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-rw-r--r--sbin/hastd/secondary.c697
1 files changed, 697 insertions, 0 deletions
diff --git a/sbin/hastd/secondary.c b/sbin/hastd/secondary.c
new file mode 100644
index 0000000..6af95b5
--- /dev/null
+++ b/sbin/hastd/secondary.c
@@ -0,0 +1,697 @@
+/*-
+ * Copyright (c) 2009-2010 The FreeBSD Foundation
+ * All rights reserved.
+ *
+ * This software was developed by Pawel Jakub Dawidek under sponsorship from
+ * the FreeBSD Foundation.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted provided that the following conditions
+ * are met:
+ * 1. Redistributions of source code must retain the above copyright
+ * notice, this list of conditions and the following disclaimer.
+ * 2. Redistributions in binary form must reproduce the above copyright
+ * notice, this list of conditions and the following disclaimer in the
+ * documentation and/or other materials provided with the distribution.
+ *
+ * THIS SOFTWARE IS PROVIDED BY THE AUTHORS AND CONTRIBUTORS ``AS IS'' AND
+ * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
+ * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
+ * ARE DISCLAIMED. IN NO EVENT SHALL THE AUTHORS OR CONTRIBUTORS BE LIABLE
+ * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
+ * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
+ * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
+ * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
+ * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
+ * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
+ * SUCH DAMAGE.
+ */
+
+#include <sys/cdefs.h>
+__FBSDID("$FreeBSD$");
+
+#include <sys/param.h>
+#include <sys/time.h>
+#include <sys/bio.h>
+#include <sys/disk.h>
+#include <sys/stat.h>
+
+#include <assert.h>
+#include <err.h>
+#include <errno.h>
+#include <fcntl.h>
+#include <libgeom.h>
+#include <pthread.h>
+#include <stdint.h>
+#include <stdio.h>
+#include <string.h>
+#include <sysexits.h>
+#include <unistd.h>
+
+#include <activemap.h>
+#include <nv.h>
+#include <pjdlog.h>
+
+#include "control.h"
+#include "hast.h"
+#include "hast_proto.h"
+#include "hastd.h"
+#include "metadata.h"
+#include "proto.h"
+#include "subr.h"
+#include "synch.h"
+
+struct hio {
+ uint64_t hio_seq;
+ int hio_error;
+ struct nv *hio_nv;
+ void *hio_data;
+ uint8_t hio_cmd;
+ uint64_t hio_offset;
+ uint64_t hio_length;
+ TAILQ_ENTRY(hio) hio_next;
+};
+
+/*
+ * Free list holds unused structures. When free list is empty, we have to wait
+ * until some in-progress requests are freed.
+ */
+static TAILQ_HEAD(, hio) hio_free_list;
+static pthread_mutex_t hio_free_list_lock;
+static pthread_cond_t hio_free_list_cond;
+/*
+ * Disk thread (the one that do I/O requests) takes requests from this list.
+ */
+static TAILQ_HEAD(, hio) hio_disk_list;
+static pthread_mutex_t hio_disk_list_lock;
+static pthread_cond_t hio_disk_list_cond;
+/*
+ * There is one recv list for every component, although local components don't
+ * use recv lists as local requests are done synchronously.
+ */
+static TAILQ_HEAD(, hio) hio_send_list;
+static pthread_mutex_t hio_send_list_lock;
+static pthread_cond_t hio_send_list_cond;
+
+/*
+ * Maximum number of outstanding I/O requests.
+ */
+#define HAST_HIO_MAX 256
+
+static void *recv_thread(void *arg);
+static void *disk_thread(void *arg);
+static void *send_thread(void *arg);
+
+static void
+init_environment(void)
+{
+ struct hio *hio;
+ unsigned int ii;
+
+ /*
+ * Initialize lists, their locks and theirs condition variables.
