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lvm2/libdm/libdevmapper.h
Peter Rajnoha 12b60e7c25
libdm: report: support reporting field IDs in headings 
Add new DM_REPORT_OUTPUT_FIELD_IDS_IN_HEADINGS report output flag.
If enabled, column IDs are reported instead of column names in report
headings.

The 'column IDs' are IDs as found in 'const struct dm_report_field_type *fields'
array that is passed during report initialization (that is, a call to
dm_report_init/dm_report_init_with_selection). In this case, the 'id'
dm_report_field_type member is used instead of the 'heading' member.
2023-08-28 15:44:57 +02:00

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/*
* Copyright (C) 2001-2004 Sistina Software, Inc. All rights reserved.
* Copyright (C) 2004-2017 Red Hat, Inc. All rights reserved.
* Copyright (C) 2006 Rackable Systems All rights reserved.
*
* This file is part of the device-mapper userspace tools.
*
* 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,
* Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
*/
#ifndef LIB_DEVICE_MAPPER_H
#define LIB_DEVICE_MAPPER_H
#include <inttypes.h>
#include <stdarg.h>
#include <sys/types.h>
#include <sys/stat.h>
#ifdef __linux__
# include <linux/types.h>
#endif
#include <limits.h>
#include <string.h>
#include <stdlib.h>
#include <stdio.h>
#include <stddef.h> /* offsetof */
#ifndef __GNUC__
# define __typeof__ typeof
#endif
/* Macros to make string defines */
#define DM_TO_STRING_EXP(A) #A
#define DM_TO_STRING(A) DM_TO_STRING_EXP(A)
#define DM_ARRAY_SIZE(a) (sizeof(a) / sizeof((a)[0]))
#ifdef __cplusplus
extern "C" {
#endif
/*****************************************************************
* The first section of this file provides direct access to the
* individual device-mapper ioctls. Since it is quite laborious to
* build the ioctl arguments for the device-mapper, people are
* encouraged to use this library.
****************************************************************/
/*
* The library user may wish to register their own
* logging function. By default errors go to stderr.
* Use dm_log_with_errno_init(NULL) to restore the default log fn.
* Error messages may have a non-zero errno.
* Debug messages may have a non-zero class.
* Aborts on internal error when env DM_ABORT_ON_INTERNAL_ERRORS is 1
*/
typedef void (*dm_log_with_errno_fn) (int level, const char *file, int line,
int dm_errno_or_class, const char *f, ...)
__attribute__ ((format(printf, 5, 6)));
void dm_log_with_errno_init(dm_log_with_errno_fn fn);
void dm_log_init_verbose(int level);
/*
* Original version of this function.
* dm_errno is set to 0.
*
* Deprecated: Use the _with_errno_ versions above instead.
*/
typedef void (*dm_log_fn) (int level, const char *file, int line,
const char *f, ...)
__attribute__ ((format(printf, 4, 5)));
void dm_log_init(dm_log_fn fn);
/*
* For backward-compatibility, indicate that dm_log_init() was used
* to set a non-default value of dm_log().
*/
int dm_log_is_non_default(void);
/*
* Number of devices currently in suspended state (via the library).
*/
int dm_get_suspended_counter(void);
enum {
DM_DEVICE_CREATE,
DM_DEVICE_RELOAD,
DM_DEVICE_REMOVE,
DM_DEVICE_REMOVE_ALL,
DM_DEVICE_SUSPEND,
DM_DEVICE_RESUME,
DM_DEVICE_INFO,
DM_DEVICE_DEPS,
DM_DEVICE_RENAME,
DM_DEVICE_VERSION,
DM_DEVICE_STATUS,
DM_DEVICE_TABLE,
DM_DEVICE_WAITEVENT,
DM_DEVICE_LIST,
DM_DEVICE_CLEAR,
DM_DEVICE_MKNODES,
DM_DEVICE_LIST_VERSIONS,
DM_DEVICE_TARGET_MSG,
DM_DEVICE_SET_GEOMETRY,
DM_DEVICE_ARM_POLL,
DM_DEVICE_GET_TARGET_VERSION
};
/*
* You will need to build a struct dm_task for
* each ioctl command you want to execute.
*/
struct dm_pool;
struct dm_task;
struct dm_timestamp;
struct dm_task *dm_task_create(int type);
void dm_task_destroy(struct dm_task *dmt);
int dm_task_set_name(struct dm_task *dmt, const char *name);
int dm_task_set_uuid(struct dm_task *dmt, const char *uuid);
/*
* Retrieve attributes after an info.
*/
struct dm_info {
int exists;
int suspended;
int live_table;
int inactive_table;
int32_t open_count;
uint32_t event_nr;
uint32_t major;
uint32_t minor; /* minor device number */
int read_only; /* 0:read-write; 1:read-only */
int32_t target_count;
int deferred_remove;
int internal_suspend;
};
struct dm_deps {
uint32_t count;
uint32_t filler;
uint64_t device[];
};
struct dm_names {
uint64_t dev;
uint32_t next; /* Offset to next struct from start of this struct */
char name[];
};
struct dm_versions {
uint32_t next; /* Offset to next struct from start of this struct */
uint32_t version[3];
char name[];
};
int dm_get_library_version(char *version, size_t size);
int dm_task_get_driver_version(struct dm_task *dmt, char *version, size_t size);
int dm_task_get_info(struct dm_task *dmt, struct dm_info *dmi);
/*
* This function returns dm device's UUID based on the value
* of the mangling mode set during preceding dm_task_run call:
* - unmangled UUID for DM_STRING_MANGLING_{AUTO, HEX},
* - UUID without any changes for DM_STRING_MANGLING_NONE.
*
* To get mangled or unmangled form of the UUID directly, use
* dm_task_get_uuid_mangled or dm_task_get_uuid_unmangled function.
*/
const char *dm_task_get_uuid(const struct dm_task *dmt);
struct dm_deps *dm_task_get_deps(struct dm_task *dmt);
struct dm_versions *dm_task_get_versions(struct dm_task *dmt);
const char *dm_task_get_message_response(struct dm_task *dmt);
/*
* These functions return device-mapper names based on the value
* of the mangling mode set during preceding dm_task_run call:
* - unmangled name for DM_STRING_MANGLING_{AUTO, HEX},
* - name without any changes for DM_STRING_MANGLING_NONE.
*
* To get mangled or unmangled form of the name directly, use
* dm_task_get_name_mangled or dm_task_get_name_unmangled function.
*/
const char *dm_task_get_name(const struct dm_task *dmt);
struct dm_names *dm_task_get_names(struct dm_task *dmt);
int dm_task_set_ro(struct dm_task *dmt);
int dm_task_set_newname(struct dm_task *dmt, const char *newname);
int dm_task_set_newuuid(struct dm_task *dmt, const char *newuuid);
int dm_task_set_minor(struct dm_task *dmt, int minor);
int dm_task_set_major(struct dm_task *dmt, int major);
int dm_task_set_major_minor(struct dm_task *dmt, int major, int minor, int allow_default_major_fallback);
int dm_task_set_uid(struct dm_task *dmt, uid_t uid);
int dm_task_set_gid(struct dm_task *dmt, gid_t gid);
int dm_task_set_mode(struct dm_task *dmt, mode_t mode);
/* See also description for DM_UDEV_DISABLE_LIBRARY_FALLBACK flag! */
int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags);
int dm_task_set_event_nr(struct dm_task *dmt, uint32_t event_nr);
int dm_task_set_geometry(struct dm_task *dmt, const char *cylinders, const char *heads, const char *sectors, const char *start);
int dm_task_set_message(struct dm_task *dmt, const char *message);
int dm_task_set_sector(struct dm_task *dmt, uint64_t sector);
int dm_task_no_flush(struct dm_task *dmt);
int dm_task_no_open_count(struct dm_task *dmt);
int dm_task_skip_lockfs(struct dm_task *dmt);
int dm_task_query_inactive_table(struct dm_task *dmt);
int dm_task_suppress_identical_reload(struct dm_task *dmt);
int dm_task_secure_data(struct dm_task *dmt);
int dm_task_retry_remove(struct dm_task *dmt);
int dm_task_deferred_remove(struct dm_task *dmt);
int dm_task_ima_measurement(struct dm_task *dmt);
/*
* Record timestamp immediately after the ioctl returns.
*/
int dm_task_set_record_timestamp(struct dm_task *dmt);
struct dm_timestamp *dm_task_get_ioctl_timestamp(struct dm_task *dmt);
/*
* Enable checks for common mistakes such as issuing ioctls in an unsafe order.
*/
int dm_task_enable_checks(struct dm_task *dmt);
typedef enum dm_add_node_e {
DM_ADD_NODE_ON_RESUME, /* add /dev/mapper node with dmsetup resume */
DM_ADD_NODE_ON_CREATE /* add /dev/mapper node with dmsetup create */
} dm_add_node_t;
int dm_task_set_add_node(struct dm_task *dmt, dm_add_node_t add_node);
/*
* Control read_ahead.
*/
#define DM_READ_AHEAD_AUTO UINT32_MAX /* Use kernel default readahead */
#define DM_READ_AHEAD_NONE 0 /* Disable readahead */
#define DM_READ_AHEAD_MINIMUM_FLAG 0x1 /* Value supplied is minimum */
/*
* Read ahead is set with DM_DEVICE_CREATE with a table or DM_DEVICE_RESUME.
*/
int dm_task_set_read_ahead(struct dm_task *dmt, uint32_t read_ahead,
uint32_t read_ahead_flags);
uint32_t dm_task_get_read_ahead(const struct dm_task *dmt,
uint32_t *read_ahead);
/*
* Use these to prepare for a create or reload.
*/
int dm_task_add_target(struct dm_task *dmt,
uint64_t start,
uint64_t size, const char *ttype, const char *params);
/*
* Format major/minor numbers correctly for input to driver.
*/
#define DM_FORMAT_DEV_BUFSIZE 13 /* Minimum bufsize to handle worst case. */
int dm_format_dev(char *buf, int bufsize, uint32_t dev_major, uint32_t dev_minor);
/* Use this to retrive target information returned from a STATUS call */
void *dm_get_next_target(struct dm_task *dmt,
void *next, uint64_t *start, uint64_t *length,
char **target_type, char **params);
/*
* Following dm_get_status_* functions will allocate approriate status structure
* from passed mempool together with the necessary character arrays.
* Destroying the mempool will release all asociated allocation.
*/
/* Parse params from STATUS call for mirror target */
typedef enum dm_status_mirror_health_e {
DM_STATUS_MIRROR_ALIVE = 'A',/* No failures */
DM_STATUS_MIRROR_FLUSH_FAILED = 'F',/* Mirror out-of-sync */
DM_STATUS_MIRROR_WRITE_FAILED = 'D',/* Mirror out-of-sync */
DM_STATUS_MIRROR_SYNC_FAILED = 'S',/* Mirror out-of-sync */
DM_STATUS_MIRROR_READ_FAILED = 'R',/* Mirror data unaffected */
DM_STATUS_MIRROR_UNCLASSIFIED = 'U' /* Bug */
} dm_status_mirror_health_t;
struct dm_status_mirror {
uint64_t total_regions;
uint64_t insync_regions;
uint32_t dev_count; /* # of devs[] elements (<= 8) */
struct dm_dev_leg_health_s {
dm_status_mirror_health_t health;
uint32_t major;
uint32_t minor;
} *devs; /* array with individual legs */
const char *log_type; /* core, disk,.... */
uint32_t log_count; /* # of logs[] elements */
struct dm_dev_log_health_s {
dm_status_mirror_health_t health;
uint32_t major;
uint32_t minor;
} *logs; /* array with individual logs */
};
int dm_get_status_mirror(struct dm_pool *mem, const char *params,
struct dm_status_mirror **status);
/* Parse params from STATUS call for raid target */
struct dm_status_raid {
uint64_t reserved;
uint64_t total_regions; /* sectors */
uint64_t insync_regions; /* sectors */
uint64_t mismatch_count;
uint32_t dev_count;
char *raid_type;
/* A - alive, a - alive not in-sync, D - dead/failed */
char *dev_health;
/* idle, frozen, resync, recover, check, repair */
char *sync_action;
uint64_t data_offset; /* RAID out-of-place reshaping */
};
int dm_get_status_raid(struct dm_pool *mem, const char *params,
struct dm_status_raid **status);
/* Parse params from STATUS call for cache target */
struct dm_status_cache {
uint64_t version; /* zero for now */
uint32_t metadata_block_size; /* in 512B sectors */
uint32_t block_size; /* AKA 'chunk_size' */
uint64_t metadata_used_blocks;
uint64_t metadata_total_blocks;
uint64_t used_blocks;
uint64_t dirty_blocks;
uint64_t total_blocks;
uint64_t read_hits;
uint64_t read_misses;
uint64_t write_hits;
uint64_t write_misses;
uint64_t demotions;
uint64_t promotions;
uint64_t feature_flags; /* DM_CACHE_FEATURE_? */
int core_argc;
char **core_argv;
char *policy_name;
int policy_argc;
char **policy_argv;
unsigned error : 1; /* detected error (switches to fail soon) */
unsigned fail : 1; /* all I/O fails */
unsigned needs_check : 1; /* metadata needs check */
unsigned read_only : 1; /* metadata may not be changed */
uint32_t reserved : 28;
};
int dm_get_status_cache(struct dm_pool *mem, const char *params,
struct dm_status_cache **status);
/*
* Parse params from STATUS call for snapshot target
*
* Snapshot target's format:
* <= 1.7.0: <used_sectors>/<total_sectors>
* >= 1.8.0: <used_sectors>/<total_sectors> <metadata_sectors>
*/
struct dm_status_snapshot {
uint64_t used_sectors; /* in 512b units */
uint64_t total_sectors;
uint64_t metadata_sectors;
unsigned has_metadata_sectors : 1; /* set when metadata_sectors is present */
unsigned invalid : 1; /* set when snapshot is invalidated */
unsigned merge_failed : 1; /* set when snapshot merge failed */
unsigned overflow : 1; /* set when snapshot overflows */
};
int dm_get_status_snapshot(struct dm_pool *mem, const char *params,
struct dm_status_snapshot **status);
/* Parse params from STATUS call for thin_pool target */
typedef enum dm_thin_discards_e {
DM_THIN_DISCARDS_IGNORE,
DM_THIN_DISCARDS_NO_PASSDOWN,
DM_THIN_DISCARDS_PASSDOWN
} dm_thin_discards_t;
struct dm_status_thin_pool {
uint64_t transaction_id;
uint64_t used_metadata_blocks;
uint64_t total_metadata_blocks;
uint64_t used_data_blocks;
uint64_t total_data_blocks;
uint64_t held_metadata_root;
uint32_t read_only; /* metadata may not be changed */
dm_thin_discards_t discards;
uint32_t fail : 1; /* all I/O fails */
uint32_t error_if_no_space : 1; /* otherwise queue_if_no_space */
uint32_t out_of_data_space : 1; /* metadata may be changed, but data may not be allocated (no rw) */
uint32_t needs_check : 1; /* metadata needs check */
uint32_t error : 1; /* detected error (switches to fail soon) */
uint32_t reserved : 27;
};
int dm_get_status_thin_pool(struct dm_pool *mem, const char *params,
struct dm_status_thin_pool **status);
/* Parse params from STATUS call for thin target */
struct dm_status_thin {
uint64_t mapped_sectors;
uint64_t highest_mapped_sector;
uint32_t fail : 1; /* Thin volume fails I/O */
uint32_t reserved : 31;
};
int dm_get_status_thin(struct dm_pool *mem, const char *params,
struct dm_status_thin **status);
/*
* device-mapper statistics support
*/
/*
* Statistics handle.
*
* Operations on dm_stats objects include managing statistics regions
* and obtaining and manipulating current counter values from the
* kernel. Methods are provided to return baisc count values and to
* derive time-based metrics when a suitable interval estimate is
* provided.
*
* Internally the dm_stats handle contains a pointer to a table of one
* or more dm_stats_region objects representing the regions registered
* with the dm_stats_create_region() method. These in turn point to a
* table of one or more dm_stats_counters objects containing the
* counter sets for each defined area within the region:
*
* dm_stats->dm_stats_region[nr_regions]->dm_stats_counters[nr_areas]
*
* This structure is private to the library and may change in future
* versions: all users should make use of the public interface and treat
* the dm_stats type as an opaque handle.
*
* Regions and counter sets are stored in order of increasing region_id.
* Depending on region specifications and the sequence of create and
* delete operations this may not correspond to increasing sector
* number: users of the library should not assume that this is the case
* unless region creation is deliberately managed to ensure this (by
* always creating regions in strict order of ascending sector address).
*
* Regions may also overlap so the same sector range may be included in
* more than one region or area: applications should be prepared to deal
* with this or manage regions such that it does not occur.
*/
struct dm_stats;
/*
* Histogram handle.
