From 8d5c90a1f4bbe548a1ae361f8d69970669d6e72e Mon Sep 17 00:00:00 2001

From: Tomas Bzatek <tbzatek@redhat.com>

Date: Fri, 13 Nov 2020 16:52:11 +0100

Subject: [PATCH 1/2] udisksdaemonutil: Refactor

 udisks_daemon_util_trigger_uevent() out of UDisksLinuxBlockObject

This decouples uevent triggering from UDisksLinuxBlockObject as sometimes

we don't have a block object yet or it's outdated.

---

 doc/udisks2-sections.txt.daemon.sections.in |   2 +

 src/udisksdaemonutil.c                      | 230 ++++++++++++++++++++

 src/udisksdaemonutil.h                      |   7 +

 src/udiskslinuxblockobject.c                | 180 ++-------------

 4 files changed, 253 insertions(+), 166 deletions(-)

diff --git a/doc/udisks2-sections.txt.daemon.sections.in b/doc/udisks2-sections.txt.daemon.sections.in

index 26c3c2cd..3030fa95 100644

--- a/doc/udisks2-sections.txt.daemon.sections.in

+++ b/doc/udisks2-sections.txt.daemon.sections.in

@@ -307,6 +307,8 @@ udisks_daemon_util_file_set_contents

 udisks_daemon_util_on_user_seat

 udisks_daemon_util_get_free_mdraid_device

 udisks_ata_identify_get_word

+udisks_daemon_util_trigger_uevent

+udisks_daemon_util_trigger_uevent_sync

 </SECTION>

 <SECTION>

diff --git a/src/udisksdaemonutil.c b/src/udisksdaemonutil.c

index 75b877a0..d16c0766 100644

--- a/src/udisksdaemonutil.c

+++ b/src/udisksdaemonutil.c

@@ -34,10 +34,14 @@

 #include <limits.h>

 #include <stdlib.h>

+#include <blockdev/blockdev.h>

+

 #include "udisksdaemon.h"

 #include "udisksdaemonutil.h"

 #include "udisksstate.h"

 #include "udiskslogging.h"

+#include "udiskslinuxdevice.h"

+#include "udiskslinuxprovider.h"

 #include "udiskslinuxblockobject.h"

 #include "udiskslinuxdriveobject.h"

@@ -1626,3 +1630,229 @@ udisks_ata_identify_get_word (const guchar *identify_data, guint word_number)

  out:

   return ret;

 }

+

+

+/* ---------------------------------------------------------------------------------------------------- */

+

+static volatile guint uevent_serial = 0;

+

+static gboolean

+trigger_uevent (const gchar *path, const gchar *str)

+{

+  gint fd;

+

+  fd = open (path, O_WRONLY);

+  if (fd < 0)

+    {

+      udisks_warning ("Error opening %s while triggering uevent: %m", path);

+      return FALSE;

+    }

+

+  if (write (fd, str, strlen (str)) != (ssize_t) strlen (str))

+    {

+      udisks_warning ("Error writing '%s' to file %s: %m", str, path);

+      close (fd);

+      return FALSE;

+    }

+

+  close (fd);

+  return TRUE;

+}

+

+typedef struct

+{

+  UDisksDaemon *daemon;

+  GMainLoop *main_loop;

+  guint serial;

+  gchar *uevent_path;

+  gboolean success;

+} SynthUeventData;

+

+static gboolean

+trigger_uevent_idle_cb (gpointer user_data)

+{

+  SynthUeventData *data = user_data;

+  gchar *str;

+

+  str = g_strdup_printf ("change %s UDISKSSERIAL=%u", udisks_daemon_get_uuid (data->daemon), data->serial);

+

+  if (! trigger_uevent (data->uevent_path, str))

+    {

+      /* kernel refused our string, try simple "change" but don't wait for it */

+      trigger_uevent (data->uevent_path, "change");

+      data->success = FALSE;

+      g_main_loop_quit (data->main_loop);

+    }

+  g_free (str);

+

+  /* remove the source */

+  return FALSE;

