This bug was originally filed and fixed as Bug#12612184. The original
fix was buggy, and it was patched by Bug#12704861. Also that patch was
buggy (potentially breaking crash recovery), and both fixes were
reverted.
This fix was not ported to the built-in InnoDB of MySQL 5.1, because
the function signatures of many core functions are different from
InnoDB Plugin and later versions. The block allocation routines and
their callers would have to changed so that they handle block
descriptors instead of page frames.
When a record is updated so that its size grows, non-updated columns
can be selected for external (off-page) storage. The bug is that the
initially inserted updated record contains an all-zero BLOB pointer to
the field that was not updated. Only after the BLOB pages have been
allocated and written, the valid pointer can be written to the record.
Between the release of the page latch in mtr_commit(mtr) after
btr_cur_pessimistic_update() and the re-latching of the page in
btr_pcur_restore_position(), other threads can see the invalid BLOB
pointer consisting of 20 zero bytes. Moreover, if the system crashes
at this point, the situation could persist after crash recovery, and
the contents of the non-updated column would be permanently lost.
The problem is amplified by the ROW_FORMAT=DYNAMIC and
ROW_FORMAT=COMPRESSED that were introduced in
innodb_file_format=barracuda in InnoDB Plugin, but the bug does exist
in all InnoDB versions.
The fix is as follows. After a pessimistic B-tree operation that needs
to write out off-page columns, allocate the pages for these columns in
the mini-transaction that performed the B-tree operation (btr_mtr),
but write the pages in a separate mini-transaction (blob_mtr). Do
mtr_commit(blob_mtr) before mtr_commit(btr_mtr). A quirk: Do not reuse
pages that were previously freed in btr_mtr. Only write the off-page
columns to 'fresh' pages.
In this way, crash recovery will see redo log entries for blob_mtr
before any redo log entry for btr_mtr. It will apply the BLOB page
writes to pages that were marked free at that point. If crash recovery
fails to see all of the btr_mtr redo log, there will be some
unreachable BLOB data in free pages, but the B-tree will be in a
consistent state.
btr_page_alloc_low(): Renamed from btr_page_alloc(). Add the parameter
init_mtr. Return an allocated block, or NULL. If init_mtr!=mtr but
the page was already X-latched in mtr, do not initialize the page.
btr_page_alloc(): Wrapper for btr_page_alloc_for_ibuf() and
btr_page_alloc_low().
btr_page_free(): Add a debug assertion that the page was a B-tree page.
btr_lift_page_up(): Return the father block.
btr_compress(), btr_cur_compress_if_useful(): Add the parameter ibool
adjust, for adjusting the cursor position.
btr_cur_pessimistic_update(): Preserve the cursor position when
big_rec will be written and the new flag BTR_KEEP_POS_FLAG is defined.
Remove a duplicate rec_get_offsets() call. Keep the X-latch on
index->lock when big_rec is needed.
btr_store_big_rec_extern_fields(): Replace update_inplace with
an operation code, and local_mtr with btr_mtr. When not doing a
fresh insert and btr_mtr has freed pages, put aside any pages that
were previously X-latched in btr_mtr, and free the pages after
writing out all data. The data must be written to 'fresh' pages,
because btr_mtr will be committed and written to the redo log after
the BLOB writes have been written to the redo log.
btr_blob_op_is_update(): Check if an operation passed to
btr_store_big_rec_extern_fields() is an update or insert-by-update.
fseg_alloc_free_page_low(), fsp_alloc_free_page(),
fseg_alloc_free_extent(), fseg_alloc_free_page_general(): Add the
parameter init_mtr. Return an allocated block, or NULL. If
init_mtr!=mtr but the page was already X-latched in mtr, do not
initialize the page.
xdes_get_descriptor_with_space_hdr(): Assert that the file space
header is being X-latched.
fsp_alloc_from_free_frag(): Refactored from fsp_alloc_free_page().
fsp_page_create(): New function, for allocating, X-latching and
potentially initializing a page. If init_mtr!=mtr but the page was
already X-latched in mtr, do not initialize the page.
fsp_free_page(): Add ut_ad(0) to the error outcomes.
fsp_free_page(), fseg_free_page_low(): Increment mtr->n_freed_pages.
fsp_alloc_seg_inode_page(), fseg_create_general(): Assert that the
page was not previously X-latched in the mini-transaction. A file
segment or inode page should never be allocated in the middle of an
mini-transaction that frees pages, such as btr_cur_pessimistic_delete().
fseg_alloc_free_page_low(): If the hinted page was allocated, skip the
check if the tablespace should be extended. Return NULL instead of
FIL_NULL on failure. Remove the flag frag_page_allocated. Instead,
return directly, because the page would already have been initialized.
