[lvm-devel] Possibility to convert to exclusive active (opened) volume on clustered VG

Raman rommer at activecloud.com
Fri Dec 6 04:10:02 UTC 2013


Hello,

Currently there is no way to convert opened volume from CR to EX or
from EX to CR lock type on clustered volume group. The only way is to
deactivate volume and activate it exclusively again. Example:

Simple cman cluster:
[root at clvmd2 ~]# cat /etc/cluster/cluster.conf
<?xml version="1.0"?>
<cluster config_version="1" name="clu">
         <clusternodes>
                 <clusternode name="clvmd1" nodeid="1"/>
                 <clusternode name="clvmd2" nodeid="2"/>
         </clusternodes>
         <cman broadcast="yes" port="5501"/>
         <totem token="60000"/>
</cluster>

Clustered volume group:
[root at clvmd1 ~]# vgs --noheadings
   vg     1   1   0 wz--nc 9.31g 9.21g

Single volume activated on both nodes:
[root at clvmd1 ~]# lvs --noheadings
   lv1  vg   -wi-a----- 100.00m
[root at clvmd2 ~]# lvs --noheadings
   lv1  vg   -wi-a----- 100.00m

Deactivating on second node and trying to acquire volume exclusively on
the first node:
[root at clvmd2 ~]# lvchange -aln vg/lv1
[root at clvmd1 ~]# lvchange -ae vg/lv1
   Error locking on node clvmd1: Device or resource busy
[root at clvmd1 ~]#

But works fine with deactivating cycle:
[root at clvmd1 ~]# lvchange -aln vg/lv1 && lvs --noheading
   lv1  vg   -wi------- 100.00m
[root at clvmd1 ~]# lvchange -ae vg/lv1 && lvs --noheading
   lv1  vg   -wi-a----- 100.00m
[root at clvmd1 ~]#

Proposed patch tries to solve this problem allowing lock conversion
for activated volumes on clustered volume groups.
-------------- next part --------------
diff --git a/daemons/clvmd/lvm-functions.c b/daemons/clvmd/lvm-functions.c
index b15732f..451d286 100644
--- a/daemons/clvmd/lvm-functions.c
+++ b/daemons/clvmd/lvm-functions.c
@@ -137,7 +137,7 @@ static const char *decode_flags(unsigned char flags)
 		flags & LCK_DMEVENTD_MONITOR_MODE ? "DMEVENTD_MONITOR|" : "",
 		flags & LCK_ORIGIN_ONLY_MODE ? "ORIGIN_ONLY|" : "",
 		flags & LCK_TEST_MODE ? "TEST|" : "",
-		flags & LCK_CONVERT ? "CONVERT|" : "",
+		flags & LCK_CONVERT_MODE ? "CONVERT|" : "",
 		flags & LCK_DMEVENTD_MONITOR_IGNORE ? "DMEVENTD_MONITOR_IGNORE|" : "");
 
 	if (len > 1)
@@ -374,7 +374,7 @@ static int do_activate_lv(char *resource, unsigned char command, unsigned char l
 	 * of exclusive lock to shared one during activation.
 	 */
 	if (command & LCK_CLUSTER_VG) {
-		status = hold_lock(resource, mode, LCKF_NOQUEUE | (lock_flags & LCK_CONVERT ? LCKF_CONVERT:0));
+		status = hold_lock(resource, mode, LCKF_NOQUEUE | (lock_flags & LCK_CONVERT_MODE ? LCKF_CONVERT:0));
 		if (status) {
 			/* Return an LVM-sensible error for this.
 			 * Forcing EIO makes the upper level return this text
diff --git a/lib/locking/cluster_locking.c b/lib/locking/cluster_locking.c
index 7cbb8f1..c94f92b 100644
--- a/lib/locking/cluster_locking.c
+++ b/lib/locking/cluster_locking.c
@@ -328,6 +328,9 @@ static int _lock_for_cluster(struct cmd_context *cmd, unsigned char clvmd_cmd,
 	if (flags & LCK_REVERT)
 		args[1] |= LCK_REVERT_MODE;
 
+	if (flags & LCK_CONVERT)
+		args[1] |= LCK_CONVERT_MODE;
+
 	if (mirror_in_sync())
 		args[1] |= LCK_MIRROR_NOSYNC_MODE;
 
diff --git a/lib/locking/locking.c b/lib/locking/locking.c
index 9433e40..831388e 100644
--- a/lib/locking/locking.c
+++ b/lib/locking/locking.c
@@ -552,8 +552,13 @@ int activate_lv_excl(struct cmd_context *cmd, struct logical_volume *lv)
 	if (lv_is_active_exclusive_locally(lv))
 		return 1;
 
