osd: Create EC Direct Read flag and pass through to EC.

This is in preperation for supporting sparse and sync reads in EC.
Such ops will only be supported for "balance reads".

Signed-off-by: Alex Ainscow <[email protected]>

Author: aainscow

src/crimson/osd/pg.cc

@@ -1615,8 +1615,7 @@ bool PG::can_discard_op(const MOSDOp& m) const {
     return true;
   }
 
-  if ((m.get_flags() & (CEPH_OSD_FLAG_BALANCE_READS |
-                        CEPH_OSD_FLAG_LOCALIZE_READS))
+  if ((m.get_flags() & CEPH_OSD_FLAGS_DIRECT_READ)
     && !is_primary()
     && (m.get_map_epoch() <
         peering_state.get_info().history.same_interval_since))

src/include/rados.h

@@ -481,8 +481,12 @@ enum {
 	CEPH_OSD_FLAG_IGNORE_REDIRECT = 0x2000000,  /* ignore redirection */
 	CEPH_OSD_FLAG_RETURNVEC = 0x4000000, /* allow overall result >= 0, and return >= 0 and buffer for each op in opvec */
 	CEPH_OSD_FLAG_SUPPORTSPOOLEIO = 0x8000000,   /* client understands pool EIO flag */
+        CEPH_OSD_FLAG_EC_DIRECT_READ = 0x10000000,  /* Erasure code doing a partial read direct to OSD. */
 };
 
+// Indicates an IO which is direct-to-OSD and may not be on the primary.
+#define CEPH_OSD_FLAGS_DIRECT_READ (CEPH_OSD_FLAG_BALANCE_READS | CEPH_OSD_FLAG_LOCALIZE_READS | CEPH_OSD_FLAG_EC_DIRECT_READ)
+
 enum {
 	CEPH_OSD_OP_FLAG_EXCL = 0x1,      /* EXCL object create */
 	CEPH_OSD_OP_FLAG_FAILOK = 0x2,    /* continue despite failure */

src/osd/OpRequest.h

@@ -48,6 +48,8 @@ struct OpRequest : public TrackedOp {
   bool need_skip_handle_cache() const { return op_info.need_skip_handle_cache(); }
   bool need_skip_promote() const { return op_info.need_skip_promote(); }
   bool allows_returnvec() const { return op_info.allows_returnvec(); }
+  bool ec_direct_read() const { return op_info.ec_direct_read(); }
+  void set_ec_direct_read() { return op_info.set_ec_direct_read(); }
 
   std::vector<OpInfo::ClassInfo> classes() const {
     return op_info.get_classes();

src/osd/PG.cc

@@ -1940,8 +1940,7 @@ bool PG::can_discard_op(OpRequestRef& op)
     return true;
   }
 
-  if ((m->get_flags() & (CEPH_OSD_FLAG_BALANCE_READS |
-			 CEPH_OSD_FLAG_LOCALIZE_READS)) &&
+  if ((m->get_flags() & CEPH_OSD_FLAGS_DIRECT_READ) &&
       !is_primary() &&
       m->get_map_epoch() < info.history.same_interval_since) {
     // Note: the Objecter will resend on interval change without the primary

src/osd/PrimaryLogPG.cc

@@ -2047,16 +2047,22 @@ void PrimaryLogPG::do_op(OpRequestRef& op)
   }
 
   // check for op with rwordered and rebalance or localize reads
-  if ((m->has_flag(CEPH_OSD_FLAG_BALANCE_READS) || m->has_flag(CEPH_OSD_FLAG_LOCALIZE_READS)) &&
-      op->rwordered()) {
+  if (m->has_flag(CEPH_OSD_FLAGS_DIRECT_READ) && op->rwordered()) {
     dout(4) << __func__ << ": rebelance or localized reads with rwordered not allowed "
        << *m << dendl;
     osd->reply_op_error(op, -EINVAL);
     return;
   }
 
-  if ((m->get_flags() & (CEPH_OSD_FLAG_BALANCE_READS |
-			 CEPH_OSD_FLAG_LOCALIZE_READS)) &&
+  if (m->get_flags() & CEPH_OSD_FLAG_EC_DIRECT_READ) {
+    if (is_primary() || is_nonprimary()) {
+      op->set_ec_direct_read();
+    } else {
+      osd->handle_misdirected_op(this, op);
+      return;
+    }
+  } else if ((m->get_flags() & (CEPH_OSD_FLAG_BALANCE_READS |
+                                CEPH_OSD_FLAG_LOCALIZE_READS)) &&
       op->may_read() &&
       !(op->may_write() || op->may_cache())) {
     // balanced reads; any replica will do

src/osd/osd_op_util.cc

@@ -52,6 +52,9 @@ bool OpInfo::need_skip_promote() const {
 bool OpInfo::allows_returnvec() const {
   return check_rmw(CEPH_OSD_RMW_FLAG_RETURNVEC);
 }
+bool OpInfo::ec_direct_read() const {
+  return check_rmw(CEPH_OSD_RMW_FLAG_EC_DIRECT_READ);
+}
 /**
  * may_read_data()
  * 
@@ -79,6 +82,7 @@ void OpInfo::set_skip_promote() { set_rmw_flags(CEPH_OSD_RMW_FLAG_SKIP_PROMOTE);
 void OpInfo::set_force_rwordered() { set_rmw_flags(CEPH_OSD_RMW_FLAG_RWORDERED); }
 void OpInfo::set_returnvec() { set_rmw_flags(CEPH_OSD_RMW_FLAG_RETURNVEC); }
 void OpInfo::set_read_data() { set_rmw_flags(CEPH_OSD_RMW_FLAG_READ_DATA); }
+void OpInfo::set_ec_direct_read() { set_rmw_flags(CEPH_OSD_RMW_FLAG_EC_DIRECT_READ); }
 
 
 int OpInfo::set_from_op(

src/osd/osd_op_util.h

@@ -59,6 +59,7 @@ class OpInfo {
   bool need_skip_handle_cache() const;
   bool need_skip_promote() const;
   bool allows_returnvec() const;
+  bool ec_direct_read() const;
 
   void set_read();
   void set_write();
@@ -72,6 +73,7 @@ class OpInfo {
   void set_force_rwordered();
   void set_returnvec();
   void set_read_data();
+  void set_ec_direct_read();
 
   int set_from_op(
     const MOSDOp *m,

src/osd/osd_types.cc

@@ -103,6 +103,7 @@ const char *ceph_osd_flag_name(unsigned flag)
   case CEPH_OSD_FLAG_IGNORE_REDIRECT: return "ignore_redirect";
   case CEPH_OSD_FLAG_RETURNVEC: return "returnvec";
   case CEPH_OSD_FLAG_SUPPORTSPOOLEIO: return "supports_pool_eio";
+  case CEPH_OSD_FLAG_EC_DIRECT_READ: return "ec_direct_read";
   default: return "???";
   }
 }

src/osd/osd_types.h

@@ -383,6 +383,7 @@ enum {
   CEPH_OSD_RMW_FLAG_RWORDERED         = (1 << 10),
   CEPH_OSD_RMW_FLAG_RETURNVEC = (1 << 11),
   CEPH_OSD_RMW_FLAG_READ_DATA  = (1 << 12),
+  CEPH_OSD_RMW_FLAG_EC_DIRECT_READ  = (1 << 13),
 };