X-Git-Url: https://git.kernel.dk/?p=fio.git;a=blobdiff_plain;f=server.c;h=5e0d322baeae1c8c4664f57f68ec9cbb23ff6d59;hp=524c8146670849c58735fc4faa041d0a6dc08095;hb=8c95307bd5f72720460ee4a46519b9a1b474e7cd;hpb=bebe639808147d587bbe776566d390b9ff98773f

diff --git a/server.c b/server.c
index 524c8146..5e0d322b 100644
--- a/server.c
+++ b/server.c
@@ -16,13 +16,16 @@
 #include <netdb.h>
 #include <syslog.h>
 #include <signal.h>
+#include <zlib.h>
 
 #include "fio.h"
 #include "server.h"
 #include "crc/crc16.h"
-#include "ieee754.h"
+#include "lib/ieee754.h"
 
-int fio_net_port = 8765;
+#include "fio_version.h"
+
+int fio_net_port = FIO_NET_PORT;
 
 int exit_backend = 0;
 
@@ -30,32 +33,115 @@ static int server_fd = -1;
 static char *fio_server_arg;
 static char *bind_sock;
 static struct sockaddr_in saddr_in;
+static struct sockaddr_in6 saddr_in6;
+static int use_ipv6;
+
+struct fio_fork_item {
+	struct flist_head list;
+	int exitval;
+	int signal;
+	int exited;
+	pid_t pid;
+};
+
+/* Created on fork on new connection */
+static FLIST_HEAD(conn_list);
+
+/* Created on job fork from connection */
+static FLIST_HEAD(job_list);
+
+static const char *fio_server_ops[FIO_NET_CMD_NR] = {
+	"",
+	"QUIT",
+	"EXIT",
+	"JOB",
+	"JOBLINE",
+	"TEXT",
+	"TS",
+	"GS",
+	"SEND_ETA",
+	"ETA",
+	"PROBE",
+	"START",
+	"STOP",
+	"DISK_UTIL",
+	"SERVER_START",
+	"ADD_JOB",
+	"CMD_RUN"
+	"CMD_IOLOG",
+};
+
+const char *fio_server_op(unsigned int op)
+{
+	static char buf[32];
 
-int fio_send_data(int sk, const void *p, unsigned int len)
+	if (op < FIO_NET_CMD_NR)
+		return fio_server_ops[op];
+
+	sprintf(buf, "UNKNOWN/%d", op);
+	return buf;
+}
+
+static ssize_t iov_total_len(const struct iovec *iov, int count)
 {
-	assert(len <= sizeof(struct fio_net_cmd) + FIO_SERVER_MAX_PDU);
+	ssize_t ret = 0;
 
-	do {
-		int ret = send(sk, p, len, 0);
+	while (count--) {
+		ret += iov->iov_len;
+		iov++;
+	}
+
+	return ret;
+}
 
+static int fio_sendv_data(int sk, struct iovec *iov, int count)
+{
+	ssize_t total_len = iov_total_len(iov, count);
+	ssize_t ret;
+
+	do {
+		ret = writev(sk, iov, count);
 		if (ret > 0) {
-			len -= ret;
-			if (!len)
+			total_len -= ret;
+			if (!total_len)
 				break;
-			p += ret;
-			continue;
+
+			while (ret) {
+				if (ret >= iov->iov_len) {
+					ret -= iov->iov_len;
+					iov++;
+					continue;
+				}
+				iov->iov_base += ret;
+				iov->iov_len -= ret;
+				ret = 0;
+			}
 		} else if (!ret)
 			break;
 		else if (errno == EAGAIN || errno == EINTR)
 			continue;
+		else
+			break;
 	} while (!exit_backend);
 
-	if (!len)
+	if (!total_len)
 		return 0;
 
+	if (errno)
+		return -errno;
+
 	return 1;
 }
 
+int fio_send_data(int sk, const void *p, unsigned int len)
+{
+	struct iovec iov = { .iov_base = (void *) p, .iov_len = len };
+
+	assert(len <= sizeof(struct fio_net_cmd) + FIO_SERVER_MAX_FRAGMENT_PDU);
+
+	return fio_sendv_data(sk, &iov, 1);
+}
+
 int fio_recv_data(int sk, void *p, unsigned int len)
 {
 	do {
@@ -71,6 +157,8 @@ int fio_recv_data(int sk, void *p, unsigned int len)
 			break;
 		else if (errno == EAGAIN || errno == EINTR)
 			continue;
+		else
+			break;
 	} while (!exit_backend);
 
 	if (!len)
@@ -86,7 +174,7 @@ static int verify_convert_cmd(struct fio_net_cmd *cmd)
 	cmd->cmd_crc16 = le16_to_cpu(cmd->cmd_crc16);
 	cmd->pdu_crc16 = le16_to_cpu(cmd->pdu_crc16);
 
-	crc = crc16(cmd, FIO_NET_CMD_CRC_SZ);
+	crc = fio_crc16(cmd, FIO_NET_CMD_CRC_SZ);
 	if (crc != cmd->cmd_crc16) {
 		log_err("fio: server bad crc on command (got %x, wanted %x)\n",
 				cmd->cmd_crc16, crc);
@@ -96,18 +184,18 @@ static int verify_convert_cmd(struct fio_net_cmd *cmd)
 	cmd->version	= le16_to_cpu(cmd->version);
 	cmd->opcode	= le16_to_cpu(cmd->opcode);
 	cmd->flags	= le32_to_cpu(cmd->flags);
-	cmd->serial	= le64_to_cpu(cmd->serial);
+	cmd->tag	= le64_to_cpu(cmd->tag);
 	cmd->pdu_len	= le32_to_cpu(cmd->pdu_len);
 
 	switch (cmd->version) {
-	case FIO_SERVER_VER2:
+	case FIO_SERVER_VER:
 		break;
 	default:
 		log_err("fio: bad server cmd version %d\n", cmd->version);
 		return 1;
 	}
 
-	if (cmd->pdu_len > FIO_SERVER_MAX_PDU) {
+	if (cmd->pdu_len > FIO_SERVER_MAX_FRAGMENT_PDU) {
 		log_err("fio: command payload too large: %u\n", cmd->pdu_len);
 		return 1;
 	}
@@ -147,8 +235,12 @@ struct fio_net_cmd *fio_net_recv_cmd(int sk)
 
 		if (first)
 			memcpy(cmdret, &cmd, sizeof(cmd));
-		else
-			assert(cmdret->opcode == cmd.opcode);
+		else if (cmdret->opcode != cmd.opcode) {
+			log_err("fio: fragment opcode mismatch (%d != %d)\n",
+					cmdret->opcode, cmd.opcode);
+			ret = 1;
+			break;
+		}
 
 		if (!cmd.pdu_len)
 			break;
@@ -160,7 +252,7 @@ struct fio_net_cmd *fio_net_recv_cmd(int sk)
 			break;
 
