nvme: Add bd_nvme_find_namespaces_for_ctrl()

docs/libblockdev-sections.txt

@@ -834,6 +834,7 @@ bd_nvme_connect
 bd_nvme_disconnect
 bd_nvme_disconnect_by_path
 bd_nvme_find_ctrls_for_ns
+bd_nvme_find_namespaces_for_ctrl
 </SECTION>
 
 <SECTION>

src/lib/plugin_apis/nvme.api

@@ -1366,7 +1366,7 @@ gboolean bd_nvme_disconnect_by_path (const gchar *path, GError **error);
 
 /**
  * bd_nvme_find_ctrls_for_ns:
- * @ns_sysfs_path: NVMe namespace device file.
+ * @ns_sysfs_path: NVMe namespace sysfs path.
  * @subsysnqn: (nullable): Limit matching to the specified subsystem NQN.
  * @host_nqn: (nullable): Limit matching to the specified host NQN.
  * @host_id: (nullable): Limit matching to the specified host ID.
@@ -1382,4 +1382,22 @@ gboolean bd_nvme_disconnect_by_path (const gchar *path, GError **error);
  */
 gchar ** bd_nvme_find_ctrls_for_ns (const gchar *ns_sysfs_path, const gchar *subsysnqn, const gchar *host_nqn, const gchar *host_id, GError **error);
 
+/**
+ * bd_nvme_find_namespaces_for_ctrl:
+ * @ctrl_sysfs_path: NVMe controller sysfs path.
+ * @subsysnqn: (nullable): Limit matching to the specified subsystem NQN.
+ * @host_nqn: (nullable): Limit matching to the specified host NQN.
+ * @host_id: (nullable): Limit matching to the specified host ID.
+ * @error: (out) (nullable): Place to store error (if any).
+ *
+ * A convenient utility function to look up all namespaces associated
+ *  with the specified NVMe controller.
+ *
+ * Returns: (transfer full) (array zero-terminated=1): list of namespace sysfs paths
+ *          or %NULL in case of an error (with @error set).
+ *
+ * Tech category: %BD_NVME_TECH_FABRICS-%BD_NVME_TECH_MODE_INITIATOR
+ */
+gchar ** bd_nvme_find_namespaces_for_ctrl (const gchar *ctrl_sysfs_path, const gchar *subsysnqn, const gchar *host_nqn, const gchar *host_id, GError **error);
+
 #endif  /* BD_NVME_API */

src/plugins/nvme/nvme-fabrics.c

@@ -440,7 +440,7 @@ gboolean bd_nvme_disconnect_by_path (const gchar *path, GError **error) {
 
 /**
  * bd_nvme_find_ctrls_for_ns:
- * @ns_sysfs_path: NVMe namespace device file.
+ * @ns_sysfs_path: NVMe namespace sysfs path.
  * @subsysnqn: (nullable): Limit matching to the specified subsystem NQN.
  * @host_nqn: (nullable): Limit matching to the specified host NQN.
  * @host_id: (nullable): Limit matching to the specified host ID.
@@ -521,6 +521,80 @@ gchar ** bd_nvme_find_ctrls_for_ns (const gchar *ns_sysfs_path, const gchar *sub
 }
 
