[PATCH net] page_pool: fix netlink dump stop/resume

[PATCH net] page_pool: fix netlink dump stop/resume

[Jakub Kicinski]

If message fills up we need to stop writing. 'break' will
only get us out of the iteration over pools of a single
netdev, we need to also stop walking netdevs.

This results in either infinite dump, or missing pools,
depending on whether message full happens on the last
netdev (infinite dump) or non-last (missing pools).

Fixes: 950ab53b77ab ("net: page_pool: implement GET in the netlink API")
Signed-off-by: Jakub Kicinski <kuba@kernel.org>
---
CC: hawk@kernel.org
---
 net/core/page_pool_user.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/net/core/page_pool_user.c b/net/core/page_pool_user.c
index ffe5244e5597..278294aca66a 100644
--- a/net/core/page_pool_user.c
+++ b/net/core/page_pool_user.c
@@ -94,11 +94,12 @@ netdev_nl_page_pool_get_dump(struct sk_buff *skb, struct netlink_callback *cb,
 			state->pp_id = pool->user.id;
 			err = fill(skb, pool, info);
 			if (err)
-				break;
+				goto out;
 		}
 
 		state->pp_id = 0;
 	}
+out:
 	mutex_unlock(&page_pools_lock);
 	rtnl_unlock();
 
-- 
2.43.2

Re: [PATCH net] page_pool: fix netlink dump stop/resume

[Eric Dumazet]

On Fri, Mar 1, 2024 at 2:13 AM Jakub Kicinski <kuba@kernel.org> wrote:
>
> If message fills up we need to stop writing. 'break' will
> only get us out of the iteration over pools of a single
> netdev, we need to also stop walking netdevs.
>
> This results in either infinite dump, or missing pools,
> depending on whether message full happens on the last
> netdev (infinite dump) or non-last (missing pools).
>
> Fixes: 950ab53b77ab ("net: page_pool: implement GET in the netlink API")
> Signed-off-by: Jakub Kicinski <kuba@kernel.org>

Reviewed-by: Eric Dumazet <edumazet@google.com>

Re: [PATCH net] page_pool: fix netlink dump stop/resume

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (main)
by David S. Miller <davem@davemloft.net>:

On Thu, 29 Feb 2024 17:13:31 -0800 you wrote:
> If message fills up we need to stop writing. 'break' will
> only get us out of the iteration over pools of a single
> netdev, we need to also stop walking netdevs.
> 
> This results in either infinite dump, or missing pools,
> depending on whether message full happens on the last
> netdev (infinite dump) or non-last (missing pools).
> 
> [...]

Here is the summary with links:
  - [net] page_pool: fix netlink dump stop/resume
    https://git.kernel.org/netdev/net/c/429679dcf7d9

You are awesome, thank you!
-- 
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html