[RFC PATCH] mkfs.f2fs: avoid dumplicate extension

[Sheng Yong <shengyong1@huawei.com>]

Before copying user specified extension to extension_list, check if it is
already in the list.

Signed-off-by: Sheng Yong <shengyong1@huawei.com>
---
 mkfs/f2fs_format.c | 23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/mkfs/f2fs_format.c b/mkfs/f2fs_format.c
index 176bdea..b7ea19f 100644
--- a/mkfs/f2fs_format.c
+++ b/mkfs/f2fs_format.c
@@ -118,6 +118,26 @@ const char *media_ext_lists[] = {
 	NULL
 };
 
+static int extension_exist(const char *name, const int len)
+{
+	const char **extlist = media_ext_lists;
+	int name_len, min_len;
+	int ret;
+
+
+	while (*extlist) {
+		name_len = strlen(*extlist);
+		min_len = name_len < len ? name_len : len;
+		ret = strncmp(*extlist, name, min_len);
+
+		if (ret == 0 && name_len == len)
+			return 1;
+		extlist++;
+	}
+
+	return 0;
+}
+
 static void configure_extension_list(void)
 {
 	const char **extlist = media_ext_lists;
@@ -144,7 +164,8 @@ static void configure_extension_list(void)
 	ue = strtok(ext_str, ",");
 	while (ue != NULL) {
 		name_len = strlen(ue);
-		memcpy(sb.extension_list[i++], ue, name_len);
+		if (!extension_exist(ue, name_len))
+			memcpy(sb.extension_list[i++], ue, name_len);
 		ue = strtok(NULL, ",");
 		if (i >= F2FS_MAX_EXTENSION)
 			break;
-- 
1.9.1


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