From 62470498cca9a209aa9904668c1949f5229123af Mon Sep 17 00:00:00 2001 From: Felix Kaechele Date: Tue, 20 Apr 2021 21:28:18 -0400 Subject: [PATCH 2/2] fix PIDFile handling Corresponding RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1869026 Rejected upstream: https://trac.nginx.org/nginx/ticket/1897 Taken from: https://git.launchpad.net/ubuntu/+source/nginx/tree/debian/patches/nginx-fix-pidfile.patch From original patch: Author: Tj Bug-Ubuntu: https://bugs.launchpad.net/ubuntu/+source/nginx/+bug/1581864 Bug-Debian: https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=876365 iLast-Update: 2020-06-24 Signed-off-by: Felix Kaechele --- src/core/nginx.c | 24 +++++++++++++++++++++--- src/os/unix/ngx_daemon.c | 8 ++++++-- 2 files changed, 27 insertions(+), 5 deletions(-) diff --git a/src/core/nginx.c b/src/core/nginx.c index 48a20e9..32c0afe 100644 --- a/src/core/nginx.c +++ b/src/core/nginx.c @@ -339,14 +339,21 @@ main(int argc, char *const *argv) ngx_process = NGX_PROCESS_MASTER; } + /* tell-tale to detect if this is parent or child process */ + ngx_int_t child_pid = NGX_BUSY; + #if !(NGX_WIN32) if (ngx_init_signals(cycle->log) != NGX_OK) { return 1; } + /* tell-tale that this code has been executed */ + child_pid--; + if (!ngx_inherited && ccf->daemon) { - if (ngx_daemon(cycle->log) != NGX_OK) { + child_pid = ngx_daemon(cycle->log); + if (child_pid == NGX_ERROR) { return 1; } @@ -359,8 +366,19 @@ main(int argc, char *const *argv) #endif - if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) { - return 1; + /* If ngx_daemon() returned the child's PID in the parent process + * after the fork() set ngx_pid to the child_pid, which gets + * written to the PID file, then exit. + * For NGX_WIN32 always write the PID file + * For others, only write it from the parent process */ + if (child_pid < NGX_OK || child_pid > NGX_OK) { + ngx_pid = child_pid > NGX_OK ? child_pid : ngx_pid; + if (ngx_create_pidfile(&ccf->pid, cycle->log) != NGX_OK) { + return 1; + } + } + if (child_pid > NGX_OK) { + exit(0); } if (ngx_log_redirect_stderr(cycle) != NGX_OK) { diff --git a/src/os/unix/ngx_daemon.c b/src/os/unix/ngx_daemon.c index 385c49b..3719854 100644 --- a/src/os/unix/ngx_daemon.c +++ b/src/os/unix/ngx_daemon.c @@ -7,14 +7,17 @@ #include #include +#include ngx_int_t ngx_daemon(ngx_log_t *log) { int fd; + /* retain the return value for passing back to caller */ + pid_t pid_child = fork(); - switch (fork()) { + switch (pid_child) { case -1: ngx_log_error(NGX_LOG_EMERG, log, ngx_errno, "fork() failed"); return NGX_ERROR; @@ -23,7 +26,8 @@ ngx_daemon(ngx_log_t *log) break; default: - exit(0); + /* let caller do the exit() */ + return pid_child; } ngx_parent = ngx_pid; -- 2.31.1