+ */
+ TAILQ_INIT(&hio_free_list);
+ mtx_init(&hio_free_list_lock);
+ cv_init(&hio_free_list_cond);
+ TAILQ_INIT(&hio_disk_list);
+ mtx_init(&hio_disk_list_lock);
+ cv_init(&hio_disk_list_cond);
+ TAILQ_INIT(&hio_send_list);
+ mtx_init(&hio_send_list_lock);
+ cv_init(&hio_send_list_cond);
+
+ /*
+ * Allocate requests pool and initialize requests.
+ */
+ for (ii = 0; ii < HAST_HIO_MAX; ii++) {
+ hio = malloc(sizeof(*hio));
+ if (hio == NULL) {
+ errx(EX_TEMPFAIL, "cannot allocate %zu bytes of memory "
+ "for hio request", sizeof(*hio));
+ }
+ hio->hio_error = 0;
+ hio->hio_data = malloc(MAXPHYS);
+ if (hio->hio_data == NULL) {
+ errx(EX_TEMPFAIL, "cannot allocate %zu bytes of memory "
+ "for gctl_data", (size_t)MAXPHYS);
+ }
+ TAILQ_INSERT_HEAD(&hio_free_list, hio, hio_next);
+ }
+}
+
+static void
+init_local(struct hast_resource *res)
+{
+
+ if (metadata_read(res, true) < 0)
+ exit(EX_NOINPUT);
+}
+
+static void
+init_remote(struct hast_resource *res, struct nv *nvin)
+{
+ uint64_t resuid;
+ struct nv *nvout;
+ unsigned char *map;
+ size_t mapsize;
+
+ map = NULL;
+ mapsize = 0;
+ nvout = nv_alloc();
+ nv_add_int64(nvout, (int64_t)res->hr_datasize, "datasize");
+ nv_add_int32(nvout, (int32_t)res->hr_extentsize, "extentsize");
+ resuid = nv_get_uint64(nvin, "resuid");
+ res->hr_primary_localcnt = nv_get_uint64(nvin, "localcnt");
+ res->hr_primary_remotecnt = nv_get_uint64(nvin, "remotecnt");
+ nv_add_uint64(nvout, res->hr_secondary_localcnt, "localcnt");
+ nv_add_uint64(nvout, res->hr_secondary_remotecnt, "remotecnt");
+ mapsize = activemap_calc_ondisk_size(res->hr_local_mediasize -
+ METADATA_SIZE, res->hr_extentsize, res->hr_local_sectorsize);
+ map = malloc(mapsize);
+ if (map == NULL) {
+ pjdlog_exitx(EX_TEMPFAIL,
+ "Unable to allocate memory (%zu bytes) for activemap.",
+ mapsize);
+ }
+ nv_add_uint32(nvout, (uint32_t)mapsize, "mapsize");
+ /*
+ * When we work as primary and secondary is missing we will increase
+ * localcnt in our metadata. When secondary is connected and synced
+ * we make localcnt be equal to remotecnt, which means nodes are more
+ * or less in sync.
+ * Split-brain condition is when both nodes are not able to communicate
+ * and are both configured as primary nodes. In turn, they can both
+ * make incompatible changes to the data and we have to detect that.
+ * Under split-brain condition we will increase our localcnt on first
+ * write and remote node will increase its localcnt on first write.
+ * When we connect we can see that primary's localcnt is greater than
+ * our remotecnt (primary was modified while we weren't watching) and
+ * our localcnt is greater than primary's remotecnt (we were modified
+ * while primary wasn't watching).
+ * There are many possible combinations which are all gathered below.
+ * Don't pay too much attention to exact numbers, the more important
+ * is to compare them. We compare secondary's local with primary's
+ * remote and secondary's remote with primary's local.
+ * Note that every case where primary's localcnt is smaller than
+ * secondary's remotecnt and where secondary's localcnt is smaller than
+ * primary's remotecnt should be impossible in practise. We will perform
+ * full synchronization then. Those cases are marked with an asterisk.
