MDEV-12699 Improve crash recovery of corrupted data pages
InnoDB crash recovery used to read every data page for which redo log exists. This is unnecessary for those pages that are initialized by the redo log. If a newly created page is corrupted, recovery could unnecessarily fail. It would suffice to reinitialize the page based on the redo log records. To add insult to injury, InnoDB crash recovery could hang if it encountered a corrupted page. We will fix also that problem. InnoDB would normally refuse to start up if it encounters a corrupted page on recovery, but that can be overridden by setting innodb_force_recovery=1. Data pages are completely initialized by the records MLOG_INIT_FILE_PAGE2 and MLOG_ZIP_PAGE_COMPRESS. MariaDB 10.4 additionally recognizes MLOG_INIT_FREE_PAGE, which notifies that a page has been freed and its contents can be discarded (filled with zeroes). The record MLOG_INDEX_LOAD notifies that redo logging has been re-enabled after being disabled. We can avoid loading the page if all buffered redo log records predate the MLOG_INDEX_LOAD record. For the internal tables of FULLTEXT INDEX, no MLOG_INDEX_LOAD records were written before commit aa3f7a10. Hence, we will skip these optimizations for tables whose name starts with FTS_. This is joint work with Thirunarayanan Balathandayuthapani. fil_space_t::enable_lsn, file_name_t::enable_lsn: The LSN of the latest recovered MLOG_INDEX_LOAD record for a tablespace. mlog_init: Page initialization operations discovered during redo log scanning. FIXME: This really belongs in recv_sys->addr_hash, and should be removed in MDEV-19176. recv_addr_state: Add the new state RECV_WILL_NOT_READ to indicate that according to mlog_init, the page will be initialized based on redo log record contents. recv_add_to_hash_table(): Set the RECV_WILL_NOT_READ state if appropriate. For now, we do not treat MLOG_ZIP_PAGE_COMPRESS as page initialization. This works around bugs in the crash recovery of ROW_FORMAT=COMPRESSED tables. recv_mark_log_index_load(): Process a MLOG_INDEX_LOAD record by resetting the state to RECV_NOT_PROCESSED and by updating the fil_name_t::enable_lsn. recv_init_crash_recovery_spaces(): Copy fil_name_t::enable_lsn to fil_space_t::enable_lsn. recv_recover_page(): Add the parameter init_lsn, to ignore any log records that precede the page initialization. Add DBUG output about skipped operations. buf_page_create(): Initialize FIL_PAGE_LSN, so that recv_recover_page() will not wrongly skip applying the page-initialization record due to the field containing some newer LSN as a leftover from a different page. Do not invoke ibuf_merge_or_delete_for_page() during crash recovery. recv_apply_hashed_log_recs(): Remove some unnecessary lookups. Note if a corrupted page was found during recovery. After invoking buf_page_create(), do invoke ibuf_merge_or_delete_for_page() via mlog_init.ibuf_merge() in the last recovery batch. ibuf_merge_or_delete_for_page(): Relax a debug assertion. innobase_start_or_create_for_mysql(): Abort startup if a corrupted page was found during recovery. Corrupted pages will not be flagged if innodb_force_recovery is set. However, the recv_sys->found_corrupt_fs flag can be set regardless of innodb_force_recovery if file names are found to be incorrect (for example, multiple files with the same tablespace ID).
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