I found three issues during the analysis:
1. Memory leak caused by temp_buf not being freed;
2. Memory leak caused when handling argv;
3. Conditional jump that depended on unitialized values.
Issue #1
--------
DESCRIPTION: when mysqlbinlog is reading from a remote location
the event temp_buf references the incoming stream (in NET
object), which is not freed by mysqlbinlog explicitly. On the
other hand, when it is reading local binary log, it points to a
temporary buffer that needs to be explicitly freed. For both
cases, the temp_buf was not freed by mysqlbinlog, instead was
set to 0. This clearly disregards the free required in the
second case, thence creating a memory leak.
FIX: we make temp_buf to be conditionally freed depending on
the value of remote_opt. Found out that similar fix is already
in most recent codebases.
Issue #2
--------
DESCRIPTION: load_defaults is called by parse_args, and it
reads default options from configuration files and put them
BEFORE the arguments that are already in argc and argv. This is
done resorting to MEM_ROOT. However, parse_args calls
handle_options immediately after which changes argv. Later when
freeing the defaults, pointers to MEM_ROOT won't match, causing
the memory not to be freed:
void free_defaults(char **argv)
{
MEM_ROOT ptr
memcpy_fixed((char*) &ptr,(char *) argv - sizeof(ptr), sizeof(ptr));
free_root(&ptr,MYF(0));
}
FIX: we remove load_defaults from parse_args and call it
before. Then we save argv with defaults in defaults_argv BEFORE
calling parse_args (which inside can then call handle_options
at will). Actually, found out that this is in fact kind of a
backport for BUG#38468 into 5.1, so I merged in the test case
as well and added error check for load_defaults call.
Fix based on:
revid:zhenxing.he@sun.com-20091002081840-uv26f0flw4uvo33y
Issue #3
--------
DESCRIPTION: the structure st_print_event_info constructor
would not initialize the sql_mode member, although it did for
sql_mode_inited (set to false). This would later raise the
warning in valgrind when printing the sql_mode in the event
header, as this print out is protected by a check against
sql_mode_inited and sql_mode variables. Given that sql_mode was
not initialized valgrind would output the warning.
FIX: we add initialization of sql_mode to the
st_print_event_info constructor.
--slave-load-tm
The MDL_SHARED lock was introduced for an object in 5.4, but the 'TABLE_LIST'
object was not initialized with the MDL_SHARED lock when applying event with
LOAD DATA INFILE into table. So the failure is caused when checking the
MDL_SHARED lock for the object.
To fix the problem, the 'TABLE_LIST' object was initialized with the MDL_SHARED
lock when applying event with LOAD DATA INFILE into table.
--slave-load-tm
The MDL_SHARED lock was introduced for an object in 5.4, but the 'TABLE_LIST'
object was not initialized with the MDL_SHARED lock when applying event with
LOAD DATA INFILE into table. So the failure is caused when checking the
MDL_SHARED lock for the object.
To fix the problem, the 'TABLE_LIST' object was initialized with the MDL_SHARED
lock when applying event with LOAD DATA INFILE into table.
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/suite/rpl/r/rpl_slow_query_log.result
Text conflict in mysql-test/suite/rpl/t/rpl_slow_query_log.test
Conflict adding files to server-tools. Created directory.
Conflict because server-tools is not versioned, but has versioned children. Versioned directory.
Conflict adding files to server-tools/instance-manager. Created directory.
Conflict because server-tools/instance-manager is not versioned, but has versioned children. Versioned directory.
Contents conflict in server-tools/instance-manager/options.cc
Text conflict in sql/mysqld.cc
into slow log
While processing a statement, down the mysql_parse execution
stack, the thd->enable_slow_log can be assigned to
opt_log_slow_admin_statements, depending whether one is executing
administrative statements, such as ALTER TABLE, OPTIMIZE,
ANALYZE, etc, or not. This can have an impact on slow logging for
statements that are executed after an administrative statement
execution is completed.
When executing statements directly from the user this is fine
because, the thd->enable_slow_log is reset right at the beginning
of the dispatch_command function, ie, everytime a new statement
is set is set to execute.
