commands: new method for defining commands

. Define a prototype for every lvm command.
. Match every user command with one definition.
. Generate help text and man pages from them.

The new file command-lines.in defines a prototype for every
unique lvm command.  A unique lvm command is a unique
combination of: command name + required option args +
required positional args.  Each of these prototypes also
includes the optional option args and optional positional
args that the command will accept, a description, and a
unique string ID for the definition.  Any valid command
will match one of the prototypes.

Here's an example of the lvresize command definitions from
command-lines.in, there are three unique lvresize commands:

lvresize --size SizeMB LV
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync, --reportformat String, --resizefs,
--stripes Number, --stripesize SizeKB, --test, --poolmetadatasize SizeMB
OP: PV ...
ID: lvresize_by_size
DESC: Resize an LV by a specified size.

lvresize LV PV ...
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --resizefs, --stripes Number, --stripesize SizeKB,
--test
ID: lvresize_by_pv
DESC: Resize an LV by a specified PV.

lvresize --poolmetadatasize SizeMB LV_thinpool
OO: --alloc Alloc, --autobackup Bool, --force,
--nofsck, --nosync, --noudevsync,
--reportformat String, --stripes Number, --stripesize SizeKB,
--test
OP: PV ...
ID: lvresize_pool_metadata_by_size
DESC: Resize a pool metadata SubLV by a specified size.

The three commands have separate definitions because they have
different required parameters.  Required parameters are specified
on the first line of the definition.  Optional options are
listed after OO, and optional positional args are listed after OP.

This data is used to generate corresponding command definition
structures for lvm in command-lines.h.  usage/help output is also
auto generated, so it is always in sync with the definitions.

Example of the corresponding generated structure in
command-lines.h for the first lvresize prototype
(these structures are never edited directly):

commands[85].name = "lvresize";
commands[85].command_line_id = "lvresize_by_size";
commands[85].command_line_enum = lvresize_by_size_CMD;
commands[85].fn = lvresize;
commands[85].ro_count = 1;
commands[85].rp_count = 1;
commands[85].oo_count = 22;
commands[85].op_count = 1;
commands[85].desc = "DESC: Resize an LV by a specified size.";
commands[85].usage = "lvresize --size Number[m|unit] LV"
" [ --resizefs, --poolmetadatasize Number[m|unit], COMMON_OPTIONS ]"
" [ PV ... ]";
commands[85].usage_common =
" [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit, --commandprofile String, --config String, --driverloaded y|n, --nosync, --noudevsync, --profile String, --reportformat String, --version, --autobackup y|n, --debug, --force, --help, --stripes Number, --stripesize Number[k|unit], --nofsck, --quiet, --test, --verbose, --yes, --commandprofile String, --config String, --debug, --driverloaded y|n, --help, --profile String, --quiet, --verbose, --version, --yes, --force, --test, --noudevsync ]";
commands[85].required_opt_args[0].opt = size_ARG;
commands[85].required_opt_args[0].def.val_bits = val_enum_to_bit(sizemb_VAL);
commands[85].required_pos_args[0].pos = 1;
commands[85].required_pos_args[0].def.val_bits = val_enum_to_bit(lv_VAL);
commands[85].optional_opt_args[0].opt = commandprofile_ARG;
commands[85].optional_opt_args[0].def.val_bits = val_enum_to_bit(string_VAL);
commands[85].optional_opt_args[1].opt = config_ARG;
commands[85].optional_opt_args[1].def.val_bits = val_enum_to_bit(string_VAL);
commands[85].optional_opt_args[2].opt = debug_ARG;
commands[85].optional_opt_args[3].opt = driverloaded_ARG;
commands[85].optional_opt_args[3].def.val_bits = val_enum_to_bit(bool_VAL);
commands[85].optional_opt_args[4].opt = help_ARG;
commands[85].optional_opt_args[5].opt = profile_ARG;
commands[85].optional_opt_args[5].def.val_bits = val_enum_to_bit(string_VAL);
commands[85].optional_opt_args[6].opt = quiet_ARG;
commands[85].optional_opt_args[7].opt = verbose_ARG;
commands[85].optional_opt_args[8].opt = version_ARG;
commands[85].optional_opt_args[9].opt = yes_ARG;
commands[85].optional_opt_args[10].opt = alloc_ARG;
commands[85].optional_opt_args[10].def.val_bits = val_enum_to_bit(alloc_VAL);
commands[85].optional_opt_args[11].opt = autobackup_ARG;
commands[85].optional_opt_args[11].def.val_bits = val_enum_to_bit(bool_VAL);
commands[85].optional_opt_args[12].opt = force_ARG;
commands[85].optional_opt_args[13].opt = nofsck_ARG;
commands[85].optional_opt_args[14].opt = nosync_ARG;
commands[85].optional_opt_args[15].opt = noudevsync_ARG;
commands[85].optional_opt_args[16].opt = reportformat_ARG;
commands[85].optional_opt_args[16].def.val_bits = val_enum_to_bit(string_VAL);
commands[85].optional_opt_args[17].opt = resizefs_ARG;
commands[85].optional_opt_args[18].opt = stripes_ARG;
commands[85].optional_opt_args[18].def.val_bits = val_enum_to_bit(number_VAL);
commands[85].optional_opt_args[19].opt = stripesize_ARG;
commands[85].optional_opt_args[19].def.val_bits = val_enum_to_bit(sizekb_VAL);
commands[85].optional_opt_args[20].opt = test_ARG;
commands[85].optional_opt_args[21].opt = poolmetadatasize_ARG;
commands[85].optional_opt_args[21].def.val_bits = val_enum_to_bit(sizemb_VAL);
commands[85].optional_pos_args[0].pos = 2;
commands[85].optional_pos_args[0].def.val_bits = val_enum_to_bit(pv_VAL);
commands[85].optional_pos_args[0].def.flags = ARG_DEF_FLAG_MAY_REPEAT;

