pid1: add env var to override default mount rate limit burst

I am hitting the rate limit on a busy system with low resources, and
it stalls the boot process which is Very Bad (TM).

1 files changed, 10 insertions, 1 deletions

diff --git a/src/core/mount.c b/src/core/mount.c
index be46e56689..f16e5c487b 100644
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -1909,6 +1909,7 @@ static void mount_enumerate(Manager *m) {
         mnt_init_debug(0);
 
         if (!m->mount_monitor) {
+                unsigned mount_rate_limit_burst = 5;
                 int fd;
 
                 m->mount_monitor = mnt_new_monitor();
@@ -1948,7 +1949,15 @@ static void mount_enumerate(Manager *m) {
                         goto fail;
                 }
 
-                r = sd_event_source_set_ratelimit(m->mount_event_source, 1 * USEC_PER_SEC, 5);
+                /* Let users override the default (5 in 1s), as it stalls the boot sequence on busy systems. */
+                const char *e = secure_getenv("SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST");
+                if (e) {
+                        r = safe_atou(e, &mount_rate_limit_burst);
+                        if (r < 0)
+                                log_debug("Invalid value in $SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST, ignoring: %s", e);
+                }
+
+                r = sd_event_source_set_ratelimit(m->mount_event_source, 1 * USEC_PER_SEC, mount_rate_limit_burst);
                 if (r < 0) {
                         log_error_errno(r, "Failed to enable rate limit for mount events: %m");
                         goto fail;