Re: dcache: remove trylock loops (was Re: [BUG] lock_parent() breakage when used from shrink_dentry_list())

[Al Viro]

On Mon, Mar 12, 2018 at 06:28:30PM -0500, Eric W. Biederman wrote:

> Given that nfs_kill_super calls generic_shutdown_super and
> generic_shutdown_super calls shrink_dcache_for_umount
> I would argue that nfsv2 and nfsv3 are buggy in the same
> case, as shrink_dcache_for_umount is called on something
> that is not the root of the filesystem's dentry tree.

That's not a problem - it will simply evict a subtree first,
then go through ->s_roots and kill each piece.