Jan Kara wrote: >> Frans Pop <elendil@xxxxxxxxx> writes: >> >>> On Tuesday 11 August 2009, Chris Mason wrote: >>>> On Tue, Aug 11, 2009 at 03:35:36PM +0200, Frans Pop wrote: >>>>> Somewhat unrelated, but what happened to the data=guarded patches >>>>> Chris Mason proposed back in April? >>>> I missed 2.6.31 but plan on sending for 2.6.32. I promised to send >>>> along a forward port of the patches a while back, but I finally have >>>> one in testing here. It should go out shortly. >>> Good to hear. I've so far stayed with data=ordered as I think I'd prefer >>> data=guarded over data=writeback. I'll certainly give it a try when it's >>> available. >> Same here. data=writeback already cost me a few files after crashes here :/ > In this regard, data=guarded need not be better than data=writeback. > We push out the data in guarded mode as late as in writeback mode > (that's where the performance benefit comes from ;). The difference is > that we increase i_size only after data are safely on disk so we cannot > expose old data. > So security-wise, guarded mode is as safe as ordered mode but in other > aspects its more like data=writeback. Yes, I think the people anxiously waiting for data=guarded may be sadly surprised at their 0-length files. For those who understand the data=writeback tradeoffs it'll be very useful in terms of more consistent results (easily-detectable 0-size or short files, vs. randomly corrupted data sprinkled around) but it's not going to be "data=ordered, but faster!" -Eric > Honza -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