*
* A histogram object represents the latency histogram values and bin
* boundaries of the histogram associated with a particular area.
*
* Operations on the handle allow the number of bins, bin boundaries,
* counts and relative proportions to be obtained as well as the
* conversion of a histogram or its bounds to a compact string
* representation.
*/
struct dm_histogram;
/*
* Allocate a dm_stats handle to use for subsequent device-mapper
* statistics operations. A program_id may be specified and will be
* used by default for subsequent operations on this handle.
*
* If program_id is NULL or the empty string a program_id will be
* automatically set to the value contained in /proc/self/comm.
*/
struct dm_stats *dm_stats_create(const char *program_id);
/*
* Bind a dm_stats handle to the specified device major and minor
* values. Any previous binding is cleared and any preexisting counter
* data contained in the handle is released.
*/
int dm_stats_bind_devno(struct dm_stats *dms, int major, int minor);
/*
* Bind a dm_stats handle to the specified device name.
* Any previous binding is cleared and any preexisting counter
* data contained in the handle is released.
*/
int dm_stats_bind_name(struct dm_stats *dms, const char *name);
/*
* Bind a dm_stats handle to the specified device UUID.
* Any previous binding is cleared and any preexisting counter
* data contained in the handle is released.
*/
int dm_stats_bind_uuid(struct dm_stats *dms, const char *uuid);
/*
* Bind a dm_stats handle to the device backing the file referenced
* by the specified file descriptor.
*
* File descriptor fd must reference a regular file, open for reading,
* in a local file system, backed by a device-mapper device, that
* supports the FIEMAP ioctl, and that returns data describing the
* physical location of extents.
*/
int dm_stats_bind_from_fd(struct dm_stats *dms, int fd);
/*
* Test whether the running kernel supports the precise_timestamps
* feature. Presence of this feature also implies histogram support.
* The library will check this call internally and fails any attempt
* to use nanosecond counters or histograms on kernels that fail to
* meet this check.
*/
int dm_message_supports_precise_timestamps(void);
/*
* Precise timetamps and histogram support.
*
* Test for the presence of precise_timestamps and histogram support.
*/
int dm_stats_driver_supports_precise(void);
int dm_stats_driver_supports_histogram(void);
/*
* Returns 1 if the specified region has the precise_timestamps feature
* enabled (i.e. produces nanosecond-precision counter values) or 0 for
* a region using the default milisecond precision.
*/
int dm_stats_get_region_precise_timestamps(const struct dm_stats *dms,
uint64_t region_id);
/*
* Returns 1 if the region at the current cursor location has the
* precise_timestamps feature enabled (i.e. produces
* nanosecond-precision counter values) or 0 for a region using the
* default milisecond precision.
*/
int dm_stats_get_current_region_precise_timestamps(const struct dm_stats *dms);
#define DM_STATS_ALL_PROGRAMS ""
/*
* Parse the response from a @stats_list message. dm_stats_list will
* allocate the necessary dm_stats and dm_stats region structures from
* the embedded dm_pool. No counter data will be obtained (the counters
* members of dm_stats_region objects are set to NULL).
*
* A program_id may optionally be supplied; if the argument is non-NULL
* only regions with a matching program_id value will be considered. If
* the argument is NULL then the default program_id associated with the
* dm_stats handle will be used. Passing the special value
* DM_STATS_ALL_PROGRAMS will cause all regions to be queried
* regardless of region program_id.
*/
int dm_stats_list(struct dm_stats *dms, const char *program_id);
#define DM_STATS_REGIONS_ALL UINT64_MAX
/*
* Populate a dm_stats object with statistics for one or more regions of
* the specified device.
*
* A program_id may optionally be supplied; if the argument is non-NULL
* only regions with a matching program_id value will be considered. If
* the argument is NULL then the default program_id associated with the
* dm_stats handle will be used. Passing the special value
* DM_STATS_ALL_PROGRAMS will cause all regions to be queried
* regardless of region program_id.
*
* Passing the special value DM_STATS_REGIONS_ALL as the region_id
* argument will attempt to retrieve all regions selected by the
* program_id argument.
*
* If region_id is used to request a single region_id to be populated
* the program_id is ignored.
*/
int dm_stats_populate(struct dm_stats *dms, const char *program_id,
uint64_t region_id);
/*
* Create a new statistics region on the device bound to dms.
*
* start and len specify the region start and length in 512b sectors.
* Passing zero for both start and len will create a region spanning
* the entire device.
*
* Step determines how to subdivide the region into discrete counter
* sets: a positive value specifies the size of areas into which the
* region should be split while a negative value will split the region
* into a number of areas equal to the absolute value of step:
*
* - a region with one area spanning the entire device:
*
* dm_stats_create_region(dms, 0, 0, -1, p, a);
*
* - a region with areas of 1MiB:
*
* dm_stats_create_region(dms, 0, 0, 1 << 11, p, a);
*
* - one 1MiB region starting at 1024 sectors with two areas:
*
* dm_stats_create_region(dms, 1024, 1 << 11, -2, p, a);
*
* If precise is non-zero attempt to create a region with nanosecond
* precision counters using the kernel precise_timestamps feature.
*
* precise - A flag to request nanosecond precision counters
* to be used for this region.
*
* histogram_bounds - specify the boundaries of a latency histogram to
* be tracked for the region. The values are expressed as an array of
* uint64_t terminated with a zero. Values must be in order of ascending
* magnitude and specify the upper bounds of successive histogram bins
* in nanoseconds (with an implicit lower bound of zero on the first bin
* and an implicit upper bound of infinity on the final bin). For
* example:
*
* uint64_t bounds_ary[] = { 1000, 2000, 3000, 0 };
*
* Specifies a histogram with four bins: 0-1000ns, 1000-2000ns,
* 2000-3000ns and >3000ns.
*
* The smallest latency value that can be tracked for a region not using
* precise_timestamps is 1ms: attempting to create a region with
* histogram boundaries < 1ms will cause the precise_timestamps feature
* to be enabled for that region automatically if it was not requested
* explicitly.
*
* program_id is an optional string argument that identifies the
* program creating the region. If program_id is NULL or the empty
* string the default program_id stored in the handle will be used.
*
* user_data is an optional string argument that is added to the
* content of the aux_data field stored with the statistics region by
* the kernel.
*
* The library may also use this space internally, for example, to
* store a group descriptor or other metadata: in this case the
* library will strip any internal data fields from the value before
* it is returned via a call to dm_stats_get_region_aux_data().
*
* The user data stored is not accessed by the library or kernel and
* may be used to store an arbitrary data word (embedded whitespace is
* not permitted).
*
* An application using both the library and direct access to the
* @stats_list device-mapper message may see the internal values stored
* in this field by the library. In such cases any string up to and
* including the first '#' in the field must be treated as an opaque
* value and preserved across any external modification of aux_data.
*
* The region_id of the newly-created region is returned in *region_id
* if it is non-NULL.
*/
int dm_stats_create_region(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
int precise, struct dm_histogram *bounds,
const char *program_id, const char *user_data);
/*
* Delete the specified statistics region. This will also mark the
* region as not-present and discard any existing statistics data.
*/
int dm_stats_delete_region(struct dm_stats *dms, uint64_t region_id);
/*
* Clear the specified statistics region. This requests the kernel to
* zero all counter values (except in-flight I/O). Note that this
* operation is not atomic with respect to reads of the counters; any IO
* events occurring between the last print operation and the clear will
* be lost. This can be avoided by using the atomic print-and-clear
* function of the dm_stats_print_region() call or by using the higher
* level dm_stats_populate() interface.
*/
int dm_stats_clear_region(struct dm_stats *dms, uint64_t region_id);
/*
* Print the current counter values for the specified statistics region
* and return them as a string. The memory for the string buffer will
* be allocated from the dm_stats handle's private pool and should be
* returned by calling dm_stats_buffer_destroy() when no longer
* required. The pointer will become invalid following any call that
* clears or reinitializes the handle (destroy, list, populate, bind).
*
* This allows applications that wish to access the raw message response
* to obtain it via a dm_stats handle; no parsing of the textual counter
* data is carried out by this function.
*
* Most users are recommended to use the dm_stats_populate() call
* instead since this will automatically parse the statistics data into
* numeric form accessible via the dm_stats_get_*() counter access
* methods.
*
* A subset of the data lines may be requested by setting the
* start_line and num_lines parameters. If both are zero all data
* lines are returned.
*
* If the clear parameter is non-zero the operation will also
* atomically reset all counter values to zero (except in-flight IO).
*/
char *dm_stats_print_region(struct dm_stats *dms, uint64_t region_id,
unsigned start_line, unsigned num_lines,
unsigned clear);
/*
* Destroy a statistics response buffer obtained from a call to
* dm_stats_print_region().
*/
void dm_stats_buffer_destroy(struct dm_stats *dms, char *buffer);
/*
* Determine the number of regions contained in a dm_stats handle
* following a dm_stats_list() or dm_stats_populate() call.
*
* The value returned is the number of registered regions visible with the
* progam_id value used for the list or populate operation and may not be
* equal to the highest present region_id (either due to program_id
* filtering or gaps in the sequence of region_id values).
*
* Always returns zero on an empty handle.
*/
uint64_t dm_stats_get_nr_regions(const struct dm_stats *dms);
/*
* Determine the number of groups contained in a dm_stats handle
* following a dm_stats_list() or dm_stats_populate() call.
*
* The value returned is the number of registered groups visible with the
* progam_id value used for the list or populate operation and may not be
* equal to the highest present group_id (either due to program_id
* filtering or gaps in the sequence of group_id values).
*
* Always returns zero on an empty handle.
*/
uint64_t dm_stats_get_nr_groups(const struct dm_stats *dms);
/*
* Test whether region_id is present in this dm_stats handle.
*/
int dm_stats_region_present(const struct dm_stats *dms, uint64_t region_id);
/*
* Returns the number of areas (counter sets) contained in the specified
* region_id of the supplied dm_stats handle.
*/
uint64_t dm_stats_get_region_nr_areas(const struct dm_stats *dms,
uint64_t region_id);
/*
* Returns the total number of areas (counter sets) in all regions of the
* given dm_stats object.
*/
uint64_t dm_stats_get_nr_areas(const struct dm_stats *dms);
/*
* Test whether group_id is present in this dm_stats handle.
*/
int dm_stats_group_present(const struct dm_stats *dms, uint64_t group_id);
/*
* Return the number of bins in the histogram configuration for the
* specified region or zero if no histogram specification is configured.
* Valid following a dm_stats_list() or dm_stats_populate() operation.
*/
int dm_stats_get_region_nr_histogram_bins(const struct dm_stats *dms,
uint64_t region_id);
/*
* Parse a histogram string with optional unit suffixes into a
* dm_histogram bounds description.
*
* A histogram string is a string of numbers "n1,n2,n3,..." that
* represent the boundaries of a histogram. The first and final bins
* have implicit lower and upper bounds of zero and infinity
* respectively and boundary values must occur in order of ascending
* magnitude. Unless a unit suffix is given all values are specified in
* nanoseconds.
*
* For example, if bounds_str="300,600,900", the region will be created
* with a histogram containing four bins. Each report will include four
* numbers a:b:c:d. a is the number of requests that took between 0 and
* 300ns to complete, b is the number of requests that took 300-600ns to
* complete, c is the number of requests that took 600-900ns to complete
* and d is the number of requests that took more than 900ns to
* complete.
*
* An optional unit suffix of 's', 'ms', 'us', or 'ns' may be used to
* specify units of seconds, miliseconds, microseconds, or nanoseconds:
*
* bounds_str="1ns,1us,1ms,1s"
* bounds_str="500us,1ms,1500us,2ms"
* bounds_str="200ms,400ms,600ms,800ms,1s"
*
* The smallest valid unit of time for a histogram specification depends
* on whether the region uses precise timestamps: for a region with the
* default milisecond precision the smallest possible histogram boundary
* magnitude is one milisecond: attempting to use a histogram with a
* boundary less than one milisecond when creating a region will cause
* the region to be created with the precise_timestamps feature enabled.
*
* On sucess a pointer to the struct dm_histogram representing the
* bounds values is returned, or NULL in the case of error. The returned
* pointer should be freed using dm_free() when no longer required.
*/
struct dm_histogram *dm_histogram_bounds_from_string(const char *bounds_str);
/*
* Parse a zero terminated array of uint64_t into a dm_histogram bounds
* description.
*
* Each value in the array specifies the upper bound of a bin in the
* latency histogram in nanoseconds. Values must appear in ascending
* order of magnitude.
*
* The smallest valid unit of time for a histogram specification depends
* on whether the region uses precise timestamps: for a region with the
* default milisecond precision the smallest possible histogram boundary
* magnitude is one milisecond: attempting to use a histogram with a
* boundary less than one milisecond when creating a region will cause
* the region to be created with the precise_timestamps feature enabled.
*/
struct dm_histogram *dm_histogram_bounds_from_uint64(const uint64_t *bounds);
/*
* Destroy the histogram bounds array obtained from a call to
* dm_histogram_bounds_from_string().
*/
void dm_histogram_bounds_destroy(struct dm_histogram *bounds);
/*
* Destroy a dm_stats object and all associated regions, counter
* sets and histograms.
*/
void dm_stats_destroy(struct dm_stats *dms);
/*
* Counter sampling interval
*/
/*
* Set the sampling interval for counter data to the specified value in
* either nanoseconds or milliseconds.
*
* The interval is used to calculate time-based metrics from the basic
* counter data: an interval must be set before calling any of the
* metric methods.
*
* For best accuracy the duration should be measured and updated at the
* end of each interval.
*
* All values are stored internally with nanosecond precision and are
* converted to or from ms when the millisecond interfaces are used.
*/
void dm_stats_set_sampling_interval_ns(struct dm_stats *dms,
uint64_t interval_ns);
void dm_stats_set_sampling_interval_ms(struct dm_stats *dms,
uint64_t interval_ms);
/*
* Retrieve the configured sampling interval in either nanoseconds or
* milliseconds.
*/
uint64_t dm_stats_get_sampling_interval_ns(const struct dm_stats *dms);
uint64_t dm_stats_get_sampling_interval_ms(const struct dm_stats *dms);
/*
* Override program_id. This may be used to change the default
* program_id value for an existing handle. If the allow_empty argument
* is non-zero a NULL or empty program_id is permitted.
*
* Use with caution! Most users of the library should set a valid,
* non-NULL program_id for every statistics region created. Failing to
* do so may result in confusing state when multiple programs are
* creating and managing statistics regions.
*
* All users of the library are encouraged to choose an unambiguous,
* unique program_id: this could be based on PID (for programs that
* create, report, and delete regions in a single process), session id,
* executable name, or some other distinguishing string.
*
* Use of the empty string as a program_id does not simplify use of the
* library or the command line tools and use of this value is strongly
* discouraged.
*/
int dm_stats_set_program_id(struct dm_stats *dms, int allow_empty,
const char *program_id);
/*
* Region properties: size, length & area_len.
*
* Region start and length are returned in units of 512b as specified
* at region creation time. The area_len value gives the size of areas
* into which the region has been subdivided. For regions with a single
* area spanning the range this value is equal to the region length.
*
* For regions created with a specified number of areas the value
* represents the size of the areas into which the kernel divided the
* region excluding any rounding of the last area size. The number of
* areas may be obtained using the dm_stats_nr_areas_region() call.
*
* All values are returned in units of 512b sectors.
*/
int dm_stats_get_region_start(const struct dm_stats *dms, uint64_t *start,
uint64_t region_id);
int dm_stats_get_region_len(const struct dm_stats *dms, uint64_t *len,
uint64_t region_id);
int dm_stats_get_region_area_len(const struct dm_stats *dms,
uint64_t *len, uint64_t region_id);
/*
* Area properties: start, offset and length.
*
* The area length is always equal to the area length of the region
* that contains it and is obtained from dm_stats_get_region_area_len().
*
* The start of an area is a function of the area_id and the containing
* region's start and area length: it gives the absolute offset into the
* containing device of the beginning of the area.
*
* The offset expresses the area's relative offset into the current
* region. I.e. the area start minus the start offset of the containing
* region.
*
* All values are returned in units of 512b sectors.
*/
int dm_stats_get_area_start(const struct dm_stats *dms, uint64_t *start,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_area_offset(const struct dm_stats *dms, uint64_t *offset,
uint64_t region_id, uint64_t area_id);
/*
* Retrieve program_id and user aux_data for a specific region.
*
* Only valid following a call to dm_stats_list().
*/
/*
* Retrieve program_id for the specified region.
*
* The returned pointer does not need to be freed separately from the
* dm_stats handle but will become invalid after a dm_stats_destroy(),
* dm_stats_list(), dm_stats_populate(), or dm_stats_bind*() of the
* handle from which it was obtained.
*/
const char *dm_stats_get_region_program_id(const struct dm_stats *dms,
uint64_t region_id);
/*
* Retrieve user aux_data set for the specified region. This function
* will return any stored user aux_data as a string in the memory
* pointed to by the aux_data argument.
*
* Any library internal aux_data fields, such as DMS_GROUP descriptors,
* are stripped before the value is returned.
*
* The returned pointer does not need to be freed separately from the
* dm_stats handle but will become invalid after a dm_stats_destroy(),
* dm_stats_list(), dm_stats_populate(), or dm_stats_bind*() of the
* handle from which it was obtained.
*/
const char *dm_stats_get_region_aux_data(const struct dm_stats *dms,
uint64_t region_id);
typedef enum dm_stats_obj_type_e {
DM_STATS_OBJECT_TYPE_NONE,
DM_STATS_OBJECT_TYPE_AREA,
DM_STATS_OBJECT_TYPE_REGION,
DM_STATS_OBJECT_TYPE_GROUP
} dm_stats_obj_type_t;
/*
* Statistics cursor
*
* A dm_stats handle maintains an optional cursor into the statistics
* tables that it stores. Iterators are provided to visit each region,
* area, or group in a handle and accessor methods are provided to
* obtain properties and values for the object at the current cursor
* position.
*
* Using the cursor simplifies walking all regions or groups when
* the tables are sparse (i.e. contains some present and some
* non-present region_id or group_id values either due to program_id
* filtering or the ordering of region and group creation and deletion).
*
* Simple macros are provided to visit each area, region, or group,
* contained in a handle and applications are encouraged to use these
* where possible.
*/
/*
* Walk flags are used to initialise a dm_stats handle's cursor control
* and to select region or group aggregation when calling a metric or
* counter property method with immediate group, region, and area ID
* values.
*
* Walk flags are stored in the uppermost word of a uint64_t so that
* a region_id or group_id may be encoded in the lower bits. This
* allows an aggregate region_id or group_id to be specified when
* retrieving counter or metric values.
*
* Flags may be ORred together when used to initialise a dm_stats_walk:
* the resulting walk will visit instance of each type specified by
* the flag combination.
*/
#define DM_STATS_WALK_AREA 0x1000000000000ULL
#define DM_STATS_WALK_REGION 0x2000000000000ULL
#define DM_STATS_WALK_GROUP 0x4000000000000ULL
#define DM_STATS_WALK_ALL 0x7000000000000ULL
#define DM_STATS_WALK_DEFAULT (DM_STATS_WALK_AREA | DM_STATS_WALK_REGION)
/*
* Skip regions from a DM_STATS_WALK_REGION that contain only a single
* area: in this case the region's aggregate values are identical to
* the values of the single contained area. Setting this flag will
* suppress these duplicate entries during a dm_stats_walk_* with the
* DM_STATS_WALK_REGION flag set.
*/
#define DM_STATS_WALK_SKIP_SINGLE_AREA 0x8000000000000ULL
/*
* Initialise the cursor control of a dm_stats handle for the specified
* walk type(s). Including a walk flag in the flags argument will cause
* any subsequent walk to visit that type of object (until the next
* call to dm_stats_walk_init()).
*/
int dm_stats_walk_init(struct dm_stats *dms, uint64_t flags);
/*
* Set the cursor of a dm_stats handle to address the first present
* group, region, or area of the currently configured walk. It is
* valid to attempt to walk a NULL stats handle or a handle containing
* no present regions; in this case any call to dm_stats_walk_next()
* becomes a no-op and all calls to dm_stats_walk_end() return true.
*/
void dm_stats_walk_start(struct dm_stats *dms);
/*
* Advance the statistics cursor to the next area, or to the next
* present region if at the end of the current region. If the end of
* the region, area, or group tables is reached a subsequent call to
* dm_stats_walk_end() will return 1 and dm_stats_object_type() called
* on the location will return DM_STATS_OBJECT_TYPE_NONE,
*/
void dm_stats_walk_next(struct dm_stats *dms);
/*
* Force the statistics cursor to advance to the next region. This will
* stop any in-progress area walk (by clearing DM_STATS_WALK_AREA) and
* advance the cursor to the next present region, the first present
* group (if DM_STATS_GROUP_WALK is set), or to the end. In this case a
* subsequent call to dm_stats_walk_end() will return 1 and a call to
* dm_stats_object_type() for the location will return
* DM_STATS_OBJECT_TYPE_NONE.
*/
void dm_stats_walk_next_region(struct dm_stats *dms);
/*
* Test whether the end of a statistics walk has been reached.
*/
int dm_stats_walk_end(struct dm_stats *dms);
/*
* Return the type of object at the location specified by region_id
* and area_id. If either region_id or area_id uses one of the special
* values DM_STATS_REGION_CURRENT or DM_STATS_AREA_CURRENT the
* corresponding region or area identifier will be taken from the
* current cursor location. If the cursor location or the value encoded
* by region_id and area_id indicates an aggregate region or group,
* this will be reflected in the value returned.
*/
dm_stats_obj_type_t dm_stats_object_type(const struct dm_stats *dms,
uint64_t region_id,
uint64_t area_id);
/*
* Return the type of object at the current stats cursor location.
*/
dm_stats_obj_type_t dm_stats_current_object_type(const struct dm_stats *dms);
/*
* Stats iterators
*
* C 'for' and 'do'/'while' style iterators for dm_stats data.
*
* It is not safe to call any function that modifies the region table
* within the loop body (i.e. dm_stats_list(), dm_stats_populate(),
* dm_stats_init(), or dm_stats_destroy()).
*
* All counter and property (dm_stats_get_*) access methods, as well as
* dm_stats_populate_region() can be safely called from loops.
*
*/
/*
* Iterate over the regions table visiting each region.
*
* If the region table is empty or unpopulated the loop body will not be
* executed.
*/
#define dm_stats_foreach_region(dms) \
for (dm_stats_walk_init((dms), DM_STATS_WALK_REGION), \
dm_stats_walk_start((dms)); \
!dm_stats_walk_end((dms)); dm_stats_walk_next_region((dms)))
/*
* Iterate over the regions table visiting each area.
*
* If the region table is empty or unpopulated the loop body will not
* be executed.
*/
#define dm_stats_foreach_area(dms) \
for (dm_stats_walk_init((dms), DM_STATS_WALK_AREA), \
dm_stats_walk_start((dms)); \
!dm_stats_walk_end((dms)); dm_stats_walk_next((dms)))
/*
* Iterate over the regions table visiting each group. Metric and
* counter methods will return values for the group.
*
* If the group table is empty or unpopulated the loop body will not
* be executed.
*/
#define dm_stats_foreach_group(dms) \
for (dm_stats_walk_init((dms), DM_STATS_WALK_GROUP), \
dm_stats_walk_start(dms); \
!dm_stats_walk_end(dms); \
dm_stats_walk_next(dms))
/*
* Start a walk iterating over the regions contained in dm_stats handle
* 'dms'.
*
* The body of the loop should call dm_stats_walk_next() or
* dm_stats_walk_next_region() to advance to the next element.
*
* The loop body is executed at least once even if the stats handle is
* empty.
*/
#define dm_stats_walk_do(dms) \
do { \
dm_stats_walk_start((dms)); \
do
/*
* Start a 'while' style loop or end a 'do..while' loop iterating over the
* regions contained in dm_stats handle 'dms'.
*/
#define dm_stats_walk_while(dms) \
while(!dm_stats_walk_end((dms))); \
} while (0)
/*
* Cursor relative property methods
*
* Calls with the prefix dm_stats_get_current_* operate relative to the
* current cursor location, returning properties for the current region
* or area of the supplied dm_stats handle.
*
*/
/*
* Returns the number of areas (counter sets) contained in the current
* region of the supplied dm_stats handle.
*/
uint64_t dm_stats_get_current_nr_areas(const struct dm_stats *dms);
/*
* Retrieve the current values of the stats cursor.
*/
uint64_t dm_stats_get_current_region(const struct dm_stats *dms);
uint64_t dm_stats_get_current_area(const struct dm_stats *dms);
/*
* Current region properties: size, length & area_len.
*
* See the comments for the equivalent dm_stats_get_* versions for a
* complete description of these methods.
*
* All values are returned in units of 512b sectors.
*/
int dm_stats_get_current_region_start(const struct dm_stats *dms,
uint64_t *start);
int dm_stats_get_current_region_len(const struct dm_stats *dms,
uint64_t *len);
int dm_stats_get_current_region_area_len(const struct dm_stats *dms,
uint64_t *area_len);
/*
* Current area properties: start and length.
*
* See the comments for the equivalent dm_stats_get_* versions for a
* complete description of these methods.
*
* All values are returned in units of 512b sectors.
*/
int dm_stats_get_current_area_start(const struct dm_stats *dms,
uint64_t *start);
int dm_stats_get_current_area_offset(const struct dm_stats *dms,
uint64_t *offset);
int dm_stats_get_current_area_len(const struct dm_stats *dms,
uint64_t *start);
/*
* Return a pointer to the program_id string for region at the current
* cursor location.
*/
const char *dm_stats_get_current_region_program_id(const struct dm_stats *dms);
/*
* Return a pointer to the user aux_data string for the region at the
* current cursor location.
*/
const char *dm_stats_get_current_region_aux_data(const struct dm_stats *dms);
/*
* Statistics groups and data aggregation.
*/
/*
* Create a new group in stats handle dms from the group descriptor
* passed in group. The group descriptor is a string containing a list
* of region_id values that will be included in the group. The first
* region_id found will be the group leader. Ranges of identifiers may
* be expressed as "M-N", where M and N are the start and end region_id
* values for the range.
*/
int dm_stats_create_group(struct dm_stats *dms, const char *group,
const char *alias, uint64_t *group_id);
/*
* Remove the specified group_id. If the remove argument is zero the
* group will be removed but the regions that it contained will remain.
* If remove is non-zero then all regions that belong to the group will
* also be removed.
*/
int dm_stats_delete_group(struct dm_stats *dms, uint64_t group_id, int remove);
/*
* Set an alias for this group or region. The alias will be returned
* instead of the normal dm-stats name for this region or group.
*/
int dm_stats_set_alias(struct dm_stats *dms, uint64_t group_id,
const char *alias);
/*
* Returns a pointer to the currently configured alias for id, or the
* name of the dm device the handle is bound to if no alias has been
* set. The pointer will be freed automatically when a new alias is set
* or when the stats handle is cleared.
*/
const char *dm_stats_get_alias(const struct dm_stats *dms, uint64_t id);
#define DM_STATS_GROUP_NONE UINT64_MAX
/*
* Return the group_id that the specified region_id belongs to, or the
* special value DM_STATS_GROUP_NONE if the region does not belong
* to any group.
*/
uint64_t dm_stats_get_group_id(const struct dm_stats *dms, uint64_t region_id);
/*
* Store a pointer to a string describing the regions that are members
* of the group specified by group_id in the memory pointed to by buf.
* The string is in the same format as the 'group' argument to
* dm_stats_create_group().
*
* The pointer does not need to be freed explicitly by the caller: it
* will become invalid following a subsequent dm_stats_list(),
* dm_stats_populate() or dm_stats_destroy() of the corresponding
* dm_stats handle.
*/
int dm_stats_get_group_descriptor(const struct dm_stats *dms,
uint64_t group_id, char **buf);
/*
* Create regions that correspond to the extents of a file in the
* filesystem and optionally place them into a group.
*
* File descriptor fd must reference a regular file, open for reading,
* in a local file system that supports the FIEMAP ioctl, and that
* returns data describing the physical location of extents.
*
* The file descriptor can be closed by the caller following the call
* to dm_stats_create_regions_from_fd().
*
* Unless nogroup is non-zero the regions will be placed into a group
* and the group alias set to the value supplied (if alias is NULL no
* group alias will be assigned).
*
* On success the function returns a pointer to an array of uint64_t
* containing the IDs of the newly created regions. The region_id
* array is terminated by the value DM_STATS_REGION_NOT_PRESENT and
* should be freed using dm_free() when no longer required.
*
* On error NULL is returned.
*
* Following a call to dm_stats_create_regions_from_fd() the handle
* is guaranteed to be in a listed state, and to contain any region
* and group identifiers created by the operation.
*
* The group_id for the new group is equal to the region_id value in
* the first array element.
*/
uint64_t *dm_stats_create_regions_from_fd(struct dm_stats *dms, int fd,
int group, int precise,
struct dm_histogram *bounds,
const char *alias);
/*
* Update a group of regions that correspond to the extents of a file
* in the filesystem, adding and removing regions to account for
* allocation changes in the underlying file.
*
* File descriptor fd must reference a regular file, open for reading,
* in a local file system that supports the FIEMAP ioctl, and that
* returns data describing the physical location of extents.
*
* The file descriptor can be closed by the caller following the call
* to dm_stats_update_regions_from_fd().
*
* On success the function returns a pointer to an array of uint64_t
* containing the IDs of the updated regions (including any existing
* regions that were not modified by the call).
*
* The region_id array is terminated by the special value
* DM_STATS_REGION_NOT_PRESENT and should be freed using dm_free()
* when no longer required.
*
* On error NULL is returned.
*
* Following a call to dm_stats_update_regions_from_fd() the handle
* is guaranteed to be in a listed state, and to contain any region
* and group identifiers created by the operation.
*
* This function cannot be used with file mapped regions that are
* not members of a group: either group the regions, or remove them
* and re-map them with dm_stats_create_regions_from_fd().
*/
uint64_t *dm_stats_update_regions_from_fd(struct dm_stats *dms, int fd,
uint64_t group_id);
/*
* The file map monitoring daemon can monitor files in two distinct
* ways: the mode affects the behaviour of the daemon when a file
* under monitoring is renamed or unlinked, and the conditions which
* cause the daemon to terminate.
*
* In both modes, the daemon will always shut down when the group
* being monitored is deleted.
*
* Follow inode:
* The daemon follows the inode of the file, as it was at the time the
* daemon started. The file descriptor referencing the file is kept
* open at all times, and the daemon will exit when it detects that
* the file has been unlinked and it is the last holder of a reference
* to the file.
*
* This mode is useful if the file is expected to be renamed, or moved
* within the file system, while it is being monitored.
*
* Follow path:
* The daemon follows the path that was given on the daemon command
* line. The file descriptor referencing the file is re-opened on each
* iteration of the daemon, and the daemon will exit if no file exists
* at this location (a tolerance is allowed so that a brief delay
* between unlink() and creat() is permitted).
*
* This mode is useful if the file is updated by unlinking the original
* and placing a new file at the same path.
*/
typedef enum dm_filemapd_mode_e {
DM_FILEMAPD_FOLLOW_INODE,
DM_FILEMAPD_FOLLOW_PATH,
DM_FILEMAPD_FOLLOW_NONE
} dm_filemapd_mode_t;
/*
* Parse a string representation of a dmfilemapd mode.
*
* Returns a valid dm_filemapd_mode_t value on success, or
* DM_FILEMAPD_FOLLOW_NONE on error.
*/
dm_filemapd_mode_t dm_filemapd_mode_from_string(const char *mode_str);
/*
* Start the dmfilemapd filemap monitoring daemon for the specified
* file descriptor, group, and file system path. The daemon will
* monitor the file for allocation changes, and when a change is
* detected, call dm_stats_update_regions_from_fd() to update the
* mapped regions for the file.
*
* The path provided to dm_stats_start_filemapd() must be an absolute
* path, and should reflect the path of 'fd' at the time that it was
* opened.
*
* The mode parameter controls the behaviour of the daemon when the
* file being monitored is unlinked or moved: see the comments for
* dm_filemapd_mode_t for a full description and possible values.
*
* The daemon can be stopped at any time by sending SIGTERM to the
* daemon pid.
*/
int dm_stats_start_filemapd(int fd, uint64_t group_id, const char *path,
dm_filemapd_mode_t mode, unsigned foreground,
unsigned verbose);
/*
* Call this to actually run the ioctl.
*/
int dm_task_run(struct dm_task *dmt);
/*
* The errno from the last device-mapper ioctl performed by dm_task_run.
*/
int dm_task_get_errno(struct dm_task *dmt);
/*
* Call this to make or remove the device nodes associated with previously
* issued commands.
*/
void dm_task_update_nodes(void);
/*
* Mangling support
*
* Character whitelist: 0-9, A-Z, a-z, #+-.:=@_
* HEX mangling format: \xNN, NN being the hex value of the character.
* (whitelist and format supported by udev)
*/
typedef enum dm_string_mangling_e {
DM_STRING_MANGLING_NONE, /* do not mangle at all */
DM_STRING_MANGLING_AUTO, /* mangle only if not already mangled with hex, error when mixed */
DM_STRING_MANGLING_HEX /* always mangle with hex encoding, no matter what the input is */
} dm_string_mangling_t;
/*
* Set/get mangling mode used for device-mapper names and uuids.
*/
int dm_set_name_mangling_mode(dm_string_mangling_t name_mangling);
dm_string_mangling_t dm_get_name_mangling_mode(void);
/*
* Get mangled/unmangled form of the device-mapper name or uuid
* irrespective of the global setting (set by dm_set_name_mangling_mode).
