/****************************************************** Undo modify of a row (c) 1997 Innobase Oy Created 2/27/1997 Heikki Tuuri *******************************************************/ #include "row0umod.h" #ifdef UNIV_NONINL #include "row0umod.ic" #endif #include "dict0dict.h" #include "dict0boot.h" #include "trx0undo.h" #include "trx0roll.h" #include "btr0btr.h" #include "mach0data.h" #include "row0undo.h" #include "row0vers.h" #include "trx0trx.h" #include "trx0rec.h" #include "row0row.h" #include "row0upd.h" #include "que0que.h" #include "log0log.h" /* Considerations on undoing a modify operation. (1) Undoing a delete marking: all index records should be found. Some of them may have delete mark already FALSE, if the delete mark operation was stopped underway, or if the undo operation ended prematurely because of a system crash. (2) Undoing an update of a delete unmarked record: the newer version of an updated secondary index entry should be removed if no prior version of the clustered index record requires its existence. Otherwise, it should be delete marked. (3) Undoing an update of a delete marked record. In this kind of update a delete marked clustered index record was delete unmarked and possibly also some of its fields were changed. Now, it is possible that the delete marked version has become obsolete at the time the undo is started. */ /*************************************************************** Checks if also the previous version of the clustered index record was modified or inserted by the same transaction, and its undo number is such that it should be undone in the same rollback. */ UNIV_INLINE ibool row_undo_mod_undo_also_prev_vers( /*=============================*/ /* out: TRUE if also previous modify or insert of this row should be undone */ undo_node_t* node, /* in: row undo node */ dulint* undo_no)/* out: the undo number */ { trx_undo_rec_t* undo_rec; trx_t* trx; trx = node->trx; if (0 != ut_dulint_cmp(node->new_trx_id, trx->id)) { *undo_no = ut_dulint_zero; return(FALSE); } undo_rec = trx_undo_get_undo_rec_low(node->new_roll_ptr, node->heap); *undo_no = trx_undo_rec_get_undo_no(undo_rec); return(ut_dulint_cmp(trx->roll_limit, *undo_no) <= 0); } /*************************************************************** Undoes a modify in a clustered index record. */ static ulint row_undo_mod_clust_low( /*===================*/ /* out: DB_SUCCESS, DB_FAIL, or error code: we may run out of file space */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr, /* in: query thread */ mtr_t* mtr, /* in: mtr */ ulint mode) /* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */ { big_rec_t* dummy_big_rec; btr_pcur_t* pcur; btr_cur_t* btr_cur; ulint err; ibool success; pcur = &(node->pcur); btr_cur = btr_pcur_get_btr_cur(pcur); success = btr_pcur_restore_position(mode, pcur, mtr); ut_ad(success); if (mode == BTR_MODIFY_LEAF) { err = btr_cur_optimistic_update(BTR_NO_LOCKING_FLAG | BTR_NO_UNDO_LOG_FLAG | BTR_KEEP_SYS_FLAG, btr_cur, node->update, node->cmpl_info, thr, mtr); } else { ut_ad(mode == BTR_MODIFY_TREE); err = btr_cur_pessimistic_update( BTR_NO_LOCKING_FLAG | BTR_NO_UNDO_LOG_FLAG | BTR_KEEP_SYS_FLAG, btr_cur, &dummy_big_rec, node->update, node->cmpl_info, thr, mtr); } return(err); } /*************************************************************** Removes a clustered index record after undo if possible. */ static ulint row_undo_mod_remove_clust_low( /*==========================*/ /* out: DB_SUCCESS, DB_FAIL, or error code: we may run out of file space */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr __attribute__((unused)), /* in: