ksmbd: remove filename in ksmbd_file

If the filename is change by underlying rename the server, fp->filename
and real filename can be different. This patch remove the uses of
fp->filename in ksmbd and replace it with d_path().

Signed-off-by: Namjae Jeon <linkinjeon@kernel.org>
Reviewed-by: Hyunchul Lee <hyc.lee@gmail.com>
Signed-off-by: Steve French <stfrench@microsoft.com>

1 files changed, 31 insertions, 9 deletions

diff --git a/fs/ksmbd/misc.c b/fs/ksmbd/misc.c
index 60e7ac62c917..1e2076a53bed 100644
--- a/fs/ksmbd/misc.c
+++ b/fs/ksmbd/misc.c
@@ -158,19 +158,41 @@ out:
  * Return : windows path string or error
  */
 
-char *convert_to_nt_pathname(char *filename)
+char *convert_to_nt_pathname(struct ksmbd_share_config *share,
+			     struct path *path)
 {
-	char *ab_pathname;
+	char *pathname, *ab_pathname, *nt_pathname;
+	int share_path_len = share->path_sz;
 
-	if (strlen(filename) == 0)
-		filename = "\\";
+	pathname = kmalloc(PATH_MAX, GFP_KERNEL);
+	if (!pathname)
+		return ERR_PTR(-EACCES);
 
-	ab_pathname = kstrdup(filename, GFP_KERNEL);
-	if (!ab_pathname)
-		return NULL;
+	ab_pathname = d_path(path, pathname, PATH_MAX);
+	if (IS_ERR(ab_pathname)) {
+		nt_pathname = ERR_PTR(-EACCES);
+		goto free_pathname;
+	}
+
+	if (strncmp(ab_pathname, share->path, share_path_len)) {
+		nt_pathname = ERR_PTR(-EACCES);
+		goto free_pathname;
+	}
+
+	nt_pathname = kzalloc(strlen(&ab_pathname[share_path_len]) + 2, GFP_KERNEL);
+	if (!nt_pathname) {
+		nt_pathname = ERR_PTR(-ENOMEM);
+		goto free_pathname;
+	}
+	if (ab_pathname[share_path_len] == '\0')
+		strcpy(nt_pathname, "/");
+	strcat(nt_pathname, &ab_pathname[share_path_len]);
+
+	ksmbd_conv_path_to_windows(nt_pathname);
 
-	ksmbd_conv_path_to_windows(ab_pathname);
-	return ab_pathname;
+free_pathname:
+	kfree(pathname);
+	return nt_pathname;
 }
 
 int get_nlink(struct kstat *st)