On 06/11/2012 12:56 PM, Benny Halevy wrote: > > It will for recovering files striped with RAID as the LAYOUTRETURN > provides the server with a reliable "commit point" where it knows > exactly what was written successfully to each stripe and can make > the most efficient decision about recovering it (if needed). > > Allowing I/O to the stripe post LAYOUTRETURN may result in data > corruption due to parity inconsistency. > The fact of the matter is that we - object guys - Which care about LAYOUTRETURN the most, have neglected to notice and fix the current situation which is even worse than After Andy's patch. Which will send multiple LAYOUTRETURNs on the same layout, and might still continue IO on returned layouts. Thanks Andy for testing and highlighting the current problem, I will prioritized this development internally at Panasas and will work on a solution ASAP. I hope one that will satisfy all. Basically my plan is to postpone the LAYOUTRETURN send to when the segment is last referenced, if a flag was set to do so, and make sure reference counting is done proper, so after flag set the last IO_done will send the LAYOUTRETURN. If that is OK with all I hope? > Benny > Thanks Boaz -- To unsubscribe from this list: send the line "unsubscribe linux-nfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
