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mariadb/sql/rpl_record.cc
Alfranio Correia 7e5cf52c3e BUG#48091 valgrind errors when slave has double not null and master has double null 
Backporting BUG#43789 to mysql-5.1-bugteam
                              
The replication was generating corrupted data, warning messages on Valgrind
and aborting on debug mode while replicating a "null" to "not null" field.
Specifically the unpack_row routine, was considering the slave's table
definition and trying to retrieve a field value, where there was nothing to be
retrieved, ignoring the fact that the value was defined as "null" by the master.
                              
To fix the problem, we proceed as follows:
                              
1 - If it is not STRICT sql_mode, implicit default values are used, regardless
if it is multi-row or single-row statement.
                              
2 - However, if it is STRICT mode, then a we do what follows:
                              
2.1 If it is a transactional engine, we do a rollback on the first NULL that is
to be set into a NOT NULL column and return an error.
                              
2.2 If it is a non-transactional engine and it is the first row to be inserted
with multi-row, we also return the error. Otherwise, we proceed with the
execution, use implicit default values and print out warning messages.
                        
Unfortunately, the current patch cannot mimic the behavior showed by the master
for updates on multi-tables and multi-row inserts. This happens because such
statements are unfolded in different row events. For instance, considering the
following updates and strict mode:
                        
(master)
create table t1 (a int);
create table t2 (a int not null);
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
                        
t1 would have (10) and t2 would have (0) as this would be handled as a
multi-row update. On the other hand, if we had the following updates:
                        
(master)
create table t1 (a int);
create table t2 (a int);
                        
(slave)
create table t1 (a int);
create table t2 (a int not null);
                        
(master)
insert into t1 values (1);
insert into t2 values (2);
update t1, t2 SET t1.a=10, t2.a=NULL;
                        
On the master t1 would have (10) and t2 would have (NULL). On
the slave, t1 would have (10) but the update on t1 would fail.
2009-10-22 01:15:45 +01:00

