Re: [PATCH 1/3] nfsd: return correct openowner when there is a race to put one in the hash

[Christoph Hellwig <hch@infradead.org>]

Good catch!

Reviewed-by: Christoph Hellwig <hch@lst.de>

But maybe it's better to write the code so that the intent is obvious:

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index f6b2a09..3c4c3d2 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -3215,11 +3215,13 @@ alloc_init_open_stateowner(unsigned int strhashval, struct nfsd4_open *open,
 	INIT_LIST_HEAD(&oo->oo_close_lru);
 	spin_lock(&clp->cl_lock);
 	ret = find_openstateowner_str_locked(strhashval, open, clp);
-	if (ret == NULL) {
-		hash_openowner(oo, clp, strhashval);
-		ret = oo;
-	} else
+	if (ret) {
 		nfs4_free_openowner(&oo->oo_owner);
+		spin_unlock(&clp->cl_lock);
+		return ret;
+	}
+
+	hash_openowner(oo, clp, strhashval);
 	spin_unlock(&clp->cl_lock);
 	return oo;
 }