 		/* Verify payload crc */
-		crc = crc16(pdu, cmd.pdu_len);
+		crc = fio_crc16(pdu, cmd.pdu_len);
 		if (crc != cmd.pdu_crc16) {
 			log_err("fio: server bad crc on payload ");
 			log_err("(got %x, wanted %x)\n", cmd.pdu_crc16, crc);
@@ -179,12 +271,21 @@ struct fio_net_cmd *fio_net_recv_cmd(int sk)
 		cmdret = NULL;
 	} else if (cmdret) {
 		/* zero-terminate text input */
-		if (cmdret->pdu_len && (cmdret->opcode == FIO_NET_CMD_TEXT ||
-		    cmdret->opcode == FIO_NET_CMD_JOB)) {
-			char *buf = (char *) cmdret->payload;
-
-			buf[cmdret->pdu_len ] = '\0';
+		if (cmdret->pdu_len) {
+			if (cmdret->opcode == FIO_NET_CMD_TEXT) {
+				struct cmd_text_pdu *pdu = (struct cmd_text_pdu *) cmdret->payload;
+				char *buf = (char *) pdu->buf;
+
+				buf[pdu->buf_len ] = '\0';
+			} else if (cmdret->opcode == FIO_NET_CMD_JOB) {
+				struct cmd_job_pdu *pdu = (struct cmd_job_pdu *) cmdret->payload;
+				char *buf = (char *) pdu->buf;
+				int len = le32_to_cpu(pdu->buf_len);
+
+				buf[len] = '\0';
+			}
 		}
+
 		/* frag flag is internal */
 		cmdret->flags &= ~FIO_NET_CMD_F_MORE;
 	}
@@ -192,31 +293,42 @@ struct fio_net_cmd *fio_net_recv_cmd(int sk)
 	return cmdret;
 }
 
-void fio_net_cmd_crc(struct fio_net_cmd *cmd)
+void fio_net_cmd_crc_pdu(struct fio_net_cmd *cmd, const void *pdu)
 {
 	uint32_t pdu_len;
 
-	cmd->cmd_crc16 = __cpu_to_le16(crc16(cmd, FIO_NET_CMD_CRC_SZ));
+	cmd->cmd_crc16 = __cpu_to_le16(fio_crc16(cmd, FIO_NET_CMD_CRC_SZ));
 
 	pdu_len = le32_to_cpu(cmd->pdu_len);
-	if (pdu_len)
-		cmd->pdu_crc16 = __cpu_to_le16(crc16(cmd->payload, pdu_len));
+	cmd->pdu_crc16 = __cpu_to_le16(fio_crc16(pdu, pdu_len));
 }
 
-int fio_net_send_cmd(int fd, uint16_t opcode, const void *buf, off_t size)
+void fio_net_cmd_crc(struct fio_net_cmd *cmd)
+{
+	fio_net_cmd_crc_pdu(cmd, cmd->payload);
+}
+
+int fio_net_send_cmd(int fd, uint16_t opcode, const void *buf, off_t size,
+		     uint64_t tag)
 {
-	struct fio_net_cmd *cmd;
-	size_t this_len;
+	struct fio_net_cmd *cmd = NULL;
+	size_t this_len, cur_len = 0;
 	int ret;
 
 	do {
 		this_len = size;
-		if (this_len > FIO_SERVER_MAX_PDU)
-			this_len = FIO_SERVER_MAX_PDU;
+		if (this_len > FIO_SERVER_MAX_FRAGMENT_PDU)
+			this_len = FIO_SERVER_MAX_FRAGMENT_PDU;
 
-		cmd = malloc(sizeof(*cmd) + this_len);
+		if (!cmd || cur_len < sizeof(*cmd) + this_len) {
+			if (cmd)
+				free(cmd);
 
-		fio_init_net_cmd(cmd, opcode, buf, this_len);
+			cur_len = sizeof(*cmd) + this_len;
+			cmd = malloc(cur_len);
+		}
+
+		fio_init_net_cmd(cmd, opcode, buf, this_len, tag);
 
 		if (this_len < size)
 			cmd->flags = __cpu_to_le32(FIO_NET_CMD_F_MORE);
@@ -224,80 +336,243 @@ int fio_net_send_cmd(int fd, uint16_t opcode, const void *buf, off_t size)
 		fio_net_cmd_crc(cmd);
 
 		ret = fio_send_data(fd, cmd, sizeof(*cmd) + this_len);
-		free(cmd);
 		size -= this_len;
 		buf += this_len;
 	} while (!ret && size);
 
+	if (cmd)
+		free(cmd);
+
 	return ret;
 }
 
-int fio_net_send_simple_cmd(int sk, uint16_t opcode, uint64_t serial)
+static int fio_net_send_simple_stack_cmd(int sk, uint16_t opcode, uint64_t tag)
 {
 	struct fio_net_cmd cmd;
 
-	fio_init_net_cmd(&cmd, opcode, NULL, 0);
+	fio_init_net_cmd(&cmd, opcode, NULL, 0, tag);
 	fio_net_cmd_crc(&cmd);
 
 	return fio_send_data(sk, &cmd, sizeof(cmd));
 }
 
-static int fio_server_send_quit_cmd(void)
+/*
+ * If 'list' is non-NULL, then allocate and store the sent command for
+ * later verification.
+ */
+int fio_net_send_simple_cmd(int sk, uint16_t opcode, uint64_t tag,
+			    struct flist_head *list)
+{
+	struct fio_net_int_cmd *cmd;
+	int ret;
+
+	if (!list)
+		return fio_net_send_simple_stack_cmd(sk, opcode, tag);
+
+	cmd = malloc(sizeof(*cmd));
+
+	fio_init_net_cmd(&cmd->cmd, opcode, NULL, 0, (uintptr_t) cmd);
+	fio_net_cmd_crc(&cmd->cmd);
+
+	INIT_FLIST_HEAD(&cmd->list);
+	gettimeofday(&cmd->tv, NULL);
+	cmd->saved_tag = tag;
+
+	ret = fio_send_data(sk, &cmd->cmd, sizeof(cmd->cmd));
+	if (ret) {
+		free(cmd);
+		return ret;
+	}
+
+	flist_add_tail(&cmd->list, list);
+	return 0;
+}
+
+int fio_net_send_quit(int sk)
 {
 	dprint(FD_NET, "server: sending quit\n");
-	return fio_net_send_simple_cmd(server_fd, FIO_NET_CMD_QUIT, 0);
+
+	return fio_net_send_simple_cmd(sk, FIO_NET_CMD_QUIT, 0, NULL);
 }
 
