New upstream version 1.11.0+dfsgupstream/1.11.0+dfsg

Signed-off-by: Daniel Baumann <daniel.baumann@progress-linux.org>

1 files changed, 1649 insertions, 0 deletions

diff --git a/collectors/proc.plugin/proc_diskstats.c b/collectors/proc.plugin/proc_diskstats.c
new file mode 100644
index 000000000..387b395a3
--- /dev/null
+++ b/collectors/proc.plugin/proc_diskstats.c
@@ -0,0 +1,1649 @@
+// SPDX-License-Identifier: GPL-3.0-or-later
+
+#include "plugin_proc.h"
+
+#define RRD_TYPE_DISK "disk"
+#define PLUGIN_PROC_MODULE_DISKSTATS_NAME "/proc/diskstats"
+#define CONFIG_SECTION_PLUGIN_PROC_DISKSTATS "plugin:" PLUGIN_PROC_CONFIG_NAME ":" PLUGIN_PROC_MODULE_DISKSTATS_NAME
+
+#define DISK_TYPE_UNKNOWN   0
+#define DISK_TYPE_PHYSICAL  1
+#define DISK_TYPE_PARTITION 2
+#define DISK_TYPE_VIRTUAL   3
+
+#define DEFAULT_EXCLUDED_DISKS "loop* ram*"
+
+static struct disk {
+    char *disk;             // the name of the disk (sda, sdb, etc, after being looked up)
+    char *device;           // the device of the disk (before being looked up)
+    unsigned long major;
+    unsigned long minor;
+    int sector_size;
+    int type;
+
+    char *mount_point;
+
+    // disk options caching
+    int do_io;
+    int do_ops;
+    int do_mops;
+    int do_iotime;
+    int do_qops;
+    int do_util;
+    int do_backlog;
+    int do_bcache;
+
+    int updated;
+
+    int device_is_bcache;
+
+    char *bcache_filename_dirty_data;
+    char *bcache_filename_writeback_rate;
+    char *bcache_filename_cache_congested;
+    char *bcache_filename_cache_available_percent;
+    char *bcache_filename_stats_five_minute_cache_hit_ratio;
+    char *bcache_filename_stats_hour_cache_hit_ratio;
+    char *bcache_filename_stats_day_cache_hit_ratio;
+    char *bcache_filename_stats_total_cache_hit_ratio;
+    char *bcache_filename_stats_total_cache_hits;
+    char *bcache_filename_stats_total_cache_misses;
+    char *bcache_filename_stats_total_cache_miss_collisions;
+    char *bcache_filename_stats_total_cache_bypass_hits;
+    char *bcache_filename_stats_total_cache_bypass_misses;
+    char *bcache_filename_stats_total_cache_readaheads;
+    char *bcache_filename_cache_read_races;
+    char *bcache_filename_cache_io_errors;
+    char *bcache_filename_priority_stats;
+
+    usec_t bcache_priority_stats_update_every_usec;
+    usec_t bcache_priority_stats_elapsed_usec;
+
+    RRDSET *st_io;
+    RRDDIM *rd_io_reads;
+    RRDDIM *rd_io_writes;
+
+    RRDSET *st_ops;
+    RRDDIM *rd_ops_reads;
+    RRDDIM *rd_ops_writes;
+
+    RRDSET *st_qops;
+    RRDDIM *rd_qops_operations;
+
+    RRDSET *st_backlog;
+    RRDDIM *rd_backlog_backlog;
+
+    RRDSET *st_util;
+    RRDDIM *rd_util_utilization;
+
+    RRDSET *st_mops;
+    RRDDIM *rd_mops_reads;
+    RRDDIM *rd_mops_writes;
+
+    RRDSET *st_iotime;
+    RRDDIM *rd_iotime_reads;
+    RRDDIM *rd_iotime_writes;
+
+    RRDSET *st_await;
+    RRDDIM *rd_await_reads;
+    RRDDIM *rd_await_writes;
+
+    RRDSET *st_avgsz;
+    RRDDIM *rd_avgsz_reads;
+    RRDDIM *rd_avgsz_writes;
+
+    RRDSET *st_svctm;
+    RRDDIM *rd_svctm_svctm;
+
+    RRDSET *st_bcache_size;
+    RRDDIM *rd_bcache_dirty_size;
+
+    RRDSET *st_bcache_usage;
+    RRDDIM *rd_bcache_available_percent;
+
+    RRDSET *st_bcache_hit_ratio;
+    RRDDIM *rd_bcache_hit_ratio_5min;
+    RRDDIM *rd_bcache_hit_ratio_1hour;
+    RRDDIM *rd_bcache_hit_ratio_1day;
+    RRDDIM *rd_bcache_hit_ratio_total;
+
+    RRDSET *st_bcache;
+    RRDDIM *rd_bcache_hits;
+    RRDDIM *rd_bcache_misses;
+    RRDDIM *rd_bcache_miss_collisions;
+
+    RRDSET *st_bcache_bypass;
+    RRDDIM *rd_bcache_bypass_hits;
+    RRDDIM *rd_bcache_bypass_misses;
+
+    RRDSET *st_bcache_rates;
+    RRDDIM *rd_bcache_rate_congested;
+    RRDDIM *rd_bcache_readaheads;
+    RRDDIM *rd_bcache_rate_writeback;
+
+    RRDSET *st_bcache_cache_allocations;
+    RRDDIM *rd_bcache_cache_allocations_unused;
+    RRDDIM *rd_bcache_cache_allocations_clean;
+    RRDDIM *rd_bcache_cache_allocations_dirty;
+    RRDDIM *rd_bcache_cache_allocations_metadata;
+    RRDDIM *rd_bcache_cache_allocations_unknown;
+
+    RRDSET *st_bcache_cache_read_races;
+    RRDDIM *rd_bcache_cache_read_races;
+    RRDDIM *rd_bcache_cache_io_errors;
+
+    struct disk *next;
+} *disk_root = NULL;
+
+#define rrdset_obsolete_and_pointer_null(st) do { if(st) { rrdset_is_obsolete(st); (st) = NULL; } } while(st)
+
+// static char *path_to_get_hw_sector_size = NULL;
+// static char *path_to_get_hw_sector_size_partitions = NULL;
+static char *path_to_sys_dev_block_major_minor_string = NULL;
+static char *path_to_sys_block_device = NULL;
+static char *path_to_sys_block_device_bcache = NULL;
+static char *path_to_sys_devices_virtual_block_device = NULL;
+static char *path_to_device_mapper = NULL;
+static char *path_to_device_label = NULL;
+static char *path_to_device_id = NULL;
+static char *path_to_veritas_volume_groups = NULL;
+static int name_disks_by_id = CONFIG_BOOLEAN_NO;
+static int global_bcache_priority_stats_update_every = 0; // disabled by default
+
+static int  global_enable_new_disks_detected_at_runtime = CONFIG_BOOLEAN_YES,
+        global_enable_performance_for_physical_disks = CONFIG_BOOLEAN_AUTO,
+        global_enable_performance_for_virtual_disks = CONFIG_BOOLEAN_AUTO,
+        global_enable_performance_for_partitions = CONFIG_BOOLEAN_NO,
+        global_do_io = CONFIG_BOOLEAN_AUTO,
+        global_do_ops = CONFIG_BOOLEAN_AUTO,
+        global_do_mops = CONFIG_BOOLEAN_AUTO,
+        global_do_iotime = CONFIG_BOOLEAN_AUTO,
+        global_do_qops = CONFIG_BOOLEAN_AUTO,
+        global_do_util = CONFIG_BOOLEAN_AUTO,
+        global_do_backlog = CONFIG_BOOLEAN_AUTO,
+        global_do_bcache = CONFIG_BOOLEAN_AUTO,
+        globals_initialized = 0,
+        global_cleanup_removed_disks = 1;
+
+static SIMPLE_PATTERN *excluded_disks = NULL;
+
+static unsigned long long int bcache_read_number_with_units(const char *filename) {
+    char buffer[50 + 1];
+    if(read_file(filename, buffer, 50) == 0) {
+        static int unknown_units_error = 10;
+
+        char *end = NULL;
+        long double value = str2ld(buffer, &end);
+        if(end && *end) {
+            if(*end == 'k')
+                return (unsigned long long int)(value * 1024.0);
+            else if(*end == 'M')
+                return (unsigned long long int)(value * 1024.0 * 1024.0);
+            else if(*end == 'G')
+                return (unsigned long long int)(value * 1024.0 * 1024.0 * 1024.0);
+            else if(unknown_units_error > 0) {
+                error("bcache file '%s' provides value '%s' with unknown units '%s'", filename, buffer, end);
+                unknown_units_error--;
+            }
+        }
+
+        return (unsigned long long int)value;
+    }
+
+    return 0;
+}
+
+void bcache_read_priority_stats(struct disk *d, const char *family, int update_every, usec_t dt) {
+    static procfile *ff = NULL;
+    static char *separators = " \t:%[]";
+
+    static ARL_BASE *arl_base = NULL;
+
+    static unsigned long long unused;
+    static unsigned long long clean;
+    static unsigned long long dirty;
+    static unsigned long long metadata;
+    static unsigned long long unknown;
+
+    // check if it is time to update this metric
+    d->bcache_priority_stats_elapsed_usec += dt;
+    if(likely(d->bcache_priority_stats_elapsed_usec < d->bcache_priority_stats_update_every_usec)) return;
