shaba/lvm2
1
0
Fork 0
mirror of git://sourceware.org/git/lvm2.git synced 2024-12-21 13:34:40 +03:00
Code Releases Activity
1b68841605
lvm2/libdm/libdm-stats.c
Zdenek Kabelac 39b7d1ba8f cleanup: typos in comments 
Collection of typos in code comments.
Should have no runtime effect.
2024-08-30 16:51:15 +02:00

5189 lines
128 KiB
C
Raw Blame History

/*
* Copyright (C) 2016 Red Hat, Inc. All rights reserved.
*
* _stats_get_extents_for_file() based in part on filefrag_fiemap() from
* e2fsprogs/misc/filefrag.c. Copyright 2003 by Theodore Ts'o.
*
* 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,
* Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
*/
#include "libdm/misc/dmlib.h"
#include "libdm/misc/kdev_t.h"
#include "math.h" /* log10() */
#include <sys/sysmacros.h>
#include <sys/ioctl.h>
#include <sys/vfs.h> /* fstatfs */
#ifdef __linux__
#include <linux/fs.h> /* FS_IOC_FIEMAP */
#endif
#ifdef HAVE_LINUX_FIEMAP_H
#include <linux/fiemap.h> /* fiemap */
#endif
#ifdef HAVE_LINUX_MAGIC_H
#include <linux/magic.h> /* BTRFS_SUPER_MAGIC */
#endif
#define DM_STATS_REGION_NOT_PRESENT UINT64_MAX
#define DM_STATS_GROUP_NOT_PRESENT DM_STATS_GROUP_NONE
#define NSEC_PER_USEC 1000L
#define NSEC_PER_MSEC 1000000L
#define NSEC_PER_SEC 1000000000L
#define PRECISE_ARG "precise_timestamps"
#define HISTOGRAM_ARG "histogram:"
#define STATS_ROW_BUF_LEN 4096
#define STATS_MSG_BUF_LEN 1024
#define STATS_FIE_BUF_LEN 2048
#define SECTOR_SHIFT 9L
/* Histogram bin */
struct dm_histogram_bin {
uint64_t upper; /* Upper bound on this bin. */
uint64_t count; /* Count value for this bin. */
};
struct dm_histogram {
/* The stats handle this histogram belongs to. */
const struct dm_stats *dms;
/* The region this histogram belongs to. */
const struct dm_stats_region *region;
uint64_t sum; /* Sum of histogram bin counts. */
int nr_bins; /* Number of histogram bins assigned. */
struct dm_histogram_bin bins[];
};
/*
* See Documentation/device-mapper/statistics.txt for full descriptions
* of the device-mapper statistics counter fields.
*/
struct dm_stats_counters {
uint64_t reads; /* Num reads completed */
uint64_t reads_merged; /* Num reads merged */
uint64_t read_sectors; /* Num sectors read */
uint64_t read_nsecs; /* Num milliseconds spent reading */
uint64_t writes; /* Num writes completed */
uint64_t writes_merged; /* Num writes merged */
uint64_t write_sectors; /* Num sectors written */
uint64_t write_nsecs; /* Num milliseconds spent writing */
uint64_t io_in_progress; /* Num I/Os currently in progress */
uint64_t io_nsecs; /* Num milliseconds spent doing I/Os */
uint64_t weighted_io_nsecs; /* Weighted num milliseconds doing I/Os */
uint64_t total_read_nsecs; /* Total time spent reading in milliseconds */
uint64_t total_write_nsecs; /* Total time spent writing in milliseconds */
struct dm_histogram *histogram; /* Histogram. */
};
struct dm_stats_region {
uint64_t region_id; /* as returned by @stats_list */
uint64_t group_id;
uint64_t start;
uint64_t len;
uint64_t step;
char *program_id;
char *aux_data;
uint64_t timescale; /* precise_timestamps is per-region */
struct dm_histogram *bounds; /* histogram configuration */
struct dm_histogram *histogram; /* aggregate cache */
struct dm_stats_counters *counters;
};
struct dm_stats_group {
uint64_t group_id;
const char *alias;
dm_bitset_t regions;
struct dm_histogram *histogram;
};
struct dm_stats {
/* device binding */
int bind_major; /* device major that this dm_stats object is bound to */
int bind_minor; /* device minor that this dm_stats object is bound to */
char *bind_name; /* device-mapper device name */
char *bind_uuid; /* device-mapper UUID */
char *program_id; /* default program_id for this handle */
const char *name; /* cached device_name used for reporting */
struct dm_pool *mem; /* memory pool for region and counter tables */
struct dm_pool *hist_mem; /* separate pool for histogram tables */
struct dm_pool *group_mem; /* separate pool for group tables */
uint64_t nr_regions; /* total number of present regions */
uint64_t max_region; /* size of the regions table */
uint64_t interval_ns; /* sampling interval in nanoseconds */
uint64_t timescale; /* default sample value multiplier */
int precise; /* use precise_timestamps when creating regions */
struct dm_stats_region *regions;
struct dm_stats_group *groups;
/* statistics cursor */
uint64_t walk_flags; /* walk control flags */
uint64_t cur_flags;
uint64_t cur_group;
uint64_t cur_region;
uint64_t cur_area;
};
static char *_stats_escape_aux_data(const char *aux_data)
{
size_t aux_data_len = strlen(aux_data);
char *escaped = dm_malloc((3 * aux_data_len + 1) * sizeof(char));
size_t index = 0, i;
if (!escaped) {
log_error("Could not allocate memory for escaped "
"aux_data string.");
return NULL;
}
for (i = 0; i < aux_data_len; i++) {
if (aux_data[i] == ' ') {
escaped[index++] = '\\';
escaped[index++] = ' ';
} else if (aux_data[i] == '\\') {
escaped[index++] = '\\';
escaped[index++] = '\\';
} else if (aux_data[i] == '\t') {
escaped[index++] = '\\';
escaped[index++] = '\t';
} else {
escaped[index++] = aux_data[i];
}
}
escaped[index] = '\0';
return escaped;
}
#define PROC_SELF_COMM "/proc/self/comm"
static char *_program_id_from_proc(void)
{
FILE *comm = NULL;
char buf[STATS_ROW_BUF_LEN];
if (!(comm = fopen(PROC_SELF_COMM, "r")))
return_NULL;
if (!fgets(buf, sizeof(buf), comm)) {
log_error("Could not read from %s", PROC_SELF_COMM);
if (fclose(comm))
stack;
return NULL;
}
if (fclose(comm))
stack;
return dm_strdup(buf);
}
static uint64_t _nr_areas(uint64_t len, uint64_t step)
{
/* Default is one area. */
if (!len || !step)
return 1;
/*
* drivers/md/dm-stats.c::message_stats_create()
* A region may be sub-divided into areas with their own counters.
* Any partial area at the end of the region is treated as an
* additional complete area.
*/
return (len + step - 1) / step;
}
static uint64_t _nr_areas_region(struct dm_stats_region *region)
{
return _nr_areas(region->len, region->step);
}
struct dm_stats *dm_stats_create(const char *program_id)
{
size_t hist_hint = sizeof(struct dm_histogram_bin);
size_t group_hint = sizeof(struct dm_stats_group);
struct dm_stats *dms = NULL;
if (!(dms = dm_zalloc(sizeof(*dms))))
return_NULL;
/* FIXME: better hint. */
if (!(dms->mem = dm_pool_create("stats_pool", 4096))) {
dm_free(dms);
return_NULL;
}
if (!(dms->hist_mem = dm_pool_create("histogram_pool", hist_hint)))
goto_bad;
if (!(dms->group_mem = dm_pool_create("group_pool", group_hint)))
goto_bad;
if (!program_id || !strlen(program_id))
dms->program_id = _program_id_from_proc();
else
dms->program_id = dm_strdup(program_id);
if (!dms->program_id) {
log_error("Could not allocate memory for program_id");
goto bad;
}
dms->bind_major = -1;
dms->bind_minor = -1;
dms->bind_name = NULL;
dms->bind_uuid = NULL;
dms->name = NULL;
/* by default all regions use msec precision */
dms->timescale = NSEC_PER_MSEC;
dms->precise = 0;
dms->nr_regions = DM_STATS_REGION_NOT_PRESENT;
dms->max_region = DM_STATS_REGION_NOT_PRESENT;
dms->regions = NULL;
/* maintain compatibility with earlier walk version */
dms->walk_flags = dms->cur_flags = DM_STATS_WALK_DEFAULT;
return dms;
bad:
dm_pool_destroy(dms->mem);
if (dms->hist_mem)
dm_pool_destroy(dms->hist_mem);
if (dms->group_mem)
dm_pool_destroy(dms->group_mem);
dm_free(dms);
return NULL;
}
/*
* Test whether the stats region pointed to by region is present.
*/
static int _stats_region_present(const struct dm_stats_region *region)
{
return !(region->region_id == DM_STATS_REGION_NOT_PRESENT);
}
/*
* Test whether the stats group pointed to by group is present.
*/
static int _stats_group_present(const struct dm_stats_group *group)
{
return !(group->group_id == DM_STATS_GROUP_NOT_PRESENT);
}
/*
* Test whether a stats group id is present.
*/
static int _stats_group_id_present(const struct dm_stats *dms, uint64_t id)
{
struct dm_stats_group *group = NULL;
if (id == DM_STATS_GROUP_NOT_PRESENT)
return 0;
if (!dms)
return_0;
if (!dms->regions)
return 0;
if (id > dms->max_region)
return 0;
group = &dms->groups[id];
return _stats_group_present(group);
}
/*
* Test whether the given region_id is a member of any group.
*/
static uint64_t _stats_region_is_grouped(const struct dm_stats* dms,
uint64_t region_id)
{
uint64_t group_id;
if (region_id == DM_STATS_GROUP_NOT_PRESENT)
return 0;
if (!_stats_region_present(&dms->regions[region_id]))
return 0;
group_id = dms->regions[region_id].group_id;
return group_id != DM_STATS_GROUP_NOT_PRESENT;
}
static void _stats_histograms_destroy(struct dm_pool *mem,
struct dm_stats_region *region)
{
/* Unpopulated handle. */
if (!region->counters)
return;
/*
* Free everything in the pool back to the first histogram.
*/
if (region->counters[0].histogram)
dm_pool_free(mem, region->counters[0].histogram);
}
static void _stats_region_destroy(struct dm_stats_region *region)
{
if (!_stats_region_present(region))
return;
region->start = region->len = region->step = 0;
region->timescale = 0;
/*
* Don't free counters and histogram bounds here: they are
* dropped from the pool along with the corresponding
* regions table.
*
* The following objects are all allocated with dm_malloc.
*/
region->counters = NULL;
region->bounds = NULL;
dm_free(region->program_id);
region->program_id = NULL;
dm_free(region->aux_data);
region->aux_data = NULL;
region->region_id = DM_STATS_REGION_NOT_PRESENT;
}
static void _stats_regions_destroy(struct dm_stats *dms)
{
struct dm_pool *mem = dms->mem;
uint64_t i;
if (!dms->regions)
return;
/* walk backwards to obey pool order */
for (i = dms->max_region; (i != DM_STATS_REGION_NOT_PRESENT); i--) {
_stats_histograms_destroy(dms->hist_mem, &dms->regions[i]);
_stats_region_destroy(&dms->regions[i]);
}
dm_pool_free(mem, dms->regions);
dms->regions = NULL;
}
static void _stats_group_destroy(struct dm_stats_group *group)
{
if (!_stats_group_present(group))
return;
group->histogram = NULL;
if (group->alias) {
dm_free((char *) group->alias);
group->alias = NULL;
}
if (group->regions) {
dm_bitset_destroy(group->regions);
group->regions = NULL;
}
group->group_id = DM_STATS_GROUP_NOT_PRESENT;
}
static void _stats_groups_destroy(struct dm_stats *dms)
{
uint64_t i;
if (!dms->groups)
return;
for (i = dms->max_region; (i != DM_STATS_REGION_NOT_PRESENT); i--)
_stats_group_destroy(&dms->groups[i]);
dm_pool_free(dms->group_mem, dms->groups);
dms->groups = NULL;
}
static int _set_stats_device(struct dm_stats *dms, struct dm_task *dmt)
{
if (dms->bind_name)
return dm_task_set_name(dmt, dms->bind_name);
if (dms->bind_uuid)
return dm_task_set_uuid(dmt, dms->bind_uuid);
if (dms->bind_major > 0)
return dm_task_set_major(dmt, dms->bind_major)
&& dm_task_set_minor(dmt, dms->bind_minor);
return_0;
}
static int _stats_bound(const struct dm_stats *dms)
{
if (dms->bind_major > 0 || dms->bind_name || dms->bind_uuid)
return 1;
/* %p format specifier expects a void pointer. */
log_error("Stats handle at %p is not bound.", (const void *)dms);
return 0;
}
static void _stats_clear_binding(struct dm_stats *dms)
{
if (dms->bind_name)
dm_pool_free(dms->mem, dms->bind_name);
if (dms->bind_uuid)
dm_pool_free(dms->mem, dms->bind_uuid);
dm_free((char *) dms->name);
dms->bind_name = dms->bind_uuid = NULL;
dms->bind_major = dms->bind_minor = -1;
dms->name = NULL;
}
int dm_stats_bind_devno(struct dm_stats *dms, int major, int minor)
{
_stats_clear_binding(dms);
_stats_regions_destroy(dms);
_stats_groups_destroy(dms);
dms->bind_major = major;
dms->bind_minor = minor;
return 1;
}
int dm_stats_bind_name(struct dm_stats *dms, const char *name)
{
_stats_clear_binding(dms);
_stats_regions_destroy(dms);
_stats_groups_destroy(dms);
if (!(dms->bind_name = dm_pool_strdup(dms->mem, name)))
return_0;
return 1;
}
int dm_stats_bind_uuid(struct dm_stats *dms, const char *uuid)
{
_stats_clear_binding(dms);
_stats_regions_destroy(dms);
_stats_groups_destroy(dms);
if (!(dms->bind_uuid = dm_pool_strdup(dms->mem, uuid)))
return_0;
return 1;
}
int dm_stats_bind_from_fd(struct dm_stats *dms, int fd)
{
int major, minor;
struct stat buf;
if (fstat(fd, &buf)) {
log_error("fstat failed for fd %d.", fd);
return 0;
}
major = (int) MAJOR(buf.st_dev);
minor = (int) MINOR(buf.st_dev);
if (!dm_stats_bind_devno(dms, major, minor))
return_0;
return 1;
}
static int _stats_check_precise_timestamps(const struct dm_stats *dms)
{
/* Already checked? */
if (dms && dms->precise)
return 1;
return dm_message_supports_precise_timestamps();
}
int dm_stats_driver_supports_precise(void)
{
return _stats_check_precise_timestamps(NULL);
}
int dm_stats_driver_supports_histogram(void)
{
return _stats_check_precise_timestamps(NULL);
}
static int _fill_hist_arg(char *hist_arg, size_t hist_len, uint64_t scale,
struct dm_histogram *bounds)
{
int i, l, len = 0, nr_bins;
char *arg = hist_arg;
uint64_t value;
nr_bins = bounds->nr_bins;
for (i = 0; i < nr_bins; i++) {
value = bounds->bins[i].upper / scale;
if ((l = dm_snprintf(arg, hist_len - len, FMTu64"%s", value,
(i == (nr_bins - 1)) ? "" : ",")) < 0)
return_0;
len += l;
arg += l;
}
return 1;
}
static void *_get_hist_arg(struct dm_histogram *bounds, uint64_t scale,
size_t *len)
{
struct dm_histogram_bin *entry, *bins;
size_t hist_len = 1; /* terminating '\0' */
double value;
entry = bins = bounds->bins;
entry += bounds->nr_bins - 1;
while(entry >= bins) {
value = (double) (entry--)->upper;
/* Use lround to avoid size_t -> double cast warning. */
hist_len += 1 + (size_t) lround(log10(value / scale));
if (entry != bins)
hist_len++; /* ',' */
}
*len = hist_len;
return dm_zalloc(hist_len);
}
static char *_build_histogram_arg(struct dm_histogram *bounds, int *precise)
{
struct dm_histogram_bin *entry, *bins;
size_t hist_len;
char *hist_arg;
uint64_t scale;
entry = bins = bounds->bins;
/* Empty histogram is invalid. */
if (!bounds->nr_bins) {
log_error("Cannot format empty histogram description.");
return NULL;
}
/* Validate entries and set *precise if precision < 1ms. */
entry += bounds->nr_bins - 1;
while (entry >= bins) {
if (entry != bins) {
if (entry->upper < (entry - 1)->upper) {
log_error("Histogram boundaries must be in "
"order of increasing magnitude.");
return 0;
}
}
/*
* Only enable precise_timestamps automatically if any
* value in the histogram bounds uses precision < 1ms.
*/
if (((entry--)->upper % NSEC_PER_MSEC) && !*precise)
*precise = 1;
}
scale = (*precise) ? 1 : NSEC_PER_MSEC;
/* Calculate hist_len and allocate a character buffer. */
if (!(hist_arg = _get_hist_arg(bounds, scale, &hist_len))) {
log_error("Could not allocate memory for histogram argument.");
return 0;
}
/* Fill hist_arg with boundary strings. */
if (!_fill_hist_arg(hist_arg, hist_len, scale, bounds))
goto_bad;
return hist_arg;
bad:
log_error("Could not build histogram arguments.");
dm_free(hist_arg);
return NULL;
}
static struct dm_task *_stats_send_message(struct dm_stats *dms, char *msg)
{
struct dm_task *dmt;
if (!(dmt = dm_task_create(DM_DEVICE_TARGET_MSG)))
return_0;
if (!_set_stats_device(dms, dmt))
goto_bad;
if (!dm_task_set_message(dmt, msg))
goto_bad;
if (!dm_task_run(dmt))
goto_bad;
return dmt;
bad:
dm_task_destroy(dmt);
return NULL;
}
/*
* Cache the dm device_name for the device bound to dms.
