From afb4290111b67b5abb2cb75e543f3605f605b92b Mon Sep 17 00:00:00 2001
From: Zdenek Kabelac <zkabelac@redhat.com>
Date: Fri, 18 Jan 2019 22:27:02 +0100
Subject: [PATCH 01/17] lv_manip: better work with PERCENT_VG modifier

When using 'lvcreate -l100%VG' and there is big disproportion between
real available space and requested setting - automatically fallback
to 100%FREE.

Difference can be seen when VG is big and already most space was
allocated, so the requestion 100%VG can end (and by spec for % modifier
it's correct) as LV with size of 1%VG.  Usually this is not a big
problem - buit in some cases - like cache-pool allocation, this
can result a big difference for chunksize selection.

With this patch it's more closely match common-sense logic without
the need of reitteration of too big changes in lvm2 core ATM.

TODO: in the future there should be allocator solving all allocations
in a single call.

(cherry picked from commit 022ebb0cfebee4ac8fdbe4e0c61e85db1038a115)

Conflicts:
	WHATS_NEW
---
 WHATS_NEW               | 1 +
 lib/metadata/lv_manip.c | 6 ++++++
 tools/lvcreate.c        | 6 ++++++
 3 files changed, 13 insertions(+)

diff --git a/WHATS_NEW b/WHATS_NEW
index f429d27..152fa5e 100644
--- a/WHATS_NEW
+++ b/WHATS_NEW
@@ -1,5 +1,6 @@
 Version 2.03.03 - 
 ====================================
+  Improve -lXXX%VG modifier which improves cache segment estimation.
   Ensure migration_threshold for cache is at least 8 chunks.
   Move VDO support towards V2 target (6.2) support.
 
diff --git a/lib/metadata/lv_manip.c b/lib/metadata/lv_manip.c
index 9794074..0c54b2c 100644
--- a/lib/metadata/lv_manip.c
+++ b/lib/metadata/lv_manip.c
@@ -5022,6 +5022,12 @@ static int _lvresize_extents_from_percent(const struct logical_volume *lv,
 		case PERCENT_VG:
 			lp->extents = percent_of_extents(lp->extents, vg->extent_count,
 							 (lp->sign != SIGN_MINUS));
+			if (lp->sign == SIGN_NONE && lp->extents > vg->free_count) {
+				lp->extents = vg->free_count;
+				log_print_unless_silent("Reducing %u%%VG to remaining free space %s in VG.",
+							old_extents,
+							display_size(vg->cmd, (uint64_t)vg->extent_size * lp->extents));
+			}
 			break;
 		case PERCENT_FREE:
 			lp->extents = percent_of_extents(lp->extents, vg->free_count,
diff --git a/tools/lvcreate.c b/tools/lvcreate.c
index 3c22794..ebe51d9 100644
--- a/tools/lvcreate.c
+++ b/tools/lvcreate.c
@@ -278,6 +278,12 @@ static int _update_extents_params(struct volume_group *vg,
 	switch (lcp->percent) {
 		case PERCENT_VG:
 			extents = percent_of_extents(lp->extents, base_calc_extents = vg->extent_count, 0);
+			if (extents > vg->free_count) {
+				extents = vg->free_count;
+				log_print_unless_silent("Reducing %u%%VG to remaining free space %s in VG.",
+							lp->extents,
+							display_size(vg->cmd, (uint64_t)vg->extent_size * extents));
+			}
 			break;
 		case PERCENT_FREE:
 			extents = percent_of_extents(lp->extents, base_calc_extents = vg->free_count, 0);
-- 
1.8.3.1