From 731d69a6bd13b7c0cdbd3607edfa681269d54828 Mon Sep 17 00:00:00 2001 From: Jakub Kicinski Date: Wed, 4 Jan 2023 20:05:26 -0800 Subject: [PATCH] devlink: restart dump based on devlink instance ids (simple) xarray gives each devlink instance an id and allows us to restart walk based on that id quite neatly. This is nice both from the perspective of code brevity and from the stability of the dump (devlink instances disappearing from before the resumption point will not cause inconsistent dumps). This patch takes care of simple cases where state->idx counts devlink instances only. Reviewed-by: Jacob Keller Reviewed-by: Jiri Pirko Signed-off-by: Jakub Kicinski --- net/devlink/core.c | 2 +- net/devlink/devl_internal.h | 16 ++++++++++++++++ net/devlink/leftover.c | 36 ++++++++---------------------------- 3 files changed, 25 insertions(+), 29 deletions(-) diff --git a/net/devlink/core.c b/net/devlink/core.c index 3a99bf84632e5..371d6821315de 100644 --- a/net/devlink/core.c +++ b/net/devlink/core.c @@ -91,7 +91,7 @@ void devlink_put(struct devlink *devlink) call_rcu(&devlink->rcu, __devlink_put_rcu); } -static struct devlink * +struct devlink * devlinks_xa_find_get(struct net *net, unsigned long *indexp, void * (*xa_find_fn)(struct xarray *, unsigned long *, unsigned long, xa_mark_t)) diff --git a/net/devlink/devl_internal.h b/net/devlink/devl_internal.h index 86b321aef3ebc..b9bb6f73a7c18 100644 --- a/net/devlink/devl_internal.h +++ b/net/devlink/devl_internal.h @@ -87,6 +87,10 @@ extern struct genl_family devlink_nl_family; devlink; devlink = devlinks_xa_find_get_next(net, &index)) struct devlink * +devlinks_xa_find_get(struct net *net, unsigned long *indexp, + void * (*xa_find_fn)(struct xarray *, unsigned long *, + unsigned long, xa_mark_t)); +struct devlink * devlinks_xa_find_get_first(struct net *net, unsigned long *indexp); struct devlink * devlinks_xa_find_get_next(struct net *net, unsigned long *indexp); @@ -104,6 +108,7 @@ enum devlink_multicast_groups { /* state held across netlink dumps */ struct devlink_nl_dump_state { + unsigned long instance; int idx; union { /* DEVLINK_CMD_REGION_READ */ @@ -117,6 +122,17 @@ struct devlink_nl_dump_state { }; }; +/* Iterate over registered devlink instances for devlink dump. + * devlink_put() needs to be called for each iterated devlink pointer + * in loop body in order to release the reference. + * Note: this is NOT a generic iterator, it makes assumptions about the use + * of @state and can only be used once per dumpit implementation. + */ +#define devlink_dump_for_each_instance_get(msg, state, devlink) \ + for (; (devlink = devlinks_xa_find_get(sock_net(msg->sk), \ + &state->instance, xa_find)); \ + state->instance++) + extern const struct genl_small_ops devlink_nl_ops[56]; struct devlink *devlink_get_from_attrs(struct net *net, struct nlattr **attrs); diff --git a/net/devlink/leftover.c b/net/devlink/leftover.c index 83cd7bd55941b..db7c095a0d75c 100644 --- a/net/devlink/leftover.c +++ b/net/devlink/leftover.c @@ -1319,17 +1319,9 @@ static int devlink_nl_cmd_get_dumpit(struct sk_buff *msg, { struct devlink_nl_dump_state *state = devlink_dump_state(cb); struct devlink *devlink; - unsigned long index; - int idx = 0; int err; - devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) { - if (idx < state->idx) { - idx++; - devlink_put(devlink); - continue; - } - + devlink_dump_for_each_instance_get(msg, state, devlink) { devl_lock(devlink); err = devlink_nl_fill(msg, devlink, DEVLINK_CMD_NEW, NETLINK_CB(cb->skb).portid, @@ -1339,10 +1331,8 @@ static int devlink_nl_cmd_get_dumpit(struct sk_buff *msg, if (err) goto out; - idx++; } out: - state->idx = idx; return msg->len; } @@ -4872,13 +4862,13 @@ static int devlink_nl_cmd_selftests_get_dumpit(struct sk_buff *msg, { struct devlink_nl_dump_state *state = devlink_dump_state(cb); struct devlink *devlink; - unsigned long index; - int idx = 0; int err = 0; - devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) { - if (idx < state->idx || !devlink->ops->selftest_check) - goto inc; + devlink_dump_for_each_instance_get(msg, state, devlink) { + if (!devlink->ops->selftest_check) { + devlink_put(devlink); + continue; + } devl_lock(devlink); err = devlink_nl_selftests_fill(msg, devlink, @@ -4890,15 +4880,13 @@ static int devlink_nl_cmd_selftests_get_dumpit(struct sk_buff *msg, devlink_put(devlink); break; } -inc: - idx++; + devlink_put(devlink); } if (err != -EMSGSIZE) return err; - state->idx = idx; return msg->len; } @@ -6747,14 +6735,9 @@ static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg, { struct devlink_nl_dump_state *state = devlink_dump_state(cb); struct devlink *devlink; - unsigned long index; - int idx = 0; int err = 0; - devlinks_xa_for_each_registered_get(sock_net(msg->sk), index, devlink) { - if (idx < state->idx) - goto inc; - + devlink_dump_for_each_instance_get(msg, state, devlink) { devl_lock(devlink); err = devlink_nl_info_fill(msg, devlink, DEVLINK_CMD_INFO_GET, NETLINK_CB(cb->skb).portid, @@ -6767,15 +6750,12 @@ static int devlink_nl_cmd_info_get_dumpit(struct sk_buff *msg, devlink_put(devlink); break; } -inc: - idx++; devlink_put(devlink); } if (err != -EMSGSIZE) return err; - state->idx = idx; return msg->len; } -- 2.30.2