Re: kernel BUG at fs/dcache.c:648! with v3.11-7890-ge5c832d

From: Linus Torvalds
Date: Wed Sep 11 2013 - 00:12:49 EST


On Tue, Sep 10, 2013 at 8:56 PM, Al Viro <viro@xxxxxxxxxxxxxxxxxx> wrote:
>
> I do. What we need on the second pass (one where we currently
> take seq_writelock()) is exclusion against writers; nothing we are
> doing is worth disturbing the readers - we don't change any data
> structures. And simple grabbing the spinlock, without touching the
> sequence number would achieve exactly that. Writers will have to
> wait and won't be able to disturb us, readers won't notice anything
> happening. So yes, this extra primitive does make sense here.

Ahh. Yes, as a fallback from the reader-side sequence lock that makes
perfect sense..

Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/