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lvm2/lib/commands/toolcontext.h
David Teigland 20773abea0 commands: new method for defining commands
. Define a prototype for every lvm command.
. Verify every user command matches one.
. 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 the metadata SubLV of a pool LV.

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" text is also
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[78].name = "lvresize";
commands[78].command_line_id = "lvresize_by_size";
commands[78].command_line_enum = lvresize_by_size_CMD;
commands[78].fn = lvresize;
commands[78].ro_count = 1;
commands[78].rp_count = 1;
commands[78].oo_count = 22;
commands[78].op_count = 1;
commands[78].desc = "DESC: Resize an LV by a specified size.";
commands[78].usage = "lvresize --size Number[m|unit] LV"
" [ --alloc contiguous|cling|normal|anywhere|inherit,
   --autobackup y|n, --nofsck, --nosync, --reportformat String,
   --resizefs, --stripes Number, --stripesize Number[k|unit],
   --poolmetadatasize Number[m|unit] ]"
" [ PV ... ]";
commands[78].usage_common =
" [ --commandprofile String, --config String, --debug,
    --driverloaded y|n, --help, --profile String, --quiet,
    --verbose, --version, --yes, --force, --test, --noudevsync ]";
commands[78].required_opt_args[0].opt = size_ARG;
commands[78].required_opt_args[0].def.val_bits = val_enum_to_bit(sizemb_VAL);
commands[78].required_pos_args[0].pos = 1;
commands[78].required_pos_args[0].def.val_bits = val_enum_to_bit(lv_VAL);
commands[78].optional_opt_args[0].opt = commandprofile_ARG;
commands[78].optional_opt_args[0].def.val_bits = val_enum_to_bit(string_VAL);
commands[78].optional_opt_args[1].opt = config_ARG;
commands[78].optional_opt_args[1].def.val_bits = val_enum_to_bit(string_VAL);
commands[78].optional_opt_args[2].opt = debug_ARG;
commands[78].optional_opt_args[3].opt = driverloaded_ARG;
commands[78].optional_opt_args[3].def.val_bits = val_enum_to_bit(bool_VAL);
commands[78].optional_opt_args[4].opt = help_ARG;
commands[78].optional_opt_args[5].opt = profile_ARG;
commands[78].optional_opt_args[5].def.val_bits = val_enum_to_bit(string_VAL);
commands[78].optional_opt_args[6].opt = quiet_ARG;
commands[78].optional_opt_args[7].opt = verbose_ARG;
commands[78].optional_opt_args[8].opt = version_ARG;
commands[78].optional_opt_args[9].opt = yes_ARG;
commands[78].optional_opt_args[10].opt = alloc_ARG;
commands[78].optional_opt_args[10].def.val_bits = val_enum_to_bit(alloc_VAL);
commands[78].optional_opt_args[11].opt = autobackup_ARG;
commands[78].optional_opt_args[11].def.val_bits = val_enum_to_bit(bool_VAL);
commands[78].optional_opt_args[12].opt = force_ARG;
commands[78].optional_opt_args[13].opt = nofsck_ARG;
commands[78].optional_opt_args[14].opt = nosync_ARG;
commands[78].optional_opt_args[15].opt = noudevsync_ARG;
commands[78].optional_opt_args[16].opt = reportformat_ARG;
commands[78].optional_opt_args[16].def.val_bits = val_enum_to_bit(string_VAL);
commands[78].optional_opt_args[17].opt = resizefs_ARG;
commands[78].optional_opt_args[18].opt = stripes_ARG;
commands[78].optional_opt_args[18].def.val_bits = val_enum_to_bit(number_VAL);
commands[78].optional_opt_args[19].opt = stripesize_ARG;
commands[78].optional_opt_args[19].def.val_bits = val_enum_to_bit(sizekb_VAL);
commands[78].optional_opt_args[20].opt = test_ARG;
commands[78].optional_opt_args[21].opt = poolmetadatasize_ARG;
commands[78].optional_opt_args[21].def.val_bits = val_enum_to_bit(sizemb_VAL);
commands[78].optional_pos_args[0].pos = 2;
commands[78].optional_pos_args[0].def.val_bits = val_enum_to_bit(pv_VAL);
commands[78].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, e.g.:

