On Tue, 26 February 2008 20:16:11 +1100, Nick Piggin wrote: > > Yeah, sync_file_range has slightly unusual semantics and introduce > the new concept, "writeout", to userspace (does "writeout" include > "in drive cache"? the kernel doesn't think so, but the only way to > make sync_file_range "safe" is if you do consider it writeout). If sync_file_range isn't safe, it should get replaced by a noop implementation. There really is no point in promising "a little" safety. One interesting aspect of this comes with COW filesystems like btrfs or logfs. Writing out data pages is not sufficient, because those will get lost unless their referencing metadata is written as well. So either we have to call fsync for those filesystems or add another callback and let filesystems override the default implementation. Jörn -- There is no worse hell than that provided by the regrets for wasted opportunities. -- Andre-Louis Moreau in Scarabouche - 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
