Commit f057ffba authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Tomasz Zawadzki
Browse files

bdev/passthru: Open base bdev first using spdk_bdev_open_ext() 



vbdev_passthru_register() gets bdev name instead of bdev pointer
as a parameter, and open the corresponding base bdev first using
spdk_bdev_open_ext().

The purpose is to fix the race condition due to the time gap
between spdk_bdev_get_by_name() and spdk_bdev_open(). A bdev pointer
is valid only while the bdev is opened.

Resize event is not supported for now.

Signed-off-by: default avatarShuhei Matsumoto <shuhei.matsumoto.xt@hitachi.com>
Change-Id: Ib8894cf857ef814f6721e4244237c8156f147426
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/4564


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarChangpeng Liu <changpeng.liu@intel.com>
Reviewed-by: default avatarPaul Luse <paul.e.luse@intel.com>
Reviewed-by: default avatarAleksey Marchuk <alexeymar@mellanox.com>
Community-CI: Mellanox Build Bot
parent c491fa5b

module/bdev/passthru/vbdev_passthru.c

+44 −29
Original line number Diff line number Diff line
@@ -614,12 +614,10 @@ static const struct spdk_bdev_fn_table vbdev_passthru_fn_table = { 
	.write_config_json	= vbdev_passthru_write_config_json,

};



/* Called when the underlying base bdev goes away. */

static void

vbdev_passthru_base_bdev_hotremove_cb(void *ctx)

vbdev_passthru_base_bdev_hotremove_cb(struct spdk_bdev *bdev_find)

{

	struct vbdev_passthru *pt_node, *tmp;

	struct spdk_bdev *bdev_find = ctx;



	TAILQ_FOREACH_SAFE(pt_node, &g_pt_nodes, link, tmp) {

		if (bdev_find == pt_node->base_bdev) {
@@ -628,25 +626,41 @@ vbdev_passthru_base_bdev_hotremove_cb(void *ctx) 
	}

}



/* Called when the underlying base bdev triggers asynchronous event such as bdev removal. */

static void

vbdev_passthru_base_bdev_event_cb(enum spdk_bdev_event_type type, struct spdk_bdev *bdev,

				  void *event_ctx)

{

	switch (type) {

	case SPDK_BDEV_EVENT_REMOVE:

		vbdev_passthru_base_bdev_hotremove_cb(bdev);

		break;

	default:

		SPDK_NOTICELOG("Unsupported bdev event: type %d\n", type);

		break;

	}

}



/* Create and register the passthru vbdev if we find it in our list of bdev names.

 * This can be called either by the examine path or RPC method.

 */

static int

vbdev_passthru_register(struct spdk_bdev *bdev)

vbdev_passthru_register(const char *bdev_name)

{

	struct bdev_names *name;

	struct vbdev_passthru *pt_node;

	struct spdk_bdev *bdev;

	int rc = 0;



	/* Check our list of names from config versus this bdev and if

	 * there's a match, create the pt_node & bdev accordingly.

	 */

	TAILQ_FOREACH(name, &g_bdev_names, link) {

		if (strcmp(name->bdev_name, bdev->name) != 0) {

		if (strcmp(name->bdev_name, bdev_name) != 0) {

			continue;

		}



		SPDK_NOTICELOG("Match on %s\n", bdev->name);

		SPDK_NOTICELOG("Match on %s\n", bdev_name);

		pt_node = calloc(1, sizeof(struct vbdev_passthru));

		if (!pt_node) {

			rc = -ENOMEM;
@@ -654,8 +668,6 @@ vbdev_passthru_register(struct spdk_bdev *bdev) 
			break;

		}



		/* The base bdev that we're attaching to. */

		pt_node->base_bdev = bdev;

		pt_node->pt_bdev.name = strdup(name->vbdev_name);

		if (!pt_node->pt_bdev.name) {

			rc = -ENOMEM;
@@ -665,6 +677,22 @@ vbdev_passthru_register(struct spdk_bdev *bdev) 
		}

		pt_node->pt_bdev.product_name = "passthru";



