nbd-server: block SIGCHLD when handling SIGTERM, and visa versa

SIGCHLD handler must be blocked during execution of SIGTERM handler,
and visa versa, because the former changes "children" hash table
iterated by the latter.

Signed-off-by: Dmitry V. Levin <ldv@altlinux.org>

diff --git a/nbd-server.c b/nbd-server.c
index 0868447f9ed717dc603df65c8a45a7e9a54ed890..80681c7e3a90867677ed5409d84bd1bd22deba0f 100644 (file)
--- a/nbd-server.c
+++ b/nbd-server.c
@@ -2454,11 +2454,14 @@ void setup_servers(GArray* servers) {
 
        sa.sa_handler = sigchld_handler;
        sigemptyset(&sa.sa_mask);
+       sigaddset(&sa.sa_mask, SIGTERM);
        sa.sa_flags = SA_RESTART;
        if(sigaction(SIGCHLD, &sa, NULL) == -1)
                err("sigaction: %m");
+
        sa.sa_handler = sigterm_handler;
        sigemptyset(&sa.sa_mask);
+       sigaddset(&sa.sa_mask, SIGCHLD);
        sa.sa_flags = SA_RESTART;
        if(sigaction(SIGTERM, &sa, NULL) == -1)
                err("sigaction: %m");