On Sat, Dec 02, 2023 at 01:34:32PM -0800, Kees Cook wrote: > On Sat, Dec 02, 2023 at 09:28:46PM +0000, Al Viro wrote: > > On Sat, Dec 02, 2023 at 01:22:13PM -0800, Kees Cook wrote: > > > Allow __free(iput) markings for easier cleanup on inode allocations. > > > > NAK. That's a bloody awful idea for that particular data type, since > > 1) ERR_PTR(...) is not uncommon and passing it to iput() is a bug. > > Ah, sounds like instead of "if (_T)", you'd rather see > "if (!IS_ERR_OR_NULL(_T))" ? > > > 2) the common pattern is to have reference-consuming primitives, > > with failure exits normally *not* having to do iput() at all. > > This I'm not following. If I make a call to "new_inode(sb)" that I end > up not using, I need to call "iput()" in it... If we wanted to do this properly then we would need to emulate consume or move semantics like Rust has. So a cleanup function for inodes based on scope for example and then another primitive that transfers/moves ownership of that refcount to the consumer. Usually this is emulate by stuff like TAKE_POINTER() and similar stuff in userspace. But I'm not sure how pleasant it would be to do this cleanly.
