ARC: Cache arc_c value during arc_evict()

[zfs.git] / cmd / zed / agents / zfs_agents.c

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License Version 1.0 (CDDL-1.0).
 * You can obtain a copy of the license from the top-level file
 * "OPENSOLARIS.LICENSE" or at <http://opensource.org/licenses/CDDL-1.0>.
 * You may not use this file except in compliance with the license.
 *
 * CDDL HEADER END
 */

/*
 * Copyright (c) 2016, Intel Corporation.
 * Copyright (c) 2018, loli10K <ezomori.nozomu@gmail.com>
 * Copyright (c) 2021 Hewlett Packard Enterprise Development LP
 */

#include <libnvpair.h>
#include <libzfs.h>
#include <stddef.h>
#include <stdlib.h>
#include <string.h>
#include <sys/list.h>
#include <sys/time.h>
#include <sys/sysevent/eventdefs.h>
#include <sys/sysevent/dev.h>
#include <sys/fm/protocol.h>
#include <sys/fm/fs/zfs.h>
#include <pthread.h>
#include <unistd.h>

#include "zfs_agents.h"
#include "fmd_api.h"
#include "../zed_log.h"

/*
 * agent dispatch code
 */

static pthread_mutex_t  agent_lock = PTHREAD_MUTEX_INITIALIZER;
static pthread_cond_t   agent_cond = PTHREAD_COND_INITIALIZER;
static list_t           agent_events;   /* list of pending events */
static int              agent_exiting;

typedef struct agent_event {
        char            ae_class[64];
        char            ae_subclass[32];
        nvlist_t        *ae_nvl;
        list_node_t     ae_node;
} agent_event_t;

pthread_t g_agents_tid;

libzfs_handle_t *g_zfs_hdl;

/* guid search data */
typedef enum device_type {
        DEVICE_TYPE_L2ARC,      /* l2arc device */
        DEVICE_TYPE_SPARE,      /* spare device */
        DEVICE_TYPE_PRIMARY     /* any primary pool storage device */
} device_type_t;

typedef struct guid_search {
        uint64_t        gs_pool_guid;
        uint64_t        gs_vdev_guid;
        const char      *gs_devid;
        device_type_t   gs_vdev_type;
        uint64_t        gs_vdev_expandtime;     /* vdev expansion time */
} guid_search_t;

/*
 * Walks the vdev tree recursively looking for a matching devid.
 * Returns B_TRUE as soon as a matching device is found, B_FALSE otherwise.
 */
static boolean_t
zfs_agent_iter_vdev(zpool_handle_t *zhp, nvlist_t *nvl, void *arg)
{
        guid_search_t *gsp = arg;
        const char *path = NULL;
        uint_t c, children;
        nvlist_t **child;
        uint64_t vdev_guid;

        /*
         * First iterate over any children.
         */
        if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_CHILDREN,
            &child, &children) == 0) {
                for (c = 0; c < children; c++) {
                        if (zfs_agent_iter_vdev(zhp, child[c], gsp)) {
                                gsp->gs_vdev_type = DEVICE_TYPE_PRIMARY;
                                return (B_TRUE);
                        }
                }
        }
        /*
         * Iterate over any spares and cache devices
         */
        if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_SPARES,
            &child, &children) == 0) {
                for (c = 0; c < children; c++) {
                        if (zfs_agent_iter_vdev(zhp, child[c], gsp)) {
                                gsp->gs_vdev_type = DEVICE_TYPE_SPARE;
                                return (B_TRUE);
                        }
                }
        }
        if (nvlist_lookup_nvlist_array(nvl, ZPOOL_CONFIG_L2CACHE,
            &child, &children) == 0) {
                for (c = 0; c < children; c++) {
                        if (zfs_agent_iter_vdev(zhp, child[c], gsp)) {
                                gsp->gs_vdev_type = DEVICE_TYPE_L2ARC;
                                return (B_TRUE);
                        }
                }
        }
        /*
         * On a devid match, grab the vdev guid and expansion time, if any.
         */
        if (gsp->gs_devid != NULL &&
            (nvlist_lookup_string(nvl, ZPOOL_CONFIG_DEVID, &path) == 0) &&
            (strcmp(gsp->gs_devid, path) == 0)) {
                (void) nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_GUID,
                    &gsp->gs_vdev_guid);
                (void) nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_EXPANSION_TIME,
                    &gsp->gs_vdev_expandtime);
                return (B_TRUE);
        }
        /*
         * Otherwise, on a vdev guid match, grab the devid and expansion
         * time. The devid might be missing on removal since its not part
         * of blkid cache and L2ARC VDEV does not contain pool guid in its
         * blkid, so this is a special case for L2ARC VDEV.
         */
        else if (gsp->gs_vdev_guid != 0 && gsp->gs_devid == NULL &&
            nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_GUID, &vdev_guid) == 0 &&
            gsp->gs_vdev_guid == vdev_guid) {
                (void) nvlist_lookup_string(nvl, ZPOOL_CONFIG_DEVID,
                    &gsp->gs_devid);
                (void) nvlist_lookup_uint64(nvl, ZPOOL_CONFIG_EXPANSION_TIME,
                    &gsp->gs_vdev_expandtime);
                return (B_TRUE);
        }

