log.c
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上传日期:2022-05-23
资源大小:18897k
文件大小:29k
- /*-
- * See the file LICENSE for redistribution information.
- *
- * Copyright (c) 1996-2002
- * Sleepycat Software. All rights reserved.
- */
- #include "db_config.h"
- #ifndef lint
- static const char revid[] = "$Id: log.c,v 11.111 2002/08/16 00:27:44 ubell Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #include <ctype.h>
- #include <stdlib.h>
- #include <string.h>
- #include <unistd.h>
- #endif
- #include "db_int.h"
- #include "dbinc/crypto.h"
- #include "dbinc/hmac.h"
- #include "dbinc/log.h"
- #include "dbinc/txn.h"
- static int __log_init __P((DB_ENV *, DB_LOG *));
- static int __log_recover __P((DB_LOG *));
- static size_t __log_region_size __P((DB_ENV *));
- static int __log_zero __P((DB_ENV *, DB_LSN *, DB_LSN *));
- /*
- * __log_open --
- * Internal version of log_open: only called from DB_ENV->open.
- *
- * PUBLIC: int __log_open __P((DB_ENV *));
- */
- int
- __log_open(dbenv)
- DB_ENV *dbenv;
- {
- DB_LOG *dblp;
- LOG *lp;
- int ret;
- /* Create/initialize the DB_LOG structure. */
- if ((ret = __os_calloc(dbenv, 1, sizeof(DB_LOG), &dblp)) != 0)
- return (ret);
- dblp->dbenv = dbenv;
- /* Join/create the log region. */
- dblp->reginfo.type = REGION_TYPE_LOG;
- dblp->reginfo.id = INVALID_REGION_ID;
- dblp->reginfo.mode = dbenv->db_mode;
- dblp->reginfo.flags = REGION_JOIN_OK;
- if (F_ISSET(dbenv, DB_ENV_CREATE))
- F_SET(&dblp->reginfo, REGION_CREATE_OK);
- if ((ret = __db_r_attach(
- dbenv, &dblp->reginfo, __log_region_size(dbenv))) != 0)
- goto err;
- /* If we created the region, initialize it. */
- if (F_ISSET(&dblp->reginfo, REGION_CREATE))
- if ((ret = __log_init(dbenv, dblp)) != 0)
- goto err;
- /* Set the local addresses. */
- lp = dblp->reginfo.primary =
- R_ADDR(&dblp->reginfo, dblp->reginfo.rp->primary);
- /*
- * If the region is threaded, then we have to lock both the handles
- * and the region, and we need to allocate a mutex for that purpose.
- */
- if (F_ISSET(dbenv, DB_ENV_THREAD) &&
- (ret = __db_mutex_setup(dbenv, &dblp->reginfo, &dblp->mutexp,
- MUTEX_ALLOC | MUTEX_NO_RLOCK)) != 0)
- goto err;
- /* Initialize the rest of the structure. */
- dblp->bufp = R_ADDR(&dblp->reginfo, lp->buffer_off);
- /*
- * Set the handle -- we may be about to run recovery, which allocates
- * log cursors. Log cursors require logging be already configured,
- * and the handle being set is what demonstrates that.
- *
- * If we created the region, run recovery. If that fails, make sure
- * we reset the log handle before cleaning up, otherwise we will try
- * and clean up again in the mainline DB_ENV initialization code.
- */
- dbenv->lg_handle = dblp;
- if (F_ISSET(&dblp->reginfo, REGION_CREATE)) {
- if ((ret = __log_recover(dblp)) != 0) {
- dbenv->lg_handle = NULL;
- goto err;
- }
- /*
- * We first take the log file size from the environment, if
- * specified. If that wasn't set, recovery may have set it
- * from the persistent information in a log file header. If
- * that didn't set it either, we default.
- */
- if (lp->log_size == 0)
- lp->log_size = lp->log_nsize = LG_MAX_DEFAULT;
- } else {
- /*
- * A process joining the region may have reset the log file
- * size, too. If so, it only affects the next log file we
- * create.
- */
- if (dbenv->lg_size != 0)
- lp->log_nsize = dbenv->lg_size;
- }
- R_UNLOCK(dbenv, &dblp->reginfo);
- return (0);
- err: if (dblp->reginfo.addr != NULL) {
- if (F_ISSET(&dblp->reginfo, REGION_CREATE))
- ret = __db_panic(dbenv, ret);
- R_UNLOCK(dbenv, &dblp->reginfo);
- (void)__db_r_detach(dbenv, &dblp->reginfo, 0);
- }
- if (dblp->mutexp != NULL)
- __db_mutex_free(dbenv, &dblp->reginfo, dblp->mutexp);
- __os_free(dbenv, dblp);
- return (ret);
- }
- /*
- * __log_init --
- * Initialize a log region in shared memory.