query thread */ mtr_t* mtr, /* in: mtr */ ulint mode) /* in: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */ { btr_pcur_t* pcur; btr_cur_t* btr_cur; ulint err; ibool success; pcur = &(node->pcur); btr_cur = btr_pcur_get_btr_cur(pcur); success = btr_pcur_restore_position(mode, pcur, mtr); if (!success) { return(DB_SUCCESS); } /* Find out if we can remove the whole clustered index record */ if (node->rec_type == TRX_UNDO_UPD_DEL_REC && !row_vers_must_preserve_del_marked(node->new_trx_id, mtr)) { /* Ok, we can remove */ } else { return(DB_SUCCESS); } if (mode == BTR_MODIFY_LEAF) { success = btr_cur_optimistic_delete(btr_cur, mtr); if (success) { err = DB_SUCCESS; } else { err = DB_FAIL; } } else { ut_ad(mode == BTR_MODIFY_TREE); /* Note that since this operation is analogous to purge, we can free also inherited externally stored fields: hence the last FALSE in the call below */ btr_cur_pessimistic_delete(&err, FALSE, btr_cur, FALSE, mtr); /* The delete operation may fail if we have little file space left: TODO: easiest to crash the database and restart with more file space */ } return(err); } /*************************************************************** Undoes a modify in a clustered index record. Sets also the node state for the next round of undo. */ static ulint row_undo_mod_clust( /*===============*/ /* out: DB_SUCCESS or error code: we may run out of file space */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { btr_pcur_t* pcur; mtr_t mtr; ulint err; ibool success; ibool more_vers; dulint new_undo_no; ut_ad(node && thr); /* Check if also the previous version of the clustered index record should be undone in this same rollback operation */ more_vers = row_undo_mod_undo_also_prev_vers(node, &new_undo_no); pcur = &(node->pcur); mtr_start(&mtr); /* Try optimistic processing of the record, keeping changes within the index page */ err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_LEAF); if (err != DB_SUCCESS) { btr_pcur_commit_specify_mtr(pcur, &mtr); /* We may have to modify tree structure: do a pessimistic descent down the index tree */ mtr_start(&mtr); err = row_undo_mod_clust_low(node, thr, &mtr, BTR_MODIFY_TREE); } btr_pcur_commit_specify_mtr(pcur, &mtr); if (err == DB_SUCCESS && node->rec_type == TRX_UNDO_UPD_DEL_REC) { mtr_start(&mtr); err = row_undo_mod_remove_clust_low(node, thr, &mtr, BTR_MODIFY_LEAF); if (err != DB_SUCCESS) { btr_pcur_commit_specify_mtr(pcur, &mtr); /* We may have to modify tree structure: do a pessimistic descent down the index tree */ mtr_start(&mtr); err = row_undo_mod_remove_clust_low(node, thr, &mtr, BTR_MODIFY_TREE); } btr_pcur_commit_specify_mtr(pcur, &mtr); } node->state = UNDO_NODE_FETCH_NEXT; trx_undo_rec_release(node->trx, node->undo_no); if (more_vers && err == DB_SUCCESS) { /* Reserve the undo log record to the prior version after committing &mtr: this is necessary to comply with the latching order, as &mtr may contain the fsp latch which is lower in the latch hierarchy than trx->undo_mutex. */ success = trx_undo_rec_reserve(node->trx, new_undo_no); if (success) { node->state = UNDO_NODE_PREV_VERS; } } return(err); } /*************************************************************** Delete marks or removes a secondary index entry if found. */ static ulint row_undo_mod_del_mark_or_remove_sec_low( /*====================================*/ /* out: DB_SUCCESS, DB_FAIL, or DB_OUT_OF_FILE_SPACE */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr, /* in: query thread */ dict_index_t* index, /* in: index */ dtuple_t* entry, /* in: index entry */ ulint mode) /* in: latch mode BTR_MODIFY_LEAF