First UPDATE under START TRANSACTION does nothing (nstate= nstate),
but anyway generates history. Since update vector is empty we get into
(!uvect->n_fields) branch which only adds history row, but does not do
update. After that we get current row with wrong (old) row_start value
and because of that second UPDATE tries to insert history row again
because it sees trx->id != row_start which is the guard to avoid
inserting multiple trx_id-based history rows under same transaction
(because we have same trx_id and we get duplicate error and this bug
demostrates that). But this try anyway fails because PK is based on
row_end which is constant under same transaction, so PK didn't change.
The fix moves vers_make_update() to an earlier stage of
calc_row_difference(). Therefore it prepares update vector before
(!uvect->n_fields) check and never gets into that branch, hence no
need to handle versioning inside that condition anymore.
Now trx->id and row_start are equal after first UPDATE and we don't
try to insert second history row.
== Cleanups and improvements ==
ha_innobase::update_row():
vers_set_fields and vers_ins_row are cleaned up into direct condition
check. SQLCOM_ALTER_TABLE check now is not used as this is dead code,
assertion is done instead.
upd_node->is_delete is set in calc_row_difference() just to keep
versioning code as much in one place as possible. vers_make_delete()
is still located in row_update_for_mysql() as this is required for
ha_innodbase::delete_row() as well.
row_ins_duplicate_error_in_clust():
Restrict DB_FOREIGN_DUPLICATE_KEY to the better conditions.
VERSIONED_DELETE is used specifically to help lower stack to
understand what caused current insert. Related to MDEV-29813.
1. Exclude merging history rows into fts index.
The check !history_fts && (index->type & DICT_FTS) was just incorrect
attempt to avoid history in fts index.
2. Don't check for duplicates for history rows.
PROBLEM:
A deadlock was possible when a transaction tried to "upgrade" an already
held Record Lock to Next Key Lock.
SOLUTION:
This patch is based on observations that:
(1) a Next Key Lock is equivalent to Record Lock combined with Gap Lock
(2) a GAP Lock never has to wait for any other lock
In case we request a Next Key Lock, we check if we already own a Record
Lock of equal or stronger mode, and if so, then we change the requested
lock type to GAP Lock, which we either already have, or can be granted
immediately, as GAP locks don't conflict with any other lock types.
(We don't consider Insert Intention Locks a Gap Lock in above statements).
The reason of why we don't upgrage Record Lock to Next Key Lock is the
following.
Imagine a transaction which does something like this:
for each row {
request lock in LOCK_X|LOCK_REC_NOT_GAP mode
request lock in LOCK_S mode
}
If we upgraded lock from Record Lock to Next Key lock, there would be
created only two lock_t structs for each page, one for
LOCK_X|LOCK_REC_NOT_GAP mode and one for LOCK_S mode, and then used
their bitmaps to mark all records from the same page.
The situation would look like this:
request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 1:
// -> creates new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode and sets bit for
// 1
request lock in LOCK_S mode on row 1:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 1,
// so it upgrades it to X
request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 2:
// -> creates a new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode (because we
// don't have any after we've upgraded!) and sets bit for 2
request lock in LOCK_S mode on row 2:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 2,
// so it upgrades it to X
...etc...etc..
Each iteration of the loop creates a new lock_t struct, and in the end we
have a lot (one for each record!) of LOCK_X locks, each with single bit
set in the bitmap. Soon we run out of space for lock_t structs.
If we create LOCK_GAP instead of lock upgrading, the above scenario works
like the following:
// -> creates new lock_t for LOCK_X|LOCK_REC_NOT_GAP mode and sets bit for
// 1
request lock in LOCK_S mode on row 1:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 1,
// so it creates LOCK_S|LOCK_GAP only and sets bit for 1
request lock in LOCK_X|LOCK_REC_NOT_GAP mode on row 2:
// -> reuses the lock_t for LOCK_X|LOCK_REC_NOT_GAP by setting bit for 2
request lock in LOCK_S mode on row 2:
// -> notices that we already have LOCK_X|LOCK_REC_NOT_GAP on the row 2,
// so it reuses LOCK_S|LOCK_GAP setting bit for 2
In the end we have just two locks per page, one for each mode:
LOCK_X|LOCK_REC_NOT_GAP and LOCK_S|LOCK_GAP.
Another benefit of this solution is that it avoids not-entirely
const-correct, (and otherwise looking risky) "upgrading".
