qga: conditionalize schema for commands requiring fsfreeze

Rather than creating stubs for every command that just return
QERR_UNSUPPORTED, use 'if' conditions in the schema to fully
exclude generation of the filesystem freezing commands on POSIX
platforms lacking the required APIs.

The command will be rejected at QMP dispatch time instead,
avoiding reimplementing rejection by blocking the stub commands.
This changes the error message for affected commands from

    {"class": "CommandNotFound", "desc": "Command FOO has been disabled"}

to

    {"class": "CommandNotFound", "desc": "The command FOO has not been found"}

This has the additional benefit that the QGA protocol reference
now documents what conditions enable use of the command.

Reviewed-by: Philippe Mathieu-Daudé <philmd@linaro.org>
Reviewed-by: Konstantin Kostiuk <kkostiuk@redhat.com>
Signed-off-by: Daniel P. Berrangé <berrange@redhat.com>
Reviewed-by: Manos Pitsidianakis <manos.pitsidianakis@linaro.org>
Message-ID: <20240712132459.3974109-14-berrange@redhat.com>
Signed-off-by: Konstantin Kostiuk <kkostiuk@redhat.com>

diff --git a/qga/commands-posix.c b/qga/commands-posix.c
index b7f96aa005c0df2490c50a0395bd447583eb0b69..9207cb7a8ff01b4d137b0d20329583e2f320eda8 100644 (file)
--- a/qga/commands-posix.c
+++ b/qga/commands-posix.c
@@ -1144,39 +1144,6 @@ error:
 
 #endif /* HAVE_GETIFADDRS */
 
-#if !defined(CONFIG_FSFREEZE)
-
-GuestFsfreezeStatus qmp_guest_fsfreeze_status(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-
-    return 0;
-}
-
-int64_t qmp_guest_fsfreeze_freeze(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-
-    return 0;
-}
-
-int64_t qmp_guest_fsfreeze_freeze_list(bool has_mountpoints,
-                                       strList *mountpoints,
-                                       Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-
-    return 0;
-}
-
-int64_t qmp_guest_fsfreeze_thaw(Error **errp)
-{
-    error_setg(errp, QERR_UNSUPPORTED);
-
-    return 0;
-}
-#endif /* CONFIG_FSFREEZE */
-
 #if !defined(CONFIG_FSTRIM)
 GuestFilesystemTrimResponse *
 qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
@@ -1189,20 +1156,6 @@ qmp_guest_fstrim(bool has_minimum, int64_t minimum, Error **errp)
 /* add unsupported commands to the list of blocked RPCs */
 GList *ga_command_init_blockedrpcs(GList *blockedrpcs)
 {
-#if !defined(CONFIG_FSFREEZE)
-    {
-        const char *list[] = {
-            "guest-fsfreeze-status",
-            "guest-fsfreeze-freeze", "guest-fsfreeze-freeze-list",
-            "guest-fsfreeze-thaw", NULL};
-        char **p = (char **)list;
-
-        while (*p) {
-            blockedrpcs = g_list_append(blockedrpcs, g_strdup(*p++));
-        }
-    }
-#endif
-
 #if !defined(CONFIG_FSTRIM)
     blockedrpcs = g_list_append(blockedrpcs, g_strdup("guest-fstrim"));
 #endif

diff --git a/qga/qapi-schema.json b/qga/qapi-schema.json
index de3fc46d2eac6c772e4a5fc4b04eb53bd6aafba3..62462f092c13bb31d78802857eaf4e7f46ab3f30 100644 (file)
--- a/qga/qapi-schema.json
+++ b/qga/qapi-schema.json
@@ -412,7 +412,8 @@
 # Since: 0.15.0
 ##
 { 'enum': 'GuestFsfreezeStatus',
-  'data': [ 'thawed', 'frozen' ] }
+  'data': [ 'thawed', 'frozen' ],
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSFREEZE'] } }
 
 ##
 # @guest-fsfreeze-status:
@@ -429,7 +430,8 @@
 # Since: 0.15.0
 ##
 { 'command': 'guest-fsfreeze-status',
-  'returns': 'GuestFsfreezeStatus' }
+  'returns': 'GuestFsfreezeStatus',
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSFREEZE'] } }
 
 ##
 # @guest-fsfreeze-freeze:
@@ -451,7 +453,8 @@
 # Since: 0.15.0
 ##
 { 'command': 'guest-fsfreeze-freeze',
-  'returns': 'int' }
+  'returns': 'int',
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSFREEZE'] } }
 
 ##
 # @guest-fsfreeze-freeze-list:
@@ -471,7 +474,8 @@
 ##
 { 'command': 'guest-fsfreeze-freeze-list',
   'data':    { '*mountpoints': ['str'] },
-  'returns': 'int' }
+  'returns': 'int',
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSFREEZE'] } }
 
 ##
 # @guest-fsfreeze-thaw:
@@ -488,7 +492,8 @@
 # Since: 0.15.0
 ##
 { 'command': 'guest-fsfreeze-thaw',
-  'returns': 'int' }
+  'returns': 'int',
+  'if': { 'any': ['CONFIG_WIN32', 'CONFIG_FSFREEZE'] } }
 
 ##
 # @GuestFilesystemTrimResult: