Revert "ipq807x: fat: Fix overflow issue"

This reverts commit 8791ff3dabaad123006cb97b041b05ff79e320e0.

Change-Id: I03af0ce35aa2df9e381b98c3842e4b88fbd35e1d
Signed-off-by: Sham Muthayyan <smuthayy@codeaurora.org>
diff --git a/board/qca/arm/common/crashdump.c b/board/qca/arm/common/crashdump.c
index 355d46a..ca7598f 100644
--- a/board/qca/arm/common/crashdump.c
+++ b/board/qca/arm/common/crashdump.c
@@ -377,7 +377,7 @@
 
 			if (cur_type == QCA_WDT_LOG_DUMP_TYPE_WLAN_MOD_INFO) {
 				snprintf(wlan_segment_name,	sizeof(wlan_segment_name),
-							 "MOD_INFO.txt");
+							 "MODULE_INFO.txt");
 				wlan_tlv_size = *(uint32_t *)(uintptr_t)tlv_info.size;
 			} else {
 				snprintf(wlan_segment_name,
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 56ee767..d087f6c 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -806,25 +806,21 @@
 static int check_overflow(fsdata *mydata, __u32 clustnum, loff_t size)
 {
 	__u32 startsect, sect_num, offset;
-	__u32 total_clusters = 0;
 
-	total_clusters = ((total_sector - mydata->rootdir_sect -
-				mydata->rootdir_size) /
-				mydata->clust_size) - 3;
-
-	/* the last sectors could be orphaned and not belong to any cluster */
-	if (clustnum >= total_clusters) {
-		return -1;
-	} else if (!clustnum) {
+	if (clustnum > 0) {
+		startsect = mydata->data_begin +
+				clustnum * mydata->clust_size;
+	} else {
 		startsect = mydata->rootdir_sect;
-		sect_num = div_u64_rem(size, mydata->sect_size, &offset);
-
-		if (offset != 0)
-			sect_num++;
-		if (startsect + sect_num > total_sector)
-			return -1;
 	}
 
+	sect_num = div_u64_rem(size, mydata->sect_size, &offset);
+
+	if (offset != 0)
+		sect_num++;
+
+	if (startsect + sect_num > total_sector)
+		return -1;
 	return 0;
 }
 
@@ -1007,9 +1003,8 @@
 	if (mydata->fatsize == 32) {
 		mydata->data_begin = mydata->rootdir_sect -
 					(mydata->clust_size * 2);
-		mydata->rootdir_size = 0;
 	} else {
-		__u16 rootdir_size;
+		int rootdir_size;
 
 		rootdir_size = ((bs.dir_entries[1]  * (int)256 +
 				 bs.dir_entries[0]) *
@@ -1018,7 +1013,6 @@
 		mydata->data_begin = mydata->rootdir_sect +
 					rootdir_size -
 					(mydata->clust_size * 2);
-		mydata->rootdir_size = rootdir_size;
 	}
 
 	mydata->fatbufnum = -1;
diff --git a/include/fat.h b/include/fat.h
index 6016b55..3038bd7 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -174,7 +174,6 @@
 	__u16	clust_size;	/* Size of clusters in sectors */
 	int	data_begin;	/* The sector of the first cluster, can be negative */
 	int	fatbufnum;	/* Used by get_fatent, init to -1 */
-	__u16   rootdir_size;   /* total sectors in rootdir */
 } fsdata;
 
 typedef int	(file_detectfs_func)(void);