1 /*
2 * CDDL HEADER START
3 *
4 * The contents of this file are subject to the terms of the
5 * Common Development and Distribution License Version 1.0 (CDDL-1.0).
6 * You can obtain a copy of the license from the top-level file
7 * "OPENSOLARIS.LICENSE" or at <http://opensource.org/licenses/CDDL-1.0>.
8 * You may not use this file except in compliance with the license.
9 *
10 * CDDL HEADER END
11 */
12
13 /*
14 * Copyright (c) 2016, 2017, Intel Corporation.
15 */
16
17 #ifdef HAVE_LIBUDEV
18
19 #include <errno.h>
20 #include <fcntl.h>
21 #include <libnvpair.h>
22 #include <libudev.h>
23 #include <libzfs.h>
24 #include <libzutil.h>
25 #include <pthread.h>
26 #include <stdlib.h>
27 #include <string.h>
28
29 #include <sys/sysevent/eventdefs.h>
30 #include <sys/sysevent/dev.h>
31
32 #include "zed_log.h"
33 #include "zed_disk_event.h"
34 #include "agents/zfs_agents.h"
35
36 /*
37 * Portions of ZED need to see disk events for disks belonging to ZFS pools.
38 * A libudev monitor is established to monitor block device actions and pass
39 * them on to internal ZED logic modules. Initially, zfs_mod.c is the only
40 * consumer and is the Linux equivalent for the illumos syseventd ZFS SLM
41 * module responsible for handling disk events for ZFS.
42 */
43
44 pthread_t g_mon_tid;
45 struct udev *g_udev;
46 struct udev_monitor *g_mon;
47
48
49 #define DEV_BYID_PATH "/dev/disk/by-id/"
50
51 /* 64MB is minimum usable disk for ZFS */
52 #define MINIMUM_SECTORS 131072
53
54
55 /*
56 * Post disk event to SLM module
57 *
58 * occurs in the context of monitor thread
59 */
60 static void
zed_udev_event(const char * class,const char * subclass,nvlist_t * nvl)61 zed_udev_event(const char *class, const char *subclass, nvlist_t *nvl)
62 {
63 char *strval;
64 uint64_t numval;
65
66 zed_log_msg(LOG_INFO, "zed_disk_event:");
67 zed_log_msg(LOG_INFO, "\tclass: %s", class);
68 zed_log_msg(LOG_INFO, "\tsubclass: %s", subclass);
69 if (nvlist_lookup_string(nvl, DEV_NAME, &strval) == 0)
70 zed_log_msg(LOG_INFO, "\t%s: %s", DEV_NAME, strval);
71 if (nvlist_lookup_string(nvl, DEV_PATH, &strval) == 0)
72 zed_log_msg(LOG_INFO, "\t%s: %s", DEV_PATH, strval);
73 if (nvlist_lookup_string(nvl, DEV_IDENTIFIER, &strval) == 0)
74 zed_log_msg(LOG_INFO, "\t%s: %s", DEV_IDENTIFIER, strval);
75 if (nvlist_lookup_boolean(nvl, DEV_IS_PART) == B_TRUE)
76 zed_log_msg(LOG_INFO, "\t%s: B_TRUE", DEV_IS_PART);
77 if (nvlist_lookup_string(nvl, DEV_PHYS_PATH, &strval) == 0)
78 zed_log_msg(LOG_INFO, "\t%s: %s", DEV_PHYS_PATH, strval);
79 if (nvlist_lookup_uint64(nvl, DEV_SIZE, &numval) == 0)
80 zed_log_msg(LOG_INFO, "\t%s: %llu", DEV_SIZE, numval);
81 if (nvlist_lookup_uint64(nvl, ZFS_EV_POOL_GUID, &numval) == 0)
82 zed_log_msg(LOG_INFO, "\t%s: %llu", ZFS_EV_POOL_GUID, numval);
83 if (nvlist_lookup_uint64(nvl, ZFS_EV_VDEV_GUID, &numval) == 0)
84 zed_log_msg(LOG_INFO, "\t%s: %llu", ZFS_EV_VDEV_GUID, numval);
85
86 (void) zfs_agent_post_event(class, subclass, nvl);
87 }
88
89 /*
90 * dev_event_nvlist: place event schema into an nv pair list
91 *
92 * NAME VALUE (example)
93 * -------------- --------------------------------------------------------
94 * DEV_NAME /dev/sdl
95 * DEV_PATH /devices/pci0000:00/0000:00:03.0/0000:04:00.0/host0/...
