From 2e98f70882f8c1a09b662137884c1435a97c9a1c Mon Sep 17 00:00:00 2001
From: "Wu, Josh" <Josh.wu@atmel.com>
Date: Thu, 8 May 2014 16:14:06 +0800
Subject: [PATCH] fs: fat_write: fix the incorrect last cluster checking
In fat_write.c, the last clust condition check is incorrect:
if ((curclust >= 0xffffff8) || (curclust >= 0xfff8)) {
... ...
}
For example, in FAT32 if curclust is 0x11000. It is a valid clust.
But on above condition check, it will be think as a last clust.
So the correct last clust check should be:
in fat32, curclust >= 0xffffff8
in fat16, curclust >= 0xfff8
in fat12, curclust >= 0xff8
This patch correct the last clust check.
Signed-off-by: Josh Wu <josh.wu@atmel.com>
---
fs/fat/fat_write.c | 2 +-
include/fat.h | 3 +++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index cef138ec96..90d6ab63bf 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -882,7 +882,7 @@ static dir_entry *find_directory_entry(fsdata *mydata, int startsect,
}
curclust = get_fatent_value(mydata, dir_curclust);
- if ((curclust >= 0xffffff8) || (curclust >= 0xfff8)) {
+ if (IS_LAST_CLUST(curclust, mydata->fatsize)) {
empty_dentptr = dentptr;
return NULL;
}
diff --git a/include/fat.h b/include/fat.h
index 65da733aef..81d9790420 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -84,6 +84,9 @@
#define START(dent) (FAT2CPU16((dent)->start) \
+ (mydata->fatsize != 32 ? 0 : \
(FAT2CPU16((dent)->starthi) << 16)))
+#define IS_LAST_CLUST(x, fatsize) ((x) >= ((fatsize) != 32 ? \
+ ((fatsize) != 16 ? 0xff8 : 0xfff8) : \
+ 0xffffff8))
#define CHECK_CLUST(x, fatsize) ((x) <= 1 || \
(x) >= ((fatsize) != 32 ? \
((fatsize) != 16 ? 0xff0 : 0xfff0) : \
--
2.39.5