* The name or uuid returned needs to be freed after use by calling dm_free!
*/
char *dm_task_get_name_mangled(const struct dm_task *dmt);
char *dm_task_get_name_unmangled(const struct dm_task *dmt);
char *dm_task_get_uuid_mangled(const struct dm_task *dmt);
char *dm_task_get_uuid_unmangled(const struct dm_task *dmt);
/*
* Configure the device-mapper directory
*/
int dm_set_dev_dir(const char *dir);
const char *dm_dir(void);
/*
* Configure sysfs directory, /sys by default
*/
int dm_set_sysfs_dir(const char *dir);
const char *dm_sysfs_dir(void);
/*
* Configure default UUID prefix string.
* Conventionally this is a short capitalised prefix indicating the subsystem
* that is managing the devices, e.g. "LVM-" or "MPATH-".
* To support stacks of devices from different subsystems, recursive functions
* stop recursing if they reach a device with a different prefix.
*/
int dm_set_uuid_prefix(const char *uuid_prefix);
const char *dm_uuid_prefix(void);
/*
* Determine whether a major number belongs to device-mapper or not.
*/
int dm_is_dm_major(uint32_t major);
/*
* Get associated device name for given major and minor number by reading
* the sysfs content. If this is a dm device, get associated dm name, the one
* that appears in /dev/mapper. DM names could be resolved this way only if
* kernel used >= 2.6.29, kernel name is found otherwise (e.g. dm-0).
* If prefer_kernel_name is set, the kernel name is always preferred over
* device-mapper name for dm devices no matter what the kernel version is.
* For non-dm devices, we always get associated kernel name, e.g sda, md0 etc.
* Returns 0 on error or if sysfs is not used (or configured incorrectly),
* otherwise returns 1 and the supplied buffer holds the device name.
*/
int dm_device_get_name(uint32_t major, uint32_t minor,
int prefer_kernel_name,
char *buf, size_t buf_size);
/*
* Determine whether a device has any holders (devices
* using this device). If sysfs is not used (or configured
* incorrectly), returns 0.
*/
int dm_device_has_holders(uint32_t major, uint32_t minor);
/*
* Determine whether a device contains mounted filesystem.
* If sysfs is not used (or configured incorrectly), returns 0.
*/
int dm_device_has_mounted_fs(uint32_t major, uint32_t minor);
/*
* Callback is invoked for individal mountinfo lines,
* minor, major and mount target are parsed and unmangled.
*/
typedef int (*dm_mountinfo_line_callback_fn) (char *line, unsigned maj, unsigned min,
char *target, void *cb_data);
/*
* Read all lines from /proc/self/mountinfo,
* for each line calls read_fn callback.
*/
int dm_mountinfo_read(dm_mountinfo_line_callback_fn read_fn, void *cb_data);
/*
* Initialise library
*/
void dm_lib_init(void) __attribute__((constructor));
/*
* Release library resources
*/
void dm_lib_release(void);
void dm_lib_exit(void) __attribute__((destructor));
/* An optimisation for clients making repeated calls involving dm ioctls */
void dm_hold_control_dev(int hold_open);
/*
* Use NULL for all devices.
*/
int dm_mknodes(const char *name);
int dm_driver_version(char *version, size_t size);
/******************************************************
* Functions to build and manipulate trees of devices *
******************************************************/
struct dm_tree;
struct dm_tree_node;
/*
* Initialise an empty dependency tree.
*
* The tree consists of a root node together with one node for each mapped
* device which has child nodes for each device referenced in its table.
*
* Every node in the tree has one or more children and one or more parents.
*
* The root node is the parent/child of every node that doesn't have other
* parents/children.
*/
struct dm_tree *dm_tree_create(void);
void dm_tree_free(struct dm_tree *tree);
/*
* List of suffixes to be ignored when matching uuids against existing devices.
*/
void dm_tree_set_optional_uuid_suffixes(struct dm_tree *dtree, const char **optional_uuid_suffixes);
/*
* Add nodes to the tree for a given device and all the devices it uses.
*/
int dm_tree_add_dev(struct dm_tree *tree, uint32_t major, uint32_t minor);
int dm_tree_add_dev_with_udev_flags(struct dm_tree *tree, uint32_t major,
uint32_t minor, uint16_t udev_flags);
/*
* Add a new node to the tree if it doesn't already exist.
*/
struct dm_tree_node *dm_tree_add_new_dev(struct dm_tree *tree,
const char *name,
const char *uuid,
uint32_t major, uint32_t minor,
int read_only,
int clear_inactive,
void *context);
struct dm_tree_node *dm_tree_add_new_dev_with_udev_flags(struct dm_tree *tree,
const char *name,
const char *uuid,
uint32_t major,
uint32_t minor,
int read_only,
int clear_inactive,
void *context,
uint16_t udev_flags);
/*
* Search for a node in the tree.
* Set major and minor to 0 or uuid to NULL to get the root node.
*/
struct dm_tree_node *dm_tree_find_node(struct dm_tree *tree,
uint32_t major,
uint32_t minor);
struct dm_tree_node *dm_tree_find_node_by_uuid(struct dm_tree *tree,
const char *uuid);
/*
* Use this to walk through all children of a given node.
* Set handle to NULL in first call.
* Returns NULL after the last child.
* Set inverted to use inverted tree.
*/
struct dm_tree_node *dm_tree_next_child(void **handle,
const struct dm_tree_node *parent,
uint32_t inverted);
/*
* Get properties of a node.
*/
const char *dm_tree_node_get_name(const struct dm_tree_node *node);
const char *dm_tree_node_get_uuid(const struct dm_tree_node *node);
const struct dm_info *dm_tree_node_get_info(const struct dm_tree_node *node);
void *dm_tree_node_get_context(const struct dm_tree_node *node);
/*
* Returns 0 when node size and its children is unchanged.
* Returns 1 when node or any of its children has increased size.
* Rerurns -1 when node or any of its children has reduced size.
*/
int dm_tree_node_size_changed(const struct dm_tree_node *dnode);
/*
* Returns the number of children of the given node (excluding the root node).
* Set inverted for the number of parents.
*/
int dm_tree_node_num_children(const struct dm_tree_node *node, uint32_t inverted);
/*
* Deactivate a device plus all dependencies.
* Ignores devices that don't have a uuid starting with uuid_prefix.
*/
int dm_tree_deactivate_children(struct dm_tree_node *dnode,
const char *uuid_prefix,
size_t uuid_prefix_len);
/*
* Preload/create a device plus all dependencies.
* Ignores devices that don't have a uuid starting with uuid_prefix.
*/
int dm_tree_preload_children(struct dm_tree_node *dnode,
const char *uuid_prefix,
size_t uuid_prefix_len);
/*
* Resume a device plus all dependencies.
* Ignores devices that don't have a uuid starting with uuid_prefix.
*/
int dm_tree_activate_children(struct dm_tree_node *dnode,
const char *uuid_prefix,
size_t uuid_prefix_len);
/*
* Suspend a device plus all dependencies.
* Ignores devices that don't have a uuid starting with uuid_prefix.
*/
int dm_tree_suspend_children(struct dm_tree_node *dnode,
const char *uuid_prefix,
size_t uuid_prefix_len);
/*
* Skip the filesystem sync when suspending.
* Does nothing with other functions.
* Use this when no snapshots are involved.
*/
void dm_tree_skip_lockfs(struct dm_tree_node *dnode);
/*
* Set the 'noflush' flag when suspending devices.
* If the kernel supports it, instead of erroring outstanding I/O that
* cannot be completed, the I/O is queued and resubmitted when the
* device is resumed. This affects multipath devices when all paths
* have failed and queue_if_no_path is set, and mirror devices when
* block_on_error is set and the mirror log has failed.
*/
void dm_tree_use_no_flush_suspend(struct dm_tree_node *dnode);
/*
* Retry removal of each device if not successful.
*/
void dm_tree_retry_remove(struct dm_tree_node *dnode);
/*
* Is the uuid prefix present in the tree?
* Only returns 0 if every node was checked successfully.
* Returns 1 if the tree walk has to be aborted.
*/
int dm_tree_children_use_uuid(struct dm_tree_node *dnode,
const char *uuid_prefix,
size_t uuid_prefix_len);
/*
* Construct tables for new nodes before activating them.
*/
int dm_tree_node_add_snapshot_origin_target(struct dm_tree_node *dnode,
uint64_t size,
const char *origin_uuid);
int dm_tree_node_add_snapshot_target(struct dm_tree_node *node,
uint64_t size,
const char *origin_uuid,
const char *cow_uuid,
int persistent,
uint32_t chunk_size);
int dm_tree_node_add_snapshot_merge_target(struct dm_tree_node *node,
uint64_t size,
const char *origin_uuid,
const char *cow_uuid,
const char *merge_uuid,
uint32_t chunk_size);
int dm_tree_node_add_error_target(struct dm_tree_node *node,
uint64_t size);
int dm_tree_node_add_zero_target(struct dm_tree_node *node,
uint64_t size);
int dm_tree_node_add_linear_target(struct dm_tree_node *node,
uint64_t size);
int dm_tree_node_add_striped_target(struct dm_tree_node *node,
uint64_t size,
uint32_t stripe_size);
#define DM_CRYPT_IV_DEFAULT UINT64_C(-1) /* iv_offset == seg offset */
/*
* Function accepts one string in cipher specification
* (chainmode and iv should be NULL because included in cipher string)
* or
* separate arguments which will be joined to "cipher-chainmode-iv"
*/
int dm_tree_node_add_crypt_target(struct dm_tree_node *node,
uint64_t size,
const char *cipher,
const char *chainmode,
const char *iv,
uint64_t iv_offset,
const char *key);
int dm_tree_node_add_mirror_target(struct dm_tree_node *node,
uint64_t size);
/* Mirror log flags */
#define DM_NOSYNC 0x00000001 /* Known already in sync */
#define DM_FORCESYNC 0x00000002 /* Force resync */
#define DM_BLOCK_ON_ERROR 0x00000004 /* On error, suspend I/O */
#define DM_CORELOG 0x00000008 /* In-memory log */
int dm_tree_node_add_mirror_target_log(struct dm_tree_node *node,
uint32_t region_size,
unsigned clustered,
const char *log_uuid,
unsigned area_count,
uint32_t flags);
int dm_tree_node_add_raid_target(struct dm_tree_node *node,
uint64_t size,
const char *raid_type,
uint32_t region_size,
uint32_t stripe_size,
uint64_t rebuilds,
uint64_t flags);
/*
* Defines below are based on kernel's dm-cache.c defines
* DM_CACHE_MIN_DATA_BLOCK_SIZE (32 * 1024 >> SECTOR_SHIFT)
* DM_CACHE_MAX_DATA_BLOCK_SIZE (1024 * 1024 * 1024 >> SECTOR_SHIFT)
*/
#define DM_CACHE_MIN_DATA_BLOCK_SIZE (UINT32_C(64))
#define DM_CACHE_MAX_DATA_BLOCK_SIZE (UINT32_C(2097152))
/*
* Max supported size for cache pool metadata device.
* Limitation is hardcoded into the kernel and bigger device sizes
* are not accepted.
*
* Limit defined in drivers/md/dm-cache-metadata.h
*/
#define DM_CACHE_METADATA_MAX_SECTORS DM_THIN_METADATA_MAX_SECTORS
/*
* Define number of elements in rebuild and writemostly arrays
* 'of struct dm_tree_node_raid_params'.
*/
struct dm_tree_node_raid_params {
const char *raid_type;
uint32_t stripes;
uint32_t mirrors;
uint32_t region_size;
uint32_t stripe_size;
/*
* 'rebuilds' and 'writemostly' are bitfields that signify
* which devices in the array are to be rebuilt or marked
* writemostly. The kernel supports up to 253 legs.
* We limit ourselves by choosing a lower value
* for DEFAULT_RAID{1}_MAX_IMAGES in defaults.h.
*/
uint64_t rebuilds;
uint64_t writemostly;
uint32_t writebehind; /* I/Os (kernel default COUNTER_MAX / 2) */
uint32_t sync_daemon_sleep; /* ms (kernel default = 5sec) */
uint32_t max_recovery_rate; /* kB/sec/disk */
uint32_t min_recovery_rate; /* kB/sec/disk */
uint32_t stripe_cache; /* sectors */
uint64_t flags; /* [no]sync */
uint32_t reserved2;
};
/*
* Version 2 of above node raid params struct to keeep API compatibility.
*
* Extended for more than 64 legs (max 253 in the MD kernel runtime!),
* delta_disks for disk add/remove reshaping,
* data_offset for out-of-place reshaping
* and data_copies for odd number of raid10 legs.
*/
#define RAID_BITMAP_SIZE 4 /* 4 * 64 bit elements in rebuilds/writemostly arrays */
struct dm_tree_node_raid_params_v2 {
const char *raid_type;
uint32_t stripes;
uint32_t mirrors;
uint32_t region_size;
uint32_t stripe_size;
int delta_disks; /* +/- number of disks to add/remove (reshaping) */
int data_offset; /* data offset to set (out-of-place reshaping) */
/*
* 'rebuilds' and 'writemostly' are bitfields that signify
* which devices in the array are to be rebuilt or marked
* writemostly. The kernel supports up to 253 legs.
* We limit ourselvs by choosing a lower value
* for DEFAULT_RAID_MAX_IMAGES.
*/
uint64_t rebuilds[RAID_BITMAP_SIZE];
uint64_t writemostly[RAID_BITMAP_SIZE];
uint32_t writebehind; /* I/Os (kernel default COUNTER_MAX / 2) */
uint32_t data_copies; /* RAID # of data copies */
uint32_t sync_daemon_sleep; /* ms (kernel default = 5sec) */
uint32_t max_recovery_rate; /* kB/sec/disk */
uint32_t min_recovery_rate; /* kB/sec/disk */
uint32_t stripe_cache; /* sectors */
uint64_t flags; /* [no]sync */
};
int dm_tree_node_add_raid_target_with_params(struct dm_tree_node *node,
uint64_t size,
const struct dm_tree_node_raid_params *p);
/* Version 2 API function taking dm_tree_node_raid_params_v2 for aforementioned extensions. */
int dm_tree_node_add_raid_target_with_params_v2(struct dm_tree_node *node,
uint64_t size,
const struct dm_tree_node_raid_params_v2 *p);
/* Cache feature_flags */
#define DM_CACHE_FEATURE_WRITEBACK 0x00000001
#define DM_CACHE_FEATURE_WRITETHROUGH 0x00000002
#define DM_CACHE_FEATURE_PASSTHROUGH 0x00000004
#define DM_CACHE_FEATURE_METADATA2 0x00000008 /* cache v1.10 */
#define DM_CACHE_FEATURE_NO_DISCARD_PASSDOWN 0x00000010
struct dm_config_node;
/*
* Use for passing cache policy and all its args e.g.:
*
* policy_settings {
* migration_threshold=2048
* sequention_threashold=100
* ...
* }
*
* For policy without any parameters use NULL.