-static int handle_job_cmd(struct fio_net_cmd *cmd)
+int fio_net_send_stop(int sk, int error, int signal)
+{
+	struct cmd_end_pdu epdu;
+
+	dprint(FD_NET, "server: sending stop (%d, %d)\n", error, signal);
+
+	epdu.error = __cpu_to_le32(error);
+	epdu.signal = __cpu_to_le32(signal);
+	return fio_net_send_cmd(sk, FIO_NET_CMD_STOP, &epdu, sizeof(epdu), 0);
+}
+
+static void fio_server_add_fork_item(pid_t pid, struct flist_head *list)
+{
+	struct fio_fork_item *ffi;
+
+	ffi = malloc(sizeof(*ffi));
+	ffi->exitval = 0;
+	ffi->signal = 0;
+	ffi->exited = 0;
+	ffi->pid = pid;
+	flist_add_tail(&ffi->list, list);
+}
+
+static void fio_server_add_conn_pid(pid_t pid)
+{
+	dprint(FD_NET, "server: forked off connection job (pid=%u)\n", pid);
+	fio_server_add_fork_item(pid, &conn_list);
+}
+
+static void fio_server_add_job_pid(pid_t pid)
+{
+	dprint(FD_NET, "server: forked off job job (pid=%u)\n", pid);
+	fio_server_add_fork_item(pid, &job_list);
+}
+
+static void fio_server_check_fork_item(struct fio_fork_item *ffi)
+{
+	int ret, status;
+
+	ret = waitpid(ffi->pid, &status, WNOHANG);
+	if (ret < 0) {
+		if (errno == ECHILD) {
+			log_err("fio: connection pid %u disappeared\n", ffi->pid);
+			ffi->exited = 1;
+		} else
+			log_err("fio: waitpid: %s\n", strerror(errno));
+	} else if (ret == ffi->pid) {
+		if (WIFSIGNALED(status)) {
+			ffi->signal = WTERMSIG(status);
+			ffi->exited = 1;
+		}
+		if (WIFEXITED(status)) {
+			if (WEXITSTATUS(status))
+				ffi->exitval = WEXITSTATUS(status);
+			ffi->exited = 1;
+		}
+	}
+}
+
+static void fio_server_fork_item_done(struct fio_fork_item *ffi)
+{
+	dprint(FD_NET, "pid %u exited, sig=%u, exitval=%d\n", ffi->pid, ffi->signal, ffi->exitval);
+
+	/*
+	 * Fold STOP and QUIT...
+	 */
+	fio_net_send_stop(server_fd, ffi->exitval, ffi->signal);
+	fio_net_send_quit(server_fd);
+	flist_del(&ffi->list);
+	free(ffi);
+}
+
+static void fio_server_check_fork_items(struct flist_head *list, int bla)
+{
+	struct flist_head *entry, *tmp;
+	struct fio_fork_item *ffi;
+
+	flist_for_each_safe(entry, tmp, list) {
+		ffi = flist_entry(entry, struct fio_fork_item, list);
+
+		fio_server_check_fork_item(ffi);
+
+		if (ffi->exited)
+			fio_server_fork_item_done(ffi);
+	}
+}
+
+static void fio_server_check_jobs(void)
+{
+	fio_server_check_fork_items(&job_list, 0);
+}
+
+static void fio_server_check_conns(void)
+{
+	fio_server_check_fork_items(&conn_list, 1);
+}
+
+static int handle_run_cmd(struct fio_net_cmd *cmd)
 {
-	char *buf = (char *) cmd->payload;
+	pid_t pid;
 	int ret;
 
-	if (parse_jobs_ini(buf, 1, 0)) {
-		fio_server_send_quit_cmd();
-		return -1;
+	set_genesis_time();
+
+	pid = fork();
+	if (pid) {
+		fio_server_add_job_pid(pid);
+		return 0;
 	}
 
-	fio_net_send_simple_cmd(server_fd, FIO_NET_CMD_START, 0);
+	ret = fio_backend();
+	_exit(ret);
+}
 
-	ret = exec_run();
-	fio_server_send_quit_cmd();
-	reset_fio_state();
-	return ret;
+static int handle_job_cmd(struct fio_net_cmd *cmd)
+{
+	struct cmd_job_pdu *pdu = (struct cmd_job_pdu *) cmd->payload;
+	void *buf = pdu->buf;
+	struct cmd_start_pdu spdu;
+
+	pdu->buf_len = le32_to_cpu(pdu->buf_len);
+	pdu->client_type = le32_to_cpu(pdu->client_type);
+
+	if (parse_jobs_ini(buf, 1, 0, pdu->client_type)) {
+		fio_net_send_quit(server_fd);
+		return -1;
+	}
+
+	spdu.jobs = cpu_to_le32(thread_number);
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_START, &spdu, sizeof(spdu), 0);
+	return 0;
 }
 
 static int handle_jobline_cmd(struct fio_net_cmd *cmd)
 {
-	struct cmd_line_pdu *pdu = (struct cmd_line_pdu *) cmd->payload;
-	char *argv[FIO_NET_CMD_JOBLINE_ARGV];
-	int ret, i;
+	void *pdu = cmd->payload;
+	struct cmd_single_line_pdu *cslp;
+	struct cmd_line_pdu *clp;
+	unsigned long offset;
+	struct cmd_start_pdu spdu;
+	char **argv;
+	int i;
+
+	clp = pdu;
+	clp->lines = le16_to_cpu(clp->lines);
+	clp->client_type = le16_to_cpu(clp->client_type);
+	argv = malloc(clp->lines * sizeof(char *));
+	offset = sizeof(*clp);
 
-	pdu->argc = le16_to_cpu(pdu->argc);
+	dprint(FD_NET, "server: %d command line args\n", clp->lines);
 
-	dprint(FD_NET, "server: %d command line args\n", pdu->argc);
+	for (i = 0; i < clp->lines; i++) {
+		cslp = pdu + offset;
+		argv[i] = (char *) cslp->text;
 
-	for (i = 0; i < pdu->argc; i++) {
-		argv[i] = (char *) pdu->argv[i];
+		offset += sizeof(*cslp) + le16_to_cpu(cslp->len);
 		dprint(FD_NET, "server: %d: %s\n", i, argv[i]);
 	}
 