Every user-entered command is compared against the set of
command structures, and matched with one.  An error is
reported if an entered command does not have the required
parameters for any definition.  The closest match is printed
as a suggestion, and running lvresize --help will display
the usage for each possible lvresize command.

The prototype syntax used for help/man output includes
required --option and positional args on the first line,
and optional --option and positional args enclosed in [ ]
on subsequent lines.

  command_name <required_opt_args> <required_pos_args>
          [ <optional_opt_args> ]
          [ <optional_pos_args> ]

$ lvresize --help
  lvresize - Resize a logical volume

  Resize an LV by a specified size.
  lvresize --size Number[m|unit] LV
        [ --resizefs,
          --poolmetadatasize Number[m|unit],
          COMMON_OPTIONS ]
        [ PV ... ]

  Resize an LV by a specified PV.
  lvresize LV PV ...
        [ --resizefs,
          COMMON_OPTIONS ]

  Resize a pool metadata SubLV by a specified size.
  lvresize --poolmetadatasize Number[m|unit] LV_thinpool
        [ COMMON_OPTIONS ]
        [ PV ... ]

  Common options:
        [ --alloc contiguous|cling|cling_by_tags|normal|anywhere|inherit,
          --commandprofile String,
          --config String,
          --driverloaded y|n,
          --nosync,
          --noudevsync,
          --profile String,
          --reportformat String,
          --version,
          --autobackup y|n,
          --debug,
          --force,
          --help,
          --stripes Number,
          --stripesize Number[k|unit],
          --nofsck,
          --quiet,
          --test,
          --verbose,
          --yes,
          --commandprofile String,
          --config String,
          --debug,
          --driverloaded y|n,
          --help,
          --profile String,
          --quiet,
          --verbose,
          --version,
          --yes,
          --force,
          --test,
          --noudevsync ]

  (Use --help --help for usage notes.)

$ lvresize --poolmetadatasize 4
  Failed to find a matching command definition.
  Closest command usage is:
  lvresize --poolmetadatasize Number[m|unit] LV_thinpool

Man page prototypes are also generated from the same original
command definitions, and are always in sync with the code
and help text.

Very early in command execution, a matching command definition
is found.  lvm then knows the operation being done, and that
the provided args conform to the definition.  This will allow
lots of ad hoc checking/validation to be removed throughout
the code.

Each command definition can also be routed to a specific
function to implement it.  The function is associated with
an enum value for the command definition (generated from
the ID string.)  These per-command-definition implementation
functions have not yet been created, so all commands
currently fall back to the existing per-command-name
implementation functions.

Using per-command-definition functions will allow lots of
code to be removed which tries to figure out what the
command is meant to do.  This is currently based on ad hoc
and complicated option analysis.  When using the new
functions, what the command is doing is already known
from the associated command definition.

