xref: /freebsd/sys/contrib/openzfs/cmd/zed/zed_conf.c (revision 22649d4dba730d46244fd2dff4fd174903c8379f)
1 // SPDX-License-Identifier: CDDL-1.0
2 /*
3  * This file and its contents are supplied under the terms of the
4  * Common Development and Distribution License ("CDDL"), version 1.0.
5  * You may only use this file in accordance with the terms of version
6  * 1.0 of the CDDL.
7  *
8  * A full copy of the text of the CDDL should have accompanied this
9  * source.  A copy of the CDDL is also available via the Internet at
10  * https://opensource.org/license/CDDL-1.0.
11  */
12 /*
13  * This file is part of the ZFS Event Daemon (ZED).
14  *
15  * Developed at Lawrence Livermore National Laboratory (LLNL-CODE-403049).
16  * Copyright (C) 2013-2014 Lawrence Livermore National Security, LLC.
17  */
18 
19 #include <assert.h>
20 #include <ctype.h>
21 #include <dirent.h>
22 #include <errno.h>
23 #include <fcntl.h>
24 #include <libgen.h>
25 #include <limits.h>
26 #include <stdio.h>
27 #include <stdlib.h>
28 #include <string.h>
29 #include <sys/types.h>
30 #include <sys/stat.h>
31 #include <sys/uio.h>
32 #include <unistd.h>
33 #include "zed.h"
34 #include "zed_conf.h"
35 #include "zed_file.h"
36 #include "zed_log.h"
37 #include "zed_strings.h"
38 
39 /*
40  * Initialise the configuration with default values.
41  */
42 void
zed_conf_init(struct zed_conf * zcp)43 zed_conf_init(struct zed_conf *zcp)
44 {
45 	memset(zcp, 0, sizeof (*zcp));
46 
47 	/* zcp->zfs_hdl opened in zed_event_init() */
48 	/* zcp->zedlets created in zed_conf_scan_dir() */
49 
50 	zcp->pid_fd = -1;		/* opened in zed_conf_write_pid() */
51 	zcp->state_fd = -1;		/* opened in zed_conf_open_state() */
52 	zcp->zevent_fd = -1;		/* opened in zed_event_init() */
53 
54 	zcp->max_jobs = 16;
55 	zcp->max_zevent_buf_len = 1 << 20;
56 
57 	if (!(zcp->pid_file = strdup(ZED_PID_FILE)) ||
58 	    !(zcp->zedlet_dir = strdup(ZED_ZEDLET_DIR)) ||
59 	    !(zcp->state_file = strdup(ZED_STATE_FILE)))
60 		zed_log_die("Failed to create conf: %s", strerror(errno));
61 }
62 
63 /*
64  * Destroy the configuration [zcp].
65  *
66  * Note: zfs_hdl & zevent_fd are destroyed via zed_event_fini().
67  */
68 void
zed_conf_destroy(struct zed_conf * zcp)69 zed_conf_destroy(struct zed_conf *zcp)
70 {
71 	if (zcp->state_fd >= 0) {
72 		if (close(zcp->state_fd) < 0)
73 			zed_log_msg(LOG_WARNING,
74 			    "Failed to close state file \"%s\": %s",
75 			    zcp->state_file, strerror(errno));
76 		zcp->state_fd = -1;
77 	}
78 	if (zcp->pid_file) {
79 		if ((unlink(zcp->pid_file) < 0) && (errno != ENOENT))
80 			zed_log_msg(LOG_WARNING,
81 			    "Failed to remove PID file \"%s\": %s",
82 			    zcp->pid_file, strerror(errno));
83 	}
84 	if (zcp->pid_fd >= 0) {
85 		if (close(zcp->pid_fd) < 0)
86 			zed_log_msg(LOG_WARNING,
87 			    "Failed to close PID file \"%s\": %s",
88 			    zcp->pid_file, strerror(errno));
89 		zcp->pid_fd = -1;
90 	}
91 	if (zcp->pid_file) {
92 		free(zcp->pid_file);
93 		zcp->pid_file = NULL;
94 	}
95 	if (zcp->zedlet_dir) {
96 		free(zcp->zedlet_dir);
97 		zcp->zedlet_dir = NULL;
98 	}
99 	if (zcp->state_file) {
100 		free(zcp->state_file);
101 		zcp->state_file = NULL;
102 	}
103 	if (zcp->zedlets) {
104 		zed_strings_destroy(zcp->zedlets);
105 		zcp->zedlets = NULL;
106 	}
107 }
108 
109 /*
110  * Display command-line help and exit.
