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| author | John Fastabend <john.fastabend@gmail.com> | 2018-03-18 12:57:05 -0700 |
|---|---|---|
| committer | Daniel Borkmann <daniel@iogearbox.net> | 2018-03-19 21:14:38 +0100 |
| commit | 8c05dbf04b2882c3c0bc43fe7668c720210877f3 (patch) | |
| tree | b13d4d3116498ab38c1493cdeb21254313c2f94d /net/core/sock.c | |
| parent | 312fc2b4c82e96a48cb2d0da2bd4816eb253c499 (diff) | |
| download | linux-8c05dbf04b2882c3c0bc43fe7668c720210877f3.tar.bz2 | |
net: generalize sk_alloc_sg to work with scatterlist rings
The current implementation of sk_alloc_sg expects scatterlist to always
start at entry 0 and complete at entry MAX_SKB_FRAGS.
Future patches will want to support starting at arbitrary offset into
scatterlist so add an additional sg_start parameters and then default
to the current values in TLS code paths.
Signed-off-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Diffstat (limited to 'net/core/sock.c')
| -rw-r--r-- | net/core/sock.c | 27 |
1 files changed, 16 insertions, 11 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index f68dff0d7bc4..4f92c2910200 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2240,19 +2240,20 @@ bool sk_page_frag_refill(struct sock *sk, struct page_frag *pfrag) EXPORT_SYMBOL(sk_page_frag_refill); int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, - int *sg_num_elem, unsigned int *sg_size, + int sg_start, int *sg_curr_index, unsigned int *sg_curr_size, int first_coalesce) { + int sg_curr = *sg_curr_index, use = 0, rc = 0; + unsigned int size = *sg_curr_size; struct page_frag *pfrag; - unsigned int size = *sg_size; - int num_elem = *sg_num_elem, use = 0, rc = 0; struct scatterlist *sge; - unsigned int orig_offset; len -= size; pfrag = sk_page_frag(sk); while (len > 0) { + unsigned int orig_offset; + if (!sk_page_frag_refill(sk, pfrag)) { rc = -ENOMEM; goto out; @@ -2270,17 +2271,21 @@ int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, orig_offset = pfrag->offset; pfrag->offset += use; - sge = sg + num_elem - 1; - if (num_elem > first_coalesce && sg_page(sg) == pfrag->page && + sge = sg + sg_curr - 1; + if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page && sg->offset + sg->length == orig_offset) { sg->length += use; } else { - sge++; + sge = sg + sg_curr; sg_unmark_end(sge); sg_set_page(sge, pfrag->page, use, orig_offset); get_page(pfrag->page); - ++num_elem; - if (num_elem == MAX_SKB_FRAGS) { + sg_curr++; + + if (sg_curr == MAX_SKB_FRAGS) + sg_curr = 0; + + if (sg_curr == sg_start) { rc = -ENOSPC; break; } @@ -2289,8 +2294,8 @@ int sk_alloc_sg(struct sock *sk, int len, struct scatterlist *sg, len -= use; } out: - *sg_size = size; - *sg_num_elem = num_elem; + *sg_curr_size = size; + *sg_curr_index = sg_curr; return rc; } EXPORT_SYMBOL(sk_alloc_sg); |