Strange disc.commit() behavior #73
Description
Hi,
i observed a strange behavior of the disc.commit() function.
I would expect, that i have to perform a commit after applying all necessary operations.
For reproducing, i created a simple test application:
#!/usr/bin/env python
#
# Requirements:
# - python
# - python-dev
# - pyparted
import parted
# Create a disk image then attach it to a loopback device (e.g. /dev/loop0)
'''
dd if=/dev/zero of=disk.img bs=512 count=2097152
losetup -f disk.img
'''
alwaysCommit = False
commitBeforeExtended = True
lengthModifier = 0
devicePath = '/dev/loop0'
device = parted.getDevice(devicePath)
disk = parted.freshDisk(device, "msdos")
# create partition 1
geometry1 = parted.Geometry(device=device, start=1, length=parted.sizeToSectors(16, 'MiB', device.sectorSize))
filesystem1 = parted.FileSystem(type='fat32', geometry=geometry1)
partition1 = parted.Partition(disk=disk,
type=parted.PARTITION_NORMAL,
fs=filesystem1,
geometry=geometry1)
disk.addPartition(partition1, constraint=device.optimalAlignedConstraint)
if alwaysCommit:
disk.commit()
# partition 2
geometry2 = parted.Geometry(device=device, start=partition1.geometry.end + 1,
length=parted.sizeToSectors(512, 'MiB', device.sectorSize))
filesystem2 = parted.FileSystem(type='ext4', geometry=geometry2)
partition2 = parted.Partition(disk=disk,
type=parted.PARTITION_NORMAL,
fs=filesystem2,
geometry=geometry2)
disk.addPartition(partition2, constraint=device.optimalAlignedConstraint)
if alwaysCommit:
disk.commit()
# partition 3
geometry3 = parted.Geometry(device=device, start=partition2.geometry.end + 1,
length=parted.sizeToSectors(512, 'MiB', device.sectorSize))
filesystem3 = parted.FileSystem(type='ext4', geometry=geometry3)
partition3 = parted.Partition(disk=disk,
type=parted.PARTITION_NORMAL,
fs=filesystem3,
geometry=geometry3)
disk.addPartition(partition3, constraint=device.optimalAlignedConstraint)
if alwaysCommit or commitBeforeExtended:
disk.commit()
# partition 4: Extended
geometry4 = parted.Geometry(device=device, start=partition3.geometry.end + 1,
end=device.length-lengthModifier)
partition4 = parted.Partition(disk=disk,
type=parted.PARTITION_EXTENDED,
geometry=geometry4)
disk.addPartition(partition4, constraint=device.optimalAlignedConstraint)
if alwaysCommit:
disk.commit()
# partition 5: Logical
geometry5 = parted.Geometry(device=device, start=partition4.geometry.start + 1,
length=parted.sizeToSectors(256, 'MiB', device.sectorSize))
filesystem5 = parted.FileSystem(type='ext4', geometry=geometry5)
partition5 = parted.Partition(disk=disk,
type=parted.PARTITION_LOGICAL,
fs=filesystem5,
geometry=geometry5)
disk.addPartition(partition5, constraint=device.optimalAlignedConstraint)
if alwaysCommit:
disk.commit()
# partition 6: Logical
geometry6 = parted.Geometry(device=device, start=partition5.geometry.end + 1,
length=parted.sizeToSectors(256, 'MiB', device.sectorSize))
filesystem6 = parted.FileSystem(type='ext4', geometry=geometry6)
partition6 = parted.Partition(disk=disk,
type=parted.PARTITION_LOGICAL,
fs=filesystem6,
geometry=geometry6)
disk.addPartition(partition6, constraint=device.optimalAlignedConstraint)
disk.commit()
My first thought was to use the options as follows, but the operation fails
alwaysCommit = False
commitBeforeExtended = False
lengthModifier = 0
[marcel@elfin-behlau pat]$ sudo ./test.py
Traceback (most recent call last):
File "./test.py", line 67, in <module>
disk.addPartition(partition4, constraint=device.optimalAlignedConstraint)
File "/usr/lib/python3.8/site-packages/parted/decorators.py", line 42, in new
ret = fn(*args, **kwds)
File "/usr/lib/python3.8/site-packages/parted/disk.py", line 244, in addPartition
result = self.__disk.add_partition(partition.getPedPartition(),
_ped.PartitionException: Can't have a partition outside the disk!
