1 /*	$NetBSD: dmeventd_mirror.c,v 1.1.1.2 2009/12/02 00:27:12 haad Exp $	*/
2 
3 /*
4  * Copyright (C) 2005 Red Hat, Inc. All rights reserved.
5  *
6  * This file is part of LVM2.
7  *
8  * This copyrighted material is made available to anyone wishing to use,
9  * modify, copy, or redistribute it subject to the terms and conditions
10  * of the GNU Lesser General Public License v.2.1.
11  *
12  * You should have received a copy of the GNU Lesser General Public License
13  * along with this program; if not, write to the Free Software Foundation,
14  * Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
15  */
16 
17 #include "lvm2cmd.h"
18 #include "errors.h"
19 
20 #include <libdevmapper.h>
21 #include <libdevmapper-event.h>
22 #include <errno.h>
23 #include <signal.h>
24 #include <string.h>
25 #include <stdio.h>
26 #include <stdlib.h>
27 #include <pthread.h>
28 #include <unistd.h>
29 
30 #include <syslog.h> /* FIXME Replace syslog with multilog */
31 /* FIXME Missing openlog? */
32 
33 #define ME_IGNORE    0
34 #define ME_INSYNC    1
35 #define ME_FAILURE   2
36 
37 /*
38  * register_device() is called first and performs initialisation.
39  * Only one device may be registered or unregistered at a time.
40  */
41 static pthread_mutex_t _register_mutex = PTHREAD_MUTEX_INITIALIZER;
42 
43 /*
44  * Number of active registrations.
45  */
46 static int _register_count = 0;
47 
48 static struct dm_pool *_mem_pool = NULL;
49 static void *_lvm_handle = NULL;
50 
51 /*
52  * Currently only one event can be processed at a time.
53  */
54 static pthread_mutex_t _event_mutex = PTHREAD_MUTEX_INITIALIZER;
55 
56 static int _get_mirror_event(char *params)
57 {
58 	int i, r = ME_INSYNC;
59 	char **args = NULL;
60 	char *dev_status_str;
61 	char *log_status_str;
62 	char *sync_str;
63 	char *p = NULL;
64 	int log_argc, num_devs;
65 
66 	/*
67 	 * dm core parms:	     0 409600 mirror
68 	 * Mirror core parms:	     2 253:4 253:5 400/400
69 	 * New-style failure params: 1 AA
70 	 * New-style log params:     3 cluster 253:3 A
71 	 *			 or  3 disk 253:3 A
72 	 *			 or  1 core
73 	 */
74 
75 	/* number of devices */
76 	if (!dm_split_words(params, 1, 0, &p))
77 		goto out_parse;
78 
79 	if (!(num_devs = atoi(p)))
80 		goto out_parse;
81 	p += strlen(p) + 1;
82 
83 	/* devices names + "400/400" + "1 AA" + 1 or 3 log parms + NULL */
84 	args = dm_malloc((num_devs + 7) * sizeof(char *));
85 	if (!args || dm_split_words(p, num_devs + 7, 0, args) < num_devs + 5)
86 		goto out_parse;
87 
88 	dev_status_str = args[2 + num_devs];
89 	log_argc = atoi(args[3 + num_devs]);
90 	log_status_str = args[3 + num_devs + log_argc];
91 	sync_str = args[num_devs];
92 
93 	/* Check for bad mirror devices */
94 	for (i = 0; i < num_devs; i++)
95 		if (dev_status_str[i] == 'D') {
96 			syslog(LOG_ERR, "Mirror device, %s, has failed.\n", args[i]);
97 			r = ME_FAILURE;
98 		}
99 
100 	/* Check for bad disk log device */
101 	if (log_argc > 1 && log_status_str[0] == 'D') {
102 		syslog(LOG_ERR, "Log device, %s, has failed.\n",
103 		       args[2 + num_devs + log_argc]);
104 		r = ME_FAILURE;
105 	}
106 
107 	if (r == ME_FAILURE)
108 		goto out;
109 
110 	p = strstr(sync_str, "/");
111 	if (p) {
112 		p[0] = '\0';
113 		if (strcmp(sync_str, p+1))
114 			r = ME_IGNORE;
115 		p[0] = '/';
116 	} else
117 		goto out_parse;
118 
119 out:
120 	if (args)
121 		dm_free(args);
122 	return r;
123 
124 out_parse:
125 	if (args)
126 		dm_free(args);
127 	syslog(LOG_ERR, "Unable to parse mirror status string.");
128 	return ME_IGNORE;
129 }
130 
131 static void _temporary_log_fn(int level,
132 			      const char *file __attribute((unused)),
133 			      int line __attribute((unused)),
134 			      int dm_errno __attribute((unused)),
135 			      const char *format)
136 {
137 	if (!strncmp(format, "WARNING: ", 9) && (level < 5))
138 		syslog(LOG_CRIT, "%s", format);
139 	else
140 		syslog(LOG_DEBUG, "%s", format);
141 }
142 
143 static int _remove_failed_devices(const char *device)
144 {
145 	int r;
146 #define CMD_SIZE 256	/* FIXME Use system restriction */
147 	char cmd_str[CMD_SIZE];
148 	char *vg = NULL, *lv = NULL, *layer = NULL;
149 
150 	if (strlen(device) > 200)  /* FIXME Use real restriction */
151 		return -ENAMETOOLONG;	/* FIXME These return code distinctions are not used so remove them! */
152 
153 	if (!dm_split_lvm_name(_mem_pool, device, &vg, &lv, &layer)) {
154 		syslog(LOG_ERR, "Unable to determine VG name from %s",
155 		       device);
156 		return -ENOMEM;	/* FIXME Replace with generic error return - reason for failure has already got logged */