96 * DEV_IDENTIFIER ata-Hitachi_HTS725050A9A362_100601PCG420VLJ37DMC
97 * DEV_PHYS_PATH pci-0000:04:00.0-sas-0x4433221101000000-lun-0
98 * DEV_IS_PART ---
99 * DEV_SIZE 500107862016
100 * ZFS_EV_POOL_GUID 17523635698032189180
101 * ZFS_EV_VDEV_GUID 14663607734290803088
102 */
103 static nvlist_t *
dev_event_nvlist(struct udev_device * dev)104 dev_event_nvlist(struct udev_device *dev)
105 {
106 nvlist_t *nvl;
107 char strval[128];
108 const char *value, *path;
109 uint64_t guid;
110
111 if (nvlist_alloc(&nvl, NV_UNIQUE_NAME, 0) != 0)
112 return (NULL);
113
114 if (zfs_device_get_devid(dev, strval, sizeof (strval)) == 0)
115 (void) nvlist_add_string(nvl, DEV_IDENTIFIER, strval);
116 if (zfs_device_get_physical(dev, strval, sizeof (strval)) == 0)
117 (void) nvlist_add_string(nvl, DEV_PHYS_PATH, strval);
118 if ((path = udev_device_get_devnode(dev)) != NULL)
119 (void) nvlist_add_string(nvl, DEV_NAME, path);
120 if ((value = udev_device_get_devpath(dev)) != NULL)
121 (void) nvlist_add_string(nvl, DEV_PATH, value);
122 value = udev_device_get_devtype(dev);
123 if ((value != NULL && strcmp("partition", value) == 0) ||
124 (udev_device_get_property_value(dev, "ID_PART_ENTRY_NUMBER")
125 != NULL)) {
126 (void) nvlist_add_boolean(nvl, DEV_IS_PART);
127 }
128 if ((value = udev_device_get_sysattr_value(dev, "size")) != NULL) {
129 uint64_t numval = DEV_BSIZE;
130
131 numval *= strtoull(value, NULL, 10);
132 (void) nvlist_add_uint64(nvl, DEV_SIZE, numval);
133 }
134
135 /*
136 * Grab the pool and vdev guids from blkid cache
137 */
138 value = udev_device_get_property_value(dev, "ID_FS_UUID");
139 if (value != NULL && (guid = strtoull(value, NULL, 10)) != 0)
140 (void) nvlist_add_uint64(nvl, ZFS_EV_POOL_GUID, guid);
141
142 value = udev_device_get_property_value(dev, "ID_FS_UUID_SUB");
143 if (value != NULL && (guid = strtoull(value, NULL, 10)) != 0)
144 (void) nvlist_add_uint64(nvl, ZFS_EV_VDEV_GUID, guid);
145
146 /*
147 * Either a vdev guid or a devid must be present for matching
148 */
149 if (!nvlist_exists(nvl, DEV_IDENTIFIER) &&
150 !nvlist_exists(nvl, ZFS_EV_VDEV_GUID)) {
151 nvlist_free(nvl);
152 return (NULL);
153 }
154
155 return (nvl);
156 }
157
158 /*
159 * Listen for block device uevents
160 */
161 static void *
zed_udev_monitor(void * arg)162 zed_udev_monitor(void *arg)
163 {
164 struct udev_monitor *mon = arg;
165 char *tmp, *tmp2;
166
167 zed_log_msg(LOG_INFO, "Waiting for new udev disk events...");
168
169 while (1) {
170 struct udev_device *dev;
171 const char *action, *type, *part, *sectors;
172 const char *bus, *uuid;
173 const char *class, *subclass;
174 nvlist_t *nvl;
175 boolean_t is_zfs = B_FALSE;
176
177 /* allow a cancellation while blocked (recvmsg) */
178 pthread_setcancelstate(PTHREAD_CANCEL_ENABLE, NULL);
179
180 /* blocks at recvmsg until an event occurs */
181 if ((dev = udev_monitor_receive_device(mon)) == NULL) {
182 zed_log_msg(LOG_WARNING, "zed_udev_monitor: receive "
183 "device error %d", errno);
184 continue;
185 }
186
187 /* allow all steps to complete before a cancellation */
188 pthread_setcancelstate(PTHREAD_CANCEL_DISABLE, NULL);
189
190 /*
191 * Strongly typed device is the preferred filter
192 */
193 type = udev_device_get_property_value(dev, "ID_FS_TYPE");
194 if (type != NULL && type[0] != '\0') {
195 if (strcmp(type, "zfs_member") == 0) {
196 is_zfs = B_TRUE;
197 } else {
198 /* not ours, so skip */