- */
- static int
- __log_init(dbenv, dblp)
- DB_ENV *dbenv;
- DB_LOG *dblp;
- {
- DB_MUTEX *flush_mutexp;
- LOG *region;
- int ret;
- void *p;
- #ifdef HAVE_MUTEX_SYSTEM_RESOURCES
- u_int8_t *addr;
- #endif
- if ((ret = __db_shalloc(dblp->reginfo.addr,
- sizeof(*region), 0, &dblp->reginfo.primary)) != 0)
- goto mem_err;
- dblp->reginfo.rp->primary =
- R_OFFSET(&dblp->reginfo, dblp->reginfo.primary);
- region = dblp->reginfo.primary;
- memset(region, 0, sizeof(*region));
- region->fid_max = 0;
- SH_TAILQ_INIT(®ion->fq);
- region->free_fid_stack = INVALID_ROFF;
- region->free_fids = region->free_fids_alloced = 0;
- /* Initialize LOG LSNs. */
- INIT_LSN(region->lsn);
- INIT_LSN(region->ready_lsn);
- INIT_LSN(region->t_lsn);
- /*
- * It's possible to be waiting for an LSN of [1][0], if a replication
- * client gets the first log record out of order. An LSN of [0][0]
- * signifies that we're not waiting.
- */
- ZERO_LSN(region->waiting_lsn);
- /*
- * Log makes note of the fact that it ran into a checkpoint on
- * startup if it did so, as a recovery optimization. A zero
- * LSN signifies that it hasn't found one [yet].
- */
- ZERO_LSN(region->cached_ckp_lsn);
- #ifdef HAVE_MUTEX_SYSTEM_RESOURCES
- /* Allocate room for the log maintenance info and initialize it. */
- if ((ret = __db_shalloc(dblp->reginfo.addr,
- sizeof(REGMAINT) + LG_MAINT_SIZE, 0, &addr)) != 0)
- goto mem_err;
- __db_maintinit(&dblp->reginfo, addr, LG_MAINT_SIZE);
- region->maint_off = R_OFFSET(&dblp->reginfo, addr);
- #endif
- if ((ret = __db_mutex_setup(dbenv, &dblp->reginfo, ®ion->fq_mutex,
- MUTEX_NO_RLOCK)) != 0)
- return (ret);
- /*
- * We must create a place for the flush mutex separately; mutexes have
- * to be aligned to MUTEX_ALIGN, and the only way to guarantee that is
- * to make sure they're at the beginning of a shalloc'ed chunk.
- */
- if ((ret = __db_shalloc(dblp->reginfo.addr,
- sizeof(DB_MUTEX), MUTEX_ALIGN, &flush_mutexp)) != 0)
- goto mem_err;
- if ((ret = __db_mutex_setup(dbenv, &dblp->reginfo, flush_mutexp,
- MUTEX_NO_RLOCK)) != 0)
- return (ret);
- region->flush_mutex_off = R_OFFSET(&dblp->reginfo, flush_mutexp);
- /* Initialize the buffer. */
- if ((ret =
- __db_shalloc(dblp->reginfo.addr, dbenv->lg_bsize, 0, &p)) != 0) {
- mem_err: __db_err(dbenv, "Unable to allocate memory for the log buffer");
- return (ret);
- }
- region->buffer_size = dbenv->lg_bsize;
- region->buffer_off = R_OFFSET(&dblp->reginfo, p);
- region->log_size = region->log_nsize = dbenv->lg_size;
- /* Initialize the commit Queue. */
- SH_TAILQ_INIT(®ion->free_commits);
- SH_TAILQ_INIT(®ion->commits);
- region->ncommit = 0;
- /*
- * Fill in the log's persistent header. Don't fill in the log file
- * sizes, as they may change at any time and so have to be filled in
- * as each log file is created.
- */
- region->persist.magic = DB_LOGMAGIC;
- region->persist.version = DB_LOGVERSION;
- region->persist.mode = (u_int32_t)dbenv->db_mode;
- return (0);
- }
- /*
- * __log_recover --
- * Recover a log.
- */
- static int
- __log_recover(dblp)
- DB_LOG *dblp;
- {
- DBT dbt;
- DB_ENV *dbenv;
- DB_LOGC *logc;
- DB_LSN lsn;
- LOG *lp;
- u_int32_t cnt, rectype;
- int ret;
- logfile_validity status;
- logc = NULL;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /*
- * Find a log file. If none exist, we simply return, leaving
- * everything initialized to a new log.
