LU-13439 lmv: qos stay on current MDT if less full

[fs/lustre-release.git] / lustre / lmv / lmv_obd.c

diff --git a/lustre/lmv/lmv_obd.c b/lustre/lmv/lmv_obd.c
index 5236e44..d231ed9 100644 (file)
--- a/lustre/lmv/lmv_obd.c
+++ b/lustre/lmv/lmv_obd.c
@@ -1461,9 +1461,10 @@ static int lmv_close(struct obd_export *exp, struct md_op_data *op_data,
 
 static struct lu_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, __u32 *mdt)
 {
-       struct lu_tgt_desc *tgt;
+       struct lu_tgt_desc *tgt, *cur = NULL;
        __u64 total_weight = 0;
        __u64 cur_weight = 0;
+       int total_usable = 0;
        __u64 rand;
        int rc;
 
@@ -1482,15 +1483,29 @@ static struct lu_tgt_desc *lmv_locate_tgt_qos(struct lmv_obd *lmv, __u32 *mdt)
                GOTO(unlock, tgt = ERR_PTR(rc));
 
        lmv_foreach_tgt(lmv, tgt) {
-               tgt->ltd_qos.ltq_usable = 0;
-               if (!tgt->ltd_exp || !tgt->ltd_active)
+               if (!tgt->ltd_exp || !tgt->ltd_active) {
+                       tgt->ltd_qos.ltq_usable = 0;
                        continue;
+               }
 
                tgt->ltd_qos.ltq_usable = 1;
                lu_tgt_qos_weight_calc(tgt);
+               if (tgt->ltd_index == *mdt) {
+                       cur = tgt;
+                       cur_weight = tgt->ltd_qos.ltq_weight;
+               }
                total_weight += tgt->ltd_qos.ltq_weight;
+               total_usable++;
+       }
+
+       /* if current MDT has higher-than-average space, stay on same MDT */
+       rand = total_weight / total_usable;
+       if (cur_weight >= rand) {
+               tgt = cur;
+               GOTO(unlock, rc = 0);
        }
 
+       cur_weight = 0;
        rand = lu_prandom_u64_max(total_weight);
 
        lmv_foreach_connected_tgt(lmv, tgt) {