+}

+

+static gboolean

+uevent_wait_timeout_cb (gpointer user_data)

+{

+  SynthUeventData *data = user_data;

+

+  data->success = FALSE;

+  g_main_loop_quit (data->main_loop);

+

+  /* remove the source */

+  return FALSE;

+}

+

+static void

+uevent_probed_cb (UDisksLinuxProvider *provider,

+                  const gchar         *action,

+                  UDisksLinuxDevice   *device,

+                  gpointer             user_data)

+{

+  SynthUeventData *data = user_data;

+  const gchar *received_serial_str;

+  gint64 received_serial;

+  gchar *endptr;

+

+  received_serial_str = g_udev_device_get_property (device->udev_device, "SYNTH_ARG_UDISKSSERIAL");

+  if (received_serial_str != NULL)

+    {

+      endptr = (gchar *) received_serial_str;

+      received_serial = g_ascii_strtoll (received_serial_str, &endptr, 0);

+      if (endptr != received_serial_str && received_serial == data->serial)

+        {

+          data->success = TRUE;

+          g_main_loop_quit (data->main_loop);

+        }

+    }

+}

+

+/**

+ * udisks_daemon_util_trigger_uevent:

+ * @daemon: A #UDisksDaemon.

+ * @device_path: Block device path.

+ *

+ * Triggers a 'change' uevent in the kernel.

+ *

+ * The triggered event will bubble up from the kernel through the udev

+ * stack and will eventually be received by the udisks daemon process

+ * itself. This method does not wait for the event to be received.

+ */

+void

+udisks_daemon_util_trigger_uevent (UDisksDaemon *daemon,

+                                   const gchar  *device_path)

+{

+  GUdevClient *gudev_client;

+  GUdevDevice *gudev_device;

+  gchar *path;

+

+  g_return_if_fail (UDISKS_IS_DAEMON (daemon));

+  g_return_if_fail (device_path != NULL);

+

+  gudev_client = udisks_linux_provider_get_udev_client (udisks_daemon_get_linux_provider (daemon));

+  gudev_device = g_udev_client_query_by_device_file (gudev_client, device_path);

+  if (gudev_device == NULL)

+    {

+      udisks_critical ("Device %s not found in udev database, skipping uevent trigger", device_path);

+      return;

+    }

+

+  path = g_build_filename (g_udev_device_get_sysfs_path (gudev_device), "uevent", NULL);

+  trigger_uevent (path, "change");

+  g_free (path);

+

+  g_object_unref (gudev_device);

+}

+

+/**

+ * udisks_daemon_util_trigger_uevent_sync:

+ * @daemon: A #UDisksDaemon.

+ * @device_path: Block device path.

+ * @timeout_seconds: Maximum time to wait for the uevent (in seconds).

+ *

+ * Triggers a 'change' uevent in the kernel and waits until it's received and

+ * processed by udisks.

+ *

+ * Unlike udisks_daemon_util_trigger_uevent() that just triggers

+ * a synthetic uevent to the kernel, this call will actually block and wait until

+ * the #UDisksLinuxProvider receives the uevent, performs probing and processes

+ * the uevent further down the UDisks object stack. Upon returning from this

+ * function call the caller may assume the event has been fully processed, all

+ * D-Bus objects are updated and settled. Typically used in busy wait for

+ * a particular D-Bus interface.

+ *

+ * Note that this uses synthetic uevent tagging and only works on linux kernel

+ * 4.13 and higher. In case an older kernel is detected this acts like the classic

+ * udisks_daemon_util_trigger_uevent() call and %FALSE is returned.

+ *

+ * Returns: %TRUE if the uevent has been successfully received, %FALSE otherwise

+ * or when the kernel version is too old.

