Ceph » rbd

If an image has snapshots where snap "A" is larger than snap "B" (resize down), when the objects corresponding to the shrunk extent are copied, the object copy state machine might improperly attempt to update the object map for snap "B" even though snap "B" is smaller than the object number. Double-checking to see if this is just a bug in librados-test-stub not properly updating the clone diff map upon truncate/zero.

seed 7464
1: Note: Google Test filter = TestDeepCopy.Stress_SmallerDstObjSize
1: [==========] Running 1 test from 1 test case.
1: [----------] Global test environment set-up.
1: [----------] 1 test from TestDeepCopy
1: [ RUN      ] TestDeepCopy.Stress_SmallerDstObjSize
1: creating image with stripe unit: 2097152, stripe count: 16
1: write: A 46495570~7422724
1: discard: 18687514~7049574
1: write: A 75508005~8378075
1: discard: 50628501~3629157
1: write: A 4510343~104088
1: discard: 8482779~3007753
1: write: A 15574073~1075868
1: discard: 61979544~7208669
1: snap: snap0
1: clone image2 -> image3
1: resize: 86665896
1: write: B 28258422~5455808
1: discard: 76028479~578801
1: write: B 53724730~3090072
1: discard: 69636337~5664914
1: write: B 38984226~1932465
1: discard: 1015741~6282050
1: write: B 52544008~7005868
1: discard: 1632344~2876879
1: snap: snap1
1: clone image3 -> image4 
1: resize: 133360625
1: write: C 111145660~2627771
1: discard: 99589161~4501740
1: write: C 65652891~708191
1: discard: 74085549~6962927
1: write: C 25056404~5981985
1: discard: 99791811~2899677
1: write: C 17866807~6142715
1: discard: 71563877~407097
1: snap: snap2
1: resize: 91725669
1: write: D 35887249~3047753
1: discard: 16795095~1265095
1: write: D 24083365~7142610
1: discard: 32408896~6891214
1: write: D 57383044~2122985
1: discard: 18762295~4652919
1: write: D 65131186~7636414
1: discard: 55874866~2643687
1: snap: snap3
1: /home/jdillaman/ceph/src/test/librbd/test_DeepCopy.cc:92: Failure
1: Value of: flags_set
1:   Actual: true
1: Expected: false
1: [  FAILED  ] TestDeepCopy.Stress_SmallerDstObjSize (517 ms)