* [PATCHv3 net-next 0/2] net: fix the features flag in sctp_gso_segment
@ 2021-01-15 9:36 Xin Long
2021-01-15 9:36 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Xin Long
0 siblings, 1 reply; 5+ messages in thread
From: Xin Long @ 2021-01-15 9:36 UTC (permalink / raw)
To: network dev, linux-sctp
Cc: Marcelo Ricardo Leitner, Neil Horman, davem, Jakub Kicinski,
Alexander Duyck
Patch 1/2 is to improve the code in skb_segment(), and it is needed
by Patch 2/2.
v1->v2:
- see Patch 1/2.
v2->v3:
- change Patch 2/2 to the right patch.
Xin Long (2):
net: move the hsize check to the else block in skb_segment
sctp: remove the NETIF_F_SG flag before calling skb_segment
net/core/skbuff.c | 11 ++++++-----
net/sctp/offload.c | 2 +-
2 files changed, 7 insertions(+), 6 deletions(-)
--
2.1.0
^ permalink raw reply [flat|nested] 5+ messages in thread
* [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment
2021-01-15 9:36 [PATCHv3 net-next 0/2] net: fix the features flag in sctp_gso_segment Xin Long
@ 2021-01-15 9:36 ` Xin Long
2021-01-15 9:36 ` [PATCHv3 net-next 2/2] sctp: remove the NETIF_F_SG flag before calling skb_segment Xin Long
2021-01-16 1:39 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Alexander Duyck
0 siblings, 2 replies; 5+ messages in thread
From: Xin Long @ 2021-01-15 9:36 UTC (permalink / raw)
To: network dev, linux-sctp
Cc: Marcelo Ricardo Leitner, Neil Horman, davem, Jakub Kicinski,
Alexander Duyck
After commit 89319d3801d1 ("net: Add frag_list support to skb_segment"),
it goes to process frag_list when !hsize in skb_segment(). However, when
using skb frag_list, sg normally should not be set. In this case, hsize
will be set with len right before !hsize check, then it won't go to
frag_list processing code.
So the right thing to do is move the hsize check to the else block, so
that it won't affect the !hsize check for frag_list processing.
v1->v2:
- change to do "hsize <= 0" check instead of "!hsize", and also move
"hsize < 0" into else block, to save some cycles, as Alex suggested.
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
net/core/skbuff.c | 11 ++++++-----
1 file changed, 6 insertions(+), 5 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index 6039069..e835193 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -3894,12 +3894,8 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
}
hsize = skb_headlen(head_skb) - offset;
- if (hsize < 0)
- hsize = 0;
- if (hsize > len || !sg)
- hsize = len;
- if (!hsize && i >= nfrags && skb_headlen(list_skb) &&
+ if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) &&
(skb_headlen(list_skb) == len || sg)) {
BUG_ON(skb_headlen(list_skb) > len);
@@ -3942,6 +3938,11 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
skb_release_head_state(nskb);
__skb_push(nskb, doffset);
} else {
+ if (hsize > len || !sg)
+ hsize = len;
+ else if (hsize < 0)
+ hsize = 0;
+
nskb = __alloc_skb(hsize + doffset + headroom,
GFP_ATOMIC, skb_alloc_rx_flag(head_skb),
NUMA_NO_NODE);
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* [PATCHv3 net-next 2/2] sctp: remove the NETIF_F_SG flag before calling skb_segment
2021-01-15 9:36 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Xin Long
@ 2021-01-15 9:36 ` Xin Long
2021-01-16 1:39 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Alexander Duyck
1 sibling, 0 replies; 5+ messages in thread
From: Xin Long @ 2021-01-15 9:36 UTC (permalink / raw)
To: network dev, linux-sctp
Cc: Marcelo Ricardo Leitner, Neil Horman, davem, Jakub Kicinski,
Alexander Duyck
It makes more sense to clear NETIF_F_SG instead of set it when
calling skb_segment() in sctp_gso_segment(), since SCTP GSO is
using head_skb's fraglist, of which all frags are linear skbs.
This will make SCTP GSO code more understandable.
Suggested-by: Alexander Duyck <alexander.duyck@gmail.com>
Signed-off-by: Xin Long <lucien.xin@gmail.com>
---
net/sctp/offload.c | 2 +-
1 file changed, 1 insertion(+), 1 deletion(-)
diff --git a/net/sctp/offload.c b/net/sctp/offload.c
index ce281a9..eb874e3 100644
--- a/net/sctp/offload.c
+++ b/net/sctp/offload.c
@@ -68,7 +68,7 @@ static struct sk_buff *sctp_gso_segment(struct sk_buff *skb,
goto out;
}
- segs = skb_segment(skb, features | NETIF_F_HW_CSUM | NETIF_F_SG);
+ segs = skb_segment(skb, (features | NETIF_F_HW_CSUM) & ~NETIF_F_SG);
if (IS_ERR(segs))
goto out;
--
2.1.0
^ permalink raw reply related [flat|nested] 5+ messages in thread
* Re: [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment
2021-01-15 9:36 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Xin Long
2021-01-15 9:36 ` [PATCHv3 net-next 2/2] sctp: remove the NETIF_F_SG flag before calling skb_segment Xin Long
@ 2021-01-16 1:39 ` Alexander Duyck
2021-01-17 3:13 ` Jakub Kicinski
1 sibling, 1 reply; 5+ messages in thread
From: Alexander Duyck @ 2021-01-16 1:39 UTC (permalink / raw)
To: Xin Long
Cc: network dev, linux-sctp @ vger . kernel . org,
Marcelo Ricardo Leitner, Neil Horman, David Miller,
Jakub Kicinski
On Fri, Jan 15, 2021 at 1:36 AM Xin Long <lucien.xin@gmail.com> wrote:
>
> After commit 89319d3801d1 ("net: Add frag_list support to skb_segment"),
> it goes to process frag_list when !hsize in skb_segment(). However, when
> using skb frag_list, sg normally should not be set. In this case, hsize
> will be set with len right before !hsize check, then it won't go to
> frag_list processing code.