*/
int dm_tree_node_add_cache_target(struct dm_tree_node *node,
uint64_t size,
uint64_t feature_flags, /* DM_CACHE_FEATURE_* */
const char *metadata_uuid,
const char *data_uuid,
const char *origin_uuid,
const char *policy_name,
const struct dm_config_node *policy_settings,
uint32_t data_block_size);
/*
* FIXME Add individual cache policy pairs <key> = value, like:
* int dm_tree_node_add_cache_policy_arg(struct dm_tree_node *dnode,
* const char *key, uint64_t value);
*/
/*
* Replicator operation mode
* Note: API for Replicator is not yet stable
*/
typedef enum dm_replicator_mode_e {
DM_REPLICATOR_SYNC, /* Synchronous replication */
DM_REPLICATOR_ASYNC_WARN, /* Warn if async replicator is slow */
DM_REPLICATOR_ASYNC_STALL, /* Stall replicator if not fast enough */
DM_REPLICATOR_ASYNC_DROP, /* Drop sites out of sync */
DM_REPLICATOR_ASYNC_FAIL, /* Fail replicator if slow */
NUM_DM_REPLICATOR_MODES
} dm_replicator_mode_t;
int dm_tree_node_add_replicator_target(struct dm_tree_node *node,
uint64_t size,
const char *rlog_uuid,
const char *rlog_type,
unsigned rsite_index,
dm_replicator_mode_t mode,
uint32_t async_timeout,
uint64_t fall_behind_data,
uint32_t fall_behind_ios);
int dm_tree_node_add_replicator_dev_target(struct dm_tree_node *node,
uint64_t size,
const char *replicator_uuid, /* Replicator control device */
uint64_t rdevice_index,
const char *rdev_uuid, /* Rimage device name/uuid */
unsigned rsite_index,
const char *slog_uuid,
uint32_t slog_flags, /* Mirror log flags */
uint32_t slog_region_size);
/* End of Replicator API */
/*
* FIXME: Defines bellow are based on kernel's dm-thin.c defines
* DATA_DEV_BLOCK_SIZE_MIN_SECTORS (64 * 1024 >> SECTOR_SHIFT)
* DATA_DEV_BLOCK_SIZE_MAX_SECTORS (1024 * 1024 * 1024 >> SECTOR_SHIFT)
*/
#define DM_THIN_MIN_DATA_BLOCK_SIZE (UINT32_C(128))
#define DM_THIN_MAX_DATA_BLOCK_SIZE (UINT32_C(2097152))
/*
* Max supported size for thin pool metadata device (17045913600 bytes)
* drivers/md/dm-thin-metadata.h THIN_METADATA_MAX_SECTORS
* But here DM_THIN_MAX_METADATA_SIZE got defined incorrectly
* Correct size is (UINT64_C(255) * ((1 << 14) - 64) * (4096 / (1 << 9)))
*/
#define DM_THIN_MAX_METADATA_SIZE (UINT64_C(255) * (1 << 14) * (4096 / (1 << 9)) - 256 * 1024)
int dm_tree_node_add_thin_pool_target(struct dm_tree_node *node,
uint64_t size,
uint64_t transaction_id,
const char *metadata_uuid,
const char *pool_uuid,
uint32_t data_block_size,
uint64_t low_water_mark,
unsigned skip_block_zeroing);
int dm_tree_node_add_thin_pool_target_v1(struct dm_tree_node *node,
uint64_t size,
uint64_t transaction_id,
const char *metadata_uuid,
const char *pool_uuid,
uint32_t data_block_size,
uint64_t low_water_mark,
unsigned skip_block_zeroing,
unsigned crop_metadata);
/* Supported messages for thin provision target */
typedef enum dm_thin_message_e {
DM_THIN_MESSAGE_CREATE_SNAP, /* device_id, origin_id */
DM_THIN_MESSAGE_CREATE_THIN, /* device_id */
DM_THIN_MESSAGE_DELETE, /* device_id */
DM_THIN_MESSAGE_SET_TRANSACTION_ID, /* current_id, new_id */
DM_THIN_MESSAGE_RESERVE_METADATA_SNAP, /* target version >= 1.1 */
DM_THIN_MESSAGE_RELEASE_METADATA_SNAP, /* target version >= 1.1 */
} dm_thin_message_t;
int dm_tree_node_add_thin_pool_message(struct dm_tree_node *node,
dm_thin_message_t type,
uint64_t id1, uint64_t id2);
/*
* Set thin pool discard features
* ignore - Disable support for discards
* no_passdown - Don't pass discards down to underlying data device,
* just remove the mapping
* Feature is available since version 1.1 of the thin target.
*/
int dm_tree_node_set_thin_pool_discard(struct dm_tree_node *node,
unsigned ignore,
unsigned no_passdown);
/*
* Set error if no space, instead of queueing for thin pool.
*/
int dm_tree_node_set_thin_pool_error_if_no_space(struct dm_tree_node *node,
unsigned error_if_no_space);
/* Start thin pool with metadata in read-only mode */
int dm_tree_node_set_thin_pool_read_only(struct dm_tree_node *node,
unsigned read_only);
/*
* FIXME: Defines bellow are based on kernel's dm-thin.c defines
* MAX_DEV_ID ((1 << 24) - 1)
*/
#define DM_THIN_MAX_DEVICE_ID (UINT32_C((1 << 24) - 1))
int dm_tree_node_add_thin_target(struct dm_tree_node *node,
uint64_t size,
const char *pool_uuid,
uint32_t device_id);
int dm_tree_node_set_thin_external_origin(struct dm_tree_node *node,
const char *external_uuid);
void dm_tree_node_set_udev_flags(struct dm_tree_node *node, uint16_t udev_flags);
void dm_tree_node_set_presuspend_node(struct dm_tree_node *node,
struct dm_tree_node *presuspend_node);
int dm_tree_node_add_target_area(struct dm_tree_node *node,
const char *dev_name,
const char *dlid,
uint64_t offset);
/*
* Only for temporarily-missing raid devices where changes are tracked.
*/
int dm_tree_node_add_null_area(struct dm_tree_node *node, uint64_t offset);
/*
* Set readahead (in sectors) after loading the node.
*/
void dm_tree_node_set_read_ahead(struct dm_tree_node *dnode,
uint32_t read_ahead,
uint32_t read_ahead_flags);
/*
* Set node callback hook before de/activation.
* Callback is called before 'activation' of node for activation tree,
* or 'deactivation' of node for deactivation tree.
*/
typedef enum dm_node_callback_e {
DM_NODE_CALLBACK_PRELOADED, /* Node has preload deps */
DM_NODE_CALLBACK_DEACTIVATED, /* Node is deactivated */
} dm_node_callback_t;
typedef int (*dm_node_callback_fn) (struct dm_tree_node *node,
dm_node_callback_t type, void *cb_data);
void dm_tree_node_set_callback(struct dm_tree_node *node,
dm_node_callback_fn cb, void *cb_data);
void dm_tree_set_cookie(struct dm_tree_node *node, uint32_t cookie);
uint32_t dm_tree_get_cookie(struct dm_tree_node *node);
/*****************************************************************************
* Library functions
*****************************************************************************/
/*******************
* Memory management
*******************/
/*
* Never use these functions directly - use the macros following instead.
*/
void *dm_malloc_wrapper(size_t s, const char *file, int line)
__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void *dm_malloc_aligned_wrapper(size_t s, size_t a, const char *file, int line)
__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void *dm_zalloc_wrapper(size_t s, const char *file, int line)
__attribute__((__malloc__)) __attribute__((__warn_unused_result__));
void *dm_realloc_wrapper(void *p, unsigned int s, const char *file, int line)
__attribute__((__warn_unused_result__));
void dm_free_wrapper(void *ptr);
char *dm_strdup_wrapper(const char *s, const char *file, int line)
__attribute__((__warn_unused_result__));
int dm_dump_memory_wrapper(void);
void dm_bounds_check_wrapper(void);
#define dm_malloc(s) dm_malloc_wrapper((s), __FILE__, __LINE__)
#define dm_malloc_aligned(s, a) dm_malloc_aligned_wrapper((s), (a), __FILE__, __LINE__)
#define dm_zalloc(s) dm_zalloc_wrapper((s), __FILE__, __LINE__)
#define dm_strdup(s) dm_strdup_wrapper((s), __FILE__, __LINE__)
#define dm_free(p) dm_free_wrapper(p)
#define dm_realloc(p, s) dm_realloc_wrapper((p), (s), __FILE__, __LINE__)
#define dm_dump_memory() dm_dump_memory_wrapper()
#define dm_bounds_check() dm_bounds_check_wrapper()
/*
* The pool allocator is useful when you are going to allocate
* lots of memory, use the memory for a bit, and then free the
* memory in one go. A surprising amount of code has this usage
* profile.
*
* You should think of the pool as an infinite, contiguous chunk
* of memory. The front of this chunk of memory contains
* allocated objects, the second half is free. dm_pool_alloc grabs
* the next 'size' bytes from the free half, in effect moving it
* into the allocated half. This operation is very efficient.
*
* dm_pool_free frees the allocated object *and* all objects
* allocated after it. It is important to note this semantic
* difference from malloc/free. This is also extremely
* efficient, since a single dm_pool_free can dispose of a large
* complex object.
*
* dm_pool_destroy frees all allocated memory.
*
* eg, If you are building a binary tree in your program, and
* know that you are only ever going to insert into your tree,
* and not delete (eg, maintaining a symbol table for a
* compiler). You can create yourself a pool, allocate the nodes
* from it, and when the tree becomes redundant call dm_pool_destroy
* (no nasty iterating through the tree to free nodes).
*
* eg, On the other hand if you wanted to repeatedly insert and
* remove objects into the tree, you would be better off
* allocating the nodes from a free list; you cannot free a
* single arbitrary node with pool.
*/
struct dm_pool;
/* constructor and destructor */
struct dm_pool *dm_pool_create(const char *name, size_t chunk_hint)
__attribute__((__warn_unused_result__));
void dm_pool_destroy(struct dm_pool *p);
/* simple allocation/free routines */
void *dm_pool_alloc(struct dm_pool *p, size_t s)
__attribute__((__warn_unused_result__));
void *dm_pool_alloc_aligned(struct dm_pool *p, size_t s, unsigned alignment)
__attribute__((__warn_unused_result__));
void dm_pool_empty(struct dm_pool *p);
void dm_pool_free(struct dm_pool *p, void *ptr);
/*
* To aid debugging, a pool can be locked. Any modifications made
* to the content of the pool while it is locked can be detected.
* Default compilation is using a crc checksum to notice modifications.
* The pool locking is using the mprotect with the compilation flag
* DEBUG_ENFORCE_POOL_LOCKING to enforce the memory protection.
*/
/* query pool lock status */
int dm_pool_locked(struct dm_pool *p);
/* mark pool as locked */
int dm_pool_lock(struct dm_pool *p, int crc)
__attribute__((__warn_unused_result__));
/* mark pool as unlocked */
int dm_pool_unlock(struct dm_pool *p, int crc)
__attribute__((__warn_unused_result__));
/*
* Object building routines:
*
* These allow you to 'grow' an object, useful for
* building strings, or filling in dynamic
* arrays.
*
* It's probably best explained with an example:
*
* char *build_string(struct dm_pool *mem)
* {
* int i;
* char buffer[16];
*
* if (!dm_pool_begin_object(mem, 128))
* return NULL;
*
* for (i = 0; i < 50; i++) {
* snprintf(buffer, sizeof(buffer), "%d, ", i);
* if (!dm_pool_grow_object(mem, buffer, 0))
* goto bad;
* }
*
* // add null
* if (!dm_pool_grow_object(mem, "\0", 1))
* goto bad;
*
* return dm_pool_end_object(mem);
*
* bad:
*
* dm_pool_abandon_object(mem);
* return NULL;
*}
*
* So start an object by calling dm_pool_begin_object
* with a guess at the final object size - if in
* doubt make the guess too small.
*
* Then append chunks of data to your object with
* dm_pool_grow_object. Finally get your object with
* a call to dm_pool_end_object.
*
* Setting delta to 0 means it will use strlen(extra).
*/
int dm_pool_begin_object(struct dm_pool *p, size_t hint);
int dm_pool_grow_object(struct dm_pool *p, const void *extra, size_t delta);
void *dm_pool_end_object(struct dm_pool *p);
void dm_pool_abandon_object(struct dm_pool *p);
/* utilities */
char *dm_pool_strdup(struct dm_pool *p, const char *str)
__attribute__((__warn_unused_result__));
char *dm_pool_strndup(struct dm_pool *p, const char *str, size_t n)
__attribute__((__warn_unused_result__));
void *dm_pool_zalloc(struct dm_pool *p, size_t s)
__attribute__((__warn_unused_result__));
/******************
* bitset functions
******************/
typedef uint32_t *dm_bitset_t;
dm_bitset_t dm_bitset_create(struct dm_pool *mem, unsigned num_bits);
void dm_bitset_destroy(dm_bitset_t bs);
int dm_bitset_equal(dm_bitset_t in1, dm_bitset_t in2);
void dm_bit_and(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2);
void dm_bit_union(dm_bitset_t out, dm_bitset_t in1, dm_bitset_t in2);
int dm_bit_get_first(dm_bitset_t bs);
int dm_bit_get_next(dm_bitset_t bs, int last_bit);
int dm_bit_get_last(dm_bitset_t bs);
int dm_bit_get_prev(dm_bitset_t bs, int last_bit);
#define DM_BITS_PER_INT ((unsigned)sizeof(int) * CHAR_BIT)
#define dm_bit(bs, i) \
((bs)[((i) / DM_BITS_PER_INT) + 1] & (0x1 << ((i) & (DM_BITS_PER_INT - 1))))
#define dm_bit_set(bs, i) \
((bs)[((i) / DM_BITS_PER_INT) + 1] |= (0x1 << ((i) & (DM_BITS_PER_INT - 1))))
#define dm_bit_clear(bs, i) \
((bs)[((i) / DM_BITS_PER_INT) + 1] &= ~(0x1 << ((i) & (DM_BITS_PER_INT - 1))))
#define dm_bit_set_all(bs) \
memset((bs) + 1, -1, ((*(bs) / DM_BITS_PER_INT) + 1) * sizeof(int))
#define dm_bit_clear_all(bs) \
memset((bs) + 1, 0, ((*(bs) / DM_BITS_PER_INT) + 1) * sizeof(int))
#define dm_bit_copy(bs1, bs2) \
memcpy((bs1) + 1, (bs2) + 1, ((*(bs2) / DM_BITS_PER_INT) + 1) * sizeof(int))
/*
* Parse a string representation of a bitset into a dm_bitset_t. The
* notation used is identical to the kernel bitmap parser (cpuset etc.)
* and supports both lists ("1,2,3") and ranges ("1-2,5-8"). If the mem
* parameter is NULL memory for the bitset will be allocated using
* dm_malloc(). Otherwise the bitset will be allocated using the supplied
* dm_pool.
*/
dm_bitset_t dm_bitset_parse_list(const char *str, struct dm_pool *mem,
size_t min_num_bits);
/* Returns number of set bits */
static inline unsigned hweight32(uint32_t i)
{
unsigned r = (i & 0x55555555) + ((i >> 1) & 0x55555555);
r = (r & 0x33333333) + ((r >> 2) & 0x33333333);
r = (r & 0x0F0F0F0F) + ((r >> 4) & 0x0F0F0F0F);
r = (r & 0x00FF00FF) + ((r >> 8) & 0x00FF00FF);
return (r & 0x0000FFFF) + ((r >> 16) & 0x0000FFFF);
}
/****************
* hash functions
****************/
struct dm_hash_table;
struct dm_hash_node;
typedef void (*dm_hash_iterate_fn) (void *data);
struct dm_hash_table *dm_hash_create(unsigned size_hint)
__attribute__((__warn_unused_result__));
void dm_hash_destroy(struct dm_hash_table *t);
void dm_hash_wipe(struct dm_hash_table *t);
void *dm_hash_lookup(struct dm_hash_table *t, const char *key);
int dm_hash_insert(struct dm_hash_table *t, const char *key, void *data);
void dm_hash_remove(struct dm_hash_table *t, const char *key);
void *dm_hash_lookup_binary(struct dm_hash_table *t, const void *key, uint32_t len);
int dm_hash_insert_binary(struct dm_hash_table *t, const void *key, uint32_t len,
void *data);
void dm_hash_remove_binary(struct dm_hash_table *t, const void *key, uint32_t len);
unsigned dm_hash_get_num_entries(struct dm_hash_table *t);
void dm_hash_iter(struct dm_hash_table *t, dm_hash_iterate_fn f);
char *dm_hash_get_key(struct dm_hash_table *t, struct dm_hash_node *n);
void *dm_hash_get_data(struct dm_hash_table *t, struct dm_hash_node *n);
struct dm_hash_node *dm_hash_get_first(struct dm_hash_table *t);
struct dm_hash_node *dm_hash_get_next(struct dm_hash_table *t, struct dm_hash_node *n);
/*
* dm_hash_insert() replaces the value of an existing
* entry with a matching key if one exists. Otherwise
* it adds a new entry.
*
* dm_hash_insert_with_val() inserts a new entry if
* another entry with the same key already exists.
* val_len is the size of the data being inserted.
*
* If two entries with the same key exist,
* (added using dm_hash_insert_allow_multiple), then:
* . dm_hash_lookup() returns the first one it finds, and
* dm_hash_lookup_with_val() returns the one with a matching
* val_len/val.
* . dm_hash_remove() removes the first one it finds, and
* dm_hash_remove_with_val() removes the one with a matching
* val_len/val.
*
* If a single entry with a given key exists, and it has
* zero val_len, then:
* . dm_hash_lookup() returns it
* . dm_hash_lookup_with_val(val_len=0) returns it
* . dm_hash_remove() removes it
* . dm_hash_remove_with_val(val_len=0) removes it
*
* dm_hash_lookup_with_count() is a single call that will
* both lookup a key's value and check if there is more
* than one entry with the given key.
*
* (It is not meant to retrieve all the entries with the
* given key. In the common case where a single entry exists
* for the key, it is useful to have a single call that will
* both look up the value and indicate if multiple values
* exist for the key.)
*
* dm_hash_lookup_with_count:
* . If no entries exist, the function returns NULL, and
* the count is set to 0.
* . If only one entry exists, the value of that entry is
* returned and count is set to 1.
* . If N entries exists, the value of the first entry is
* returned and count is set to N.
