don't do anything special for stored generated columns
in MyISAM repair code.
add an assert that if there are virtual indexed columns, they
_must_ be beyond the file->s->base.reclength boundary
We do not accept:
1. We did not have this problem (fixed earlier and better)
d982e717ab Bug#27510150: MYSQLDUMP FAILS FOR SPECIFIC --WHERE CLAUSES
2. We do not have such options (an DBUG_ASSERT put just in case)
bbc2e37fe4 Bug#27759871: BACKRONYM ISSUE IS STILL IN MYSQL 5.7
3. Serg fixed it in other way in this release:
e48d775c6f Bug#27980823: HEAP OVERFLOW VULNERABILITIES IN MYSQL CLIENT LIBRARY
Description:- MyISAM table gets corrupted with concurrent
executions of INSERT, DELETE statements in a particular
sequence.
Analysis:- Due to the inappropriate manipulation of w_lock
and r_lock associated with a MyISAM table, there arises a
scenario where the table's state information becomes
invalid.
Fix:- A lock is introduced to resolve this issue.
Modern compilers (such as GCC 8) emit warnings that the
'register' keyword is deprecated and not valid C++17.
Let us remove most use of the 'register' keyword.
Code in 'extra/' is not touched.
don't allocate them on THD::mem_root on every init(HA_STATUS_CONST) call,
do it once in open() (because they don't change) on TABLE::mem_root
(so they stay valid until the table is closed)
- Fix win64 pointer truncation warnings
(usually coming from misusing 0x%lx and long cast in DBUG)
- Also fix printf-format warnings
Make the above mentioned warnings fatal.
- fix pthread_join on Windows to set return value.
MyISAM only allows online alter if autoincrement didn't change.
MyISAM detects that by comparing new autoinc value from create_info,
with the old one, stored in MYI. But in partitioned tables,
create_info->auto_increment_value is for the whole table, max of
autoinc values of individual MYI partitions. So *some* MYI partitions
will inevitably think that alter table changes auto_increment value
and will deny online alter.
Fix: only compare autoinc values, if the user has used AUTO_INCREMENT
in the ALTER TABLE statement.
The sole purpose of handlerton::release_temporary_latches and its wrapper
function was to release the InnoDB adaptive hash index latch
(btr_search_latch).
When the btr_search_latch was split into an array of latches
in MySQL 5.7.8 as part of the Oracle Bug#20985298 fix, the "caching"
of the latch across storage engine API calls was removed. As part of that,
the function trx_search_latch_release_if_reserved() was changed to an
assertion and the function trx_reserve_search_latch_if_not_reserved()
was removed, and handlerton::release_temporary_latches() practically
became a no-op.
Note: MDEV-12121 replaced the function
trx_search_latch_release_if_reserved()
with the more appropriately named macro trx_assert_no_search_latch().
Don't rebuild the table for ALTER TABLE delay_key_write changes.
After that, delay_key_write value in .frm may differ from the
value in .MYI. We'll do what .frm says.
The issue was that my_errno was not set properly when a repair was killed,
which confused the rpl_killed_ddl script.
I also added an extra test line in varchar.inc to ensure we don't give
duplicate error rows.
MyISAM in compute_vcols() - which is used only in mi_check code -
was computing indexed vcols into an internally allocated buffer
(not record[0]) and the buffer was calculated to be long enough to fit
every keyseg (a keyseg knows where its value in a record buffer is
and the length of the value).
This logic didn' work for prefix keys, because the keyseg length is the
length of a prefix, but the record buffer needs to fit the complete
value of a vcol. In this bug MyISAM was writing a 2K varchar
into a buffer too short.
Also it didn't work for repair-with-keycache, because that code
recalculats all vcols, not only indexed ones.
So, the buffer size (MYISAM_SHARE::vreclength) should include all
vcols' full lengths. But it was calculated in mi_open and low-level
MyISAM code has no knowledge of vcols.
As a fix we now recalculate MYISAM_SHARE::vreclength in
ha_myisam::setup_vcols_for_repair() which is always called
before compute_vcols().
