On Tue, Aug 5, 2008 at 8:24 PM, Bob Copeland [off-list ref] wrote:

On Tue, Aug 05, 2008 at 09:29:26AM +0800, Dave Young wrote:

quoted

With the patch I cann't reproduce the bug with 27-rc1 now.

quoted

 [<c02375a6>] ? debugfs_create_file+0x46/0x210
 [<c02375a6>] ? debugfs_create_file+0x46/0x210
 [<c02375a6>] debugfs_create_file+0x46/0x210
 [<c02377f1>] debugfs_create_dir+0x21/0x30
 [<f8901f6d>] ieee80211_sta_debugfs_add+0x2d/0x150 [mac80211]
 [<f88eba89>] sta_info_debugfs_add_work+0x89/0x130 [mac80211]
 [<f890a170>] ? rate_control_pid_add_sta_debugfs+0x0/0x30 [mac80211]

I wonder if there were two separate problems here.  I looked into
this with some detail yesterday and agree with Johannes that the above
trace is on locking the parent directory's i_mutex, but I too couldn't
see any problems with sta_info_debugfs_add_work.  Other stuff could also
modify the directory with or without rtnl_lock, but not in a way that
to my untrained eyes would lead to deadlock.

Yes,. I think so. It's the original bug for me, while testing I found
the mutex deadlock problem.

But this week I will have no time to trace it. so if I have time I
will keep tracing the problem

Or is the trace just wrong?

--
Bob Copeland %% www.bobcopeland.com

-- 
Regards
dave