Commit cf80faee authored by Jacob Keller's avatar Jacob Keller Committed by David S. Miller
Browse files

devlink: add function to take snapshot while locked 



A future change is going to add a new devlink command to request
a snapshot on demand. This function will want to call the
devlink_region_snapshot_create function while already holding the
devlink instance lock.

Extract the logic of this function into a static function prefixed by
`__` to indicate that it is an internal helper function. Modify the
original function to be implemented in terms of the new locked
function.

Signed-off-by: default avatarJacob Keller <jacob.e.keller@intel.com>
Reviewed-by: default avatarJiri Pirko <jiri@mellanox.com>
Reviewed-by: default avatarJakub Kicinski <kuba@kernel.org>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 6d82f67e

net/core/devlink.c

+47 −31
Original line number Diff line number Diff line
@@ -3768,6 +3768,52 @@ out_free_msg: 
	nlmsg_free(msg);

}



/**

 *	__devlink_region_snapshot_create - create a new snapshot

 *	This will add a new snapshot of a region. The snapshot

 *	will be stored on the region struct and can be accessed

 *	from devlink. This is useful for future analyses of snapshots.

 *	Multiple snapshots can be created on a region.

 *	The @snapshot_id should be obtained using the getter function.

 *

 *	Must be called only while holding the devlink instance lock.

 *

 *	@region: devlink region of the snapshot

 *	@data: snapshot data

 *	@snapshot_id: snapshot id to be created

 */

static int

__devlink_region_snapshot_create(struct devlink_region *region,

				 u8 *data, u32 snapshot_id)

{

	struct devlink *devlink = region->devlink;

	struct devlink_snapshot *snapshot;



	lockdep_assert_held(&devlink->lock);



	/* check if region can hold one more snapshot */

	if (region->cur_snapshots == region->max_snapshots)

		return -ENOMEM;



	if (devlink_region_snapshot_get_by_id(region, snapshot_id))

		return -EEXIST;



	snapshot = kzalloc(sizeof(*snapshot), GFP_KERNEL);

	if (!snapshot)

		return -ENOMEM;



	snapshot->id = snapshot_id;

	snapshot->region = region;

	snapshot->data = data;



	list_add_tail(&snapshot->list, &region->snapshot_list);



	region->cur_snapshots++;



	devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);

	return 0;

}



static void devlink_region_snapshot_del(struct devlink_region *region,

					struct devlink_snapshot *snapshot)

{
@@ -7753,42 +7799,12 @@ int devlink_region_snapshot_create(struct devlink_region *region, 
				   u8 *data, u32 snapshot_id)

{

	struct devlink *devlink = region->devlink;

	struct devlink_snapshot *snapshot;

	int err;



	mutex_lock(&devlink->lock);



	/* check if region can hold one more snapshot */

	if (region->cur_snapshots == region->max_snapshots) {

		err = -ENOMEM;

		goto unlock;

	}



	if (devlink_region_snapshot_get_by_id(region, snapshot_id)) {

		err = -EEXIST;

		goto unlock;

	}



	snapshot = kzalloc(sizeof(*snapshot), GFP_KERNEL);

	if (!snapshot) {

		err = -ENOMEM;

		goto unlock;

	}



	snapshot->id = snapshot_id;

	snapshot->region = region;

	snapshot->data = data;



	list_add_tail(&snapshot->list, &region->snapshot_list);



	region->cur_snapshots++;



	devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);

	err = __devlink_region_snapshot_create(region, data, snapshot_id);

	mutex_unlock(&devlink->lock);

	return 0;



unlock:

	mutex_unlock(&devlink->lock);

	return err;

}

EXPORT_SYMBOL_GPL(devlink_region_snapshot_create);

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