True, I realised I misspoke there a second before hitting publish. Of
course battery-backed disk storage doesn't help if in the absence of
fsync() the OS hasn't pushed any data anywhere near said storage yet!
(And I do tend to assume that the journalling layer doesn't have lethal
data-eating bugs, or at least none that bite me. Should they do so, well,
that sort of rare disaster is what backups are for.)
If fsync() is slow, the problem is that fsync() is slow; the solution is
to speed it up, not rip the calls out of things like your text editor. (FF
using fsync() for transient-but-bulky state like the awesome bar is nuts,
FWIW I use KDE4 and ext4 and have turned barriers off (battery-backed RAID
array, again) and have had not a single instance of sudden death by
zeroing. So it doesn't happen to everyone.