 
+/**
+ * bd_nvme_find_namespaces_for_ctrl:
+ * @ctrl_sysfs_path: NVMe controller sysfs path.
+ * @subsysnqn: (nullable): Limit matching to the specified subsystem NQN.
+ * @host_nqn: (nullable): Limit matching to the specified host NQN.
+ * @host_id: (nullable): Limit matching to the specified host ID.
+ * @error: (out) (nullable): Place to store error (if any).
+ *
+ * A convenient utility function to look up all namespaces associated
+ *  with the specified NVMe controller.
+ *
+ * Returns: (transfer full) (array zero-terminated=1): list of namespace sysfs paths
+ *          or %NULL in case of an error (with @error set).
+ *
+ * Tech category: %BD_NVME_TECH_FABRICS-%BD_NVME_TECH_MODE_INITIATOR
+ */
+gchar ** bd_nvme_find_namespaces_for_ctrl (const gchar *ctrl_sysfs_path, const gchar *subsysnqn, const gchar *host_nqn, const gchar *host_id, GError **error G_GNUC_UNUSED) {
+    GPtrArray *ptr_array;
+    nvme_root_t root;
+    nvme_host_t h;
+    nvme_subsystem_t s;
+    nvme_ctrl_t c;
+    nvme_ns_t n;
+    char realp[PATH_MAX];
+    gchar *subsysnqn_p;
+
+    /* libnvme strips trailing spaces and newlines when reading values from sysfs */
+    subsysnqn_p = g_strdup (subsysnqn);
+    if (subsysnqn_p)
+        g_strchomp (subsysnqn_p);
+
+    ptr_array = g_ptr_array_new ();
+
+    root = nvme_scan (NULL);
+    g_warn_if_fail (root != NULL);
+
+    nvme_for_each_host (root, h) {
+        if (host_nqn && g_strcmp0 (nvme_host_get_hostnqn (h), host_nqn) != 0)
+            continue;
+        if (host_id && g_strcmp0 (nvme_host_get_hostid (h), host_id) != 0)
+            continue;
+
+        nvme_for_each_subsystem (h, s) {
+            if (subsysnqn && g_strcmp0 (nvme_subsystem_get_nqn (s), subsysnqn_p) != 0)
+                continue;
+
+            nvme_subsystem_for_each_ctrl (s, c) {
+                if (realpath (nvme_ctrl_get_sysfs_dir (c), realp) &&
+                    g_strcmp0 (realp, ctrl_sysfs_path) == 0) {
+                    /* Found matching controller, add all its namespaces */
+                    nvme_ctrl_for_each_ns (c, n) {
+                        if (realpath (nvme_ns_get_sysfs_dir (n), realp)) {
+                            g_ptr_array_add (ptr_array, g_strdup (realp));
+                        }
+                    }
+                    /* Also check subsystem-level namespaces */
+                    nvme_subsystem_for_each_ns (s, n) {
+                        if (realpath (nvme_ns_get_sysfs_dir (n), realp)) {
+                            g_ptr_array_add (ptr_array, g_strdup (realp));
+                        }
+                    }
+                    break;
+                }
+            }
+        }
+    }
+    nvme_free_tree (root);
+    g_free (subsysnqn_p);
+
+    g_ptr_array_add (ptr_array, NULL);  /* trailing NULL element */
+    return (gchar **) g_ptr_array_free (ptr_array, FALSE);
+}
+
+
 /**
  * bd_nvme_get_host_nqn:
  * @error: (out) (nullable): Place to store error (if any).

src/plugins/nvme/nvme.h

@@ -629,5 +629,11 @@ gchar **               bd_nvme_find_ctrls_for_ns     (const gchar       *ns_sysf
                                                       const gchar       *host_id,
                                                       GError           **error);
 
+gchar **               bd_nvme_find_namespaces_for_ctrl (const gchar       *ctrl_sysfs_path,
+                                                         const gchar       *subsysnqn,
+                                                         const gchar       *host_nqn,
+                                                         const gchar       *host_id,
+                                                         GError           **error);
+
 
 #endif  /* BD_NVME */

tests/nvme_test.py

@@ -476,6 +476,32 @@ def test_connect_multiple_ns(self):
             ctrl_sysfs_paths = BlockDev.nvme_find_ctrls_for_ns(ns_sysfs_path, self.SUBNQN, self.hostnqn, "unknownhostid")
             self.assertEqual(len(ctrl_sysfs_paths), 0)
 
+            # test bd_nvme_find_namespaces_for_ctrl()
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, None, None, None)
+            self.assertIsNotNone(ns_sysfs_paths)
+            self.assertEqual(len(ns_sysfs_paths), NUM_NS)
+            self.assertIn(ns_sysfs_path, ns_sysfs_paths)
+
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path + "xxx", None, None, None)
+            self.assertEqual(len(ns_sysfs_paths), 0)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, self.SUBNQN, None, None)
+            self.assertEqual(len(ns_sysfs_paths), NUM_NS)
+            self.assertIn(ns_sysfs_path, ns_sysfs_paths)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, self.SUBNQN, self.hostnqn, None)
+            self.assertEqual(len(ns_sysfs_paths), NUM_NS)
+            self.assertIn(ns_sysfs_path, ns_sysfs_paths)
+
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, "unknownsubsysnqn", None, None)
+            self.assertEqual(len(ns_sysfs_paths), 0)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, None, "unknownhostnqn", None)
+            self.assertEqual(len(ns_sysfs_paths), 0)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, self.SUBNQN, "unknownhostnqn", None)
+            self.assertEqual(len(ns_sysfs_paths), 0)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, None, None, "unknownhostid")
+            self.assertEqual(len(ns_sysfs_paths), 0)
+            ns_sysfs_paths = BlockDev.nvme_find_namespaces_for_ctrl(ctrl_sysfs_path, self.SUBNQN, self.hostnqn, "unknownhostid")
+            self.assertEqual(len(ns_sysfs_paths), 0)
+
         # disconnect
         BlockDev.nvme_disconnect_by_path(ctrls[0])
         for c in ctrls: