/***************************************************************************** Copyright (c) 1995, 2017, Oracle and/or its affiliates. All rights reserved. Copyright (c) 2009, Google Inc. Copyright (c) 2017, 2018, MariaDB Corporation. Portions of this file contain modifications contributed and copyrighted by Google, Inc. Those modifications are gratefully acknowledged and are described briefly in the InnoDB documentation. The contributions by Google are incorporated with their permission, and subject to the conditions contained in the file COPYING.Google. This program is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; version 2 of the License. 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 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 Street, Suite 500, Boston, MA 02110-1335 USA *****************************************************************************/ /**************************************************//** @file include/log0log.h Database log Created 12/9/1995 Heikki Tuuri *******************************************************/ #ifndef log0log_h #define log0log_h #include "univ.i" #include "dyn0buf.h" #include "sync0rw.h" #include "log0types.h" #include "os0event.h" #include "os0file.h" /** Redo log group */ struct log_group_t; /** Magic value to use instead of log checksums when they are disabled */ #define LOG_NO_CHECKSUM_MAGIC 0xDEADBEEFUL /* Margin for the free space in the smallest log group, before a new query step which modifies the database, is started */ #define LOG_CHECKPOINT_FREE_PER_THREAD (4 * UNIV_PAGE_SIZE) #define LOG_CHECKPOINT_EXTRA_FREE (8 * UNIV_PAGE_SIZE) typedef ulint (*log_checksum_func_t)(const byte* log_block); /** Pointer to the log checksum calculation function. Protected with log_sys->mutex. */ extern log_checksum_func_t log_checksum_algorithm_ptr; /** Append a string to the log. @param[in] str string @param[in] len string length @param[out] start_lsn start LSN of the log record @return end lsn of the log record, zero if did not succeed */ UNIV_INLINE lsn_t log_reserve_and_write_fast( const void* str, ulint len, lsn_t* start_lsn); /***********************************************************************//** Checks if there is need for a log buffer flush or a new checkpoint, and does this if yes. Any database operation should call this when it has modified more than about 4 pages. NOTE that this function may only be called when the OS thread owns no synchronization objects except the dictionary mutex. */ UNIV_INLINE void log_free_check(void); /*================*/ /** Extends the log buffer. @param[in] len requested minimum size in bytes */ void log_buffer_extend( ulint len); /** Check margin not to overwrite transaction log from the last checkpoint. If would estimate the log write to exceed the log_group_capacity, waits for the checkpoint is done enough. @param[in] len length of the data to be written */ void log_margin_checkpoint_age( ulint len); /** Open the log for log_write_low. The log must be closed with log_close. @param[in] len length of the data to be written @return start lsn of the log record */ lsn_t log_reserve_and_open( ulint len); /************************************************************//** Writes to the log the string given. It is assumed that the caller holds the log mutex. */ void log_write_low( /*==========*/ const byte* str, /*!< in: string */ ulint str_len); /*!< in: string length */ /************************************************************//** Closes the log. @return lsn */ lsn_t log_close(void); /*===========*/ /************************************************************//** Gets the current lsn. @return current lsn */ UNIV_INLINE lsn_t log_get_lsn(void); /*=============*/ /************************************************************//** Gets the current lsn. @return current lsn */ UNIV_INLINE lsn_t log_get_lsn_nowait(void); /*=============*/ /************************************************************//** Gets the last lsn that is fully flushed to disk. @return last flushed lsn */ UNIV_INLINE ib_uint64_t log_get_flush_lsn(void); /*=============*/ /**************************************************************** Gets the