*/
static int _stats_set_name_cache(struct dm_stats *dms)
{
struct dm_task *dmt;
if (dms->name)
return 1;
if (!(dmt = dm_task_create(DM_DEVICE_INFO)))
return_0;
if (!_set_stats_device(dms, dmt))
goto_bad;
if (!dm_task_run(dmt))
goto_bad;
if (!(dms->name = dm_strdup(dm_task_get_name(dmt))))
goto_bad;
dm_task_destroy(dmt);
return 1;
bad:
log_error("Could not retrieve device-mapper name for device.");
dm_task_destroy(dmt);
return 0;
}
/*
* update region group_id values
*/
static void _stats_update_groups(struct dm_stats *dms)
{
struct dm_stats_group *group;
uint64_t group_id, i;
for (group_id = 0; group_id < dms->max_region + 1; group_id++) {
if (!_stats_group_id_present(dms, group_id))
continue;
group = &dms->groups[group_id];
for (i = dm_bit_get_first(group->regions);
i != DM_STATS_GROUP_NOT_PRESENT;
i = dm_bit_get_next(group->regions, i))
dms->regions[i].group_id = group_id;
}
}
static void _check_group_regions_present(struct dm_stats *dms,
struct dm_stats_group *group)
{
dm_bitset_t regions = group->regions;
int64_t i, group_id;
group_id = i = dm_bit_get_first(regions);
for (; i > 0; i = dm_bit_get_next(regions, i))
if (!_stats_region_present(&dms->regions[i])) {
log_warn("Group descriptor " FMTd64 " contains "
"non-existent region_id " FMTd64 ".",
group_id, i);
dm_bit_clear(regions, i);
}
}
/*
* Parse a DMS_GROUP group descriptor embedded in a region's aux_data.
*
* DMS_GROUP="ALIAS:MEMBERS"
*
* ALIAS: group alias
* MEMBERS: list of group member region ids.
*
*/
#define DMS_GROUP_TAG "DMS_GROUP="
#define DMS_GROUP_TAG_LEN (sizeof(DMS_GROUP_TAG) - 1)
#define DMS_GROUP_SEP ':'
#define DMS_AUX_SEP "#"
#define DMS_AUX_SEP_CHAR '#'
#define DMS_GROUP_QUOTE '"'
static int _parse_aux_data_group(struct dm_stats *dms,
struct dm_stats_region *region,
struct dm_stats_group *group)
{
char *alias, *c, *end;
dm_bitset_t regions;
memset(group, 0, sizeof(*group));
group->group_id = DM_STATS_GROUP_NOT_PRESENT;
/* find start of group tag */
c = strstr(region->aux_data, DMS_GROUP_TAG);
if (!c)
return 1; /* no group is not an error */
/* extract alias from quotes */
alias = c + strlen(DMS_GROUP_TAG) + 1;
c = strchr(c, DMS_GROUP_SEP);
if (!c) {
log_error("Found malformed group tag while reading aux_data");
return 0;
}
/* terminate alias and advance to members accounting for closing quote */
*(c - 1) = '\0';
c++;
log_debug("Read alias '%s' from aux_data", alias);
if (!c) {
log_error("Found malformed group descriptor while "
"reading aux_data, expected '%c'", DMS_GROUP_SEP);
return 0;
}
/* if user aux_data follows make sure we have a terminated
* string to pass to dm_bitset_parse_list().
*/
end = strstr(c, DMS_AUX_SEP);
if (!end)
end = c + strlen(c);
*(end++) = '\0';
if (!(regions = dm_bitset_parse_list(c, NULL, 0))) {
log_error("Could not parse member list while "
"reading group aux_data");
return 0;
}
group->group_id = dm_bit_get_first(regions);
if (group->group_id != region->region_id) {
log_error("Found invalid group descriptor in region " FMTu64
" aux_data.", region->region_id);
group->group_id = DM_STATS_GROUP_NOT_PRESENT;
goto bad;
}
group->regions = regions;
group->alias = NULL;
if (strlen(alias)) {
group->alias = dm_strdup(alias);
if (!group->alias) {
log_error("Could not allocate memory for group alias");
goto bad;
}
}
/* separate group tag from user aux_data */
if ((strlen(end) > 1) || strncmp(end, "-", 1))
c = dm_strdup(end);
else
c = dm_strdup("");
if (!c) {
log_error("Could not allocate memory for user aux_data");
goto bad_alias;
}
dm_free(region->aux_data);
region->aux_data = c;
log_debug("Found group_id " FMTu64 ": alias=\"%s\"", group->group_id,
(group->alias) ? group->alias : "");
return 1;
bad_alias:
dm_free((char *) group->alias);
bad:
dm_bitset_destroy(regions);
return 0;
}
/*
* Parse a histogram specification returned by the kernel in a
* @stats_list response.
*/
static int _stats_parse_histogram_spec(struct dm_stats *dms,
struct dm_stats_region *region,
const char *histogram)
{
const char valid_chars[] = "0123456789,";
uint64_t scale = region->timescale, this_val = 0;
struct dm_pool *mem = dms->hist_mem;
struct dm_histogram_bin cur;
struct dm_histogram hist = { 0 };
int nr_bins = 1;
const char *c, *v, *val_start;
char *p, *endptr = NULL;
/* Advance past "histogram:". */
histogram = strchr(histogram, ':');
if (!histogram) {
log_error("Could not parse histogram description.");
return 0;
}
histogram++;
/* @stats_list rows are newline terminated. */
if ((p = strchr(histogram, '\n')))
*p = '\0';
if (!dm_pool_begin_object(mem, sizeof(cur)))
return_0;
hist.nr_bins = 0; /* fix later */
hist.region = region;
hist.dms = dms;
if (!dm_pool_grow_object(mem, &hist, sizeof(hist)))
goto_bad;
c = histogram;
do {
for (v = valid_chars; *v; v++)
if (*c == *v)
break;
if (!*v) {
stack;
goto badchar;
}
if (*c == ',') {
log_error("Invalid histogram description: %s",
histogram);
goto bad;
} else {
val_start = c;
endptr = NULL;
errno = 0;
this_val = strtoull(val_start, &endptr, 10);
if (errno || !endptr) {
log_error("Could not parse histogram boundary.");
goto bad;
}
c = endptr; /* Advance to units, comma, or end. */
if (*c == ',')
c++;
else if (*c || (*c == ' ')) { /* Expected ',' or NULL. */
stack;
goto badchar;
}
if (*c == ',')
c++;
cur.upper = scale * this_val;
cur.count = 0;
if (!dm_pool_grow_object(mem, &cur, sizeof(cur)))
goto_bad;
nr_bins++;
}
} while (*c && (*c != ' '));
/* final upper bound. */
cur.upper = UINT64_MAX;
if (!dm_pool_grow_object(mem, &cur, sizeof(cur)))
goto_bad;
region->bounds = dm_pool_end_object(mem);
if (!region->bounds)
return_0;
region->bounds->nr_bins = nr_bins;
log_debug("Added region histogram spec with %d entries.", nr_bins);
return 1;
badchar:
log_error("Invalid character in histogram: '%c' (0x%x)", *c, *c);
bad:
dm_pool_abandon_object(mem);
return 0;
}
static int _stats_parse_string_data(char *string_data, char **program_id,
char **aux_data, char **stats_args)
{
char *p, *next_gap, *empty_string = (char *)"";
size_t len;
/*
* String data format:
* <program_id> <aux_data> [precise_timestamps] [histogram:n1,n2,n3,..]
*/
/* Remove trailing whitespace */
len = strlen(string_data);
if (len > 0 && (string_data)[len - 1] == '\n') {
(string_data)[len - 1] = '\0';
}
p = strchr(string_data, ' ');
*program_id = string_data;
if (!p) {
*aux_data = *stats_args = empty_string;
return 1;
}
*p = '\0';
p++;
if (strstr(p, DMS_GROUP_TAG)) {
*aux_data = p;
/* Skip over the group tag */
if ((next_gap = strchr(p, DMS_AUX_SEP_CHAR)))
next_gap = strchr(next_gap, ' ');
if (next_gap) {
*(next_gap++) = '\0';
*stats_args = next_gap++;
} else
*stats_args = empty_string;
} else {
next_gap = strchr(p, ' ');
if (next_gap) {
*next_gap = '\0';
*aux_data = p;
*stats_args = next_gap + 1;
} else {
*aux_data = p;
*stats_args = empty_string;
}
}
if (!strncmp(*program_id, "-", 1))
*program_id = empty_string;
if (!strncmp(*aux_data, "-", 1))
*aux_data = empty_string;
return 1;
}
static int _stats_parse_list_region(struct dm_stats *dms,
struct dm_stats_region *region, char *line)
{
char string_data[STATS_ROW_BUF_LEN] = { 0 };
char *p, *program_id, *aux_data, *stats_args;
int r;
/*
* Parse fixed fields, line format:
*
* <region_id>: <start_sector>+<length> <step> <string data>
*
* Maximum string data size is 4096 - 1 bytes.
*/
r = sscanf(line, FMTu64 ": " FMTu64 "+" FMTu64 " " FMTu64 " %4095c",
&region->region_id, &region->start, &region->len,
&region->step, string_data);
if (r != 5) {
return 0;
}
if (!_stats_parse_string_data(string_data, &program_id, &aux_data, &stats_args)) {
return_0;
}
region->timescale = strstr(stats_args, PRECISE_ARG) ? 1 : NSEC_PER_MSEC;
p = strstr(stats_args, HISTOGRAM_ARG);
if (p) {
if (!_stats_parse_histogram_spec(dms, region, p)) {
return_0;
}
} else {
region->bounds = NULL;
}
region->histogram = NULL;
region->group_id = DM_STATS_GROUP_NOT_PRESENT;
if (!(region->program_id = dm_strdup(program_id))) {
return_0;
}
if (!(region->aux_data = dm_strdup(aux_data))) {
dm_free(region->program_id);
return_0;
}
region->counters = NULL;
return 1;
}
static int _stats_parse_list(struct dm_stats *dms, const char *resp)
{
uint64_t max_region = 0, nr_regions = 0;
struct dm_stats_region cur, fill;
struct dm_stats_group cur_group;
struct dm_pool *mem = dms->mem, *group_mem = dms->group_mem;
char line[STATS_ROW_BUF_LEN];
FILE *list_rows;
if (!resp) {
log_error("Could not parse NULL @stats_list response.");
return 0;
}
_stats_regions_destroy(dms);
_stats_groups_destroy(dms);
/* no regions */
if (!strlen(resp)) {
dms->nr_regions = dms->max_region = 0;
dms->regions = NULL;
return 1;
}
/*
* dm_task_get_message_response() returns a 'const char *' but
* since fmemopen also permits "w" it expects a 'char *'.
*/
/* coverity[alloc_strlen] intentional */
if (!(list_rows = fmemopen((char *)resp, strlen(resp), "r")))
return_0;
/* begin region table */
if (!dm_pool_begin_object(mem, 1024))
goto_bad;
/* begin group table */
if (!dm_pool_begin_object(group_mem, 32))
goto_bad;
while(fgets(line, sizeof(line), list_rows)) {
cur_group.group_id = DM_STATS_GROUP_NOT_PRESENT;
cur_group.regions = NULL;
cur_group.alias = NULL;
if (!_stats_parse_list_region(dms, &cur, line))
goto_bad;
/* handle holes in the list of region_ids */
if (cur.region_id > max_region) {
memset(&fill, 0, sizeof(fill));
memset(&cur_group, 0, sizeof(cur_group));
fill.region_id = DM_STATS_REGION_NOT_PRESENT;
cur_group.group_id = DM_STATS_GROUP_NOT_PRESENT;
do {
if (!dm_pool_grow_object(mem, &fill, sizeof(fill)))
goto_bad;
if (!dm_pool_grow_object(group_mem, &cur_group,
sizeof(cur_group)))
goto_bad;
} while (max_region++ < (cur.region_id - 1));
}
if (cur.aux_data)
if (!_parse_aux_data_group(dms, &cur, &cur_group))
log_error("Failed to parse group descriptor "
"from region_id " FMTu64 " aux_data:"
"'%s'", cur.region_id, cur.aux_data);
/* continue */
if (!dm_pool_grow_object(mem, &cur, sizeof(cur)))
goto_bad;
if (!dm_pool_grow_object(group_mem, &cur_group,
sizeof(cur_group)))
goto_bad;
max_region++;
nr_regions++;
}
if (!nr_regions)
/* no region data read from @stats_list */
goto bad;
dms->nr_regions = nr_regions;
dms->max_region = max_region - 1;
dms->regions = dm_pool_end_object(mem);
dms->groups = dm_pool_end_object(group_mem);
dm_stats_foreach_group(dms)
_check_group_regions_present(dms, &dms->groups[dms->cur_group]);
_stats_update_groups(dms);
if (fclose(list_rows))
stack;
return 1;
bad:
if (fclose(list_rows))
stack;
dm_pool_abandon_object(mem);
dm_pool_abandon_object(group_mem);
return 0;
}
int dm_stats_list(struct dm_stats *dms, const char *program_id)
{
char msg[STATS_MSG_BUF_LEN];
struct dm_task *dmt;
int r;
if (!_stats_bound(dms))
return_0;
/* allow zero-length program_id for list */
if (!program_id)
program_id = dms->program_id;
if (!_stats_set_name_cache(dms))
return_0;
if (dms->regions)
_stats_regions_destroy(dms);
r = dm_snprintf(msg, sizeof(msg), "@stats_list %s", program_id);
if (r < 0) {
log_error("Failed to prepare stats message.");
return 0;
}
if (!(dmt = _stats_send_message(dms, msg)))
return_0;
if (!_stats_parse_list(dms, dm_task_get_message_response(dmt))) {
log_error("Could not parse @stats_list response.");
goto bad;
}
dm_task_destroy(dmt);
return 1;
bad:
dm_task_destroy(dmt);
return 0;
}
/*
* Parse histogram data returned from a @stats_print operation.
*/
static int _stats_parse_histogram(struct dm_pool *mem, char *hist_str,
struct dm_histogram **histogram,
struct dm_stats_region *region)
{
const char valid_chars[] = "0123456789:";
struct dm_histogram *bounds = region->bounds;
struct dm_histogram hist = {
.nr_bins = region->bounds->nr_bins
};
const char *c, *v, *val_start;
struct dm_histogram_bin cur;
uint64_t sum = 0, this_val;
char *endptr = NULL;
int bin = 0;
c = hist_str;
if (!dm_pool_begin_object(mem, sizeof(cur)))
return_0;
if (!dm_pool_grow_object(mem, &hist, sizeof(hist)))
goto_bad;
do {
memset(&cur, 0, sizeof(cur));
for (v = valid_chars; *v; v++)
if (*c == *v)
break;
if (!*v)
goto badchar;
if (*c == ',')
goto badchar;
else {
val_start = c;
endptr = NULL;
errno = 0;
this_val = strtoull(val_start, &endptr, 10);
if (errno || !endptr) {
log_error("Could not parse histogram value.");
goto bad;
}
c = endptr; /* Advance to colon, or end. */
if (*c == ':')
c++;
else if (*c & (*c != '\n'))
/* Expected ':', '\n', or NULL. */
goto badchar;
if (*c == ':')
c++;
cur.upper = bounds->bins[bin].upper;
cur.count = this_val;
sum += this_val;
if (!dm_pool_grow_object(mem, &cur, sizeof(cur)))
goto_bad;
bin++;
}
} while (*c && (*c != '\n'));
log_debug("Added region histogram data with %d entries.", hist.nr_bins);
*histogram = dm_pool_end_object(mem);
(*histogram)->sum = sum;
return 1;
badchar:
log_error("Invalid character in histogram data: '%c' (0x%x)", *c, *c);
bad:
dm_pool_abandon_object(mem);
return 0;
}
static int _stats_parse_region(struct dm_stats *dms, const char *resp,
struct dm_stats_region *region,
uint64_t timescale)
{
struct dm_histogram *hist = NULL;
struct dm_pool *mem = dms->mem;
struct dm_stats_counters cur;
FILE *stats_rows = NULL;
uint64_t start = 0, len = 0;
char row[STATS_ROW_BUF_LEN];
int r;
if (!resp) {
log_error("Could not parse empty @stats_print response.");
return 0;
}
region->start = UINT64_MAX;
if (!dm_pool_begin_object(mem, 512))
goto_bad;
/*
* dm_task_get_message_response() returns a 'const char *' but
* since fmemopen also permits "w" it expects a 'char *'.
*/
/* coverity[alloc_strlen] intentional */
stats_rows = fmemopen((char *)resp, strlen(resp), "r");
if (!stats_rows)
goto_bad;
/*
* Output format for each step-sized area of a region:
*
* <start_sector>+<length> counters
*
* The first 11 counters have the same meaning as
* /sys/block/ * /stat or /proc/diskstats.
*
* Please refer to Documentation/iostats.txt for details.
*
* 1. the number of reads completed
* 2. the number of reads merged
* 3. the number of sectors read
* 4. the number of milliseconds spent reading
* 5. the number of writes completed
* 6. the number of writes merged
* 7. the number of sectors written
* 8. the number of milliseconds spent writing
* 9. the number of I/Os currently in progress
* 10. the number of milliseconds spent doing I/Os
* 11. the weighted number of milliseconds spent doing I/Os
*
* Additional counters:
* 12. the total time spent reading in milliseconds
* 13. the total time spent writing in milliseconds
*
*/
while (fgets(row, sizeof(row), stats_rows)) {
r = sscanf(row, FMTu64 "+" FMTu64 /* start+len */
/* reads */
FMTu64 " " FMTu64 " " FMTu64 " " FMTu64 " "
/* writes */
FMTu64 " " FMTu64 " " FMTu64 " " FMTu64 " "
/* in flight & io nsecs */
FMTu64 " " FMTu64 " " FMTu64 " "
/* tot read/write nsecs */
FMTu64 " " FMTu64, &start, &len,
&cur.reads, &cur.reads_merged, &cur.read_sectors,
&cur.read_nsecs,
&cur.writes, &cur.writes_merged, &cur.write_sectors,
&cur.write_nsecs,
&cur.io_in_progress,
&cur.io_nsecs, &cur.weighted_io_nsecs,
&cur.total_read_nsecs, &cur.total_write_nsecs);
if (r != 15) {
log_error("Could not parse @stats_print row.");
goto bad;
}
/* scale time values up if needed */
if (timescale != 1) {
cur.read_nsecs *= timescale;
cur.write_nsecs *= timescale;
cur.io_nsecs *= timescale;
cur.weighted_io_nsecs *= timescale;
cur.total_read_nsecs *= timescale;
cur.total_write_nsecs *= timescale;
}
if (region->bounds) {
/* Find first histogram separator. */
char *hist_str = strchr(row, ':');
if (!hist_str) {
log_error("Could not parse histogram value.");
goto bad;
}
/* Find space preceding histogram. */
while (hist_str && *(hist_str - 1) != ' ')
hist_str--;
/* Use a separate pool for histogram objects since we
* are growing the area table and each area's histogram
* table simultaneously.
