On Tue, Nov 12, 2024 at 03:48:10PM -0800, Linus Torvalds wrote: > On Tue, 12 Nov 2024 at 15:06, Amir Goldstein <amir73il@xxxxxxxxx> wrote: > > > > I am fine not optimizing out the legacy FS_ACCESS_PERM event > > and just making sure not to add new bad code, if that is what you prefer > > and I also am fine with using two FMODE_ flags if that is prefered. > > So iirc we do have a handful of FMODE flags left. Not many, but I do > think a new one would be fine. 8, 13, 24, 30 and 31. > But if anybody is really worried about running out of f_mode bits, we > could almost certainly turn the existing > > unsigned int f_flags; > > into a bitfield, and make it be something like > > unsigned int f_flags:26, f_special:6; > > instead, with the rule being that "f_special" only gets set at open > time and never any other time (to avoid any data races with fcntl() > touching the other 24 bits in the word). Ugh... Actually, I would rather mask that on fcntl side (and possibly moved FMODE_RANDOM/FMODE_NOREUSE over there as well). Would make for simpler rules for locking - ->f_mode would be never changed past open, ->f_flags would have all changes under ->f_lock.
