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[Libguestfs] [PATCH] Generic partition creation interface.



This creates a generic partition table interface.  One immediate
advantage is that you can create GPT partitions which can be larger
than 2 TB.

For example, here is a 1 exabyte partition:

  ><fs> sparse /mnt/tmp/test/test.img 1E
  ><fs> run
  ><fs> part-init gpt /dev/vda 
  ><fs> part-add /dev/vda primary 0 0
  ><fs> list-devices 
  /dev/vda
  ><fs> list-partitions 
  /dev/vda1
  ><fs> blockdev-getsize64 /dev/vda1 
  1099511627775983104

Rich.

-- 
Richard Jones, Virtualization Group, Red Hat http://people.redhat.com/~rjones
virt-p2v converts physical machines to virtual machines.  Boot with a
live CD or over the network (PXE) and turn machines into Xen guests.
http://et.redhat.com/~rjones/virt-p2v
>From 89a57362b57ad13d4021b82c841120b48607bb8f Mon Sep 17 00:00:00 2001
From: Richard Jones <rjones redhat com>
Date: Wed, 4 Nov 2009 23:15:26 +0000
Subject: [PATCH] Generic partition creation interface.

The current sfdisk interface works, but is somewhat limited
since it can only deal with MBR-style partitions.  For disks
larger than 2TB, MBR partitions are unsuitable and we need
to provide access to other partition table types (eg. GPT).

This commit introduces a generic partition creation interface
which should be future-proof and extensible.

The implementation is based on parted.
---
 appliance/packagelist.in |    1 +
 daemon/Makefile.am       |    1 +
 daemon/parted.c          |  170 ++++++++++++++++++++++++++++++++++++++++++++++
 po/POTFILES.in           |    1 +
 src/MAX_PROC_NR          |    2 +-
 src/generator.ml         |  103 ++++++++++++++++++++++++++++
 6 files changed, 277 insertions(+), 1 deletions(-)
 create mode 100644 daemon/parted.c