157 	}
158 
159 	/* FIXME Is any sanity-checking required on %s? */
160 	if (CMD_SIZE <= snprintf(cmd_str, CMD_SIZE, "lvconvert --config devices{ignore_suspended_devices=1} --repair --use-policies %s/%s", vg, lv)) {
161 		/* this error should be caught above, but doesn't hurt to check again */
162 		syslog(LOG_ERR, "Unable to form LVM command: Device name too long");
163 		dm_pool_empty(_mem_pool);  /* FIXME: not safe with multiple threads */
164 		return -ENAMETOOLONG; /* FIXME Replace with generic error return - reason for failure has already got logged */
165 	}
166 
167 	r = lvm2_run(_lvm_handle, cmd_str);
168 
169 	if (r == ECMD_PROCESSED) {
170 		snprintf(cmd_str, CMD_SIZE, "vgreduce --removemissing %s", vg);
171 		if (lvm2_run(_lvm_handle, cmd_str) != 1)
172 			syslog(LOG_ERR, "Unable to remove failed PVs from VG %s", vg);
173 	}
174 
175 	dm_pool_empty(_mem_pool);  /* FIXME: not safe with multiple threads */
176 	return (r == ECMD_PROCESSED) ? 0 : -1;
177 }
178 
179 void process_event(struct dm_task *dmt,
180 		   enum dm_event_mask event __attribute((unused)),
181 		   void **unused __attribute((unused)))
182 {
183 	void *next = NULL;
184 	uint64_t start, length;
185 	char *target_type = NULL;
186 	char *params;
187 	const char *device = dm_task_get_name(dmt);
188 
189 	if (pthread_mutex_trylock(&_event_mutex)) {
190 		syslog(LOG_NOTICE, "Another thread is handling an event.  Waiting...");
191 		pthread_mutex_lock(&_event_mutex);
192 	}
193 	do {
194 		next = dm_get_next_target(dmt, next, &start, &length,
195 					  &target_type, &params);
196 
197 		if (!target_type) {
198 			syslog(LOG_INFO, "%s mapping lost.\n", device);
199 			continue;
200 		}
201 
202 		if (strcmp(target_type, "mirror")) {
203 			syslog(LOG_INFO, "%s has unmirrored portion.\n", device);
204 			continue;
205 		}
206 
207 		switch(_get_mirror_event(params)) {
208 		case ME_INSYNC:
209 			/* FIXME: all we really know is that this
210 			   _part_ of the device is in sync
211 			   Also, this is not an error
212 			*/
213 			syslog(LOG_NOTICE, "%s is now in-sync\n", device);
214 			break;
215 		case ME_FAILURE:
216 			syslog(LOG_ERR, "Device failure in %s\n", device);
217 			if (_remove_failed_devices(device))
218 				/* FIXME Why are all the error return codes unused? Get rid of them? */
219 				syslog(LOG_ERR, "Failed to remove faulty devices in %s\n",
220 				       device);
221 			/* Should check before warning user that device is now linear
222 			else
223 				syslog(LOG_NOTICE, "%s is now a linear device.\n",
224 					device);
225 			*/
226 			break;
227 		case ME_IGNORE:
228 			break;
229 		default:
230 			/* FIXME Provide value then! */
231 			syslog(LOG_INFO, "Unknown event received.\n");
232 		}
233 	} while (next);
234 
235 	pthread_mutex_unlock(&_event_mutex);
236 }
237 
238 int register_device(const char *device,
239 		    const char *uuid __attribute((unused)),
240 		    int major __attribute((unused)),
241 		    int minor __attribute((unused)),
242 		    void **unused __attribute((unused)))
243 {
244 	int r = 0;
245 
246 	pthread_mutex_lock(&_register_mutex);
247 
248 	/*
249 	 * Need some space for allocations.  1024 should be more
250 	 * than enough for what we need (device mapper name splitting)
251 	 */
252 	if (!_mem_pool && !(_mem_pool = dm_pool_create("mirror_dso", 1024)))
253 		goto out;
254 
255 	if (!_lvm_handle) {
256 		lvm2_log_fn(_temporary_log_fn);
257 		if (!(_lvm_handle = lvm2_init())) {
258 			dm_pool_destroy(_mem_pool);
259 			_mem_pool = NULL;
260 			goto out;
261 		}
262 		lvm2_log_level(_lvm_handle, LVM2_LOG_SUPPRESS);
263 		/* FIXME Temporary: move to dmeventd core */
264 		lvm2_run(_lvm_handle, "_memlock_inc");
265 	}
266 
267 	syslog(LOG_INFO, "Monitoring mirror device %s for events\n", device);
268 
269 	_register_count++;
270 	r = 1;
271 
272 out:
273 	pthread_mutex_unlock(&_register_mutex);
274 
275 	return r;
276 }
277 
278 int unregister_device(const char *device,
279 		      const char *uuid __attribute((unused)),
280 		      int major __attribute((unused)),
281 		      int minor __attribute((unused)),
282 		      void **unused __attribute((unused)))
283 {
284 	pthread_mutex_lock(&_register_mutex);
285 
286 	syslog(LOG_INFO, "No longer monitoring mirror device %s for events\n",
287 	       device);
288 
289 	if (!--_register_count) {
290 		dm_pool_destroy(_mem_pool);
291 		_mem_pool = NULL;
292 		lvm2_run(_lvm_handle, "_memlock_dec");
293 		lvm2_exit(_lvm_handle);
294 		_lvm_handle = NULL;
295 	}
296 
297 	pthread_mutex_unlock(&_register_mutex);
298 
299 	return 1;
300 }
301