>>>>> "Andreas" == Andreas Dilger <adilger@xxxxxxxxx> writes: Andreas> I don't like adding a data copy in the IO path at all. No thanks! Andreas> I'd definitely prefer that the filesystem be in charge of Andreas> deciding whether this is needed or not. Absolutely. At the block layer we obviously have no idea whether the filesystem is safe or not. So in my current tree the protection is only generated if the relevant bio flag is set (unless the application already added it, obviously). Andreas> If the use of the data copy can be constrained to only the Andreas> minimum required cases (e.g. if fs checks for rewrite on page Andreas> that is marked as Writeback and either copies or blocks until Andreas> writeback is complete, as a mount option) that would be Andreas> better. At that point we can compare on different hardware Andreas> whether copying or blocking should be the default. Agreed. As Chris mentioned we've got somebody on our team working through the filesystem issues now. I'm hoping we can provide a status update at LSF2011. -- Martin K. Petersen Oracle Linux Engineering -- To unsubscribe from this list: send the line "unsubscribe linux-scsi" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
