Messages in this thread | | | Date | Fri, 17 Nov 2006 00:40:53 +0100 | From | Pavel Machek <> | Subject | Re: [PATCH 2.6.19 5/5] fs: freeze_bdev with semaphore not mutex |
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On Fri 2006-11-17 10:23:49, David Chinner wrote: > On Sun, Nov 12, 2006 at 11:43:05PM +0100, Rafael J. Wysocki wrote: > > On Sunday, 12 November 2006 23:30, David Chinner wrote: > > > And how does freezing them at that point in time guarantee consistent > > > filesystem state? > > > > If the work queues are frozen, there won't be any fs-related activity _after_ > > we create the suspend image. > > fs-related activity before or after the suspend image is captured is > not a problem - it's fs-related activity _during_ the suspend that > is an issue here. If we have async I/O completing during the suspend > image capture, we've got problems....
fs-related activity _after_ image is captured definitely is a problem -- it breaks swsusp invariants.
During image capture, any fs-related activity is not possible, as we are running interrupts disabled, DMA disabled. Pavel -- (english) http://www.livejournal.com/~pavelmachek (cesky, pictures) http://atrey.karlin.mff.cuni.cz/~pavel/picture/horses/blog.html - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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