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cc5de4e702
This patch lands the last case which needs to be handled by the fsid change code. Namely, this is the case where a multidisk filesystem has already undergone at least one successful fsid change i.e all disks have the METADATA_UUID incompat bit and power failure occurs as another fsid change is in progress. When such an event occurs, disks could be split in 2 groups. One of the groups will have both METADATA_UUID and CHANGING_FSID_V2 flags set coupled with old fsid/metadata_uuid pairs. The other group of disks will have only METADATA_UUID bit set and their fsid will be different than the one in disks in the first group. Here we look at the following cases: a) A disk from the first group is scanned first, so fs_devices is created with stale fsid/metdata_uuid. Then when a disk from the second group is scanned it needs to first check whether there exists such an fs_devices that has fsid_change set to true (because it was created with a disk having the CHANGING_FSID_V2 flag), the metadata_uuid and fsid of the fs_devices will be different (since it was created by a disk which already has had at least 1 successful fsid change) and finally the metadata_uuid of the fs_devices will equal that of the currently scanned disk (because metadata_uuid never really changes). When the correct fs_devices is found the information from the scanned disk will replace the current one in fs_devices since the scanned disk will have higher generation number. b) A disk from the second group is scanned so fs_devices is created as usual with differing fsid/metdata_uid. Then when a disk from the first group is scanned the code detects that it has both CHANGING_FSID_V2 and METADATA_UUID flags set and will search for fs_devices that has differing metadata_uuid/fsid and whose metadata_uuid is the same as that of the scanned device. Signed-off-by: Nikolay Borisov <nborisov@suse.com> Signed-off-by: David Sterba <dsterba@suse.com>
Linux kernel
============
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In order to build the documentation, use ``make htmldocs`` or
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