ethtool: rss: make sure dump takes the rss lock

After commit 040cef30b5e6 ("net: ethtool: move get_rxfh callback
under the rss_lock") we're expected to take rss_lock around get.
Switch dump to using the new prep helper and move the locking into it.

Link: https://patch.msgid.link/20250708220640.2738464-2-kuba@kernel.org
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/net/ethtool/rss.c b/net/ethtool/rss.c
index 4e8ca2c3817508cda8aaedf28dfea89284a36a06..37a7b20fcd07e06f5c10db74846981f883f1d1c9 100644 (file)
--- a/net/ethtool/rss.c
+++ b/net/ethtool/rss.c
@@ -64,6 +64,7 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
        ret = ethnl_ops_begin(dev);
        if (ret < 0)
                return ret;
+       mutex_lock(&dev->ethtool->rss_lock);
 
        data->indir_size = 0;
        data->hkey_size = 0;
@@ -77,7 +78,7 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
        rss_config = kzalloc(total_size, GFP_KERNEL);
        if (!rss_config) {
                ret = -ENOMEM;
-               goto out_ops;
+               goto out_unlock;
        }
 
        if (data->indir_size)
@@ -92,11 +93,12 @@ rss_prepare_get(const struct rss_req_info *request, struct net_device *dev,
 
        ret = ops->get_rxfh(dev, &rxfh);
        if (ret)
-               goto out_ops;
+               goto out_unlock;
 
        data->hfunc = rxfh.hfunc;
        data->input_xfrm = rxfh.input_xfrm;
-out_ops:
+out_unlock:
+       mutex_unlock(&dev->ethtool->rss_lock);
        ethnl_ops_complete(dev);
        return ret;
 }
@@ -108,12 +110,16 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
        struct ethtool_rxfh_context *ctx;
        u32 total_size, indir_bytes;
        u8 *rss_config;
+       int ret;
 
        data->no_key_fields = !dev->ethtool_ops->rxfh_per_ctx_key;
 
+       mutex_lock(&dev->ethtool->rss_lock);
        ctx = xa_load(&dev->ethtool->rss_ctx, request->rss_context);
-       if (!ctx)
-               return -ENOENT;
+       if (!ctx) {
+               ret = -ENOENT;
+               goto out_unlock;
+       }
 
        data->indir_size = ctx->indir_size;
        data->hkey_size = ctx->key_size;
@@ -123,8 +129,10 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
        indir_bytes = data->indir_size * sizeof(u32);
        total_size = indir_bytes + data->hkey_size;
        rss_config = kzalloc(total_size, GFP_KERNEL);
-       if (!rss_config)
-               return -ENOMEM;
+       if (!rss_config) {
+               ret = -ENOMEM;
+               goto out_unlock;
+       }
 
        data->indir_table = (u32 *)rss_config;
        memcpy(data->indir_table, ethtool_rxfh_context_indir(ctx), indir_bytes);
@@ -135,7 +143,10 @@ rss_prepare_ctx(const struct rss_req_info *request, struct net_device *dev,
                       data->hkey_size);
        }
 
-       return 0;
+       ret = 0;
+out_unlock:
+       mutex_unlock(&dev->ethtool->rss_lock);
+       return ret;
 }
 
 static int
@@ -156,7 +167,6 @@ rss_prepare_data(const struct ethnl_req_info *req_base,
        struct rss_req_info *request = RSS_REQINFO(req_base);
        struct net_device *dev = reply_base->dev;
        const struct ethtool_ops *ops;
-       int ret;
 
        ops = dev->ethtool_ops;
        if (!ops->get_rxfh)
@@ -166,11 +176,7 @@ rss_prepare_data(const struct ethnl_req_info *req_base,
        if (request->rss_context && !ops->create_rxfh_context)
                return -EOPNOTSUPP;
 
-       mutex_lock(&dev->ethtool->rss_lock);
-       ret = rss_prepare(request, dev, data, info);
-       mutex_unlock(&dev->ethtool->rss_lock);
-
-       return ret;
+       return rss_prepare(request, dev, data, info);
 }
 
 static int
@@ -294,11 +300,7 @@ rss_dump_one_ctx(struct sk_buff *skb, struct netlink_callback *cb,
        if (ret < 0)
                goto err_cancel;
 
-       /* Context 0 is not currently storred or cached in the XArray */
-       if (!rss_context)
-               ret = rss_prepare_get(&req, dev, &data, info);
-       else
-               ret = rss_prepare_ctx(&req, dev, &data, info);
+       ret = rss_prepare(&req, dev, &data, info);
        if (ret)
                goto err_cancel;