The fix was ported from
mysql/mysql-server@bfba840dfamysql/mysql-server@75cefdb1f7
Reviewed by: Marko Mäkelä
fil_node_open_file_low(): Always acquire an advisory lock on
the system tablespace. Originally, we already did this in
SysTablespace::open_file(), but SysTablespace::open_or_create()
would release those locks when it is closing the file handles.
This is a 10.5+ specific follow up to
commit 0ee1082bd2 (MDEV-28495).
Thanks to Daniel Black for verifying this bug.
- When foreign_key_check is disabled, allowing to modify the
column which is part of foreign key constraint can lead to
refusal of TRUNCATE TABLE, OPTIMIZE TABLE later. So it make
sense to block the column modify operation when foreign key
is involved irrespective of foreign_key_check variable.
Correct way to modify the charset of the column when fk is involved:
SET foreign_key_checks=OFF;
ALTER TABLE child DROP FOREIGN KEY fk, MODIFY m VARCHAR(200) CHARSET utf8mb4;
ALTER TABLE parent MODIFY m VARCHAR(200) CHARSET utf8mb4;
ALTER TABLE child ADD CONSTRAINT FOREIGN KEY (m) REFERENCES PARENT(m);
SET foreign_key_checks=ON;
fk_check_column_changes(): Remove the FOREIGN_KEY_CHECKS while
checking the column change for foreign key constraint. This
is the partial revert of commit 5f1f2fc0e4
and it changes the behaviour of copy alter algorithm
ha_innobase::prepare_inplace_alter_table(): Find the modified
column and check whether it is part of existing and newly
added foreign key constraint.
recv_sys_t::parse(): For undo tablespace truncation mini-transactions,
remember the start_lsn instead of the end LSN. This is what we expect
after commit 461402a564 (MDEV-30479).
After further I/O on a tablespace has been stopped
(for example due to DROP TABLE or an operation that
rebuilds a table), page cleaner thread tries to
flush the pending writes for the tablespace and
releases the tablespace reference even though it was not
acquired.
fil_space_t::flush(): Don't release the tablespace when it is
being stopped and closed
Thanks to Marko Mäkelä for suggesting this patch.
innodb_undo_log_truncate_update(): A callback function. If
SET GLOBAL innodb_undo_log_truncate=ON, invoke
srv_wake_purge_thread_if_not_active().
srv_wake_purge_thread_if_not_active(): If innodb_undo_log_truncate=ON,
always wake up the purge subsystem.
srv_do_purge(): If the history is empty, invoke
trx_purge_truncate_history() in order to free undo log pages.
trx_purge_truncate_history(): If head.trx_no==0, consider the
cached undo logs to be free.
trx_purge(): Remove the parameter "bool truncate" and let the
caller invoke trx_purge_truncate_history() directly.
Reviewed by: Vladislav Lesin
purge_sys_t::sees(): Wrapper for view.sees().
trx_purge_truncate_history(): Invoke purge_sys.sees() instead of
comparing to head.trx_no, to determine if undo pages can be safely freed.
The test innodb.cursor-restore-locking was adjusted by Vladislav Lesin,
as was the the debug instrumentation in row_purge_del_mark().
Reviewed by: Vladislav Lesin
recv_sys_t::apply(): When applying an undo log truncation operation,
invoke os_file_truncate() on space->recv_size, which must not be
less than the original truncated file size.
Alternatively, as pointed out by Thirunarayanan Balathandayuthapani,
we could assign space->size = t.pages, so that
fil_system_t::extend_to_recv_size() would extend the file back
to space->recv_size.
fil_space_t::add(): If a file handle was passed, invoke
fil_node_t::find_metadata() before releasing fil_system.mutex.
The call was moved from fil_ibd_create().
This is a 10.5 version of commit e3b06156c6
from 10.6.
trx_purge_truncate_rseg_history(): Add a parameter to specify if
the entire rollback segment is safe to be freed. If not, we may
still be able to invoke trx_undo_truncate_start() and free some pages.
trx_purge_truncate_history(): Relax a condition that would prevent
undo log truncation if the undo log tablespaces were "contaminated"
by the bug that commit e0084b9d31 fixed.
That is, trx_purge_truncate_rseg_history() would have invoked
flst_remove() on TRX_RSEG_HISTORY but not reduced TRX_RSEG_HISTORY_SIZE.
To avoid any regression with normal operation, we implement this
fixup during slow shutdown only. The condition on the history list
being empty is necessary: without it, in the test
innodb.undo_truncate_recover there may be much fewer than the
expected 90,000 calls to row_purge() before the truncation.
