David Woodhouse wrote: > I'd still quite like to make it work though -- file systems that care > can always use explicit barriers to ensure that the DISCARD requests are > handled before any subsequent reallocation and write to the same > sectors. Wouldn't an explicit barrier be (a) slow if it's a hard-barrier, and (b) as a soft-barrier, overly constrain scheduling, because the only ordering required is against a subsequent overlapping write? Explicit soft or hard barrier *before* DISCARD does need to be an option. Think of journalling: Step 1 = commit "deleted file" to journal, 2 = hard barrier, 3 = DISCARD file data. Barrier after does not seem to be required. -- Jamie -- 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