-	if (parse_cmd_line(pdu->argc, argv)) {
-		fio_server_send_quit_cmd();
+	if (parse_cmd_line(clp->lines, argv, clp->client_type)) {
+		fio_net_send_quit(server_fd);
+		free(argv);
 		return -1;
 	}
 
-	fio_net_send_simple_cmd(server_fd, FIO_NET_CMD_START, 0);
+	free(argv);
 
-	ret = exec_run();
-	fio_server_send_quit_cmd();
-	reset_fio_state();
-	return ret;
+	spdu.jobs = cpu_to_le32(thread_number);
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_START, &spdu, sizeof(spdu), 0);
+	return 0;
 }
 
 static int handle_probe_cmd(struct fio_net_cmd *cmd)
 {
 	struct cmd_probe_pdu probe;
 
+	dprint(FD_NET, "server: sending probe reply\n");
+
 	memset(&probe, 0, sizeof(probe));
 	gethostname((char *) probe.hostname, sizeof(probe.hostname));
 #ifdef FIO_BIG_ENDIAN
@@ -307,14 +582,63 @@ static int handle_probe_cmd(struct fio_net_cmd *cmd)
 	probe.fio_minor = FIO_MINOR;
 	probe.fio_patch = FIO_PATCH;
 
-	return fio_net_send_cmd(server_fd, FIO_NET_CMD_PROBE, &probe, sizeof(probe));
+	probe.os	= FIO_OS;
+	probe.arch	= FIO_ARCH;
+
+	probe.bpp	= sizeof(void *);
+
+	return fio_net_send_cmd(server_fd, FIO_NET_CMD_PROBE, &probe, sizeof(probe), cmd->tag);
+}
+
+static int handle_send_eta_cmd(struct fio_net_cmd *cmd)
+{
+	struct jobs_eta *je;
+	size_t size;
+	int i;
+
+	if (!thread_number)
+		return 0;
+
+	size = sizeof(*je) + thread_number * sizeof(char) + 1;
+	je = malloc(size);
+	memset(je, 0, size);
+
+	if (!calc_thread_status(je, 1)) {
+		free(je);
+		return 0;
+	}
+
+	dprint(FD_NET, "server sending status\n");
+
+	je->nr_running		= cpu_to_le32(je->nr_running);
+	je->nr_ramp		= cpu_to_le32(je->nr_ramp);
+	je->nr_pending		= cpu_to_le32(je->nr_pending);
+	je->files_open		= cpu_to_le32(je->files_open);
+
+	for (i = 0; i < 2; i++) {
+		je->m_rate[i]	= cpu_to_le32(je->m_rate[i]);
+		je->t_rate[i]	= cpu_to_le32(je->t_rate[i]);
+		je->m_iops[i]	= cpu_to_le32(je->m_iops[i]);
+		je->t_iops[i]	= cpu_to_le32(je->t_iops[i]);
+		je->rate[i]	= cpu_to_le32(je->rate[i]);
+		je->iops[i]	= cpu_to_le32(je->iops[i]);
+	}
+
+	je->elapsed_sec		= cpu_to_le64(je->elapsed_sec);
+	je->eta_sec		= cpu_to_le64(je->eta_sec);
+	je->nr_threads		= cpu_to_le32(je->nr_threads);
+
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_ETA, je, size, cmd->tag);
+	free(je);
+	return 0;
 }
 
 static int handle_command(struct fio_net_cmd *cmd)
 {
 	int ret;
 
-	dprint(FD_NET, "server: got opcode %d\n", cmd->opcode);
+	dprint(FD_NET, "server: got op [%s], pdu=%u, tag=%lx\n",
+			fio_server_op(cmd->opcode), cmd->pdu_len, cmd->tag);
 
 	switch (cmd->opcode) {
 	case FIO_NET_CMD_QUIT:
@@ -332,19 +656,29 @@ static int handle_command(struct fio_net_cmd *cmd)
 	case FIO_NET_CMD_PROBE:
 		ret = handle_probe_cmd(cmd);
 		break;
+	case FIO_NET_CMD_SEND_ETA:
+		ret = handle_send_eta_cmd(cmd);
+		break;
+	case FIO_NET_CMD_RUN:
+		ret = handle_run_cmd(cmd);
+		break;
 	default:
-		log_err("fio: unknown opcode: %d\n", cmd->opcode);
+		log_err("fio: unknown opcode: %s\n",fio_server_op(cmd->opcode));
 		ret = 1;
 	}
 
 	return ret;
 }
 
-static int handle_connection(int sk, int block)
+static int handle_connection(int sk)
 {
 	struct fio_net_cmd *cmd = NULL;
 	int ret = 0;
 
+	reset_fio_state();
+	INIT_FLIST_HEAD(&job_list);
+	server_fd = sk;
+
 	/* read forever */
 	while (!exit_backend) {
 		struct pollfd pfd = {
@@ -361,8 +695,7 @@ static int handle_connection(int sk, int block)
 				log_err("fio: poll: %s\n", strerror(errno));
 				break;
 			} else if (!ret) {
-				if (!block)
-					return 0;
+				fio_server_check_jobs();
 				continue;
 			}
 
@@ -374,6 +707,8 @@ static int handle_connection(int sk, int block)
 			}
 		} while (!exit_backend);
 
+		fio_server_check_jobs();
+
 		if (ret < 0)
 			break;
 
@@ -394,13 +729,8 @@ static int handle_connection(int sk, int block)
 	if (cmd)
 		free(cmd);
 
-	return ret;
-}
-
-void fio_server_idle_loop(void)
-{
-	if (server_fd != -1)
-		handle_connection(server_fd, 0);
+	close(sk);
+	_exit(ret);
 }
 
 static int accept_loop(int listen_sk)
@@ -408,61 +738,86 @@ static int accept_loop(int listen_sk)
 	struct sockaddr_in addr;
 	fio_socklen_t len = sizeof(addr);
 	struct pollfd pfd;
-	int ret, sk, flags, exitval = 0;
+	int ret = 0, sk, flags, exitval = 0;
 
 	dprint(FD_NET, "server enter accept loop\n");
 
 	flags = fcntl(listen_sk, F_GETFL);
 	flags |= O_NONBLOCK;
 	fcntl(listen_sk, F_SETFL, flags);
-again:
-	pfd.fd = listen_sk;
-	pfd.events = POLLIN;
-	do {
-		ret = poll(&pfd, 1, 100);
-		if (ret < 0) {
-			if (errno == EINTR)
-				break;
-			log_err("fio: poll: %s\n", strerror(errno));
-			goto out;
-		} else if (!ret)
-			continue;
 
