Messages in this thread | | | Date | Fri, 1 Jun 2007 17:53:36 +1000 | From | David Chinner <> | Subject | Re: [RFD] BIO_RW_BARRIER - what it means for devices, filesystems, and dm/md. |
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On Fri, Jun 01, 2007 at 03:59:51PM +1000, Neil Brown wrote: > On Friday June 1, dgc@sgi.com wrote: > > On Thu, May 31, 2007 at 02:31:21PM -0400, Phillip Susi wrote: > > > David Chinner wrote: > > > >That sounds like a good idea - we can leave the existing > > > >WRITE_BARRIER behaviour unchanged and introduce a new WRITE_ORDERED > > > >behaviour that only guarantees ordering. The filesystem can then > > > >choose which to use where appropriate.... > > > > > > So what if you want a synchronous write, but DON'T care about the order? > > > > submit_bio(WRITE_SYNC, bio); > > > > Already there, already used by XFS, JFS and direct I/O. > > Are you sure? > > You seem to be saying that WRITE_SYNC causes the write to be safe on > media before the request returns.
Sorry, I wasn't really all that clear :/
What I'm saying the *interface* for higher layer to tell the block layers that a sync write is being executed is already there. i.e. we can already tell the block layer that we are doing a synchronous I/O.
Cheers,
Dave. -- Dave Chinner Principal Engineer SGI Australian Software Group - 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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