The user XA commit execution branch was caught not have been covered
with MDEV-21953 fixes.
The XA involved deadlock is resolved now to apply the former fixes
pattern.
Along the fixes the following changes have been implemented.
- MDL lock attribute correction
- dissociation of the externally completed XA from the current
thread's xid_state in the error branches
- cleanup_context() preseves the prepared XA
- wait_for_prior_commit() is relocated to satisfy both
the binlog ON (log-slave-updates and skip-log-bin)
and OFF slave execution branches.
The MariaDB code base uses strcat() and strcpy() in several
places. These are known to have memory safety issues and their usage is
discouraged. Common security scanners like Flawfinder flags them. In MariaDB we
should start using modern and safer variants on these functions.
This is similar to memory issues fixes in 19af1890b5
and 9de9f105b5 but now replace use of strcat()
and strcpy() with safer options strncat() and strncpy().
However, add '\0' forcefully to make sure the result string is correct since
for these two functions it is not guaranteed what new string will be null-terminated.
Example:
size_t dest_len = sizeof(g->Message);
strncpy(g->Message, "Null json tree", dest_len); strncat(g->Message, ":",
sizeof(g->Message) - strlen(g->Message)); size_t wrote_sz = strlen(g->Message);
size_t cur_len = wrote_sz >= dest_len ? dest_len - 1 : wrote_sz;
g->Message[cur_len] = '\0';
All new code of the whole pull request, including one or several files
that are either new files or modified ones, are contributed under the BSD-new
license. I am contributing on behalf of my employer Amazon Web Services
-- Reviewer and co-author Vicențiu Ciorbaru <vicentiu@mariadb.org>
-- Reviewer additions:
* The initial function implementation was flawed. Replaced with a simpler
and also correct version.
* Simplified code by making use of snprintf instead of chaining strcat.
* Simplified code by removing dynamic string construction in the first
place and using static strings if possible. See connect storage engine
changes.
The MDEV-25004 test innodb_fts.versioning is omitted because ever since
commit 685d958e38 InnoDB would not allow
writes to a database where the redo log file ib_logfile0 is missing.
to copy datafile
- Mariabackup fails to copy the undo log tablespace when it undergoes
truncation. So Mariabackup should detect the redo log which does
undo tablespace truncation and also backup should read the minimum
file size of the tablespace and ignore the error while reading.
- Throw error when innodb undo tablespace read failed, but backup
doesn't find the redo log for undo tablespace truncation
io_watching_thread(): Declare as a detachable thread, similar to
log_copying_thread().
stop_backup_threads(): Wait for both log_copying_thread and
io_watching_thread to clear their flags. Expect log_sys.mutex
to be held by the caller.
xtrabackup_backup_func(): Initialize log_copying_stop before
creating io_watching_thread. This prevents a race condition
where io_watching_thread() could wait on the condition variable
before it had been fully initialized. This race condition would
cause a hang in the GNU libc implementation of pthread_cond_destroy()
at the end of stop_backup_threads().
This race condition was introduced in
commit 38fd7b7d91 (MDEV-21452).
The variable was not really being used for anything. The parameters
innodb_read_io_threads, innodb_write_io_threads have replaced
innodb_file_io_threads.
- Mariabackup fails to open the undo tablespaces while applying delta
files to the corresponding data file. Mariabackup opens the
undo tablespaces first time in srv_undo_tablespaces_init() and does
tries to open the undo tablespaces in xtrabackup_apply_deltas() with
conflicting mode and leads to the failure.
- Mariabackup should close the undo tablespaces before applying
the incremental delta files.
os_file_read(): Merged with os_file_read_no_error_handling().
Crashing on a partial page read is as unhelpful as crashing on a
corrupted page read (commit 0b47c126e3).
Report the file name if it is available via IORequest.
