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| author | Marko Mäkelä <marko.makela@mariadb.com> | 2022-07-27 14:15:14 +0300 |
|---|---|---|
| committer | Marko Mäkelä <marko.makela@mariadb.com> | 2022-07-27 14:15:14 +0300 |
| commit | 0ee1082bd2e7e7049c4f0e686bad53cf7ba053ab (patch) | |
| tree | 7c561152e00fbe0b35d6bf8d2b5b627de2050319 /storage/innobase/include/os0file.h | |
| parent | bd935a41060199a17019453d6e187e8edd7929ba (diff) | |
| download | mariadb-git-0ee1082bd2e7e7049c4f0e686bad53cf7ba053ab.tar.gz | |
MDEV-28495 InnoDB corruption due to lack of file locking
Starting with commit da094188f60bf67e3d90227304a4ea256fe2630f (MDEV-24393),
MariaDB will no longer acquire advisory file locks on InnoDB data
files by default, because it would create a large number of
entries in Linux /proc/locks.
The motivation for acquiring the file locks is to prevent accidental
concurrent startup of multiple server processes on the same data files.
Such mistake still turns out to be relatively common, based on
corruption bug reports from the community.
To prevent corruption due to concurrent startup attempts, the
Aria storage engine would unconditionally acquire an advisory lock
on one of its log files.
Solution: InnoDB will always lock its system tablespace files.
(Ever since commit 685d958e38b825ad9829be311f26729cccf37c46
the InnoDB log file will not necessarily be open while the
server is running, because it can be accessed via memory-mapped I/O.)
If more protection is desired, then the option --external-locking
can be used.
The mandatory advisory lock also fixes intermittent failures of
some crash recovery tests. It turns out that when the mtr test harness
kills and restarts the server, it will not actually ensure that the
old process has terminated before starting the new one.
Diffstat (limited to 'storage/innobase/include/os0file.h')
| -rw-r--r-- | storage/innobase/include/os0file.h | 10 |
1 files changed, 9 insertions, 1 deletions
diff --git a/storage/innobase/include/os0file.h b/storage/innobase/include/os0file.h index f942626c399..159a4789f17 100644 --- a/storage/innobase/include/os0file.h +++ b/storage/innobase/include/os0file.h @@ -2,7 +2,7 @@ Copyright (c) 1995, 2017, Oracle and/or its affiliates. All Rights Reserved. Copyright (c) 2009, Percona Inc. -Copyright (c) 2013, 2021, MariaDB Corporation. +Copyright (c) 2013, 2022, MariaDB Corporation. Portions of this file contain modifications contributed and copyrighted by Percona Inc.. Those modifications are @@ -640,6 +640,14 @@ os_file_set_nocache( const char* operation_name); #endif +#ifndef _WIN32 /* On Microsoft Windows, mandatory locking is used */ +/** Obtain an exclusive lock on a file. +@param fd file descriptor +@param name file name +@return 0 on success */ +int os_file_lock(int fd, const char *name); +#endif + /** NOTE! Use the corresponding macro os_file_create(), not directly this function! Opens an existing file or creates a new. |