diff --git a/appliance/packagelist.in b/appliance/packagelist.in
index 7363668..f7bd83a 100644
--- a/appliance/packagelist.in
+++ b/appliance/packagelist.in
@@ -40,6 +40,7 @@ lvm2
 module-init-tools
 net-tools
 ntfs-3g
+parted
 procps
 strace
 zerofree
diff --git a/daemon/Makefile.am b/daemon/Makefile.am
index db311ab..72e1896 100644
--- a/daemon/Makefile.am
+++ b/daemon/Makefile.am
@@ -60,6 +60,7 @@ guestfsd_SOURCES = \
 	mount.c \
 	names.c \
 	ntfs.c \
+	parted.c \
 	pingdaemon.c \
 	proto.c \
 	readdir.c \
diff --git a/daemon/parted.c b/daemon/parted.c
new file mode 100644
index 0000000..032a64e
--- /dev/null
+++ b/daemon/parted.c
@@ -0,0 +1,170 @@
+/* libguestfs - the guestfsd daemon
+ * Copyright (C) 2009 Red Hat Inc.
+ *
+ * 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., 675 Mass Ave, Cambridge, MA 02139, USA.
+ */
+
+#include <config.h>
+
+#include <stdio.h>
+#include <stdlib.h>
+#include <stdint.h>
+#include <inttypes.h>
+#include <string.h>
+#include <unistd.h>
+
+#include "daemon.h"
+#include "actions.h"
+
+/* XXX parted sends error messages to stdout!!!  This is an upstream
+ * parted bug and I have no intention of fixing it here.
+ */
+
+int
+do_part_init (const char *parttype, const char *device)
+{
+  char *err;
+  int r;
+
+  /* Check and translate parttype. */
+  if (strcmp (parttype, "aix") == 0 ||
+      strcmp (parttype, "amiga") == 0 ||
+      strcmp (parttype, "bsd") == 0 ||
+      strcmp (parttype, "dasd") == 0 ||
+      strcmp (parttype, "dvh") == 0 ||
+      strcmp (parttype, "gpt") == 0 ||
+      strcmp (parttype, "mac") == 0 ||
+      strcmp (parttype, "msdos") == 0 ||
+      strcmp (parttype, "pc98") == 0 ||
+      strcmp (parttype, "sun") == 0)
+    ;
+  else if (strcmp (parttype, "rdb") == 0)
+    parttype = "amiga";
+  else if (strcmp (parttype, "efi") == 0)
+    parttype = "gpt";
+  else if (strcmp (parttype, "mbr") == 0)
+    parttype = "msdos";
+  else {
+    reply_with_error ("part-init: unknown partition type: %s: common choices are \"gpt\" and \"msdos\"", parttype);
+    return -1;
+  }
+
+  r = command (NULL, &err,
+               "/sbin/parted", "-s", device, "mklabel", parttype, NULL);
+  if (r == -1) {
+    reply_with_perror ("part-init: %s: %s", device, err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+
+  udev_settle ();
+
+  return 0;
+}
+
+int
+do_part_add (const char *device, const char *prlogex,
+             int64_t startmb, int64_t endmb)
+{
+  char *err;
+  int r;
+  char startstr[32];
+  char endstr[32];
+
+  /* Check and translate prlogex. */
+  if (strcmp (prlogex, "primary") == 0 ||
+      strcmp (prlogex, "logical") == 0 ||
+      strcmp (prlogex, "extended") == 0)
+    ;
+  else if (strcmp (prlogex, "p") == 0)
+    prlogex = "primary";
+  else if (strcmp (prlogex, "l") == 0)
+    prlogex = "logical";
+  else if (strcmp (prlogex, "e") == 0)
+    prlogex = "extended";
+  else {
+    reply_with_error ("part-add: unknown partition type: %s: this should be \"primary\", \"logical\" or \"extended\"", prlogex);
+    return -1;
+  }
+
+  if (startmb < 0) {
+    reply_with_error ("part-add: startmb cannot be negative");
+    return -1;
+  }
+
+  if (endmb < 0) {
+    reply_with_error ("part-add: endmb cannot be negative");
+    return -1;
+  }
+
+  /* Special value of endmb meaning "to the end of the disk".
+   * Unfortunately parted doesn't make this easy - we have to work out
+   * how big the disk is ourselves.
+   */
+  if (endmb == 0) {
+    endmb = do_blockdev_getsize64 (device);
+    if (endmb == -1)
+      /* do_blockdev_getsize64 has called reply_with_error */
+      return -1;
+
+    /* That's bytes, convert to MB. */
+    endmb /= 1024L * 1024;
+  }
+
+  snprintf (startstr, sizeof startstr, "%" PRIi64, startmb);
+  snprintf (endstr, sizeof endstr, "%" PRIi64, endmb);
+
+  r = command (NULL, &err,
+               "/sbin/parted", "-s", device, "mkpart",
+                 prlogex, startstr, endstr, NULL);
+  if (r == -1) {
+    reply_with_perror ("part-add: %s: %s", device, err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+
+  udev_settle ();
+
+  return 0;
+}
+
+int
+do_part_bootable (const char *device, int partnum, int bootable)
+{
+  char *err;
+  int r;
+  char partstr[16];
+
+  snprintf (partstr, sizeof partstr, "%d", partnum);
+
+  r = command (NULL, &err,
+               "/sbin/parted", "-s", device, "set", partstr, "boot",
+               bootable ? "on" : "off", NULL);
+  if (r == -1) {
+    reply_with_perror ("part-bootable: %s: %s", device, err);
+    free (err);
+    return -1;
+  }
+
+  free (err);
+
+  udev_settle ();
+
+  return 0;
+}
diff --git a/po/POTFILES.in b/po/POTFILES.in
index d7d12f7..a125f2a 100644
--- a/po/POTFILES.in
+++ b/po/POTFILES.in
@@ -35,6 +35,7 @@ daemon/modprobe.c
 daemon/mount.c
 daemon/names.c
 daemon/ntfs.c
+daemon/parted.c
 daemon/pingdaemon.c
 daemon/proto.c
 daemon/readdir.c
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index c92ba56..cd7da05 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-207
+210
diff --git a/src/generator.ml b/src/generator.ml
index a06e208..7960ea6 100755
--- a/src/generator.ml
+++ b/src/generator.ml
@@ -3893,6 +3893,109 @@ bytes of the file, starting at C<offset>, from file C<path>.
 This may read fewer bytes than requested.  For further details
 see the L<pread(2)> system call.");
 