log group capacity. It is OK to read the value without holding log_sys->mutex because it is constant. @return log group capacity */ UNIV_INLINE lsn_t log_get_capacity(void); /*==================*/ /**************************************************************** Get log_sys::max_modified_age_async. It is OK to read the value without holding log_sys::mutex because it is constant. @return max_modified_age_async */ UNIV_INLINE lsn_t log_get_max_modified_age_async(void); /*================================*/ /** Initializes the redo logging subsystem. */ void log_sys_init(); /** Initialize the redo log. @param[in] n_files number of files */ void log_init(ulint n_files); /** Calculate the recommended highest values for lsn - last_checkpoint_lsn and lsn - buf_get_oldest_modification(). @param[in] file_size requested innodb_log_file_size @retval true on success @retval false if the smallest log group is too small to accommodate the number of OS threads in the database server */ bool log_set_capacity(ulonglong file_size) MY_ATTRIBUTE((warn_unused_result)); /******************************************************//** Completes an i/o to a log file. */ void log_io_complete( /*============*/ log_group_t* group); /*!< in: log group */ /******************************************************//** This function is called, e.g., when a transaction wants to commit. It checks that the log has been written to the log file up to the last log entry written by the transaction. If there is a flush running, it waits and checks if the flush flushed enough. If not, starts a new flush. */ void log_write_up_to( /*============*/ lsn_t lsn, /*!< in: log sequence number up to which the log should be written, LSN_MAX if not specified */ bool flush_to_disk); /*!< in: true if we want the written log also to be flushed to disk */ /** write to the log file up to the last log entry. @param[in] sync whether we want the written log also to be flushed to disk. */ void log_buffer_flush_to_disk( bool sync = true); /****************************************************************//** This functions writes the log buffer to the log file and if 'flush' is set it forces a flush of the log file as well. This is meant to be called from background master thread only as it does not wait for the write (+ possible flush) to finish. */ void log_buffer_sync_in_background( /*==========================*/ bool flush); /*checkpoint_buf. @param[in] group log group @param[in] header 0 or LOG_CHEKCPOINT_1 or LOG_CHECKPOINT2 */ void log_group_header_read( const log_group_t* group, ulint header); /** Write checkpoint info to the log header and invoke log_mutex_exit(). @param[in] sync whether to wait for the write to complete @param[in] end_lsn start LSN of the MLOG_CHECKPOINT mini-transaction */ void log_write_checkpoint_info(bool sync, lsn_t end_lsn); /** Set extra data to be written to the redo log during checkpoint. @param[in] buf data to be appended on checkpoint, or NULL @return pointer to previous data to be appended on checkpoint */ mtr_buf_t* log_append_on_checkpoint( mtr_buf_t* buf); /** Checks that there is enough free space in the log to start a new query step. Flushes the log buffer or makes a new checkpoint if necessary. NOTE: this function may only be called if the calling thread owns no synchronization objects! */ void log_check_margins(void); /********************************************************//** Sets the field values in group to correspond to a given lsn. For this function to work, the values must already be correctly initialized to correspond to some lsn, for instance, a checkpoint lsn. */ void log_group_set_fields( /*=================*/ log_group_t* group, /*!< in/out: group */ lsn_t lsn); /*!< in: lsn for which the values should be set */ /************************************************************//** Gets a log block flush bit. @return TRUE if this block was the first to be written in a log flush */ UNIV_INLINE ibool log_block_get_flush_bit( /*====================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Gets a log block number stored in the header. @return log block number stored in the block header */ UNIV_INLINE ulint log_block_get_hdr_no( /*=================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Gets a log block data length. @return log block data length measured as a byte offset from the block start */ UNIV_INLINE ulint log_block_get_data_len( /*===================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Sets the log block data length. */ UNIV_INLINE void log_block_set_data_len( /*===================*/ byte* log_block, /*!