*/
if (!_stats_parse_histogram(dms->hist_mem, hist_str,
&hist, region))
goto_bad;
hist->dms = dms;
hist->region = region;
}
cur.histogram = hist;
if (!dm_pool_grow_object(mem, &cur, sizeof(cur)))
goto_bad;
if (region->start == UINT64_MAX) {
region->start = start;
region->step = len; /* area size is always uniform. */
}
}
if (region->start == UINT64_MAX)
/* no area data read from @stats_print */
goto bad;
region->len = (start + len) - region->start;
region->timescale = timescale;
region->counters = dm_pool_end_object(mem);
if (fclose(stats_rows))
stack;
return 1;
bad:
if (stats_rows)
if (fclose(stats_rows))
stack;
dm_pool_abandon_object(mem);
return 0;
}
static void _stats_walk_next_present(const struct dm_stats *dms,
uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a,
uint64_t *cur_g)
{
struct dm_stats_region *cur = NULL;
/* start of walk: region loop advances *cur_r to 0. */
if (*cur_r != DM_STATS_REGION_NOT_PRESENT)
cur = &dms->regions[*cur_r];
/* within current region? */
if (cur && (*flags & DM_STATS_WALK_AREA)) {
if (++(*cur_a) < _nr_areas_region(cur))
return;
else
*cur_a = 0;
}
/* advance to next present, non-skipped region or end */
/* count can start as UINT64_MAX, probably rework to use post++ */
/* coverity[overflow_const] overflow is expected here */
while (++(*cur_r) <= dms->max_region) {
cur = &dms->regions[*cur_r];
if (!_stats_region_present(cur))
continue;
if ((*flags & DM_STATS_WALK_SKIP_SINGLE_AREA))
if (!(*flags & DM_STATS_WALK_AREA))
if (_nr_areas_region(cur) < 2)
continue;
/* matching region found */
break;
}
return;
}
static void _stats_walk_next(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a, uint64_t *cur_g)
{
if (!dms || !dms->regions)
return;
if (*flags & DM_STATS_WALK_AREA) {
/* advance to next area, region, or end */
_stats_walk_next_present(dms, flags, cur_r, cur_a, cur_g);
return;
}
if (*flags & DM_STATS_WALK_REGION) {
/* enable region aggregation */
*cur_a = DM_STATS_WALK_REGION;
_stats_walk_next_present(dms, flags, cur_r, cur_a, cur_g);
return;
}
if (*flags & DM_STATS_WALK_GROUP) {
/* enable group aggregation */
*cur_r = *cur_a = DM_STATS_WALK_GROUP;
while (!_stats_group_id_present(dms, ++(*cur_g))
&& (*cur_g) < dms->max_region + 1)
; /* advance to next present group or end */
return;
}
log_error("stats_walk_next called with empty walk flags");
}
static void _group_walk_start(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a, uint64_t *cur_g)
{
if (!(*flags & DM_STATS_WALK_GROUP))
return;
*cur_a = *cur_r = DM_STATS_WALK_GROUP;
*cur_g = 0;
/* advance to next present group or end */
while ((*cur_g) <= dms->max_region) {
if (_stats_region_is_grouped(dms, *cur_g))
break;
(*cur_g)++;
}
if (*cur_g > dms->max_region)
/* no groups to walk */
*flags &= ~DM_STATS_WALK_GROUP;
}
static void _stats_walk_start(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a,
uint64_t *cur_g)
{
log_debug("starting stats walk with %s %s %s %s",
(*flags & DM_STATS_WALK_AREA) ? "AREA" : "",
(*flags & DM_STATS_WALK_REGION) ? "REGION" : "",
(*flags & DM_STATS_WALK_GROUP) ? "GROUP" : "",
(*flags & DM_STATS_WALK_SKIP_SINGLE_AREA) ? "SKIP" : "");
if (!dms->regions)
return;
if (!(*flags & (DM_STATS_WALK_AREA | DM_STATS_WALK_REGION))) {
_group_walk_start(dms, flags, cur_r, cur_a, cur_g);
return;
}
/* initialise cursor state */
*cur_a = 0;
*cur_r = DM_STATS_REGION_NOT_PRESENT;
*cur_g = DM_STATS_GROUP_NOT_PRESENT;
if (!(*flags & DM_STATS_WALK_AREA))
*cur_a = DM_STATS_WALK_REGION;
/* advance to first present, non-skipped region */
_stats_walk_next_present(dms, flags, cur_r, cur_a, cur_g);
}
#define DM_STATS_WALK_MASK (DM_STATS_WALK_AREA \
| DM_STATS_WALK_REGION \
| DM_STATS_WALK_GROUP \
| DM_STATS_WALK_SKIP_SINGLE_AREA)
int dm_stats_walk_init(struct dm_stats *dms, uint64_t flags)
{
if (!dms)
return_0;
if (flags & ~DM_STATS_WALK_MASK) {
log_error("Unknown value in walk flags: 0x" FMTx64,
(uint64_t) (flags & ~DM_STATS_WALK_MASK));
return 0;
}
dms->walk_flags = flags;
log_debug("dm_stats_walk_init: initialised flags to " FMTx64, flags);
return 1;
}
void dm_stats_walk_start(struct dm_stats *dms)
{
if (!dms || !dms->regions)
return;
dms->cur_flags = dms->walk_flags;
_stats_walk_start(dms, &dms->cur_flags,
&dms->cur_region, &dms->cur_area,
&dms->cur_group);
}
void dm_stats_walk_next(struct dm_stats *dms)
{
_stats_walk_next(dms, &dms->cur_flags,
&dms->cur_region, &dms->cur_area,
&dms->cur_group);
}
void dm_stats_walk_next_region(struct dm_stats *dms)
{
dms->cur_flags &= ~DM_STATS_WALK_AREA;
_stats_walk_next(dms, &dms->cur_flags,
&dms->cur_region, &dms->cur_area,
&dms->cur_group);
}
/*
* Return 1 if any regions remain that are present and not skipped
* by the current walk flags or 0 otherwise.
*/
static uint64_t _stats_walk_any_unskipped(const struct dm_stats *dms,
uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a)
{
struct dm_stats_region *region;
uint64_t i;
if (*cur_r > dms->max_region)
return 0;
for (i = *cur_r; i <= dms->max_region; i++) {
region = &dms->regions[i];
if (!_stats_region_present(region))
continue;
if ((*flags & DM_STATS_WALK_SKIP_SINGLE_AREA)
&& !(*flags & DM_STATS_WALK_AREA))
if (_nr_areas_region(region) < 2)
continue;
return 1;
}
return 0;
}
static void _stats_walk_end_areas(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a,
uint64_t *cur_g)
{
int end = !_stats_walk_any_unskipped(dms, flags, cur_r, cur_a);
if (!(*flags & DM_STATS_WALK_AREA))
return;
if (!end)
return;
*flags &= ~DM_STATS_WALK_AREA;
if (*flags & DM_STATS_WALK_REGION) {
/* start region walk */
*cur_a = DM_STATS_WALK_REGION;
*cur_r = DM_STATS_REGION_NOT_PRESENT;
_stats_walk_next_present(dms, flags, cur_r, cur_a, cur_g);
if (!_stats_walk_any_unskipped(dms, flags, cur_r, cur_a)) {
/* no more regions */
*flags &= ~DM_STATS_WALK_REGION;
if (!(*flags & DM_STATS_WALK_GROUP))
*cur_r = dms->max_region;
}
}
if (*flags & DM_STATS_WALK_REGION)
return;
if (*flags & DM_STATS_WALK_GROUP)
_group_walk_start(dms, flags, cur_r, cur_a, cur_g);
}
static int _stats_walk_end(const struct dm_stats *dms, uint64_t *flags,
uint64_t *cur_r, uint64_t *cur_a, uint64_t *cur_g)
{
if (*flags & DM_STATS_WALK_AREA) {
_stats_walk_end_areas(dms, flags, cur_r, cur_a, cur_g);
goto out;
}
if (*flags & DM_STATS_WALK_REGION) {
if (!_stats_walk_any_unskipped(dms, flags, cur_r, cur_a)) {
*flags &= ~DM_STATS_WALK_REGION;
_group_walk_start(dms, flags, cur_r, cur_a, cur_g);
}
goto out;
}
if (*flags & DM_STATS_WALK_GROUP) {
if (*cur_g <= dms->max_region)
goto out;
*flags &= ~DM_STATS_WALK_GROUP;
}
out:
return !(*flags & ~DM_STATS_WALK_SKIP_SINGLE_AREA);
}
int dm_stats_walk_end(struct dm_stats *dms)
{
if (!dms)
return 1;
if (_stats_walk_end(dms, &dms->cur_flags,
&dms->cur_region, &dms->cur_area,
&dms->cur_group)) {
dms->cur_flags = dms->walk_flags;
return 1;
}
return 0;
}
dm_stats_obj_type_t dm_stats_object_type(const struct dm_stats *dms,
uint64_t region_id,
uint64_t area_id)
{
uint64_t group_id;
region_id = (region_id == DM_STATS_REGION_CURRENT)
? dms->cur_region : region_id ;
area_id = (area_id == DM_STATS_AREA_CURRENT)
? dms->cur_area : area_id ;
if (region_id == DM_STATS_REGION_NOT_PRESENT)
/* no region */
return DM_STATS_OBJECT_TYPE_NONE;
if (region_id & DM_STATS_WALK_GROUP) {
if (region_id == DM_STATS_WALK_GROUP)
/* indirect group_id from cursor */
group_id = dms->cur_group;
else
/* immediate group_id encoded in region_id */
group_id = region_id & ~DM_STATS_WALK_GROUP;
if (!_stats_group_id_present(dms, group_id))
return DM_STATS_OBJECT_TYPE_NONE;
return DM_STATS_OBJECT_TYPE_GROUP;
}
if (region_id > dms->max_region)
/* end of table */
return DM_STATS_OBJECT_TYPE_NONE;
if (area_id & DM_STATS_WALK_REGION)
/* aggregate region */
return DM_STATS_OBJECT_TYPE_REGION;
/* plain region_id and area_id */
return DM_STATS_OBJECT_TYPE_AREA;
}
dm_stats_obj_type_t dm_stats_current_object_type(const struct dm_stats *dms)
{
/* dm_stats_object_type will decode region/area */
return dm_stats_object_type(dms,
DM_STATS_REGION_CURRENT,
DM_STATS_AREA_CURRENT);
}
uint64_t dm_stats_get_region_nr_areas(const struct dm_stats *dms,
uint64_t region_id)
{
struct dm_stats_region *region = NULL;
/* groups or aggregate regions cannot be subdivided */
if (region_id & DM_STATS_WALK_GROUP)
return 1;
region = &dms->regions[region_id];
return _nr_areas_region(region);
}
uint64_t dm_stats_get_current_nr_areas(const struct dm_stats *dms)
{
/* groups or aggregate regions cannot be subdivided */
if (dms->cur_region & DM_STATS_WALK_GROUP)
return 1;
return dm_stats_get_region_nr_areas(dms, dms->cur_region);
}
uint64_t dm_stats_get_nr_areas(const struct dm_stats *dms)
{
uint64_t nr_areas = 0, flags = DM_STATS_WALK_AREA;
/* use a separate cursor */
uint64_t cur_region = 0, cur_area = 0, cur_group = 0;
/* no regions to visit? */
if (!dms->regions)
return 0;
flags = DM_STATS_WALK_AREA;
_stats_walk_start(dms, &flags, &cur_region, &cur_area, &cur_group);
do {
nr_areas += dm_stats_get_current_nr_areas(dms);
_stats_walk_next(dms, &flags,
&cur_region, &cur_area,
&cur_group);
} while (!_stats_walk_end(dms, &flags,
&cur_region, &cur_area,
&cur_group));
return nr_areas;
}
int dm_stats_group_present(const struct dm_stats *dms, uint64_t group_id)
{
return _stats_group_id_present(dms, group_id);
}
int dm_stats_get_region_nr_histogram_bins(const struct dm_stats *dms,
uint64_t region_id)
{
region_id = (region_id == DM_STATS_REGION_CURRENT)
? dms->cur_region : region_id ;
/* FIXME: support group histograms if all region bounds match */
if (region_id & DM_STATS_WALK_GROUP)
return 0;
if (!dms->regions[region_id].bounds)
return 0;
return dms->regions[region_id].bounds->nr_bins;
}
/*
* Fill buf with a list of set regions in the regions bitmap. Consecutive
* ranges of set region IDs are output using "M-N" range notation.
*
* The number of bytes consumed is returned or zero on error.
*/
static size_t _stats_group_tag_fill(const struct dm_stats *dms,
dm_bitset_t regions,
char *buf, size_t buflen)
{
int i, j, r, next, last = 0;
size_t used = 0;
last = dm_bit_get_last(regions);
i = dm_bit_get_first(regions);
for(; i >= 0; i = dm_bit_get_next(regions, i)) {
/* find range end */
j = i;
do
next = j + 1;
while ((j = dm_bit_get_next(regions, j)) == next);
/* set to last set bit */
j = next - 1;
/* handle range vs. single region */
if (i != j)
r = dm_snprintf(buf, buflen, FMTu64 "-" FMTu64 "%s",
(uint64_t) i, (uint64_t) j,
(j == last) ? "" : ",");
else
r = dm_snprintf(buf, buflen, FMTu64 "%s", (uint64_t) i,
(i == last) ? "" : ",");
if (r < 0)
goto_bad;
i = next; /* skip handled bits if in range */
buf += r;
used += r;
}
return used;
bad:
log_error("Could not format group list.");
return 0;
}
/*
* Calculate the space required to hold a string description of the group
* described by the regions bitset using comma separated list in range
* notation ("A,B,C,M-N").
*/
static size_t _stats_group_tag_len(const struct dm_stats *dms,
dm_bitset_t regions)
{
int64_t i, j, next, nr_regions = 0;
size_t buflen = 0, id_len = 0;
/* check region ids and find last set bit */
i = dm_bit_get_first(regions);
for (; i >= 0; i = dm_bit_get_next(regions, i)) {
/* length of region_id or range start in characters */
id_len = (i) ? 1 + (size_t) log10(i) : 1;
buflen += id_len;
j = i;
do
next = j + 1;
while ((j = dm_bit_get_next(regions, j)) == next);
/* set to last set bit */
j = next - 1;
nr_regions += j - i + 1;
/* handle range */
if (i != j) {
/* j is always > i, which is always >= 0 */
id_len = 1 + (size_t) log10(j);
buflen += id_len + 1; /* range end plus "-" */
}
buflen++;
i = next; /* skip bits if handling range */
}
return buflen;
}
/*
* Build a DMS_GROUP="..." tag for the group specified by group_id,
* to be stored in the corresponding region's aux_data field.
*/
static char *_build_group_tag(struct dm_stats *dms, uint64_t group_id)
{
char *aux_string, *buf;
dm_bitset_t regions;
const char *alias;
size_t buflen = 0;
int r;
regions = dms->groups[group_id].regions;
alias = dms->groups[group_id].alias;
buflen = _stats_group_tag_len(dms, regions);
if (!buflen)
return_0;
buflen += DMS_GROUP_TAG_LEN;
buflen += 1 + (alias ? strlen(alias) + 2 : 0); /* 'alias:' */
buf = aux_string = dm_malloc(buflen);
if (!buf) {
log_error("Could not allocate memory for aux_data string.");
return NULL;
}
if (!_dm_strncpy(buf, DMS_GROUP_TAG, DMS_GROUP_TAG_LEN + 1))
goto_bad;
buf += DMS_GROUP_TAG_LEN;
buflen -= DMS_GROUP_TAG_LEN;
if (alias)
r = dm_snprintf(buf, buflen, "\"%s\"%c", alias, DMS_GROUP_SEP);
else
r = dm_snprintf(buf, buflen, "%c", DMS_GROUP_SEP);
if (r < 0)
goto_bad;
buf += r;
buflen -= r;
r = _stats_group_tag_fill(dms, regions, buf, buflen);
if (!r)
goto_bad;
return aux_string;
bad:
log_error("Could not format group aux_data.");
dm_free(aux_string);
return NULL;
}
/*
* Store updated aux_data for a region. The aux_data is passed to the
* kernel using the @stats_set_aux message. Any required group tag is
* generated from the current group table and included in the message.
*/
static int _stats_set_aux(struct dm_stats *dms,
uint64_t region_id, const char *user_data)
{
char *group_tag = NULL, *group_tag_escaped = NULL;
struct dm_task *dmt = NULL;
char msg[STATS_MSG_BUF_LEN];
int r = 0;
/* group data required? */
if (_stats_group_id_present(dms, region_id)) {
group_tag = _build_group_tag(dms, region_id);
if (!group_tag) {
log_error("Could not build group descriptor for "
"region ID " FMTu64, region_id);
goto bad;
}
group_tag_escaped = _stats_escape_aux_data(group_tag);
if (!group_tag_escaped)
goto bad;
}
if (dm_snprintf(msg, sizeof(msg), "@stats_set_aux " FMTu64 " %s%s%s ",
region_id, (group_tag_escaped) ? group_tag_escaped : "",
(group_tag_escaped) ? DMS_AUX_SEP : "",
(strlen(user_data)) ? user_data : "-") < 0) {
log_error("Could not prepare @stats_set_aux message");
goto bad;
}
if (!(dmt = _stats_send_message(dms, msg)))
goto_bad;
/* no response to a @stats_set_aux message */
dm_task_destroy(dmt);
r = 1;
bad:
dm_free(group_tag_escaped);
dm_free(group_tag);
return r;
}
/*
* Maximum length of a "start+end" range string:
* Two 20 digit uint64_t, '+', and NULL.
