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Prevent two parallel flushes of the same object

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This commit is contained in:
Vitaliy Filippov
2019-11-15 13:58:35 +03:00
parent 71194f014a
commit c38c8ab029
4 changed files with 83 additions and 21 deletions
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blockstore_flush.cpp
+69 -17
View File
@@ -46,6 +46,34 @@ void journal_flusher_t::loop()
}
}
void journal_flusher_t::queue_flush(obj_ver_id ov)
{
auto it = flush_versions.find(ov.oid);
if (it != flush_versions.end())
{
it->second = ov.version;
}
else
{
flush_versions[ov.oid] = ov.version;
flush_queue.push_back(ov.oid);
}
}
void journal_flusher_t::unshift_flush(obj_ver_id ov)
{
auto it = flush_versions.find(ov.oid);
if (it != flush_versions.end())
{
it->second = ov.version;
}
else
{
flush_versions[ov.oid] = ov.version;
flush_queue.push_front(ov.oid);
}
}
#define await_sqe(label) \
resume_##label:\
sqe = bs->get_sqe();\
@@ -85,11 +113,26 @@ void journal_flusher_co::loop()
resume_0:
if (!flusher->flush_queue.size())
return;
cur = flusher->flush_queue.front();
cur.oid = flusher->flush_queue.front();
cur.version = flusher->flush_versions[cur.oid];
flusher->flush_queue.pop_front();
flusher->flush_versions.erase(cur.oid);
dirty_end = bs->dirty_db.find(cur);
if (dirty_end != bs->dirty_db.end())
{
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it != flusher->sync_to_repeat.end())
{
// We don't flush different parts of history of the same object in parallel
// So we check if someone is already flushing this object
// In that case we set sync_to_repeat to 2 and pick another object
// Another coroutine will see this "2" and re-queue the object after it finishes
repeat_it->second = cur.version;
wait_state = 0;
goto resume_0;
}
else
repeat_it->second = 0;
dirty_it = dirty_end;
flusher->active_flushers++;
flusher->active_until_sync++;
@@ -99,7 +142,7 @@ resume_0:
skip_copy = false;
do
{
if (dirty_it->second.state == ST_J_STABLE)
if (dirty_it->second.state == ST_J_STABLE && !skip_copy)
{
// First we submit all reads
offset = dirty_it->second.offset;
@@ -127,8 +170,6 @@ resume_0:
break;
}
}
// So subsequent stabilizers don't flush the entry again
dirty_it->second.state = ST_J_MOVE_READ_SUBMITTED;
}
else if (dirty_it->second.state == ST_D_STABLE)
{
@@ -139,16 +180,10 @@ resume_0:
}
skip_copy = true;
}
else if (IS_STABLE(dirty_it->second.state))
{
// Other coroutine is already flushing it, stop
break;
}
else
else if (!IS_STABLE(dirty_it->second.state))
{
throw new std::runtime_error("BUG: Unexpected dirty_entry state during flush: " + std::to_string(dirty_it->second.state));
}
dirty_start = dirty_it;
dirty_it--;
} while (dirty_it != bs->dirty_db.begin() && dirty_it->first.oid == cur.oid);
if (wait_count == 0 && clean_loc == UINT64_MAX)
@@ -156,6 +191,13 @@ resume_0:
// Nothing to flush
flusher->active_flushers--;
flusher->active_until_sync--;
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it->second != 0)
{
// Requeue version
flusher->unshift_flush({ .oid = cur.oid, .version = repeat_it->second });
}
flusher->sync_to_repeat.erase(repeat_it);
wait_state = 0;
goto resume_0;
}
@@ -313,24 +355,34 @@ resume_0:
.version = cur.version,
.location = clean_loc,
};
for (dirty_it = dirty_start; dirty_it != dirty_end; dirty_it++)
dirty_it = dirty_end;
do
{
if (IS_BIG_WRITE(dirty_it->second.state) && dirty_it->second.location != clean_loc)
{
allocator_set(bs->data_alloc, dirty_it->second.location >> bs->block_order, false);
}
int used = --bs->journal.used_sectors[dirty_it->second.journal_sector];
if (used == 1)
if (used == 0)
{
bs->journal.used_sectors.erase(dirty_it->second.journal_sector);
}
}
// Then, basically, remove the whole version range from dirty_db...
// FIXME not until dirty_start, until other object. And wait for previous flushes.
bs->dirty_db.erase(dirty_start, std::next(dirty_end));
dirty_it--;
} while (dirty_it != bs->dirty_db.begin() && dirty_it->first.oid == cur.oid);
// Then, basically, remove everything up to the current version from dirty_db...
if (dirty_it->first.oid != cur.oid)
dirty_it++;
bs->dirty_db.erase(dirty_it, std::next(dirty_end));
// FIXME: ...and clear unused part of the journal (with some interval, not for every flushed op)
wait_state = 0;
flusher->active_flushers--;
repeat_it = flusher->sync_to_repeat.find(cur.oid);
if (repeat_it->second != 0)
{
// Requeue version
flusher->unshift_flush({ .oid = cur.oid, .version = repeat_it->second });
}
flusher->sync_to_repeat.erase(repeat_it);
goto resume_0;
}
}