< in/out: log block */ ulint len); /*!< in: data length */ /************************************************************//** Calculates the checksum for a log block. @return checksum */ UNIV_INLINE ulint log_block_calc_checksum( /*====================*/ const byte* block); /*!< in: log block */ /** Calculates the checksum for a log block using the CRC32 algorithm. @param[in] block log block @return checksum */ UNIV_INLINE ulint log_block_calc_checksum_crc32( const byte* block); /** Calculates the checksum for a log block using the "no-op" algorithm. @param[in] block the redo log block @return the calculated checksum value */ UNIV_INLINE ulint log_block_calc_checksum_none(const byte* block); /************************************************************//** Gets a log block checksum field value. @return checksum */ UNIV_INLINE ulint log_block_get_checksum( /*===================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Sets a log block checksum field value. */ UNIV_INLINE void log_block_set_checksum( /*===================*/ byte* log_block, /*!< in/out: log block */ ulint checksum); /*!< in: checksum */ /************************************************************//** Gets a log block first mtr log record group offset. @return first mtr log record group byte offset from the block start, 0 if none */ UNIV_INLINE ulint log_block_get_first_rec_group( /*==========================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Sets the log block first mtr log record group offset. */ UNIV_INLINE void log_block_set_first_rec_group( /*==========================*/ byte* log_block, /*!< in/out: log block */ ulint offset); /*!< in: offset, 0 if none */ /************************************************************//** Gets a log block checkpoint number field (4 lowest bytes). @return checkpoint no (4 lowest bytes) */ UNIV_INLINE ulint log_block_get_checkpoint_no( /*========================*/ const byte* log_block); /*!< in: log block */ /************************************************************//** Initializes a log block in the log buffer. */ UNIV_INLINE void log_block_init( /*===========*/ byte* log_block, /*!< in: pointer to the log buffer */ lsn_t lsn); /*!< in: lsn within the log block */ /************************************************************//** Converts a lsn to a log block number. @return log block number, it is > 0 and <= 1G */ UNIV_INLINE ulint log_block_convert_lsn_to_no( /*========================*/ lsn_t lsn); /*!< in: lsn of a byte within the block */ /******************************************************//** Prints info of the log. */ void log_print( /*======*/ FILE* file); /*!< in: file where to print */ /******************************************************//** Peeks the current lsn. @return TRUE if success, FALSE if could not get the log system mutex */ ibool log_peek_lsn( /*=========*/ lsn_t* lsn); /*!< out: if returns TRUE, current lsn is here */ /**********************************************************************//** Refreshes the statistics used to print per-second averages. */ void log_refresh_stats(void); /*===================*/ /********************************************************//** Closes all log groups. */ void log_group_close_all(void); /*=====================*/ /** Shut down the redo log subsystem. */ void log_shutdown(); /** Whether to generate and require checksums on the redo log pages */ extern my_bool innodb_log_checksums; /* Values used as flags */ #define LOG_FLUSH 7652559 #define LOG_CHECKPOINT 78656949 /* The counting of lsn's starts from this value: this must be non-zero */ #define LOG_START_LSN ((lsn_t) (16 * OS_FILE_LOG_BLOCK_SIZE)) #define LOG_BUFFER_SIZE (srv_log_buffer_size * UNIV_PAGE_SIZE) /* Offsets of a log block header */ #define LOG_BLOCK_HDR_NO 0 /* block number which must be > 0 and is allowed to wrap around at 2G; the highest bit is set to 1 if this is the first log block in a log flush write segment */ #define LOG_BLOCK_FLUSH_BIT_MASK 0x80000000UL /* mask used to get the highest bit in the preceding field */ #define LOG_BLOCK_HDR_DATA_LEN 4 /* number of bytes of log written to this block */ #define LOG_BLOCK_FIRST_REC_GROUP 6 /* offset of the first start of an mtr log record group in this log block, 0 if none; if the value is the same as LOG_BLOCK_HDR_DATA_LEN, it means that the first rec group has not yet been catenated to this log block, but if it will, it will start at this offset; an archive recovery can start parsing the log records starting from this offset in this log block, if value not 0 */ #define LOG_BLOCK_CHECKPOINT_NO 8 /* 4 lower bytes of the value of log_sys->next_checkpoint_no when the log block was last written to: if the block has not yet been written full, this value is only updated before a log buffer flush */ #define LOG_BLOCK_HDR_SIZE 12 /* size of the log block header in bytes */ /* Offsets of a log block trailer from the end of the block */ #define LOG_BLOCK_CHECKSUM 4 /* 4 byte checksum of the log block contents; in InnoDB versions < 3.23.52 this did not contain the checksum but the same value as .._HDR_NO */ #define LOG_BLOCK_TRL_SIZE 4 /* trailer size in bytes */ /** Offsets inside the checkpoint pages (redo log format version 1) @{ */ /** Checkpoint number */ #define LOG_CHECKPOINT_NO 0 /** Log sequence number up to which all changes have been flushed */ #define LOG_CHECKPOINT_LSN 8 /** Byte offset of the log record corresponding to LOG_CHECKPOINT_LSN */ #define LOG_CHECKPOINT_OFFSET 16 /** log_sys_t::buf_size at the time of the checkpoint (not used) */ #define LOG_CHECKPOINT_LOG_BUF_SIZE 24 /** MariaDB 10.2.5 encrypted redo log encryption key version (32 bits)*/ #define LOG_CHECKPOINT_CRYPT_KEY 32 /** MariaDB 10.2.5 encrypted redo log random nonce (32 bits) */ #define LOG_CHECKPOINT_CRYPT_NONCE 36 /** MariaDB 10.2.5 encrypted redo log random message (MY_AES_BLOCK_SIZE) */ #define LOG_CHECKPOINT_CRYPT_MESSAGE 40 /** start LSN of the MLOG_CHECKPOINT mini-transaction corresponding to this checkpoint, or 0 if the information has not been written */ #define LOG_CHECKPOINT_END_LSN OS_FILE_LOG_BLOCK_SIZE - 16 /* @} */ /** Offsets of a log file header */ /* @{ */ /** Log file header format identifier (32-bit unsigned big-endian integer). This used to be called LOG_GROUP_ID and always written as 0, because InnoDB never supported more than one copy of the redo log. */ #define LOG_HEADER_FORMAT 0 /** 4 unused (zero-initialized) bytes. In format version 0, the LOG_FILE_START_LSN started here, 4 bytes earlier than LOG_HEADER_START_LSN, which the LOG_FILE_START_LSN was renamed to. */ #define LOG_HEADER_PAD1 4 /** LSN of the start of data in this log file (with format version 1; in format version 0, it was called LOG_FILE_START_LSN and at offset 4). */ #define LOG_HEADER_START_LSN 8 /** A null-terminated string which will contain either the string 'ibbackup' and the creation time if the log file was created by mysqlbackup --restore, or the MySQL version that created the redo log file. */ #define LOG_HEADER_CREATOR 16 /** End of the log file creator field. */ #define LOG_HEADER_CREATOR_END (LOG_HEADER_CREATOR + 32) /** Contents of the LOG_HEADER_CREATOR field */ #define LOG_HEADER_CREATOR_CURRENT \ "MariaDB " \ IB_TO_STR(MYSQL_VERSION_MAJOR) "." \ IB_TO_STR(MYSQL_VERSION_MINOR) "." \ IB_TO_STR(MYSQL_VERSION_PATCH) /** The original (not version-tagged) InnoDB redo log format */ #define LOG_HEADER_FORMAT_3_23 0 /** The MySQL 5.7.9/MariaDB 10.2.2 log format */ #define LOG_HEADER_FORMAT_10_2 1 /** The MariaDB 10.3.2 log format */ #define LOG_HEADER_FORMAT_10_3 103 /** The redo log format identifier corresponding to the current format version. Stored in LOG_HEADER_FORMAT. */ #define LOG_HEADER_FORMAT_CURRENT LOG_HEADER_FORMAT_10_3 /** Encrypted MariaDB redo log */ #define LOG_HEADER_FORMAT_ENCRYPTED (1U<<31) /* @} */ #define LOG_CHECKPOINT_1 OS_FILE_LOG_BLOCK_SIZE /* first checkpoint field in the log header; we