3.0-stable review patch. If anyone has any objections, please let me know.
------------------ From: Thomas Graf <[email protected]> [ Upstream commit 25a6e6b84fba601eff7c28d30da8ad7cfbef0d43 ] Allocating skbs when sending out neighbour discovery messages currently uses sock_alloc_send_skb() based on a per net namespace socket and thus share a socket wmem buffer space. If a netdevice is temporarily unable to transmit due to carrier loss or for other reasons, the queued up ndisc messages will cosnume all of the wmem space and will thus prevent from any more skbs to be allocated even for netdevices that are able to transmit packets. The number of neighbour discovery messages sent is very limited, use of alloc_skb() bypasses the socket wmem buffer size enforcement while the manual call to skb_set_owner_w() maintains the socket reference needed for the IPv6 output path. This patch has orginally been posted by Eric Dumazet in a modified form. Signed-off-by: Thomas Graf <[email protected]> Cc: Eric Dumazet <[email protected]> Cc: Hannes Frederic Sowa <[email protected]> Cc: Stephen Warren <[email protected]> Cc: Fabio Estevam <[email protected]> Tested-by: Fabio Estevam <[email protected]> Tested-by: Stephen Warren <[email protected]> Acked-by: Hannes Frederic Sowa <[email protected]> Signed-off-by: David S. Miller <[email protected]> Signed-off-by: Greg Kroah-Hartman <[email protected]> --- net/ipv6/ndisc.c | 16 +++++++++------- 1 file changed, 9 insertions(+), 7 deletions(-) --- a/net/ipv6/ndisc.c +++ b/net/ipv6/ndisc.c @@ -456,7 +456,6 @@ struct sk_buff *ndisc_build_skb(struct n struct sk_buff *skb; struct icmp6hdr *hdr; int len; - int err; u8 *opt; if (!dev->addr_len) @@ -466,14 +465,12 @@ struct sk_buff *ndisc_build_skb(struct n if (llinfo) len += ndisc_opt_addr_space(dev); - skb = sock_alloc_send_skb(sk, - (MAX_HEADER + sizeof(struct ipv6hdr) + - len + LL_ALLOCATED_SPACE(dev)), - 1, &err); + skb = alloc_skb((MAX_HEADER + sizeof(struct ipv6hdr) + + len + LL_ALLOCATED_SPACE(dev)), GFP_ATOMIC); if (!skb) { ND_PRINTK0(KERN_ERR - "ICMPv6 ND: %s() failed to allocate an skb, err=%d.\n", - __func__, err); + "ICMPv6 ND: %s() failed to allocate an skb.\n", + __func__); return NULL; } @@ -501,6 +498,11 @@ struct sk_buff *ndisc_build_skb(struct n csum_partial(hdr, len, 0)); + /* Manually assign socket ownership as we avoid calling + * sock_alloc_send_pskb() to bypass wmem buffer limits + */ + skb_set_owner_w(skb, sk); + return skb; } -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