111  *
112  * If [got_err] is 0, output to stdout and exit normally;
113  * otherwise, output to stderr and exit with a failure status.
114  */
115 static void
_zed_conf_display_help(const char * prog,boolean_t got_err)116 _zed_conf_display_help(const char *prog, boolean_t got_err)
117 {
118 	struct opt { const char *o, *d, *v; };
119 
120 	FILE *fp = got_err ? stderr : stdout;
121 
122 	struct opt *oo;
123 	struct opt iopts[] = {
124 		{ .o = "-h", .d = "Display help" },
125 		{ .o = "-L", .d = "Display license information" },
126 		{ .o = "-V", .d = "Display version information" },
127 		{},
128 	};
129 	struct opt nopts[] = {
130 		{ .o = "-v", .d = "Be verbose" },
131 		{ .o = "-f", .d = "Force daemon to run" },
132 		{ .o = "-F", .d = "Run daemon in the foreground" },
133 		{ .o = "-I",
134 		    .d = "Idle daemon until kernel module is (re)loaded" },
135 		{ .o = "-M", .d = "Lock all pages in memory" },
136 		{ .o = "-P", .d = "$PATH for ZED to use (only used by ZTS)" },
137 		{ .o = "-Z", .d = "Zero state file" },
138 		{},
139 	};
140 	struct opt vopts[] = {
141 		{ .o = "-d DIR", .d = "Read enabled ZEDLETs from DIR.",
142 		    .v = ZED_ZEDLET_DIR },
143 		{ .o = "-p FILE", .d = "Write daemon's PID to FILE.",
144 		    .v = ZED_PID_FILE },
145 		{ .o = "-s FILE", .d = "Write daemon's state to FILE.",
146 		    .v = ZED_STATE_FILE },
147 		{ .o = "-j JOBS", .d = "Start at most JOBS at once.",
148 		    .v = "16" },
149 		{ .o = "-b LEN", .d = "Cap kernel event buffer at LEN entries.",
150 		    .v = "1048576" },
151 		{},
152 	};
153 
154 	fprintf(fp, "Usage: %s [OPTION]...\n", (prog ? prog : "zed"));
155 	fprintf(fp, "\n");
156 	for (oo = iopts; oo->o; ++oo)
157 		fprintf(fp, "    %*s %s\n", -8, oo->o, oo->d);
158 	fprintf(fp, "\n");
159 	for (oo = nopts; oo->o; ++oo)
160 		fprintf(fp, "    %*s %s\n", -8, oo->o, oo->d);
161 	fprintf(fp, "\n");
162 	for (oo = vopts; oo->o; ++oo)
163 		fprintf(fp, "    %*s %s [%s]\n", -8, oo->o, oo->d, oo->v);
164 	fprintf(fp, "\n");
165 
166 	exit(got_err ? EXIT_FAILURE : EXIT_SUCCESS);
167 }
168 
169 /*
170  * Display license information to stdout and exit.
171  */
172 static void
_zed_conf_display_license(void)173 _zed_conf_display_license(void)
174 {
175 	printf(
176 	    "The ZFS Event Daemon (ZED) is distributed under the terms of the\n"
177 	    "  Common Development and Distribution License (CDDL-1.0)\n"
178 	    "  <http://opensource.org/licenses/CDDL-1.0>.\n"
179 	    "\n"
180 	    "Developed at Lawrence Livermore National Laboratory"
181 	    " (LLNL-CODE-403049).\n"
182 	    "\n");
183 
184 	exit(EXIT_SUCCESS);
185 }
186 
187 /*
188  * Display version information to stdout and exit.
