[lvm-devel] 2018-06-01-stable - snapshot: improve checking of merging snapshot

[Zdenek Kabelac]

Gitweb:        https://sourceware.org/git/?p=lvm2.git;a=commitdiff;h=ba6ed5c90c5a191f63c14ee9795f298eba689932
Commit:        ba6ed5c90c5a191f63c14ee9795f298eba689932
Parent:        e0c94d883a3ca033df562d63a1074b4be97d98ef
Author:        Zdenek Kabelac <zkabelac at redhat.com>
AuthorDate:    Mon Jun 11 22:19:20 2018 +0200
Committer:     Zdenek Kabelac <zkabelac at redhat.com>
CommitterDate: Fri Jun 22 15:05:22 2018 +0200

snapshot: improve checking of merging snapshot

Add runtime detection for 'lvs -o+seg_monitor' and 'vgchange --monitor'.
This fix should avoid unnecessary timeout on systemd shutdown.
---
 WHATS_NEW               |    1 +
 lib/activate/activate.c |    3 ++-
 lib/metadata/lv.c       |    3 ++-
 3 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/WHATS_NEW b/WHATS_NEW
index 36523f5..f24b4d0 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.02.180 - 
 =================================
+  Fix unmonitoring of merging snapshots.
   Add missing -l description in fsadm man page.
   Cache can uses metadata format 2 with cleaner policy.
   Avoid showing internal error in lvs output or pvmoved LVs.
diff --git a/lib/activate/activate.c b/lib/activate/activate.c
index 985215a..56ec732 100644
--- a/lib/activate/activate.c
+++ b/lib/activate/activate.c
@@ -1907,7 +1907,8 @@ int monitor_dev_for_events(struct cmd_context *cmd, const struct logical_volume
 	 * In case of a snapshot device, we monitor lv->snapshot->lv,
 	 * not the actual LV itself.
 	 */
-	if (lv_is_cow(lv) && (laopts->no_merging || !lv_is_merging_cow(lv))) {
+	if (lv_is_cow(lv) && (laopts->no_merging || !lv_is_merging_cow(lv) ||
+			      lv_has_target_type(lv->vg->cmd->mem, lv, NULL, TARGET_NAME_SNAPSHOT))) {
 		if (!(r = monitor_dev_for_events(cmd, lv->snapshot->lv, NULL, monitor)))
 			stack;
 		return r;
diff --git a/lib/metadata/lv.c b/lib/metadata/lv.c
index b19ae34..2abe42d 100644
--- a/lib/metadata/lv.c
+++ b/lib/metadata/lv.c
@@ -301,7 +301,8 @@ char *lvseg_monitor_dup(struct dm_pool *mem, const struct lv_segment *seg)
 	int pending = 0, monitored = 0;
 	struct lv_segment *segm = (struct lv_segment *) seg;
 
-	if (lv_is_cow(seg->lv) && !lv_is_merging_cow(seg->lv))
+	if (lv_is_cow(seg->lv) && (!lv_is_merging_cow(seg->lv) ||
+				   lv_has_target_type(seg->lv->vg->cmd->mem, seg->lv, NULL, TARGET_NAME_SNAPSHOT)))
 		segm = first_seg(seg->lv->snapshot->lv);
 
 	// log_debug("Query LV:%s mon:%s segm:%s tgtm:%p  segmon:%d statusm:%d", seg->lv->name, segm->lv->name, segm->segtype->name, segm->segtype->ops->target_monitored, seg_monitored(segm), (int)(segm->status & PVMOVE));