So, this first phase validates every user-entered command
against the set of command prototypes, then calls the existing
implementation.  The second phase can associate an implementation
function with each definition, and take further advantage of the
known operation to avoid the complicated option analysis.

scripts/command-lines.in

@@ -280,7 +280,7 @@ OO_LVCONVERT: --alloc Alloc, --background, --force, --noudevsync,
 # current LV type.
 
 lvconvert --merge LV_linear_striped_raid_thin_snapshot|VG|Tag ...
-OO: --background, --interval Number
+OO: --background, --interval Number, OO_LVCONVERT
 ID: lvconvert_merge
 DESC: Merge LV that was previously split from a mirror.
 DESC: Merge thin LV into its origin LV.
@@ -563,6 +563,7 @@ DESC: Separate a COW snapshot from its origin LV.
 # The purpose of this command is not entirely clear.
 
 lvconvert LV_mirror
+OO: OO_LVCONVERT
 ID: lvconvert_poll_mirror
 DESC: Poll mirror LV to collapse resync layers.
 
@@ -571,6 +572,7 @@ DESC: Poll mirror LV to collapse resync layers.
 # FIXME: add a new option defining this operation, e.g. --swapmetadata
 
 lvconvert --poolmetadata LV LV_thinpool_cachepool
+OO: OO_LVCONVERT
 ID: lvconvert_swap_pool_metadata
 DESC: Swap metadata LV in a thin pool or cache pool (temporary command).
 
@@ -896,7 +898,7 @@ DESC: (infers --type thin).
 DESC: Create a sparse snapshot of a virtual origin LV
 DESC: (infers --type snapshot).
 DESC: Chooses --type thin or --type snapshot according to
-DESC: confing setting sparse_segtype_default.
+DESC: config setting sparse_segtype_default.
 
 ---
 

scripts/create-commands.c

@@ -108,6 +108,8 @@ static struct opt_name opt_names[ARG_COUNT + 1] = {
 struct cmd_name {
 	const char *name;
 	const char *desc;
+	int variants;
+	int common_options[ARG_COUNT + 1];
 };
 
 /* create table of command names, e.g. vgcreate */
@@ -133,7 +135,7 @@ struct oo_line {
 int cmd_count;
 struct command cmd_array[MAX_CMDS];
 
-struct command common_options; /* for printing common usage */
+struct command lvm_all; /* for printing common options for all lvm commands */
 
 #define MAX_OO_LINES 256
 int oo_line_count;
@@ -499,6 +501,19 @@ static const char *cmd_name_desc(const char *name)
 	return NULL;
 }
 
+static struct cmd_name *find_command_name(const char *str)
+{
+	int i;
+
+	for (i = 0; i < MAX_CMD_NAMES; i++) {
+		if (!cmd_names[i].name)
+			break;
+		if (!strcmp(cmd_names[i].name, str))
+			return &cmd_names[i];
+	}
+	return NULL;
+}
+
 static int is_opt_name(char *str)
 {
 	if (!strncmp(str, "--", 2))
@@ -1173,35 +1188,156 @@ void print_command_count(void)
 	printf("};\n");
 }
 
-static int is_common_opt(int opt)
+static int is_lvm_all_opt(int opt)
 {
 	int oo;
 
-	for (oo = 0; oo < common_options.oo_count; oo++) {
-		if (common_options.optional_opt_args[oo].opt == opt)
+	for (oo = 0; oo < lvm_all.oo_count; oo++) {
+		if (lvm_all.optional_opt_args[oo].opt == opt)
 			return 1;
 	}
 	return 0;
 }
 
-/*
- * For certain commands (esp commands like lvcreate with many variants), common
- * options should not be printed for every variation, but once for all.  The
- * list of commands this applies to is fixed for now but could be encoded in
- * command-lines.in.
- *
- * The common options are defined in OO_USAGE_COMMON.  Those options
- * are skipped when creating the usage strings for each variation of
- * these commands.  Instead they are set in the usage_common string.
- */
-
-void print_usage(struct command *cmd, int skip_required)
+static void factor_common_options(void)
 {
-	int onereq = (cmd->cmd_flags & CMD_FLAG_ONE_REQUIRED_OPT) ? 1 : 0;
-	int i, sep, ro, rp, oo, op;
+	int cn, opt_enum, ci, oo, found;
+	struct command *cmd;
 
