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a57eba2bb4
Wrap all creation of child processes inside ctdb_fork() which is used to track all processes we have spawned. Capture SIGCHLD to track also which child processes have terminated. Wrap kill() inside ctdb_kill() and make sure that we never send a !0 signal to a child process pid that has already terminated (and might have been replaced with a (This used to be ctdb commit f73a4b1495830bcdd094a93732a89dd53b3c2f78)
125 lines
2.9 KiB
C
125 lines
2.9 KiB
C
/*
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functions to track and manage processes
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Copyright (C) Ronnie Sahlberg 2012
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 3 of the License, or
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(at your option) any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, see <http://www.gnu.org/licenses/>.
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*/
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#include "includes.h"
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#include "system/wait.h"
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#include "../include/ctdb_client.h"
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#include "../include/ctdb_private.h"
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#include "../common/rb_tree.h"
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/*
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* This function forks a child process and drops the realtime
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* scheduler for the child process.
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*/
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pid_t ctdb_fork(struct ctdb_context *ctdb)
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{
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pid_t pid;
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char *process;
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pid = fork();
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if (pid == -1) {
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return -1;
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}
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if (pid == 0) {
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if (ctdb->do_setsched) {
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ctdb_restore_scheduler(ctdb);
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}
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ctdb->can_send_controls = false;
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return 0;
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}
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if (getpid() != ctdb->ctdbd_pid) {
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return pid;
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}
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process = talloc_asprintf(ctdb->child_processes, "process:%d", (int)pid);
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trbt_insert32(ctdb->child_processes, pid, process);
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return pid;
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}
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static void ctdb_sigchld_handler(struct tevent_context *ev,
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struct tevent_signal *te, int signum, int count,
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void *dont_care,
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void *private_data)
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{
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struct ctdb_context *ctdb = talloc_get_type(private_data, struct ctdb_context);
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int status;
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pid_t pid = -1;
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while (pid != 0) {
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pid = waitpid(-1, &status, WNOHANG);
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if (pid == -1) {
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DEBUG(DEBUG_ERR, (__location__ " waitpid() returned error. errno:%d\n", errno));
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return;
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}
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if (pid > 0) {
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char *process;
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if (getpid() != ctdb->ctdbd_pid) {
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continue;
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}
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process = trbt_lookup32(ctdb->child_processes, pid);
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if (process == NULL) {
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DEBUG(DEBUG_ERR,("Got SIGCHLD from pid:%d we didn not spawn with ctdb_fork\n", pid));
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}
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DEBUG(DEBUG_DEBUG, ("SIGCHLD from %d %s\n", (int)pid, process));
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talloc_free(process);
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}
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}
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}
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struct tevent_signal *
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ctdb_init_sigchld(struct ctdb_context *ctdb)
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{
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struct tevent_signal *se;
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ctdb->child_processes = trbt_create(ctdb, 0);
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se = tevent_add_signal(ctdb->ev, ctdb, SIGCHLD, 0, ctdb_sigchld_handler, ctdb);
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return se;
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}
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int
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ctdb_kill(struct ctdb_context *ctdb, pid_t pid, int signum)
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{
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char *process;
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if (signum == 0) {
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return kill(pid, signum);
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}
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if (getpid() != ctdb->ctdbd_pid) {
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return kill(pid, signum);
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}
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process = trbt_lookup32(ctdb->child_processes, pid);
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if (process == NULL) {
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DEBUG(DEBUG_ERR,("ctdb_kill: trying to kill(%d, %d) a process that does not exist\n", pid, signum));
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return 0;
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}
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return kill(pid, signum);
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}
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