Support rounding of percentage upward

We want to keep this logic -
when LV is extend - extend the LV by at least given amount,
when LV is reduced - reduce the LV by at most given amount.

So for this the rounding needs to be used.
Current logic which seems to satisfy give rule is to round up all
extent values for LV resize upward except for values with '-' sign
that are round downward.

This patch also fixes the problem when  lvextend --use-polices tried
to extend LV the by i.e. 20% - but the resulting 20% were smaller
the extent size thus before this patch no extension happened.

3 files changed, 9 insertions, 3 deletions

diff --git a/man/lvextend.8.in b/man/lvextend.8.in
index 0b273ab7..44c9789a 100644
--- a/man/lvextend.8.in
+++ b/man/lvextend.8.in
@@ -43,6 +43,7 @@ free space for the specified PhysicalVolume(s) with the suffix %PVS,
 as a percentage of the remaining free space in the Volume Group
 with the suffix %FREE, or (for a snapshot) as a percentage of the total
 space in the Origin Logical Volume with the suffix %ORIGIN.
+The resulting value is rounded upward.
 .TP
 .I \-L, \-\-size [+]LogicalVolumeSize[bBsSkKmMgGtTpPeE]
 Extend or set the logical volume size in units of megabytes.
diff --git a/man/lvreduce.8.in b/man/lvreduce.8.in
index 4cfde2b8..0a3dcb3f 100644
--- a/man/lvreduce.8.in
+++ b/man/lvreduce.8.in
@@ -66,6 +66,8 @@ size of the Logical Volume with the suffix \fI%LV\fP, as a percentage of the
 remaining free space in the Volume Group with the suffix \fI%FREE\fP, or (for
 a snapshot) as a percentage of the total space in the Origin Logical
 Volume with the suffix \fI%ORIGIN\fP.
+The resulting value for the substraction is rounded downward, for the absolute
+size it is rounded upward.
 .TP
 .IR \fB\-L ", " \fB\-\-size " [" \- ] LogicalVolumeSize [ bBsSkKmMgGtTpPeE ]
 Reduce or set the logical volume size in units of megabytes.
diff --git a/man/lvresize.8.in b/man/lvresize.8.in
index e534d3bb..7e859932 100644
--- a/man/lvresize.8.in
+++ b/man/lvresize.8.in
@@ -54,15 +54,18 @@ the remaining free space of the PhysicalVolumes on the command line with the
 suffix \fI%PVS\fP, as a percentage of the remaining free space in the
 Volume Group with the suffix \fI%FREE\fP, or (for a snapshot) as a percentage
 of the total space in the Origin Logical Volume with the suffix \fI%ORIGIN\fP.
+The resulting value is rounded downward for the substraction otherwise
+it is rounded upward.
 .TP
 .IR \fB\-L ", " \fB\-\-size " [" + | - ] LogicalVolumeSize [ bBsSkKmMgGtTpPeE ]
 Change or set the logical volume size in units of megabytes.
 A size suffix of \fIM\fP for megabytes,
 \fIG\fP for gigabytes, \fIT\fP for terabytes, \fIP\fP for petabytes
 or \fIE\fP for exabytes is optional.
-With the \fI+\fP or \fI-\fP sign the value is added to or subtracted from
-the actual size of the logical volume and without it, the value is taken as an
-absolute one.
+With the \fI+\fP or \fI-\fP sign the value is added or subtracted
+from the actual size of the logical volume and rounded
+to the full extent size and without it,
+the value is taken as an absolute one.
 .TP
 .BR \-i ", " \-\-stripes " " \fIStripes
 Gives the number of stripes to use when extending a Logical Volume.