vol: rate-limit volume usage updates

[openafs.git] / src / vol / volume.c

diff --git a/src/vol/volume.c b/src/vol/volume.c
index 287041e..ba8ed51 100644 (file)
--- a/src/vol/volume.c
+++ b/src/vol/volume.c
@@ -479,6 +479,8 @@ VOptDefaults(ProgramType pt, VolumePackageOptions *opts)
     opts->interrupt_rxcall = NULL;
     opts->offline_timeout = -1;
     opts->offline_shutdown_timeout = -1;
+    opts->usage_threshold = 128;
+    opts->usage_rate_limit = 5;
 
 #ifdef FAST_RESTART
     opts->unsafe_attach = 1;
@@ -6674,10 +6676,16 @@ VBumpVolumeUsage_r(Volume * vp)
     if (now - V_dayUseDate(vp) > OneDay)
        VAdjustVolumeStatistics_r(vp);
     /*
-     * Save the volume header image to disk after every 128 bumps to dayUse.
+     * Save the volume header image to disk after a threshold of bumps to dayUse,
+     * at most every usage_rate_limit seconds.
      */
-    if ((V_dayUse(vp)++ & 127) == 0) {
+    V_dayUse(vp)++;
+    vp->usage_bumps_outstanding++;
+    if (vp->usage_bumps_outstanding >= vol_opts.usage_threshold
+       && vp->usage_bumps_next_write <= now) {
        Error error;
+       vp->usage_bumps_outstanding = 0;
+       vp->usage_bumps_next_write = now + vol_opts.usage_rate_limit;
        VUpdateVolume_r(&error, vp, VOL_UPDATE_WAIT);
     }
 }
@@ -7929,7 +7937,7 @@ GetVolHeaderFromLRU(void)
      * could VWaitExclusiveState_r instead, but not waiting is faster and
      * easier to do */
     for (queue_Scan(&volume_hdr_LRU, qh, nqh, volHeader)) {
-       if (!hd->back || !VIsExclusiveState(V_attachState(hd->back))) {
+       if (!qh->back || !VIsExclusiveState(V_attachState(qh->back))) {
            queue_Remove(qh);
            hd = qh;
            break;