/***************************************************************************** Copyright (c) 1996, 2019, Oracle and/or its affiliates. All Rights Reserved. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License, version 2.0, as published by the Free Software Foundation. This program is also distributed with certain software (including but not limited to OpenSSL) that is licensed under separate terms, as designated in a particular file or component or in included license documentation. The authors of MySQL hereby grant you an additional permission to link the program and your derivative works with the separately licensed software that they have included with MySQL. This program is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License, version 2.0, for more details. You should have received a copy of the GNU General Public License along with this program; if not, write to the Free Software Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA *****************************************************************************/ /** @file trx/trx0undo.cc Transaction undo log Created 3/26/1996 Heikki Tuuri *******************************************************/ #include #include #include "fsp0fsp.h" #include "ha_prototypes.h" #include "trx0undo.h" #include "my_dbug.h" #ifndef UNIV_HOTBACKUP #include "clone0clone.h" #include "current_thd.h" #include "dict0dd.h" #include "mach0data.h" #include "mtr0log.h" #include "srv0mon.h" #include "srv0srv.h" #include "srv0start.h" #include "trx0purge.h" #include "trx0rec.h" #include "trx0rseg.h" #include "trx0trx.h" #include "lizard0txn.h" #include "lizard0undo.h" #include "lizard0fsp.h" #include "lizard0scn.h" #include "lizard0mon.h" #include "lizard0sys.h" #include "lizard0cleanout.h" /* How should the old versions in the history list be managed? ---------------------------------------------------------- If each transaction is given a whole page for its update undo log, file space consumption can be 10 times higher than necessary. Therefore, partly filled update undo log pages should be reusable. But then there is no way individual pages can be ordered so that the ordering agrees with the serialization numbers of the transactions on the pages. Thus, the history list must be formed of undo logs, not their header pages as it was in the old implementation. However, on a single header page the transactions are placed in the order of their serialization numbers. As old versions are purged, we may free the page when the last transaction on the page has been purged. A problem is that the purge has to go through the transactions in the serialization order. This means that we have to look through all rollback segments for the one that has the smallest transaction number in its history list. When should we do a purge? A purge is necessary when space is running out in any of the rollback segments. Then we may have to purge also old version which might be needed by some consistent read. How do we trigger the start of a purge? When a transaction writes to an undo log, it may notice that the space is running out. When a read view is closed, it may make some history superfluous. The server can have an utility which periodically checks if it can purge some history. In a parallellized purge we have the problem that a query thread can remove a delete marked clustered index record before another query thread has processed an earlier version of the record, which cannot then be done because the row cannot be constructed from the clustered index record. To avoid this problem, we will store in the update and delete mark undo record also the columns necessary to construct the secondary index entries which are modified. We can latch the stack of versions of a single clustered index record by taking a latch on the clustered index page. As long as the latch is held, no new versions can be added and no versions removed by undo. But, a purge can still remove old versions from the bottom of the stack. */ /* How to protect rollback segments, undo logs, and history lists with ------------------------------------------------------------------- latches? ------- The contention of the trx_sys_t::mutex should be minimized. When a transaction does its first insert or modify in an index, an undo log is assigned for it. Then we must have an x-latch to the rollback segment header. When the transaction does more modifys or rolls back, the undo log is protected with undo_mutex in the transaction. When the transaction commits, its insert undo log is either reset and cached for a fast reuse, or freed. In these cases we must have an x-latch on the rollback segment page. The update undo log is put to the history list. If it is not suitable for reuse, its slot in the rollback segment is reset. In both cases, an x-latch must be acquired on the rollback segment. The purge operation steps through the history list without modifying it until a truncate operation occurs, which can remove undo logs from the end of the list and release undo log segments. In stepping through the list, s-latches on the undo log pages are enough, but in a truncate, x-latches must be obtained on the rollback segment and individual pages. */ #endif /* !UNIV_HOTBACKUP */ /** Initializes the fields in an undo log segment page. */ void trx_undo_page_init( page_t *undo_page, /*!< in: undo log segment page */ ulint type, /*!< in: undo log segment type */ mtr_t *mtr); /*!< in: mtr */ #ifndef UNIV_HOTBACKUP /** Creates and initializes an undo log memory object. @param[in] rseg rollback segment memory object @param[in] id slot index within rseg @param[in] type type of the log: TRX_UNDO_INSERT or TRX_UNDO_UPDATE @param[in] trx_id id of the trx for which the undo log is created @param[in] xid X/Open XA transaction identification @param[in] page_no undo log header page number @param[in] offset undo log header byte offset on page @return own: the undo log memory object */ trx_undo_t *trx_undo_mem_create(trx_rseg_t *rseg, ulint id, ulint type, trx_id_t trx_id, const XID *xid, page_no_t page_no, ulint offset); #endif /* !UNIV_HOTBACKUP */ /** Initializes a cached insert undo log header page for new use. NOTE that this function has its own log record type MLOG_UNDO_HDR_REUSE. You must NOT change the operation of this function! @return undo log header byte offset on page */ static ulint trx_undo_insert_header_reuse( page_t *undo_page, /*!< in/out: insert undo log segment header page, x-latched */ trx_id_t trx_id, /*!< in: transaction id */ mtr_t *mtr); /*!< in: mtr */ #ifndef UNIV_HOTBACKUP /** Gets the previous record in an undo log from the previous page. @return undo log record, the page s-latched, NULL if none */ static trx_undo_rec_t *trx_undo_get_prev_rec_from_prev_page( trx_undo_rec_t *rec, /*!< in: undo record */ page_no_t page_no, /*!< in: undo log header page number */ ulint offset, /*!< in: undo log header offset on page */ bool shared, /*!< in: true=S-latch, false=X-latch */ mtr_t *mtr) /*!< in: mtr */ { space_id_t space; page_no_t prev_page_no; page_t *prev_page; page_t *undo_page; undo_page = page_align(rec); prev_page_no = flst_get_prev_addr( undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE, mtr) .page; if (prev_page_no == FIL_NULL) { return (NULL); } space = page_get_space_id(undo_page); bool found; const page_size_t &page_size = fil_space_get_page_size(space, &found); ut_ad(found); buf_block_t *block = buf_page_get(page_id_t(space, prev_page_no), page_size, shared ? RW_S_LATCH : RW_X_LATCH, mtr); buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE); prev_page = buf_block_get_frame(block); return (trx_undo_page_get_last_rec(prev_page, page_no, offset)); } /** Gets the previous record in an undo log. @return undo log record, the page s-latched, NULL if none */ trx_undo_rec_t *trx_undo_get_prev_rec( trx_undo_rec_t *rec, /*!< in: undo record */ page_no_t page_no, /*!< in: undo log header page number */ ulint offset, /*!< in: undo log header offset on page */ bool shared, /*!< in: true=S-latch, false=X-latch */ mtr_t *mtr) /*!