commands: add NO_METADATA_PROCESSING command flagdev-prajnoha-avoid-some-init-for-simple-commands

Mark commands that do not handle LVM metadata with the new
NO_METADATA_PROCESSING flag:

  - lvmconfig (config, dumpconfig)
  - devtypes
  - formats
  - segtypes
  - systemid
  - tags
  - version

Recognize this flag during command/context initialization and
skip init for lvmetad, lvmpolld, lvmlockd and switch to using
"no locking" (locking_type=0) for such commands.

4 files changed, 25 insertions, 15 deletions

diff --git a/lib/locking/locking.c b/lib/locking/locking.c
index c88a85b82..22e83d2b1 100644
--- a/lib/locking/locking.c
+++ b/lib/locking/locking.c
@@ -119,8 +119,9 @@ int init_locking(int type, struct cmd_context *cmd, int suppress_messages)
 	switch (type) {
 	case 0:
 		init_no_locking(&_locking, cmd, suppress_messages);
-		log_warn("WARNING: Locking disabled. Be careful! "
-			  "This could corrupt your metadata.");
+		log_warn_suppress(suppress_messages,
+			"WARNING: Locking disabled. Be careful! "
+			"This could corrupt your metadata.");
 		return 1;
 
 	case 1:
diff --git a/tools/commands.h b/tools/commands.h
index 7f4b4e274..0ab578d4b 100644
--- a/tools/commands.h
+++ b/tools/commands.h
@@ -30,7 +30,7 @@ xx(e2fsadm,
 
 xx(config,
    "Display and manipulate configuration information",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "config\n"
    "\t[-f|--file filename]\n"
    "\t[--type {current|default|diff|full|list|missing|new|profilable|profilable-command|profilable-metadata}\n"
@@ -60,7 +60,7 @@ xx(config,
 
 xx(devtypes,
    "Display recognised built-in block device types",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "devtypes\n"
    "\t[--aligned]\n"
    "\t[--binary]\n"
@@ -86,7 +86,7 @@ xx(devtypes,
 
 xx(dumpconfig,
    "Display and manipulate configuration information",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "dumpconfig\n"
    "\t[-f|--file filename]\n"
    "\t[--type {current|default|diff|full|list|missing|new|profilable|profilable-command|profilable-metadata}\n"
@@ -116,12 +116,12 @@ xx(dumpconfig,
 
 xx(formats,
    "List available metadata formats",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "formats\n")
 
 xx(help,
    "Display help for commands",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "help <command>\n")
 
 /*********
@@ -491,7 +491,7 @@ xx(lvmchange,
 
 xx(lvmconfig,
    "Display and manipulate configuration information",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "lvmconfig\n"
    "\t[-f|--file filename]\n"
    "\t[--type {current|default|diff|full|list|missing|new|profilable|profilable-command|profilable-metadata}\n"
@@ -979,17 +979,17 @@ xx(pvscan,
 
 xx(segtypes,
    "List available segment types",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "segtypes\n")
 
 xx(systemid,
    "Display the system ID, if any, currently set on this host",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "systemid\n")
 
 xx(tags,
    "List tags defined on this host",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "tags\n")
 
 xx(vgcfgbackup,
@@ -1409,5 +1409,5 @@ xx(vgsplit,
 
 xx(version,
    "Display software and driver version information",
-   PERMITTED_READ_ONLY,
+   PERMITTED_READ_ONLY | NO_METADATA_PROCESSING,
    "version\n")
diff --git a/tools/lvmcmdline.c b/tools/lvmcmdline.c
index 7fb52a199..9844411d6 100644
--- a/tools/lvmcmdline.c
+++ b/tools/lvmcmdline.c
@@ -1463,6 +1463,11 @@ static int _init_lvmlockd(struct cmd_context *cmd)
 	return 1;
 }
 
+static int _cmd_no_meta_proc(struct cmd_context *cmd)
+{
+	return cmd->command->flags & NO_METADATA_PROCESSING;
+}
+
 int lvm_run_command(struct cmd_context *cmd, int argc, char **argv)
 {
 	struct dm_config_tree *config_string_cft;
@@ -1584,7 +1589,9 @@ int lvm_run_command(struct cmd_context *cmd, int argc, char **argv)
 		goto out;
 	}
 
-	if (arg_count(cmd, readonly_ARG)) {
+	if (_cmd_no_meta_proc(cmd))
+		locking_type = 0;
+	else if (arg_count(cmd, readonly_ARG)) {
 		if (find_config_tree_bool(cmd, global_use_lvmlockd_CFG, NULL)) {
 			/*
 			 * FIXME: we could use locking_type 5 here if that didn't
@@ -1607,12 +1614,12 @@ int lvm_run_command(struct cmd_context *cmd, int argc, char **argv)
 	else
 		locking_type = -1;
 
-	if (!init_locking(locking_type, cmd, arg_count(cmd, sysinit_ARG))) {
+	if (!init_locking(locking_type, cmd, _cmd_no_meta_proc(cmd) || arg_count(cmd, sysinit_ARG))) {
 		ret = ECMD_FAILED;
 		goto_out;
 	}
 
-	if (!_init_lvmlockd(cmd)) {
+	if (!_cmd_no_meta_proc(cmd) && !_init_lvmlockd(cmd)) {
 		ret = ECMD_FAILED;
 		goto_out;
 	}
diff --git a/tools/tools.h b/tools/tools.h
index 5ee5786d2..4ed893fc4 100644
--- a/tools/tools.h
+++ b/tools/tools.h
@@ -103,6 +103,8 @@ struct arg_value_group_list {
 #define ONE_VGNAME_ARG		0x00000010
 /* Command needs a shared lock on a VG; it only reads the VG. */
 #define LOCKD_VG_SH		0x00000020
+/* Command does not process any metadata. */
+#define NO_METADATA_PROCESSING	0x00000040
  
 /* a register of the lvm commands */
 struct command {