That is, we would truncate the undo tablespace before actually having
processed all undo log records in it.
To truncate such "contaminated" or "bloated" undo log tablespaces
(when using innodb_undo_tablespaces=2 or more)
you can execute the following SQL:
BEGIN;INSERT mysql.innodb_table_stats VALUES('','',DEFAULT,0,0,0);ROLLBACK;
SET GLOBAL innodb_undo_log_truncate=ON, innodb_fast_shutdown=0;
SHUTDOWN;
The first line creates a dummy InnoDB transaction, to ensure that there
will be some history to be purged during shutdown and that the undo
tablespaces will be truncated.
The problem seems to be a deadlock between KILL command execution
and BF abort issued by an applier, where:
* KILL has locked victim's LOCK_thd_kill and LOCK_thd_data.
* Applier has innodb side global lock mutex and victim trx mutex.
* KILL is calling innobase_kill_query, and is blocked by innodb
global lock mutex.
* Applier is in wsrep_innobase_kill_one_trx and is blocked by
victim's LOCK_thd_kill.
The fix in this commit removes the TOI replication of KILL command
and makes KILL execution less intrusive operation. Aborting the
victim happens now by using awake_no_mutex() and ha_abort_transaction().
If the KILL happens when the transaction is committing, the
KILL operation is postponed to happen after the statement
has completed in order to avoid KILL to interrupt commit
processing.
Notable changes in this commit:
* wsrep client connections's error state may remain sticky after
client connection is closed. This error message will then pop
up for the next client session issuing first SQL statement.
This problem raised with test galera.galera_bf_kill.
The fix is to reset wsrep client error state, before a THD is
reused for next connetion.
* Release THD locks in wsrep_abort_transaction when locking
innodb mutexes. This guarantees same locking order as with applier
BF aborting.
* BF abort from MDL was changed to do BF abort on server/wsrep-lib
side first, and only then do the BF abort on InnoDB side. This
removes the need to call back from InnoDB for BF aborts which originate
from MDL and simplifies the locking.
* Removed wsrep_thd_set_wsrep_aborter() from service_wsrep.h.
The manipulation of the wsrep_aborter can be done solely on
server side. Moreover, it is now debug only variable and
could be excluded from optimized builds.
* Remove LOCK_thd_kill from wsrep_thd_LOCK/UNLOCK to allow more
fine grained locking for SR BF abort which may require locking
of victim LOCK_thd_kill. Added explicit call for
wsrep_thd_kill_LOCK/UNLOCK where appropriate.
* Wsrep-lib was updated to version which allows external
locking for BF abort calls.
Changes to MTR tests:
* Disable galera_bf_abort_group_commit. This test is going to
be removed (MDEV-30855).
* Record galera_gcache_recover_manytrx as result file was incomplete.
Trivial change.
* Make galera_create_table_as_select more deterministic:
Wait until CTAS execution has reached MDL wait for multi-master
conflict case. Expected error from multi-master conflict is
ER_QUERY_INTERRUPTED. This is because CTAS does not yet have open
wsrep transaction when it is waiting for MDL, query gets interrupted
instead of BF aborted. This should be addressed in separate task.
* A new test galera_kill_group_commit to verify correct behavior
when KILL is executed while the transaction is committing.
Co-authored-by: Seppo Jaakola <seppo.jaakola@iki.fi>
Co-authored-by: Jan Lindström <jan.lindstrom@galeracluster.com>
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
This is a backport from 10.5.
The problem seems to be a deadlock between KILL command execution
and BF abort issued by an applier, where:
* KILL has locked victim's LOCK_thd_kill and LOCK_thd_data.
* Applier has innodb side global lock mutex and victim trx mutex.
* KILL is calling innobase_kill_query, and is blocked by innodb
global lock mutex.
* Applier is in wsrep_innobase_kill_one_trx and is blocked by
victim's LOCK_thd_kill.
The fix in this commit removes the TOI replication of KILL command
and makes KILL execution less intrusive operation. Aborting the
victim happens now by using awake_no_mutex() and ha_abort_transaction().
If the KILL happens when the transaction is committing, the
KILL operation is postponed to happen after the statement
has completed in order to avoid KILL to interrupt commit
processing.
Notable changes in this commit:
* wsrep client connections's error state may remain sticky after
client connection is closed. This error message will then pop
up for the next client session issuing first SQL statement.
This problem raised with test galera.galera_bf_kill.
