commit 03ed86585e1bfbaf5df1e3488b6268b8887ca427

Author: Peter Rajnoha <prajnoha@redhat.com>

Date:   Tue May 14 11:17:52 2013 +0200

    lvm2-2_02_99-add-dm-disable-udev-env-var-and-fix-noudevsync-arg.patch

---

 WHATS_NEW                  |  2 ++

 WHATS_NEW_DM               |  1 +

 lib/commands/toolcontext.c | 62 ++++++++++++++++++++++++++++++++++------------

 libdm/libdm-common.c       | 43 ++++++++++++++++++++++++++------

 tools/lvmcmdline.c         |  4 +--

 5 files changed, 86 insertions(+), 26 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW

index 1bdfeb0..8516f40 100644

--- a/WHATS_NEW

+++ b/WHATS_NEW

@@ -1,5 +1,7 @@

 Version 2.02.99 - 

 ===================================

+  Recognize DM_DISABLE_UDEV environment variable for a complete fallback.

+  Do not verify udev operations if --noudevsync command option is used.

   Fix blkdeactivate to handle nested mountpoints and mangled mount paths.

   Fix a crash-inducing race condition in lvmetad while updating metadata.

   Fix possible race while removing metadata from lvmetad.

diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM

index e0b8d51..9574fdf 100644

--- a/WHATS_NEW_DM

+++ b/WHATS_NEW_DM

@@ -1,5 +1,6 @@

 Version 1.02.78 - 

 ===================================

+  Add DM_DISABLE_UDEV environment variable to manage dev nodes by libdm only.

   Automatically deactivate failed preloaded dm tree node.

   Fix dm_task_set_cookie to properly process udev flags if udev_sync disabled.

diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c

index eb1a90b..80d0f3e 100644

--- a/lib/commands/toolcontext.c

+++ b/lib/commands/toolcontext.c

@@ -211,6 +211,21 @@ static void _init_logging(struct cmd_context *cmd)

 	reset_lvm_errno(1);

 }

+static int _check_disable_udev(const char *msg) {

+	if (getenv("DM_DISABLE_UDEV")) {

+		log_very_verbose("DM_DISABLE_UDEV environment variable set. "

+				 "Overriding configuration to use "

+				 "udev_rules=0, udev_sync=0, verify_udev_operations=1.");

+		if (udev_is_running())

+			log_warn("Udev is running and DM_DISABLE_UDEV environment variable is set. "

+				 "Bypassing udev, LVM will %s.", msg);

+

+		return 1;

+	}

+

+	return 0;

+}

+

 #ifdef UDEV_SYNC_SUPPORT

 /*

  * Until the DM_UEVENT_GENERATED_FLAG was introduced in kernel patch 

@@ -237,6 +252,7 @@ static int _process_config(struct cmd_context *cmd)

 	const struct dm_config_value *cv;

 	int64_t pv_min_kb;

 	const char *lvmetad_socket;

+	int udev_disabled = 0;

 	/* umask */

 	cmd->default_settings.umask = find_config_tree_int(cmd,

@@ -310,13 +326,20 @@ static int _process_config(struct cmd_context *cmd)

 		return 0;

 	}

-	cmd->default_settings.udev_rules = find_config_tree_int(cmd,

-								"activation/udev_rules",

-								DEFAULT_UDEV_RULES);

+	/*

+	 * If udev is disabled using DM_DISABLE_UDEV environment

+	 * variable, override existing config and hardcode these:

+	 *   - udev_rules = 0

+	 *   - udev_sync = 0

+	 *   - udev_fallback = 1

+	 */

+	udev_disabled = _check_disable_udev("manage logical volume symlinks in device directory");

-	cmd->default_settings.udev_sync = find_config_tree_int(cmd,

-								"activation/udev_sync",

-								DEFAULT_UDEV_SYNC);

+	cmd->default_settings.udev_rules = udev_disabled ? 0 :

+		find_config_tree_int(cmd, "activation/udev_rules", DEFAULT_UDEV_RULES);

+

+	cmd->default_settings.udev_sync = udev_disabled ? 0 :

+		find_config_tree_int(cmd, "activation/udev_sync", DEFAULT_UDEV_SYNC);

 	init_retry_deactivation(find_config_tree_int(cmd, "activation/retry_deactivation",

 							DEFAULT_RETRY_DEACTIVATION));

@@ -326,14 +349,12 @@ static int _process_config(struct cmd_context *cmd)

 #ifdef UDEV_SYNC_SUPPORT

 	/*

-	 * We need udev rules to be applied, otherwise we would end up with no

-	 * nodes and symlinks! However, we can disable the synchronization itself

-	 * in runtime and still have only udev to create the nodes and symlinks

-	 * without any fallback.

+	 * Use udev fallback automatically in case udev

+	 * is disabled via DM_DISABLE_UDEV environment

+	 * variable or udev rules are switched off.

 	 */

-	cmd->default_settings.udev_fallback = cmd->default_settings.udev_rules ?

-		find_config_tree_int(cmd, "activation/verify_udev_operations",

-				     DEFAULT_VERIFY_UDEV_OPERATIONS) : 1;

+	cmd->default_settings.udev_fallback = !cmd->default_settings.udev_rules || udev_disabled ? 1 :

+		find_config_tree_int(cmd, "activation/verify_udev_operations", DEFAULT_VERIFY_UDEV_OPERATIONS);

 	/* Do not rely fully on udev if the udev support is known to be incomplete. */

 	if (!cmd->default_settings.udev_fallback && !_dm_driver_has_stable_udev_support()) {

@@ -693,9 +714,18 @@ static int _init_dev_cache(struct cmd_context *cmd)

 	if (!dev_cache_init(cmd))

 		return_0;

-	device_list_from_udev = udev_is_running() ?