This can be fixed by using an length modifier, but the "hack" fails with an assert.
alwaysCommit = False
commitBeforeExtended = False
lengthModifier = 1
Backtrace has 20 calls on stack:
20: /usr/lib/libparted.so.2(ped_assert+0x46) [0x7fdc917e6476]
19: /usr/lib/libparted.so.2(+0x259da) [0x7fdc917fd9da]
18: /usr/lib/libparted.so.2(+0x1307a) [0x7fdc917eb07a]
17: /usr/lib/libparted.so.2(ped_disk_add_partition+0x1ce) [0x7fdc917eb8fe]
16: /usr/lib/python3.8/site-packages/_ped.cpython-38-x86_64-linux-gnu.so(py_ped_disk_add_partition+0xcc) [0x7fdc918c259c]
15: /usr/lib/libpython3.8.so.1.0(+0x16eb07) [0x7fdc91dd1b07]
14: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalFrameDefault+0x7de) [0x7fdc91e520ce]
13: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalCodeWithName+0x3cb) [0x7fdc91e3ee3b]
12: /usr/lib/libpython3.8.so.1.0(_PyFunction_Vectorcall+0x39b) [0x7fdc91e4024b]
11: /usr/lib/libpython3.8.so.1.0(PyObject_Call+0x2f8) [0x7fdc91d91418]
10: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalFrameDefault+0x2413) [0x7fdc91e53d03]
9: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalCodeWithName+0x3cb) [0x7fdc91e3ee3b]
8: /usr/lib/libpython3.8.so.1.0(+0x1dd892) [0x7fdc91e40892]
7: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalFrameDefault+0x11ac) [0x7fdc91e52a9c]
6: /usr/lib/libpython3.8.so.1.0(_PyEval_EvalCodeWithName+0x3cb) [0x7fdc91e3ee3b]
5: /usr/lib/libpython3.8.so.1.0(PyEval_EvalCode+0x23) [0x7fdc91ec83d3]
4: /usr/lib/libpython3.8.so.1.0(+0x265428) [0x7fdc91ec8428]
3: /usr/lib/libpython3.8.so.1.0(+0x269623) [0x7fdc91ecc623]
2: /usr/lib/libpython3.8.so.1.0(PyRun_FileExFlags+0x97) [0x7fdc91d673e7]
1: /usr/lib/libpython3.8.so.1.0(PyRun_SimpleFileExFlags+0x390) [0x7fdc91d71f4a]
Aborted
Committing after adding an partition, results in strange partition size ( loop0p2 is only 255M instead of 512M, /dev/loop0p3 is 510M)
alwaysCommit = True
commitBeforeExtended = False
lengthModifier = 0
Disk /dev/loop0: 4 GiB, 4294967296 bytes, 8388608 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0xb80d081d
Device Boot Start End Sectors Size Id Type
/dev/loop0p1 1 32768 32768 16M b W95 FAT32
/dev/loop0p2 522240 1044479 522240 255M 83 Linux
/dev/loop0p3 1044480 2088959 1044480 510M 83 Linux
/dev/loop0p4 2088960 8355839 6266880 3G 5 Extended
/dev/loop0p5 2091008 2611199 520192 254M 83 Linux
/dev/loop0p6 2613248 3133439 520192 254M 83 Linux
Only if i commit before creating the extended partion, everything works as expected:
alwaysCommit = False
commitBeforeExtended = False
lengthModifier = 1
Disk /dev/loop0: 4 GiB, 4294967296 bytes, 8388608 sectors
Units: sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disklabel type: dos
Disk identifier: 0x265e0c9c
Device Boot Start End Sectors Size Id Type
/dev/loop0p1 1 32768 32768 16M b W95 FAT32
/dev/loop0p2 32769 1081344 1048576 512M 83 Linux
/dev/loop0p3 1081345 2129920 1048576 512M 83 Linux
/dev/loop0p4 2611200 8355839 5744640 2.8G 5 Extended
/dev/loop0p5 2613248 3133439 520192 254M 83 Linux
/dev/loop0p6 3135488 3655679 520192 254M 83 Linux