*/
#define RANGE_LEN 42
static int _stats_create_region(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
int precise, const char *hist_arg,
const char *program_id, const char *aux_data)
{
char msg[STATS_MSG_BUF_LEN], range[RANGE_LEN], *endptr = NULL;
const char *err = NULL;
const char *precise_str = PRECISE_ARG;
const char *resp, *opt_args = NULL;
char *aux_data_escaped = NULL;
struct dm_task *dmt = NULL;
int r = 0, nr_opt = 0;
if (!_stats_bound(dms))
return_0;
if (!program_id || !strlen(program_id))
program_id = dms->program_id;
if (start || len) {
if (dm_snprintf(range, sizeof(range), FMTu64 "+" FMTu64,
start, len) < 0) {
err ="range";
goto_bad;
}
}
if (precise < 0)
precise = dms->precise;
if (precise)
nr_opt++;
else
precise_str = "";
if (hist_arg)
nr_opt++;
else
hist_arg = "";
aux_data_escaped = _stats_escape_aux_data(aux_data);
if (!aux_data_escaped)
return_0;
if (nr_opt) {
if ((dm_asprintf((char **)&opt_args, "%d %s %s%s", nr_opt,
precise_str,
(strlen(hist_arg)) ? HISTOGRAM_ARG : "",
hist_arg)) < 0) {
err = PRECISE_ARG " option.";
goto_bad;
}
} else
opt_args = dm_strdup("");
if (dm_snprintf(msg, sizeof(msg), "@stats_create %s %s" FMTu64
" %s %s %s", (start || len) ? range : "-",
(step < 0) ? "/" : "",
(uint64_t)llabs(step),
opt_args, program_id, aux_data) < 0) {
err = "message";
goto_bad;
}
if (!(dmt = _stats_send_message(dms, msg)))
goto_out;
resp = dm_task_get_message_response(dmt);
if (!resp) {
log_error("Could not parse empty @stats_create response.");
goto out;
}
if (region_id) {
errno = 0;
*region_id = strtoull(resp, &endptr, 10);
if (errno || resp == endptr)
goto_out;
}
r = 1;
goto out;
bad:
log_error("Could not prepare @stats_create %s.", err);
out:
if (dmt)
dm_task_destroy(dmt);
dm_free((void *) opt_args);
dm_free(aux_data_escaped);
return r;
}
DM_EXPORT_NEW_SYMBOL(int, dm_stats_create_region, 1_02_107)
(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)
{
char *hist_arg = NULL;
int r = 0;
/* Nanosecond counters and histograms both need precise_timestamps. */
if ((precise || bounds) && !_stats_check_precise_timestamps(dms))
return_0;
if (bounds) {
/* _build_histogram_arg enables precise if vals < 1ms. */
if (!(hist_arg = _build_histogram_arg(bounds, &precise)))
goto_out;
}
r = _stats_create_region(dms, region_id, start, len, step,
precise, hist_arg, program_id, user_data);
dm_free(hist_arg);
out:
return r;
}
static void _stats_clear_group_regions(struct dm_stats *dms, uint64_t group_id)
{
struct dm_stats_group *group;
uint64_t i;
group = &dms->groups[group_id];
for (i = dm_bit_get_first(group->regions);
i != DM_STATS_GROUP_NOT_PRESENT;
i = dm_bit_get_next(group->regions, i))
dms->regions[i].group_id = DM_STATS_GROUP_NOT_PRESENT;
}
static int _stats_remove_region_id_from_group(struct dm_stats *dms,
uint64_t region_id)
{
struct dm_stats_region *region = &dms->regions[region_id];
uint64_t group_id = region->group_id;
dm_bitset_t regions = dms->groups[group_id].regions;
if (!_stats_region_is_grouped(dms, region_id))
return_0;
dm_bit_clear(regions, region_id);
/* removing group leader? */
if (region_id == group_id) {
_stats_clear_group_regions(dms, group_id);
_stats_group_destroy(&dms->groups[group_id]);
}
return _stats_set_aux(dms, group_id, dms->regions[group_id].aux_data);
}
static int _stats_delete_region(struct dm_stats *dms, uint64_t region_id)
{
char msg[STATS_MSG_BUF_LEN];
struct dm_task *dmt;
if (_stats_region_is_grouped(dms, region_id))
if (!_stats_remove_region_id_from_group(dms, region_id)) {
log_error("Could not remove region ID " FMTu64 " from "
"group ID " FMTu64,
region_id, dms->regions[region_id].group_id);
return 0;
}
if (dm_snprintf(msg, sizeof(msg), "@stats_delete " FMTu64, region_id) < 0) {
log_error("Could not prepare @stats_delete message.");
return 0;
}
dmt = _stats_send_message(dms, msg);
if (!dmt)
return_0;
dm_task_destroy(dmt);
return 1;
}
int dm_stats_delete_region(struct dm_stats *dms, uint64_t region_id)
{
int listed = 0;
if (!_stats_bound(dms))
return_0;
/*
* To correctly delete a region, that may be part of a group, a
* listed handle is required, since the region may need to be
* removed from another region's group descriptor; earlier
* versions of the region deletion interface do not have this
* requirement since there are no dependencies between regions.
*
* Listing a previously unlisted handle has numerous
* side-effects on other calls and operations (e.g. stats
* walks), especially when returning to a function that depends
* on the state of the region table, or statistics cursor.
*
* To avoid changing the semantics of the API, and the need for
* a versioned symbol, maintain a flag indicating when a listing
* has been carried out, and drop the region table before
* returning.
*
* This ensures compatibility with programs compiled against
* earlier versions of libdm.
*/
if (!dms->regions && !(listed = dm_stats_list(dms, dms->program_id))) {
log_error("Could not obtain region list while deleting "
"region ID " FMTu64, region_id);
goto bad;
}
if (!dm_stats_get_nr_regions(dms)) {
log_error("Could not delete region ID " FMTu64 ": "
"no regions found", region_id);
goto bad;
}
/* includes invalid and special region_id values */
if (!dm_stats_region_present(dms, region_id)) {
log_error("Region ID " FMTu64 " does not exist", region_id);
goto bad;
}
if (!_stats_delete_region(dms, region_id))
goto bad;
if (!listed)
/* wipe region and mark as not present */
_stats_region_destroy(&dms->regions[region_id]);
else
/* return handle to prior state */
_stats_regions_destroy(dms);
return 1;
bad:
if (listed)
_stats_regions_destroy(dms);
return 0;
}
int dm_stats_clear_region(struct dm_stats *dms, uint64_t region_id)
{
char msg[STATS_MSG_BUF_LEN];
struct dm_task *dmt;
if (!_stats_bound(dms))
return_0;
if (dm_snprintf(msg, sizeof(msg), "@stats_clear " FMTu64, region_id) < 0) {
log_error("Could not prepare @stats_clear message.");
return 0;
}
dmt = _stats_send_message(dms, msg);
if (!dmt)
return_0;
dm_task_destroy(dmt);
return 1;
}
static struct dm_task *_stats_print_region(struct dm_stats *dms,
uint64_t region_id, unsigned start_line,
unsigned num_lines, unsigned clear)
{
/* @stats_print[_clear] <region_id> [<start_line> <num_lines>] */
char msg[STATS_MSG_BUF_LEN], lines[RANGE_LEN];
struct dm_task *dmt = NULL;
const char *err = NULL;
if (start_line || num_lines)
if (dm_snprintf(lines, sizeof(lines),
"%u %u", start_line, num_lines) < 0) {
err = "row specification";
goto_bad;
}
if (dm_snprintf(msg, sizeof(msg), "@stats_print%s " FMTu64 " %s",
(clear) ? "_clear" : "",
region_id, (start_line || num_lines) ? lines : "") < 0) {
err = "message";
goto_bad;
}
if (!(dmt = _stats_send_message(dms, msg)))
return_NULL;
return dmt;
bad:
log_error("Could not prepare @stats_print %s.", err);
return NULL;
}
char *dm_stats_print_region(struct dm_stats *dms, uint64_t region_id,
unsigned start_line, unsigned num_lines,
unsigned clear)
{
char *resp = NULL;
struct dm_task *dmt = NULL;
const char *response;
if (!_stats_bound(dms))
return_0;
/*
* FIXME: 'print' can be emulated for groups or aggregate regions
* by populating the handle and emitting aggregate counter data
* in the kernel print format.
*/
if (region_id == DM_STATS_WALK_GROUP)
return_0;
dmt = _stats_print_region(dms, region_id,
start_line, num_lines, clear);
if (!dmt)
return_0;
if (!(response = dm_task_get_message_response(dmt)))
goto_out;
if (!(resp = dm_pool_strdup(dms->mem, response)))
log_error("Could not allocate memory for response buffer.");
out:
dm_task_destroy(dmt);
return resp;
}
void dm_stats_buffer_destroy(struct dm_stats *dms, char *buffer)
{
dm_pool_free(dms->mem, buffer);
}
uint64_t dm_stats_get_nr_regions(const struct dm_stats *dms)
{
if (!dms)
return_0;
if (!dms->regions)
return 0;
return dms->nr_regions;
}
uint64_t dm_stats_get_nr_groups(const struct dm_stats *dms)
{
uint64_t group_id, nr_groups = 0;
if (!dms)
return_0;
/* no regions or groups? */
if (!dms->regions || !dms->groups)
return 0;
for (group_id = 0; group_id <= dms->max_region; group_id++)
if (dms->groups[group_id].group_id
!= DM_STATS_GROUP_NOT_PRESENT)
nr_groups++;
return nr_groups;
}
/**
* Test whether region_id is present in this set of stats data.
*/
int dm_stats_region_present(const struct dm_stats *dms, uint64_t region_id)
{
if (!dms->regions)
return_0;
if (region_id > dms->max_region)
return 0;
return _stats_region_present(&dms->regions[region_id]);
}
static int _dm_stats_populate_region(struct dm_stats *dms, uint64_t region_id,
const char *resp)
{
struct dm_stats_region *region = &dms->regions[region_id];
if (!_stats_bound(dms))
return_0;
if (!region) {
log_error("Cannot populate empty handle before dm_stats_list().");
return 0;
}
if (!_stats_parse_region(dms, resp, region, region->timescale)) {
log_error("Could not parse @stats_print message response.");
return 0;
}
region->region_id = region_id;
return 1;
}
int dm_stats_populate(struct dm_stats *dms, const char *program_id,
uint64_t region_id)
{
int all_regions = (region_id == DM_STATS_REGIONS_ALL);
struct dm_task *dmt = NULL; /* @stats_print task */
uint64_t saved_flags; /* saved walk flags */
const char *resp;
/*
* We are about do destroy and re-create the region table, so it
* is safe to use the cursor embedded in the stats handle: just
* save a copy of the current walk_flags to restore later.
*/
saved_flags = dms->walk_flags;
if (!_stats_bound(dms))
return_0;
if ((!all_regions) && (region_id & DM_STATS_WALK_GROUP)) {
log_error("Invalid region_id for dm_stats_populate: "
"DM_STATS_WALK_GROUP");
return 0;
}
/* allow zero-length program_id for populate */
if (!program_id)
program_id = dms->program_id;
if (all_regions && !dm_stats_list(dms, program_id)) {
log_error("Could not parse @stats_list response.");
goto bad;
} else if (!_stats_set_name_cache(dms)) {
goto_bad;
}
if (!dms->nr_regions) {
log_verbose("No stats regions registered: %s", dms->name);
return 0;
}
dms->walk_flags = DM_STATS_WALK_REGION;
dm_stats_walk_start(dms);
do {
region_id = (all_regions)
? dm_stats_get_current_region(dms) : region_id;
/* obtain all lines and clear counter values */
if (!(dmt = _stats_print_region(dms, region_id, 0, 0, 1)))
goto_bad;
resp = dm_task_get_message_response(dmt);
if (!_dm_stats_populate_region(dms, region_id, resp)) {
dm_task_destroy(dmt);
goto_bad;
}
dm_task_destroy(dmt);
dm_stats_walk_next(dms);
} while (all_regions && !dm_stats_walk_end(dms));
dms->walk_flags = saved_flags;
return 1;
bad:
dms->walk_flags = saved_flags;
_stats_regions_destroy(dms);
dms->regions = NULL;
return 0;
}
/**
* destroy a dm_stats object and all associated regions and counter sets.
*/
void dm_stats_destroy(struct dm_stats *dms)
{
if (!dms)
return;
_stats_regions_destroy(dms);
_stats_groups_destroy(dms);
_stats_clear_binding(dms);
dm_pool_destroy(dms->mem);
dm_pool_destroy(dms->hist_mem);
dm_pool_destroy(dms->group_mem);
dm_free(dms->program_id);
dm_free((char *) dms->name);
dm_free(dms);
}
/*
* Walk each area that is a member of region_id rid.
* i is a variable of type int that holds the current area_id.
*/
#define _foreach_region_area(dms, rid, i) \
for ((i) = 0; (i) < _nr_areas_region(&dms->regions[(rid)]); (i)++) \
/*
* Walk each region that is a member of group_id gid.
* i is a variable of type int that holds the current region_id.
*/
#define _foreach_group_region(dms, gid, i) \
for ((i) = dm_bit_get_first((dms)->groups[(gid)].regions); \
(i) != DM_STATS_GROUP_NOT_PRESENT; \
(i) = dm_bit_get_next((dms)->groups[(gid)].regions, (i))) \
/*
* Walk each region that is a member of group_id gid visiting each
* area within the region.
* i is a variable of type int that holds the current region_id.
* j is a variable of type int variable that holds the current area_id.
*/
#define _foreach_group_area(dms, gid, i, j) \
_foreach_group_region(dms, gid, i) \
_foreach_region_area(dms, i, j)
static uint64_t _stats_get_counter(const struct dm_stats *dms,
const struct dm_stats_counters *area,
dm_stats_counter_t counter)
{
switch(counter) {
case DM_STATS_READS_COUNT:
return area->reads;
case DM_STATS_READS_MERGED_COUNT:
return area->reads_merged;
case DM_STATS_READ_SECTORS_COUNT:
return area->read_sectors;
case DM_STATS_READ_NSECS:
return area->read_nsecs;
case DM_STATS_WRITES_COUNT:
return area->writes;
case DM_STATS_WRITES_MERGED_COUNT:
return area->writes_merged;
case DM_STATS_WRITE_SECTORS_COUNT:
return area->write_sectors;
case DM_STATS_WRITE_NSECS:
return area->write_nsecs;
case DM_STATS_IO_IN_PROGRESS_COUNT:
return area->io_in_progress;
case DM_STATS_IO_NSECS:
return area->io_nsecs;
case DM_STATS_WEIGHTED_IO_NSECS:
return area->weighted_io_nsecs;
case DM_STATS_TOTAL_READ_NSECS:
return area->total_read_nsecs;
case DM_STATS_TOTAL_WRITE_NSECS:
return area->total_write_nsecs;
case DM_STATS_NR_COUNTERS:
default:
log_error("Attempt to read invalid counter: %d", counter);
}
return 0;
}
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 i, j, sum = 0; /* aggregation */
int sum_regions = 0;
struct dm_stats_region *region;
struct dm_stats_counters *area;
region_id = (region_id == DM_STATS_REGION_CURRENT)
? dms->cur_region : region_id ;
area_id = (area_id == DM_STATS_REGION_CURRENT)
? dms->cur_area : area_id ;
sum_regions = !!(region_id & DM_STATS_WALK_GROUP);
if (region_id == DM_STATS_WALK_GROUP)
/* group walk using the cursor */
region_id = dms->cur_group;
else if (region_id & DM_STATS_WALK_GROUP)
/* group walk using immediate group_id */
region_id &= ~DM_STATS_WALK_GROUP;
region = &dms->regions[region_id];
/*
* All statistics aggregation takes place here: aggregate metrics
* are calculated as normal using the aggregated counter values
* returned for the region or group specified.
*/
if (_stats_region_is_grouped(dms, region_id) && (sum_regions)) {
/* group */
if (area_id & DM_STATS_WALK_GROUP)
_foreach_group_area(dms, region->group_id, i, j) {
area = &dms->regions[i].counters[j];
sum += _stats_get_counter(dms, area, counter);
}
else
_foreach_group_region(dms, region->group_id, i) {
area = &dms->regions[i].counters[area_id];
sum += _stats_get_counter(dms, area, counter);
}
} else if (area_id == DM_STATS_WALK_REGION) {
/* aggregate region */
_foreach_region_area(dms, region_id, j) {
area = &dms->regions[region_id].counters[j];
sum += _stats_get_counter(dms, area, counter);
}
} else {
/* plain region / area */
area = &region->counters[area_id];
sum = _stats_get_counter(dms, area, counter);
}
return sum;
}
/*
* Methods for accessing named counter fields. All methods share the
* following naming scheme and prototype:
*
* uint64_t dm_stats_get_COUNTER(const struct dm_stats *, uint64_t, uint64_t)
*
* Where the two integer arguments are the region_id and area_id
* respectively.
*
* name is the name of the counter (lower case)
* counter is the part of the enum name following DM_STATS_ (upper case)
*/
#define MK_STATS_GET_COUNTER_FN(name, counter) \
uint64_t dm_stats_get_ ## name(const struct dm_stats *dms, \
uint64_t region_id, uint64_t area_id) \
{ \
return dm_stats_get_counter(dms, DM_STATS_ ## counter, \
region_id, area_id); \
}
MK_STATS_GET_COUNTER_FN(reads, READS_COUNT)
MK_STATS_GET_COUNTER_FN(reads_merged, READS_MERGED_COUNT)
MK_STATS_GET_COUNTER_FN(read_sectors, READ_SECTORS_COUNT)
MK_STATS_GET_COUNTER_FN(read_nsecs, READ_NSECS)
MK_STATS_GET_COUNTER_FN(writes, WRITES_COUNT)
MK_STATS_GET_COUNTER_FN(writes_merged, WRITES_MERGED_COUNT)
MK_STATS_GET_COUNTER_FN(write_sectors, WRITE_SECTORS_COUNT)
MK_STATS_GET_COUNTER_FN(write_nsecs, WRITE_NSECS)
MK_STATS_GET_COUNTER_FN(io_in_progress, IO_IN_PROGRESS_COUNT)
MK_STATS_GET_COUNTER_FN(io_nsecs, IO_NSECS)
MK_STATS_GET_COUNTER_FN(weighted_io_nsecs, WEIGHTED_IO_NSECS)
MK_STATS_GET_COUNTER_FN(total_read_nsecs, TOTAL_READ_NSECS)
MK_STATS_GET_COUNTER_FN(total_write_nsecs, TOTAL_WRITE_NSECS)
#undef MK_STATS_GET_COUNTER_FN
/*
* Floating point stats metric functions
*
* Called from dm_stats_get_metric() to calculate the value of
* the requested metric.
