libceph: introduce ceph_osd_request_target, calc_target()

Introduce ceph_osd_request_target, containing all mapping-related
fields of ceph_osd_request and calc_target() for calculating mappings
and populating it.

Signed-off-by: Ilya Dryomov <idryomov@gmail.com>

2 files changed, 276 insertions, 2 deletions

diff --git a/net/ceph/osd_client.c b/net/ceph/osd_client.c
index 0ff400a56cd6..cff3a7e29233 100644
--- a/net/ceph/osd_client.c
+++ b/net/ceph/osd_client.c
@@ -299,6 +299,30 @@ static void osd_req_op_data_release(struct ceph_osd_request *osd_req,
 }
 
 /*
+ * Assumes @t is zero-initialized.
+ */
+static void target_init(struct ceph_osd_request_target *t)
+{
+        ceph_oid_init(&t->base_oid);
+        ceph_oloc_init(&t->base_oloc);
+        ceph_oid_init(&t->target_oid);
+        ceph_oloc_init(&t->target_oloc);
+
+        ceph_osds_init(&t->acting);
+        ceph_osds_init(&t->up);
+        t->size = -1;
+        t->min_size = -1;
+
+        t->osd = CEPH_HOMELESS_OSD;
+}
+
+static void target_destroy(struct ceph_osd_request_target *t)
+{
+        ceph_oid_destroy(&t->base_oid);
+        ceph_oid_destroy(&t->target_oid);
+}
+
+/*
  * requests
  */
 static void ceph_osdc_release_request(struct kref *kref)
@@ -1273,6 +1297,11 @@ void ceph_osdc_set_request_linger(struct ceph_osd_client *osdc,
 }
 EXPORT_SYMBOL(ceph_osdc_set_request_linger);
 
+static bool __pool_full(struct ceph_pg_pool_info *pi)
+{
+        return pi->flags & CEPH_POOL_FLAG_FULL;
+}
+
 /*
  * Returns whether a request should be blocked from being sent
  * based on the current osdmap and osd_client settings.
@@ -1289,6 +1318,20 @@ static bool __req_should_be_paused(struct ceph_osd_client *osdc,
                 (req->r_flags & CEPH_OSD_FLAG_WRITE && pausewr);
 }
 
+static bool target_should_be_paused(struct ceph_osd_client *osdc,
+                                    const struct ceph_osd_request_target *t,
+                                    struct ceph_pg_pool_info *pi)
+{
+        bool pauserd = ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSERD);
+        bool pausewr = ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_PAUSEWR) ||
+                       ceph_osdmap_flag(osdc->osdmap, CEPH_OSDMAP_FULL) ||
+                       __pool_full(pi);
+
+        WARN_ON(pi->id != t->base_oloc.pool);
+        return (t->flags & CEPH_OSD_FLAG_READ && pauserd) ||
+               (t->flags & CEPH_OSD_FLAG_WRITE && pausewr);
+}
+
 /*
  * Calculate mapping of a request to a PG.  Takes tiering into account.
  */
@@ -1328,6 +1371,116 @@ static int __calc_request_pg(struct ceph_osdmap *osdmap,
                                          &req->r_target_oloc, pg_out);
 }
 