-		if (pfd.revents & POLLIN)
-			break;
-	} while (!exit_backend);
+	while (!exit_backend) {
+		pid_t pid;
 
-	if (exit_backend)
-		goto out;
+		pfd.fd = listen_sk;
+		pfd.events = POLLIN;
+		do {
+			ret = poll(&pfd, 1, 100);
+			if (ret < 0) {
+				if (errno == EINTR)
+					break;
+				log_err("fio: poll: %s\n", strerror(errno));
+				break;
+			} else if (!ret) {
+				fio_server_check_conns();
+				continue;
+			}
 
-	sk = accept(listen_sk, (struct sockaddr *) &addr, &len);
-	if (sk < 0) {
-		log_err("fio: accept: %s\n", strerror(errno));
-		return -1;
-	}
+			if (pfd.revents & POLLIN)
+				break;
+		} while (!exit_backend);
 
-	dprint(FD_NET, "server: connect from %s\n", inet_ntoa(addr.sin_addr));
+		fio_server_check_conns();
 
-	server_fd = sk;
+		if (exit_backend || ret < 0)
+			break;
 
-	exitval = handle_connection(sk, 1);
+		sk = accept(listen_sk, (struct sockaddr *) &addr, &len);
+		if (sk < 0) {
+			log_err("fio: accept: %s\n", strerror(errno));
+			return -1;
+		}
 
-	server_fd = -1;
-	close(sk);
+		dprint(FD_NET, "server: connect from %s\n", inet_ntoa(addr.sin_addr));
 
-	if (!exit_backend)
-		goto again;
+		pid = fork();
+		if (pid) {
+			close(sk);
+			fio_server_add_conn_pid(pid);
+			continue;
+		}
+
+		/* exits */
+		handle_connection(sk);
+	}
 
-out:
 	return exitval;
 }
 
-int fio_server_text_output(const char *buf, unsigned int len)
+int fio_server_text_output(int level, const char *buf, size_t len)
 {
-	if (server_fd != -1)
-		return fio_net_send_cmd(server_fd, FIO_NET_CMD_TEXT, buf, len);
+	struct cmd_text_pdu *pdu;
+	unsigned int tlen;
+	struct timeval tv;
+
+	if (server_fd == -1)
+		return log_local_buf(buf, len);
+
+	tlen = sizeof(*pdu) + len;
+	pdu = malloc(tlen);
+
+	pdu->level	= __cpu_to_le32(level);
+	pdu->buf_len	= __cpu_to_le32(len);
+
+	gettimeofday(&tv, NULL);
+	pdu->log_sec	= __cpu_to_le64(tv.tv_sec);
+	pdu->log_usec	= __cpu_to_le64(tv.tv_usec);
 
-	return fwrite(buf, len, 1, f_err);
+	memcpy(pdu->buf, buf, len);
+
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_TEXT, pdu, tlen, 0);
+	free(pdu);
+	return len;
 }
 
 static void convert_io_stat(struct io_stat *dst, struct io_stat *src)
@@ -512,10 +867,11 @@ void fio_server_send_ts(struct thread_stat *ts, struct group_run_stats *rs)
 	strcpy(p.ts.verror, ts->verror);
 	strcpy(p.ts.description, ts->description);
 
-	p.ts.error	= cpu_to_le32(ts->error);
-	p.ts.groupid	= cpu_to_le32(ts->groupid);
-	p.ts.pid	= cpu_to_le32(ts->pid);
-	p.ts.members	= cpu_to_le32(ts->members);
+	p.ts.error		= cpu_to_le32(ts->error);
+	p.ts.thread_number	= cpu_to_le32(ts->thread_number);
+	p.ts.groupid		= cpu_to_le32(ts->groupid);
+	p.ts.pid		= cpu_to_le32(ts->pid);
+	p.ts.members		= cpu_to_le32(ts->members);
 
 	for (i = 0; i < 2; i++) {
 		convert_io_stat(&p.ts.clat_stat[i], &ts->clat_stat[i]);
@@ -532,9 +888,10 @@ void fio_server_send_ts(struct thread_stat *ts, struct group_run_stats *rs)
 	p.ts.clat_percentiles	= cpu_to_le64(ts->clat_percentiles);
 
 	for (i = 0; i < FIO_IO_U_LIST_MAX_LEN; i++) {
-		fio_fp64_t *fp = &p.ts.percentile_list[i];
+		fio_fp64_t *src = &ts->percentile_list[i];
+		fio_fp64_t *dst = &p.ts.percentile_list[i];
 
-		fp->u.i = __cpu_to_le64(fio_double_to_uint64(fp->u.f));
+		dst->u.i = __cpu_to_le64(fio_double_to_uint64(src->u.f));
 	}
 
 	for (i = 0; i < FIO_IO_U_MAP_NR; i++) {
@@ -573,7 +930,7 @@ void fio_server_send_ts(struct thread_stat *ts, struct group_run_stats *rs)
 
 	convert_gs(&p.rs, rs);
 
-	fio_net_send_cmd(server_fd, FIO_NET_CMD_TS, &p, sizeof(p));
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_TS, &p, sizeof(p), 0);
 }
 
 void fio_server_send_gs(struct group_run_stats *rs)
@@ -583,69 +940,192 @@ void fio_server_send_gs(struct group_run_stats *rs)
 	dprint(FD_NET, "server sending group run stats\n");
 
 	convert_gs(&gs, rs);
-	fio_net_send_cmd(server_fd, FIO_NET_CMD_GS, &gs, sizeof(gs));
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_GS, &gs, sizeof(gs), 0);
 }
 
-void fio_server_send_status(void)
+static void convert_agg(struct disk_util_agg *dst, struct disk_util_agg *src)
 {
-	struct jobs_eta *je;
-	size_t size;
-	void *buf;
 	int i;
 
-	size = sizeof(*je) + thread_number * sizeof(char);
-	buf = malloc(size);
-	memset(buf, 0, size);
-	je = buf;
-
-	if (!calc_thread_status(je)) {
-		free(je);
-		return;
+	for (i = 0; i < 2; i++) {
+		dst->ios[i]	= cpu_to_le32(src->ios[i]);
+		dst->merges[i]	= cpu_to_le32(src->merges[i]);
+		dst->sectors[i]	= cpu_to_le64(src->sectors[i]);
+		dst->ticks[i]	= cpu_to_le32(src->ticks[i]);
 	}
 
