Description:
The following patch leads to thread deadlock in mysql-5.7. It turns out that
it is another case of both BUG#26225783 and Bug #80919.
diff --git a/storage/innobase/buf/buf0buf.cc b/storage/innobase/buf/buf0buf.cc
index ddfebaf..23baa6c 100644
--- a/storage/innobase/buf/buf0buf.cc
+++ b/storage/innobase/buf/buf0buf.cc
@@ -4617,6 +4617,9 @@ got_block:
fix_block->made_dirty_with_no_latch = dirty_with_no_latch;
}
+ rw_lock_x_lock(&block->lock);
+ rw_lock_x_unlock(&block->lock);
+
mtr_memo_type_t fix_type;
switch (rw_latch) {
The following messages are taken from error log:
########################################
DEADLOCK of threads detected!
rw-lock 0x7f4e85c9c840 --Thread 139975224411904 has waited at buf0buf.cc line 4620 for 0.00 seconds the semaphore:
X-lock on RW-latch at 0x7f4e85c9c840 created in file buf0buf.cc line 1460
a writer (thread id 139974972262144) has reserved it in mode exclusive
number of readers 0, waiters flag 1, lock_word: 0
Last time read locked in file btr0cur.cc line 5697
Last time write locked in file /home/thiru/mysql-server/mysql-server/5.7/storage/innobase/include/mtr0mtr.ic line 153
Locked: thread 139974972262144 file mtr0mtr.ic line 153 X-LOCK
Locked: thread 139974972262144 file mtr0mtr.ic line 153 X-LOCK
rw-lock 0x7f4e85c502c8 --Thread 139974972262144 has waited at buf0buf.cc line 4620 for 0.00 seconds the semaphore:
X-lock (wait_ex) on RW-latch at 0x7f4e85c502c8 created in file buf0buf.cc line 1460
a writer (thread id 139974972262144) has reserved it in mode wait exclusive
number of readers 1, waiters flag 0, lock_word: ffffffffefffffff
Last time read locked in file btr0cur.cc line 5736
Last time write locked in file /home/thiru/mysql-server/mysql-server/5.7/storage/innobase/include/mtr0mtr.ic line 117
Locked: thread 139975224411904 file btr0cur.cc line 5736 S-LOCK
Locked: thread 139975224411904 file btr0cur.cc line 5736 S-LOCK
2019-09-10T10:07:24.066654Z 0 [ERROR] [FATAL] InnoDB: ######################################## Deadlock Detected!
How to repeat:
./mtr --big-test --mysqld=--innodb-page-size=4k innodb.innodb_bulk_create_index{,,} --parallel=auto --repeat=5
Suggested fix:
Follow the latching order rules outlined in High Level Architecture of https://dev.mysql.com/worklog/task/?id=6326
