- During alter operation of compressed table, page split operation
chooses the first record of the page as split record and it leads
to empty left page. This issue caused by the commit 77b3959b5c (MDEV-28457).
page_rec_is_second(), page_rec_is_second_last(): Removed the functions
since it is a deadcode.
The function rec_get_offsets_func() used to hit ut_error
due to an invalid rec_get_status() value of a
ROW_FORMAT!=REDUNDANT record. This fix is twofold:
We will not only avoid a crash on corruption in this case,
but we will also make more effort to validate each record
every time we are iterating over index page records.
rec_get_offsets_func(): Do not crash on a corrupted record.
page_rec_get_nth(): Return nullptr on error.
page_dir_slot_get_rec_validate(): Like page_dir_slot_get_rec(),
but validate the pointer and return nullptr on error.
page_cur_search_with_match(), page_cur_search_with_match_bytes(),
page_dir_split_slot(), page_cur_move_to_next():
Indicate failure in a return value.
page_cur_search(): Replaced with page_cur_search_with_match().
rec_get_next_ptr_const(), rec_get_next_ptr(): Replaced with
page_rec_get_next_low().
TODO: rtr_page_split_initialize_nodes(), rtr_update_mbr_field(),
and possibly other SPATIAL INDEX functions fail to properly handle
errors.
Reviewed by: Thirunarayanan Balathandayuthapani
Tested by: Matthias Leich
Performance tested by: Axel Schwenke
A prominent remaining source of crashes on corrupted index pages
is page directory corruption.
A frequent caller of page_dir_find_owner_slot() is page_rec_get_prev().
Some of those calls can be replaced with simpler logic that is less
prone to fail.
page_dir_find_owner_slot(),
page_rec_get_prev(), page_rec_get_prev_const(),
btr_pcur_move_to_prev(), btr_pcur_move_to_prev_on_page(),
btr_cur_upd_rec_sys(),
page_delete_rec_list_end(),
rtr_page_copy_rec_list_end_no_locks(),
rtr_page_copy_rec_list_start_no_locks(): Return an error code on failure.
fil_space_t::io(), buf_page_get_low(): Use DB_CORRUPTION for
out-of-bounds page reads.
PageBulk::getSplitRec(), PageBulk::copyOut(): Simplify the code.
btr_validate_level(): Prevent some more CHECK TABLE crashes on
corrupted pages.
btr_block_get(), btr_pcur_move_to_next_page(): Implement some checks that
were previously only part of IndexPurge::next().
IndexPurge::next(): Use btr_pcur_move_to_next_page().