-	dprint(FD_NET, "server sending status\n");
+	dst->io_ticks		= cpu_to_le32(src->io_ticks);
+	dst->time_in_queue	= cpu_to_le32(src->time_in_queue);
+	dst->slavecount		= cpu_to_le32(src->slavecount);
+	dst->max_util.u.i	= __cpu_to_le64(fio_double_to_uint64(src->max_util.u.f));
+}
 
-	je->nr_running		= cpu_to_le32(je->nr_running);
-	je->nr_ramp		= cpu_to_le32(je->nr_ramp);
-	je->nr_pending		= cpu_to_le32(je->nr_pending);
-	je->files_open		= cpu_to_le32(je->files_open);
-	je->m_rate		= cpu_to_le32(je->m_rate);
-	je->t_rate		= cpu_to_le32(je->t_rate);
-	je->m_iops		= cpu_to_le32(je->m_iops);
-	je->t_iops		= cpu_to_le32(je->t_iops);
+static void convert_dus(struct disk_util_stat *dst, struct disk_util_stat *src)
+{
+	int i;
+
+	strcpy((char *) dst->name, (char *) src->name);
 
 	for (i = 0; i < 2; i++) {
-		je->rate[i]	= cpu_to_le32(je->rate[i]);
-		je->iops[i]	= cpu_to_le32(je->iops[i]);
+		dst->ios[i]	= cpu_to_le32(src->ios[i]);
+		dst->merges[i]	= cpu_to_le32(src->merges[i]);
+		dst->sectors[i]	= cpu_to_le64(src->sectors[i]);
+		dst->ticks[i]	= cpu_to_le32(src->ticks[i]);
 	}
 
-	je->elapsed_sec		= cpu_to_le32(je->nr_running);
-	je->eta_sec		= cpu_to_le64(je->eta_sec);
+	dst->io_ticks		= cpu_to_le32(src->io_ticks);
+	dst->time_in_queue	= cpu_to_le32(src->time_in_queue);
+	dst->msec		= cpu_to_le64(src->msec);
+}
 
-	fio_net_send_cmd(server_fd, FIO_NET_CMD_ETA, buf, size);
-	free(je);
+void fio_server_send_du(void)
+{
+	struct disk_util *du;
+	struct flist_head *entry;
+	struct cmd_du_pdu pdu;
+
+	dprint(FD_NET, "server: sending disk_util %d\n", !flist_empty(&disk_list));
+
+	memset(&pdu, 0, sizeof(pdu));
+
+	flist_for_each(entry, &disk_list) {
+		du = flist_entry(entry, struct disk_util, list);
+
+		convert_dus(&pdu.dus, &du->dus);
+		convert_agg(&pdu.agg, &du->agg);
+
+		fio_net_send_cmd(server_fd, FIO_NET_CMD_DU, &pdu, sizeof(pdu), 0);
+	}
 }
 
-int fio_server_log(const char *format, ...)
+/*
+ * Send a command with a separate PDU, not inlined in the command
+ */
+static int fio_send_cmd_ext_pdu(int sk, uint16_t opcode, const void *buf,
+				off_t size, uint64_t tag, uint32_t flags)
 {
-	char buffer[1024];
-	va_list args;
-	size_t len;
+	struct fio_net_cmd cmd;
+	struct iovec iov[2];
 
-	dprint(FD_NET, "server log\n");
+	iov[0].iov_base = &cmd;
+	iov[0].iov_len = sizeof(cmd);
+	iov[1].iov_base = (void *) buf;
+	iov[1].iov_len = size;
 
-	va_start(args, format);
-	len = vsnprintf(buffer, sizeof(buffer), format, args);
-	va_end(args);
+	__fio_init_net_cmd(&cmd, opcode, size, tag);
+	cmd.flags = __cpu_to_le32(flags);
+	fio_net_cmd_crc_pdu(&cmd, buf);
 
-	return fio_server_text_output(buffer, len);
+	return fio_sendv_data(sk, iov, 2);
+}
+
+int fio_send_iolog(struct thread_data *td, struct io_log *log, const char *name)
+{
+	struct cmd_iolog_pdu pdu;
+	z_stream stream;
+	void *out_pdu;
+	int i, ret = 0;
+
+	pdu.thread_number = cpu_to_le32(td->thread_number);
+	pdu.nr_samples = __cpu_to_le32(log->nr_samples);
+	pdu.log_type = cpu_to_le32(log->log_type);
+	strcpy((char *) pdu.name, name);
+
+	for (i = 0; i < log->nr_samples; i++) {
+		struct io_sample *s = &log->log[i];
+
+		s->time	= cpu_to_le64(s->time);
+		s->val	= cpu_to_le64(s->val);
+		s->ddir	= cpu_to_le32(s->ddir);
+		s->bs	= cpu_to_le32(s->bs);
+	}
+
+	/*
+	 * Dirty - since the log is potentially huge, compress it into
+	 * FIO_SERVER_MAX_FRAGMENT_PDU chunks and let the receiving
+	 * side defragment it.
+	 */
+	out_pdu = malloc(FIO_SERVER_MAX_FRAGMENT_PDU);
+
+	stream.zalloc = Z_NULL;
+	stream.zfree = Z_NULL;
+	stream.opaque = Z_NULL;
+
+	if (deflateInit(&stream, Z_DEFAULT_COMPRESSION) != Z_OK) {
+		ret = 1;
+		goto err;
+	}
+
+	/*
+	 * Send header first, it's not compressed.
+	 */
+	ret = fio_send_cmd_ext_pdu(server_fd, FIO_NET_CMD_IOLOG, &pdu,
+					sizeof(pdu), 0, FIO_NET_CMD_F_MORE);
+	if (ret)
+		goto err_zlib;
+
+	stream.next_in = (void *) log->log;
+	stream.avail_in = log->nr_samples * sizeof(struct io_sample);
+
+	do {
+		unsigned int this_len, flags = 0;
+		int ret;
+
+		stream.avail_out = FIO_SERVER_MAX_FRAGMENT_PDU;
+		stream.next_out = out_pdu;
+		ret = deflate(&stream, Z_FINISH);
+		/* may be Z_OK, or Z_STREAM_END */
+		if (ret < 0)
+			goto err_zlib;
+
+		this_len = FIO_SERVER_MAX_FRAGMENT_PDU - stream.avail_out;
+
+		if (stream.avail_in)
+			flags = FIO_NET_CMD_F_MORE;
+
+		ret = fio_send_cmd_ext_pdu(server_fd, FIO_NET_CMD_IOLOG,
+					   out_pdu, this_len, 0, flags);
+		if (ret)
+			goto err_zlib;
+	} while (stream.avail_in);
+
+err_zlib:
+	deflateEnd(&stream);
+err:
+	free(out_pdu);
+	return ret;
+}
+
+void fio_server_send_add_job(struct thread_data *td)
+{
+	struct cmd_add_job_pdu pdu;
+
+	memset(&pdu, 0, sizeof(pdu));
+	pdu.thread_number = cpu_to_le32(td->thread_number);
+	pdu.groupid = cpu_to_le32(td->groupid);
+	convert_thread_options_to_net(&pdu.top, &td->o);
+
+	fio_net_send_cmd(server_fd, FIO_NET_CMD_ADD_JOB, &pdu, sizeof(pdu), 0);
+}
+
+void fio_server_send_start(struct thread_data *td)
+{
+	assert(server_fd != -1);
+
+	fio_net_send_simple_cmd(server_fd, FIO_NET_CMD_SERVER_START, 0, NULL);
 }
 
