On 4/15/14, 1:44 PM, Theodore Ts'o wrote: > On Tue, Apr 15, 2014 at 11:15:41AM -0500, Eric Sandeen wrote: >> >> I tend to agree, better to fix the kernel than to add a knob to turn it >> off. And fsx changes can happen a lot quicker than kernel changes. [1] >> >> And if it's really unsafe, and you really want to add a knob, I'd at least >> default it to off until it's non-corrupting, and add a message that >> this tunable will go away as soon as it's stable, so you'll have no >> qualms about quickly deprecating it... > > Yeah, I went back and forth on this. One of there reasons why I added > a kernel knob is that *I* can make the kernel change a lot faster than > it would be to tweak all of the various xfstests program to globally > disable certain operations in fsx, fstress, etc. > > I also had a sneaking suspicion that we might have a similar issue > with the INSERT RANGE patches which are coming down the pike, and so > having a general way of also being able INSERT RANGE if to be able to > quickly determine whether a potential bug was caused by INSERT RANGE > or some other pending changes might also be useful. > > I freely admit it is a bit of a hack, though. Does the hack smell > less bad if we wrap it in CONFIG_EXT4FS_DEBUG? > >> [1] it'd be nifty to make an env. var in xfstests which can globally >> disable certain fsx operations across all tests which run fsx... > > Yes, although as I mentioned above, it would be really nice if it > worked across all of the various tests, and not just be limited to > fsx, or even just fsx and fstress. Well, for tests which are specific to collapse range, it'd be trivial to add a "collapse" group, and exclude it. For generic stress tests which happen to do collapse range, it'd take a bit more. But that'd probably still be the generic solution. XFS got bitten too, there were collapse range problems. But the fixes are already in the pipe AFAIK. -Eric > - Ted > > > -- 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