*
* int _metric_name(const struct dm_stats *dms,
* struct dm_stats_counters *c,
* double *value);
*
* Calculate a metric value from the counter data for the given
* identifiers and store it in the memory pointed to by value,
* applying group or region aggregation if enabled.
*
* Return one on success or zero on failure.
*
* To add a new metric:
*
* o Add a new name to the dm_stats_metric_t enum.
* o Create a _metric_fn() to calculate the new metric.
* o Add _metric_fn to the _metrics function table
* (entries in enum order).
* o Do not add a new named public function for the metric -
* users of new metrics are encouraged to convert to the enum
* based metric interface.
*
*/
static int _rd_merges_per_sec(const struct dm_stats *dms, double *rrqm,
uint64_t region_id, uint64_t area_id)
{
double mrgs;
mrgs = (double) dm_stats_get_counter(dms, DM_STATS_READS_MERGED_COUNT,
region_id, area_id);
*rrqm = mrgs / (double) dms->interval_ns;
return 1;
}
static int _wr_merges_per_sec(const struct dm_stats *dms, double *wrqm,
uint64_t region_id, uint64_t area_id)
{
double mrgs;
mrgs = (double) dm_stats_get_counter(dms, DM_STATS_WRITES_MERGED_COUNT,
region_id, area_id);
*wrqm = mrgs / (double) dms->interval_ns;
return 1;
}
static int _reads_per_sec(const struct dm_stats *dms, double *rd_s,
uint64_t region_id, uint64_t area_id)
{
double reads;
reads = (double) dm_stats_get_counter(dms, DM_STATS_READS_COUNT,
region_id, area_id);
*rd_s = (reads * NSEC_PER_SEC) / (double) dms->interval_ns;
return 1;
}
static int _writes_per_sec(const struct dm_stats *dms, double *wr_s,
uint64_t region_id, uint64_t area_id)
{
double writes;
writes = (double) dm_stats_get_counter(dms, DM_STATS_WRITES_COUNT,
region_id, area_id);
*wr_s = (writes * NSEC_PER_SEC) / (double) dms->interval_ns;
return 1;
}
static int _read_sectors_per_sec(const struct dm_stats *dms, double *rsec_s,
uint64_t region_id, uint64_t area_id)
{
double sect;
sect = (double) dm_stats_get_counter(dms, DM_STATS_READ_SECTORS_COUNT,
region_id, area_id);
*rsec_s = (sect * (double) NSEC_PER_SEC) / (double) dms->interval_ns;
return 1;
}
static int _write_sectors_per_sec(const struct dm_stats *dms, double *wsec_s,
uint64_t region_id, uint64_t area_id)
{
double sect;
sect = (double) dm_stats_get_counter(dms, DM_STATS_WRITE_SECTORS_COUNT,
region_id, area_id);
*wsec_s = (sect * (double) NSEC_PER_SEC) / (double) dms->interval_ns;
return 1;
}
static int _average_request_size(const struct dm_stats *dms, double *arqsz,
uint64_t region_id, uint64_t area_id)
{
double ios, sectors;
ios = (double) (dm_stats_get_counter(dms, DM_STATS_READS_COUNT,
region_id, area_id)
+ dm_stats_get_counter(dms, DM_STATS_WRITES_COUNT,
region_id, area_id));
sectors = (double) (dm_stats_get_counter(dms, DM_STATS_READ_SECTORS_COUNT,
region_id, area_id)
+ dm_stats_get_counter(dms, DM_STATS_WRITE_SECTORS_COUNT,
region_id, area_id));
if (ios > 0.0)
*arqsz = sectors / ios;
else
*arqsz = 0.0;
return 1;
}
static int _average_queue_size(const struct dm_stats *dms, double *qusz,
uint64_t region_id, uint64_t area_id)
{
double io_ticks;
io_ticks = (double) dm_stats_get_counter(dms, DM_STATS_WEIGHTED_IO_NSECS,
region_id, area_id);
if (io_ticks > 0.0)
*qusz = io_ticks / (double) dms->interval_ns;
else
*qusz = 0.0;
return 1;
}
static int _average_wait_time(const struct dm_stats *dms, double *await,
uint64_t region_id, uint64_t area_id)
{
uint64_t io_ticks, nr_ios;
io_ticks = dm_stats_get_counter(dms, DM_STATS_READ_NSECS,
region_id, area_id);
io_ticks += dm_stats_get_counter(dms, DM_STATS_WRITE_NSECS,
region_id, area_id);
nr_ios = dm_stats_get_counter(dms, DM_STATS_READS_COUNT,
region_id, area_id);
nr_ios += dm_stats_get_counter(dms, DM_STATS_WRITES_COUNT,
region_id, area_id);
if (nr_ios > 0)
*await = (double) io_ticks / (double) nr_ios;
else
*await = 0.0;
return 1;
}
static int _average_rd_wait_time(const struct dm_stats *dms, double *await,
uint64_t region_id, uint64_t area_id)
{
uint64_t rd_io_ticks, nr_rd_ios;
rd_io_ticks = dm_stats_get_counter(dms, DM_STATS_READ_NSECS,
region_id, area_id);
nr_rd_ios = dm_stats_get_counter(dms, DM_STATS_READS_COUNT,
region_id, area_id);
/*
* If rd_io_ticks is > 0 this should imply that nr_rd_ios is
* also > 0 (unless a kernel bug exists). Test for both here
* before using the IO count as a divisor (Coverity).
*/
if (rd_io_ticks > 0 && nr_rd_ios > 0)
*await = (double) rd_io_ticks / (double) nr_rd_ios;
else
*await = 0.0;
return 1;
}
static int _average_wr_wait_time(const struct dm_stats *dms, double *await,
uint64_t region_id, uint64_t area_id)
{
uint64_t wr_io_ticks, nr_wr_ios;
wr_io_ticks = dm_stats_get_counter(dms, DM_STATS_WRITE_NSECS,
region_id, area_id);
nr_wr_ios = dm_stats_get_counter(dms, DM_STATS_WRITES_COUNT,
region_id, area_id);
/*
* If wr_io_ticks is > 0 this should imply that nr_wr_ios is
* also > 0 (unless a kernel bug exists). Test for both here
* before using the IO count as a divisor (Coverity).
*/
if (wr_io_ticks > 0 && nr_wr_ios > 0)
*await = (double) wr_io_ticks / (double) nr_wr_ios;
else
*await = 0.0;
return 1;
}
static int _throughput(const struct dm_stats *dms, double *tput,
uint64_t region_id, uint64_t area_id)
{
uint64_t nr_ios;
nr_ios = dm_stats_get_counter(dms, DM_STATS_READS_COUNT,
region_id, area_id);
nr_ios += dm_stats_get_counter(dms, DM_STATS_WRITES_COUNT,
region_id, area_id);
*tput = ((double) NSEC_PER_SEC * (double) nr_ios)
/ (double) (dms->interval_ns);
return 1;
}
static int _utilization(const struct dm_stats *dms, double *util,
uint64_t region_id, uint64_t area_id)
{
uint64_t io_nsecs, interval_ns = dms->interval_ns;
/**
* If io_nsec > interval_ns there is something wrong with the clock
* for the last interval; do not allow a value > 100% utilization
* to be passed to a dm_make_percent() call. We expect to see these
* at startup if counters have not been cleared before the first read.
*
* A zero interval_ns is also an error since metrics cannot be
* calculated without a defined interval - return zero and emit a
* backtrace in this case.
*/
io_nsecs = dm_stats_get_counter(dms, DM_STATS_IO_NSECS,
region_id, area_id);
if (!interval_ns) {
*util = 0.0;
return_0;
}
io_nsecs = ((io_nsecs < interval_ns) ? io_nsecs : interval_ns);
*util = (double) io_nsecs / (double) interval_ns;
return 1;
}
static int _service_time(const struct dm_stats *dms, double *svctm,
uint64_t region_id, uint64_t area_id)
{
double tput, util;
if (!_throughput(dms, &tput, region_id, area_id))
return 0;
if (!_utilization(dms, &util, region_id, area_id))
return 0;
util *= 100;
/* avoid NAN with zero counter values */
if ( (uint64_t) tput == 0 || (uint64_t) util == 0) {
*svctm = 0.0;
return 1;
}
*svctm = ((double) NSEC_PER_SEC * dm_percent_to_float(util))
/ (100.0 * tput);
return 1;
}
/*
* Table in enum order:
* 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
*
*/
typedef int (*_metric_fn_t)(const struct dm_stats *, double *,
uint64_t, uint64_t);
const _metric_fn_t _metrics[DM_STATS_NR_METRICS] = {
_rd_merges_per_sec,
_wr_merges_per_sec,
_reads_per_sec,
_writes_per_sec,
_read_sectors_per_sec,
_write_sectors_per_sec,
_average_request_size,
_average_queue_size,
_average_wait_time,
_average_rd_wait_time,
_average_wr_wait_time,
_service_time,
_throughput,
_utilization
};
int dm_stats_get_metric(const struct dm_stats *dms, int metric,
uint64_t region_id, uint64_t area_id, double *value)
{
if (!dms->interval_ns)
return_0;
/*
* Decode DM_STATS_{REGION,AREA}_CURRENT here; counters will then
* be returned for the actual current region and area.
*
* DM_STATS_WALK_GROUP is passed through to the counter methods -
* aggregates for the group are returned and used to calculate
* the metric for the group totals.
*/
region_id = (region_id == DM_STATS_REGION_CURRENT)
? dms->cur_region : region_id ;
area_id = (area_id == DM_STATS_REGION_CURRENT)
? dms->cur_area : area_id ;
if (metric < 0 || metric >= DM_STATS_NR_METRICS) {
log_error("Attempt to read invalid metric: %d", metric);
return 0;
}
return _metrics[metric](dms, value, region_id, area_id);
}
/**
* Methods for accessing stats metrics. All methods share the
* following naming scheme and prototype:
*
* uint64_t dm_stats_get_metric(struct dm_stats *,
* int, int,
* uint64_t, uint64_t,
* double *v)
*
* Where the two integer arguments are the region_id and area_id
* respectively.
*
* name is the name of the metric (lower case)
* metric is the part of the enum name following DM_STATS_ (upper case)
*/
#define MK_STATS_GET_METRIC_FN(name, metric, meta) \
int dm_stats_get_ ## name(const struct dm_stats *dms, double *meta, \
uint64_t region_id, uint64_t area_id) \
{ \
return dm_stats_get_metric(dms, DM_STATS_ ## metric, \
region_id, area_id, meta); \
}
MK_STATS_GET_METRIC_FN(rd_merges_per_sec, RD_MERGES_PER_SEC, rrqm)
MK_STATS_GET_METRIC_FN(wr_merges_per_sec, WR_MERGES_PER_SEC, wrqm)
MK_STATS_GET_METRIC_FN(reads_per_sec, READS_PER_SEC, rd_s)
MK_STATS_GET_METRIC_FN(writes_per_sec, WRITES_PER_SEC, wr_s)
MK_STATS_GET_METRIC_FN(read_sectors_per_sec, READ_SECTORS_PER_SEC, rsec_s)
MK_STATS_GET_METRIC_FN(write_sectors_per_sec, WRITE_SECTORS_PER_SEC, wsec_s)
MK_STATS_GET_METRIC_FN(average_request_size, AVERAGE_REQUEST_SIZE, arqsz)
MK_STATS_GET_METRIC_FN(average_queue_size, AVERAGE_QUEUE_SIZE, qusz)
MK_STATS_GET_METRIC_FN(average_wait_time, AVERAGE_WAIT_TIME, await)
MK_STATS_GET_METRIC_FN(average_rd_wait_time, AVERAGE_RD_WAIT_TIME, await)
MK_STATS_GET_METRIC_FN(average_wr_wait_time, AVERAGE_WR_WAIT_TIME, await)
MK_STATS_GET_METRIC_FN(service_time, SERVICE_TIME, svctm)
MK_STATS_GET_METRIC_FN(throughput, THROUGHPUT, tput)
/*
* Utilization is an exception since it used the dm_percent_t type in the
* original named function based interface: preserve this behaviour for
* backwards compatibility with existing users.
*
* The same metric may be accessed as a double via the enum based metric
* interface.
*/
int dm_stats_get_utilization(const struct dm_stats *dms, dm_percent_t *util,
uint64_t region_id, uint64_t area_id)
{
double _util;
if (!dm_stats_get_metric(dms, DM_STATS_UTILIZATION,
region_id, area_id, &_util))
return_0;
/* scale up utilization value in the range [0.00..1.00] */
*util = dm_make_percent(DM_PERCENT_1 * _util, DM_PERCENT_1);
return 1;
}
void dm_stats_set_sampling_interval_ms(struct dm_stats *dms, uint64_t interval_ms)
{
/* All times use nsecs internally. */
dms->interval_ns = interval_ms * NSEC_PER_MSEC;
}
void dm_stats_set_sampling_interval_ns(struct dm_stats *dms, uint64_t interval_ns)
{
dms->interval_ns = interval_ns;
}
uint64_t dm_stats_get_sampling_interval_ms(const struct dm_stats *dms)
{
/* All times use nsecs internally. */
return (dms->interval_ns / NSEC_PER_MSEC);
}
uint64_t dm_stats_get_sampling_interval_ns(const struct dm_stats *dms)
{
/* All times use nsecs internally. */
return (dms->interval_ns);
}
int dm_stats_set_program_id(struct dm_stats *dms, int allow_empty,
const char *program_id)
{
if (!allow_empty && (!program_id || !strlen(program_id))) {
log_error("Empty program_id not permitted without "
"allow_empty=1");
return 0;
}
if (!program_id)
program_id = "";
dm_free(dms->program_id);
if (!(dms->program_id = dm_strdup(program_id)))
return_0;
return 1;
}
uint64_t dm_stats_get_current_region(const struct dm_stats *dms)
{
return dms->cur_region;
}
uint64_t dm_stats_get_current_area(const struct dm_stats *dms)
{
return dms->cur_area & ~DM_STATS_WALK_ALL;
}
int dm_stats_get_region_start(const struct dm_stats *dms, uint64_t *start,
uint64_t region_id)
{
if (!dms || !dms->regions)
return_0;
/* start is unchanged when aggregating areas */
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
/* use start of first region as group start */
if (region_id & DM_STATS_WALK_GROUP) {
if (region_id == DM_STATS_WALK_GROUP)
region_id = dms->cur_group;
else
region_id &= ~DM_STATS_WALK_GROUP;
}
*start = dms->regions[region_id].start;
return 1;
}
int dm_stats_get_region_len(const struct dm_stats *dms, uint64_t *len,
uint64_t region_id)
{
uint64_t i;
if (!dms || !dms->regions)
return_0;
*len = 0;
/* length is unchanged when aggregating areas */
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
if (region_id & DM_STATS_WALK_GROUP) {
/* decode region / group ID */
if (region_id == DM_STATS_WALK_GROUP)
region_id = dms->cur_group;
else
region_id &= ~DM_STATS_WALK_GROUP;
/* use sum of region sizes as group size */
if (_stats_region_is_grouped(dms, region_id))
_foreach_group_region(dms, dms->cur_group, i)
*len += dms->regions[i].len;
else {
log_error("Group ID " FMTu64 " does not exist",
region_id);
return 0;
}
} else
*len = dms->regions[region_id].len;
return 1;
}
int dm_stats_get_region_area_len(const struct dm_stats *dms, uint64_t *len,
uint64_t region_id)
{
if (!dms || !dms->regions)
return_0;
/* groups are not subdivided - area size equals group size */
if (region_id & (DM_STATS_WALK_GROUP | DM_STATS_WALK_REGION))
/* get_region_len will decode region_id */
return dm_stats_get_region_len(dms, len, region_id);
*len = dms->regions[region_id].step;
return 1;
}
int dm_stats_get_current_region_start(const struct dm_stats *dms,
uint64_t *start)
{
return dm_stats_get_region_start(dms, start, dms->cur_region);
}
int dm_stats_get_current_region_len(const struct dm_stats *dms,
uint64_t *len)
{
return dm_stats_get_region_len(dms, len, dms->cur_region);
}
int dm_stats_get_current_region_area_len(const struct dm_stats *dms,
uint64_t *step)
{
return dm_stats_get_region_area_len(dms, step, dms->cur_region);
}
int dm_stats_get_area_start(const struct dm_stats *dms, uint64_t *start,
uint64_t region_id, uint64_t area_id)
{
struct dm_stats_region *region;
if (!dms || !dms->regions)
return_0;
/* group or region area start equals region start */
if (region_id & (DM_STATS_WALK_GROUP | DM_STATS_WALK_REGION))
return dm_stats_get_region_start(dms, start, region_id);
region = &dms->regions[region_id];
*start = region->start + region->step * area_id;
return 1;
}
int dm_stats_get_area_offset(const struct dm_stats *dms, uint64_t *offset,
uint64_t region_id, uint64_t area_id)
{
if (!dms || !dms->regions)
return_0;
/* no areas for groups or aggregate regions */
if (region_id & (DM_STATS_WALK_GROUP | DM_STATS_WALK_REGION))
*offset = 0;
else
*offset = dms->regions[region_id].step * area_id;
return 1;
}
int dm_stats_get_current_area_start(const struct dm_stats *dms,
uint64_t *start)
{
return dm_stats_get_area_start(dms, start,
dms->cur_region, dms->cur_area);
}
int dm_stats_get_current_area_offset(const struct dm_stats *dms,
uint64_t *offset)
{
return dm_stats_get_area_offset(dms, offset,
dms->cur_region, dms->cur_area);
}
int dm_stats_get_current_area_len(const struct dm_stats *dms,
uint64_t *len)
{
return dm_stats_get_region_area_len(dms, len, dms->cur_region);
}
const char *dm_stats_get_region_program_id(const struct dm_stats *dms,
uint64_t region_id)
{
const char *program_id = NULL;
if (region_id & DM_STATS_WALK_GROUP)
return dms->program_id;
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
program_id = dms->regions[region_id].program_id;
return (program_id) ? program_id : "";
}
const char *dm_stats_get_region_aux_data(const struct dm_stats *dms,
uint64_t region_id)
{
const char *aux_data = NULL;
if (region_id & DM_STATS_WALK_GROUP)
return "";
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
aux_data = dms->regions[region_id].aux_data;
return (aux_data) ? aux_data : "" ;
}
int dm_stats_set_alias(struct dm_stats *dms, uint64_t group_id, const char *alias)
{
struct dm_stats_group *group = NULL;
const char *old_alias = NULL;
if (!dms->regions || !dms->groups || !alias)
return_0;
if (!_stats_region_is_grouped(dms, group_id)) {
log_error("Cannot set alias for ungrouped region ID "
FMTu64, group_id);
return 0;
}
if (group_id & DM_STATS_WALK_GROUP) {
if (group_id == DM_STATS_WALK_GROUP)
group_id = dms->cur_group;
else
group_id &= ~DM_STATS_WALK_GROUP;
}
if (group_id != dms->regions[group_id].group_id) {
/* dm_stats_set_alias() must be called on the group ID. */
log_error("Cannot set alias for group member " FMTu64 ".",
group_id);
return 0;
}
group = &dms->groups[group_id];
old_alias = group->alias;
group->alias = dm_strdup(alias);
if (!group->alias) {
log_error("Could not allocate memory for alias.");
goto bad;
}
if (!_stats_set_aux(dms, group_id, dms->regions[group_id].aux_data)) {
log_error("Could not set new aux_data");
goto bad;
}
dm_free((char *) old_alias);
return 1;
bad:
dm_free((char *) group->alias);
group->alias = old_alias;
return 0;
}
const char *dm_stats_get_alias(const struct dm_stats *dms, uint64_t id)
{
const struct dm_stats_region *region;
id = (id == DM_STATS_REGION_CURRENT) ? dms->cur_region : id;
if (id & DM_STATS_WALK_GROUP) {
if (id == DM_STATS_WALK_GROUP)
id = dms->cur_group;
else
id &= ~DM_STATS_WALK_GROUP;
}
region = &dms->regions[id];
if (!_stats_region_is_grouped(dms, id)
|| !dms->groups[region->group_id].alias)
return dms->name;
return dms->groups[region->group_id].alias;
}
const char *dm_stats_get_current_region_program_id(const struct dm_stats *dms)
{
return dm_stats_get_region_program_id(dms, dms->cur_region);
}
const char *dm_stats_get_current_region_aux_data(const struct dm_stats *dms)
{
return dm_stats_get_region_aux_data(dms, dms->cur_region);
}
int dm_stats_get_region_precise_timestamps(const struct dm_stats *dms,
uint64_t region_id)
{
struct dm_stats_region *region;
if (region_id == DM_STATS_REGION_CURRENT)
region_id = dms->cur_region;
if (region_id == DM_STATS_WALK_GROUP)
region_id = dms->cur_group;
else if (region_id & DM_STATS_WALK_GROUP)
region_id &= ~DM_STATS_WALK_GROUP;
region = &dms->regions[region_id];
return region->timescale == 1;
}
int dm_stats_get_current_region_precise_timestamps(const struct dm_stats *dms)
{
return dm_stats_get_region_precise_timestamps(dms,
DM_STATS_REGION_CURRENT);
}
/*
* Histogram access methods.