 static int fio_init_server_ip(void)
 {
+	struct sockaddr *addr;
+	fio_socklen_t socklen;
 	int sk, opt;
 
-	sk = socket(AF_INET, SOCK_STREAM, 0);
+	if (use_ipv6)
+		sk = socket(AF_INET6, SOCK_STREAM, 0);
+	else
+		sk = socket(AF_INET, SOCK_STREAM, 0);
+
 	if (sk < 0) {
 		log_err("fio: socket: %s\n", strerror(errno));
 		return -1;
@@ -665,9 +1145,17 @@ static int fio_init_server_ip(void)
 	}
 #endif
 
-	saddr_in.sin_family = AF_INET;
+	if (use_ipv6) {
+		addr = (struct sockaddr *) &saddr_in6;
+		socklen = sizeof(saddr_in6);
+		saddr_in6.sin6_family = AF_INET6;
+	} else {
+		addr = (struct sockaddr *) &saddr_in;
+		socklen = sizeof(saddr_in);
+		saddr_in.sin_family = AF_INET;
+	}
 
-	if (bind(sk, (struct sockaddr *) &saddr_in, sizeof(saddr_in)) < 0) {
+	if (bind(sk, addr, socklen) < 0) {
 		log_err("fio: bind: %s\n", strerror(errno));
 		close(sk);
 		return -1;
@@ -723,14 +1211,32 @@ static int fio_init_server_connection(void)
 	if (sk < 0)
 		return sk;
 
-	if (!bind_sock)
-		sprintf(bind_str, "%s:%u", inet_ntoa(saddr_in.sin_addr), fio_net_port);
-	else
+	if (!bind_sock) {
+		char *p, port[16];
+		const void *src;
+		int af;
+
+		if (use_ipv6) {
+			af = AF_INET6;
+			src = &saddr_in6.sin6_addr;
+		} else {
+			af = AF_INET;
+			src = &saddr_in.sin_addr;
+		}
+
+		p = (char *) inet_ntop(af, src, bind_str, sizeof(bind_str));
+
+		sprintf(port, ",%u", fio_net_port);
+		if (p)
+			strcat(p, port);
+		else
+			strcpy(bind_str, port);
+	} else
 		strcpy(bind_str, bind_sock);
 
 	log_info("fio: server listening on %s\n", bind_str);
 
-	if (listen(sk, 1) < 0) {
+	if (listen(sk, 0) < 0) {
 		log_err("fio: listen: %s\n", strerror(errno));
 		return -1;
 	}
@@ -738,73 +1244,129 @@ static int fio_init_server_connection(void)
 	return sk;
 }
 
+int fio_server_parse_host(const char *host, int *ipv6, struct in_addr *inp,
+			  struct in6_addr *inp6)
+
+{
+	int ret = 0;
+
+	if (*ipv6)
+		ret = inet_pton(AF_INET6, host, inp6);
+	else
+		ret = inet_pton(AF_INET, host, inp);
+
+	if (ret != 1) {
+		struct hostent *hent;
+
+		hent = gethostbyname(host);
+		if (!hent) {
+			log_err("fio: failed to resolve <%s>\n", host);
+			return 0;
+		}
+
+		if (*ipv6) {
+			if (hent->h_addrtype != AF_INET6) {
+				log_info("fio: falling back to IPv4\n");
+				*ipv6 = 0;
+			} else
+				memcpy(inp6, hent->h_addr_list[0], 16);
+		}
+		if (!*ipv6) {
+			if (hent->h_addrtype != AF_INET) {
+				log_err("fio: lookup type mismatch\n");
+				return 0;
+			}
+			memcpy(inp, hent->h_addr_list[0], 4);
+		}
+		ret = 1;
+	}
+
+	return !(ret == 1);
+}
+
+/*
+ * Parse a host/ip/port string. Reads from 'str'.
+ *
+ * Outputs:
+ *
+ * For IPv4:
+ *	*ptr is the host, *port is the port, inp is the destination.
+ * For IPv6:
+ *	*ptr is the host, *port is the port, inp6 is the dest, and *ipv6 is 1.
+ * For local domain sockets:
+ *	*ptr is the filename, *is_sock is 1.
+ */
 int fio_server_parse_string(const char *str, char **ptr, int *is_sock,
-			    int *port, struct in_addr *inp)
+			    int *port, struct in_addr *inp,
+			    struct in6_addr *inp6, int *ipv6)
 {
+	const char *host = str;
+	char *portp;
+	int lport = 0;
+
 	*ptr = NULL;
 	*is_sock = 0;
-	*port = 0;
+	*port = fio_net_port;
+	*ipv6 = 0;
 
 	if (!strncmp(str, "sock:", 5)) {
 		*ptr = strdup(str + 5);
 		*is_sock = 1;
-	} else {
-		const char *host = str;
-		char *portp;
-		int lport = 0;
-
-		/*
-		 * Is it ip:<ip or host>:port
-		 */
-		if (!strncmp(host, "ip:", 3))
-			host += 3;
-		else if (host[0] == ':') {
-			/* String is :port */
-			host++;
-			lport = atoi(host);
+
+		return 0;
+	}
+
+	/*
+	 * Is it ip:<ip or host>:port
+	 */
+	if (!strncmp(host, "ip:", 3))
+		host += 3;
+	else if (!strncmp(host, "ip4:", 4))
+		host += 4;
+	else if (!strncmp(host, "ip6:", 4)) {
+		host += 4;
+		*ipv6 = 1;
+	} else if (host[0] == ':') {
+		/* String is :port */
+		host++;
+		lport = atoi(host);
+		if (!lport || lport > 65535) {
+			log_err("fio: bad server port %u\n", port);
+			return 1;
+		}
+		/* no hostname given, we are done */
+		*port = lport;
+		return 0;
+	}
+
+	/*
+	 * If no port seen yet, check if there's a last ':' at the end
+	 */
+	if (!lport) {
+		portp = strchr(host, ',');
+		if (portp) {
+			*portp = '\0';
+			portp++;
+			lport = atoi(portp);
 			if (!lport || lport > 65535) {
 				log_err("fio: bad server port %u\n", port);
 				return 1;
 			}
-			/* no hostname given, we are done */
-			*port = lport;
-			return 0;
 		}
+	}
 
