[PATCH 4/6] nfsd: use nfsd_v4client() in nfsd_breaker_owns_lease()

[NeilBrown <neilb@suse.de>]

nfsd_breaker_owns_lease() current open-codes the same test that
nfsd_v4client() performs.

With this patch we use nfsd_v4client() instead.

Also as i_am_nfsd() is only used in combination with kthread_data(),
replace it with nfsd_current_rqst() which combines the two and returns a
valid svc_rqst, or NULL.

The test for NULL is moved into nfsd_v4client() for code clarity.

Signed-off-by: NeilBrown <neilb@suse.de>
---
 fs/nfsd/nfs4state.c | 7 ++-----
 fs/nfsd/nfsd.h      | 4 ++--
 fs/nfsd/nfssvc.c    | 6 ++++--
 3 files changed, 8 insertions(+), 9 deletions(-)

diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index eadb7d1a7f13..c2edd8a21bd4 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -5274,11 +5274,8 @@ static bool nfsd_breaker_owns_lease(struct file_lease *fl)
 	struct svc_rqst *rqst;
 	struct nfs4_client *clp;
 
-	if (!i_am_nfsd())
-		return false;
-	rqst = kthread_data(current);
-	/* Note rq_prog == NFS_ACL_PROGRAM is also possible: */
-	if (rqst->rq_prog != NFS_PROGRAM || rqst->rq_vers < 4)
+	rqst = nfsd_current_rqst();
+	if (!nfsd_v4client(rqst))
 		return false;
 	clp = *(rqst->rq_lease_breaker);
 	return dl->dl_stid.sc_client == clp;
diff --git a/fs/nfsd/nfsd.h b/fs/nfsd/nfsd.h
index 0f499066aa72..e6626b22ab17 100644
--- a/fs/nfsd/nfsd.h
+++ b/fs/nfsd/nfsd.h
@@ -114,7 +114,7 @@ int		nfsd_pool_stats_open(struct inode *, struct file *);
 int		nfsd_pool_stats_release(struct inode *, struct file *);
 void		nfsd_shutdown_threads(struct net *net);
 
-bool		i_am_nfsd(void);
+struct svc_rqst *nfsd_current_rqst(void);
 
 struct nfsdfs_client {
 	struct kref cl_ref;
@@ -155,7 +155,7 @@ extern int nfsd_max_blksize;
 
 static inline int nfsd_v4client(struct svc_rqst *rq)
 {
-	return rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
+	return rq && rq->rq_prog == NFS_PROGRAM && rq->rq_vers == 4;
 }
 static inline struct user_namespace *
 nfsd_user_namespace(const struct svc_rqst *rqstp)
diff --git a/fs/nfsd/nfssvc.c b/fs/nfsd/nfssvc.c
index 89d7918de7b1..f6ce51eb232e 100644
--- a/fs/nfsd/nfssvc.c
+++ b/fs/nfsd/nfssvc.c
@@ -642,9 +642,11 @@ void nfsd_shutdown_threads(struct net *net)
 	mutex_unlock(&nfsd_mutex);
 }
 
-bool i_am_nfsd(void)
+struct svc_rqst *nfsd_current_rqst(void)
 {
-	return kthread_func(current) == nfsd;
+	if (kthread_func(current) == nfsd)
+		return kthread_data(current);
+	return NULL;
 }
 
 int nfsd_create_serv(struct net *net)
-- 
2.44.0