Fixes yet another deadlock on calling sta_info_flush()
with the sdata_lock() held. Should make it easier to
reason about locking in the future, since the sdata_lock()
is now held on all mesh work.
Signed-off-by: Thomas Pedersen <thomas@xxxxxxxxxxx>
---
v2:
read all changed bits & drop macro (Johannes)
net/mac80211/ieee80211_i.h | 1 +
net/mac80211/mesh.c | 44 ++++++++++++++++++++++++++++++++------------
net/mac80211/mesh.h | 2 ++
3 files changed, 35 insertions(+), 12 deletions(-)
diff --git a/net/mac80211/ieee80211_i.h b/net/mac80211/ieee80211_i.h
index 7a6f1a0..f79156d 100644
--- a/net/mac80211/ieee80211_i.h
+++ b/net/mac80211/ieee80211_i.h
@@ -543,6 +543,7 @@ 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;
diff --git a/net/mac80211/mesh.c b/net/mac80211/mesh.c
index d5faf91..2499679 100644
--- a/net/mac80211/mesh.c
+++ b/net/mac80211/mesh.c
@@ -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 +716,15 @@ 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))
- return;
- ieee80211_bss_info_change_notify(sdata, changed);
+ struct ieee80211_if_mesh *ifmsh = &sdata->u.mesh;
+ u32 bit;
+
+ /* if we race with running work, worst case this work becomes a noop */
+ for_each_set_bit(bit, (unsigned long *)&changed,
+ sizeof(changed) * BITS_PER_BYTE)
+ set_bit(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)
@@ -969,6 +967,26 @@ 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, (unsigned long *)&ifmsh->mbss_changed,
+ sizeof(changed) * BITS_PER_BYTE)
+ changed |= test_and_clear_bit(BIT(bit), &ifmsh->mbss_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))
+ 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;
@@ -999,6 +1017,8 @@ 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);
}
diff --git a/net/mac80211/mesh.h b/net/mac80211/mesh.h
index 8b4d9a3..be28f9b 100644
--- a/net/mac80211/mesh.h
+++ b/net/mac80211/mesh.h
@@ -57,6 +57,7 @@ enum mesh_path_flags {
* grow
* @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_WORK_MBSS_CHANGED: rebuild beacon and notify driver of BSS changes
* mesh nodes
*/
enum mesh_deferred_task_flags {
@@ -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,
};
/**
--
1.7.10.4
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