LVM: Break out lv_create

We are going to want to reuse this.

lv_create doesn't (want to) take a $gho, but the $vg and $lv names
directly (so that callers can use it when they don't have a suitable
$gho whose $gho->{Lvdev} they want to use).

In the one existing call site we pass $gho->{Vg} and $gho->{Lv} so
that the effect is the same.

There is a minor functional change: $gho->{Lvdev} has been put through
lv_dev_mapper.  But we don't care about that in lv_create (since the
LVM operations, and dd, are perfectly happy to use the `real',
non-/dev/mapper, names).  So we can just use /dev/$vg/$lv.

Signed-off-by: Ian Jackson <Ian.Jackson@eu.citrix.com>
Signed-off-by: Robert Ho <robert.hu@intel.com>
Tested-by: Robert Ho <robert.hu@intel.com>
Acked-by: Ian Campbell <ian.campbell@citrix.com>
---
v17: Discuss change to /dev/$vg/$lv from $gho->{Lvdev}.
v14: New patch
v15: Change some trivial typo, so to resolve conflicts with
     production tree.

diff --git a/Osstest/TestSupport.pm b/Osstest/TestSupport.pm
index b70f19f6b41fa6bcb845e4da629b183995319310..b507ada52572fb6921c52bba7e82c4706fc3a15e 100644 (file)
--- a/Osstest/TestSupport.pm
+++ b/Osstest/TestSupport.pm
@@ -63,7 +63,7 @@ BEGIN {
                       target_install_packages target_install_packages_norec
                       target_jobdir target_extract_jobdistpath_subdir
                       target_extract_jobdistpath
-                      lv_dev_mapper
+                      lv_create lv_dev_mapper
 
                       poll_loop tcpconnect await_tcp
                       contents_make_cpio file_simple_write_contents
@@ -713,6 +713,15 @@ sub poll_loop ($$$&) {
     logm("$what: ok. (${waited}s)");
 }
 
+sub lv_create ($$$$) {
+    my ($ho, $vg, $lv, $mb) = @_;
+    my $lvdev = "/dev/$vg/$lv";
+    target_cmd_root($ho, "lvremove -f $lvdev ||:");
+    target_cmd_root($ho, "lvcreate -L ${mb}M -n $lv $vg");
+    target_cmd_root($ho, "dd if=/dev/zero of=$lvdev count=10");
+    return $lvdev;
+}
+
 sub lv_dev_mapper ($$) {
     my ($vg,$lv) = @_;
     $vg =~ s/-/--/g;
@@ -1692,9 +1701,7 @@ sub prepareguest ($$$$$$) {
 
 sub prepareguest_part_lvmdisk ($$$) {
     my ($ho, $gho, $disk_mb) = @_;
-    target_cmd_root($ho, "lvremove -f $gho->{Lvdev} ||:");
-    target_cmd_root($ho, "lvcreate -L ${disk_mb}M -n $gho->{Lv} $gho->{Vg}");
-    target_cmd_root($ho, "dd if=/dev/zero of=$gho->{Lvdev} count=10");
+    lv_create($ho, $gho->{Vg}, $gho->{Lv}, $disk_mb);
 }
 
 sub make_vhd ($$$) {