/*- * See the file LICENSE for redistribution information. * * Copyright (c) 1996-2002 * Sleepycat Software. All rights reserved. */ /* * Copyright (c) 1995, 1996 * The President and Fellows of Harvard University. All rights reserved. * * This code is derived from software contributed to Berkeley by * Margo Seltzer. * * 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: txn.c,v 1.1.1.1 2003/02/15 04:56:20 zarzycki Exp $"; #endif /* not lint */ #ifndef NO_SYSTEM_INCLUDES #include #include #if TIME_WITH_SYS_TIME #include #include #else #if HAVE_SYS_TIME_H #include #else #include #endif #endif #include #endif #include "db_int.h" #include "dbinc/crypto.h" #include "dbinc/hmac.h" #include "dbinc/db_page.h" #include "dbinc/db_shash.h" #include "dbinc/hash.h" #include "dbinc/lock.h" #include "dbinc/log.h" #include "dbinc/txn.h" #define SET_LOG_FLAGS(dbenv, txnp, lflags) \ do { \ lflags = DB_COMMIT | DB_PERMANENT; \ if (F_ISSET(txnp, TXN_SYNC)) \ lflags |= DB_FLUSH; \ else if (!F_ISSET(txnp, TXN_NOSYNC) && \ !F_ISSET(dbenv, DB_ENV_TXN_NOSYNC)) { \ if (F_ISSET(dbenv, DB_ENV_TXN_WRITE_NOSYNC)) \ lflags |= DB_WRNOSYNC; \ else \ lflags |= DB_FLUSH; \ } \ } while (0) /* * __txn_isvalid enumerated types. We cannot simply use the transaction * statuses, because different statuses need to be handled differently * depending on the caller. */ typedef enum { TXN_OP_ABORT, TXN_OP_COMMIT, TXN_OP_DISCARD, TXN_OP_PREPARE } txnop_t; static int __txn_begin_int __P((DB_TXN *, int)); static int __txn_end __P((DB_TXN *, int)); static int __txn_isvalid __P((const DB_TXN *, TXN_DETAIL **, txnop_t)); static int __txn_set_timeout __P(( DB_TXN *, db_timeout_t, u_int32_t)); static int __txn_undo __P((DB_TXN *)); #ifndef db_create /* * txn_abort -- * txn_begin -- * txn_commit -- * * When we switched to methods in 4.0, we guessed txn_{abort,begin,commit} * were the interfaces applications would likely use and not be willing to * change, due to the sheer volume of the calls. Provide wrappers -- we * could do txn_abort and txn_commit using macros, but not txn_begin, as * the name of the field is txn_begin, we didn't want to modify it. * * The issue with txn_begin hits us in another way. If configured with the * --with-uniquename option, we use #defines to re-define DB's interfaces * to unique names. We can't do that for these functions because txn_begin * is also a field name in the DB_ENV structure, and the #defines we use go * at the end of the db.h file -- we get control too late to #define a field * name. So, modify the script that generates the unique names #defines to * not generate them for these three functions, and don't include the three * functions in libraries built with that configuration option. * * EXTERN: int txn_abort __P((DB_TXN *)); * EXTERN: int txn_begin __P((DB_ENV *, DB_TXN *, DB_TXN **, u_int32_t)); * EXTERN: int txn_commit __P((DB_TXN *, u_int32_t)); */ int txn_abort(txnp) DB_TXN *txnp; { return (txnp->abort(txnp)); } int txn_begin(dbenv, parent, txnpp, flags) DB_ENV *dbenv; DB_TXN *parent, **txnpp; u_int32_t flags; { return (dbenv->txn_begin(dbenv, parent, txnpp, flags)); } int txn_commit(txnp, flags) DB_TXN *txnp; u_int32_t flags; { return (txnp->commit(txnp, flags)); } #endif /* !db_create */ /* * __txn_begin -- * This is a wrapper to the actual begin process. Normal transaction * begin allocates a DB_TXN structure for the caller, while XA transaction * begin does not. Other than that, both call into common __txn_begin_int * code. * * Internally, we