diff options
| author | Olivier Gayot <[email protected]> | 2025-02-17 11:18:25 +0100 |
|---|---|---|
| committer | Olivier Gayot <[email protected]> | 2025-02-21 09:36:08 +0100 |
| commit | e67611532bb84e39980ca60ab37fc08f304a15a5 (patch) | |
| tree | 2e383e8f1933e0a4c4a569e37370159c019abdb4 | |
| parent | 52496fc9bc3e0a5b47e8cc98f4b87c1978d264b3 (diff) | |
block: drop legacy multipath detection mechanism
There is multiple problems with the legacy multipath detection:
* it detects IMSM RAID 1 devices as a multipath disk (false positive)
* it does not always detect actual multipath devices (false negative)
* it is used as an alternative method to detect multipath devices even when
multipath-tools does not detect any (and this leads to potential false
positives)
Let's drop this mechanism. If we want proper multipath support, we have
multipath-tools.
LP: #2094979
Signed-off-by: Olivier Gayot <[email protected]>
(cherry picked from commit 5dfa84cf888df74076b780060ae545fe9de067f6)
| -rw-r--r-- | curtin/block/__init__.py | 59 |
1 files changed, 3 insertions, 56 deletions
diff --git a/curtin/block/__init__.py b/curtin/block/__init__.py index f0445aef..497372d9 100644 --- a/curtin/block/__init__.py +++ b/curtin/block/__init__.py @@ -7,6 +7,7 @@ import os import stat import sys import tempfile +from typing import Optional from curtin import util from curtin.block import lvm @@ -566,60 +567,6 @@ def blkid(devs=None, cache=True): return data -def _legacy_detect_multipath(target_mountpoint=None): - """ - Detect if the operating system has been installed to a multipath device. - """ - # The obvious way to detect multipath is to use multipath utility which is - # provided by the multipath-tools package. Unfortunately, multipath-tools - # package is not available in all ephemeral images hence we can't use it. - # Another reasonable way to detect multipath is to look for two (or more) - # devices with the same World Wide Name (WWN) which can be fetched using - # scsi_id utility. This way doesn't work as well because WWNs are not - # unique in some cases which leads to false positives which may prevent - # system from booting (see LP: #1463046 for details). - # Taking into account all the issues mentioned above, curent implementation - # detects multipath by looking for a filesystem with the same UUID - # as the target device. It relies on the fact that all alternative routes - # to the same disk observe identical partition information including UUID. - # There are some issues with this approach as well though. We won't detect - # multipath disk if it doesn't any filesystems. Good news is that - # target disk will always have a filesystem because curtin creates them - # while installing the system. - rescan_block_devices() - binfo = blkid(cache=False) - LOG.debug("legacy_detect_multipath found blkid info: %s", binfo) - # get_devices_for_mp may return multiple devices by design. It is not yet - # implemented but it should return multiple devices when installer creates - # separate disk partitions for / and /boot. We need to do UUID-based - # multipath detection against each of target devices. - target_devs = get_devices_for_mp(target_mountpoint) - LOG.debug("target_devs: %s" % target_devs) - for devpath, data in binfo.items(): - # We need to figure out UUID of the target device first - if devpath not in target_devs: - continue - # This entry contains information about one of target devices - target_uuid = data.get('UUID') - # UUID-based multipath detection won't work if target partition - # doesn't have UUID assigned - if not target_uuid: - LOG.warn("Target partition %s doesn't have UUID assigned", - devpath) - continue - LOG.debug("%s: %s" % (devpath, data.get('UUID', ""))) - # Iterating over available devices to see if any other device - # has the same UUID as the target device. If such device exists - # we probably installed the system to the multipath device. - for other_devpath, other_data in binfo.items(): - if ((other_data.get('UUID') == target_uuid) and - (other_devpath != devpath)): - return True - # No other devices have the same UUID as the target devices. - # We probably installed the system to the non-multipath device. - return False - - def _device_is_multipathed(devpath): devpath = os.path.realpath(devpath) info = udevadm_info(devpath) @@ -668,7 +615,7 @@ def md_get_devices_list(devpath): return _md_get_members_list(devpath, state_is_not_spare) -def detect_multipath(target_mountpoint=None): +def detect_multipath(target_mountpoint=None) -> Optional[str]: if multipath.multipath_supported(): for device in (os.path.realpath(dev) for (dev, _mp, _vfs, _opts, _freq, _passno) @@ -682,7 +629,7 @@ def detect_multipath(target_mountpoint=None): if _device_is_multipathed(device): return device - return _legacy_detect_multipath(target_mountpoint) + return None def get_scsi_wwid(device, replace_whitespace=False): |