+    d->bcache_priority_stats_elapsed_usec = 0;
+
+    // initialize ARL
+    if(unlikely(!arl_base)) {
+        arl_base = arl_create("bcache/priority_stats", NULL, 60);
+        arl_expect(arl_base, "Unused", &unused);
+        arl_expect(arl_base, "Clean", &clean);
+        arl_expect(arl_base, "Dirty", &dirty);
+        arl_expect(arl_base, "Metadata", &metadata);
+    }
+
+    ff = procfile_reopen(ff, d->bcache_filename_priority_stats, separators, PROCFILE_FLAG_DEFAULT);
+    if(likely(ff)) ff = procfile_readall(ff);
+    if(unlikely(!ff)) {
+        separators = " \t:%[]";
+        return;
+    }
+
+    // do not reset the separators on every iteration
+    separators = NULL;
+
+    arl_begin(arl_base);
+    unused = clean = dirty = metadata = unknown = 0;
+
+    size_t lines = procfile_lines(ff), l;
+
+    for(l = 0; l < lines ;l++) {
+        size_t words = procfile_linewords(ff, l);
+        if(unlikely(words < 2)) {
+            if(unlikely(words)) error("Cannot read '%s' line %zu. Expected 2 params, read %zu.", d->bcache_filename_priority_stats, l, words);
+            continue;
+        }
+
+        if(unlikely(arl_check(arl_base,
+                procfile_lineword(ff, l, 0),
+                procfile_lineword(ff, l, 1)))) break;
+    }
+
+    unknown = 100 - unused - clean - dirty - metadata;
+
+    // create / update the cache allocations chart
+    {
+        if(unlikely(!d->st_bcache_cache_allocations)) {
+            d->st_bcache_cache_allocations = rrdset_create_localhost(
+                    "disk_bcache_cache_alloc"
+                    , d->device
+                    , d->disk
+                    , family
+                    , "disk.bcache_cache_alloc"
+                    , "BCache Cache Allocations"
+                    , "percentage"
+                    , PLUGIN_PROC_NAME
+                    , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                    , NETDATA_CHART_PRIO_BCACHE_CACHE_ALLOC
+                    , update_every
+                    , RRDSET_TYPE_STACKED
+            );
+
+            d->rd_bcache_cache_allocations_unused    = rrddim_add(d->st_bcache_cache_allocations, "unused",     NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            d->rd_bcache_cache_allocations_dirty     = rrddim_add(d->st_bcache_cache_allocations, "dirty",      NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            d->rd_bcache_cache_allocations_clean     = rrddim_add(d->st_bcache_cache_allocations, "clean",      NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            d->rd_bcache_cache_allocations_metadata  = rrddim_add(d->st_bcache_cache_allocations, "metadata",   NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            d->rd_bcache_cache_allocations_unknown   = rrddim_add(d->st_bcache_cache_allocations, "undefined",  NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+
+            d->bcache_priority_stats_update_every_usec = update_every * USEC_PER_SEC;
+        }
+        else rrdset_next(d->st_bcache_cache_allocations);
+
+        rrddim_set_by_pointer(d->st_bcache_cache_allocations, d->rd_bcache_cache_allocations_unused, unused);
+        rrddim_set_by_pointer(d->st_bcache_cache_allocations, d->rd_bcache_cache_allocations_dirty, dirty);
+        rrddim_set_by_pointer(d->st_bcache_cache_allocations, d->rd_bcache_cache_allocations_clean, clean);
+        rrddim_set_by_pointer(d->st_bcache_cache_allocations, d->rd_bcache_cache_allocations_metadata, metadata);
+        rrddim_set_by_pointer(d->st_bcache_cache_allocations, d->rd_bcache_cache_allocations_unknown, unknown);
+        rrdset_done(d->st_bcache_cache_allocations);
+    }
+}
+
+static inline int is_major_enabled(int major) {
+    static int8_t *major_configs = NULL;
+    static size_t major_size = 0;
+
+    if(major < 0) return 1;
+
+    size_t wanted_size = (size_t)major + 1;
+
+    if(major_size < wanted_size) {
+        major_configs = reallocz(major_configs, wanted_size * sizeof(int8_t));
+
+        size_t i;
+        for(i = major_size; i < wanted_size ; i++)
+            major_configs[i] = -1;
+
+        major_size = wanted_size;
+    }
+
+    if(major_configs[major] == -1) {
+        char buffer[CONFIG_MAX_NAME + 1];
+        snprintfz(buffer, CONFIG_MAX_NAME, "performance metrics for disks with major %d", major);
+        major_configs[major] = (char)config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, buffer, 1);
+    }
+
+    return (int)major_configs[major];
+}
+
+static inline int get_disk_name_from_path(const char *path, char *result, size_t result_size, unsigned long major, unsigned long minor, char *disk, char *prefix, int depth) {
+    //info("DEVICE-MAPPER ('%s', %lu:%lu): examining directory '%s' (allowed depth %d).", disk, major, minor, path, depth);
+
+    int found = 0;
+
+    DIR *dir = opendir(path);
+    if (!dir) {
+        error("DEVICE-MAPPER ('%s', %lu:%lu): Cannot open directory '%s'.", disk, major, minor, path);
+        goto failed;
+    }
+
+    struct dirent *de = NULL;
+    while ((de = readdir(dir))) {
+        if(de->d_type == DT_DIR) {
+            if((de->d_name[0] == '.' && de->d_name[1] == '\0') || (de->d_name[0] == '.' && de->d_name[1] == '.' && de->d_name[2] == '\0'))
+                continue;
+
+            if(depth <= 0) {
+                error("DEVICE-MAPPER ('%s', %lu:%lu): Depth limit reached for path '%s/%s'. Ignoring path.", disk, major, minor, path, de->d_name);
+                break;
+            }
+            else {
+                char *path_nested = NULL;
+                char *prefix_nested = NULL;
+
+                {
+                    char buffer[FILENAME_MAX + 1];
+                    snprintfz(buffer, FILENAME_MAX, "%s/%s", path, de->d_name);
+                    path_nested = strdupz(buffer);
+
+                    snprintfz(buffer, FILENAME_MAX, "%s%s%s", (prefix)?prefix:"", (prefix)?"_":"", de->d_name);
+                    prefix_nested = strdupz(buffer);
+                }
+
+                found = get_disk_name_from_path(path_nested, result, result_size, major, minor, disk, prefix_nested, depth - 1);
+                freez(path_nested);
+                freez(prefix_nested);
+
+                if(found) break;
+            }
+        }
+        else if(de->d_type == DT_LNK || de->d_type == DT_BLK) {
+            char filename[FILENAME_MAX + 1];
+
+            if(de->d_type == DT_LNK) {
+                snprintfz(filename, FILENAME_MAX, "%s/%s", path, de->d_name);
+                ssize_t len = readlink(filename, result, result_size - 1);
+                if(len <= 0) {
+                    error("DEVICE-MAPPER ('%s', %lu:%lu): Cannot read link '%s'.", disk, major, minor, filename);
+                    continue;
+                }
+
+                result[len] = '\0';
+                if(result[0] != '/')
+                    snprintfz(filename, FILENAME_MAX, "%s/%s", path, result);
+                else
+                    strncpyz(filename, result, FILENAME_MAX);
+            }
+            else {
+                snprintfz(filename, FILENAME_MAX, "%s/%s", path, de->d_name);
+            }
+
+            struct stat sb;
+            if(stat(filename, &sb) == -1) {
+                error("DEVICE-MAPPER ('%s', %lu:%lu): Cannot stat() file '%s'.", disk, major, minor, filename);
+                continue;