or BTR_MODIFY_TREE */ { ibool found; btr_pcur_t pcur; btr_cur_t* btr_cur; ibool success; ibool old_has; ulint err; mtr_t mtr; mtr_t mtr_vers; log_free_check(); mtr_start(&mtr); found = row_search_index_entry(index, entry, mode, &pcur, &mtr); btr_cur = btr_pcur_get_btr_cur(&pcur); if (!found) { /* Not found */ btr_pcur_close(&pcur); mtr_commit(&mtr); return(DB_SUCCESS); } /* We should remove the index record if no prior version of the row, which cannot be purged yet, requires its existence. If some requires, we should delete mark the record. */ mtr_start(&mtr_vers); success = btr_pcur_restore_position(BTR_SEARCH_LEAF, &(node->pcur), &mtr_vers); ut_a(success); old_has = row_vers_old_has_index_entry(FALSE, btr_pcur_get_rec(&(node->pcur)), &mtr_vers, index, entry); if (old_has) { err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG, btr_cur, TRUE, thr, &mtr); ut_ad(err == DB_SUCCESS); } else { /* Remove the index record */ if (mode == BTR_MODIFY_LEAF) { success = btr_cur_optimistic_delete(btr_cur, &mtr); if (success) { err = DB_SUCCESS; } else { err = DB_FAIL; } } else { ut_ad(mode == BTR_MODIFY_TREE); btr_cur_pessimistic_delete(&err, FALSE, btr_cur, TRUE, &mtr); /* The delete operation may fail if we have little file space left: TODO: easiest to crash the database and restart with more file space */ } } btr_pcur_commit_specify_mtr(&(node->pcur), &mtr_vers); btr_pcur_close(&pcur); mtr_commit(&mtr); return(err); } /*************************************************************** Delete marks or removes a secondary index entry if found. NOTE that if we updated the fields of a delete-marked secondary index record so that alphabetically they stayed the same, e.g., 'abc' -> 'aBc', we cannot return to the original values because we do not know them. But this should not cause problems because in row0sel.c, in queries we always retrieve the clustered index record or an earlier version of it, if the secondary index record through which we do the search is delete-marked. */ static ulint row_undo_mod_del_mark_or_remove_sec( /*================================*/ /* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr, /* in: query thread */ dict_index_t* index, /* in: index */ dtuple_t* entry) /* in: index entry */ { ulint err; err = row_undo_mod_del_mark_or_remove_sec_low(node, thr, index, entry, BTR_MODIFY_LEAF); if (err == DB_SUCCESS) { return(err); } err = row_undo_mod_del_mark_or_remove_sec_low(node, thr, index, entry, BTR_MODIFY_TREE); return(err); } /*************************************************************** Delete unmarks a secondary index entry which must be found. It might not be delete-marked at the moment, but it does not harm to unmark it anyway. We also need to update the fields of the secondary index record if we updated its fields but alphabetically they stayed the same, e.g., 'abc' -> 'aBc'. */ static ulint row_undo_mod_del_unmark_sec_and_undo_update( /*========================================*/ /* out: DB_FAIL or DB_SUCCESS or DB_OUT_OF_FILE_SPACE */ ulint mode, /* in: search mode: BTR_MODIFY_LEAF or BTR_MODIFY_TREE */ que_thr_t* thr, /* in: query thread */ dict_index_t* index, /* in: index */ dtuple_t* entry) /* in: index entry */ { mem_heap_t* heap; btr_pcur_t pcur; upd_t* update; ulint err = DB_SUCCESS; ibool found; big_rec_t* dummy_big_rec; mtr_t mtr; trx_t* trx = thr_get_trx(thr); log_free_check(); mtr_start(&mtr); found = row_search_index_entry(index, entry, mode, &pcur, &mtr); if (!found) { fputs("InnoDB: error in sec index entry del undo in\n" "InnoDB: ", stderr); dict_index_name_print(stderr, trx, index); fputs("\n" "InnoDB: tuple ", stderr); dtuple_print(stderr, entry); fputs("\n" "InnoDB: record ", stderr); rec_print(stderr, btr_pcur_get_rec(&pcur), index); putc('\n', stderr); trx_print(stderr, trx, 0); fputs("\n" "InnoDB: Submit a detailed bug report" " to http://bugs.mysql.com\n", stderr); } else { btr_cur_t* btr_cur = btr_pcur_get_btr_cur(&pcur); err = btr_cur_del_mark_set_sec_rec(BTR_NO_LOCKING_FLAG, btr_cur, FALSE, thr, &mtr); ut_a(err == DB_SUCCESS); heap = mem_heap_create(100); update = row_upd_build_sec_rec_difference_binary( index, entry, btr_cur_get_rec(btr_cur), trx, heap); if (upd_get_n_fields(update) == 0) { /* Do nothing */ } else if (mode == BTR_MODIFY_LEAF) { /* Try an optimistic updating of the record, keeping changes within the page */ err = btr_cur_optimistic_update( BTR_KEEP_SYS_FLAG | BTR_NO_LOCKING_FLAG, btr_cur, update, 0, thr, &mtr); if (err == DB_OVERFLOW || err == DB_UNDERFLOW) { err = DB_FAIL; } } else { ut_a(mode == BTR_MODIFY_TREE); err = btr_cur_pessimistic_update( BTR_KEEP_SYS_FLAG | BTR_NO_LOCKING_FLAG, btr_cur, &dummy_big_rec, update, 0, thr, &mtr); } mem_heap_free(heap); } btr_pcur_close(&pcur); mtr_commit(&mtr); return(err); } /*************************************************************** Undoes a modify in secondary indexes when undo record type is UPD_DEL. */ static ulint row_undo_mod_upd_del_sec( /*=====================*/ /* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { mem_heap_t* heap; dtuple_t* entry; dict_index_t* index; ulint err; heap = mem_heap_create(1024); while (node->index != NULL) { index = node->index; entry = row_build_index_entry(node->row, index, heap); err = row_undo_mod_del_mark_or_remove_sec(node, thr, index, entry); if (err != DB_SUCCESS) { mem_heap_free(heap); return(err); } node->index = dict_table_get_next_index(node->index); } mem_heap_free(heap); return(DB_SUCCESS); } /*************************************************************** Undoes a modify in secondary indexes when undo record type is DEL_MARK. */ static ulint row_undo_mod_del_mark_sec( /*======================*/ /* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { mem_heap_t* heap; dtuple_t* entry; dict_index_t* index; ulint err; heap = mem_heap_create(1024); while (node->index != NULL) { index = node->index; entry = row_build_index_entry(node->row, index, heap); err = row_undo_mod_del_unmark_sec_and_undo_update( BTR_MODIFY_LEAF, thr, index, entry); if (err == DB_FAIL) { err = row_undo_mod_del_unmark_sec_and_undo_update( BTR_MODIFY_TREE, thr, index, entry); } if (err != DB_SUCCESS) { mem_heap_free(heap); return(err); } node->index = dict_table_get_next_index(node->index); } mem_heap_free(heap); return(DB_SUCCESS); } /*************************************************************** Undoes a modify in secondary indexes when undo record type is UPD_EXIST. */ static ulint row_undo_mod_upd_exist_sec( /*=======================*/ /* out: DB_SUCCESS or DB_OUT_OF_FILE_SPACE */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { mem_heap_t* heap; dtuple_t* entry; dict_index_t* index; ulint err; if (node->cmpl_info & UPD_NODE_NO_ORD_CHANGE) { /* No change in secondary indexes */ return(DB_SUCCESS); } heap = mem_heap_create(1024); while (node->index != NULL) { index = node->index; if (row_upd_changes_ord_field_binary(node->row, node->index, node->update)) { /* Build the newest version of the index entry */ entry = row_build_index_entry(node->row, index, heap); /* NOTE that if we updated the fields of a delete-marked secondary index record so that alphabetically they stayed the same, e.g., 'abc' -> 'aBc', we cannot return to the