+ * Regular synchronization means that only extents marked as dirty are
+ * synchronized (regular synchronization).
+ *
+ * SECONDARY METADATA PRIMARY METADATA
+ * local=3 remote=3 local=2 remote=2* ?! Full sync from secondary.
+ * local=3 remote=3 local=2 remote=3* ?! Full sync from primary.
+ * local=3 remote=3 local=2 remote=4* ?! Full sync from primary.
+ * local=3 remote=3 local=3 remote=2 Primary is out-of-date,
+ * regular sync from secondary.
+ * local=3 remote=3 local=3 remote=3 Regular sync just in case.
+ * local=3 remote=3 local=3 remote=4* ?! Full sync from primary.
+ * local=3 remote=3 local=4 remote=2 Split-brain condition.
+ * local=3 remote=3 local=4 remote=3 Secondary out-of-date,
+ * regular sync from primary.
+ * local=3 remote=3 local=4 remote=4* ?! Full sync from primary.
+ */
+ if (res->hr_resuid == 0) {
+ /*
+ * Provider is used for the first time. Initialize everything.
+ */
+ assert(res->hr_secondary_localcnt == 0);
+ res->hr_resuid = resuid;
+ if (metadata_write(res) < 0)
+ exit(EX_NOINPUT);
+ memset(map, 0xff, mapsize);
+ nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
+ } else if (
+ /* Is primary is out-of-date? */
+ (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
+ res->hr_secondary_remotecnt == res->hr_primary_localcnt) ||
+ /* Node are more or less in sync? */
+ (res->hr_secondary_localcnt == res->hr_primary_remotecnt &&
+ res->hr_secondary_remotecnt == res->hr_primary_localcnt) ||
+ /* Is secondary is out-of-date? */
+ (res->hr_secondary_localcnt == res->hr_primary_remotecnt &&
+ res->hr_secondary_remotecnt < res->hr_primary_localcnt)) {
+ /*
+ * Nodes are more or less in sync or one of the nodes is
+ * out-of-date.
+ * It doesn't matter at this point which one, we just have to
+ * send out local bitmap to the remote node.
+ */
+ if (pread(res->hr_localfd, map, mapsize, METADATA_SIZE) !=
+ (ssize_t)mapsize) {
+ pjdlog_exit(LOG_ERR, "Unable to read activemap");
+ }
+ if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
+ res->hr_secondary_remotecnt == res->hr_primary_localcnt) {
+ /* Primary is out-of-date, sync from secondary. */
+ nv_add_uint8(nvout, HAST_SYNCSRC_SECONDARY, "syncsrc");
+ } else {
+ /*
+ * Secondary is out-of-date or counts match.
+ * Sync from primary.
+ */
+ nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
+ }
+ } else if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
+ res->hr_primary_localcnt > res->hr_secondary_remotecnt) {
+ /*
+ * Not good, we have split-brain condition.
+ */
+ pjdlog_error("Split-brain detected, exiting.");
+ nv_add_string(nvout, "Split-brain condition!", "errmsg");
+ free(map);
+ map = NULL;
+ mapsize = 0;
+ } else /* if (res->hr_secondary_localcnt < res->hr_primary_remotecnt ||
+ res->hr_primary_localcnt < res->hr_secondary_remotecnt) */ {
+ /*
+ * This should never happen in practise, but we will perform
+ * full synchronization.
