CQs: fix a read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id#15595
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read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id`
read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id`read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id`
Contributor
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Checking. |
Contributor
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Could you provide me with the crash log for this? Both to confirm the fix and to write a regression test case. |
Collaborator
Author
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@lhoguin I will dig in, they were logs from last Friday. |
Collaborator
Author
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Below a standard CT The failure can be seen in |
read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id`read_rom_q_tail/4 crash when tune_read/2 rounds past end_seq_id
Contributor
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Thank you. I can reproduce. |
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During recovery when all transient messages are dropped
the code could crash because the #q_tail{} resulting
from reading messages into memory had a start seqid
higher than the end seqid, due to tune_read rounding
up the read range past segment boundaries and the code
not noticing it went above the end seqid.
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Contributor
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I have amended and pushed the change. I added a regression test based on the CT logs and tweaked the code, notably removing the check in the second clause because it is already covered by |
lhoguin
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(cherry picked from commit f43a079)
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(cherry picked from commit 0934fa5)
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Note that on v4.2.x, the general problem is still present but under different conditions, namely DeltaSeqId1 =:= DeltaSeqIdEnd. Unlike in `main`, DeltaSeqIdEnd cannot read past DeltaSeqId.
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CQs: fix a `read_rom_q_tail/4` crash when `tune_read/2` rounds past `end_seq_id` (backport #15595)
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tune_read/2may round up the read range to a segment boundary, advancingstart_seq_idpastend_seq_id. Guard against this in both branches ofread_from_q_tail;4.This scenario was detected by a sporadic failure in
classic_queue_prop_SUITEwhich now passes 200 times in a row.