DAOS-187 vos: reorganize vos I/O functions

Based on recent changes of object model, VOS I/O functions has been
modified for a few times and there are some legacy code.

This patch cleans up those legacy code:
- reorganize code for recx fetch and update
- no data copy in btree member functions anymore, object I/O routines
  will copy in/out data for non-zc I/O.
- eliminate the restriction of iov buffer must align with record size
- return 0 and set record sizes to 0 for nonexistent object/dkey/akey
- cleanup for for recx hole fetching
- release unused spaces for record zc overwrite.
- remove unused checks from vos_tree
- minor fixes for vos tests

Change-Id: I528245734bcb7433127538e7cd4c5b5b4bf0e52d
Signed-off-by: Liang Zhen <[email protected]>
Reviewed-on: https://review.whamcloud.com/24496
Tested-by: Jenkins
Reviewed-by: Johann Lombardi <[email protected]>

src/vos/tests/vts_discard.c

@@ -164,10 +164,9 @@ io_fetch(struct io_test_args *arg, daos_epoch_t fetch_epoch,
 			       &req->sgl, false);
 	if (rc)
 		D_GOTO(exit, rc);
-	if (!rc && req->rex.rx_rsize == 0)
+	if (req->rex.rx_rsize == 0)
 		return -DER_NONEXIST;
 
-
 	assert_memory_equal(req->update_buf, req->fetch_buf, UPDATE_BUF_SIZE);
 
 exit:
@@ -328,7 +327,6 @@ io_near_epoch_tests(struct io_test_args *arg, char *dkey,
 	D_ALLOC(reqs,  (num * sizeof(struct io_req *)));
 	D_ALLOC(punch, (num * sizeof(bool)));
 
-
 	for (i = 0; i < num; i++) {
 		struct daos_uuid l_cookie;
 
@@ -344,7 +342,6 @@ io_near_epoch_tests(struct io_test_args *arg, char *dkey,
 		else
 			uuid_copy(l_cookie.uuid, cookie[i].uuid);
 
-
 		rc = io_update(arg, epoch[i], &l_cookie, dkey,
 			       akey, &cntrs, &reqs[i], idx[i],
 			       UPDATE_VERBOSE);
@@ -439,7 +436,7 @@ io_near_epoch_punch(void **state)
 	int			idx[3], rc = 0;
 	unsigned long		flags[3];
 
-	memset(&flags, '0', 3 * sizeof(unsigned long));
+	memset(&flags, 0, 3 * sizeof(unsigned long));
 	set_key_and_index(&dkey_buf[0], &akey_buf[0], &idx[0]);
 	set_near_epoch_tests(&cookie[0], &epoch[0], &idx[0], 3);
 
@@ -461,7 +458,7 @@ io_discard_punch(void **state)
 	int			idx[3], rc = 0;
 	unsigned long		flags[3];
 
-	memset(&flags, '0', 3 * sizeof(unsigned long));
+	memset(&flags, 0, 3 * sizeof(unsigned long));
 	set_key_and_index(&dkey_buf[0], &akey_buf[0], &idx[0]);
 	set_near_epoch_tests(&cookie[0], &epoch[0], &idx[0], 3);
 
@@ -890,7 +887,7 @@ static const struct CMUnitTest discard_tests[] = {
 		io_near_epoch_punch,
 		io_multikey_discard_setup,
 		io_multikey_discard_teardown},
-	{ "VOS302.2: VOS discard punched record test",
+	{ "VOS302.3: VOS discard punched record test",
 		io_discard_punch,
 		io_multikey_discard_setup,
 		io_multikey_discard_teardown},

src/vos/tests/vts_io.c

@@ -841,25 +841,20 @@ io_update_and_fetch_incorrect_dkey(struct io_test_args *arg,
 	memset(fetch_buf, 0, UPDATE_BUF_SIZE);
 	daos_iov_set(&val_iov, &fetch_buf[0], UPDATE_BUF_SIZE);
 
-	rex.rx_rsize = DAOS_REC_ANY;
+	/* will be set to zero after fetching a nonexistent key */
+	rex.rx_rsize = -1;
 
 	/* Injecting an incorrect dkey for fetch! */
 	dts_key_gen(&dkey_buf[0], UPDATE_DKEY_SIZE, UPDATE_DKEY);
 
 	rc = io_test_obj_fetch(arg, fetch_epoch, &dkey, &vio, &sgl, true);
-	if (rc)
-		goto exit;
-	assert_memory_equal(update_buf, fetch_buf, UPDATE_BUF_SIZE);
+	assert_int_equal(rc, 0);
+	assert_int_equal(rex.rx_rsize, 0);
 exit:
 	return rc;
 }
 
-/**
- * NB: this test assumes arg->oid is already created and
- * used to insert in previous tests..
- * If run independently this will be treated as a new object
- * and return success
- */
+/** fetch from a nonexistent object */
 static void
 io_fetch_wo_object(void **state)
 {
@@ -897,9 +892,13 @@ io_fetch_wo_object(void **state)
 	memset(fetch_buf, 0, UPDATE_BUF_SIZE);
 	daos_iov_set(&val_iov, &fetch_buf[0], UPDATE_BUF_SIZE);
 
-	rex.rx_rsize = DAOS_REC_ANY;
+	/* should be set to zero after fetching a nonexistent object */
+	rex.rx_rsize = -1;
+	arg->oid = gen_oid();
+
 	rc = io_test_obj_fetch(arg, 1, &dkey, &vio, &sgl, true);
-	assert_int_equal(rc, -DER_NONEXIST);
+	assert_int_equal(rc, 0);
+	assert_int_equal(rex.rx_rsize, 0);
 }
 
 static int
@@ -981,24 +980,18 @@ static void
 io_fetch_no_exist_dkey(void **state)
 {
 	struct io_test_args	*arg = *state;
-	int			rc;
 
 	arg->ta_flags = 0;
-
-	rc = io_update_and_fetch_incorrect_dkey(arg, 1, 1);
-	assert_int_equal(rc, -DER_NONEXIST);
+	io_update_and_fetch_incorrect_dkey(arg, 1, 1);
 }
 
 static void
 io_fetch_no_exist_dkey_zc(void **state)
 {
 	struct io_test_args	*arg = *state;
-	int			rc;
 
 	arg->ta_flags = TF_ZERO_COPY;
-
-	rc = io_update_and_fetch_incorrect_dkey(arg, 1, 1);
-	assert_int_equal(rc, -DER_NONEXIST);
+	io_update_and_fetch_incorrect_dkey(arg, 1, 1);
 }
 
 static void