lsblk: add basic function to build devices tree

Signed-off-by: Karel Zak <kzak@redhat.com>

1 files changed, 257 insertions, 0 deletions

diff --git a/misc-utils/lsblk-devtree.c b/misc-utils/lsblk-devtree.c
new file mode 100644
index 000000000..3c71d24e4
--- /dev/null
+++ b/misc-utils/lsblk-devtree.c
@@ -0,0 +1,257 @@
+
+#include "lsblk.h"
+#include "sysfs.h"
+
+
+void lsblk_reset_iter(struct lsblk_iter *itr, int direction)
+{
+	if (direction == -1)
+		direction = itr->direction;
+
+	memset(itr, 0, sizeof(*itr));
+	itr->direction = direction;
+}
+
+struct lsblk_device *lsblk_new_device(struct lsblk_devtree *tree)
+{
+	struct lsblk_device *dev;
+
+	dev = calloc(1, sizeof(*dev));
+	if (!dev)
+		return NULL;
+
+	dev->refcount = 1;
+
+	dev->tree = tree;
+	lsblk_ref_devtree(dev->tree);
+
+        INIT_LIST_HEAD(&dev->deps);
+	INIT_LIST_HEAD(&dev->ls_roots);
+	INIT_LIST_HEAD(&dev->ls_devices);
+
+	DBG(DEV, ul_debugobj(dev, "alloc"));
+	return dev;
+}
+
+void lsblk_ref_device(struct lsblk_device *dev)
+{
+	if (dev)
+		dev->refcount++;
+}
+
+
+static int device_remove_dependence(struct lsblk_device *dev, struct lsblk_devdep *dep)
+{
+	if (!dev || !dep || !list_empty(&dev->deps))
+		return -EINVAL;
+
+	DBG(DEV, ul_debugobj(dev, "  remove-deallocate dependence 0x%p", dep));
+	list_del_init(&dep->ls_deps);
+	lsblk_unref_device(dep->child);
+	free(dep);
+	return 0;
+}
+
+static int device_remove_dependences(struct lsblk_device *dev)
+{
+	if (!dev)
+		return -EINVAL;
+
+	DBG(DEV, ul_debugobj(dev, "remove all depencences"));
+	while (!list_empty(&dev->deps)) {
+		struct lsblk_devdep *dp = list_entry(dev->deps.next,
+					struct lsblk_devdep, ls_deps);
+		device_remove_dependence(dev, dp);
+	}
+	return 0;
+}
+
+void lsblk_unref_device(struct lsblk_device *dev)
+{
+	if (dev)
+		return;
+
+	if (--dev->refcount <= 0) {
+		DBG(DEV, ul_debugobj(dev, "dealloc"));
+
+		device_remove_dependences(dev);
+		lsblk_device_free_properties(dev->properties);
+
+		list_del_init(&dev->ls_roots);
+		list_del_init(&dev->ls_devices);
+
+		free(dev->name);
+		free(dev->dm_name);
+		free(dev->filename);
+		free(dev->mountpoint);
+
+		ul_unref_path(dev->sysfs);
+		lsblk_ref_devtree(dev->tree);
+
+		free(dev);
+	}
+}
+
+struct lsblk_devdep *lsblk_device_new_dependence(struct lsblk_device *parent, struct lsblk_device *child)
+{
+	struct lsblk_devdep *dp;
+
+	if (!parent || !child) {
+		errno = EINVAL;
+		return NULL;
+	}
+
+	dp = calloc(1, sizeof(*dp));
+	if (!dp)
+		return NULL;
+
+	INIT_LIST_HEAD(&dp->ls_deps);
+
+	lsblk_ref_device(child);
+	dp->child = child;
+
+        DBG(DEV, ul_debugobj(parent, "add dependence 0x%p [%s->%s]", dp, parent->name, child->name));
+        list_add_tail(&dp->ls_deps, &parent->deps);
+
+	return dp;
+}
+
+int lsblk_device_next_child(struct lsblk_device *dev,
+			  struct lsblk_iter *itr,
+			  struct lsblk_device **child)
