fs: fat: correct first cluster for '..'

The FAT specification [1] requires that for a '..' directory entry pointing
to the root directory the fields DIR_FstClusHi and DIR_FstClusLo are 0.

[1] Microsoft FAT Specification, Microsoft Corporation, August 30 2005

Fixes: 31a18d570d96 ("fs: fat: support mkdir")
Signed-off-by: Heinrich Schuchardt <xypron.glpk@gmx.de>
Acked-by: Marek Szyprowski <m.szyprowski@samsung.com>

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 7afc8388b236f765b99ca3191b56b763965f28e6..4da342f9c900122fac011579c01c2c9410eb1a13 100644 (file)
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -1468,7 +1468,11 @@ int fat_mkdir(const char *new_dirname)
        memcpy(dotdent[1].name, "..      ", 8);
        memcpy(dotdent[1].ext, "   ", 3);
        dotdent[1].attr = ATTR_DIR | ATTR_ARCH;
-       set_start_cluster(mydata, &dotdent[1], itr->start_clust);
+
+       if (itr->is_root)
+               set_start_cluster(mydata, &dotdent[1], 0);
+       else
+               set_start_cluster(mydata, &dotdent[1], itr->start_clust);
 
        ret = set_contents(mydata, retdent, 0, (__u8 *)dotdent,
                           bytesperclust, &actwrite);