-	if (skip_required)
-		goto oo_count;
+	for (cn = 0; cn < MAX_CMD_NAMES; cn++) {
+		if (!cmd_names[cn].name)
+			break;
+
+		for (ci = 0; ci < cmd_count; ci++) {
+			cmd = &cmd_array[ci];
+
+			if (strcmp(cmd->name, cmd_names[cn].name))
+				continue;
+
+			cmd_names[cn].variants++;
+		}
+
+		for (opt_enum = 0; opt_enum < ARG_COUNT; opt_enum++) {
+
+			for (ci = 0; ci < cmd_count; ci++) {
+				cmd = &cmd_array[ci];
+
+				if (strcmp(cmd->name, cmd_names[cn].name))
+					continue;
+
+				found = 0;
+
+				for (oo = 0; oo < cmd->oo_count; oo++) {
+					if (cmd->optional_opt_args[oo].opt == opt_enum) {
+						found = 1;
+						break;
+					}
+				}
+
+				if (!found)
+					goto next_opt;
+			}
+
+			/* all commands starting with this name use this option */
+			cmd_names[cn].common_options[opt_enum] = 1;
+ next_opt:
+			;
+		}
+	}
+
+	/*
+	for (cn = 0; cn < MAX_CMD_NAMES; cn++) {
+		if (!cmd_names[cn].name)
+			break;
+
+		printf("%s (%d)\n", cmd_names[cn].name, cmd_names[cn].variants);
+		for (opt_enum = 0; opt_enum < ARG_COUNT; opt_enum++) {
+			if (cmd_names[cn].common_options[opt_enum])
+				printf("  %s\n", opt_names[opt_enum].long_opt);
+		}
+	}
+	*/
+}
+
+void print_usage_common(struct command *cmd)
+{
+	struct cmd_name *cname;
+	int i, sep, ro, rp, oo, op, opt_enum;
+
+	if (!(cname = find_command_name(cmd->name)))
+		return;
+
+	sep = 0;
+
+	/*
+	 * when there's more than one variant, options that
+	 * are common to all commands with a common name.
+	 */
+
+	if (cname->variants < 2)
+		goto all;
+
+	for (opt_enum = 0; opt_enum < ARG_COUNT; opt_enum++) {
+		if (!cname->common_options[opt_enum])
+			continue;
+
+		if (is_lvm_all_opt(opt_enum))
+			continue;
+
+		if (!sep) {
+			printf("\n");
+			printf("\" [");
+		} else {
+			printf(",");
+		}
+
+		for (oo = 0; oo < cmd->oo_count; oo++) {
+			if (cmd->optional_opt_args[oo].opt != opt_enum)
+				continue;
+
+			printf(" %s", opt_names[opt_enum].long_opt);
+			if (cmd->optional_opt_args[oo].def.val_bits) {
+				printf(" ");
+				print_def(&cmd->optional_opt_args[oo].def, 1);
+			}
+			sep = 1;
+			break;
+		}
+	}
+
+ all:
+	/* options that are common to all lvm commands */
+
+	for (oo = 0; oo < lvm_all.oo_count; oo++) {
+		opt_enum = lvm_all.optional_opt_args[oo].opt;
+
+		if (!sep) {
+			printf("\n");
+			printf("\" [");
+		} else {
+			printf(",");
+		}
+
+		printf(" %s", opt_names[opt_enum].long_opt);
+		if (lvm_all.optional_opt_args[oo].def.val_bits) {
+			printf(" ");
+			print_def(&lvm_all.optional_opt_args[oo].def, 1);
+		}
+		sep = 1;
+	}
+
+	printf(" ]\"");
+	printf(";\n");
+}
+
+void print_usage(struct command *cmd)
+{
+	struct cmd_name *cname;
+	int onereq = (cmd->cmd_flags & CMD_FLAG_ONE_REQUIRED_OPT) ? 1 : 0;
+	int i, sep, ro, rp, oo, op, opt_enum;
+
+	if (!(cname = find_command_name(cmd->name)))
+		return;
 
 	printf("\"%s", cmd->name);
 
@@ -1240,30 +1376,40 @@ void print_usage(struct command *cmd, int skip_required)
 	sep = 0;
 
 	if (cmd->oo_count) {
+		printf("\n");
+		printf("\" [");
+
 		for (oo = 0; oo < cmd->oo_count; oo++) {
-			/* skip common opts which are in the usage_common string */
-			if ((cmd != &common_options) && is_common_opt(cmd->optional_opt_args[oo].opt))
+			opt_enum = cmd->optional_opt_args[oo].opt;
+
+			/*
+			 * Skip common opts which are in the usage_common string.
+			 * The common opts are those in lvm_all and in
+			 * cname->common_options.
+			 */
+
+			if (is_lvm_all_opt(opt_enum))
 				continue;
 
-			if (!sep) {
-				printf("\n");
-				printf("\" [");
-			}
+			if ((cname->variants > 1) && cname->common_options[opt_enum])
+				continue;
 
 			if (sep)
 				printf(",");
 
-			printf(" %s", opt_names[cmd->optional_opt_args[oo].opt].long_opt);
+			printf(" %s", opt_names[opt_enum].long_opt);
 			if (cmd->optional_opt_args[oo].def.val_bits) {
 				printf(" ");
 				print_def(&cmd->optional_opt_args[oo].def, 1);
 			}
 			sep = 1;
 		}
-	}
 
-	if (sep)
+		if (sep)
+			printf(",");
+		printf(" COMMON_OPTIONS");
 		printf(" ]\"");
+	}
 
  op_count:
 	if (!cmd->op_count)
@@ -1352,7 +1498,7 @@ static void print_def_man(struct arg_def *def, int usage)
 
 			else if (val_enum == constnum_VAL) {
 				printf("\\fB");
-				printf("ll%u", (unsigned long long)def->num);
+				printf("%llu", (unsigned long long)def->num);
 				printf("\\fP");
 			}
 
@@ -1393,13 +1539,14 @@ static void print_def_man(struct arg_def *def, int usage)
 		printf(" ...");
 }
 
-void print_cmd_man(struct command *cmd, int skip_required)
+void print_man_usage(struct command *cmd)
 {
+	struct cmd_name *cname;
 	int onereq = (cmd->cmd_flags & CMD_FLAG_ONE_REQUIRED_OPT) ? 1 : 0;
-	int i, sep, ro, rp, oo, op;
+	int i, sep, ro, rp, oo, op, opt_enum;
 
-	if (skip_required)
-		goto oo_count;
+	if (!(cname = find_command_name(cmd->name)))
+		return;
 
 	printf("\\fB%s\\fP", cmd->name);
 
@@ -1424,6 +1571,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 
 		sep = 0;
 
+		/* print required options with a short opt */
 		for (ro = 0; ro < cmd->ro_count; ro++) {
 			if (!opt_names[cmd->required_opt_args[ro].opt].short_opt)
 				continue;
@@ -1451,6 +1599,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 			sep = 1;
 		}
 
+		/* print required options without a short opt */
 		for (ro = 0; ro < cmd->ro_count; ro++) {
 			if (opt_names[cmd->required_opt_args[ro].opt].short_opt)
 				continue;
@@ -1476,6 +1625,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 		printf(".RE\n");
 	}
 
+	/* print required positional args on a new line after the onereq set */
 	if (cmd->rp_count) {
 		printf(".RS 4\n");
 		for (rp = 0; rp < cmd->rp_count; rp++) {
@@ -1498,7 +1648,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 
 	/*
 	 * all are required options, print as:
-	 * -a|--a, -b|--b
+	 * -a|--aaa <val> -b|--bbb <val>
 	 */
 
 	if (cmd->ro_count) {
@@ -1518,6 +1668,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 		}
 	}
 
+	/* print required positional args on the same line as the required options */
 	if (cmd->rp_count) {
 		for (rp = 0; rp < cmd->rp_count; rp++) {
 			if (cmd->required_pos_args[rp].def.val_bits) {
@@ -1539,22 +1690,29 @@ void print_cmd_man(struct command *cmd, int skip_required)
 
 	sep = 0;
 
-	printf(".br\n");
-
 	if (cmd->oo_count) {
+		printf(".RS 4\n");
+		printf("[");
+
+		/* print optional options with short opts */
 
 		for (oo = 0; oo < cmd->oo_count; oo++) {
-			/* skip common opts which are in the usage_common string */
-			if ((cmd != &common_options) && is_common_opt(cmd->optional_opt_args[oo].opt))
+			opt_enum = cmd->optional_opt_args[oo].opt;
+
+			if (!opt_names[opt_enum].short_opt)
 				continue;
 