fseg_find_free_frag_page_slot() would return ULINT_UNDEFINED on error,
not FIL_NULL. Correct a bogus assertion.
fseg_alloc_free_page(): Redefine as a wrapper macro around
fseg_alloc_free_page_general().
buf_block_buf_fix_inc(): Move the definition from the buf0buf.ic to
buf0buf.h, so that it can be called from other modules.
mtr_t: Add n_freed_pages (number of pages that have been freed).
page_rec_get_nth_const(), page_rec_get_nth(): The inverse function of
page_rec_get_n_recs_before(), get the nth record of the record
list. This is faster than iterating the linked list. Refactored from
page_get_middle_rec().
trx_undo_rec_copy(): Add a debug assertion for the length.
trx_undo_add_page(): Return a block descriptor or NULL instead of a
page number or FIL_NULL.
trx_undo_report_row_operation(): Add debug assertions.
trx_sys_create_doublewrite_buf(): Assert that each page was not
previously X-latched.
page_cur_insert_rec_zip_reorg(): Make use of page_rec_get_nth().
row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG, so that
the repositioning of the cursor can be avoided.
row_ins_index_entry_low(): Add DEBUG_SYNC points before and after
writing off-page columns. If inserting by updating a delete-marked
record, do not reposition the cursor or commit the mini-transaction
before writing the off-page columns.
row_build(): Tighten a debug assertion about null BLOB pointers.
row_upd_clust_rec(): Add DEBUG_SYNC points before and after writing
off-page columns. Do not reposition the cursor or commit the
mini-transaction before writing the off-page columns.
rb:939 approved by Jimmy Yang
If we meet DB_TOO_MANY_CONCURRENT_TRXS during the execution tab_create_graph from row_create_table_for_mysql(), .ibd file for the table should be created already but was not deleted for the error handling.
rb:875 approved by Jimmy Yang
InnoDB: Remove HAVE_purify, UNIV_INIT_MEM_TO_ZERO, UNIV_SET_MEM_TO_ZERO.
The compile-time setting HAVE_purify can mask potential bugs.
It is being set in PB2 Valgrind runs. We should simply get rid of it,
and replace it with UNIV_MEM_INVALID() to declare uninitialized memory
as such in Valgrind-instrumented binaries.
os_mem_alloc_large(), ut_malloc_low(): Remove the parameter set_to_zero.
ut_malloc(): Define as a macro that invokes ut_malloc_low().
buf_pool_init(): Never initialize the buffer pool frames. All pages
must be initialized before flushing them to disk.
mem_heap_alloc(): Never initialize the allocated memory block.
os_mem_alloc_nocache(), ut_test_malloc(): Unused function, remove.
rb:813 approved by Jimmy Yang
btr_pcur_restore_position_func(): When the cursor was positioned at
the tree infimum or supremum, initialize pos_state and latch_mode. The
assertion failed, because pos_state was BTR_PCUR_WAS_POSITIONED. In
the test failure of WL#5874, the purge thread attempted to restore the
cursor position on the infimum record (the clustered index was empty).
btr_pcur_detach(), btr_pcur_is_detached(): Unused functions, remove.
rb:804 approved by Inaam Rana
Bug#12612184 RACE CONDITION AFTER BTR_CUR_PESSIMISTIC_UPDATE()
The fix introduced potentially more severe crash recovery problems
than the bug causes. Revert the fix for now.
This was an attempt to address problems with the Bug#12612184 fix.
Even with this follow-up fix, crash recovery can be broken.
Let us fix the bug later.
hash index at shutdown
btr_search_disable(): Just drop the entire adaptive hash index,
without dropping every record separately.
buf_pool_clear_hash_index(): Renamed and simplified from
buf_pool_drop_hash_index(). Set block->index = NULL for every block in
the buffer pool. Do not release the btr_search_latch. The caller will
have to adjust other data structures.
Remove block->is_hashed. It is redundant, should be always equal to
block->index != NULL.
Remove btr_search_fully_disabled, btr_search_enabled_mutex, and
SYNC_SEARCH_SYS_CONF. We drop the AHI in one pass, without releasing
the btr_search_latch in between.
