On Sun, Apr 1, 2012 at 5:57 AM, Alexey Dobriyan <adobriyan@xxxxxxxxx> wrote:
>
> BSD added closefrom(fd) which is OK for this exact purpose but suboptimal
> on the bigger scale. closefrom(2) does only close(2) (obviously :-)
> closefrom(2) siletly ignores errors from close(2) which in theory is not OK
> for userspace.
>
> So, don't add closefrom(2), add nextfd(2).
I don't disagree with this, but I don't think it's worth a new file of
its own - I think it should go next to dup() and friends (currently in
fs/fcntl.h).
Also, I think you should:
(a) at a minimum use the bitmap. It's easy:
struct fdtable *fdt;
rcu_read_lock();
fdt = files_fdtable(current->files);
.. maximum fd in fdt->max_fds ...
.. you have the bitmap in fdt->open_fds ..
(b) I'd also suggest you add a "flag" argument and have at least one
bit option for "search for next *free* file table entry". I'm not sure
anybody wants it, but it is kind of the same operation, and having a
"flags" field means that it's extensible in the future if people want
to find the next cloexec fd or whatever. Or if they just want to find
the *last* fd, or something.
But I think the concept makes sense.
Linus
--
To unsubscribe from this list: send the line "unsubscribe linux-fsdevel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
