CREATE TABLE bug13510739 (c INTEGER NOT NULL, PRIMARY KEY (c)) ENGINE=INNODB;
INSERT INTO bug13510739 VALUES (1), (2), (3), (4);
DELETE FROM bug13510739 WHERE c=2;
HANDLER bug13510739 OPEN;
HANDLER bug13510739 READ `primary` = (2);
HANDLER bug13510739 READ `primary` NEXT; <-- crash
The bug is that in the particular testcase row_search_for_mysql() picked up
a delete-marked record and quit, leaving the cursor non-positioned state and
on the subsequent 'get next' call the code crashed because of the
non-positioned cursor.
In row0sel.cc (line numbers from mysql-trunk):
4653 if (rec_get_deleted_flag(rec, comp)) {
...
4679 if (index == clust_index && unique_search) {
4680
4681 err = DB_RECORD_NOT_FOUND;
4682
4683 goto normal_return;
4684 }
it quit from here, not storing the cursor position.
In contrast, if the record=2 is not found at all (e.g. sleep(1) after DELETE
to let the purge wipe it away completely) then 'get = 2' does find record=3
and quits from here:
4366 if (0 != cmp_dtuple_rec(search_tuple, rec, offsets)) {
...
4394 btr_pcur_store_position(pcur, &mtr);
4395
4396 err = DB_RECORD_NOT_FOUND;
4397 #if 0
4398 ut_print_name(stderr, trx, FALSE, index->name);
4399 fputs(" record not found 3\n", stderr);
4400 #endif
4401
4402 goto normal_return;
Another fix could be to extend the condition on line 4366 to hold only if
seach_tuple matches rec AND if rec is not delete marked.
Notice that in the above test case if we wait about 1 second somewhere after
DELETE and before 'get = 2', then the testcase does not crash and returns 4
instead. Not sure if this is the correct behavior, but this bugfix removes
the crash and makes the code return what it also returns in the non-crashing
case (if rec=2 is not found during 'get = 2', e.g. we have sleep(1) there).
Approved by: Marko (http://bur03.no.oracle.com/rb/r/863/)
The counter handler_read_key (SSV::ha_read_key_count) is incremented
incorrectly.
The mysql server maintains a per thread system_status_var (SSV)
object. This object contains among other things the counter
SSV::ha_read_key_count. The purpose of this counter is to measure the
number of requests to read a row based on a key (or the number of
index lookups).
This counter was wrongly incremented in the
ha_innobase::innobase_get_index(). The fix removes
this increment statement (for both innodb and innodb_plugin).
The various callers of the innobase_get_index() was checked to
determine if anybody must increment this counter (if they first call
innobase_get_index() and then perform an index lookup). It was found
that no caller of innobase_get_index() needs to worry about the
SSV::ha_read_key_count counter.
SMALL KEY CACHE
The server crashed on division by zero because the key cache was not
initialized and the block length was 0 which was used in a division.
The fix was to not allow CACHE INDEX if the key cache was not initiallized.
Thus never try LOAD INDEX INTO CACHE for an uninitialized key cache.
Also added some windows files/directories to .bzrignore.
handle_segfault is the signal handler code of mysqld. however, it makes
calls to potentially unsafe functions localtime_r, fprintf, fflush.
include/my_stacktrace.h:
Add safe versions of itoa() write() and snprintf().
libmysqld/CMakeLists.txt:
Move signal handler to separate file.
mysys/stacktrace.c:
Remove unsafe function calls.
sql/CMakeLists.txt:
Move signal handler to separate file.
sql/Makefile.am:
Move signal handler to separate file.
sql/mysqld.cc:
Move signal handler to separate file.
sql/signal_handler.cc:
Remove unsafe function calls.
readline.cc: In function char* batch_readline(LINE_BUFFER*):
readline.cc:60:9: error: out_length may be used uninitialized in this function
log.cc: In function int find_uniq_filename(char*):
log.cc:1857:8: error: number may be used uninitialized in this function
WITH MYISAM_USE_MMAP ENABLED
MySQL server can crash due to segmentation fault when
started with myisam_use_mmap.
The reason behind this being, while making a request to
unmap (munmap) the previously mapped memory (mmap), the
size passed was 7 bytes larger than the size requested at
the time of mapping. This can eventually unmap the adjacent
memory mapped block, belonging to some other memory-map pool.
