Commit bd5a7847 authored by Mike Gerdts's avatar Mike Gerdts Committed by Tomasz Zawadzki
Browse files

blob_bdev: support read-only devices 



External snapshots, which will be introduced in a later commit, will
need read-only blob_bdev instances. This support is partially needed to
support underlying devices that are naturally read-only and partially to
provide an extra layer of protection against accidental writes.

Signed-off-by: default avatarMike Gerdts <mgerdts@nvidia.com>
Change-Id: Ibcb28d00ad644a6053aa5f4de15471c2cd8e348a
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/14968


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
Reviewed-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
parent 45e0a2a3

include/spdk/blob_bdev.h

+29 −0
Original line number Diff line number Diff line 
/*   SPDX-License-Identifier: BSD-3-Clause

 *   Copyright (C) 2017 Intel Corporation.

 *   All rights reserved.

 *   Copyright (c) 2022 NVIDIA CORPORATION & AFFILIATES. All rights reserved.

 */



/** \file
@@ -21,6 +22,17 @@ struct spdk_bs_dev; 
struct spdk_bdev;

struct spdk_bdev_module;



struct spdk_bdev_bs_dev_opts {

	/**

	 * The size of this structure according to the caller of this library is used for ABI

	 * compatibility. The library uses this field to know how many fields in this structure are

	 * valid. And the library will populate any remaining fields with default values.

	 * New added fields should be put at the end of the struct.

	 */

	size_t opts_size;

};

SPDK_STATIC_ASSERT(sizeof(struct spdk_bdev_bs_dev_opts) == 8, "Incorrect size");



/**

 * Create a blobstore block device from a bdev.

 *
@@ -34,6 +46,23 @@ struct spdk_bdev_module; 
int spdk_bdev_create_bs_dev_ext(const char *bdev_name, spdk_bdev_event_cb_t event_cb,

				void *event_ctx, struct spdk_bs_dev **bs_dev);



/**

 * Create a blobstore block device from a bdev.

 *

 * \param bdev_name The bdev to use.

 * \param write If true, open device read-write, else open read-only.

 * \param opts Additonal options; none currently supported.

 * \param opts_size Size of structure referenced by opts.

 * \param event_cb Called when the bdev triggers asynchronous event.

 * \param event_ctx Argument passed to function event_cb.

 * \param bs_dev Output parameter for a pointer to the blobstore block device.

 * \return 0 if operation is successful, or suitable errno value otherwise.

 */

int spdk_bdev_create_bs_dev(const char *bdev_name, bool write,

			    struct spdk_bdev_bs_dev_opts *opts, size_t opts_size,

			    spdk_bdev_event_cb_t event_cb, void *event_ctx,

			    struct spdk_bs_dev **bs_dev);



/**

 * Claim the bdev module for the given blobstore.

 *

module/blob/bdev/blob_bdev.c

+18 −4
Original line number Diff line number Diff line
@@ -412,13 +412,20 @@ blob_bdev_init(struct blob_bdev *b, struct spdk_bdev_desc *desc) 
}



int

spdk_bdev_create_bs_dev_ext(const char *bdev_name, spdk_bdev_event_cb_t event_cb,

			    void *event_ctx, struct spdk_bs_dev **_bs_dev)

spdk_bdev_create_bs_dev(const char *bdev_name, bool write,

			struct spdk_bdev_bs_dev_opts *opts, size_t opts_size,

			spdk_bdev_event_cb_t event_cb, void *event_ctx,

			struct spdk_bs_dev **bs_dev)

{

	struct blob_bdev *b;

	struct spdk_bdev_desc *desc;

	int rc;



	if (opts != NULL && opts_size != sizeof(*opts)) {

		SPDK_ERRLOG("bdev name '%s': unsupported options\n", bdev_name);

		return -EINVAL;

	}



	b = calloc(1, sizeof(*b));



	if (b == NULL) {
@@ -426,7 +433,7 @@ spdk_bdev_create_bs_dev_ext(const char *bdev_name, spdk_bdev_event_cb_t event_cb 
		return -ENOMEM;

	}



	rc = spdk_bdev_open_ext(bdev_name, true, event_cb, event_ctx, &desc);

	rc = spdk_bdev_open_ext(bdev_name, write, event_cb, event_ctx, &desc);

	if (rc != 0) {

		free(b);

		return rc;
@@ -434,7 +441,14 @@ spdk_bdev_create_bs_dev_ext(const char *bdev_name, spdk_bdev_event_cb_t event_cb 


	blob_bdev_init(b, desc);



	*_bs_dev = &b->bs_dev;

	*bs_dev = &b->bs_dev;



	return 0;

