Commit 428b17a0 authored by Shuhei Matsumoto's avatar Shuhei Matsumoto Committed by Tomasz Zawadzki
Browse files

bdev: Add spdk_for_each_bdev/bdev_leaf for clean up and further improvements 



To execute a callback function for each registered bdev or unclaimed
bdev, add new public APIs, spdk_for_each_bdev() and
spdk_for_each_bdev_leaf().

These functions are safe for race conditions by opening before and
closing after executing the provided callback function.

Signed-off-by: default avatarShuhei Matsumoto <smatsumoto@nvidia.com>
Change-Id: I59b702ffec7b4fc5e9779de5a3a75d44922b829b
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/12088


Tested-by: default avatarSPDK CI Jenkins <sys_sgci@intel.com>
Community-CI: Broadcom CI <spdk-ci.pdl@broadcom.com>
Community-CI: Mellanox Build Bot
Reviewed-by: default avatarBen Walker <benjamin.walker@intel.com>
Reviewed-by: default avatarJim Harris <james.r.harris@intel.com>
parent 941ca7e0

CHANGELOG.md

+3 −0
Original line number Diff line number Diff line
@@ -14,6 +14,9 @@ Removed deprecated spdk_bdev_module_finish_done(). Use spdk_bdev_module_fini_don 


A new API `spdk_bdev_unregister_by_name` was added to handle race conditions correctly.



New APIs, `spdk_for_each_bdev` and `spdk_for_each_bdev_leaf`, were added to provide iteration

safe for race conditions.



### idxd



A new parameter `flags` was added to all low level submission and preparation

doc/bdev_pg.md

+1 −1
Original line number Diff line number Diff line
@@ -63,7 +63,7 @@ to tear down the bdev library, call spdk_bdev_finish(). 
All block devices have a simple string name. At any time, a pointer to the

device object can be obtained by calling spdk_bdev_get_by_name(), or the entire

set of bdevs may be iterated using spdk_bdev_first() and spdk_bdev_next() and

their variants.

their variants or spdk_for_each_bdev() and its variant.



Some block devices may also be given aliases, which are also string names.

Aliases behave like symlinks - they can be used interchangeably with the real

include/spdk/bdev.h

+38 −0
Original line number Diff line number Diff line
@@ -378,6 +378,44 @@ int spdk_bdev_open_ext(const char *bdev_name, bool write, spdk_bdev_event_cb_t e 
 */

void spdk_bdev_close(struct spdk_bdev_desc *desc);



/**

 * Callback function for spdk_for_each_bdev() and spdk_for_each_bdev_leaf().

 *

 * \param ctx Context passed to the callback.

 * \param bdev Block device the callback handles.

 */

typedef int (*spdk_for_each_bdev_fn)(void *ctx, struct spdk_bdev *bdev);



/**

 * Call the provided callback function for every registered block device.

 * If fn returns negated errno, spdk_for_each_bdev() terminates iteration.

 *

 * spdk_for_each_bdev() opens before and closes after executing the provided

 * callback function for each bdev internally.

 *

 * \param ctx Context passed to the callback function.

 * \param fn Callback function for each block device.

 *

 * \return 0 if operation is sucessful, or suitable errno value one of the

 * callback returned otherwise.

 */

int spdk_for_each_bdev(void *ctx, spdk_for_each_bdev_fn fn);



/**

 * Call the provided callback function for every block device without virtual

 * block devices on top.

 *

 * spdk_for_each_bdev_leaf() opens before and closes after executing the provided

 * callback function for each unclaimed bdev internally.

 *

 * \param ctx Context passed to the callback function.

 * \param fn Callback funciton for each block device without virtual block devices on top.

 *

 * \return 0 if operation is successful, or suitable errno value one of the

 * callback returned otherwise.

 */

int spdk_for_each_bdev_leaf(void *ctx, spdk_for_each_bdev_fn fn);



/**

 * Get the bdev associated with a bdev descriptor.

 *

lib/bdev/bdev.c

+76 −0
Original line number Diff line number Diff line
@@ -6572,6 +6572,82 @@ spdk_bdev_desc_get_bdev(struct spdk_bdev_desc *desc) 
	return desc->bdev;

}



int

spdk_for_each_bdev(void *ctx, spdk_for_each_bdev_fn fn)

{

	struct spdk_bdev *bdev, *tmp;

	struct spdk_bdev_desc *desc;

	int rc = 0;



	assert(fn != NULL);



	pthread_mutex_lock(&g_bdev_mgr.mutex);

	bdev = spdk_bdev_first();

	while (bdev != NULL) {

		rc = bdev_desc_alloc(bdev, _tmp_bdev_event_cb, NULL, &desc);

		if (rc != 0) {

			break;

		}

		rc = bdev_open(bdev, false, desc);

		if (rc != 0) {

			bdev_desc_free(desc);

			break;

		}

		pthread_mutex_unlock(&g_bdev_mgr.mutex);



		rc = fn(ctx, bdev);



		pthread_mutex_lock(&g_bdev_mgr.mutex);

		tmp = spdk_bdev_next(bdev);

		bdev_close(bdev, desc);

		if (rc != 0) {

			break;

		}

		bdev = tmp;

	}

	pthread_mutex_unlock(&g_bdev_mgr.mutex);



	return rc;

}



int

spdk_for_each_bdev_leaf(void *ctx, spdk_for_each_bdev_fn fn)

{

	struct spdk_bdev *bdev, *tmp;

	struct spdk_bdev_desc *desc;

	int rc = 0;



	assert(fn != NULL);



	pthread_mutex_lock(&g_bdev_mgr.mutex);

	bdev = spdk_bdev_first_leaf();

	while (bdev != NULL) {

		rc = bdev_desc_alloc(bdev, _tmp_bdev_event_cb, NULL, &desc);

		if (rc != 0) {

			break;

		}

		rc = bdev_open(bdev, false, desc);

		if (rc != 0) {

			bdev_desc_free(desc);

			break;

		}

		pthread_mutex_unlock(&g_bdev_mgr.mutex);



		rc = fn(ctx, bdev);



		pthread_mutex_lock(&g_bdev_mgr.mutex);

		tmp = spdk_bdev_next_leaf(bdev);

		bdev_close(bdev, desc);

		if (rc != 0) {

			break;

		}

		bdev = tmp;

	}

	pthread_mutex_unlock(&g_bdev_mgr.mutex);



	return rc;

}



void

spdk_bdev_io_get_iovec(struct spdk_bdev_io *bdev_io, struct iovec **iovp, int *iovcntp)

{

lib/bdev/spdk_bdev.map

+2 −0
Original line number Diff line number Diff line
@@ -15,6 +15,8 @@ 
	spdk_bdev_next;

	spdk_bdev_first_leaf;

	spdk_bdev_next_leaf;

	spdk_for_each_bdev;

	spdk_for_each_bdev_leaf;

	spdk_bdev_open_ext;

	spdk_bdev_close;

	spdk_bdev_desc_get_bdev;