+            }
+
+            if((sb.st_mode & S_IFMT) != S_IFBLK) {
+                //info("DEVICE-MAPPER ('%s', %lu:%lu): file '%s' is not a block device.", disk, major, minor, filename);
+                continue;
+            }
+
+            if(major(sb.st_rdev) != major || minor(sb.st_rdev) != minor) {
+                //info("DEVICE-MAPPER ('%s', %lu:%lu): filename '%s' does not match %lu:%lu.", disk, major, minor, filename, (unsigned long)major(sb.st_rdev), (unsigned long)minor(sb.st_rdev));
+                continue;
+            }
+
+            //info("DEVICE-MAPPER ('%s', %lu:%lu): filename '%s' matches.", disk, major, minor, filename);
+
+            snprintfz(result, result_size - 1, "%s%s%s", (prefix)?prefix:"", (prefix)?"_":"", de->d_name);
+            found = 1;
+            break;
+        }
+    }
+    closedir(dir);
+
+
+failed:
+
+    if(!found)
+        result[0] = '\0';
+
+    return found;
+}
+
+static inline char *get_disk_name(unsigned long major, unsigned long minor, char *disk) {
+    char result[FILENAME_MAX + 1] = "";
+
+    if(!path_to_device_mapper || !*path_to_device_mapper || !get_disk_name_from_path(path_to_device_mapper, result, FILENAME_MAX + 1, major, minor, disk, NULL, 0))
+        if(!path_to_device_label || !*path_to_device_label || !get_disk_name_from_path(path_to_device_label, result, FILENAME_MAX + 1, major, minor, disk, NULL, 0))
+            if(!path_to_veritas_volume_groups || !*path_to_veritas_volume_groups || !get_disk_name_from_path(path_to_veritas_volume_groups, result, FILENAME_MAX + 1, major, minor, disk, "vx", 2))
+                if(name_disks_by_id != CONFIG_BOOLEAN_YES || !path_to_device_id || !*path_to_device_id || !get_disk_name_from_path(path_to_device_id, result, FILENAME_MAX + 1, major, minor, disk, NULL, 0))
+                    strncpy(result, disk, FILENAME_MAX);
+
+    if(!result[0])
+        strncpy(result, disk, FILENAME_MAX);
+
+    netdata_fix_chart_name(result);
+    return strdup(result);
+}
+
+static void get_disk_config(struct disk *d) {
+    int def_enable = global_enable_new_disks_detected_at_runtime;
+
+    if(def_enable != CONFIG_BOOLEAN_NO && (simple_pattern_matches(excluded_disks, d->device) || simple_pattern_matches(excluded_disks, d->disk)))
+        def_enable = CONFIG_BOOLEAN_NO;
+
+    char var_name[4096 + 1];
+    snprintfz(var_name, 4096, CONFIG_SECTION_PLUGIN_PROC_DISKSTATS ":%s", d->disk);
+
+    def_enable = config_get_boolean_ondemand(var_name, "enable", def_enable);
+    if(unlikely(def_enable == CONFIG_BOOLEAN_NO)) {
+        // the user does not want any metrics for this disk
+        d->do_io = CONFIG_BOOLEAN_NO;
+        d->do_ops = CONFIG_BOOLEAN_NO;
+        d->do_mops = CONFIG_BOOLEAN_NO;
+        d->do_iotime = CONFIG_BOOLEAN_NO;
+        d->do_qops = CONFIG_BOOLEAN_NO;
+        d->do_util = CONFIG_BOOLEAN_NO;
+        d->do_backlog = CONFIG_BOOLEAN_NO;
+        d->do_bcache = CONFIG_BOOLEAN_NO;
+    }
+    else {
+        // this disk is enabled
+        // check its direct settings
+
+        int def_performance = CONFIG_BOOLEAN_AUTO;
+
+        // since this is 'on demand' we can figure the performance settings
+        // based on the type of disk
+
+        if(!d->device_is_bcache) {
+            switch(d->type) {
+                default:
+                case DISK_TYPE_UNKNOWN:
+                    break;
+
+                case DISK_TYPE_PHYSICAL:
+                    def_performance = global_enable_performance_for_physical_disks;
+                    break;
+
+                case DISK_TYPE_PARTITION:
+                    def_performance = global_enable_performance_for_partitions;
+                    break;
+
+                case DISK_TYPE_VIRTUAL:
+                    def_performance = global_enable_performance_for_virtual_disks;
+                    break;
+            }
+        }
+
+        // check if we have to disable performance for this disk
+        if(def_performance)
+            def_performance = is_major_enabled((int)d->major);
+
+        // ------------------------------------------------------------
+        // now we have def_performance and def_space
+        // to work further
+
+        // def_performance
+        // check the user configuration (this will also show our 'on demand' decision)
+        def_performance = config_get_boolean_ondemand(var_name, "enable performance metrics", def_performance);
+
+        int ddo_io = CONFIG_BOOLEAN_NO,
+                ddo_ops = CONFIG_BOOLEAN_NO,
+                ddo_mops = CONFIG_BOOLEAN_NO,
+                ddo_iotime = CONFIG_BOOLEAN_NO,
+                ddo_qops = CONFIG_BOOLEAN_NO,
+                ddo_util = CONFIG_BOOLEAN_NO,
+                ddo_backlog = CONFIG_BOOLEAN_NO,
+                ddo_bcache = CONFIG_BOOLEAN_NO;
+
+        // we enable individual performance charts only when def_performance is not disabled
+        if(unlikely(def_performance != CONFIG_BOOLEAN_NO)) {
+            ddo_io = global_do_io,
+            ddo_ops = global_do_ops,
+            ddo_mops = global_do_mops,
+            ddo_iotime = global_do_iotime,
+            ddo_qops = global_do_qops,
+            ddo_util = global_do_util,
+            ddo_backlog = global_do_backlog,
+            ddo_bcache = global_do_bcache;
+        }
+
+        d->do_io      = config_get_boolean_ondemand(var_name, "bandwidth", ddo_io);
+        d->do_ops     = config_get_boolean_ondemand(var_name, "operations", ddo_ops);
+        d->do_mops    = config_get_boolean_ondemand(var_name, "merged operations", ddo_mops);
+        d->do_iotime  = config_get_boolean_ondemand(var_name, "i/o time", ddo_iotime);
+        d->do_qops    = config_get_boolean_ondemand(var_name, "queued operations", ddo_qops);
+        d->do_util    = config_get_boolean_ondemand(var_name, "utilization percentage", ddo_util);
+        d->do_backlog = config_get_boolean_ondemand(var_name, "backlog", ddo_backlog);
+
+        if(d->device_is_bcache)
+            d->do_bcache  = config_get_boolean_ondemand(var_name, "bcache", ddo_bcache);
+        else
+            d->do_bcache = 0;
+    }
+}
+
+static struct disk *get_disk(unsigned long major, unsigned long minor, char *disk) {
+    static struct mountinfo *disk_mountinfo_root = NULL;
+
+    struct disk *d;
+
+    // search for it in our RAM list.
+    // this is sequential, but since we just walk through
+    // and the number of disks / partitions in a system
+    // should not be that many, it should be acceptable
+    for(d = disk_root; d ; d = d->next)
+        if(unlikely(d->major == major && d->minor == minor))
+            return d;
+
+    // not found
+    // create a new disk structure
+    d = (struct disk *)callocz(1, sizeof(struct disk));
+
+    d->disk = get_disk_name(major, minor, disk);
+    d->device = strdupz(disk);
+    d->major = major;
+    d->minor = minor;
+    d->type = DISK_TYPE_UNKNOWN; // Default type. Changed later if not correct.
+    d->sector_size = 512; // the default, will be changed below
+    d->next = NULL;
+
+    // append it to the list
+    if(unlikely(!disk_root))
+        disk_root = d;
+    else {
+        struct disk *last;
+        for(last = disk_root; last->next ;last = last->next);
+        last->next = d;
+    }
+
+    char buffer[FILENAME_MAX + 1];
+
+    // find if it is a physical disk
+    // by checking if /sys/block/DISK is readable.
