Speedup consequent activation calls

Stop calling fs_unlock() from lv_de/activate().
Start using internal lvm fs cookie for dm_tree.
Stop directly calling dm_udev_wait() and
dm_tree_set/get_cookie() from activate code -
it's now called through fs_unlock() function.

Add lvm_do_fs_unlock()

Call fs_unlock() when unlocking vg where implicit unlock solves the
problem also for cluster - thus no extra command for clustering
environment is required - only lvm_do_fs_unlock() function is added
to call lvm's fs_unlock() while holding lvm_lock mutex in clvmd.

Add fs_unlock() also to set_lv() so the command waits until devices
are ready for regular open (i.e. wiping its begining).

Move fs_unlock() prototype to activation.h to keep fs.h private
in lib/activate dir and not expose other functions from this header.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.80 - 
 ====================================
+  Speedup consequent activation calls by using internal cookie.
   Add internal lvm library cookie.
   Speedup command processing by caching resolved config tree.
   Pass config_tree to renamed function import_vg_from_config_tree().

daemons/clvmd/clvmd-command.c

@@ -214,6 +214,7 @@ static int lock_vg(struct local_client *client)
 	if (lkid == 0)
 	    return EINVAL;
 
+	lvm_do_fs_unlock(); /* Wait for devices */
 	status = sync_unlock(lockname, lkid);
 	if (status)
 	    status = errno;

daemons/clvmd/lvm-functions.c

@@ -894,6 +894,13 @@ struct dm_hash_node *get_next_excl_lock(struct dm_hash_node *v, char **name)
 	return v;
 }
 
+void lvm_do_fs_unlock(void)
+{
+	pthread_mutex_lock(&lvm_lock);
+	fs_unlock();
+	pthread_mutex_unlock(&lvm_lock);
+}
+
 /* Called to initialise the LVM context of the daemon */
 int init_clvm(int using_gulm, char **argv)
 {

daemons/clvmd/lvm-functions.h

@@ -36,5 +36,6 @@ extern char *get_last_lvm_error(void);
 extern void do_lock_vg(unsigned char command, unsigned char lock_flags,
 		      char *resource);
 extern struct dm_hash_node *get_next_excl_lock(struct dm_hash_node *v, char **name);
+void lvm_do_fs_unlock(void);
 
 #endif

lib/activate/activate.c

@@ -1206,7 +1206,6 @@ int lv_deactivate(struct cmd_context *cmd, const char *lvid_s)
 	memlock_inc(cmd);
 	r = _lv_deactivate(lv);
 	memlock_dec(cmd);
-	fs_unlock();
 
 	if (!lv_info(cmd, lv, 0, &info, 1, 0) || info.exists)
 		r = 0;
@@ -1305,7 +1304,6 @@ static int _lv_activate(struct cmd_context *cmd, const char *lvid_s,
 	if (!(r = _lv_activate_lv(lv, 0)))
 		stack;
 	memlock_dec(cmd);
-	fs_unlock();
 
 	if (r && !monitor_dev_for_events(cmd, lv, 0, 1))
 		stack;

lib/activate/activate.h

@@ -121,4 +121,9 @@ int pv_uses_vg(struct physical_volume *pv,
  */
 int device_is_usable(struct device *dev);
 
+/*
+ * Declaration moved here from fs.h to keep header fs.h hidden
+ */
+void fs_unlock(void);
+
 #endif

lib/activate/dev_manager.c

@@ -1622,7 +1622,6 @@ static int _clean_tree(struct dev_manager *dm, struct dm_tree_node *root, char *
 	struct dm_tree_node *child;
 	char *vgname, *lvname, *layer;
 	const char *name, *uuid;
-	int r;
 
 	while ((child = dm_tree_next_child(&handle, root, 0))) {
 		if (!(name = dm_tree_node_get_name(child)))
@@ -1644,12 +1643,7 @@ static int _clean_tree(struct dev_manager *dm, struct dm_tree_node *root, char *
 		if (non_toplevel_tree_dlid && !strcmp(non_toplevel_tree_dlid, uuid))
 			continue;
 
-		dm_tree_set_cookie(root, 0);
-		r = dm_tree_deactivate_children(root, uuid, strlen(uuid));
-		if (!dm_udev_wait(dm_tree_get_cookie(root)))
-			stack;
-
-		if (!r)
+		if (!dm_tree_deactivate_children(root, uuid, strlen(uuid)))
 			return_0;
 	}
 
