoCtx io_ctx;
   librbd::Image image;
-  r = utils::init_and_open_image(pool_name, namespace_name, image_name, "",
-                                 "", false, &rados, &io_ctx, &image);
+  r = utils::init_and_open_image(pool_name, namespace_name, image_name, "", "",
+                                 false, &rados, &io_ctx, &image);
   if (r < 0) {
-    std::cerr << "rbd: failed to open image " << image_name << ": "
-              << cpp_strerror(r) << std::endl;
     return r;
   }
 
   r = image.invalidate_cache();
   if (r < 0) {
-    std::cerr << "rbd: failed to discard the cache of image " << image_name << ": "
+    std::cerr << "rbd: invalidating persistent cache failed: "
               << cpp_strerror(r) << std::endl;
     return r;
   }
 
-  image.close();
   return 0;
 }
 
-Shell::Action action_discard(
-  {"image-cache", "invalidate"}, {}, "Discard existing / dirty image cache", "",
-  &get_arguments, &execute_discard);
+Shell::Action action_invalidate(
+  {"persistent-cache", "invalidate"}, {},
+  "Invalidate (discard) existing / dirty persistent cache.", "",
+  &get_arguments_invalidate, &execute_invalidate);
 
-} // namespace image_cache
+} // namespace persistent_cache
 } // namespace action
 } // namespace rbd