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https://issues.apache.org/jira/browse/HBASE-20975?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel
]
Allan Yang updated HBASE-20975:
-------------------------------
Description:
Find this one when investigating HBASE-20921, too.
Here is some code from executeRollback in ProcedureExecutor.java.
{code}
boolean reuseLock = false;
while (stackTail --> 0) {
final Procedure proc = subprocStack.get(stackTail);
LockState lockState;
//If reuseLock, then don't acquire the lock
if (!reuseLock && (lockState = acquireLock(proc)) !=
LockState.LOCK_ACQUIRED) {
return lockState;
}
lockState = executeRollback(proc);
boolean abortRollback = lockState != LockState.LOCK_ACQUIRED;
abortRollback |= !isRunning() || !store.isRunning();
//If the next procedure in the stack is the current one, then reuseLock =
true
reuseLock = stackTail > 0 && (subprocStack.get(stackTail - 1) == proc) &&
!abortRollback;
//If reuseLock, don't releaseLock
if (!reuseLock) {
releaseLock(proc, false);
}
if (abortRollback) {
return lockState;
}
subprocStack.remove(stackTail);
if (proc.isYieldAfterExecutionStep(getEnvironment())) {
return LockState.LOCK_YIELD_WAIT;
}
//But, here, lock is released no matter reuseLock is true or false
if (proc != rootProc) {
execCompletionCleanup(proc);
}
}
{code}
You can see my comments in the code above, reuseLock can cause the procedure
executing(rollback) without a lock. Though I haven't found any bugs introduced
by this issue, it is indeed a potential bug need to fix.
I think we can just remove the reuseLock logic. Acquire and release lock every
time.
Find another case that during rolling back, the procedure's lock may not be
released properly:
see comment
was:
Find this one when investigating HBASE-20921, too.
Here is some code from executeRollback in ProcedureExecutor.java.
{code}
boolean reuseLock = false;
while (stackTail --> 0) {
final Procedure proc = subprocStack.get(stackTail);
LockState lockState;
//If reuseLock, then don't acquire the lock
if (!reuseLock && (lockState = acquireLock(proc)) !=
LockState.LOCK_ACQUIRED) {
return lockState;
}
lockState = executeRollback(proc);
boolean abortRollback = lockState != LockState.LOCK_ACQUIRED;
abortRollback |= !isRunning() || !store.isRunning();
//If the next procedure in the stack is the current one, then reuseLock =
true
reuseLock = stackTail > 0 && (subprocStack.get(stackTail - 1) == proc) &&
!abortRollback;
//If reuseLock, don't releaseLock
if (!reuseLock) {
releaseLock(proc, false);
}
if (abortRollback) {
return lockState;
}
subprocStack.remove(stackTail);
if (proc.isYieldAfterExecutionStep(getEnvironment())) {
return LockState.LOCK_YIELD_WAIT;
}
//But, here, lock is released no matter reuseLock is true or false
if (proc != rootProc) {
execCompletionCleanup(proc);
}
}
{code}
You can see my comments in the code above, reuseLock can cause the procedure
executing(rollback) without a lock. Though I haven't found any bugs introduced
by this issue, it is indeed a potential bug need to fix.
I think we can just remove the reuseLock logic. Acquire and release lock every
time.
> Lock may not be taken or released while rolling back procedure
> --------------------------------------------------------------
>
> Key: HBASE-20975
> URL: https://issues.apache.org/jira/browse/HBASE-20975
> Project: HBase
> Issue Type: Sub-task
> Components: amv2
> Affects Versions: 2.1.0, 2.0.1
> Reporter: Allan Yang
> Assignee: Allan Yang
> Priority: Major
> Attachments: HBASE-20975.branch-2.0.001.patch,
> HBASE-20975.branch-2.0.002.patch, HBASE-20975.branch-2.0.003.patch,
> HBASE-20975.branch-2.0.004.patch
>
>
> Find this one when investigating HBASE-20921, too.
> Here is some code from executeRollback in ProcedureExecutor.java.
> {code}
> boolean reuseLock = false;
> while (stackTail --> 0) {
> final Procedure proc = subprocStack.get(stackTail);
> LockState lockState;
> //If reuseLock, then don't acquire the lock
> if (!reuseLock && (lockState = acquireLock(proc)) !=
> LockState.LOCK_ACQUIRED) {
> return lockState;
> }
> lockState = executeRollback(proc);
> boolean abortRollback = lockState != LockState.LOCK_ACQUIRED;
> abortRollback |= !isRunning() || !store.isRunning();
> //If the next procedure in the stack is the current one, then reuseLock
> = true
> reuseLock = stackTail > 0 && (subprocStack.get(stackTail - 1) == proc)
> && !abortRollback;
> //If reuseLock, don't releaseLock
> if (!reuseLock) {
> releaseLock(proc, false);
> }
> if (abortRollback) {
> return lockState;
> }
> subprocStack.remove(stackTail);
> if (proc.isYieldAfterExecutionStep(getEnvironment())) {
> return LockState.LOCK_YIELD_WAIT;
> }
> //But, here, lock is released no matter reuseLock is true or false
> if (proc != rootProc) {
> execCompletionCleanup(proc);
> }
> }
> {code}
> You can see my comments in the code above, reuseLock can cause the procedure
> executing(rollback) without a lock. Though I haven't found any bugs
> introduced by this issue, it is indeed a potential bug need to fix.
> I think we can just remove the reuseLock logic. Acquire and release lock
> every time.
> Find another case that during rolling back, the procedure's lock may not be
> released properly:
> see comment
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