Hence the subsequent call to mmap can map a region which was
still a valid memory mapped area.
Fixed by removing the extra 7-byte margin which was erroneously
added to the size, used for unmappping.
storage/myisam/mi_close.c:
Bug#11756764 48726: MYSQLD KEEPS CRASHING WITH SIGSEGV
WITH MYISAM_USE_MMAP ENABLED
Added a condition to call _mi_unmap_file() in case
of compressed records. mi_munmap_file() is called
otherwise.
storage/myisam/mi_packrec.c:
Bug#11756764 48726: MYSQLD KEEPS CRASHING WITH SIGSEGV
WITH MYISAM_USE_MMAP ENABLED
mi_dynmap_file() function, after successfully executing
mmap, stores the total size in info->s->mapped_length
variable. Now, if mi_dynmap_file() is invoked with a size
with an extra 7-byte margin (MEMMAP_EXTRA_MARGIN),
the margin will eventually also get stored in mapped_length.
So, un-mapping function can simply use the value stored in
mapped_length in order to unmap the previously mapped
region.
AND HANG IN SHOW TABLE STATUS.
ISSUE: Table corruption due to concurrent queries.
Different threads running insert and check
query leads to table corruption. Not properly locked,
rows are inserted in between check query.
SOLUTION: In check query mutex lock is acquired
for a longer time to handle concurrent
insert and check query.
NOTE: Additionally we backported the fix for CHECKSUM
issue(bug#11758979).
rb://816
approved by: Marko Makela
The title is misleading. This bug was actually introduced by
bug 12635227 and was unearthed by a later optimization.
We need to free buf_page_t structs that we are allocating using
malloc() at shutdown.
The bug was accidentally fixed by fixing
Bug#11759688 52020: InnoDB can still deadlock on just INSERT...ON DUPLICATE KEY
a.k.a. the reintroduction of
Bug#7975 deadlock without any locking, simple select and update
a.k.a. Bug#7975 deadlock without any locking, simple select and update
Bug#7975 was reintroduced when the storage engine API was made
pluggable in MySQL 5.1. Instead of looking at thd->lex directly, we
rely on handler::extra(). But, we were looking at the wrong extra()
flag, and we were ignoring the TRX_DUP_REPLACE flag in places where we
should obey it.
innodb_replace.test: Add tests for hopefully all affected statement
types, so that bug should never ever resurface. This kind of tests
should have been added when fixing Bug#7975 in MySQL 5.0.3 in the
first place.
rb:806 approved by Sunny Bains
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
row_rename_table_for_mysql(): Return DB_ERROR instead of DB_SUCCESS
when fil_rename_tablespace() returns an error. This bug was introduced
in the InnoDB Plugin.
Approved by Sunny Bains over IM.
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.
In the ON UPDATE CASCADE clause of FOREIGN KEY constraints, the
calculated update vector was not fully initialized. This bug was
introduced in the InnoDB Plugin when implementing support for
ROW_FORMAT=DYNAMIC.
Additionally, the data type information was not initialized, but
apparently it has never been needed in this case. Nevertheless, it is
not good programming practice to pass uninitialized values around.
calc_row_difference(): Declare the update field uninitialized in
Valgrind. Copy the data type information as well, except when the
field is SQL NULL. In the built-in InnoDB, initialize
ufield->extern_storage = FALSE (an initialization bug that had gone
unnoticed this far). The InnoDB Plugin and later have this flag to
dfield_t and have always initialized it properly.
row_ins_cascade_calc_update_vec(): Reduce the scope of some
pointers. Initialize orig_len. (This caused the bug in InnoDB Plugin
and later.)
row_ins_foreign_check_on_constraint(): Simplify a condition. Declare
the update vector uninitialized.
rb:771 approved by Jimmy Yang
PARENT FOR OTHER ONE
Do not try to lookup key_nr'th key in 'table' because there may not be such
a key there. key_nr is the number of the key in the _child_ table name, not
in the parent table.
Instead just print the fields of the record that are covered by the first key
defined on the parent table.
This bug gets a better fix in MySQL 5.6, which is too risky for 5.1 and 5.5.
Approved by: Jon Olav Hauglid (via IM)
BREAKS SOURCE RELEASE BUILD
Some of the required files were not getting copied while
performing 'make dist' and hence the build failed for
the created distribution source.
Added the missing files to Makefile.am.