Replace void* with const rec_t* and add assertions on btr_search_latch
and btr_search_enabled to ha0ha.h, ha0ha.ic, ha0ha.c.
page_set_max_trx_id(): Ignore the adaptive hash index. I forgot to
push this in rb:750.
btr0sea.c: Always after acquiring btr_search_latch, check for
block->index==NULL or !btr_search_enabled. We can now set
block->index=NULL while only holding btr_search_latch in exclusive
mode. Always acquire btr_search_latch before reading block->index,
except in shortcuts when testing for block->index == NULL.
ha_clear(), ha_search(): Unused function, remove.
buf_page_peek_if_search_hashed(): Remove. This function may avoid
latching a page at the cost of doing a duplicate buf_pool->page_hash
lookup.
rb:775 approved by Inaam Rana
rw_lock_x_lock_func(): Assert that the thread is not already holding
the lock in a conflicting mode (RW_LOCK_SHARED).
rw_lock_s_lock_func(): Assert that the thread is not already holding
the lock in a conflicting mode (RW_LOCK_EX).
Bug 12980094 - ASSERTION IN INNODB DETECTED IN RQG_PARTITION_DDL
Bug 13034534 - RQG TESTS FAIL ON WINDOWS WITH CRASH NEAR RW_LOCK_DEBUG_PRINT
All access to struct rw_lock_debug_struct must be protected by rw_lock_debug_mutex_enter().
InnoDB acquires an x-latch on btr_search_latch for certain in-place updates
that do affect the adaptive hash index. These operations do not really need
to be protected by the btr_search_latch:
* updating DB_TRX_ID
* updating DB_ROLL_PTR
* updating PAGE_MAX_TRX_ID
* updating the delete-mark flag
rb:750 approved by Sunny Bains
The fix of Bug#12612184 broke crash recovery. When a record that
contains off-page columns (BLOBs) is updated, we must first write redo
log about the BLOB page writes, and only after that write the redo log
about the B-tree changes. The buggy fix would log the B-tree changes
first, meaning that after recovery, we could end up having a record
that contains a null BLOB pointer.
Because we will be redo logging the writes off the off-page columns
before the B-tree changes, we must make sure that the pages chosen for
the off-page columns are free both before and after the B-tree
changes. In this way, the worst thing that can happen in crash
recovery is that the BLOBs are written to free pages, but the B-tree
changes are not applied. The BLOB pages would correctly remain free in
this case. To achieve this, we must allocate the BLOB pages in the
mini-transaction of the B-tree operation. A further quirk is that BLOB
pages are allocated from the same file segment as leaf pages. Because
of this, we must temporarily "hide" any leaf pages that were freed
during the B-tree operation by "fake allocating" them prior to writing
the BLOBs, and freeing them again before the mtr_commit() of the
B-tree operation, in btr_mark_freed_leaves().
btr_cur_mtr_commit_and_start(): Remove this faulty function that was
introduced in the Bug#12612184 fix. The problem that this function was
trying to address was that when we did mtr_commit() the BLOB writes
before the mtr_commit() of the update, the new BLOB pages could have
overwritten clustered index B-tree leaf pages that were freed during
the update. If recovery applied the redo log of the BLOB writes but
did not see the log of the record update, the index tree would be
corrupted. The correct solution is to make the freed clustered index
pages unavailable to the BLOB allocation. This function is also a
likely culprit of InnoDB hangs that were observed when testing the
Bug#12612184 fix.
btr_mark_freed_leaves(): Mark all freed clustered index leaf pages of
a mini-transaction allocated (nonfree=TRUE) before storing the BLOBs,
or freed (nonfree=FALSE) before committing the mini-transaction.
btr_freed_leaves_validate(): A debug function for checking that all
clustered index leaf pages that have been marked free in the
mini-transaction are consistent (have not been zeroed out).
btr_page_alloc_low(): Refactored from btr_page_alloc(). Return the
number of the allocated page, or FIL_NULL if out of space. Add the
parameter "mtr_t* init_mtr" for specifying the mini-transaction where
the page should be initialized, or if this is a "fake allocation"
(init_mtr=NULL) by btr_mark_freed_leaves(nonfree=TRUE).
btr_page_alloc(): Add the parameter init_mtr, allowing the page to be
initialized and X-latched in a different mini-transaction than the one
that is used for the allocation. Invoke btr_page_alloc_low(). If a
clustered index leaf page was previously freed in mtr, remove it from
the memo of previously freed pages.
btr_page_free(): Assert that the page is a B-tree page and it has been
X-latched by the mini-transaction. If the freed page was a leaf page
of a clustered index, link it by a MTR_MEMO_FREE_CLUST_LEAF marker to
the mini-transaction.
btr_store_big_rec_extern_fields_func(): Add the parameter alloc_mtr,
which is NULL (old behaviour in inserts) and the same as local_mtr in
updates. If alloc_mtr!=NULL, the BLOB pages will be allocated from it
instead of the mini-transaction that is used for writing the BLOBs.
fsp_alloc_from_free_frag(): Refactored from
fsp_alloc_free_page(). Allocate the specified page from a partially
free extent.
fseg_alloc_free_page_low(), fseg_alloc_free_page_general(): Add the
parameter "mtr_t* init_mtr" for specifying the mini-transaction where
the page should be initialized, or NULL if this is a "fake allocation"
that prevents the reuse of a previously freed B-tree page for BLOB
storage. If init_mtr==NULL, try harder to reallocate the specified page
and assert that it succeeded.
fsp_alloc_free_page(): Add the parameter "mtr_t* init_mtr" for
specifying the mini-transaction where the page should be initialized.
