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authorJohn Fastabend <john.fastabend@gmail.com>2018-03-18 12:56:49 -0700
committerDaniel Borkmann <daniel@iogearbox.net>2018-03-19 21:14:38 +0100
commit2c3682f0be97a5f57c6c8b40fa154dfc77efb461 (patch)
tree186c43b0505e50aec6c151e5645fed98add35c8c /net/core/sock.c
parentMerge branch 'bpf-tools-build-improvements' (diff)
downloadlinux-dev-2c3682f0be97a5f57c6c8b40fa154dfc77efb461.tar.xz
linux-dev-2c3682f0be97a5f57c6c8b40fa154dfc77efb461.zip
sock: make static tls function alloc_sg generic sock helper
The TLS ULP module builds scatterlists from a sock using page_frag_refill(). This is going to be useful for other ULPs so move it into sock file for more general use. In the process remove useless goto at end of while loop. 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.c56
1 files changed, 56 insertions, 0 deletions
diff --git a/net/core/sock.c b/net/core/sock.c
index 27f218bba43f..f68dff0d7bc4 100644
--- a/net/core/sock.c
+++ b/net/core/sock.c
@@ -2239,6 +2239,62 @@ 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 first_coalesce)
+{
+ 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) {
+ if (!sk_page_frag_refill(sk, pfrag)) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ use = min_t(int, len, pfrag->size - pfrag->offset);
+
+ if (!sk_wmem_schedule(sk, use)) {
+ rc = -ENOMEM;
+ goto out;
+ }
+
+ sk_mem_charge(sk, use);
+ size += use;
+ orig_offset = pfrag->offset;
+ pfrag->offset += use;
+
+ sge = sg + num_elem - 1;
+ if (num_elem > first_coalesce && sg_page(sg) == pfrag->page &&
+ sg->offset + sg->length == orig_offset) {
+ sg->length += use;
+ } else {
+ sge++;
+ 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) {
+ rc = -ENOSPC;
+ break;
+ }
+ }
+
+ len -= use;
+ }
+out:
+ *sg_size = size;
+ *sg_num_elem = num_elem;
+ return rc;
+}
+EXPORT_SYMBOL(sk_alloc_sg);
+
static void __lock_sock(struct sock *sk)
__releases(&sk->sk_lock.slock)
__acquires(&sk->sk_lock.slock)