On Sun, Jan 24, 2016 at 09:34:56AM +1100, Dave Chinner wrote: > On Sat, Jan 23, 2016 at 02:58:54PM +0000, Al Viro wrote: > > ->i_mutex wrappers (with small prereq in lustre), fix for too > > Please explain, Al? > > I haven't heard anything about there being i_mutex changes pending, > and this commit says "over the coming cycle ->i_mutex will become > rwsem". That's a complete surprise to me, and not something that > should be done with no warning. > > What's the locking model? How are filesystems supposed to use it? > Are they even allowed to use read-mode locking, and if so, what > operations is it going to be safe to hold the lock in read mode? > > Why is this change considered valid now, when previously there's > always been significant push-back to any suggestion that we should > make the i_mutex a rwsem so we can do shared read-only access > locking on inode operations? FWIW, I'm not opposed to making such a locking change - I'm more concerned about the fact I'm finding out about plans for such a fundamental locking change from a pull request on the last day of a merge window.... Cheers, Dave. -- Dave Chinner david@xxxxxxxxxxxxx -- 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
