1/*-
2 * SPDX-License-Identifier: BSD-2-Clause
3 *
4 * Copyright (c) 2009 The FreeBSD Foundation
5 * Copyright (c) 2010-2011 Pawel Jakub Dawidek <pawel@dawidek.net>
6 * All rights reserved.
7 *
8 * This software was developed by Pawel Jakub Dawidek under sponsorship from
9 * the FreeBSD Foundation.
10 *
11 * Redistribution and use in source and binary forms, with or without
12 * modification, are permitted provided that the following conditions
13 * are met:
14 * 1. Redistributions of source code must retain the above copyright
15 *    notice, this list of conditions and the following disclaimer.
16 * 2. Redistributions in binary form must reproduce the above copyright
17 *    notice, this list of conditions and the following disclaimer in the
18 *    documentation and/or other materials provided with the distribution.
19 *
20 * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
21 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23 * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
24 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
25 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
26 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
27 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
28 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
29 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
30 * SUCH DAMAGE.
31 */
32
33#include <sys/types.h>
34#include <sys/time.h>
35#include <sys/bio.h>
36#include <sys/disk.h>
37#include <sys/stat.h>
38
39#include <geom/gate/g_gate.h>
40
41#include <err.h>
42#include <errno.h>
43#include <fcntl.h>
44#include <libgeom.h>
45#include <pthread.h>
46#include <signal.h>
47#include <stdint.h>
48#include <stdio.h>
49#include <string.h>
50#include <sysexits.h>
51#include <unistd.h>
52
53#include <activemap.h>
54#include <nv.h>
55#include <rangelock.h>
56
57#include "control.h"
58#include "event.h"
59#include "hast.h"
60#include "hast_proto.h"
61#include "hastd.h"
62#include "hooks.h"
63#include "metadata.h"
64#include "proto.h"
65#include "pjdlog.h"
66#include "refcnt.h"
67#include "subr.h"
68#include "synch.h"
69
70/* The is only one remote component for now. */
71#define	ISREMOTE(no)	((no) == 1)
72
73struct hio {
74	/*
75	 * Number of components we are still waiting for.
76	 * When this field goes to 0, we can send the request back to the
77	 * kernel. Each component has to decrease this counter by one
78	 * even on failure.
79	 */
80	refcnt_t		 hio_countdown;
81	/*
82	 * Each component has a place to store its own error.
83	 * Once the request is handled by all components we can decide if the
84	 * request overall is successful or not.
85	 */
86	int			*hio_errors;
87	/*
88	 * Structure used to communicate with GEOM Gate class.
89	 */
90	struct g_gate_ctl_io	 hio_ggio;
91	/*
92	 * Request was already confirmed to GEOM Gate.
93	 */
94	bool			 hio_done;
95	/*
96	 * Number of components we are still waiting before sending write
97	 * completion ack to GEOM Gate. Used for memsync.
98	 */
99	refcnt_t		 hio_writecount;
100	/*
101	 * Memsync request was acknowledged by remote.
102	 */
103	bool			 hio_memsyncacked;
104	/*
105	 * Remember replication from the time the request was initiated,
106	 * so we won't get confused when replication changes on reload.
107	 */
108	int			 hio_replication;
109	TAILQ_ENTRY(hio)	*hio_next;
110};
111#define	hio_free_next	hio_next[0]
112#define	hio_done_next	hio_next[0]
113
114/*
115 * Free list holds unused structures. When free list is empty, we have to wait
116 * until some in-progress requests are freed.
117 */
118static TAILQ_HEAD(, hio) hio_free_list;
119static size_t hio_free_list_size;
120static pthread_mutex_t hio_free_list_lock;
121static pthread_cond_t hio_free_list_cond;
122/*
123 * There is one send list for every component. One requests is placed on all
124 * send lists - each component gets the same request, but each component is
125 * responsible for managing his own send list.
126 */
127static TAILQ_HEAD(, hio) *hio_send_list;
128static size_t *hio_send_list_size;
129static pthread_mutex_t *hio_send_list_lock;
130static pthread_cond_t *hio_send_list_cond;
131#define	hio_send_local_list_size	hio_send_list_size[0]
132#define	hio_send_remote_list_size	hio_send_list_size[1]
133/*
134 * There is one recv list for every component, although local components don't
135 * use recv lists as local requests are done synchronously.
136 */
137static TAILQ_HEAD(, hio) *hio_recv_list;
138static size_t *hio_recv_list_size;
139static pthread_mutex_t *hio_recv_list_lock;
140static pthread_cond_t *hio_recv_list_cond;
141#define	hio_recv_remote_list_size	hio_recv_list_size[1]
142/*
143 * Request is placed on done list by the slowest component (the one that
144 * decreased hio_countdown from 1 to 0).
145 */
146static TAILQ_HEAD(, hio) hio_done_list;
147static size_t hio_done_list_size;
148static pthread_mutex_t hio_done_list_lock;
149static pthread_cond_t hio_done_list_cond;
150/*
151 * Structure below are for interaction with sync thread.
152 */
153static bool sync_inprogress;
154static pthread_mutex_t sync_lock;
155static pthread_cond_t sync_cond;
156/*
157 * The lock below allows to synchornize access to remote connections.
158 */
159static pthread_rwlock_t *hio_remote_lock;
160
161/*
162 * Lock to synchronize metadata updates. Also synchronize access to
163 * hr_primary_localcnt and hr_primary_remotecnt fields.
164 */
165static pthread_mutex_t metadata_lock;
166
167/*
168 * Maximum number of outstanding I/O requests.
169 */
170#define	HAST_HIO_MAX	256
171/*
172 * Number of components. At this point there are only two components: local
173 * and remote, but in the future it might be possible to use multiple local
174 * and remote components.
175 */
176#define	HAST_NCOMPONENTS	2
177
178#define	ISCONNECTED(res, no)	\
179	((res)->hr_remotein != NULL && (res)->hr_remoteout != NULL)
180
181#define	QUEUE_INSERT1(hio, name, ncomp)	do {				\
182	mtx_lock(&hio_##name##_list_lock[(ncomp)]);			\
183	if (TAILQ_EMPTY(&hio_##name##_list[(ncomp)]))			\
184		cv_broadcast(&hio_##name##_list_cond[(ncomp)]);		\
185	TAILQ_INSERT_TAIL(&hio_##name##_list[(ncomp)], (hio),		\
186	    hio_next[(ncomp)]);						\
187	hio_##name##_list_size[(ncomp)]++;				\
188	mtx_unlock(&hio_##name##_list_lock[(ncomp)]);			\
189} while (0)
190#define	QUEUE_INSERT2(hio, name)	do {				\
191	mtx_lock(&hio_##name##_list_lock);				\
192	if (TAILQ_EMPTY(&hio_##name##_list))				\
193		cv_broadcast(&hio_##name##_list_cond);			\
194	TAILQ_INSERT_TAIL(&hio_##name##_list, (hio), hio_##name##_next);\
195	hio_##name##_list_size++;					\
196	mtx_unlock(&hio_##name##_list_lock);				\
197} while (0)
198#define	QUEUE_TAKE1(hio, name, ncomp, timeout)	do {			\
199	bool _last;							\
200									\
201	mtx_lock(&hio_##name##_list_lock[(ncomp)]);			\
202	_last = false;							\
203	while (((hio) = TAILQ_FIRST(&hio_##name##_list[(ncomp)])) == NULL && !_last) { \
204		cv_timedwait(&hio_##name##_list_cond[(ncomp)],		\
205		    &hio_##name##_list_lock[(ncomp)], (timeout));	\
206		if ((timeout) != 0)					\
207			_last = true;					\
208	}								\
209	if (hio != NULL) {						\
210		PJDLOG_ASSERT(hio_##name##_list_size[(ncomp)] != 0);	\
211		hio_##name##_list_size[(ncomp)]--;			\
212		TAILQ_REMOVE(&hio_##name##_list[(ncomp)], (hio),	\
213		    hio_next[(ncomp)]);					\
214	}								\
215	mtx_unlock(&hio_##name##_list_lock[(ncomp)]);			\
216} while (0)
217#define	QUEUE_TAKE2(hio, name)	do {					\
218	mtx_lock(&hio_##name##_list_lock);				\
219	while (((hio) = TAILQ_FIRST(&hio_##name##_list)) == NULL) {	\
220		cv_wait(&hio_##name##_list_cond,			\
221		    &hio_##name##_list_lock);				\
222	}								\
223	PJDLOG_ASSERT(hio_##name##_list_size != 0);			\
224	hio_##name##_list_size--;					\
225	TAILQ_REMOVE(&hio_##name##_list, (hio), hio_##name##_next);	\
226	mtx_unlock(&hio_##name##_list_lock);				\
227} while (0)
228
229#define ISFULLSYNC(hio)	((hio)->hio_replication == HAST_REPLICATION_FULLSYNC)
230#define ISMEMSYNC(hio)	((hio)->hio_replication == HAST_REPLICATION_MEMSYNC)
231#define ISASYNC(hio)	((hio)->hio_replication == HAST_REPLICATION_ASYNC)
232
233#define	SYNCREQ(hio)		do {					\
234	(hio)->hio_ggio.gctl_unit = -1;					\
235	(hio)->hio_ggio.gctl_seq = 1;					\
236} while (0)
237#define	ISSYNCREQ(hio)		((hio)->hio_ggio.gctl_unit == -1)
238#define	SYNCREQDONE(hio)	do { (hio)->hio_ggio.gctl_unit = -2; } while (0)
239#define	ISSYNCREQDONE(hio)	((hio)->hio_ggio.gctl_unit == -2)
240
241#define ISMEMSYNCWRITE(hio)	(ISMEMSYNC(hio) &&			\
242	    (hio)->hio_ggio.gctl_cmd == BIO_WRITE && !ISSYNCREQ(hio))
243
244static struct hast_resource *gres;
245
246static pthread_mutex_t range_lock;
247static struct rangelocks *range_regular;
248static bool range_regular_wait;
249static pthread_cond_t range_regular_cond;
250static struct rangelocks *range_sync;
251static bool range_sync_wait;
252static pthread_cond_t range_sync_cond;
253static bool fullystarted;
254
255static void *ggate_recv_thread(void *arg);
256static void *local_send_thread(void *arg);
257static void *remote_send_thread(void *arg);
258static void *remote_recv_thread(void *arg);
259static void *ggate_send_thread(void *arg);
260static void *sync_thread(void *arg);
261static void *guard_thread(void *arg);
262
263static void
264output_status_aux(struct nv *nvout)
265{
266
267	nv_add_uint64(nvout, (uint64_t)hio_free_list_size,
268	    "idle_queue_size");
269	nv_add_uint64(nvout, (uint64_t)hio_send_local_list_size,
270	    "local_queue_size");
271	nv_add_uint64(nvout, (uint64_t)hio_send_remote_list_size,
272	    "send_queue_size");
273	nv_add_uint64(nvout, (uint64_t)hio_recv_remote_list_size,
274	    "recv_queue_size");
275	nv_add_uint64(nvout, (uint64_t)hio_done_list_size,
276	    "done_queue_size");
277}
278
279static void
280cleanup(struct hast_resource *res)
281{
282	int rerrno;
283
284	/* Remember errno. */
285	rerrno = errno;
286
287	/* Destroy ggate provider if we created one. */
288	if (res->hr_ggateunit >= 0) {
289		struct g_gate_ctl_destroy ggiod;
290
291		bzero(&ggiod, sizeof(ggiod));
292		ggiod.gctl_version = G_GATE_VERSION;
293		ggiod.gctl_unit = res->hr_ggateunit;
294		ggiod.gctl_force = 1;
295		if (ioctl(res->hr_ggatefd, G_GATE_CMD_DESTROY, &ggiod) == -1) {
296			pjdlog_errno(LOG_WARNING,
297			    "Unable to destroy hast/%s device",
298			    res->hr_provname);
299		}
300		res->hr_ggateunit = -1;
301	}
302
303	/* Restore errno. */
304	errno = rerrno;
305}
306
307static __dead2 void
308primary_exit(int exitcode, const char *fmt, ...)
