Callers of skb_seq_read() are currently forced to call skb_abort_seq_read()
even when consuming all the data because the last call to skb_seq_read (the
one that returns 0 to indicate the end) fails to unmap the last fragment page.
With this patch callers will be allowed to traverse the SKB data by calling
skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally
intended (and documented in the original commit 677e90eda - "[NET]: Zerocopy
sequential reading of skb data"), that is, only call skb_abort_seq_read() if
the sequential read is actually aborted.
Signed-off-by: Wedson Almeida Filho <[email protected]>
---
drivers/scsi/libiscsi_tcp.c | 1 -
net/batman-adv/main.c | 1 -
net/core/skbuff.c | 7 ++++++-
3 files changed, 6 insertions(+), 3 deletions(-)
diff --git a/drivers/scsi/libiscsi_tcp.c b/drivers/scsi/libiscsi_tcp.c
index 552e8a2..448eae8 100644
--- a/drivers/scsi/libiscsi_tcp.c
+++ b/drivers/scsi/libiscsi_tcp.c
@@ -906,7 +906,6 @@ int iscsi_tcp_recv_skb(struct iscsi_conn *conn, struct sk_buff *skb,
ISCSI_DBG_TCP(conn, "no more data avail. Consumed %d\n",
consumed);
*status = ISCSI_TCP_SKB_DONE;
- skb_abort_seq_read(&seq);
goto skb_done;
}
BUG_ON(segment->copied >= segment->size);
diff --git a/net/batman-adv/main.c b/net/batman-adv/main.c
index 51aafd6..08125f3 100644
--- a/net/batman-adv/main.c
+++ b/net/batman-adv/main.c
@@ -473,7 +473,6 @@ __be32 batadv_skb_crc32(struct sk_buff *skb, u8 *payload_ptr)
crc = crc32c(crc, data, len);
consumed += len;
}
- skb_abort_seq_read(&st);
return htonl(crc);
}
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index cfd777b..26ea1cf 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -2554,8 +2554,13 @@ unsigned int skb_seq_read(unsigned int consumed, const u8 **data,
unsigned int block_limit, abs_offset = consumed + st->lower_offset;
skb_frag_t *frag;
- if (unlikely(abs_offset >= st->upper_offset))
+ if (unlikely(abs_offset >= st->upper_offset)) {
+ if (st->frag_data) {
+ kunmap_atomic(st->frag_data);
+ st->frag_data = NULL;
+ }
return 0;
+ }
next_skb:
block_limit = skb_headlen(st->cur_skb) + st->stepped_offset;
--
1.7.9.5
From: Wedson Almeida Filho <[email protected]>
Date: Mon, 24 Jun 2013 18:25:20 -0700
> Callers of skb_seq_read() are currently forced to call skb_abort_seq_read()
> even when consuming all the data because the last call to skb_seq_read (the
> one that returns 0 to indicate the end) fails to unmap the last fragment page.
>
> With this patch callers will be allowed to traverse the SKB data by calling
> skb_prepare_seq_read() once and repeatedly calling skb_seq_read() as originally
> intended (and documented in the original commit 677e90eda - "[NET]: Zerocopy
> sequential reading of skb data"), that is, only call skb_abort_seq_read() if
> the sequential read is actually aborted.
>
> Signed-off-by: Wedson Almeida Filho <[email protected]>
This patch doesn't even come close to applying to the net-next tree,
please respin this patch properly and resubmit.
Thanks.
On Tue, Jun 25, 2013 at 4:20 PM, David Miller <[email protected]> wrote:
> This patch doesn't even come close to applying to the net-next tree,
> please respin this patch properly and resubmit.
Where can I pull the net-next tree from?
git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git?
Thanks
>> This patch doesn't even come close to applying to the net-next tree,
>> please respin this patch properly and resubmit.
>
> Where can I pull the net-next tree from?
> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git?
David, would you mind clarifying where I can find net-next? The only
one I could find was the one I mention above and it already has my
patch in it (though with the previous comment).
Thanks
From: Wedson Almeida Filho <[email protected]>
Date: Thu, 27 Jun 2013 15:03:40 -0700
>>> This patch doesn't even come close to applying to the net-next tree,
>>> please respin this patch properly and resubmit.
>>
>> Where can I pull the net-next tree from?
>> git://git.kernel.org/pub/scm/linux/kernel/git/davem/net-next.git?
>
> David, would you mind clarifying where I can find net-next? The only
> one I could find was the one I mention above and it already has my
> patch in it (though with the previous comment).
Yes that is where my net-next tree is, as clearly stated the
"NETWORKING [GENERAL]" sercion of the MAINTAINERS file.
On Thu, Jun 27, 2013 at 4:22 PM, David Miller <[email protected]> wrote:
>> David, would you mind clarifying where I can find net-next? The only
>> one I could find was the one I mention above and it already has my
>> patch in it (though with the previous comment).
>
> Yes that is where my net-next tree is, as clearly stated the
> "NETWORKING [GENERAL]" sercion of the MAINTAINERS file.
Ok, thanks for the info, now I know where the definitive answer is.
Anyway, why are you asking me to respin this patch? If I do it based
on this tree, there will be no changes in it.
From: Wedson Almeida Filho <[email protected]>
Date: Thu, 27 Jun 2013 17:35:15 -0700
> On Thu, Jun 27, 2013 at 4:22 PM, David Miller <[email protected]> wrote:
>
>>> David, would you mind clarifying where I can find net-next? The only
>>> one I could find was the one I mention above and it already has my
>>> patch in it (though with the previous comment).
>>
>> Yes that is where my net-next tree is, as clearly stated the
>> "NETWORKING [GENERAL]" sercion of the MAINTAINERS file.
>
> Ok, thanks for the info, now I know where the definitive answer is.
>
> Anyway, why are you asking me to respin this patch? If I do it based
> on this tree, there will be no changes in it.
Nevermind then.