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Diffstat (limited to 'include/linux/skbuff.h')
-rw-r--r--include/linux/skbuff.h35
1 files changed, 34 insertions, 1 deletions
diff --git a/include/linux/skbuff.h b/include/linux/skbuff.h
index 0bd6520329f6..686a666d073d 100644
--- a/include/linux/skbuff.h
+++ b/include/linux/skbuff.h
@@ -454,9 +454,15 @@ enum {
* all frags to avoid possible bad checksum
*/
SKBFL_SHARED_FRAG = BIT(1),
+
+ /* segment contains only zerocopy data and should not be
+ * charged to the kernel memory.
+ */
+ SKBFL_PURE_ZEROCOPY = BIT(2),
};
#define SKBFL_ZEROCOPY_FRAG (SKBFL_ZEROCOPY_ENABLE | SKBFL_SHARED_FRAG)
+#define SKBFL_ALL_ZEROCOPY (SKBFL_ZEROCOPY_FRAG | SKBFL_PURE_ZEROCOPY)
/*
* The callback notifies userspace to release buffers when skb DMA is done in
@@ -1464,6 +1470,17 @@ static inline struct ubuf_info *skb_zcopy(struct sk_buff *skb)
return is_zcopy ? skb_uarg(skb) : NULL;
}
+static inline bool skb_zcopy_pure(const struct sk_buff *skb)
+{
+ return skb_shinfo(skb)->flags & SKBFL_PURE_ZEROCOPY;
+}
+
+static inline bool skb_pure_zcopy_same(const struct sk_buff *skb1,
+ const struct sk_buff *skb2)
+{
+ return skb_zcopy_pure(skb1) == skb_zcopy_pure(skb2);
+}
+
static inline void net_zcopy_get(struct ubuf_info *uarg)
{
refcount_inc(&uarg->refcnt);
@@ -1528,7 +1545,7 @@ static inline void skb_zcopy_clear(struct sk_buff *skb, bool zerocopy_success)
if (!skb_zcopy_is_nouarg(skb))
uarg->callback(skb, uarg, zerocopy_success);
- skb_shinfo(skb)->flags &= ~SKBFL_ZEROCOPY_FRAG;
+ skb_shinfo(skb)->flags &= ~SKBFL_ALL_ZEROCOPY;
}
}
@@ -1675,6 +1692,22 @@ static inline int skb_unclone(struct sk_buff *skb, gfp_t pri)
return 0;
}
+/* This variant of skb_unclone() makes sure skb->truesize is not changed */
+static inline int skb_unclone_keeptruesize(struct sk_buff *skb, gfp_t pri)
+{
+ might_sleep_if(gfpflags_allow_blocking(pri));
+
+ if (skb_cloned(skb)) {
+ unsigned int save = skb->truesize;
+ int res;
+
+ res = pskb_expand_head(skb, 0, 0, pri);
+ skb->truesize = save;
+ return res;
+ }
+ return 0;
+}
+
/**
* skb_header_cloned - is the header a clone
* @skb: buffer to check