9:28 a.m.
This action moves second(backup) GPT header to the end of the disk.
It is usable in in-place image expanding, since free space after
second GPT header is unusable. To use additional space, we have
to move second header. This is what sgdisk -e does.
However, sgdisk -e may perform additional actions if the partition
table has unexpected params (e.g. if we call sgdisk -e /dev/sda1,
it may fix partition table thus destroying the filesystem).
To prevent such cases, we do a dry-run at first and fail if
additional actions are scheduled.
---
daemon/parted.c | 33 ++++++++++++++++++++
generator/actions.ml | 14 +++++++++
src/MAX_PROC_NR | 2 +-
tests/daemon/Makefile.am | 3 +-
tests/daemon/test-expand-gpt.pl | 69 +++++++++++++++++++++++++++++++++++++++++
5 files changed, 119 insertions(+), 2 deletions(-)
create mode 100755 tests/daemon/test-expand-gpt.pl
diff --git a/daemon/parted.c b/daemon/parted.c
index df6b7e7..033c136 100644
--- a/daemon/parted.c
+++ b/daemon/parted.c
@@ -928,3 +928,36 @@ do_part_get_mbr_part_type (const char *device, int partnum)
reply_with_error ("strdup failed");
return NULL;
}
+
+int
+do_part_expand_gpt(const char *device)
+{
+ CLEANUP_FREE char *err = NULL;
+
+ /* If something is broken, sgdisk may try to correct it.
+ * (e.g. recreate partition table and so on).
+ * We do not want such behavior, so dry-run at first.*/
+ int r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
+ str_sgdisk, "--pretend", "-e", device, NULL);
+
+ if (r == -1) {
+ reply_with_error ("%s --pretend -e %s: %s", str_sgdisk, device, err);
+ return -1;
+ }
+ if (err && strlen(err) != 0) {
+ /* Unexpected actions. */
+ reply_with_error ("%s --pretend -e %s: %s", str_sgdisk, device, err);
+ return -1;
+ }
+
+ /* Now we can do a real run. */
+ r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
+ str_sgdisk, "-e", device, NULL);
+
+ if (r == -1) {
+ reply_with_error ("%s -e %s: %s", str_sgdisk, device, err);
+ return -1;
+ }
+
+ return 0;
+}
diff --git a/generator/actions.ml b/generator/actions.ml
index 7ab8ee4..3a14683 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12787,6 +12787,20 @@ See also L<ntfsresize(8)>, L<resize2fs(8)>,
L<btrfs(8)>, L<xfs_info(8)>." };
longdesc = "\
This is the internal call which implements C<guestfs_feature_available>." };
+ { defaults with
+ name = "part_expand_gpt"; added = (1, 31, 29);
+ style = RErr, [Device "device"], [];
+ proc_nr = Some 459;
+ optional = Some "gdisk";
+ shortdesc = "move backup GPT header to the end of the disk";
+ longdesc = "\
+Move backup GPT data structures to the end of the disk.
+This is useful in case of in-place image expand
+since disk space after backup GPT header is not usable.
+This is equivalent to C<sgdisk -e>.
+
+See also L<sgdisk(8)>." };
+
]
(* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index c92ddb6..658bd78 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-458
+459
diff --git a/tests/daemon/Makefile.am b/tests/daemon/Makefile.am
index bb380c5..329b00c 100644
--- a/tests/daemon/Makefile.am
+++ b/tests/daemon/Makefile.am
@@ -25,7 +25,8 @@ check_DATA = captive-daemon.pm
TESTS = \
test-daemon-start.pl \
- test-btrfs.pl
+ test-btrfs.pl \
+ test-expand-gpt.pl
TESTS_ENVIRONMENT = $(top_builddir)/run --test $(VG)
diff --git a/tests/daemon/test-expand-gpt.pl b/tests/daemon/test-expand-gpt.pl
new file mode 100755
index 0000000..637b90e
--- /dev/null
+++ b/tests/daemon/test-expand-gpt.pl
@@ -0,0 +1,69 @@
+#!/usr/bin/env perl
+# Copyright (C) 2015 Maxim Perevedentsev mperevedentsev(a)virtuozzo.com
+#
+# This program is free software; you can redistribute it and/or modify
+# it under the terms of the GNU General Public License as published by
+# the Free Software Foundation; either version 2 of the License, or
+# (at your option) any later version.
+#
+# This program is distributed in the hope that it will be useful,
+# but WITHOUT ANY WARRANTY; without even the implied warranty of
+# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+# GNU General Public License for more details.
+#
+# You should have received a copy of the GNU General Public License
+# along with this program; if not, write to the Free Software
+# Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
+
+use strict;
+use warnings;
+
+use Sys::Guestfs;
+
+sub tests {
+ my $g = Sys::Guestfs->new ();
+
+ foreach ("gpt", "mbr") {
+ $g->disk_create ("disk_$_.img", "qcow2", 50 * 1024 * 1024);
+ $g->add_drive ("disk_$_.img");
+ }
+
+ $g->launch ();
+
+ $g->part_disk ("/dev/sda", "gpt");
+ $g->part_disk ("/dev/sdb", "mbr");
+
+ $g->close ();
+
+ die if system ("qemu-img resize disk_gpt.img 100M &>/dev/null");
+
+ $g = Sys::Guestfs->new ();
+
+ foreach ("gpt", "mbr") {
+ $g->add_drive ("disk_$_.img");
+ }
+
+ $g->launch ();
+ die if $g->part_expand_gpt ("/dev/sda");
+
+ my $output = $g->debug ("sh", ["sgdisk", "-p",
"/dev/sda"]);
+ die if $output eq "";
+ $output =~ s/\n/ /g;
+ $output =~ s/.*last usable sector is (\d+).*/$1/g;
+
+ my $end_sectors = 100 * 1024 * 2 - $output;
+ die unless $end_sectors <= 34;
+
+ # Negative tests.
+ eval { $g->part_expand_gpt ("/dev/sdb") };
+ die unless $@;
+ eval { $g->part_expand_gpt ("/dev/sda1") };
+ die unless $@;
+}
+
+eval { tests() };
+system ("rm -f disk_*.img");
+if ($@) {
+ die;
+}
+exit 0
--
1.8.3.1