Ah, ok sorry now I see:
brauner@wittgenstein|~/src/git/linux/vfs/vfs.super|vfs.super $%> > git describe --contains e88e0d366f9cfbb810b0c8509dc5d130d5a53e02 v6.6-vfs.tmpfs~2
which means support for O_DIRECT was merged in v6.6.
Ah, ok sorry now I see:
brauner@ wittgenstein| ~/src/git/ linux/vfs/ vfs.super| vfs.super $%> 810b0c8509dc5d1 30d5a53e02
> git describe --contains e88e0d366f9cfbb
v6.6-vfs.tmpfs~2
which means support for O_DIRECT was merged in v6.6.