Hi Steffen,
Sorry about the delay. Travel got in the way. >> BDI_CAP_STABLE_WRITES should take care of this. What's the configuration >> that fails? > > Apologies, if the commit description sounds unfair. I did not mean to > blame anyone. It's just the collection of issues we saw in distros over > the years. Some of the old issues might be fixed with above zfcp patch > or common code changes. Unfortunately, I could not handle the DIX things > we saw. I think, DIF by itself provides a lot of the protection benefit > and was not affected by the encountered issues. We would like to give > users an easy way to operate in such setup. I don't have a problem with zfcp having a parameter that affects the host protection mask, the other drivers do that too. However, these knobs exist exclusively for debugging and testing purposes. They are not something regular users should twiddle to switch features on or off. So DIF and DIX should always be enabled in the driver. And there is no point in ever operating without DIF enabled if the hardware is capable. If there is a desire to disable DIX protection for whatever reason (legacy code doing bad things), do so using the block layer sysfs knobs. That's where the policy of whether to generate and verify protection information resides, not in the HBA driver. And if there are unaddressed issues in the I/O stack that prevents you from having integrity enabled, I'd prefer to know about them so they can be fixed rather than circumventing them through driver module parameter. Hope that makes sense. -- Martin K. Petersen Oracle Linux Engineering
