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xen/netback: don't leak pages on failure in xen_netbk_tx_check_gop.

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Signed-off-by: Matthew Daley <mattjd@gmail.com>
Reviewed-by: Konrad Rzeszutek Wilk <konrad.wilk@oracle.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
Acked-by: Jan Beulich <JBeulich@suse.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
This commit is contained in:
Matthew Daley 2013-02-06 23:41:36 +00:00 committed by David S. Miller
parent 48856286b6
commit 7d5145d8eb
1 changed files with 13 additions and 25 deletions
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38
drivers/net/xen-netback/netback.c
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@ -147,7 +147,8 @@ void xen_netbk_remove_xenvif(struct xenvif *vif)
atomic_dec(&netbk->netfront_count);
}
static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx);
static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx,
u8 status);
static void make_tx_response(struct xenvif *vif,
struct xen_netif_tx_request *txp,
s8 st);
@ -1007,30 +1008,20 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
{
struct gnttab_copy *gop = *gopp;
u16 pending_idx = *((u16 *)skb->data);
struct pending_tx_info *pending_tx_info = netbk->pending_tx_info;
struct xenvif *vif = pending_tx_info[pending_idx].vif;
struct xen_netif_tx_request *txp;
struct skb_shared_info *shinfo = skb_shinfo(skb);
int nr_frags = shinfo->nr_frags;
int i, err, start;
/* Check status of header. */
err = gop->status;
if (unlikely(err)) {
pending_ring_idx_t index;
index = pending_index(netbk->pending_prod++);
txp = &pending_tx_info[pending_idx].req;
make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
netbk->pending_ring[index] = pending_idx;
xenvif_put(vif);
}
if (unlikely(err))
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
/* Skip first skb fragment if it is on same page as header fragment. */
start = (frag_get_pending_idx(&shinfo->frags[0]) == pending_idx);
for (i = start; i < nr_frags; i++) {
int j, newerr;
pending_ring_idx_t index;
pending_idx = frag_get_pending_idx(&shinfo->frags[i]);
@ -1039,16 +1030,12 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
if (likely(!newerr)) {
/* Had a previous error? Invalidate this fragment. */
if (unlikely(err))
xen_netbk_idx_release(netbk, pending_idx);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
continue;
}
/* Error on this fragment: respond to client with an error. */
txp = &netbk->pending_tx_info[pending_idx].req;
make_tx_response(vif, txp, XEN_NETIF_RSP_ERROR);
index = pending_index(netbk->pending_prod++);
netbk->pending_ring[index] = pending_idx;
xenvif_put(vif);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_ERROR);
/* Not the first error? Preceding frags already invalidated. */
if (err)
@ -1056,10 +1043,10 @@ static int xen_netbk_tx_check_gop(struct xen_netbk *netbk,
/* First error: invalidate header and preceding fragments. */
pending_idx = *((u16 *)skb->data);
xen_netbk_idx_release(netbk, pending_idx);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
for (j = start; j < i; j++) {
pending_idx = frag_get_pending_idx(&shinfo->frags[j]);
xen_netbk_idx_release(netbk, pending_idx);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
}
/* Remember the error: invalidate all subsequent fragments. */
@ -1093,7 +1080,7 @@ static void xen_netbk_fill_frags(struct xen_netbk *netbk, struct sk_buff *skb)
/* Take an extra reference to offset xen_netbk_idx_release */
get_page(netbk->mmap_pages[pending_idx]);
xen_netbk_idx_release(netbk, pending_idx);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
}
}
@ -1476,7 +1463,7 @@ static void xen_netbk_tx_submit(struct xen_netbk *netbk)
txp->size -= data_len;
} else {
/* Schedule a response immediately. */
xen_netbk_idx_release(netbk, pending_idx);
xen_netbk_idx_release(netbk, pending_idx, XEN_NETIF_RSP_OKAY);
}
if (txp->flags & XEN_NETTXF_csum_blank)
@ -1528,7 +1515,8 @@ static void xen_netbk_tx_action(struct xen_netbk *netbk)
xen_netbk_tx_submit(netbk);
}
static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx)
static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx,
u8 status)
{
struct xenvif *vif;
struct pending_tx_info *pending_tx_info;
@ -1542,7 +1530,7 @@ static void xen_netbk_idx_release(struct xen_netbk *netbk, u16 pending_idx)
vif = pending_tx_info->vif;
make_tx_response(vif, &pending_tx_info->req, XEN_NETIF_RSP_OKAY);
make_tx_response(vif, &pending_tx_info->req, status);
index = pending_index(netbk->pending_prod++);
netbk->pending_ring[index] = pending_idx;