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/* Copyright 2007 MySQL AB. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; version 2 of the License.
This program is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
GNU General Public License for more details.
You should have received a copy of the GNU General Public License
along with this program; if not, write to the Free Software
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
#include "mysql_priv.h"
#include "rpl_rli.h"
#include "rpl_record.h"
#include "slave.h" // Need to pull in slave_print_msg
#include "rpl_utility.h"
#include "rpl_rli.h"
/**
Pack a record of data for a table into a format suitable for
transfer via the binary log.
The format for a row in transfer with N fields is the following:
ceil(N/8) null bytes:
One null bit for every column *regardless of whether it can be
null or not*. This simplifies the decoding. Observe that the
number of null bits is equal to the number of set bits in the
@c cols bitmap. The number of null bytes is the smallest number
of bytes necessary to store the null bits.
Padding bits are 1.
N packets:
Each field is stored in packed format.
@param table Table describing the format of the record
@param cols Bitmap with a set bit for each column that should
be stored in the row
@param row_data Pointer to memory where row will be written
@param record Pointer to record that should be packed. It is
assumed that the pointer refers to either @c
record[0] or @c record[1], but no such check is
made since the code does not rely on that.
@return The number of bytes written at @c row_data.
*/
#if !defined(MYSQL_CLIENT)
size_t
pack_row(TABLE *table, MY_BITMAP const* cols,
uchar *row_data, const uchar *record)
{
Field **p_field= table->field, *field;
int const null_byte_count= (bitmap_bits_set(cols) + 7) / 8;
uchar *pack_ptr = row_data + null_byte_count;
uchar *null_ptr = row_data;
my_ptrdiff_t const rec_offset= record - table->record[0];
my_ptrdiff_t const def_offset= table->s->default_values - table->record[0];
DBUG_ENTER("pack_row");
/*
We write the null bits and the packed records using one pass
through all the fields. The null bytes are written little-endian,
i.e., the first fields are in the first byte.
*/
unsigned int null_bits= (1U << 8) - 1;
// Mask to mask out the correct but among the null bits
unsigned int null_mask= 1U;
for ( ; (field= *p_field) ; p_field++)
{
DBUG_PRINT("debug", ("null_mask=%d; null_ptr=%p; row_data=%p; null_byte_count=%d",
null_mask, null_ptr, row_data, null_byte_count));
if (bitmap_is_set(cols, p_field - table->field))
{
my_ptrdiff_t offset;
if (field->is_null(rec_offset))
{
offset= def_offset;
null_bits |= null_mask;
}
else
{
offset= rec_offset;
null_bits &= ~null_mask;
/*
We only store the data of the field if it is non-null
For big-endian machines, we have to make sure that the
length is stored in little-endian format, since this is the
format used for the binlog.
*/
#ifndef DBUG_OFF
const uchar *old_pack_ptr= pack_ptr;
#endif
pack_ptr= field->pack(pack_ptr, field->ptr + offset,
field->max_data_length(), TRUE);
DBUG_PRINT("debug", ("field: %s; pack_ptr: 0x%lx;"
" pack_ptr':0x%lx; bytes: %d",
field->field_name, (ulong) old_pack_ptr,
(ulong) pack_ptr,
(int) (pack_ptr - old_pack_ptr)));
}
null_mask <<= 1;
if ((null_mask & 0xFF) == 0)
{
DBUG_ASSERT(null_ptr < row_data + null_byte_count);
null_mask = 1U;
*null_ptr++ = null_bits;
null_bits= (1U << 8) - 1;
}
}
}
/*
Write the last (partial) byte, if there is one
*/
if ((null_mask & 0xFF) > 1)
{
DBUG_ASSERT(null_ptr < row_data + null_byte_count);
*null_ptr++ = null_bits;
}
/*
The null pointer should now point to the first byte of the
packed data. If it doesn't, something is very wrong.
*/
DBUG_ASSERT(null_ptr == row_data + null_byte_count);
DBUG_DUMP("row_data", row_data, pack_ptr - row_data);
DBUG_RETURN(static_cast<size_t>(pack_ptr - row_data));
}
#endif
/**
Unpack a row into @c table->record[0].
The function will always unpack into the @c table->record[0]
record. This is because there are too many dependencies on where
the various member functions of Field and subclasses expect to
write.
The row is assumed to only consist of the fields for which the corresponding
bit in bitset @c cols is set; the other parts of the record are left alone.
At most @c colcnt columns are read: if the table is larger than
that, the remaining fields are not filled in.
@param rli Relay log info
@param table Table to unpack into
@param colcnt Number of columns to read from record
@param row_data
Packed row data
@param cols Pointer to bitset describing columns to fill in
@param row_end Pointer to variable that will hold the value of the
one-after-end position for the row
@param master_reclength
Pointer to variable that will be set to the length of the
record on the master side
@retval 0 No error
@retval ER_NO_DEFAULT_FOR_FIELD
Returned if one of the fields existing on the slave but not on the
master does not have a default value (and isn't nullable)
*/
#if !defined(MYSQL_CLIENT) && defined(HAVE_REPLICATION)
int
unpack_row(Relay_log_info const *rli,
TABLE *table, uint const colcnt,
uchar const *const row_data, MY_BITMAP const *cols,
uchar const **const row_end, ulong *const master_reclength,
const bool abort_on_warning, const bool first_row)
{
