From: Johannes Berg <johannes.berg@xxxxxxxxx>
In the future, when we start notifying drivers,
state transitions could potentially fail. To make
it easier to distinguish between programming bugs
and driver failures:
* rename sta_info_move_state() to
sta_info_pre_move_state() which can only be
called before the station is inserted (and
check this with a new station flag).
* rename sta_info_move_state_checked() to just
plain sta_info_move_state(), as it will be
the regular function that can fail for more
than just one reason (bad transition or an
error from the driver)
This makes the programming model easier -- one of
the functions can only be called before insertion
and can't fail, the other can fail.
Signed-off-by: Johannes Berg <johannes.berg@xxxxxxxxx>
---
v2: fix deadlock in error path (Thanks Eliad!)
v3: break on sta down failure (Thanks again Eliad)
net/mac80211/cfg.c | 22 ++++++++--------------
net/mac80211/debugfs_sta.c | 5 +++--
net/mac80211/ibss.c | 6 +++---
net/mac80211/iface.c | 6 +++---
net/mac80211/mesh_plink.c | 6 +++---
net/mac80211/mlme.c | 17 +++++++++++++----
net/mac80211/sta_info.c | 19 ++++++++++++++-----
net/mac80211/sta_info.h | 17 ++++++++++++-----
8 files changed, 59 insertions(+), 39 deletions(-)
--- a/net/mac80211/debugfs_sta.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/debugfs_sta.c 2012-01-12 09:25:55.000000000 +0100
@@ -63,14 +63,15 @@ static ssize_t sta_flags_read(struct fil
test_sta_flag(sta, WLAN_STA_##flg) ? #flg "\n" : ""
int res = scnprintf(buf, sizeof(buf),
- "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
+ "%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s%s",
TEST(AUTH), TEST(ASSOC), TEST(PS_STA),
TEST(PS_DRIVER), TEST(AUTHORIZED),
TEST(SHORT_PREAMBLE),
TEST(WME), TEST(WDS), TEST(CLEAR_PS_FILT),
TEST(MFP), TEST(BLOCK_BA), TEST(PSPOLL),
TEST(UAPSD), TEST(SP), TEST(TDLS_PEER),
- TEST(TDLS_PEER_AUTH));
+ TEST(TDLS_PEER_AUTH), TEST(4ADDR_EVENT),
+ TEST(INSERTED));
#undef TEST
return simple_read_from_buffer(userbuf, count, ppos, buf, res);
}
--- a/net/mac80211/sta_info.h 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/sta_info.h 2012-01-12 09:25:56.000000000 +0100
@@ -52,6 +52,7 @@
* @WLAN_STA_SP: Station is in a service period, so don't try to
* reply to other uAPSD trigger frames or PS-Poll.
* @WLAN_STA_4ADDR_EVENT: 4-addr event was already sent for this frame.
+ * @WLAN_STA_INSERTED: This station is inserted into the hash table.
*/
enum ieee80211_sta_info_flags {
WLAN_STA_AUTH,
@@ -71,6 +72,7 @@ enum ieee80211_sta_info_flags {
WLAN_STA_UAPSD,
WLAN_STA_SP,
WLAN_STA_4ADDR_EVENT,
+ WLAN_STA_INSERTED,
};
enum ieee80211_sta_state {
@@ -427,13 +429,17 @@ static inline int test_and_set_sta_flag(
return test_and_set_bit(flag, &sta->_flags);
}
-int sta_info_move_state_checked(struct sta_info *sta,
- enum ieee80211_sta_state new_state);
+int sta_info_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state);
-static inline void sta_info_move_state(struct sta_info *sta,
- enum ieee80211_sta_state new_state)
+static inline void sta_info_pre_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state)
{
- int ret = sta_info_move_state_checked(sta, new_state);
+ int ret;
+
+ WARN_ON_ONCE(test_sta_flag(sta, WLAN_STA_INSERTED));
+
+ ret = sta_info_move_state(sta, new_state);
WARN_ON_ONCE(ret);
}
@@ -544,6 +550,7 @@ int sta_info_insert(struct sta_info *sta
int sta_info_insert_rcu(struct sta_info *sta) __acquires(RCU);
int sta_info_reinsert(struct sta_info *sta);
+int __must_check __sta_info_destroy(struct sta_info *sta);
int sta_info_destroy_addr(struct ieee80211_sub_if_data *sdata,
const u8 *addr);
int sta_info_destroy_addr_bss(struct ieee80211_sub_if_data *sdata,
--- a/net/mac80211/sta_info.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/sta_info.c 2012-01-12 09:30:39.000000000 +0100
@@ -405,6 +405,8 @@ static int sta_info_insert_finish(struct
sta_info_hash_add(local, sta);
list_add(&sta->list, &local->sta_list);
+
+ set_sta_flag(sta, WLAN_STA_INSERTED);
} else {
sta->dummy = false;
}
@@ -709,7 +711,7 @@ static bool sta_info_cleanup_expire_buff
return have_buffered;
}
-static int __must_check __sta_info_destroy(struct sta_info *sta)
+int __must_check __sta_info_destroy(struct sta_info *sta)
{
struct ieee80211_local *local;
struct ieee80211_sub_if_data *sdata;
@@ -724,6 +726,8 @@ static int __must_check __sta_info_destr
local = sta->local;
sdata = sta->sdata;
+ lockdep_assert_held(&local->sta_mtx);
+
/*
