[PATCH 5/5] nfsd: clean up nfsd_mode_check()

["J. Bruce Fields" <bfields@redhat.com>]

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

Signed-off-by: J. Bruce Fields <bfields@redhat.com>
---
 fs/nfsd/nfsfh.c |   52 +++++++++++++++++++++++++++++-----------------------
 1 files changed, 29 insertions(+), 23 deletions(-)

diff --git a/fs/nfsd/nfsfh.c b/fs/nfsd/nfsfh.c
index dc0f9ff..b4fd50e 100644
--- a/fs/nfsd/nfsfh.c
+++ b/fs/nfsd/nfsfh.c
@@ -59,30 +59,36 @@ 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;
-		/*
-		 * err_symlink is our catch-all error in the v4 case; this
-		 * looks odd, but:
-		 *	- the comment next to ERR_SYMLINK in file is
-		 *	  "should be file/directory"
-		 *	- we happen to know this will cause the linux v4
-		 *	  client to do the right thing on attempts to open
-		 *	  something other than a regular file:
-		 */
-		else if (rqstp->rq_vers == 4)
-			return nfserr_symlink;
-		else
-			return nfserr_inval;
-	}
-	return 0;
+	mode &= S_IFMT;
+
+	if (requested == 0) /* the caller doesn't care */
+		return 0;
+	if (mode == requested)
+		return 0;
+	/*
+	 * 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;
+	/*
+	 * err_symlink is our catch-all error in the v4 case; this
+	 * looks odd, but:
+	 *	- the comment next to ERR_SYMLINK in file is
+	 *	  "should be file/directory"
+	 *	- we happen to know this will cause the linux v4
+	 *	  client to do the right thing on attempts to open
+	 *	  something other than a regular file:
+	 */
+	if (rqstp->rq_vers == 4)
+		return nfserr_symlink;
+	return nfserr_inval;
 }
 
 static __be32 nfsd_setuser_and_check_port(struct svc_rqst *rqstp,
-- 
1.7.4.1