Re: [PATCH 09/10] netdevsim: support taking immediate snapshot via devlink

From: Jiri Pirko <jiri@resnulli.us>
To: Jacob Keller <jacob.e.keller@intel.com>
Cc: netdev@vger.kernel.org, Jakub Kicinski <kuba@kernel.org>
Subject: Re: [PATCH 09/10] netdevsim: support taking immediate snapshot via devlink
Date: Wed, 25 Mar 2020 17:50:46 +0100	[thread overview]
Message-ID: <20200325165046.GA11304@nanopsycho.orion> (raw)
In-Reply-To: <20200324223445.2077900-10-jacob.e.keller@intel.com>

Tue, Mar 24, 2020 at 11:34:44PM CET, jacob.e.keller@intel.com wrote:
>Implement the .snapshot region operation for the dummy data region. This
>enables a region snapshot to be taken upon request via the new
>DEVLINK_CMD_REGION_SNAPSHOT command.
>
>Signed-off-by: Jacob Keller <jacob.e.keller@intel.com>
>---
> drivers/net/netdevsim/dev.c                   | 27 +++++++++++++++----
> .../drivers/net/netdevsim/devlink.sh          | 15 +++++++++++
> 2 files changed, 37 insertions(+), 5 deletions(-)
>
>diff --git a/drivers/net/netdevsim/dev.c b/drivers/net/netdevsim/dev.c
>index f9420b77e5fd..876efe71efff 100644
>--- a/drivers/net/netdevsim/dev.c
>+++ b/drivers/net/netdevsim/dev.c
>@@ -39,13 +39,11 @@ static struct dentry *nsim_dev_ddir;
> 
> #define NSIM_DEV_DUMMY_REGION_SIZE (1024 * 32)
> 
>-static ssize_t nsim_dev_take_snapshot_write(struct file *file,
>-					    const char __user *data,
>-					    size_t count, loff_t *ppos)
>+static int
>+nsim_dev_take_snapshot(struct devlink *devlink, struct netlink_ext_ack *extack,
>+		       u8 **data)
> {
>-	struct nsim_dev *nsim_dev = file->private_data;
> 	void *dummy_data;
>-	int err, id;
> 
> 	dummy_data = kmalloc(NSIM_DEV_DUMMY_REGION_SIZE, GFP_KERNEL);
> 	if (!dummy_data)
>@@ -53,6 +51,24 @@ static ssize_t nsim_dev_take_snapshot_write(struct file *file,
> 
> 	get_random_bytes(dummy_data, NSIM_DEV_DUMMY_REGION_SIZE);
> 
>+	*data = dummy_data;
>+
>+	return 0;
>+}
>+
>+static ssize_t nsim_dev_take_snapshot_write(struct file *file,
>+					    const char __user *data,
>+					    size_t count, loff_t *ppos)
>+{
>+	struct nsim_dev *nsim_dev = file->private_data;
>+	u8 *dummy_data;
>+	int err, id;
>+
>+	err = nsim_dev_take_snapshot(priv_to_devlink(nsim_dev), NULL,
>+				     &dummy_data);
>+	if (err)
>+		return err;
>+
> 	id = devlink_region_snapshot_id_get(priv_to_devlink(nsim_dev));
> 	if (id < 0) {
> 		pr_err("Failed to get snapshot id\n");
>@@ -346,6 +362,7 @@ static void nsim_devlink_param_load_driverinit_values(struct devlink *devlink)
> static const struct devlink_region_ops dummy_region_ops = {
> 	.name = "dummy",
> 	.destructor = &kfree,
>+	.snapshot = nsim_dev_take_snapshot,
> };
> 
> static int nsim_dev_dummy_region_init(struct nsim_dev *nsim_dev,
>diff --git a/tools/testing/selftests/drivers/net/netdevsim/devlink.sh b/tools/testing/selftests/drivers/net/netdevsim/devlink.sh
>index 025a84c2ab5a..f23383fd108c 100755
>--- a/tools/testing/selftests/drivers/net/netdevsim/devlink.sh
>+++ b/tools/testing/selftests/drivers/net/netdevsim/devlink.sh
>@@ -141,6 +141,21 @@ regions_test()
> 
> 	check_region_snapshot_count dummy post-first-delete 2
> 
>+	devlink region new $DL_HANDLE/dummy

Looks like you haven't run the selftest with the current patchset
version.

>+	check_err $? "Failed to create a new a snapshot"
>+
>+	check_region_snapshot_count dummy post-request 3
>+
>+	devlink region new $DL_HANDLE/dummy snapshot 25
>+	check_err $? "Failed to create a new snapshot with id 25"
>+
>+	check_region_snapshot_count dummy post-request 4
>+
>+	devlink region del $DL_HANDLE/dummy snapshot 25
>+	check_err $? "Failed to delete snapshot with id 25"
>+
>+	check_region_snapshot_count dummy post-request 3
>+
> 	log_test "regions test"
> }
> 
>-- 
>2.24.1
>