*/
void *dm_hash_lookup_with_val(struct dm_hash_table *t, const char *key,
const void *val, uint32_t val_len);
void dm_hash_remove_with_val(struct dm_hash_table *t, const char *key,
const void *val, uint32_t val_len);
int dm_hash_insert_allow_multiple(struct dm_hash_table *t, const char *key,
const void *val, uint32_t val_len);
void *dm_hash_lookup_with_count(struct dm_hash_table *t, const char *key, int *count);
#define dm_hash_iterate(v, h) \
for (v = dm_hash_get_first((h)); v; \
v = dm_hash_get_next((h), v))
/****************
* list functions
****************/
/*
* A list consists of a list head plus elements.
* Each element has 'next' and 'previous' pointers.
* The list head's pointers point to the first and the last element.
*/
struct dm_list {
struct dm_list *n, *p;
};
/*
* String list.
*/
struct dm_str_list {
struct dm_list list;
const char *str;
};
/*
* Initialise a list before use.
* The list head's next and previous pointers point back to itself.
*/
#define DM_LIST_HEAD_INIT(name) { &(name), &(name) }
#define DM_LIST_INIT(name) struct dm_list name = DM_LIST_HEAD_INIT(name)
void dm_list_init(struct dm_list *head);
/*
* Insert an element before 'head'.
* If 'head' is the list head, this adds an element to the end of the list.
*/
void dm_list_add(struct dm_list *head, struct dm_list *elem);
/*
* Insert an element after 'head'.
* If 'head' is the list head, this adds an element to the front of the list.
*/
void dm_list_add_h(struct dm_list *head, struct dm_list *elem);
/*
* Delete an element from its list.
* Note that this doesn't change the element itself - it may still be safe
* to follow its pointers.
*/
void dm_list_del(struct dm_list *elem);
/*
* Remove an element from existing list and insert before 'head'.
*/
void dm_list_move(struct dm_list *head, struct dm_list *elem);
/*
* Join 'head1' to the end of 'head'.
*/
void dm_list_splice(struct dm_list *head, struct dm_list *head1);
/*
* Is the list empty?
*/
int dm_list_empty(const struct dm_list *head);
/*
* Is this the first element of the list?
*/
int dm_list_start(const struct dm_list *head, const struct dm_list *elem);
/*
* Is this the last element of the list?
*/
int dm_list_end(const struct dm_list *head, const struct dm_list *elem);
/*
* Return first element of the list or NULL if empty
*/
struct dm_list *dm_list_first(const struct dm_list *head);
/*
* Return last element of the list or NULL if empty
*/
struct dm_list *dm_list_last(const struct dm_list *head);
/*
* Return the previous element of the list, or NULL if we've reached the start.
*/
struct dm_list *dm_list_prev(const struct dm_list *head, const struct dm_list *elem);
/*
* Return the next element of the list, or NULL if we've reached the end.
*/
struct dm_list *dm_list_next(const struct dm_list *head, const struct dm_list *elem);
/*
* Given the address v of an instance of 'struct dm_list' called 'head'
* contained in a structure of type t, return the containing structure.
*/
#define dm_list_struct_base(v, t, head) \
((t *)((char *)(v) - offsetof(t, head)))
/*
* Given the address v of an instance of 'struct dm_list list' contained in
* a structure of type t, return the containing structure.
*/
#define dm_list_item(v, t) dm_list_struct_base((v), t, list)
/*
* Given the address v of one known element e in a known structure of type t,
* return another element f.
*/
#define dm_struct_field(v, t, e, f) \
(((t *)((uintptr_t)(v) - offsetof(t, e))->f)
/*
* Given the address v of a known element e in a known structure of type t,
* return the list head 'list'
*/
#define dm_list_head(v, t, e) dm_struct_field(v, t, e, list)
/*
* Set v to each element of a list in turn.
*/
#define dm_list_iterate(v, head) \
for (v = (head)->n; v != head; v = v->n)
/*
* Set v to each element in a list in turn, starting from the element
* in front of 'start'.
* You can use this to 'unwind' a list_iterate and back out actions on
* already-processed elements.
* If 'start' is 'head' it walks the list backwards.
*/
#define dm_list_uniterate(v, head, start) \
for (v = (start)->p; v != head; v = v->p)
/*
* A safe way to walk a list and delete and free some elements along
* the way.
* t must be defined as a temporary variable of the same type as v.
*/
#define dm_list_iterate_safe(v, t, head) \
for (v = (head)->n, t = v->n; v != head; v = t, t = v->n)
/*
* Walk a list, setting 'v' in turn to the containing structure of each item.
* The containing structure should be the same type as 'v'.
* The 'struct dm_list' variable within the containing structure is 'field'.
*/
#define dm_list_iterate_items_gen(v, head, field) \
for (v = dm_list_struct_base((head)->n, __typeof__(*v), field); \
&v->field != (head); \
v = dm_list_struct_base(v->field.n, __typeof__(*v), field))
/*
* Walk a list, setting 'v' in turn to the containing structure of each item.
* The containing structure should be the same type as 'v'.
* The list should be 'struct dm_list list' within the containing structure.
*/
#define dm_list_iterate_items(v, head) dm_list_iterate_items_gen(v, (head), list)
/*
* Walk a list, setting 'v' in turn to the containing structure of each item.
* The containing structure should be the same type as 'v'.
* The 'struct dm_list' variable within the containing structure is 'field'.
* t must be defined as a temporary variable of the same type as v.
*/
#define dm_list_iterate_items_gen_safe(v, t, head, field) \
for (v = dm_list_struct_base((head)->n, __typeof__(*v), field), \
t = dm_list_struct_base(v->field.n, __typeof__(*v), field); \
&v->field != (head); \
v = t, t = dm_list_struct_base(v->field.n, __typeof__(*v), field))
/*
* Walk a list, setting 'v' in turn to the containing structure of each item.
* The containing structure should be the same type as 'v'.
* The list should be 'struct dm_list list' within the containing structure.
* t must be defined as a temporary variable of the same type as v.
*/
#define dm_list_iterate_items_safe(v, t, head) \
dm_list_iterate_items_gen_safe(v, t, (head), list)
/*
* Walk a list backwards, setting 'v' in turn to the containing structure
* of each item.
* The containing structure should be the same type as 'v'.
* The 'struct dm_list' variable within the containing structure is 'field'.
*/
#define dm_list_iterate_back_items_gen(v, head, field) \
for (v = dm_list_struct_base((head)->p, __typeof__(*v), field); \
&v->field != (head); \
v = dm_list_struct_base(v->field.p, __typeof__(*v), field))
/*
* Walk a list backwards, setting 'v' in turn to the containing structure
* of each item.
* The containing structure should be the same type as 'v'.
* The list should be 'struct dm_list list' within the containing structure.
*/
#define dm_list_iterate_back_items(v, head) dm_list_iterate_back_items_gen(v, (head), list)
/*
* Return the number of elements in a list by walking it.
*/
unsigned int dm_list_size(const struct dm_list *head);
/*********
* selinux
*********/
/*
* Obtain SELinux security context assigned for the path and set this
* context for creating a new file system object. This security context
* is global and it is used until reset to default policy behaviour
* by calling 'dm_prepare_selinux_context(NULL, 0)'.
*/
int dm_prepare_selinux_context(const char *path, mode_t mode);
/*
* Set SELinux context for existing file system object.
*/
int dm_set_selinux_context(const char *path, mode_t mode);
/*********************
* string manipulation
*********************/
/*
* Break up the name of a mapped device into its constituent
* Volume Group, Logical Volume and Layer (if present).
* If mem is supplied, the result is allocated from the mempool.
* Otherwise the strings are changed in situ.
*/
int dm_split_lvm_name(struct dm_pool *mem, const char *dmname,
char **vgname, char **lvname, char **layer);
/*
* Destructively split buffer into NULL-separated words in argv.
* Returns number of words.
*/
int dm_split_words(char *buffer, unsigned max,
unsigned ignore_comments, /* Not implemented */
char **argv);
/*
* Returns -1 if buffer too small
*/
int dm_snprintf(char *buf, size_t bufsize, const char *format, ...)
__attribute__ ((format(printf, 3, 4)));
/*
* Returns pointer to the last component of the path.
*/
const char *dm_basename(const char *path);
/*
* Returns number of occurrences of 'c' in 'str' of length 'size'.
*/
unsigned dm_count_chars(const char *str, size_t len, const int c);
/*
* Length of string after escaping double quotes and backslashes.
*/
size_t dm_escaped_len(const char *str);
/*
* <vg>-<lv>-<layer> or if !layer just <vg>-<lv>.
*/
char *dm_build_dm_name(struct dm_pool *mem, const char *vgname,
const char *lvname, const char *layer);
char *dm_build_dm_uuid(struct dm_pool *mem, const char *prefix, const char *lvid, const char *layer);
/*
* Copies a string, quoting double quotes with backslashes.
*/
char *dm_escape_double_quotes(char *out, const char *src);
/*
* Undo quoting in situ.
*/
void dm_unescape_double_quotes(char *src);
/*
* Unescape colons and "at" signs in situ and save the substrings
* starting at the position of the first unescaped colon and the
* first unescaped "at" sign. This is normally used to unescape
* device names used as PVs.
*/
void dm_unescape_colons_and_at_signs(char *src,
char **substr_first_unquoted_colon,
char **substr_first_unquoted_at_sign);
/*
* Replacement for strncpy() function.
*
* Copies no more than n bytes from string pointed by src to the buffer
* pointed by dest and ensure string is finished with '\0'.
* Returns 0 if the whole string does not fit.
*/
int dm_strncpy(char *dest, const char *src, size_t n);
/*
* Recognize unit specifier in the 'units' arg and return a factor
* representing that unit. If the 'units' contains a prefix with digits,
* the 'units' is considered to be a custom unit.
*
* Also, set 'unit_type' output arg to the character that represents
* the unit specified. The 'unit_type' character equals to the unit
* character itself recognized in the 'units' arg for canonical units.
* Otherwise, the 'unit_type' character is set to 'U' for custom unit.
*
* An example for k/K canonical units and 8k/8K custom units:
*
* units unit_type return value (factor)
* k k 1024
* K K 1000
* 8k U 1024*8
* 8K U 1000*8
* etc...
*
* Recognized units:
*
* h/H - human readable (returns 1 for both)
* b/B - byte (returns 1 for both)
* s/S - sector (returns 512 for both)
* k/K - kilo (returns 1024/1000 respectively)
* m/M - mega (returns 1024^2/1000^2 respectively)
* g/G - giga (returns 1024^3/1000^3 respectively)
* t/T - tera (returns 1024^4/1000^4 respectively)
* p/P - peta (returns 1024^5/1000^5 respectively)
* e/E - exa (returns 1024^6/1000^6 respectively)
*
* Only one units character is allowed in the 'units' arg
* if strict mode is enabled by 'strict' arg.
*
* The 'endptr' output arg, if not NULL, saves the pointer
* in the 'units' string which follows the unit specifier
* recognized (IOW the position where the parsing of the
* unit specifier stopped).
*
* Returns the unit factor or 0 if no unit is recognized.
*/
uint64_t dm_units_to_factor(const char *units, char *unit_type,
int strict, const char **endptr);
/*
* Type of unit specifier used by dm_size_to_string().
*/
typedef enum dm_size_suffix_e {
DM_SIZE_LONG = 0, /* Megabyte */
DM_SIZE_SHORT = 1, /* MB or MiB */
DM_SIZE_UNIT = 2 /* M or m */
} dm_size_suffix_t;
/*
* Convert a size (in 512-byte sectors) into a printable string using units of unit_type.
* An upper-case unit_type indicates output units based on powers of 1000 are
* required; a lower-case unit_type indicates powers of 1024.
* For correct operation, unit_factor must be one of:
* 0 - the correct value will be calculated internally;
* or the output from dm_units_to_factor() corresponding to unit_type;
* or 'u' or 'U', an arbitrary number of bytes to use as the power base.
* Set include_suffix to 1 to include a suffix of suffix_type.
* Set use_si_units to 0 for suffixes that don't distinguish between 1000 and 1024.
* Set use_si_units to 1 for a suffix that does distinguish.
*/
const char *dm_size_to_string(struct dm_pool *mem, uint64_t size,
char unit_type, int use_si_units,
uint64_t unit_factor, int include_suffix,
dm_size_suffix_t suffix_type);
/**************************
* file/stream manipulation
**************************/
/*
* Create a directory (with parent directories if necessary).
* Returns 1 on success, 0 on failure.
*/
int dm_create_dir(const char *dir);
int dm_is_empty_dir(const char *dir);
/*
* Close a stream, with nicer error checking than fclose's.
* Derived from gnulib's close-stream.c.
*
* Close "stream". Return 0 if successful, and EOF (setting errno)
* otherwise. Upon failure, set errno to 0 if the error number
* cannot be determined. Useful mainly for writable streams.
*/
int dm_fclose(FILE *stream);
/*
* Returns size of a buffer which is allocated with dm_malloc.
* Pointer to the buffer is stored in *buf.
* Returns -1 on failure leaving buf undefined.
*/
int dm_asprintf(char **buf, const char *format, ...)
__attribute__ ((format(printf, 2, 3)));
int dm_vasprintf(char **buf, const char *format, va_list ap)
__attribute__ ((format(printf, 2, 0)));
/*
* create lockfile (pidfile) - create and lock a lock file
* @lockfile: location of lock file
*
* Returns: 1 on success, 0 otherwise, errno is handled internally
*/
int dm_create_lockfile(const char* lockfile);
/*
* Query whether a daemon is running based on its lockfile
*
* Returns: 1 if running, 0 if not
*/
int dm_daemon_is_running(const char* lockfile);
/*********************
* regular expressions
*********************/
struct dm_regex;
/*
* Initialise an array of num patterns for matching.
* Uses memory from mem.
*/
struct dm_regex *dm_regex_create(struct dm_pool *mem, const char * const *patterns,
unsigned num_patterns);
/*
* Match string s against the patterns.
* Returns the index of the highest pattern in the array that matches,
* or -1 if none match.
*/
int dm_regex_match(struct dm_regex *regex, const char *s);
/*
* This is useful for regression testing only. The idea is if two
* fingerprints are different, then the two dfas are certainly not
* isomorphic. If two fingerprints _are_ the same then it's very likely
* that the dfas are isomorphic.
*
* This function must be called before any matching is done.
*/
uint32_t dm_regex_fingerprint(struct dm_regex *regex);
/******************
* percent handling
******************/
/*
* A fixed-point representation of percent values. One percent equals to
* DM_PERCENT_1 as defined below. Values that are not multiples of DM_PERCENT_1
* represent fractions, with precision of 1/1000000 of a percent. See
* dm_percent_to_float for a conversion to a floating-point representation.
*
* You should always use dm_make_percent when building dm_percent_t values. The
* implementation of dm_make_percent is biased towards the middle: it ensures that
* the result is DM_PERCENT_0 or DM_PERCENT_100 if and only if this is the actual
* value -- it never rounds any intermediate value (> 0 or < 100) to either 0
* or 100.
*/
#define DM_PERCENT_CHAR '%'
typedef enum dm_percent_range_e {
DM_PERCENT_0 = 0,
DM_PERCENT_1 = 1000000,
DM_PERCENT_100 = 100 * DM_PERCENT_1,
DM_PERCENT_INVALID = -1,
DM_PERCENT_FAILED = -2
} dm_percent_range_t;
typedef int32_t dm_percent_t;
float dm_percent_to_float(dm_percent_t percent);
/*
* Return adjusted/rounded float for better percent value printing.
* Function ensures for given precision of digits:
* 100.0% returns only when the value is DM_PERCENT_100
* for close smaller values rounds to nearest smaller value
* 0.0% returns only for value DM_PERCENT_0
* for close bigger values rounds to nearest bigger value
* In all other cases returns same value as dm_percent_to_float()
*/
float dm_percent_to_round_float(dm_percent_t percent, unsigned digits);
dm_percent_t dm_make_percent(uint64_t numerator, uint64_t denominator);
/********************
* timestamp handling
********************/
/*
* Create a dm_timestamp object to use with dm_timestamp_get.
*/
struct dm_timestamp *dm_timestamp_alloc(void);
/*
* Update dm_timestamp object to represent the current time.
*/
int dm_timestamp_get(struct dm_timestamp *ts);
/*
* Copy a timestamp from ts_old to ts_new.
*/
void dm_timestamp_copy(struct dm_timestamp *ts_new, struct dm_timestamp *ts_old);
/*
* Compare two timestamps.
*
* Return: -1 if ts1 is less than ts2
* 0 if ts1 is equal to ts2
* 1 if ts1 is greater than ts2
*/
int dm_timestamp_compare(struct dm_timestamp *ts1, struct dm_timestamp *ts2);
/*
* Return the absolute difference in nanoseconds between
* the dm_timestamp objects ts1 and ts2.
*
* Callers that need to know whether ts1 is before, equal to, or after ts2
* in addition to the magnitude should use dm_timestamp_compare.
*/
uint64_t dm_timestamp_delta(struct dm_timestamp *ts1, struct dm_timestamp *ts2);
/*
* Destroy a dm_timestamp object.
