void rb_insert(struct rb_tree *t, struct rb_node *n, struct rb_callbacks *cb) {
/* insert node into the correct location in the tree, then link it in to
recolor the tree */
struct rb_node *parent = t->root;
while (parent) {
if (cb->cmp(n, parent) < 0) {
if (!parent->left) {
parent->left = n;
break;
}
parent = parent->left;
} else {
if (!parent->right) {
parent->right = n;
break;
}
parent = parent->right;
}
}
n->parent = parent;
rb_link(t, n, cb);
}
static struct fs_entry *vfs_lookup(struct fs_entry *dir, const char *name,
bool create, int *rc)
{
struct fs_node *node = dir->node;
struct rb_node **plink = &dir->children.root;
struct rb_node *parent = 0;
if (!node->ops->lookup) {
*rc = -ENOTSUP;
return 0;
}
const bool enabled = spin_lock_irqsave(&dir->lock);
while (*plink) {
struct fs_entry *entry = TREE_ENTRY(*plink, struct fs_entry,
link);
const int cmp = strcmp(entry->name, name);
if (!cmp) {
*rc = 0;
vfs_entry_get(entry);
spin_unlock_irqrestore(&dir->lock, enabled);
return entry;
}
parent = *plink;
if (cmp < 0)
plink = &parent->right;
else
plink = &parent->left;
}
struct fs_entry *entry = vfs_entry_create(name);
if (!entry) {
spin_unlock_irqrestore(&dir->lock, enabled);
*rc = -ENOMEM;
return 0;
}
rb_link(&entry->link, parent, plink);
rb_insert(&entry->link, &dir->children);
entry->parent = vfs_entry_get(dir);
entry->cached = true;
spin_unlock_irqrestore(&dir->lock, enabled);
*rc = node->ops->lookup(node, entry);
if (*rc && !create) {
vfs_entry_put(entry);
return 0;
}
return entry;
}