-		/*
-		 * If no port seen yet, check if there's a last ':' at the end
-		 */
-		if (!lport) {
-			portp = strchr(host, ':');
-			if (portp) {
-				*portp = '\0';
-				portp++;
-				lport = atoi(portp);
-				if (!lport || lport > 65535) {
-					log_err("fio: bad server port %u\n", port);
-					return 1;
-				}
-			}
-		}
-
-		if (lport)
-			*port = lport;
-
-		*ptr = strdup(host);
+	if (lport)
+		*port = lport;
 
-		if (inet_aton(host, inp) != 1) {
-			struct hostent *hent;
+	if (!strlen(host))
+		return 0;
 
-			hent = gethostbyname(host);
-			if (!hent) {
-				printf("FAIL\n");
-				free(*ptr);
-				*ptr = NULL;
-				return 1;
-			}
+	*ptr = strdup(host);
 
-			memcpy(inp, hent->h_addr, 4);
-		}
+	if (fio_server_parse_host(*ptr, ipv6, inp, inp6)) {
+		free(*ptr);
+		*ptr = NULL;
+		return 1;
 	}
 
 	if (*port == 0)
@@ -827,16 +1389,28 @@ int fio_server_parse_string(const char *str, char **ptr, int *is_sock,
  */
 static int fio_handle_server_arg(void)
 {
-	int unused;
+	int port = fio_net_port;
+	int is_sock, ret = 0;
 
 	saddr_in.sin_addr.s_addr = htonl(INADDR_ANY);
-	saddr_in.sin_port = htons(fio_net_port);
 
 	if (!fio_server_arg)
-		return 0;
+		goto out;
 
-	return fio_server_parse_string(fio_server_arg, &bind_sock, &unused,
-					&fio_net_port, &saddr_in.sin_addr);
+	ret = fio_server_parse_string(fio_server_arg, &bind_sock, &is_sock,
+					&port, &saddr_in.sin_addr,
+					&saddr_in6.sin6_addr, &use_ipv6);
+
+	if (!is_sock && bind_sock) {
+		free(bind_sock);
+		bind_sock = NULL;
+	}
+
+out:
+	fio_net_port = port;
+	saddr_in.sin_port = htons(port);
+	saddr_in6.sin6_port = htons(port);
+	return ret;
 }
 
 static int fio_server(void)
@@ -866,52 +1440,106 @@ static int fio_server(void)
 	return ret;
 }
 
-static void sig_int(int sig)
+void fio_server_got_signal(int signal)
 {
-	fio_terminate_threads(TERMINATE_ALL);
-	exit_backend = 1;
+	if (signal == SIGPIPE)
+		server_fd = -1;
+	else {
+		log_info("\nfio: terminating on signal %d\n", signal);
+		exit_backend = 1;
+	}
 }
 
-static void server_signal_handler(void)
+static int check_existing_pidfile(const char *pidfile)
 {
-	struct sigaction act;
+	struct stat sb;
+	char buf[16];
+	pid_t pid;
+	FILE *f;
+
+	if (stat(pidfile, &sb))
+		return 0;
+
+	f = fopen(pidfile, "r");
+	if (!f)
+		return 0;
+
+	if (fread(buf, sb.st_size, 1, f) <= 0) {
+		fclose(f);
+		return 1;
+	}
+	fclose(f);
 
-	memset(&act, 0, sizeof(act));
-	act.sa_handler = sig_int;
-	act.sa_flags = SA_RESTART;
-	sigaction(SIGINT, &act, NULL);
+	pid = atoi(buf);
+	if (kill(pid, SIGCONT) < 0)
+		return errno != ESRCH;
 
-	memset(&act, 0, sizeof(act));
-	act.sa_handler = sig_int;
-	act.sa_flags = SA_RESTART;
-	sigaction(SIGTERM, &act, NULL);
+	return 1;
 }
 
-int fio_start_server(int daemonize)
+static int write_pid(pid_t pid, const char *pidfile)
+{
+	FILE *fpid;
+
+	fpid = fopen(pidfile, "w");
+	if (!fpid) {
+		log_err("fio: failed opening pid file %s\n", pidfile);
+		return 1;
+	}
+
+	fprintf(fpid, "%u\n", (unsigned int) pid);
+	fclose(fpid);
+	return 0;
+}
+
+/*
+ * If pidfile is specified, background us.
+ */
+int fio_start_server(char *pidfile)
 {
 	pid_t pid;
+	int ret;
 
-	server_signal_handler();
+#if defined(WIN32)
+	WSADATA wsd;
+	WSAStartup(MAKEWORD(2,2), &wsd);
+#endif
 
-	if (!daemonize)
+	if (!pidfile)
 		return fio_server();
 
-	openlog("fio", LOG_NDELAY|LOG_NOWAIT|LOG_PID, LOG_USER);
+	if (check_existing_pidfile(pidfile)) {
+		log_err("fio: pidfile %s exists and server appears alive\n",
+								pidfile);
+		return -1;
+	}
+
 	pid = fork();
 	if (pid < 0) {
-		syslog(LOG_ERR, "failed server fork");
+		log_err("fio: failed server fork: %s", strerror(errno));
+		free(pidfile);
 		return -1;
-	} else if (pid)
-		exit(0);
+	} else if (pid) {
+		int ret = write_pid(pid, pidfile);
+
+		exit(ret);
+	}
 
 	setsid();
+	openlog("fio", LOG_NDELAY|LOG_NOWAIT|LOG_PID, LOG_USER);
+	log_syslog = 1;
 	close(STDIN_FILENO);
 	close(STDOUT_FILENO);
 	close(STDERR_FILENO);
 	f_out = NULL;
 	f_err = NULL;
-	log_syslog = 1;
-	return fio_server();
+
+	ret = fio_server();
+
+	closelog();
+	unlink(pidfile);
+	free(pidfile);
+	return ret;
 }
 
 void fio_server_set_arg(const char *arg)