< in: mtr */ { trx_undo_rec_t *prev_rec; prev_rec = trx_undo_page_get_prev_rec(rec, page_no, offset); if (prev_rec) { return (prev_rec); } /* We have to go to the previous undo log page to look for the previous record */ return ( trx_undo_get_prev_rec_from_prev_page(rec, page_no, offset, shared, mtr)); } /** Gets the next record in an undo log from the next page. @param[in] space undo log header space @param[in] page_size page size @param[in] undo_page undo log page @param[in] page_no undo log header page number @param[in] offset undo log header offset on page @param[in] mode latch mode: RW_S_LATCH or RW_X_LATCH @param[in,out] mtr mini-transaction @return undo log record, the page latched, NULL if none */ static trx_undo_rec_t *trx_undo_get_next_rec_from_next_page( space_id_t space, const page_size_t &page_size, const page_t *undo_page, page_no_t page_no, ulint offset, ulint mode, mtr_t *mtr) { const trx_ulogf_t *log_hdr; page_no_t next_page_no; page_t *next_page; ulint next; if (page_no == page_get_page_no(undo_page)) { log_hdr = undo_page + offset; next = mach_read_from_2(log_hdr + TRX_UNDO_NEXT_LOG); if (next != 0) { return (NULL); } } next_page_no = flst_get_next_addr( undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE, mtr) .page; if (next_page_no == FIL_NULL) { return (NULL); } const page_id_t next_page_id(space, next_page_no); if (mode == RW_S_LATCH) { next_page = trx_undo_page_get_s_latched(next_page_id, page_size, mtr); } else { ut_ad(mode == RW_X_LATCH); next_page = trx_undo_page_get(next_page_id, page_size, mtr); } return (trx_undo_page_get_first_rec(next_page, page_no, offset)); } /** Gets the next record in an undo log. @return undo log record, the page s-latched, NULL if none */ trx_undo_rec_t *trx_undo_get_next_rec( trx_undo_rec_t *rec, /*!< in: undo record */ page_no_t page_no, /*!< in: undo log header page number */ ulint offset, /*!< in: undo log header offset on page */ mtr_t *mtr) /*!< in: mtr */ { space_id_t space; trx_undo_rec_t *next_rec; next_rec = trx_undo_page_get_next_rec(rec, page_no, offset); if (next_rec) { return (next_rec); } space = page_get_space_id(page_align(rec)); bool found; const page_size_t &page_size = fil_space_get_page_size(space, &found); ut_ad(found); return (trx_undo_get_next_rec_from_next_page( space, page_size, page_align(rec), page_no, offset, RW_S_LATCH, mtr)); } /** Gets the first record in an undo log. @param[out] modifier_trx_id the modifier trx identifier. @param[in] space undo log header space @param[in] page_size page size @param[in] page_no undo log header page number @param[in] offset undo log header offset on page @param[in] mode latching mode: RW_S_LATCH or RW_X_LATCH @param[in,out] mtr mini-transaction @return undo log record, the page latched, NULL if none */ trx_undo_rec_t *trx_undo_get_first_rec(trx_id_t *modifier_trx_id, space_id_t space, const page_size_t &page_size, page_no_t page_no, ulint offset, ulint mode, mtr_t *mtr) { page_t *undo_page; trx_undo_rec_t *rec; const page_id_t page_id(space, page_no); if (mode == RW_S_LATCH) { undo_page = trx_undo_page_get_s_latched(page_id, page_size, mtr); } else { undo_page = trx_undo_page_get(page_id, page_size, mtr); } if (modifier_trx_id != nullptr) { trx_ulogf_t *undo_header = undo_page + offset; *modifier_trx_id = mach_read_from_8(undo_header + TRX_UNDO_TRX_ID); } rec = trx_undo_page_get_first_rec(undo_page, page_no, offset); if (rec) { return (rec); } return (trx_undo_get_next_rec_from_next_page(space, page_size, undo_page, page_no, offset, mode, mtr)); } /*============== UNDO LOG FILE COPY CREATION AND FREEING ==================*/ /** Writes the mtr log entry of an undo log page initialization. */ UNIV_INLINE void trx_undo_page_init_log(page_t *undo_page, /*!< in: undo log page */ ulint type, /*!< in: undo log type */ mtr_t *mtr) /*!< in: mtr */ { mlog_write_initial_log_record(undo_page, MLOG_UNDO_INIT, mtr); mlog_catenate_ulint_compressed(mtr, type); } #else /* !UNIV_HOTBACKUP */ #define trx_undo_page_init_log(undo_page, type, mtr) ((void)0) #endif /* !UNIV_HOTBACKUP */ /** Parses the redo log entry of an undo log page initialization. @return end of log record or NULL */ byte *trx_undo_parse_page_init(const byte *ptr, /*!< in: buffer */ const byte *end_ptr, /*!< in: buffer end */ page_t *page, /*!< in: page or NULL */ mtr_t *mtr) /*!< in: mtr or NULL */ { ulint type; type = mach_parse_compressed(&ptr, end_ptr); if (ptr == NULL) { return (NULL); } if (page) { trx_undo_page_init(page, type, mtr); } return (const_cast(ptr)); } /** Initializes the fields in an undo log segment page. */ void trx_undo_page_init(page_t *undo_page, /*!< in: undo log segment page */ ulint type, /*!< in: undo log segment type */ mtr_t *mtr) /*!< in: mtr */ { trx_upagef_t *page_hdr; page_hdr = undo_page + TRX_UNDO_PAGE_HDR; mach_write_to_2(page_hdr + TRX_UNDO_PAGE_TYPE, type); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START, TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_HDR_SIZE); fil_page_set_type(undo_page, FIL_PAGE_UNDO_LOG); trx_undo_page_init_log(undo_page, type, mtr); } #ifndef UNIV_HOTBACKUP /** Creates a new undo log segment in file. @return DB_SUCCESS if page creation OK possible error codes are: DB_TOO_MANY_CONCURRENT_TRXS DB_OUT_OF_FILE_SPACE */ static MY_ATTRIBUTE((warn_unused_result)) dberr_t trx_undo_seg_create( trx_rseg_t *rseg MY_ATTRIBUTE((unused)), /*!< in: rollback segment */ trx_rsegf_t *rseg_hdr, /*!< in: rollback segment header, page x-latched */ ulint type, /*!< in: type of the segment: TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ ulint *id, /*!< out: slot index within rseg header */ page_t **undo_page, /*!< out: segment header page x-latched, NULL if there was an error */ mtr_t *mtr) /*!< in: mtr */ { ulint slot_no = ULINT_UNDEFINED; space_id_t space; buf_block_t *block; trx_upagef_t *page_hdr; trx_usegf_t *seg_hdr; ulint n_reserved; bool success; dberr_t err = DB_SUCCESS; ut_ad(mtr != NULL); ut_ad(id != NULL); ut_ad(rseg_hdr != NULL); ut_ad(mutex_own(&(rseg->mutex))); #ifdef UNIV_DEBUG if (!srv_inject_too_many_concurrent_trxs) #endif { slot_no = trx_rsegf_undo_find_free(rseg_hdr, mtr); } if (slot_no == ULINT_UNDEFINED) { ib::error(ER_IB_MSG_1212) << "Cannot find a free slot for an undo log." " You may have too many active transactions running concurrently." " Please add more rollback segments or undo tablespaces."; return (DB_TOO_MANY_CONCURRENT_TRXS); } space = page_get_space_id(page_align(rseg_hdr)); success = fsp_reserve_free_extents(&n_reserved, space, 2, FSP_UNDO, mtr); if (!success) { return (DB_OUT_OF_FILE_SPACE); } /* Allocate a new file segment for the undo log */ block = fseg_create_general(space, 0, TRX_UNDO_SEG_HDR + TRX_UNDO_FSEG_HEADER, TRUE, mtr); fil_space_release_free_extents(space, n_reserved); if (block == NULL) { /* No space left */ return (DB_OUT_OF_FILE_SPACE); } buf_block_dbg_add_level(block, SYNC_TRX_UNDO_PAGE); *undo_page = buf_block_get_frame(block); page_hdr = *undo_page + TRX_UNDO_PAGE_HDR; seg_hdr = *undo_page + TRX_UNDO_SEG_HDR; trx_undo_page_init(*undo_page, type, mtr); mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_FREE, TRX_UNDO_SEG_HDR + TRX_UNDO_SEG_HDR_SIZE, MLOG_2BYTES, mtr); mlog_write_ulint(seg_hdr + TRX_UNDO_LAST_LOG, 0, MLOG_2BYTES, mtr); flst_init(seg_hdr + TRX_UNDO_PAGE_LIST, mtr); flst_add_last(seg_hdr + TRX_UNDO_PAGE_LIST, page_hdr + TRX_UNDO_PAGE_NODE, mtr); trx_rsegf_set_nth_undo(rseg_hdr, slot_no, page_get_page_no(*undo_page), mtr); *id = slot_no; MONITOR_INC(MONITOR_NUM_UNDO_SLOT_USED); return (err); } /** Writes the mtr log entry of an undo log header initialization. */ UNIV_INLINE void trx_undo_header_create_log( const page_t *undo_page, /*!< in: undo log header page */ trx_id_t trx_id, /*!< in: transaction id */ mtr_t *mtr) /*!< in: mtr */ { mlog_write_initial_log_record(undo_page, MLOG_UNDO_HDR_CREATE, mtr); mlog_catenate_ull_compressed(mtr, trx_id); } #else /* !UNIV_HOTBACKUP */ #define trx_undo_header_create_log(undo_page, trx_id, mtr) ((void)0) #endif /* !UNIV_HOTBACKUP */ /** Creates a new undo log header in file. NOTE that this function has its own log record type MLOG_UNDO_HDR_CREATE. You must NOT change the operation of this function! @return header byte offset on page */ ulint trx_undo_header_create(page_t *undo_page, /*!< in/out: undo log segment header page, x-latched; it is assumed that there is TRX_UNDO_LOG_HDR_SIZE bytes free space on it */ trx_id_t trx_id, /*!< in: transaction id */ commit_scn_t *prev_image, /*!< out: previous scn/utc if have. Only used in TXN undo header. Pass in as NULL if don't care. */ mtr_t *mtr) /*!