Also, implement MDEV-11027 a little differently from 5.5 and 10.0:
recv_apply_hashed_log_recs(): Change the return type back to void
(DB_SUCCESS was always returned).
Report progress also via systemd using sd_notifyf().
Also, implement MDEV-11027 a little differently from 5.5:
recv_sys_t::report(ib_time_t): Determine whether progress should
be reported.
recv_apply_hashed_log_recs(): Rename the parameter to last_batch.
TOCTOU bug. The path is checked to be valid, symlinks are resolved.
Then the resolved path is opened. Between the check and the open,
there's a window when one can replace some path component with a
symlink, bypassing validity checks.
Fix: after we resolved all symlinks in the path, don't allow open()
to resolve symlinks, there should be none.
Compared to the old MyISAM/Aria code:
* fastpath. Opening of not-symlinked files is just one open(),
no fn_format() and lstat() anymore.
* opening of symlinked tables doesn't do fn_format() and lstat() either.
it also doesn't to realpath() (which was lstat-ing every path
component), instead if opens every path component with O_PATH.
* share->data_file_name stores realpath(path) not readlink(path). So,
SHOW CREATE TABLE needs to do lstat/readlink() now (see ::info()),
and certain error messages (cannot open file "XXX") show the real
file path with all symlinks resolved.
move TABLE::key_read into handler. Because in index merge and DS-MRR
there can be many handlers per table, and some of them use
key read while others don't. "keyread" is really per handler,
not per TABLE property.
When updating a table with virtual BLOB columns, the following might
happen:
- an old record is read from the table, it has no virtual blob values
- update_virtual_fields() is run, vcol blob gets its value into the
record. But only a pointer to the value is in the table->record[0],
the value is in Field_blob::value String (but it doesn't have to be!
it can be in the record, if the column is just a copy of another
columns: ... b VARCHAR, c BLOB AS (b) ...)
- store_record(table,record[1]), old record now is in record[1]
- fill_record() prepares new values in record[0], vcol blob is updated,
new value replaces the old one in the Field_blob::value
- now both record[1] and record[0] have a pointer that points to the
*new* vcol blob value. Or record[1] has a pointer to nowhere if
Field_blob::value had to realloc.
To fix this I have introduced a new String object 'read_value' in
Field_blob. When updating virtual columns when a row has been read,
the allocated value is stored in 'read_value' instead of 'value'. The
allocated blobs for the new row is stored in 'value' as before.
I also made, as a safety precaution, the insert delayed handling of
blobs more general by using value to store strings instead of the
record. This ensures that virtual functions on delayed insert should
work in as in the case of normal insert.
Triggers are now properly updating the read, write and vcol maps for used
fields. This means that we don't need VCOL_UPDATE_FOR_READ_WRITE anymore
and there is no need for any other special handling of triggers in
update_virtual_fields().
To be able to test how many times virtual fields are invoked, I also
relaxed rules that one can use local (@) variables in DEFAULT and non
persistent virtual field expressions.
* don't issue an error for ER_KEY_BASED_ON_GENERATED_VIRTUAL_COLUMN
* support keyread on vcols
* callback into the server to compute vcol values from mi_check/mi_repair
* DMLs just work. Automatically.
- Used same fix as for MyISAM: High level collation byte stored in unused
bit_end position.
- Moved language from header to base_info
- Removed unused bit_end part in HA_KEY_SEG
During REPAIR TABLE of a MyISAM table, a temporary data file (.TMD)
is created. When repair finishes, this file is renamed to the original
.MYD file. The problem was that during this rename, we copied the
stats from the old file to the new file with chmod/chown. If a user
managed to replace the temporary file before chmod/chown was executed,
it was possible to get an arbitrary file with the privileges of the
mysql user.
This patch fixes the problem by not copying stats from the old
file to the new file. This is not needed as the new file was
created with the correct stats. This fix only changes server
behavior - external utilities such as myisamchk still does
chmod/chown.
No test case provided since the problem involves synchronization
with file system operations.