309{
310	va_list ap;
311
312	PJDLOG_ASSERT(exitcode != EX_OK);
313	va_start(ap, fmt);
314	pjdlogv_errno(LOG_ERR, fmt, ap);
315	va_end(ap);
316	cleanup(gres);
317	exit(exitcode);
318}
319
320static __dead2 void
321primary_exitx(int exitcode, const char *fmt, ...)
322{
323	va_list ap;
324
325	va_start(ap, fmt);
326	pjdlogv(exitcode == EX_OK ? LOG_INFO : LOG_ERR, fmt, ap);
327	va_end(ap);
328	cleanup(gres);
329	exit(exitcode);
330}
331
332static int
333hast_activemap_flush(struct hast_resource *res) __unlocks(res->hr_amp_lock)
334{
335	const unsigned char *buf;
336	size_t size;
337	int ret;
338
339	mtx_lock(&res->hr_amp_diskmap_lock);
340	buf = activemap_bitmap(res->hr_amp, &size);
341	mtx_unlock(&res->hr_amp_lock);
342	PJDLOG_ASSERT(buf != NULL);
343	PJDLOG_ASSERT((size % res->hr_local_sectorsize) == 0);
344	ret = 0;
345	if (pwrite(res->hr_localfd, buf, size, METADATA_SIZE) !=
346	    (ssize_t)size) {
347		pjdlog_errno(LOG_ERR, "Unable to flush activemap to disk");
348		res->hr_stat_activemap_write_error++;
349		ret = -1;
350	}
351	if (ret == 0 && res->hr_metaflush == 1 &&
352	    g_flush(res->hr_localfd) == -1) {
353		if (errno == EOPNOTSUPP) {
354			pjdlog_warning("The %s provider doesn't support flushing write cache. Disabling it.",
355			    res->hr_localpath);
356			res->hr_metaflush = 0;
357		} else {
358			pjdlog_errno(LOG_ERR,
359			    "Unable to flush disk cache on activemap update");
360			res->hr_stat_activemap_flush_error++;
361			ret = -1;
362		}
363	}
364	mtx_unlock(&res->hr_amp_diskmap_lock);
365	return (ret);
366}
367
368static bool
369real_remote(const struct hast_resource *res)
370{
371
372	return (strcmp(res->hr_remoteaddr, "none") != 0);
373}
374
375static void
376init_environment(struct hast_resource *res __unused)
377{
378	struct hio *hio;
379	unsigned int ii, ncomps;
380
381	/*
382	 * In the future it might be per-resource value.
383	 */
384	ncomps = HAST_NCOMPONENTS;
385
386	/*
387	 * Allocate memory needed by lists.
388	 */
389	hio_send_list = malloc(sizeof(hio_send_list[0]) * ncomps);
390	if (hio_send_list == NULL) {
391		primary_exitx(EX_TEMPFAIL,
392		    "Unable to allocate %zu bytes of memory for send lists.",
393		    sizeof(hio_send_list[0]) * ncomps);
394	}
395	hio_send_list_size = malloc(sizeof(hio_send_list_size[0]) * ncomps);
396	if (hio_send_list_size == NULL) {
397		primary_exitx(EX_TEMPFAIL,
398		    "Unable to allocate %zu bytes of memory for send list counters.",
399		    sizeof(hio_send_list_size[0]) * ncomps);
400	}
401	hio_send_list_lock = malloc(sizeof(hio_send_list_lock[0]) * ncomps);
402	if (hio_send_list_lock == NULL) {
403		primary_exitx(EX_TEMPFAIL,
404		    "Unable to allocate %zu bytes of memory for send list locks.",
405		    sizeof(hio_send_list_lock[0]) * ncomps);
406	}
407	hio_send_list_cond = malloc(sizeof(hio_send_list_cond[0]) * ncomps);
408	if (hio_send_list_cond == NULL) {
409		primary_exitx(EX_TEMPFAIL,
410		    "Unable to allocate %zu bytes of memory for send list condition variables.",
411		    sizeof(hio_send_list_cond[0]) * ncomps);
412	}
413	hio_recv_list = malloc(sizeof(hio_recv_list[0]) * ncomps);
414	if (hio_recv_list == NULL) {
415		primary_exitx(EX_TEMPFAIL,
416		    "Unable to allocate %zu bytes of memory for recv lists.",
417		    sizeof(hio_recv_list[0]) * ncomps);
418	}
419	hio_recv_list_size = malloc(sizeof(hio_recv_list_size[0]) * ncomps);
420	if (hio_recv_list_size == NULL) {
421		primary_exitx(EX_TEMPFAIL,
422		    "Unable to allocate %zu bytes of memory for recv list counters.",
423		    sizeof(hio_recv_list_size[0]) * ncomps);
424	}
425	hio_recv_list_lock = malloc(sizeof(hio_recv_list_lock[0]) * ncomps);
426	if (hio_recv_list_lock == NULL) {
427		primary_exitx(EX_TEMPFAIL,
428		    "Unable to allocate %zu bytes of memory for recv list locks.",
429		    sizeof(hio_recv_list_lock[0]) * ncomps);
430	}
431	hio_recv_list_cond = malloc(sizeof(hio_recv_list_cond[0]) * ncomps);
432	if (hio_recv_list_cond == NULL) {
433		primary_exitx(EX_TEMPFAIL,
434		    "Unable to allocate %zu bytes of memory for recv list condition variables.",
435		    sizeof(hio_recv_list_cond[0]) * ncomps);
436	}
437	hio_remote_lock = malloc(sizeof(hio_remote_lock[0]) * ncomps);
438	if (hio_remote_lock == NULL) {
439		primary_exitx(EX_TEMPFAIL,
440		    "Unable to allocate %zu bytes of memory for remote connections locks.",
441		    sizeof(hio_remote_lock[0]) * ncomps);
442	}
443
444	/*
445	 * Initialize lists, their counters, locks and condition variables.
446	 */
447	TAILQ_INIT(&hio_free_list);
448	mtx_init(&hio_free_list_lock);
449	cv_init(&hio_free_list_cond);
450	for (ii = 0; ii < HAST_NCOMPONENTS; ii++) {
451		TAILQ_INIT(&hio_send_list[ii]);
452		hio_send_list_size[ii] = 0;
453		mtx_init(&hio_send_list_lock[ii]);
454		cv_init(&hio_send_list_cond[ii]);
455		TAILQ_INIT(&hio_recv_list[ii]);
456		hio_recv_list_size[ii] = 0;
457		mtx_init(&hio_recv_list_lock[ii]);
458		cv_init(&hio_recv_list_cond[ii]);
459		rw_init(&hio_remote_lock[ii]);
460	}
461	TAILQ_INIT(&hio_done_list);
462	mtx_init(&hio_done_list_lock);
463	cv_init(&hio_done_list_cond);
464	mtx_init(&metadata_lock);
465
466	/*
467	 * Allocate requests pool and initialize requests.
468	 */
469	for (ii = 0; ii < HAST_HIO_MAX; ii++) {
470		hio = malloc(sizeof(*hio));
471		if (hio == NULL) {
472			primary_exitx(EX_TEMPFAIL,
473			    "Unable to allocate %zu bytes of memory for hio request.",
474			    sizeof(*hio));
475		}
476		refcnt_init(&hio->hio_countdown, 0);
477		hio->hio_errors = malloc(sizeof(hio->hio_errors[0]) * ncomps);
478		if (hio->hio_errors == NULL) {
479			primary_exitx(EX_TEMPFAIL,
480			    "Unable allocate %zu bytes of memory for hio errors.",
481			    sizeof(hio->hio_errors[0]) * ncomps);
482		}
483		hio->hio_next = malloc(sizeof(hio->hio_next[0]) * ncomps);
484		if (hio->hio_next == NULL) {
485			primary_exitx(EX_TEMPFAIL,
486			    "Unable allocate %zu bytes of memory for hio_next field.",
487			    sizeof(hio->hio_next[0]) * ncomps);
488		}
489		hio->hio_ggio.gctl_version = G_GATE_VERSION;
490		hio->hio_ggio.gctl_data = malloc(MAXPHYS);
491		if (hio->hio_ggio.gctl_data == NULL) {
492			primary_exitx(EX_TEMPFAIL,
493			    "Unable to allocate %zu bytes of memory for gctl_data.",
494			    MAXPHYS);
495		}
496		hio->hio_ggio.gctl_length = MAXPHYS;
497		hio->hio_ggio.gctl_error = 0;
498		TAILQ_INSERT_HEAD(&hio_free_list, hio, hio_free_next);
499		hio_free_list_size++;
500	}
501}
502
503static bool
504init_resuid(struct hast_resource *res)
505{
506
507	mtx_lock(&metadata_lock);
508	if (res->hr_resuid != 0) {
509		mtx_unlock(&metadata_lock);
510		return (false);
511	} else {
512		/* Initialize unique resource identifier. */
513		arc4random_buf(&res->hr_resuid, sizeof(res->hr_resuid));
514		mtx_unlock(&metadata_lock);
515		if (metadata_write(res) == -1)
516			exit(EX_NOINPUT);
517		return (true);
518	}
519}
520
521static void
522init_local(struct hast_resource *res)
523{
524	unsigned char *buf;
525	size_t mapsize;
526
527	if (metadata_read(res, true) == -1)
528		exit(EX_NOINPUT);
529	mtx_init(&res->hr_amp_lock);
530	if (activemap_init(&res->hr_amp, res->hr_datasize, res->hr_extentsize,
531	    res->hr_local_sectorsize, res->hr_keepdirty) == -1) {
532		primary_exit(EX_TEMPFAIL, "Unable to create activemap");
533	}
534	mtx_init(&range_lock);
535	cv_init(&range_regular_cond);
536	if (rangelock_init(&range_regular) == -1)
537		primary_exit(EX_TEMPFAIL, "Unable to create regular range lock");
538	cv_init(&range_sync_cond);
539	if (rangelock_init(&range_sync) == -1)
540		primary_exit(EX_TEMPFAIL, "Unable to create sync range lock");
541	mapsize = activemap_ondisk_size(res->hr_amp);
542	buf = calloc(1, mapsize);
543	if (buf == NULL) {
544		primary_exitx(EX_TEMPFAIL,
545		    "Unable to allocate buffer for activemap.");
546	}
547	if (pread(res->hr_localfd, buf, mapsize, METADATA_SIZE) !=
548	    (ssize_t)mapsize) {
549		primary_exit(EX_NOINPUT, "Unable to read activemap");
550	}
551	activemap_copyin(res->hr_amp, buf, mapsize);
552	free(buf);
553	if (res->hr_resuid != 0)
554		return;
555	/*
556	 * We're using provider for the first time. Initialize local and remote
557	 * counters. We don't initialize resuid here, as we want to do it just
558	 * in time. The reason for this is that we want to inform secondary
559	 * that there were no writes yet, so there is no need to synchronize
560	 * anything.
561	 */
562	res->hr_primary_localcnt = 0;
563	res->hr_primary_remotecnt = 0;
564	if (metadata_write(res) == -1)
565		exit(EX_NOINPUT);
566}
567
568static int
569primary_connect(struct hast_resource *res, struct proto_conn **connp)
570{
571	struct proto_conn *conn;
572	int16_t val;
573
574	val = 1;
575	if (proto_send(res->hr_conn, &val, sizeof(val)) == -1) {
576		primary_exit(EX_TEMPFAIL,
577		    "Unable to send connection request to parent");
578	}
579	if (proto_recv(res->hr_conn, &val, sizeof(val)) == -1) {
580		primary_exit(EX_TEMPFAIL,
581		    "Unable to receive reply to connection request from parent");
582	}
583	if (val != 0) {
584		errno = val;
585		pjdlog_errno(LOG_WARNING, "Unable to connect to %s",
586		    res->hr_remoteaddr);
587		return (-1);
588	}
589	if (proto_connection_recv(res->hr_conn, true, &conn) == -1) {
590		primary_exit(EX_TEMPFAIL,
591		    "Unable to receive connection from parent");
592	}
593	if (proto_connect_wait(conn, res->hr_timeout) == -1) {
594		pjdlog_errno(LOG_WARNING, "Unable to connect to %s",
595		    res->hr_remoteaddr);
596		proto_close(conn);
597		return (-1);
598	}
599	/* Error in setting timeout is not critical, but why should it fail? */
600	if (proto_timeout(conn, res->hr_timeout) == -1)
601		pjdlog_errno(LOG_WARNING, "Unable to set connection timeout");
602
603	*connp = conn;
604
605	return (0);
606}
607
608/*
609 * Function instructs GEOM_GATE to handle reads directly from within the kernel.