		/* The base bdev that we're attaching to. */

		rc = spdk_bdev_open_ext(bdev_name, true, vbdev_passthru_base_bdev_event_cb,

					NULL, &pt_node->base_desc);

		if (rc) {

			if (rc != -ENODEV) {

				SPDK_ERRLOG("could not open bdev %s\n", bdev_name);

			}

			free(pt_node->pt_bdev.name);

			free(pt_node);

			break;

		}

		SPDK_NOTICELOG("base bdev opened\n");



		bdev = spdk_bdev_desc_get_bdev(pt_node->base_desc);

		pt_node->base_bdev = bdev;



		/* Copy some properties from the underlying base bdev. */

		pt_node->pt_bdev.write_cache = bdev->write_cache;

		pt_node->pt_bdev.required_alignment = bdev->required_alignment;
@@ -691,24 +719,12 @@ vbdev_passthru_register(struct spdk_bdev *bdev) 
					name->vbdev_name);

		SPDK_NOTICELOG("io_device created at: 0x%p\n", pt_node);



		rc = spdk_bdev_open(bdev, true, vbdev_passthru_base_bdev_hotremove_cb,

				    bdev, &pt_node->base_desc);

		if (rc) {

			SPDK_ERRLOG("could not open bdev %s\n", spdk_bdev_get_name(bdev));

			TAILQ_REMOVE(&g_pt_nodes, pt_node, link);

			spdk_io_device_unregister(pt_node, NULL);

			free(pt_node->pt_bdev.name);

			free(pt_node);

			break;

		}

		SPDK_NOTICELOG("bdev opened\n");



		/* Save the thread where the base device is opened */

		pt_node->thread = spdk_get_thread();



		rc = spdk_bdev_module_claim_bdev(bdev, pt_node->base_desc, pt_node->pt_bdev.module);

		if (rc) {

			SPDK_ERRLOG("could not claim bdev %s\n", spdk_bdev_get_name(bdev));

			SPDK_ERRLOG("could not claim bdev %s\n", bdev_name);

			spdk_bdev_close(pt_node->base_desc);

			TAILQ_REMOVE(&g_pt_nodes, pt_node, link);

			spdk_io_device_unregister(pt_node, NULL);
@@ -740,10 +756,9 @@ vbdev_passthru_register(struct spdk_bdev *bdev) 
int

bdev_passthru_create_disk(const char *bdev_name, const char *vbdev_name)

{

	struct spdk_bdev *bdev = NULL;

	int rc = 0;

	int rc;



	/* Insert the bdev into our global name list even if it doesn't exist yet,

	/* Insert the bdev name into our global name list even if it doesn't exist yet,

	 * it may show up soon...

	 */

	rc = vbdev_passthru_insert_name(bdev_name, vbdev_name);
@@ -751,16 +766,16 @@ bdev_passthru_create_disk(const char *bdev_name, const char *vbdev_name) 
		return rc;

	}



	bdev = spdk_bdev_get_by_name(bdev_name);

	if (!bdev) {

	rc = vbdev_passthru_register(bdev_name);

	if (rc == -ENODEV) {

		/* This is not an error, we tracked the name above and it still

		 * may show up later.

		 */

		SPDK_NOTICELOG("vbdev creation deferred pending base bdev arrival\n");

		return 0;

		rc = 0;

	}



	return vbdev_passthru_register(bdev);

	return rc;

}



void
@@ -801,7 +816,7 @@ bdev_passthru_delete_disk(struct spdk_bdev *bdev, spdk_bdev_unregister_cb cb_fn, 
static void

vbdev_passthru_examine(struct spdk_bdev *bdev)

{

	vbdev_passthru_register(bdev);

	vbdev_passthru_register(bdev->name);



	spdk_bdev_module_examine_done(&passthru_if);

}