Jamie Lokier wrote: > Theodore Tso wrote: >> On Fri, May 16, 2008 at 02:09:56PM -0500, Eric Sandeen wrote: >>> To ensure that bits are truly on-disk after an fsync, >>> we should call blkdev_issue_flush if barriers are supported. >> This patch isn't necessary, and in fact will cause a double flush. >> When you call fsync(), it calls ext4_force_commit(), and we do a the >> equivalent of a blkdev_issue_flush() today (which is what happenes >> when you do a submit_bh(WRITE_BARRIER, bh), which is what setting >> set_ordered_mode(bh) ends up causing. > > ISTR fsync() on ext3 did not always force a commit, if in-place data > writes did not change any metadata. I think that might still be true, but I'm still looking through it (in the background...) I tried blktrace to see what was going on but I'm not sure what an "NB" in the RWBS field means, anyone know? -Eric -- 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