write alternately to the checkpoint fields when we make new checkpoints; this field is only defined in the first log file of a log group */ #define LOG_CHECKPOINT_2 (3 * OS_FILE_LOG_BLOCK_SIZE) /* second checkpoint field in the log header */ #define LOG_FILE_HDR_SIZE (4 * OS_FILE_LOG_BLOCK_SIZE) /** The state of a log group */ enum log_group_state_t { /** No corruption detected */ LOG_GROUP_OK, /** Corrupted */ LOG_GROUP_CORRUPTED }; typedef ib_mutex_t LogSysMutex; typedef ib_mutex_t FlushOrderMutex; /** Log group consists of a number of log files, each of the same size; a log group is implemented as a space in the sense of the module fil0fil. Currently, this is only protected by log_sys->mutex. However, in the case of log_write_up_to(), we will access some members only with the protection of log_sys->write_mutex, which should affect nothing for now. */ struct log_group_t{ /** number of files in the group */ ulint n_files; /** format of the redo log: e.g., LOG_HEADER_FORMAT_CURRENT */ ulint format; /** individual log file size in bytes, including the header */ lsn_t file_size; /** corruption status */ log_group_state_t state; /** lsn used to fix coordinates within the log group */ lsn_t lsn; /** the byte offset of the above lsn */ lsn_t lsn_offset; /** unaligned buffers */ byte** file_header_bufs_ptr; /** buffers for each file header in the group */ byte** file_header_bufs; /** used only in recovery: recovery scan succeeded up to this lsn in this log group */ lsn_t scanned_lsn; /** unaligned checkpoint header */ byte* checkpoint_buf_ptr; /** buffer for writing a checkpoint header */ byte* checkpoint_buf; /** @return whether the redo log is encrypted */ bool is_encrypted() const { return((format & LOG_HEADER_FORMAT_ENCRYPTED) != 0); } /** @return capacity in bytes */ inline lsn_t capacity() const { return((file_size - LOG_FILE_HDR_SIZE) * n_files); } }; /** Redo log buffer */ struct log_t{ char pad1[CACHE_LINE_SIZE]; /*!< Padding to prevent other memory update hotspots from residing on the same memory cache line */ lsn_t lsn; /*!< log sequence number */ ulint buf_free; /*!< first free offset within the log buffer in use */ char pad2[CACHE_LINE_SIZE];/*!< Padding */ LogSysMutex mutex; /*!< mutex protecting the log */ char pad3[CACHE_LINE_SIZE]; /*!< Padding */ LogSysMutex write_mutex; /*!< mutex protecting writing to log file and accessing to log_group_t */ char pad4[CACHE_LINE_SIZE];/*!< Padding */ FlushOrderMutex log_flush_order_mutex;/*!< mutex to serialize access to the flush list when we are putting dirty blocks in the list. The idea behind this mutex is to be able to release log_sys->mutex during mtr_commit and still ensure that insertions in the flush_list happen in the LSN order. */ byte* buf; /*!< Memory of double the buf_size is allocated here. This pointer will change however to either the first half or the second half in turns, so that log write/flush to disk don't block concurrent mtrs which will write log to this buffer. Care to switch back to the first half before freeing/resizing must be undertaken. */ bool first_in_use; /*!< true if buf points to the first half of the aligned(buf_ptr), false if the second half */ ulint buf_size; /*!< log buffer size of each in bytes */ ulint max_buf_free; /*!< recommended maximum value of buf_free for the buffer in use, after which the buffer is flushed */ bool check_flush_or_checkpoint; /*!< this is set when there may be need to flush the log buffer, or preflush buffer pool pages, or make a checkpoint; this MUST be TRUE when lsn - last_checkpoint_lsn > max_checkpoint_age; this flag is peeked at by log_free_check(), which does not reserve the log mutex */ /** the redo log */ log_group_t log; /** The fields involved in the log buffer flush @{ */ ulint buf_next_to_write;/*!< first offset in the log buffer where the byte content may not exist written to file, e.g., the start offset of a log record catenated later; this is advanced when a flush operation is completed to all the log groups */ volatile bool is_extending; /*!< this is set to true during extend the log buffer size */ lsn_t write_lsn; /*!< last written lsn */ lsn_t current_flush_lsn;/*!