*/
void dm_timestamp_destroy(struct dm_timestamp *ts);
/*********************
* reporting functions
*********************/
struct dm_report_object_type {
uint32_t id; /* Powers of 2 */
const char *desc;
const char *prefix; /* field id string prefix (optional) */
/* FIXME: convert to proper usage of const pointers here */
void *(*data_fn)(void *object); /* callback from report_object() */
};
struct dm_report_field;
/*
* dm_report_field_type flags
*/
#define DM_REPORT_FIELD_MASK 0x00000FFF
#define DM_REPORT_FIELD_ALIGN_MASK 0x0000000F
#define DM_REPORT_FIELD_ALIGN_LEFT 0x00000001
#define DM_REPORT_FIELD_ALIGN_RIGHT 0x00000002
#define DM_REPORT_FIELD_TYPE_MASK 0x00000FF0
#define DM_REPORT_FIELD_TYPE_NONE 0x00000000
#define DM_REPORT_FIELD_TYPE_STRING 0x00000010
#define DM_REPORT_FIELD_TYPE_NUMBER 0x00000020
#define DM_REPORT_FIELD_TYPE_SIZE 0x00000040
#define DM_REPORT_FIELD_TYPE_PERCENT 0x00000080
#define DM_REPORT_FIELD_TYPE_STRING_LIST 0x00000100
#define DM_REPORT_FIELD_TYPE_TIME 0x00000200
/* For use with reserved values only! */
#define DM_REPORT_FIELD_RESERVED_VALUE_MASK 0x0000000F
#define DM_REPORT_FIELD_RESERVED_VALUE_NAMED 0x00000001 /* only named value, less strict form of reservation */
#define DM_REPORT_FIELD_RESERVED_VALUE_RANGE 0x00000002 /* value is range - low and high value defined */
#define DM_REPORT_FIELD_RESERVED_VALUE_DYNAMIC_VALUE 0x00000004 /* value is computed in runtime */
#define DM_REPORT_FIELD_RESERVED_VALUE_FUZZY_NAMES 0x00000008 /* value names are recognized in runtime */
#define DM_REPORT_FIELD_TYPE_ID_LEN 32
#define DM_REPORT_FIELD_TYPE_HEADING_LEN 32
struct dm_report;
struct dm_report_field_type {
uint32_t type; /* object type id */
uint32_t flags; /* DM_REPORT_FIELD_* */
uint32_t offset; /* byte offset in the object */
int32_t width; /* default width */
/* string used to specify the field */
const char id[DM_REPORT_FIELD_TYPE_ID_LEN];
/* string printed in header */
const char heading[DM_REPORT_FIELD_TYPE_HEADING_LEN];
int (*report_fn)(struct dm_report *rh, struct dm_pool *mem,
struct dm_report_field *field, const void *data,
void *private_data);
const char *desc; /* description of the field */
};
/*
* Per-field reserved value.
*/
struct dm_report_field_reserved_value {
/* field_num is the position of the field in 'fields'
array passed to dm_report_init_with_selection */
uint32_t field_num;
/* the value is of the same type as the field
identified by field_num */
const void *value;
};
/*
* Reserved value is a 'value' that is used directly if any of the 'names' is hit
* or in case of fuzzy names, if such fuzzy name matches.
*
* If type is any of DM_REPORT_FIELD_TYPE_*, the reserved value is recognized
* for all fields of that type.
*
* If type is DM_REPORT_FIELD_TYPE_NONE, the reserved value is recognized
* for the exact field specified - hence the type of the value is automatically
* the same as the type of the field itself.
*
* The array of reserved values is used to initialize reporting with
* selection enabled (see also dm_report_init_with_selection function).
*/
struct dm_report_reserved_value {
const uint32_t type; /* DM_REPORT_FIELD_RESERVED_VALUE_* and DM_REPORT_FIELD_TYPE_* */
const void *value; /* reserved value:
uint64_t for DM_REPORT_FIELD_TYPE_NUMBER
uint64_t for DM_REPORT_FIELD_TYPE_SIZE (number of 512-byte sectors)
uint64_t for DM_REPORT_FIELD_TYPE_PERCENT
const char* for DM_REPORT_FIELD_TYPE_STRING
struct dm_report_field_reserved_value for DM_REPORT_FIELD_TYPE_NONE
dm_report_reserved_handler* if DM_REPORT_FIELD_RESERVED_VALUE_{DYNAMIC_VALUE,FUZZY_NAMES} is used */
const char **names; /* null-terminated array of static names for this reserved value */
const char *description; /* description of the reserved value */
};
/*
* Available actions for dm_report_reserved_value_handler.
*/
typedef enum dm_report_reserved_action_e {
DM_REPORT_RESERVED_PARSE_FUZZY_NAME,
DM_REPORT_RESERVED_GET_DYNAMIC_VALUE,
} dm_report_reserved_action_t;
/*
* Generic reserved value handler to process reserved value names and/or values.
*
* Actions and their input/output:
*
* DM_REPORT_RESERVED_PARSE_FUZZY_NAME
* data_in: const char *fuzzy_name
* data_out: const char *canonical_name, NULL if fuzzy_name not recognized
*
* DM_REPORT_RESERVED_GET_DYNAMIC_VALUE
* data_in: const char *canonical_name
* data_out: void *value, NULL if canonical_name not recognized
*
* All actions return:
*
* -1 if action not implemented
* 0 on error
* 1 on success
*/
typedef int (*dm_report_reserved_handler) (struct dm_report *rh,
struct dm_pool *mem,
uint32_t field_num,
dm_report_reserved_action_t action,
const void *data_in,
const void **data_out);
/*
* The dm_report_value_cache_{set,get} are helper functions to store and retrieve
* various values used during reporting (dm_report_field_type.report_fn) and/or
* selection processing (dm_report_reserved_handler instances) to avoid
* recalculation of these values or to share values among calls.
*/
int dm_report_value_cache_set(struct dm_report *rh, const char *name, const void *data);
const void *dm_report_value_cache_get(struct dm_report *rh, const char *name);
/*
* dm_report_init output_flags
*/
#define DM_REPORT_OUTPUT_MASK 0x000000FF
#define DM_REPORT_OUTPUT_ALIGNED 0x00000001
#define DM_REPORT_OUTPUT_BUFFERED 0x00000002
#define DM_REPORT_OUTPUT_HEADINGS 0x00000004
#define DM_REPORT_OUTPUT_FIELD_NAME_PREFIX 0x00000008
#define DM_REPORT_OUTPUT_FIELD_UNQUOTED 0x00000010
#define DM_REPORT_OUTPUT_COLUMNS_AS_ROWS 0x00000020
#define DM_REPORT_OUTPUT_MULTIPLE_TIMES 0x00000040
#define DM_REPORT_OUTPUT_FIELD_IDS_IN_HEADINGS 0x00000080
struct dm_report *dm_report_init(uint32_t *report_types,
const struct dm_report_object_type *types,
const struct dm_report_field_type *fields,
const char *output_fields,
const char *output_separator,
uint32_t output_flags,
const char *sort_keys,
void *private_data);
struct dm_report *dm_report_init_with_selection(uint32_t *report_types,
const struct dm_report_object_type *types,
const struct dm_report_field_type *fields,
const char *output_fields,
const char *output_separator,
uint32_t output_flags,
const char *sort_keys,
const char *selection,
const struct dm_report_reserved_value reserved_values[],
void *private_data);
/*
* Report an object, pass it through the selection criteria if they
* are present and display the result on output if it passes the criteria.
*/
int dm_report_object(struct dm_report *rh, void *object);
/*
* The same as dm_report_object, but display the result on output only if
* 'do_output' arg is set. Also, save the result of selection in 'selected'
* arg if it's not NULL (either 1 if the object passes, otherwise 0).
*/
int dm_report_object_is_selected(struct dm_report *rh, void *object, int do_output, int *selected);
/*
* Compact report output so that if field value is empty for all rows in
* the report, drop the field from output completely (including headers).
* Compact output is applicable only if report is buffered, otherwise
* this function has no effect.
*/
int dm_report_compact_fields(struct dm_report *rh);
/*
* The same as dm_report_compact_fields, but for selected fields only.
* The "fields" arg is comma separated list of field names (the same format
* as used for "output_fields" arg in dm_report_init fn).
*/
int dm_report_compact_given_fields(struct dm_report *rh, const char *fields);
/*
* Returns 1 if there is no data waiting to be output.
*/
int dm_report_is_empty(struct dm_report *rh);
/*
* Destroy report content without doing output.
*/
void dm_report_destroy_rows(struct dm_report *rh);
int dm_report_output(struct dm_report *rh);
/*
* Output the report headings for a columns-based report, even if they
* have already been shown. Useful for repeating reports that wish to
* issue a periodic reminder of the column headings.
*/
int dm_report_column_headings(struct dm_report *rh);
void dm_report_free(struct dm_report *rh);
/*
* Prefix added to each field name with DM_REPORT_OUTPUT_FIELD_NAME_PREFIX
*/
int dm_report_set_output_field_name_prefix(struct dm_report *rh,
const char *report_prefix);
int dm_report_set_selection(struct dm_report *rh, const char *selection);
/*
* Report functions are provided for simple data types.
* They take care of allocating copies of the data.
*/
int dm_report_field_string(struct dm_report *rh, struct dm_report_field *field,
const char *const *data);
int dm_report_field_string_list(struct dm_report *rh, struct dm_report_field *field,
const struct dm_list *data, const char *delimiter);
int dm_report_field_string_list_unsorted(struct dm_report *rh, struct dm_report_field *field,
const struct dm_list *data, const char *delimiter);
int dm_report_field_int32(struct dm_report *rh, struct dm_report_field *field,
const int32_t *data);
int dm_report_field_uint32(struct dm_report *rh, struct dm_report_field *field,
const uint32_t *data);
int dm_report_field_int(struct dm_report *rh, struct dm_report_field *field,
const int *data);
int dm_report_field_uint64(struct dm_report *rh, struct dm_report_field *field,
const uint64_t *data);
int dm_report_field_percent(struct dm_report *rh, struct dm_report_field *field,
const dm_percent_t *data);
/*
* For custom fields, allocate the data in 'mem' and use
* dm_report_field_set_value().
* 'sortvalue' may be NULL if it matches 'value'
*/
void dm_report_field_set_value(struct dm_report_field *field, const void *value,
const void *sortvalue);
/*
* Report group support.
*/
struct dm_report_group;
typedef enum dm_report_group_type_e {
DM_REPORT_GROUP_SINGLE,
DM_REPORT_GROUP_BASIC,
DM_REPORT_GROUP_JSON,
DM_REPORT_GROUP_JSON_STD
} dm_report_group_type_t;
struct dm_report_group *dm_report_group_create(dm_report_group_type_t type, void *data);
int dm_report_group_push(struct dm_report_group *group, struct dm_report *report, void *data);
int dm_report_group_pop(struct dm_report_group *group);
int dm_report_group_output_and_pop_all(struct dm_report_group *group);
int dm_report_group_destroy(struct dm_report_group *group);
/*
* Stats counter access methods
*
* Each method returns the corresponding stats counter value from the
* supplied dm_stats handle for the specified region_id and area_id.
* If either region_id or area_id uses one of the special values
* DM_STATS_REGION_CURRENT or DM_STATS_AREA_CURRENT then the region
* or area is selected according to the current state of the dm_stats
* handle's embedded cursor.
*
* Two methods are provided to access counter values: a named function
* for each available counter field and a single function that accepts
* an enum value specifying the required field. New code is encouraged
* to use the enum based interface as calls to the named functions are
* implemented using the enum method internally.
*
* See the kernel documentation for complete descriptions of each
* counter field:
*
* Documentation/device-mapper/statistics.txt
* Documentation/iostats.txt
*
* reads: the number of reads completed
* reads_merged: the number of reads merged
* read_sectors: the number of sectors read
* read_nsecs: the number of nanoseconds spent reading
* writes: the number of writes completed
* writes_merged: the number of writes merged
* write_sectors: the number of sectors written
* write_nsecs: the number of nanoseconds spent writing
* io_in_progress: the number of I/Os currently in progress
* io_nsecs: the number of nanoseconds spent doing I/Os
* weighted_io_nsecs: the weighted number of nanoseconds spent doing I/Os
* total_read_nsecs: the total time spent reading in nanoseconds
* total_write_nsecs: the total time spent writing in nanoseconds
*/
#define DM_STATS_REGION_CURRENT UINT64_MAX
#define DM_STATS_AREA_CURRENT UINT64_MAX
typedef enum dm_stats_counter_e {
DM_STATS_READS_COUNT,
DM_STATS_READS_MERGED_COUNT,
DM_STATS_READ_SECTORS_COUNT,
DM_STATS_READ_NSECS,
DM_STATS_WRITES_COUNT,
DM_STATS_WRITES_MERGED_COUNT,
DM_STATS_WRITE_SECTORS_COUNT,
DM_STATS_WRITE_NSECS,
DM_STATS_IO_IN_PROGRESS_COUNT,
DM_STATS_IO_NSECS,
DM_STATS_WEIGHTED_IO_NSECS,
DM_STATS_TOTAL_READ_NSECS,
DM_STATS_TOTAL_WRITE_NSECS,
DM_STATS_NR_COUNTERS
} dm_stats_counter_t;
uint64_t dm_stats_get_counter(const struct dm_stats *dms,
dm_stats_counter_t counter,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_reads(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_reads_merged(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_read_sectors(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_read_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_writes(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_writes_merged(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_write_sectors(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_write_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_io_in_progress(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_io_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_weighted_io_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_total_read_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
uint64_t dm_stats_get_total_write_nsecs(const struct dm_stats *dms,
uint64_t region_id, uint64_t area_id);
/*
* Derived statistics access methods
*
* Each method returns the corresponding value calculated from the
* counters stored in the supplied dm_stats handle for the specified
* region_id and area_id. If either region_id or area_id uses one of the
* special values DM_STATS_REGION_CURRENT or DM_STATS_AREA_CURRENT then
* the region or area is selected according to the current state of the
* dm_stats handle's embedded cursor.
*
* The set of metrics is based on the fields provided by the Linux
* iostats program.
*
* rd_merges_per_sec: the number of reads merged per second
* wr_merges_per_sec: the number of writes merged per second
* reads_per_sec: the number of reads completed per second
* writes_per_sec: the number of writes completed per second
* read_sectors_per_sec: the number of sectors read per second
* write_sectors_per_sec: the number of sectors written per second
* average_request_size: the average size of requests submitted
* service_time: the average service time (in ns) for requests issued
* average_queue_size: the average queue length
* average_wait_time: the average time for requests to be served (in ns)
* average_rd_wait_time: the average read wait time
* average_wr_wait_time: the average write wait time
*/
typedef enum dm_stats_metric_e {
DM_STATS_RD_MERGES_PER_SEC,
DM_STATS_WR_MERGES_PER_SEC,
DM_STATS_READS_PER_SEC,
DM_STATS_WRITES_PER_SEC,
DM_STATS_READ_SECTORS_PER_SEC,
DM_STATS_WRITE_SECTORS_PER_SEC,
DM_STATS_AVERAGE_REQUEST_SIZE,
DM_STATS_AVERAGE_QUEUE_SIZE,
DM_STATS_AVERAGE_WAIT_TIME,
DM_STATS_AVERAGE_RD_WAIT_TIME,
DM_STATS_AVERAGE_WR_WAIT_TIME,
DM_STATS_SERVICE_TIME,
DM_STATS_THROUGHPUT,
DM_STATS_UTILIZATION,
DM_STATS_NR_METRICS
} dm_stats_metric_t;
int dm_stats_get_metric(const struct dm_stats *dms, int metric,
uint64_t region_id, uint64_t area_id, double *value);
int dm_stats_get_rd_merges_per_sec(const struct dm_stats *dms, double *rrqm,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_wr_merges_per_sec(const struct dm_stats *dms, double *rrqm,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_reads_per_sec(const struct dm_stats *dms, double *rd_s,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_writes_per_sec(const struct dm_stats *dms, double *wr_s,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_read_sectors_per_sec(const struct dm_stats *dms,
double *rsec_s, uint64_t region_id,
uint64_t area_id);
int dm_stats_get_write_sectors_per_sec(const struct dm_stats *dms,
double *wr_s, uint64_t region_id,
uint64_t area_id);
int dm_stats_get_average_request_size(const struct dm_stats *dms,
double *arqsz, uint64_t region_id,
uint64_t area_id);
int dm_stats_get_service_time(const struct dm_stats *dms, double *svctm,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_average_queue_size(const struct dm_stats *dms, double *qusz,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_average_wait_time(const struct dm_stats *dms, double *await,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_average_rd_wait_time(const struct dm_stats *dms,
double *await, uint64_t region_id,
uint64_t area_id);
int dm_stats_get_average_wr_wait_time(const struct dm_stats *dms,
double *await, uint64_t region_id,
uint64_t area_id);
int dm_stats_get_throughput(const struct dm_stats *dms, double *tput,
uint64_t region_id, uint64_t area_id);
int dm_stats_get_utilization(const struct dm_stats *dms, dm_percent_t *util,
uint64_t region_id, uint64_t area_id);
/*
* Statistics histogram access methods.