+ */
+ assert(res->hr_secondary_localcnt < res->hr_primary_remotecnt ||
+ res->hr_primary_localcnt < res->hr_secondary_remotecnt);
+ mapsize = activemap_calc_ondisk_size(res->hr_local_mediasize -
+ METADATA_SIZE, res->hr_extentsize,
+ res->hr_local_sectorsize);
+ memset(map, 0xff, mapsize);
+ if (res->hr_secondary_localcnt > res->hr_primary_remotecnt) {
+ /* In this one of five cases sync from secondary. */
+ nv_add_uint8(nvout, HAST_SYNCSRC_SECONDARY, "syncsrc");
+ } else {
+ /* For the rest four cases sync from primary. */
+ nv_add_uint8(nvout, HAST_SYNCSRC_PRIMARY, "syncsrc");
+ }
+ pjdlog_warning("This should never happen, asking for full synchronization (primary(local=%ju, remote=%ju), secondary(local=%ju, remote=%ju)).",
+ (uintmax_t)res->hr_primary_localcnt,
+ (uintmax_t)res->hr_primary_remotecnt,
+ (uintmax_t)res->hr_secondary_localcnt,
+ (uintmax_t)res->hr_secondary_remotecnt);
+ }
+ if (hast_proto_send(res, res->hr_remotein, nvout, map, mapsize) < 0) {
+ pjdlog_errno(LOG_WARNING, "Unable to send activemap to %s",
+ res->hr_remoteaddr);
+ nv_free(nvout);
+ exit(EX_TEMPFAIL);
+ }
+ if (res->hr_secondary_localcnt > res->hr_primary_remotecnt &&
+ res->hr_primary_localcnt > res->hr_secondary_remotecnt) {
+ /* Exit on split-brain. */
+ exit(EX_CONFIG);
+ }
+}
+
+void
+hastd_secondary(struct hast_resource *res, struct nv *nvin)
+{
+ pthread_t td;
+ pid_t pid;
+ int error;
+
+ /*
+ * Create communication channel between parent and child.
+ */
+ if (proto_client("socketpair://", &res->hr_ctrl) < 0) {
+ KEEP_ERRNO((void)pidfile_remove(pfh));
+ pjdlog_exit(EX_OSERR,
+ "Unable to create control sockets between parent and child");
+ }
+
+ pid = fork();
+ if (pid < 0) {
+ KEEP_ERRNO((void)pidfile_remove(pfh));
+ pjdlog_exit(EX_OSERR, "Unable to fork");
+ }
+
+ if (pid > 0) {
+ /* This is parent. */
+ proto_close(res->hr_remotein);
+ res->hr_remotein = NULL;
+ proto_close(res->hr_remoteout);
+ res->hr_remoteout = NULL;
+ res->hr_workerpid = pid;
+ return;
+ }
+ (void)pidfile_close(pfh);
+
+ setproctitle("%s (secondary)", res->hr_name);
+
+ init_local(res);
+ init_remote(res, nvin);
+ init_environment();
+
+ error = pthread_create(&td, NULL, recv_thread, res);
+ assert(error == 0);
+ error = pthread_create(&td, NULL, disk_thread, res);
+ assert(error == 0);
+ error = pthread_create(&td, NULL, send_thread, res);
+ assert(error == 0);
+ (void)ctrl_thread(res);
+}
+
+static void
+reqlog(int loglevel, int debuglevel, int error, struct hio *hio, const char *fmt, ...)
