queue-5.15/nfsd-allow-nfsd_file_get-to-sanely-handle-a-null-poi.patch

   1 From ac437762dc04468ae96b618199d2c97c22c7ebc9 Mon Sep 17 00:00:00 2001
   2 From: Sasha Levin <sashal@kernel.org>
   3 Date: Fri, 6 Jan 2023 10:33:47 -0500
   4 Subject: nfsd: allow nfsd_file_get to sanely handle a NULL pointer
   5
   6 From: Jeff Layton <jlayton@kernel.org>
   7
   8 [ Upstream commit 70f62231cdfd52357836733dd31db787e0412ab2 ]
   9
  10 ...and remove some now-useless NULL pointer checks in its callers.
  11
  12 Suggested-by: NeilBrown <neilb@suse.de>
  13 Signed-off-by: Jeff Layton <jlayton@kernel.org>
  14 Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
  15 ---
  16  fs/nfsd/filecache.c | 5 ++---
  17  fs/nfsd/nfs4state.c | 4 +---
  18  2 files changed, 3 insertions(+), 6 deletions(-)
  19
  20 diff --git a/fs/nfsd/filecache.c b/fs/nfsd/filecache.c
  21 index 68c7c82f8b3bb..206742bbbd682 100644
  22 --- a/fs/nfsd/filecache.c
  23 +++ b/fs/nfsd/filecache.c
  24 @@ -451,7 +451,7 @@ static bool nfsd_file_lru_remove(struct nfsd_file *nf)
  25  struct nfsd_file *
  26  nfsd_file_get(struct nfsd_file *nf)
  27  {
  28 -       if (likely(refcount_inc_not_zero(&nf->nf_ref)))
  29 +       if (nf && refcount_inc_not_zero(&nf->nf_ref))
  30                 return nf;
  31         return NULL;
  32  }
  33 @@ -1106,8 +1106,7 @@ nfsd_file_do_acquire(struct svc_rqst *rqstp, struct svc_fh *fhp,
  34         rcu_read_lock();
  35         nf = rhashtable_lookup(&nfsd_file_rhash_tbl, &key,
  36                                nfsd_file_rhash_params);
  37 -       if (nf)
  38 -               nf = nfsd_file_get(nf);
  39 +       nf = nfsd_file_get(nf);
  40         rcu_read_unlock();
  41
  42         if (nf) {
  43 diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
  44 index 5c261cc807e8e..628e564e530bf 100644
  45 --- a/fs/nfsd/nfs4state.c
  46 +++ b/fs/nfsd/nfs4state.c
  47 @@ -602,9 +602,7 @@ put_nfs4_file(struct nfs4_file *fi)
  48  static struct nfsd_file *
  49  __nfs4_get_fd(struct nfs4_file *f, int oflag)
  50  {
  51 -       if (f->fi_fds[oflag])
  52 -               return nfsd_file_get(f->fi_fds[oflag]);
  53 -       return NULL;
  54 +       return nfsd_file_get(f->fi_fds[oflag]);
  55  }
  56
  57  static struct nfsd_file *
  58 --
  59 2.43.0
  60