diff --git a/src/basic/def.h b/src/basic/def.h index 7c4161eb72..cbef137410 100644 --- a/src/basic/def.h +++ b/src/basic/def.h @@ -35,6 +35,9 @@ * the watchdog pings will keep the loop busy. */ #define DEFAULT_EXIT_USEC (30*USEC_PER_SEC) +/* The default value for the net.unix.max_dgram_qlen sysctl */ +#define DEFAULT_UNIX_MAX_DGRAM_QLEN 512UL + #define SYSTEMD_CGROUP_CONTROLLER "name=systemd" #define SIGNALS_CRASH_HANDLER SIGSEGV,SIGILL,SIGFPE,SIGBUS,SIGQUIT,SIGABRT diff --git a/src/core/main.c b/src/core/main.c index 593b974566..dd21b26971 100644 --- a/src/core/main.c +++ b/src/core/main.c @@ -1242,12 +1242,50 @@ static int status_welcome(void) { static int write_container_id(void) { const char *c; + int r; c = getenv("container"); if (isempty(c)) return 0; - return write_string_file("/run/systemd/container", c, WRITE_STRING_FILE_CREATE); + r = write_string_file("/run/systemd/container", c, WRITE_STRING_FILE_CREATE); + if (r < 0) + return log_warning_errno(r, "Failed to write /run/systed/container, ignoring: %m"); + + return 1; +} + +static int bump_unix_max_dgram_qlen(void) { + _cleanup_free_ char *qlen = NULL; + unsigned long v; + int r; + + /* Let's bump the net.unix.max_dgram_qlen sysctl. The kernel + * default of 16 is simply too low. We set the value really + * really early during boot, so that it is actually applied to + * all our sockets, including the $NOTIFY_SOCKET one. */ + + r = read_one_line_file("/proc/sys/net/unix/max_dgram_qlen", &qlen); + if (r < 0) + return log_warning_errno(r, "Failed to read AF_UNIX datagram queue length, ignoring: %m"); + + r = safe_atolu(qlen, &v); + if (r < 0) + return log_warning_errno(r, "Failed to parse AF_UNIX datagram queue length, ignoring: %m"); + + if (v >= DEFAULT_UNIX_MAX_DGRAM_QLEN) + return 0; + + qlen = mfree(qlen); + if (asprintf(&qlen, "%lu\n", DEFAULT_UNIX_MAX_DGRAM_QLEN) < 0) + return log_oom(); + + r = write_string_file("/proc/sys/net/unix/max_dgram_qlen", qlen, 0); + if (r < 0) + return log_full_errno(IN_SET(r, -EROFS, -EPERM, -EACCES) ? LOG_DEBUG : LOG_WARNING, r, + "Failed to bump AF_UNIX datagram queue length, ignoring: %m"); + + return 1; } int main(int argc, char *argv[]) { @@ -1613,6 +1651,7 @@ int main(int argc, char *argv[]) { hostname_setup(); machine_id_setup(NULL); loopback_setup(); + bump_unix_max_dgram_qlen(); test_mtab(); test_usr(); diff --git a/sysctl.d/50-default.conf b/sysctl.d/50-default.conf index 2097551c33..def151bb84 100644 --- a/sysctl.d/50-default.conf +++ b/sysctl.d/50-default.conf @@ -35,9 +35,6 @@ net.ipv4.conf.all.promote_secondaries = 1 # Fair Queue CoDel packet scheduler to fight bufferbloat net.core.default_qdisc = fq_codel -# Make sure we can queue more than just a few datagrams in AF_UNIX sockets. -net.unix.max_dgram_qlen = 512 - # Enable hard and soft link protection fs.protected_hardlinks = 1 fs.protected_symlinks = 1