objclass: add cls_get_osd_min_alloc_size helper

Signed-off-by: Mykola Golub <mgolub@suse.com>

src/objclass/class_api.cc

@@ -796,3 +796,9 @@ bool cls_has_chunk(cls_method_context_t hctx, string fp_oid)
 
   return false;
 }
+
+uint64_t cls_get_osd_min_alloc_size(cls_method_context_t hctx) {
+  PrimaryLogPG::OpContext *ctx = *(PrimaryLogPG::OpContext **)hctx;
+
+  return ctx->pg->get_min_alloc_size();
+}

src/objclass/objclass.h

@@ -178,6 +178,8 @@ int cls_cxx_chunk_write_and_set(cls_method_context_t hctx, int ofs, int len,
 		   int set_len);
 bool cls_has_chunk(cls_method_context_t hctx, std::string fp_oid);
 
+extern uint64_t cls_get_osd_min_alloc_size(cls_method_context_t hctx);
+
 #endif
 
 #endif

src/os/ObjectStore.h

@@ -277,6 +277,11 @@ public:
   virtual bool wants_journal() = 0;  //< prefers a journal
   virtual bool allows_journal() = 0; //< allows a journal
 
+  // return store min allocation size, if applicable
+  virtual uint64_t get_min_alloc_size() const {
+    return 0;
+  }
+
   /// enumerate hardware devices (by 'devname', e.g., 'sda' as in /sys/block/sda)
   virtual int get_devices(std::set<std::string> *devls) {
     return -EOPNOTSUPP;

src/os/bluestore/BlueStore.h

@@ -2387,6 +2387,10 @@ public:
   bool wants_journal() override { return false; };
   bool allows_journal() override { return false; };
 
+  uint64_t get_min_alloc_size() const override {
+    return min_alloc_size;
+  }
+
   int get_devices(set<string> *ls) override;
 
   bool is_rotational() override;

src/osd/PG.cc

@@ -3857,3 +3857,7 @@ void PG::with_heartbeat_peers(std::function<void(int)> f)
   }
   heartbeat_peer_lock.Unlock();
 }
+
+uint64_t PG::get_min_alloc_size() const {
+  return osd->store->get_min_alloc_size();
+}

src/osd/PG.h

@@ -564,6 +564,8 @@ public:
   virtual void get_dynamic_perf_stats(DynamicPerfStats *stats) {
   }
 
+  uint64_t get_min_alloc_size() const;
+
   // reference counting
 #ifdef PG_DEBUG_REFS
   uint64_t get_with_id();

src/test/librados_test_stub/LibradosTestStub.cc

@@ -1503,3 +1503,7 @@ int cls_cxx_chunk_write_and_set(cls_method_handle_t, int,
 int cls_cxx_map_read_header(cls_method_handle_t, bufferlist *) {
   return -ENOTSUP;
 }
+
+uint64_t cls_get_osd_min_alloc_size(cls_method_context_t hctx) {
+  return 0;
+}