On Thu, Jul 31, 2014 at 10:16:55AM -0700, Christoph Hellwig wrote: > On Thu, Jul 31, 2014 at 05:33:09PM +1000, Dave Chinner wrote: > > Hi folks, > > > > Really two patch series in one. The first two patches remove the > > bitfield based superblock update method and replace it with a simple > > "update and log everything" operation. Superblock updates are > > now relatively rare so there's no need to optimise for single field > > updates. This patchset removes all that complex code and makes > > everything nice and simple. > > Is there any deeper rationale why you want to get rid of it? Tangential - cleaning up the mess of separate project quota inode support. We do lots of dancing around with bit flags and updates in different functions, and it really just complicates the code. The recent problems with the quota flags getting screwed up by repair due not using the sb-to-disk code properly in userspace was the initial source of the problem - it's just an unmaintainable PITA that leads to bugs. So the first step to fixing that is removing all of the unnecessary obfuscation and complexity from the kernel code, then port it over to userspace(*). Besides, when we log a single field in the superblock, we're really logging the surrounding 128 byte chunk, so we really are logging most of the superbock on every change right now. And if we want to move to single regions for logged buffers, then we'll be logging the entire sb every time anyway. So, really, it makes no sense to do this special bitfield based update and logging stuff anymore. Cheers, Dave. (*) I haven't posted the "trash all quota state" patch set for repair yet - given that repair doesn't validate the quota inode contents, and we quotacheck unconditionally after a repair run, there's no point trying to check or repair quota state or inodes at all - just trash them and let the kernel rebuild it from scratch on the next mount.... -- Dave Chinner david@xxxxxxxxxxxxx _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
