On Mon, 23 Jun 2008, Andrew Morton wrote: > > I don't know why it was done like this, or if anybody actually tested > > any of it, but AFAIKS the best way to fix this is to simply not > > clear any uptodate bits upon write errors. > > There's a plausible-sounding reason for this behaviour which I forgot > about three years ago. Maybe Linus remembers? We have to drop the data at _some_ point. Maybe some errors are transient, but a whole lot aren't. Jank out your USB memory stick, and those writes will continue fail. So you can't just keep things dirty - and that also implies that the buffer sure as heck isn't up-to-date either. Yes, we could haev a "retry once or twice", but quite frankly, that has always been left to the low-level driver. By the time the buffer cache or page cache sees the error, it should be considered more than "transient", and the data in memory is simply not _useful_ any more. So clearing the uptodate bit seems to be the logical thing to do. But on the other hand, it's probably not helping much either, so I don't personally care if we keep it "uptodate" - as long as the dirty bit doesn't get set, and as long as there is *some* way to get rid of the bad buffer later. Linus -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
