zfs-builds-mm/zfs-0.8.4/cmd/zed/zed_disk_event.c

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2020-07-19 16:21:53 +02:00
/*
* 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, 2017, Intel Corporation.
*/
#ifdef HAVE_LIBUDEV
#include <errno.h>
#include <fcntl.h>
#include <libnvpair.h>
#include <libudev.h>
#include <libzfs.h>
#include <libzutil.h>
#include <pthread.h>
#include <stdlib.h>
#include <string.h>
#include <sys/sysevent/eventdefs.h>
#include <sys/sysevent/dev.h>
#include "zed_log.h"
#include "zed_disk_event.h"
#include "agents/zfs_agents.h"
/*
* Portions of ZED need to see disk events for disks belonging to ZFS pools.
* A libudev monitor is established to monitor block device actions and pass
* them on to internal ZED logic modules. Initially, zfs_mod.c is the only
* consumer and is the Linux equivalent for the illumos syseventd ZFS SLM
* module responsible for handling disk events for ZFS.
*/
pthread_t g_mon_tid;
struct udev *g_udev;
struct udev_monitor *g_mon;
#define DEV_BYID_PATH "/dev/disk/by-id/"
/* 64MB is minimum usable disk for ZFS */
#define MINIMUM_SECTORS 131072
/*
* Post disk event to SLM module
*
* occurs in the context of monitor thread
*/
static void
zed_udev_event(const char *class, const char *subclass, nvlist_t *nvl)
{
char *strval;
uint64_t numval;
zed_log_msg(LOG_INFO, "zed_disk_event:");
zed_log_msg(LOG_INFO, "\tclass: %s", class);
zed_log_msg(LOG_INFO, "\tsubclass: %s", subclass);
if (nvlist_lookup_string(nvl, DEV_NAME, &strval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %s", DEV_NAME, strval);
if (nvlist_lookup_string(nvl, DEV_PATH, &strval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %s", DEV_PATH, strval);
if (nvlist_lookup_string(nvl, DEV_IDENTIFIER, &strval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %s", DEV_IDENTIFIER, strval);
if (nvlist_lookup_string(nvl, DEV_PHYS_PATH, &strval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %s", DEV_PHYS_PATH, strval);
if (nvlist_lookup_uint64(nvl, DEV_SIZE, &numval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %llu", DEV_SIZE, numval);
if (nvlist_lookup_uint64(nvl, ZFS_EV_POOL_GUID, &numval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %llu", ZFS_EV_POOL_GUID, numval);
if (nvlist_lookup_uint64(nvl, ZFS_EV_VDEV_GUID, &numval) == 0)
zed_log_msg(LOG_INFO, "\t%s: %llu", ZFS_EV_VDEV_GUID, numval);
(void) zfs_agent_post_event(class, subclass, nvl);
}
/*
* dev_event_nvlist: place event schema into an nv pair list
*
* NAME VALUE (example)
* -------------- --------------------------------------------------------
* DEV_NAME /dev/sdl
* DEV_PATH /devices/pci0000:00/0000:00:03.0/0000:04:00.0/host0/...
* DEV_IDENTIFIER ata-Hitachi_HTS725050A9A362_100601PCG420VLJ37DMC
* DEV_PHYS_PATH pci-0000:04:00.0-sas-0x4433221101000000-lun-0
* DEV_IS_PART ---
* DEV_SIZE 500107862016
* ZFS_EV_POOL_GUID 17523635698032189180
* ZFS_EV_VDEV_GUID 14663607734290803088
*/
static nvlist_t *
dev_event_nvlist(struct udev_device *dev)
{
nvlist_t *nvl;
char strval[128];
const char *value, *path;
uint64_t guid;
if (nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0) != 0)
return (NULL);
if (zfs_device_get_devid(dev, strval, sizeof (strval)) == 0)
(void) nvlist_add_string(nvl, DEV_IDENTIFIER, strval);
if (zfs_device_get_physical(dev, strval, sizeof (strval)) == 0)
(void) nvlist_add_string(nvl, DEV_PHYS_PATH, strval);
if ((path = udev_device_get_devnode(dev)) != NULL)
(void) nvlist_add_string(nvl, DEV_NAME, path);
if ((value = udev_device_get_devpath(dev)) != NULL)
(void) nvlist_add_string(nvl, DEV_PATH, value);
value = udev_device_get_devtype(dev);
if ((value != NULL && strcmp("partition", value) == 0) ||
(udev_device_get_property_value(dev, "ID_PART_ENTRY_NUMBER")
!= NULL)) {
(void) nvlist_add_boolean(nvl, DEV_IS_PART);
