Merge 10.6 into 10.7

Author: dr-m

mysql-test/suite/innodb/r/innodb-alter-debug.result

@@ -132,4 +132,14 @@ ALTER TABLE t1 RENAME KEY idx TO idx1, ALGORITHM=COPY;
 disconnect con1;
 connection default;
 DROP TABLE t1;
+#
+# MDEV-26903 Assertion ctx->trx->state == TRX_STATE_ACTIVE on DROP INDEX
+#
+CREATE TABLE t1(a INT PRIMARY KEY, b INT, INDEX(b)) ENGINE=InnoDB;
+SET @save_dbug=@@debug_dbug;
+SET debug_dbug='+d,innodb_table_deadlock';
+ALTER TABLE t1 DROP INDEX b, ALGORITHM=INPLACE;
+ERROR 40001: Deadlock found when trying to get lock; try restarting transaction
+SET debug_dbug=@save_dbug;
+DROP TABLE t1;
 # End of 10.6 tests

mysql-test/suite/innodb/t/innodb-alter-debug.test

@@ -177,6 +177,18 @@ disconnect con1;
 connection default;
 DROP TABLE t1;
 
+--echo #
+--echo # MDEV-26903 Assertion ctx->trx->state == TRX_STATE_ACTIVE on DROP INDEX
+--echo #
+
+CREATE TABLE t1(a INT PRIMARY KEY, b INT, INDEX(b)) ENGINE=InnoDB;
+SET @save_dbug=@@debug_dbug;
+SET debug_dbug='+d,innodb_table_deadlock';
+--error ER_LOCK_DEADLOCK
+ALTER TABLE t1 DROP INDEX b, ALGORITHM=INPLACE;
+SET debug_dbug=@save_dbug;
+DROP TABLE t1;
+
 --echo # End of 10.6 tests
 
 # Wait till all disconnects are completed

storage/innobase/handler/ha_innodb.cc

@@ -150,6 +150,11 @@ void close_thread_tables(THD* thd);
 #include "wsrep_sst.h"
 #endif /* WITH_WSREP */
 
+#ifdef HAVE_URING
+/** The Linux kernel version if io_uring() is considered unsafe */
+static const char *io_uring_may_be_unsafe;
+#endif
+
 #define INSIDE_HA_INNOBASE_CC
 
 #define EQ_CURRENT_THD(thd) ((thd) == current_thd)
@@ -4041,6 +4046,14 @@ static int innodb_init_params()
 	cases, we ignore the setting of innodb_use_native_aio. */
 	srv_use_native_aio = FALSE;
 #endif
+#ifdef HAVE_URING
+	if (srv_use_native_aio && io_uring_may_be_unsafe) {
+		sql_print_warning("innodb_use_native_aio may cause "
+				  "hangs with this kernel %s; see "
+				  "https://jira.mariadb.org/browse/MDEV-26674",
+				  io_uring_may_be_unsafe);
+	}
+#endif
 
 #ifndef _WIN32
 	ut_ad(srv_file_flush_method <= SRV_O_DIRECT_NO_FSYNC);
@@ -19401,10 +19414,29 @@ static MYSQL_SYSVAR_STR(version, innodb_version_str,
   PLUGIN_VAR_NOCMDOPT | PLUGIN_VAR_READONLY,
   "InnoDB version", NULL, NULL, INNODB_VERSION_STR);
 
+#ifdef HAVE_URING
+# include <sys/utsname.h>
+static utsname uname_for_io_uring;
+#endif
+
+static bool innodb_use_native_aio_default()
+{
+#ifdef HAVE_URING
+  utsname &u= uname_for_io_uring;
+  if (!uname(&u) && u.release[0] == '5' && u.release[1] == '.' &&
+      u.release[2] == '1' && u.release[3] > '0' && u.release[3] < '6')
+  {
+    io_uring_may_be_unsafe= u.release;
+    return false; /* working around io_uring hangs (MDEV-26674) */
+  }
+#endif
+  return true;
+}
+
 static MYSQL_SYSVAR_BOOL(use_native_aio, srv_use_native_aio,
   PLUGIN_VAR_NOCMDARG | PLUGIN_VAR_READONLY,
   "Use native AIO if supported on this platform.",
-  NULL, NULL, TRUE);
+  NULL, NULL, innodb_use_native_aio_default());
 
 #ifdef HAVE_LIBNUMA
 static MYSQL_SYSVAR_BOOL(numa_interleave, srv_numa_interleave,

storage/innobase/handler/handler0alter.cc

@@ -8678,6 +8678,8 @@ inline bool rollback_inplace_alter_table(Alter_inplace_info *ha_alter_info,
     /* If we have not started a transaction yet,
     (almost) nothing has been or needs to be done. */
     dict_sys.lock(SRW_LOCK_CALL);
+  else if (ctx->trx->state == TRX_STATE_NOT_STARTED)
+    goto free_and_exit;
   else if (ctx->new_table)
   {
     ut_ad(ctx->trx->state == TRX_STATE_ACTIVE);

storage/innobase/lock/lock0lock.cc

@@ -3433,6 +3433,7 @@ lock_table_other_has_incompatible(
 static dberr_t lock_table_low(dict_table_t *table, lock_mode mode,
                               que_thr_t *thr, trx_t *trx)
 {
+  DBUG_EXECUTE_IF("innodb_table_deadlock", return DB_DEADLOCK;);
   lock_t *wait_for=
     lock_table_other_has_incompatible(trx, LOCK_WAIT, table, mode);
   dberr_t err= DB_SUCCESS;