[PATCH v2 2/2] NFSv4 account for selinux security context when deciding to share superblock

[Trond Myklebust]

On Fri, 2021-02-19 at 12:20 -0500, Olga Kornievskaia wrote:
> Trond/Anna,
> 
> I'd like your opinion here. Some static checking flags a "ctx"
> assignment in nfs_fill_super() in the new patch. In an existing code
> there is a check for it is NULL before dereferencing. However, "ctx"
> can never be null. nfs_get_tree_common() which calls nfs_fill_super()
> and passes in "ctx" gets it from the passed in "fs_context". If the
> passed in arg can be null then we are dereferencing in var assignment
> so things would blow up there. So "ctx" can never be null.
> 
> Should I create another clean up patch to remove the check for null
> ctx in nfs_fill_super() to make static analyzers happy?
> 

Yes, at this point, nfs_fill_super() is only called from
nfs_get_tree_common(), which would crash and burn well before if ctx
were an invalid pointer.

So please go ahead, and remove the check for ctx being NULL in
nfs_fill_super().

-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust at hammerspace.com