[PATCH v2 1/2] nfsd: allow nfsd_file_get to sanely handle a NULL pointer

[Jeff Layton <jlayton@kernel.org>]

...and remove some now-useless NULL pointer checks in its callers.

Suggested-by: NeilBrown <neilb@suse.de>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
---
 fs/nfsd/filecache.c | 5 ++---
 fs/nfsd/nfs4state.c | 4 +---
 2 files changed, 3 insertions(+), 6 deletions(-)

diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
index 0ef070349014..58ac93e7e680 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -452,7 +452,7 @@ static bool nfsd_file_lru_remove(struct nfsd_file *nf)
 struct nfsd_file *
 nfsd_file_get(struct nfsd_file *nf)
 {
-	if (likely(refcount_inc_not_zero(&nf->nf_ref)))
+	if (nf && refcount_inc_not_zero(&nf->nf_ref))
 		return nf;
 	return NULL;
 }
@@ -1096,8 +1096,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
 	rcu_read_lock();
 	nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
 			       nfsd_file_rhash_params);
-	if (nf)
-		nf = nfsd_file_get(nf);
+	nf = nfsd_file_get(nf);
 	rcu_read_unlock();
 
 	if (nf) {
diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
index 4809ae0f0138..655fcfec0ace 100644
--- a/fs/nfsd/nfs4state.c
+++ b/fs/nfsd/nfs4state.c
@@ -602,9 +602,7 @@ put_nfs4_file(struct nfs4_file *fi)
 static struct nfsd_file *
 __nfs4_get_fd(struct nfs4_file *f, int oflag)
 {
-	if (f->fi_fds[oflag])
-		return nfsd_file_get(f->fi_fds[oflag]);
-	return NULL;
+	return nfsd_file_get(f->fi_fds[oflag]);
 }
 
 static struct nfsd_file *
-- 
2.39.0