        return (B_FALSE);
}

static int
zfs_agent_iter_pool(zpool_handle_t *zhp, void *arg)
{
        guid_search_t *gsp = arg;
        nvlist_t *config, *nvl;

        /*
         * For each vdev in this pool, look for a match by devid
         */
        if ((config = zpool_get_config(zhp, NULL)) != NULL) {
                if (nvlist_lookup_nvlist(config, ZPOOL_CONFIG_VDEV_TREE,
                    &nvl) == 0) {
                        (void) zfs_agent_iter_vdev(zhp, nvl, gsp);
                }
        }
        /*
         * if a match was found then grab the pool guid
         */
        if (gsp->gs_vdev_guid && gsp->gs_devid) {
                (void) nvlist_lookup_uint64(config, ZPOOL_CONFIG_POOL_GUID,
                    &gsp->gs_pool_guid);
        }

        zpool_close(zhp);
        return (gsp->gs_devid != NULL && gsp->gs_vdev_guid != 0);
}

void
zfs_agent_post_event(const char *class, const char *subclass, nvlist_t *nvl)
{
        agent_event_t *event;

        if (subclass == NULL)
                subclass = "";

        event = malloc(sizeof (agent_event_t));
        if (event == NULL || nvlist_dup(nvl, &event->ae_nvl, 0) != 0) {
                if (event)
                        free(event);
                return;
        }

        if (strcmp(class, "sysevent.fs.zfs.vdev_check") == 0) {
                class = EC_ZFS;
                subclass = ESC_ZFS_VDEV_CHECK;
        }

        /*
         * On Linux, we don't get the expected FM_RESOURCE_REMOVED ereport
         * from the vdev_disk layer after a hot unplug. Fortunately we do
         * get an EC_DEV_REMOVE from our disk monitor and it is a suitable
         * proxy so we remap it here for the benefit of the diagnosis engine.
         * Starting in OpenZFS 2.0, we do get FM_RESOURCE_REMOVED from the spa
         * layer. Processing multiple FM_RESOURCE_REMOVED events is not harmful.
         */
        if ((strcmp(class, EC_DEV_REMOVE) == 0) &&
            (strcmp(subclass, ESC_DISK) == 0) &&
            (nvlist_exists(nvl, ZFS_EV_VDEV_GUID) ||
            nvlist_exists(nvl, DEV_IDENTIFIER))) {
                nvlist_t *payload = event->ae_nvl;
                struct timeval tv;
                int64_t tod[2];
                uint64_t pool_guid = 0, vdev_guid = 0;
                guid_search_t search = { 0 };
                device_type_t devtype = DEVICE_TYPE_PRIMARY;
                const char *devid = NULL;

                class = "resource.fs.zfs.removed";
                subclass = "";

                (void) nvlist_add_string(payload, FM_CLASS, class);
                (void) nvlist_lookup_string(nvl, DEV_IDENTIFIER, &devid);
                (void) nvlist_lookup_uint64(nvl, ZFS_EV_POOL_GUID, &pool_guid);
                (void) nvlist_lookup_uint64(nvl, ZFS_EV_VDEV_GUID, &vdev_guid);