Do not allow init_mtr == NULL, because this function is never to be
used for "fake allocations".
mtr_t: Add the operation MTR_MEMO_FREE_CLUST_LEAF and the flag
mtr->freed_clust_leaf for quickly determining if any
MTR_MEMO_FREE_CLUST_LEAF operations have been posted.
row_ins_index_entry_low(): When columns are being made off-page in
insert-by-update, invoke btr_mark_freed_leaves(nonfree=TRUE) and pass
the mini-transaction as the alloc_mtr to
btr_store_big_rec_extern_fields(). Finally, invoke
btr_mark_freed_leaves(nonfree=FALSE) to avoid leaking pages.
row_build(): Correct a comment, and add a debug assertion that a
record that contains NULL BLOB pointers must be a fresh insert.
row_upd_clust_rec(): When columns are being moved off-page, invoke
btr_mark_freed_leaves(nonfree=TRUE) and pass the mini-transaction as
the alloc_mtr to btr_store_big_rec_extern_fields(). Finally, invoke
btr_mark_freed_leaves(nonfree=FALSE) to avoid leaking pages.
buf_reset_check_index_page_at_flush(): Remove. The function
fsp_init_file_page_low() already sets
bpage->check_index_page_at_flush=FALSE.
There is a known issue in tablespace extension. If the request to
allocate a BLOB page leads to the tablespace being extended, crash
recovery could see BLOB writes to pages that are off the tablespace
file bounds. This should trigger an assertion failure in fil_io() at
crash recovery. The safe thing would be to write redo log about the
tablespace extension to the mini-transaction of the BLOB write, not to
the mini-transaction of the record update. However, there is no redo
log record for file extension in the current redo log format.
rb:693 approved by Sunny Bains
discarded in buf_page_create()
This bug turned out to be a false alarm, a bug in the UNIV_SYNC_DEBUG
diagnostic code. Because of this, the patch was not backported to the
built-in InnoDB in MySQL 5.1. Furthermore, there is no test case for
InnoDB Plugin in MySQL 5.1, because the delete buffering in MySQL 5.5
makes triggering the failure much easier.
When a freed page for which there exist orphaned buffered changes is
allocated and reused for something else, buf_page_create() will discard
the buffered changes by invoking ibuf_merge_or_delete_for_page().
This would violate the InnoDB latching order.
Tweak the latching order as follows. Move SYNC_IBUF_MUTEX below
SYNC_FSP_PAGE, where it logically belongs, and assign new latching
levels for the ibuf->index->lock and the insert buffer B-tree pages:
#define SYNC_IBUF_MUTEX 370 /* ibuf_mutex */
#define SYNC_IBUF_INDEX_TREE 360
#define SYNC_IBUF_TREE_NODE_NEW 359
#define SYNC_IBUF_TREE_NODE 358
btr_block_get(), btr_page_get(): In UNIV_SYNC_DEBUG, add the parameter
"index" for determining the appropriate latching order
(SYNC_IBUF_TREE_NODE or SYNC_TREE_NODE).
btr_page_alloc_for_ibuf(), btr_create(): Use SYNC_IBUF_TREE_NODE_NEW
instead of SYNC_TREE_NODE_NEW for insert buffer pages.
btr_cur_search_to_nth_level(), btr_pcur_restore_position_func(): Use
SYNC_IBUF_TREE_NODE instead of SYNC_TREE_NODE for insert buffer pages.
btr_search_guess_on_hash(): Assert that the index is not an insert buffer tree.
dict_index_add_to_cache(): Use SYNC_IBUF_INDEX_TREE for the insert
buffer tree (ibuf->index->lock).
ibuf0ibuf.c: Use SYNC_IBUF_TREE_NODE or SYNC_IBUF_TREE_NODE_NEW for
all B-tree pages.
ibuf_merge_or_delete_for_page(): Assert that the user page is
BUF_IO_READ fixed. Only in this way it is OK to latch it as
SYNC_IBUF_TREE_NODE instead of the proper SYNC_TREE_NODE (which would
violate the changed latching order).
sync_thread_add_level(): Remove the special tweak for
SYNC_IBUF_MUTEX. Add rules for the added latching levels.
rb:591 approved by Jimmy Yang
The title of the bug is a little confusing. The actual fix is to
reintroduce random readahead inside InnoDB with a dynamic, global
switch innodb_random_read_ahead [default = off].