-			if (!opt_names[cmd->optional_opt_args[oo].opt].short_opt)
+			/*
+			 * Skip common opts which are in the usage_common string.
+			 * The common opts are those in lvm_all and in
+			 * cname->common_options.
+			 */
+
+			if (is_lvm_all_opt(opt_enum))
 				continue;
 
-			if (!sep) {
-				printf(".RS 4\n");
-				printf("[");
-			}
+			if ((cname->variants > 1) && cname->common_options[opt_enum])
+				continue;
 
 			if (sep) {
 				printf(",");
@@ -1563,8 +1721,8 @@ void print_cmd_man(struct command *cmd, int skip_required)
 			}
 
 			printf(" \\fB-%c\\fP|\\fB%s\\fP",
-				opt_names[cmd->optional_opt_args[oo].opt].short_opt,
-				opt_names[cmd->optional_opt_args[oo].opt].long_opt);
+				opt_names[opt_enum].short_opt,
+				opt_names[opt_enum].long_opt);
 
 			if (cmd->optional_opt_args[oo].def.val_bits) {
 				printf(" ");
@@ -1573,18 +1731,25 @@ void print_cmd_man(struct command *cmd, int skip_required)
 			sep = 1;
 		}
 
+		/* print optional options without short opts */
+
 		for (oo = 0; oo < cmd->oo_count; oo++) {
-			/* skip common opts which are in the usage_common string */
-			if ((cmd != &common_options) && is_common_opt(cmd->optional_opt_args[oo].opt))
+			opt_enum = cmd->optional_opt_args[oo].opt;
+
+			if (opt_names[opt_enum].short_opt)
 				continue;
 
-			if (opt_names[cmd->optional_opt_args[oo].opt].short_opt)
+			/*
+			 * Skip common opts which are in the usage_common string.
+			 * The common opts are those in lvm_all and in
+			 * cname->common_options.
+			 */
+
+			if (is_lvm_all_opt(opt_enum))
 				continue;
 
-			if (!sep) {
-				printf(".RS 4\n");
-				printf("[");
-			}
+			if ((cname->variants > 1) && cname->common_options[opt_enum])
+				continue;
 
 			if (sep) {
 				printf(",");
@@ -1595,7 +1760,7 @@ void print_cmd_man(struct command *cmd, int skip_required)
 			/* space alignment without short opt */
 			printf("   ");
 
-			printf(" \\fB%s\\fP", opt_names[cmd->optional_opt_args[oo].opt].long_opt);
+			printf(" \\fB%s\\fP", opt_names[opt_enum].long_opt);
 
 			if (cmd->optional_opt_args[oo].def.val_bits) {
 				printf(" ");
@@ -1603,9 +1768,15 @@ void print_cmd_man(struct command *cmd, int skip_required)
 			}
 			sep = 1;
 		}
-	}
 
-	if (sep) {
+		if (sep) {
+			printf(",");
+			printf("\n.br\n");
+			printf(" ");
+			/* space alignment without short opt */
+			printf("   ");
+		}
+		printf(" COMMON_OPTIONS");
 		printf(" ]\n");
 		printf(".RE\n");
 		printf(".br\n");
@@ -1634,6 +1805,151 @@ void print_cmd_man(struct command *cmd, int skip_required)
 	printf("\n");
 }
 