- */
- if ((ret = __log_find(dblp, 0, &cnt, &status)) != 0)
- return (ret);
- if (cnt == 0)
- return (0);
- /*
- * If the last file is an old version, readable or no, start a new
- * file. Don't bother finding the end of the last log file;
- * we assume that it's valid in its entirety, since the user
- * should have shut down cleanly or run recovery before upgrading.
- */
- if (status == DB_LV_OLD_READABLE || status == DB_LV_OLD_UNREADABLE) {
- lp->lsn.file = lp->s_lsn.file = cnt + 1;
- lp->lsn.offset = lp->s_lsn.offset = 0;
- goto skipsearch;
- }
- DB_ASSERT(status == DB_LV_NORMAL);
- /*
- * We have the last useful log file and we've loaded any persistent
- * information. Set the end point of the log past the end of the last
- * file. Read the last file, looking for the last checkpoint and
- * the log's end.
- */
- lp->lsn.file = cnt + 1;
- lp->lsn.offset = 0;
- lsn.file = cnt;
- lsn.offset = 0;
- /*
- * Allocate a cursor and set it to the first record. This shouldn't
- * fail, leave error messages on.
- */
- if ((ret = dbenv->log_cursor(dbenv, &logc, 0)) != 0)
- return (ret);
- F_SET(logc, DB_LOG_LOCKED);
- memset(&dbt, 0, sizeof(dbt));
- if ((ret = logc->get(logc, &lsn, &dbt, DB_SET)) != 0)
- goto err;
- /*
- * Read to the end of the file. This may fail at some point, so
- * turn off error messages.
- */
- F_SET(logc, DB_LOG_SILENT_ERR);
- while (logc->get(logc, &lsn, &dbt, DB_NEXT) == 0) {
- if (dbt.size < sizeof(u_int32_t))
- continue;
- memcpy(&rectype, dbt.data, sizeof(u_int32_t));
- if (rectype == DB___txn_ckp)
- /*
- * If we happen to run into a checkpoint, cache its
- * LSN so that the transaction system doesn't have
- * to walk this log file again looking for it.
- */
- lp->cached_ckp_lsn = lsn;
- }
- F_CLR(logc, DB_LOG_SILENT_ERR);
- /*
- * We now know where the end of the log is. Set the first LSN that
- * we want to return to an application and the LSN of the last known
- * record on disk.
- */
- lp->lsn = lsn;
- lp->s_lsn = lsn;
- lp->lsn.offset += logc->c_len;
- lp->s_lsn.offset += logc->c_len;
- /* Set up the current buffer information, too. */
- lp->len = logc->c_len;
- lp->b_off = 0;
- lp->w_off = lp->lsn.offset;
- skipsearch:
- if (FLD_ISSET(dbenv->verbose, DB_VERB_RECOVERY))
- __db_err(dbenv,
- "Finding last valid log LSN: file: %lu offset %lu",
- (u_long)lp->lsn.file, (u_long)lp->lsn.offset);
- err: if (logc != NULL)
- (void)logc->close(logc, 0);
- return (ret);
- }
- /*
- * __log_find --
- * Try to find a log file. If find_first is set, valp will contain
- * the number of the first readable log file, else it will contain the number
- * of the last log file (which may be too old to read).
- *
- * PUBLIC: int __log_find __P((DB_LOG *, int, u_int32_t *, logfile_validity *));
- */
- int
- __log_find(dblp, find_first, valp, statusp)
- DB_LOG *dblp;
- int find_first;
- u_int32_t *valp;
- logfile_validity *statusp;
- {
- DB_ENV *dbenv;
- logfile_validity logval_status, status;
- u_int32_t clv, logval;
- int cnt, fcnt, ret;
- const char *dir;
- char *c, **names, *p, *q, savech;
- dbenv = dblp->dbenv;
- logval_status = status = DB_LV_NONEXISTENT;
- /* Return a value of 0 as the log file number on failure. */
- *valp = 0;
- /* Find the directory name. */
- if ((ret = __log_name(dblp, 1, &p, NULL, 0)) != 0)
- return (ret);
- if ((q = __db_rpath(p)) == NULL) {
- COMPQUIET(savech, 0);
- dir = PATH_DOT;
- } else {
- savech = *q;
- *q = ' ';
- dir = p;
- }
- /* Get the list of file names. */
- ret = __os_dirlist(dbenv, dir, &names, &fcnt);
- /*
- * !!!
- * We overwrote a byte in the string with a nul. Restore the string
- * so that the diagnostic checks in the memory allocation code work
- * and any error messages display the right file name.
