WIP: Partitioning locking and refactoring #955
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tbzatek
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I'm still thinking whether we should try harder with acquiring exclusive lock when busy - 500ms might not be enough. Specifically the mentioned blogpost says: |
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| self.udev_settle() | ||
| time.sleep(5) | ||
| device.Format('empty', d, dbus_interface=self.iface_prefix + '.Block') | ||
| pass |
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We might want to keep the retry here for the wipefs call.
vojtechtrefny
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This is a partial revert of commit cf47eee that depends on full object update after partitioning. That is still work in progress (see storaged-project#955) and prone to race conditions. ====================================================================== FAIL: test_60_resolve_device (test_10_basic.UdisksBaseTest) ---------------------------------------------------------------------- Traceback (most recent call last): File "/home/jenkins/workspace/udisks-pr/arch/x86_64/distro/centos_9s/type/udisks/src/tests/dbus-tests/test_10_basic.py", line 335, in test_60_resolve_device self.assertEquals(part_name_val, part_label) AssertionError: dbus.String('', variant_level=1) != 'PRTLBLX'
Advisory locking of block devices undergoing major changes is getting increasingly useful and subject for extended use over the daemon. See this great writeup: https://systemd.io/BLOCK_DEVICE_LOCKING/
Nowadays with synthetic uevent tagging in use partitioning can become more predictable. The right approach should be to acquire an advisory lock, make changes, unlock and trigger re-read. Changing the shared lock to exclusive seems to make a big difference and the underlying libblockdev-3 partitioning copes with it just fine.
Rather advisory this alerts the state cleanup thread to avoid touching this device.
Advisory BSD lock is now held on a partition table block device and extra BLKRRPART ioctl is issued on it afterwards.
In case a protective partition table is created by a particular mkfs tool, avoid issuing BLKRRPART on a partition block device and find a parent device that is supposed to hold a partition table.
Should not be necessary anymore now that we're more predictable. Added proper wipe on cleanup though.
This reverts commit 3c41385.
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Constantly failing tests in #933 led me to chase for an explanation and managed to find a deficiency in object update after partitioning. Just another race condition that only reproduced in the CI, never locally.
The biggest difference made changing the advisory lock from shared to exclusive.