From b2c3effa9e233ead382cabf46c371d6485b94b15 Mon Sep 17 00:00:00 2001
From: Scott Moser <smoser@ubuntu.com>
Date: Mon, 21 Mar 2011 21:35:54 -0400
Subject: fix bug with resizefs module

instead of using blkid on /dev/root, create a device node ourselves with
the correct device number of '/', then use blkid and resize2fs on that.

I believe the problem was that /dev/root was occasionally not being present
due to race.

LP: #726938
---
 ChangeLog                            |  2 ++
 cloudinit/CloudConfig/cc_resizefs.py | 35 +++++++++++++++++++++++++++++------
 2 files changed, 31 insertions(+), 6 deletions(-)

diff --git a/ChangeLog b/ChangeLog
index 61cb6e70..aac22ff4 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -3,6 +3,8 @@
    It would not be run if 'upgrade' or packages were set to be installed
  - fix bug in part-handler code, that prevented working part-handlers
    (LP: #739694)
+ - fix bug in resizefs cloud-config that would cause trace based on
+   failure of 'blkid /dev/root' (LP: #726938)
 0.6.1:
  - fix bug in fixing permission on /var/log/cloud-init.log (LP: #704509)
  - improve comment strings in rsyslog file tools/21-cloudinit.conf
diff --git a/cloudinit/CloudConfig/cc_resizefs.py b/cloudinit/CloudConfig/cc_resizefs.py
index ebb95227..e396b283 100644
--- a/cloudinit/CloudConfig/cc_resizefs.py
+++ b/cloudinit/CloudConfig/cc_resizefs.py
@@ -18,6 +18,9 @@
 import cloudinit.util as util
 import subprocess
 import traceback
+import os
+import stat
+import tempfile
 
 def handle(name,cfg,cloud,log,args):
     if len(args) != 0:
@@ -29,21 +32,38 @@ def handle(name,cfg,cloud,log,args):
 
     if not resize_root: return
 
-    log.debug("resizing root filesystem on first boot")
+    # this really only uses the filename from mktemp, then we mknod into it
+    (fd, devpth) = tempfile.mkstemp()
+    os.unlink(devpth)
+    os.close(fd)
+    
+    try:
+       st_dev=os.stat("/").st_dev
+       dev=os.makedev(os.major(st_dev),os.minor(st_dev))
+       os.mknod(devpth, 0400 | stat.S_IFBLK, dev)
+    except:
+        log.warn("Failed to make device node to resize /")
+        raise
 
-    cmd = ['blkid', '-c', '/dev/null', '-sTYPE', '-ovalue', '/dev/root']
+    cmd = [ 'blkid', '-c', '/dev/null', '-sTYPE', '-ovalue', devpth ]
     try:
         (fstype,err) = util.subp(cmd)
     except subprocess.CalledProcessError as e:
-        log.warn("Failed to get filesystem type via %s" % cmd)
+        log.warn("Failed to get filesystem type of maj=%s, min=%s via: %s" %
+            (os.major(st_dev), os.minor(st_dev), cmd))
         log.warn("output=%s\nerror=%s\n", e.output[0], e.output[1])
+        os.unlink(devpth)
         raise
 
+    log.debug("resizing root filesystem (type=%s, maj=%i, min=%i)" % 
+        (fstype.rstrip("\n"), os.major(st_dev), os.minor(st_dev)))
+
     if fstype.startswith("ext"):
-        resize_cmd = [ 'resize2fs', '/dev/root' ]
+        resize_cmd = [ 'resize2fs', devpth ]
     elif fstype == "xfs":
-        resize_cmd = [ 'xfs_growfs', '/dev/root' ]
+        resize_cmd = [ 'xfs_growfs', devpth ]
     else:
+        os.unlink(devpth)
         log.debug("not resizing unknown filesystem %s" % fstype)
         return
 
@@ -52,5 +72,8 @@ def handle(name,cfg,cloud,log,args):
     except subprocess.CalledProcessError as e:
         log.warn("Failed to resize filesystem (%s)" % resize_cmd)
         log.warn("output=%s\nerror=%s\n", e.output[0], e.output[1])
+        os.unlink(devpth)
         raise
-        
+
+    os.unlink(devpth)
+    return
-- 
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