@@ -1669,9 +1663,12 @@ static int _tree_action(struct dev_manager *dm, struct logical_volume *lv,
 
 	if (!(root = dm_tree_find_node(dtree, 0, 0))) {
 		log_error("Lost dependency tree root node");
-		goto out;
+		goto out_no_root;
 	}
 
+	/* Restore fs cookie */
+	dm_tree_set_cookie(root, fs_get_cookie());
+
 	if (!(dlid = build_dm_uuid(dm->mem, lv->lvid.s, origin_only ? "real" : NULL)))
 		goto_out;
 
@@ -1684,10 +1681,7 @@ static int _tree_action(struct dev_manager *dm, struct logical_volume *lv,
 		break;
 	case DEACTIVATE:
  		/* Deactivate LV and all devices it references that nothing else has open. */
-		dm_tree_set_cookie(root, 0);
 		r = dm_tree_deactivate_children(root, dlid, ID_LEN + sizeof(UUID_PREFIX) - 1);
-		if (!dm_udev_wait(dm_tree_get_cookie(root)))
-			stack;
 		if (!r)
 			goto_out;
 		if (!_remove_lv_symlinks(dm, root))
@@ -1708,10 +1702,7 @@ static int _tree_action(struct dev_manager *dm, struct logical_volume *lv,
 			goto_out;
 
 		/* Preload any devices required before any suspensions */
-		dm_tree_set_cookie(root, 0);
 		r = dm_tree_preload_children(root, dlid, ID_LEN + sizeof(UUID_PREFIX) - 1);
-		if (!dm_udev_wait(dm_tree_get_cookie(root)))
-			stack;
 		if (!r)
 			goto_out;
 
@@ -1719,10 +1710,7 @@ static int _tree_action(struct dev_manager *dm, struct logical_volume *lv,
 			dm->flush_required = 1;
 
 		if (action == ACTIVATE) {
-			dm_tree_set_cookie(root, 0);
 			r = dm_tree_activate_children(root, dlid, ID_LEN + sizeof(UUID_PREFIX) - 1);
-			if (!dm_udev_wait(dm_tree_get_cookie(root)))
-				stack;
 			if (!r)
 				goto_out;
 			if (!_create_lv_symlinks(dm, root)) {
@@ -1740,6 +1728,9 @@ static int _tree_action(struct dev_manager *dm, struct logical_volume *lv,
 	r = 1;
 
 out:
+	/* Save fs cookie for udev settle, do not wait here */
+	fs_set_cookie(dm_tree_get_cookie(root));
+out_no_root:
 	dm_tree_free(dtree);
 
 	return r;

lib/activate/fs.c

@@ -15,6 +15,7 @@
 
 #include "lib.h"
 #include "fs.h"
+#include "activate.h"
 #include "toolcontext.h"
 #include "lvm-string.h"
 #include "lvm-file.h"

lib/activate/fs.h

@@ -29,7 +29,7 @@ int fs_del_lv_byname(const char *dev_dir, const char *vg_name,
 		     const char *lv_name, int check_udev);
 int fs_rename_lv(struct logical_volume *lv, const char *dev, 
 		 const char *old_vgname, const char *old_lvname);
-void fs_unlock(void);
+/* void fs_unlock(void);  moved to activate.h */
 uint32_t fs_get_cookie(void);
 void fs_set_cookie(uint32_t cookie);
 

lib/locking/file_locking.c

@@ -215,6 +215,7 @@ static int _lock_file(const char *file, uint32_t flags)
 		state = 'W';
 		break;
 	case LCK_UNLOCK:
+		fs_unlock(); /* Wait until devices are available */
 		return _release_lock(file, 1);
 	default:
 		log_error("Unrecognised lock type: %d", flags & LCK_TYPE_MASK);

lib/metadata/lv_manip.c

@@ -3022,6 +3022,8 @@ int set_lv(struct cmd_context *cmd, struct logical_volume *lv,
 		return 0;
 	}
 
+	fs_unlock();  /* Wait until devices are available */
+
 	log_verbose("Clearing start of logical volume \"%s\"", lv->name);
 
 	if (!(dev = dev_cache_get(name, NULL))) {