+ */

+gboolean

+udisks_daemon_util_trigger_uevent_sync (UDisksDaemon *daemon,

+                                        const gchar  *device_path,

+                                        guint         timeout_seconds)

+{

+  UDisksLinuxProvider *provider;

+  GUdevClient *gudev_client;

+  GUdevDevice *gudev_device;

+  SynthUeventData data;

+  GMainContext *main_context;

+  GSource *idle_source;

+  GSource *timeout_source;

+

+  g_return_val_if_fail (UDISKS_IS_DAEMON (daemon), FALSE);

+  g_return_val_if_fail (device_path != NULL, FALSE);

+

+  if (bd_utils_check_linux_version (4, 13, 0) < 0)

+    {

+      udisks_daemon_util_trigger_uevent (daemon, device_path);

+      return FALSE;

+    }

+

+  provider = udisks_daemon_get_linux_provider (daemon);

+  gudev_client = udisks_linux_provider_get_udev_client (provider);

+  gudev_device = g_udev_client_query_by_device_file (gudev_client, device_path);

+  if (gudev_device == NULL)

+    {

+      udisks_critical ("Device %s not found in udev database, skipping uevent trigger", device_path);

+      return FALSE;

+    }

+

+  data.daemon = daemon;

+  data.uevent_path = g_build_filename (g_udev_device_get_sysfs_path (gudev_device), "uevent", NULL);

+  data.serial = g_atomic_int_add (&uevent_serial, 1);

+

+  main_context = g_main_context_new ();

+  g_main_context_push_thread_default (main_context);

+  data.main_loop = g_main_loop_new (main_context, FALSE);

+

+  /* queue the actual trigger in the loop */

+  idle_source = g_idle_source_new ();

+  g_source_set_callback (idle_source, (GSourceFunc) trigger_uevent_idle_cb, &data, NULL);

+  g_source_attach (idle_source, main_context);

+  g_source_unref (idle_source);

+

+  /* add timeout as a fallback */

+  timeout_source = g_timeout_source_new_seconds (timeout_seconds);

+  g_source_set_callback (timeout_source, (GSourceFunc) uevent_wait_timeout_cb, &data, NULL);

+  g_source_attach (timeout_source, main_context);

+  g_source_unref (timeout_source);

+

+  /* catch incoming uevents */

+  g_signal_connect (provider, "uevent-probed", G_CALLBACK (uevent_probed_cb), &data);

+

+  data.success = FALSE;

+  g_main_loop_run (data.main_loop);

+

+  g_signal_handlers_disconnect_by_func (provider, uevent_probed_cb, &data);

+  g_main_context_pop_thread_default (main_context);

+

+  g_main_loop_unref (data.main_loop);

+  g_main_context_unref (main_context);

+

+  g_free (data.uevent_path);

+  g_object_unref (gudev_device);

+

+  return data.success;

+}

+

+/* ---------------------------------------------------------------------------------------------------- */

diff --git a/src/udisksdaemonutil.h b/src/udisksdaemonutil.h

index 4fe36214..2edf2122 100644

--- a/src/udisksdaemonutil.h

+++ b/src/udisksdaemonutil.h

@@ -51,6 +51,13 @@ guint64 udisks_daemon_util_block_get_size (GUdevDevice *device,

                                            gboolean    *out_media_available,

                                            gboolean    *out_media_change_detected);

+void udisks_daemon_util_trigger_uevent (UDisksDaemon *daemon,

+                                        const gchar  *device_path);

+

+gboolean udisks_daemon_util_trigger_uevent_sync (UDisksDaemon *daemon,

+                                                 const gchar  *device_path,

+                                                 guint         timeout_seconds);

+

 gchar *udisks_daemon_util_resolve_link (const gchar *path,

                                         const gchar *name);

diff --git a/src/udiskslinuxblockobject.c b/src/udiskslinuxblockobject.c

index 42ab17d7..5a68c84b 100644

--- a/src/udiskslinuxblockobject.c

+++ b/src/udiskslinuxblockobject.c

@@ -38,8 +38,6 @@

 #include <stdlib.h>

 #include <glib/gstdio.h>

-#include <blockdev/blockdev.h>

-

 #include "udiskslogging.h"

 #include "udisksdaemon.h"

 #include "udisksdaemonutil.h"

@@ -959,122 +957,24 @@ on_mount_monitor_mount_removed (UDisksMountMonitor  *monitor,

