diff options
Diffstat (limited to 'net/core/sock.c')
-rw-r--r-- | net/core/sock.c | 61 |
1 files changed, 61 insertions, 0 deletions
diff --git a/net/core/sock.c b/net/core/sock.c index a8962d912895..f704324d1219 100644 --- a/net/core/sock.c +++ b/net/core/sock.c @@ -2237,6 +2237,67 @@ 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_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; + struct scatterlist *sge; + + 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; + } + + 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 + sg_curr - 1; + if (sg_curr > first_coalesce && sg_page(sg) == pfrag->page && + sg->offset + sg->length == orig_offset) { + sg->length += use; + } else { + sge = sg + sg_curr; + sg_unmark_end(sge); + sg_set_page(sge, pfrag->page, use, orig_offset); + get_page(pfrag->page); + sg_curr++; + + if (sg_curr == MAX_SKB_FRAGS) + sg_curr = 0; + + if (sg_curr == sg_start) { + rc = -ENOSPC; + break; + } + } + + len -= use; + } +out: + *sg_curr_size = size; + *sg_curr_index = sg_curr; + return rc; +} +EXPORT_SYMBOL(sk_alloc_sg); + static void __lock_sock(struct sock *sk) __releases(&sk->sk_lock.slock) __acquires(&sk->sk_lock.slock) |