$ lvresize --help
  lvresize - Resize a logical volume

  Resize an LV by a specified size.
  lvresize --size Number[m|unit] LV
  	[ --alloc contiguous|cling|normal|anywhere|inherit,
	  --autobackup y|n,
	  --nofsck,
	  --nosync,
	  --reportformat String,
	  --resizefs,
	  --stripes Number,
	  --stripesize Number[k|unit],
	  --poolmetadatasize Number[m|unit] ]
  	[ PV ... ]

  Resize an LV by a specified PV.
  lvresize LV PV ...
  	[ --alloc contiguous|cling|normal|anywhere|inherit,
	  --autobackup y|n,
	  --nofsck,
	  --nosync,
	  --reportformat String,
	  --resizefs,
	  --stripes Number,
	  --stripesize Number[k|unit] ]

  Resize the metadata SubLV of a pool LV.
  lvresize --poolmetadatasize Number[m|unit] LV_thinpool
  	[ --alloc contiguous|cling|normal|anywhere|inherit,
	  --autobackup y|n,
	  --nofsck,
	  --nosync,
	  --reportformat String,
	  --stripes Number,
	  --stripesize Number[k|unit] ]
  	[ PV ... ]

  Common options:
  	[ --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 implementation.

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.
2016-10-20 13:40:27 -05:00

