[PATCH 04/18] fs: fat: correct first cluster for '..'

[Heinrich Schuchardt]

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 at gmx.de>
Acked-by: Marek Szyprowski <m.szyprowski at samsung.com>
---
 fs/fat/fat_write.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index 7afc8388b2..4da342f9c9 100644
--- 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);
--
2.29.2