+{
+ char msg[1024];
+ va_list ap;
+ int len;
+
+ va_start(ap, fmt);
+ len = vsnprintf(msg, sizeof(msg), fmt, ap);
+ va_end(ap);
+ if ((size_t)len < sizeof(msg)) {
+ switch (hio->hio_cmd) {
+ case HIO_READ:
+ (void)snprintf(msg + len, sizeof(msg) - len,
+ "READ(%ju, %ju).", (uintmax_t)hio->hio_offset,
+ (uintmax_t)hio->hio_length);
+ break;
+ case HIO_DELETE:
+ (void)snprintf(msg + len, sizeof(msg) - len,
+ "DELETE(%ju, %ju).", (uintmax_t)hio->hio_offset,
+ (uintmax_t)hio->hio_length);
+ break;
+ case HIO_FLUSH:
+ (void)snprintf(msg + len, sizeof(msg) - len, "FLUSH.");
+ break;
+ case HIO_WRITE:
+ (void)snprintf(msg + len, sizeof(msg) - len,
+ "WRITE(%ju, %ju).", (uintmax_t)hio->hio_offset,
+ (uintmax_t)hio->hio_length);
+ break;
+ default:
+ (void)snprintf(msg + len, sizeof(msg) - len,
+ "UNKNOWN(%u).", (unsigned int)hio->hio_cmd);
+ break;
+ }
+ }
+ pjdlog_common(loglevel, debuglevel, error, "%s", msg);
+}
+
+static int
+requnpack(struct hast_resource *res, struct hio *hio)
+{
+
+ hio->hio_cmd = nv_get_uint8(hio->hio_nv, "cmd");
+ if (hio->hio_cmd == 0) {
+ pjdlog_error("Header contains no 'cmd' field.");
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ switch (hio->hio_cmd) {
+ case HIO_READ:
+ case HIO_WRITE:
+ case HIO_DELETE:
+ hio->hio_offset = nv_get_uint64(hio->hio_nv, "offset");
+ if (nv_error(hio->hio_nv) != 0) {
+ pjdlog_error("Header is missing 'offset' field.");
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ hio->hio_length = nv_get_uint64(hio->hio_nv, "length");
+ if (nv_error(hio->hio_nv) != 0) {
+ pjdlog_error("Header is missing 'length' field.");
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ if (hio->hio_length == 0) {
+ pjdlog_error("Data length is zero.");
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ if (hio->hio_length > MAXPHYS) {
+ pjdlog_error("Data length is too large (%ju > %ju).",
+ (uintmax_t)hio->hio_length, (uintmax_t)MAXPHYS);
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ if ((hio->hio_offset % res->hr_local_sectorsize) != 0) {
+ pjdlog_error("Offset %ju is not multiple of sector size.",
+ (uintmax_t)hio->hio_offset);
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ if ((hio->hio_length % res->hr_local_sectorsize) != 0) {
+ pjdlog_error("Length %ju is not multiple of sector size.",
+ (uintmax_t)hio->hio_length);
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ if (hio->hio_offset + hio->hio_length >
+ (uint64_t)res->hr_datasize) {
+ pjdlog_error("Data offset is too large (%ju > %ju).",
+ (uintmax_t)(hio->hio_offset + hio->hio_length),
+ (uintmax_t)res->hr_datasize);
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ break;
+ default:
+ pjdlog_error("Header contains invalid 'cmd' (%hhu).",
+ hio->hio_cmd);
+ hio->hio_error = EINVAL;
+ goto end;
+ }
+ hio->hio_error = 0;
+end:
+ return (hio->hio_error);
+}
+
+/*
+ * Thread receives requests from the primary node.
+ */
+static void *
+recv_thread(void *arg)
+{
+ struct hast_resource *res = arg;
+ struct hio *hio;
+ bool wakeup;
+
