LU-14996 lov: prefer mirrors on non-rotational OSTs

[fs/lustre-release.git] / lustre / lod / lod_lov.c

diff --git a/lustre/lod/lod_lov.c b/lustre/lod/lod_lov.c
index 10ab3fa..ae80072 100644 (file)
--- a/lustre/lod/lod_lov.c
+++ b/lustre/lod/lod_lov.c
@@ -589,10 +589,12 @@ int lod_alloc_comp_entries(struct lod_object *lo,
 
 int lod_fill_mirrors(struct lod_object *lo)
 {
+       struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
        struct lod_layout_component *lod_comp;
+       bool found_preferred = false;
        int mirror_idx = -1;
        __u16 mirror_id = 0xffff;
-       int i;
+       int i, pref;
        ENTRY;
 
        LASSERT(equi(!lo->ldo_is_composite, lo->ldo_mirror_count == 0));
@@ -601,17 +603,34 @@ int lod_fill_mirrors(struct lod_object *lo)
                RETURN(0);
 
        lod_comp = &lo->ldo_comp_entries[0];
+
        for (i = 0; i < lo->ldo_comp_cnt; i++, lod_comp++) {
                int stale = !!(lod_comp->llc_flags & LCME_FL_STALE);
                int preferred = !!(lod_comp->llc_flags & LCME_FL_PREF_WR);
+               int j;
+
+               pref = 0;
+               /* calculate component preference over all used OSTs */
+               for (j = 0; j < lod_comp->llc_stripes_allocated; j++) {
+                       int idx = lod_comp->llc_ost_indices[j];
+                       struct obd_statfs *osfs = &OST_TGT(lod,idx)->ltd_statfs;
+
+                       if (osfs->os_state & OS_STATFS_NONROT)
+                               pref++;
+               }
 
                if (mirror_id_of(lod_comp->llc_id) == mirror_id) {
                        lo->ldo_mirrors[mirror_idx].lme_stale |= stale;
                        lo->ldo_mirrors[mirror_idx].lme_prefer |= preferred;
+                       lo->ldo_mirrors[mirror_idx].lme_preference += pref;
                        lo->ldo_mirrors[mirror_idx].lme_end = i;
                        continue;
                }
 
+               if (mirror_idx >= 0 && preferred &&
+                   !lo->ldo_mirrors[mirror_idx].lme_stale)
+                       found_preferred = true;
+
                /* new mirror */
                ++mirror_idx;
                if (mirror_idx >= lo->ldo_mirror_count)
@@ -622,12 +641,34 @@ int lod_fill_mirrors(struct lod_object *lo)
                lo->ldo_mirrors[mirror_idx].lme_id = mirror_id;
                lo->ldo_mirrors[mirror_idx].lme_stale = stale;
                lo->ldo_mirrors[mirror_idx].lme_prefer = preferred;
+               lo->ldo_mirrors[mirror_idx].lme_preference = pref;
                lo->ldo_mirrors[mirror_idx].lme_start = i;
                lo->ldo_mirrors[mirror_idx].lme_end = i;
        }
        if (mirror_idx != lo->ldo_mirror_count - 1)
                RETURN(-EINVAL);
 
+       if (!found_preferred && mirror_idx > 0) {
+               int best = -1;
+
+               /*
+                * if no explicited preferred found, then find a mirror
+                * with higher number of non-rotational OSTs
+                * */
+               pref = -1;
+               for (i = 0; i <= mirror_idx; i++) {
+                       if (lo->ldo_mirrors[i].lme_stale)
+                               continue;
+                       if (lo->ldo_mirrors[i].lme_preference > pref) {
+                               pref = lo->ldo_mirrors[i].lme_preference;
+                               best = i;
+                       }
+               }
+
+               LASSERT(best >= 0);
+               lo->ldo_mirrors[best].lme_prefer = 1;
+       }
+
        RETURN(0);
 }