< in: mtr */ { trx_upagef_t *page_hdr; trx_usegf_t *seg_hdr; trx_ulogf_t *log_hdr; ulint prev_log; ulint free; ulint new_free; ut_ad(mtr && undo_page); page_hdr = undo_page + TRX_UNDO_PAGE_HDR; seg_hdr = undo_page + TRX_UNDO_SEG_HDR; free = mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE); log_hdr = undo_page + free; new_free = free + TRX_UNDO_LOG_OLD_HDR_SIZE; ut_a(free + TRX_UNDO_LOG_GTID_XA_HDR_SIZE < UNIV_PAGE_SIZE - 100); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START, new_free); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, new_free); mach_write_to_2(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE); prev_log = mach_read_from_2(seg_hdr + TRX_UNDO_LAST_LOG); if (prev_log != 0) { trx_ulogf_t *prev_log_hdr; prev_log_hdr = undo_page + prev_log; mach_write_to_2(prev_log_hdr + TRX_UNDO_NEXT_LOG, free); } mach_write_to_2(seg_hdr + TRX_UNDO_LAST_LOG, free); log_hdr = undo_page + free; mach_write_to_2(log_hdr + TRX_UNDO_DEL_MARKS, TRUE); mach_write_to_8(log_hdr + TRX_UNDO_TRX_ID, trx_id); mach_write_to_2(log_hdr + TRX_UNDO_LOG_START, new_free); mach_write_to_1(log_hdr + TRX_UNDO_FLAGS, 0); mach_write_to_1(log_hdr + TRX_UNDO_DICT_TRANS, FALSE); mach_write_to_2(log_hdr + TRX_UNDO_NEXT_LOG, 0); mach_write_to_2(log_hdr + TRX_UNDO_PREV_LOG, prev_log); /** Save the current image (SCN/UTC). There might be two case: 1. prev_image->scn = 0, prev_image->utc = 0, if the first time use the space 2. prev_image is in allocated steate, if the space is reused. */ if (prev_image) { /** Copy commit scn info */ commit_scn_t cmmt = lizard::trx_undo_hdr_read_scn(log_hdr, mtr); if (!commit_scn_is_uninitial(cmmt)) *prev_image = cmmt; } /** Init the scn as NULL */ lizard::trx_undo_hdr_init_scn(log_hdr, mtr); /* Write the log record about the header creation */ trx_undo_header_create_log(undo_page, trx_id, mtr); return (free); } #ifndef UNIV_HOTBACKUP /** Write X/Open XA Transaction Identification (XID) to undo log header */ static void trx_undo_write_xid( trx_ulogf_t *log_hdr, /*!< in: undo log header */ const XID *xid, /*!< in: X/Open XA Transaction Identification */ mtr_t *mtr) /*!< in: mtr */ { mlog_write_ulint(log_hdr + TRX_UNDO_XA_FORMAT, static_cast(xid->get_format_id()), MLOG_4BYTES, mtr); mlog_write_ulint(log_hdr + TRX_UNDO_XA_TRID_LEN, static_cast(xid->get_gtrid_length()), MLOG_4BYTES, mtr); mlog_write_ulint(log_hdr + TRX_UNDO_XA_BQUAL_LEN, static_cast(xid->get_bqual_length()), MLOG_4BYTES, mtr); mlog_write_string(log_hdr + TRX_UNDO_XA_XID, reinterpret_cast(xid->get_data()), XIDDATASIZE, mtr); } dberr_t trx_undo_gtid_add_update_undo(trx_t *trx, bool prepare, bool rollback) { ut_ad(!(prepare && rollback)); /* Check if GTID persistence is needed. */ auto >id_persistor = clone_sys->get_gtid_persistor(); bool alloc = gtid_persistor.trx_check_set(trx, prepare, rollback); if (!alloc) { return (DB_SUCCESS); } /* For GTID persistence we need update undo segment. */ auto undo_ptr = &trx->rsegs.m_redo; dberr_t db_err = DB_SUCCESS; if (!undo_ptr->update_undo) { ut_ad(!rollback); mutex_enter(&trx->undo_mutex); db_err = trx_undo_assign_undo(trx, undo_ptr, TRX_UNDO_UPDATE); mutex_exit(&trx->undo_mutex); } /* In rare cases we might find no available update undo segment for insert only transactions. It is still fine to return error at prepare stage. Cannot do it earlier as GTID information is not known before. Keep the debug assert to know if it really happens ever. */ if (db_err != DB_SUCCESS) { ut_ad(false); trx->persists_gtid = false; ib::error(ER_IB_CLONE_GTID_PERSIST) << "Could not allocate undo segment" << " slot for persisting GTID. DB Error: " << db_err; } return (db_err); } bool trx_undo_t::gtid_allocated(bool is_prepare) const { if (is_prepare) { return m_gtid_storage == Gtid_storage::PREPARE_AND_COMMIT; } return m_gtid_storage == Gtid_storage::COMMIT || m_gtid_storage == Gtid_storage::PREPARE_AND_COMMIT; } std::tuple trx_undo_t::gtid_get_details(bool is_prepare) const { int flag = is_prepare ? TRX_UNDO_FLAG_XA_PREPARE_GTID : TRX_UNDO_FLAG_GTID; size_t size = is_prepare ? TRX_UNDO_LOG_GTID_XA : TRX_UNDO_LOG_GTID; return std::make_tuple(flag, size); } void trx_undo_gtid_set(trx_t *trx, trx_undo_t *undo, bool is_xa_prepare) { int gtid_flag; /* For XA prepare we store the GTID separately. */ std::tie(gtid_flag, std::ignore) = undo->gtid_get_details(is_xa_prepare); /* Reset GTID flag */ undo->flag &= ~gtid_flag; if (!trx->persists_gtid) { return; } /* Verify that we have allocated for GTID */ if (!undo->gtid_allocated(is_xa_prepare)) { ut_ad(false); ib::error(ER_IB_CLONE_GTID_PERSIST) << "Could not persist GTID as space for GTID is not allocated."; return; } undo->flag |= gtid_flag; } void trx_undo_gtid_read_and_persist(trx_ulogf_t *undo_header) { /* Check if undo log has GTID. */ auto flag = mach_read_ulint(undo_header + TRX_UNDO_FLAGS, MLOG_1BYTE); /* Extract and add GTID information of the transaction to the persister. */ Gtid_desc gtid_desc; /* Get GTID persister */ auto >id_persistor = clone_sys->get_gtid_persistor(); /* Extract and add XA prepare GTID, if there. */ if ((flag & TRX_UNDO_FLAG_XA_PREPARE_GTID) != 0) { /* Get GTID format version. */ gtid_desc.m_version = static_cast( mach_read_from_1(undo_header + TRX_UNDO_LOG_GTID_VERSION)); /* Get GTID information string. */ memcpy(>id_desc.m_info[0], undo_header + TRX_UNDO_LOG_GTID_XA, TRX_UNDO_LOG_GTID_LEN); /* Mark GTID valid. */ gtid_desc.m_is_set = true; /* No concurrency is involved during recovery but satisfy the interface requirement. */ trx_sys_mutex_enter(); gtid_persistor.add(gtid_desc); trx_sys_mutex_exit(); } if ((flag & TRX_UNDO_FLAG_GTID) == 0) { return; } /* Get GTID format version. */ gtid_desc.m_version = static_cast( mach_read_from_1(undo_header + TRX_UNDO_LOG_GTID_VERSION)); /* Get GTID information string. */ memcpy(>id_desc.m_info[0], undo_header + TRX_UNDO_LOG_GTID, TRX_UNDO_LOG_GTID_LEN); /* Mark GTID valid. */ gtid_desc.m_is_set = true; /* No concurrency is involved during recovery but satisfy the interface requirement. */ trx_sys_mutex_enter(); gtid_persistor.add(gtid_desc); gtid_persistor.add_undo_gtids(gtid_desc); trx_sys_mutex_exit(); } void trx_undo_gtid_write(trx_t *trx, trx_ulogf_t *undo_header, trx_undo_t *undo, mtr_t *mtr, bool is_xa_prepare) { int gtid_flag; size_t gtid_offset; std::tie(gtid_flag, gtid_offset) = undo->gtid_get_details(is_xa_prepare); if ((undo->flag & gtid_flag) == 0) { return; } /* Reset GTID flag */ undo->flag &= ~gtid_flag; /* We must have allocated for GTID but add a safe check. */ if (!undo->gtid_allocated(is_xa_prepare)) { ut_ad(false); return; } /** Txn undo cann't write gtid information */ ut_ad((undo->flag & TRX_UNDO_FLAG_TXN) == 0); Gtid_desc gtid_desc; auto >id_persistor = clone_sys->get_gtid_persistor(); gtid_persistor.get_gtid_info(trx, gtid_desc); if (gtid_desc.m_is_set) { /* Persist GTID version */ mlog_write_ulint(undo_header + TRX_UNDO_LOG_GTID_VERSION, gtid_desc.m_version, MLOG_1BYTE, mtr); /* Persist fixed length GTID */ ut_ad(TRX_UNDO_LOG_GTID_LEN == GTID_INFO_SIZE); mlog_write_string(undo_header + gtid_offset, >id_desc.m_info[0], TRX_UNDO_LOG_GTID_LEN, mtr); undo->flag |= gtid_flag; } mlog_write_ulint(undo_header + TRX_UNDO_FLAGS, undo->flag, MLOG_1BYTE, mtr); } /** Read X/Open XA Transaction Identification (XID) from undo log header */ static void trx_undo_read_xid( trx_ulogf_t *log_hdr, /*!< in: undo log header */ XID *xid) /*!