From 9398d0509fd30cd775aa32ef5a50fe6bc810170c Mon Sep 17 00:00:00 2001
From: William Brown <wililam@adelaide.edu.au>
Date: Thu, 2 Jul 2015 07:56:56 +0930
Subject: [PATCH] Changes to allow FS resize in filesystem

---
 system/filesystem.py | 85 ++++++++++++++++++++++++++++++++++++++------
 1 file changed, 74 insertions(+), 11 deletions(-)

diff --git a/system/filesystem.py b/system/filesystem.py
index a2f979ecd0b..0a98a8e2fdc 100644
--- a/system/filesystem.py
+++ b/system/filesystem.py
@@ -41,6 +41,12 @@ options:
     description:
     - If yes, allows to create new filesystem on devices that already has filesystem.
     required: false
+  resizefs:
+    choices: [ "yes", "no" ]
+    default: "no"
+    description:
+    - If yes, if the block device and filessytem size differ, grow the filesystem into the space. Note, XFS Will only grow if mounted.
+    required: false
   opts:
     description:
     - List of options to be passed to mkfs command.
@@ -63,17 +69,68 @@ def main():
             dev=dict(required=True, aliases=['device']),
             opts=dict(),
             force=dict(type='bool', default='no'),
+            resizefs=dict(type='bool', default='no'),
         ),
         supports_check_mode=True,
     )
 
+    # There is no "single command" to manipulate filesystems, so we map them all out and their options
+    fs_cmd_map = {
+        'ext2' : {
+            'mkfs' : 'mkfs.ext2',
+            'grow' : 'resize2fs',
+            'grow_flag' : None,
+            'force_flag' : '-F',
+        },
+        'ext3' : {
+            'mkfs' : 'mkfs.ext3',
+            'grow' : 'resize2fs',
+            'grow_flag' : None,
+            'force_flag' : '-F',
+        },
+        'ext4' : {
+            'mkfs' : 'mkfs.ext4',
+            'grow' : 'resize2fs',
+            'grow_flag' : None,
+            'force_flag' : '-F',
+        },
+        'ext4dev' : {
+            'mkfs' : 'mkfs.ext4',
+            'grow' : 'resize2fs',
+            'grow_flag' : None,
+            'force_flag' : '-F',
+        },
+        'xfs' : {
+            'mkfs' : 'mkfs.xfs',
+            'grow' : 'xfs_growfs',
+            'grow_flag' : None,
+            'force_flag' : '-f',
+        },
+        'btrfs' : {
+            'mkfs' : 'mkfs.btrfs',
+            'grow' : 'btrfs',
+            'grow_flag' : 'filesystem resize',
+            'force_flag' : '-f',
+        }
+    }
+
     dev = module.params['dev']
     fstype = module.params['fstype']
     opts = module.params['opts']
     force = module.boolean(module.params['force'])
+    resizefs = module.boolean(module.params['resizefs'])
 
     changed = False
 
+    try:
+        _ = fs_cmd_map[fstype]
+    except KeyError:
+        module.exit_json(changed=False, msg="WARNING: module does not support this filesystem yet. %s" % fstype)
+
+    mkfscmd = fs_cmd_map[fstype]['mkfs']
+    force_flag = fs_cmd_map[fstype]['force_flag']
+    growcmd = fs_cmd_map[fstype]['grow']
+
     if not os.path.exists(dev):
         module.fail_json(msg="Device %s not found."%dev)
 
@@ -82,9 +139,21 @@ def main():
     rc,raw_fs,err = module.run_command("%s -c /dev/null -o value -s TYPE %s" % (cmd, dev))
     fs = raw_fs.strip()
 
-
-    if fs == fstype:
+    if fs == fstype and resizefs == False:
         module.exit_json(changed=False)
+    elif fs == fstype and resizefs == True:
+        cmd = module.get_bin_path(growcmd, required=True)
+        if module.check_mode:
+            module.exit_json(changed=True, msg="May resize filesystem")
+        else:
+            rc,out,err = module.run_command("%s %s" % (cmd, dev))
+            # Sadly there is no easy way to determine if this has changed. For now, just say "true" and move on.
+            #  in the future, you would have to parse the output to determine this.
+            #  thankfully, these are safe operations if no change is made.
+            if rc == 0:
+                module.exit_json(changed=True, msg=out)
+            else:
+                module.fail_json(msg="Resizing filesystem %s on device '%s' failed"%(fstype,dev), rc=rc, err=err)
     elif fs and not force:
         module.fail_json(msg="'%s' is already used as %s, use force=yes to overwrite"%(dev,fs), rc=rc, err=err)
 
@@ -93,19 +162,13 @@ def main():
     if module.check_mode:
         changed = True
     else:
-        mkfs = module.get_bin_path('mkfs', required=True)
+        mkfs = module.get_bin_path(mkfscmd, required=True)
         cmd = None
-        if fstype in ['ext2', 'ext3', 'ext4', 'ext4dev']:
-          force_flag="-F"
-        elif fstype in ['xfs', 'btrfs']:
-          force_flag="-f"
-        else:
-          force_flag=""
 
         if opts is None:
-            cmd = "%s -t %s %s '%s'" % (mkfs, fstype, force_flag, dev)
+            cmd = "%s %s '%s'" % (mkfs, force_flag, dev)
         else:
-            cmd = "%s -t %s %s %s '%s'" % (mkfs, fstype, force_flag, opts, dev)
+            cmd = "%s %s %s '%s'" % (mkfs, force_flag, opts, dev)
         rc,_,err = module.run_command(cmd)
         if rc == 0:
             changed = True