Re: [PATCH] fs: nfsd: nfs4state.c: Use built-in RCU list checking

From: J. Bruce Fields
Date: Tue Mar 03 2020 - 11:54:41 EST


Applying for 5.7, thanks.--b.

On Thu, Feb 13, 2020 at 08:33:31PM +0530, madhuparnabhowmik10@xxxxxxxxx wrote:
> From: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
>
> list_for_each_entry_rcu() has built-in RCU and lock checking.
>
> Pass cond argument to list_for_each_entry_rcu() to silence
> false lockdep warning when CONFIG_PROVE_RCU_LIST is enabled
> by default.
>
> Signed-off-by: Madhuparna Bhowmik <madhuparnabhowmik10@xxxxxxxxx>
> ---
> fs/nfsd/nfs4state.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index 369e574c5092..3a80721fe53d 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -4295,7 +4295,8 @@ find_file_locked(struct knfsd_fh *fh, unsigned int hashval)
> {
> struct nfs4_file *fp;
>
> - hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash) {
> + hlist_for_each_entry_rcu(fp, &file_hashtbl[hashval], fi_hash,
> + lockdep_is_held(&state_lock)) {
> if (fh_match(&fp->fi_fhandle, fh)) {
> if (refcount_inc_not_zero(&fp->fi_ref))
> return fp;
> --
> 2.17.1