}
if ((value = udev_device_get_sysattr_value(dev, "size")) != NULL) {
uint64_t numval = DEV_BSIZE;
numval *= strtoull(value, NULL, 10);
(void) nvlist_add_uint64(nvl, DEV_SIZE, numval);
}
/*
* Grab the pool and vdev guids from blkid cache
*/
value = udev_device_get_property_value(dev, "ID_FS_UUID");
if (value != NULL && (guid = strtoull(value, NULL, 10)) != 0)
(void) nvlist_add_uint64(nvl, ZFS_EV_POOL_GUID, guid);
value = udev_device_get_property_value(dev, "ID_FS_UUID_SUB");
if (value != NULL && (guid = strtoull(value, NULL, 10)) != 0)
(void) nvlist_add_uint64(nvl, ZFS_EV_VDEV_GUID, guid);
/*
* Either a vdev guid or a devid must be present for matching
*/
if (!nvlist_exists(nvl, DEV_IDENTIFIER) &&
!nvlist_exists(nvl, ZFS_EV_VDEV_GUID)) {
nvlist_free(nvl);
return (NULL);
}
return (nvl);
}
/*
* Listen for block device uevents
*/
static void *
zed_udev_monitor(void *arg)
{
struct udev_monitor *mon = arg;
char *tmp, *tmp2;
zed_log_msg(LOG_INFO, "Waiting for new udev disk events...");
while (1) {
struct udev_device *dev;
const char *action, *type, *part, *sectors;
const char *bus, *uuid;
const char *class, *subclass;
nvlist_t *nvl;
boolean_t is_zfs = B_FALSE;
/* allow a cancellation while blocked (recvmsg) */
pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
/* blocks at recvmsg until an event occurs */
if ((dev = udev_monitor_receive_device(mon)) == NULL) {
zed_log_msg(LOG_WARNING, "zed_udev_monitor: receive "
"device error %d", errno);
continue;
}
/* allow all steps to complete before a cancellation */
pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
/*
* Strongly typed device is the preferred filter
*/
type = udev_device_get_property_value(dev, "ID_FS_TYPE");
if (type != NULL && type[0] != '\0') {
if (strcmp(type, "zfs_member") == 0) {
is_zfs = B_TRUE;
} else {
/* not ours, so skip */
zed_log_msg(LOG_INFO, "zed_udev_monitor: skip "
"%s (in use by %s)",
udev_device_get_devnode(dev), type);
udev_device_unref(dev);
continue;
}
}
/*
* if this is a disk and it is partitioned, then the
* zfs label will reside in a DEVTYPE=partition and
* we can skip passing this event
*/
type = udev_device_get_property_value(dev, "DEVTYPE");
part = udev_device_get_property_value(dev,
"ID_PART_TABLE_TYPE");
if (type != NULL && type[0] != '\0' &&
strcmp(type, "disk") == 0 &&
part != NULL && part[0] != '\0') {
/* skip and wait for partition event */
udev_device_unref(dev);
continue;
}
/*
* ignore small partitions
*/
sectors = udev_device_get_property_value(dev,
"ID_PART_ENTRY_SIZE");
if (sectors == NULL)
sectors = udev_device_get_sysattr_value(dev, "size");
if (sectors != NULL &&
strtoull(sectors, NULL, 10) < MINIMUM_SECTORS) {
udev_device_unref(dev);
continue;
}
/*
* If the blkid probe didn't find ZFS, then a persistent
* device id string is required in the message schema
* for matching with vdevs. Preflight here for expected
* udev information.
*/
bus = udev_device_get_property_value(dev, "ID_BUS");
uuid = udev_device_get_property_value(dev, "DM_UUID");
if (!is_zfs && (bus == NULL && uuid == NULL)) {
zed_log_msg(LOG_INFO, "zed_udev_monitor: %s no devid "
"source", udev_device_get_devnode(dev));
udev_device_unref(dev);
continue;
}
action = udev_device_get_action(dev);
if (strcmp(action, "add") == 0) {
class = EC_DEV_ADD;
subclass = ESC_DISK;
} else if (strcmp(action, "remove") == 0) {
class = EC_DEV_REMOVE;
subclass = ESC_DISK;
} else if (strcmp(action, "change") == 0) {
class = EC_DEV_STATUS;
subclass = ESC_DEV_DLE;
} else {
zed_log_msg(LOG_WARNING, "zed_udev_monitor: %s unknown",
action);
udev_device_unref(dev);
continue;
}
/*
* Special case an EC_DEV_ADD for multipath devices
*
* When a multipath device is created, udev reports the
* following:
*
* 1. "add" event of the dm device for the multipath device
* (like /dev/dm-3).