610 */
611static void
612enable_direct_reads(struct hast_resource *res)
613{
614	struct g_gate_ctl_modify ggiomodify;
615
616	bzero(&ggiomodify, sizeof(ggiomodify));
617	ggiomodify.gctl_version = G_GATE_VERSION;
618	ggiomodify.gctl_unit = res->hr_ggateunit;
619	ggiomodify.gctl_modify = GG_MODIFY_READPROV | GG_MODIFY_READOFFSET;
620	strlcpy(ggiomodify.gctl_readprov, res->hr_localpath,
621	    sizeof(ggiomodify.gctl_readprov));
622	ggiomodify.gctl_readoffset = res->hr_localoff;
623	if (ioctl(res->hr_ggatefd, G_GATE_CMD_MODIFY, &ggiomodify) == 0)
624		pjdlog_debug(1, "Direct reads enabled.");
625	else
626		pjdlog_errno(LOG_WARNING, "Failed to enable direct reads");
627}
628
629static int
630init_remote(struct hast_resource *res, struct proto_conn **inp,
631    struct proto_conn **outp)
632{
633	struct proto_conn *in, *out;
634	struct nv *nvout, *nvin;
635	const unsigned char *token;
636	unsigned char *map;
637	const char *errmsg;
638	int32_t extentsize;
639	int64_t datasize;
640	uint32_t mapsize;
641	uint8_t version;
642	size_t size;
643	int error;
644
645	PJDLOG_ASSERT((inp == NULL && outp == NULL) || (inp != NULL && outp != NULL));
646	PJDLOG_ASSERT(real_remote(res));
647
648	in = out = NULL;
649	errmsg = NULL;
650
651	if (primary_connect(res, &out) == -1)
652		return (ECONNREFUSED);
653
654	error = ECONNABORTED;
655
656	/*
657	 * First handshake step.
658	 * Setup outgoing connection with remote node.
659	 */
660	nvout = nv_alloc();
661	nv_add_string(nvout, res->hr_name, "resource");
662	nv_add_uint8(nvout, HAST_PROTO_VERSION, "version");
663	if (nv_error(nvout) != 0) {
664		pjdlog_common(LOG_WARNING, 0, nv_error(nvout),
665		    "Unable to allocate header for connection with %s",
666		    res->hr_remoteaddr);
667		nv_free(nvout);
668		goto close;
669	}
670	if (hast_proto_send(res, out, nvout, NULL, 0) == -1) {
671		pjdlog_errno(LOG_WARNING,
672		    "Unable to send handshake header to %s",
673		    res->hr_remoteaddr);
674		nv_free(nvout);
675		goto close;
676	}
677	nv_free(nvout);
678	if (hast_proto_recv_hdr(out, &nvin) == -1) {
679		pjdlog_errno(LOG_WARNING,
680		    "Unable to receive handshake header from %s",
681		    res->hr_remoteaddr);
682		goto close;
683	}
684	errmsg = nv_get_string(nvin, "errmsg");
685	if (errmsg != NULL) {
686		pjdlog_warning("%s", errmsg);
687		if (nv_exists(nvin, "wait"))
688			error = EBUSY;
689		nv_free(nvin);
690		goto close;
691	}
692	version = nv_get_uint8(nvin, "version");
693	if (version == 0) {
694		/*
695		 * If no version is sent, it means this is protocol version 1.
696		 */
697		version = 1;
698	}
699	if (version > HAST_PROTO_VERSION) {
700		pjdlog_warning("Invalid version received (%hhu).", version);
701		nv_free(nvin);
702		goto close;
703	}
704	res->hr_version = version;
705	pjdlog_debug(1, "Negotiated protocol version %d.", res->hr_version);
706	token = nv_get_uint8_array(nvin, &size, "token");
707	if (token == NULL) {
708		pjdlog_warning("Handshake header from %s has no 'token' field.",
709		    res->hr_remoteaddr);
710		nv_free(nvin);
711		goto close;
712	}
713	if (size != sizeof(res->hr_token)) {
714		pjdlog_warning("Handshake header from %s contains 'token' of wrong size (got %zu, expected %zu).",
715		    res->hr_remoteaddr, size, sizeof(res->hr_token));
716		nv_free(nvin);
717		goto close;
718	}
719	bcopy(token, res->hr_token, sizeof(res->hr_token));
720	nv_free(nvin);
721
722	/*
723	 * Second handshake step.
724	 * Setup incoming connection with remote node.
725	 */
726	if (primary_connect(res, &in) == -1)
727		goto close;
728
729	nvout = nv_alloc();
730	nv_add_string(nvout, res->hr_name, "resource");
731	nv_add_uint8_array(nvout, res->hr_token, sizeof(res->hr_token),
732	    "token");
733	if (res->hr_resuid == 0) {
734		/*
735		 * The resuid field was not yet initialized.
736		 * Because we do synchronization inside init_resuid(), it is
737		 * possible that someone already initialized it, the function
738		 * will return false then, but if we successfully initialized
739		 * it, we will get true. True means that there were no writes
740		 * to this resource yet and we want to inform secondary that
741		 * synchronization is not needed by sending "virgin" argument.
742		 */
743		if (init_resuid(res))
744			nv_add_int8(nvout, 1, "virgin");
745	}
746	nv_add_uint64(nvout, res->hr_resuid, "resuid");
747	nv_add_uint64(nvout, res->hr_primary_localcnt, "localcnt");
748	nv_add_uint64(nvout, res->hr_primary_remotecnt, "remotecnt");
749	if (nv_error(nvout) != 0) {
750		pjdlog_common(LOG_WARNING, 0, nv_error(nvout),
751		    "Unable to allocate header for connection with %s",
752		    res->hr_remoteaddr);
753		nv_free(nvout);
754		goto close;
755	}
756	if (hast_proto_send(res, in, nvout, NULL, 0) == -1) {
757		pjdlog_errno(LOG_WARNING,
758		    "Unable to send handshake header to %s",
759		    res->hr_remoteaddr);
760		nv_free(nvout);
761		goto close;
762	}
763	nv_free(nvout);
764	if (hast_proto_recv_hdr(out, &nvin) == -1) {
765		pjdlog_errno(LOG_WARNING,
766		    "Unable to receive handshake header from %s",
767		    res->hr_remoteaddr);
768		goto close;
769	}
770	errmsg = nv_get_string(nvin, "errmsg");
771	if (errmsg != NULL) {
772		pjdlog_warning("%s", errmsg);
773		nv_free(nvin);
774		goto close;
775	}
776	datasize = nv_get_int64(nvin, "datasize");
777	if (datasize != res->hr_datasize) {
778		pjdlog_warning("Data size differs between nodes (local=%jd, remote=%jd).",
779		    (intmax_t)res->hr_datasize, (intmax_t)datasize);
780		nv_free(nvin);
781		goto close;
782	}
783	extentsize = nv_get_int32(nvin, "extentsize");
784	if (extentsize != res->hr_extentsize) {
785		pjdlog_warning("Extent size differs between nodes (local=%zd, remote=%zd).",
786		    (ssize_t)res->hr_extentsize, (ssize_t)extentsize);
787		nv_free(nvin);
788		goto close;
789	}
790	res->hr_secondary_localcnt = nv_get_uint64(nvin, "localcnt");
791	res->hr_secondary_remotecnt = nv_get_uint64(nvin, "remotecnt");
792	res->hr_syncsrc = nv_get_uint8(nvin, "syncsrc");
793	if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY)
794		enable_direct_reads(res);
795	if (nv_exists(nvin, "virgin")) {
796		/*
797		 * Secondary was reinitialized, bump localcnt if it is 0 as
798		 * only we have the data.
799		 */
800		PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_PRIMARY);
801		PJDLOG_ASSERT(res->hr_secondary_localcnt == 0);
802
803		if (res->hr_primary_localcnt == 0) {
804			PJDLOG_ASSERT(res->hr_secondary_remotecnt == 0);
805
806			mtx_lock(&metadata_lock);
807			res->hr_primary_localcnt++;
808			pjdlog_debug(1, "Increasing localcnt to %ju.",
809			    (uintmax_t)res->hr_primary_localcnt);
810			(void)metadata_write(res);
811			mtx_unlock(&metadata_lock);
812		}
813	}
814	map = NULL;
815	mapsize = nv_get_uint32(nvin, "mapsize");
816	if (mapsize > 0) {
817		map = malloc(mapsize);
818		if (map == NULL) {
819			pjdlog_error("Unable to allocate memory for remote activemap (mapsize=%ju).",
820			    (uintmax_t)mapsize);
821			nv_free(nvin);
822			goto close;
823		}
824		/*
825		 * Remote node have some dirty extents on its own, lets
826		 * download its activemap.
827		 */
828		if (hast_proto_recv_data(res, out, nvin, map,
829		    mapsize) == -1) {
830			pjdlog_errno(LOG_ERR,
831			    "Unable to receive remote activemap");
832			nv_free(nvin);
833			free(map);
834			goto close;
835		}
836		mtx_lock(&res->hr_amp_lock);
837		/*
838		 * Merge local and remote bitmaps.
839		 */
840		activemap_merge(res->hr_amp, map, mapsize);
841		free(map);
842		/*
843		 * Now that we merged bitmaps from both nodes, flush it to the
844		 * disk before we start to synchronize.
845		 */
846		(void)hast_activemap_flush(res);
847	}
848	nv_free(nvin);
849#ifdef notyet
850	/* Setup directions. */
851	if (proto_send(out, NULL, 0) == -1)
852		pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
853	if (proto_recv(in, NULL, 0) == -1)
854		pjdlog_errno(LOG_WARNING, "Unable to set connection direction");
855#endif
856	pjdlog_info("Connected to %s.", res->hr_remoteaddr);
857	if (res->hr_original_replication == HAST_REPLICATION_MEMSYNC &&
858	    res->hr_version < 2) {
859		pjdlog_warning("The 'memsync' replication mode is not supported by the remote node, falling back to 'fullsync' mode.");
860		res->hr_replication = HAST_REPLICATION_FULLSYNC;
861	} else if (res->hr_replication != res->hr_original_replication) {
862		/*
863		 * This is in case hastd disconnected and was upgraded.
864		 */
865		res->hr_replication = res->hr_original_replication;
866	}
867	if (inp != NULL && outp != NULL) {
868		*inp = in;
869		*outp = out;
870	} else {
871		res->hr_remotein = in;
872		res->hr_remoteout = out;
873	}
874	event_send(res, EVENT_CONNECT);
875	return (0);
876close:
877	if (errmsg != NULL && strcmp(errmsg, "Split-brain condition!") == 0)
878		event_send(res, EVENT_SPLITBRAIN);
879	proto_close(out);
880	if (in != NULL)
881		proto_close(in);
882	return (error);
883}
884
885static void
886sync_start(void)
887{
888
889	mtx_lock(&sync_lock);
890	sync_inprogress = true;
891	mtx_unlock(&sync_lock);
892	cv_signal(&sync_cond);
893}
894
895static void
896sync_stop(void)
897{
898
899	mtx_lock(&sync_lock);
900	if (sync_inprogress)
901		sync_inprogress = false;
902	mtx_unlock(&sync_lock);
903}
904
905static void
906init_ggate(struct hast_resource *res)
907{
908	struct g_gate_ctl_create ggiocreate;
909	struct g_gate_ctl_cancel ggiocancel;
910
911	/*
912	 * We communicate with ggate via /dev/ggctl. Open it.
913	 */
914	res->hr_ggatefd = open("/dev/" G_GATE_CTL_NAME, O_RDWR);
915	if (res->hr_ggatefd == -1)
916		primary_exit(EX_OSFILE, "Unable to open /dev/" G_GATE_CTL_NAME);
917	/*
918	 * Create provider before trying to connect, as connection failure
919	 * is not critical, but may take some time.