*
* Methods to access latency histograms for regions that have them
* enabled. Each histogram contains a configurable number of bins
* spanning a user defined latency interval.
*
* The bin count, upper and lower bin bounds, and bin values are
* made available via the following area methods.
*
* Methods to obtain a simple string representation of the histogram
* and its bounds are also provided.
*/
/*
* Retrieve a pointer to the histogram associated with the specified
* area. If the area does not have a histogram configured this function
* returns NULL.
*
* The pointer does not need to be freed explicitly by the caller: it
* will become invalid following a subsequent dm_stats_list(),
* dm_stats_populate() or dm_stats_destroy() of the corresponding
* dm_stats handle.
*
* If region_id or area_id is one of the special values
* DM_STATS_REGION_CURRENT or DM_STATS_AREA_CURRENT the current cursor
* value is used to select the region or area.
*/
struct dm_histogram *dm_stats_get_histogram(const struct dm_stats *dms,
uint64_t region_id,
uint64_t area_id);
/*
* Return the number of bins in the specified histogram handle.
*/
int dm_histogram_get_nr_bins(const struct dm_histogram *dmh);
/*
* Get the lower bound of the specified bin of the histogram for the
* area specified by region_id and area_id. The value is returned in
* nanoseconds.
*/
uint64_t dm_histogram_get_bin_lower(const struct dm_histogram *dmh, int bin);
/*
* Get the upper bound of the specified bin of the histogram for the
* area specified by region_id and area_id. The value is returned in
* nanoseconds.
*/
uint64_t dm_histogram_get_bin_upper(const struct dm_histogram *dmh, int bin);
/*
* Get the width of the specified bin of the histogram for the area
* specified by region_id and area_id. The width is equal to the bin
* upper bound minus the lower bound and yields the range of latency
* values covered by this bin. The value is returned in nanoseconds.
*/
uint64_t dm_histogram_get_bin_width(const struct dm_histogram *dmh, int bin);
/*
* Get the value of the specified bin of the histogram for the area
* specified by region_id and area_id.
*/
uint64_t dm_histogram_get_bin_count(const struct dm_histogram *dmh, int bin);
/*
* Get the percentage (relative frequency) of the specified bin of the
* histogram for the area specified by region_id and area_id.
*/
dm_percent_t dm_histogram_get_bin_percent(const struct dm_histogram *dmh,
int bin);
/*
* Return the total observations (sum of bin counts) for the histogram
* of the area specified by region_id and area_id.
*/
uint64_t dm_histogram_get_sum(const struct dm_histogram *dmh);
/*
* Histogram formatting flags.
*/
#define DM_HISTOGRAM_SUFFIX 0x1
#define DM_HISTOGRAM_VALUES 0x2
#define DM_HISTOGRAM_PERCENT 0X4
#define DM_HISTOGRAM_BOUNDS_LOWER 0x10
#define DM_HISTOGRAM_BOUNDS_UPPER 0x20
#define DM_HISTOGRAM_BOUNDS_RANGE 0x30
/*
* Return a string representation of the supplied histogram's values and
* bin boundaries.
*
* The bin argument selects the bin to format. If this argument is less
* than zero all bins will be included in the resulting string.
*
* width specifies a minimum width for the field in characters; if it is
* zero the width will be determined automatically based on the options
* selected for formatting. A value less than zero disables field width
* control: bin boundaries and values will be output with a minimum
* amount of whitespace.
*
* flags is a collection of flag arguments that control the string format:
*
* DM_HISTOGRAM_VALUES - Include bin values in the string.
* DM_HISTOGRAM_SUFFIX - Include time unit suffixes when printing bounds.
* DM_HISTOGRAM_PERCENT - Format bin values as a percentage.
*
* DM_HISTOGRAM_BOUNDS_LOWER - Include the lower bound of each bin.
* DM_HISTOGRAM_BOUNDS_UPPER - Include the upper bound of each bin.
* DM_HISTOGRAM_BOUNDS_RANGE - Show the span of each bin as "lo-up".
*
* The returned pointer does not need to be freed explicitly by the
* caller: it will become invalid following a subsequent
* dm_stats_list(), dm_stats_populate() or dm_stats_destroy() of the
* corresponding dm_stats handle.
*/
const char *dm_histogram_to_string(const struct dm_histogram *dmh, int bin,
int width, int flags);
/*************************
* config file parse/print
*************************/
typedef enum dm_config_value_type_e {
DM_CFG_INT,
DM_CFG_FLOAT,
DM_CFG_STRING,
DM_CFG_EMPTY_ARRAY
} dm_config_value_type_t;
struct dm_config_value {
dm_config_value_type_t type;
union dm_config_value_u {
int64_t i;
float f;
double d; /* Unused. */
const char *str;
} v;
struct dm_config_value *next; /* For arrays */
uint32_t format_flags;
};
struct dm_config_node {
const char *key;
struct dm_config_node *parent, *sib, *child;
struct dm_config_value *v;
int id;
};
struct dm_config_tree {
struct dm_config_node *root;
struct dm_config_tree *cascade;
struct dm_pool *mem;
void *custom;
};
struct dm_config_tree *dm_config_create(void);
struct dm_config_tree *dm_config_from_string(const char *config_settings);
int dm_config_parse(struct dm_config_tree *cft, const char *start, const char *end);
int dm_config_parse_without_dup_node_check(struct dm_config_tree *cft, const char *start, const char *end);
void *dm_config_get_custom(struct dm_config_tree *cft);
void dm_config_set_custom(struct dm_config_tree *cft, void *custom);
/*
* When searching, first_cft is checked before second_cft.
*/
struct dm_config_tree *dm_config_insert_cascaded_tree(struct dm_config_tree *first_cft, struct dm_config_tree *second_cft);
/*
* If there's a cascaded dm_config_tree, remove the top layer
* and return the layer below. Otherwise return NULL.
*/
struct dm_config_tree *dm_config_remove_cascaded_tree(struct dm_config_tree *cft);
/*
* Create a new, uncascaded config tree equivalent to the input cascade.
*/
struct dm_config_tree *dm_config_flatten(struct dm_config_tree *cft);
void dm_config_destroy(struct dm_config_tree *cft);
/* Simple output line by line. */
typedef int (*dm_putline_fn)(const char *line, void *baton);
/* More advaced output with config node reference. */
typedef int (*dm_config_node_out_fn)(const struct dm_config_node *cn, const char *line, void *baton);
/*
* Specification for advanced config node output.
*/
struct dm_config_node_out_spec {
dm_config_node_out_fn prefix_fn; /* called before processing config node lines */
dm_config_node_out_fn line_fn; /* called for each config node line */
dm_config_node_out_fn suffix_fn; /* called after processing config node lines */
};
/* Write the node and any subsequent siblings it has. */
int dm_config_write_node(const struct dm_config_node *cn, dm_putline_fn putline, void *baton);
int dm_config_write_node_out(const struct dm_config_node *cn, const struct dm_config_node_out_spec *out_spec, void *baton);
/* Write given node only without subsequent siblings. */
int dm_config_write_one_node(const struct dm_config_node *cn, dm_putline_fn putline, void *baton);
int dm_config_write_one_node_out(const struct dm_config_node *cn, const struct dm_config_node_out_spec *out_spec, void *baton);
struct dm_config_node *dm_config_find_node(const struct dm_config_node *cn, const char *path);
int dm_config_has_node(const struct dm_config_node *cn, const char *path);
int dm_config_remove_node(struct dm_config_node *parent, struct dm_config_node *remove);
const char *dm_config_find_str(const struct dm_config_node *cn, const char *path, const char *fail);
const char *dm_config_find_str_allow_empty(const struct dm_config_node *cn, const char *path, const char *fail);
int dm_config_find_int(const struct dm_config_node *cn, const char *path, int fail);
int64_t dm_config_find_int64(const struct dm_config_node *cn, const char *path, int64_t fail);
float dm_config_find_float(const struct dm_config_node *cn, const char *path, float fail);
const struct dm_config_node *dm_config_tree_find_node(const struct dm_config_tree *cft, const char *path);
const char *dm_config_tree_find_str(const struct dm_config_tree *cft, const char *path, const char *fail);
const char *dm_config_tree_find_str_allow_empty(const struct dm_config_tree *cft, const char *path, const char *fail);
int dm_config_tree_find_int(const struct dm_config_tree *cft, const char *path, int fail);
int64_t dm_config_tree_find_int64(const struct dm_config_tree *cft, const char *path, int64_t fail);
float dm_config_tree_find_float(const struct dm_config_tree *cft, const char *path, float fail);
int dm_config_tree_find_bool(const struct dm_config_tree *cft, const char *path, int fail);
/*
* Understands (0, ~0), (y, n), (yes, no), (on,
* off), (true, false).
*/
int dm_config_find_bool(const struct dm_config_node *cn, const char *path, int fail);
int dm_config_value_is_bool(const struct dm_config_value *v);
int dm_config_get_uint32(const struct dm_config_node *cn, const char *path, uint32_t *result);
int dm_config_get_uint64(const struct dm_config_node *cn, const char *path, uint64_t *result);
int dm_config_get_str(const struct dm_config_node *cn, const char *path, const char **result);
int dm_config_get_list(const struct dm_config_node *cn, const char *path, const struct dm_config_value **result);
int dm_config_get_section(const struct dm_config_node *cn, const char *path, const struct dm_config_node **result);
unsigned dm_config_maybe_section(const char *str, unsigned len);
const char *dm_config_parent_name(const struct dm_config_node *n);
struct dm_config_node *dm_config_clone_node_with_mem(struct dm_pool *mem, const struct dm_config_node *node, int siblings);
struct dm_config_node *dm_config_create_node(struct dm_config_tree *cft, const char *key);
struct dm_config_value *dm_config_create_value(struct dm_config_tree *cft);
struct dm_config_node *dm_config_clone_node(struct dm_config_tree *cft, const struct dm_config_node *cn, int siblings);
/*
* Common formatting flags applicable to all config node types (lower 16 bits).
*/
#define DM_CONFIG_VALUE_FMT_COMMON_ARRAY 0x00000001 /* value is array */
#define DM_CONFIG_VALUE_FMT_COMMON_EXTRA_SPACES 0x00000002 /* add spaces in "key = value" pairs in constrast to "key=value" for better readability */
/*
* Type-related config node formatting flags (higher 16 bits).
*/
/* int-related formatting flags */
#define DM_CONFIG_VALUE_FMT_INT_OCTAL 0x00010000 /* print number in octal form */
/* string-related formatting flags */
#define DM_CONFIG_VALUE_FMT_STRING_NO_QUOTES 0x00010000 /* do not print quotes around string value */
void dm_config_value_set_format_flags(struct dm_config_value *cv, uint32_t format_flags);
uint32_t dm_config_value_get_format_flags(struct dm_config_value *cv);
struct dm_pool *dm_config_memory(struct dm_config_tree *cft);
/* Udev device directory. */
#define DM_UDEV_DEV_DIR "/dev/"
/* Cookie prefixes.
*
* The cookie value consists of a prefix (16 bits) and a base (16 bits).
* We can use the prefix to store the flags. These flags are sent to
* kernel within given dm task. When returned back to userspace in
* DM_COOKIE udev environment variable, we can control several aspects
* of udev rules we use by decoding the cookie prefix. When doing the
* notification, we replace the cookie prefix with DM_COOKIE_MAGIC,
* so we notify the right semaphore.
*
* It is still possible to use cookies for passing the flags to udev
* rules even when udev_sync is disabled. The base part of the cookie
* will be zero (there's no notification semaphore) and prefix will be
* set then. However, having udev_sync enabled is highly recommended.
*/
#define DM_COOKIE_MAGIC 0x0D4D
#define DM_UDEV_FLAGS_MASK 0xFFFF0000
#define DM_UDEV_FLAGS_SHIFT 16
/*
* DM_UDEV_DISABLE_DM_RULES_FLAG is set in case we need to disable
* basic device-mapper udev rules that create symlinks in /dev/<DM_DIR>
* directory. However, we can't reliably prevent creating default
* nodes by udev (commonly /dev/dm-X, where X is a number).
*/
#define DM_UDEV_DISABLE_DM_RULES_FLAG 0x0001
/*
* DM_UDEV_DISABLE_SUBSYTEM_RULES_FLAG is set in case we need to disable
* subsystem udev rules, but still we need the general DM udev rules to
* be applied (to create the nodes and symlinks under /dev and /dev/disk).
*/
#define DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG 0x0002
/*
* DM_UDEV_DISABLE_DISK_RULES_FLAG is set in case we need to disable
* general DM rules that set symlinks in /dev/disk directory.
*/
#define DM_UDEV_DISABLE_DISK_RULES_FLAG 0x0004
/*
* DM_UDEV_DISABLE_OTHER_RULES_FLAG is set in case we need to disable
* all the other rules that are not general device-mapper nor subsystem
* related (the rules belong to other software or packages). All foreign
* rules should check this flag directly and they should ignore further
* rule processing for such event.
*/
#define DM_UDEV_DISABLE_OTHER_RULES_FLAG 0x0008
/*
* DM_UDEV_LOW_PRIORITY_FLAG is set in case we need to instruct the
* udev rules to give low priority to the device that is currently
* processed. For example, this provides a way to select which symlinks
* could be overwritten by high priority ones if their names are equal.
* Common situation is a name based on FS UUID while using origin and
* snapshot devices.
*/
#define DM_UDEV_LOW_PRIORITY_FLAG 0x0010
/*
* DM_UDEV_DISABLE_LIBRARY_FALLBACK is set in case we need to disable
* libdevmapper's node management. We will rely on udev completely
* and there will be no fallback action provided by libdevmapper if
* udev does something improperly. Using the library fallback code has
* a consequence that you need to take into account: any device node
* or symlink created without udev is not recorded in udev database
* which other applications may read to get complete list of devices.
* For this reason, use of DM_UDEV_DISABLE_LIBRARY_FALLBACK is
* recommended on systems where udev is used. Keep library fallback
* enabled just for exceptional cases where you need to debug udev-related
* problems. If you hit such problems, please contact us through upstream
* LVM2 development mailing list (see also README file). This flag is
* currently not set by default in libdevmapper so you need to set it
* explicitly if you're sure that udev is behaving correctly on your
* setups.
*/
#define DM_UDEV_DISABLE_LIBRARY_FALLBACK 0x0020
/*
* DM_UDEV_PRIMARY_SOURCE_FLAG is automatically appended by
* libdevmapper for all ioctls generating udev uevents. Once used in
* udev rules, we know if this is a real "primary sourced" event or not.
* We need to distinguish real events originated in libdevmapper from
* any spurious events to gather all missing information (e.g. events
* generated as a result of "udevadm trigger" command or as a result
* of the "watch" udev rule).
*/
#define DM_UDEV_PRIMARY_SOURCE_FLAG 0x0040
/*
* Udev flags reserved for use by any device-mapper subsystem.
*/
#define DM_SUBSYSTEM_UDEV_FLAG0 0x0100
#define DM_SUBSYSTEM_UDEV_FLAG1 0x0200
#define DM_SUBSYSTEM_UDEV_FLAG2 0x0400
#define DM_SUBSYSTEM_UDEV_FLAG3 0x0800
#define DM_SUBSYSTEM_UDEV_FLAG4 0x1000
#define DM_SUBSYSTEM_UDEV_FLAG5 0x2000
#define DM_SUBSYSTEM_UDEV_FLAG6 0x4000
#define DM_SUBSYSTEM_UDEV_FLAG7 0x8000
int dm_cookie_supported(void);
/*
* Udev synchronization functions.
*/
void dm_udev_set_sync_support(int sync_with_udev);
int dm_udev_get_sync_support(void);
void dm_udev_set_checking(int checking);
int dm_udev_get_checking(void);
/*
* Default value to get new auto generated cookie created
*/
#define DM_COOKIE_AUTO_CREATE 0
int dm_udev_create_cookie(uint32_t *cookie);
int dm_udev_complete(uint32_t cookie);
int dm_udev_wait(uint32_t cookie);
/*
* dm_dev_wait_immediate
* If *ready is 1 on return, the wait is complete.
* If *ready is 0 on return, the wait is incomplete and either
* this function or dm_udev_wait() must be called again.
* Returns 0 on error, when neither function should be called again.
*/
int dm_udev_wait_immediate(uint32_t cookie, int *ready);
#define DM_DEV_DIR_UMASK 0022
#define DM_CONTROL_NODE_UMASK 0177
#ifdef __cplusplus
}
#endif
#endif /* LIB_DEVICE_MAPPER_H */
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