diff options
Diffstat (limited to 'storage/bdb/db/db_meta.c')
| -rw-r--r-- | storage/bdb/db/db_meta.c | 452 |
1 files changed, 452 insertions, 0 deletions
diff --git a/storage/bdb/db/db_meta.c b/storage/bdb/db/db_meta.c new file mode 100644 index 00000000000..015ef5c8fc7 --- /dev/null +++ b/storage/bdb/db/db_meta.c @@ -0,0 +1,452 @@ +/*- + * See the file LICENSE for redistribution information. + * + * Copyright (c) 1996-2002 + * Sleepycat Software. All rights reserved. + */ +/* + * Copyright (c) 1990, 1993, 1994, 1995, 1996 + * Keith Bostic. All rights reserved. + */ +/* + * Copyright (c) 1990, 1993, 1994, 1995 + * The Regents of the University of California. All rights reserved. + * + * This code is derived from software contributed to Berkeley by + * Mike Olson. + * + * Redistribution and use in source and binary forms, with or without + * modification, are permitted provided that the following conditions + * are met: + * 1. Redistributions of source code must retain the above copyright + * notice, this list of conditions and the following disclaimer. + * 2. Redistributions in binary form must reproduce the above copyright + * notice, this list of conditions and the following disclaimer in the + * documentation and/or other materials provided with the distribution. + * 3. Neither the name of the University nor the names of its contributors + * may be used to endorse or promote products derived from this software + * without specific prior written permission. + * + * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND + * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE + * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE + * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE + * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL + * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS + * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) + * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT + * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY + * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF + * SUCH DAMAGE. + */ + +#include "db_config.h" + +#ifndef lint +static const char revid[] = "$Id: db_meta.c,v 11.61 2002/08/08 03:57:48 bostic Exp $"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <string.h> +#endif + +#include "db_int.h" +#include "dbinc/db_page.h" +#include "dbinc/db_shash.h" +#include "dbinc/lock.h" +#include "dbinc/db_am.h" + +static void __db_init_meta __P((void *, u_int32_t, db_pgno_t, u_int32_t)); + +/* + * __db_init_meta -- + * Helper function for __db_new that initializes the important fields in + * a meta-data page (used instead of P_INIT). We need to make sure that we + * retain the page number and LSN of the existing page. + */ +static void +__db_init_meta(p, pgsize, pgno, pgtype) + void *p; + u_int32_t pgsize; + db_pgno_t pgno; + u_int32_t pgtype; +{ + DB_LSN save_lsn; + DBMETA *meta; + + meta = (DBMETA *)p; + save_lsn = meta->lsn; + memset(meta, 0, sizeof(DBMETA)); + meta->lsn = save_lsn; + meta->pagesize = pgsize; + meta->pgno = pgno; + meta->type = (u_int8_t)pgtype; +} + +/* + * __db_new -- + * Get a new page, preferably from the freelist. + * + * PUBLIC: int __db_new __P((DBC *, u_int32_t, PAGE **)); + */ +int +__db_new(dbc, type, pagepp) + DBC *dbc; + u_int32_t type; + PAGE **pagepp; +{ + DBMETA *meta; + DB *dbp; + DB_LOCK metalock; + DB_LSN lsn; + DB_MPOOLFILE *mpf; + PAGE *h; + db_pgno_t pgno, newnext; + int meta_flags, extend, ret; + + meta = NULL; + meta_flags = 0; + dbp = dbc->dbp; + mpf = dbp->mpf; + h = NULL; + newnext = PGNO_INVALID; + + pgno = PGNO_BASE_MD; + if ((ret = __db_lget(dbc, + LCK_ALWAYS, pgno, DB_LOCK_WRITE, 0, &metalock)) != 0) + goto err; + if ((ret = mpf->get(mpf, &pgno, 0, (PAGE **)&meta)) != 0) + goto err; + if (meta->free == PGNO_INVALID) { + pgno = meta->last_pgno + 1; + ZERO_LSN(lsn); + extend = 1; + } else { + pgno = meta->free; + if ((ret = mpf->get(mpf, &pgno, 0, &h)) != 0) + goto err; + + /* + * We want to take the first page off the free list and + * then set meta->free to the that page's next_pgno, but + * we need to log the change first. + */ + newnext = h->next_pgno; + lsn = h->lsn; + extend = 0; + } + + /* + * Log the allocation before fetching the new page. If we + * don't have room in the log then we don't want to tell + * mpool to extend the file. + */ + if (DBC_LOGGING(dbc)) { + if ((ret = __db_pg_alloc_log(dbp, dbc->txn, &LSN(meta), 0, + &LSN(meta), PGNO_BASE_MD, &lsn, pgno, + (u_int32_t)type, newnext)) != 0) + goto err; + } else + LSN_NOT_LOGGED(LSN(meta)); + + meta_flags = DB_MPOOL_DIRTY; + meta->free = newnext; + + if (extend == 1) { + meta->last_pgno++; + if ((ret = mpf->get(mpf, &pgno, DB_MPOOL_NEW, &h)) != 0) + goto err; + ZERO_LSN(h->lsn); + h->pgno = pgno; + DB_ASSERT(pgno == meta->last_pgno); + } + LSN(h) = LSN(meta); + + DB_ASSERT(TYPE(h) == P_INVALID); + + if (TYPE(h) != P_INVALID) + return (__db_panic(dbp->dbenv, EINVAL)); + + (void)mpf->put(mpf, (PAGE *)meta, DB_MPOOL_DIRTY); + (void)__TLPUT(dbc, metalock); + + switch (type) { + case P_BTREEMETA: + case P_HASHMETA: + case P_QAMMETA: + __db_init_meta(h, dbp->pgsize, h->pgno, type); + break; + default: + P_INIT(h, dbp->pgsize, + h->pgno, PGNO_INVALID, PGNO_INVALID, 0, type); + break; + } + + /* + * If dirty reads are enabled and we are in a transaction, we could + * abort this allocation after the page(s) pointing to this + * one have their locks downgraded. This would permit dirty readers + * to access this page which is ok, but they must be off the + * page when we abort. This will also prevent updates happening + * to this page until we commit. + */ + if (F_ISSET(dbc->dbp, DB_AM_DIRTY) && dbc->txn != NULL) { + if ((ret = __db_lget(dbc, 0, + h->pgno, DB_LOCK_WWRITE, 0, &metalock)) != 0) + goto err; + } + *pagepp = h; + return (0); + +err: if (h != NULL) + (void)mpf->put(mpf, h, 0); + if (meta != NULL) + (void)mpf->put(mpf, meta, meta_flags); + (void)__TLPUT(dbc, metalock); + return (ret); +} + +/* + * __db_free -- + * Add a page to the head of the freelist. + * + * PUBLIC: int __db_free __P((DBC *, PAGE *)); + */ +int +__db_free(dbc, h) + DBC *dbc; + PAGE *h; +{ + DBMETA *meta; + DB *dbp; + DBT ldbt; + DB_LOCK metalock; + DB_MPOOLFILE *mpf; + db_pgno_t pgno; + u_int32_t dirty_flag; + int ret, t_ret; + + dbp = dbc->dbp; + mpf = dbp->mpf; + + /* + * Retrieve the metadata page and insert the page at the head of + * the free list. If either the lock get or page get routines + * fail, then we need to put the page with which we were called + * back because our caller assumes we take care of it. + */ + dirty_flag = 0; + pgno = PGNO_BASE_MD; + if ((ret = __db_lget(dbc, + LCK_ALWAYS, pgno, DB_LOCK_WRITE, 0, &metalock)) != 0) + goto err; + if ((ret = mpf->get(mpf, &pgno, 0, (PAGE **)&meta)) != 0) { + (void)__TLPUT(dbc, metalock); + goto err; + } + + DB_ASSERT(h->pgno != meta->free); + /* Log the change. */ + if (DBC_LOGGING(dbc)) { + memset(&ldbt, 0, sizeof(ldbt)); + ldbt.data = h; + ldbt.size = P_OVERHEAD(dbp); + if ((ret = __db_pg_free_log(dbp, + dbc->txn, &LSN(meta), 0, h->pgno, + &LSN(meta), PGNO_BASE_MD, &ldbt, meta->free)) != 0) { + (void)mpf->put(mpf, (PAGE *)meta, 0); + (void)__TLPUT(dbc, metalock); + goto err; + } + } else + LSN_NOT_LOGGED(LSN(meta)); + LSN(h) = LSN(meta); + + P_INIT(h, dbp->pgsize, h->pgno, PGNO_INVALID, meta->free, 0, P_INVALID); + + meta->free = h->pgno; + + /* Discard the metadata page. */ + if ((t_ret = + mpf->put(mpf, (PAGE *)meta, DB_MPOOL_DIRTY)) != 0 && ret == 0) + ret = t_ret; + if ((t_ret = __TLPUT(dbc, metalock)) != 0 && ret == 0) + ret = t_ret; + + /* Discard the caller's page reference. */ + dirty_flag = DB_MPOOL_DIRTY; +err: if ((t_ret = mpf->put(mpf, h, dirty_flag)) != 0 && ret == 0) + ret = t_ret; + + /* + * XXX + * We have to unlock the caller's