189  */
190 static void
_zed_conf_display_version(void)191 _zed_conf_display_version(void)
192 {
193 	printf("%s-%s-%s\n",
194 	    ZFS_META_NAME, ZFS_META_VERSION, ZFS_META_RELEASE);
195 
196 	exit(EXIT_SUCCESS);
197 }
198 
199 /*
200  * Copy the [path] string to the [resultp] ptr.
201  * If [path] is not an absolute path, prefix it with the current working dir.
202  * If [resultp] is non-null, free its existing string before assignment.
203  */
204 static void
_zed_conf_parse_path(char ** resultp,const char * path)205 _zed_conf_parse_path(char **resultp, const char *path)
206 {
207 	char buf[PATH_MAX];
208 
209 	assert(resultp != NULL);
210 	assert(path != NULL);
211 
212 	if (*resultp)
213 		free(*resultp);
214 
215 	if (path[0] == '/') {
216 		*resultp = strdup(path);
217 	} else {
218 		if (!getcwd(buf, sizeof (buf)))
219 			zed_log_die("Failed to get current working dir: %s",
220 			    strerror(errno));
221 
222 		if (strlcat(buf, "/", sizeof (buf)) >= sizeof (buf) ||
223 		    strlcat(buf, path, sizeof (buf)) >= sizeof (buf))
224 			zed_log_die("Failed to copy path: %s",
225 			    strerror(ENAMETOOLONG));
226 
227 		*resultp = strdup(buf);
228 	}
229 
230 	if (!*resultp)
231 		zed_log_die("Failed to copy path: %s", strerror(ENOMEM));
232 }
233 
234 /*
235  * Parse the command-line options into the configuration [zcp].
236  */
237 void
zed_conf_parse_opts(struct zed_conf * zcp,int argc,char ** argv)238 zed_conf_parse_opts(struct zed_conf *zcp, int argc, char **argv)
239 {
240 	const char * const opts = ":hLVd:p:P:s:vfFMZIj:b:";
241 	int opt;
242 	unsigned long raw;
243 
244 	if (!zcp || !argv || !argv[0])
245 		zed_log_die("Failed to parse options: Internal error");
246 
247 	opterr = 0;			/* suppress default getopt err msgs */
248 
249 	while ((opt = getopt(argc, argv, opts)) != -1) {
250 		switch (opt) {
251 		case 'h':
252 			_zed_conf_display_help(argv[0], B_FALSE);
253 			break;
254 		case 'L':
255 			_zed_conf_display_license();
256 			break;
257 		case 'V':
258 			_zed_conf_display_version();
259 			break;
260 		case 'd':
261 			_zed_conf_parse_path(&zcp->zedlet_dir, optarg);
262 			break;
263 		case 'I':
264 			zcp->do_idle = 1;
265 			break;
266 		case 'p':
267 			_zed_conf_parse_path(&zcp->pid_file, optarg);
268 			break;
269 		case 'P':
270 			_zed_conf_parse_path(&zcp->path, optarg);
271 			break;
272 		case 's':
273 			_zed_conf_parse_path(&zcp->state_file, optarg);
274 			break;
275 		case 'v':
276 			zcp->do_verbose = 1;
277 			break;
278 		case 'f':
279 			zcp->do_force = 1;
280 			break;
281 		case 'F':
282 			zcp->do_foreground = 1;
283 			break;
284 		case 'M':
285 			zcp->do_memlock = 1;
286 			break;
287 		case 'Z':
288 			zcp->do_zero = 1;
289 			break;
290 		case 'j':
291 			errno = 0;
292 			raw = strtoul(optarg, NULL, 0);
293 			if (errno == ERANGE || raw > INT16_MAX) {
294 				zed_log_die("%lu is too many jobs", raw);
295 			} if (raw == 0) {
296 				zed_log_die("0 jobs makes no sense");
297 			} else {
298 				zcp->max_jobs = raw;
299 			}
300 			break;
301 		case 'b':
302 			errno = 0;
303 			raw = strtoul(optarg, NULL, 0);
304 			if (errno == ERANGE || raw > INT32_MAX) {
305 				zed_log_die("%lu is too large", raw);
306 			} if (raw == 0) {
307 				zcp->max_zevent_buf_len = INT32_MAX;
308 			} else {
309 				zcp->max_zevent_buf_len = raw;
310 			}
311 			break;
312 		case '?':
313 		default:
314 			if (optopt == '?')