original values because we do not know them. But this should not cause problems because in row0sel.c, in queries we always retrieve the clustered index record or an earlier version of it, if the secondary index record through which we do the search is delete-marked. */ err = row_undo_mod_del_mark_or_remove_sec(node, thr, index, entry); if (err != DB_SUCCESS) { mem_heap_free(heap); return(err); } /* We may have to update the delete mark in the secondary index record of the previous version of the row. We also need to update the fields of the secondary index record if we updated its fields but alphabetically they stayed the same, e.g., 'abc' -> 'aBc'. */ row_upd_index_replace_new_col_vals(entry, index, node->update, NULL); err = row_undo_mod_del_unmark_sec_and_undo_update( BTR_MODIFY_LEAF, thr, index, entry); if (err == DB_FAIL) { err = row_undo_mod_del_unmark_sec_and_undo_update( BTR_MODIFY_TREE, thr, index, entry); } if (err != DB_SUCCESS) { mem_heap_free(heap); return(err); } } node->index = dict_table_get_next_index(node->index); } mem_heap_free(heap); return(DB_SUCCESS); } /*************************************************************** Parses the row reference and other info in a modify undo log record. */ static void row_undo_mod_parse_undo_rec( /*========================*/ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { dict_index_t* clust_index; byte* ptr; dulint undo_no; dulint table_id; dulint trx_id; dulint roll_ptr; ulint info_bits; ulint type; ulint cmpl_info; ibool dummy_extern; trx_t* trx; ut_ad(node && thr); trx = thr_get_trx(thr); ptr = trx_undo_rec_get_pars(node->undo_rec, &type, &cmpl_info, &dummy_extern, &undo_no, &table_id); node->rec_type = type; node->table = dict_table_get_on_id(table_id, trx); /* TODO: other fixes associated with DROP TABLE + rollback in the same table by another user */ if (node->table == NULL) { /* Table was dropped */ return; } if (node->table->ibd_file_missing) { /* We skip undo operations to missing .ibd files */ node->table = NULL; return; } clust_index = dict_table_get_first_index(node->table); ptr = trx_undo_update_rec_get_sys_cols(ptr, &trx_id, &roll_ptr, &info_bits); ptr = trx_undo_rec_get_row_ref(ptr, clust_index, &(node->ref), node->heap); trx_undo_update_rec_get_update(ptr, clust_index, type, trx_id, roll_ptr, info_bits, trx, node->heap, &(node->update)); node->new_roll_ptr = roll_ptr; node->new_trx_id = trx_id; node->cmpl_info = cmpl_info; } /*************************************************************** Undoes a modify operation on a row of a table. */ ulint row_undo_mod( /*=========*/ /* out: DB_SUCCESS or error code */ undo_node_t* node, /* in: row undo node */ que_thr_t* thr) /* in: query thread */ { ibool found; ulint err; ut_ad(node && thr); ut_ad(node->state == UNDO_NODE_MODIFY); row_undo_mod_parse_undo_rec(node, thr); if (node->table == NULL) { found = FALSE; } else { found = row_undo_search_clust_to_pcur(node); } if (!found) { /* It is already undone, or will be undone by another query thread, or table was dropped */ trx_undo_rec_release(node->trx, node->undo_no); node->state = UNDO_NODE_FETCH_NEXT; return(DB_SUCCESS); } node->index = dict_table_get_next_index( dict_table_get_first_index(node->table)); if (node->rec_type == TRX_UNDO_UPD_EXIST_REC) { err = row_undo_mod_upd_exist_sec(node, thr); } else if (node->rec_type == TRX_UNDO_DEL_MARK_REC) { err = row_undo_mod_del_mark_sec(node, thr); } else { ut_ad(node->rec_type == TRX_UNDO_UPD_DEL_REC); err = row_undo_mod_upd_del_sec(node, thr); } if (err != DB_SUCCESS) { return(err); } err = row_undo_mod_clust(node, thr); return(err); }