Messages in this thread | | | Date | Sun, 12 May 2013 23:36:55 -0400 | From | Theodore Ts'o <> | Subject | Re: EXT4 panic at jbd2_journal_put_journal_head() in 3.9+ |
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On Sun, May 12, 2013 at 08:11:59PM -0700, Tony Luck wrote: > > My best guess as to why this commit causes problems is that there are places > where updates to individual fields in this structure used to be independent > because they were to whole words. Now we have bitfileds there are races > between access to different fields in the same word.
Yeah, except we access the fields while holding a lock.... wait a minute. We're using bit_spinlocks().... and am I missing something?
Where are the barrier statements to prevent the CPU or the compiler from reordering statements around bit_spin_lock()? But if that's the problem, I would have expected lots of other things to be broken.
- Ted
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