< out: X/Open XA Transaction Identification */ { xid->set_format_id( static_cast(mach_read_from_4(log_hdr + TRX_UNDO_XA_FORMAT))); xid->set_gtrid_length( static_cast(mach_read_from_4(log_hdr + TRX_UNDO_XA_TRID_LEN))); xid->set_bqual_length( static_cast(mach_read_from_4(log_hdr + TRX_UNDO_XA_BQUAL_LEN))); xid->set_data(log_hdr + TRX_UNDO_XA_XID, XIDDATASIZE); } /** Adds space for the XA XID after an undo log old-style header. @param[in,out] undo_page Undo log segment header page @param[in,out] log_hdr Undo log header @param[in,out] mtr Mini-transaction @param[in] gtid_storage GTID storage type */ void trx_undo_header_add_space_for_xid( page_t *undo_page, trx_ulogf_t *log_hdr, mtr_t *mtr, trx_undo_t::Gtid_storage gtid_storage) { trx_upagef_t *page_hdr = undo_page + TRX_UNDO_PAGE_HDR; ulint free = mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE); /* free is now the end offset of the old style undo log header */ ut_a(free == (ulint)(log_hdr - undo_page) + TRX_UNDO_LOG_OLD_HDR_SIZE); ulint new_limit = TRX_UNDO_LOG_XA_HDR_SIZE; switch (gtid_storage) { case trx_undo_t::Gtid_storage::COMMIT: new_limit = TRX_UNDO_LOG_GTID_HDR_SIZE; break; case trx_undo_t::Gtid_storage::PREPARE_AND_COMMIT: new_limit = TRX_UNDO_LOG_GTID_XA_HDR_SIZE; break; case trx_undo_t::Gtid_storage::NONE: new_limit = TRX_UNDO_LOG_XA_HDR_SIZE; break; default: ut_ad(false); } ulint new_free = free + (new_limit - TRX_UNDO_LOG_OLD_HDR_SIZE); /* Add space for a XID after the header, update the free offset fields on the undo log page and in the undo log header */ mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_START, new_free, MLOG_2BYTES, mtr); mlog_write_ulint(page_hdr + TRX_UNDO_PAGE_FREE, new_free, MLOG_2BYTES, mtr); mlog_write_ulint(log_hdr + TRX_UNDO_LOG_START, new_free, MLOG_2BYTES, mtr); } /** Writes the mtr log entry of an undo log header reuse. */ UNIV_INLINE void trx_undo_insert_header_reuse_log( const page_t *undo_page, /*!< in: undo log header page */ trx_id_t trx_id, /*!< in: transaction id */ mtr_t *mtr) /*!< in: mtr */ { mlog_write_initial_log_record(undo_page, MLOG_UNDO_HDR_REUSE, mtr); mlog_catenate_ull_compressed(mtr, trx_id); } #else /* !UNIV_HOTBACKUP */ #define trx_undo_insert_header_reuse_log(undo_page, trx_id, mtr) ((void)0) #endif /* !UNIV_HOTBACKUP */ /** Parse the redo log entry of an undo log page header create or reuse. @param[in] type MLOG_UNDO_HDR_CREATE or MLOG_UNDO_HDR_REUSE @param[in] ptr redo log record @param[in] end_ptr end of log buffer @param[in,out] page page frame or NULL @param[in,out] mtr mini-transaction or NULL @return end of log record or NULL */ byte *trx_undo_parse_page_header(mlog_id_t type, const byte *ptr, const byte *end_ptr, page_t *page, mtr_t *mtr) { trx_id_t trx_id = mach_u64_parse_compressed(&ptr, end_ptr); if (ptr != NULL && page != NULL) { switch (type) { case MLOG_UNDO_HDR_CREATE: trx_undo_header_create(page, trx_id, nullptr, mtr); return (const_cast(ptr)); case MLOG_UNDO_HDR_REUSE: trx_undo_insert_header_reuse(page, trx_id, mtr); return (const_cast(ptr)); default: break; } ut_ad(0); } return (const_cast(ptr)); } /** Initializes a cached insert undo log header page for new use. NOTE that this function has its own log record type MLOG_UNDO_HDR_REUSE. You must NOT change the operation of this function! @return undo log header byte offset on page */ static ulint trx_undo_insert_header_reuse( page_t *undo_page, /*!< in/out: insert undo log segment header page, x-latched */ trx_id_t trx_id, /*!< in: transaction id */ mtr_t *mtr) /*!< in: mtr */ { trx_upagef_t *page_hdr; trx_usegf_t *seg_hdr; trx_ulogf_t *log_hdr; ulint free; ulint new_free; ut_ad(mtr && undo_page); page_hdr = undo_page + TRX_UNDO_PAGE_HDR; seg_hdr = undo_page + TRX_UNDO_SEG_HDR; free = TRX_UNDO_SEG_HDR + TRX_UNDO_SEG_HDR_SIZE; ut_a(free + TRX_UNDO_LOG_GTID_XA_HDR_SIZE < UNIV_PAGE_SIZE - 100); log_hdr = undo_page + free; new_free = free + TRX_UNDO_LOG_OLD_HDR_SIZE; /* Insert undo data is not needed after commit: we may free all the space on the page */ ut_a(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_INSERT); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_START, new_free); mach_write_to_2(page_hdr + TRX_UNDO_PAGE_FREE, new_free); mach_write_to_2(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE); log_hdr = undo_page + free; mach_write_to_8(log_hdr + TRX_UNDO_TRX_ID, trx_id); mach_write_to_2(log_hdr + TRX_UNDO_LOG_START, new_free); mach_write_to_1(log_hdr + TRX_UNDO_FLAGS, 0); mach_write_to_1(log_hdr + TRX_UNDO_DICT_TRANS, FALSE); lizard::trx_undo_hdr_init_scn(log_hdr, mtr); /* Write the log record MLOG_UNDO_HDR_REUSE */ trx_undo_insert_header_reuse_log(undo_page, trx_id, mtr); return (free); } #ifndef UNIV_HOTBACKUP /** Tries to add a page to the undo log segment where the undo log is placed. @return X-latched block if success, else NULL */ buf_block_t *trx_undo_add_page( trx_t *trx, /*!< in: transaction */ trx_undo_t *undo, /*!< in: undo log memory object */ trx_undo_ptr_t *undo_ptr, /*!< in: assign undo log from referred rollback segment. */ mtr_t *mtr) /*!< in: mtr which does not have a latch to any undo log page; the caller must have reserved the rollback segment mutex */ { page_t *header_page; buf_block_t *new_block; page_t *new_page; trx_rseg_t *rseg; ulint n_reserved; ut_ad(mutex_own(&(trx->undo_mutex))); ut_ad(mutex_own(&(undo_ptr->rseg->mutex))); /* Lizard: txn undo log segment can only have log header */ lizard_verify_txn_tablespace_by_id(undo->space, false); rseg = undo_ptr->rseg; if (rseg->curr_size == rseg->max_size) { return (NULL); } header_page = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, mtr); if (!fsp_reserve_free_extents(&n_reserved, undo->space, 1, FSP_UNDO, mtr)) { return (NULL); } new_block = fseg_alloc_free_page_general( TRX_UNDO_SEG_HDR + TRX_UNDO_FSEG_HEADER + header_page, undo->top_page_no + 1, FSP_UP, TRUE, mtr, mtr); fil_space_release_free_extents(undo->space, n_reserved); if (new_block == NULL) { /* No space left */ return (NULL); } ut_ad(rw_lock_get_x_lock_count(&new_block->lock) == 1); buf_block_dbg_add_level(new_block, SYNC_TRX_UNDO_PAGE); undo->last_page_no = new_block->page.id.page_no(); new_page = buf_block_get_frame(new_block); trx_undo_page_init(new_page, undo->type, mtr); flst_add_last(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_PAGE_LIST, new_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE, mtr); undo->size++; rseg->curr_size++; return (new_block); } /** Frees an undo log page that is not the header page. @return last page number in remaining log */ static page_no_t trx_undo_free_page( trx_rseg_t *rseg, /*!< in: rollback segment */ ibool in_history, /*!< in: TRUE if the undo log is in the history list */ space_id_t space, /*!< in: space */ page_no_t hdr_page_no, /*!< in: header page number */ page_no_t page_no, /*!< in: page number to free: must not be the header page */ mtr_t *mtr) /*!< in: mtr which does not have a latch to any undo log page; the caller must have reserved the rollback segment mutex */ { page_t *header_page; page_t *undo_page; fil_addr_t last_addr; trx_rsegf_t *rseg_header; ulint hist_size; ut_a(hdr_page_no != page_no); ut_ad(mutex_own(&(rseg->mutex))); lizard_verify_txn_tablespace_by_id(space, false); undo_page = trx_undo_page_get(page_id_t(space, page_no), rseg->page_size, mtr); header_page = trx_undo_page_get(page_id_t(space, hdr_page_no), rseg->page_size, mtr); flst_remove(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_PAGE_LIST, undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_NODE, mtr); fseg_free_page(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_FSEG_HEADER, space, page_no, false, mtr); last_addr = flst_get_last(header_page + TRX_UNDO_SEG_HDR + TRX_UNDO_PAGE_LIST, mtr); rseg->curr_size--; if (in_history) { rseg_header = trx_rsegf_get(space, rseg->page_no, rseg->page_size, mtr); hist_size = mtr_read_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE, MLOG_4BYTES, mtr); ut_ad(hist_size > 0); mlog_write_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE, hist_size - 1, MLOG_4BYTES, mtr); } return (last_addr.page); } /** Frees the last undo log page. The caller must hold the rollback segment mutex. */ void trx_undo_free_last_page_func( #ifdef UNIV_DEBUG const trx_t *trx, /*!< in: transaction */ #endif /* UNIV_DEBUG */ trx_undo_t *undo, /*!< in/out: undo log memory copy */ mtr_t *mtr) /*!< in/out: mini-transaction which does not have a latch to any undo log page or which has allocated the undo log page */ { ut_ad(mutex_own(&trx->undo_mutex)); ut_ad(undo->hdr_page_no != undo->last_page_no); ut_ad(undo->size > 0); undo->last_page_no = trx_undo_free_page(undo->rseg, FALSE, undo->space, undo->hdr_page_no, undo->last_page_no, mtr); undo->size--; } /** Empties an undo log header page of undo records for that undo log. Other undo logs may still have records on that page, if it is an update undo log. @param[in] space space @param[in] page_size page size @param[in] hdr_page_no header page number @param[in] hdr_offset header offset @param[in,out] mtr mini-transaction */ static void trx_undo_empty_header_page(space_id_t space, const page_size_t &page_size, page_no_t hdr_page_no, ulint hdr_offset, mtr_t *mtr) { page_t *header_page; trx_ulogf_t *log_hdr; ulint end; header_page = trx_undo_page_get(page_id_t(space, hdr_page_no), page_size, mtr); log_hdr = header_page + hdr_offset; end = trx_undo_page_get_end(header_page, hdr_page_no, hdr_offset); mlog_write_ulint(log_hdr + TRX_UNDO_LOG_START, end, MLOG_2BYTES, mtr); } /** Truncates an undo log from the end. This function is used during a rollback to free space from an undo log. */ void trx_undo_truncate_end_func( #ifdef UNIV_DEBUG const trx_t *trx, /*!