+    snprintfz(buffer, FILENAME_MAX, path_to_sys_block_device, disk);
+    if(likely(access(buffer, R_OK) == 0)) {
+        // assign it here, but it will be overwritten if it is not a physical disk
+        d->type = DISK_TYPE_PHYSICAL;
+    }
+
+    // find if it is a partition
+    // by checking if /sys/dev/block/MAJOR:MINOR/partition is readable.
+    snprintfz(buffer, FILENAME_MAX, path_to_sys_dev_block_major_minor_string, major, minor, "partition");
+    if(likely(access(buffer, R_OK) == 0)) {
+        d->type = DISK_TYPE_PARTITION;
+    }
+    else {
+        // find if it is a virtual disk
+        // by checking if /sys/devices/virtual/block/DISK is readable.
+        snprintfz(buffer, FILENAME_MAX, path_to_sys_devices_virtual_block_device, disk);
+        if(likely(access(buffer, R_OK) == 0)) {
+            d->type = DISK_TYPE_VIRTUAL;
+        }
+        else {
+            // find if it is a virtual device
+            // by checking if /sys/dev/block/MAJOR:MINOR/slaves has entries
+            snprintfz(buffer, FILENAME_MAX, path_to_sys_dev_block_major_minor_string, major, minor, "slaves/");
+            DIR *dirp = opendir(buffer);
+            if (likely(dirp != NULL)) {
+                struct dirent *dp;
+                while ((dp = readdir(dirp))) {
+                    // . and .. are also files in empty folders.
+                    if (unlikely(strcmp(dp->d_name, ".") == 0 || strcmp(dp->d_name, "..") == 0)) {
+                        continue;
+                    }
+
+                    d->type = DISK_TYPE_VIRTUAL;
+
+                    // Stop the loop after we found one file.
+                    break;
+                }
+                if (unlikely(closedir(dirp) == -1))
+                    error("Unable to close dir %s", buffer);
+            }
+        }
+    }
+
+    // ------------------------------------------------------------------------
+    // check if we can find its mount point
+
+    // mountinfo_find() can be called with NULL disk_mountinfo_root
+    struct mountinfo *mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
+    if(unlikely(!mi)) {
+        // mountinfo_free_all can be called with NULL
+        mountinfo_free_all(disk_mountinfo_root);
+        disk_mountinfo_root = mountinfo_read(0);
+        mi = mountinfo_find(disk_mountinfo_root, d->major, d->minor);
+    }
+
+    if(unlikely(mi))
+        d->mount_point = strdupz(mi->mount_point);
+    else
+        d->mount_point = NULL;
+
+    // ------------------------------------------------------------------------
+    // find the disk sector size
+
+    /*
+     * sector size is always 512 bytes inside the kernel #3481
+     *
+    {
+        char tf[FILENAME_MAX + 1], *t;
+        strncpyz(tf, d->device, FILENAME_MAX);
+
+        // replace all / with !
+        for(t = tf; *t ;t++)
+            if(unlikely(*t == '/')) *t = '!';
+
+        if(likely(d->type == DISK_TYPE_PARTITION))
+            snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size_partitions, d->major, d->minor, tf);
+        else
+            snprintfz(buffer, FILENAME_MAX, path_to_get_hw_sector_size, tf);
+
+        FILE *fpss = fopen(buffer, "r");
+        if(likely(fpss)) {
+            char buffer2[1024 + 1];
+            char *tmp = fgets(buffer2, 1024, fpss);
+
+            if(likely(tmp)) {
+                d->sector_size = str2i(tmp);
+                if(unlikely(d->sector_size <= 0)) {
+                    error("Invalid sector size %d for device %s in %s. Assuming 512.", d->sector_size, d->device, buffer);
+                    d->sector_size = 512;
+                }
+            }
+            else error("Cannot read data for sector size for device %s from %s. Assuming 512.", d->device, buffer);
+
+            fclose(fpss);
+        }
+        else error("Cannot read sector size for device %s from %s. Assuming 512.", d->device, buffer);
+    }
+    */
+
+    // ------------------------------------------------------------------------
+    // check if the device is a bcache
+
+    struct stat bcache;
+    snprintfz(buffer, FILENAME_MAX, path_to_sys_block_device_bcache, disk);
+    if(unlikely(stat(buffer, &bcache) == 0 && (bcache.st_mode & S_IFMT) == S_IFDIR)) {
+        // we have the 'bcache' directory
+        d->device_is_bcache = 1;
+
+        char buffer2[FILENAME_MAX + 1];
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/cache/congested", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_cache_congested = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/readahead", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_readaheads = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/cache/cache0/priority_stats", buffer); // only one cache is supported by bcache
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_priority_stats = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/cache/internal/cache_read_races", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_cache_read_races = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/cache/cache0/io_errors", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_cache_io_errors = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/dirty_data", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_dirty_data = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/writeback_rate", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_writeback_rate = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/cache/cache_available_percent", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_cache_available_percent = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_hits", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_hits = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_five_minute/cache_hit_ratio", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_five_minute_cache_hit_ratio = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_hour/cache_hit_ratio", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_hour_cache_hit_ratio = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_day/cache_hit_ratio", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_day_cache_hit_ratio = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_hit_ratio", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_hit_ratio = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_misses", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_misses = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_bypass_hits", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_bypass_hits = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_bypass_misses", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_bypass_misses = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+
+        snprintfz(buffer2, FILENAME_MAX, "%s/stats_total/cache_miss_collisions", buffer);
+        if(access(buffer2, R_OK) == 0)
+            d->bcache_filename_stats_total_cache_miss_collisions = strdupz(buffer2);
+        else
+            error("bcache file '%s' cannot be read.", buffer2);
+    }
+
+    get_disk_config(d);
+    return d;
+}
+
+int do_proc_diskstats(int update_every, usec_t dt) {
+    static procfile *ff = NULL;
+
+    if(unlikely(!globals_initialized)) {
+        globals_initialized = 1;
+
+        global_enable_new_disks_detected_at_runtime = config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "enable new disks detected at runtime", global_enable_new_disks_detected_at_runtime);
+        global_enable_performance_for_physical_disks = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "performance metrics for physical disks", global_enable_performance_for_physical_disks);
+        global_enable_performance_for_virtual_disks = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "performance metrics for virtual disks", global_enable_performance_for_virtual_disks);
+        global_enable_performance_for_partitions = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "performance metrics for partitions", global_enable_performance_for_partitions);
+
+        global_do_io      = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "bandwidth for all disks", global_do_io);
+        global_do_ops     = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "operations for all disks", global_do_ops);
+        global_do_mops    = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "merged operations for all disks", global_do_mops);
+        global_do_iotime  = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "i/o time for all disks", global_do_iotime);
+        global_do_qops    = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "queued operations for all disks", global_do_qops);
+        global_do_util    = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "utilization percentage for all disks", global_do_util);
+        global_do_backlog = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "backlog for all disks", global_do_backlog);
+        global_do_bcache  = config_get_boolean_ondemand(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "bcache for all disks", global_do_bcache);
+        global_bcache_priority_stats_update_every = (int)config_get_number(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "bcache priority stats update every", global_bcache_priority_stats_update_every);
+
+        global_cleanup_removed_disks = config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "remove charts of removed disks" , global_cleanup_removed_disks);
+        
+        char buffer[FILENAME_MAX + 1];
+
+        snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/block/%s");
+        path_to_sys_block_device = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get block device", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/block/%s/bcache");
+        path_to_sys_block_device_bcache = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get block device bcache", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/devices/virtual/block/%s");
+        path_to_sys_devices_virtual_block_device = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get virtual block device", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/dev/block/%lu:%lu/%s");
+        path_to_sys_dev_block_major_minor_string = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get block device infos", buffer);
+
+        //snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/block/%s/queue/hw_sector_size");
+        //path_to_get_hw_sector_size = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get h/w sector size", buffer);
+
+        //snprintfz(buffer, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/sys/dev/block/%lu:%lu/subsystem/%s/../queue/hw_sector_size");
+        //path_to_get_hw_sector_size_partitions = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to get h/w sector size for partitions", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s/dev/mapper", netdata_configured_host_prefix);
+        path_to_device_mapper = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to device mapper", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s/dev/disk/by-label", netdata_configured_host_prefix);
+        path_to_device_label = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to /dev/disk/by-label", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s/dev/disk/by-id", netdata_configured_host_prefix);
+        path_to_device_id = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to /dev/disk/by-id", buffer);
+
+        snprintfz(buffer, FILENAME_MAX, "%s/dev/vx/dsk", netdata_configured_host_prefix);
+        path_to_veritas_volume_groups = config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "path to /dev/vx/dsk", buffer);
+
+        name_disks_by_id = config_get_boolean(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "name disks by id", name_disks_by_id);
+
+        excluded_disks = simple_pattern_create(
+                config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "exclude disks", DEFAULT_EXCLUDED_DISKS)
+                , NULL
+                , SIMPLE_PATTERN_EXACT
+        );
+    }
+
+    // --------------------------------------------------------------------------
+
+    if(unlikely(!ff)) {
+        char filename[FILENAME_MAX + 1];
+        snprintfz(filename, FILENAME_MAX, "%s%s", netdata_configured_host_prefix, "/proc/diskstats");
+        ff = procfile_open(config_get(CONFIG_SECTION_PLUGIN_PROC_DISKSTATS, "filename to monitor", filename), " \t", PROCFILE_FLAG_DEFAULT);
+    }
+    if(unlikely(!ff)) return 0;
+
+    ff = procfile_readall(ff);
+    if(unlikely(!ff)) return 0; // we return 0, so that we will retry to open it next time
+
+    size_t lines = procfile_lines(ff), l;
+
+    collected_number system_read_kb = 0, system_write_kb = 0;
+
+    for(l = 0; l < lines ;l++) {
+        // --------------------------------------------------------------------------
+        // Read parameters
+
+        char *disk;
+        unsigned long       major = 0, minor = 0;
+
+        collected_number    reads = 0,  mreads = 0,  readsectors = 0,  readms = 0,
+                            writes = 0, mwrites = 0, writesectors = 0, writems = 0,
+                            queued_ios = 0, busy_ms = 0, backlog_ms = 0;
+
+        collected_number    last_reads = 0,  last_readsectors = 0,  last_readms = 0,
+                            last_writes = 0, last_writesectors = 0, last_writems = 0,
+                            last_busy_ms = 0;
+
+        size_t words = procfile_linewords(ff, l);
+        if(unlikely(words < 14)) continue;
+
+        major           = str2ul(procfile_lineword(ff, l, 0));
+        minor           = str2ul(procfile_lineword(ff, l, 1));
+        disk            = procfile_lineword(ff, l, 2);
+
+        // # of reads completed # of writes completed
+        // This is the total number of reads or writes completed successfully.