Approved by: Sunny Bains
rb://696
Refactor the !rec_offs_any_extern relaxation in row_build().
trx_assert_active(trx_id): Assert that the given transaction is active.
(In the 5.1 built-in InnoDB, there is no trx->is_recovered field.)
trx_assert_recovered(trx_id): Assert that the given transaction is
active and has been recovered after a crash.
row_build(): Replace a bunch of code with an assertion that invokes
trx_assert_active() or trx_assert_recovered() and row_get_rec_trx_id().
row_get_trx_id_offset(): Make the function inlined. Remove the unused
parameter rec, and make all parameters const.
row_get_rec_trx_id(), row_get_rec_roll_ptr(): Make all parameters const.
rb:691 approved by Jimmy Yang
approved by: Marko
rb://681
Coalescing of free buf_page_t descriptors can prove to be one severe
bottleneck in performance of compression. One such workload where it
hurts badly is DROP TABLE. This patch removes buf_page_t allocations
from buf_buddy and uses ut_malloc instead.
In order to further reduce overhead of colaescing we no longer attempt
to coalesce a block if the corresponding free_list is less than 16 in
size.
The buf_pool->zip_clean list is only needed for debugging, or for
recomputing buf_pool->page_hash when resizing the buffer pool. Buffer
pool resizing was never fully implemented. Remove the resizing code,
and define buf_pool->zip_clean only in debug builds.
buf_pool->zip_clean, buf_LRU_insert_zip_clean(): Enclose in
#if defined UNIV_DEBUG || UNIV_BUF_DEBUG.
buf_chunk_free(), buf_chunk_all_free(), buf_pool_shrink(),
buf_pool_page_hash_rebuild(), buf_pool_resize(): Remove (unreachable code).
rb:671 approved by Inaam Rana
Replace UNIV_BLOB_NULL_DEBUG with UNIV_DEBUG||UNIV_BLOB_LIGHT_DEBUG.
Fix known bogus failures.
btr_cur_optimistic_update(): If rec_offs_any_null_extern(), assert that
the current transaction is an incomplete transaction that is being
rolled back in crash recovery.
row_build(): If rec_offs_any_null_extern(), assert that the transaction
that last updated the record was recovered during crash recovery
(and will soon be rolled back).
btr_cur_compress_if_useful(), btr_compress(): Add the parameter ibool
adjust. If adjust=TRUE, adjust the cursor position after compressing
the page.
btr_lift_page_up(): Return a pointer to the father page.
BTR_KEEP_POS_FLAG: A new flag for btr_cur_pessimistic_update().
btr_cur_pessimistic_update(): If *big_rec != NULL and flags &
BTR_KEEP_POS_FLAG, keep the cursor positioned on the updated record.
Also, do not release the index tree x-lock if *big_rec != NULL.
btr_cur_mtr_commit_and_start(): Commits and restarts a
mini-transaction so that it will retain an x-lock on index->lock and
the page of the cursor. This is invoked when
btr_cur_pessimistic_update() returns *big_rec != NULL.
In all callers of btr_cur_pessimistic_update() that do not pass
BTR_KEEP_POS_FLAG, assert that *big_rec == NULL.
btr_cur_compress(): Unused function [in the built-in MySQL 5.1], remove.
page_rec_get_nth(): Return the nth record on the page (an inverse
function of page_rec_get_n_recs_before()). Refactored from
page_get_middle_rec().
page_get_middle_rec(): Invoke page_rec_get_nth().
page_cur_insert_rec_zip_reorg(): Make use of the page directory
shortcuts in page_rec_get_nth() instead of scanning the whole list of
records.
row_ins_clust_index_entry_by_modify(): Pass BTR_KEEP_POS_FLAG to
btr_cur_pessimistic_update().
row_ins_index_entry_low(): If row_ins_clust_index_entry_by_modify()
returns a big_rec, invoke btr_cur_mtr_commit_and_start() in order to
commit and start the mini-transaction without releasing the x-locks on
index->lock and the cursor page, and write the big_rec. Releasing the
page latch in mtr_commit() caused a race condition.
row_upd_clust_rec(): Pass BTR_KEEP_POS_FLAG to
btr_cur_pessimistic_update(). If it returns a big_rec, invoke
btr_cur_mtr_commit_and_start() in order to commit and start the
mini-transaction without releasing the x-locks on index->lock and the
cursor page, and write the big_rec. Releasing the page latch in
mtr_commit() caused a race condition.
sync_thread_add_level(): Add the parameter ibool relock. When TRUE,
bypass the latching order rules.
rw_lock_add_debug_info(): For nested X-lock requests, pass relock=TRUE
to sync_thread_add_level().
rb:678 approved by Jimmy Yang
Some ut_a(!rec_offs_any_null_extern()) assertion failures are indicating
genuine BLOB bugs, others are bogus failures when rolling back incomplete
transactions at crash recovery. This needs more work, and until I get a
chance to work on it, other testing must not be disrupted by this.
