[Libguestfs] [PATCH 1/1] New partition API: part_resize

Nikos Skalkotos
Sat, 29 Jul 2017 17:51:04 -0000

This can be used to enlarge or shrink an existing partition.
---
 daemon/parted.c           | 31 +++++++++++++++++++++++++++++++
 generator/actions_core.ml | 22 ++++++++++++++++++++++
 generator/proc_nr.ml      |  1 +
 lib/MAX_PROC_NR           |  2 +-
 4 files changed, 55 insertions(+), 1 deletion(-)

diff --git a/daemon/parted.c b/daemon/parted.c
index 72e1b8420..f1205cadf 100644
--- a/daemon/parted.c
+++ b/daemon/parted.c
@@ -178,6 +178,37 @@ do_part_del (const char *device, int partnum)
 }

 int
+do_part_resize (const char *device, int partnum, int64_t endsect)
+{
+  int r;
+  CLEANUP_FREE char *err = NULL;
+  char endstr[32];
+  char partnum_str[16];
+
+  if (partnum <= 0) {
+    reply_with_error ("partition number must be >= 1");
+    return -1;
+  }
+
+  snprintf (partnum_str, sizeof partnum_str, "%d", partnum);
+  snprintf (endstr, sizeof endstr, "%" PRIi64 "s",
endsect);
+
+  udev_settle ();
+
+  r = commandf (NULL, &err, COMMAND_FLAG_FOLD_STDOUT_ON_STDERR,
+                "parted", "-s", "--", device,
"resizepart", partnum_str,
+                endstr, NULL);
+  if (r == -1) {
+    reply_with_error ("parted: %s: %s:", device, err);
+    return -1;
+  }
+
+  udev_settle();
+
+  return 0;
+}
+
+int
 do_part_disk (const char *device, const char *parttype)
 {
   int r;
diff --git a/generator/actions_core.ml b/generator/actions_core.ml
index ea0735676..939aec7ee 100644
--- a/generator/actions_core.ml
+++ b/generator/actions_core.ml
@@ -9646,4 +9646,26 @@ be mountable but require special options.  Filesystems
may
 not all belong to a single logical operating system
 (use C<guestfs_inspect_os> to look for OSes)." };

+  { defaults with
+    name = "part_resize"; added = (1, 37, 20);
+    style = RErr, [String (Device, "device"); Int
"partnum"; Int64 "endsect"], [];
+    tests = [
+      InitEmpty, Always, TestRun (
+        [["part_init"; "/dev/sda"; "mbr"];
+         ["part_add"; "/dev/sda"; "primary";
"1"; "-1025"];
+         ["part_resize"; "/dev/sda"; "1";
"-1"]]), []
+    ];
+    shortdesc = "resize a partition";
+    longdesc = "\
+This command resizes the partition numbered C<partnum> on C<device>
+by moving the end position.
+
+Note that this does not modify any filesystem present in the partition.
+If you wish to do this, you will need to use filesystem resizing
+commands like C<guestfs_resize2fs>.
+
+When growing a partition you will want to grow the filesystem
+afterwards, but when shrinking, you need to shrink the filesystem
+before the partition." };
+
 ]
diff --git a/generator/proc_nr.ml b/generator/proc_nr.ml
index dec02f5fa..7895063b6 100644
--- a/generator/proc_nr.ml
+++ b/generator/proc_nr.ml
@@ -484,6 +484,7 @@ let proc_nr = [
 474, "internal_yara_scan";
 475, "file_architecture";
 476, "list_filesystems";
+477, "part_resize";
 ]

 (* End of list.  If adding a new entry, add it at the end of the list
diff --git a/lib/MAX_PROC_NR b/lib/MAX_PROC_NR
index b86395733..bf2c10d23 100644
--- a/lib/MAX_PROC_NR
+++ b/lib/MAX_PROC_NR
@@ -1 +1 @@
-476
+477
--
2.13.3