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    SubjectRe: 2.6.19-rc3-git7: scsi_device_unbusy: inconsistent lock state

    * Jens Axboe <jens.axboe@oracle.com> wrote:

    > > > things may be allocated from that path, so we pass gfp_mask around. I'll
    > > > double check it tonight, but I don't currently see what could be wrong.
    > > > Would lockdep complain about:
    > > >
    > > > spin_lock_irqsave(lock, flags);
    > > > ...
    > > > spin_unlock_irq(lock);
    > > > ...
    > > > spin_lock_irq(lock);
    > > > ...
    > > > spin_unlock_irqrestore(lock, flags);
    > >
    > > this is fine for lockdep IF and only IF there is no "out lock" held
    > > around this that requires irqs to be off. So if you do
    > >
    > > spin_lock_irqsave(lock1, flags);
    > > ...
    > > spin_lock_irqsave(lock2, flags);
    > > spin_unlock_irq(lock2)
    > > ...
    > >
    > > then lockdep WILL complain, and rightfully so, about a violation since
    > > lock1 gets violated here ;)
    >
    > Naturally, that is a bug fair and simple, nothing to do with lockdep.

    well, finding such locking bugs is the main purpose of lockdep, so there
    is at least some connection i'd say ;-)

    Ingo
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