On Thu, Jul 30, 2009 at 12:29:57PM +0900, ?????? shin hong wrote: > Hi. I am reporting a suspected deadlock bug. > > generic_shutdown_super() acquires lock_super(sb) > and then acquires lock_kernel(). It hasn't since commit a9e220f8322e2b0e0b8903fe00265461cffad3f0. Please work against a current kernel. > However, do_remount() acquires lock_super() while > it holds lock_kernel(). > > Therefore, concurrent execution of generic_shutdown_super() > and do_remount() may result deadlock. The reason this wasn't a problem before the commit above is that generic_shutdown_super() can never execute concurrently with do_remount. For generic_shutdown_super() to be called, there must be no remaining references to the super_block. do_remount() must hold a reference to the super_block. CONFIG_LOCKDEP finds lock inversion problems; I suspect you're wasting your time looking for them by hand. -- Matthew Wilcox Intel Open Source Technology Centre "Bill, look, we understand that you're interested in selling us this operating system, but compare it to ours. We can't possibly take such a retrograde step." -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
