vfs: uapi: retire octal and hex numbers in favor of (1 << n) for O_ flags

A recent build failure[1] exposed the diffculty of working with the
current octal and hex definitions of O_ flags when trying to find a gap
for a new flag. This difficulty is compounded by the fact that O_ flags
may have architectural specific values.

Replace the hex/octal #defines, which are hard to parse when looking for
free bits, with explicit bit shifts like (1 << 11). Also, add comments
that identify which architectures redefine some of the seemingly free
("cursed") bits in uapi/asm-generic/fcntl.h. These should not be used to
define new O_ flags (for now, at least).

The translastion was done with Claude Opus 4.8, and verified with a
(non-AI) gawk script. The accounting of which architectures claim
which bit-gaps in uapi/asm-generic/fcntl.h is also done by hand.

[1]: https://lore.kernel.org/all/agruPPybCx8q2XcJ@sirena.org.uk/

Assisted-by: Claude:Opus 4.8
Signed-off-by: Jori Koolstra <jkoolstra@xs4all.nl>
Link: https://patch.msgid.link/20260604222405.5382-1-jkoolstra@xs4all.nl
Signed-off-by: Christian Brauner (Amutable) <brauner@kernel.org>

0 files changed, 0 insertions, 0 deletions