commit 7389913c708d3f19ca029cf3f150bbfb08a768d3
Date: Sat Sep 17 17:05:17 2011 -0400
Enable mount options, particularly 'read-only', for greater safety.
Provide parameters for mounting options, and code to recognize and
implement various 'read-only' flag possibilities.
diff --git a/imgcreate/fs.py b/imgcreate/fs.py
index 69fb5f1..e71032e 100644
--- a/imgcreate/fs.py
+++ b/imgcreate/fs.py
@@ -122,9 +122,10 @@ def e2fsck(fs):
class BindChrootMount:
"""Represents a bind mount of a directory into a chroot."""
- def __init__(self, src, chroot, dest = None):
+ def __init__(self, src, chroot, dest=None, ops=None):
self.src = src
self.root = chroot
+ self.ops = ops
if not dest:
dest = src
@@ -132,17 +133,35 @@ class BindChrootMount:
self.mounted = False
- def mount(self):
+ def mount(self, ops=None):
if self.mounted:
return
makedirs(self.dest)
- rc = call(["/bin/mount", "--bind", self.src, self.dest])
+ args = ['/bin/mount', '--bind', self.src, self.dest]
+ rc = call(args)
if rc != 0:
raise MountError("Bind-mounting '%s' to '%s' failed" %
(self.src, self.dest))
+ if ops is None:
+ ops = self.ops
+ if ops in (['-o', 'remount,ro'], 'remount,ro,bind', 'remount,ro',
+ ['-o', 'ro'], ['ro'], ['-r'], 'ro', '-r'):
+ self.remount('ro')
+
self.mounted = True
+ def remount(self, ops):
+ if not self.mounted:
+ return
+
+ remount_ops = ''.join(('remount,', ops))
+ args = ['/bin/mount', '-o', remount_ops, self.dest]
+ rc = call(args)
+ if rc != 0:
+ raise MountError("%s of '%s' to '%s' failed." %
+ (remount_ops, self.src, self.dest))
+
def unmount(self):
if not self.mounted:
return
@@ -161,9 +180,11 @@ class BindChrootMount:
class LoopbackMount:
"""LoopbackMount compatibility layer for old API"""
- def __init__(self, lofile, mountdir, fstype = None):
- self.diskmount = DiskMount(LoopbackDisk(lofile,size = 0),mountdir,fstype,rmmountdir = True)
+ def __init__(self, lofile, mountdir, fstype=None, ops=None):
+ self.diskmount = DiskMount(LoopbackDisk(lofile, size=0), mountdir,
+ fstype, rmmountdir=True, ops=None)
self.losetup = False
+ self.ops = ops
def cleanup(self):
self.diskmount.cleanup()
@@ -177,7 +198,7 @@ class LoopbackMount:
self.losetup = False
self.loopdev = None
- def loopsetup(self):
+ def loopsetup(self, ops=None):
if self.losetup:
return
@@ -191,15 +212,22 @@ class LoopbackMount:
self.loopdev = losetupOutput.split()[0]
- rc = call(["/sbin/losetup", self.loopdev, self.lofile])
+ args = ['/sbin/losetup', self.loopdev, self.lofile]
+ if ops is None:
+ ops = self.ops
+ if ops in (['-o', 'ro'], ['ro'], ['-r'], 'ro', '-r'):
+ ops = ['-r']
+ # This is the only additional option supported, so far.
+ args += ops
+ rc = call(args)
if rc != 0:
raise MountError("Failed to allocate loop device for '%s'" %
self.lofile)
self.losetup = True
- def mount(self):
- self.diskmount.mount()
+ def mount(self, ops=None):
+ self.diskmount.mount(ops)
class SparseLoopbackMount(LoopbackMount):
"""SparseLoopbackMount compatibility layer for old API"""
@@ -290,9 +318,10 @@ class RawDisk(Disk):
class LoopbackDisk(Disk):
"""A Disk backed by a file via the loop module."""
- def __init__(self, lofile, size):
+ def __init__(self, lofile, size, ops=None):
Disk.__init__(self, size)
self.lofile = lofile
+ self.ops = ops
def fixed(self):
return False
@@ -300,7 +329,7 @@ class LoopbackDisk(Disk):
def exists(self):
return os.path.exists(self.lofile)
- def create(self):
+ def create(self, ops=None):
if self.device is not None:
return
@@ -313,9 +342,16 @@ class LoopbackDisk(Disk):
self.lofile)
device = losetupOutput.split()[0]
+ args = ['/sbin/losetup', device, self.lofile]
+ if ops is None:
+ ops = self.ops
+ if ops in (['-o', 'ro'], ['ro'], ['-r'], 'ro', '-r'):
+ ops = ['-r']
+ # This is the only additional option supported, so far.
+ args += ops
logging.info("Losetup add %s mapping to %s" % (device, self.lofile))
- rc = call(["/sbin/losetup", device, self.lofile])
+ rc = call(args)
if rc != 0:
raise MountError("Failed to allocate loop device for '%s'" %
self.lofile)
@@ -329,11 +365,10 @@ class LoopbackDisk(Disk):
self.device = None
-
class SparseLoopbackDisk(LoopbackDisk):
"""A Disk backed by a sparse file via the loop module."""