page in the caller! + */ + return (ret); +} + +#ifdef DEBUG +/* + * __db_lprint -- + * Print out the list of locks currently held by a cursor. + * + * PUBLIC: int __db_lprint __P((DBC *)); + */ +int +__db_lprint(dbc) + DBC *dbc; +{ + DB *dbp; + DB_LOCKREQ req; + + dbp = dbc->dbp; + + if (LOCKING_ON(dbp->dbenv)) { + req.op = DB_LOCK_DUMP; + dbp->dbenv->lock_vec(dbp->dbenv, dbc->locker, 0, &req, 1, NULL); + } + return (0); +} +#endif + +/* + * Implement the rules for transactional locking. We can release the previous + * lock if we are not in a transaction or COUPLE_ALWAYS is specifed (used in + * record locking). If we are doing dirty reads then we can release read locks + * and down grade write locks. + */ +#define DB_PUT_ACTION(dbc, action, lockp) \ + (((action == LCK_COUPLE || action == LCK_COUPLE_ALWAYS) && \ + LOCK_ISSET(*lockp)) ? \ + (dbc->txn == NULL || action == LCK_COUPLE_ALWAYS || \ + (F_ISSET(dbc, DBC_DIRTY_READ) && \ + (lockp)->mode == DB_LOCK_DIRTY)) ? LCK_COUPLE : \ + (F_ISSET((dbc)->dbp, DB_AM_DIRTY) && \ + (lockp)->mode == DB_LOCK_WRITE) ? LCK_DOWNGRADE : 0 : 0) + +/* + * __db_lget -- + * The standard lock get call. + * + * PUBLIC: int __db_lget __P((DBC *, + * PUBLIC: int, db_pgno_t, db_lockmode_t, u_int32_t, DB_LOCK *)); + */ +int +__db_lget(dbc, action, pgno, mode, lkflags, lockp) + DBC *dbc; + int action; + db_pgno_t pgno; + db_lockmode_t mode; + u_int32_t lkflags; + DB_LOCK *lockp; +{ + DB *dbp; + DB_ENV *dbenv; + DB_LOCKREQ couple[2], *reqp; + DB_TXN *txn; + int has_timeout, ret; + + dbp = dbc->dbp; + dbenv = dbp->dbenv; + txn = dbc->txn; + + /* + * We do not always check if we're configured for locking before + * calling __db_lget to acquire the lock. + */ + if (CDB_LOCKING(dbenv) || + !LOCKING_ON(dbenv) || F_ISSET(dbc, DBC_COMPENSATE) || + (F_ISSET(dbc, DBC_RECOVER) && + (action != LCK_ROLLBACK || F_ISSET(dbenv, DB_ENV_REP_CLIENT))) || + (action != LCK_ALWAYS && F_ISSET(dbc, DBC_OPD))) { + LOCK_INIT(*lockp); + return (0); + } + + dbc->lock.pgno = pgno; + if (lkflags & DB_LOCK_RECORD) + dbc->lock.type = DB_RECORD_LOCK; + else + dbc->lock.type = DB_PAGE_LOCK; + lkflags &= ~DB_LOCK_RECORD; + + /* + * If the transaction enclosing this cursor has DB_LOCK_NOWAIT set, + * pass that along to the lock call. + */ + if (DB_NONBLOCK(dbc)) + lkflags |= DB_LOCK_NOWAIT; + + if (F_ISSET(dbc, DBC_DIRTY_READ) && mode == DB_LOCK_READ) + mode = DB_LOCK_DIRTY; + + has_timeout = txn != NULL && F_ISSET(txn, TXN_LOCKTIMEOUT); + + switch (DB_PUT_ACTION(dbc, action, lockp)) { + case LCK_COUPLE: +lck_couple: couple[0].op = has_timeout? DB_LOCK_GET_TIMEOUT : DB_LOCK_GET; + couple[0].obj = &dbc->lock_dbt; + couple[0].mode = mode; + if (action == LCK_COUPLE_ALWAYS) + action = LCK_COUPLE; + UMRW_SET(couple[0].timeout); + if (has_timeout) + couple[0].timeout = txn->lock_timeout; + if (action == LCK_COUPLE) { + couple[1].op = DB_LOCK_PUT; + couple[1].lock = *lockp; + } + + ret = dbenv->lock_vec(dbenv, dbc->locker, + lkflags, couple, action == LCK_COUPLE ? 2 : 1, &reqp); + if (ret == 0 || reqp == &couple[1]) + *lockp = couple[0].lock; + break; + case LCK_DOWNGRADE: + if ((ret = dbenv->lock_downgrade( + dbenv, lockp, DB_LOCK_WWRITE, 0)) != 0) + return (ret); + /* FALL THROUGH */ + default: + if (has_timeout) + goto lck_couple; + ret = dbenv->lock_get(dbenv, + dbc->locker, lkflags, &dbc->lock_dbt, mode, lockp); + break; + } + + return (ret); +} + +/* + * __db_lput -- + * The standard lock put call. + * + * PUBLIC: int __db_lput __P((DBC *, DB_LOCK *)); + */ +int +__db_lput(dbc, lockp) + DBC *dbc; + DB_LOCK *lockp; +{ + DB_ENV *dbenv; + int ret; + + dbenv = dbc->dbp->dbenv; + + switch (DB_PUT_ACTION(dbc, LCK_COUPLE, lockp)) { + case LCK_COUPLE: + ret = dbenv->lock_put(dbenv, lockp); + break; + case LCK_DOWNGRADE: + ret = __lock_downgrade(dbenv, lockp, DB_LOCK_WWRITE, 0); + break; + default: + ret = 0; + break; + } + + return (ret); +} |