use TXN_DETAIL structures, but the DB_TXN structure * provides access to the transaction ID and the offset in the transaction * region of the TXN_DETAIL structure. * * PUBLIC: int __txn_begin __P((DB_ENV *, DB_TXN *, DB_TXN **, u_int32_t)); */ int __txn_begin(dbenv, parent, txnpp, flags) DB_ENV *dbenv; DB_TXN *parent, **txnpp; u_int32_t flags; { DB_LOCKREGION *region; DB_TXN *txn; int ret; *txnpp = NULL; PANIC_CHECK(dbenv); ENV_REQUIRES_CONFIG(dbenv, dbenv->tx_handle, "txn_begin", DB_INIT_TXN); if ((ret = __db_fchk(dbenv, "txn_begin", flags, DB_DIRTY_READ | DB_TXN_NOWAIT | DB_TXN_NOSYNC | DB_TXN_SYNC)) != 0) return (ret); if ((ret = __db_fcchk(dbenv, "txn_begin", flags, DB_TXN_NOSYNC, DB_TXN_SYNC)) != 0) return (ret); if ((ret = __os_calloc(dbenv, 1, sizeof(DB_TXN), &txn)) != 0) return (ret); txn->mgrp = dbenv->tx_handle; txn->parent = parent; TAILQ_INIT(&txn->kids); TAILQ_INIT(&txn->events); txn->flags = TXN_MALLOC; if (LF_ISSET(DB_DIRTY_READ)) F_SET(txn, TXN_DIRTY_READ); if (LF_ISSET(DB_TXN_NOSYNC)) F_SET(txn, TXN_NOSYNC); if (LF_ISSET(DB_TXN_SYNC)) F_SET(txn, TXN_SYNC); if (LF_ISSET(DB_TXN_NOWAIT)) F_SET(txn, TXN_NOWAIT); if ((ret = __txn_begin_int(txn, 0)) != 0) goto err; if (parent != NULL) TAILQ_INSERT_HEAD(&parent->kids, txn, klinks); if (LOCKING_ON(dbenv)) { region = ((DB_LOCKTAB *)dbenv->lk_handle)->reginfo.primary; if (parent != NULL) { ret = __lock_inherit_timeout(dbenv, parent->txnid, txn->txnid); /* No parent locker set yet. */ if (ret == EINVAL) { parent = NULL; ret = 0; } if (ret != 0) goto err; } /* * Parent is NULL if we have no parent * or it has no timeouts set. */ if (parent == NULL && region->tx_timeout != 0) if ((ret = __lock_set_timeout(dbenv, txn->txnid, region->tx_timeout, DB_SET_TXN_TIMEOUT)) != 0) goto err; } *txnpp = txn; return (0); err: __os_free(dbenv, txn); return (ret); } /* * __txn_xa_begin -- * XA version of txn_begin. * * PUBLIC: int __txn_xa_begin __P((DB_ENV *, DB_TXN *)); */ int __txn_xa_begin(dbenv, txn) DB_ENV *dbenv; DB_TXN *txn; { PANIC_CHECK(dbenv); memset(txn, 0, sizeof(DB_TXN)); txn->mgrp = dbenv->tx_handle; TAILQ_INIT(&txn->kids); TAILQ_INIT(&txn->events); return (__txn_begin_int(txn, 0)); } /* * __txn_compensate_begin * Begin an compensation transaction. This is a special interface * that is used only for transactions that must be started to compensate * for actions during an abort. Currently only used for allocations. * * PUBLIC: int __txn_compensate_begin __P((DB_ENV *, DB_TXN **txnp)); */ int __txn_compensate_begin(dbenv, txnpp) DB_ENV *dbenv; DB_TXN **txnpp; { DB_TXN *txn; int ret; PANIC_CHECK(dbenv); if ((ret = __os_calloc(dbenv, 1, sizeof(DB_TXN), &txn)) != 0) return (ret); txn->mgrp = dbenv->tx_handle; TAILQ_INIT(&txn->kids); TAILQ_INIT(&txn->events); txn->flags = TXN_MALLOC; F_SET(txn, TXN_COMPENSATE); *txnpp = txn; return (__txn_begin_int(txn, 1)); } /* * __txn_begin_int -- * Normal DB version of txn_begin. */ static int __txn_begin_int(txn, internal) DB_TXN *txn; int internal; { DB_ENV *dbenv; DB_LSN begin_lsn, null_lsn; DB_TXNMGR *mgr; DB_TXNREGION *region; TXN_DETAIL *td; size_t off; u_int32_t id, *ids; int nids, ret; mgr = txn->mgrp; dbenv = mgr->dbenv; region = mgr->reginfo.primary; /* * We do not have to write begin records (and if we do not, then we * need never write records for read-only transactions). However, * we do need to find the current LSN so that we can store it in the * transaction structure, so we can know where to take checkpoints. * * XXX * We should