The fix is to reset wsrep client error state, before a THD is
reused for next connetion.
* Release THD locks in wsrep_abort_transaction when locking
innodb mutexes. This guarantees same locking order as with applier
BF aborting.
* BF abort from MDL was changed to do BF abort on server/wsrep-lib
side first, and only then do the BF abort on InnoDB side. This
removes the need to call back from InnoDB for BF aborts which originate
from MDL and simplifies the locking.
* Removed wsrep_thd_set_wsrep_aborter() from service_wsrep.h.
The manipulation of the wsrep_aborter can be done solely on
server side. Moreover, it is now debug only variable and
could be excluded from optimized builds.
* Remove LOCK_thd_kill from wsrep_thd_LOCK/UNLOCK to allow more
fine grained locking for SR BF abort which may require locking
of victim LOCK_thd_kill. Added explicit call for
wsrep_thd_kill_LOCK/UNLOCK where appropriate.
* Wsrep-lib was updated to version which allows external
locking for BF abort calls.
Changes to MTR tests:
* Disable galera_bf_abort_group_commit. This test is going to
be removed (MDEV-30855).
* Record galera_gcache_recover_manytrx as result file was incomplete.
Trivial change.
* Make galera_create_table_as_select more deterministic:
Wait until CTAS execution has reached MDL wait for multi-master
conflict case. Expected error from multi-master conflict is
ER_QUERY_INTERRUPTED. This is because CTAS does not yet have open
wsrep transaction when it is waiting for MDL, query gets interrupted
instead of BF aborted. This should be addressed in separate task.
* A new test galera_kill_group_commit to verify correct behavior
when KILL is executed while the transaction is committing.
Co-authored-by: Seppo Jaakola <seppo.jaakola@iki.fi>
Co-authored-by: Jan Lindström <jan.lindstrom@galeracluster.com>
Signed-off-by: Julius Goryavsky <julius.goryavsky@mariadb.com>
rw_trx_hash_t::find() acquires element->mutex, then unpins pins, used for
lf_hash element search. After that the "element" can be deallocated and
reused by some other thread.
If we take a look rw_trx_hash_t::insert()->lf_hash_insert()->lf_alloc_new()
calls, we will not find any element->mutex acquisition, as it was not
initialized yet before it's allocation. rw_trx_hash_t::insert() can reuse
the chunk, unpinned in rw_trx_hash_t::find().
The scenario is the following:
1. Thread 1 have just executed lf_hash_search() in
rw_trx_hash_t::find(), but have not acquired element->mutex yet.
2. Thread 2 have removed the element from hash table with
rw_trx_hash_t::erase() call.
3. Thread 1 acquired element->mutex and unpinned pin 2 pin with
lf_hash_search_unpin(pins) call.
4. Some thread purged memory of the element.
5. Thread 3 reused the memory for the element, filled element->id,
element->trx.
6. Thread 1 crashes with failed "DBUG_ASSERT(trx_id == trx->id)"
assertion.
Note that trx_t objects are also reused, see the code around trx_pools
for details.
The fix is to invoke "lf_hash_search_unpin(pins);" after element->trx is
stored in local variable in rw_trx_hash_t::find().
Reviewed by: Nikita Malyavin, Marko Mäkelä.
There is room between mutex_exit(&fil_system.mutex) and
mutex_enter(&fil_system.mutex) calls in fil_node_open_file(). During this
room another thread can open the node, and ut_ad(!node->is_open())
assertion in fil_node_open_file_low() can fail.
The fix is not to open node if it was already opened by another thread.
trx_purge_truncate_history(): Only call trx_purge_truncate_rseg_history()
if the rollback segment is safe to process. This will avoid leaking undo
log pages that are not yet ready to be processed. This fixes a regression
that was introduced in
commit 0de3be8cfd (MDEV-30671).
trx_sys_t::any_active_transactions(): Separately count XA PREPARE
transactions.
srv_purge_should_exit(): Terminate slow shutdown if the history size
does not change and XA PREPARE transactions exist in the system.
This will avoid a hang of the test innodb.recovery_shutdown.
Tested by: Matthias Leich
buf_read_page_low(): Remove an error message and a debug assertion
that can be triggered when using innodb_page_size=4k and
innodb_file_per_table=0. In that case, buf_read_ahead_linear()
may be invoked on page 255, which is one less than the first
page of the doublewrite buffer (256).
fil_space_t::flush_freed(): Renamed from buf_flush_freed_pages();
this is a backport of aa45850687 from 10.6.