315 				_zed_conf_display_help(argv[0], B_FALSE);
316 
317 			fprintf(stderr, "%s: Invalid option '-%c'\n\n",
318 			    argv[0], optopt);
319 			_zed_conf_display_help(argv[0], B_TRUE);
320 			break;
321 		}
322 	}
323 }
324 
325 /*
326  * Scan the [zcp] zedlet_dir for files to exec based on the event class.
327  * Files must be executable by user, but not writable by group or other.
328  * Dotfiles are ignored.
329  *
330  * Return 0 on success with an updated set of zedlets,
331  * or -1 on error with errno set.
332  */
333 int
zed_conf_scan_dir(struct zed_conf * zcp)334 zed_conf_scan_dir(struct zed_conf *zcp)
335 {
336 	zed_strings_t *zedlets;
337 	DIR *dirp;
338 	struct dirent *direntp;
339 	char pathname[PATH_MAX];
340 	struct stat st;
341 	int n;
342 
343 	if (!zcp) {
344 		errno = EINVAL;
345 		zed_log_msg(LOG_ERR, "Failed to scan zedlet dir: %s",
346 		    strerror(errno));
347 		return (-1);
348 	}
349 	zedlets = zed_strings_create();
350 	if (!zedlets) {
351 		errno = ENOMEM;
352 		zed_log_msg(LOG_WARNING, "Failed to scan dir \"%s\": %s",
353 		    zcp->zedlet_dir, strerror(errno));
354 		return (-1);
355 	}
356 	dirp = opendir(zcp->zedlet_dir);
357 	if (!dirp) {
358 		int errno_bak = errno;
359 		zed_log_msg(LOG_WARNING, "Failed to open dir \"%s\": %s",
360 		    zcp->zedlet_dir, strerror(errno));
361 		zed_strings_destroy(zedlets);
362 		errno = errno_bak;
363 		return (-1);
364 	}
365 	while ((direntp = readdir(dirp))) {
366 		if (direntp->d_name[0] == '.')
367 			continue;
368 
369 		n = snprintf(pathname, sizeof (pathname),
370 		    "%s/%s", zcp->zedlet_dir, direntp->d_name);
371 		if ((n < 0) || (n >= sizeof (pathname))) {
372 			zed_log_msg(LOG_WARNING, "Failed to stat \"%s\": %s",
373 			    direntp->d_name, strerror(ENAMETOOLONG));
374 			continue;
375 		}
376 		if (stat(pathname, &st) < 0) {
377 			zed_log_msg(LOG_WARNING, "Failed to stat \"%s\": %s",
378 			    pathname, strerror(errno));
379 			continue;
380 		}
381 		if (!S_ISREG(st.st_mode)) {
382 			zed_log_msg(LOG_INFO,
383 			    "Ignoring \"%s\": not a regular file",
384 			    direntp->d_name);
385 			continue;
386 		}
387 		if ((st.st_uid != 0) && !zcp->do_force) {
388 			zed_log_msg(LOG_NOTICE,
389 			    "Ignoring \"%s\": not owned by root",
390 			    direntp->d_name);
391 			continue;
392 		}
393 		if (!(st.st_mode & S_IXUSR)) {
394 			zed_log_msg(LOG_INFO,
395 			    "Ignoring \"%s\": not executable by user",
396 			    direntp->d_name);
397 			continue;
398 		}
399 		if ((st.st_mode & S_IWGRP) && !zcp->do_force) {
400 			zed_log_msg(LOG_NOTICE,
401 			    "Ignoring \"%s\": writable by group",
402 			    direntp->d_name);
403 			continue;
404 		}
405 		if ((st.st_mode & S_IWOTH) && !zcp->do_force) {
406 			zed_log_msg(LOG_NOTICE,
407 			    "Ignoring \"%s\": writable by other",
408 			    direntp->d_name);
409 			continue;
410 		}
411 		if (zed_strings_add(zedlets, NULL, direntp->d_name) < 0) {
412 			zed_log_msg(LOG_WARNING,
413 			    "Failed to register \"%s\": %s",
414 			    direntp->d_name, strerror(errno));
415 			continue;
416 		}
417 		if (zcp->do_verbose)
418 			zed_log_msg(LOG_INFO,
419 			    "Registered zedlet \"%s\"", direntp->d_name);
420 	}
421 	if (closedir(dirp) < 0) {
422 		int errno_bak = errno;
423 		zed_log_msg(LOG_WARNING, "Failed to close dir \"%s\": %s",
424 		    zcp->zedlet_dir, strerror(errno));
425 		zed_strings_destroy(zedlets);
426 		errno = errno_bak;
427 		return (-1);
428 	}
429 	if (zcp->zedlets)
430 		zed_strings_destroy(zcp->zedlets);
431 
432 	zcp->zedlets = zedlets;
433 	return (0);
434 }
435 
436 /*
437  * Write the PID file specified in [zcp].