251 lines
7.4 KiB
C

/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2009 Red Hat, Inc. All rights reserved.
*
* This file is part of LVM2.
*
* This copyrighted material is made available to anyone wishing to use,
* modify, copy, or redistribute it subject to the terms and conditions
* of the GNU Lesser General Public License v.2.1.
*
* You should have received a copy of the GNU Lesser General Public License
* along with this program; if not, write to the Free Software Foundation,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef _LVM_TOOLCONTEXT_H
#define _LVM_TOOLCONTEXT_H
#include "dev-cache.h"
#include "dev-type.h"
#include <limits.h>
/*
* Config options that can be changed while commands are processed
*/
struct config_info {
int debug;
int debug_classes;
int verbose;
int silent;
int test;
int syslog;
int activation;
int suffix;
int archive; /* should we archive ? */
int backup; /* should we backup ? */
int read_ahead; /* DM_READ_AHEAD_NONE or _AUTO */
int udev_rules;
int udev_sync;
int udev_fallback;
int cache_vgmetadata;
const char *msg_prefix;
const char *fmt_name;
uint64_t unit_factor;
int cmd_name; /* Show command name? */
mode_t umask;
char unit_type;
char _padding[1];
};
struct dm_config_tree;
struct profile_params;
struct archive_params;
struct backup_params;
struct arg_values;
struct config_tree_list {
struct dm_list list;
struct dm_config_tree *cft;
};
struct cmd_context_initialized_parts {
unsigned config:1; /* used to reinitialize config if previous init was not successful */
unsigned filters:1;
unsigned connections:1;
};
struct cmd_report {
int log_only;
dm_report_group_type_t report_group_type;
struct dm_report_group *report_group;
struct dm_report *log_rh;
const char *log_name;
log_report_t saved_log_report_state;
};
/* FIXME Split into tool & library contexts */
/* command-instance-related variables needed by library */
struct cmd_context {
/*
* Memory handlers.
*/
struct dm_pool *libmem; /* for permanent config data */
struct dm_pool *mem; /* transient: cleared between each command */
/*
* Command line and arguments.
*/
const char *cmd_line;
const char *name; /* needed before cmd->command is set */
struct command *command;
char **argv;
struct arg_values *opt_arg_values;
struct dm_list arg_value_groups;
/*
* Format handlers.
*/
const struct format_type *fmt; /* current format to use by default */
struct format_type *fmt_backup; /* format to use for backups */
struct dm_list formats; /* available formats */
struct dm_list segtypes; /* available segment types */
/*
* Machine and system identification.
*/
const char *system_id;
const char *hostname;
const char *kernel_vsn;
/*
* Device identification.
*/
struct dev_types *dev_types; /* recognized extra device types. */
/*
* Initialization state.
*/
struct cmd_context_initialized_parts initialized;
/*
* Switches.
*/
unsigned is_long_lived:1; /* optimises persistent_filter handling */
unsigned is_interactive:1;
unsigned check_pv_dev_sizes:1;
unsigned handles_missing_pvs:1;
unsigned handles_unknown_segments:1;
unsigned use_linear_target:1;
unsigned partial_activation:1;
unsigned degraded_activation:1;
unsigned auto_set_activation_skip:1;
unsigned si_unit_consistency:1;
unsigned report_binary_values_as_numeric:1;
unsigned report_mark_hidden_devices:1;
unsigned metadata_read_only:1;
unsigned ignore_clustered_vgs:1;
unsigned threaded:1; /* set if running within a thread e.g. clvmd */
unsigned independent_metadata_areas:1; /* active formats have MDAs outside PVs */
unsigned unknown_system_id:1;
unsigned include_historical_lvs:1; /* also process/report/display historical LVs */
unsigned record_historical_lvs:1; /* record historical LVs */
unsigned include_foreign_vgs:1; /* report/display cmds can reveal foreign VGs */
unsigned include_shared_vgs:1; /* report/display cmds can reveal lockd VGs */
unsigned include_active_foreign_vgs:1; /* cmd should process foreign VGs with active LVs */
unsigned vg_read_print_access_error:1; /* print access errors from vg_read */
unsigned lockd_gl_disable:1;
unsigned lockd_vg_disable:1;
unsigned lockd_lv_disable:1;
unsigned lockd_gl_removed:1;
unsigned lockd_vg_rescan:1;
unsigned lockd_vg_default_sh:1;
unsigned lockd_vg_enforce_sh:1;
unsigned vg_notify:1;
unsigned lv_notify:1;
unsigned pv_notify:1;
/*
* Filtering.
*/
struct dev_filter *lvmetad_filter; /* pre-lvmetad filter chain */
struct dev_filter *filter; /* post-lvmetad filter chain */
struct dev_filter *full_filter; /* lvmetad_filter + filter */
int dump_filter; /* Dump filter when exiting? */
/*
* Configuration.
*/
struct dm_list config_files; /* master lvm config + any existing tag configs */
struct profile_params *profile_params; /* profile handling params including loaded profile configs */
struct dm_config_tree *cft; /* the whole cascade: CONFIG_STRING -> CONFIG_PROFILE -> CONFIG_FILE/CONFIG_MERGED_FILES */
struct dm_hash_table *cft_def_hash; /* config definition hash used for validity check (item type + item recognized) */
struct config_info default_settings; /* selected settings with original default/configured value which can be changed during cmd processing */
struct config_info current_settings; /* may contain changed values compared to default_settings */
/*
* Archives and backups.
*/
struct archive_params *archive_params;
struct backup_params *backup_params;
const char *stripe_filler;
/*
* Host tags.
*/
struct dm_list tags; /* list of defined tags */
int hosttags;
/*
* Paths.
*/
const char *lib_dir; /* cache value global/library_dir */
char system_dir[PATH_MAX];
char dev_dir[PATH_MAX];
char proc_dir[PATH_MAX];
/*
* Reporting.
*/
struct cmd_report cmd_report;
/*
* Buffers.
*/
char display_buffer[NAME_LEN * 10]; /* ring buffer for upto 10 longest vg/lv names */
unsigned display_lvname_idx; /* index to ring buffer */
char *linebuffer;
/*
* Others - unsorted.
*/
const char *report_list_item_separator;
const char *time_format;
unsigned rand_seed;
struct dm_list unused_duplicate_devs; /* save preferences between lvmcache instances */
};
/*
* system_dir may be NULL to use the default value.
* The environment variable LVM_SYSTEM_DIR always takes precedence.
*/
struct cmd_context *create_toolcontext(unsigned is_long_lived,
const char *system_dir,
unsigned set_buffering,
unsigned threaded,
unsigned set_connections,
unsigned set_filters);
void destroy_toolcontext(struct cmd_context *cmd);
int refresh_toolcontext(struct cmd_context *cmd);
int refresh_filters(struct cmd_context *cmd);
int process_profilable_config(struct cmd_context *cmd);
int config_files_changed(struct cmd_context *cmd);
int init_lvmcache_orphans(struct cmd_context *cmd);
int init_filters(struct cmd_context *cmd, unsigned load_persistent_cache);
int init_connections(struct cmd_context *cmd);
/*
* A config context is a very light weight cmd struct that
* is only used for reading config settings from lvm.conf,
* which are at cmd->cft.
*/
struct cmd_context *create_config_context(void);
void destroy_config_context(struct cmd_context *cmd);
struct format_type *get_format_by_name(struct cmd_context *cmd, const char *format);
const char *system_id_from_string(struct cmd_context *cmd, const char *str);
#endif