199 zed_log_msg(LOG_INFO, "zed_udev_monitor: skip "
200 "%s (in use by %s)",
201 udev_device_get_devnode(dev), type);
202 udev_device_unref(dev);
203 continue;
204 }
205 }
206
207 /*
208 * if this is a disk and it is partitioned, then the
209 * zfs label will reside in a DEVTYPE=partition and
210 * we can skip passing this event
211 */
212 type = udev_device_get_property_value(dev, "DEVTYPE");
213 part = udev_device_get_property_value(dev,
214 "ID_PART_TABLE_TYPE");
215 if (type != NULL && type[0] != '\0' &&
216 strcmp(type, "disk") == 0 &&
217 part != NULL && part[0] != '\0') {
218 zed_log_msg(LOG_INFO,
219 "%s: skip %s since it has a %s partition already",
220 __func__,
221 udev_device_get_property_value(dev, "DEVNAME"),
222 part);
223 /* skip and wait for partition event */
224 udev_device_unref(dev);
225 continue;
226 }
227
228 /*
229 * ignore small partitions
230 */
231 sectors = udev_device_get_property_value(dev,
232 "ID_PART_ENTRY_SIZE");
233 if (sectors == NULL)
234 sectors = udev_device_get_sysattr_value(dev, "size");
235 if (sectors != NULL &&
236 strtoull(sectors, NULL, 10) < MINIMUM_SECTORS) {
237 zed_log_msg(LOG_INFO,
238 "%s: %s sectors %s < %llu (minimum)",
239 __func__,
240 udev_device_get_property_value(dev, "DEVNAME"),
241 sectors, MINIMUM_SECTORS);
242 udev_device_unref(dev);
243 continue;
244 }
245
246 /*
247 * If the blkid probe didn't find ZFS, then a persistent
248 * device id string is required in the message schema
249 * for matching with vdevs. Preflight here for expected
250 * udev information.
251 */
252 bus = udev_device_get_property_value(dev, "ID_BUS");
253 uuid = udev_device_get_property_value(dev, "DM_UUID");
254 if (!is_zfs && (bus == NULL && uuid == NULL)) {
255 zed_log_msg(LOG_INFO, "zed_udev_monitor: %s no devid "
256 "source", udev_device_get_devnode(dev));
257 udev_device_unref(dev);
258 continue;
259 }
260
261 action = udev_device_get_action(dev);
262 if (strcmp(action, "add") == 0) {
263 class = EC_DEV_ADD;
264 subclass = ESC_DISK;
265 } else if (strcmp(action, "remove") == 0) {
266 class = EC_DEV_REMOVE;
267 subclass = ESC_DISK;
268 } else if (strcmp(action, "change") == 0) {
269 class = EC_DEV_STATUS;
270 subclass = ESC_DEV_DLE;
271 } else {
272 zed_log_msg(LOG_WARNING, "zed_udev_monitor: %s unknown",
273 action);
274 udev_device_unref(dev);
275 continue;
276 }
277
278 /*
279 * Special case an EC_DEV_ADD for multipath devices
280 *
281 * When a multipath device is created, udev reports the
282 * following:
283 *
284 * 1. "add" event of the dm device for the multipath device
285 * (like /dev/dm-3).
286 * 2. "change" event to create the actual multipath device
287 * symlink (like /dev/mapper/mpatha). The event also
288 * passes back the relevant DM vars we care about, like
289 * DM_UUID.
290 * 3. Another "change" event identical to #2 (that we ignore).
291 *
292 * To get the behavior we want, we treat the "change" event
293 * in #2 as a "add" event; as if "/dev/mapper/mpatha" was
294 * a new disk being added.
295 */
296 if (strcmp(class, EC_DEV_STATUS) == 0 &&
297 udev_device_get_property_value(dev, "DM_UUID") &&
298 udev_device_get_property_value(dev, "MPATH_SBIN_PATH")) {
299 tmp = (char *)udev_device_get_devnode(dev);
300 tmp2 = zfs_get_underlying_path(tmp);
301 if (tmp && tmp2 && (strcmp(tmp, tmp2) != 0)) {
302 /*
303 * We have a real underlying device, which
304 * means that this multipath "change" event is
305 * an "add" event.
