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 9f5e911..623d11c 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 65da733..81d9790 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) : \