Re: [PATCH] staging: erofs: harden inode lookup for 32-bit platforms

From: Dan Carpenter
Date: Thu Oct 11 2018 - 06:18:30 EST

On Thu, Oct 11, 2018 at 05:46:26PM +0800, Gao Xiang wrote:
> On 2018/10/11 16:44, Dan Carpenter wrote:
> > On Tue, Oct 09, 2018 at 10:07:13PM +0800, Gao Xiang wrote:
> >> This patch introduces inode hash function, test and set callbacks,
> >> and iget5_locked to find the right inode for 32-bit platforms.
> >>
> >
> > The way I read this changelog, we're trying to deal with corrupt file
> > systems? Is that correct? Presumably in the current code it could lead
> > to a Oops or something?
> No, this commit isn't trying to deal with corrupt file systems.
> In EROFS, the nid is not continuous and it represents the inode offset
> inode offset = nid * 32.
> Therefore the nid is 64-bit both for 32-bit and 64-bit platforms. However,
> i_ino is 'unsigned long', which means for 32-bit platforms, i_ino is not enough
> to contain the nid.
> Therefore, we should use iget5_locked for this case.

I guess what I'm saying is, what are the user visible effects of this
patch? It's hard for me to tell from the patch description. Could you
please re-write the description and send a v2?

dan carpenter