From 9f419f3851041e0c8170629f0639813dbfc79d5e Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 8 May 2013 21:34:22 +0200 Subject: cfg80211: move cfg80211_get_dev_from_ifindex under wext The function is only used and needed by the wext code for scanning, so move it there. Signed-off-by: Johannes Berg --- net/wireless/scan.c | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index fd99ea495b7e..2ce44a712f13 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -1040,6 +1040,27 @@ void cfg80211_unlink_bss(struct wiphy *wiphy, struct cfg80211_bss *pub) EXPORT_SYMBOL(cfg80211_unlink_bss); #ifdef CONFIG_CFG80211_WEXT +static struct cfg80211_registered_device * +cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) +{ + struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV); + struct net_device *dev; + + mutex_lock(&cfg80211_mutex); + dev = dev_get_by_index(net, ifindex); + if (!dev) + goto out; + if (dev->ieee80211_ptr) { + rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); + mutex_lock(&rdev->mtx); + } else + rdev = ERR_PTR(-ENODEV); + dev_put(dev); + out: + mutex_unlock(&cfg80211_mutex); + return rdev; +} + int cfg80211_wext_siwscan(struct net_device *dev, struct iw_request_info *info, union iwreq_data *wrqu, char *extra) -- cgit v1.2.3 From 5fe231e873729fa2f57cdc417d5c1f80871e2d7d Mon Sep 17 00:00:00 2001 From: Johannes Berg Date: Wed, 8 May 2013 21:45:15 +0200 Subject: cfg80211: vastly simplify locking Virtually all code paths in cfg80211 already (need to) hold the RTNL. As such, there's little point in having another four mutexes for various parts of the code, they just cause lock ordering issues (and much of the time, the RTNL and a few of the others need thus be held.) Simplify all this by getting rid of the extra four mutexes and just use the RTNL throughout. Only a few code changes were needed to do this and we can get rid of a work struct for bonus points. Signed-off-by: Johannes Berg --- net/wireless/scan.c | 42 +++++++++++++++++------------------------- 1 file changed, 17 insertions(+), 25 deletions(-) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index 2ce44a712f13..dd01b58fa78c 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -169,7 +169,7 @@ void ___cfg80211_scan_done(struct cfg80211_registered_device *rdev, bool leak) union iwreq_data wrqu; #endif - lockdep_assert_held(&rdev->sched_scan_mtx); + ASSERT_RTNL(); request = rdev->scan_req; @@ -230,9 +230,9 @@ void __cfg80211_scan_done(struct work_struct *wk) rdev = container_of(wk, struct cfg80211_registered_device, scan_done_wk); - mutex_lock(&rdev->sched_scan_mtx); + rtnl_lock(); ___cfg80211_scan_done(rdev, false); - mutex_unlock(&rdev->sched_scan_mtx); + rtnl_unlock(); } void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted) @@ -241,6 +241,7 @@ void cfg80211_scan_done(struct cfg80211_scan_request *request, bool aborted) WARN_ON(request != wiphy_to_dev(request->wiphy)->scan_req); request->aborted = aborted; + request->notified = true; queue_work(cfg80211_wq, &wiphy_to_dev(request->wiphy)->scan_done_wk); } EXPORT_SYMBOL(cfg80211_scan_done); @@ -255,7 +256,7 @@ void __cfg80211_sched_scan_results(struct work_struct *wk) request = rdev->sched_scan_req; - mutex_lock(&rdev->sched_scan_mtx); + rtnl_lock(); /* we don't have sched_scan_req anymore if the scan is stopping */ if (request) { @@ -270,7 +271,7 @@ void __cfg80211_sched_scan_results(struct work_struct *wk) nl80211_send_sched_scan_results(rdev, request->dev); } - mutex_unlock(&rdev->sched_scan_mtx); + rtnl_unlock(); } void cfg80211_sched_scan_results(struct wiphy *wiphy) @@ -289,9 +290,9 @@ void cfg80211_sched_scan_stopped(struct wiphy *wiphy) trace_cfg80211_sched_scan_stopped(wiphy); - mutex_lock(&rdev->sched_scan_mtx); + rtnl_lock(); __cfg80211_stop_sched_scan(rdev, true); - mutex_unlock(&rdev->sched_scan_mtx); + rtnl_unlock(); } EXPORT_SYMBOL(cfg80211_sched_scan_stopped); @@ -300,7 +301,7 @@ int __cfg80211_stop_sched_scan(struct cfg80211_registered_device *rdev, { struct net_device *dev; - lockdep_assert_held(&rdev->sched_scan_mtx); + ASSERT_RTNL(); if (!rdev->sched_scan_req) return -ENOENT; @@ -1043,21 +1044,19 @@ EXPORT_SYMBOL(cfg80211_unlink_bss); static struct cfg80211_registered_device * cfg80211_get_dev_from_ifindex(struct net *net, int ifindex) { - struct cfg80211_registered_device *rdev = ERR_PTR(-ENODEV); + struct cfg80211_registered_device *rdev; struct net_device *dev; - mutex_lock(&cfg80211_mutex); + ASSERT_RTNL(); + dev = dev_get_by_index(net, ifindex); if (!dev) - goto out; - if (dev->ieee80211_ptr) { + return ERR_PTR(-ENODEV); + if (dev->ieee80211_ptr) rdev = wiphy_to_dev(dev->ieee80211_ptr->wiphy); - mutex_lock(&rdev->mtx); - } else + else rdev = ERR_PTR(-ENODEV); dev_put(dev); - out: - mutex_unlock(&cfg80211_mutex); return rdev; } @@ -1083,7 +1082,6 @@ int cfg80211_wext_siwscan(struct net_device *dev, if (IS_ERR(rdev)) return PTR_ERR(rdev); - mutex_lock(&rdev->sched_scan_mtx); if (rdev->scan_req) { err = -EBUSY; goto out; @@ -1190,9 +1188,7 @@ int cfg80211_wext_siwscan(struct net_device *dev, dev_hold(dev); } out: - mutex_unlock(&rdev->sched_scan_mtx); kfree(creq); - cfg80211_unlock_rdev(rdev); return err; } EXPORT_SYMBOL_GPL(cfg80211_wext_siwscan); @@ -1491,10 +1487,8 @@ int cfg80211_wext_giwscan(struct net_device *dev, if (IS_ERR(rdev)) return PTR_ERR(rdev); - if (rdev->scan_req) { - res = -EAGAIN; - goto out; - } + if (rdev->scan_req) + return -EAGAIN; res = ieee80211_scan_results(rdev, info, extra, data->length); data->length = 0; @@ -1503,8 +1497,6 @@ int cfg80211_wext_giwscan(struct net_device *dev, res = 0; } - out: - cfg80211_unlock_rdev(rdev); return res; } EXPORT_SYMBOL_GPL(cfg80211_wext_giwscan); -- cgit v1.2.3 From 0e3a39b5620bc84f25ffb0592b05b0350e8b0520 Mon Sep 17 00:00:00 2001 From: Ben Greear Date: Wed, 19 Jun 2013 14:06:27 -0700 Subject: wireless: add comments about bss refcounting Should help the next person that tries to understand the bss refcounting logic. Signed-off-by: Ben Greear Signed-off-by: Johannes Berg --- net/wireless/scan.c | 4 ++++ 1 file changed, 4 insertions(+) (limited to 'net/wireless/scan.c') diff --git a/net/wireless/scan.c b/net/wireless/scan.c index dd01b58fa78c..ae8c186b50d6 100644 --- a/net/wireless/scan.c +++ b/net/wireless/scan.c @@ -523,6 +523,7 @@ static int cmp_bss(struct cfg80211_bss *a, } } +/* Returned bss is reference counted and must be cleaned up appropriately. */ struct cfg80211_bss *cfg80211_get_bss(struct wiphy *wiphy, struct ieee80211_channel *channel, const u8 *bssid, @@ -678,6 +679,7 @@ static bool cfg80211_combine_bsses(struct cfg80211_registered_device *dev, return true; } +/* Returned bss is reference counted and must be cleaned up appropriately. */ static struct cfg80211_internal_bss * cfg80211_bss_update(struct cfg80211_registered_device *dev, struct cfg80211_internal_bss *tmp) @@ -866,6 +868,7 @@ cfg80211_get_bss_channel(struct wiphy *wiphy, const u8 *ie, size_t ielen, return channel; } +/* Returned bss is reference counted and must be cleaned up appropriately. */ struct cfg80211_bss* cfg80211_inform_bss(struct wiphy *wiphy, struct ieee80211_channel *channel, @@ -923,6 +926,7 @@ cfg80211_inform_bss(struct wiphy *wiphy, } EXPORT_SYMBOL(cfg80211_inform_bss); +/* Returned bss is reference counted and must be cleaned up appropriately. */ struct cfg80211_bss * cfg80211_inform_bss_frame(struct wiphy *wiphy, struct ieee80211_channel *channel, -- cgit v1.2.3