}



int

spdk_bdev_create_bs_dev_ext(const char *bdev_name, spdk_bdev_event_cb_t event_cb,

			    void *event_ctx, struct spdk_bs_dev **bs_dev)

{

	return spdk_bdev_create_bs_dev(bdev_name, true, NULL, 0, event_cb, event_ctx, bs_dev);

}

test/unit/lib/blob/blob_bdev.c/blob_bdev_ut.c

+71 −0
Original line number Diff line number Diff line
@@ -190,6 +190,75 @@ create_bs_dev(void) 


	blob_bdev = (struct blob_bdev *)bs_dev;

	CU_ASSERT(blob_bdev->desc != NULL);

	CU_ASSERT(blob_bdev->desc->write);

	CU_ASSERT(blob_bdev->desc->bdev == g_bdev);

	CU_ASSERT(blob_bdev->desc->claim_type == SPDK_BDEV_CLAIM_NONE);

	CU_ASSERT(bdev.claim_type == SPDK_BDEV_CLAIM_NONE);



	bs_dev->destroy(bs_dev);

	CU_ASSERT(bdev.open_cnt == 0);

	g_bdev = NULL;

}



static void

create_bs_dev_ro(void)

{

	struct spdk_bdev bdev;

	struct spdk_bs_dev *bs_dev = NULL;

	struct blob_bdev *blob_bdev;

	struct spdk_bdev_bs_dev_opts opts = { 0 };

	int rc;



	/* opts with the wrong size returns -EINVAL */

	rc = spdk_bdev_create_bs_dev("nope", false, &opts, sizeof(opts) + 8, NULL, NULL, &bs_dev);

	CU_ASSERT(rc == -EINVAL);



	/* opts with the right size is OK, but can still fail if the device doesn't exist. */

	opts.opts_size = sizeof(opts);

	rc = spdk_bdev_create_bs_dev("nope", false, &opts, sizeof(opts), NULL, NULL, &bs_dev);

	CU_ASSERT(rc == -ENODEV);



	init_bdev(&bdev, "bdev0", 16);

	g_bdev = &bdev;



	/* The normal way to create a read-only device */

	rc = spdk_bdev_create_bs_dev("bdev0", false, NULL, 0, NULL, NULL, &bs_dev);

	CU_ASSERT(rc == 0);

	SPDK_CU_ASSERT_FATAL(bs_dev != NULL);

	CU_ASSERT(bdev.open_cnt == 1);



	blob_bdev = (struct blob_bdev *)bs_dev;

	CU_ASSERT(blob_bdev->desc != NULL);

	CU_ASSERT(!blob_bdev->desc->write);

	CU_ASSERT(blob_bdev->desc->bdev == g_bdev);

	CU_ASSERT(blob_bdev->desc->claim_type == SPDK_BDEV_CLAIM_NONE);

	CU_ASSERT(bdev.claim_type == SPDK_BDEV_CLAIM_NONE);



	bs_dev->destroy(bs_dev);

	CU_ASSERT(bdev.open_cnt == 0);

	g_bdev = NULL;

}



static void

create_bs_dev_rw(void)

{

	struct spdk_bdev bdev;

	struct spdk_bs_dev *bs_dev = NULL;

	struct blob_bdev *blob_bdev;

	int rc;



	init_bdev(&bdev, "bdev0", 16);

	g_bdev = &bdev;



	/* This is equivalent to spdk_bdev_create_bs_dev_ext() */

	rc = spdk_bdev_create_bs_dev("bdev0", true, NULL, 0, NULL, NULL, &bs_dev);

	CU_ASSERT(rc == 0);

	SPDK_CU_ASSERT_FATAL(bs_dev != NULL);

	CU_ASSERT(bdev.open_cnt == 1);



	blob_bdev = (struct blob_bdev *)bs_dev;

	CU_ASSERT(blob_bdev->desc != NULL);

	CU_ASSERT(blob_bdev->desc->write);

	CU_ASSERT(blob_bdev->desc->bdev == g_bdev);

	CU_ASSERT(blob_bdev->desc->claim_type == SPDK_BDEV_CLAIM_NONE);

	CU_ASSERT(bdev.claim_type == SPDK_BDEV_CLAIM_NONE);
@@ -258,6 +327,8 @@ main(int argc, char **argv) 
	suite = CU_add_suite("blob_bdev", NULL, NULL);



	CU_ADD_TEST(suite, create_bs_dev);

	CU_ADD_TEST(suite, create_bs_dev_ro);

	CU_ADD_TEST(suite, create_bs_dev_rw);

	CU_ADD_TEST(suite, claim_bs_dev);



	CU_basic_set_mode(CU_BRM_VERBOSE);