< in: transaction whose undo log it is */ #endif /* UNIV_DEBUG */ trx_undo_t *undo, /*!< in: undo log */ undo_no_t limit) /*!< in: all undo records with undo number >= this value should be truncated */ { page_t *undo_page; page_no_t last_page_no; trx_undo_rec_t *rec; trx_undo_rec_t *trunc_here; mtr_t mtr; ut_ad(mutex_own(&(trx->undo_mutex))); ut_ad(mutex_own(&undo->rseg->mutex)); for (;;) { mtr_start(&mtr); if (fsp_is_system_temporary(undo->rseg->space_id)) { mtr.set_log_mode(MTR_LOG_NO_REDO); ut_ad(trx->rsegs.m_noredo.rseg == undo->rseg); } else { ut_ad(trx->rsegs.m_redo.rseg == undo->rseg); } trunc_here = NULL; last_page_no = undo->last_page_no; undo_page = trx_undo_page_get(page_id_t(undo->space, last_page_no), undo->page_size, &mtr); rec = trx_undo_page_get_last_rec(undo_page, undo->hdr_page_no, undo->hdr_offset); while (rec) { if (trx_undo_rec_get_undo_no(rec) >= limit) { /* Truncate at least this record off, maybe more */ trunc_here = rec; } else { goto function_exit; } rec = trx_undo_page_get_prev_rec(rec, undo->hdr_page_no, undo->hdr_offset); } if (last_page_no == undo->hdr_page_no) { goto function_exit; } ut_ad(last_page_no == undo->last_page_no); trx_undo_free_last_page(trx, undo, &mtr); mtr_commit(&mtr); } function_exit: if (trunc_here) { mlog_write_ulint(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_FREE, trunc_here - undo_page, MLOG_2BYTES, &mtr); } mtr_commit(&mtr); } /** Truncate the head of an undo log. NOTE that only whole pages are freed; the header page is not freed, but emptied, if all the records there are below the limit. @param[in,out] rseg rollback segment @param[in] hdr_page_no header page number @param[in] hdr_offset header offset on the page @param[in] limit first undo number to preserve (everything below the limit will be truncated) */ void trx_undo_truncate_start(trx_rseg_t *rseg, page_no_t hdr_page_no, ulint hdr_offset, undo_no_t limit) { page_t *undo_page; trx_undo_rec_t *rec; trx_undo_rec_t *last_rec; page_no_t page_no; mtr_t mtr; ut_ad(mutex_own(&(rseg->mutex))); if (!limit) { return; } loop: mtr_start(&mtr); if (fsp_is_system_temporary(rseg->space_id)) { mtr.set_log_mode(MTR_LOG_NO_REDO); } rec = trx_undo_get_first_rec(nullptr, rseg->space_id, rseg->page_size, hdr_page_no, hdr_offset, RW_X_LATCH, &mtr); if (rec == NULL) { /* Already empty */ mtr_commit(&mtr); return; } undo_page = page_align(rec); last_rec = trx_undo_page_get_last_rec(undo_page, hdr_page_no, hdr_offset); if (trx_undo_rec_get_undo_no(last_rec) >= limit) { mtr_commit(&mtr); return; } page_no = page_get_page_no(undo_page); if (page_no == hdr_page_no) { trx_undo_empty_header_page(rseg->space_id, rseg->page_size, hdr_page_no, hdr_offset, &mtr); } else { trx_undo_free_page(rseg, TRUE, rseg->space_id, hdr_page_no, page_no, &mtr); } mtr_commit(&mtr); goto loop; } /** Frees an undo log segment which is not in the history list. @param[in] undo undo log @param[in] noredo whether the undo tablespace is redo logged */ static void trx_undo_seg_free(const trx_undo_t *undo, bool noredo) { trx_rseg_t *rseg; fseg_header_t *file_seg; trx_rsegf_t *rseg_header; trx_usegf_t *seg_header; ibool finished; mtr_t mtr; rseg = undo->rseg; lizard_verify_txn_tablespace_by_id(undo->space, false); do { mtr_start(&mtr); if (noredo) { mtr.set_log_mode(MTR_LOG_NO_REDO); } mutex_enter(&(rseg->mutex)); seg_header = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, &mtr) + TRX_UNDO_SEG_HDR; file_seg = seg_header + TRX_UNDO_FSEG_HEADER; finished = fseg_free_step(file_seg, false, &mtr); if (finished) { /* Update the rseg header */ rseg_header = trx_rsegf_get(rseg->space_id, rseg->page_no, rseg->page_size, &mtr); trx_rsegf_set_nth_undo(rseg_header, undo->id, FIL_NULL, &mtr); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_USED); } mutex_exit(&(rseg->mutex)); mtr_commit(&mtr); } while (!finished); } /*========== UNDO LOG MEMORY COPY INITIALIZATION =====================*/ /** Creates and initializes an undo log memory object for a newly created rseg. The memory object is inserted in the appropriate list in the rseg. @return own: the undo log memory object */ static trx_undo_t *trx_undo_mem_init( trx_rseg_t *rseg, /*!< in: rollback segment memory object */ ulint id, /*!< in: slot index within rseg */ page_no_t page_no, /*!< in: undo log segment page number */ mtr_t *mtr) /*!< in: mtr */ { page_t *undo_page; trx_upagef_t *page_header; trx_usegf_t *seg_header; trx_ulogf_t *undo_header; trx_undo_t *undo; ulint type; ulint state; trx_id_t trx_id; ulint offset; fil_addr_t last_addr; page_t *last_page; trx_undo_rec_t *rec; XID xid; ut_a(id < TRX_RSEG_N_SLOTS); undo_page = trx_undo_page_get(page_id_t(rseg->space_id, page_no), rseg->page_size, mtr); page_header = undo_page + TRX_UNDO_PAGE_HDR; type = mtr_read_ulint(page_header + TRX_UNDO_PAGE_TYPE, MLOG_2BYTES, mtr); seg_header = undo_page + TRX_UNDO_SEG_HDR; state = mach_read_from_2(seg_header + TRX_UNDO_STATE); offset = mach_read_from_2(seg_header + TRX_UNDO_LAST_LOG); undo_header = undo_page + offset; trx_id = mach_read_from_8(undo_header + TRX_UNDO_TRX_ID); auto flag = mtr_read_ulint(undo_header + TRX_UNDO_FLAGS, MLOG_1BYTE, mtr); bool xid_exists = ((flag & TRX_UNDO_FLAG_XID) != 0); /* Lizard: Confirm txn undo extension */ bool txn_exists = ((flag & TRX_UNDO_FLAG_TXN) != 0); if (txn_exists) { lizard_trx_undo_hdr_txn_validation(undo_page, undo_header, mtr); } /* Read X/Open XA transaction identification if it exists, or set it to NULL. */ xid.reset(); if (xid_exists) { trx_undo_read_xid(undo_header, &xid); } mutex_enter(&(rseg->mutex)); undo = trx_undo_mem_create(rseg, id, type, trx_id, &xid, page_no, offset); mutex_exit(&(rseg->mutex)); undo->dict_operation = mtr_read_ulint(undo_header + TRX_UNDO_DICT_TRANS, MLOG_1BYTE, mtr); undo->flag = flag; undo->m_gtid_storage = trx_undo_t::Gtid_storage::NONE; if ((flag & TRX_UNDO_FLAG_XA_PREPARE_GTID) != 0) { /* Prepare GTID implies space is allocated for both prepare and commit GTID. */ undo->m_gtid_storage = trx_undo_t::Gtid_storage::PREPARE_AND_COMMIT; } else if ((flag & TRX_UNDO_FLAG_GTID) != 0) { /* Space is allocated for only commit GTID. */ undo->m_gtid_storage = trx_undo_t::Gtid_storage::COMMIT; } undo->state = state; undo->size = flst_get_len(seg_header + TRX_UNDO_PAGE_LIST); /** Lizard: Confirm the undo scn */ undo->cmmt = lizard::trx_undo_hdr_read_scn(undo_header, mtr); lizard_undo_scn_validation(undo); if (type == TRX_UNDO_TXN) { undo->prev_image = lizard::txn_undo_hdr_read_prev_scn(undo_header, mtr); assert_commit_scn_allocated(undo->prev_image); } else { assert_commit_scn_initial(undo->prev_image); } /* If the log segment is being freed, the page list is inconsistent! */ if (state == TRX_UNDO_TO_FREE) { goto add_to_list; } last_addr = flst_get_last(seg_header + TRX_UNDO_PAGE_LIST, mtr); undo->last_page_no = last_addr.page; undo->top_page_no = last_addr.page; last_page = trx_undo_page_get(page_id_t(rseg->space_id, undo->last_page_no), rseg->page_size, mtr); rec = trx_undo_page_get_last_rec(last_page, page_no, offset); if (rec == NULL) { undo->empty = TRUE; } else { undo->empty = FALSE; undo->top_offset = rec - last_page; undo->top_undo_no = trx_undo_rec_get_undo_no(rec); } add_to_list: if (type == TRX_UNDO_INSERT) { if (state != TRX_UNDO_CACHED) { UT_LIST_ADD_LAST(rseg->insert_undo_list, undo); } else { UT_LIST_ADD_LAST(rseg->insert_undo_cached, undo); MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED); } } else if (type == TRX_UNDO_UPDATE) { ut_ad(type == TRX_UNDO_UPDATE); if (state != TRX_UNDO_CACHED) { UT_LIST_ADD_LAST(rseg->update_undo_list, undo); /* For XA prepared transaction and XA rolled back transaction, we could have GTID to be persisted. */ if (state == TRX_UNDO_PREPARED || state == TRX_UNDO_ACTIVE) { trx_undo_gtid_read_and_persist(undo_header); } } else { UT_LIST_ADD_LAST(rseg->update_undo_cached, undo); MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED); } } else { /** Lizard: transaction undo log segment */ ut_ad(type == TRX_UNDO_TXN); if (state != TRX_UNDO_CACHED) { UT_LIST_ADD_LAST(rseg->txn_undo_list, undo); } else { UT_LIST_ADD_LAST(rseg->txn_undo_cached, undo); MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED); LIZARD_MONITOR_INC_TXN_CACHED(1); } } return (undo); } /** Initializes the undo log lists for a rollback segment memory copy. This function is only called when the database is started or a new rollback segment is created. @return the combined size of undo log segments in pages */ ulint trx_undo_lists_init( trx_rseg_t *rseg) /*!