[PATCH 2/2] fs/ntfs3: keep PrintName not changed when creating symlink

[Zhenyan Wang]

When creating a symlink, ntfs3 converts all the '/' to '\' in both
PrintName and SubstituteName.

When reading this symlink, ntfs3 converts all the '\' to '/'. So if you
create a symlink to 'a\b', the result of readlink would be 'a/b'.

Fix this by converting SubstituteName only because SubstituteName is
used by NT kernel to read symlink while PrintName isn't; PrintName is
left unchanged to ensure consistency.

Signed-off-by: Zhenyan Wang <maximwang110@xxxxxxxxx>
---
 fs/ntfs3/inode.c | 22 +++++++++-------------
 1 file changed, 9 insertions(+), 13 deletions(-)

diff --git a/fs/ntfs3/inode.c b/fs/ntfs3/inode.c
index 6717563..000ac34 100644
--- a/fs/ntfs3/inode.c
+++ b/fs/ntfs3/inode.c
@@ -1091,6 +1091,7 @@ ntfs_create_reparse_buffer(struct ntfs_sb_info *sbi, const char *symname,
 	int i, err;
 	struct REPARSE_DATA_BUFFER *rp;
 	__le16 *rp_name;
+	__le16 *sub_name;
 	typeof(rp->SymbolicLinkReparseBuffer) *rs;
 	bool is_absolute;
 
@@ -1118,12 +1119,6 @@ ntfs_create_reparse_buffer(struct ntfs_sb_info *sbi, const char *symname,
 		goto out;
 	}
 
-	/* Translate Linux '/' into Windows '\'. */
-	for (i = 0; i < err; i++) {
-		if (rp_name[i] == cpu_to_le16('/'))
-			rp_name[i] = cpu_to_le16('\\');
-	}
-
 	rp->ReparseTag = IO_REPARSE_TAG_SYMLINK;
 	rp->ReparseDataLength =
 		cpu_to_le16(*nsize - offsetof(struct REPARSE_DATA_BUFFER,
@@ -1142,9 +1137,16 @@ ntfs_create_reparse_buffer(struct ntfs_sb_info *sbi, const char *symname,
 	 */
 	rs->Flags = cpu_to_le32(is_absolute ? 0 : SYMLINK_FLAG_RELATIVE);
 
-	memmove(rp_name + err + (is_absolute ? 4 : 0), rp_name,
+	sub_name = rp_name + err + (is_absolute ? 4 : 0);
+	memmove(sub_name, rp_name,
 		sizeof(short) * err);
 
+	/* Translate Linux '/' into Windows '\'. */
+	for (i = 0; i < err; i++) {
+		if (sub_name[i] == cpu_to_le16('/'))
+			sub_name[i] = cpu_to_le16('\\');
+	}
+
 	if (is_absolute) {
 		/* Decorate SubstituteName. */
 		rp_name += err;
@@ -2031,12 +2033,6 @@ static noinline int ntfs_readlink_hlp(const struct dentry *link_de,
 	if (err < 0)
 		goto out;
 
-	/* Translate Windows '\' into Linux '/'. */
-	for (i = 0; i < err; i++) {
-		if (buffer[i] == '\\')
-			buffer[i] = '/';
-	}
-
 	/* Always set last zero. */
 	buffer[err] = 0;
 
-- 
2.53.0