Re: [PATCH v17 02/10] fs/ntfs3: Add initialization of super block

On Thu, Dec 31, 2020 at 06:23:53PM +0300, Konstantin Komarov wrote:

+void fnd_clear(struct ntfs_fnd *fnd)
+{
+	int i;
+
+	for (i = 0; i < fnd->level; i++) {
+		struct indx_node *n = fnd->nodes[i];
+
+		if (!n)
+			continue;
+
+		put_indx_node(n);
+		fnd->nodes[i] = NULL;
+	}
+	fnd->level = 0;
+	fnd->root_de = NULL;
+}
+
+static int fnd_push(struct ntfs_fnd *fnd, struct indx_node *n,
+		    struct NTFS_DE *e)
+{
+	int i;
+
+	i = fnd->level;
+	if (i < 0 || i >= ARRAY_SIZE(fnd->nodes))
+		return -EINVAL;
+	fnd->nodes[i] = n;
+	fnd->de[i] = e;
+	fnd->level += 1;
+	return 0;
+}
+
+static struct indx_node *fnd_pop(struct ntfs_fnd *fnd)
+{
+	struct indx_node *n;
+	int i = fnd->level;
+
+	i -= 1;
+	n = fnd->nodes[i];
+	fnd->nodes[i] = NULL;
+	fnd->level = i;
+
+	return n;
+}
+
+static bool fnd_is_empty(struct ntfs_fnd *fnd)
+{
+	if (!fnd->level)
+		return !fnd->root_de;
+
+	return !fnd->de[fnd->level - 1];
+}
+
+struct ntfs_fnd *fnd_get(struct ntfs_index *indx)
+{
+	struct ntfs_fnd *fnd = ntfs_alloc(sizeof(struct ntfs_fnd), 1);
+
+	if (!fnd)
+		return NULL;
+
+	return fnd;
+}

This should be initilized. What about that indx. Is that neccasarry?
Also no need to check NULL because if it is NULL we can just return it. 

+
+void fnd_put(struct ntfs_fnd *fnd)
+{
+	if (!fnd)
+		return;
+	fnd_clear(fnd);
+	ntfs_free(fnd);
+}

+/*
+ * indx_insert_entry
+ *
+ * inserts new entry into index
+ */
+int indx_insert_entry(struct ntfs_index *indx, struct ntfs_inode *ni,
+		      const struct NTFS_DE *new_de, const void *ctx,
+		      struct ntfs_fnd *fnd)
+{
+	int err;
+	int diff;
+	struct NTFS_DE *e;
+	struct ntfs_fnd *fnd_a = NULL;
+	struct INDEX_ROOT *root;
+
+	if (!fnd) {
+		fnd_a = fnd_get(indx);

Here we get uninitilized fnd.

+		if (!fnd_a) {
+			err = -ENOMEM;
+			goto out1;
+		}
+		fnd = fnd_a;
+	}
+
+	root = indx_get_root(indx, ni, NULL, NULL);
+	if (!root) {
+		err = -EINVAL;
+		goto out;
+	}
+
+	if (fnd_is_empty(fnd)) {

And example here we try to touch it.

+		/* Find the spot the tree where we want to insert the new entry. */
+		err = indx_find(indx, ni, root, new_de + 1,
+				le16_to_cpu(new_de->key_size), ctx, &diff, &e,
+				fnd);
+		if (err)
+			goto out;
+
+		if (!diff) {
+			err = -EEXIST;
+			goto out;
+		}
+	}
+
+	if (!fnd->level) {
+		/* The root is also a leaf, so we'll insert the new entry into it. */
+		err = indx_insert_into_root(indx, ni, new_de, fnd->root_de, ctx,
+					    fnd);
+		if (err)
+			goto out;
+	} else {
+		/* found a leaf buffer, so we'll insert the new entry into it.*/
+		err = indx_insert_into_buffer(indx, ni, root, new_de, ctx,
+					      fnd->level - 1, fnd);
+		if (err)
+			goto out;
+	}
+
+out:
+	fnd_put(fnd_a);
+out1:
+	return err;
+}