438  * Return 0 on success, -1 on error.
439  *
440  * This must be called after fork()ing to become a daemon (so the correct PID
441  * is recorded), but before daemonization is complete and the parent process
442  * exits (for synchronization with systemd).
443  */
444 int
zed_conf_write_pid(struct zed_conf * zcp)445 zed_conf_write_pid(struct zed_conf *zcp)
446 {
447 	char buf[PATH_MAX];
448 	int n;
449 	char *p;
450 	mode_t mask;
451 	int rv;
452 
453 	if (!zcp || !zcp->pid_file) {
454 		errno = EINVAL;
455 		zed_log_msg(LOG_ERR, "Failed to create PID file: %s",
456 		    strerror(errno));
457 		return (-1);
458 	}
459 	assert(zcp->pid_fd == -1);
460 	/*
461 	 * Create PID file directory if needed.
462 	 */
463 	n = strlcpy(buf, zcp->pid_file, sizeof (buf));
464 	if (n >= sizeof (buf)) {
465 		errno = ENAMETOOLONG;
466 		zed_log_msg(LOG_ERR, "Failed to create PID file: %s",
467 		    strerror(errno));
468 		goto err;
469 	}
470 	p = strrchr(buf, '/');
471 	if (p)
472 		*p = '\0';
473 
474 	if ((mkdirp(buf, 0755) < 0) && (errno != EEXIST)) {
475 		zed_log_msg(LOG_ERR, "Failed to create directory \"%s\": %s",
476 		    buf, strerror(errno));
477 		goto err;
478 	}
479 	/*
480 	 * Obtain PID file lock.
481 	 */
482 	mask = umask(0);
483 	umask(mask | 022);
484 	zcp->pid_fd = open(zcp->pid_file, O_RDWR | O_CREAT | O_CLOEXEC, 0644);
485 	umask(mask);
486 	if (zcp->pid_fd < 0) {
487 		zed_log_msg(LOG_ERR, "Failed to open PID file \"%s\": %s",
488 		    zcp->pid_file, strerror(errno));
489 		goto err;
490 	}
491 	rv = zed_file_lock(zcp->pid_fd);
492 	if (rv < 0) {
493 		zed_log_msg(LOG_ERR, "Failed to lock PID file \"%s\": %s",
494 		    zcp->pid_file, strerror(errno));
495 		goto err;
496 	} else if (rv > 0) {
497 		pid_t pid = zed_file_is_locked(zcp->pid_fd);
498 		if (pid < 0) {
499 			zed_log_msg(LOG_ERR,
500 			    "Failed to test lock on PID file \"%s\"",
501 			    zcp->pid_file);
502 		} else if (pid > 0) {
503 			zed_log_msg(LOG_ERR,
504 			    "Found PID %d bound to PID file \"%s\"",
505 			    pid, zcp->pid_file);
506 		} else {
507 			zed_log_msg(LOG_ERR,
508 			    "Inconsistent lock state on PID file \"%s\"",
509 			    zcp->pid_file);
510 		}
511 		goto err;
512 	}
513 	/*
514 	 * Write PID file.
