/* functions to track and manage processes Copyright (C) Ronnie Sahlberg 2012 This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 3 of the License, or (at your option) any later version. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with this program; if not, see . */ #include "replace.h" #include "system/wait.h" #include "system/network.h" #include #include #include "lib/util/debug.h" #include "ctdb_private.h" #include "ctdb_client.h" #include "common/rb_tree.h" #include "common/system.h" #include "common/common.h" #include "common/logging.h" void ctdb_set_child_info(TALLOC_CTX *mem_ctx, const char *child_name_fmt, ...) { if (child_name_fmt != NULL) { va_list ap; char *t; va_start(ap, child_name_fmt); t = talloc_vasprintf(mem_ctx, child_name_fmt, ap); debug_extra = talloc_asprintf(mem_ctx, "%s:", t); talloc_free(t); va_end(ap); } } void ctdb_track_child(struct ctdb_context *ctdb, pid_t pid) { char *process; /* Only CTDB main daemon should track child processes */ if (getpid() != ctdb->ctdbd_pid) { return; } process = talloc_asprintf(ctdb->child_processes, "process:%d", (int)pid); trbt_insert32(ctdb->child_processes, pid, process); } /* * This function forks a child process and drops the realtime * scheduler for the child process. */ pid_t ctdb_fork(struct ctdb_context *ctdb) { pid_t pid; pid = fork(); if (pid == -1) { DEBUG(DEBUG_ERR, (__location__ " fork() failed (%s)\n", strerror(errno))); return -1; } if (pid == 0) { ctdb_set_child_info(ctdb, NULL); /* Close the Unix Domain socket and the TCP socket. * This ensures that none of the child processes will * look like the main daemon when it is not running. * tevent needs to be stopped before closing sockets. */ if (ctdb->ev != NULL) { talloc_free(ctdb->ev); ctdb->ev = NULL; } if (ctdb->daemon.sd != -1) { close(ctdb->daemon.sd); ctdb->daemon.sd = -1; } if (ctdb->methods != NULL && ctdb->methods->shutdown != NULL) { ctdb->methods->shutdown(ctdb); } /* The child does not need to be realtime */ if (ctdb->do_setsched) { reset_scheduler(); } ctdb->can_send_controls = false; return 0; } ctdb_track_child(ctdb, pid); return pid; } static void ctdb_sigchld_handler(struct tevent_context *ev, struct tevent_signal *te, int signum, int count, void *dont_care, void *private_data) { struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context); int status; pid_t pid = -1; while (pid != 0) { pid = waitpid(-1, &status, WNOHANG); if (pid == -1) { DEBUG(DEBUG_ERR, (__location__ " waitpid() returned error. errno:%d\n", errno)); return; } if (pid > 0) { char *process; if (getpid() != ctdb->ctdbd_pid) { continue; } process = trbt_lookup32(ctdb->child_processes, pid); if (process == NULL) { DEBUG(DEBUG_ERR,("Got SIGCHLD from pid:%d we didn not spawn with ctdb_fork\n", pid)); } DEBUG(DEBUG_DEBUG, ("SIGCHLD from %d %s\n", (int)pid, process)); talloc_free(process); } } } struct tevent_signal * ctdb_init_sigchld(struct ctdb_context *ctdb) { struct tevent_signal *se; ctdb->child_processes = trbt_create(ctdb, 0); se = tevent_add_signal(ctdb->ev, ctdb, SIGCHLD, 0, ctdb_sigchld_handler, ctdb); return se; } int ctdb_kill(struct ctdb_context *ctdb, pid_t pid, int signum) { char *process; if (signum == 0) { return kill(pid, signum); } if (getpid() != ctdb->ctdbd_pid) { return kill(pid, signum); } process = trbt_lookup32(ctdb->child_processes, pid); if (process == NULL) { DEBUG(DEBUG_ERR,("ctdb_kill: trying to kill(%d, %d) a process that does not exist\n", pid, signum)); return 0; } return kill(pid, signum); }