On Mon, Dec 17, 2018 at 03:53:46PM -0700, Andreas Dilger wrote:
> > +#define EXT4_IGET_NORMAL 1
> > +#define EXT4_IGET_HANDLE 2
>
> It would be better to make this:
>
> enum ext4_iget_flags {
> EXT4_IGET_RESERVED = 0x00, /* just guessing, see further below */
> EXT4_IGET_NORMAL = 0x01,
> EXT4_IGET_HANDLE = 0x02,
> };
>
> > - inode = ext4_iget(sb, ino);
> > + inode = ext4_iget(sb, ino, 0);
>
> What does "0" mean? It isn't in the list of EXT4_IGET_* flags. I'm guessing it
> means that access to reserved or otherwise invalid inodes is allowed?
The flags are boolean OR'ed together, much like O_TRUNC | O_CREAT,
etc. So an enum isn't really appropriate. So 0 means we're not
enforcing "must be a normal inode" rules, and we're also not going to
avoid throwing an EXT4_ERROR if the inode number is invalid.
I had thought it was obvious that flags can be or'ed together, and
that "modes" are what might use an enum. I personally like flags
because the can be more expressive, although I can see that "modes"
are simpler since there is a much smaller set of valid modes, and you
don't have to worry about define what happens when flags interact in
unusual/unexpected ways.
It sounds like should add more explicit documentation at the very
least so it's more clear what's going on.
- Ted