DBUG_ENTER("unpack_row");
DBUG_ASSERT(row_data);
size_t const master_null_byte_count= (bitmap_bits_set(cols) + 7) / 8;
int error= 0;
uchar const *null_ptr= row_data;
uchar const *pack_ptr= row_data + master_null_byte_count;
Field **const begin_ptr = table->field;
Field **field_ptr;
Field **const end_ptr= begin_ptr + colcnt;
DBUG_ASSERT(null_ptr < row_data + master_null_byte_count);
// Mask to mask out the correct bit among the null bits
unsigned int null_mask= 1U;
// The "current" null bits
unsigned int null_bits= *null_ptr++;
uint i= 0;
table_def *tabledef= ((Relay_log_info*)rli)->get_tabledef(table);
for (field_ptr= begin_ptr ; field_ptr < end_ptr && *field_ptr ; ++field_ptr)
{
Field *const f= *field_ptr;
/*
No need to bother about columns that does not exist: they have
gotten default values when being emptied above.
*/
if (bitmap_is_set(cols, field_ptr - begin_ptr))
{
if ((null_mask & 0xFF) == 0)
{
DBUG_ASSERT(null_ptr < row_data + master_null_byte_count);
null_mask= 1U;
null_bits= *null_ptr++;
}
DBUG_ASSERT(null_mask & 0xFF); // One of the 8 LSB should be set
/* Field...::unpack() cannot return 0 */
DBUG_ASSERT(pack_ptr != NULL);
if (null_bits & null_mask)
{
if (f->maybe_null())
{
DBUG_PRINT("debug", ("Was NULL; null mask: 0x%x; null bits: 0x%x",
null_mask, null_bits));
f->set_null();
}
else
{
MYSQL_ERROR::enum_warning_level error_type=
MYSQL_ERROR::WARN_LEVEL_NOTE;
if (abort_on_warning && (table->file->has_transactions() ||
first_row))
{
error = HA_ERR_ROWS_EVENT_APPLY;
error_type= MYSQL_ERROR::WARN_LEVEL_ERROR;
}
else
{
f->set_default();
error_type= MYSQL_ERROR::WARN_LEVEL_WARN;
}
push_warning_printf(current_thd, error_type,
ER_BAD_NULL_ERROR,
ER(ER_BAD_NULL_ERROR),
f->field_name);
}
}
else
{
f->set_notnull();
/*
We only unpack the field if it was non-null.
Use the master's size information if available else call
normal unpack operation.
*/
uint16 const metadata= tabledef->field_metadata(i);
#ifndef DBUG_OFF
uchar const *const old_pack_ptr= pack_ptr;
#endif
pack_ptr= f->unpack(f->ptr, pack_ptr, metadata, TRUE);
DBUG_PRINT("debug", ("field: %s; metadata: 0x%x;"
" pack_ptr: 0x%lx; pack_ptr': 0x%lx; bytes: %d",
f->field_name, metadata,
(ulong) old_pack_ptr, (ulong) pack_ptr,
(int) (pack_ptr - old_pack_ptr)));
}
null_mask <<= 1;
}
i++;
}
/*
throw away master's extra fields
*/
uint max_cols= min(tabledef->size(), cols->n_bits);
for (; i < max_cols; i++)
{
if (bitmap_is_set(cols, i))
{
if ((null_mask & 0xFF) == 0)
{
DBUG_ASSERT(null_ptr < row_data + master_null_byte_count);
null_mask= 1U;
null_bits= *null_ptr++;
}
DBUG_ASSERT(null_mask & 0xFF); // One of the 8 LSB should be set
if (!((null_bits & null_mask) && tabledef->maybe_null(i)))
pack_ptr+= tabledef->calc_field_size(i, (uchar *) pack_ptr);
null_mask <<= 1;
}
}
/*
We should now have read all the null bytes, otherwise something is
really wrong.
*/
DBUG_ASSERT(null_ptr == row_data + master_null_byte_count);
DBUG_DUMP("row_data", row_data, pack_ptr - row_data);
*row_end = pack_ptr;
if (master_reclength)
{
if (*field_ptr)
*master_reclength = (*field_ptr)->ptr - table->record[0];
else
*master_reclength = table->s->reclength;
}
DBUG_RETURN(error);
}
/**
Fills @c table->record[0] with default values.
First @c restore_record() is called to restore the default values for
record concerning the given table. Then, if @c check is true,
a check is performed to see if fields are have default value or can
be NULL. Otherwise error is reported.
@param table Table whose record[0] buffer is prepared.
@param skip Number of columns for which default/nullable check
should be skipped.
@param check Specifies if lack of default error needs checking.
@param abort_on_warning
Controls how to react on lack of a field's default.
The parameter mimics the master side one for
@c check_that_all_fields_are_given_values.
@returns 0 on success or a handler level error code
*/
int prepare_record(TABLE *const table,
const uint skip, const bool check,
const bool abort_on_warning, const bool first_row)
{
DBUG_ENTER("prepare_record");
int error= 0;
restore_record(table, s->default_values);
/*
This skip should be revisited in 6.0, because in 6.0 RBR one
can have holes in the row (as the grain of the writeset is
the column and not the entire row).
*/
if (skip >= table->s->fields || !check)
DBUG_RETURN(0);
/*
For fields the extra fields on the slave, we check if they have a default.
The check follows the same rules as the INSERT query without specifying an
explicit value for a field not having the explicit default
(@c check_that_all_fields_are_given_values()).
*/
for (Field **field_ptr= table->field+skip; *field_ptr; ++field_ptr)
{
uint32 const mask= NOT_NULL_FLAG | NO_DEFAULT_VALUE_FLAG;
Field *const f= *field_ptr;
if ((f->flags & NO_DEFAULT_VALUE_FLAG) &&
(f->real_type() != MYSQL_TYPE_ENUM))
{
MYSQL_ERROR::enum_warning_level error_type=
MYSQL_ERROR::WARN_LEVEL_NOTE;
if (abort_on_warning && (table->file->has_transactions() ||
first_row))
{
error= HA_ERR_ROWS_EVENT_APPLY;
error_type= MYSQL_ERROR::WARN_LEVEL_ERROR;
}
else
{
f->set_default();
error_type= MYSQL_ERROR::WARN_LEVEL_WARN;
}
push_warning_printf(current_thd, error_type,
ER_NO_DEFAULT_FOR_FIELD,
ER(ER_NO_DEFAULT_FOR_FIELD),
f->field_name);
}
}
DBUG_RETURN(error);
}
#endif // HAVE_REPLICATION
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