Re: [PATCH v2 15/30] xfs: Define usercopy region in xfs_inode slab cache

[Kees Cook]

On Tue, Aug 29, 2017 at 1:14 AM, Christoph Hellwig <hch@xxxxxxxxxxxxx> wrote:
> One thing I've been wondering is wether we should actually just
> get rid of the online area.  Compared to reading an inode from
> disk a single additional kmalloc is negligible, and not having the
> inline data / extent list would allow us to reduce the inode size
> significantly.
>
> Kees/David:  how many of these patches are file systems with some
> sort of inline data?  Given that it's only about 30 patches declaring
> allocations either entirely valid for user copy or not might end up
> being nicer in many ways than these offsets.

9 filesystems use some form of inline data: xfs, vxfs, ufs, orangefs,
exofs, befs, jfs, ext2, and ext4. How much of each slab is whitelisted
varies by filesystem (e.g. ext2/4 uses i_data for other things, but
ufs and orangefs and have a dedicate field for symlink names).

-Kees

-- 
Kees Cook
Pixel Security