- */
- if (q != NULL)
- *q = savech;
- if (ret != 0) {
- __db_err(dbenv, "%s: %s", dir, db_strerror(ret));
- __os_free(dbenv, p);
- return (ret);
- }
- /* Search for a valid log file name. */
- for (cnt = fcnt, clv = logval = 0; --cnt >= 0;) {
- if (strncmp(names[cnt], LFPREFIX, sizeof(LFPREFIX) - 1) != 0)
- continue;
- /*
- * Names of the form log.[0-9]* are reserved for DB. Other
- * names sharing LFPREFIX, such as "log.db", are legal.
- */
- for (c = names[cnt] + sizeof(LFPREFIX) - 1; *c != ' '; c++)
- if (!isdigit((int)*c))
- break;
- if (*c != ' ')
- continue;
- /*
- * Use atol, not atoi; if an "int" is 16-bits, the largest
- * log file name won't fit.
- */
- clv = atol(names[cnt] + (sizeof(LFPREFIX) - 1));
- /*
- * If searching for the first log file, we want to return the
- * oldest log file we can read, or, if no readable log files
- * exist, the newest log file we can't read (the crossover
- * point between the old and new versions of the log file).
- *
- * If we're searching for the last log file, we want to return
- * the newest log file, period.
- *
- * Readable log files should never preceede unreadable log
- * files, that would mean the admin seriously screwed up.
- */
- if (find_first) {
- if (logval != 0 &&
- status != DB_LV_OLD_UNREADABLE && clv > logval)
- continue;
- } else
- if (logval != 0 && clv < logval)
- continue;
- if ((ret = __log_valid(dblp, clv, 1, &status)) != 0) {
- __db_err(dbenv, "Invalid log file: %s: %s",
- names[cnt], db_strerror(ret));
- goto err;
- }
- switch (status) {
- case DB_LV_NONEXISTENT:
- /* __log_valid never returns DB_LV_NONEXISTENT. */
- DB_ASSERT(0);
- break;
- case DB_LV_INCOMPLETE:
- /*
- * The last log file may not have been initialized --
- * it's possible to create a log file but not write
- * anything to it. If performing recovery (that is,
- * if find_first isn't set), ignore the file, it's
- * not interesting. If we're searching for the first
- * log record, return the file (assuming we don't find
- * something better), as the "real" first log record
- * is likely to be in the log buffer, and we want to
- * set the file LSN for our return.
- */
- if (find_first)
- goto found;
- break;
- case DB_LV_OLD_UNREADABLE:
- /*
- * If we're searching for the first log file, then we
- * only want this file if we don't yet have a file or
- * already have an unreadable file and this one is
- * newer than that one. If we're searching for the
- * last log file, we always want this file because we
- * wouldn't be here if it wasn't newer than our current
- * choice.
- */
- if (!find_first || logval == 0 ||
- (status == DB_LV_OLD_UNREADABLE && clv > logval))
- goto found;
- break;
- case DB_LV_NORMAL:
- case DB_LV_OLD_READABLE:
- found: logval = clv;
- logval_status = status;
- break;
- }
- }
- *valp = logval;
- err: __os_dirfree(dbenv, names, fcnt);
- __os_free(dbenv, p);
- *statusp = logval_status;
- return (ret);
- }
- /*
- * log_valid --
- * Validate a log file. Returns an error code in the event of
- * a fatal flaw in a the specified log file; returns success with
- * a code indicating the currentness and completeness of the specified
- * log file if it is not unexpectedly flawed (that is, if it's perfectly
- * normal, if it's zero-length, or if it's an old version).
- *
- * PUBLIC: int __log_valid __P((DB_LOG *, u_int32_t, int, logfile_validity *));
- */
- int
- __log_valid(dblp, number, set_persist, statusp)
- DB_LOG *dblp;
- u_int32_t number;
- int set_persist;
- logfile_validity *statusp;
- {
- DB_CIPHER *db_cipher;
- DB_ENV *dbenv;
- DB_FH fh;
- HDR *hdr;
- LOG *region;
- LOGP *persist;
- logfile_validity status;
- size_t hdrsize, nw, recsize;
- int is_hmac, need_free, ret;
- u_int8_t *tmp;
- char *fname;
- dbenv = dblp->dbenv;
- db_cipher = dbenv->crypto_handle;
- persist = NULL;
- status = DB_LV_NORMAL;
- /* Try to open the log file. */
- if ((ret = __log_name(dblp,
- number, &fname, &fh, DB_OSO_RDONLY | DB_OSO_SEQ)) != 0) {
- __os_free(dbenv, fname);
- return (ret);
- }
- need_free = 0;
- hdrsize = HDR_NORMAL_SZ;
- is_hmac = 0;
- recsize = sizeof(LOGP);
- if (CRYPTO_ON(dbenv)) {
- hdrsize = HDR_CRYPTO_SZ;
- recsize = sizeof(LOGP);
- recsize += db_cipher->adj_size(recsize);
- is_hmac = 1;
- }
- if ((ret = __os_calloc(dbenv, 1, recsize + hdrsize, &tmp)) != 0)
- return (ret);
- need_free = 1;
- hdr = (HDR *)tmp;
- persist = (LOGP *)(tmp + hdrsize);
- /* Try to read the header. */
- if ((ret = __os_read(dbenv, &fh, tmp, recsize + hdrsize, &nw)) != 0 ||
- nw != recsize + hdrsize) {
- if (ret == 0)
- status = DB_LV_INCOMPLETE;
- else
- /*
- * The error was a fatal read error, not just an
- * incompletely initialized log file.
