Commit 9ca1b22d authored by Eric Dumazet's avatar Eric Dumazet Committed by David S. Miller
Browse files

net: splice: avoid high order page splitting



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: default avatarEric Dumazet <edumazet@google.com>
Cc: Willy Tarreau <w@1wt.eu>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent 81135548
......@@ -1707,20 +1707,6 @@ 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,
......@@ -1728,6 +1714,8 @@ 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;
......@@ -1738,24 +1726,16 @@ 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;
}
......
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