From 5bdff860e71f864e1f472010b0284ff6ae222b5d Mon Sep 17 00:00:00 2001 From: Pawel Jakub Dawidek Date: Mon, 30 Aug 2010 23:26:10 +0000 Subject: [PATCH] Because it is very hard to make fork(2) from threaded process safe (we are limited to async-signal safe functions in the child process), move all hooks execution to the main (non-threaded) process. Do it by maintaining connection (socketpair) between child and parent and sending events from the child to parent, so it can execute the hook. This is step in right direction for others reasons too. For example there is one less problem to drop privs in worker processes. MFC after: 2 weeks Obtained from: Wheel Systems Sp. z o.o. http://www.wheelsystems.com --- sbin/hastd/Makefile | 2 +- sbin/hastd/hast.h | 2 ++ sbin/hastd/hastd.c | 44 ++++++++++++++++++++++++++++++++---------- sbin/hastd/primary.c | 39 +++++++++++++++++++------------------ sbin/hastd/secondary.c | 21 ++++++++++++++++---- 5 files changed, 74 insertions(+), 34 deletions(-) diff --git a/sbin/hastd/Makefile b/sbin/hastd/Makefile index bfb62f4f11f6..6e3147dcd31e 100644 --- a/sbin/hastd/Makefile +++ b/sbin/hastd/Makefile @@ -5,7 +5,7 @@ PROG= hastd SRCS= activemap.c SRCS+= control.c -SRCS+= ebuf.c +SRCS+= ebuf.c event.c SRCS+= hast_proto.c hastd.c hooks.c SRCS+= metadata.c SRCS+= nv.c diff --git a/sbin/hastd/hast.h b/sbin/hastd/hast.h index 71379178e767..a42865f0d061 100644 --- a/sbin/hastd/hast.h +++ b/sbin/hastd/hast.h @@ -181,6 +181,8 @@ struct hast_resource { pid_t hr_workerpid; /* Control connection between parent and child. */ struct proto_conn *hr_ctrl; + /* Events from child to parent. */ + struct proto_conn *hr_event; /* Activemap structure. */ struct activemap *hr_amp; diff --git a/sbin/hastd/hastd.c b/sbin/hastd/hastd.c index ccc25cfe0f44..6ddcbd2f831e 100644 --- a/sbin/hastd/hastd.c +++ b/sbin/hastd/hastd.c @@ -52,6 +52,7 @@ __FBSDID("$FreeBSD$"); #include #include "control.h" +#include "event.h" #include "hast.h" #include "hast_proto.h" #include "hastd.h" @@ -158,6 +159,11 @@ child_exit(void) role2str(res->hr_role)); child_exit_log(pid, status); proto_close(res->hr_ctrl); + res->hr_ctrl = NULL; + if (res->hr_event != NULL) { + proto_close(res->hr_event); + res->hr_event = NULL; + } res->hr_workerpid = 0; if (res->hr_role == HAST_ROLE_PRIMARY) { /* @@ -624,9 +630,10 @@ listen_accept(void) static void main_loop(void) { - fd_set rfds; - int cfd, lfd, maxfd, ret; + struct hast_resource *res; struct timeval timeout; + int fd, maxfd, ret; + fd_set rfds; timeout.tv_sec = REPORT_INTERVAL; timeout.tv_usec = 0; @@ -646,14 +653,20 @@ main_loop(void) hastd_reload(); } - cfd = proto_descriptor(cfg->hc_controlconn); - lfd = proto_descriptor(cfg->hc_listenconn); - maxfd = cfd > lfd ? cfd : lfd; - /* Setup descriptors for select(2). */ FD_ZERO(&rfds); - FD_SET(cfd, &rfds); - FD_SET(lfd, &rfds); + maxfd = fd = proto_descriptor(cfg->hc_controlconn); + FD_SET(fd, &rfds); + fd = proto_descriptor(cfg->hc_listenconn); + FD_SET(fd, &rfds); + maxfd = fd > maxfd ? fd : maxfd; + TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) { + if (res->hr_event == NULL) + continue; + fd = proto_descriptor(res->hr_event); + FD_SET(fd, &rfds); + maxfd = fd > maxfd ? fd : maxfd; + } ret = select(maxfd + 1, &rfds, NULL, NULL, &timeout); if (ret == 0) @@ -665,10 +678,21 @@ main_loop(void) pjdlog_exit(EX_OSERR, "select() failed"); } - if (FD_ISSET(cfd, &rfds)) + if (FD_ISSET(proto_descriptor(cfg->hc_controlconn), &rfds)) control_handle(cfg); - if (FD_ISSET(lfd, &rfds)) + if (FD_ISSET(proto_descriptor(cfg->hc_listenconn), &rfds)) listen_accept(); + TAILQ_FOREACH(res, &cfg->hc_resources, hr_next) { + if (res->hr_event == NULL) + continue; + if (FD_ISSET(proto_descriptor(res->hr_event), &rfds)) { + if (event_recv(res) == 0) + continue; + /* The worker process exited? */ + proto_close(res->hr_event); + res->hr_event = NULL; + } + } } } diff --git a/sbin/hastd/primary.c b/sbin/hastd/primary.c index e018e89a186f..a8a2d41f87a8 100644 --- a/sbin/hastd/primary.c +++ b/sbin/hastd/primary.c @@ -58,6 +58,7 @@ __FBSDID("$FreeBSD$"); #include #include "control.h" +#include "event.h" #include "hast.h" #include "hast_proto.h" #include "hastd.h" @@ -225,12 +226,6 @@ static void *ggate_send_thread(void *arg); static void *sync_thread(void *arg); static void *guard_thread(void *arg); -static void -dummy_sighandler(int sig __unused) -{ - /* Nothing to do. */ -} - static void cleanup(struct hast_resource *res) { @@ -429,8 +424,6 @@ init_environment(struct hast_resource *res __unused) /* * Turn on signals handling. */ - /* Because SIGCHLD is ignored by default, setup dummy handler for it. */ - PJDLOG_VERIFY(signal(SIGCHLD, dummy_sighandler) != SIG_ERR); PJDLOG_VERIFY(sigfillset(&mask) == 0); PJDLOG_VERIFY(sigprocmask(SIG_SETMASK, &mask, NULL) == 0); } @@ -672,11 +665,11 @@ init_remote(struct hast_resource *res, struct proto_conn **inp, res->hr_remotein = in; res->hr_remoteout = out; } - hook_exec(res->hr_exec, "connect", res->hr_name, NULL); + event_send(res, EVENT_CONNECT); return (true); close: if (errmsg != NULL && strcmp(errmsg, "Split-brain condition!") == 0) - hook_exec(res->hr_exec, "split-brain", res->hr_name, NULL); + event_send(res, EVENT_SPLITBRAIN); proto_close(out); if (in != NULL) proto_close(in); @@ -774,6 +767,14 @@ hastd_primary(struct hast_resource *res) pjdlog_exit(EX_OSERR, "Unable to create control sockets between parent and child"); } + /* + * Create communication channel between child and parent. + */ + if (proto_client("socketpair://", &res->hr_event) < 0) { + KEEP_ERRNO((void)pidfile_remove(pfh)); + pjdlog_exit(EX_OSERR, + "Unable to create event sockets between child and parent"); + } pid = fork(); if (pid < 0) { @@ -783,6 +784,8 @@ hastd_primary(struct hast_resource *res) if (pid > 0) { /* This is parent. */ + /* Declare that we are receiver. */ + proto_recv(res->hr_event, NULL, 0); res->hr_workerpid = pid; return; } @@ -797,7 +800,9 @@ hastd_primary(struct hast_resource *res) signal(SIGHUP, SIG_DFL); signal(SIGCHLD, SIG_DFL); - hook_init(); + /* Declare that we are sender. */ + proto_send(res->hr_event, NULL, 0); + init_local(res); if (real_remote(res) && init_remote(res, NULL, NULL)) sync_start(); @@ -896,7 +901,7 @@ remote_close(struct hast_resource *res, int ncomp) */ sync_stop(); - hook_exec(res->hr_exec, "disconnect", res->hr_name, NULL); + event_send(res, EVENT_DISCONNECT); } /* @@ -1512,7 +1517,7 @@ sync_thread(void *arg __unused) pjdlog_info("Synchronization interrupted. " "%jd bytes synchronized so far.", (intmax_t)synced); - hook_exec(res->hr_exec, "syncintr", res->hr_name, NULL); + event_send(res, EVENT_SYNCINTR); } while (!sync_inprogress) { dorewind = true; @@ -1545,8 +1550,7 @@ sync_thread(void *arg __unused) pjdlog_info("Synchronization started. %ju bytes to go.", (uintmax_t)(res->hr_extentsize * activemap_ndirty(res->hr_amp))); - hook_exec(res->hr_exec, "syncstart", - res->hr_name, NULL); + event_send(res, EVENT_SYNCSTART); } } if (offset < 0) { @@ -1563,8 +1567,7 @@ sync_thread(void *arg __unused) pjdlog_info("Synchronization complete. " "%jd bytes synchronized.", (intmax_t)synced); - hook_exec(res->hr_exec, "syncdone", - res->hr_name, NULL); + event_send(res, EVENT_SYNCDONE); } mtx_lock(&metadata_lock); res->hr_syncsrc = HAST_SYNCSRC_UNDEF; @@ -1950,7 +1953,6 @@ guard_thread(void *arg) PJDLOG_VERIFY(sigaddset(&mask, SIGHUP) == 0); PJDLOG_VERIFY(sigaddset(&mask, SIGINT) == 0); PJDLOG_VERIFY(sigaddset(&mask, SIGTERM) == 0); - PJDLOG_VERIFY(sigaddset(&mask, SIGCHLD) == 0); timeout.tv_nsec = 0; signo = -1; @@ -1969,7 +1971,6 @@ guard_thread(void *arg) default: break; } - hook_check(signo == SIGCHLD); pjdlog_debug(2, "remote_guard: Checking connections."); now = time(NULL); diff --git a/sbin/hastd/secondary.c b/sbin/hastd/secondary.c index d1575e8a5a7e..14016f703db1 100644 --- a/sbin/hastd/secondary.c +++ b/sbin/hastd/secondary.c @@ -54,6 +54,7 @@ __FBSDID("$FreeBSD$"); #include #include "control.h" +#include "event.h" #include "hast.h" #include "hast_proto.h" #include "hastd.h" @@ -325,7 +326,7 @@ init_remote(struct hast_resource *res, struct nv *nvin) if (res->hr_secondary_localcnt > res->hr_primary_remotecnt && res->hr_primary_localcnt > res->hr_secondary_remotecnt) { /* Exit on split-brain. */ - hook_exec(res->hr_exec, "split-brain", res->hr_name, NULL); + event_send(res, EVENT_SPLITBRAIN); exit(EX_CONFIG); } } @@ -345,6 +346,14 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin) pjdlog_exit(EX_OSERR, "Unable to create control sockets between parent and child"); } + /* + * Create communication channel between child and parent. + */ + if (proto_client("socketpair://", &res->hr_event) < 0) { + KEEP_ERRNO((void)pidfile_remove(pfh)); + pjdlog_exit(EX_OSERR, + "Unable to create event sockets between child and parent"); + } pid = fork(); if (pid < 0) { @@ -358,6 +367,8 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin) res->hr_remotein = NULL; proto_close(res->hr_remoteout); res->hr_remoteout = NULL; + /* Declare that we are receiver. */ + proto_recv(res->hr_event, NULL, 0); res->hr_workerpid = pid; return; } @@ -372,17 +383,19 @@ hastd_secondary(struct hast_resource *res, struct nv *nvin) signal(SIGHUP, SIG_DFL); signal(SIGCHLD, SIG_DFL); + /* Declare that we are sender. */ + proto_send(res->hr_event, NULL, 0); + /* Error in setting timeout is not critical, but why should it fail? */ if (proto_timeout(res->hr_remotein, 0) < 0) pjdlog_errno(LOG_WARNING, "Unable to set connection timeout"); if (proto_timeout(res->hr_remoteout, res->hr_timeout) < 0) pjdlog_errno(LOG_WARNING, "Unable to set connection timeout"); - hook_init(); init_local(res); init_remote(res, nvin); init_environment(); - hook_exec(res->hr_exec, "connect", res->hr_name, NULL); + event_send(res, EVENT_CONNECT); error = pthread_create(&td, NULL, recv_thread, res); assert(error == 0); @@ -515,7 +528,7 @@ secondary_exit(int exitcode, const char *fmt, ...) va_start(ap, fmt); pjdlogv_errno(LOG_ERR, fmt, ap); va_end(ap); - hook_exec(gres->hr_exec, "disconnect", gres->hr_name, NULL); + event_send(gres, EVENT_DISCONNECT); exit(exitcode); }