Re: [PATCH v15 7/9] open: introduce openat2(2) syscall

On 2019-11-13, Al Viro viro@zeniv.linux.org.uk wrote:

On Tue, Nov 05, 2019 at 08:05:51PM +1100, Aleksa Sarai wrote:

...

+/*

• • Arguments for how openat2(2) should open the target path. If @resolve is
• • zero, then openat2(2) operates very similarly to openat(2).
• • However, unlike openat(2), unknown bits in @flags result in -EINVAL rather
• • than being silently ignored. @mode must be zero unless one of {O_CREAT,
• • O_TMPFILE} are set, and @upgrade_mask must be zero unless O_PATH is set.
• • @flags: O_* flags.
• • @mode: O_CREAT/O_TMPFILE file mode.
• • @upgrade_mask: UPGRADE_* flags (to restrict O_PATH re-opening).

???

Sorry, that was left over from a previous revision (where the magic-link re-opening restrictions were part of this series).

...

• • @resolve: RESOLVE_* flags.
• */

+struct open_how {

• __aligned_u64 flags;
• __u16 mode;
• __u16 __padding[3]; /* must be zeroed */
• __aligned_u64 resolve;

+};