set this value when we write the first log record, not * here. */ if (DBENV_LOGGING(dbenv)) __log_txn_lsn(dbenv, &begin_lsn, NULL, NULL); R_LOCK(dbenv, &mgr->reginfo); if (!F_ISSET(txn, TXN_COMPENSATE) && F_ISSET(region, TXN_IN_RECOVERY)) { __db_err(dbenv, "operation not permitted during recovery"); ret = EINVAL; goto err; } /* Make sure that we aren't still recovering prepared transactions. */ if (!internal && region->stat.st_nrestores != 0) { __db_err(dbenv, "recovery of prepared but not yet committed transactions is incomplete"); ret = EINVAL; goto err; } /* * Allocate a new transaction id. Our current valid range can span * the maximum valid value, so check for it and wrap manually. */ if (region->last_txnid == TXN_MAXIMUM && region->cur_maxid != TXN_MAXIMUM) region->last_txnid = TXN_MINIMUM - 1; if (region->last_txnid == region->cur_maxid) { if ((ret = __os_malloc(dbenv, sizeof(u_int32_t) * region->maxtxns, &ids)) != 0) goto err; nids = 0; for (td = SH_TAILQ_FIRST(®ion->active_txn, __txn_detail); td != NULL; td = SH_TAILQ_NEXT(td, links, __txn_detail)) ids[nids++] = td->txnid; region->last_txnid = TXN_MINIMUM - 1; region->cur_maxid = TXN_MAXIMUM; if (nids != 0) __db_idspace(ids, nids, ®ion->last_txnid, ®ion->cur_maxid); __os_free(dbenv, ids); if (DBENV_LOGGING(dbenv) && (ret = __txn_recycle_log(dbenv, NULL, &null_lsn, 0, region->last_txnid, region->cur_maxid)) != 0) goto err; } /* Allocate a new transaction detail structure. */ if ((ret = __db_shalloc(mgr->reginfo.addr, sizeof(TXN_DETAIL), 0, &td)) != 0) { __db_err(dbenv, "Unable to allocate memory for transaction detail"); goto err; } /* Place transaction on active transaction list. */ SH_TAILQ_INSERT_HEAD(®ion->active_txn, td, links, __txn_detail); id = ++region->last_txnid; ++region->stat.st_nbegins; if (++region->stat.st_nactive > region->stat.st_maxnactive) region->stat.st_maxnactive = region->stat.st_nactive; td->txnid = id; td->begin_lsn = begin_lsn; ZERO_LSN(td->last_lsn); td->status = TXN_RUNNING; if (txn->parent != NULL) td->parent = txn->parent->off; else td->parent = INVALID_ROFF; td->flags = 0; off = R_OFFSET(&mgr->reginfo, td); R_UNLOCK(dbenv, &mgr->reginfo); ZERO_LSN(txn->last_lsn); txn->txnid = id; txn->off = (u_int32_t)off; txn->abort = __txn_abort; txn->commit = __txn_commit; txn->discard = __txn_discard; txn->id = __txn_id; txn->prepare = __txn_prepare; txn->set_timeout = __txn_set_timeout; /* * If this is a transaction family, we must link the child to the * maximal grandparent in the lock table for deadlock detection. */ if (txn->parent != NULL && LOCKING_ON(dbenv)) if ((ret = __lock_addfamilylocker(dbenv, txn->parent->txnid, txn->txnid)) != 0) return (ret); if (F_ISSET(txn, TXN_MALLOC)) { MUTEX_THREAD_LOCK(dbenv, mgr->mutexp); TAILQ_INSERT_TAIL(&mgr->txn_chain, txn, links); MUTEX_THREAD_UNLOCK(dbenv, mgr->mutexp); } return (0); err: R_UNLOCK(dbenv, &mgr->reginfo); return (ret); } /* * __txn_commit -- * Commit a transaction. * * PUBLIC: int __txn_commit __P((DB_TXN *, u_int32_t)); */ int __txn_commit(txnp, flags) DB_TXN *txnp; u_int32_t flags; { DB_ENV *dbenv; DB_LOCKREQ request; DB_TXN *kid; TXN_DETAIL *td; u_int32_t lflags; int ret, t_ret; dbenv = txnp->mgrp->dbenv; PANIC_CHECK(dbenv); if ((ret = __txn_isvalid(txnp, &td, TXN_OP_COMMIT)) != 0) return (ret); /* * We clear flags that are incorrect, ignoring any flag errors, and * default to synchronous operations. By definition, transaction * handles are dead when we return, and this error should never * happen, but we don't want to fail in the field 'cause the app is * specifying the wrong flag for some reason. */ if (__db_fchk(dbenv, "DB_TXN->commit", flags, DB_TXN_NOSYNC | DB_TXN_SYNC) != 0) flags = DB_TXN_SYNC; if (__db_fcchk(dbenv, "DB_TXN->commit", flags, DB_TXN_NOSYNC, DB_TXN_SYNC) != 0) flags = DB_TXN_SYNC; if (LF_ISSET(DB_TXN_NOSYNC)) { F_CLR(txnp, TXN_SYNC); F_SET(txnp, TXN_NOSYNC); } if (LF_ISSET(DB_TXN_SYNC)) { F_CLR(txnp, TXN_NOSYNC); F_SET(txnp, TXN_SYNC); } /* * Commit any unresolved children. If anyone fails to commit, * then try to abort the rest of the kids and then abort the parent. * Abort should never fail; if it does, we bail out immediately. */ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL) if ((ret = kid->commit(kid, flags)) != 0) while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL) if ((t_ret = kid->abort(kid)) != 0) return (__db_panic(dbenv, t_ret)); /* * Process any aborted pages from our children. * We delay putting pages on the free list that are newly * allocated and then aborted so that we can undo other * allocations, if necessary, without worrying about * these pages which were not on the free list before. */ if (txnp->txn_list != NULL) { t_ret = __db_do_the_limbo(dbenv, NULL, txnp, txnp->txn_list); __db_txnlist_end(dbenv, txnp->txn_list); txnp->txn_list = NULL; if (t_ret != 0 && ret == 0) ret = t_ret; } if (ret != 0) goto err; /* * If there are any log records, write a log record and sync the log, * else do no log writes. If the commit is for a child transaction, * we do not need to commit the child synchronously since it may still * abort (if its parent aborts), and otherwise its parent or ultimate * ancestor will write synchronously. */ if (DBENV_LOGGING(dbenv) && !IS_ZERO_LSN(txnp->last_lsn)) { if (txnp->parent == NULL) { /* * We are about to free all the read locks * for this transaction below. Some of those * locks might be handle locks which should * not be freed, because they will be freed * when the handle is closed. Check the * events and preprocess any trades now so * that we don't release the locks below. */ if ((ret = __txn_doevents(dbenv, txnp, 0, 1)) != 0) goto err; request.op = DB_LOCK_PUT_READ; if (LOCKING_ON(dbenv) && (ret = dbenv->lock_vec( dbenv, txnp->txnid, 0, &request, 1, NULL)) != 0) goto err; SET_LOG_FLAGS(dbenv, txnp, lflags); if ((ret = __txn_regop_log(dbenv, txnp, &txnp->last_lsn, lflags, TXN_COMMIT, (int32_t)time(NULL))) != 0) goto err; } else { /* Log the commit in the parent! */ if ((ret = __txn_child_log(dbenv, txnp->parent, &txnp->parent->last_lsn, 0, txnp->txnid, &txnp->last_lsn)) != 0) { goto err; } F_SET(txnp->parent, TXN_CHILDCOMMIT); } } /* This is OK because __txn_end can only fail with a panic. */ return (__txn_end(txnp, 1)); err: /* * If we are prepared, then we "must" be able to commit. We * panic here because even though the coordinator might be * able to retry it is not clear it would know to do that. * Otherwise we'll try to abort. If that is successful, * then we return whatever was in ret (i.e., the reason we failed). * If the abort was unsuccessful, then abort probably returned * DB_RUNRECOVERY and we need to propagate that up. */ if (td->status == TXN_PREPARED) return (__db_panic(dbenv, ret)); if ((t_ret = txnp->abort(txnp)) != 0) ret = t_ret; return (ret); } /* * __txn_abort -- * Abort a transaction. * * PUBLIC: int __txn_abort __P((DB_TXN *)); */ int __txn_abort(txnp) DB_TXN *txnp; { DB_ENV *dbenv; DB_LOCKREQ request; DB_TXN *kid; TXN_DETAIL *td; u_int32_t lflags; int ret; dbenv = txnp->mgrp->dbenv; PANIC_CHECK(dbenv); /* Ensure that abort always fails fatally. */ if ((ret = __txn_isvalid(txnp, &td, TXN_OP_ABORT)) != 0) return (__db_panic(dbenv, ret)); /* * Try to abort any unresolved children. * * Abort either succeeds or panics the region. As soon as we * see any failure, we just get out of here and return the panic * up. */ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL) if ((ret = kid->abort(kid)) != 0) return (ret); if (LOCKING_ON(dbenv)) { /* * We are about to free all the read locks for this transaction * below. Some of those locks might be handle locks which * should not be freed, because they will be freed when the * handle is closed. Check the events and preprocess any * trades now so that we don't release the locks below. */ if ((ret = __txn_doevents(dbenv, txnp, 0, 1)) != 0) return (__db_panic(dbenv, ret)); /* Turn off timeouts. */ if ((ret = __lock_set_timeout(dbenv, txnp->txnid, 0, DB_SET_TXN_TIMEOUT)) != 0) return (__db_panic(dbenv, ret)); if ((ret = __lock_set_timeout(dbenv, txnp->txnid, 0, DB_SET_LOCK_TIMEOUT)) != 0) return (__db_panic(dbenv, ret)); request.op = DB_LOCK_UPGRADE_WRITE; if ((ret = dbenv->lock_vec( dbenv, txnp->txnid, 0, &request, 1, NULL)) != 0) return (__db_panic(dbenv, ret)); } if ((ret = __txn_undo(txnp)) != 0) return (__db_panic(dbenv, ret)); /* * Normally, we do not need to log aborts. However, if we * are a distributed transaction (i.e., we have a prepare), * then we log the abort so we know that this transaction * was actually completed. */ SET_LOG_FLAGS(dbenv, txnp, lflags); if (DBENV_LOGGING(dbenv) && td->status == TXN_PREPARED && (ret = __txn_regop_log(dbenv, txnp, &txnp->last_lsn, lflags, TXN_ABORT, (int32_t)time(NULL))) != 0) return (__db_panic(dbenv, ret)); /* __txn_end always panics if it errors, so pass the return along. */ return (__txn_end(txnp, 0)); } /* * __txn_discard -- * Free the per-process resources associated with this txn handle. * * PUBLIC: int __txn_discard __P((DB_TXN *, u_int32_t flags)); */ int __txn_discard(txnp, flags) DB_TXN *txnp; u_int32_t flags; { DB_ENV *dbenv; DB_TXN *freep; TXN_DETAIL *td; int ret; COMPQUIET(flags, 0); dbenv = txnp->mgrp->dbenv; freep = NULL; PANIC_CHECK(dbenv); if ((ret = __txn_isvalid(txnp, &td, TXN_OP_DISCARD)) != 0) return (ret); /* Should be no children. */ DB_ASSERT(TAILQ_FIRST(&txnp->kids) == NULL); DB_ASSERT(F_ISSET(td, TXN_RESTORED)); /* Free the space. */ MUTEX_THREAD_LOCK(dbenv, txnp->mgrp->mutexp); txnp->mgrp->n_discards++; if (F_ISSET(txnp, TXN_MALLOC)) { TAILQ_REMOVE(&txnp->mgrp->txn_chain, txnp, links); freep = txnp; } MUTEX_THREAD_UNLOCK(dbenv, txnp->mgrp->mutexp); if (freep != NULL) __os_free(dbenv, freep); return (0); } /* * __txn_prepare -- * Flush the log so a future commit is guaranteed to succeed. * * PUBLIC: int __txn_prepare __P((DB_TXN *, u_int8_t *)); */ int __txn_prepare(txnp, gid) DB_TXN *txnp; u_int8_t *gid; { DBT xid; DB_ENV *dbenv; DB_TXN *kid; TXN_DETAIL *td; u_int32_t lflags; int ret; dbenv = txnp->mgrp->dbenv; PANIC_CHECK(dbenv); if ((ret = __txn_isvalid(txnp, &td, TXN_OP_PREPARE)) != 0) return (ret); /* Commit any unresolved children. */ while ((kid = TAILQ_FIRST(&txnp->kids)) != NULL) if ((ret = kid->commit(kid, DB_TXN_NOSYNC)) != 0) return (ret); /* * In XA, the global transaction ID in the txn_detail structure is * already set; in a non-XA environment, we must set it here. XA * requires that the transaction be either ENDED or SUSPENDED when * prepare is called, so we know that if the xa_status isn't in one * of those states, then we are calling prepare directly and we need * to fill in the td->xid. */ if (DBENV_LOGGING(dbenv)) { memset(&xid, 0, sizeof(xid)); if (td->xa_status != TXN_XA_ENDED && td->xa_status != TXN_XA_SUSPENDED) /* Regular prepare; fill in the gid. */ memcpy(td->xid, gid, sizeof(td->xid)); xid.size = sizeof(td->xid); xid.data = td->xid; SET_LOG_FLAGS(dbenv, txnp, lflags); if ((ret = __txn_xa_regop_log(dbenv, txnp, &txnp->last_lsn, lflags, TXN_PREPARE, &xid, td->format, td->gtrid, td->bqual, &td->begin_lsn)) != 0) { __db_err(dbenv, "DB_TXN->prepare: log_write failed %s", db_strerror(ret)); return (ret); } } MUTEX_THREAD_LOCK(dbenv, txnp->mgrp->mutexp); td->status = TXN_PREPARED; MUTEX_THREAD_UNLOCK(dbenv, txnp->mgrp->mutexp); return (0); } /* * __txn_id -- * Return the transaction ID. * * PUBLIC: u_int32_t __txn_id __P((DB_TXN *)); */ u_int32_t __txn_id(txnp) DB_TXN *txnp; { return (txnp->txnid); } /* * __txn_set_timeout -- * Set timeout values in the txn structure. */ static int __txn_set_timeout(txnp, timeout, op) DB_TXN *txnp; db_timeout_t timeout; u_int32_t op; { if (op != DB_SET_TXN_TIMEOUT && op != DB_SET_LOCK_TIMEOUT) return (__db_ferr(txnp->mgrp->dbenv, "DB_TXN->set_timeout", 0)); return (__lock_set_timeout( txnp->mgrp->dbenv, txnp->txnid, timeout, op)); } /* * __txn_isvalid -- * Return 0 if the txnp is reasonable, otherwise panic. */ static int __txn_isvalid(txnp, tdp, op) const DB_TXN *txnp; TXN_DETAIL **tdp; txnop_t op; { DB_TXNMGR *mgrp; DB_TXNREGION *region; TXN_DETAIL *tp; mgrp = txnp->mgrp; region = mgrp->reginfo.primary; /* Check for recovery. */ if (!F_ISSET(txnp, TXN_COMPENSATE) && F_ISSET(region, TXN_IN_RECOVERY)) { __db_err(mgrp->dbenv, "operation not permitted during recovery"); goto err; } /* Check for live cursors. */ if (txnp->cursors != 0) { __db_err(mgrp->dbenv, "transaction has active cursors"); goto err; } /* Check transaction's state. */ tp = (TXN_DETAIL *)R_ADDR(&mgrp->reginfo, txnp->off); if (tdp != NULL) *tdp = tp; /* Handle any operation specific checks. */ switch (op) { case TXN_OP_DISCARD: /* * Since we're just tossing the per-process space; there are * a lot of problems with the transaction that we can tolerate. */ /* Transaction is already been reused. */ if (txnp->txnid != tp->txnid) return (0); /* What we've got had better be a restored transaction. */ if (!F_ISSET(tp, TXN_RESTORED)) { __db_err(mgrp->dbenv, "not a restored transaction"); return (__db_panic(mgrp->dbenv, EINVAL)); } return (0); case TXN_OP_PREPARE: if (txnp->parent != NULL) { /* * This is not fatal, because you could imagine an * application that simply prepares everybody because * it doesn't distinguish between children and parents. * I'm not arguing this is good, but I could imagine * someone doing it. */ __db_err(mgrp->dbenv, "Prepare disallowed on child transactions"); return (EINVAL); } break; case TXN_OP_ABORT: case TXN_OP_COMMIT: default: break; } switch (tp->status) { case TXN_PREPARED: if (op == TXN_OP_PREPARE) { __db_err(mgrp->dbenv, "transaction already prepared"); /* * Txn_prepare doesn't blow away the user handle, so * in this case, give the user the opportunity to * abort or commit. */ return (EINVAL); } break; case TXN_RUNNING: break; case TXN_ABORTED: case TXN_COMMITTED: default: __db_err(mgrp->dbenv, "transaction already %s", tp->status == TXN_COMMITTED ? "committed" : "aborted"); goto err; } return (0); err: /* * If there's a serious