                (void) gettimeofday(&tv, NULL);
                tod[0] = tv.tv_sec;
                tod[1] = tv.tv_usec;
                (void) nvlist_add_int64_array(payload, FM_EREPORT_TIME, tod, 2);

                /*
                 * If devid is missing but vdev_guid is available, find devid
                 * and pool_guid from vdev_guid.
                 * For multipath, spare and l2arc devices ZFS_EV_VDEV_GUID or
                 * ZFS_EV_POOL_GUID may be missing so find them.
                 */
                if (devid == NULL || pool_guid == 0 || vdev_guid == 0) {
                        if (devid == NULL)
                                search.gs_vdev_guid = vdev_guid;
                        else
                                search.gs_devid = devid;
                        zpool_iter(g_zfs_hdl, zfs_agent_iter_pool, &search);
                        if (devid == NULL)
                                devid = search.gs_devid;
                        if (pool_guid == 0)
                                pool_guid = search.gs_pool_guid;
                        if (vdev_guid == 0)
                                vdev_guid = search.gs_vdev_guid;
                        devtype = search.gs_vdev_type;
                }

                /*
                 * We want to avoid reporting "remove" events coming from
                 * libudev for VDEVs which were expanded recently (10s) and
                 * avoid activating spares in response to partitions being
                 * deleted and created in rapid succession.
                 */
                if (search.gs_vdev_expandtime != 0 &&
                    search.gs_vdev_expandtime + 10 > tv.tv_sec) {
                        zed_log_msg(LOG_INFO, "agent post event: ignoring '%s' "
                            "for recently expanded device '%s'", EC_DEV_REMOVE,
                            devid);
                        fnvlist_free(payload);
                        free(event);
                        goto out;
                }

                (void) nvlist_add_uint64(payload,
                    FM_EREPORT_PAYLOAD_ZFS_POOL_GUID, pool_guid);
                (void) nvlist_add_uint64(payload,
                    FM_EREPORT_PAYLOAD_ZFS_VDEV_GUID, vdev_guid);
                switch (devtype) {
                case DEVICE_TYPE_L2ARC:
                        (void) nvlist_add_string(payload,
                            FM_EREPORT_PAYLOAD_ZFS_VDEV_TYPE,
                            VDEV_TYPE_L2CACHE);
                        break;
                case DEVICE_TYPE_SPARE:
                        (void) nvlist_add_string(payload,
                            FM_EREPORT_PAYLOAD_ZFS_VDEV_TYPE, VDEV_TYPE_SPARE);
                        break;
                case DEVICE_TYPE_PRIMARY:
                        (void) nvlist_add_string(payload,
                            FM_EREPORT_PAYLOAD_ZFS_VDEV_TYPE, VDEV_TYPE_DISK);
                        break;
                }

                zed_log_msg(LOG_INFO, "agent post event: mapping '%s' to '%s'",
                    EC_DEV_REMOVE, class);
        }

        (void) strlcpy(event->ae_class, class, sizeof (event->ae_class));
        (void) strlcpy(event->ae_subclass, subclass,
            sizeof (event->ae_subclass));

        (void) pthread_mutex_lock(&agent_lock);
        list_insert_tail(&agent_events, event);
        (void) pthread_mutex_unlock(&agent_lock);

out:
        (void) pthread_cond_signal(&agent_cond);
}

static void
zfs_agent_dispatch(const char *class, const char *subclass, nvlist_t *nvl)
{
        /*
         * The diagnosis engine subscribes to the following events.
         * On illumos these subscriptions reside in:
         *      /usr/lib/fm/fmd/plugins/zfs-diagnosis.conf
         */
        if (strstr(class, "ereport.fs.zfs.") != NULL ||
            strstr(class, "resource.fs.zfs.") != NULL ||
            strcmp(class, "sysevent.fs.zfs.vdev_remove") == 0 ||
            strcmp(class, "sysevent.fs.zfs.vdev_remove_dev") == 0 ||
            strcmp(class, "sysevent.fs.zfs.pool_destroy") == 0) {
                fmd_module_recv(fmd_module_hdl("zfs-diagnosis"), nvl, class);
        }

