nfsd: fix wrong check in write_v4_end_grace()

commit dd838821f0a29781b185cd8fb8e48d5c177bd838 upstream.

Commit 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before
nfsd startup" is trying to fix a NULL dereference issue, but it
mistakenly checks if the nfsd server is started. So fix it.

Fixes: 62a063b8e7d1 "nfsd4: fix crash on writing v4_end_grace before nfsd startup"
Cc: stable@vger.kernel.org
Reviewed-by: Joseph Qi <joseph.qi@linux.alibaba.com>
Signed-off-by: Yihao Wu <wuyihao@linux.alibaba.com>
Signed-off-by: J. Bruce Fields <bfields@redhat.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/fs/nfsd/nfsctl.c b/fs/nfsd/nfsctl.c
index 797a155..f704f90 100644 (file)
--- a/fs/nfsd/nfsctl.c
+++ b/fs/nfsd/nfsctl.c
@@ -1103,7 +1103,7 @@ static ssize_t write_v4_end_grace(struct file *file, char *buf, size_t size)
                case 'Y':
                case 'y':
                case '1':
-                       if (nn->nfsd_serv)
+                       if (!nn->nfsd_serv)
                                return -EBUSY;
                        nfsd4_end_grace(nn);
                        break;