+ for (;;) {
+ pjdlog_debug(2, "recv: Taking free request.");
+ mtx_lock(&hio_free_list_lock);
+ while ((hio = TAILQ_FIRST(&hio_free_list)) == NULL) {
+ pjdlog_debug(2, "recv: No free requests, waiting.");
+ cv_wait(&hio_free_list_cond, &hio_free_list_lock);
+ }
+ TAILQ_REMOVE(&hio_free_list, hio, hio_next);
+ mtx_unlock(&hio_free_list_lock);
+ pjdlog_debug(2, "recv: (%p) Got request.", hio);
+ if (hast_proto_recv_hdr(res->hr_remotein, &hio->hio_nv) < 0) {
+ pjdlog_exit(EX_TEMPFAIL,
+ "Unable to receive request header");
+ }
+ if (requnpack(res, hio) != 0)
+ goto send_queue;
+ reqlog(LOG_DEBUG, 2, -1, hio,
+ "recv: (%p) Got request header: ", hio);
+ if (hio->hio_cmd == HIO_WRITE) {
+ if (hast_proto_recv_data(res, res->hr_remotein,
+ hio->hio_nv, hio->hio_data, MAXPHYS) < 0) {
+ pjdlog_exit(EX_TEMPFAIL,
+ "Unable to receive reply data");
+ }
+ }
+ pjdlog_debug(2, "recv: (%p) Moving request to the disk queue.",
+ hio);
+ mtx_lock(&hio_disk_list_lock);
+ wakeup = TAILQ_EMPTY(&hio_disk_list);
+ TAILQ_INSERT_TAIL(&hio_disk_list, hio, hio_next);
+ mtx_unlock(&hio_disk_list_lock);
+ if (wakeup)
+ cv_signal(&hio_disk_list_cond);
+ continue;
+send_queue:
+ pjdlog_debug(2, "recv: (%p) Moving request to the send queue.",
+ hio);
+ mtx_lock(&hio_send_list_lock);
+ wakeup = TAILQ_EMPTY(&hio_send_list);
+ TAILQ_INSERT_TAIL(&hio_send_list, hio, hio_next);
+ mtx_unlock(&hio_send_list_lock);
+ if (wakeup)
+ cv_signal(&hio_send_list_cond);
+ }
+ /* NOTREACHED */
+ return (NULL);
+}
+
+/*
+ * Thread reads from or writes to local component and also handles DELETE and
+ * FLUSH requests.
+ */
+static void *
+disk_thread(void *arg)
+{
+ struct hast_resource *res = arg;
+ struct hio *hio;
+ ssize_t ret;
+ bool clear_activemap, wakeup;
+
+ clear_activemap = true;
+
+ for (;;) {
+ pjdlog_debug(2, "disk: Taking request.");
+ mtx_lock(&hio_disk_list_lock);
+ while ((hio = TAILQ_FIRST(&hio_disk_list)) == NULL) {
+ pjdlog_debug(2, "disk: No requests, waiting.");
+ cv_wait(&hio_disk_list_cond, &hio_disk_list_lock);
+ }
+ TAILQ_REMOVE(&hio_disk_list, hio, hio_next);
+ mtx_unlock(&hio_disk_list_lock);
+ while (clear_activemap) {
+ unsigned char *map;
+ size_t mapsize;
+
+ /*
+ * When first request is received, it means that primary
+ * already received our activemap, merged it and stored
+ * locally. We can now safely clear our activemap.
+ */
+ mapsize =
+ activemap_calc_ondisk_size(res->hr_local_mediasize -
+ METADATA_SIZE, res->hr_extentsize,
+ res->hr_local_sectorsize);
+ map = calloc(1, mapsize);
+ if (map == NULL) {
+ pjdlog_warning("Unable to allocate memory to clear local activemap.");
+ break;
+ }
+ if (pwrite(res->hr_localfd, map, mapsize,
+ METADATA_SIZE) != (ssize_t)mapsize) {
+ pjdlog_errno(LOG_WARNING,
+ "Unable to store cleared activemap");
+ free(map);
+ break;
+ }
+ free(map);
+ clear_activemap = false;
+ pjdlog_debug(1, "Local activemap cleared.");
+ }
+ reqlog(LOG_DEBUG, 2, -1, hio, "disk: (%p) Got request: ", hio);
+ /* Handle the actual request. */
+ switch (hio->hio_cmd) {
