On Sat, May 16, 2015 at 09:38:08AM +1000, Dave Chinner wrote: > > Both readdir() and path component lookup are technically read > > operations, so why the hell do we use a mutex, rather than just > > get a read-write lock for reading? Yeah, it's that (d) above. I > > might trust xfs and ext4 to get their internal exclusions for > > allocations etc right when called concurrently for the same > > directory. But the others? > > They just use a write lock for everything and *nothing changes* - > this is a simple problem to solve. > > The argument "filesystem developers are stupid" is not a > compelling argument against changing locking. You're just being > insulting, even though you probably don't realise it. Er... Remember the clusterfuck around the ->i_size and alignment checks on XFS DIO writes? Just this cycle. Correctness of XFS locking is nothing to boast about - it *is* convoluted as hell and you guys are not superhuman enough to reliably spot the problems in that nest of horrors. Nobody is. PS: I've no idea whether I'm being insulting or not and frankly, I don't give a damn; unlike Linus I hadn't signed off on the "code of conflict" nonsense. Anyone who feels like complaining is quite welcome to it. -- To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