- */
- __db_err(dbenv, "Ignoring log file: %s: %s",
- fname, db_strerror(ret));
- (void)__os_closehandle(dbenv, &fh);
- goto err;
- }
- (void)__os_closehandle(dbenv, &fh);
- /*
- * Now we have to validate the persistent record. We have
- * several scenarios we have to deal with:
- *
- * 1. User has crypto turned on:
- * - They're reading an old, unencrypted log file
- * . We will fail the record size match check below.
- * - They're reading a current, unencrypted log file
- * . We will fail the record size match check below.
- * - They're reading an old, encrypted log file [NOT YET]
- * . After decryption we'll fail the version check. [NOT YET]
- * - They're reading a current, encrypted log file
- * . We should proceed as usual.
- * 2. User has crypto turned off:
- * - They're reading an old, unencrypted log file
- * . We will fail the version check.
- * - They're reading a current, unencrypted log file
- * . We should proceed as usual.
- * - They're reading an old, encrypted log file [NOT YET]
- * . We'll fail the magic number check (it is encrypted).
- * - They're reading a current, encrypted log file
- * . We'll fail the magic number check (it is encrypted).
- */
- if (CRYPTO_ON(dbenv)) {
- /*
- * If we are trying to decrypt an unencrypted log
- * we can only detect that by having an unreasonable
- * data length for our persistent data.
- */
- if ((hdr->len - hdrsize) != sizeof(LOGP)) {
- __db_err(dbenv, "log record size mismatch");
- goto err;
- }
- /* Check the checksum and decrypt. */
- if ((ret = __db_check_chksum(dbenv, db_cipher, &hdr->chksum[0],
- (u_int8_t *)persist, hdr->len - hdrsize, is_hmac)) != 0) {
- __db_err(dbenv, "log record checksum mismatch");
- goto err;
- }
- if ((ret = db_cipher->decrypt(dbenv, db_cipher->data,
- &hdr->iv[0], (u_int8_t *)persist, hdr->len - hdrsize)) != 0)
- goto err;
- }
- /* Validate the header. */
- if (persist->magic != DB_LOGMAGIC) {
- __db_err(dbenv,
- "Ignoring log file: %s: magic number %lx, not %lx",
- fname, (u_long)persist->magic, (u_long)DB_LOGMAGIC);
- ret = EINVAL;
- goto err;
- }
- /*
- * Set our status code to indicate whether the log file
- * belongs to an unreadable or readable old version; leave it
- * alone if and only if the log file version is the current one.
- */
- if (persist->version > DB_LOGVERSION) {
- /* This is a fatal error--the log file is newer than DB. */
- __db_err(dbenv,
- "Ignoring log file: %s: unsupported log version %lu",
- fname, (u_long)persist->version);
- ret = EINVAL;
- goto err;
- } else if (persist->version < DB_LOGOLDVER) {
- status = DB_LV_OLD_UNREADABLE;
- /*
- * We don't want to set persistent info based on an
- * unreadable region, so jump to "err".
- */
- goto err;
- } else if (persist->version < DB_LOGVERSION)
- status = DB_LV_OLD_READABLE;
- /*
- * Only if we have a current log do we verify the checksum.
- * We could not check the checksum before checking the magic
- * and version because old log hdrs have the length and checksum
- * in a different location.
- */
- if (!CRYPTO_ON(dbenv) && ((ret = __db_check_chksum(dbenv,
- db_cipher, &hdr->chksum[0], (u_int8_t *)persist,
- hdr->len - hdrsize, is_hmac)) != 0)) {
- __db_err(dbenv, "log record checksum mismatch");
- goto err;
- }
- /*
- * If the log is readable so far and we're doing system initialization,
- * set the region's persistent information based on the headers.
- *
- * Always set the current log file size. Only set the next log file's
- * size if the application hasn't set it already.
- *
- * XXX
- * Always use the persistent header's mode, regardless of what was set
- * in the current environment. We've always done it this way, but it's
- * probably a bug -- I can't think of a way not-changing the mode would
- * be a problem, though.