920	 */
921	bzero(&ggiocreate, sizeof(ggiocreate));
922	ggiocreate.gctl_version = G_GATE_VERSION;
923	ggiocreate.gctl_mediasize = res->hr_datasize;
924	ggiocreate.gctl_sectorsize = res->hr_local_sectorsize;
925	ggiocreate.gctl_flags = 0;
926	ggiocreate.gctl_maxcount = 0;
927	ggiocreate.gctl_timeout = 0;
928	ggiocreate.gctl_unit = G_GATE_NAME_GIVEN;
929	snprintf(ggiocreate.gctl_name, sizeof(ggiocreate.gctl_name), "hast/%s",
930	    res->hr_provname);
931	if (ioctl(res->hr_ggatefd, G_GATE_CMD_CREATE, &ggiocreate) == 0) {
932		pjdlog_info("Device hast/%s created.", res->hr_provname);
933		res->hr_ggateunit = ggiocreate.gctl_unit;
934		return;
935	}
936	if (errno != EEXIST) {
937		primary_exit(EX_OSERR, "Unable to create hast/%s device",
938		    res->hr_provname);
939	}
940	pjdlog_debug(1,
941	    "Device hast/%s already exists, we will try to take it over.",
942	    res->hr_provname);
943	/*
944	 * If we received EEXIST, we assume that the process who created the
945	 * provider died and didn't clean up. In that case we will start from
946	 * where he left of.
947	 */
948	bzero(&ggiocancel, sizeof(ggiocancel));
949	ggiocancel.gctl_version = G_GATE_VERSION;
950	ggiocancel.gctl_unit = G_GATE_NAME_GIVEN;
951	snprintf(ggiocancel.gctl_name, sizeof(ggiocancel.gctl_name), "hast/%s",
952	    res->hr_provname);
953	if (ioctl(res->hr_ggatefd, G_GATE_CMD_CANCEL, &ggiocancel) == 0) {
954		pjdlog_info("Device hast/%s recovered.", res->hr_provname);
955		res->hr_ggateunit = ggiocancel.gctl_unit;
956		return;
957	}
958	primary_exit(EX_OSERR, "Unable to take over hast/%s device",
959	    res->hr_provname);
960}
961
962void
963hastd_primary(struct hast_resource *res)
964{
965	pthread_t td;
966	pid_t pid;
967	int error, mode, debuglevel;
968
969	/*
970	 * Create communication channel for sending control commands from
971	 * parent to child.
972	 */
973	if (proto_client(NULL, "socketpair://", &res->hr_ctrl) == -1) {
974		/* TODO: There's no need for this to be fatal error. */
975		KEEP_ERRNO((void)pidfile_remove(pfh));
976		pjdlog_exit(EX_OSERR,
977		    "Unable to create control sockets between parent and child");
978	}
979	/*
980	 * Create communication channel for sending events from child to parent.
981	 */
982	if (proto_client(NULL, "socketpair://", &res->hr_event) == -1) {
983		/* TODO: There's no need for this to be fatal error. */
984		KEEP_ERRNO((void)pidfile_remove(pfh));
985		pjdlog_exit(EX_OSERR,
986		    "Unable to create event sockets between child and parent");
987	}
988	/*
989	 * Create communication channel for sending connection requests from
990	 * child to parent.
991	 */
992	if (proto_client(NULL, "socketpair://", &res->hr_conn) == -1) {
993		/* TODO: There's no need for this to be fatal error. */
994		KEEP_ERRNO((void)pidfile_remove(pfh));
995		pjdlog_exit(EX_OSERR,
996		    "Unable to create connection sockets between child and parent");
997	}
998
999	pid = fork();
1000	if (pid == -1) {
1001		/* TODO: There's no need for this to be fatal error. */
1002		KEEP_ERRNO((void)pidfile_remove(pfh));
1003		pjdlog_exit(EX_TEMPFAIL, "Unable to fork");
1004	}
1005
1006	if (pid > 0) {
1007		/* This is parent. */
1008		/* Declare that we are receiver. */
1009		proto_recv(res->hr_event, NULL, 0);
1010		proto_recv(res->hr_conn, NULL, 0);
1011		/* Declare that we are sender. */
1012		proto_send(res->hr_ctrl, NULL, 0);
1013		res->hr_workerpid = pid;
1014		return;
1015	}
1016
1017	gres = res;
1018	res->output_status_aux = output_status_aux;
1019	mode = pjdlog_mode_get();
1020	debuglevel = pjdlog_debug_get();
1021
1022	/* Declare that we are sender. */
1023	proto_send(res->hr_event, NULL, 0);
1024	proto_send(res->hr_conn, NULL, 0);
1025	/* Declare that we are receiver. */
1026	proto_recv(res->hr_ctrl, NULL, 0);
1027	descriptors_cleanup(res);
1028
1029	descriptors_assert(res, mode);
1030
1031	pjdlog_init(mode);
1032	pjdlog_debug_set(debuglevel);
1033	pjdlog_prefix_set("[%s] (%s) ", res->hr_name, role2str(res->hr_role));
1034	setproctitle("%s (%s)", res->hr_name, role2str(res->hr_role));
1035
1036	init_local(res);
1037	init_ggate(res);
1038	init_environment(res);
1039
1040	if (drop_privs(res) != 0) {
1041		cleanup(res);
1042		exit(EX_CONFIG);
1043	}
1044	pjdlog_info("Privileges successfully dropped.");
1045
1046	/*
1047	 * Create the guard thread first, so we can handle signals from the
1048	 * very beginning.
1049	 */
1050	error = pthread_create(&td, NULL, guard_thread, res);
1051	PJDLOG_ASSERT(error == 0);
1052	/*
1053	 * Create the control thread before sending any event to the parent,
1054	 * as we can deadlock when parent sends control request to worker,
1055	 * but worker has no control thread started yet, so parent waits.
1056	 * In the meantime worker sends an event to the parent, but parent
1057	 * is unable to handle the event, because it waits for control
1058	 * request response.
1059	 */
1060	error = pthread_create(&td, NULL, ctrl_thread, res);
1061	PJDLOG_ASSERT(error == 0);
1062	if (real_remote(res)) {
1063		error = init_remote(res, NULL, NULL);
1064		if (error == 0) {
1065			sync_start();
1066		} else if (error == EBUSY) {
1067			time_t start = time(NULL);
1068
1069			pjdlog_warning("Waiting for remote node to become %s for %ds.",
1070			    role2str(HAST_ROLE_SECONDARY),
1071			    res->hr_timeout);
1072			for (;;) {
1073				sleep(1);
1074				error = init_remote(res, NULL, NULL);
1075				if (error != EBUSY)
1076					break;
1077				if (time(NULL) > start + res->hr_timeout)
1078					break;
1079			}
1080			if (error == EBUSY) {
1081				pjdlog_warning("Remote node is still %s, starting anyway.",
1082				    role2str(HAST_ROLE_PRIMARY));
1083			}
1084		}
1085	}
1086	error = pthread_create(&td, NULL, ggate_recv_thread, res);
1087	PJDLOG_ASSERT(error == 0);
1088	error = pthread_create(&td, NULL, local_send_thread, res);
1089	PJDLOG_ASSERT(error == 0);
1090	error = pthread_create(&td, NULL, remote_send_thread, res);
1091	PJDLOG_ASSERT(error == 0);
1092	error = pthread_create(&td, NULL, remote_recv_thread, res);
1093	PJDLOG_ASSERT(error == 0);
1094	error = pthread_create(&td, NULL, ggate_send_thread, res);
1095	PJDLOG_ASSERT(error == 0);
1096	fullystarted = true;
1097	(void)sync_thread(res);
1098}
1099
1100static void
1101reqlog(int loglevel, int debuglevel, struct g_gate_ctl_io *ggio,
1102    const char *fmt, ...)
1103{
1104	char msg[1024];
1105	va_list ap;
1106
1107	va_start(ap, fmt);
1108	(void)vsnprintf(msg, sizeof(msg), fmt, ap);
1109	va_end(ap);
1110	switch (ggio->gctl_cmd) {
1111	case BIO_READ:
1112		(void)snprlcat(msg, sizeof(msg), "READ(%ju, %ju).",
1113		    (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1114		break;
1115	case BIO_DELETE:
1116		(void)snprlcat(msg, sizeof(msg), "DELETE(%ju, %ju).",
1117		    (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1118		break;
1119	case BIO_FLUSH:
1120		(void)snprlcat(msg, sizeof(msg), "FLUSH.");
1121		break;
1122	case BIO_WRITE:
1123		(void)snprlcat(msg, sizeof(msg), "WRITE(%ju, %ju).",
1124		    (uintmax_t)ggio->gctl_offset, (uintmax_t)ggio->gctl_length);
1125		break;
1126	default:
1127		(void)snprlcat(msg, sizeof(msg), "UNKNOWN(%u).",
1128		    (unsigned int)ggio->gctl_cmd);
1129		break;
1130	}
1131	pjdlog_common(loglevel, debuglevel, -1, "%s", msg);
1132}
1133
1134static void
1135remote_close(struct hast_resource *res, int ncomp)
1136{
1137
1138	rw_wlock(&hio_remote_lock[ncomp]);
1139	/*
1140	 * Check for a race between dropping rlock and acquiring wlock -
1141	 * another thread can close connection in-between.
1142	 */
1143	if (!ISCONNECTED(res, ncomp)) {
1144		PJDLOG_ASSERT(res->hr_remotein == NULL);
1145		PJDLOG_ASSERT(res->hr_remoteout == NULL);
1146		rw_unlock(&hio_remote_lock[ncomp]);
1147		return;
1148	}
1149
1150	PJDLOG_ASSERT(res->hr_remotein != NULL);
1151	PJDLOG_ASSERT(res->hr_remoteout != NULL);
1152
1153	pjdlog_debug(2, "Closing incoming connection to %s.",
1154	    res->hr_remoteaddr);
1155	proto_close(res->hr_remotein);
1156	res->hr_remotein = NULL;
1157	pjdlog_debug(2, "Closing outgoing connection to %s.",
1158	    res->hr_remoteaddr);
1159	proto_close(res->hr_remoteout);
1160	res->hr_remoteout = NULL;
1161
1162	rw_unlock(&hio_remote_lock[ncomp]);
1163
1164	pjdlog_warning("Disconnected from %s.", res->hr_remoteaddr);
1165
1166	/*
1167	 * Stop synchronization if in-progress.
1168	 */
1169	sync_stop();
1170
1171	event_send(res, EVENT_DISCONNECT);
1172}
1173
1174/*
1175 * Acknowledge write completion to the kernel, but don't update activemap yet.
1176 */
1177static void
1178write_complete(struct hast_resource *res, struct hio *hio)
1179{
1180	struct g_gate_ctl_io *ggio;
1181	unsigned int ncomp;
1182
1183	PJDLOG_ASSERT(!hio->hio_done);
1184
1185	ggio = &hio->hio_ggio;
1186	PJDLOG_ASSERT(ggio->gctl_cmd == BIO_WRITE);
1187
1188	/*
1189	 * Bump local count if this is first write after
1190	 * connection failure with remote node.
