Message ID | 20171114161852.6633-4-jiri@resnulli.us |
---|---|
State | RFC, archived |
Delegated to: | David Miller |
Headers | show |
Series | Add support for resource abstraction | expand |
On Tue, 14 Nov 2017 17:18:44 +0100, Jiri Pirko wrote: > +static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) > +{ > + struct devlink *devlink = info->user_ptr[0]; > + int err; > + > + if (!devlink->ops->reload) > + return -EOPNOTSUPP; > + > + err = devlink_resources_validate(devlink, NULL, info); > + if (err) > + return err; > + > + mutex_unlock(&devlink->lock); > + err = devlink->ops->reload(devlink); > + mutex_lock(&devlink->lock); > + > + return err; > +} I'm a bit confused with the locking, why is devlink->lock not held around the validation?
Wed, Nov 15, 2017 at 09:03:59AM CET, jakub.kicinski@netronome.com wrote: >On Tue, 14 Nov 2017 17:18:44 +0100, Jiri Pirko wrote: >> +static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) >> +{ >> + struct devlink *devlink = info->user_ptr[0]; >> + int err; >> + >> + if (!devlink->ops->reload) >> + return -EOPNOTSUPP; >> + >> + err = devlink_resources_validate(devlink, NULL, info); >> + if (err) >> + return err; >> + >> + mutex_unlock(&devlink->lock); >> + err = devlink->ops->reload(devlink); >> + mutex_lock(&devlink->lock); >> + >> + return err; >> +} > >I'm a bit confused with the locking, why is devlink->lock not held >around the validation? It is.
On 11/15/2017 10:03 AM, Jakub Kicinski wrote: > On Tue, 14 Nov 2017 17:18:44 +0100, Jiri Pirko wrote: >> +static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) >> +{ >> + struct devlink *devlink = info->user_ptr[0]; >> + int err; >> + >> + if (!devlink->ops->reload) >> + return -EOPNOTSUPP; >> + >> + err = devlink_resources_validate(devlink, NULL, info); >> + if (err) >> + return err; >> + >> + mutex_unlock(&devlink->lock); >> + err = devlink->ops->reload(devlink); >> + mutex_lock(&devlink->lock); >> + >> + return err; >> +} > > I'm a bit confused with the locking, why is devlink->lock not held > around the validation? > As Jiri mentioned it is held. The per devlink instance lock is taken by default for each doit operation in the pre_doit(), because it operates on a specific devlink instance. The lock is released before performing the reload itself because during the reload the driver register/unregisters devlink objects like sb/dpipe /ports, which require the lock again, so this is done in order to avoid recursive locking.
diff --git a/include/net/devlink.h b/include/net/devlink.h index 960e80a..a33bda4 100644 --- a/include/net/devlink.h +++ b/include/net/devlink.h @@ -265,6 +265,7 @@ struct devlink_resource { #define DEVLINK_RESOURCE_ID_PARENT_TOP 0 struct devlink_ops { + int (*reload)(struct devlink *devlink); int (*port_type_set)(struct devlink_port *devlink_port, enum devlink_port_type port_type); int (*port_split)(struct devlink *devlink, unsigned int port_index, diff --git a/include/uapi/linux/devlink.h b/include/uapi/linux/devlink.h index 1ee1c72..ea4fa25 100644 --- a/include/uapi/linux/devlink.h +++ b/include/uapi/linux/devlink.h @@ -73,6 +73,11 @@ enum devlink_command { DEVLINK_CMD_RESOURCE_SET, DEVLINK_CMD_RESOURCE_DUMP, + /* Hot driver reload, used to query updated resources. The devlink + * instance is not released during the process + */ + DEVLINK_CMD_RELOAD, + /* add new commands above here */ __DEVLINK_CMD_MAX, DEVLINK_CMD_MAX = __DEVLINK_CMD_MAX - 1 diff --git a/net/core/devlink.c b/net/core/devlink.c index 6ae644f..d93f176 100644 --- a/net/core/devlink.c +++ b/net/core/devlink.c @@ -2468,6 +2468,55 @@ static int devlink_nl_cmd_resource_dump(struct sk_buff *skb, return devlink_resource_fill(info, DEVLINK_CMD_RESOURCE_DUMP, 0); } +static int +devlink_resources_validate(struct devlink *devlink, + struct devlink_resource *resource, + struct genl_info *info) +{ + struct list_head *resource_list; + int err = 0; + + if (resource) + resource_list = &resource->resource_list; + else + resource_list = &devlink->resource_list; + + list_for_each_entry(resource, resource_list, list) { + if (resource->resource_ops && + resource->resource_ops->size_validate) { + err = resource->resource_ops->size_validate(devlink, + resource->size, + &resource->resource_list, + info->extack); + if (err) + return err; + } + err = devlink_resources_validate(devlink, resource, info); + if (err) + return err; + } + return err; +} + +static int devlink_nl_cmd_reload(struct sk_buff *skb, struct genl_info *info) +{ + struct devlink *devlink = info->user_ptr[0]; + int err; + + if (!devlink->ops->reload) + return -EOPNOTSUPP; + + err = devlink_resources_validate(devlink, NULL, info); + if (err) + return err; + + mutex_unlock(&devlink->lock); + err = devlink->ops->reload(devlink); + mutex_lock(&devlink->lock); + + return err; +} + 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 }, @@ -2658,6 +2707,13 @@ static const struct genl_ops devlink_nl_ops[] = { .flags = GENL_ADMIN_PERM, .internal_flags = DEVLINK_NL_FLAG_NEED_DEVLINK, }, + { + .cmd = DEVLINK_CMD_RELOAD, + .doit = devlink_nl_cmd_reload, + .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 = {