+{
+	int rc = 1;
+
+	if (!dev || !itr || !child)
+		return -EINVAL;
+	*child = NULL;
+
+	if (!itr->head)
+		LSBLK_ITER_INIT(itr, &dev->deps);
+	if (itr->p != itr->head) {
+		struct lsblk_devdep *dp = NULL;
+
+		LSBLK_ITER_ITERATE(itr, dp, struct lsblk_devdep, ls_deps);
+
+		*child = dp->child;
+		rc = 0;
+	}
+
+	return rc;
+}
+
+struct lsblk_devtree *lsblk_new_devtree()
+{
+	struct lsblk_devtree *tr;
+
+	tr = calloc(1, sizeof(*tr));
+	if (!tr)
+		return NULL;
+
+	tr->refcount = 1;
+
+	INIT_LIST_HEAD(&tr->roots);
+	INIT_LIST_HEAD(&tr->devices);
+
+	DBG(TREE, ul_debugobj(tr, "alloc"));
+	return tr;
+}
+
+void lsblk_ref_devtree(struct lsblk_devtree *tr)
+{
+	if (tr)
+		tr->refcount++;
+}
+
+void lsblk_unref_devtree(struct lsblk_devtree *tr)
+{
+	if (tr)
+		return;
+
+	if (--tr->refcount <= 0) {
+		DBG(TREE, ul_debugobj(tr, "dealloc"));
+
+		while (!list_empty(&tr->roots)) {
+			struct lsblk_device *dev = list_entry(tr->roots.next,
+						struct lsblk_device, ls_roots);
+			lsblk_unref_device(dev);
+		}
+		while (!list_empty(&tr->devices)) {
+			struct lsblk_device *dev = list_entry(tr->devices.next,
+						struct lsblk_device, ls_devices);
+			lsblk_unref_device(dev);
+		}
+		free(tr);
+	}
+}
+
+int lsblk_devtree_add_root(struct lsblk_devtree *tr, struct lsblk_device *dev)
+{
+	lsblk_ref_device(dev);
+
+        DBG(TREE, ul_debugobj(tr, "add root device 0x%p [%s]", dev, dev->name));
+        list_add_tail(&dev->ls_roots, &tr->roots);
+	return 0;
+}
+
+int lsblk_devtree_next_root(struct lsblk_devtree *tr,
+			    struct lsblk_iter *itr,
+			    struct lsblk_device **dev)
+{
+	int rc = 1;
+
+	if (!tr || !itr || !dev)
+		return -EINVAL;
+	*dev = NULL;
+	if (!itr->head)
+		LSBLK_ITER_INIT(itr, &tr->roots);
+	if (itr->p != itr->head) {
+		LSBLK_ITER_ITERATE(itr, *dev, struct lsblk_device, ls_roots);
+		rc = 0;
+	}
+	return rc;
+}
+
+int lsblk_devtree_add_device(struct lsblk_devtree *tr, struct lsblk_device *dev)
+{
+	lsblk_ref_device(dev);
+
+        DBG(TREE, ul_debugobj(tr, "add device 0x%p [%s]", dev, dev->name));
+        list_add_tail(&dev->ls_devices, &tr->devices);
+	return 0;
+}
+
+int lsblk_devtree_next_device(struct lsblk_devtree *tr,
+			    struct lsblk_iter *itr,
+			    struct lsblk_device **dev)
+{
+	int rc = 1;
+
+	if (!tr || !itr || !dev)
+		return -EINVAL;
+	*dev = NULL;
+	if (!itr->head)
+		LSBLK_ITER_INIT(itr, &tr->devices);
+	if (itr->p != itr->head) {
+		LSBLK_ITER_ITERATE(itr, *dev, struct lsblk_device, ls_devices);
+		rc = 0;
+	}
+	return rc;
+}
+
+struct lsblk_device *lsblk_devtree_get_device(struct lsblk_devtree *tr, const char *name)
+{
+	struct lsblk_device *dev = NULL;
+	struct lsblk_iter itr;
+
+	lsblk_reset_iter(&itr, LSBLK_ITER_FORWARD);
+
+	while (lsblk_devtree_next_device(tr, &itr, &dev) == 0) {
+		if (strcmp(name, dev->name) == 0)
+			return dev;
+	}
+
+	return NULL;
+}
+
+