On Wednesday February 26, ptb@it.uc3m.es wrote: > > What is also puzzling me is that despite the horrible potential for > what might happen from doing the original users end_io early, I > can't see any consequences in actual tests! > > I am writing stuff to a file on a raid1 mirror mount, then dismantling > the mount, the device, and rmmoding the driver. Then I put it all back > again. On remount the data in the file is all perfect. Yet it was built > with plenty of async writes! Surely the buffers in some of those writes > should have been pointing nowhere and been full of rubbish? > I suspect that mostly you are writing from a cache, and the data will probably stay around. To be able to demonstrate a problem you probably need very high memory pressure so things don't stay in cache long, lots of metadata updates, and probably some for of journalling filesystem like I mentioned previously. Have very long latencies for the delayed write would also make the problem more likely. Even if you cannot demonstrate a problem, I'm sure one would be noticed sooner or later if you released this sort of code into the wild and people used it. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
