hammer: rbd: snap rollback: restore the link to parent #8535
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| const SnapInfo& si(it->second); | ||
| // current parent does not match the one of the snapshot being reverting to | ||
| bool should_update_parent = ictx->parent_md.spec != si.parent.spec || | ||
| ictx->parent_md.overlap != si.parent.overlap; |
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If the overlap changes (but parent record still exists), the cls set_parent method will return -EEXISTS when trying to update the parent record. Therefore, you will need to remove_parent first. Also need to support the case where HEAD is associated with a parent but the rollback snapshot doesn't have a parent.
asheplyakov
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Done.
Done.
Done.
I've added parent info checks, however think it's important to verify if the actual data matches the expected one.
I've implemented no parent -> parent, parent -> no parent tests, however I don't quite understand which operations can change the overlap size. Any hints, please? |
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@asheplyakov The only way to change the overlap size is to shrink the image. So if you resize the image down past the original parent size, the overlap is now smaller. |
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I've added a test which verifies that rollback handles such a modification. Does the patch look OK now? |
| CephContext *cct = ictx->cct; | ||
| int r = 0; | ||
| std::map<librados::snap_t, SnapInfo>::const_iterator it = ictx->snap_info.find(snap_id); | ||
| assert(it != ictx->snap_info.end()); |
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Probably sufficient to just return -ENOENT in this case.
So snapshot, flatten, rollback of a cloned image does not loose any data Fixes: ceph#14512 Signed-off-by: Alexey Sheplyakov <asheplyakov@mirantis.com>
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lgtm |
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👍 -- good to merge once 0.94.7 is released. |
ghost
merged commit 
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smithfarm
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http://tracker.ceph.com/issues/14512