On the other hand, for slave SQL thread (sql_thd) the story is a
bit different. When in SBR the sql_thd applies statements by
calling mysql_parse. Right after, it calls log_slow_statement
function to log them if they take too long. Calling mysql_parse
directly is fine, but also means that dispatch_command function
is bypassed. As a consequence, thd->enable_slow_log does not get
a chance to be reset before the next statement to be executed by
the sql_thd. If the statement just executed by the sql_thd was an
administrative statement and logging of admin statements was
disabled, this means that sql_thd->enable_slow_log will be set to
0 (disabled) from that moment on. End result: sql_thd stops
logging slow statements.
We fix this by resetting the value of sql_thd->enable_slow_log to
the value of opt_log_slow_slave_statements right after
log_slow_stement is called by the sql_thd.
Cherry-pick a fix Bug#37148 from next-mr, to preserve
file ids of the added files, and ensure that all the necessary
changes have been pulled.
Since initially Bug#37148 was null-merged into 6.0,
the changeset that is now being cherry-picked was likewise
null merged into next-4284.
Now that Bug#37148 has been reapplied to 6.0, try to make
it work with next-4284. This is also necessary to be able
to pull other changes from 5.1-rep into next-4284.
To resolve the merge issues use this changeset applied
to 6.0:
revid:jperkin@sun.com-20091216103628-ylhqf7s6yegui2t9
revno: 3776.1.1
committer: He Zhenxing <zhenxing.he@sun.com>
branch nick: 6.0-codebase-bugfixing
timestamp: Thu 2009-12-17 17:02:50 +0800
message:
Fix merge problem with Bug#37148
Fix Bug#50555 "handler commands crash server in my_hash_first()"
as a post-merge fix (the new handler tests are not passing
otherwise).
- in hash.c, don't call calc_hash if ! my_hash_inited().
- add tests and results for the test case for Bug#50555
Rename method as to not hide a base.
Reorder attributes initialization.
Remove unused variable.
Rework code to silence a warning due to assignment used as truth value.
When replicating from 4.1 master to 5.0 slave START SLAVE UNTIL can stop too late.
The necessary in calculating of the beginning of an event the event's length
did not correspond to the master's genuine information at the event's execution time.
That piece of info was changed at the event's relay-logging due to binlog_version<4 event
conversion by IO thread.
Fixed with storing the master genuine Query_log_event size into a new status
variable at relay-logging of the event. The stored info is extacted at the event
execution and participate further to caclulate the correct start position of the event
in the until-pos stopping routine.
The new status variable's algorithm will be only active when the event comes
from the master of version < 5.0 (binlog_version < 4).
enabled binary
The test case injects an error in the server by deleting the
temporary file that it uses during the load data statement
execution. The error consisted of closing, deleting and setting
the file descriptor to -1 right before calling mysql_file_write.
Although, this error injection seems to work OK in Unix like
environments, in Windows, this would cause the server to hit an
assertion in 'my_get_open_flags':
DBUG_ASSERT(fd >= MY_FILE_MIN && fd < (int)my_file_limit)
We fix this by changing the error injection to just call the
macro my_delete_allow_opened, instead of the close + delete + set
fd=-1. The macro deletes the file and is platform
independent. Additionally, this required some changes to how the
assertion is handled in the test case to make it cope with this
change.
variable
The User_var_log_event was not serializing the unsigned
flag. This would cause the slave to always assume signed values.
We fix this by extending the User_var_log_event to also contain
information on the unsigned_flag, meaning that it gets into the
binlog as well, therefore the slave will get this information as
well. Events without information on unsigned flag (old events)
are treated as they were before (always signed: unsigned_flag=
FALSE).
The information on the unsigned_flag, is shipped in an extra byte
appended to the end of the User_var_log_event and added by this
patch. This extra byte holds values for general purpose
User_var_log_event flags which are now packed in the binlog as
well. One of these flags contains information about whether the
value is signed or unsigned (currently this extra byte is only
used to hold data on the unsigned flag, in the future we can use
it to pack extra flags if there is the need to).
