On Tue, Aug 18, 2015 at 09:59:58AM +0000, Alexey Skidanov wrote: > > My question is regarding the barrier=0/1 mount option. On the one > hand, the "mount" man page says "This enables/disables the use of > write barriers in the jbd code". From there I understand that this > option changes the behaviour of journalling code only. But on the > other hand, this option change the the behaviour of fsync() (at > least in case of ext4): the flush request is issued only if barrier > mount option is 1. The bug is in the mount man page. It may have been true for ext3 oh, a decade or more ago when we didn't have an optimized fdatasync(2) implementation. (Ext4 may have predated Linux *having* fdatasync(2) support.) But no one has bothered to update documentation, because all of the people who care knew what it meant, and most users don't bother changing the defaults. Cheers, - Ted -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