515 	 */
516 	n = snprintf(buf, sizeof (buf), "%d\n", (int)getpid());
517 	if ((n < 0) || (n >= sizeof (buf))) {
518 		errno = ERANGE;
519 		zed_log_msg(LOG_ERR, "Failed to write PID file \"%s\": %s",
520 		    zcp->pid_file, strerror(errno));
521 	} else if (write(zcp->pid_fd, buf, n) != n) {
522 		zed_log_msg(LOG_ERR, "Failed to write PID file \"%s\": %s",
523 		    zcp->pid_file, strerror(errno));
524 	} else if (fdatasync(zcp->pid_fd) < 0) {
525 		zed_log_msg(LOG_ERR, "Failed to sync PID file \"%s\": %s",
526 		    zcp->pid_file, strerror(errno));
527 	} else {
528 		return (0);
529 	}
530 
531 err:
532 	if (zcp->pid_fd >= 0) {
533 		(void) close(zcp->pid_fd);
534 		zcp->pid_fd = -1;
535 	}
536 	return (-1);
537 }
538 
539 /*
540  * Open and lock the [zcp] state_file.
541  * Return 0 on success, -1 on error.
542  *
543  * FIXME: Move state information into kernel.
544  */
545 int
zed_conf_open_state(struct zed_conf * zcp)546 zed_conf_open_state(struct zed_conf *zcp)
547 {
548 	char dirbuf[PATH_MAX];
549 	int n;
550 	char *p;
551 	int rv;
552 
553 	if (!zcp || !zcp->state_file) {
554 		errno = EINVAL;
555 		zed_log_msg(LOG_ERR, "Failed to open state file: %s",
556 		    strerror(errno));
557 		return (-1);
558 	}
559 	n = strlcpy(dirbuf, zcp->state_file, sizeof (dirbuf));
560 	if (n >= sizeof (dirbuf)) {
561 		errno = ENAMETOOLONG;
562 		zed_log_msg(LOG_WARNING, "Failed to open state file: %s",
563 		    strerror(errno));
564 		return (-1);
565 	}
566 	p = strrchr(dirbuf, '/');
567 	if (p)
568 		*p = '\0';
569 
570 	if ((mkdirp(dirbuf, 0755) < 0) && (errno != EEXIST)) {
571 		zed_log_msg(LOG_WARNING,
572 		    "Failed to create directory \"%s\": %s",
573 		    dirbuf, strerror(errno));
574 		return (-1);
575 	}
576 	if (zcp->state_fd >= 0) {
577 		if (close(zcp->state_fd) < 0) {
578 			zed_log_msg(LOG_WARNING,
579 			    "Failed to close state file \"%s\": %s",
580 			    zcp->state_file, strerror(errno));
581 			return (-1);
582 		}
583 	}
584 	if (zcp->do_zero)
585 		(void) unlink(zcp->state_file);
586 
587 	zcp->state_fd = open(zcp->state_file,
588 	    O_RDWR | O_CREAT | O_CLOEXEC, 0644);
589 	if (zcp->state_fd < 0) {
590 		zed_log_msg(LOG_WARNING, "Failed to open state file \"%s\": %s",
591 		    zcp->state_file, strerror(errno));
592 		return (-1);
593 	}
594 	rv = zed_file_lock(zcp->state_fd);
595 	if (rv < 0) {
596 		zed_log_msg(LOG_WARNING, "Failed to lock state file \"%s\": %s",
597 		    zcp->state_file, strerror(errno));
598 		return (-1);
599 	}
600 	if (rv > 0) {
601 		pid_t pid = zed_file_is_locked(zcp->state_fd);
602 		if (pid < 0) {
603 			zed_log_msg(LOG_WARNING,
604 			    "Failed to test lock on state file \"%s\"",
605 			    zcp->state_file);
606 		} else if (pid > 0) {
607 			zed_log_msg(LOG_WARNING,
608 			    "Found PID %d bound to state file \"%s\"",
609 			    pid, zcp->state_file);
610 		} else {
611 			zed_log_msg(LOG_WARNING,
612 			    "Inconsistent lock state on state file \"%s\"",
613 			    zcp->state_file);
614 		}
615 		return (-1);
616 	}
617 	return (0);
618 }
619 
620 /*
621  * Read the opened [zcp] state_file to obtain the eid & etime of the last event
622  * processed.  Write the state from the last event to the [eidp] & [etime] args
623  * passed by reference.  Note that etime[] is an array of size 2.