-	if (!activate_lv_excl_local(cmd, lv))
-		return_0;
+	if (lv_is_active_locally(lv)) {
+		if (!activate_lv_excl_local_convert(cmd, lv))
+			return_0;
+	} else {
+		if (!activate_lv_excl_local(cmd, lv))
+			return_0;
+	}
 
 	if (lv_is_active_exclusive(lv))
 		return 1;
diff --git a/lib/locking/locking.h b/lib/locking/locking.h
index aa42138..32576af 100644
--- a/lib/locking/locking.h
+++ b/lib/locking/locking.h
@@ -103,6 +103,7 @@ int check_lvm1_vg_inactive(struct cmd_context *cmd, const char *vgname);
 #define LCK_CACHE	0x00000100U	/* Operation on cache only using P_ lock */
 #define LCK_ORIGIN_ONLY	0x00000200U	/* Operation should bypass any snapshots */
 #define LCK_REVERT	0x00000400U	/* Revert any incomplete change */
+#define LCK_CONVERT	0x00000800U	/* Try lock conversion */
 
 /*
  * Additional lock bits for cluster communication via args[1]
@@ -110,10 +111,7 @@ int check_lvm1_vg_inactive(struct cmd_context *cmd, const char *vgname);
 #define LCK_PARTIAL_MODE        	0x01	/* Partial activation? */
 #define LCK_MIRROR_NOSYNC_MODE		0x02	/* Mirrors don't require sync */
 #define LCK_DMEVENTD_MONITOR_MODE	0x04	/* Register with dmeventd */
-
-/* Not yet used. */
-#define LCK_CONVERT			0x08	/* Convert existing lock */
-
+#define LCK_CONVERT_MODE		0x08	/* Convert existing lock */
 #define LCK_TEST_MODE			0x10    /* Test mode: No activation */
 #define LCK_ORIGIN_ONLY_MODE		0x20	/* Same as above */
 #define LCK_DMEVENTD_MONITOR_IGNORE     0x40	/* Whether to ignore dmeventd */
@@ -183,6 +181,8 @@ int check_lvm1_vg_inactive(struct cmd_context *cmd, const char *vgname);
 #define activate_lv(cmd, lv)	lock_lv_vol(cmd, lv, LCK_LV_ACTIVATE | LCK_HOLD)
 #define activate_lv_excl_local(cmd, lv)	\
 				lock_lv_vol(cmd, lv, LCK_LV_EXCLUSIVE | LCK_HOLD | LCK_LOCAL)
+#define activate_lv_excl_local_convert(cmd, lv)	\
+				lock_lv_vol(cmd, lv, LCK_LV_EXCLUSIVE | LCK_HOLD | LCK_LOCAL | LCK_CONVERT)
 #define activate_lv_excl_remote(cmd, lv)	\
 				lock_lv_vol(cmd, lv, LCK_LV_EXCLUSIVE | LCK_HOLD | LCK_REMOTE)
 
@@ -191,6 +191,8 @@ int activate_lv_excl(struct cmd_context *cmd, struct logical_volume *lv);
 
 #define activate_lv_local(cmd, lv)	\
 	lock_lv_vol(cmd, lv, LCK_LV_ACTIVATE | LCK_HOLD | LCK_LOCAL)
+#define activate_lv_local_convert(cmd, lv)	\
+	lock_lv_vol(cmd, lv, LCK_LV_ACTIVATE | LCK_HOLD | LCK_LOCAL | LCK_CONVERT)
 #define deactivate_lv_local(cmd, lv)	\
 	lock_lv_vol(cmd, lv, LCK_LV_DEACTIVATE | LCK_LOCAL)
 #define drop_cached_metadata(vg)	\
diff --git a/lib/metadata/lv.c b/lib/metadata/lv.c
index 3e1458c..2cec240 100644
--- a/lib/metadata/lv.c
+++ b/lib/metadata/lv.c
@@ -773,13 +773,23 @@ deactivate:
 		if (_lv_is_exclusive(lv)) {
 			log_verbose("Activating logical volume \"%s\" exclusively locally.",
 				    lv->name);
-			if (!activate_lv_excl_local(cmd, lv))
-				return_0;
+			if (vg_is_clustered(lv->vg) && lv_is_active_locally(lv)) {
+				if (!activate_lv_excl_local_convert(cmd, lv))
+					return_0;
+			} else {
+				if (!activate_lv_excl_local(cmd, lv))
+					return_0;
+			}
 		} else {
 			log_verbose("Activating logical volume \"%s\" locally.",
 				    lv->name);
-			if (!activate_lv_local(cmd, lv))
-				return_0;
+			if (vg_is_clustered(lv->vg) && lv_is_active_locally(lv)) {
+				if (!activate_lv_local_convert(cmd, lv))
+					return_0;
+			} else {
+				if (!activate_lv_local(cmd, lv))
+					return_0;
+			}
 		}
 		break;
 	case CHANGE_AE:


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