1191	 */
1192	ncomp = 1;
1193	rw_rlock(&hio_remote_lock[ncomp]);
1194	if (!ISCONNECTED(res, ncomp)) {
1195		mtx_lock(&metadata_lock);
1196		if (res->hr_primary_localcnt == res->hr_secondary_remotecnt) {
1197			res->hr_primary_localcnt++;
1198			pjdlog_debug(1, "Increasing localcnt to %ju.",
1199			    (uintmax_t)res->hr_primary_localcnt);
1200			(void)metadata_write(res);
1201		}
1202		mtx_unlock(&metadata_lock);
1203	}
1204	rw_unlock(&hio_remote_lock[ncomp]);
1205	if (ioctl(res->hr_ggatefd, G_GATE_CMD_DONE, ggio) == -1)
1206		primary_exit(EX_OSERR, "G_GATE_CMD_DONE failed");
1207	hio->hio_done = true;
1208}
1209
1210/*
1211 * Thread receives ggate I/O requests from the kernel and passes them to
1212 * appropriate threads:
1213 * WRITE - always goes to both local_send and remote_send threads
1214 * READ (when the block is up-to-date on local component) -
1215 *	only local_send thread
1216 * READ (when the block isn't up-to-date on local component) -
1217 *	only remote_send thread
1218 * DELETE - always goes to both local_send and remote_send threads
1219 * FLUSH - always goes to both local_send and remote_send threads
1220 */
1221static void *
1222ggate_recv_thread(void *arg)
1223{
1224	struct hast_resource *res = arg;
1225	struct g_gate_ctl_io *ggio;
1226	struct hio *hio;
1227	unsigned int ii, ncomp, ncomps;
1228	int error;
1229
1230	for (;;) {
1231		pjdlog_debug(2, "ggate_recv: Taking free request.");
1232		QUEUE_TAKE2(hio, free);
1233		pjdlog_debug(2, "ggate_recv: (%p) Got free request.", hio);
1234		ggio = &hio->hio_ggio;
1235		ggio->gctl_unit = res->hr_ggateunit;
1236		ggio->gctl_length = MAXPHYS;
1237		ggio->gctl_error = 0;
1238		hio->hio_done = false;
1239		hio->hio_replication = res->hr_replication;
1240		pjdlog_debug(2,
1241		    "ggate_recv: (%p) Waiting for request from the kernel.",
1242		    hio);
1243		if (ioctl(res->hr_ggatefd, G_GATE_CMD_START, ggio) == -1) {
1244			if (sigexit_received)
1245				pthread_exit(NULL);
1246			primary_exit(EX_OSERR, "G_GATE_CMD_START failed");
1247		}
1248		error = ggio->gctl_error;
1249		switch (error) {
1250		case 0:
1251			break;
1252		case ECANCELED:
1253			/* Exit gracefully. */
1254			if (!sigexit_received) {
1255				pjdlog_debug(2,
1256				    "ggate_recv: (%p) Received cancel from the kernel.",
1257				    hio);
1258				pjdlog_info("Received cancel from the kernel, exiting.");
1259			}
1260			pthread_exit(NULL);
1261		case ENOMEM:
1262			/*
1263			 * Buffer too small? Impossible, we allocate MAXPHYS
1264			 * bytes - request can't be bigger than that.
1265			 */
1266			/* FALLTHROUGH */
1267		case ENXIO:
1268		default:
1269			primary_exitx(EX_OSERR, "G_GATE_CMD_START failed: %s.",
1270			    strerror(error));
1271		}
1272
1273		ncomp = 0;
1274		ncomps = HAST_NCOMPONENTS;
1275
1276		for (ii = 0; ii < ncomps; ii++)
1277			hio->hio_errors[ii] = EINVAL;
1278		reqlog(LOG_DEBUG, 2, ggio,
1279		    "ggate_recv: (%p) Request received from the kernel: ",
1280		    hio);
1281
1282		/*
1283		 * Inform all components about new write request.
1284		 * For read request prefer local component unless the given
1285		 * range is out-of-date, then use remote component.
1286		 */
1287		switch (ggio->gctl_cmd) {
1288		case BIO_READ:
1289			res->hr_stat_read++;
1290			ncomps = 1;
1291			mtx_lock(&metadata_lock);
1292			if (res->hr_syncsrc == HAST_SYNCSRC_UNDEF ||
1293			    res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
1294				/*
1295				 * This range is up-to-date on local component,
1296				 * so handle request locally.
1297				 */
1298				 /* Local component is 0 for now. */
1299				ncomp = 0;
1300			} else /* if (res->hr_syncsrc ==
1301			    HAST_SYNCSRC_SECONDARY) */ {
1302				PJDLOG_ASSERT(res->hr_syncsrc ==
1303				    HAST_SYNCSRC_SECONDARY);
1304				/*
1305				 * This range is out-of-date on local component,
1306				 * so send request to the remote node.
1307				 */
1308				 /* Remote component is 1 for now. */
1309				ncomp = 1;
1310			}
1311			mtx_unlock(&metadata_lock);
1312			break;
1313		case BIO_WRITE:
1314			res->hr_stat_write++;
1315			if (res->hr_resuid == 0 &&
1316			    res->hr_primary_localcnt == 0) {
1317				/* This is first write. */
1318				res->hr_primary_localcnt = 1;
1319			}
1320			for (;;) {
1321				mtx_lock(&range_lock);
1322				if (rangelock_islocked(range_sync,
1323				    ggio->gctl_offset, ggio->gctl_length)) {
1324					pjdlog_debug(2,
1325					    "regular: Range offset=%jd length=%zu locked.",
1326					    (intmax_t)ggio->gctl_offset,
1327					    (size_t)ggio->gctl_length);
1328					range_regular_wait = true;
1329					cv_wait(&range_regular_cond, &range_lock);
1330					range_regular_wait = false;
1331					mtx_unlock(&range_lock);
1332					continue;
1333				}
1334				if (rangelock_add(range_regular,
1335				    ggio->gctl_offset, ggio->gctl_length) == -1) {
1336					mtx_unlock(&range_lock);
1337					pjdlog_debug(2,
1338					    "regular: Range offset=%jd length=%zu is already locked, waiting.",
1339					    (intmax_t)ggio->gctl_offset,
1340					    (size_t)ggio->gctl_length);
1341					sleep(1);
1342					continue;
1343				}
1344				mtx_unlock(&range_lock);
1345				break;
1346			}
1347			mtx_lock(&res->hr_amp_lock);
1348			if (activemap_write_start(res->hr_amp,
1349			    ggio->gctl_offset, ggio->gctl_length)) {
1350				res->hr_stat_activemap_update++;
1351				(void)hast_activemap_flush(res);
1352			} else {
1353				mtx_unlock(&res->hr_amp_lock);
1354			}
1355			if (ISMEMSYNC(hio)) {
1356				hio->hio_memsyncacked = false;
1357				refcnt_init(&hio->hio_writecount, ncomps);
1358			}
1359			break;
1360		case BIO_DELETE:
1361			res->hr_stat_delete++;
1362			break;
1363		case BIO_FLUSH:
1364			res->hr_stat_flush++;
1365			break;
1366		}
1367		pjdlog_debug(2,
1368		    "ggate_recv: (%p) Moving request to the send queues.", hio);
1369		refcnt_init(&hio->hio_countdown, ncomps);
1370		for (ii = ncomp; ii < ncomps; ii++)
1371			QUEUE_INSERT1(hio, send, ii);
1372	}
1373	/* NOTREACHED */
1374	return (NULL);
1375}
1376
1377/*
1378 * Thread reads from or writes to local component.
1379 * If local read fails, it redirects it to remote_send thread.
1380 */
1381static void *
1382local_send_thread(void *arg)
1383{
1384	struct hast_resource *res = arg;
1385	struct g_gate_ctl_io *ggio;
1386	struct hio *hio;
1387	unsigned int ncomp, rncomp;
1388	ssize_t ret;
1389
1390	/* Local component is 0 for now. */
1391	ncomp = 0;
1392	/* Remote component is 1 for now. */
1393	rncomp = 1;
1394
1395	for (;;) {
1396		pjdlog_debug(2, "local_send: Taking request.");
1397		QUEUE_TAKE1(hio, send, ncomp, 0);
1398		pjdlog_debug(2, "local_send: (%p) Got request.", hio);
1399		ggio = &hio->hio_ggio;
1400		switch (ggio->gctl_cmd) {
1401		case BIO_READ:
1402			ret = pread(res->hr_localfd, ggio->gctl_data,
1403			    ggio->gctl_length,
1404			    ggio->gctl_offset + res->hr_localoff);
1405			if (ret == ggio->gctl_length)
1406				hio->hio_errors[ncomp] = 0;
1407			else if (!ISSYNCREQ(hio)) {
1408				/*
1409				 * If READ failed, try to read from remote node.
1410				 */
1411				if (ret == -1) {
1412					reqlog(LOG_WARNING, 0, ggio,
1413					    "Local request failed (%s), trying remote node. ",
1414					    strerror(errno));
1415				} else if (ret != ggio->gctl_length) {
1416					reqlog(LOG_WARNING, 0, ggio,
1417					    "Local request failed (%zd != %jd), trying remote node. ",
1418					    ret, (intmax_t)ggio->gctl_length);
1419				}
1420				QUEUE_INSERT1(hio, send, rncomp);
1421				continue;
1422			}
1423			break;
1424		case BIO_WRITE:
1425			ret = pwrite(res->hr_localfd, ggio->gctl_data,
1426			    ggio->gctl_length,
1427			    ggio->gctl_offset + res->hr_localoff);
1428			if (ret == -1) {
1429				hio->hio_errors[ncomp] = errno;
1430				reqlog(LOG_WARNING, 0, ggio,
1431				    "Local request failed (%s): ",
1432				    strerror(errno));
1433			} else if (ret != ggio->gctl_length) {
1434				hio->hio_errors[ncomp] = EIO;
1435				reqlog(LOG_WARNING, 0, ggio,
1436				    "Local request failed (%zd != %jd): ",
1437				    ret, (intmax_t)ggio->gctl_length);
1438			} else {
1439				hio->hio_errors[ncomp] = 0;
1440				if (ISASYNC(hio)) {
1441					ggio->gctl_error = 0;
1442					write_complete(res, hio);
1443				}
1444			}
1445			break;
1446		case BIO_DELETE:
1447			ret = g_delete(res->hr_localfd,
1448			    ggio->gctl_offset + res->hr_localoff,
1449			    ggio->gctl_length);
1450			if (ret == -1) {
1451				hio->hio_errors[ncomp] = errno;
1452				reqlog(LOG_WARNING, 0, ggio,
1453				    "Local request failed (%s): ",
1454				    strerror(errno));
1455			} else {
1456				hio->hio_errors[ncomp] = 0;
1457			}
1458			break;
1459		case BIO_FLUSH:
1460			if (!res->hr_localflush) {
1461				ret = -1;
1462				errno = EOPNOTSUPP;
1463				break;
1464			}
1465			ret = g_flush(res->hr_localfd);
1466			if (ret == -1) {
1467				if (errno == EOPNOTSUPP)
1468					res->hr_localflush = false;
1469				hio->hio_errors[ncomp] = errno;
1470				reqlog(LOG_WARNING, 0, ggio,
1471				    "Local request failed (%s): ",
1472				    strerror(errno));
1473			} else {
1474				hio->hio_errors[ncomp] = 0;
1475			}
1476			break;
1477		}
1478		if (ISMEMSYNCWRITE(hio)) {
1479			if (refcnt_release(&hio->hio_writecount) == 0) {
1480				write_complete(res, hio);
1481			}
1482		}
1483		if (refcnt_release(&hio->hio_countdown) > 0)
1484			continue;
1485		if (ISSYNCREQ(hio)) {
1486			mtx_lock(&sync_lock);
1487			SYNCREQDONE(hio);
1488			mtx_unlock(&sync_lock);
1489			cv_signal(&sync_cond);
1490		} else {
1491			pjdlog_debug(2,
1492			    "local_send: (%p) Moving request to the done queue.",
1493			    hio);
1494			QUEUE_INSERT2(hio, done);
1495		}
1496	}
1497	/* NOTREACHED */
1498	return (NULL);
1499}
1500
1501static void
1502keepalive_send(struct hast_resource *res, unsigned int ncomp)
1503{
1504	struct nv *nv;
1505
1506	rw_rlock(&hio_remote_lock[ncomp]);
1507
1508	if (!ISCONNECTED(res, ncomp)) {
1509		rw_unlock(&hio_remote_lock[ncomp]);
1510		return;
1511	}
1512
1513	PJDLOG_ASSERT(res->hr_remotein != NULL);
1514	PJDLOG_ASSERT(res->hr_remoteout != NULL);
1515
1516	nv = nv_alloc();
1517	nv_add_uint8(nv, HIO_KEEPALIVE, "cmd");
1518	if (nv_error(nv) != 0) {
1519		rw_unlock(&hio_remote_lock[ncomp]);
1520		nv_free(nv);
1521		pjdlog_debug(1,
1522		    "keepalive_send: Unable to prepare header to send.");
1523		return;
1524	}
1525	if (hast_proto_send(res, res->hr_remoteout, nv, NULL, 0) == -1) {
1526		rw_unlock(&hio_remote_lock[ncomp]);
1527		pjdlog_common(LOG_DEBUG, 1, errno,
1528		    "keepalive_send: Unable to send request");
1529		nv_free(nv);
1530		remote_close(res, ncomp);
1531		return;
1532	}
1533
1534	rw_unlock(&hio_remote_lock[ncomp]);
1535	nv_free(nv);
1536	pjdlog_debug(2, "keepalive_send: Request sent.");
1537}
1538
1539/*
1540 * Thread sends request to secondary node.