624  * Return 0 on success, -1 on error.
625  */
626 int
zed_conf_read_state(struct zed_conf * zcp,uint64_t * eidp,int64_t etime[])627 zed_conf_read_state(struct zed_conf *zcp, uint64_t *eidp, int64_t etime[])
628 {
629 	ssize_t len;
630 	struct iovec iov[3];
631 	ssize_t n;
632 
633 	if (!zcp || !eidp || !etime) {
634 		errno = EINVAL;
635 		zed_log_msg(LOG_ERR,
636 		    "Failed to read state file: %s", strerror(errno));
637 		return (-1);
638 	}
639 	if (lseek(zcp->state_fd, 0, SEEK_SET) == (off_t)-1) {
640 		zed_log_msg(LOG_WARNING,
641 		    "Failed to reposition state file offset: %s",
642 		    strerror(errno));
643 		return (-1);
644 	}
645 	len = 0;
646 	iov[0].iov_base = eidp;
647 	len += iov[0].iov_len = sizeof (*eidp);
648 	iov[1].iov_base = &etime[0];
649 	len += iov[1].iov_len = sizeof (etime[0]);
650 	iov[2].iov_base = &etime[1];
651 	len += iov[2].iov_len = sizeof (etime[1]);
652 
653 	n = readv(zcp->state_fd, iov, 3);
654 	if (n == 0) {
655 		*eidp = 0;
656 	} else if (n < 0) {
657 		zed_log_msg(LOG_WARNING,
658 		    "Failed to read state file \"%s\": %s",
659 		    zcp->state_file, strerror(errno));
660 		return (-1);
661 	} else if (n != len) {
662 		errno = EIO;
663 		zed_log_msg(LOG_WARNING,
664 		    "Failed to read state file \"%s\": Read %zd of %zd bytes",
665 		    zcp->state_file, n, len);
666 		return (-1);
667 	}
668 	return (0);
669 }
670 
671 /*
672  * Write the [eid] & [etime] of the last processed event to the opened
673  * [zcp] state_file.  Note that etime[] is an array of size 2.
674  * Return 0 on success, -1 on error.
675  */
676 int
zed_conf_write_state(struct zed_conf * zcp,uint64_t eid,int64_t etime[])677 zed_conf_write_state(struct zed_conf *zcp, uint64_t eid, int64_t etime[])
678 {
679 	ssize_t len;
680 	struct iovec iov[3];
681 	ssize_t n;
682 
683 	if (!zcp) {
684 		errno = EINVAL;
685 		zed_log_msg(LOG_ERR,
686 		    "Failed to write state file: %s", strerror(errno));
687 		return (-1);
688 	}
689 	if (lseek(zcp->state_fd, 0, SEEK_SET) == (off_t)-1) {
690 		zed_log_msg(LOG_WARNING,
691 		    "Failed to reposition state file offset: %s",
692 		    strerror(errno));
693 		return (-1);
694 	}
695 	len = 0;
696 	iov[0].iov_base = &eid;
697 	len += iov[0].iov_len = sizeof (eid);
698 	iov[1].iov_base = &etime[0];
699 	len += iov[1].iov_len = sizeof (etime[0]);
700 	iov[2].iov_base = &etime[1];
701 	len += iov[2].iov_len = sizeof (etime[1]);
702 
703 	n = writev(zcp->state_fd, iov, 3);
704 	if (n < 0) {
705 		zed_log_msg(LOG_WARNING,
706 		    "Failed to write state file \"%s\": %s",
707 		    zcp->state_file, strerror(errno));
708 		return (-1);
709 	}
710 	if (n != len) {
711 		errno = EIO;
712 		zed_log_msg(LOG_WARNING,
713 		    "Failed to write state file \"%s\": Wrote %zd of %zd bytes",
714 		    zcp->state_file, n, len);
715 		return (-1);
716 	}
717 	if (fdatasync(zcp->state_fd) < 0) {
718 		zed_log_msg(LOG_WARNING,
719 		    "Failed to sync state file \"%s\": %s",
720 		    zcp->state_file, strerror(errno));
721 		return (-1);
722 	}
723 	return (0);
724 }
725