[PATCH 4/6] fs: fat: update parent dirs metadata on rename

[Gabriel Dalimonte <gabriel.dalimonte@gmail.com>]

None of the existing fat code appears to update parent dir properties
however, the POSIX specification for rename() mentions that the
last modified timestamp should be updated. In addition, I believe
the ATTR_ARCH attribute should also be reset on the parent directories
as the content of those directories has changed.

Signed-off-by: Gabriel Dalimonte <gabriel.dalimonte@gmail.com>
---

 fs/fat/fat_write.c | 42 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 42 insertions(+)

diff --git a/fs/fat/fat_write.c b/fs/fat/fat_write.c
index f9f7051e30..2559e38d5b 100644
--- a/fs/fat/fat_write.c
+++ b/fs/fat/fat_write.c
@@ -1912,6 +1912,42 @@ exit:
 	return ret;
 }
 
+/**
+ * update_parent_dir_props - updates the modified time and resets the archive
+ * attribute for the parent directory
+ *
+ * @itr:	iterator positioned anywhere in a directory whose parent should be
+ *	updated
+ * @Return:	0 for success
+ */
+static int update_parent_dir_props(fat_itr *itr)
+{
+	int ret = 0;
+	__u32 target_clust = itr->start_clust;
+	/* For START macro */
+	fsdata *mydata = itr->fsdata;
+
+	if (!itr->is_root) {
+		ret = fat_itr_parent(itr);
+		if (ret)
+			return ret;
+
+		while (fat_itr_next(itr)) {
+			if (START(itr->dent) == target_clust)
+				goto update;
+		}
+
+		/* dent not found */
+		return -EIO;
+update:
+		dentry_set_time(itr->dent);
+		itr->dent->attr |= ATTR_ARCH;
+		ret = flush_dir(itr);
+	}
+
+	return ret;
+}
+
 /**
  * fat_rename - rename/move a file or directory
  *
@@ -2086,7 +2122,12 @@ int fat_rename(const char *old_path, const char *new_path)
 		ret = flush_dir(new_itr);
 		if (ret)
 			goto exit;
+		/* restore directory location to update parent props below */
+		fat_itr_child(new_itr, new_itr);
 	}
+	ret = update_parent_dir_props(new_itr);
+	if (ret)
+		goto exit;
 
 	/* refresh old in case write happened to the same block. */
 	ret = fat_move_to_cluster(old_itr, old_itr->dent_clust);
@@ -2097,6 +2138,7 @@ int fat_rename(const char *old_path, const char *new_path)
 	if (ret)
 		goto exit;
 
+	ret = update_parent_dir_props(old_itr);
 exit:
 	free(new_datablock.fatbuf);
 	free(old_datablock.fatbuf);
-- 
2.34.1