 /* ---------------------------------------------------------------------------------------------------- */

-static volatile guint uevent_serial = 0;

-

-static gboolean

-trigger_uevent (const gchar *path, const gchar *str)

-{

-  gint fd;

-

-  fd = open (path, O_WRONLY);

-  if (fd < 0)

-    {

-      udisks_warning ("Error opening %s while triggering uevent: %m", path);

-      return FALSE;

-    }

-

-  if (write (fd, str, strlen (str)) != (ssize_t) strlen (str))

-    {

-      udisks_warning ("Error writing '%s' to file %s: %m", str, path);

-      close (fd);

-      return FALSE;

-    }

-

-  close (fd);

-  return TRUE;

-}

-

-typedef struct

-{

-  UDisksLinuxBlockObject *object;

-  GMainLoop *main_loop;

-  guint serial;

-  gchar *uevent_path;

-  gboolean success;

-} SynthUeventData;

-

-static gboolean

-trigger_uevent_idle_cb (gpointer user_data)

-{

-  SynthUeventData *data = user_data;

-  gchar *str;

-

-  str = g_strdup_printf ("change %s UDISKSSERIAL=%u", udisks_daemon_get_uuid (data->object->daemon), data->serial);

-

-  if (! trigger_uevent (data->uevent_path, str))

-    {

-      /* kernel refused our string, try simple "change" but don't wait for it */

-      trigger_uevent (data->uevent_path, "change");

-      data->success = FALSE;

-      g_main_loop_quit (data->main_loop);

-    }

-  g_free (str);

-

-  /* remove the source */

-  return FALSE;

-}

-

-static gboolean

-uevent_wait_timeout_cb (gpointer user_data)

-{

-  SynthUeventData *data = user_data;

-

-  data->success = FALSE;

-  g_main_loop_quit (data->main_loop);

-

-  /* remove the source */

-  return FALSE;

-}

-

-static void

-uevent_probed_cb (UDisksLinuxProvider *provider,

-                  const gchar         *action,

-                  UDisksLinuxDevice   *device,

-                  gpointer             user_data)

-{

-  SynthUeventData *data = user_data;

-  const gchar *received_serial_str;

-  gint64 received_serial;

-  gchar *endptr;

-

-  received_serial_str = g_udev_device_get_property (device->udev_device, "SYNTH_ARG_UDISKSSERIAL");

-  if (received_serial_str != NULL)

-    {

-      endptr = (gchar *) received_serial_str;

-      received_serial = g_ascii_strtoll (received_serial_str, &endptr, 0);

-      if (endptr != received_serial_str && received_serial == data->serial)

-        {

-          data->success = TRUE;

-          g_main_loop_quit (data->main_loop);

-        }

-    }

-}

-

 /**

  * udisks_linux_block_object_trigger_uevent:

  * @object: A #UDisksLinuxBlockObject.

  *

  * Triggers a 'change' uevent in the kernel.

  *

- * The triggered event will bubble up from the kernel through the udev

- * stack and will eventually be received by the udisks daemon process

- * itself. This method does not wait for the event to be received.

+ * Refer to udisks_daemon_util_trigger_uevent() for detailed description.

  */

 void

 udisks_linux_block_object_trigger_uevent (UDisksLinuxBlockObject *object)

 {

-  UDisksLinuxDevice *device;

-  gchar *path;

+  gchar *device_file;

   g_return_if_fail (UDISKS_IS_LINUX_BLOCK_OBJECT (object));

-  device = udisks_linux_block_object_get_device (object);

-  path = g_strconcat (g_udev_device_get_sysfs_path (device->udev_device), "/uevent", NULL);

-

-  trigger_uevent (path, "change");

-

-  g_free (path);

-  g_object_unref (device);

+  device_file = udisks_linux_block_object_get_device_file (object);

+  udisks_daemon_util_trigger_uevent (object->daemon, device_file);

+  g_free (device_file);

 }

 /**

@@ -1083,19 +983,10 @@ udisks_linux_block_object_trigger_uevent (UDisksLinuxBlockObject *object)

  * @timeout_seconds: Maximum time to wait for the uevent (in seconds).