+        reads           = str2ull(procfile_lineword(ff, l, 3));  // rd_ios
+        writes          = str2ull(procfile_lineword(ff, l, 7));  // wr_ios
+
+        // # of reads merged # of writes merged
+        // Reads and writes which are adjacent to each other may be merged for
+        // efficiency.  Thus two 4K reads may become one 8K read before it is
+        // ultimately handed to the disk, and so it will be counted (and queued)
+        mreads          = str2ull(procfile_lineword(ff, l, 4));  // rd_merges_or_rd_sec
+        mwrites         = str2ull(procfile_lineword(ff, l, 8));  // wr_merges
+
+        // # of sectors read # of sectors written
+        // This is the total number of sectors read or written successfully.
+        readsectors     = str2ull(procfile_lineword(ff, l, 5));  // rd_sec_or_wr_ios
+        writesectors    = str2ull(procfile_lineword(ff, l, 9));  // wr_sec
+
+        // # of milliseconds spent reading # of milliseconds spent writing
+        // This is the total number of milliseconds spent by all reads or writes (as
+        // measured from __make_request() to end_that_request_last()).
+        readms          = str2ull(procfile_lineword(ff, l, 6));  // rd_ticks_or_wr_sec
+        writems         = str2ull(procfile_lineword(ff, l, 10)); // wr_ticks
+
+        // # of I/Os currently in progress
+        // The only field that should go to zero. Incremented as requests are
+        // given to appropriate struct request_queue and decremented as they finish.
+        queued_ios      = str2ull(procfile_lineword(ff, l, 11)); // ios_pgr
+
+        // # of milliseconds spent doing I/Os
+        // This field increases so long as field queued_ios is nonzero.
+        busy_ms         = str2ull(procfile_lineword(ff, l, 12)); // tot_ticks
+
+        // weighted # of milliseconds spent doing I/Os
+        // This field is incremented at each I/O start, I/O completion, I/O
+        // merge, or read of these stats by the number of I/Os in progress
+        // (field queued_ios) times the number of milliseconds spent doing I/O since the
+        // last update of this field.  This can provide an easy measure of both
+        // I/O completion time and the backlog that may be accumulating.
+        backlog_ms      = str2ull(procfile_lineword(ff, l, 13)); // rq_ticks
+
+
+        // --------------------------------------------------------------------------
+        // remove slashes from disk names
+        char *s;
+        for(s = disk; *s ;s++)
+            if(*s == '/') *s = '_';
+
+        // --------------------------------------------------------------------------
+        // get a disk structure for the disk
+
+        struct disk *d = get_disk(major, minor, disk);
+        d->updated = 1;
+
+        // --------------------------------------------------------------------------
+        // count the global system disk I/O of physical disks
+
+        if(unlikely(d->type == DISK_TYPE_PHYSICAL)) {
+            system_read_kb  += readsectors * d->sector_size / 1024;
+            system_write_kb += writesectors * d->sector_size / 1024;
+        }
+
+        // --------------------------------------------------------------------------
+        // Set its family based on mount point
+
+        char *family = d->mount_point;
+        if(!family) family = d->disk;
+
+
+        // --------------------------------------------------------------------------
+        // Do performance metrics
+
+        if(d->do_io == CONFIG_BOOLEAN_YES || (d->do_io == CONFIG_BOOLEAN_AUTO && (readsectors || writesectors))) {
+            d->do_io = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_io)) {
+                d->st_io = rrdset_create_localhost(
+                        RRD_TYPE_DISK
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.io"
+                        , "Disk I/O Bandwidth"
+                        , "kilobytes/s"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_IO
+                        , update_every
+                        , RRDSET_TYPE_AREA
+                );
+
+                d->rd_io_reads  = rrddim_add(d->st_io, "reads",  NULL, d->sector_size, 1024,      RRD_ALGORITHM_INCREMENTAL);
+                d->rd_io_writes = rrddim_add(d->st_io, "writes", NULL, d->sector_size * -1, 1024, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_io);
+
+            last_readsectors  = rrddim_set_by_pointer(d->st_io, d->rd_io_reads, readsectors);
+            last_writesectors = rrddim_set_by_pointer(d->st_io, d->rd_io_writes, writesectors);
+            rrdset_done(d->st_io);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_ops == CONFIG_BOOLEAN_YES || (d->do_ops == CONFIG_BOOLEAN_AUTO && (reads || writes))) {
+            d->do_ops = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_ops)) {
+                d->st_ops = rrdset_create_localhost(
+                        "disk_ops"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.ops"
+                        , "Disk Completed I/O Operations"
+                        , "operations/s"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_OPS
+                        , update_every
+                        , RRDSET_TYPE_LINE
+                );
+
+                rrdset_flag_set(d->st_ops, RRDSET_FLAG_DETAIL);
+
+                d->rd_ops_reads  = rrddim_add(d->st_ops, "reads",  NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                d->rd_ops_writes = rrddim_add(d->st_ops, "writes", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_ops);
+
+            last_reads  = rrddim_set_by_pointer(d->st_ops, d->rd_ops_reads, reads);
+            last_writes = rrddim_set_by_pointer(d->st_ops, d->rd_ops_writes, writes);
+            rrdset_done(d->st_ops);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_qops == CONFIG_BOOLEAN_YES || (d->do_qops == CONFIG_BOOLEAN_AUTO && queued_ios)) {
+            d->do_qops = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_qops)) {
+                d->st_qops = rrdset_create_localhost(
+                        "disk_qops"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.qops"
+                        , "Disk Current I/O Operations"
+                        , "operations"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_QOPS
+                        , update_every
+                        , RRDSET_TYPE_LINE
+                );
+
+                rrdset_flag_set(d->st_qops, RRDSET_FLAG_DETAIL);
+
+                d->rd_qops_operations = rrddim_add(d->st_qops, "operations", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+            }
+            else rrdset_next(d->st_qops);
+
+            rrddim_set_by_pointer(d->st_qops, d->rd_qops_operations, queued_ios);
+            rrdset_done(d->st_qops);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_backlog == CONFIG_BOOLEAN_YES || (d->do_backlog == CONFIG_BOOLEAN_AUTO && backlog_ms)) {
+            d->do_backlog = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_backlog)) {
+                d->st_backlog = rrdset_create_localhost(
+                        "disk_backlog"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.backlog"
+                        , "Disk Backlog"
+                        , "backlog (ms)"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_BACKLOG
+                        , update_every
+                        , RRDSET_TYPE_AREA
+                );
+
+                rrdset_flag_set(d->st_backlog, RRDSET_FLAG_DETAIL);
+
+                d->rd_backlog_backlog = rrddim_add(d->st_backlog, "backlog", NULL, 1, 10, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_backlog);
+
+            rrddim_set_by_pointer(d->st_backlog, d->rd_backlog_backlog, backlog_ms);
+            rrdset_done(d->st_backlog);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_util == CONFIG_BOOLEAN_YES || (d->do_util == CONFIG_BOOLEAN_AUTO && busy_ms)) {
+            d->do_util = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_util)) {
+                d->st_util = rrdset_create_localhost(
+                        "disk_util"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.util"
+                        , "Disk Utilization Time"
+                        , "% of time working"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_UTIL
