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

Similar to 24a4542c. 24a4542c can only be set 1 in 1s at most,
sometimes we may need to set to something else(such as 1 in 2s).
So it's best to let the user decide.

This also allows users to solve #34690.

diff --git a/docs/ENVIRONMENT.md b/docs/ENVIRONMENT.md
index f6f1216c054f472d84b83670e4f8a9b1fb4920a5..cf5fb91eb96862b0e75e4d7107d62e0763170a64 100644 (file)
--- a/docs/ENVIRONMENT.md
+++ b/docs/ENVIRONMENT.md
@@ -351,6 +351,13 @@ All tools:
   default is not appropriate for a given system. Defaults to `5`, accepts
   positive integers.
 
+* `$SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_INTERVAL_SEC` — can be set to override the mount
+  units interval rate limit for parsing `/proc/self/mountinfo`. Similar to
+  `$SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_BURST`, the interval limit maybe adjusted when
+  the default is not appropriate for a given system. The default value is 1 and the
+  default application time unit is second, and the time unit can beoverriden as usual
+  by specifying it explicitly, see the systemd.time(7) man page.
+
 `systemd-remount-fs`:
 
 * `$SYSTEMD_REMOUNT_ROOT_RW=1` — if set and no entry for the root directory

diff --git a/src/core/mount.c b/src/core/mount.c
index 0a403b6759222723d78117a757f0c67b61e133a5..19dd09c58fddecefc88d5e3f7bab755c9a2a2eba 100644 (file)
--- a/src/core/mount.c
+++ b/src/core/mount.c
@@ -1997,6 +1997,7 @@ static void mount_enumerate(Manager *m) {
         mnt_init_debug(0);
 
         if (!m->mount_monitor) {
+                usec_t mount_rate_limit_interval = 1 * USEC_PER_SEC;
                 unsigned mount_rate_limit_burst = 5;
                 int fd;
 
@@ -2038,14 +2039,21 @@ static void mount_enumerate(Manager *m) {
                 }
 
                 /* 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");
+                const char *e = secure_getenv("SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_INTERVAL_SEC");
+                if (e) {
+                        r = parse_sec(e, &mount_rate_limit_interval);
+                        if (r < 0)
+                                log_debug_errno(r, "Invalid value in $SYSTEMD_DEFAULT_MOUNT_RATE_LIMIT_INTERVAL_SEC, ignoring: %s", e);
+                }
+
+                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);
+                                log_debug_errno(r, "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);
+                r = sd_event_source_set_ratelimit(m->mount_event_source, mount_rate_limit_interval, mount_rate_limit_burst);
                 if (r < 0) {
                         log_error_errno(r, "Failed to enable rate limit for mount events: %m");
                         goto fail;