+ case HIO_READ:
+ ret = pread(res->hr_localfd, hio->hio_data,
+ hio->hio_length,
+ hio->hio_offset + res->hr_localoff);
+ if (ret < 0)
+ hio->hio_error = errno;
+ else if (ret != (int64_t)hio->hio_length)
+ hio->hio_error = EIO;
+ else
+ hio->hio_error = 0;
+ break;
+ case HIO_WRITE:
+ ret = pwrite(res->hr_localfd, hio->hio_data,
+ hio->hio_length,
+ hio->hio_offset + res->hr_localoff);
+ if (ret < 0)
+ hio->hio_error = errno;
+ else if (ret != (int64_t)hio->hio_length)
+ hio->hio_error = EIO;
+ else
+ hio->hio_error = 0;
+ break;
+ case HIO_DELETE:
+ ret = g_delete(res->hr_localfd,
+ hio->hio_offset + res->hr_localoff,
+ hio->hio_length);
+ if (ret < 0)
+ hio->hio_error = errno;
+ else
+ hio->hio_error = 0;
+ break;
+ case HIO_FLUSH:
+ ret = g_flush(res->hr_localfd);
+ if (ret < 0)
+ hio->hio_error = errno;
+ else
+ hio->hio_error = 0;
+ break;
+ }
+ if (hio->hio_error != 0) {
+ reqlog(LOG_ERR, 0, hio->hio_error, hio,
+ "Request failed: ");
+ }
+ pjdlog_debug(2, "disk: (%p) Moving request to the send queue.",
+ hio);
+ mtx_lock(&hio_send_list_lock);
+ wakeup = TAILQ_EMPTY(&hio_send_list);
+ TAILQ_INSERT_TAIL(&hio_send_list, hio, hio_next);
+ mtx_unlock(&hio_send_list_lock);
+ if (wakeup)
+ cv_signal(&hio_send_list_cond);
+ }
+ /* NOTREACHED */
+ return (NULL);
+}
+
+/*
+ * Thread sends requests back to primary node.
+ */
+static void *
+send_thread(void *arg)
+{
+ struct hast_resource *res = arg;
+ struct nv *nvout;
+ struct hio *hio;
+ void *data;
+ size_t length;
+ bool wakeup;
+
+ for (;;) {
+ pjdlog_debug(2, "send: Taking request.");
+ mtx_lock(&hio_send_list_lock);
+ while ((hio = TAILQ_FIRST(&hio_send_list)) == NULL) {
+ pjdlog_debug(2, "send: No requests, waiting.");
+ cv_wait(&hio_send_list_cond, &hio_send_list_lock);
+ }
+ TAILQ_REMOVE(&hio_send_list, hio, hio_next);
+ mtx_unlock(&hio_send_list_lock);
+ reqlog(LOG_DEBUG, 2, -1, hio, "send: (%p) Got request: ", hio);
+ nvout = nv_alloc();
+ /* Copy sequence number. */
+ nv_add_uint64(nvout, nv_get_uint64(hio->hio_nv, "seq"), "seq");
+ switch (hio->hio_cmd) {
+ case HIO_READ:
+ if (hio->hio_error == 0) {
+ data = hio->hio_data;
+ length = hio->hio_length;
+ break;
+ }
+ /*
+ * We send no data in case of an error.
+ */
+ /* FALLTHROUGH */
+ case HIO_DELETE:
+ case HIO_FLUSH:
+ case HIO_WRITE:
+ data = NULL;
+ length = 0;
+ break;
+ default:
+ abort();
+ break;
+ }
+ if (hio->hio_error != 0)
+ nv_add_int16(nvout, hio->hio_error, "error");
+ if (hast_proto_send(res, res->hr_remoteout, nvout, data,
+ length) < 0) {
+ pjdlog_exit(EX_TEMPFAIL, "Unable to send reply.");
+ }
+ nv_free(nvout);
+ pjdlog_debug(2, "disk: (%p) Moving request to the free queue.",
+ hio);
+ nv_free(hio->hio_nv);
+ hio->hio_error = 0;
+ mtx_lock(&hio_free_list_lock);
+ wakeup = TAILQ_EMPTY(&hio_free_list);
+ TAILQ_INSERT_TAIL(&hio_free_list, hio, hio_next);
+ mtx_unlock(&hio_free_list_lock);
+ if (wakeup)
+ cv_signal(&hio_free_list_cond);
+ }
+ /* NOTREACHED */
+ return (NULL);
+}
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