< end lsn for the current running write + flush operation */ lsn_t flushed_to_disk_lsn; /*!< how far we have written the log AND flushed to disk */ ulint n_pending_flushes;/*!< number of currently pending flushes; protected by log_sys_t::mutex */ os_event_t flush_event; /*!< this event is in the reset state when a flush is running; os_event_set() and os_event_reset() are protected by log_sys_t::mutex */ ulint n_log_ios; /*!< number of log i/os initiated thus far */ ulint n_log_ios_old; /*!< number of log i/o's at the previous printout */ time_t last_printout_time;/*!< when log_print was last time called */ /* @} */ /** Fields involved in checkpoints @{ */ lsn_t log_group_capacity; /*!< capacity of the log group; if the checkpoint age exceeds this, it is a serious error because it is possible we will then overwrite log and spoil crash recovery */ lsn_t max_modified_age_async; /*!< when this recommended value for lsn - buf_pool_get_oldest_modification() is exceeded, we start an asynchronous preflush of pool pages */ lsn_t max_modified_age_sync; /*!< when this recommended value for lsn - buf_pool_get_oldest_modification() is exceeded, we start a synchronous preflush of pool pages */ lsn_t max_checkpoint_age_async; /*!< when this checkpoint age is exceeded we start an asynchronous writing of a new checkpoint */ lsn_t max_checkpoint_age; /*!< this is the maximum allowed value for lsn - last_checkpoint_lsn when a new query step is started */ ib_uint64_t next_checkpoint_no; /*!< next checkpoint number */ lsn_t last_checkpoint_lsn; /*!< latest checkpoint lsn */ lsn_t next_checkpoint_lsn; /*!< next checkpoint lsn */ mtr_buf_t* append_on_checkpoint; /*!< extra redo log records to write during a checkpoint, or NULL if none. The pointer is protected by log_sys->mutex, and the data must remain constant as long as this pointer is not NULL. */ ulint n_pending_checkpoint_writes; /*!< number of currently pending checkpoint writes */ rw_lock_t checkpoint_lock;/*!< this latch is x-locked when a checkpoint write is running; a thread should wait for this without owning the log mutex */ byte* checkpoint_buf_ptr;/* unaligned checkpoint header */ byte* checkpoint_buf; /*!< checkpoint header is read to this buffer */ /* @} */ /** @return whether the redo log is encrypted */ bool is_encrypted() const { return(log.is_encrypted()); } }; /** Redo log system */ extern log_t* log_sys; /** Test if flush order mutex is owned. */ #define log_flush_order_mutex_own() \ mutex_own(&log_sys->log_flush_order_mutex) /** Acquire the flush order mutex. */ #define log_flush_order_mutex_enter() do { \ mutex_enter(&log_sys->log_flush_order_mutex); \ } while (0) /** Release the flush order mutex. */ # define log_flush_order_mutex_exit() do { \ mutex_exit(&log_sys->log_flush_order_mutex); \ } while (0) /** Test if log sys mutex is owned. */ #define log_mutex_own() mutex_own(&log_sys->mutex) /** Test if log sys write mutex is owned. */ #define log_write_mutex_own() mutex_own(&log_sys->write_mutex) /** Acquire the log sys mutex. */ #define log_mutex_enter() mutex_enter(&log_sys->mutex) /** Acquire the log sys write mutex. */ #define log_write_mutex_enter() mutex_enter(&log_sys->write_mutex) /** Acquire all the log sys mutexes. */ #define log_mutex_enter_all() do { \ mutex_enter(&log_sys->write_mutex); \ mutex_enter(&log_sys->mutex); \ } while (0) /** Release the log sys mutex. */ #define log_mutex_exit() mutex_exit(&log_sys->mutex) /** Release the log sys write mutex.*/ #define log_write_mutex_exit() mutex_exit(&log_sys->write_mutex) /** Release all the log sys mutexes. */ #define log_mutex_exit_all() do { \ mutex_exit(&log_sys->mutex); \ mutex_exit(&log_sys->write_mutex); \ } while (0) /** Calculate the offset of an lsn within a log group. @param[in] lsn log sequence number @param[in] group log group @return offset within the log group */ lsn_t log_group_calc_lsn_offset( lsn_t lsn, const log_group_t* group); /* log scrubbing speed, in bytes/sec */ extern ulonglong innodb_scrub_log_speed; /** Event to wake up log_scrub_thread */ extern os_event_t log_scrub_event; /** Whether log_scrub_thread is active */ extern bool log_scrub_thread_active; #include "log0log.ic" #endif