1541 */
1542static void *
1543remote_send_thread(void *arg)
1544{
1545	struct hast_resource *res = arg;
1546	struct g_gate_ctl_io *ggio;
1547	time_t lastcheck, now;
1548	struct hio *hio;
1549	struct nv *nv;
1550	unsigned int ncomp;
1551	bool wakeup;
1552	uint64_t offset, length;
1553	uint8_t cmd;
1554	void *data;
1555
1556	/* Remote component is 1 for now. */
1557	ncomp = 1;
1558	lastcheck = time(NULL);
1559
1560	for (;;) {
1561		pjdlog_debug(2, "remote_send: Taking request.");
1562		QUEUE_TAKE1(hio, send, ncomp, HAST_KEEPALIVE);
1563		if (hio == NULL) {
1564			now = time(NULL);
1565			if (lastcheck + HAST_KEEPALIVE <= now) {
1566				keepalive_send(res, ncomp);
1567				lastcheck = now;
1568			}
1569			continue;
1570		}
1571		pjdlog_debug(2, "remote_send: (%p) Got request.", hio);
1572		ggio = &hio->hio_ggio;
1573		switch (ggio->gctl_cmd) {
1574		case BIO_READ:
1575			cmd = HIO_READ;
1576			data = NULL;
1577			offset = ggio->gctl_offset;
1578			length = ggio->gctl_length;
1579			break;
1580		case BIO_WRITE:
1581			cmd = HIO_WRITE;
1582			data = ggio->gctl_data;
1583			offset = ggio->gctl_offset;
1584			length = ggio->gctl_length;
1585			break;
1586		case BIO_DELETE:
1587			cmd = HIO_DELETE;
1588			data = NULL;
1589			offset = ggio->gctl_offset;
1590			length = ggio->gctl_length;
1591			break;
1592		case BIO_FLUSH:
1593			cmd = HIO_FLUSH;
1594			data = NULL;
1595			offset = 0;
1596			length = 0;
1597			break;
1598		default:
1599			PJDLOG_ABORT("invalid condition");
1600		}
1601		nv = nv_alloc();
1602		nv_add_uint8(nv, cmd, "cmd");
1603		nv_add_uint64(nv, (uint64_t)ggio->gctl_seq, "seq");
1604		nv_add_uint64(nv, offset, "offset");
1605		nv_add_uint64(nv, length, "length");
1606		if (ISMEMSYNCWRITE(hio))
1607			nv_add_uint8(nv, 1, "memsync");
1608		if (nv_error(nv) != 0) {
1609			hio->hio_errors[ncomp] = nv_error(nv);
1610			pjdlog_debug(2,
1611			    "remote_send: (%p) Unable to prepare header to send.",
1612			    hio);
1613			reqlog(LOG_ERR, 0, ggio,
1614			    "Unable to prepare header to send (%s): ",
1615			    strerror(nv_error(nv)));
1616			/* Move failed request immediately to the done queue. */
1617			goto done_queue;
1618		}
1619		/*
1620		 * Protect connection from disappearing.
1621		 */
1622		rw_rlock(&hio_remote_lock[ncomp]);
1623		if (!ISCONNECTED(res, ncomp)) {
1624			rw_unlock(&hio_remote_lock[ncomp]);
1625			hio->hio_errors[ncomp] = ENOTCONN;
1626			goto done_queue;
1627		}
1628		/*
1629		 * Move the request to recv queue before sending it, because
1630		 * in different order we can get reply before we move request
1631		 * to recv queue.
1632		 */
1633		pjdlog_debug(2,
1634		    "remote_send: (%p) Moving request to the recv queue.",
1635		    hio);
1636		mtx_lock(&hio_recv_list_lock[ncomp]);
1637		wakeup = TAILQ_EMPTY(&hio_recv_list[ncomp]);
1638		TAILQ_INSERT_TAIL(&hio_recv_list[ncomp], hio, hio_next[ncomp]);
1639		hio_recv_list_size[ncomp]++;
1640		mtx_unlock(&hio_recv_list_lock[ncomp]);
1641		if (hast_proto_send(res, res->hr_remoteout, nv, data,
1642		    data != NULL ? length : 0) == -1) {
1643			hio->hio_errors[ncomp] = errno;
1644			rw_unlock(&hio_remote_lock[ncomp]);
1645			pjdlog_debug(2,
1646			    "remote_send: (%p) Unable to send request.", hio);
1647			reqlog(LOG_ERR, 0, ggio,
1648			    "Unable to send request (%s): ",
1649			    strerror(hio->hio_errors[ncomp]));
1650			remote_close(res, ncomp);
1651		} else {
1652			rw_unlock(&hio_remote_lock[ncomp]);
1653		}
1654		nv_free(nv);
1655		if (wakeup)
1656			cv_signal(&hio_recv_list_cond[ncomp]);
1657		continue;
1658done_queue:
1659		nv_free(nv);
1660		if (ISSYNCREQ(hio)) {
1661			if (refcnt_release(&hio->hio_countdown) > 0)
1662				continue;
1663			mtx_lock(&sync_lock);
1664			SYNCREQDONE(hio);
1665			mtx_unlock(&sync_lock);
1666			cv_signal(&sync_cond);
1667			continue;
1668		}
1669		if (ggio->gctl_cmd == BIO_WRITE) {
1670			mtx_lock(&res->hr_amp_lock);
1671			if (activemap_need_sync(res->hr_amp, ggio->gctl_offset,
1672			    ggio->gctl_length)) {
1673				(void)hast_activemap_flush(res);
1674			} else {
1675				mtx_unlock(&res->hr_amp_lock);
1676			}
1677			if (ISMEMSYNCWRITE(hio)) {
1678				if (refcnt_release(&hio->hio_writecount) == 0) {
1679					if (hio->hio_errors[0] == 0)
1680						write_complete(res, hio);
1681				}
1682			}
1683		}
1684		if (refcnt_release(&hio->hio_countdown) > 0)
1685			continue;
1686		pjdlog_debug(2,
1687		    "remote_send: (%p) Moving request to the done queue.",
1688		    hio);
1689		QUEUE_INSERT2(hio, done);
1690	}
1691	/* NOTREACHED */
1692	return (NULL);
1693}
1694
1695/*
1696 * Thread receives answer from secondary node and passes it to ggate_send
1697 * thread.
1698 */
1699static void *
1700remote_recv_thread(void *arg)
1701{
1702	struct hast_resource *res = arg;
1703	struct g_gate_ctl_io *ggio;
1704	struct hio *hio;
1705	struct nv *nv;
1706	unsigned int ncomp;
1707	uint64_t seq;
1708	bool memsyncack;
1709	int error;
1710
1711	/* Remote component is 1 for now. */
1712	ncomp = 1;
1713
1714	for (;;) {
1715		/* Wait until there is anything to receive. */
1716		mtx_lock(&hio_recv_list_lock[ncomp]);
1717		while (TAILQ_EMPTY(&hio_recv_list[ncomp])) {
1718			pjdlog_debug(2, "remote_recv: No requests, waiting.");
1719			cv_wait(&hio_recv_list_cond[ncomp],
1720			    &hio_recv_list_lock[ncomp]);
1721		}
1722		mtx_unlock(&hio_recv_list_lock[ncomp]);
1723
1724		memsyncack = false;
1725
1726		rw_rlock(&hio_remote_lock[ncomp]);
1727		if (!ISCONNECTED(res, ncomp)) {
1728			rw_unlock(&hio_remote_lock[ncomp]);
1729			/*
1730			 * Connection is dead, so move all pending requests to
1731			 * the done queue (one-by-one).
1732			 */
1733			mtx_lock(&hio_recv_list_lock[ncomp]);
1734			hio = TAILQ_FIRST(&hio_recv_list[ncomp]);
1735			PJDLOG_ASSERT(hio != NULL);
1736			TAILQ_REMOVE(&hio_recv_list[ncomp], hio,
1737			    hio_next[ncomp]);
1738			hio_recv_list_size[ncomp]--;
1739			mtx_unlock(&hio_recv_list_lock[ncomp]);
1740			hio->hio_errors[ncomp] = ENOTCONN;
1741			goto done_queue;
1742		}
1743		if (hast_proto_recv_hdr(res->hr_remotein, &nv) == -1) {
1744			pjdlog_errno(LOG_ERR,
1745			    "Unable to receive reply header");
1746			rw_unlock(&hio_remote_lock[ncomp]);
1747			remote_close(res, ncomp);
1748			continue;
1749		}
1750		rw_unlock(&hio_remote_lock[ncomp]);
1751		seq = nv_get_uint64(nv, "seq");
1752		if (seq == 0) {
1753			pjdlog_error("Header contains no 'seq' field.");
1754			nv_free(nv);
1755			continue;
1756		}
1757		memsyncack = nv_exists(nv, "received");
1758		mtx_lock(&hio_recv_list_lock[ncomp]);
1759		TAILQ_FOREACH(hio, &hio_recv_list[ncomp], hio_next[ncomp]) {
1760			if (hio->hio_ggio.gctl_seq == seq) {
1761				TAILQ_REMOVE(&hio_recv_list[ncomp], hio,
1762				    hio_next[ncomp]);
1763				hio_recv_list_size[ncomp]--;
1764				break;
1765			}
1766		}
1767		mtx_unlock(&hio_recv_list_lock[ncomp]);
1768		if (hio == NULL) {
1769			pjdlog_error("Found no request matching received 'seq' field (%ju).",
1770			    (uintmax_t)seq);
1771			nv_free(nv);
1772			continue;
1773		}
1774		ggio = &hio->hio_ggio;
1775		error = nv_get_int16(nv, "error");
1776		if (error != 0) {
1777			/* Request failed on remote side. */
1778			hio->hio_errors[ncomp] = error;
1779			reqlog(LOG_WARNING, 0, ggio,
1780			    "Remote request failed (%s): ", strerror(error));
1781			nv_free(nv);
1782			goto done_queue;
1783		}
1784		switch (ggio->gctl_cmd) {
1785		case BIO_READ:
1786			rw_rlock(&hio_remote_lock[ncomp]);
1787			if (!ISCONNECTED(res, ncomp)) {
1788				rw_unlock(&hio_remote_lock[ncomp]);
1789				nv_free(nv);
1790				goto done_queue;
1791			}
1792			if (hast_proto_recv_data(res, res->hr_remotein, nv,
1793			    ggio->gctl_data, ggio->gctl_length) == -1) {
1794				hio->hio_errors[ncomp] = errno;
1795				pjdlog_errno(LOG_ERR,
1796				    "Unable to receive reply data");
1797				rw_unlock(&hio_remote_lock[ncomp]);
1798				nv_free(nv);
1799				remote_close(res, ncomp);
1800				goto done_queue;
1801			}
1802			rw_unlock(&hio_remote_lock[ncomp]);
1803			break;
1804		case BIO_WRITE:
1805		case BIO_DELETE:
1806		case BIO_FLUSH:
1807			break;
1808		default:
1809			PJDLOG_ABORT("invalid condition");
1810		}
1811		hio->hio_errors[ncomp] = 0;
1812		nv_free(nv);
1813done_queue:
1814		if (ISMEMSYNCWRITE(hio)) {
1815			if (!hio->hio_memsyncacked) {
1816				PJDLOG_ASSERT(memsyncack ||
1817				    hio->hio_errors[ncomp] != 0);
1818				/* Remote ack arrived. */
1819				if (refcnt_release(&hio->hio_writecount) == 0) {
1820					if (hio->hio_errors[0] == 0)
1821						write_complete(res, hio);
1822				}
1823				hio->hio_memsyncacked = true;
1824				if (hio->hio_errors[ncomp] == 0) {
1825					pjdlog_debug(2,
1826					    "remote_recv: (%p) Moving request "
1827					    "back to the recv queue.", hio);
1828					mtx_lock(&hio_recv_list_lock[ncomp]);
1829					TAILQ_INSERT_TAIL(&hio_recv_list[ncomp],
1830					    hio, hio_next[ncomp]);
1831					hio_recv_list_size[ncomp]++;
1832					mtx_unlock(&hio_recv_list_lock[ncomp]);
1833					continue;
1834				}
1835			} else {
1836				PJDLOG_ASSERT(!memsyncack);
1837				/* Remote final reply arrived. */
1838			}
1839		}
1840		if (refcnt_release(&hio->hio_countdown) > 0)
1841			continue;
1842		if (ISSYNCREQ(hio)) {
1843			mtx_lock(&sync_lock);
1844			SYNCREQDONE(hio);
1845			mtx_unlock(&sync_lock);
1846			cv_signal(&sync_cond);
1847		} else {
1848			pjdlog_debug(2,
1849			    "remote_recv: (%p) Moving request to the done queue.",
1850			    hio);
1851			QUEUE_INSERT2(hio, done);
1852		}
1853	}
1854	/* NOTREACHED */
1855	return (NULL);
1856}
1857
1858/*
1859 * Thread sends answer to the kernel.