If UNIV_DEBUG or UNIV_BLOB_LIGHT_DEBUG is enabled, add
!rec_offs_any_null_extern() assertions, ensuring that records do not
contain null pointers to externally stored columns in inappropriate
places.
btr_cur_optimistic_update(): Assert !rec_offs_any_null_extern().
Incomplete records must never be updated or deleted. This assertion
will cover also the pessimistic route.
row_build(): Assert !rec_offs_any_null_extern(). Search tuples must
never be built from incomplete index entries.
row_rec_to_index_entry(): Assert !rec_offs_any_null_extern() unless
ROW_COPY_DATA is requested. ROW_COPY_DATA is used for
multi-versioning, and therefore it might be valid to copy the most
recent (uncommitted) version while it contains a null pointer to
off-page columns.
row_vers_build_for_consistent_read(),
row_vers_build_for_semi_consistent_read(): Assert !rec_offs_any_null_extern()
on all versions except the most recent one.
trx_undo_prev_version_build(): Assert !rec_offs_any_null_extern() on
the previous version.
rb:682 approved by Sunny Bains
causes future shutdown hang
InnoDB would hang on shutdown if any XA transactions exist in the
system in the PREPARED state. This has been masked by the fact that
MySQL would roll back any PREPARED transaction on shutdown, in the
spirit of Bug #12161 Xa recovery and client disconnection.
[mysql-test-run] do_shutdown_server: Interpret --shutdown_server 0 as
a request to kill the server immediately without initiating a
shutdown procedure.
xid_cache_insert(): Initialize XID_STATE::rm_error in order to avoid a
bogus error message on XA ROLLBACK of a recovered PREPARED transaction.
innobase_commit_by_xid(), innobase_rollback_by_xid(): Free the InnoDB
transaction object after rolling back a PREPARED transaction.
trx_get_trx_by_xid(): Only consider transactions whose
trx->is_prepared flag is set. The MySQL layer seems to prevent
attempts to roll back connected transactions that are in the PREPARED
state from another connection, but it is better to play it safe. The
is_prepared flag was introduced in the InnoDB Plugin.
trx_n_prepared: A new counter, counting the number of InnoDB
transactions in the PREPARED state.
logs_empty_and_mark_files_at_shutdown(): On shutdown, allow
trx_n_prepared transactions to exist in the system.
trx_undo_free_prepared(), trx_free_prepared(): New functions, to free
the memory objects of PREPARED transactions on shutdown. This is not
needed in the built-in InnoDB, because it would collect all allocated
memory on shutdown. The InnoDB Plugin needs this because of
innodb_use_sys_malloc.
trx_sys_close(): Invoke trx_free_prepared() on all remaining
transactions.
sync_array_print_long_waits(): Return the longest waiting thread ID
and the longest waited-for lock. Only if those remain unchanged
between calls in srv_error_monitor_thread(), increment
fatal_cnt. Otherwise, reset fatal_cnt.
Background: There is a built-in watchdog in InnoDB whose purpose is to
kill the server when some thread is stuck waiting for a mutex or
rw-lock. Before this fix, the logic was flawed.
The function sync_array_print_long_waits() returns TRUE if it finds a
lock wait that exceeds 10 minutes (srv_fatal_semaphore_wait_threshold).
The function srv_error_monitor_thread() will kill the server if this
happens 10 times in a row (fatal_cnt reaches 10), checked every 30
seconds. This is wrong, because this situation does not mean that the
server is hung. If the server is very busy for a little over 15
minutes, it will be killed.
