[Libguestfs] [PATCH 2/3] New APIs: part-set-gpt-guid and part-get-gpt-guid

[Richard W.M. Jones]

In GPT, each partition has a GUID assigned randomly.  Allow this GUID
to be written and read.

Note this is different from the GUID type code which is used to
identify the type of the partition.
---
 daemon/parted.c      | 33 +++++++++++++++++++++++++++++++++
 generator/actions.ml | 36 ++++++++++++++++++++++++++++++++++++
 src/MAX_PROC_NR      |  2 +-
 3 files changed, 70 insertions(+), 1 deletion(-)

diff --git a/daemon/parted.c b/daemon/parted.c
index 877ef10..a7bcb99 100644
--- a/daemon/parted.c
+++ b/daemon/parted.c
@@ -812,6 +812,32 @@ do_part_set_gpt_type (const char *device, int partnum, const char *guid)
   return 0;
 }
 
+int
+do_part_set_gpt_guid (const char *device, int partnum, const char *guid)
+{
+  if (partnum <= 0) {
+    reply_with_error ("partition number must be >= 1");
+    return -1;
+  }
+
+  CLEANUP_FREE char *typecode = NULL;
+  if (asprintf (&typecode, "%i:%s", partnum, guid) == -1) {
+    reply_with_perror ("asprintf");
+    return -1;
+  }
+
+  CLEANUP_FREE char *err = NULL;
+  int r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
+                    str_sgdisk, device, "-u", typecode, NULL);
+
+  if (r == -1) {
+    reply_with_error ("%s %s -u %s: %s", str_sgdisk, device, typecode, err);
+    return -1;
+  }
+
+  return 0;
+}
+
 static char *
 sgdisk_info_extract_field (const char *device, int partnum, const char *field,
                            char *(*extract) (const char *path))
@@ -922,6 +948,13 @@ do_part_get_gpt_type (const char *device, int partnum)
 }
 
 char *
+do_part_get_gpt_guid (const char *device, int partnum)
+{
+  return sgdisk_info_extract_field (device, partnum,
+                                    "Partition unique GUID", extract_uuid);
+}
+
+char *
 do_part_get_name (const char *device, int partnum)
 {
   CLEANUP_FREE char *parttype;
diff --git a/generator/actions.ml b/generator/actions.ml
index 985bb81..6b37712 100644
--- a/generator/actions.ml
+++ b/generator/actions.ml
@@ -12413,6 +12413,42 @@ Recover the chunk tree of btrfs filesystem by scannning the devices one by one."
     longdesc = "\
 Recover bad superblocks from good copies." };
 
+  { defaults with
+    name = "part_set_gpt_guid";
+    style = RErr, [Device "device"; Int "partnum"; GUID "guid"], [];
+    proc_nr = Some 446;
+    optional = Some "gdisk";
+    tests = [
+      InitGPT, Always, TestLastFail (
+        [["part_set_gpt_guid"; "/dev/sda"; "1"; "f"]]), [];
+      InitGPT, Always, TestResultString (
+        [["part_set_gpt_guid"; "/dev/sda"; "1";
+          "01234567-89AB-CDEF-0123-456789ABCDEF"];
+         ["part_get_gpt_guid"; "/dev/sda"; "1"]],
+        "01234567-89AB-CDEF-0123-456789ABCDEF"), [];
+    ];
+    shortdesc = "set the GUID of a GPT partition";
+    longdesc = "\
+Set the GUID of numbered GPT partition C<partnum> to C<guid>.  Return an
+error if the partition table of C<device> isn't GPT, or if C<guid> is not a
+valid GUID." };
+
+  { defaults with
+    name = "part_get_gpt_guid";
+    style = RString "guid", [Device "device"; Int "partnum"], [];
+    proc_nr = Some 447;
+    optional = Some "gdisk";
+    tests = [
+      InitGPT, Always, TestResultString (
+        [["part_set_gpt_guid"; "/dev/sda"; "1";
+          "01234567-89AB-CDEF-0123-456789ABCDEF"];
+         ["part_get_gpt_guid"; "/dev/sda"; "1"]],
+        "01234567-89AB-CDEF-0123-456789ABCDEF"), [];
+    ];
+    shortdesc = "get the GUID of a GPT partition";
+    longdesc = "\
+Return the GUID of numbered GPT partition C<partnum>." };
+
 ]
 
 (* Non-API meta-commands available only in guestfish.
diff --git a/src/MAX_PROC_NR b/src/MAX_PROC_NR
index e5a135a..e9b7520 100644
--- a/src/MAX_PROC_NR
+++ b/src/MAX_PROC_NR
@@ -1 +1 @@
-445
+447
-- 
2.1.0