Use partprobe to re-read partition table

The `blkdev` command is fragile re-reading partition tables if a
partition is mounted. This change replaces it with the `partprobe`
command.

Closes-Bug: https://bugs.launchpad.net/cloud-init/+bug/1920939
Signed-off-by: Nicolas Bock <nicolas.bock@canonical.com>

cloudinit/config/cc_disk_setup.py

@@ -113,6 +113,7 @@
 LSBLK_CMD = subp.which("lsblk")
 BLKID_CMD = subp.which("blkid")
 BLKDEV_CMD = subp.which("blockdev")
+PARTPROBE_CMD = subp.which("partprobe")
 WIPEFS_CMD = subp.which("wipefs")
 
 LANG_C_ENV = {'LANG': 'C'}
@@ -688,10 +689,10 @@ def read_parttbl(device):
     Use partprobe instead of 'udevadm'. Partprobe is the only
     reliable way to probe the partition table.
     """
-    blkdev_cmd = [BLKDEV_CMD, '--rereadpt', device]
+    partprobe_cmd = [PARTPROBE_CMD, device]
     util.udevadm_settle()
     try:
-        subp.subp(blkdev_cmd)
+        subp.subp(partprobe_cmd)
     except Exception as e:
         util.logexc(LOG, "Failed reading the partition table %s" % e)
 

tools/.github-cla-signers

@@ -29,6 +29,7 @@ manuelisimo
 marlluslustosa
 matthewruffell
 mitechie
+nicolasbock
 nishigori
 olivierlemasle
 omBratteng