306 *
307 * If the multipath device and the underlying
308 * dev are the same name (i.e. /dev/dm-5), then
309 * there is no real underlying disk for this
310 * multipath device, and so this "change" event
311 * really is a multipath removal.
312 */
313 class = EC_DEV_ADD;
314 subclass = ESC_DISK;
315 } else {
316 tmp = (char *)
317 udev_device_get_property_value(dev,
318 "DM_NR_VALID_PATHS");
319 /* treat as a multipath remove */
320 if (tmp != NULL && strcmp(tmp, "0") == 0) {
321 class = EC_DEV_REMOVE;
322 subclass = ESC_DISK;
323 }
324 }
325 free(tmp2);
326 }
327
328 /*
329 * Special case an EC_DEV_ADD for scsi_debug devices
330 *
331 * These devices require a udevadm trigger command after
332 * creation in order to register the vdev_id scsidebug alias
333 * rule (adds a persistent path (phys_path) used for fault
334 * management automated tests in the ZFS test suite.
335 *
336 * After udevadm trigger command, event registers as a "change"
337 * event but needs to instead be handled as another "add" event
338 * to allow for disk labeling and partitioning to occur.
339 */
340 if (strcmp(class, EC_DEV_STATUS) == 0 &&
341 udev_device_get_property_value(dev, "ID_VDEV") &&
342 udev_device_get_property_value(dev, "ID_MODEL")) {
343 const char *id_model, *id_model_sd = "scsi_debug";
344
345 id_model = udev_device_get_property_value(dev,
346 "ID_MODEL");
347 if (strcmp(id_model, id_model_sd) == 0) {
348 class = EC_DEV_ADD;
349 subclass = ESC_DISK;
350 }
351 }
352
353 if ((nvl = dev_event_nvlist(dev)) != NULL) {
354 zed_udev_event(class, subclass, nvl);
355 nvlist_free(nvl);
356 }
357
358 udev_device_unref(dev);
359 }
360
361 return (NULL);
362 }
363
364 int
zed_disk_event_init()365 zed_disk_event_init()
366 {
367 int fd, fflags;
368
369 if ((g_udev = udev_new()) == NULL) {
370 zed_log_msg(LOG_WARNING, "udev_new failed (%d)", errno);
371 return (-1);
372 }
373
374 /* Set up a udev monitor for block devices */
375 g_mon = udev_monitor_new_from_netlink(g_udev, "udev");
376 udev_monitor_filter_add_match_subsystem_devtype(g_mon, "block", "disk");
377 udev_monitor_filter_add_match_subsystem_devtype(g_mon, "block",
378 "partition");
379 udev_monitor_enable_receiving(g_mon);
380
381 /* Make sure monitoring socket is blocking */
382 fd = udev_monitor_get_fd(g_mon);
383 if ((fflags = fcntl(fd, F_GETFL)) & O_NONBLOCK)
384 (void) fcntl(fd, F_SETFL, fflags & ~O_NONBLOCK);
385
386 /* spawn a thread to monitor events */
387 if (pthread_create(&g_mon_tid, NULL, zed_udev_monitor, g_mon) != 0) {
388 udev_monitor_unref(g_mon);
389 udev_unref(g_udev);
390 zed_log_msg(LOG_WARNING, "pthread_create failed");
391 return (-1);
392 }
393
394 pthread_setname_np(g_mon_tid, "udev monitor");
395 zed_log_msg(LOG_INFO, "zed_disk_event_init");
396
397 return (0);
398 }
399
400 void
zed_disk_event_fini()401 zed_disk_event_fini()
402 {
403 /* cancel monitor thread at recvmsg() */
404 (void) pthread_cancel(g_mon_tid);
405 (void) pthread_join(g_mon_tid, NULL);
406
407 /* cleanup udev resources */
408 udev_monitor_unref(g_mon);
409 udev_unref(g_udev);
410
411 zed_log_msg(LOG_INFO, "zed_disk_event_fini");
412 }
413
414 #else
415
416 #include "zed_disk_event.h"
417
418 int
zed_disk_event_init()419 zed_disk_event_init()
420 {
421 return (0);
422 }
423
424 void
zed_disk_event_fini()425 zed_disk_event_fini()
426 {
427 }
428
429 #endif /* HAVE_LIBUDEV */
430