Some work on allowing resize2fs to shrink an LV

diff --git a/lvm/lvm-lib.pl b/lvm/lvm-lib.pl
index 705d1d2..e3a4edd 100644 (file)
--- a/lvm/lvm-lib.pl
+++ b/lvm/lvm-lib.pl
@@ -416,8 +416,17 @@ return $? ? $out : undef;
 sub can_resize_filesystem
 {
 if ($_[0] eq "ext2" || $_[0] eq "ext3") {
-       return &has_command("e2fsadm") ? 2 :
-              &has_command("resize2fs") ? 1 : 0;
+       if (&has_command("e2fsadm")) {
+               return 2;       # Can extend and reduce
+               }
+       elsif (&has_command("resize2fs")) {
+               # Only new versions can reduce a FS
+               local $out = &backquote_command("resize2fs");
+               return $out =~ /resize2fs\s+([0-9\.]+)/i && $1 > 1.4 ? 2 : 1;
+               }
+       else {
+               return 0;
+               }
        }
 # This is supposed to work, but doesn't for me!
 #elsif ($_[0] eq "xfs") {
@@ -454,13 +463,24 @@ if ($_[1] eq "ext2" || $_[1] eq "ext3") {
                return $? ? $out : undef;
                }
        else {
-               # Need to resize LVM first, then filesystem
-               local $err = &resize_logical_volume($_[0], $_[2]);
-               return $err if ($err);
-
-               local $cmd = "resize2fs -f '$_[0]->{'device'}'";
-               local $out = &backquote_logged("$cmd 2>&1");
-               return $? ? $out : undef;
+               if ($_[2] > $_[0]->{'size'}) {
+                       # Need to enlarge LV first, then filesystem
+                       local $err = &resize_logical_volume($_[0], $_[2]);
+                       return $err if ($err);
+
+                       local $cmd = "resize2fs -f '$_[0]->{'device'}'";
+                       local $out = &backquote_logged("$cmd 2>&1");
+                       return $? ? $out : undef;
+                       }
+               else {
+                       # Need to shrink filesystem first, then LV
+                       local $cmd = "resize2fs -f '$_[0]->{'device'}' $_[2]k";
+                       local $out = &backquote_logged("$cmd 2>&1");
+                       return $? ? $out : undef;
+
+                       local $err = &resize_logical_volume($_[0], $_[2]);
+                       return $err if ($err);
+                       }
                }
        }
 elsif ($_[1] eq "xfs") {