< in: rollback segment memory object */ { ulint size = 0; trx_rsegf_t *rseg_header; ulint i; mtr_t mtr; mtr_start(&mtr); rseg_header = trx_rsegf_get_new(rseg->space_id, rseg->page_no, rseg->page_size, &mtr); for (i = 0; i < TRX_RSEG_N_SLOTS; i++) { page_no_t page_no; page_no = trx_rsegf_get_nth_undo(rseg_header, i, &mtr); /* In forced recovery: try to avoid operations which look at database pages; undo logs are rapidly changing data, and the probability that they are in an inconsistent state is high */ if (page_no != FIL_NULL && srv_force_recovery < SRV_FORCE_NO_UNDO_LOG_SCAN) { trx_undo_t *undo; undo = trx_undo_mem_init(rseg, i, page_no, &mtr); size += undo->size; mtr_commit(&mtr); mtr_start(&mtr); rseg_header = trx_rsegf_get(rseg->space_id, rseg->page_no, rseg->page_size, &mtr); /* Found a used slot */ MONITOR_INC(MONITOR_NUM_UNDO_SLOT_USED); } } mtr_commit(&mtr); return (size); } /** Creates and initializes an undo log memory object. @param[in] rseg rollback segment memory object @param[in] id slot index within rseg @param[in] type type of the log: TRX_UNDO_INSERT or TRX_UNDO_UPDATE @param[in] trx_id id of the trx for which the undo log is created @param[in] xid X/Open XA transaction identification @param[in] page_no undo log header page number @param[in] offset undo log header byte offset on page @return own: the undo log memory object */ trx_undo_t *trx_undo_mem_create(trx_rseg_t *rseg, ulint id, ulint type, trx_id_t trx_id, const XID *xid, page_no_t page_no, ulint offset) { trx_undo_t *undo; ut_ad(mutex_own(&(rseg->mutex))); ut_a(id < TRX_RSEG_N_SLOTS); undo = static_cast(ut_malloc_nokey(sizeof(*undo))); if (undo == NULL) { return (NULL); } undo->id = id; undo->type = type; undo->state = TRX_UNDO_ACTIVE; undo->del_marks = FALSE; undo->trx_id = trx_id; undo->xid = *xid; undo->dict_operation = FALSE; undo->flag = 0; undo->m_gtid_storage = trx_undo_t::Gtid_storage::NONE; undo->rseg = rseg; undo->space = rseg->space_id; undo->page_size.copy_from(rseg->page_size); undo->hdr_page_no = page_no; undo->hdr_offset = offset; undo->last_page_no = page_no; undo->size = 1; undo->empty = TRUE; undo->top_page_no = page_no; undo->guess_block = NULL; undo->withdraw_clock = 0; /** Lizard: init undo scn */ undo->cmmt = COMMIT_SCN_NULL; undo->prev_image = COMMIT_SCN_NULL; return (undo); } /** Initializes a cached undo log object for new use. */ static void trx_undo_mem_init_for_reuse( trx_undo_t *undo, /*!< in: undo log to init */ trx_id_t trx_id, /*!< in: id of the trx for which the undo log is created */ const XID *xid, /*!< in: X/Open XA transaction identification*/ ulint offset) /*!< in: undo log header byte offset on page */ { ut_ad(mutex_own(&((undo->rseg)->mutex))); ut_a(undo->id < TRX_RSEG_N_SLOTS); undo->state = TRX_UNDO_ACTIVE; undo->del_marks = FALSE; undo->trx_id = trx_id; undo->xid = *xid; undo->dict_operation = FALSE; undo->flag = 0; undo->m_gtid_storage = trx_undo_t::Gtid_storage::NONE; undo->hdr_offset = offset; undo->empty = TRUE; /** Lizard: init undo scn */ undo->cmmt = COMMIT_SCN_NULL; undo->prev_image = COMMIT_SCN_NULL; } /** Frees an undo log memory copy. */ void trx_undo_mem_free(trx_undo_t *undo) /*!< in: the undo object to be freed */ { ut_a(undo->id < TRX_RSEG_N_SLOTS); ut_free(undo); } /** Create a new undo log in the given rollback segment. @param[in] trx transaction @param[in] rseg rollback segment memory copy @param[in] type type of the log: TRX_UNDO_INSERT or TRX_UNDO_UPDATE @param[in] trx_id id of the trx for which the undo log is created @param[in] xid X/Open transaction identification @param[in] gtid_storage GTID storage type @param[out] undo the new undo log object, undefined if did not succeed @param[in] mtr mini-transation @retval DB_SUCCESS if successful in creating the new undo lob object, @retval DB_TOO_MANY_CONCURRENT_TRXS @retval DB_OUT_OF_FILE_SPACE @retval DB_OUT_OF_MEMORY */ MY_ATTRIBUTE((warn_unused_result)) dberr_t trx_undo_create(trx_t *trx, trx_rseg_t *rseg, ulint type, trx_id_t trx_id, const XID *xid, trx_undo_t::Gtid_storage gtid_storage, trx_undo_t **undo, mtr_t *mtr) { trx_rsegf_t *rseg_header; page_no_t page_no; ulint offset; ulint id; page_t *undo_page; commit_scn_t prev_image = COMMIT_SCN_LOST; ut_ad(mutex_own(&(rseg->mutex))); if (rseg->curr_size == rseg->max_size) { return (DB_OUT_OF_FILE_SPACE); } rseg->curr_size++; rseg_header = trx_rsegf_get(rseg->space_id, rseg->page_no, rseg->page_size, mtr); auto err = trx_undo_seg_create(rseg, rseg_header, type, &id, &undo_page, mtr); if (err != DB_SUCCESS) { /* Did not succeed */ rseg->curr_size--; return (err); } page_no = page_get_page_no(undo_page); offset = trx_undo_header_create(undo_page, trx_id, nullptr, mtr); /** Lizard: add UBA into undo log header */ undo_addr_t undo_addr = {rseg->space_id, page_no, offset, lizard::SCN_NULL, true, lizard::GCN_NULL}; /* GTID storage is needed only for update undo log. */ if (type != TRX_UNDO_UPDATE) { gtid_storage = trx_undo_t::Gtid_storage::NONE; } trx_undo_header_add_space_for_xid(undo_page, undo_page + offset, mtr, gtid_storage); /** Lizard: special for txn undo */ if (type == TRX_UNDO_TXN) { /** Follow the XA will be txn extension information */ lizard::trx_undo_hdr_add_space_for_txn(undo_page, undo_page + offset, mtr); /** Current undo log hdr is UBA */ lizard::trx_undo_hdr_write_uba(undo_page + offset, undo_addr, mtr); } else { /** UBA is come from trx->txn_desc */ lizard::trx_undo_hdr_write_uba(undo_page + offset, trx, mtr); } *undo = trx_undo_mem_create(rseg, id, type, trx_id, xid, page_no, offset); /** Lizard: Already use txn extension, so set TRX_UNDO_FLAG_TXN in advance. */ if (type == TRX_UNDO_TXN) { lizard::trx_undo_hdr_init_for_txn(*undo, undo_page, undo_page + offset, prev_image, mtr); ut_ad((*undo)->flag == TRX_UNDO_FLAG_TXN); lizard::txn_undo_hash_insert(*undo); lizard::lizard_stats.txn_undo_log_create.inc(); } if (*undo == nullptr) { return DB_OUT_OF_MEMORY; } (*undo)->m_gtid_storage = gtid_storage; return DB_SUCCESS; } /*================ UNDO LOG ASSIGNMENT AND CLEANUP =====================*/ /** Reuses a cached undo log. @param[in,out] trx transaction @param[in,out] rseg rollback segment memory object @param[in] type type of the log: TRX_UNDO_INSERT or TRX_UNDO_UPDATE @param[in] trx_id id of the trx for which the undo log is used @param[in] xid X/Open XA transaction identification @param[in] gtid_storage GTID storage type @param[in,out] mtr Mini-transaction @return the undo log memory object, NULL if none cached */ trx_undo_t *trx_undo_reuse_cached(trx_t *trx, trx_rseg_t *rseg, ulint type, trx_id_t trx_id, const XID *xid, trx_undo_t::Gtid_storage gtid_storage, mtr_t *mtr) { trx_undo_t *undo; commit_scn_t prev_image = COMMIT_SCN_LOST; ut_ad(mutex_own(&(rseg->mutex))); if (type == TRX_UNDO_INSERT) { undo = UT_LIST_GET_FIRST(rseg->insert_undo_cached); if (undo == NULL) { return (NULL); } UT_LIST_REMOVE(rseg->insert_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); } else if (type == TRX_UNDO_UPDATE) { ut_ad(type == TRX_UNDO_UPDATE); undo = UT_LIST_GET_FIRST(rseg->update_undo_cached); if (undo == NULL) { return (NULL); } UT_LIST_REMOVE(rseg->update_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); } else { ut_ad(type == TRX_UNDO_TXN); undo = UT_LIST_GET_FIRST(rseg->txn_undo_cached); if (undo == NULL) { return (NULL); } UT_LIST_REMOVE(rseg->txn_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); LIZARD_MONITOR_DEC_TXN_CACHED(1); lizard::lizard_stats.txn_undo_log_reuse.inc(); } ut_ad(undo->size == 1); ut_a(undo->id < TRX_RSEG_N_SLOTS); auto undo_page = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, mtr); ulint offset; if (type == TRX_UNDO_INSERT) { offset = trx_undo_insert_header_reuse(undo_page, trx_id, mtr); gtid_storage = trx_undo_t::Gtid_storage::NONE; trx_undo_header_add_space_for_xid(undo_page, undo_page + offset, mtr, gtid_storage); /** UBA is come from trx->txn_desc */ lizard::trx_undo_hdr_write_uba(undo_page + offset, trx, mtr); } else if (type == TRX_UNDO_UPDATE) { ut_a(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_UPDATE); offset = trx_undo_header_create(undo_page, trx_id, nullptr, mtr); trx_undo_header_add_space_for_xid(undo_page, undo_page + offset, mtr, gtid_storage); /** UBA is come from trx->txn_desc */ lizard::trx_undo_hdr_write_uba(undo_page + offset, trx, mtr); } else { ut_a(mach_read_from_2(undo_page + TRX_UNDO_PAGE_HDR + TRX_UNDO_PAGE_TYPE) == TRX_UNDO_TXN); offset = trx_undo_header_create(undo_page, trx_id, &prev_image, mtr); gtid_storage = trx_undo_t::Gtid_storage::NONE; trx_undo_header_add_space_for_xid(undo_page, undo_page + offset, mtr, gtid_storage); /* Lizard: special for txn undo log header */ /** Lizard: add UBA into undo log header */ undo_addr_t undo_addr = {undo->space, undo->hdr_page_no, offset, lizard::SCN_NULL, true, lizard::GCN_NULL}; /** Current undo log hdr is UBA */ lizard::trx_undo_hdr_write_uba(undo_page + offset, undo_addr, mtr); /** Follow the XA will be txn extension information */ lizard::trx_undo_hdr_add_space_for_txn(undo_page, undo_page + offset, mtr); } trx_undo_mem_init_for_reuse(undo, trx_id, xid, offset); undo->m_gtid_storage = gtid_storage; if (type == TRX_UNDO_TXN) { lizard::trx_undo_hdr_init_for_txn(undo, undo_page, undo_page + offset, prev_image, mtr); ut_ad(undo->flag == TRX_UNDO_FLAG_TXN); } return (undo); } /** Marks an undo log header as a header of a data dictionary operation transaction. */ static void trx_undo_mark_as_dict_operation( trx_t *trx, /*!< in: dict op transaction */ trx_undo_t *undo, /*!< in: assigned undo log */ mtr_t *mtr) /*!< in: mtr */ { page_t *hdr_page; hdr_page = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, mtr); mlog_write_ulint(hdr_page + undo->hdr_offset + TRX_UNDO_DICT_TRANS, TRUE, MLOG_1BYTE, mtr); undo->dict_operation = TRUE; } /** Assigns an undo log for a transaction. A new undo log is created or a cached undo log reused. @return DB_SUCCESS if undo log assign successful, possible error codes are: DB_TOO_MANY_CONCURRENT_TRXS DB_OUT_OF_FILE_SPACE DB_READ_ONLY DB_OUT_OF_MEMORY */ dberr_t trx_undo_assign_undo( trx_t *trx, /*!< in: transaction */ trx_undo_ptr_t *undo_ptr, /*!< in: assign undo log from referred rollback segment. */ ulint type) /*!< in: TRX_UNDO_INSERT or TRX_UNDO_UPDATE */ { trx_rseg_t *rseg; trx_undo_t *undo; mtr_t mtr; dberr_t err = DB_SUCCESS; ut_ad(trx); /* In case of read-only scenario trx->rsegs.m_redo.rseg can be NULL but still request for assigning undo logs is valid as temporary tables can be updated in read-only mode. If there is no rollback segment assigned to trx and still there is object being updated there is something wrong and so this condition check. */ ut_ad(trx_is_rseg_assigned(trx)); rseg = undo_ptr->rseg; ut_ad(mutex_own(&(trx->undo_mutex))); bool no_redo = (&trx->rsegs.m_noredo == undo_ptr); /* If none of the undo pointers are assigned then this is first time transaction is allocating undo segment. */ bool is_first = (undo_ptr->insert_undo == nullptr && undo_ptr->update_undo == nullptr); /* If any undo segment is assigned it is guaranteed that Innodb would persist GTID. Call it before any undo segment is assigned for transaction. We allocate space for GTID only if GTID is persisted. */ trx_undo_t::Gtid_storage gtid_storage{trx_undo_t::Gtid_storage::NONE}; if (!no_redo) { auto >id_persistor = clone_sys->get_gtid_persistor(); if (is_first) { gtid_persistor.set_persist_gtid(trx, true); } /* Check if the undo segment needs to allocate for GTID. */ gtid_storage = gtid_persistor.persists_gtid(trx); } if (!no_redo) { /** Lizard: always assign txn undo log segment for durable table */ err = lizard::trx_always_assign_txn_undo(trx); if (err != DB_SUCCESS) goto txn_error; } mtr_start(&mtr); if (no_redo) { mtr.set_log_mode(MTR_LOG_NO_REDO); } else { ut_ad(&trx->rsegs.m_redo == undo_ptr); } mutex_enter(&rseg->mutex); DBUG_EXECUTE_IF("ib_create_table_fail_too_many_trx", err = DB_TOO_MANY_CONCURRENT_TRXS; goto func_exit;); undo = #ifdef UNIV_DEBUG srv_inject_too_many_concurrent_trxs ? nullptr : #endif trx_undo_reuse_cached(trx, rseg, type, trx->id, trx->xid, gtid_storage, &mtr); if (undo == nullptr) { err = trx_undo_create(trx, rseg, type, trx->id, trx->xid, gtid_storage, &undo, &mtr); if (err != DB_SUCCESS) { goto func_exit; } } if (type == TRX_UNDO_INSERT) { UT_LIST_ADD_FIRST(rseg->insert_undo_list, undo); ut_ad(undo_ptr->insert_undo == NULL); undo_ptr->insert_undo = undo; } else { UT_LIST_ADD_FIRST(rseg->update_undo_list, undo); ut_ad(undo_ptr->update_undo == NULL); undo_ptr->update_undo = undo; } if (trx->mysql_thd && !trx->ddl_operation && thd_is_dd_update_stmt(trx->mysql_thd)) { trx->ddl_operation = true; } if (trx->ddl_operation || trx_get_dict_operation(trx) != TRX_DICT_OP_NONE) { trx_undo_mark_as_dict_operation(trx, undo, &mtr); } /* For GTID persistence we might add undo segment to prepared transaction. If the transaction is in prepared state, we need to set XA properties. */ if (trx_state_eq(trx, TRX_STATE_PREPARED)) { ut_ad(!is_first); undo->set_prepared(trx->xid); } func_exit: mutex_exit(&(rseg->mutex)); mtr_commit(&mtr); txn_error: return (err); } /** Sets the state of the undo log segment at a transaction finish. @return undo log segment header page, x-latched */ page_t *trx_undo_set_state_at_finish( trx_undo_t *undo, /*!< in: undo log memory copy */ mtr_t *mtr) /*!< in: mtr */ { trx_usegf_t *seg_hdr; trx_upagef_t *page_hdr; page_t *undo_page; ulint state; ulint free_offset; ut_a(undo->id < TRX_RSEG_N_SLOTS); /** Set scn before cleanup undo */ assert_undo_scn_initial(undo); undo_page = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, mtr); seg_hdr = undo_page + TRX_UNDO_SEG_HDR; page_hdr = undo_page + TRX_UNDO_PAGE_HDR; lizard_trx_undo_hdr_uba_validation(undo_page + undo->hdr_offset, mtr); free_offset = mach_read_from_2(page_hdr + TRX_UNDO_PAGE_FREE); if (undo->type == TRX_UNDO_TXN) { ut_ad(undo->size == 1); state = lizard::decide_txn_undo_state_at_finish(free_offset); } else if (undo->size == 1 && free_offset < TRX_UNDO_PAGE_REUSE_LIMIT) { state = TRX_UNDO_CACHED; } else if (undo->type == TRX_UNDO_INSERT) { state = TRX_UNDO_TO_FREE; } else { state = TRX_UNDO_TO_PURGE; } undo->state = state; mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, state, MLOG_2BYTES, mtr); return (undo_page); } /** Set the state of the undo log segment at a XA PREPARE or XA ROLLBACK. @param[in,out] trx transaction @param[in,out] undo insert_undo or update_undo log @param[in] rollback false=XA PREPARE, true=XA ROLLBACK @param[in,out] mtr mini-transaction @return undo log segment header page, x-latched */ page_t *trx_undo_set_state_at_prepare(trx_t *trx, trx_undo_t *undo, bool rollback, mtr_t *mtr) { trx_usegf_t *seg_hdr; trx_ulogf_t *undo_header; page_t *undo_page; ulint offset; ut_ad(trx && undo && mtr); ut_a(undo->id < TRX_RSEG_N_SLOTS); undo_page = trx_undo_page_get(page_id_t(undo->space, undo->hdr_page_no), undo->page_size, mtr); seg_hdr = undo_page + TRX_UNDO_SEG_HDR; offset = mach_read_from_2(seg_hdr + TRX_UNDO_LAST_LOG); undo_header = undo_page + offset; lizard_trx_undo_hdr_uba_validation(undo_header, mtr); /* Write GTID information if there. */ trx_undo_gtid_write(trx, undo_header, undo, mtr, !rollback); if (rollback) { ut_ad(undo->state == TRX_UNDO_PREPARED); mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, TRX_UNDO_ACTIVE, MLOG_2BYTES, mtr); return (undo_page); } ut_ad(undo->state == TRX_UNDO_ACTIVE); undo->set_prepared(trx->xid); mlog_write_ulint(seg_hdr + TRX_UNDO_STATE, undo->state, MLOG_2BYTES, mtr); mlog_write_ulint(undo_header + TRX_UNDO_FLAGS, undo->flag, MLOG_1BYTE, mtr); trx_undo_write_xid(undo_header, &undo->xid, mtr); return (undo_page); } /** Adds the update undo log header as the first in the history list, and frees the memory object, or puts it to the list of cached update undo log segments. */ void trx_undo_update_cleanup( trx_t *trx, /*!< in: trx owning the update undo log */ trx_undo_ptr_t *undo_ptr, /*!< in: update undo log. */ page_t *undo_page, /*!< in: update undo log header page, x-latched */ bool update_rseg_history_len, /*!