From: Benjamin Berg <benjamin.berg@xxxxxxxxx>
It is reasonable to hold bss_lock for a little bit longer after
cfg80211_bss_update is done. Right now, this does not make any big
difference, but doing so in preparation for the next patch which adds
a call to the driver.
Signed-off-by: Benjamin Berg <benjamin.berg@xxxxxxxxx>
Signed-off-by: Gregory Greenman <gregory.greenman@xxxxxxxxx>
---
net/wireless/scan.c | 66 ++++++++++++++++++++++++++++-----------------
1 file changed, 42 insertions(+), 24 deletions(-)
diff --git a/net/wireless/scan.c b/net/wireless/scan.c
index 19e7014f8bc3..8984f74da891 100644
--- a/net/wireless/scan.c
+++ b/net/wireless/scan.c
@@ -1701,10 +1701,10 @@ cfg80211_update_known_bss(struct cfg80211_registered_device *rdev,
}
/* Returned bss is reference counted and must be cleaned up appropriately. */
-struct cfg80211_internal_bss *
-cfg80211_bss_update(struct cfg80211_registered_device *rdev,
- struct cfg80211_internal_bss *tmp,
- bool signal_valid, unsigned long ts)
+static struct cfg80211_internal_bss *
+__cfg80211_bss_update(struct cfg80211_registered_device *rdev,
+ struct cfg80211_internal_bss *tmp,
+ bool signal_valid, unsigned long ts)
{
struct cfg80211_internal_bss *found = NULL;
@@ -1713,10 +1713,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
tmp->ts = ts;
- spin_lock_bh(&rdev->bss_lock);
-
if (WARN_ON(!rcu_access_pointer(tmp->pub.ies))) {
- spin_unlock_bh(&rdev->bss_lock);
return NULL;
}
@@ -1724,7 +1721,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
if (found) {
if (!cfg80211_update_known_bss(rdev, found, tmp, signal_valid))
- goto drop;
+ return NULL;
} else {
struct cfg80211_internal_bss *new;
struct cfg80211_internal_bss *hidden;
@@ -1744,7 +1741,7 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
ies = (void *)rcu_dereference(tmp->pub.proberesp_ies);
if (ies)
kfree_rcu(ies, rcu_head);
- goto drop;
+ return NULL;
}
memcpy(new, tmp, sizeof(*new));
new->refcount = 1;
@@ -1775,14 +1772,14 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
*/
if (!cfg80211_combine_bsses(rdev, new)) {
bss_ref_put(rdev, new);
- goto drop;
+ return NULL;
}
}
if (rdev->bss_entries >= bss_entries_limit &&
!cfg80211_bss_expire_oldest(rdev)) {
bss_ref_put(rdev, new);
- goto drop;
+ return NULL;
}
/* This must be before the call to bss_ref_get */
@@ -1799,12 +1796,22 @@ cfg80211_bss_update(struct cfg80211_registered_device *rdev,
rdev->bss_generation++;
bss_ref_get(rdev, found);
- spin_unlock_bh(&rdev->bss_lock);
return found;
- drop:
+}
+
+struct cfg80211_internal_bss *
+cfg80211_bss_update(struct cfg80211_registered_device *rdev,
+ struct cfg80211_internal_bss *tmp,
+ bool signal_valid, unsigned long ts)
+{
+ struct cfg80211_internal_bss *res;
+
+ spin_lock_bh(&rdev->bss_lock);
+ res = __cfg80211_bss_update(rdev, tmp, signal_valid, ts);
spin_unlock_bh(&rdev->bss_lock);
- return NULL;
+
+ return res;
}
int cfg80211_get_ies_channel_number(const u8 *ie, size_t ielen,
@@ -2015,15 +2022,15 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
rcu_assign_pointer(tmp.pub.ies, ies);
signal_valid = data->chan == channel;
- res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid, ts);
+ spin_lock_bh(&rdev->bss_lock);
+ res = __cfg80211_bss_update(rdev, &tmp, signal_valid, ts);
if (!res)
- return NULL;
+ goto drop;
if (non_tx_data) {
/* this is a nontransmitting bss, we need to add it to
* transmitting bss' list if it is not there
*/
- spin_lock_bh(&rdev->bss_lock);
if (cfg80211_add_nontrans_list(non_tx_data->tx_bss,
&res->pub)) {
if (__cfg80211_unlink_bss(rdev, res)) {
@@ -2031,15 +2038,19 @@ cfg80211_inform_single_bss_data(struct wiphy *wiphy,
res = NULL;
}
}
- spin_unlock_bh(&rdev->bss_lock);
if (!res)
- return NULL;
+ goto drop;
}
+ spin_unlock_bh(&rdev->bss_lock);
trace_cfg80211_return_bss(&res->pub);
- /* cfg80211_bss_update gives us a referenced result */
+ /* __cfg80211_bss_update gives us a referenced result */
return &res->pub;
+
+drop:
+ spin_unlock_bh(&rdev->bss_lock);
+ return NULL;
}
static const struct element
@@ -2376,6 +2387,7 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy,
struct ieee80211_mgmt *mgmt, size_t len,
gfp_t gfp)
{
+ struct cfg80211_registered_device *rdev = wiphy_to_rdev(wiphy);
struct cfg80211_internal_bss tmp = {}, *res;
struct cfg80211_bss_ies *ies;
struct ieee80211_channel *channel;
@@ -2485,14 +2497,20 @@ cfg80211_inform_single_bss_frame_data(struct wiphy *wiphy,
ether_addr_copy(tmp.parent_bssid, data->parent_bssid);
signal_valid = data->chan == channel;
- res = cfg80211_bss_update(wiphy_to_rdev(wiphy), &tmp, signal_valid,
- jiffies);
+ spin_lock_bh(&rdev->bss_lock);
+ res = __cfg80211_bss_update(rdev, &tmp, signal_valid, jiffies);
if (!res)
- return NULL;
+ goto drop;
+
+ spin_unlock_bh(&rdev->bss_lock);
trace_cfg80211_return_bss(&res->pub);
- /* cfg80211_bss_update gives us a referenced result */
+ /* __cfg80211_bss_update gives us a referenced result */
return &res->pub;
+
+drop:
+ spin_unlock_bh(&rdev->bss_lock);
+ return NULL;
}
struct cfg80211_bss *
--
2.38.1
