On Fri, 2014-01-03 at 18:03 +-0100, David Sterba wrote: +AD4- On Fri, Jan 03, 2014 at 06:22:57PM +-0800, Wang Shilong wrote: +AD4- +AD4- We only intent to fua the first superblock in every device from +AD4- +AD4- comments, fix it. +AD4- +AD4- Good catch, this could gain some speedup when there are up to 2 less +AD4- flushes. +AD4- +AD4- There's one thing that's a different from currnet behaviour: +AD4- Without this patch, all the superblocks are written with FUA, now only +AD4- the first one, so my question is what if the first fails and the others +AD4- succeed but do not get flushed immediatelly? +AD4- +AD4- This is more of a theoretical scenario, and if the 1st superblock write +AD4- fails more serious problems can be expected. But let's say the write +AD4- error of 1st is transient, do you or others think that it's reasonable +AD4- to try to write all the remainig sb's with FUA? Not a bad idea, if we get a failure on the first SB, fua the others? I think it does make sense to do the others non-fua, just because they only get used in emergencies anyway. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