Invoke log_write_up_to() on last_freed_lsn, instead of avoiding
the operation when the log has not yet been written.
A more costly alternative would be that log_checkpoint() would invoke
this function on every affected tablespace.
buf_read_ahead_linear(): Correct some calculations that were broken
in commit b1ab211dee (MDEV-15053).
Thanks to Daniel Black for providing a test case and initial debugging.
Tested by: Matthias Leich
When commit a5a2ef079c
implemented asynchronous doublewrite, the writes via
the doublewrite buffer started to be counted incorrectly,
without multiplying them by innodb_page_size.
srv_export_innodb_status(): Correctly count the
Innodb_data_written.
buf_dblwr_t: Remove submitted(), because it is close to written()
and only Innodb_data_written was interested in it. According to
its name, it should count completed and not submitted writes.
Tested by: Axel Schwenke
- `mariadb-backup --backup` was fixed to fetch the value of the
@@aria_log_dir_path server variable and copy aria_log* files
from @@aria_log_dir_path directory to the backup directory.
Absolute and relative (to --datadir) paths are supported.
Before this change aria_log* files were copied to the backup
only if they were in the default location in @@datadir.
- `mariadb-backup --copy-back` now understands a new my.cnf and command line
parameter --aria-log-dir-path.
`mariadb-backup --copy-back` in the main loop in copy_back()
(when copying back from the backup directory to --datadir)
was fixed to ignore all aria_log* files.
A new function copy_back_aria_logs() was added.
It consists of a separate loop copying back aria_log* files from
the backup directory to the directory specified in --aria-log-dir-path.
Absolute and relative (to --datadir) paths are supported.
If --aria-log-dir-path is not specified,
aria_log* files are copied to --datadir by default.
- The function is_absolute_path() was fixed to understand MTR style
paths on Windows with forward slashes, e.g.
--aria-log-dir-path=D:/Buildbot/amd64-windows/build/mysql-test/var/...
trx_purge_free_segment(): The buffer-fix only prevents a block from
being freed completely from the buffer pool, but it will not prevent
the block from being evicted. Recheck the page identifier after
acquiring an exclusive page latch. If it has changed, backtrack and
invoke buf_page_get_gen() to look up the page normally.
stored externally
row_merge_buf_add(): Has strict assert that fixed length mismatch
shouldn't happen while rebuilding the redundant row format table
btr_index_rec_validate(): Fixed size column can be stored externally.
So sum of inline stored length and external stored length of the
column should be equal to total column length
This issue happens when race condition happens when DDL
and fts optimize thread. DDL adds the new index to fts cache.
At the same time, fts optimize thread clears the cache
and reinitialize it. Take cache init lock before reinitializing
the cache. fts_sync_commit() should take dict_sys mutex
to avoid the deadlock with create index.
- Adding a new argument "flag" to MY_COLLATION_HANDLER::strnncollsp_nchars()
and a flag MY_STRNNCOLLSP_NCHARS_EMULATE_TRIMMED_TRAILING_SPACES.
The flag defines if strnncollsp_nchars() should emulate trailing spaces
which were possibly trimmed earlier (e.g. in InnoDB CHAR compression).
This is important for NOPAD collations.
For example, with this input:
- str1= 'a ' (Latin letter a followed by one space)
- str2= 'a ' (Latin letter a followed by two spaces)
- nchars= 3
if the flag is given, strnncollsp_nchars() will virtually restore
one trailing space to str1 up to nchars (3) characters and compare two
strings as equal:
- str1= 'a ' (one extra trailing space emulated)
- str2= 'a ' (as is)
If the flag is not given, strnncollsp_nchars() does not add trailing
virtual spaces, so in case of a NOPAD collation, str1 will be compared
as less than str2 because it is shorter.
- Field_string::cmp_prefix() now passes the new flag.
Field_varstring::cmp_prefix() and Field_blob::cmp_prefix() do
not pass the new flag.
- The branch in cmp_whole_field() in storage/innobase/rem/rem0cmp.cc
(which handles the CHAR data type) now also passed the new flag.
- Fixing UCA collations to respect the new flag.
Other collations are possibly also affected, however
I had no success in making an SQL script demonstrating the problem.
Other collations will be extended to respect this flags in a separate
patch later.
- Changing the meaning of the last parameter of Field::cmp_prefix()
from "number of bytes" (internal length)
to "number of characters" (user visible length).
The code calling cmp_prefix() from handler.cc was wrong.
After this change, the call in handler.cc became correct.