  *

  * Triggers a 'change' uevent in the kernel and waits until it's received and

- * processed by udisks.

- *

- * Unlike udisks_linux_block_object_trigger_uevent() that just triggers

- * a synthetic uevent to the kernel, this call will actually block and wait until

- * the #UDisksLinuxProvider receives the uevent, performs probing and processes

- * the uevent further down the UDisks object stack. Upon returning from this

- * function call the caller may assume the event has been fully processed, all

- * D-Bus objects are updated and settled. Typically used in busy wait for

- * a particular D-Bus interface.

+ * processed through the uevent queue.

  *

- * Note that this uses synthetic uevent tagging and only works on linux kernel

- * 4.13 and higher. In case an older kernel is detected this acts like the classic

- * udisks_linux_block_object_trigger_uevent() call and %FALSE is returned.

+ * This is a convenient wrapper around udisks_daemon_util_trigger_uevent_sync().

+ * Refer to this function for detailed documentation.

  *

  * Returns: %TRUE if the uevent has been successfully received, %FALSE otherwise

  * or when the kernel version is too old.

@@ -1104,59 +995,16 @@ gboolean

 udisks_linux_block_object_trigger_uevent_sync (UDisksLinuxBlockObject *object,

                                                guint                   timeout_seconds)

 {

-  UDisksLinuxDevice *device;

-  UDisksLinuxProvider *provider;

-  SynthUeventData data;

-  GMainContext *main_context;

-  GSource *idle_source;

-  GSource *timeout_source;

+  gchar *device_file;

+  gboolean ret;

   g_return_val_if_fail (UDISKS_IS_LINUX_BLOCK_OBJECT (object), FALSE);

-  if (bd_utils_check_linux_version (4, 13, 0) < 0)

-    {

-      udisks_linux_block_object_trigger_uevent (object);

-      return FALSE;

-    }

-

-  data.object = object;

-  device = udisks_linux_block_object_get_device (object);

-  data.uevent_path = g_strconcat (g_udev_device_get_sysfs_path (device->udev_device), "/uevent", NULL);

-  data.serial = g_atomic_int_add (&uevent_serial, 1);

-

-  main_context = g_main_context_new ();

-  g_main_context_push_thread_default (main_context);

-  data.main_loop = g_main_loop_new (main_context, FALSE);

-

-  /* queue the actual trigger in the loop */

-  idle_source = g_idle_source_new ();

-  g_source_set_callback (idle_source, (GSourceFunc) trigger_uevent_idle_cb, &data, NULL);

-  g_source_attach (idle_source, main_context);

-  g_source_unref (idle_source);

+  device_file = udisks_linux_block_object_get_device_file (object);

+  ret = udisks_daemon_util_trigger_uevent_sync (object->daemon, device_file, timeout_seconds);

+  g_free (device_file);

-  /* add timeout as a fallback */

-  timeout_source = g_timeout_source_new_seconds (timeout_seconds);

-  g_source_set_callback (timeout_source, (GSourceFunc) uevent_wait_timeout_cb, &data, NULL);

-  g_source_attach (timeout_source, main_context);

-  g_source_unref (timeout_source);

-

-  /* catch incoming uevents */

-  provider = udisks_daemon_get_linux_provider (object->daemon);

-  g_signal_connect (provider, "uevent-probed", G_CALLBACK (uevent_probed_cb), &data);

-

-  data.success = FALSE;

-  g_main_loop_run (data.main_loop);

-

-  g_signal_handlers_disconnect_by_func (provider, uevent_probed_cb, &data);

-  g_main_context_pop_thread_default (main_context);

-

-  g_main_loop_unref (data.main_loop);

-  g_main_context_unref (main_context);

-

-  g_free (data.uevent_path);

-  g_object_unref (device);

-

-  return data.success;

+  return ret;

 }

 /* ---------------------------------------------------------------------------------------------------- */

-- 

2.26.2