-		find_config_tree_bool(cmd, "devices/obtain_device_list_from_udev",

-				      DEFAULT_OBTAIN_DEVICE_LIST_FROM_UDEV) : 0;

+	/*

+	 * Override existing config and hardcode device_list_from_udev = 0 if:

+	 *   - udev is not running

+	 *   - udev is disabled using DM_DISABLE_UDEV environment variable

+	 */

+	if (_check_disable_udev("obtain device list by scanning device directory"))

+		device_list_from_udev = 0;

+	else

+		device_list_from_udev = udev_is_running() ?

+			find_config_tree_bool(cmd, "devices/obtain_device_list_from_udev",

+					      DEFAULT_OBTAIN_DEVICE_LIST_FROM_UDEV) : 0;

+

 	init_obtain_device_list_from_udev(device_list_from_udev);

 	if (!(cn = find_config_tree_node(cmd, "devices/scan"))) {

diff --git a/libdm/libdm-common.c b/libdm/libdm-common.c

index afdac89..075fba8 100644

--- a/libdm/libdm-common.c

+++ b/libdm/libdm-common.c

@@ -74,6 +74,8 @@ static dm_string_mangling_t _name_mangling_mode = DEFAULT_DM_NAME_MANGLING;

 static struct selabel_handle *_selabel_handle = NULL;

 #endif

+static int _udev_disabled = 0;

+

 #ifdef UDEV_SYNC_SUPPORT

 static int _semaphore_supported = -1;

 static int _udev_running = -1;

@@ -85,6 +87,9 @@ void dm_lib_init(void)

 {

 	const char *env;

+	if ((env = getenv("DM_DISABLE_UDEV")))

+		_udev_disabled = 1;

+

 	env = getenv(DM_DEFAULT_NAME_MANGLING_MODE_ENV_VAR_NAME);

 	if (env && *env) {

 		if (!strcasecmp(env, "none"))

@@ -1814,6 +1819,26 @@ out:

 	return r;

 }

+static void _set_cookie_flags(struct dm_task *dmt, uint16_t flags)

+{

+	if (!dm_cookie_supported())

+		return;

+

+	if (_udev_disabled) {

+		/*

+		 * If udev is disabled, hardcode this functionality:

+		 *   - we want libdm to create the nodes

+		 *   - we don't want the /dev/mapper and any subsystem

+		 *     related content to be created by udev if udev

+		 *     rules are installed

+		 */

+		flags &= ~DM_UDEV_DISABLE_LIBRARY_FALLBACK;

+		flags |= DM_UDEV_DISABLE_DM_RULES_FLAG | DM_UDEV_DISABLE_SUBSYSTEM_RULES_FLAG;

+	}

+

+	dmt->event_nr = flags << DM_UDEV_FLAGS_SHIFT;

+}

+

 #ifndef UDEV_SYNC_SUPPORT

 void dm_udev_set_sync_support(int sync_with_udev)

 {

@@ -1835,8 +1860,8 @@ int dm_udev_get_checking(void)

 int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags)

 {

-	if (dm_cookie_supported())

-		dmt->event_nr = flags << DM_UDEV_FLAGS_SHIFT;

+	_set_cookie_flags(dmt, flags);

+

 	*cookie = 0;

 	dmt->cookie_set = 1;

@@ -1908,8 +1933,13 @@ static void _check_udev_sync_requirements_once(void)

 	if (_semaphore_supported < 0)

 		_semaphore_supported = _check_semaphore_is_supported();

-	if (_udev_running < 0)

+	if (_udev_running < 0) {

 		_udev_running = _check_udev_is_running();

+		if (_udev_disabled && _udev_running)

+			log_warn("Udev is running and DM_DISABLE_UDEV environment variable is set. "

+				 "Bypassing udev, device-mapper library will manage device "

+				 "nodes in device directory.");

+	}

 }

 void dm_udev_set_sync_support(int sync_with_udev)

@@ -1922,8 +1952,8 @@ int dm_udev_get_sync_support(void)

 {

 	_check_udev_sync_requirements_once();

-	return _semaphore_supported && dm_cookie_supported() &&

-		_udev_running && _sync_with_udev;

+	return !_udev_disabled && _semaphore_supported &&

+		dm_cookie_supported() &&_udev_running && _sync_with_udev;

 }

 void dm_udev_set_checking(int checking)

@@ -2203,8 +2233,7 @@ int dm_task_set_cookie(struct dm_task *dmt, uint32_t *cookie, uint16_t flags)

 {

 	int semid;

-	if (dm_cookie_supported())

-		dmt->event_nr = flags << DM_UDEV_FLAGS_SHIFT;

+	_set_cookie_flags(dmt, flags);

 	if (!dm_udev_get_sync_support()) {

 		*cookie = 0;

diff --git a/tools/lvmcmdline.c b/tools/lvmcmdline.c

index 39a8c58..652d57e 100644

--- a/tools/lvmcmdline.c

+++ b/tools/lvmcmdline.c

@@ -901,10 +901,8 @@ static int _get_settings(struct cmd_context *cmd)

 	} else

 		init_trust_cache(0);

-	if (arg_count(cmd, noudevsync_ARG)) {

+	if (arg_count(cmd, noudevsync_ARG))

 		cmd->current_settings.udev_sync = 0;

-		cmd->current_settings.udev_fallback = 1;

-	}

 	/* Handle synonyms */

 	if (!_merge_synonym(cmd, resizable_ARG, resizeable_ARG) ||