bdev: Add resize event

This patch adds RESIZE event to block device API.

Signed-off-by: Evgeniy Kochetov <evgeniik@mellanox.com>
Signed-off-by: Sasha Kotchubievsky <sashakot@mellanox.com>
Signed-off-by: Alexey Marchuk <alexeymar@mellanox.com>
Change-Id: Ic9fe359d19544fa0a48eed91216b858097e82995
Reviewed-on: https://review.gerrithub.io/c/spdk/spdk/+/468543
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Shuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>

CHANGELOG.md

@@ -49,6 +49,9 @@ asynchronous event such as bdev removal. spdk_bdev_open_ext function takes bdev
 an argument instead of bdev structure to avoid a race condition that can happen when the bdev
 is being removed between a call to get its structure based on a name and actually openning it.
 
+New 'resize' event has been added to notify about change of block count property of block device.
+Event is delivered only if block device was opened with spdk_bdev_open_ext function.
+
 ### blobstore
 
 A new spdk_bdev_create_bs_dev_from_desc function has been added and spdk_bdev_create_bs_dev

include/spdk/bdev.h

@@ -1,8 +1,8 @@
 /*-
  *   BSD LICENSE
  *
- *   Copyright (c) Intel Corporation.
- *   All rights reserved.
+ *   Copyright (c) Intel Corporation. All rights reserved.
+ *   Copyright (c) 2019 Mellanox Technologies LTD. All rights reserved.
  *
  *   Redistribution and use in source and binary forms, with or without
  *   modification, are permitted provided that the following conditions
@@ -63,6 +63,7 @@ extern "C" {
 /** Asynchronous event type */
 enum spdk_bdev_event_type {
 	SPDK_BDEV_EVENT_REMOVE,
+	SPDK_BDEV_EVENT_RESIZE
 };
 
 /**

lib/bdev/bdev.c

@@ -2669,9 +2669,35 @@ _spdk_bdev_desc_free(struct spdk_bdev_desc *desc)
 	free(desc);
 }
 
+static void
+_resize_notify(void *arg)
+{
+	struct spdk_bdev_desc *desc = arg;
+
+	pthread_mutex_lock(&desc->mutex);
+	desc->refs--;
+	if (!desc->closed) {
+		pthread_mutex_unlock(&desc->mutex);
+		desc->callback.event_fn(SPDK_BDEV_EVENT_RESIZE,
+					desc->bdev,
+					desc->callback.ctx);
+		return;
+	} else if (0 == desc->refs) {
+		/* This descriptor was closed after this resize_notify message was sent.
+		 * spdk_bdev_close() could not free the descriptor since this message was
+		 * in flight, so we free it now using _spdk_bdev_desc_free().
+		 */
+		pthread_mutex_unlock(&desc->mutex);
+		_spdk_bdev_desc_free(desc);
+		return;
+	}
+	pthread_mutex_unlock(&desc->mutex);
+}
+
 int
 spdk_bdev_notify_blockcnt_change(struct spdk_bdev *bdev, uint64_t size)
 {
+	struct spdk_bdev_desc *desc;
 	int ret;
 
 	pthread_mutex_lock(&bdev->internal.mutex);
@@ -2682,6 +2708,14 @@ spdk_bdev_notify_blockcnt_change(struct spdk_bdev *bdev, uint64_t size)
 		ret = -EBUSY;
 	} else {
 		bdev->blockcnt = size;
+		TAILQ_FOREACH(desc, &bdev->internal.open_descs, link) {
+			pthread_mutex_lock(&desc->mutex);
+			if (desc->callback.open_with_ext && !desc->closed) {
+				desc->refs++;
+				spdk_thread_send_msg(desc->thread, _resize_notify, desc);
+			}
+			pthread_mutex_unlock(&desc->mutex);
+		}
 		ret = 0;
 	}
 

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

@@ -431,7 +431,9 @@ bdev_open_cb1(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *even
 	struct spdk_bdev_desc *desc = *(struct spdk_bdev_desc **)event_ctx;
 
 	g_event_type1 = type;
-	spdk_bdev_close(desc);
+	if (SPDK_BDEV_EVENT_REMOVE == type) {
+		spdk_bdev_close(desc);
+	}
 }
 
 static void
@@ -440,7 +442,9 @@ bdev_open_cb2(enum spdk_bdev_event_type type, struct spdk_bdev *bdev, void *even
 	struct spdk_bdev_desc *desc = *(struct spdk_bdev_desc **)event_ctx;
 
 	g_event_type2 = type;
-	spdk_bdev_close(desc);
+	if (SPDK_BDEV_EVENT_REMOVE == type) {
+		spdk_bdev_close(desc);
+	}
 }
 
 static void
@@ -635,6 +639,7 @@ num_blocks_test(void)
 {
 	struct spdk_bdev bdev;
 	struct spdk_bdev_desc *desc = NULL;
+	struct spdk_bdev_desc *desc_ext = NULL;
 	int rc;
 
 	memset(&bdev, 0, sizeof(bdev));
@@ -659,10 +664,30 @@ num_blocks_test(void)
 	/* Shrinking block number */
 	CU_ASSERT(spdk_bdev_notify_blockcnt_change(&bdev, 20) != 0);
 
+	/* In case bdev opened with ext API */
+	rc = spdk_bdev_open_ext("num_blocks", false, bdev_open_cb1, &desc_ext, &desc_ext);
+	CU_ASSERT(rc == 0);
+	SPDK_CU_ASSERT_FATAL(desc_ext != NULL);
+
+	g_event_type1 = 0xFF;
+	/* Growing block number */
+	CU_ASSERT(spdk_bdev_notify_blockcnt_change(&bdev, 90) == 0);
+
+	poll_threads();
+	CU_ASSERT_EQUAL(g_event_type1, SPDK_BDEV_EVENT_RESIZE);
+
+	g_event_type1 = 0xFF;
+	/* Growing block number and closing */
+	CU_ASSERT(spdk_bdev_notify_blockcnt_change(&bdev, 100) == 0);
+
 	spdk_bdev_close(desc);
+	spdk_bdev_close(desc_ext);
 	spdk_bdev_unregister(&bdev, NULL, NULL);
 
 	poll_threads();
+
+	/* Callback is not called for closed device */
+	CU_ASSERT_EQUAL(g_event_type1, 0xFF);
 }
 
 static void