1860 */
1861static void *
1862ggate_send_thread(void *arg)
1863{
1864	struct hast_resource *res = arg;
1865	struct g_gate_ctl_io *ggio;
1866	struct hio *hio;
1867	unsigned int ii, ncomps;
1868
1869	ncomps = HAST_NCOMPONENTS;
1870
1871	for (;;) {
1872		pjdlog_debug(2, "ggate_send: Taking request.");
1873		QUEUE_TAKE2(hio, done);
1874		pjdlog_debug(2, "ggate_send: (%p) Got request.", hio);
1875		ggio = &hio->hio_ggio;
1876		for (ii = 0; ii < ncomps; ii++) {
1877			if (hio->hio_errors[ii] == 0) {
1878				/*
1879				 * One successful request is enough to declare
1880				 * success.
1881				 */
1882				ggio->gctl_error = 0;
1883				break;
1884			}
1885		}
1886		if (ii == ncomps) {
1887			/*
1888			 * None of the requests were successful.
1889			 * Use the error from local component except the
1890			 * case when we did only remote request.
1891			 */
1892			if (ggio->gctl_cmd == BIO_READ &&
1893			    res->hr_syncsrc == HAST_SYNCSRC_SECONDARY)
1894				ggio->gctl_error = hio->hio_errors[1];
1895			else
1896				ggio->gctl_error = hio->hio_errors[0];
1897		}
1898		if (ggio->gctl_error == 0 && ggio->gctl_cmd == BIO_WRITE) {
1899			mtx_lock(&res->hr_amp_lock);
1900			if (activemap_write_complete(res->hr_amp,
1901			    ggio->gctl_offset, ggio->gctl_length)) {
1902				res->hr_stat_activemap_update++;
1903				(void)hast_activemap_flush(res);
1904			} else {
1905				mtx_unlock(&res->hr_amp_lock);
1906			}
1907		}
1908		if (ggio->gctl_cmd == BIO_WRITE) {
1909			/*
1910			 * Unlock range we locked.
1911			 */
1912			mtx_lock(&range_lock);
1913			rangelock_del(range_regular, ggio->gctl_offset,
1914			    ggio->gctl_length);
1915			if (range_sync_wait)
1916				cv_signal(&range_sync_cond);
1917			mtx_unlock(&range_lock);
1918			if (!hio->hio_done)
1919				write_complete(res, hio);
1920		} else {
1921			if (ioctl(res->hr_ggatefd, G_GATE_CMD_DONE, ggio) == -1) {
1922				primary_exit(EX_OSERR,
1923				    "G_GATE_CMD_DONE failed");
1924			}
1925		}
1926		if (hio->hio_errors[0]) {
1927			switch (ggio->gctl_cmd) {
1928			case BIO_READ:
1929				res->hr_stat_read_error++;
1930				break;
1931			case BIO_WRITE:
1932				res->hr_stat_write_error++;
1933				break;
1934			case BIO_DELETE:
1935				res->hr_stat_delete_error++;
1936				break;
1937			case BIO_FLUSH:
1938				res->hr_stat_flush_error++;
1939				break;
1940			}
1941		}
1942		pjdlog_debug(2,
1943		    "ggate_send: (%p) Moving request to the free queue.", hio);
1944		QUEUE_INSERT2(hio, free);
1945	}
1946	/* NOTREACHED */
1947	return (NULL);
1948}
1949
1950/*
1951 * Thread synchronize local and remote components.
1952 */
1953static void *
1954sync_thread(void *arg __unused)
1955{
1956	struct hast_resource *res = arg;
1957	struct hio *hio;
1958	struct g_gate_ctl_io *ggio;
1959	struct timeval tstart, tend, tdiff;
1960	unsigned int ii, ncomp, ncomps;
1961	off_t offset, length, synced;
1962	bool dorewind, directreads;
1963	int syncext;
1964
1965	ncomps = HAST_NCOMPONENTS;
1966	dorewind = true;
1967	synced = 0;
1968	offset = -1;
1969	directreads = false;
1970
1971	for (;;) {
1972		mtx_lock(&sync_lock);
1973		if (offset >= 0 && !sync_inprogress) {
1974			gettimeofday(&tend, NULL);
1975			timersub(&tend, &tstart, &tdiff);
1976			pjdlog_info("Synchronization interrupted after %#.0T. "
1977			    "%NB synchronized so far.", &tdiff,
1978			    (intmax_t)synced);
1979			event_send(res, EVENT_SYNCINTR);
1980		}
1981		while (!sync_inprogress) {
1982			dorewind = true;
1983			synced = 0;
1984			cv_wait(&sync_cond, &sync_lock);
1985		}
1986		mtx_unlock(&sync_lock);
1987		/*
1988		 * Obtain offset at which we should synchronize.
1989		 * Rewind synchronization if needed.
1990		 */
1991		mtx_lock(&res->hr_amp_lock);
1992		if (dorewind)
1993			activemap_sync_rewind(res->hr_amp);
1994		offset = activemap_sync_offset(res->hr_amp, &length, &syncext);
1995		if (syncext != -1) {
1996			/*
1997			 * We synchronized entire syncext extent, we can mark
1998			 * it as clean now.
1999			 */
2000			if (activemap_extent_complete(res->hr_amp, syncext))
2001				(void)hast_activemap_flush(res);
2002			else
2003				mtx_unlock(&res->hr_amp_lock);
2004		} else {
2005			mtx_unlock(&res->hr_amp_lock);
2006		}
2007		if (dorewind) {
2008			dorewind = false;
2009			if (offset == -1)
2010				pjdlog_info("Nodes are in sync.");
2011			else {
2012				pjdlog_info("Synchronization started. %NB to go.",
2013				    (intmax_t)(res->hr_extentsize *
2014				    activemap_ndirty(res->hr_amp)));
2015				event_send(res, EVENT_SYNCSTART);
2016				gettimeofday(&tstart, NULL);
2017			}
2018		}
2019		if (offset == -1) {
2020			sync_stop();
2021			pjdlog_debug(1, "Nothing to synchronize.");
2022			/*
2023			 * Synchronization complete, make both localcnt and
2024			 * remotecnt equal.
2025			 */
2026			ncomp = 1;
2027			rw_rlock(&hio_remote_lock[ncomp]);
2028			if (ISCONNECTED(res, ncomp)) {
2029				if (synced > 0) {
2030					int64_t bps;
2031
2032					gettimeofday(&tend, NULL);
2033					timersub(&tend, &tstart, &tdiff);
2034					bps = (int64_t)((double)synced /
2035					    ((double)tdiff.tv_sec +
2036					    (double)tdiff.tv_usec / 1000000));
2037					pjdlog_info("Synchronization complete. "
2038					    "%NB synchronized in %#.0lT (%NB/sec).",
2039					    (intmax_t)synced, &tdiff,
2040					    (intmax_t)bps);
2041					event_send(res, EVENT_SYNCDONE);
2042				}
2043				mtx_lock(&metadata_lock);
2044				if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY)
2045					directreads = true;
2046				res->hr_syncsrc = HAST_SYNCSRC_UNDEF;
2047				res->hr_primary_localcnt =
2048				    res->hr_secondary_remotecnt;
2049				res->hr_primary_remotecnt =
2050				    res->hr_secondary_localcnt;
2051				pjdlog_debug(1,
2052				    "Setting localcnt to %ju and remotecnt to %ju.",
2053				    (uintmax_t)res->hr_primary_localcnt,
2054				    (uintmax_t)res->hr_primary_remotecnt);
2055				(void)metadata_write(res);
2056				mtx_unlock(&metadata_lock);
2057			}
2058			rw_unlock(&hio_remote_lock[ncomp]);
2059			if (directreads) {
2060				directreads = false;
2061				enable_direct_reads(res);
2062			}
2063			continue;
2064		}
2065		pjdlog_debug(2, "sync: Taking free request.");
2066		QUEUE_TAKE2(hio, free);
2067		pjdlog_debug(2, "sync: (%p) Got free request.", hio);
2068		/*
2069		 * Lock the range we are going to synchronize. We don't want
2070		 * race where someone writes between our read and write.
2071		 */
2072		for (;;) {
2073			mtx_lock(&range_lock);
2074			if (rangelock_islocked(range_regular, offset, length)) {
2075				pjdlog_debug(2,
2076				    "sync: Range offset=%jd length=%jd locked.",
2077				    (intmax_t)offset, (intmax_t)length);
2078				range_sync_wait = true;
2079				cv_wait(&range_sync_cond, &range_lock);
2080				range_sync_wait = false;
2081				mtx_unlock(&range_lock);
2082				continue;
2083			}
2084			if (rangelock_add(range_sync, offset, length) == -1) {
2085				mtx_unlock(&range_lock);
2086				pjdlog_debug(2,
2087				    "sync: Range offset=%jd length=%jd is already locked, waiting.",
2088				    (intmax_t)offset, (intmax_t)length);
2089				sleep(1);
2090				continue;
2091			}
2092			mtx_unlock(&range_lock);
2093			break;
2094		}
2095		/*
2096		 * First read the data from synchronization source.
2097		 */
2098		SYNCREQ(hio);
2099		ggio = &hio->hio_ggio;
2100		ggio->gctl_cmd = BIO_READ;
2101		ggio->gctl_offset = offset;
2102		ggio->gctl_length = length;
2103		ggio->gctl_error = 0;
2104		hio->hio_done = false;
2105		hio->hio_replication = res->hr_replication;
2106		for (ii = 0; ii < ncomps; ii++)
2107			hio->hio_errors[ii] = EINVAL;
2108		reqlog(LOG_DEBUG, 2, ggio, "sync: (%p) Sending sync request: ",
2109		    hio);
2110		pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2111		    hio);
2112		mtx_lock(&metadata_lock);
2113		if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
2114			/*
2115			 * This range is up-to-date on local component,
2116			 * so handle request locally.
2117			 */
2118			 /* Local component is 0 for now. */
2119			ncomp = 0;
2120		} else /* if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY) */ {
2121			PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_SECONDARY);
2122			/*
2123			 * This range is out-of-date on local component,
2124			 * so send request to the remote node.
2125			 */
2126			 /* Remote component is 1 for now. */
2127			ncomp = 1;
2128		}
2129		mtx_unlock(&metadata_lock);
2130		refcnt_init(&hio->hio_countdown, 1);
2131		QUEUE_INSERT1(hio, send, ncomp);
2132
2133		/*
2134		 * Let's wait for READ to finish.
2135		 */
2136		mtx_lock(&sync_lock);
2137		while (!ISSYNCREQDONE(hio))
2138			cv_wait(&sync_cond, &sync_lock);
2139		mtx_unlock(&sync_lock);
2140
2141		if (hio->hio_errors[ncomp] != 0) {
2142			pjdlog_error("Unable to read synchronization data: %s.",
2143			    strerror(hio->hio_errors[ncomp]));
2144			goto free_queue;
2145		}
2146
2147		/*
2148		 * We read the data from synchronization source, now write it
2149		 * to synchronization target.