        /*
         * The retire agent subscribes to the following events.
         * On illumos these subscriptions reside in:
         *      /usr/lib/fm/fmd/plugins/zfs-retire.conf
         *
         * NOTE: faults events come directly from our diagnosis engine
         * and will not pass through the zfs kernel module.
         */
        if (strcmp(class, FM_LIST_SUSPECT_CLASS) == 0 ||
            strcmp(class, "resource.fs.zfs.removed") == 0 ||
            strcmp(class, "resource.fs.zfs.statechange") == 0 ||
            strcmp(class, "sysevent.fs.zfs.vdev_remove")  == 0) {
                fmd_module_recv(fmd_module_hdl("zfs-retire"), nvl, class);
        }

        /*
         * The SLM module only consumes disk events and vdev check events
         *
         * NOTE: disk events come directly from disk monitor and will
         * not pass through the zfs kernel module.
         */
        if (strstr(class, "EC_dev_") != NULL ||
            strcmp(class, EC_ZFS) == 0) {
                (void) zfs_slm_event(class, subclass, nvl);
        }
}

/*
 * Events are consumed and dispatched from this thread
 * An agent can also post an event so event list lock
 * is not held when calling an agent.
 * One event is consumed at a time.
 */
static void *
zfs_agent_consumer_thread(void *arg)
{
        (void) arg;

        for (;;) {
                agent_event_t *event;

                (void) pthread_mutex_lock(&agent_lock);

                /* wait for an event to show up */
                while (!agent_exiting && list_is_empty(&agent_events))
                        (void) pthread_cond_wait(&agent_cond, &agent_lock);

                if (agent_exiting) {
                        (void) pthread_mutex_unlock(&agent_lock);
                        zed_log_msg(LOG_INFO, "zfs_agent_consumer_thread: "
                            "exiting");
                        return (NULL);
                }

                if ((event = list_remove_head(&agent_events)) != NULL) {
                        (void) pthread_mutex_unlock(&agent_lock);

                        /* dispatch to all event subscribers */
                        zfs_agent_dispatch(event->ae_class, event->ae_subclass,
                            event->ae_nvl);

                        nvlist_free(event->ae_nvl);
                        free(event);
                        continue;
                }

                (void) pthread_mutex_unlock(&agent_lock);
        }

        return (NULL);
}

void
zfs_agent_init(libzfs_handle_t *zfs_hdl)
{
        fmd_hdl_t *hdl;

        g_zfs_hdl = zfs_hdl;

        if (zfs_slm_init() != 0)
                zed_log_die("Failed to initialize zfs slm");
        zed_log_msg(LOG_INFO, "Add Agent: init");

        hdl = fmd_module_hdl("zfs-diagnosis");
        _zfs_diagnosis_init(hdl);
        if (!fmd_module_initialized(hdl))
                zed_log_die("Failed to initialize zfs diagnosis");

        hdl = fmd_module_hdl("zfs-retire");
        _zfs_retire_init(hdl);
        if (!fmd_module_initialized(hdl))
                zed_log_die("Failed to initialize zfs retire");

        list_create(&agent_events, sizeof (agent_event_t),
            offsetof(struct agent_event, ae_node));

        if (pthread_create(&g_agents_tid, NULL, zfs_agent_consumer_thread,
            NULL) != 0) {
                list_destroy(&agent_events);
                zed_log_die("Failed to initialize agents");
        }
        pthread_setname_np(g_agents_tid, "agents");
}

void
zfs_agent_fini(void)
{
        fmd_hdl_t *hdl;
        agent_event_t *event;

        agent_exiting = 1;
        (void) pthread_cond_signal(&agent_cond);

        /* wait for zfs_enum_pools thread to complete */
        (void) pthread_join(g_agents_tid, NULL);

        /* drain any pending events */
        while ((event = list_remove_head(&agent_events)) != NULL) {
                nvlist_free(event->ae_nvl);
                free(event);
        }

        list_destroy(&agent_events);

        if ((hdl = fmd_module_hdl("zfs-retire")) != NULL) {
                _zfs_retire_fini(hdl);
                fmd_hdl_unregister(hdl);
        }
        if ((hdl = fmd_module_hdl("zfs-diagnosis")) != NULL) {
                _zfs_diagnosis_fini(hdl);
                fmd_hdl_unregister(hdl);
        }

        zed_log_msg(LOG_INFO, "Add Agent: fini");
        zfs_slm_fini();

        g_zfs_hdl = NULL;
}