< in: if true: update rseg history len else skip updating it. */ ulint n_added_logs, /*!< in: number of logs added */ mtr_t *mtr) /*!< in: mtr */ { trx_rseg_t *rseg; trx_undo_t *undo; undo = undo_ptr->update_undo; rseg = undo_ptr->rseg; ut_ad(mutex_own(&(rseg->mutex))); assert_undo_scn_allocated(undo); trx_purge_add_update_undo_to_history( trx, undo_ptr, undo_page, update_rseg_history_len, n_added_logs, mtr); UT_LIST_REMOVE(rseg->update_undo_list, undo); undo_ptr->update_undo = NULL; if (undo->state == TRX_UNDO_CACHED) { UT_LIST_ADD_FIRST(rseg->update_undo_cached, undo); MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED); } else { ut_ad(undo->state == TRX_UNDO_TO_PURGE); trx_undo_mem_free(undo); } } /** Frees an insert undo log after a transaction commit or rollback. Knowledge of inserts is not needed after a commit or rollback, therefore the data can be discarded. @param[in,out] undo_ptr undo log to clean up @param[in] noredo whether the undo tablespace is redo logged */ void trx_undo_insert_cleanup(trx_undo_ptr_t *undo_ptr, bool noredo) { trx_undo_t *undo; trx_rseg_t *rseg; undo = undo_ptr->insert_undo; ut_ad(undo != NULL); /** Insert undo log is under init state forever */ assert_undo_scn_initial(undo); rseg = undo_ptr->rseg; ut_ad(noredo == fsp_is_system_temporary(rseg->space_id)); mutex_enter(&(rseg->mutex)); UT_LIST_REMOVE(rseg->insert_undo_list, undo); undo_ptr->insert_undo = NULL; if (undo->state == TRX_UNDO_CACHED) { UT_LIST_ADD_FIRST(rseg->insert_undo_cached, undo); MONITOR_INC(MONITOR_NUM_UNDO_SLOT_CACHED); } else { ut_ad(undo->state == TRX_UNDO_TO_FREE); /* Delete first the undo log segment in the file */ mutex_exit(&(rseg->mutex)); trx_undo_seg_free(undo, noredo); mutex_enter(&(rseg->mutex)); ut_ad(rseg->curr_size > undo->size); rseg->curr_size -= undo->size; trx_undo_mem_free(undo); } mutex_exit(&(rseg->mutex)); } /** At shutdown, frees the undo logs of a PREPARED transaction. */ void trx_undo_free_prepared(trx_t *trx) /*!< in/out: PREPARED transaction */ { ut_ad(srv_shutdown_state.load() == SRV_SHUTDOWN_EXIT_THREADS); if (trx->rsegs.m_txn.txn_undo) { ut_a(trx->rsegs.m_txn.txn_undo->state == TRX_UNDO_PREPARED); UT_LIST_REMOVE(trx->rsegs.m_txn.rseg->txn_undo_list, trx->rsegs.m_txn.txn_undo); trx_undo_mem_free(trx->rsegs.m_txn.txn_undo); trx->rsegs.m_txn.txn_undo = NULL; } if (trx->rsegs.m_redo.update_undo) { ut_a(trx->rsegs.m_redo.update_undo->state == TRX_UNDO_PREPARED); UT_LIST_REMOVE(trx->rsegs.m_redo.rseg->update_undo_list, trx->rsegs.m_redo.update_undo); trx_undo_mem_free(trx->rsegs.m_redo.update_undo); trx->rsegs.m_redo.update_undo = NULL; } if (trx->rsegs.m_redo.insert_undo) { ut_a(trx->rsegs.m_redo.insert_undo->state == TRX_UNDO_PREPARED); UT_LIST_REMOVE(trx->rsegs.m_redo.rseg->insert_undo_list, trx->rsegs.m_redo.insert_undo); trx_undo_mem_free(trx->rsegs.m_redo.insert_undo); trx->rsegs.m_redo.insert_undo = NULL; } if (trx->rsegs.m_noredo.update_undo) { ut_a(trx->rsegs.m_noredo.update_undo->state == TRX_UNDO_PREPARED); UT_LIST_REMOVE(trx->rsegs.m_noredo.rseg->update_undo_list, trx->rsegs.m_noredo.update_undo); trx_undo_mem_free(trx->rsegs.m_noredo.update_undo); trx->rsegs.m_noredo.update_undo = NULL; } if (trx->rsegs.m_noredo.insert_undo) { ut_a(trx->rsegs.m_noredo.insert_undo->state == TRX_UNDO_PREPARED); UT_LIST_REMOVE(trx->rsegs.m_noredo.rseg->insert_undo_list, trx->rsegs.m_noredo.insert_undo); trx_undo_mem_free(trx->rsegs.m_noredo.insert_undo); trx->rsegs.m_noredo.insert_undo = NULL; } } bool trx_undo_truncate_tablespace(undo::Tablespace *marked_space) { #ifdef UNIV_DEBUG static int truncate_fail_count; DBUG_EXECUTE_IF( "ib_undo_trunc_fail_truncate", if (++truncate_fail_count == 1) { ib::info() << "ib_undo_trunc_fail_truncate"; return (false); }); #endif /* UNIV_DEBUG */ bool success = true; space_id_t old_space_id = marked_space->id(); space_id_t space_num = undo::id2num(old_space_id); Rsegs *marked_rsegs = marked_space->rsegs(); ut_a(!lizard::fsp_is_txn_tablespace_by_id(old_space_id)); undo::unuse_space_id(old_space_id); space_id_t new_space_id = undo::use_next_space_id(space_num); fil_space_t *space = fil_space_get(old_space_id); bool is_encrypted = FSP_FLAGS_GET_ENCRYPTION(space->flags); /* Step-1: Truncate tablespace by replacement with a new space_id. */ success = fil_replace_tablespace(old_space_id, new_space_id, SRV_UNDO_TABLESPACE_SIZE_IN_PAGES); if (!success) { return (success); } DBUG_EXECUTE_IF("ib_undo_trunc_empty_file", ib::info(ER_IB_MSG_UNDO_TRUNC_EMPTY_FILE); DBUG_SUICIDE();); /* This undo tablespace is unused. Lock the Rsegs before the file_space because SYNC_RSEGS > SYNC_FSP. */ marked_rsegs->x_lock(); /* Step-2: Re-initialize tablespace header. Avoid REDO logging as we don't want to apply the action if server crashes. For fix-up we have UNDO-truncate-ddl-log. */ log_free_check(); mtr_t mtr; mtr_start(&mtr); mtr_set_log_mode(&mtr, MTR_LOG_NO_REDO); /* Why return value is not being checked here? */ fsp_header_init(new_space_id, SRV_UNDO_TABLESPACE_SIZE_IN_PAGES, &mtr, false); /* Step-3: Add the RSEG_ARRAY page. */ trx_rseg_array_create(new_space_id, &mtr); mtr_commit(&mtr); /* Step-4: Re-initialize rollback segment header that resides in truncated tablespaces. */ DBUG_EXECUTE_IF("ib_undo_trunc_before_rsegs", ib::info(ER_IB_MSG_UNDO_TRUNK_BEFORE_RSEG); DBUG_SUICIDE();); for (auto rseg : *marked_rsegs) { trx_rsegf_t *rseg_header; log_free_check(); mtr_start(&mtr); mtr_set_log_mode(&mtr, MTR_LOG_NO_REDO); mtr_x_lock(fil_space_get_latch(new_space_id), &mtr); rseg->space_id = new_space_id; rseg->page_no = trx_rseg_header_create(new_space_id, univ_page_size, PAGE_NO_MAX, rseg->id, &mtr); ut_a(rseg->page_no != FIL_NULL); rseg_header = trx_rsegf_get_new(new_space_id, rseg->page_no, rseg->page_size, &mtr); /* Before re-initialization ensure that we free the existing structure. There can't be any active transactions. */ ut_a(UT_LIST_GET_LEN(rseg->update_undo_list) == 0); ut_a(UT_LIST_GET_LEN(rseg->insert_undo_list) == 0); ut_a(UT_LIST_GET_LEN(rseg->txn_undo_list) == 0); trx_undo_t *next_undo; for (trx_undo_t *undo = UT_LIST_GET_FIRST(rseg->update_undo_cached); undo != NULL; undo = next_undo) { next_undo = UT_LIST_GET_NEXT(undo_list, undo); UT_LIST_REMOVE(rseg->update_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); trx_undo_mem_free(undo); } for (trx_undo_t *undo = UT_LIST_GET_FIRST(rseg->insert_undo_cached); undo != NULL; undo = next_undo) { next_undo = UT_LIST_GET_NEXT(undo_list, undo); UT_LIST_REMOVE(rseg->insert_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); trx_undo_mem_free(undo); } for (trx_undo_t *undo = UT_LIST_GET_FIRST(rseg->txn_undo_cached); undo != NULL; undo = next_undo) { /** Lizard: impossible, just for the code completion */ ut_a(0); next_undo = UT_LIST_GET_NEXT(undo_list, undo); UT_LIST_REMOVE(rseg->txn_undo_cached, undo); MONITOR_DEC(MONITOR_NUM_UNDO_SLOT_CACHED); LIZARD_MONITOR_DEC_TXN_CACHED(1); trx_undo_mem_free(undo); } UT_LIST_INIT(rseg->update_undo_list, &trx_undo_t::undo_list); UT_LIST_INIT(rseg->update_undo_cached, &trx_undo_t::undo_list); UT_LIST_INIT(rseg->insert_undo_list, &trx_undo_t::undo_list); UT_LIST_INIT(rseg->insert_undo_cached, &trx_undo_t::undo_list); UT_LIST_INIT(rseg->txn_undo_list, &trx_undo_t::undo_list); UT_LIST_INIT(rseg->txn_undo_cached, &trx_undo_t::undo_list); rseg->max_size = mtr_read_ulint(rseg_header + TRX_RSEG_MAX_SIZE, MLOG_4BYTES, &mtr); /* Initialize the undo log lists according to the rseg header */ rseg->curr_size = mtr_read_ulint(rseg_header + TRX_RSEG_HISTORY_SIZE, MLOG_4BYTES, &mtr) + 1; mtr_commit(&mtr); ut_ad(rseg->curr_size == 1); ut_ad(rseg->trx_ref_count == 0); rseg->last_page_no = FIL_NULL; rseg->last_offset = 0; rseg->last_del_marks = FALSE; rseg->last_scn = 0; } /* If tablespace is to be encrypted, encrypt it now */ if (is_encrypted && srv_undo_log_encrypt) { mtr_t mtr; mtr_start(&mtr); ut_d(bool ret =) set_undo_tablespace_encryption(new_space_id, &mtr, false); /* Don't expect any error here (unless keyring plugin is uninstalled). In that case too, continue truncation processing of tablespace. */ ut_ad(!ret); mtr_commit(&mtr); } marked_rsegs->x_unlock(); /* Increment the space ID for this undo space now so that if anyone refers to this space, it is completely initialized. */ marked_space->set_space_id(new_space_id); return (success); } #endif /* !UNIV_HOTBACKUP */