Messages in this thread | | | Date | Mon, 7 Dec 2009 14:20:09 +0100 | From | Andi Kleen <> | Subject | Re: NFS lockdep lock misordering mmap_sem<->i_mutex_key with 2.6.32-git1 |
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On Mon, Dec 07, 2009 at 09:19:28PM +0900, KOSAKI Motohiro wrote: > > > > While booting 2.6.32-git1 on a NFS root box I got the following > > lockdep warning early at boot. I haven't looked at details. > > It seems typical ABBA deadlock. > > vfs_readdir [grab i_mutex] > nfs_readdir > nfs_do_filldir > filldir > copy_to_user > [page_fault] [grab mmap_sem] > > sys_mmap [grab mmap_sem] > do_mmap_pgoff > mmap_region > nfs_file_mmap > nfs_revalidate_mapping > nfs_invalidate_mapping [grab i_mutex] > > I guess recent lockdep improvement find old bug.
Thanks for the analysis.
I guess should never do copy_*_user while holding i_mutex? There might be lots of cases like that.
-Andi
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