Method ll_read_block

src/client/Client.cc:17141–17172

}

int Client::ll_read_block(Inode *in, uint64_t blockid,
			  char *buf,
			  uint64_t offset,
			  uint64_t length,
			  file_layout_t* layout)
{
  RWRef_t mref_reader(mount_state, CLIENT_MOUNTING);
  if (!mref_reader.is_state_satisfied())
    return -ENOTCONN;

  vinodeno_t vino = _get_vino(in);
  object_t oid = file_object_t(vino.ino, blockid);
  C_SaferCond onfinish;
  bufferlist bl;

  objecter->read(oid,
		 object_locator_t(layout->pool_id),
		 offset,
		 length,
		 vino.snapid,
		 &bl,
		 CEPH_OSD_FLAG_READ,
                 &onfinish);

  int r = onfinish.wait();
  if (r >= 0) {
      bl.begin().copy(bl.length(), buf);
      r = bl.length();
  }

  return r;
}

/* It appears that the OSD doesn't return success unless the entire
   buffer was written, return the write length on success. */