From 7aa1a6b71c9af4651f6b3a164c84096a84d24285 Mon Sep 17 00:00:00 2001
From: Tien Fong Chee <tfchee@altera.com>
Date: Wed, 27 Jul 2016 23:08:56 -0700
Subject: [PATCH] fs/fat/fatwrite: Local variable as buffer to store dir_slot
entries
fill_dir_slot use get_contents_vfatname_block as a temporary buffer for
constructing a list of dir_slot entries. To save the memory and providing
correct type of memory for above usage, a local buffer with accurate size
declaration is introduced.
The local array size 640 is used because for long file name entry,
each entry use 32 bytes, one entry can store up to 13 characters.
The maximum number of entry possible is 20. So, total size is
32*20=640bytes.
Signed-off-by: Genevieve Chan <ccheauya@altera.com>
Signed-off-by: Tien Fong Chee <tfchee@altera.com>
---
fs/fat/fat_write.c | 3 ++-
include/fat.h | 2 ++
2 files changed, 4 insertions(+), 1 deletion(-)
diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 0583af310a..40a3860e47 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -327,7 +327,8 @@ static void flush_dir_table(fsdata *mydata, dir_entry **dentptr);
static void
fill_dir_slot(fsdata *mydata, dir_entry **dentptr, const char *l_name)
{
- dir_slot *slotptr = (dir_slot *)get_contents_vfatname_block;
+ __u8 temp_dir_slot_buffer[MAX_LFN_SLOT * sizeof(dir_slot)];
+ dir_slot *slotptr = (dir_slot *)temp_dir_slot_buffer;
__u8 counter = 0, checksum;
int idx = 0, ret;
diff --git a/include/fat.h b/include/fat.h
index 8ec91cda75..e38f3808af 100644
--- a/include/fat.h
+++ b/include/fat.h
@@ -33,6 +33,8 @@
#define FAT16BUFSIZE (FATBUFSIZE/2)
#define FAT32BUFSIZE (FATBUFSIZE/4)
+/* Maximum number of entry for long file name according to spec */
+#define MAX_LFN_SLOT 20
/* Filesystem identifiers */
#define FAT12_SIGN "FAT12 "
--
2.39.5