| Message ID | 1314896685-2932-2-git-send-email-javier@cozybit.com (mailing list archive) |
|---|---|
| State | Not Applicable, archived |
| Headers | show |
On Thu, 2011-09-01 at 10:04 -0700, Javier Cardona wrote: > Under failure conditions, the mesh stack sends PERR messages to the > previous sender of the failed frame. This happens in the tx feedback > path, in which the transmission queue lock may be taken. Avoid a > deadlock by sending the path error via the pending queue. > > Signed-off-by: Javier Cardona <javier@cozybit.com> > Reviewed-by: Johannes Berg <johannes@sipsolutions.net> > --- > v2: - Helper to prepare skb for deferred transmission (Johannes) > - Reword comment (Johannes) > > net/mac80211/mesh_hwmp.c | 30 ++++++++++++++++++++++++++++-- > 1 files changed, 28 insertions(+), 2 deletions(-) > > diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c > index fd4f76a..cda4818 100644 > --- a/net/mac80211/mesh_hwmp.c > +++ b/net/mac80211/mesh_hwmp.c > @@ -8,6 +8,7 @@ > */ > > #include <linux/slab.h> > +#include "wme.h" > #include "mesh.h" > > #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG > @@ -202,6 +203,25 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, > return 0; > } > > + > +static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, > + struct sk_buff *skb) > +{ > + struct ieee80211_local *local = sdata->local; > + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); > + > + skb_set_mac_header(skb, 0); > + skb_set_network_header(skb, 0); > + skb_set_transport_header(skb, 0); > + > + /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ > + skb_set_queue_mapping(skb, IEEE80211_AC_VO); > + skb->priority = 7; > + > + info->control.vif = &sdata->vif; > + ieee80211_set_qos_hdr(local, skb); > +} Maybe add a note that if the frame might be encrypted enough headroom needs to be there? johannes -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
diff --git a/net/mac80211/mesh_hwmp.c b/net/mac80211/mesh_hwmp.c index fd4f76a..cda4818 100644 --- a/net/mac80211/mesh_hwmp.c +++ b/net/mac80211/mesh_hwmp.c @@ -8,6 +8,7 @@ */ #include <linux/slab.h> +#include "wme.h" #include "mesh.h" #ifdef CONFIG_MAC80211_VERBOSE_MHWMP_DEBUG @@ -202,6 +203,25 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, return 0; } + +static void prepare_frame_for_deferred_tx(struct ieee80211_sub_if_data *sdata, + struct sk_buff *skb) +{ + struct ieee80211_local *local = sdata->local; + struct ieee80211_tx_info *info = IEEE80211_SKB_CB(skb); + + skb_set_mac_header(skb, 0); + skb_set_network_header(skb, 0); + skb_set_transport_header(skb, 0); + + /* Send all internal mgmt frames on VO. Accordingly set TID to 7. */ + skb_set_queue_mapping(skb, IEEE80211_AC_VO); + skb->priority = 7; + + info->control.vif = &sdata->vif; + ieee80211_set_qos_hdr(local, skb); +} + /** * mesh_send_path error - Sends a PERR mesh management frame * @@ -209,6 +229,10 @@ static int mesh_path_sel_frame_tx(enum mpath_frame_type action, u8 flags, * @target_sn: SN of the broken destination * @target_rcode: reason code for this PERR * @ra: node this frame is addressed to + * + * Note: This function may be called with driver locks taken that the driver + * also acquires in the TX path. To avoid a deadlock we don't transmit the + * frame directly but add it to the pending queue instead. */ int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, __le16 target_rcode, const u8 *ra, @@ -222,7 +246,7 @@ int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, if (!skb) return -1; - skb_reserve(skb, local->hw.extra_tx_headroom); + skb_reserve(skb, local->tx_headroom + local->hw.extra_tx_headroom); /* 25 is the size of the common mgmt part (24) plus the size of the * common action part (1) */ @@ -263,7 +287,9 @@ int mesh_path_error_tx(u8 ttl, u8 *target, __le32 target_sn, pos += 4; memcpy(pos, &target_rcode, 2); - ieee80211_tx_skb(sdata, skb); + /* see note in function header */ + prepare_frame_for_deferred_tx(sdata, skb); + ieee80211_add_pending_skb(local, skb); return 0; }