[PATCH net-next v3 2/5] net: core: factor out the GSO device limit check
COOLING4d
From: Wang Zhan <hidden>
Date: 2026-09-28 04:41:31
Subsystem:
networking [general], the rest · Maintainers:
"David S. Miller", Eric Dumazet, Jakub Kicinski, Paolo Abeni, Linus Torvalds
Revision v3 of 3 in this series.
Revisions (3)
- v1 [diff vs current]
- v2 [diff vs current]
- v3 current
gso_features_check() decides whether an egress device can offload a GSO skb as a single TSO frame by comparing the segment count and the frame length against the device limits. The resegmentation path added by a later patch caps the MSS segments per output skb and needs the same features computed without those limits, so put the two tests in a helper and gate them with one flag. No functional changes. Assisted-by: LLM Signed-off-by: Wang Zhan <redacted> --- v3: - rename the helper to gso_within_dev_limits - move the check_gso_limits flag and the wrapper split here from patch 4 v2: https://lore.kernel.org/20260918084651.3022878-2-wang.zhan@smartx.com/ (local) v1: https://lore.kernel.org/20260917063854.2011613-2-wang.zhan@smartx.com/ (local) --- net/core/dev.c | 29 +++++++++++++++++++---------- 1 file changed, 19 insertions(+), 10 deletions(-)
diff --git a/net/core/dev.c b/net/core/dev.c
index ffa9b0c27788c..d66b667071837 100644
--- a/net/core/dev.c
+++ b/net/core/dev.c@@ -3834,17 +3834,19 @@ static bool skb_gso_has_extension_hdr(const struct sk_buff *skb) skb_inner_network_header_len(skb) != sizeof(struct ipv6hdr))); } +static bool +gso_within_dev_limits(const struct sk_buff *skb, const struct net_device *dev) +{ + return skb_shinfo(skb)->gso_segs <= READ_ONCE(dev->gso_max_segs) && + skb->len < netif_get_gso_max_size(dev, vlan_get_protocol(skb)); +} + static netdev_features_t gso_features_check(const struct sk_buff *skb, struct net_device *dev, - netdev_features_t features) + netdev_features_t features, + bool check_limits) { - u16 gso_segs = skb_shinfo(skb)->gso_segs; - - if (gso_segs > READ_ONCE(dev->gso_max_segs)) - return features & ~NETIF_F_GSO_MASK; - - if (unlikely(skb->len >= - netif_get_gso_max_size(dev, vlan_get_protocol(skb)))) + if (check_limits && !gso_within_dev_limits(skb, dev)) return features & ~NETIF_F_GSO_MASK; if (!skb_shinfo(skb)->gso_type) {
@@ -3893,13 +3895,15 @@ static netdev_features_t gso_features_check(const struct sk_buff *skb, return features; } -netdev_features_t netif_skb_features(struct sk_buff *skb) +static netdev_features_t +__netif_skb_features(struct sk_buff *skb, bool check_gso_limits) { struct net_device *dev = skb->dev; netdev_features_t features = dev->features; if (skb_is_gso(skb)) - features = gso_features_check(skb, dev, features); + features = gso_features_check(skb, dev, features, + check_gso_limits); /* If encapsulation offload request, verify we are testing * hardware encapsulation features instead of standard
@@ -3922,6 +3926,11 @@ netdev_features_t netif_skb_features(struct sk_buff *skb) return harmonize_features(skb, features); } + +netdev_features_t netif_skb_features(struct sk_buff *skb) +{ + return __netif_skb_features(skb, true); +} EXPORT_SYMBOL(netif_skb_features); static int xmit_one(struct sk_buff *skb, struct net_device *dev,
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2.47.3