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| author | Johannes Berg <johannes@sipsolutions.net> | 2008-10-07 12:04:29 +0200 |
|---|---|---|
| committer | John W. Linville <linville@tuxdriver.com> | 2008-10-14 20:46:41 -0400 |
| commit | 63044e9f54b6bac50d2380bf4d14f63e9e7de72b (patch) | |
| tree | 9ceddf721c869fb9450429fd4932d8c40b765486 /net/mac80211/debugfs_sta.c | |
| parent | 45527c2c4f698f8927239cfdec9f515cafed5f10 (diff) | |
| download | lwn-63044e9f54b6bac50d2380bf4d14f63e9e7de72b.tar.gz lwn-63044e9f54b6bac50d2380bf4d14f63e9e7de72b.zip | |
mac80211: fix debugfs lockup
When debugfs_create_dir fails, sta_info_debugfs_add_work will not
terminate because it will find the same station again and again.
This is possible whenever debugfs fails for whatever reason; one
reason is a race condition in mac80211, unfortunately we cannot
do much about it, so just document it, it just means some station
may be missing from debugfs.
Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Cc: Robin Holt <holt@sgi.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
Diffstat (limited to 'net/mac80211/debugfs_sta.c')
| -rw-r--r-- | net/mac80211/debugfs_sta.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/net/mac80211/debugfs_sta.c b/net/mac80211/debugfs_sta.c index b9902e425f09..189d0bafa91a 100644 --- a/net/mac80211/debugfs_sta.c +++ b/net/mac80211/debugfs_sta.c @@ -249,11 +249,22 @@ void ieee80211_sta_debugfs_add(struct sta_info *sta) DECLARE_MAC_BUF(mbuf); u8 *mac; + sta->debugfs.add_has_run = true; + if (!stations_dir) return; mac = print_mac(mbuf, sta->sta.addr); + /* + * This might fail due to a race condition: + * When mac80211 unlinks a station, the debugfs entries + * remain, but it is already possible to link a new + * station with the same address which triggers adding + * it to debugfs; therefore, if the old station isn't + * destroyed quickly enough the old station's debugfs + * dir might still be around. + */ sta->debugfs.dir = debugfs_create_dir(mac, stations_dir); if (!sta->debugfs.dir) return; |