nfsd: clean up nfsd_mode_check()

Add some more comments, simplify logic, do & S_IFMT just once, name
"type" more helpfully.

Signed-off-by: J. Bruce Fields <bfields@redhat.com>

1 files changed, 18 insertions, 12 deletions

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index 8cd49b9bf085..c763de5c1157 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -59,19 +59,25 @@ static int nfsd_acceptable(void *expv, struct dentry *dentry)
  * the write call).
  */
 static inline __be32
-nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int type)
+nfsd_mode_check(struct svc_rqst *rqstp, umode_t mode, int requested)
 {
-        if (type > 0 && (mode & S_IFMT) != type) {
-                if (rqstp->rq_vers == 4 && (mode & S_IFMT) == S_IFLNK)
-                        return nfserr_symlink;
-                else if (type == S_IFDIR)
-                        return nfserr_notdir;
-                else if ((mode & S_IFMT) == S_IFDIR)
-                        return nfserr_isdir;
-                else
-                        return nfserr_inval;
-        }
-        return 0;
+        mode &= S_IFMT;
+
+        if (requested == 0) /* the caller doesn't care */
+                return nfs_ok;
+        if (mode == requested)
+                return nfs_ok;
+        /*
+         * v4 has an error more specific than err_notdir which we should
+         * return in preference to err_notdir:
+         */
+        if (rqstp->rq_vers == 4 && mode == S_IFLNK)
+                return nfserr_symlink;
+        if (requested == S_IFDIR)
+                return nfserr_notdir;
+        if (mode == S_IFDIR)
+                return nfserr_isdir;
+        return nfserr_inval;
 }
 
 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,