Commit f81a9ded authored by Thomas Pedersen's avatar Thomas Pedersen Committed by Johannes Berg
Browse files

mac80211: update mesh beacon on workqueue 



Instead of updating the mesh beacon immediately when
requested (which would require the sdata_lock()), defer it
to the mac80211 workqueue.

Fixes yet another deadlock on calling sta_info_flush()
with the sdata_lock() held from ieee80211_stop_mesh(). We
could just drop the sdata_lock() around the
mesh_sta_cleanup() call, but this path is also taken from
several non-locked error paths.

Signed-off-by: default avatarThomas Pedersen <thomas@cozybit.com>
[fix comment position]
Signed-off-by: default avatarJohannes Berg <johannes.berg@intel.com>
parent a1193be8

net/mac80211/ieee80211_i.h

+1 −0
Original line number Diff line number Diff line
@@ -544,6 +544,7 @@ struct ieee80211_if_mesh { 
	struct timer_list mesh_path_root_timer;



	unsigned long wrkq_flags;

	unsigned long mbss_changed;



	u8 mesh_id[IEEE80211_MAX_MESH_ID_LEN];

	size_t mesh_id_len;

net/mac80211/mesh.c

+41 −12
Original line number Diff line number Diff line
@@ -161,11 +161,8 @@ void mesh_sta_cleanup(struct sta_info *sta) 
		del_timer_sync(&sta->plink_timer);

	}



	if (changed) {

		sdata_lock(sdata);

	if (changed)

		ieee80211_mbss_info_change_notify(sdata, changed);

		sdata_unlock(sdata);

	}

}



int mesh_rmc_init(struct ieee80211_sub_if_data *sdata)
@@ -719,14 +716,18 @@ ieee80211_mesh_rebuild_beacon(struct ieee80211_sub_if_data *sdata) 
void ieee80211_mbss_info_change_notify(struct ieee80211_sub_if_data *sdata,

				       u32 changed)

{

	if (sdata->vif.bss_conf.enable_beacon &&

	    (changed & (BSS_CHANGED_BEACON |

			BSS_CHANGED_HT |

			BSS_CHANGED_BASIC_RATES |

			BSS_CHANGED_BEACON_INT)))

		if (ieee80211_mesh_rebuild_beacon(sdata))

	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	unsigned long bits = changed;

	u32 bit;



	if (!bits)

		return;

	ieee80211_bss_info_change_notify(sdata, changed);



	/* if we race with running work, worst case this work becomes a noop */

	for_each_set_bit(bit, &bits, sizeof(changed) * BITS_PER_BYTE)

		set_bit(bit, &ifmsh->mbss_changed);

	set_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags);

	ieee80211_queue_work(&sdata->local->hw, &sdata->work);

}



int ieee80211_start_mesh(struct ieee80211_sub_if_data *sdata)
@@ -799,6 +800,10 @@ void ieee80211_stop_mesh(struct ieee80211_sub_if_data *sdata) 
	del_timer_sync(&sdata->u.mesh.mesh_path_root_timer);

	del_timer_sync(&sdata->u.mesh.mesh_path_timer);



	/* clear any mesh work (for next join) we may have accrued */

	ifmsh->wrkq_flags = 0;

	ifmsh->mbss_changed = 0;



	local->fif_other_bss--;

	atomic_dec(&local->iff_allmultis);

	ieee80211_configure_filter(local);
@@ -965,6 +970,28 @@ out: 
	sdata_unlock(sdata);

}



static void mesh_bss_info_changed(struct ieee80211_sub_if_data *sdata)

{

	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;

	u32 bit, changed = 0;



	for_each_set_bit(bit, &ifmsh->mbss_changed,

			 sizeof(changed) * BITS_PER_BYTE) {

		clear_bit(bit, &ifmsh->mbss_changed);

		changed |= BIT(bit);

	}



	if (sdata->vif.bss_conf.enable_beacon &&

	    (changed & (BSS_CHANGED_BEACON |

			BSS_CHANGED_HT |

			BSS_CHANGED_BASIC_RATES |

			BSS_CHANGED_BEACON_INT)))

		if (ieee80211_mesh_rebuild_beacon(sdata))

			return;



	ieee80211_bss_info_change_notify(sdata, changed);

}



void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata)

{

	struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
@@ -995,6 +1022,8 @@ void ieee80211_mesh_work(struct ieee80211_sub_if_data *sdata) 
	if (test_and_clear_bit(MESH_WORK_DRIFT_ADJUST, &ifmsh->wrkq_flags))

		mesh_sync_adjust_tbtt(sdata);



	if (test_and_clear_bit(MESH_WORK_MBSS_CHANGED, &ifmsh->wrkq_flags))

		mesh_bss_info_changed(sdata);

out:

	sdata_unlock(sdata);

}

net/mac80211/mesh.h

+2 −0
Original line number Diff line number Diff line
@@ -58,6 +58,7 @@ enum mesh_path_flags { 
 * @MESH_WORK_ROOT: the mesh root station needs to send a frame

 * @MESH_WORK_DRIFT_ADJUST: time to compensate for clock drift relative to other

 * mesh nodes

 * @MESH_WORK_MBSS_CHANGED: rebuild beacon and notify driver of BSS changes

 */

enum mesh_deferred_task_flags {

	MESH_WORK_HOUSEKEEPING,
@@ -65,6 +66,7 @@ enum mesh_deferred_task_flags { 
	MESH_WORK_GROW_MPP_TABLE,

	MESH_WORK_ROOT,

	MESH_WORK_DRIFT_ADJUST,

	MESH_WORK_MBSS_CHANGED,

};



/**

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