+enum calc_target_result {
+        CALC_TARGET_NO_ACTION = 0,
+        CALC_TARGET_NEED_RESEND,
+        CALC_TARGET_POOL_DNE,
+};
+
+static enum calc_target_result calc_target(struct ceph_osd_client *osdc,
+                                           struct ceph_osd_request_target *t,
+                                           u32 *last_force_resend,
+                                           bool any_change)
+{
+        struct ceph_pg_pool_info *pi;
+        struct ceph_pg pgid, last_pgid;
+        struct ceph_osds up, acting;
+        bool force_resend = false;
+        bool need_check_tiering = false;
+        bool need_resend = false;
+        bool sort_bitwise = ceph_osdmap_flag(osdc->osdmap,
+                                             CEPH_OSDMAP_SORTBITWISE);
+        enum calc_target_result ct_res;
+        int ret;
+
+        pi = ceph_pg_pool_by_id(osdc->osdmap, t->base_oloc.pool);
+        if (!pi) {
+                t->osd = CEPH_HOMELESS_OSD;
+                ct_res = CALC_TARGET_POOL_DNE;
+                goto out;
+        }
+
+        if (osdc->osdmap->epoch == pi->last_force_request_resend) {
+                if (last_force_resend &&
+                    *last_force_resend < pi->last_force_request_resend) {
+                        *last_force_resend = pi->last_force_request_resend;
+                        force_resend = true;
+                } else if (!last_force_resend) {
+                        force_resend = true;
+                }
+        }
+        if (ceph_oid_empty(&t->target_oid) || force_resend) {
+                ceph_oid_copy(&t->target_oid, &t->base_oid);
+                need_check_tiering = true;
+        }
+        if (ceph_oloc_empty(&t->target_oloc) || force_resend) {
+                ceph_oloc_copy(&t->target_oloc, &t->base_oloc);
+                need_check_tiering = true;
+        }
+
+        if (need_check_tiering &&
+            (t->flags & CEPH_OSD_FLAG_IGNORE_OVERLAY) == 0) {
+                if (t->flags & CEPH_OSD_FLAG_READ && pi->read_tier >= 0)
+                        t->target_oloc.pool = pi->read_tier;
+                if (t->flags & CEPH_OSD_FLAG_WRITE && pi->write_tier >= 0)
+                        t->target_oloc.pool = pi->write_tier;
+        }
+
+        ret = ceph_object_locator_to_pg(osdc->osdmap, &t->target_oid,
+                                        &t->target_oloc, &pgid);
+        if (ret) {
+                WARN_ON(ret != -ENOENT);
+                t->osd = CEPH_HOMELESS_OSD;
+                ct_res = CALC_TARGET_POOL_DNE;
+                goto out;
+        }
+        last_pgid.pool = pgid.pool;
+        last_pgid.seed = ceph_stable_mod(pgid.seed, t->pg_num, t->pg_num_mask);
+
+        ceph_pg_to_up_acting_osds(osdc->osdmap, &pgid, &up, &acting);
+        if (any_change &&
+            ceph_is_new_interval(&t->acting,
+                                 &acting,
+                                 &t->up,
+                                 &up,
+                                 t->size,
+                                 pi->size,
+                                 t->min_size,
+                                 pi->min_size,
+                                 t->pg_num,
+                                 pi->pg_num,
+                                 t->sort_bitwise,
+                                 sort_bitwise,
+                                 &last_pgid))
+                force_resend = true;
+
+        if (t->paused && !target_should_be_paused(osdc, t, pi)) {
+                t->paused = false;
+                need_resend = true;
+        }
+
+        if (ceph_pg_compare(&t->pgid, &pgid) ||
+            ceph_osds_changed(&t->acting, &acting, any_change) ||
+            force_resend) {
+                t->pgid = pgid; /* struct */
+                ceph_osds_copy(&t->acting, &acting);
+                ceph_osds_copy(&t->up, &up);
+                t->size = pi->size;
+                t->min_size = pi->min_size;
+                t->pg_num = pi->pg_num;
+                t->pg_num_mask = pi->pg_num_mask;
+                t->sort_bitwise = sort_bitwise;
+
+                t->osd = acting.primary;
+                need_resend = true;
+        }
+
+        ct_res = need_resend ? CALC_TARGET_NEED_RESEND : CALC_TARGET_NO_ACTION;
+out:
+        dout("%s t %p -> ct_res %d osd %d\n", __func__, t, ct_res, t->osd);
+        return ct_res;
+}
+
 static void __enqueue_request(struct ceph_osd_request *req)
 {
         struct ceph_osd_client *osdc = req->r_osdc;
@@ -1805,12 +1958,12 @@ static void handle_reply(struct ceph_osd_client *osdc, struct ceph_msg *msg)
                 redir.oloc.pool = -1;
         }
 
-        if (redir.oloc.pool != -1) {
+        if (!ceph_oloc_empty(&redir.oloc)) {
                 dout("redirect pool %lld\n", redir.oloc.pool);
 
                 __unregister_request(osdc, req);
 
-                req->r_target_oloc = redir.oloc; /* struct */
+                ceph_oloc_copy(&req->r_target_oloc, &redir.oloc);
 