Consider this example. Thread T1 is waiting for mutex M. Some time
later, threads T2..Tn start waiting for the same mutex M. If T1 keeps
waiting for 600 seconds, fatal_cnt will be incremented to 1. So far,
so good. Now, if M is granted to T1, the server was obviously not
stuck. But, T2..Tn keeps waiting, and their wait time will be longer
than 600 seconds. If 5 minutes later, some Tn has still been waiting
for more than 10 minutes for the mutex M, the server can be killed,
even though it is not stuck.
rb:622 approved by Jimmy Yang
and compressed tables
buf_LRU_drop_page_hash_for_tablespace(): after releasing and
reacquiring the buffer pool mutex, do not dereference any block
descriptor pointer that is not known to be a pointer to an
uncompressed page frame (type buf_block_t; state ==
BUF_BLOCK_FILE_PAGE). Also, defer the acquisition of the block_mutex
until it is needed.
buf_page_get_gen(): Add mode == BUF_GET_IF_IN_POOL_PEEK for
buffer-fixing a block without making it young in the LRU list.
buf_page_get_gen(), buf_page_init(), buf_LRU_block_remove_hashed_page():
Set bpage->state = BUF_BLOCK_ZIP_FREE before buf_buddy_free(bpage),
so that similar race conditions might be detected a little easier.
btr_search_drop_page_hash_when_freed(): Use BUF_GET_IF_IN_POOL_PEEK
when dropping the hash indexes.
rb://528 approved by Jimmy Yang
rw_lock_create_func(): Initialize lock->writer_thread, so that Valgrind
will not complain even when Valgrind instrumentation is not enabled.
Flag lock->writer_thread uninitialized, so that Valgrind can complain
when it is used uninitialized.
rw_lock_set_writer_id_and_recursion_flag(): Revert the bogus Valgrind
instrumentation that was pushed in the first attempt to fix this bug.
by silencing a bogus Valgrind warning:
==4392== Conditional jump or move depends on uninitialised value(s)
==4392== at 0x5A18416: rw_lock_set_writer_id_and_recursion_flag (sync0rw.ic:283)
==4392== by 0x5A1865C: rw_lock_x_lock_low (sync0rw.c:558)
==4392== by 0x5A18481: rw_lock_x_lock_func (sync0rw.c:617)
==4392== by 0x597EEE6: mtr_x_lock_func (mtr0mtr.ic:271)
==4392== by 0x597EBBD: fsp_header_init (fsp0fsp.c:970)
==4392== by 0x5A15E78: innobase_start_or_create_for_mysql (srv0start.c:1508)
==4392== by 0x598B789: innobase_init(void*) (ha_innodb.cc:2282)
os_compare_and_swap_thread_id() is defined as
__sync_bool_compare_and_swap(). From the GCC doc:
`bool __sync_bool_compare_and_swap (TYPE *ptr, TYPE oldval TYPE newval, ...)'
...
The "bool" version returns true if the comparison is successful and
NEWVAL was written.
So it is not possible that the return value is uninitialized, no matter what
the arguments to os_compare_and_swap_thread_id() are. Probably Valgrind gets
confused by the implementation of the GCC internal function
__sync_bool_compare_and_swap().
This option is known to be broken when tablespaces contain off-page
columns after crash recovery. It has only been tested when creating
the data files from the scratch.
btr_blob_dbg_t: A map from page_no:heap_no:field_no to first_blob_page_no.
This map is instantiated for every clustered index in index->blobs.
It is protected by index->blobs_mutex.
btr_blob_dbg_msg_issue(): Issue a diagnostic message.
Invoked when btr_blob_dbg_msg is set.
btr_blob_dbg_rbt_insert(): Insert a btr_blob_dbg_t into index->blobs.
btr_blob_dbg_rbt_delete(): Remove a btr_blob_dbg_t from index->blobs.
btr_blob_dbg_cmp(): Comparator for btr_blob_dbg_t.
btr_blob_dbg_add_blob(): Add a BLOB reference to the map.
btr_blob_dbg_add_rec(): Add all BLOB references from a record to the map.
btr_blob_dbg_print(): Display the map of BLOB references in an index.
btr_blob_dbg_remove_rec(): Remove all BLOB references of a record from
the map.
btr_blob_dbg_is_empty(): Check that no BLOB references exist to or
from a page. Disowned references from delete-marked records are
tolerated.
btr_blob_dbg_op(): Perform an operation on all BLOB references on a
B-tree page.
btr_blob_dbg_add(): Add all BLOB references from a B-tree page to the
map.
btr_blob_dbg_remove(): Remove all BLOB references from a B-tree page
from the map.
btr_blob_dbg_restore(): Restore the BLOB references after a failed
page reorganize.
btr_blob_dbg_set_deleted_flag(): Modify the 'deleted' flag in the BLOB
references of a record.
btr_blob_dbg_owner(): Own or disown a BLOB reference.
btr_page_create(), btr_page_free_low(): Assert that no BLOB references exist.
btr_create(): Create index->blobs for clustered indexes.
btr_page_reorganize_low(): Invoke btr_blob_dbg_remove() before copying
the records. Invoke btr_blob_dbg_restore() if the operation fails.
btr_page_empty(), btr_lift_page_up(), btr_compress(), btr_discard_page():
Invoke btr_blob_dbg_remove().
btr_cur_del_mark_set_clust_rec(): Invoke btr_blob_dbg_set_deleted_flag().
