From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Dumazet Subject: [PATCH net-next] net: splice: fix __splice_segment() Date: Fri, 11 Jan 2013 16:46:37 -0800 Message-ID: <1357951597.20249.247.camel@edumazet-glaptop> References: <1357750898.27446.33.camel@edumazet-glaptop> <1357751372.27446.40.camel@edumazet-glaptop> <1357801149.27446.1142.camel@edumazet-glaptop> <20130110072136.GK9943@1wt.eu> <1357831787.27446.2168.camel@edumazet-glaptop> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: netdev To: Willy Tarreau , David Miller Return-path: Received: from mail-pb0-f47.google.com ([209.85.160.47]:34069 "EHLO mail-pb0-f47.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754903Ab3ALAqk (ORCPT ); Fri, 11 Jan 2013 19:46:40 -0500 Received: by mail-pb0-f47.google.com with SMTP id un1so1229713pbc.6 for ; Fri, 11 Jan 2013 16:46:40 -0800 (PST) In-Reply-To: <1357831787.27446.2168.camel@edumazet-glaptop> Sender: netdev-owner@vger.kernel.org List-ID: From: Eric Dumazet commit 9ca1b22d6d2 (net: splice: avoid high order page splitting) forgot that skb->head could need a copy into several page frags. This could be the case for loopback traffic mostly. Also remove now useless skb argument from linear_to_page() and __splice_segment() prototypes. Signed-off-by: Eric Dumazet Cc: Willy Tarreau --- net/core/skbuff.c | 28 +++++++++++++++------------- 1 file changed, 15 insertions(+), 13 deletions(-) diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 1e1b9ea..2568c44 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1652,7 +1652,7 @@ static void sock_spd_release(struct splice_pipe_desc *spd, unsigned int i) static struct page *linear_to_page(struct page *page, unsigned int *len, unsigned int *offset, - struct sk_buff *skb, struct sock *sk) + struct sock *sk) { struct page_frag *pfrag = sk_page_frag(sk); @@ -1685,14 +1685,14 @@ static bool spd_can_coalesce(const struct splice_pipe_desc *spd, static bool spd_fill_page(struct splice_pipe_desc *spd, struct pipe_inode_info *pipe, struct page *page, unsigned int *len, unsigned int offset, - struct sk_buff *skb, bool linear, + bool linear, struct sock *sk) { if (unlikely(spd->nr_pages == MAX_SKB_FRAGS)) return true; if (linear) { - page = linear_to_page(page, len, &offset, skb, sk); + page = linear_to_page(page, len, &offset, sk); if (!page) return true; } @@ -1711,13 +1711,11 @@ static bool spd_fill_page(struct splice_pipe_desc *spd, static bool __splice_segment(struct page *page, unsigned int poff, unsigned int plen, unsigned int *off, - unsigned int *len, struct sk_buff *skb, + unsigned int *len, struct splice_pipe_desc *spd, bool linear, struct sock *sk, struct pipe_inode_info *pipe) { - unsigned int flen; - if (!*len) return true; @@ -1732,12 +1730,16 @@ static bool __splice_segment(struct page *page, unsigned int poff, plen -= *off; *off = 0; - flen = min(*len, plen); - - if (spd_fill_page(spd, pipe, page, &flen, poff, skb, linear, sk)) - return true; + do { + unsigned int flen = min(*len, plen); - *len -= flen; + if (spd_fill_page(spd, pipe, page, &flen, poff, + linear, sk)) + return true; + poff += flen; + plen -= flen; + *len -= flen; + } while (*len && plen); return false; } @@ -1760,7 +1762,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, if (__splice_segment(virt_to_page(skb->data), (unsigned long) skb->data & (PAGE_SIZE - 1), skb_headlen(skb), - offset, len, skb, spd, + offset, len, spd, skb_head_is_locked(skb), sk, pipe)) return true; @@ -1773,7 +1775,7 @@ static bool __skb_splice_bits(struct sk_buff *skb, struct pipe_inode_info *pipe, if (__splice_segment(skb_frag_page(f), f->page_offset, skb_frag_size(f), - offset, len, skb, spd, false, sk, pipe)) + offset, len, spd, false, sk, pipe)) return true; }