+  ("part_init", (RErr, [String "parttype"; Device "device"]), 208, [],
+   [InitEmpty, Always, TestRun (
+      [["part_init"; "gpt"; "/dev/sda"]])],
+   "create an empty partition table",
+   "\
+This creates an empty partition table on C<device> of one of the
+partition types listed below.  Usually C<parttype> should be
+either C<msdos> or C<gpt> (for large disks).
+
+Initially there are no partitions.  Following this, you should
+call C<guestfs_part_add> for each partition required.
+
+Possible values for C<parttype> are:
+
+=over 4
+
+=item aix
+
+AIX disk labels.
+
+=item amiga | rdb
+
+Amiga \"Rigid Disk Block\" format.
+
+=item bsd
+
+BSD disk labels.
+
+=item dasd
+
+DASD, used on IBM mainframes.
+
+=item dvh
+
+MIPS/SGI volumes.
+
+=item efi | gpt
+
+Intel EFI / GPT partition table.
+
+This is recommended for <= 2 TB partitions that will be accessed
+from Linux and Intel-based Mac OS X.  It also has limited backwards
+compatibility with the C<mbr> format.
+
+=item mac
+
+Old Mac partition format.  Modern Macs use C<gpt>.
+
+=item mbr | msdos
+
+The standard PC \"Master Boot Record\" (MBR) format used
+by MS-DOS and Windows.  This partition type will B<only> work
+for device sizes up to 2 TB.  For large disks we recommend
+using C<gpt>.
+
+=item pc98
+
+NEC PC-98 format, common in Japan apparently.
+
+=item sun
+
+Sun disk labels.
+
+=back");
+
+  ("part_add", (RErr, [Device "device"; String "prlogex"; Int64 "startmb"; Int64 "endmb"]), 209, [],
+   [InitEmpty, Always, TestRun (
+      [["part_init"; "mbr"; "/dev/sda"];
+       ["part_add"; "/dev/sda"; "primary"; "0"; "0"]])],
+   "add a partition to the device",
+   "\
+This command adds a partition to C<device>.  If there is no partition
+table on the device, call C<guestfs_part_init> first.
+
+The C<prlogex> parameter is the type of partition.  Normally you
+should pass C<p> or C<primary> here, but MBR partition tables also
+support C<l> (or C<logical>) and C<e> (or C<extended>) partition
+types.
+
+C<startmb> and C<endmb> are the start and end of the partition
+in I<megabytes>.  (Usually partitions cannot be placed on
+arbitrary boundaries, so these are just hints and the partitions
+will be placed as close as possible).
+
+As a special case, if C<endmb> is C<0>, then this means the
+end of the disk.  So to create a single partition covering the
+whole disk, use C<startmb> = C<endmb> = 0.");
+
+  ("part_bootable", (RErr, [Device "device"; Int "partnum"; Bool "bootable"]), 210, [],
+   [InitEmpty, Always, TestRun (
+      [["part_init"; "mbr"; "/dev/sda"];
+       ["part_add"; "/dev/sda"; "primary"; "0"; "0"];
+       ["part_bootable"; "/dev/sda"; "1"; "true"]])],
+   "make a partition bootable",
+   "\
+This sets the bootable flag on partition numbered C<partnum> on
+device C<device>.  Note that partitions are numbered from 1.
+
+The bootable flag is used by some PC BIOSes to determine which
+partition to boot from.  It is by no means universally recognized,
+and in any case if your operating system installed a boot
+sector on the device itself, then that takes precedence.");
+
 ]
 
 let all_functions = non_daemon_functions @ daemon_functions
-- 
1.6.5.rc2


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