}
}
+/**
+ * check an OST's availability
+ * \param[in] env execution environment
+ * \param[in] lo lod object
+ * \param[in] dt dt object
+ * \param[in] index mirror index
+ *
+ * \retval negative if failed
+ * \retval 1 if \a dt is available
+ * \retval 0 if \a dt is not available
+ */
+static inline int lod_check_ost_avail(const struct lu_env *env,
+ struct lod_object *lo,
+ struct dt_object *dt, int index)
+{
+ struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+ struct lod_tgt_desc *ost;
+ __u32 idx;
+ int type = LU_SEQ_RANGE_OST;
+ int rc;
+
+ rc = lod_fld_lookup(env, lod, lu_object_fid(&dt->do_lu), &idx, &type);
+ if (rc < 0) {
+ CERROR("%s: can't locate "DFID":rc = %d\n",
+ lod2obd(lod)->obd_name, PFID(lu_object_fid(&dt->do_lu)),
+ rc);
+ return rc;
+ }
+
+ ost = OST_TGT(lod, idx);
+ if (ost->ltd_statfs.os_state &
+ (OS_STATE_READONLY | OS_STATE_ENOSPC | OS_STATE_ENOINO) ||
+ ost->ltd_active == 0) {
+ CDEBUG(D_LAYOUT, DFID ": mirror %d OST%d unavail, rc = %d\n",
+ PFID(lod_object_fid(lo)), index, idx, rc);
+ return 0;
+ }
+
+ return 1;
+}
+
+/**
+ * Pick primary mirror for write
+ * \param[in] env execution environment
+ * \param[in] lo object
+ * \param[in] extent write range
+ */
+static int lod_primary_pick(const struct lu_env *env, struct lod_object *lo,
+ struct lu_extent *extent)
+{
+ struct lod_device *lod = lu2lod_dev(lo->ldo_obj.do_lu.lo_dev);
+ unsigned int seq = 0;
+ struct lod_layout_component *lod_comp;
+ int i, j, rc;
+ int picked = -1, second_pick = -1, third_pick = -1;
+ ENTRY;
+
+ if (OBD_FAIL_CHECK(OBD_FAIL_FLR_RANDOM_PICK_MIRROR)) {
+ get_random_bytes(&seq, sizeof(seq));
+ seq %= lo->ldo_mirror_count;
+ }
+
+ /**
+ * Pick a mirror as the primary, and check the availability of OSTs.
+ *
+ * This algo can be revised later after knowing the topology of
+ * cluster.
+ */
+ lod_qos_statfs_update(env, lod);
+ for (i = 0; i < lo->ldo_mirror_count; i++) {
+ bool ost_avail = true;
+ int index = (i + seq) % lo->ldo_mirror_count;
+
+ if (lo->ldo_mirrors[index].lme_stale) {
+ CDEBUG(D_LAYOUT, DFID": mirror %d stale\n",
+ PFID(lod_object_fid(lo)), index);
+ continue;
+ }
+
+ /* 2nd pick is for the primary mirror containing unavail OST */
+ if (lo->ldo_mirrors[index].lme_primary && second_pick < 0)
+ second_pick = index;
+
+ /* 3rd pick is for non-primary mirror containing unavail OST */
+ if (second_pick < 0 && third_pick < 0)
+ third_pick = index;
+
+ /**
+ * we found a non-primary 1st pick, we'd like to find a
+ * potential pirmary mirror.
+ */
+ if (picked >= 0 && !lo->ldo_mirrors[index].lme_primary)
+ continue;
+
+ /* check the availability of OSTs */
+ lod_foreach_mirror_comp(lod_comp, lo, index) {
+ if (!lod_comp_inited(lod_comp) || !lod_comp->llc_stripe)
+ continue;
+
+ for (j = 0; j < lod_comp->llc_stripe_count; j++) {
+ struct dt_object *dt = lod_comp->llc_stripe[j];
+
+ rc = lod_check_ost_avail(env, lo, dt, index);
+ if (rc < 0)
+ RETURN(rc);
+
+ ost_avail = !!rc;
+ if (!ost_avail)
+ break;
+ } /* for all dt object in one component */
+ if (!ost_avail)
+ break;
+ } /* for all components in a mirror */
+
+ /**
+ * the OSTs where allocated objects locates in the components
+ * of the mirror are available.
+ */
+ if (!ost_avail)
+ continue;
+
+ /* this mirror has all OSTs available */
+ picked = index;
+
+ /**
+ * primary with all OSTs are available, this is the perfect
+ * 1st pick.
+ */
+ if (lo->ldo_mirrors[index].lme_primary)
+ break;
+ } /* for all mirrors */
+
+ /* failed to pick a sound mirror, lower our expectation */
+ if (picked < 0)
+ picked = second_pick;
+ if (picked < 0)
+ picked = third_pick;
+ if (picked < 0)
+ RETURN(-ENODATA);
+
+ RETURN(picked);
+}
+
static int lod_declare_update_rdonly(const struct lu_env *env,
struct lod_object *lo, struct md_layout_change *mlc,
struct thandle *th)
struct lod_layout_component *lod_comp;
struct layout_intent *layout = mlc->mlc_intent;
struct lu_extent extent = layout->li_extent;
- unsigned int seq = 0;
int picked;
- int i;
int rc;
ENTRY;
CDEBUG(D_LAYOUT, DFID": trying to write :"DEXT"\n",
PFID(lod_object_fid(lo)), PEXT(&extent));
- if (OBD_FAIL_CHECK(OBD_FAIL_FLR_RANDOM_PICK_MIRROR)) {
- get_random_bytes(&seq, sizeof(seq));
- seq %= lo->ldo_mirror_count;
- }
-
- /**
- * Pick a mirror as the primary.
- * Now it only picks the first mirror that has primary flag set and
- * doesn't have any stale components. This algo should be revised
- * later after knowing the topology of cluster or the availability of
- * OSTs.
- */
- for (picked = -1, i = 0; i < lo->ldo_mirror_count; i++) {
- int index = (i + seq) % lo->ldo_mirror_count;
-
- if (!lo->ldo_mirrors[index].lme_stale) {
- if (lo->ldo_mirrors[index].lme_primary) {
- picked = index;
- break;
- }
-
- if (picked < 0)
- picked = index;
- }
- }
- if (picked < 0) /* failed to pick a primary */
- RETURN(-ENODATA);
+ picked = lod_primary_pick(env, lo, &extent);
+ if (picked < 0)
+ RETURN(picked);
CDEBUG(D_LAYOUT, DFID": picked mirror %u as primary\n",
PFID(lod_object_fid(lo)), lo->ldo_mirrors[picked].lme_id);
if (lod_comp_inited(lod_comp))
continue;
- CDEBUG(D_LAYOUT, "instantiate: %u / %u\n",
- i, lod_comp_index(lo, lod_comp));
-
info->lti_comp_idx[info->lti_count++] =
lod_comp_index(lo, lod_comp);
}
git://git.whamcloud.com / fs / lustre-release.git / blobdiff