- */
- if (set_persist) {
- region = dblp->reginfo.primary;
- region->log_size = persist->log_size;
- if (region->log_nsize == 0)
- region->log_nsize = persist->log_size;
- region->persist.mode = persist->mode;
- }
- err: __os_free(dbenv, fname);
- if (need_free)
- __os_free(dbenv, tmp);
- *statusp = status;
- return (ret);
- }
- /*
- * __log_dbenv_refresh --
- * Clean up after the log system on a close or failed open. Called only
- * from __dbenv_refresh. (Formerly called __log_close.)
- *
- * PUBLIC: int __log_dbenv_refresh __P((DB_ENV *));
- */
- int
- __log_dbenv_refresh(dbenv)
- DB_ENV *dbenv;
- {
- DB_LOG *dblp;
- int ret, t_ret;
- dblp = dbenv->lg_handle;
- /* We may have opened files as part of XA; if so, close them. */
- F_SET(dblp, DBLOG_RECOVER);
- ret = __dbreg_close_files(dbenv);
- /* Discard the per-thread lock. */
- if (dblp->mutexp != NULL)
- __db_mutex_free(dbenv, &dblp->reginfo, dblp->mutexp);
- /* Detach from the region. */
- if ((t_ret =
- __db_r_detach(dbenv, &dblp->reginfo, 0)) != 0 && ret == 0)
- ret = t_ret;
- /* Close open files, release allocated memory. */
- if (F_ISSET(&dblp->lfh, DB_FH_VALID) &&
- (t_ret = __os_closehandle(dbenv, &dblp->lfh)) != 0 && ret == 0)
- ret = t_ret;
- if (dblp->dbentry != NULL)
- __os_free(dbenv, dblp->dbentry);
- __os_free(dbenv, dblp);
- dbenv->lg_handle = NULL;
- return (ret);
- }
- /*
- * __log_stat --
- * Return log statistics.
- *
- * PUBLIC: int __log_stat __P((DB_ENV *, DB_LOG_STAT **, u_int32_t));
- */
- int
- __log_stat(dbenv, statp, flags)
- DB_ENV *dbenv;
- DB_LOG_STAT **statp;
- u_int32_t flags;
- {
- DB_LOG *dblp;
- DB_LOG_STAT *stats;
- LOG *region;
- int ret;
- PANIC_CHECK(dbenv);
- ENV_REQUIRES_CONFIG(dbenv,
- dbenv->lg_handle, "DB_ENV->log_stat", DB_INIT_LOG);
- *statp = NULL;
- if ((ret = __db_fchk(dbenv,
- "DB_ENV->log_stat", flags, DB_STAT_CLEAR)) != 0)
- return (ret);
- dblp = dbenv->lg_handle;
- region = dblp->reginfo.primary;
- if ((ret = __os_umalloc(dbenv, sizeof(DB_LOG_STAT), &stats)) != 0)
- return (ret);
- /* Copy out the global statistics. */
- R_LOCK(dbenv, &dblp->reginfo);
- *stats = region->stat;
- if (LF_ISSET(DB_STAT_CLEAR))
- memset(®ion->stat, 0, sizeof(region->stat));
- stats->st_magic = region->persist.magic;
- stats->st_version = region->persist.version;
- stats->st_mode = region->persist.mode;
- stats->st_lg_bsize = region->buffer_size;
- stats->st_lg_size = region->log_nsize;
- stats->st_region_wait = dblp->reginfo.rp->mutex.mutex_set_wait;
- stats->st_region_nowait = dblp->reginfo.rp->mutex.mutex_set_nowait;
- if (LF_ISSET(DB_STAT_CLEAR)) {
- dblp->reginfo.rp->mutex.mutex_set_wait = 0;
- dblp->reginfo.rp->mutex.mutex_set_nowait = 0;
- }
- stats->st_regsize = dblp->reginfo.rp->size;
- stats->st_cur_file = region->lsn.file;
- stats->st_cur_offset = region->lsn.offset;
- stats->st_disk_file = region->s_lsn.file;
- stats->st_disk_offset = region->s_lsn.offset;
- R_UNLOCK(dbenv, &dblp->reginfo);
- *statp = stats;
- return (0);
- }
- /*
- * __log_get_cached_ckp_lsn --
- * Retrieve any last checkpoint LSN that we may have found on startup.
- *
- * PUBLIC: void __log_get_cached_ckp_lsn __P((DB_ENV *, DB_LSN *));
- */
- void
- __log_get_cached_ckp_lsn(dbenv, ckp_lsnp)
- DB_ENV *dbenv;
- DB_LSN *ckp_lsnp;
- {
- DB_LOG *dblp;
- LOG *lp;
- dblp = (DB_LOG *)dbenv->lg_handle;
- lp = (LOG *)dblp->reginfo.primary;
- R_LOCK(dbenv, &dblp->reginfo);
- *ckp_lsnp = lp->cached_ckp_lsn;
- R_UNLOCK(dbenv, &dblp->reginfo);
- }
- /*
- * __log_region_size --
- * Return the amount of space needed for the log region.
