[PATCH net-next v3 06/11] devlink: Add support for region snapshot delete command

[Alex Vesker]

Add support for DEVLINK_CMD_REGION_DEL used
for deleting a snapshot from a region. The snapshot ID is required.
Also added notification support for NEW and DEL of snapshots.

Signed-off-by: Alex Vesker <va...@mellanox.com>
Signed-off-by: Jiri Pirko <j...@mellanox.com>
---
 include/uapi/linux/devlink.h |  2 +
 net/core/devlink.c           | 93 ++++++++++++++++++++++++++++++++++++++++++++
 2 files changed, 95 insertions(+)

diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h
index abde4e3..d212e02 100644
--- a/include/uapi/linux/devlink.h
+++ b/include/uapi/linux/devlink.h
@@ -85,6 +85,8 @@ enum devlink_command {
 
        DEVLINK_CMD_REGION_GET,
        DEVLINK_CMD_REGION_SET,
+       DEVLINK_CMD_REGION_NEW,
+       DEVLINK_CMD_REGION_DEL,
 
        /* add new commands above here */
        __DEVLINK_CMD_MAX,
diff --git a/net/core/devlink.c b/net/core/devlink.c
index cb75e26..fc08363 100644
--- a/net/core/devlink.c
+++ b/net/core/devlink.c
@@ -3236,6 +3236,58 @@ static int devlink_nl_region_fill(struct sk_buff *msg, 
struct devlink *devlink,
        return err;
 }
 
+static void devlink_nl_region_notify(struct devlink_region *region,
+                                    struct devlink_snapshot *snapshot,
+                                    enum devlink_command cmd)
+{
+       struct devlink *devlink = region->devlink;
+       struct sk_buff *msg;
+       void *hdr;
+       int err;
+
+       WARN_ON(cmd != DEVLINK_CMD_REGION_NEW && cmd != DEVLINK_CMD_REGION_DEL);
+
+       msg = nlmsg_new(NLMSG_DEFAULT_SIZE, GFP_KERNEL);
+       if (!msg)
+               return;
+
+       hdr = genlmsg_put(msg, 0, 0, &devlink_nl_family, 0, cmd);
+       if (!hdr)
+               goto out_free_msg;
+
+       err = devlink_nl_put_handle(msg, devlink);
+       if (err)
+               goto out_cancel_msg;
+
+       err = nla_put_string(msg, DEVLINK_ATTR_REGION_NAME,
+                            region->name);
+       if (err)
+               goto out_cancel_msg;
+
+       if (snapshot) {
+               err = nla_put_u32(msg, DEVLINK_ATTR_REGION_SNAPSHOT_ID,
+                                 snapshot->id);
+               if (err)
+                       goto out_cancel_msg;
+       } else {
+               err = nla_put_u64_64bit(msg, DEVLINK_ATTR_REGION_SIZE,
+                                       region->size, DEVLINK_ATTR_PAD);
+               if (err)
+                       goto out_cancel_msg;
+       }
+       genlmsg_end(msg, hdr);
+
+       genlmsg_multicast_netns(&devlink_nl_family, devlink_net(devlink),
+                               msg, 0, DEVLINK_MCGRP_CONFIG, GFP_KERNEL);
+
+       return;
+
+out_cancel_msg:
+       genlmsg_cancel(msg, hdr);
+out_free_msg:
+       nlmsg_free(msg);
+}
+
 static int devlink_nl_cmd_region_get_doit(struct sk_buff *skb,
                                          struct genl_info *info)
 {
@@ -3307,6 +3359,35 @@ static int devlink_nl_cmd_region_get_dumpit(struct 
sk_buff *msg,
        return msg->len;
 }
 
+static int devlink_nl_cmd_region_del(struct sk_buff *skb,
+                                    struct genl_info *info)
+{
+       struct devlink *devlink = info->user_ptr[0];
+       struct devlink_snapshot *snapshot;
+       struct devlink_region *region;
+       const char *region_name;
+       u32 snapshot_id;
+
+       if (!info->attrs[DEVLINK_ATTR_REGION_NAME] ||
+           !info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID])
+               return -EINVAL;
+
+       region_name = nla_data(info->attrs[DEVLINK_ATTR_REGION_NAME]);
+       snapshot_id = nla_get_u32(info->attrs[DEVLINK_ATTR_REGION_SNAPSHOT_ID]);
+
+       region = devlink_region_get_by_name(devlink, region_name);
+       if (!region)
+               return -EINVAL;
+
+       snapshot = devlink_region_snapshot_get_by_id(region, snapshot_id);
+       if (!snapshot)
+               return -EINVAL;
+
+       devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_DEL);
+       devlink_region_snapshot_del(snapshot);
+       return 0;
+}
+
 static const struct nla_policy devlink_nl_policy[DEVLINK_ATTR_MAX + 1] = {
        [DEVLINK_ATTR_BUS_NAME] = { .type = NLA_NUL_STRING },
        [DEVLINK_ATTR_DEV_NAME] = { .type = NLA_NUL_STRING },
@@ -3331,6 +3412,7 @@ static int devlink_nl_cmd_region_get_dumpit(struct 
sk_buff *msg,
        [DEVLINK_ATTR_PARAM_TYPE] = { .type = NLA_U8 },
        [DEVLINK_ATTR_PARAM_VALUE_CMODE] = { .type = NLA_U8 },
        [DEVLINK_ATTR_REGION_NAME] = { .type = NLA_NUL_STRING },
+       [DEVLINK_ATTR_REGION_SNAPSHOT_ID] = { .type = NLA_U32 },
 };
 
 static const struct genl_ops devlink_nl_ops[] = {
@@ -3537,6 +3619,13 @@ static int devlink_nl_cmd_region_get_dumpit(struct 
sk_buff *msg,
                .flags = GENL_ADMIN_PERM,
                .internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
        },
+       {
+               .cmd = DEVLINK_CMD_REGION_DEL,
+               .doit = devlink_nl_cmd_region_del,
+               .policy = devlink_nl_policy,
+               .flags = GENL_ADMIN_PERM,
+               .internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK,
+       },
 };
 
 static struct genl_family devlink_nl_family __ro_after_init = {
@@ -4363,6 +4452,7 @@ struct devlink_region *devlink_region_create(struct 
devlink *devlink,
        region->size = region_size;
        INIT_LIST_HEAD(&region->snapshot_list);
        list_add_tail(&region->list, &devlink->region_list);
+       devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_NEW);
 
        mutex_unlock(&devlink->lock);
        return region;
@@ -4390,6 +4480,8 @@ void devlink_region_destroy(struct devlink_region *region)
                devlink_region_snapshot_del(snapshot);
 
        list_del(&region->list);
+
+       devlink_nl_region_notify(region, NULL, DEVLINK_CMD_REGION_DEL);
        mutex_unlock(&devlink->lock);
        kfree(region);
 }
@@ -4467,6 +4559,7 @@ int devlink_region_snapshot_create(struct devlink_region 
*region, u64 data_len,
 
        region->cur_snapshots++;
 
+       devlink_nl_region_notify(region, snapshot, DEVLINK_CMD_REGION_NEW);
        mutex_unlock(&devlink->lock);
        return 0;
 
-- 
1.8.3.1