*/
static void _sum_histogram_bins(const struct dm_stats *dms,
struct dm_histogram *dmh_aggr,
uint64_t region_id, uint64_t area_id)
{
struct dm_stats_region *region;
struct dm_histogram_bin *bins;
struct dm_histogram *dmh_cur;
int bin;
region = &dms->regions[region_id];
dmh_cur = region->counters[area_id].histogram;
bins = dmh_aggr->bins;
for (bin = 0; bin < dmh_aggr->nr_bins; bin++)
bins[bin].count += dmh_cur->bins[bin].count;
}
/*
* Create an aggregate histogram for a sub-divided region or a group.
*/
static struct dm_histogram *_aggregate_histogram(const struct dm_stats *dms,
uint64_t region_id,
uint64_t area_id)
{
struct dm_histogram *dmh_aggr, *dmh_cur, **dmh_cachep;
uint64_t group_id = DM_STATS_GROUP_NOT_PRESENT;
int bin, nr_bins, group = 1;
size_t hist_size;
if (area_id == DM_STATS_WALK_REGION) {
/* region aggregation */
group = 0;
if (!_stats_region_present(&dms->regions[region_id]))
return_NULL;
if (!dms->regions[region_id].bounds)
return_NULL;
if (!dms->regions[region_id].counters)
return dms->regions[region_id].bounds;
if (dms->regions[region_id].histogram)
return dms->regions[region_id].histogram;
dmh_cur = dms->regions[region_id].counters[0].histogram;
dmh_cachep = &dms->regions[region_id].histogram;
nr_bins = dms->regions[region_id].bounds->nr_bins;
} else {
/* group aggregation */
group_id = region_id;
area_id = DM_STATS_WALK_GROUP;
if (!_stats_group_id_present(dms, group_id))
return_NULL;
if (!dms->regions[group_id].bounds)
return_NULL;
if (!dms->regions[group_id].counters)
return dms->regions[group_id].bounds;
if (dms->groups[group_id].histogram)
return dms->groups[group_id].histogram;
dmh_cur = dms->regions[group_id].counters[0].histogram;
dmh_cachep = &dms->groups[group_id].histogram;
nr_bins = dms->regions[group_id].bounds->nr_bins;
}
hist_size = sizeof(*dmh_aggr)
+ nr_bins * sizeof(struct dm_histogram_bin);
if (!(dmh_aggr = dm_pool_zalloc(dms->hist_mem, hist_size))) {
log_error("Could not allocate group histogram");
return 0;
}
dmh_aggr->nr_bins = dmh_cur->nr_bins;
dmh_aggr->dms = dms;
if (!group)
_foreach_region_area(dms, region_id, area_id) {
_sum_histogram_bins(dms, dmh_aggr, region_id, area_id);
}
else {
_foreach_group_area(dms, group_id, region_id, area_id) {
_sum_histogram_bins(dms, dmh_aggr, region_id, area_id);
}
}
for (bin = 0; bin < nr_bins; bin++) {
dmh_aggr->sum += dmh_aggr->bins[bin].count;
dmh_aggr->bins[bin].upper = dmh_cur->bins[bin].upper;
}
/* cache aggregate histogram for subsequent access */
*dmh_cachep = dmh_aggr;
return dmh_aggr;
}
struct dm_histogram *dm_stats_get_histogram(const struct dm_stats *dms,
uint64_t region_id,
uint64_t area_id)
{
int aggr = 0;
if (region_id == DM_STATS_REGION_CURRENT) {
region_id = dms->cur_region;
if (region_id & DM_STATS_WALK_GROUP) {
region_id = dms->cur_group;
aggr = 1;
}
} else if (region_id & DM_STATS_WALK_GROUP) {
region_id &= ~DM_STATS_WALK_GROUP;
aggr = 1;
}
area_id = (area_id == DM_STATS_AREA_CURRENT)
? dms->cur_area : area_id ;
if (area_id == DM_STATS_WALK_REGION)
aggr = 1;
if (aggr)
return _aggregate_histogram(dms, region_id, area_id);
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
if (!dms->regions[region_id].counters)
return dms->regions[region_id].bounds;
return dms->regions[region_id].counters[area_id].histogram;
}
int dm_histogram_get_nr_bins(const struct dm_histogram *dmh)
{
return dmh->nr_bins;
}
uint64_t dm_histogram_get_bin_lower(const struct dm_histogram *dmh, int bin)
{
return (!bin) ? 0 : dmh->bins[bin - 1].upper;
}
uint64_t dm_histogram_get_bin_upper(const struct dm_histogram *dmh, int bin)
{
return dmh->bins[bin].upper;
}
uint64_t dm_histogram_get_bin_width(const struct dm_histogram *dmh, int bin)
{
uint64_t upper, lower;
upper = dm_histogram_get_bin_upper(dmh, bin);
lower = dm_histogram_get_bin_lower(dmh, bin);
return (upper - lower);
}
uint64_t dm_histogram_get_bin_count(const struct dm_histogram *dmh, int bin)
{
return dmh->bins[bin].count;
}
uint64_t dm_histogram_get_sum(const struct dm_histogram *dmh)
{
return dmh->sum;
}
dm_percent_t dm_histogram_get_bin_percent(const struct dm_histogram *dmh,
int bin)
{
uint64_t value = dm_histogram_get_bin_count(dmh, bin);
uint64_t width = dm_histogram_get_bin_width(dmh, bin);
uint64_t total = dm_histogram_get_sum(dmh);
double val = (double) value;
if (!total || !value || !width)
return DM_PERCENT_0;
return dm_make_percent((uint64_t) val, total);
}
/*
* Histogram string helper functions: used to construct histogram and
* bin boundary strings from numeric data.
*/
/*
* Allocate an unbound histogram object with nr_bins bins. Only used
* for histograms used to hold bounds values as arguments for calls to
* dm_stats_create_region().
*/
static struct dm_histogram *_alloc_dm_histogram(int nr_bins)
{
/* Allocate space for dm_histogram + nr_entries. */
size_t size = sizeof(struct dm_histogram) +
(unsigned) nr_bins * sizeof(struct dm_histogram_bin);
return dm_zalloc(size);
}
/*
* Parse a histogram bounds string supplied by the user. The string
* consists of a list of numbers, "n1,n2,n3,..." with optional 'ns',
* 'us', 'ms', or 's' unit suffixes.
*
* The scale parameter indicates the timescale used for this region: one
* for nanoscale resolution and NSEC_PER_MSEC for milliseconds.
*
* On return bounds contains a pointer to an array of uint64_t
* histogram bounds values expressed in units of nanoseconds.
*/
struct dm_histogram *dm_histogram_bounds_from_string(const char *bounds_str)
{
const char valid_chars[] = "0123456789,muns";
uint64_t this_val = 0, mult = 1;
const char *c, *v, *val_start;
struct dm_histogram_bin *cur;
struct dm_histogram *dmh;
int nr_entries = 1;
char *endptr;
c = bounds_str;
/* Count number of bounds entries. */
while(*c)
if (*(c++) == ',')
nr_entries++;
c = bounds_str;
if (!(dmh = _alloc_dm_histogram(nr_entries)))
return_0;
dmh->nr_bins = nr_entries;
cur = dmh->bins;
do {
for (v = valid_chars; *v; v++)
if (*c == *v)
break;
if (!*v) {
stack;
goto badchar;
}
if (*c == ',') {
log_error("Empty histogram bin not allowed: %s",
bounds_str);
goto bad;
} else {
val_start = c;
endptr = NULL;
this_val = strtoull(val_start, &endptr, 10);
if (!endptr) {
log_error("Could not parse histogram bound.");
goto bad;
}
c = endptr; /* Advance to units, comma, or end. */
if (*c == 's') {
mult = NSEC_PER_SEC;
c++; /* Advance over 's'. */
} else if (*(c + 1) == 's') {
if (*c == 'm')
mult = NSEC_PER_MSEC;
else if (*c == 'u')
mult = NSEC_PER_USEC;
else if (*c == 'n')
mult = 1;
else {
stack;
goto badchar;
}
c += 2; /* Advance over 'ms', 'us', or 'ns'. */
} else if (*c == ',')
c++;
else if (*c) { /* Expected ',' or NULL. */
stack;
goto badchar;
}
if (*c == ',')
c++;
this_val *= mult;
(cur++)->upper = this_val;
}
} while (*c);
/* Bounds histograms have no owner. */
dmh->dms = NULL;
dmh->region = NULL;
return dmh;
badchar:
log_error("Invalid character in histogram: %c", *c);
bad:
dm_free(dmh);
return NULL;
}
struct dm_histogram *dm_histogram_bounds_from_uint64(const uint64_t *bounds)
{
const uint64_t *entry = bounds;
struct dm_histogram_bin *cur;
struct dm_histogram *dmh;
int nr_entries = 1;
if (!bounds || !bounds[0]) {
log_error("Could not parse empty histogram bounds array");
return 0;
}
/* Count number of bounds entries. */
while(*entry)
if (*(++entry))
nr_entries++;
entry = bounds;
if (!(dmh = _alloc_dm_histogram(nr_entries)))
return_0;
dmh->nr_bins = nr_entries;
cur = dmh->bins;
while (*entry)
(cur++)->upper = *(entry++);
/* Bounds histograms have no owner. */
dmh->dms = NULL;
dmh->region = NULL;
return dmh;
}
void dm_histogram_bounds_destroy(struct dm_histogram *bounds)
{
if (!bounds)
return;
/* Bounds histograms are not bound to any handle or region. */
if (bounds->dms || bounds->region) {
log_error("Freeing invalid histogram bounds pointer %p.",
(void *) bounds);
stack;
}
/* dm_free() expects a (void *). */
dm_free((void *) bounds);
}
/*
* Scale a bounds value down from nanoseconds to the largest possible
* whole unit suffix.
*/
static void _scale_bound_value_to_suffix(uint64_t *bound, const char **suffix)
{
*suffix = "ns";
if (!(*bound % NSEC_PER_SEC)) {
*bound /= NSEC_PER_SEC;
*suffix = "s";
} else if (!(*bound % NSEC_PER_MSEC)) {
*bound /= NSEC_PER_MSEC;
*suffix = "ms";
} else if (!(*bound % NSEC_PER_USEC)) {
*bound /= NSEC_PER_USEC;
*suffix = "us";
}
}
#define DM_HISTOGRAM_BOUNDS_MASK 0x30
#define BOUNDS_LEN 64
static int _make_bounds_string(char *buf, size_t size, uint64_t lower,
uint64_t upper, int flags, int width)
{
char bound_buf[BOUNDS_LEN];
const char *l_suff = NULL;
const char *u_suff = NULL;
const char *sep = "";
int bounds = flags & DM_HISTOGRAM_BOUNDS_MASK;
if (!bounds)
return_0;
*buf = '\0';
if (flags & DM_HISTOGRAM_SUFFIX) {
_scale_bound_value_to_suffix(&lower, &l_suff);
_scale_bound_value_to_suffix(&upper, &u_suff);
} else
l_suff = u_suff = "";
if (flags & DM_HISTOGRAM_VALUES)
sep = ":";
if (bounds > DM_HISTOGRAM_BOUNDS_LOWER) {
/* Handle infinite uppermost bound. */
if (upper == UINT64_MAX) {
if (dm_snprintf(bound_buf, sizeof(bound_buf),
">" FMTu64 "%s", lower, l_suff) < 0)
goto_out;
/* Only display an 'upper' string for final bin. */
bounds = DM_HISTOGRAM_BOUNDS_UPPER;
} else {
if (dm_snprintf(bound_buf, sizeof(bound_buf),
FMTu64 "%s", upper, u_suff) < 0)
goto_out;
}
} else if (bounds == DM_HISTOGRAM_BOUNDS_LOWER) {
if ((dm_snprintf(bound_buf, sizeof(bound_buf), FMTu64 "%s",
lower, l_suff)) < 0)
goto_out;
}
switch (bounds) {
case DM_HISTOGRAM_BOUNDS_LOWER:
case DM_HISTOGRAM_BOUNDS_UPPER:
return dm_snprintf(buf, size, "%*s%s", width, bound_buf, sep);
case DM_HISTOGRAM_BOUNDS_RANGE:
return dm_snprintf(buf, size, FMTu64 "%s-%s%s",
lower, l_suff, bound_buf, sep);
}
out:
return 0;
}
#define BOUND_WIDTH_NOSUFFIX 10 /* 999999999 nsecs */
#define BOUND_WIDTH 6 /* bounds string up to 9999xs */
#define COUNT_WIDTH 6 /* count string: up to 9999 */
#define PERCENT_WIDTH 6 /* percent string : 0.00-100.00% */
#define DM_HISTOGRAM_VALUES_MASK 0x06
const char *dm_histogram_to_string(const struct dm_histogram *dmh, int bin,
int width, int flags)
{
char buf[BOUNDS_LEN], bounds_buf[BOUNDS_LEN];
int minwidth, bounds, values, start, last;
uint64_t lower, upper, val_u64; /* bounds of the current bin. */
/* Use the histogram pool for string building. */
struct dm_pool *mem = dmh->dms->hist_mem;
const char *sep = "";
int bounds_width;
ssize_t len = 0;
float val_flt;
bounds = flags & DM_HISTOGRAM_BOUNDS_MASK;
values = flags & DM_HISTOGRAM_VALUES;
if (bin < 0) {
start = 0;
last = dmh->nr_bins - 1;
} else
start = last = bin;
minwidth = width;
if (width < 0 || !values)
width = minwidth = 0; /* no padding */
else if (flags & DM_HISTOGRAM_PERCENT)
width = minwidth = (width) ? : PERCENT_WIDTH;
else if (flags & DM_HISTOGRAM_VALUES)
width = minwidth = (width) ? : COUNT_WIDTH;
if (values && !width)
sep = ":";
/* Set bounds string to the empty string. */
bounds_buf[0] = '\0';
if (!dm_pool_begin_object(mem, 64))
return_0;
for (bin = start; bin <= last; bin++) {
if (bounds) {
/* Default bounds width depends on time suffixes. */
bounds_width = (!(flags & DM_HISTOGRAM_SUFFIX))
? BOUND_WIDTH_NOSUFFIX
: BOUND_WIDTH ;
bounds_width = (!width) ? width : bounds_width;
lower = dm_histogram_get_bin_lower(dmh, bin);
upper = dm_histogram_get_bin_upper(dmh, bin);
len = sizeof(bounds_buf);
len = _make_bounds_string(bounds_buf, len,
lower, upper, flags,
bounds_width);
/*
* Comma separates "bounds: value" pairs unless
* --noheadings is used.
