bdev: remove bdev_register_examine_thread deprecation

Starting in SPDK 23.01, calling spdk_bdev_register() and
spdk_bdev_examine() from a thread other than the app thread was
deprecated. This commit removes the deprecation and as such calling
these functions from a thread other than the app thread is an error.

As a side effect of this commit, all bdev module examine_config() and
examine_disk() callbacks will be called on the app thread.

Change-Id: Idaae06608101e2a513d9312ac5544ffe94effe4a
Signed-off-by: Mike Gerdts <mgerdts@nvidia.com>
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15826
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Shuhei Matsumoto <smatsumoto@nvidia.com>

deprecation.md

@@ -58,20 +58,6 @@ and will be removed in SPDK 23.05.
 Deprecated `spdk_nvme_ctrlr_prepare_for_reset` API, which will be removed in SPDK 22.01.
 For PCIe transport, `spdk_nvme_ctrlr_disconnect` should be used before freeing I/O qpairs.
 
-### bdev
-
-#### `bdev_register_examine_thread`
-
-Deprecated calling `spdk_bdev_register()` and `spdk_bdev_examine()` from a thread other than the
-app thread. See `spdk_thread_get_app_thread()`. Starting in SPDK 23.05, calling
-`spdk_bdev_register()` or `spdk_bdev_examine()` from a thread other than the app thread will return
-an error.
-
-With the removal of this deprecation, calls to vbdev modules' `examine_disk()` and
-`examine_config()` callbacks will happen only on the app thread. This means that vbdev module
-maintainers will not need to make any changes to examine callbacks that call `spdk_bdev_register()`
-on the same thread as the examine callback uses.
-
 ### gpt
 
 #### `old_gpt_guid`

lib/bdev/bdev.c

@@ -73,9 +73,6 @@ int __itt_init_ittlib(const char *, __itt_group_id);
 static void log_already_claimed(enum spdk_log_level level, const int line, const char *func,
 				const char *detail, struct spdk_bdev *bdev);
 
-SPDK_LOG_DEPRECATION_REGISTER(bdev_register_examine_thread,
-			      "bdev register and examine on non-app thread", "SPDK 23.05", 0);
-
 SPDK_LOG_DEPRECATION_REGISTER(vtune_support, "Intel(R) VTune integration", "SPDK 23.05", 0);
 
 static const char *qos_rpc_type[] = {"rw_ios_per_sec",
@@ -770,9 +767,12 @@ spdk_bdev_examine(const char *name)
 {
 	struct spdk_bdev *bdev;
 	struct spdk_bdev_examine_item *item;
+	struct spdk_thread *thread = spdk_get_thread();
 
-	if (spdk_unlikely(spdk_thread_get_app_thread() != spdk_get_thread())) {
+	if (spdk_unlikely(spdk_thread_get_app_thread() != thread)) {
-		SPDK_LOG_DEPRECATED(bdev_register_examine_thread);
+		SPDK_ERRLOG("Cannot examine bdev %s on thread %p (%s)\n", name, thread,
+			    thread ? spdk_thread_get_name(thread) : "null");
+		return -EINVAL;
 	}
 
 	if (g_bdev_opts.bdev_auto_examine) {
@@ -7370,10 +7370,13 @@ int
 spdk_bdev_register(struct spdk_bdev *bdev)
 {
 	struct spdk_bdev_desc *desc;
+	struct spdk_thread *thread = spdk_get_thread();
 	int rc;
 
 	if (spdk_unlikely(spdk_thread_get_app_thread() != spdk_get_thread())) {
-		SPDK_LOG_DEPRECATED(bdev_register_examine_thread);
+		SPDK_ERRLOG("Cannot examine bdev %s on thread %p (%s)\n", bdev->name, thread,
+			    thread ? spdk_thread_get_name(thread) : "null");
+		return -EINVAL;
 	}
 
 	rc = bdev_register(bdev);

test/unit/lib/bdev/mt/bdev.c/bdev_ut.c

@@ -2354,19 +2354,6 @@ bdev_init_wt_cb(void *done, int rc)
 }
 
 
-static uint64_t
-get_wrong_thread_hits(void)
-{
-	static uint64_t previous = 0;
-	uint64_t ret, current;
-
-	current = spdk_deprecation_get_hits(_deprecated_bdev_register_examine_thread);
-	ret = current - previous;
-	previous = current;
-
-	return ret;
-}
-
 static int
 wrong_thread_setup(void)
 {
@@ -2380,18 +2367,13 @@ wrong_thread_setup(void)
 
 	set_thread(1);
 
-	/* Ignore return, just setting the base for the next time it is called. */
-	get_wrong_thread_hits();
-
 	return 0;
 }
 
 static int
 wrong_thread_teardown(void)
 {
-	int rc;
+	int rc = 0;
-
-	rc = get_wrong_thread_hits();
 
 	set_thread(0);
 