- * Make the region large enough to hold txn_max transaction
- * detail structures plus some space to hold thread handles
- * and the beginning of the shalloc region and anything we
- * need for mutex system resource recording.
- */
- static size_t
- __log_region_size(dbenv)
- DB_ENV *dbenv;
- {
- size_t s;
- s = dbenv->lg_regionmax + dbenv->lg_bsize;
- #ifdef HAVE_MUTEX_SYSTEM_RESOURCES
- if (F_ISSET(dbenv, DB_ENV_THREAD))
- s += sizeof(REGMAINT) + LG_MAINT_SIZE;
- #endif
- return (s);
- }
- /*
- * __log_region_destroy
- * Destroy any region maintenance info.
- *
- * PUBLIC: void __log_region_destroy __P((DB_ENV *, REGINFO *));
- */
- void
- __log_region_destroy(dbenv, infop)
- DB_ENV *dbenv;
- REGINFO *infop;
- {
- __db_shlocks_destroy(infop, (REGMAINT *)R_ADDR(infop,
- ((LOG *)R_ADDR(infop, infop->rp->primary))->maint_off));
- COMPQUIET(dbenv, NULL);
- COMPQUIET(infop, NULL);
- }
- /*
- * __log_vtruncate
- * This is a virtual truncate. We set up the log indicators to
- * make everyone believe that the given record is the last one in the
- * log. Returns with the next valid LSN (i.e., the LSN of the next
- * record to be written). This is used in replication to discard records
- * in the log file that do not agree with the master.
- *
- * PUBLIC: int __log_vtruncate __P((DB_ENV *, DB_LSN *, DB_LSN *));
- */
- int
- __log_vtruncate(dbenv, lsn, ckplsn)
- DB_ENV *dbenv;
- DB_LSN *lsn, *ckplsn;
- {
- DBT log_dbt;
- DB_FH fh;
- DB_LOG *dblp;
- DB_LOGC *logc;
- DB_LSN end_lsn;
- LOG *lp;
- u_int32_t bytes, c_len;
- int fn, ret, t_ret;
- char *fname;
- /* Need to find out the length of this soon-to-be-last record. */
- if ((ret = dbenv->log_cursor(dbenv, &logc, 0)) != 0)
- return (ret);
- memset(&log_dbt, 0, sizeof(log_dbt));
- ret = logc->get(logc, lsn, &log_dbt, DB_SET);
- c_len = logc->c_len;
- if ((t_ret = logc->close(logc, 0)) != 0 && ret == 0)
- ret = t_ret;
- if (ret != 0)
- return (ret);
- /* Now do the truncate. */
- dblp = (DB_LOG *)dbenv->lg_handle;
- lp = (LOG *)dblp->reginfo.primary;
- R_LOCK(dbenv, &dblp->reginfo);
- end_lsn = lp->lsn;
- lp->lsn = *lsn;
- lp->len = c_len;
- lp->lsn.offset += lp->len;
- /*
- * I am going to assume that the number of bytes written since
- * the last checkpoint doesn't exceed a 32-bit number.
- */
- DB_ASSERT(lp->lsn.file >= ckplsn->file);
- bytes = 0;
- if (ckplsn->file != lp->lsn.file) {
- bytes = lp->log_size - ckplsn->offset;
- if (lp->lsn.file > ckplsn->file + 1)
- bytes += lp->log_size *
- (lp->lsn.file - ckplsn->file - 1);
- bytes += lp->lsn.offset;
- } else
- bytes = lp->lsn.offset - ckplsn->offset;
- lp->stat.st_wc_mbytes += bytes / MEGABYTE;
- lp->stat.st_wc_bytes += bytes % MEGABYTE;
- /*
- * If the saved lsn is greater than our new end of log, reset it
- * to our current end of log.
- */
- if (log_compare(&lp->s_lsn, lsn) > 0)
- lp->s_lsn = lp->lsn;
- /*
- * If the new end of log is in the middle of the buffer,
- * don't change the w_off or f_lsn. If the new end is
- * before the w_off then reset w_off and f_lsn to the new
- * end of log.
