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path: root/drivers/net/xen-netback/netback.c
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Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r--drivers/net/xen-netback/netback.c86
1 files changed, 63 insertions, 23 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c
index 1844a47..c65b636 100644
--- a/drivers/net/xen-netback/netback.c
+++ b/drivers/net/xen-netback/netback.c
@@ -1030,14 +1030,21 @@ static int xenvif_tx_check_gop(struct xenvif_queue *queue,
{
struct gnttab_map_grant_ref *gop_map = *gopp_map;
u16 pending_idx = XENVIF_TX_CB(skb)->pending_idx;
+ /* This always points to the shinfo of the skb being checked, which
+ * could be either the first or the one on the frag_list
+ */
struct skb_shared_info *shinfo = skb_shinfo(skb);
+ /* If this is non-NULL, we are currently checking the frag_list skb, and
+ * this points to the shinfo of the first one
+ */
+ struct skb_shared_info *first_shinfo = NULL;
int nr_frags = shinfo->nr_frags;
+ const bool sharedslot = nr_frags &&
+ frag_get_pending_idx(&shinfo->frags[0]) == pending_idx;
int i, err;
- struct sk_buff *first_skb = NULL;
/* Check status of header. */
err = (*gopp_copy)->status;
- (*gopp_copy)++;
if (unlikely(err)) {
if (net_ratelimit())
netdev_dbg(queue->vif->dev,
@@ -1045,8 +1052,12 @@ static int xenvif_tx_check_gop(struct xenvif_queue *queue,
(*gopp_copy)->status,
pending_idx,
(*gopp_copy)->source.u.ref);
- xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
+ /* The first frag might still have this slot mapped */
+ if (!sharedslot)
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_ERROR);
}
+ (*gopp_copy)++;
check_frags:
for (i = 0; i < nr_frags; i++, gop_map++) {
@@ -1062,8 +1073,19 @@ check_frags:
pending_idx,
gop_map->handle);
/* Had a previous error? Invalidate this fragment. */
- if (unlikely(err))
+ if (unlikely(err)) {
xenvif_idx_unmap(queue, pending_idx);
+ /* If the mapping of the first frag was OK, but
+ * the header's copy failed, and they are
+ * sharing a slot, send an error
+ */
+ if (i == 0 && sharedslot)
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_ERROR);
+ else
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
continue;
}
@@ -1075,42 +1097,53 @@ check_frags:
gop_map->status,
pending_idx,
gop_map->ref);
+
xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_ERROR);
/* Not the first error? Preceding frags already invalidated. */
if (err)
continue;
- /* First error: invalidate preceding fragments. */
+
+ /* First error: if the header haven't shared a slot with the
+ * first frag, release it as well.
+ */
+ if (!sharedslot)
+ xenvif_idx_release(queue,
+ XENVIF_TX_CB(skb)->pending_idx,
+ XEN_NETIF_RSP_OKAY);
+
+ /* Invalidate preceding fragments of this skb. */
for (j = 0; j < i; j++) {
pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
xenvif_idx_unmap(queue, pending_idx);
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
+
+ /* And if we found the error while checking the frag_list, unmap
+ * the first skb's frags
+ */
+ if (first_shinfo) {
+ for (j = 0; j < first_shinfo->nr_frags; j++) {
+ pending_idx = frag_get_pending_idx(&first_shinfo->frags[j]);
+ xenvif_idx_unmap(queue, pending_idx);
+ xenvif_idx_release(queue, pending_idx,
+ XEN_NETIF_RSP_OKAY);
+ }
}
/* Remember the error: invalidate all subsequent fragments. */
err = newerr;
}
- if (skb_has_frag_list(skb)) {
- first_skb = skb;
- skb = shinfo->frag_list;
- shinfo = skb_shinfo(skb);
+ if (skb_has_frag_list(skb) && !first_shinfo) {
+ first_shinfo = skb_shinfo(skb);
+ shinfo = skb_shinfo(skb_shinfo(skb)->frag_list);
nr_frags = shinfo->nr_frags;
goto check_frags;
}
- /* There was a mapping error in the frag_list skb. We have to unmap
- * the first skb's frags
- */
- if (first_skb && err) {
- int j;
- shinfo = skb_shinfo(first_skb);
- for (j = 0; j < shinfo->nr_frags; j++) {
- pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
- xenvif_idx_unmap(queue, pending_idx);
- }
- }
-
*gopp_map = gop_map;
return err;
}
@@ -1518,7 +1551,16 @@ static int xenvif_tx_submit(struct xenvif_queue *queue)
/* Check the remap error code. */
if (unlikely(xenvif_tx_check_gop(queue, skb, &gop_map, &gop_copy))) {
+ /* If there was an error, xenvif_tx_check_gop is
+ * expected to release all the frags which were mapped,
+ * so kfree_skb shouldn't do it again
+ */
skb_shinfo(skb)->nr_frags = 0;
+ if (skb_has_frag_list(skb)) {
+ struct sk_buff *nskb =
+ skb_shinfo(skb)->frag_list;
+ skb_shinfo(nskb)->nr_frags = 0;
+ }
kfree_skb(skb);
continue;
}
@@ -1822,8 +1864,6 @@ void xenvif_idx_unmap(struct xenvif_queue *queue, u16 pending_idx)
tx_unmap_op.status);
BUG();
}
-
- xenvif_idx_release(queue, pending_idx, XEN_NETIF_RSP_OKAY);
}
static inline int rx_work_todo(struct xenvif_queue *queue)
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