@@ -2412,12 +2394,20 @@ wrong_thread_teardown(void)
 	return rc;
 }
 
+static void
+_bdev_unregistered_wt(void *ctx, int rc)
+{
+	struct spdk_thread **threadp = ctx;
+
+	*threadp = spdk_get_thread();
+}
+
 static void
 spdk_bdev_register_wt(void)
 {
 	struct spdk_bdev bdev = { 0 };
 	int rc;
-	bool done;
+	struct spdk_thread *unreg_thread;
 
 	bdev.name = "wt_bdev";
 	bdev.fn_table = &fn_table;
@@ -2427,26 +2417,29 @@ spdk_bdev_register_wt(void)
 
 	/* Can register only on app thread */
 	rc = spdk_bdev_register(&bdev);
-	CU_ASSERT(rc == 0);
+	CU_ASSERT(rc == -EINVAL);
-	CU_ASSERT(get_wrong_thread_hits() == 1);
 
 	/* Can unregister on any thread */
-	done = false;
+	set_thread(0);
-	spdk_bdev_unregister(&bdev, _bdev_unregistered, &done);
-	poll_threads();
-	CU_ASSERT(get_wrong_thread_hits() == 0);
-	CU_ASSERT(done);
-
-	/* Can unregister by name on any thread */
 	rc = spdk_bdev_register(&bdev);
 	CU_ASSERT(rc == 0);
-	CU_ASSERT(get_wrong_thread_hits() == 1);
+	set_thread(1);
-	done = false;
+	unreg_thread = NULL;
-	rc = spdk_bdev_unregister_by_name(bdev.name, bdev.module, _bdev_unregistered, &done);
+	spdk_bdev_unregister(&bdev, _bdev_unregistered_wt, &unreg_thread);
+	poll_threads();
+	CU_ASSERT(unreg_thread == spdk_get_thread());
+
+	/* Can unregister by name on any thread */
+	set_thread(0);
+	rc = spdk_bdev_register(&bdev);
+	CU_ASSERT(rc == 0);
+	set_thread(1);
+	unreg_thread = NULL;
+	rc = spdk_bdev_unregister_by_name(bdev.name, bdev.module, _bdev_unregistered_wt,
+					  &unreg_thread);
 	CU_ASSERT(rc == 0);
 	poll_threads();
-	CU_ASSERT(get_wrong_thread_hits() == 0);
+	CU_ASSERT(unreg_thread == spdk_get_thread());
-	CU_ASSERT(done);
 }
 
 static void
@@ -2473,12 +2466,9 @@ spdk_bdev_examine_wt(void)
 
 	/* Can examine only on the app thread */
 	rc = spdk_bdev_examine("ut_bdev_wt");
-	CU_ASSERT(rc == 0);
+	CU_ASSERT(rc == -EINVAL);
-	poll_threads();
-	CU_ASSERT(get_wrong_thread_hits() == 1);
 	unregister_bdev(&g_bdev);
 	CU_ASSERT(spdk_bdev_get_by_name("ut_bdev_wt") == NULL);
-	CU_ASSERT(get_wrong_thread_hits() == 0);
 
 	/* Can wait for examine on app thread, callback called on app thread. */
 	set_thread(0);
@@ -2488,11 +2478,9 @@ spdk_bdev_examine_wt(void)
 	rc = spdk_bdev_wait_for_examine(wait_for_examine_cb, &thread);
 	CU_ASSERT(rc == 0);
 	poll_threads();
-	CU_ASSERT(get_wrong_thread_hits() == 0);
 	CU_ASSERT(thread == spdk_get_thread());
 	unregister_bdev(&g_bdev);
 	CU_ASSERT(spdk_bdev_get_by_name("ut_bdev_wt") == NULL);
-	CU_ASSERT(get_wrong_thread_hits() == 0);
 
 	/* Can wait for examine on non-app thread, callback called on same thread. */
 	set_thread(0);
@@ -2502,11 +2490,9 @@ spdk_bdev_examine_wt(void)
 	rc = spdk_bdev_wait_for_examine(wait_for_examine_cb, &thread);
 	CU_ASSERT(rc == 0);
 	poll_threads();
-	CU_ASSERT(get_wrong_thread_hits() == 0);
 	CU_ASSERT(thread == spdk_get_thread());
 	unregister_bdev(&g_bdev);
 	CU_ASSERT(spdk_bdev_get_by_name("ut_bdev_wt") == NULL);
-	CU_ASSERT(get_wrong_thread_hits() == 0);
 
 	unregister_bdev(&g_bdev);
 	g_bdev_opts.bdev_auto_examine = save_auto_examine;