On Tue, Feb 15, 2022 at 10:56:29AM +0100, Miklos Szeredi wrote: > Doing "lock_rename() + lookup last components" would fix this race. No go - thanks to the possibility of AT_SYMLINK_FOLLOW there. Think of it - we'd need to * lock parents (both at the same time) * look up the last component of source * if it turns a symlink - unlock parents and repeat the entire thing for its body, except when asked not to. * when we are done with the source, look the last component of target up ... and then there is sodding -ESTALE handling, with all the elegance that brings in. > If this was only done on retry, then that would prevent possible > performance regressions, at the cost of extra complexity. Extra compared to the above, that is. How delightful...