*/
sep = (width || !values) ? "," : ":";
/* Adjust width by real bounds length if set. */
width -= (width) ? (len - (bounds_width + 1)) : 0;
/* -ve width indicates specified width was overrun. */
width = (width > 0) ? width : 0;
}
if (bin == last)
sep = "";
if (flags & DM_HISTOGRAM_PERCENT) {
dm_percent_t pr;
pr = dm_histogram_get_bin_percent(dmh, bin);
val_flt = dm_percent_to_float(pr);
len = dm_snprintf(buf, sizeof(buf), "%s%*.2f%%%s",
bounds_buf, width, val_flt, sep);
} else if (values) {
val_u64 = dmh->bins[bin].count;
len = dm_snprintf(buf, sizeof(buf), "%s%*"PRIu64"%s",
bounds_buf, width, val_u64, sep);
} else if (bounds)
len = dm_snprintf(buf, sizeof(buf), "%s%s", bounds_buf,
sep);
else {
*buf = '\0';
len = 0;
}
if (len < 0)
goto_bad;
width = minwidth; /* re-set histogram column width. */
if (!dm_pool_grow_object(mem, buf, (size_t) len))
goto_bad;
}
if (!dm_pool_grow_object(mem, "\0", 1))
goto_bad;
return (const char *) dm_pool_end_object(mem);
bad:
dm_pool_abandon_object(mem);
return NULL;
}
/*
* A lightweight representation of an extent (region, area, file
* system block or extent etc.). A table of extents can be used
* to sort and to efficiently find holes or overlaps among a set
* of tuples of the form (id, start, len).
*/
struct _extent {
struct dm_list list;
uint64_t id;
uint64_t start;
uint64_t len;
};
/* last address in an extent */
#define _extent_end(a) ((a)->start + (a)->len - 1)
/* a and b must be sorted by increasing start sector */
#define _extents_overlap(a, b) (_extent_end(a) > (b)->start)
/*
* Comparison function to sort extents in ascending start order.
*/
static int _extent_start_compare(const void *p1, const void *p2)
{
const struct _extent *r1, *r2;
r1 = (const struct _extent *) p1;
r2 = (const struct _extent *) p2;
if (r1->start < r2->start)
return -1;
else if (r1->start == r2->start)
return 0;
return 1;
}
static int _stats_create_group(struct dm_stats *dms, dm_bitset_t regions,
const char *alias, uint64_t *group_id)
{
struct dm_stats_group *group;
*group_id = dm_bit_get_first(regions);
/* group has no regions? */
if (*group_id == DM_STATS_GROUP_NOT_PRESENT)
return_0;
group = &dms->groups[*group_id];
if (group->regions) {
log_error(INTERNAL_ERROR "Unexpected group state while"
"creating group ID bitmap" FMTu64, *group_id);
return 0;
}
group->group_id = *group_id;
group->regions = regions;
if (alias)
group->alias = dm_strdup(alias);
else
group->alias = NULL;
/* force an update of the group tag stored in aux_data */
if (!_stats_set_aux(dms, *group_id, dms->regions[*group_id].aux_data))
goto bad;
return 1;
bad:
group->group_id = DM_STATS_GROUP_NOT_PRESENT;
group->regions = NULL;
dm_free((char *) group->alias);
return 0;
}
static int _stats_group_check_overlap(const struct dm_stats *dms,
dm_bitset_t regions, int count)
{
struct dm_list ext_list = DM_LIST_HEAD_INIT(ext_list);
struct _extent *ext, *tmp, *next, *map = NULL;
size_t map_size = (dms->max_region + 1) * sizeof(*map);
int i = 0, id, overlap, merged;
map = dm_pool_alloc(dms->mem, map_size);
if (!map) {
log_error("Could not allocate memory for region map");
return 0;
}
/* build a table of extents in order of region_id */
for (id = dm_bit_get_first(regions); id >= 0;
id = dm_bit_get_next(regions, id)) {
dm_list_init(&map[i].list);
map[i].id = id;
map[i].start = dms->regions[id].start;
map[i].len = dms->regions[id].len;
i++;
}
/* A single region cannot overlap itself. */
if (i == 1) {
dm_pool_free(dms->mem, map);
return 1;
}
/* sort by extent.start */
qsort(map, count, sizeof(*map), _extent_start_compare);
for (i = 0; i < count; i++)
dm_list_add(&ext_list, &map[i].list);
overlap = 0;
merge:
merged = 0;
dm_list_iterate_items_safe(ext, tmp, &ext_list) {
next = dm_list_item(dm_list_next(&ext_list, &ext->list),
struct _extent);
if (!next)
continue;
if (_extents_overlap(ext, next)) {
log_warn("WARNING: region IDs " FMTu64 " and "
FMTu64 " overlap. Some events will be "
"counted twice.", ext->id, next->id);
/* merge larger extent into smaller */
if (_extent_end(ext) > _extent_end(next)) {
next->id = ext->id;
next->len = ext->len;
}
if (ext->start < next->start)
next->start = ext->start;
dm_list_del(&ext->list);
overlap = merged = 1;
}
}
/* continue until no merge candidates remain */
if (merged)
goto merge;
dm_pool_free(dms->mem, map);
return (overlap == 0);
}
static void _stats_copy_histogram_bounds(struct dm_histogram *to,
struct dm_histogram *from)
{
int i;
to->nr_bins = from->nr_bins;
for (i = 0; i < to->nr_bins; i++)
to->bins[i].upper = from->bins[i].upper;
}
/*
* Compare histogram bounds h1 and h2, and return 1 if they match (i.e.
* have the same number of bins and identical bin boundary values), or 0
* otherwise.
*/
static int _stats_check_histogram_bounds(struct dm_histogram *h1,
struct dm_histogram *h2)
{
int i;
if (!h1 || !h2)
return 0;
if (h1->nr_bins != h2->nr_bins)
return 0;
for (i = 0; i < h1->nr_bins; i++)
if (h1->bins[i].upper != h2->bins[i].upper)
return 0;
return 1;
}
/*
* Create a new group in stats handle dms from the group description
* passed in group.
*/
int dm_stats_create_group(struct dm_stats *dms, const char *members,
const char *alias, uint64_t *group_id)
{
struct dm_histogram *check = NULL, *bounds;
int i, count = 0, precise = 0;
dm_bitset_t regions;
if (!dms->regions || !dms->groups) {
log_error("Could not create group: no regions found.");
return 0;
};
if (!(regions = dm_bitset_parse_list(members, NULL, 0))) {
log_error("Could not parse list: '%s'", members);
return 0;
}
if (!(check = dm_pool_zalloc(dms->hist_mem, sizeof(*check)))) {
log_error("Could not allocate memory for bounds check");
goto bad;
}
/* too many bits? */
if ((*regions - 1) > dms->max_region) {
log_error("Invalid region ID: %d", *regions - 1);
goto bad;
}
/*
* Check that each region_id in the bitmap meets the group
* constraints: present, not already grouped, and if any
* histogram is present that they all have the same bounds.
*/
for (i = dm_bit_get_first(regions); i >= 0;
i = dm_bit_get_next(regions, i)) {
if (!dm_stats_region_present(dms, i)) {
log_error("Region ID %d does not exist", i);
goto bad;
}
if (_stats_region_is_grouped(dms, i)) {
log_error("Region ID %d already a member of group ID "
FMTu64, i, dms->regions[i].group_id);
goto bad;
}
if (dms->regions[i].timescale == 1)
precise++;
/* check for matching histogram bounds */
bounds = dms->regions[i].bounds;
if (bounds && !check->nr_bins)
_stats_copy_histogram_bounds(check, bounds);
else if (bounds) {
if (!_stats_check_histogram_bounds(check, bounds)) {
log_error("All region histogram bounds "
"must match exactly");
goto bad;
}
}
count++;
}
if (precise && (precise != count))
log_warn("WARNING: Grouping regions with different clock resolution: "
"precision may be lost.");
if (!_stats_group_check_overlap(dms, regions, count))
log_very_verbose("Creating group with overlapping regions.");
if (!_stats_create_group(dms, regions, alias, group_id))
goto bad;
dm_pool_free(dms->hist_mem, check);
return 1;
bad:
dm_pool_free(dms->hist_mem, check);
dm_bitset_destroy(regions);
return 0;
}
/*
* Remove the specified group_id.
*/
int dm_stats_delete_group(struct dm_stats *dms, uint64_t group_id,
int remove_regions)
{
struct dm_stats_region *leader;
dm_bitset_t regions;
uint64_t i;
if (group_id > dms->max_region) {
log_error("Invalid group ID: " FMTu64, group_id);
return 0;
}
if (!_stats_group_id_present(dms, group_id)) {
log_error("Group ID " FMTu64 " does not exist", group_id);
return 0;
}
regions = dms->groups[group_id].regions;
leader = &dms->regions[group_id];
/* delete all but the group leader */
for (i = (*regions - 1); i > leader->region_id; i--) {
if (dm_bit(regions, i)) {
dm_bit_clear(regions, i);
if (remove_regions && !dm_stats_delete_region(dms, i))
log_warn("WARNING: Failed to delete region "
FMTu64 " on %s.", i, dms->name);
}
}
/* clear group and mark as not present */
_stats_clear_group_regions(dms, group_id);
_stats_group_destroy(&dms->groups[group_id]);
/* delete leader or clear aux_data */
if (remove_regions)
return dm_stats_delete_region(dms, group_id);
else if (!_stats_set_aux(dms, group_id, leader->aux_data))
return 0;
return 1;
}
uint64_t dm_stats_get_group_id(const struct dm_stats *dms, uint64_t region_id)
{
region_id = (region_id == DM_STATS_REGION_CURRENT)
? dms->cur_region : region_id;
if (region_id & DM_STATS_WALK_GROUP) {
if (region_id == DM_STATS_WALK_GROUP)
return dms->cur_group;
else
return region_id & ~DM_STATS_WALK_GROUP;
}
if (region_id & DM_STATS_WALK_REGION)
region_id &= ~DM_STATS_WALK_REGION;
return dms->regions[region_id].group_id;
}
int dm_stats_get_group_descriptor(const struct dm_stats *dms,
uint64_t group_id, char **buf)
{
dm_bitset_t regions = dms->groups[group_id].regions;
size_t buflen;
buflen = _stats_group_tag_len(dms, regions);
*buf = dm_pool_alloc(dms->mem, buflen);
if (!*buf) {
log_error("Could not allocate memory for regions string");
return 0;
}
if (!_stats_group_tag_fill(dms, regions, *buf, buflen))
return 0;
return 1;
}
#ifdef HAVE_LINUX_FIEMAP_H
/*
* Resize the group bitmap corresponding to group_id so that it can
* contain at least num_regions members.
*/
static int _stats_resize_group(struct dm_stats_group *group,
uint64_t num_regions)
{
uint64_t last_bit = dm_bit_get_last(group->regions);
dm_bitset_t new, old;
if (last_bit >= num_regions) {
log_error("Cannot resize group bitmap to " FMTu64
" with bit " FMTu64 " set.", num_regions, last_bit);
return 0;
}
log_very_verbose("Resizing group bitmap from " FMTu32 " to " FMTu64
" (last_bit: " FMTu64 ").", group->regions[0],
num_regions, last_bit);
new = dm_bitset_create(NULL, (unsigned) num_regions);
if (!new) {
log_error("Could not allocate memory for new group bitmap.");
return 0;
}
old = group->regions;
dm_bit_copy(new, old);
group->regions = new;
dm_bitset_destroy(old);
return 1;
}
/*
* Group a table of region_ids corresponding to the extents of a file.
*/
static int _stats_group_file_regions(struct dm_stats *dms, uint64_t *region_ids,
uint64_t count, const char *alias)
{
dm_bitset_t regions = dm_bitset_create(NULL, dms->nr_regions);
uint64_t i, group_id = DM_STATS_GROUP_NOT_PRESENT;
char *members = NULL;
size_t buflen;
if (!regions) {
log_error("Cannot map file: failed to allocate group bitmap.");
return 0;
}
for (i = 0; i < count; i++)
dm_bit_set(regions, region_ids[i]);
buflen = _stats_group_tag_len(dms, regions);
members = dm_malloc(buflen);
if (!members) {
log_error("Cannot map file: failed to allocate group "
"descriptor.");
dm_bitset_destroy(regions);
return 0;
}
if (!_stats_group_tag_fill(dms, regions, members, buflen))
goto bad;
/*
* overlaps should not be possible: overlapping file extents
* returned by FIEMAP imply a kernel bug or a corrupt fs.
*/
if (!_stats_group_check_overlap(dms, regions, count))
log_very_verbose("Creating group with overlapping regions.");
if (!_stats_create_group(dms, regions, alias, &group_id))
goto bad;
dm_free(members);
return 1;
bad:
dm_bitset_destroy(regions);
dm_free(members);
return 0;
}
static int _stats_add_file_extent(int fd, struct dm_pool *mem, uint64_t id,
struct fiemap_extent *fm_ext)
{
struct _extent extent;
/* final address of list is unknown */
memset(&extent.list, 0, sizeof(extent.list));
/* convert bytes to dm (512b) sectors */
extent.start = fm_ext->fe_physical >> SECTOR_SHIFT;
extent.len = fm_ext->fe_length >> SECTOR_SHIFT;
extent.id = id;
log_very_verbose("Extent " FMTu64 " on fd %d at " FMTu64 "+"
FMTu64, extent.id, fd, extent.start, extent.len);
if (!dm_pool_grow_object(mem, &extent,
sizeof(extent))) {
log_error("Cannot map file: failed to grow extent map.");
return 0;
}
return 1;
}
/* test for the boundary of an extent */
#define ext_boundary(ext, exp) \
((ext).fe_logical != 0) && \
((ext).fe_physical != (exp))
/*
* Copy fields from fiemap_extent 'from' to the fiemap_extent
* pointed to by 'to'.
*/
#define ext_copy(to, from) \
do { \
*(to) = *(from); \
} while (0)
static uint64_t _stats_map_extents(int fd, struct dm_pool *mem,
struct fiemap *fiemap,
struct fiemap_extent *fm_ext,
struct fiemap_extent *fm_last,
struct fiemap_extent *fm_pending,
uint64_t next_extent,
int *eof)
{
uint64_t expected = 0, nr_extents = next_extent;
unsigned int i;
/*
* Loop over the returned extents adding the fm_pending extent
* to the table of extents each time a discontinuity (or eof)
* is detected.
*
* We use a pointer to fm_pending in the caller since it is
* possible that logical extents comprising a single physical
* extent are returned by successive FIEMAP calls.
*/
for (i = 0; i < fiemap->fm_mapped_extents; i++) {
expected = fm_last->fe_physical + fm_last->fe_length;
if (fm_ext[i].fe_flags & FIEMAP_EXTENT_LAST)
*eof = 1;
/* cannot map extents that are not yet allocated. */
if (fm_ext[i].fe_flags
& (FIEMAP_EXTENT_UNKNOWN | FIEMAP_EXTENT_DELALLOC))
continue;
/*
* Begin a new extent if the current physical address differs
* from the expected address yielded by fm_last.fe_physical +
* fm_last.fe_length.
*
* A logical discontinuity is seen at the start of the file if
* unwritten space exists before the first extent: do not add
* any extent record until we have accumulated a non-zero length
* in fm_pending.
*/
if (fm_pending->fe_length &&
ext_boundary(fm_ext[i], expected)) {
if (!_stats_add_file_extent(fd, mem, nr_extents,
fm_pending))
goto_bad;
nr_extents++;
/* Begin a new pending extent. */
ext_copy(fm_pending, fm_ext + i);
} else {
expected = 0;
/* Begin a new pending extent for extent 0. If there is
* a hole at the start of the file, the first allocated
* extent will have a non-zero fe_logical. Detect this
* case by testing fm_pending->fe_length: if no length
* has been accumulated we are handling the first
* physical extent of the file.
*/
if (!fm_pending->fe_length || fm_ext[i].fe_logical == 0)
ext_copy(fm_pending, fm_ext + i);
else
/* accumulate this logical extent's length */
fm_pending->fe_length += fm_ext[i].fe_length;
}
*fm_last = fm_ext[i];
}
/*
* If the file only has a single extent, no boundary is ever
* detected to trigger addition of the first extent.
*/
if (*eof || (fm_ext[i - 1].fe_logical == 0)) {
_stats_add_file_extent(fd, mem, nr_extents, fm_pending);
nr_extents++;
}
fiemap->fm_start = (fm_ext[i - 1].fe_logical +
fm_ext[i - 1].fe_length);
/* return the number of extents found in this call. */
return nr_extents - next_extent;
bad:
/* signal mapping error to caller */
*eof = -1;
return 0;
}
/*
* Read the extents of an open file descriptor into a table of struct _extent.
*
* Based on e2fsprogs/misc/filefrag.c::filefrag_fiemap().
*
* Copyright 2003 by Theodore Ts'o.
*
*/
static struct _extent *_stats_get_extents_for_file(struct dm_pool *mem, int fd,
uint64_t *count)
{
struct fiemap_extent fm_last = {0}, fm_pending = {0}, *fm_ext = NULL;
struct fiemap *fiemap = NULL;
int eof = 0, nr_extents = 0;
struct _extent *extents;
unsigned long flags = 0;
uint64_t *buf;
/* grow temporary extent table in the pool */
if (!dm_pool_begin_object(mem, sizeof(*extents)))
return NULL;
buf = dm_zalloc(STATS_FIE_BUF_LEN);
if (!buf) {
log_error("Could not allocate memory for FIEMAP buffer.");
goto bad;
}
/* initialise pointers into the ioctl buffer. */
fiemap = (struct fiemap *) buf;
fm_ext = &fiemap->fm_extents[0];
/* space available per ioctl */
*count = (STATS_FIE_BUF_LEN - sizeof(*fiemap))
/ sizeof(struct fiemap_extent);
flags = FIEMAP_FLAG_SYNC;
do {
/* start of ioctl loop - zero size and set count to bufsize */
fiemap->fm_length = ~0ULL;
fiemap->fm_flags = flags;
fiemap->fm_extent_count = *count;
/* get count-sized chunk of extents */
if (ioctl(fd, FS_IOC_FIEMAP, (unsigned long) fiemap) < 0) {
if (errno == EBADR)
log_err_once("FIEMAP failed with unknown "
"flags %x.", fiemap->fm_flags);
goto bad;
}
/* If 0 extents are returned, more ioctls are not needed */
if (fiemap->fm_mapped_extents == 0)
break;
nr_extents += _stats_map_extents(fd, mem, fiemap, fm_ext,
&fm_last, &fm_pending,
nr_extents, &eof);
/* check for extent mapping error */
if (eof < 0)
goto bad;
} while (eof == 0);
if (!nr_extents) {
log_error("Cannot map file: no allocated extents.");
goto bad;
}
/* return total number of extents */
*count = nr_extents;
extents = dm_pool_end_object(mem);
/* free FIEMAP buffer. */
dm_free(buf);
return extents;
bad:
*count = 0;
dm_pool_abandon_object(mem);
dm_free(buf);
return NULL;
}
#define MATCH_EXTENT(e, s, l) \
(((e).start == (s)) && ((e).len == (l)))
static struct _extent *_find_extent(uint64_t nr_extents, struct _extent *extents,
uint64_t start, uint64_t len)
{
size_t i;
for (i = 0; i < nr_extents; i++)
if (MATCH_EXTENT(extents[i], start, len))
return extents + i;
return NULL;
}
/*
* Clean up a table of region_id values that were created during a
* failed dm_stats_create_regions_from_fd, or dm_stats_update_regions_from_fd
* operation.