The code calling cmp_prefix() from key_rec_cmp() in key.cc
was adjusted according to this change.
- Old strnncollsp_nchar() related tests in unittest/strings/strings-t.c
now pass the new flag.
A few new tests also were added, without the flag.
Let us make innodb_buffer_pool_filename a read-only variable
so that a malicious user cannot cause an important file to be
deleted on InnoDB shutdown. An attempt to delete a directory
will fail because it is not a regular file, but what if the
variable pointed to (say) ibdata1, ib_logfile0 or some *.ibd file?
It does not seem to make much sense for this parameter to be
configurable in the first place, but we will not change that in order
to avoid breaking compatibility.
handle_slave_io(), handle_slave_sql(), os_thread_exit():
Remove a redundant pthread_exit(nullptr) call, because it
would cause SIGSEGV.
mysql_print_status(): Add MEM_MAKE_DEFINED() to work around
some missing instrumentation around mallinfo2().
que_graph_free_stat_list(): Invoke que_node_get_next(node) before
que_graph_free_recursive(node). That is the logical and
MSAN_OPTIONS=poison_in_dtor=1 compatible way of freeing memory.
ins_node_t::~ins_node_t(): Invoke mem_heap_free(entry_sys_heap).
que_graph_free_recursive(): Rely on ins_node_t::~ins_node_t().
fts_t::~fts_t(): Invoke mem_heap_free(fts_heap).
fts_free(): Replace with direct calls to fts_t::~fts_t().
The failures in free_root() due to MSAN_OPTIONS=poison_in_dtor=1
will be covered in MDEV-30942.
The solution is to suppress error messages for missing tablespaces if
mariabackup is launched with "--prepare --export" options.
"mariabackup --prepare --export" invokes itself with --mysqld parameter.
If the parameter is set, then it starts server to feed "FLUSH TABLES ...
FOR EXPORT;" queries for exported tablespaces. This is "normal" server
start, that's why new srv_operation value is introduced.
Reviewed by Marko Makela.
btr_cur_upd_rec_in_place(): Avoid calling page_zip_write_rec() if we
are not modifying any fields that are stored in compressed format.
btr_cur_update_in_place_zip_check(): New function to check if a
ROW_FORMAT=COMPRESSED record can actually be updated in place.
btr_cur_pessimistic_update(): If the BTR_KEEP_POS_FLAG is not set
(we are in a ROLLBACK and cannot write any BLOBs), ignore the potential
overflow and let page_zip_reorganize() or page_zip_compress() handle it.
This avoids a failure when an attempted UPDATE of an NULL column to 0 is
rolled back. During the ROLLBACK, we would try to move a non-updated
long column to off-page storage in order to avoid a compression failure
of the ROW_FORMAT=COMPRESSED page.
page_zip_write_trx_id_and_roll_ptr(): Remove an assertion that would fail
in row_upd_rec_in_place() because the uncompressed page would already
have been modified there.
This is a 10.5 version of commit ff3d4395d8
(different because of commit 08ba388713).
row_upd_rec_in_place(): Avoid calling page_zip_write_rec() if we
are not modifying any fields that are stored in compressed format.
btr_cur_update_in_place_zip_check(): New function to check if a
ROW_FORMAT=COMPRESSED record can actually be updated in place.
btr_cur_pessimistic_update(): If the BTR_KEEP_POS_FLAG is not set
(we are in a ROLLBACK and cannot write any BLOBs), ignore the potential
overflow and let page_zip_reorganize() or page_zip_compress() handle it.
This avoids a failure when an attempted UPDATE of an NULL column to 0 is
rolled back. During the ROLLBACK, we would try to move a non-updated
long column to off-page storage in order to avoid a compression failure
of the ROW_FORMAT=COMPRESSED page.
page_zip_write_trx_id_and_roll_ptr(): Remove an assertion that would fail
in row_upd_rec_in_place() because the uncompressed page would already
have been modified there.
Thanks to Jean-François Gagné for providing a copy of a page that
triggered these bugs on the ROLLBACK of UPDATE and DELETE.
A 10.6 version of this was tested by Matthias Leich using
cmake -DWITH_INNODB_EXTRA_DEBUG=ON a.k.a. UNIV_ZIP_DEBUG.
buf_LRU_block_remove_hashed(): Ever since
commit 2e814d4702
we could get page_zip_validate() failures after an ALTER TABLE
operation was aborted and BtrBulk::pageCommit() had never been
executed on some blocks.