* 2. "change" event to create the actual multipath device
* symlink (like /dev/mapper/mpatha). The event also
* passes back the relevant DM vars we care about, like
* DM_UUID.
* 3. Another "change" event identical to #2 (that we ignore).
*
* To get the behavior we want, we treat the "change" event
* in #2 as a "add" event; as if "/dev/mapper/mpatha" was
* a new disk being added.
*/
if (strcmp(class, EC_DEV_STATUS) == 0 &&
udev_device_get_property_value(dev, "DM_UUID") &&
udev_device_get_property_value(dev, "MPATH_SBIN_PATH")) {
tmp = (char *)udev_device_get_devnode(dev);
tmp2 = zfs_get_underlying_path(tmp);
if (tmp && tmp2 && (strcmp(tmp, tmp2) != 0)) {
/*
* We have a real underlying device, which
* means that this multipath "change" event is
* an "add" event.
*
* If the multipath device and the underlying
* dev are the same name (i.e. /dev/dm-5), then
* there is no real underlying disk for this
* multipath device, and so this "change" event
* really is a multipath removal.
*/
class = EC_DEV_ADD;
subclass = ESC_DISK;
} else {
tmp = (char *)
udev_device_get_property_value(dev,
"DM_NR_VALID_PATHS");
/* treat as a multipath remove */
if (tmp != NULL && strcmp(tmp, "0") == 0) {
class = EC_DEV_REMOVE;
subclass = ESC_DISK;
}
}
free(tmp2);
}
/*
* Special case an EC_DEV_ADD for scsi_debug devices
*
* These devices require a udevadm trigger command after
* creation in order to register the vdev_id scsidebug alias
* rule (adds a persistent path (phys_path) used for fault
* management automated tests in the ZFS test suite.
*
* After udevadm trigger command, event registers as a "change"
* event but needs to instead be handled as another "add" event
* to allow for disk labeling and partitioning to occur.
*/
if (strcmp(class, EC_DEV_STATUS) == 0 &&
udev_device_get_property_value(dev, "ID_VDEV") &&
udev_device_get_property_value(dev, "ID_MODEL")) {
const char *id_model, *id_model_sd = "scsi_debug";
id_model = udev_device_get_property_value(dev,
"ID_MODEL");
if (strcmp(id_model, id_model_sd) == 0) {
class = EC_DEV_ADD;
subclass = ESC_DISK;
}
}
if ((nvl = dev_event_nvlist(dev)) != NULL) {
zed_udev_event(class, subclass, nvl);
nvlist_free(nvl);
}
udev_device_unref(dev);
}
return (NULL);
}
int
zed_disk_event_init()
{
int fd, fflags;
if ((g_udev = udev_new()) == NULL) {
zed_log_msg(LOG_WARNING, "udev_new failed (%d)", errno);
return (-1);
}
/* Set up a udev monitor for block devices */
g_mon = udev_monitor_new_from_netlink(g_udev, "udev");
udev_monitor_filter_add_match_subsystem_devtype(g_mon, "block", "disk");
udev_monitor_filter_add_match_subsystem_devtype(g_mon, "block",
"partition");
udev_monitor_enable_receiving(g_mon);
/* Make sure monitoring socket is blocking */
fd = udev_monitor_get_fd(g_mon);
if ((fflags = fcntl(fd, F_GETFL)) & O_NONBLOCK)
(void) fcntl(fd, F_SETFL, fflags & ~O_NONBLOCK);
/* spawn a thread to monitor events */
if (pthread_create(&g_mon_tid, NULL, zed_udev_monitor, g_mon) != 0) {
udev_monitor_unref(g_mon);
udev_unref(g_udev);
zed_log_msg(LOG_WARNING, "pthread_create failed");
return (-1);
}
zed_log_msg(LOG_INFO, "zed_disk_event_init");
return (0);
}
void
zed_disk_event_fini()
{
/* cancel monitor thread at recvmsg() */
(void) pthread_cancel(g_mon_tid);
(void) pthread_join(g_mon_tid, NULL);
/* cleanup udev resources */
udev_monitor_unref(g_mon);
udev_unref(g_udev);
zed_log_msg(LOG_INFO, "zed_disk_event_fini");
}
#else
#include "zed_disk_event.h"
int
zed_disk_event_init()
{
return (0);
}
void
zed_disk_event_fini()
{
}
#endif /* HAVE_LIBUDEV */