On Fri, Apr 21, 2023 at 04:00:17AM +0100, Al Viro wrote: > On Wed, Mar 15, 2023 at 02:33:48PM +0530, Kirtikumar Anandrao Ramchandani wrote: > > While I am going through the code at the moment, I think there is one more > > issue. It probably can't just compare "old_dir" and "new_dir", since those > > are just pointers to structs. So, both addresses can be completely > > different, and still represent the same folder, yes? > > No, they can not. We should never have different in-core instances of > struct inode representing the same on-disk object - otherwise all locking > goes to hell, for example. ... and we should never, ever have two dentries aliasing the same directory inode, so d_inode() part is also not needed and actively confusing, since anyone running into it is likely to go "Why is it written that way? What is it protecting against? Where does <such and such code> protect itself against the same situation?". And there's a _lot_ of code that would break horribly if we ever run into such. Defensive programming can be harmful...