* Before removing the station from the driver and
* rate control, it might still start new aggregation
@@ -765,8 +769,13 @@ static int __must_check __sta_info_destr
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
RCU_INIT_POINTER(sdata->u.vlan.sta, NULL);
- while (sta->sta_state > IEEE80211_STA_NONE)
- sta_info_move_state(sta, sta->sta_state - 1);
+ while (sta->sta_state > IEEE80211_STA_NONE) {
+ int err = sta_info_move_state(sta, sta->sta_state - 1);
+ if (err) {
+ WARN_ON_ONCE(1);
+ break;
+ }
+ }
if (sta->uploaded) {
if (sdata->vif.type == NL80211_IFTYPE_AP_VLAN)
@@ -1408,8 +1417,8 @@ void ieee80211_sta_set_buffered(struct i
}
EXPORT_SYMBOL(ieee80211_sta_set_buffered);
-int sta_info_move_state_checked(struct sta_info *sta,
- enum ieee80211_sta_state new_state)
+int sta_info_move_state(struct sta_info *sta,
+ enum ieee80211_sta_state new_state)
{
might_sleep();
--- a/net/mac80211/cfg.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/cfg.c 2012-01-12 09:25:55.000000000 +0100
@@ -776,12 +776,10 @@ static int sta_apply_parameters(struct i
if (set & BIT(NL80211_STA_FLAG_AUTHENTICATED) &&
!test_sta_flag(sta, WLAN_STA_AUTH)) {
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTH);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTH);
if (ret)
return ret;
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_ASSOC);
+ ret = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
if (ret)
return ret;
}
@@ -789,11 +787,9 @@ static int sta_apply_parameters(struct i
if (mask & BIT(NL80211_STA_FLAG_AUTHORIZED)) {
if (set & BIT(NL80211_STA_FLAG_AUTHORIZED))
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTHORIZED);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
else
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_ASSOC);
+ ret = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
if (ret)
return ret;
}
@@ -805,12 +801,10 @@ static int sta_apply_parameters(struct i
if (!(set & BIT(NL80211_STA_FLAG_AUTHENTICATED)) &&
test_sta_flag(sta, WLAN_STA_AUTH)) {
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_AUTH);
+ ret = sta_info_move_state(sta, IEEE80211_STA_AUTH);
if (ret)
return ret;
- ret = sta_info_move_state_checked(sta,
- IEEE80211_STA_NONE);
+ ret = sta_info_move_state(sta, IEEE80211_STA_NONE);
if (ret)
return ret;
}
@@ -944,8 +938,8 @@ static int ieee80211_add_station(struct
if (!sta)
return -ENOMEM;
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
err = sta_apply_parameters(local, sta, params);
if (err) {
--- a/net/mac80211/ibss.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/ibss.c 2012-01-12 09:25:55.000000000 +0100
@@ -289,9 +289,9 @@ static struct sta_info *ieee80211_ibss_f
addr, sdata->name);
#endif
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
rate_control_rate_init(sta);
--- a/net/mac80211/iface.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/iface.c 2012-01-12 09:25:55.000000000 +0100
@@ -318,9 +318,9 @@ static int ieee80211_do_open(struct net_
goto err_del_interface;
}
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
res = sta_info_insert(sta);
if (res) {
--- a/net/mac80211/mesh_plink.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/mesh_plink.c 2012-01-12 09:17:53.000000000 +0100
@@ -96,9 +96,9 @@ static struct sta_info *mesh_plink_alloc
if (!sta)
return NULL;
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTH);
+ sta_info_pre_move_state(sta, IEEE80211_STA_ASSOC);
+ sta_info_pre_move_state(sta, IEEE80211_STA_AUTHORIZED);
set_sta_flag(sta, WLAN_STA_WME);
--- a/net/mac80211/mlme.c 2012-01-12 09:17:52.000000000 +0100
+++ b/net/mac80211/mlme.c 2012-01-12 09:25:56.000000000 +0100
@@ -1587,10 +1587,19 @@ static bool ieee80211_assoc_success(stru
return false;
}
- sta_info_move_state(sta, IEEE80211_STA_AUTH);
- sta_info_move_state(sta, IEEE80211_STA_ASSOC);
- if (!(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
- sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ err = sta_info_move_state(sta, IEEE80211_STA_AUTH);
+ if (!err)
+ err = sta_info_move_state(sta, IEEE80211_STA_ASSOC);
+ if (!err && !(ifmgd->flags & IEEE80211_STA_CONTROL_PORT))
+ err = sta_info_move_state(sta, IEEE80211_STA_AUTHORIZED);
+ if (err) {
+ printk(KERN_DEBUG
+ "%s: failed to move station %pM to desired state\n",
+ sdata->name, sta->sta.addr);
+ WARN_ON(__sta_info_destroy(sta));
+ mutex_unlock(&sdata->local->sta_mtx);
+ return false;
+ }
rates = 0;
basic_rates = 0;
--
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