[PATCH 6.1 005/451] nfsd: allow nfsd_file_get to sanely handle a NULL pointer

From: Sasha Levin
Date: Mon Mar 25 2024 - 02:12:33 EST


From: Jeff Layton <jlayton@xxxxxxxxxx>

[ Upstream commit 70f62231cdfd52357836733dd31db787e0412ab2 ]

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

Suggested-by: NeilBrown <neilb@xxxxxxx>
Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
Signed-off-by: Chuck Lever <chuck.lever@xxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 697acf5c3c681..6e8712bd7c998 100644
--- a/fs/nfsd/filecache.c
+++ b/fs/nfsd/filecache.c
@@ -431,7 +431,7 @@ 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;
}
@@ -1086,8 +1086,7 @@ 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 b9d694ec25d19..e4522e86e984e 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 *
--
2.43.0