2150		 */
2151		SYNCREQ(hio);
2152		ggio->gctl_cmd = BIO_WRITE;
2153		for (ii = 0; ii < ncomps; ii++)
2154			hio->hio_errors[ii] = EINVAL;
2155		reqlog(LOG_DEBUG, 2, ggio, "sync: (%p) Sending sync request: ",
2156		    hio);
2157		pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2158		    hio);
2159		mtx_lock(&metadata_lock);
2160		if (res->hr_syncsrc == HAST_SYNCSRC_PRIMARY) {
2161			/*
2162			 * This range is up-to-date on local component,
2163			 * so we update remote component.
2164			 */
2165			 /* Remote component is 1 for now. */
2166			ncomp = 1;
2167		} else /* if (res->hr_syncsrc == HAST_SYNCSRC_SECONDARY) */ {
2168			PJDLOG_ASSERT(res->hr_syncsrc == HAST_SYNCSRC_SECONDARY);
2169			/*
2170			 * This range is out-of-date on local component,
2171			 * so we update it.
2172			 */
2173			 /* Local component is 0 for now. */
2174			ncomp = 0;
2175		}
2176		mtx_unlock(&metadata_lock);
2177
2178		pjdlog_debug(2, "sync: (%p) Moving request to the send queue.",
2179		    hio);
2180		refcnt_init(&hio->hio_countdown, 1);
2181		QUEUE_INSERT1(hio, send, ncomp);
2182
2183		/*
2184		 * Let's wait for WRITE to finish.
2185		 */
2186		mtx_lock(&sync_lock);
2187		while (!ISSYNCREQDONE(hio))
2188			cv_wait(&sync_cond, &sync_lock);
2189		mtx_unlock(&sync_lock);
2190
2191		if (hio->hio_errors[ncomp] != 0) {
2192			pjdlog_error("Unable to write synchronization data: %s.",
2193			    strerror(hio->hio_errors[ncomp]));
2194			goto free_queue;
2195		}
2196
2197		synced += length;
2198free_queue:
2199		mtx_lock(&range_lock);
2200		rangelock_del(range_sync, offset, length);
2201		if (range_regular_wait)
2202			cv_signal(&range_regular_cond);
2203		mtx_unlock(&range_lock);
2204		pjdlog_debug(2, "sync: (%p) Moving request to the free queue.",
2205		    hio);
2206		QUEUE_INSERT2(hio, free);
2207	}
2208	/* NOTREACHED */
2209	return (NULL);
2210}
2211
2212void
2213primary_config_reload(struct hast_resource *res, struct nv *nv)
2214{
2215	unsigned int ii, ncomps;
2216	int modified, vint;
2217	const char *vstr;
2218
2219	pjdlog_info("Reloading configuration...");
2220
2221	PJDLOG_ASSERT(res->hr_role == HAST_ROLE_PRIMARY);
2222	PJDLOG_ASSERT(gres == res);
2223	nv_assert(nv, "remoteaddr");
2224	nv_assert(nv, "sourceaddr");
2225	nv_assert(nv, "replication");
2226	nv_assert(nv, "checksum");
2227	nv_assert(nv, "compression");
2228	nv_assert(nv, "timeout");
2229	nv_assert(nv, "exec");
2230	nv_assert(nv, "metaflush");
2231
2232	ncomps = HAST_NCOMPONENTS;
2233
2234#define MODIFIED_REMOTEADDR	0x01
2235#define MODIFIED_SOURCEADDR	0x02
2236#define MODIFIED_REPLICATION	0x04
2237#define MODIFIED_CHECKSUM	0x08
2238#define MODIFIED_COMPRESSION	0x10
2239#define MODIFIED_TIMEOUT	0x20
2240#define MODIFIED_EXEC		0x40
2241#define MODIFIED_METAFLUSH	0x80
2242	modified = 0;
2243
2244	vstr = nv_get_string(nv, "remoteaddr");
2245	if (strcmp(gres->hr_remoteaddr, vstr) != 0) {
2246		/*
2247		 * Don't copy res->hr_remoteaddr to gres just yet.
2248		 * We want remote_close() to log disconnect from the old
2249		 * addresses, not from the new ones.
2250		 */
2251		modified |= MODIFIED_REMOTEADDR;
2252	}
2253	vstr = nv_get_string(nv, "sourceaddr");
2254	if (strcmp(gres->hr_sourceaddr, vstr) != 0) {
2255		strlcpy(gres->hr_sourceaddr, vstr, sizeof(gres->hr_sourceaddr));
2256		modified |= MODIFIED_SOURCEADDR;
2257	}
2258	vint = nv_get_int32(nv, "replication");
2259	if (gres->hr_replication != vint) {
2260		gres->hr_replication = vint;
2261		modified |= MODIFIED_REPLICATION;
2262	}
2263	vint = nv_get_int32(nv, "checksum");
2264	if (gres->hr_checksum != vint) {
2265		gres->hr_checksum = vint;
2266		modified |= MODIFIED_CHECKSUM;
2267	}
2268	vint = nv_get_int32(nv, "compression");
2269	if (gres->hr_compression != vint) {
2270		gres->hr_compression = vint;
2271		modified |= MODIFIED_COMPRESSION;
2272	}
2273	vint = nv_get_int32(nv, "timeout");
2274	if (gres->hr_timeout != vint) {
2275		gres->hr_timeout = vint;
2276		modified |= MODIFIED_TIMEOUT;
2277	}
2278	vstr = nv_get_string(nv, "exec");
2279	if (strcmp(gres->hr_exec, vstr) != 0) {
2280		strlcpy(gres->hr_exec, vstr, sizeof(gres->hr_exec));
2281		modified |= MODIFIED_EXEC;
2282	}
2283	vint = nv_get_int32(nv, "metaflush");
2284	if (gres->hr_metaflush != vint) {
2285		gres->hr_metaflush = vint;
2286		modified |= MODIFIED_METAFLUSH;
2287	}
2288
2289	/*
2290	 * Change timeout for connected sockets.
2291	 * Don't bother if we need to reconnect.
2292	 */
2293	if ((modified & MODIFIED_TIMEOUT) != 0 &&
2294	    (modified & (MODIFIED_REMOTEADDR | MODIFIED_SOURCEADDR)) == 0) {
2295		for (ii = 0; ii < ncomps; ii++) {
2296			if (!ISREMOTE(ii))
2297				continue;
2298			rw_rlock(&hio_remote_lock[ii]);
2299			if (!ISCONNECTED(gres, ii)) {
2300				rw_unlock(&hio_remote_lock[ii]);
2301				continue;
2302			}
2303			rw_unlock(&hio_remote_lock[ii]);
2304			if (proto_timeout(gres->hr_remotein,
2305			    gres->hr_timeout) == -1) {
2306				pjdlog_errno(LOG_WARNING,
2307				    "Unable to set connection timeout");
2308			}
2309			if (proto_timeout(gres->hr_remoteout,
2310			    gres->hr_timeout) == -1) {
2311				pjdlog_errno(LOG_WARNING,
2312				    "Unable to set connection timeout");
2313			}
2314		}
2315	}
2316	if ((modified & (MODIFIED_REMOTEADDR | MODIFIED_SOURCEADDR)) != 0) {
2317		for (ii = 0; ii < ncomps; ii++) {
2318			if (!ISREMOTE(ii))
2319				continue;
2320			remote_close(gres, ii);
2321		}
2322		if (modified & MODIFIED_REMOTEADDR) {
2323			vstr = nv_get_string(nv, "remoteaddr");
2324			strlcpy(gres->hr_remoteaddr, vstr,
2325			    sizeof(gres->hr_remoteaddr));
2326		}
2327	}
2328#undef	MODIFIED_REMOTEADDR
2329#undef	MODIFIED_SOURCEADDR
2330#undef	MODIFIED_REPLICATION
2331#undef	MODIFIED_CHECKSUM
2332#undef	MODIFIED_COMPRESSION
2333#undef	MODIFIED_TIMEOUT
2334#undef	MODIFIED_EXEC
2335#undef	MODIFIED_METAFLUSH
2336
2337	pjdlog_info("Configuration reloaded successfully.");
2338}
2339
2340static void
2341guard_one(struct hast_resource *res, unsigned int ncomp)
2342{
2343	struct proto_conn *in, *out;
2344
2345	if (!ISREMOTE(ncomp))
2346		return;
2347
2348	rw_rlock(&hio_remote_lock[ncomp]);
2349
2350	if (!real_remote(res)) {
2351		rw_unlock(&hio_remote_lock[ncomp]);
2352		return;
2353	}
2354
2355	if (ISCONNECTED(res, ncomp)) {
2356		PJDLOG_ASSERT(res->hr_remotein != NULL);
2357		PJDLOG_ASSERT(res->hr_remoteout != NULL);
2358		rw_unlock(&hio_remote_lock[ncomp]);
2359		pjdlog_debug(2, "remote_guard: Connection to %s is ok.",
2360		    res->hr_remoteaddr);
2361		return;
2362	}
2363
2364	PJDLOG_ASSERT(res->hr_remotein == NULL);
2365	PJDLOG_ASSERT(res->hr_remoteout == NULL);
2366	/*
2367	 * Upgrade the lock. It doesn't have to be atomic as no other thread
2368	 * can change connection status from disconnected to connected.
2369	 */
2370	rw_unlock(&hio_remote_lock[ncomp]);
2371	pjdlog_debug(2, "remote_guard: Reconnecting to %s.",
2372	    res->hr_remoteaddr);
2373	in = out = NULL;
2374	if (init_remote(res, &in, &out) == 0) {
2375		rw_wlock(&hio_remote_lock[ncomp]);
2376		PJDLOG_ASSERT(res->hr_remotein == NULL);
2377		PJDLOG_ASSERT(res->hr_remoteout == NULL);
2378		PJDLOG_ASSERT(in != NULL && out != NULL);
2379		res->hr_remotein = in;
2380		res->hr_remoteout = out;
2381		rw_unlock(&hio_remote_lock[ncomp]);
2382		pjdlog_info("Successfully reconnected to %s.",
2383		    res->hr_remoteaddr);
2384		sync_start();
2385	} else {
2386		/* Both connections should be NULL. */
2387		PJDLOG_ASSERT(res->hr_remotein == NULL);
2388		PJDLOG_ASSERT(res->hr_remoteout == NULL);
2389		PJDLOG_ASSERT(in == NULL && out == NULL);
2390		pjdlog_debug(2, "remote_guard: Reconnect to %s failed.",
2391		    res->hr_remoteaddr);
2392	}
2393}
2394
2395/*
2396 * Thread guards remote connections and reconnects when needed, handles
2397 * signals, etc.
2398 */
2399static void *
2400guard_thread(void *arg)
2401{
2402	struct hast_resource *res = arg;
2403	unsigned int ii, ncomps;
2404	struct timespec timeout;
2405	time_t lastcheck, now;
2406	sigset_t mask;
2407	int signo;
2408
2409	ncomps = HAST_NCOMPONENTS;
2410	lastcheck = time(NULL);
2411
2412	PJDLOG_VERIFY(sigemptyset(&mask) == 0);
2413	PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0);
2414	PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0);
2415
2416	timeout.tv_sec = HAST_KEEPALIVE;
2417	timeout.tv_nsec = 0;
2418	signo = -1;
2419
2420	for (;;) {
2421		switch (signo) {
2422		case SIGINT:
2423		case SIGTERM:
2424			sigexit_received = true;
2425			primary_exitx(EX_OK,
2426			    "Termination signal received, exiting.");
2427			break;
2428		default:
2429			break;
2430		}
2431
2432		/*
2433		 * Don't check connections until we fully started,
2434		 * as we may still be looping, waiting for remote node
2435		 * to switch from primary to secondary.
2436		 */
2437		if (fullystarted) {
2438			pjdlog_debug(2, "remote_guard: Checking connections.");
2439			now = time(NULL);
2440			if (lastcheck + HAST_KEEPALIVE <= now) {
2441				for (ii = 0; ii < ncomps; ii++)
2442					guard_one(res, ii);
2443				lastcheck = now;
2444			}
2445		}
2446		signo = sigtimedwait(&mask, NULL, &timeout);
2447	}
2448	/* NOTREACHED */
2449	return (NULL);
2450}
2451