+                        , update_every
+                        , RRDSET_TYPE_AREA
+                );
+
+                rrdset_flag_set(d->st_util, RRDSET_FLAG_DETAIL);
+
+                d->rd_util_utilization = rrddim_add(d->st_util, "utilization", NULL, 1, 10, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_util);
+
+            last_busy_ms = rrddim_set_by_pointer(d->st_util, d->rd_util_utilization, busy_ms);
+            rrdset_done(d->st_util);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_mops == CONFIG_BOOLEAN_YES || (d->do_mops == CONFIG_BOOLEAN_AUTO && (mreads || mwrites))) {
+            d->do_mops = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_mops)) {
+                d->st_mops = rrdset_create_localhost(
+                        "disk_mops"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.mops"
+                        , "Disk Merged Operations"
+                        , "merged operations/s"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_MOPS
+                        , update_every
+                        , RRDSET_TYPE_LINE
+                );
+
+                rrdset_flag_set(d->st_mops, RRDSET_FLAG_DETAIL);
+
+                d->rd_mops_reads  = rrddim_add(d->st_mops, "reads",  NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                d->rd_mops_writes = rrddim_add(d->st_mops, "writes", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_mops);
+
+            rrddim_set_by_pointer(d->st_mops, d->rd_mops_reads,  mreads);
+            rrddim_set_by_pointer(d->st_mops, d->rd_mops_writes, mwrites);
+            rrdset_done(d->st_mops);
+        }
+
+        // --------------------------------------------------------------------
+
+        if(d->do_iotime == CONFIG_BOOLEAN_YES || (d->do_iotime == CONFIG_BOOLEAN_AUTO && (readms || writems))) {
+            d->do_iotime = CONFIG_BOOLEAN_YES;
+
+            if(unlikely(!d->st_iotime)) {
+                d->st_iotime = rrdset_create_localhost(
+                        "disk_iotime"
+                        , d->device
+                        , d->disk
+                        , family
+                        , "disk.iotime"
+                        , "Disk Total I/O Time"
+                        , "milliseconds/s"
+                        , PLUGIN_PROC_NAME
+                        , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                        , NETDATA_CHART_PRIO_DISK_IOTIME
+                        , update_every
+                        , RRDSET_TYPE_LINE
+                );
+
+                rrdset_flag_set(d->st_iotime, RRDSET_FLAG_DETAIL);
+
+                d->rd_iotime_reads  = rrddim_add(d->st_iotime, "reads",  NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                d->rd_iotime_writes = rrddim_add(d->st_iotime, "writes", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+            }
+            else rrdset_next(d->st_iotime);
+
+            last_readms  = rrddim_set_by_pointer(d->st_iotime, d->rd_iotime_reads, readms);
+            last_writems = rrddim_set_by_pointer(d->st_iotime, d->rd_iotime_writes, writems);
+            rrdset_done(d->st_iotime);
+        }
+
+        // --------------------------------------------------------------------
+        // calculate differential charts
+        // only if this is not the first time we run
+
+        if(likely(dt)) {
+            if( (d->do_iotime == CONFIG_BOOLEAN_YES || (d->do_iotime == CONFIG_BOOLEAN_AUTO && (readms || writems))) &&
+                (d->do_ops    == CONFIG_BOOLEAN_YES || (d->do_ops    == CONFIG_BOOLEAN_AUTO && (reads || writes)))) {
+
+                if(unlikely(!d->st_await)) {
+                    d->st_await = rrdset_create_localhost(
+                            "disk_await"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.await"
+                            , "Average Completed I/O Operation Time"
+                            , "ms per operation"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_DISK_AWAIT
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    rrdset_flag_set(d->st_await, RRDSET_FLAG_DETAIL);
+
+                    d->rd_await_reads  = rrddim_add(d->st_await, "reads",  NULL,  1, 1, RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_await_writes = rrddim_add(d->st_await, "writes", NULL, -1, 1, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_await);
+
+                rrddim_set_by_pointer(d->st_await, d->rd_await_reads,  (reads  - last_reads)  ? (readms  - last_readms)  / (reads  - last_reads)  : 0);
+                rrddim_set_by_pointer(d->st_await, d->rd_await_writes, (writes - last_writes) ? (writems - last_writems) / (writes - last_writes) : 0);
+                rrdset_done(d->st_await);
+            }
+
+            if( (d->do_io  == CONFIG_BOOLEAN_YES || (d->do_io  == CONFIG_BOOLEAN_AUTO && (readsectors || writesectors))) &&
+                (d->do_ops == CONFIG_BOOLEAN_YES || (d->do_ops == CONFIG_BOOLEAN_AUTO && (reads || writes)))) {
+
+                if(unlikely(!d->st_avgsz)) {
+                    d->st_avgsz = rrdset_create_localhost(
+                            "disk_avgsz"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.avgsz"
+                            , "Average Completed I/O Operation Bandwidth"
+                            , "kilobytes per operation"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_DISK_AVGSZ
+                            , update_every
+                            , RRDSET_TYPE_AREA
+                    );
+
+                    rrdset_flag_set(d->st_avgsz, RRDSET_FLAG_DETAIL);
+
+                    d->rd_avgsz_reads  = rrddim_add(d->st_avgsz, "reads",  NULL, d->sector_size, 1024,      RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_avgsz_writes = rrddim_add(d->st_avgsz, "writes", NULL, d->sector_size * -1, 1024, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_avgsz);
+
+                rrddim_set_by_pointer(d->st_avgsz, d->rd_avgsz_reads,  (reads  - last_reads)  ? (readsectors  - last_readsectors)  / (reads  - last_reads)  : 0);
+                rrddim_set_by_pointer(d->st_avgsz, d->rd_avgsz_writes, (writes - last_writes) ? (writesectors - last_writesectors) / (writes - last_writes) : 0);
+                rrdset_done(d->st_avgsz);
+            }
+
+            if( (d->do_util == CONFIG_BOOLEAN_YES || (d->do_util == CONFIG_BOOLEAN_AUTO && busy_ms)) &&
+                (d->do_ops  == CONFIG_BOOLEAN_YES || (d->do_ops  == CONFIG_BOOLEAN_AUTO && (reads || writes)))) {
+
+                if(unlikely(!d->st_svctm)) {
+                    d->st_svctm = rrdset_create_localhost(
+                            "disk_svctm"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.svctm"
+                            , "Average Service Time"
+                            , "ms per operation"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_DISK_SVCTM
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    rrdset_flag_set(d->st_svctm, RRDSET_FLAG_DETAIL);
+
+                    d->rd_svctm_svctm = rrddim_add(d->st_svctm, "svctm", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_svctm);
+
+                rrddim_set_by_pointer(d->st_svctm, d->rd_svctm_svctm, ((reads - last_reads) + (writes - last_writes)) ? (busy_ms - last_busy_ms) / ((reads - last_reads) + (writes - last_writes)) : 0);
+                rrdset_done(d->st_svctm);
+            }
+        }
+
+        // --------------------------------------------------------------------------
+        // read bcache metrics and generate the bcache charts
+
+        if(d->device_is_bcache && d->do_bcache != CONFIG_BOOLEAN_NO) {
+            unsigned long long int
+                    stats_total_cache_bypass_hits = 0,
+                    stats_total_cache_bypass_misses = 0,
+                    stats_total_cache_hits = 0,
+                    stats_total_cache_miss_collisions = 0,
+                    stats_total_cache_misses = 0,
+                    stats_five_minute_cache_hit_ratio = 0,
+                    stats_hour_cache_hit_ratio = 0,
+                    stats_day_cache_hit_ratio = 0,
+                    stats_total_cache_hit_ratio = 0,
+                    cache_available_percent = 0,
+                    cache_readaheads = 0,
