Gitweb: http://git.fedorahosted.org/git/?p=lvm2.git;a=commitdiff;h=4891a735d343db264... Commit: 4891a735d343db26460f1b6218169c458d59f2a1 Parent: fb8cc7c63f7f5ab9e0d6d2d38f29169346a54087 Author: Peter Rajnoha prajnoha@redhat.com AuthorDate: Thu Nov 29 14:03:48 2012 +0100 Committer: Peter Rajnoha prajnoha@redhat.com CommitterDate: Thu Nov 29 14:03:48 2012 +0100
udev: recognize DM_DISABLE_UDEV environment variable
Setting this environment variable will cause a full fallback to old direct node and symlink management in libdevmapper and lvm2.
It means:
- disabling udev synchronization (--noudevsync in dmsetup and --noudevsync + activation/udev_sync=0 lvm2 config) - disabling dm and any subsystem related udev rules (--noudevrules in dmsetup and activation/udev_rules=0 lvm2 config) - management of nodes/symlinks under /dev directly by libdevmapper/lvm2 (--verifyudev in dmsetup and activation/verify_udev_operations=1 lvm2 config) - not obtaining any device list from udev database (devices/obtain_device_list_from_udev=0 lvm2 config)
Note: we could set all of these before - there's no functional change! However the DM_DISABLE_UDEV environment variable is a nice shortcut to make it easier for libdevmapper users so that one can switch off all of the udev management off at one go directly on the command line, without a need to modify any source or add any extra switches. --- WHATS_NEW | 1 + WHATS_NEW_DM | 1 + lib/commands/toolcontext.c | 55 +++++++++++++++++++++++++++++++------------ libdm/libdm-common.c | 34 ++++++++++++++++++++++++--- 4 files changed, 71 insertions(+), 20 deletions(-)
diff --git a/WHATS_NEW b/WHATS_NEW index 657b3a4..ca1b539 100644 --- a/WHATS_NEW +++ b/WHATS_NEW @@ -1,5 +1,6 @@ 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 lvm2api and return lvseg discards property as string. Allow forced vgcfgrestore of lvm2 metadata with thin volumes. diff --git a/WHATS_NEW_DM b/WHATS_NEW_DM index 3f8d9c9..3ea0502 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. Fix dm_task_set_cookie to properly process udev flags if udev_sync disabled.
Version 1.02.77 - 15th October 2012 diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c index aec4df3..57ce1fe 100644 --- a/lib/commands/toolcontext.c +++ b/lib/commands/toolcontext.c @@ -237,6 +237,7 @@ 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 +311,25 @@ 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 + */ + 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."); + udev_disabled = 1; + } + + cmd->default_settings.udev_rules = udev_disabled ? 0 : + find_config_tree_int(cmd, "activation/udev_rules", DEFAULT_UDEV_RULES);
- cmd->default_settings.udev_sync = find_config_tree_int(cmd, - "activation/udev_sync", - DEFAULT_UDEV_SYNC); + 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 +339,12 @@ 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 +704,21 @@ 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 (getenv("DM_DISABLE_UDEV")) { + log_very_verbose("DM_DISABLE_UDEV environment variable set. " + "Overriding configuration to use " + "device_list_from_udev=0"); + 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..2d79efa 100644 --- a/libdm/libdm-common.c +++ b/libdm/libdm-common.c @@ -75,6 +75,7 @@ static struct selabel_handle *_selabel_handle = NULL; #endif
#ifdef UDEV_SYNC_SUPPORT +static int _udev_disabled = 0; static int _semaphore_supported = -1; static int _udev_running = -1; static int _sync_with_udev = 1; @@ -85,6 +86,9 @@ 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 +1818,26 @@ 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 +1859,8 @@ 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;
@@ -1920,6 +1944,9 @@ void dm_udev_set_sync_support(int sync_with_udev)
int dm_udev_get_sync_support(void) { + if (_udev_disabled) + return 0; + _check_udev_sync_requirements_once();
return _semaphore_supported && dm_cookie_supported() && @@ -2203,8 +2230,7 @@ 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;
lvm2-commits@lists.fedorahosted.org
-
Peter Rajnoha