>
> So the right thing to do is move the hsize check to the else block, so
> that it won't affect the !hsize check for frag_list processing.
>
> v1->v2:
> - change to do "hsize <= 0" check instead of "!hsize", and also move
> "hsize < 0" into else block, to save some cycles, as Alex suggested.
>
> Signed-off-by: Xin Long <lucien.xin@gmail.com>
Looks good to me.
Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
> ---
> net/core/skbuff.c | 11 ++++++-----
> 1 file changed, 6 insertions(+), 5 deletions(-)
>
> diff --git a/net/core/skbuff.c b/net/core/skbuff.c
> index 6039069..e835193 100644
> --- a/net/core/skbuff.c
> +++ b/net/core/skbuff.c
> @@ -3894,12 +3894,8 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
> }
>
> hsize = skb_headlen(head_skb) - offset;
> - if (hsize < 0)
> - hsize = 0;
> - if (hsize > len || !sg)
> - hsize = len;
>
> - if (!hsize && i >= nfrags && skb_headlen(list_skb) &&
> + if (hsize <= 0 && i >= nfrags && skb_headlen(list_skb) &&
> (skb_headlen(list_skb) == len || sg)) {
> BUG_ON(skb_headlen(list_skb) > len);
>
> @@ -3942,6 +3938,11 @@ struct sk_buff *skb_segment(struct sk_buff *head_skb,
> skb_release_head_state(nskb);
> __skb_push(nskb, doffset);
> } else {
> + if (hsize > len || !sg)
> + hsize = len;
> + else if (hsize < 0)
> + hsize = 0;
> +
> nskb = __alloc_skb(hsize + doffset + headroom,
> GFP_ATOMIC, skb_alloc_rx_flag(head_skb),
> NUMA_NO_NODE);
> --
> 2.1.0
>
^ permalink raw reply [flat|nested] 5+ messages in thread
* Re: [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment
2021-01-16 1:39 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Alexander Duyck
@ 2021-01-17 3:13 ` Jakub Kicinski
0 siblings, 0 replies; 5+ messages in thread
From: Jakub Kicinski @ 2021-01-17 3:13 UTC (permalink / raw)
To: Alexander Duyck, Xin Long
Cc: network dev, linux-sctp @ vger . kernel . org,
Marcelo Ricardo Leitner, Neil Horman
On Fri, 15 Jan 2021 17:39:02 -0800 Alexander Duyck wrote:
> On Fri, Jan 15, 2021 at 1:36 AM Xin Long <lucien.xin@gmail.com> wrote:
> >
> > After commit 89319d3801d1 ("net: Add frag_list support to skb_segment"),
> > it goes to process frag_list when !hsize in skb_segment(). However, when
> > using skb frag_list, sg normally should not be set. In this case, hsize
> > will be set with len right before !hsize check, then it won't go to
> > frag_list processing code.
> >
> > So the right thing to do is move the hsize check to the else block, so
> > that it won't affect the !hsize check for frag_list processing.
> >
> > v1->v2:
> > - change to do "hsize <= 0" check instead of "!hsize", and also move
> > "hsize < 0" into else block, to save some cycles, as Alex suggested.
> >
> > Signed-off-by: Xin Long <lucien.xin@gmail.com>
>
> Looks good to me.
>
> Reviewed-by: Alexander Duyck <alexanderduyck@fb.com>
Applied, thanks!
^ permalink raw reply [flat|nested] 5+ messages in thread
end of thread, other threads:[~2021-01-17 3:14 UTC | newest]
Thread overview: 5+ messages (download: mbox.gz / follow: Atom feed)
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2021-01-15 9:36 [PATCHv3 net-next 0/2] net: fix the features flag in sctp_gso_segment Xin Long
2021-01-15 9:36 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Xin Long
2021-01-15 9:36 ` [PATCHv3 net-next 2/2] sctp: remove the NETIF_F_SG flag before calling skb_segment Xin Long
2021-01-16 1:39 ` [PATCHv3 net-next 1/2] net: move the hsize check to the else block in skb_segment Alexander Duyck
2021-01-17 3:13 ` Jakub Kicinski
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