Re: [1/8] readdir-plus system call - LSF/MM follow up

[Abhijith Das <adas@redhat.com>]

Zack, thanks for taking a peek at the patches.

> 
> Some quick things that struck me as I glanced through the patches:
> 
> - Please post the patch series, don't make us go digging through
>   bugzilla.

Duly noted. I wasn't hoping for my patches to be a serious submission, just something I wrote up as a POC. I was mainly looking to (re)start a conversation about readdirplus to see what's the best way to go about doing this. Your point applies nonetheless; I'll post my patchset again, properly.

> 
> - Don't use variable size types in the ABI or you'll have to add compat_
>   wrappers to fix it all up on the stack when going between 32bit
>   userspace and 64bit kernelspace.  This is going to be especially nasty
>   if this is a giant sequence of variable length blobs.
> 
>   +struct linux_xdirent {
>   +	unsigned long        xd_ino;
>   +	char                 xd_type;
>   +	unsigned long        xd_off;
>   +	struct xstat         xd_stat;
>   +	unsigned long        xd_reclen;
>   +	struct xdirent_blob  xd_blob;
>   +};
> 
>   Notice how, in contrast, David was careful to use naturally aligned
>   fixed-width types in his xstat patch.
> 

Yes, you're right. I'll fix this.

> - z

Cheers!
--Abhi