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata_fatal.result
Text conflict in mysql-test/suite/rpl/r/rpl_stm_log.result
Text conflict in mysql-test/t/mysqlbinlog.test
Text conflict in sql/sql_acl.cc
Text conflict in sql/sql_servers.cc
Text conflict in sql/sql_update.cc
Text conflict in support-files/mysql.spec.sh
BUG#49481: RBR: MyISAM and bit fields may cause slave to stop on delete:
cant find record
BUG#49482: RBR: Replication may break on deletes when MyISAM tables +
char field are used
When using MyISAM tables, despite the fact that the null bit is
set for some fields, their old value is still in the row. This
can cause the comparison of records to fail when the slave is
doing an index or range scan.
We fix this by avoiding memcmp for MyISAM tables when comparing
records. Additionally, when comparing field by field, we first
check if both fields are not null and if so, then we compare
them. If just one field is null we return failure immediately. If
both fields are null, we move on to the next field.
Conflicts:
Text conflict in .bzr-mysql/default.conf
Text conflict in mysql-test/extra/rpl_tests/rpl_loaddata.test
Text conflict in mysql-test/r/mysqlbinlog2.result
Text conflict in mysql-test/suite/binlog/r/binlog_stm_mix_innodb_myisam.result
Text conflict in mysql-test/suite/binlog/r/binlog_unsafe.result
Text conflict in mysql-test/suite/rpl/r/rpl_insert_id.result
Text conflict in mysql-test/suite/rpl/r/rpl_loaddata.result
Text conflict in mysql-test/suite/rpl/r/rpl_stm_auto_increment_bug33029.result
Text conflict in mysql-test/suite/rpl/r/rpl_udf.result
Text conflict in mysql-test/suite/rpl/t/rpl_slow_query_log.test
Text conflict in sql/field.h
Text conflict in sql/log.cc
Text conflict in sql/log_event.cc
Text conflict in sql/log_event_old.cc
Text conflict in sql/mysql_priv.h
Text conflict in sql/share/errmsg.txt
Text conflict in sql/sp.cc
Text conflict in sql/sql_acl.cc
Text conflict in sql/sql_base.cc
Text conflict in sql/sql_class.h
Text conflict in sql/sql_db.cc
Text conflict in sql/sql_delete.cc
Text conflict in sql/sql_insert.cc
Text conflict in sql/sql_lex.cc
Text conflict in sql/sql_lex.h
Text conflict in sql/sql_load.cc
Text conflict in sql/sql_table.cc
Text conflict in sql/sql_update.cc
Text conflict in sql/sql_view.cc
Conflict adding files to storage/innobase. Created directory.
Conflict because storage/innobase is not versioned, but has versioned children. Versioned directory.
Conflict adding file storage/innobase. Moved existing file to storage/innobase.moved.
Conflict adding files to storage/innobase/handler. Created directory.
Conflict because storage/innobase/handler is not versioned, but has versioned children. Versioned directory.
Contents conflict in storage/innobase/handler/ha_innodb.cc
For tables with metadata sizes ranging from 251 to 255 the size
of the event data (m_data_size) was being improperly calculated
in the Table_map_log_event constructor. This was due to the fact
that when writing the Table_map_log_event body (in
Table_map_log_event::write_data_body) a call to net_store_length
is made for packing the m_field_metadata_size. It happens that
net_store_length uses *one* byte for storing
m_field_metadata_size when it is smaller than 251 but *three*
bytes when it exceeds that value. BUG 42749 had already
pinpointed and fix this fact, but the fix was incomplete, as the
calculation in the Table_map_log_event constructor considers 255
instead of 251 as the threshold to increment m_data_size by
three. Thence, the window for having a mismatch between the
number of bytes written and the number of bytes accounted in the
event length (m_data_size) was left open for
m_field_metadata_size values between 251 and 255.
We fix this by changing the condition in the Table_map_log_event
constructor to match the one in the net_store_length, ie,
increment one byte if m_field_metadata_size < 251 and three if it
exceeds this value.
In statement-based or mixed-mode replication, use DROP TEMPORARY TABLE
to drop multiple tables causes different errors on master and slave,
when one or more of these tables do not exist. Because when executed
on slave, it would automatically add IF EXISTS to the query to ignore
all ER_BAD_TABLE_ERROR errors.
To fix the problem, do not add IF EXISTS when executing DROP TEMPORARY
TABLE on the slave, and clear the ER_BAD_TABLE_ERROR error after
execution if the query does not expect any errors.
