commit 811db05e50b042c7ce3dc3ca9cfd3eccac464caa
Author: Peter Rajnoha <prajnoha@redhat.com>
Date: Tue May 14 11:22:58 2013 +0200
lvm2-2_02_99-fix-premature-dm-version-checking-which-caused-useless-mapper-control-access.patch
---
WHATS_NEW | 1 +
lib/activate/dev_manager.c | 58 +++++++++++++++++++++++++++++++++++++++++++---
lib/commands/toolcontext.c | 46 +++++++-----------------------------
3 files changed, 64 insertions(+), 41 deletions(-)
diff --git a/WHATS_NEW b/WHATS_NEW
index 8516f40..eb7897d 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
Version 2.02.99 -
===================================
+ Fix premature DM version checking which caused useless mapper/control access.
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.
diff --git a/lib/activate/dev_manager.c b/lib/activate/dev_manager.c
index 31c1c27..7abd43b 100644
--- a/lib/activate/dev_manager.c
+++ b/lib/activate/dev_manager.c
@@ -1016,6 +1016,58 @@ int dev_manager_mknodes(const struct logical_volume *lv)
return r;
}
+#ifdef UDEV_SYNC_SUPPORT
+/*
+ * Until the DM_UEVENT_GENERATED_FLAG was introduced in kernel patch
+ * 856a6f1dbd8940e72755af145ebcd806408ecedd
+ * some operations could not be performed by udev, requiring our fallback code.
+ */
+static int _dm_driver_has_stable_udev_support(void)
+{
+ char vsn[80];
+ unsigned maj, min, patchlevel;
+
+ return driver_version(vsn, sizeof(vsn)) &&
+ (sscanf(vsn, "%u.%u.%u", &maj, &min, &patchlevel) == 3) &&
+ (maj == 4 ? min >= 18 : maj > 4);
+}
+
+static int _check_udev_fallback(struct cmd_context *cmd)
+{
+ struct config_info *settings = &cmd->current_settings;
+
+ if (settings->udev_fallback != -1)
+ goto out;
+
+ /*
+ * Use udev fallback automatically in case udev
+ * is disabled via DM_DISABLE_UDEV environment
+ * variable or udev rules are switched off.
+ */
+ settings->udev_fallback = !settings->udev_rules ? 1 :
+ find_config_tree_bool(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 (!settings->udev_fallback && !_dm_driver_has_stable_udev_support()) {
+ log_very_verbose("Kernel driver has incomplete udev support so "
+ "LVM will check and perform some operations itself.");
+ settings->udev_fallback = 1;
+ }
+out:
+ return settings->udev_fallback;
+}
+
+#else /* UDEV_SYNC_SUPPORT */
+
+static int _check_udev_fallback(struct cmd_context *cmd)
+{
+ /* We must use old node/symlink creation code if not compiled with udev support at all! */
+ return cmd->current_settings.udev_fallback = 1;
+}
+
+#endif /* UDEV_SYNC_SUPPORT */
+
static uint16_t _get_udev_flags(struct dev_manager *dm, struct logical_volume *lv,
const char *layer)
{
@@ -1025,7 +1077,7 @@ static uint16_t _get_udev_flags(struct dev_manager *dm, struct logical_volume *l
* Instruct also libdevmapper to disable udev
* fallback in accordance to LVM2 settings.
*/
- if (!dm->cmd->current_settings.udev_fallback)
+ if (!_check_udev_fallback(dm->cmd))
udev_flags |= DM_UDEV_DISABLE_LIBRARY_FALLBACK;
/*
@@ -2036,7 +2088,7 @@ static int _create_lv_symlinks(struct dev_manager *dm, struct dm_tree_node *root
int r = 1;
/* Nothing to do if udev fallback is disabled. */
- if (!dm->cmd->current_settings.udev_fallback) {
+ if (!_check_udev_fallback(dm->cmd)) {
fs_set_create();
return 1;
}
@@ -2084,7 +2136,7 @@ static int _remove_lv_symlinks(struct dev_manager *dm, struct dm_tree_node *root
int r = 1;
/* Nothing to do if udev fallback is disabled. */
- if (!dm->cmd->current_settings.udev_fallback)
+ if (!_check_udev_fallback(dm->cmd))
return 1;
while ((child = dm_tree_next_child(&handle, root, 0))) {
diff --git a/lib/commands/toolcontext.c b/lib/commands/toolcontext.c
index 80d0f3e..61d5c26 100644
--- a/lib/commands/toolcontext.c
+++ b/lib/commands/toolcontext.c
@@ -226,23 +226,6 @@ static int _check_disable_udev(const char *msg) {
return 0;
}
-#ifdef UDEV_SYNC_SUPPORT
-/*
- * Until the DM_UEVENT_GENERATED_FLAG was introduced in kernel patch
- * 856a6f1dbd8940e72755af145ebcd806408ecedd
- * some operations could not be performed by udev, requiring our fallback code.
- */
-static int _dm_driver_has_stable_udev_support(void)
-{
- char vsn[80];
- unsigned maj, min, patchlevel;
-
- return driver_version(vsn, sizeof(vsn)) &&
- (sscanf(vsn, "%u.%u.%u", &maj, &min, &patchlevel) == 3) &&
- (maj == 4 ? min >= 18 : maj > 4);
-}
-#endif
-
static int _process_config(struct cmd_context *cmd)
{
mode_t old_umask;
@@ -341,33 +324,20 @@ static int _process_config(struct cmd_context *cmd)
cmd->default_settings.udev_sync = udev_disabled ? 0 :
find_config_tree_int(cmd, "activation/udev_sync", DEFAULT_UDEV_SYNC);
+ /*
+ * Set udev_fallback lazily on first use since it requires
+ * checking DM driver version which is an extra ioctl!
+ * This also prevents unnecessary use of mapper/control.
+ * If udev is disabled globally, set fallback mode immediately.
+ */
+ cmd->default_settings.udev_fallback = udev_disabled ? 1 : -1;
+
init_retry_deactivation(find_config_tree_int(cmd, "activation/retry_deactivation",
DEFAULT_RETRY_DEACTIVATION));
init_activation_checks(find_config_tree_int(cmd, "activation/checks",
DEFAULT_ACTIVATION_CHECKS));
-#ifdef UDEV_SYNC_SUPPORT
- /*
- * 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 || 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()) {
- log_very_verbose("Kernel driver has incomplete udev support so "
- "LVM will check and perform some operations itself.");
- cmd->default_settings.udev_fallback = 1;
- }
-
-#else
- /* We must use old node/symlink creation code if not compiled with udev support at all! */
- cmd->default_settings.udev_fallback = 1;
-#endif
-
cmd->use_linear_target = find_config_tree_int(cmd,
"activation/use_linear_target",
DEFAULT_USE_LINEAR_TARGET);