*/
static void _stats_cleanup_region_ids(struct dm_stats *dms, uint64_t *regions,
uint64_t nr_regions)
{
uint64_t i;
for (i = 0; i < nr_regions; i++)
if (!_stats_delete_region(dms, regions[i]))
log_error("Could not delete region " FMTu64 ".", i);
}
/*
* First update pass: prune no-longer-allocated extents from the group
* and build a table of the remaining extents so that their creation
* can be skipped in the second pass.
*/
static int _stats_unmap_regions(struct dm_stats *dms, uint64_t group_id,
struct dm_pool *mem, struct _extent *extents,
struct _extent **old_extents, uint64_t *count,
int *regroup)
{
struct dm_stats_region *region = NULL;
struct dm_stats_group *group = NULL;
uint64_t nr_kept, nr_old;
struct _extent ext = { .id = 0 };
int64_t i;
group = &dms->groups[group_id];
log_very_verbose("Checking for changed file extents in group ID "
FMTu64, group_id);
if (!dm_pool_begin_object(mem, sizeof(**old_extents))) {
log_error("Could not allocate extent table.");
return 0;
}
nr_kept = nr_old = 0; /* counts of old and retained extents */
/*
* First pass: delete de-allocated extents and set regroup=1 if
* deleting the current group leader.
*/
i = dm_bit_get_last(group->regions);
for (; i >= 0; i = dm_bit_get_prev(group->regions, i)) {
region = &dms->regions[i];
nr_old++;
if (extents && _find_extent(*count, extents,
region->start, region->len)) {
ext.start = region->start;
ext.len = region->len;
ext.id = i;
nr_kept++;
if (!dm_pool_grow_object(mem, &ext, sizeof(ext)))
goto out;
log_very_verbose("Kept region " FMTu64, i);
} else {
if (i == (int64_t)group_id)
*regroup = 1;
if (!_stats_delete_region(dms, i)) {
log_error("Could not remove region ID " FMTu64,
i);
goto out;
}
log_very_verbose("Deleted region " FMTu64, i);
}
}
*old_extents = dm_pool_end_object(mem);
if (!*old_extents) {
log_error("Could not finalize region extent table.");
goto out;
}
log_very_verbose("Kept " FMTd64 " of " FMTd64 " old extents",
nr_kept, nr_old);
log_very_verbose("Found " FMTu64 " new extents",
*count - nr_kept);
return (int) nr_kept;
out:
dm_pool_abandon_object(mem);
return -1;
}
/*
* Create or update a set of regions representing the extents of a file
* and return a table of uint64_t region_id values. The number of regions
* created is returned in the memory pointed to by count (which must be
* non-NULL).
*
* If group_id is not equal to DM_STATS_GROUP_NOT_PRESENT, it is assumed
* that group_id corresponds to a group containing existing regions that
* were mapped to this file at an earlier time: regions will be added or
* removed to reflect the current status of the file.
*/
static uint64_t *_stats_map_file_regions(struct dm_stats *dms, int fd,
struct dm_histogram *bounds,
int precise, uint64_t group_id,
uint64_t *count, int *regroup)
{
struct _extent *extents = NULL, *old_extents = NULL;
uint64_t *regions = NULL, fail_region, i, num_bits;
struct dm_stats_group *group = NULL;
struct dm_pool *extent_mem = NULL;
struct _extent *old_ext;
char *hist_arg = NULL;
struct statfs fsbuf = { 0 };
int64_t nr_kept = 0;
struct stat buf;
int update;
*count = 0;
update = _stats_group_id_present(dms, group_id);
#ifdef BTRFS_SUPER_MAGIC
if (fstatfs(fd, &fsbuf)) {
log_error("fstatfs failed for fd %d", fd);
return 0;
}
if (fsbuf.f_type == BTRFS_SUPER_MAGIC) {
log_error("Cannot map file: btrfs does not provide "
"physical FIEMAP extent data.");
return 0;
}
#endif
if (fstat(fd, &buf)) {
log_error("fstat failed for fd %d", fd);
return 0;
}
if (!(buf.st_mode & S_IFREG)) {
log_error("Not a regular file");
return 0;
}
if (!dm_is_dm_major(major(buf.st_dev))) {
log_error("Cannot map file: not a device-mapper device.");
return 0;
}
/*
* If regroup is set here, we are creating a new filemap: otherwise
* we are updating a group with a valid group identifier in group_id.
*/
if (update)
log_very_verbose("Updating extents from fd %d with group ID "
FMTu64 " on (%d:%d)", fd, group_id,
major(buf.st_dev), minor(buf.st_dev));
else
log_very_verbose("Mapping extents from fd %d on (%d:%d)",
fd, major(buf.st_dev), minor(buf.st_dev));
/* Use a temporary, private pool for the extent table. This avoids
* hijacking the dms->mem (region table) pool which would lead to
* interleaving temporary allocations with dm_stats_list() data,
* causing complications in the error path.
*/
if (!(extent_mem = dm_pool_create("extents", sizeof(*extents))))
return_NULL;
if (!(extents = _stats_get_extents_for_file(extent_mem, fd, count))) {
log_very_verbose("No extents found in fd %d", fd);
if (!update)
goto out;
}
if (update) {
group = &dms->groups[group_id];
if ((nr_kept = _stats_unmap_regions(dms, group_id, extent_mem,
extents, &old_extents,
count, regroup)) < 0)
goto_out;
}
if (bounds)
if (!(hist_arg = _build_histogram_arg(bounds, &precise)))
goto_out;
/* make space for end-of-table marker */
if (!(regions = dm_malloc((1 + *count) * sizeof(*regions)))) {
log_error("Could not allocate memory for region IDs.");
goto out;
}
/*
* Second pass (first for non-update case): create regions for
* all extents not retained from the prior mapping, and insert
* retained regions into the table of region_id values.
*
* If a regroup is not scheduled, set group bits for newly
* created regions in the group leader bitmap.
*/
for (i = 0; i < *count; i++) {
if (update) {
if ((old_ext = _find_extent((uint64_t) nr_kept,
old_extents,
extents[i].start,
extents[i].len))) {
regions[i] = old_ext->id;
continue;
}
}
if (!_stats_create_region(dms, regions + i, extents[i].start,
extents[i].len, -1, precise, hist_arg,
dms->program_id, "")) {
log_error("Failed to create region " FMTu64 " of "
FMTu64 " at " FMTu64 ".", i, *count,
extents[i].start);
goto out_remove;
}
log_very_verbose("Created new region mapping " FMTu64 "+" FMTu64
" with region ID " FMTu64, extents[i].start,
extents[i].len, regions[i]);
if (!*regroup && update) {
/* expand group bitmap */
if (regions[i] > (group->regions[0] - 1)) {
num_bits = regions[i] + *count;
if (!_stats_resize_group(group, num_bits)) {
log_error("Failed to resize group "
"bitmap.");
goto out_remove;
}
}
dm_bit_set(group->regions, regions[i]);
}
}
regions[*count] = DM_STATS_REGION_NOT_PRESENT;
/* Update group leader aux_data for new group members. */
if (!*regroup && update)
if (!_stats_set_aux(dms, group_id,
dms->regions[group_id].aux_data))
log_error("Failed to update group aux_data.");
if (bounds)
dm_free(hist_arg);
/* the extent table will be empty if the file has been truncated. */
if (extents)
dm_pool_free(extent_mem, extents);
dm_pool_destroy(extent_mem);
return regions;
out_remove:
/* New region creation may begin to fail part-way through creating
* a set of file mapped regions: in this case we need to roll back
* the regions that were already created and return the handle to
* a consistent state. A listed handle is required for this: use a
* single list operation and call _stats_delete_region() directly
* to avoid a @stats_list ioctl and list parsing for each region.
*/
if (!dm_stats_list(dms, NULL))
goto out;
fail_region = i;
_stats_cleanup_region_ids(dms, regions, fail_region);
*count = 0;
out:
dm_pool_destroy(extent_mem);
dm_free(hist_arg);
dm_free(regions);
return NULL;
}
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)
{
uint64_t *regions, count;
int regroup = 1;
if (alias && !group) {
log_error("Cannot set alias without grouping regions.");
return NULL;
}
if (!(regions = _stats_map_file_regions(dms, fd, bounds, precise,
DM_STATS_GROUP_NOT_PRESENT,
&count, &regroup)))
return NULL;
if (!group)
return regions;
/* refresh handle */
if (!dm_stats_list(dms, NULL))
goto_out;
if (!_stats_group_file_regions(dms, regions, count, alias))
goto_out;
return regions;
out:
_stats_cleanup_region_ids(dms, regions, count);
dm_free(regions);
return NULL;
}
uint64_t *dm_stats_update_regions_from_fd(struct dm_stats *dms, int fd,
uint64_t group_id)
{
struct dm_histogram *bounds = NULL;
int nr_bins, precise, regroup;
uint64_t *regions = NULL, count = 0;
const char *alias = NULL;
if (!dms->regions || !dm_stats_group_present(dms, group_id)) {
if (!dm_stats_list(dms, dms->program_id)) {
log_error("Could not obtain region list while "
"updating group " FMTu64 ".", group_id);
return NULL;
}
}
if (!dm_stats_group_present(dms, group_id)) {
log_error("Group ID " FMTu64 " does not exist.", group_id);
return NULL;
}
/*
* If the extent corresponding to the group leader's region has been
* deallocated, _stats_map_file_regions() will remove the region and
* the group. In this case, regroup will be set by the call and the
* group will be re-created using saved values.
*/
regroup = 0;
/*
* A copy of the alias is needed to re-create the group when regroup=1.
*/
if (dms->groups[group_id].alias) {
alias = dm_strdup(dms->groups[group_id].alias);
if (!alias) {
log_error("Failed to allocate group alias string.");
return NULL;
}
}
if (dms->regions[group_id].bounds) {
/*
* A copy of the histogram bounds must be passed to
* _stats_map_file_regions() to be used when creating new
* regions: it is not safe to use the copy in the current group
* leader since it may be destroyed during the first group
* update pass.
*/
nr_bins = dms->regions[group_id].bounds->nr_bins;
bounds = _alloc_dm_histogram(nr_bins);
if (!bounds) {
log_error("Could not allocate memory for group "
"histogram bounds.");
goto out;
}
_stats_copy_histogram_bounds(bounds,
dms->regions[group_id].bounds);
}
precise = (dms->regions[group_id].timescale == 1);
regions = _stats_map_file_regions(dms, fd, bounds, precise,
group_id, &count, &regroup);
if (!regions)
goto_out;
if (!dm_stats_list(dms, NULL))
goto_bad;
/* regroup if there are regions to group */
if (regroup && (*regions != DM_STATS_REGION_NOT_PRESENT))
if (!_stats_group_file_regions(dms, regions, count, alias))
goto_bad;
dm_free(bounds);
dm_free((char *) alias);
return regions;
bad:
_stats_cleanup_region_ids(dms, regions, count);
out:
dm_free(regions);
dm_free(bounds);
dm_free((char *) alias);
return NULL;
}
#else /* !HAVE_LINUX_FIEMAP */
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)
{
log_error("File mapping requires FIEMAP ioctl support.");
return 0;
}
uint64_t *dm_stats_update_regions_from_fd(struct dm_stats *dms, int fd,
uint64_t group_id)
{
log_error("File mapping requires FIEMAP ioctl support.");
return 0;
}
#endif /* HAVE_LINUX_FIEMAP */
#ifdef DMFILEMAPD
static const char _filemapd_mode_names[][8] = {
"inode",
"path",
};
dm_filemapd_mode_t dm_filemapd_mode_from_string(const char *mode_str)
{
const dm_filemapd_mode_t _mode[] = {
DM_FILEMAPD_FOLLOW_INODE,
DM_FILEMAPD_FOLLOW_PATH
};
unsigned i;
if (mode_str)
for (i = 0; i < DM_ARRAY_SIZE(_filemapd_mode_names); ++i)
if (!strcmp(_filemapd_mode_names[i], mode_str))
return _mode[i];
log_error("Could not parse dmfilemapd mode: %s",
(mode_str) ? mode_str : "");
return DM_FILEMAPD_FOLLOW_NONE;
}
#define DM_FILEMAPD "dmfilemapd"
#define NR_FILEMAPD_ARGS 7 /* includes argv[0] */
/*
* Start dmfilemapd to monitor the specified file descriptor, and to
* update the group given by 'group_id' when the file's allocation
* changes.
*
* usage: dmfilemapd <fd> <group_id> <mode> [<foreground>[<log_level>]]
*/
int dm_stats_start_filemapd(int fd, uint64_t group_id, const char *path,
dm_filemapd_mode_t mode, unsigned foreground,
unsigned verbose)
{
char fd_str[8], group_str[8], fg_str[2], verb_str[2];
const char *mode_str = _filemapd_mode_names[mode];
char *args[NR_FILEMAPD_ARGS + 1];
pid_t pid = 0;
int argc = 0;
if (fd < 0) {
log_error("dmfilemapd file descriptor must be "
"non-negative: %d", fd);
return 0;
}
if (path[0] != '/') {
log_error("Path argument must specify an absolute path.");
return 0;
}
if (mode > DM_FILEMAPD_FOLLOW_PATH) {
log_error("Invalid dmfilemapd mode argument: "
"Must be DM_FILEMAPD_FOLLOW_INODE or "
"DM_FILEMAPD_FOLLOW_PATH");
return 0;
}
if (foreground > 1) {
log_error("Invalid dmfilemapd foreground argument. "
"Must be 0 or 1: %d.", foreground);
return 0;
}
if (verbose > 3) {
log_error("Invalid dmfilemapd verbose argument. "
"Must be 0..3: %d.", verbose);
return 0;
}
/* set argv[0] */
args[argc++] = (char *) DM_FILEMAPD;
/* set <fd> */
if ((dm_snprintf(fd_str, sizeof(fd_str), "%d", fd)) < 0) {
log_error("Could not format fd argument.");
return 0;
}
args[argc++] = fd_str;
/* set <group_id> */
if ((dm_snprintf(group_str, sizeof(group_str), FMTu64, group_id)) < 0) {
log_error("Could not format group_id argument.");
return 0;
}
args[argc++] = group_str;
/* set <path> */
args[argc++] = (char *) path;
/* set <mode> */
args[argc++] = (char *) mode_str;
/* set <foreground> */
if ((dm_snprintf(fg_str, sizeof(fg_str), "%u", foreground)) < 0) {
log_error("Could not format foreground argument.");
return 0;
}
args[argc++] = fg_str;
/* set <verbose> */
if ((dm_snprintf(verb_str, sizeof(verb_str), "%u", verbose)) < 0) {
log_error("Could not format verbose argument.");
return 0;
}
args[argc++] = verb_str;
/* terminate args[argc] */
args[argc] = NULL;
log_very_verbose("Spawning daemon as '%s %d " FMTu64 " \"%s\" %s %u %u'",
*args, fd, group_id, path, mode_str,
foreground, verbose);
if (!foreground && ((pid = fork()) < 0)) {
log_error("Failed to fork dmfilemapd process.");
return 0;
}
if (pid > 0) {
log_very_verbose("Forked dmfilemapd process as pid %d", pid);
return 1;
}
execvp(args[0], args);
log_sys_error("execvp", args[0]);
if (!foreground)
_exit(127);
return 0;
}
# else /* !DMFILEMAPD */
dm_filemapd_mode_t dm_filemapd_mode_from_string(const char *mode_str)
{
return 0;
};
int dm_stats_start_filemapd(int fd, uint64_t group_id, const char *path,
dm_filemapd_mode_t mode, unsigned foreground,
unsigned verbose)
{
log_error("dmfilemapd support disabled.");
return 0;
}
#endif /* DMFILEMAPD */
/*
* Backward compatible dm_stats_create_region() implementations.
*
* Keep these at the end of the file to avoid adding clutter around the
* current dm_stats_create_region() version.
*/
#if defined(GNU_SYMVER)
DM_EXPORT_SYMBOL(dm_stats_create_region, 1_02_106)
int dm_stats_create_region_v1_02_106(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
int precise, const char *program_id,
const char *aux_data);
int dm_stats_create_region_v1_02_106(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
int precise, const char *program_id,
const char *aux_data)
{
/* 1.02.106 lacks histogram argument. */
return _stats_create_region(dms, region_id, start, len, step, precise,
NULL, program_id, aux_data);
}
DM_EXPORT_SYMBOL(dm_stats_create_region, 1_02_104)
int dm_stats_create_region_v1_02_104(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
const char *program_id, const char *aux_data);
int dm_stats_create_region_v1_02_104(struct dm_stats *dms, uint64_t *region_id,
uint64_t start, uint64_t len, int64_t step,
const char *program_id, const char *aux_data)
{
/* 1.02.104 lacks histogram and precise arguments. */
return _stats_create_region(dms, region_id, start, len, step, 0, NULL,
program_id, aux_data);
}
#endif
View Git Blame Copy Permalink