+void print_man_usage_common(struct command *cmd)
+{
+	struct cmd_name *cname;
+	int i, sep, ro, rp, oo, op, opt_enum;
+
+	if (!(cname = find_command_name(cmd->name)))
+		return;
+
+	sep = 0;
+
+	printf(".RS 4\n");
+	printf("[");
+
+	/*
+	 * when there's more than one variant, options that
+	 * are common to all commands with a common name.
+	 */
+
+	if (cname->variants < 2)
+		goto all;
+
+	/* print those with short opts */
+	for (opt_enum = 0; opt_enum < ARG_COUNT; opt_enum++) {
+		if (!cname->common_options[opt_enum])
+			continue;
+
+		if (!opt_names[opt_enum].short_opt)
+			continue;
+
+		if (is_lvm_all_opt(opt_enum))
+			continue;
+
+		if (sep) {
+			printf(",");
+			printf("\n.br\n");
+			printf(" ");
+		}
+
+		for (oo = 0; oo < cmd->oo_count; oo++) {
+			if (cmd->optional_opt_args[oo].opt != opt_enum)
+				continue;
+
+			printf(" \\fB-%c\\fP|\\fB%s\\fP",
+				opt_names[opt_enum].short_opt,
+				opt_names[opt_enum].long_opt);
+
+			if (cmd->optional_opt_args[oo].def.val_bits) {
+				printf(" ");
+				print_def_man(&cmd->optional_opt_args[oo].def, 1);
+			}
+			sep = 1;
+			break;
+		}
+
+	}
+
+	/* print those without short opts */
+	for (opt_enum = 0; opt_enum < ARG_COUNT; opt_enum++) {
+		if (!cname->common_options[opt_enum])
+			continue;
+
+		if (opt_names[opt_enum].short_opt)
+			continue;
+
+		if (is_lvm_all_opt(opt_enum))
+			continue;
+
+		if (sep) {
+			printf(",");
+			printf("\n.br\n");
+			printf(" ");
+		}
+
+		for (oo = 0; oo < cmd->oo_count; oo++) {
+			if (cmd->optional_opt_args[oo].opt != opt_enum)
+				continue;
+
+			/* space alignment without short opt */
+			printf("   ");
+
+			printf(" \\fB%s\\fP", opt_names[opt_enum].long_opt);
+
+			if (cmd->optional_opt_args[oo].def.val_bits) {
+				printf(" ");
+				print_def_man(&cmd->optional_opt_args[oo].def, 1);
+			}
+			sep = 1;
+			break;
+		}
+	}
+ all:
+	/* options that are common to all lvm commands */
+
+	/* those with short opts */
+	for (oo = 0; oo < lvm_all.oo_count; oo++) {
+		opt_enum = lvm_all.optional_opt_args[oo].opt;
+
+		if (!opt_names[opt_enum].short_opt)
+			continue;
+
+		if (sep) {
+			printf(",");
+			printf("\n.br\n");
+			printf(" ");
+		}
+
+		printf(" \\fB-%c\\fP|\\fB%s\\fP",
+			opt_names[opt_enum].short_opt,
+			opt_names[opt_enum].long_opt);
+
+		if (lvm_all.optional_opt_args[oo].def.val_bits) {
+			printf(" ");
+			print_def(&lvm_all.optional_opt_args[oo].def, 1);
+		}
+		sep = 1;
+	}
+
+	/* those without short opts */
+	for (oo = 0; oo < lvm_all.oo_count; oo++) {
+		opt_enum = lvm_all.optional_opt_args[oo].opt;
+
+		if (opt_names[opt_enum].short_opt)
+			continue;
+
+		if (sep) {
+			printf(",");
+			printf("\n.br\n");
+			printf(" ");
+		}
+
+		/* space alignment without short opt */
+		printf("   ");
+
+		printf(" \\fB%s\\fP", opt_names[opt_enum].long_opt);
+
+		if (lvm_all.optional_opt_args[oo].def.val_bits) {
+			printf(" ");
+			print_def(&lvm_all.optional_opt_args[oo].def, 1);
+		}
+		sep = 1;
+	}
+	printf(" ]\"");
+	printf(";\n");
+}
+
 #define DESC_LINE 256
 
 void print_desc_man(const char *desc)
@@ -1674,16 +1990,16 @@ void print_desc_man(const char *desc)
 	}
 }
 
-void print_command_man(void)
+void print_man_command(void)
 {
 	struct command *cmd;
 	const char *last_cmd_name = NULL;
 	const char *desc;
 	int i, j, ro, rp, oo, op;
 
-	include_optional_opt_args(&common_options, "OO_USAGE_COMMON");
+	include_optional_opt_args(&lvm_all, "OO_USAGE_COMMON");
 
-	printf(".TH LVM_ALL 8\n");
+	printf(".TH LVM_COMMANDS 8\n");
 
 	for (i = 0; i < cmd_count; i++) {
 
@@ -1711,12 +2027,12 @@ void print_command_man(void)
 			printf(".P\n");
 		}
 
-		print_cmd_man(cmd, 0);
+		print_man_usage(cmd);
 
 		if ((i == (cmd_count - 1)) || strcmp(cmd->name, cmd_array[i+1].name)) {
 			printf("Common options:\n");
 			printf(".\n");
-			print_cmd_man(&common_options, 1);
+			print_man_usage_common(cmd);
 		}
 
 		printf("\n");
@@ -1729,7 +2045,7 @@ void print_command_struct(int only_usage)
 	struct command *cmd;
 	int i, j, ro, rp, oo, op;
 
