On Mon, Nov 11, 2024 at 09:02:38AM -0500, Jeff Layton wrote:
> On Mon, 2024-11-11 at 20:57 +0800, Zorro Lang wrote:
> > Lots of fstests cases fail on nfs, e.g. [1]. The dmesg output as [2].
> > I tested on linux v6.12-rc6+, with HEAD=da4373fbcf006deda90e5e6a87c499e0ff747572
> >
> > Thanks,
> > Zorro
> >
>
> This looks wrong:
>
> static inline void nfs_to_nfsd_file_put_local(struct nfsd_file *localio)
> {
> /*
> * Once reference to nfsd_serv is dropped, NFSD could be
> * unloaded, so ensure safe return from nfsd_file_put_local()
> * by always taking RCU.
> */
> rcu_read_lock();
> nfs_to->nfsd_file_put_local(localio);
> rcu_read_unlock();
> }
>
> nfsd_file_put_local() calls nfsd_file_put, which can sleep. What
> exactly is the scenario that you're guarding against with the RCU read
> lock?
nfs_to lifetime vs nfsd unload. But anyway, this was fixed in the 2nd
patch of my recent LOCALIO series that I posted on Friday, see:
https://lore.kernel.org/linux-nfs/20241108234002.16392-3-snitzer@xxxxxxxxxx/
Would be good to get this in before 6.12 final (Neil gave his
Reviewed-by last night).
Thanks,
Mike