- */
- if (lp->w_off >= lp->lsn.offset) {
- lp->f_lsn = lp->lsn;
- lp->w_off = lp->lsn.offset;
- lp->b_off = 0;
- } else
- lp->b_off = lp->lsn.offset - lp->w_off;
- ZERO_LSN(lp->waiting_lsn);
- lp->ready_lsn = lp->lsn;
- lp->wait_recs = 0;
- lp->rcvd_recs = 0;
- /* Now throw away any extra log files that we have around. */
- for (fn = lp->lsn.file + 1;; fn++) {
- if (__log_name(dblp, fn, &fname, &fh, DB_OSO_RDONLY) != 0) {
- __os_free(dbenv, fname);
- break;
- }
- (void)__os_closehandle(dbenv, &fh);
- ret = __os_unlink(dbenv, fname);
- __os_free(dbenv, fname);
- if (ret != 0)
- goto err;
- }
- /* Truncate the log to the new point. */
- if ((ret = __log_zero(dbenv, &lp->lsn, &end_lsn)) != 0)
- goto err;
- err: R_UNLOCK(dbenv, &dblp->reginfo);
- return (ret);
- }
- /*
- * __log_is_outdated --
- * Used by the replication system to identify if a client's logs
- * are too old. The log represented by dbenv is compared to the file
- * number passed in fnum. If the log file fnum does not exist and is
- * lower-numbered than the current logs, the we return *outdatedp non
- * zero, else we return it 0.
- *
- * PUBLIC: int __log_is_outdated __P((DB_ENV *dbenv,
- * PUBLIC: u_int32_t fnum, int *outdatedp));
- */
- int
- __log_is_outdated(dbenv, fnum, outdatedp)
- DB_ENV *dbenv;
- u_int32_t fnum;
- int *outdatedp;
- {
- DB_LOG *dblp;
- LOG *lp;
- char *name;
- int ret;
- u_int32_t cfile;
- dblp = dbenv->lg_handle;
- *outdatedp = 0;
- if ((ret = __log_name(dblp, fnum, &name, NULL, 0)) != 0)
- return (ret);
- /* If the file exists, we're just fine. */
- if (__os_exists(name, NULL) == 0)
- goto out;
- /*
- * It didn't exist, decide if the file number is too big or
- * too little. If it's too little, then we need to indicate
- * that the LSN is outdated.
- */
- R_LOCK(dbenv, &dblp->reginfo);
- lp = (LOG *)dblp->reginfo.primary;
- cfile = lp->lsn.file;
- R_UNLOCK(dbenv, &dblp->reginfo);
- if (cfile > fnum)
- *outdatedp = 1;
- out: __os_free(dbenv, name);
- return (ret);
- }
- /*
- * __log_zero --
- * Zero out the tail of a log after a truncate.
- */
- static int
- __log_zero(dbenv, from_lsn, to_lsn)
- DB_ENV *dbenv;
- DB_LSN *from_lsn, *to_lsn;
- {
- char *lname;
- DB_LOG *dblp;
- LOG *lp;
- int ret;
- size_t nbytes, len, nw;
- u_int8_t buf[4096];
- u_int32_t mbytes, bytes;
- dblp = dbenv->lg_handle;
- lp = (LOG *)dblp->reginfo.primary;
- lname = NULL;
- if (dblp->lfname != lp->lsn.file) {
- if (F_ISSET(&dblp->lfh, DB_FH_VALID))
- (void)__os_closehandle(dbenv, &dblp->lfh);
- dblp->lfname = lp->lsn.file;
- }
- if (from_lsn->file != to_lsn->file) {
- /* We removed some log files; have to 0 to end of file. */
- if (!F_ISSET(&dblp->lfh, DB_FH_VALID) && (ret =
- __log_name(dblp, dblp->lfname, &lname, &dblp->lfh, 0)) != 0)
- return (ret);
- if ((ret = __os_ioinfo(dbenv,
- NULL, &dblp->lfh, &mbytes, &bytes, NULL)) != 0)
- goto err;
- len = mbytes * MEGABYTE + bytes - from_lsn->offset;
- } else if (to_lsn->offset <= from_lsn->offset)
- return (0);
- else
- len = to_lsn->offset = from_lsn->offset;
- memset(buf, 0, sizeof(buf));
- /* Initialize the write position. */
- if (!F_ISSET(&dblp->lfh, DB_FH_VALID) &&
- (ret = __log_name(dblp, dblp->lfname, &lname, &dblp->lfh, 0)) != 0)
- goto err;
- if ((ret = __os_seek(dbenv,
- &dblp->lfh, 0, 0, from_lsn->offset, 0, DB_OS_SEEK_SET)) != 0)
- return (ret);
- while (len > 0) {
- nbytes = len > sizeof(buf) ? sizeof(buf) : len;
- if ((ret =
- __os_write(dbenv, &dblp->lfh, buf, nbytes, &nw)) != 0)
- return (ret);
- len -= nbytes;
- }
- err: if (lname != NULL)
- __os_free(dbenv, lname);
- return (0);
- }