-	include_optional_opt_args(&common_options, "OO_USAGE_COMMON");
+	include_optional_opt_args(&lvm_all, "OO_USAGE_COMMON");
 
 	printf("/* Do not edit. This file is generated by scripts/create-commands */\n");
 	printf("/* using command definitions from scripts/command-lines.in */\n");
@@ -1739,8 +2055,8 @@ void print_command_struct(int only_usage)
 		cmd = &cmd_array[i];
 
 		if (only_usage) {
-			print_usage(cmd, 0);
-			print_usage(&common_options, 1);
+			print_usage(cmd);
+			print_usage_common(cmd);
 			printf("\n");
 			continue;
 		}
@@ -1759,11 +2075,11 @@ void print_command_struct(int only_usage)
 
 		printf("commands[%d].desc = \"%s\";\n", i, cmd->desc ?: "");
 		printf("commands[%d].usage = ", i);
-		print_usage(cmd, 0);
+		print_usage(cmd);
 
 		if (cmd->oo_count) {
 			printf("commands[%d].usage_common = ", i);
-			print_usage(&common_options, 1);
+			print_usage_common(cmd);
 		} else {
 			printf("commands[%d].usage_common = \"NULL\";\n", i);
 		}
@@ -1932,8 +2248,8 @@ static void print_ambiguous(void)
 			}
 
 			printf("Ambiguous commands %d and %d:\n", i, j);
-			print_usage(cmd, 0);
-			print_usage(dup, 0);
+			print_usage(cmd);
+			print_usage(dup);
 			printf("\n");
 
 			dups[found].i = i;
@@ -1973,11 +2289,11 @@ static void print_help(int argc, char *argv[])
 {
 	printf("%s --output struct|count|usage|expanded <filename>\n", argv[0]);
 	printf("\n");
-	printf("struct:    print C structures.\n");
+	printf("struct:    print C structures for command-lines.h\n");
+	printf("count:     print defines and enums for command-lines-count.h\n");
+	printf("ambiguous: print commands differing only by LV types\n");
 	printf("usage:     print usage format.\n");
 	printf("expanded:  print expanded input format.\n");
-	printf("count:     print #define COMMAND_COUNT <Number>\n");
-	printf("ambiguous: print commands differing only by LV types\n");
 }
 
 int main(int argc, char *argv[])
@@ -2143,10 +2459,14 @@ int main(int argc, char *argv[])
 
 	fclose(file);
 
+	factor_common_options();
+
 	if (!outputformat)
 		print_command_struct(1);
-	else if (!strcmp(outputformat, "struct"))
+	else if (!strcmp(outputformat, "struct")) {
 		print_command_struct(0);
+		print_ambiguous();
+	}
 	else if (!strcmp(outputformat, "count"))
 		print_command_count();
 	else if (!strcmp(outputformat, "usage"))
@@ -2156,7 +2476,7 @@ int main(int argc, char *argv[])
 	else if (!strcmp(outputformat, "ambiguous"))
 		print_ambiguous();
 	else if (!strcmp(outputformat, "man"))
-		print_command_man();
+		print_man_command();
 	else
 		print_help(argc, argv);
 }

tools/vals.h

@@ -116,8 +116,7 @@ val(permission_VAL, permission_arg, "Permission", "rw|r")
 val(metadatatype_VAL, metadatatype_arg, "MetadataType", "lvm2|lvm1")
 val(units_VAL, string_arg, "Units", "hHbBsSkKmMgGtTpPeE")
 val(segtype_VAL, segtype_arg, "SegType", "linear|striped|snapshot|mirror|raid*|thin|cache|thin-pool|cache-pool")
-/* FIXME: cling_by_tags is left out of help text because it makes the line wrap */
-val(alloc_VAL, alloc_arg, "Alloc", "contiguous|cling|normal|anywhere|inherit")
+val(alloc_VAL, alloc_arg, "Alloc", "contiguous|cling|cling_by_tags|normal|anywhere|inherit")
 val(locktype_VAL, locktype_arg, "LockType", "sanlock|dlm|none")
 val(readahead_VAL, readahead_arg, "Readahead", "auto|none|NumberSectors")
 val(metadatacopies_VAL, metadatacopies_arg, "MetadataCopies", "all|unmanaged|Number")