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-rw-r--r--net/core/datagram.c14
-rw-r--r--net/core/skbuff.c37
2 files changed, 43 insertions, 8 deletions
diff --git a/net/core/datagram.c b/net/core/datagram.c
index 35791f86bd1a..8c702904d960 100644
--- a/net/core/datagram.c
+++ b/net/core/datagram.c
@@ -610,10 +610,16 @@ fault:
}
EXPORT_SYMBOL(skb_copy_datagram_from_iter);
-int __zerocopy_sg_from_iter(struct sock *sk, struct sk_buff *skb,
- struct iov_iter *from, size_t length)
+int __zerocopy_sg_from_iter(struct msghdr *msg, struct sock *sk,
+ struct sk_buff *skb, struct iov_iter *from,
+ size_t length)
{
- int frag = skb_shinfo(skb)->nr_frags;
+ int frag;
+
+ if (msg && msg->sg_from_iter)
+ return msg->sg_from_iter(sk, skb, from, length);
+
+ frag = skb_shinfo(skb)->nr_frags;
while (length && iov_iter_count(from)) {
struct page *pages[MAX_SKB_FRAGS];
@@ -699,7 +705,7 @@ int zerocopy_sg_from_iter(struct sk_buff *skb, struct iov_iter *from)
if (skb_copy_datagram_from_iter(skb, 0, from, copy))
return -EFAULT;
- return __zerocopy_sg_from_iter(NULL, skb, from, ~0U);
+ return __zerocopy_sg_from_iter(NULL, NULL, skb, from, ~0U);
}
EXPORT_SYMBOL(zerocopy_sg_from_iter);
diff --git a/net/core/skbuff.c b/net/core/skbuff.c
index c4a751781581..974bbbbe7138 100644
--- a/net/core/skbuff.c
+++ b/net/core/skbuff.c
@@ -669,11 +669,18 @@ static void skb_release_data(struct sk_buff *skb)
&shinfo->dataref))
goto exit;
- skb_zcopy_clear(skb, true);
+ if (skb_zcopy(skb)) {
+ bool skip_unref = shinfo->flags & SKBFL_MANAGED_FRAG_REFS;
+
+ skb_zcopy_clear(skb, true);
+ if (skip_unref)
+ goto free_head;
+ }
for (i = 0; i < shinfo->nr_frags; i++)
__skb_frag_unref(&shinfo->frags[i], skb->pp_recycle);
+free_head:
if (shinfo->frag_list)
kfree_skb_list(shinfo->frag_list);
@@ -898,7 +905,10 @@ EXPORT_SYMBOL(skb_dump);
*/
void skb_tx_error(struct sk_buff *skb)
{
- skb_zcopy_clear(skb, true);
+ if (skb) {
+ skb_zcopy_downgrade_managed(skb);
+ skb_zcopy_clear(skb, true);
+ }
}
EXPORT_SYMBOL(skb_tx_error);
@@ -1196,7 +1206,7 @@ static struct ubuf_info *msg_zerocopy_alloc(struct sock *sk, size_t size)
uarg->len = 1;
uarg->bytelen = size;
uarg->zerocopy = 1;
- uarg->flags = SKBFL_ZEROCOPY_FRAG;
+ uarg->flags = SKBFL_ZEROCOPY_FRAG | SKBFL_DONT_ORPHAN;
refcount_set(&uarg->refcnt, 1);
sock_hold(sk);
@@ -1215,6 +1225,10 @@ struct ubuf_info *msg_zerocopy_realloc(struct sock *sk, size_t size,
const u32 byte_limit = 1 << 19; /* limit to a few TSO */
u32 bytelen, next;
+ /* there might be non MSG_ZEROCOPY users */
+ if (uarg->callback != msg_zerocopy_callback)
+ return NULL;
+
/* realloc only when socket is locked (TCP, UDP cork),
* so uarg->len and sk_zckey access is serialized
*/
@@ -1357,7 +1371,7 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
if (orig_uarg && uarg != orig_uarg)
return -EEXIST;
- err = __zerocopy_sg_from_iter(sk, skb, &msg->msg_iter, len);
+ err = __zerocopy_sg_from_iter(msg, sk, skb, &msg->msg_iter, len);
if (err == -EFAULT || (err == -EMSGSIZE && skb->len == orig_len)) {
struct sock *save_sk = skb->sk;
@@ -1374,6 +1388,16 @@ int skb_zerocopy_iter_stream(struct sock *sk, struct sk_buff *skb,
}
EXPORT_SYMBOL_GPL(skb_zerocopy_iter_stream);
+void __skb_zcopy_downgrade_managed(struct sk_buff *skb)
+{
+ int i;
+
+ skb_shinfo(skb)->flags &= ~SKBFL_MANAGED_FRAG_REFS;
+ for (i = 0; i < skb_shinfo(skb)->nr_frags; i++)
+ skb_frag_ref(skb, i);
+}
+EXPORT_SYMBOL_GPL(__skb_zcopy_downgrade_managed);
+
static int skb_zerocopy_clone(struct sk_buff *nskb, struct sk_buff *orig,
gfp_t gfp_mask)
{
@@ -1692,6 +1716,8 @@ int pskb_expand_head(struct sk_buff *skb, int nhead, int ntail,
BUG_ON(skb_shared(skb));
+ skb_zcopy_downgrade_managed(skb);
+
size = SKB_DATA_ALIGN(size);
if (skb_pfmemalloc(skb))
@@ -3486,6 +3512,8 @@ void skb_split(struct sk_buff *skb, struct sk_buff *skb1, const u32 len)
int pos = skb_headlen(skb);
const int zc_flags = SKBFL_SHARED_FRAG | SKBFL_PURE_ZEROCOPY;
+ skb_zcopy_downgrade_managed(skb);
+
skb_shinfo(skb1)->flags |= skb_shinfo(skb)->flags & zc_flags;
skb_zerocopy_clone(skb1, skb, 0);
if (len < pos) /* Split line is inside header. */
@@ -3834,6 +3862,7 @@ int skb_append_pagefrags(struct sk_buff *skb, struct page *page,
if (skb_can_coalesce(skb, i, page, offset)) {
skb_frag_size_add(&skb_shinfo(skb)->frags[i - 1], size);
} else if (i < MAX_SKB_FRAGS) {
+ skb_zcopy_downgrade_managed(skb);
get_page(page);
skb_fill_page_desc(skb, i, page, offset, size);
} else {