+                    cache_read_races = 0,
+                    cache_io_errors = 0,
+                    cache_congested = 0,
+                    dirty_data = 0,
+                    writeback_rate = 0;
+
+            // read the bcache values
+
+            if(d->bcache_filename_dirty_data)
+                dirty_data = bcache_read_number_with_units(d->bcache_filename_dirty_data);
+
+            if(d->bcache_filename_writeback_rate)
+                writeback_rate = bcache_read_number_with_units(d->bcache_filename_writeback_rate);
+
+            if(d->bcache_filename_cache_congested)
+                cache_congested = bcache_read_number_with_units(d->bcache_filename_cache_congested);
+
+            if(d->bcache_filename_cache_available_percent)
+                read_single_number_file(d->bcache_filename_cache_available_percent, &cache_available_percent);
+
+            if(d->bcache_filename_stats_five_minute_cache_hit_ratio)
+                read_single_number_file(d->bcache_filename_stats_five_minute_cache_hit_ratio, &stats_five_minute_cache_hit_ratio);
+
+            if(d->bcache_filename_stats_hour_cache_hit_ratio)
+                read_single_number_file(d->bcache_filename_stats_hour_cache_hit_ratio, &stats_hour_cache_hit_ratio);
+
+            if(d->bcache_filename_stats_day_cache_hit_ratio)
+                read_single_number_file(d->bcache_filename_stats_day_cache_hit_ratio, &stats_day_cache_hit_ratio);
+
+            if(d->bcache_filename_stats_total_cache_hit_ratio)
+                read_single_number_file(d->bcache_filename_stats_total_cache_hit_ratio, &stats_total_cache_hit_ratio);
+
+            if(d->bcache_filename_stats_total_cache_hits)
+                read_single_number_file(d->bcache_filename_stats_total_cache_hits, &stats_total_cache_hits);
+
+            if(d->bcache_filename_stats_total_cache_misses)
+                read_single_number_file(d->bcache_filename_stats_total_cache_misses, &stats_total_cache_misses);
+
+            if(d->bcache_filename_stats_total_cache_miss_collisions)
+                read_single_number_file(d->bcache_filename_stats_total_cache_miss_collisions, &stats_total_cache_miss_collisions);
+
+            if(d->bcache_filename_stats_total_cache_bypass_hits)
+                read_single_number_file(d->bcache_filename_stats_total_cache_bypass_hits, &stats_total_cache_bypass_hits);
+
+            if(d->bcache_filename_stats_total_cache_bypass_misses)
+                read_single_number_file(d->bcache_filename_stats_total_cache_bypass_misses, &stats_total_cache_bypass_misses);
+
+            if(d->bcache_filename_stats_total_cache_readaheads)
+                cache_readaheads = bcache_read_number_with_units(d->bcache_filename_stats_total_cache_readaheads);
+
+            if(d->bcache_filename_cache_read_races)
+                read_single_number_file(d->bcache_filename_cache_read_races, &cache_read_races);
+
+            if(d->bcache_filename_cache_io_errors)
+                read_single_number_file(d->bcache_filename_cache_io_errors, &cache_io_errors);
+
+            if(d->bcache_filename_priority_stats && global_bcache_priority_stats_update_every >= 1)
+                bcache_read_priority_stats(d, family, global_bcache_priority_stats_update_every, dt);
+
+            // update the charts
+
+            {
+                if(unlikely(!d->st_bcache_hit_ratio)) {
+                    d->st_bcache_hit_ratio = rrdset_create_localhost(
+                            "disk_bcache_hit_ratio"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_hit_ratio"
+                            , "BCache Cache Hit Ratio"
+                            , "percentage"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_HIT_RATIO
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    d->rd_bcache_hit_ratio_5min  = rrddim_add(d->st_bcache_hit_ratio, "5min",  NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_bcache_hit_ratio_1hour = rrddim_add(d->st_bcache_hit_ratio, "1hour", NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_bcache_hit_ratio_1day  = rrddim_add(d->st_bcache_hit_ratio, "1day",  NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_bcache_hit_ratio_total = rrddim_add(d->st_bcache_hit_ratio, "ever",  NULL, 1, 1, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_bcache_hit_ratio);
+
+                rrddim_set_by_pointer(d->st_bcache_hit_ratio, d->rd_bcache_hit_ratio_5min, stats_five_minute_cache_hit_ratio);
+                rrddim_set_by_pointer(d->st_bcache_hit_ratio, d->rd_bcache_hit_ratio_1hour, stats_hour_cache_hit_ratio);
+                rrddim_set_by_pointer(d->st_bcache_hit_ratio, d->rd_bcache_hit_ratio_1day, stats_day_cache_hit_ratio);
+                rrddim_set_by_pointer(d->st_bcache_hit_ratio, d->rd_bcache_hit_ratio_total, stats_total_cache_hit_ratio);
+                rrdset_done(d->st_bcache_hit_ratio);
+            }
+
+            {
+
+                if(unlikely(!d->st_bcache_rates)) {
+                    d->st_bcache_rates = rrdset_create_localhost(
+                            "disk_bcache_rates"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_rates"
+                            , "BCache Rates"
+                            , "KB/s"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_RATES
+                            , update_every
+                            , RRDSET_TYPE_AREA
+                    );
+
+                    d->rd_bcache_rate_congested = rrddim_add(d->st_bcache_rates, "congested", NULL,  1, 1024, RRD_ALGORITHM_ABSOLUTE);
+                    d->rd_bcache_rate_writeback = rrddim_add(d->st_bcache_rates, "writeback", NULL, -1, 1024, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_bcache_rates);
+
+                rrddim_set_by_pointer(d->st_bcache_rates, d->rd_bcache_rate_writeback, writeback_rate);
+                rrddim_set_by_pointer(d->st_bcache_rates, d->rd_bcache_rate_congested, cache_congested);
+                rrdset_done(d->st_bcache_rates);
+            }
+
+            {
+                if(unlikely(!d->st_bcache_size)) {
+                    d->st_bcache_size = rrdset_create_localhost(
+                            "disk_bcache_size"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_size"
+                            , "BCache Cache Sizes"
+                            , "MB"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_SIZE
+                            , update_every
+                            , RRDSET_TYPE_AREA
+                    );
+
+                    d->rd_bcache_dirty_size = rrddim_add(d->st_bcache_size, "dirty", NULL,  1, 1024 * 1024, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_bcache_size);
+
+                rrddim_set_by_pointer(d->st_bcache_size, d->rd_bcache_dirty_size, dirty_data);
+                rrdset_done(d->st_bcache_size);
+            }
+
+            {
+                if(unlikely(!d->st_bcache_usage)) {
+                    d->st_bcache_usage = rrdset_create_localhost(
+                            "disk_bcache_usage"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_usage"
+                            , "BCache Cache Usage"
+                            , "percent"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_USAGE
+                            , update_every
+                            , RRDSET_TYPE_AREA
+                    );
+
+                    d->rd_bcache_available_percent = rrddim_add(d->st_bcache_usage, "avail", NULL,  1, 1, RRD_ALGORITHM_ABSOLUTE);
+                }
+                else rrdset_next(d->st_bcache_usage);
+
+                rrddim_set_by_pointer(d->st_bcache_usage, d->rd_bcache_available_percent, cache_available_percent);
+                rrdset_done(d->st_bcache_usage);
+            }
+
+            {
+
+                if(unlikely(!d->st_bcache_cache_read_races)) {
+                    d->st_bcache_cache_read_races = rrdset_create_localhost(
+                            "disk_bcache_cache_read_races"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_cache_read_races"
+                            , "BCache Cache Read Races"
+                            , "operations/s"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_CACHE_READ_RACES