                 /*
                  * Start redirect requests with nofail=true.  If
diff --git a/net/ceph/osdmap.c b/net/ceph/osdmap.c
index 66c3ebead92f..7d4a5b43085e 100644
--- a/net/ceph/osdmap.c
+++ b/net/ceph/osdmap.c
@@ -1521,6 +1521,32 @@ void ceph_oid_destroy(struct ceph_object_id *oid)
 }
 EXPORT_SYMBOL(ceph_oid_destroy);
 
+/*
+ * osds only
+ */
+static bool __osds_equal(const struct ceph_osds *lhs,
+                         const struct ceph_osds *rhs)
+{
+        if (lhs->size == rhs->size &&
+            !memcmp(lhs->osds, rhs->osds, rhs->size * sizeof(rhs->osds[0])))
+                return true;
+
+        return false;
+}
+
+/*
+ * osds + primary
+ */
+static bool osds_equal(const struct ceph_osds *lhs,
+                       const struct ceph_osds *rhs)
+{
+        if (__osds_equal(lhs, rhs) &&
+            lhs->primary == rhs->primary)
+                return true;
+
+        return false;
+}
+
 static bool osds_valid(const struct ceph_osds *set)
 {
         /* non-empty set */
@@ -1553,6 +1579,101 @@ void ceph_osds_copy(struct ceph_osds *dest, const struct ceph_osds *src)
         dest->primary = src->primary;
 }
 
+static bool is_split(const struct ceph_pg *pgid,
+                     u32 old_pg_num,
+                     u32 new_pg_num)
+{
+        int old_bits = calc_bits_of(old_pg_num);
+        int old_mask = (1 << old_bits) - 1;
+        int n;
+
+        WARN_ON(pgid->seed >= old_pg_num);
+        if (new_pg_num <= old_pg_num)
+                return false;
+
+        for (n = 1; ; n++) {
+                int next_bit = n << (old_bits - 1);
+                u32 s = next_bit | pgid->seed;
+
+                if (s < old_pg_num || s == pgid->seed)
+                        continue;
+                if (s >= new_pg_num)
+                        break;
+
+                s = ceph_stable_mod(s, old_pg_num, old_mask);
+                if (s == pgid->seed)
+                        return true;
+        }
+
+        return false;
+}
+
+bool ceph_is_new_interval(const struct ceph_osds *old_acting,
+                          const struct ceph_osds *new_acting,
+                          const struct ceph_osds *old_up,
+                          const struct ceph_osds *new_up,
+                          int old_size,
+                          int new_size,
+                          int old_min_size,
+                          int new_min_size,
+                          u32 old_pg_num,
+                          u32 new_pg_num,
+                          bool old_sort_bitwise,
+                          bool new_sort_bitwise,
+                          const struct ceph_pg *pgid)
+{
+        return !osds_equal(old_acting, new_acting) ||
+               !osds_equal(old_up, new_up) ||
+               old_size != new_size ||
+               old_min_size != new_min_size ||
+               is_split(pgid, old_pg_num, new_pg_num) ||
+               old_sort_bitwise != new_sort_bitwise;
+}
+
+static int calc_pg_rank(int osd, const struct ceph_osds *acting)
+{
+        int i;
+
+        for (i = 0; i < acting->size; i++) {
+                if (acting->osds[i] == osd)
+                        return i;
+        }
+
+        return -1;
+}
+
+static bool primary_changed(const struct ceph_osds *old_acting,
+                            const struct ceph_osds *new_acting)
+{
+        if (!old_acting->size && !new_acting->size)
+                return false; /* both still empty */
+
+        if (!old_acting->size ^ !new_acting->size)
+                return true; /* was empty, now not, or vice versa */
+
+        if (old_acting->primary != new_acting->primary)
+                return true; /* primary changed */
+
+        if (calc_pg_rank(old_acting->primary, old_acting) !=
+            calc_pg_rank(new_acting->primary, new_acting))
+                return true;
+
+        return false; /* same primary (tho replicas may have changed) */
+}
+
+bool ceph_osds_changed(const struct ceph_osds *old_acting,
+                       const struct ceph_osds *new_acting,
+                       bool any_change)
+{
+        if (primary_changed(old_acting, new_acting))
+                return true;
+
+        if (any_change && !__osds_equal(old_acting, new_acting))
+                return true;
+
+        return false;
+}
+
 /*
  * calculate file layout from given offset, length.
  * fill in correct oid, logical length, and object extent