Other cases of modifying the delete mark are either in the secondary
index or during crash recovery, which we do not promise to support.
btr_cur_set_ownership_of_extern_field(): Invoke btr_blob_dbg_owner().
btr_store_big_rec_extern_fields(): Invoke btr_blob_dbg_add_blob().
btr_free_externally_stored_field(): Invoke btr_blob_dbg_assert_empty()
on the first BLOB page.
page_cur_insert_rec_low(), page_cur_insert_rec_zip(),
page_copy_rec_list_end_to_created_page(): Invoke btr_blob_dbg_add_rec().
page_cur_insert_rec_zip_reorg(), page_copy_rec_list_end(),
page_copy_rec_list_start(): After failure, invoke
btr_blob_dbg_remove() and btr_blob_dbg_add().
page_cur_delete_rec(): Invoke btr_blob_dbg_remove_rec().
page_delete_rec_list_end(): Invoke btr_blob_dbg_op(btr_blob_dbg_remove_rec).
page_zip_reorganize(): Invoke btr_blob_dbg_remove() before copying the records.
page_zip_copy_recs(): Invoke btr_blob_dbg_add().
row_upd_rec_in_place(): Invoke btr_blob_dbg_rbt_delete() and
btr_blob_dbg_rbt_insert().
innobase_start_or_create_for_mysql(): Warn when UNIV_BLOB_DEBUG is enabled.
rb://550 approved by Jimmy Yang
btr_rec_get_field_ref_offs(), btr_rec_get_field_ref(): New functions.
Get the pointer to an externally stored field.
btr_cur_set_ownership_of_extern_field(): Assert that the BLOB has not
already been disowned.
btr_store_big_rec_extern_fields(): Rename to
btr_store_big_rec_extern_fields_func() and add the debug parameter
update_in_place. All pointers to externally stored columns in the
record must either be zero or they must be pointers to inherited
columns, owned by this record or an earlier record version. For any
BLOB that is stored, the BLOB pointer must previously have been
zero. When the function completes, all BLOB pointers must be nonzero
and owned by the record.
rb://549 approved by Jimmy Yang
It was the enabling of UNIV_DEBUG_FILE_ACCESSES that caught Bug #55284
in the first place. This is a very light piece of of debug code, and
there really is no reason why it is not enabled in all debug builds.
rb://551 approved by Jimmy Yang
trx rollback or purge
This patch does not relax the failing debug assertion during purge.
That will be revisited once we have managed to repeat the assertion failure.
row_upd_changes_ord_field_binary_func(): Renamed from
row_upd_changes_ord_field_binary(). Add the parameter que_thr_t* in
UNIV_DEBUG builds. When the off-page column cannot be retrieved,
assert that the current transaction is a recovered one and that it is
the one that is currently being rolled back.
row_upd_changes_ord_field_binary(): A wrapper macro for
row_upd_changes_ord_field_binary_func() that discards the que_thr_t*
parameter unless UNIV_DEBUG is defined.
row_purge_upd_exist_or_extern_func(): Renamed from
row_purge_upd_exist_or_extern(). Add the parameter que_thr_t* in
UNIV_DEBUG builds.
row_purge_upd_exist_or_extern(): A wrapper macro for
row_purge_upd_exist_or_extern_func() that discards the que_thr_t*
parameter unless UNIV_DEBUG is defined.
Make trx_roll_crash_recv_trx const. If there were a 'do not
dereference' attribute, it would be appropriate as well.
rb://588 approved by Jimmy Yang
trx_get_trx_by_xid(): Invalidate trx->xid after a successful lookup,
so that subsequent callers will not find the same transaction.
The only callers of trx_get_trx_by_xid() will be invoking
innobase_commit_low() or innobase_rollback_trx(), and those code paths
should not depend on trx->xid.
rb://584 approved by Jimmy Yang
buf_block_alloc(): ulint zip_size is always 0.
buf_LRU_get_free_block(): ulint zip_size is always 0.
buf_LRU_free_block(): ibool* buf_pool_mutex_released is always NULL.
Remove these parameters.
buf_LRU_get_free_block(): Simplify the initialization of block->page.zip
and release buf_pool_mutex() earlier.
rw_lock_debug_print(): Add parameter FILE* for specifying the output stream.
rw_lock_list_print_info(): Invoke rw_lock_debug_print() on file, not stderr.
"rows examined" estimates". This change implements "innodb_stats_method"
with options of "nulls_equal", "nulls_unequal" and "null_ignored".
rb://553 approved by Marko
