diff options
author | Zoltan Kiss <zoltan.kiss@citrix.com> | 2014-07-18 19:08:02 +0100 |
---|---|---|
committer | David S. Miller <davem@davemloft.net> | 2014-07-20 20:56:05 -0700 |
commit | 1a998d3e6bc1e44f4c0bc7509bdedef8ed3845ec (patch) | |
tree | 343f6de6312d5fa186b808a800bff404a2047367 /drivers/net/xen-netback/netback.c | |
parent | 7801db8aec957fa6610efe0ee26a6c8bc0f1d73b (diff) |
xen-netback: Fix handling frag_list on grant op error path
The error handling for skb's with frag_list was completely wrong, it caused
double unmap attempts to happen if the error was on the first skb. Move it to
the right place in the loop.
Signed-off-by: Zoltan Kiss <zoltan.kiss@citrix.com>
Reported-by: Armin Zentai <armin.zentai@ezit.hu>
Cc: netdev@vger.kernel.org
Cc: linux-kernel@vger.kernel.org
Cc: xen-devel@lists.xenproject.org
Signed-off-by: David S. Miller <davem@davemloft.net>
Diffstat (limited to 'drivers/net/xen-netback/netback.c')
-rw-r--r-- | drivers/net/xen-netback/netback.c | 37 |
1 files changed, 20 insertions, 17 deletions
diff --git a/drivers/net/xen-netback/netback.c b/drivers/net/xen-netback/netback.c index 1844a47636b6..a773f2016bad 100644 --- a/drivers/net/xen-netback/netback.c +++ b/drivers/net/xen-netback/netback.c @@ -1030,10 +1030,16 @@ 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; int i, err; - struct sk_buff *first_skb = NULL; /* Check status of header. */ err = (*gopp_copy)->status; @@ -1086,31 +1092,28 @@ check_frags: xenvif_idx_unmap(queue, pending_idx); } + /* 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); + } + } + /* 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; } |