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    d->rd_bcache_cache_read_races = rrddim_add(d->st_bcache_cache_read_races, "races",  NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
+                    d->rd_bcache_cache_io_errors  = rrddim_add(d->st_bcache_cache_read_races, "errors", NULL, 1, 1, RRD_ALGORITHM_INCREMENTAL);
+                }
+                else rrdset_next(d->st_bcache_cache_read_races);
+
+                rrddim_set_by_pointer(d->st_bcache_cache_read_races, d->rd_bcache_cache_read_races, cache_read_races);
+                rrddim_set_by_pointer(d->st_bcache_cache_read_races, d->rd_bcache_cache_io_errors, cache_io_errors);
+                rrdset_done(d->st_bcache_cache_read_races);
+            }
+
+            if(d->do_bcache == CONFIG_BOOLEAN_YES || (d->do_bcache == CONFIG_BOOLEAN_AUTO && (stats_total_cache_hits != 0 || stats_total_cache_misses != 0 || stats_total_cache_miss_collisions != 0))) {
+
+                if(unlikely(!d->st_bcache)) {
+                    d->st_bcache = rrdset_create_localhost(
+                            "disk_bcache"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache"
+                            , "BCache Cache I/O Operations"
+                            , "operations/s"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_OPS
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    rrdset_flag_set(d->st_bcache, RRDSET_FLAG_DETAIL);
+
+                    d->rd_bcache_hits            = rrddim_add(d->st_bcache, "hits",       NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                    d->rd_bcache_misses          = rrddim_add(d->st_bcache, "misses",     NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+                    d->rd_bcache_miss_collisions = rrddim_add(d->st_bcache, "collisions", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+                    d->rd_bcache_readaheads      = rrddim_add(d->st_bcache, "readaheads", NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                }
+                else rrdset_next(d->st_bcache);
+
+                rrddim_set_by_pointer(d->st_bcache, d->rd_bcache_hits, stats_total_cache_hits);
+                rrddim_set_by_pointer(d->st_bcache, d->rd_bcache_misses, stats_total_cache_misses);
+                rrddim_set_by_pointer(d->st_bcache, d->rd_bcache_miss_collisions, stats_total_cache_miss_collisions);
+                rrddim_set_by_pointer(d->st_bcache, d->rd_bcache_readaheads, cache_readaheads);
+                rrdset_done(d->st_bcache);
+            }
+
+            if(d->do_bcache == CONFIG_BOOLEAN_YES || (d->do_bcache == CONFIG_BOOLEAN_AUTO && (stats_total_cache_bypass_hits != 0 || stats_total_cache_bypass_misses != 0))) {
+
+                if(unlikely(!d->st_bcache_bypass)) {
+                    d->st_bcache_bypass = rrdset_create_localhost(
+                            "disk_bcache_bypass"
+                            , d->device
+                            , d->disk
+                            , family
+                            , "disk.bcache_bypass"
+                            , "BCache Cache Bypass I/O Operations"
+                            , "operations/s"
+                            , PLUGIN_PROC_NAME
+                            , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                            , NETDATA_CHART_PRIO_BCACHE_BYPASS
+                            , update_every
+                            , RRDSET_TYPE_LINE
+                    );
+
+                    rrdset_flag_set(d->st_bcache_bypass, RRDSET_FLAG_DETAIL);
+
+                    d->rd_bcache_bypass_hits   = rrddim_add(d->st_bcache_bypass, "hits",   NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+                    d->rd_bcache_bypass_misses = rrddim_add(d->st_bcache_bypass, "misses", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+                }
+                else rrdset_next(d->st_bcache_bypass);
+
+                rrddim_set_by_pointer(d->st_bcache_bypass, d->rd_bcache_bypass_hits, stats_total_cache_bypass_hits);
+                rrddim_set_by_pointer(d->st_bcache_bypass, d->rd_bcache_bypass_misses, stats_total_cache_bypass_misses);
+                rrdset_done(d->st_bcache_bypass);
+            }
+        }
+    }
+
+
+    // ------------------------------------------------------------------------
+    // update the system total I/O
+
+    if(global_do_io == CONFIG_BOOLEAN_YES || (global_do_io == CONFIG_BOOLEAN_AUTO && (system_read_kb || system_write_kb))) {
+        static RRDSET *st_io = NULL;
+        static RRDDIM *rd_in = NULL, *rd_out = NULL;
+
+        if(unlikely(!st_io)) {
+            st_io = rrdset_create_localhost(
+                    "system"
+                    , "io"
+                    , NULL
+                    , "disk"
+                    , NULL
+                    , "Disk I/O"
+                    , "kilobytes/s"
+                    , PLUGIN_PROC_NAME
+                    , PLUGIN_PROC_MODULE_DISKSTATS_NAME
+                    , NETDATA_CHART_PRIO_SYSTEM_IO
+                    , update_every
+                    , RRDSET_TYPE_AREA
+            );
+
+            rd_in  = rrddim_add(st_io, "in",  NULL,  1, 1, RRD_ALGORITHM_INCREMENTAL);
+            rd_out = rrddim_add(st_io, "out", NULL, -1, 1, RRD_ALGORITHM_INCREMENTAL);
+        }
+        else rrdset_next(st_io);
+
+        rrddim_set_by_pointer(st_io, rd_in, system_read_kb);
+        rrddim_set_by_pointer(st_io, rd_out, system_write_kb);
+        rrdset_done(st_io);
+    }
+
+
+    // ------------------------------------------------------------------------
+    // cleanup removed disks
+
+    struct disk *d = disk_root, *last = NULL;
+    while(d) {
+        if(unlikely(global_cleanup_removed_disks && !d->updated)) {
+            struct disk *t = d;
+
+            rrdset_obsolete_and_pointer_null(d->st_avgsz);
+            rrdset_obsolete_and_pointer_null(d->st_await);
+            rrdset_obsolete_and_pointer_null(d->st_backlog);
+            rrdset_obsolete_and_pointer_null(d->st_io);
+            rrdset_obsolete_and_pointer_null(d->st_iotime);
+            rrdset_obsolete_and_pointer_null(d->st_mops);
+            rrdset_obsolete_and_pointer_null(d->st_ops);
+            rrdset_obsolete_and_pointer_null(d->st_qops);
+            rrdset_obsolete_and_pointer_null(d->st_svctm);
+            rrdset_obsolete_and_pointer_null(d->st_util);
+            rrdset_obsolete_and_pointer_null(d->st_bcache);
+            rrdset_obsolete_and_pointer_null(d->st_bcache_bypass);
+            rrdset_obsolete_and_pointer_null(d->st_bcache_rates);
+            rrdset_obsolete_and_pointer_null(d->st_bcache_size);
+            rrdset_obsolete_and_pointer_null(d->st_bcache_usage);
+            rrdset_obsolete_and_pointer_null(d->st_bcache_hit_ratio);
+
+            if(d == disk_root) {
+                disk_root = d = d->next;
+                last = NULL;
+            }
+            else if(last) {
+                last->next = d = d->next;
+            }
+
+            freez(t->bcache_filename_dirty_data);
+            freez(t->bcache_filename_writeback_rate);
+            freez(t->bcache_filename_cache_congested);
+            freez(t->bcache_filename_cache_available_percent);
+            freez(t->bcache_filename_stats_five_minute_cache_hit_ratio);
+            freez(t->bcache_filename_stats_hour_cache_hit_ratio);
+            freez(t->bcache_filename_stats_day_cache_hit_ratio);
+            freez(t->bcache_filename_stats_total_cache_hit_ratio);
+            freez(t->bcache_filename_stats_total_cache_hits);
+            freez(t->bcache_filename_stats_total_cache_misses);
+            freez(t->bcache_filename_stats_total_cache_miss_collisions);
+            freez(t->bcache_filename_stats_total_cache_bypass_hits);
+            freez(t->bcache_filename_stats_total_cache_bypass_misses);
+            freez(t->bcache_filename_stats_total_cache_readaheads);
+            freez(t->bcache_filename_cache_read_races);
+            freez(t->bcache_filename_cache_io_errors);
+            freez(t->bcache_filename_priority_stats);
+
+            freez(t->disk);
+            freez(t->device);
+            freez(t->mount_point);
+            freez(t);
+        }
+        else {
+            d->updated = 0;
+            last = d;
+            d = d->next;
+        }
+    }
+
+    return 0;
+}