Re: [Maria-developers] 0552ed86782: MDEV-21804 Assertion `marked_for_read()' failed upon INSERT into table with long unique blob under binlog_row_image=NOBLOB

Hi, Sachin! ok to push with one change, see below. On Jun 03, Sachin wrote:

revision-id: 0552ed86782 (mariadb-10.4.11-223-g0552ed86782) parent(s): 61b2cd38d48 author: Sachin committer: Sachin timestamp: 2020-06-02 08:24:02 +0530 message:

MDEV-21804 Assertion `marked_for_read()' failed upon INSERT into table with long unique blob under binlog_row_image=NOBLOB

Problem:- Calling mark_columns_per_binlog_row_image() earlier may change the result of mark_virtual_columns_for_write() , Since it can set the bitmap on for virtual column, and henceforth mark_virtual_column_deps(field) will never be called in mark_virtual_column_with_deps.

This bug is not specific for long unique, It also fails for this case create table t2(id int primary key, a blob, b varchar(20) as (LEFT(a,2)));

diff --git a/sql/table.cc b/sql/table.cc index bc8ddbc0f9d..8edbbe8d599 100644 --- a/sql/table.cc +++ b/sql/table.cc @@ -7040,7 +7040,6 @@ void TABLE::mark_columns_needed_for_update() DBUG_ENTER("TABLE::mark_columns_needed_for_update"); bool need_signal= false;

- mark_columns_per_binlog_row_image();

if (triggers) triggers->mark_fields_used(TRG_EVENT_UPDATE); @@ -7048,6 +7047,7 @@ void TABLE::mark_columns_needed_for_update() mark_default_fields_for_write(FALSE); if (vfield) need_signal|= mark_virtual_columns_for_write(FALSE); + mark_columns_per_binlog_row_image();

I think that's too early. In that if() below you can see

if (file->ha_table_flags() & HA_REQUIRES_KEY_COLUMNS_FOR_DELETE) { KEY *end= key_info + s->keys;

... if (bitmap_fast_test_and_set(read_set, idx)) continue; if (field[idx]->vcol_info) mark_virtual_col(field[idx]); and mark_columns_per_binlog_row_image() might break that. Better to put mark_columns_per_binlog_row_image() at the very end, just before signalling.

@@ -7132,7 +7132,6 @@ void TABLE::mark_columns_needed_for_update() void TABLE::mark_columns_needed_for_insert() { DBUG_ENTER("mark_columns_needed_for_insert"); - mark_columns_per_binlog_row_image();

if (triggers) { @@ -7152,6 +7151,7 @@ void TABLE::mark_columns_needed_for_insert() /* Mark virtual columns for insert */ if (vfield) mark_virtual_columns_for_write(TRUE); + mark_columns_per_binlog_row_image();

this looks ok.

if (check_constraints) mark_check_constraint_columns_for_read(); DBUG_VOID_RETURN;

Regards, Sergei VP of MariaDB Server Engineering and security@mariadb.org