From: Daniel Rosenberg <drosen@google.com>
Date: Fri, 10 Mar 2017 20:39:42 +0000 (-0800)
Subject: ANDROID: sdcardfs: Use case insensitive hash function
X-Git-Tag: release-20171130_firefly~4^2~100^2~201
X-Git-Url: http://demsky.eecs.uci.edu/git/?a=commitdiff_plain;h=989624c14f9b69dfa67007886661b16d8aad05f9;p=firefly-linux-kernel-4.4.55.git

ANDROID: sdcardfs: Use case insensitive hash function

Case insensitive comparisons don't help us much if
we hash to different buckets...

Signed-off-by: Daniel Rosenberg <drosen@google.com>
bug: 36004503
Change-Id: I91e00dbcd860a709cbd4f7fd7fc6d855779f3285
---

diff --git a/fs/sdcardfs/packagelist.c b/fs/sdcardfs/packagelist.c
index 68f8f4571615..e72fe83f7837 100644
--- a/fs/sdcardfs/packagelist.c
+++ b/fs/sdcardfs/packagelist.c
@@ -20,6 +20,7 @@
 
 #include "sdcardfs.h"
 #include <linux/hashtable.h>
+#include <linux/ctype.h>
 #include <linux/delay.h>
 #include <linux/radix-tree.h>
 #include <linux/dcache.h>
@@ -44,10 +45,18 @@ static DEFINE_HASHTABLE(ext_to_groupid, 8);
 
 static struct kmem_cache *hashtable_entry_cachep;
 
+static unsigned int full_name_case_hash(const unsigned char *name, unsigned int len)
+{
+	unsigned long hash = init_name_hash();
+	while (len--)
+		hash = partial_name_hash(tolower(*name++), hash);
+	return end_name_hash(hash);
+}
+
 static void inline qstr_init(struct qstr *q, const char *name) {
 	q->name = name;
 	q->len = strlen(q->name);
-	q->hash = full_name_hash(q->name, q->len);
+	q->hash = full_name_case_hash(q->name, q->len);
 }
 
 static inline int qstr_copy(const struct qstr *src, struct qstr *dest) {