- def __init__(self, lofile, size):
- LoopbackDisk.__init__(self, lofile, size)
+ def __init__(self, lofile, size, ops=None):
+ LoopbackDisk.__init__(self, lofile, size, ops=None)
def expand(self, create = False, size = None):
flags = os.O_WRONLY
@@ -362,9 +397,9 @@ class SparseLoopbackDisk(LoopbackDisk):
os.ftruncate(fd, size)
os.close(fd)
- def create(self):
+ def create(self, ops=None):
self.expand(create = True)
- LoopbackDisk.create(self)
+ LoopbackDisk.create(self, ops=None)
class Mount:
"""A generic base class to deal with mounting things."""
@@ -382,15 +417,17 @@ class Mount:
class DiskMount(Mount):
"""A Mount object that handles mounting of a Disk."""
- def __init__(self, disk, mountdir, fstype = None, rmmountdir = True):
+ def __init__(self, disk, mountdir, fstype=None, rmmountdir=True, ops=None):
Mount.__init__(self, mountdir)
self.disk = disk
self.fstype = fstype
+ self.ops = ops
self.rmmountdir = rmmountdir
self.mounted = False
self.rmdir = False
+ self.created = False
def cleanup(self):
Mount.cleanup(self)
@@ -420,12 +457,12 @@ class DiskMount(Mount):
pass
self.rmdir = False
-
def __create(self):
- self.disk.create()
-
+ if not self.created:
+ self.disk.create()
+ self.created = True
- def mount(self):
+ def mount(self, ops=None):
if self.mounted:
return
@@ -440,6 +477,10 @@ class DiskMount(Mount):
args = [ "/bin/mount", self.disk.device, self.mountdir ]
if self.fstype:
args.extend(["-t", self.fstype])
+ if ops is None:
+ ops = self.ops
+ if ops is not None:
+ args.extend(['-o', ops])
rc = call(args)
if rc != 0:
@@ -448,6 +489,17 @@ class DiskMount(Mount):
self.mounted = True
+ def remount(self, ops):
+ if not self.mounted:
+ return
+
+ remount_ops = ''.join(('remount,', ops))
+ args = ['/bin/mount', '-o', remount_ops, self.mountdir]
+ rc = call(args)
+ if rc != 0:
+ raise MountError("%s of '%s' to '%s' failed." %
+ (remount_ops, self.disk.device, self.mountdir))
+
class ExtDiskMount(DiskMount):
"""A DiskMount object that is able to format/resize ext[23] filesystems."""
def __init__(self, disk, mountdir, fstype, blocksize, fslabel,
@@ -456,6 +508,7 @@ class ExtDiskMount(DiskMount):
self.blocksize = blocksize
self.fslabel = "_" + fslabel
self.tmpdir = tmpdir
+ self.created = False
def __format_filesystem(self):
logging.info("Formating %s filesystem on %s" % (self.fstype, self.disk.device))
@@ -487,6 +540,8 @@ class ExtDiskMount(DiskMount):
return size
def __create(self):
+ if self.created:
+ return
resize = False
if not self.disk.fixed() and self.disk.exists():
resize = True
@@ -498,6 +553,8 @@ class ExtDiskMount(DiskMount):
else:
self.__format_filesystem()
+ self.created = True
+
def mount(self):
self.__create()
DiskMount.mount(self)
@@ -535,10 +592,12 @@ class ExtDiskMount(DiskMount):
self.__resize_filesystem(size)
return minsize
+
class DeviceMapperSnapshot(object):
- def __init__(self, imgloop, cowloop):
+ def __init__(self, imgloop, cowloop, ops=None):
self.imgloop = imgloop
self.cowloop = cowloop
+ self.ops = ops
self.__created = False
self.__name = None
@@ -546,15 +605,16 @@ class DeviceMapperSnapshot(object):
def get_path(self):
if self.__name is None:
return None
+ return self.device
return os.path.join("/dev/mapper", self.__name)
path = property(get_path)
- def create(self):
+ def create(self, ops=None):
if self.__created:
return
- self.imgloop.create()
- self.cowloop.create()
+ self.imgloop.create(self.ops)
+ self.cowloop.create(self.ops)
self.__name = "imgcreate-%d-%d" % (os.getpid(),
random.randint(0, 2**16))
@@ -567,13 +627,22 @@ class DeviceMapperSnapshot(object):
args = ["/sbin/dmsetup", "create", self.__name,
"--uuid", "LIVECD-%s" % self.__name, "--table", table]
+ if ops is None:
+ ops = self.ops
+ if ops in (['-o', 'ro'], ['ro'], ['-r'], 'ro', '-r',
+ ['--readonly'], '--readonly'):
+ ops = ['--readonly']
+ # This is the only additional option supported, so far.
+ args += ops
if call(args) != 0:
+ time.sleep(1)
self.cowloop.cleanup()
self.imgloop.cleanup()
raise SnapshotError("Could not create snapshot device using: " +
string.join(args, " "))
self.__created = True
+ self.device = os.path.join('/dev/mapper', self.__name)
def remove(self, ignore_errors = False):
if not self.__created: