| Date | Tue, 26 Mar 2013 13:22:15 -0400 | From | Steven Rostedt <> | Subject | [PATCH 76/86] net: splice: avoid high order page splitting |
| |
3.6.11.1 stable review patch. If anyone has any objections, please let me know.
------------------
From: Eric Dumazet <edumazet@google.com>
[ Upstream commit 4678414601960b3d60b651d82e2913c48c53508d ]
splice() can handle pages of any order, but network code tries hard to split them in PAGE_SIZE units. Not quite successfully anyway, as __splice_segment() assumed poff < PAGE_SIZE. This is true for the skb->data part, not necessarily for the fragments.
This patch removes this logic to give the pages as they are in the skb.
Signed-off-by: Eric Dumazet <edumazet@google.com> Cc: Willy Tarreau <w@1wt.eu> Signed-off-by: David S. Miller <davem@davemloft.net> --- net/core/skbuff.c | 38 +++++++++----------------------------- 1 file changed, 9 insertions(+), 29 deletions(-)
diff --git a/net/core/skbuff.c b/net/core/skbuff.c index 9708777..8e6a22c 100644 --- a/net/core/skbuff.c +++ b/net/core/skbuff.c @@ -1682,20 +1682,6 @@ static bool spd_fill_page(struct splice_pipe_desc *spd, return false; } -static inline void __segment_seek(struct page **page, unsigned int *poff, - unsigned int *plen, unsigned int off) -{ - unsigned long n; - - *poff += off; - n = *poff / PAGE_SIZE; - if (n) - *page = nth_page(*page, n); - - *poff = *poff % PAGE_SIZE; - *plen -= off; -} - static bool __splice_segment(struct page *page, unsigned int poff, unsigned int plen, unsigned int *off, unsigned int *len, struct sk_buff *skb, @@ -1703,6 +1689,8 @@ static bool __splice_segment(struct page *page, unsigned int poff, struct sock *sk, struct pipe_inode_info *pipe) { + unsigned int flen; + if (!*len) return true; @@ -1713,24 +1701,16 @@ static bool __splice_segment(struct page *page, unsigned int poff, } /* ignore any bits we already processed */ - if (*off) { - __segment_seek(&page, &poff, &plen, *off); - *off = 0; - } - - do { - unsigned int flen = min(*len, plen); + poff += *off; + plen -= *off; + *off = 0; - /* the linear region may spread across several pages */ - flen = min_t(unsigned int, flen, PAGE_SIZE - poff); + flen = min(*len, plen); - if (spd_fill_page(spd, pipe, page, &flen, poff, skb, linear, sk)) - return true; - - __segment_seek(&page, &poff, &plen, flen); - *len -= flen; + if (spd_fill_page(spd, pipe, page, &flen, poff, skb, linear, sk)) + return true; - } while (*len && plen); + *len -= flen; return false; } -- 1.7.10.4
|