Messages in this thread | | | Date | Thu, 20 Sep 2012 16:25:36 -0700 | From | Anton Vorontsov <> | Subject | Re: [PATCH] pstore: avoid recursive spinlocks in the oops_in_progress case |
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On Thu, Sep 20, 2012 at 11:09:36PM +0000, Luck, Tony wrote: > > Mm... why break? > > We don't know what the back-end driver will do if we allow another call > while a previous one is still in progress. It might end up corrupting the > backing non-volatile storage and losing some previously saved records.
True, but the lock is used to protect pstore->buf, I doubt that any backend will actually want to grab it, no?
Since it is pstore that is handing the buffer to backend, it is pstore's worry to do proper locking.
> Existing drivers (ERST and EFI) are dependent on f/w ... so things might > work on some platforms, yet be horribly bad on others. > > The patch as it was written converts a deadlock (hang) case into a "lose > this log, but keep going" case. Which seems to be an improvement without > taking any risks about what the backend will do.
But why backends should (or want/will want to) grab this lock?..
If a backend needs its own locking in ->write callback, then it'll have to use its own lock, I guess.
Thanks, Anton.
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