problem with the transaction, panic. TXN * handles are dead by definition when we return, and if you use * a cursor you forgot to close, we have no idea what will happen. */ return (__db_panic(mgrp->dbenv, EINVAL)); } /* * __txn_end -- * Internal transaction end routine. */ static int __txn_end(txnp, is_commit) DB_TXN *txnp; int is_commit; { DB_ENV *dbenv; DB_LOCKREQ request; DB_TXNMGR *mgr; DB_TXNREGION *region; TXN_DETAIL *tp; int do_closefiles, ret; mgr = txnp->mgrp; dbenv = mgr->dbenv; region = mgr->reginfo.primary; do_closefiles = 0; /* Process commit events. */ if ((ret = __txn_doevents(dbenv, txnp, is_commit, 0)) != 0) return (__db_panic(dbenv, ret)); /* Release the locks. */ request.op = txnp->parent == NULL || is_commit == 0 ? DB_LOCK_PUT_ALL : DB_LOCK_INHERIT; /* * __txn_end cannot return an simple error, we MUST return * success/failure from commit or abort, ignoring any internal * errors. So, we panic if something goes wrong. We can't * deadlock here because we're not acquiring any new locks, * so DB_LOCK_DEADLOCK is just as fatal as any other error. */ if (LOCKING_ON(dbenv) && (ret = dbenv->lock_vec( dbenv, txnp->txnid, DB_LOCK_FREE_LOCKER, &request, 1, NULL)) != 0) return (__db_panic(dbenv, ret)); /* End the transaction. */ R_LOCK(dbenv, &mgr->reginfo); tp = (TXN_DETAIL *)R_ADDR(&mgr->reginfo, txnp->off); SH_TAILQ_REMOVE(®ion->active_txn, tp, links, __txn_detail); if (F_ISSET(tp, TXN_RESTORED)) { region->stat.st_nrestores--; do_closefiles = region->stat.st_nrestores == 0; } __db_shalloc_free(mgr->reginfo.addr, tp); if (is_commit) region->stat.st_ncommits++; else region->stat.st_naborts++; --region->stat.st_nactive; R_UNLOCK(dbenv, &mgr->reginfo); /* * The transaction cannot get more locks, remove its locker info, * if any. */ if (LOCKING_ON(dbenv) && (ret = __lock_freefamilylocker(dbenv->lk_handle, txnp->txnid)) != 0) return (__db_panic(dbenv, ret)); if (txnp->parent != NULL) TAILQ_REMOVE(&txnp->parent->kids, txnp, klinks); /* Free the space. */ if (F_ISSET(txnp, TXN_MALLOC)) { MUTEX_THREAD_LOCK(dbenv, mgr->mutexp); TAILQ_REMOVE(&mgr->txn_chain, txnp, links); MUTEX_THREAD_UNLOCK(dbenv, mgr->mutexp); __os_free(dbenv, txnp); } if (do_closefiles) { F_SET((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); (void)__dbreg_close_files(dbenv); F_CLR((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); mgr->n_discards = 0; (void)dbenv->txn_checkpoint(dbenv, 0, 0, DB_FORCE); } return (0); } /* * __txn_undo -- * Undo the transaction with id txnid. Returns 0 on success and * errno on failure. */ static int __txn_undo(txnp) DB_TXN *txnp; { DBT rdbt; DB_ENV *dbenv; DB_LOGC *logc; DB_LSN key_lsn; DB_TXN *ptxn; DB_TXNMGR *mgr; int ret, t_ret; void *txnlist; mgr = txnp->mgrp; dbenv = mgr->dbenv; logc = NULL; txnlist = NULL; if (!DBENV_LOGGING(dbenv)) return (0); /* * This is the simplest way to code this, but if the mallocs during * recovery turn out to be a performance issue, we can do the * allocation here and use DB_DBT_USERMEM. */ memset(&rdbt, 0, sizeof(rdbt)); key_lsn = txnp->last_lsn; /* * Allocate a txnlist for children and aborted page allocs. * We need to associate the list with the maximal parent * so that aborted pages are recovered when that transaction * is commited or aborted. */ for (ptxn = txnp->parent; ptxn != NULL && ptxn->parent != NULL;) ptxn = ptxn->parent; if (ptxn != NULL && ptxn->txn_list != NULL) txnlist = ptxn->txn_list; else if (txnp->txn_list != NULL) txnlist = txnp->txn_list; else if ((ret = __db_txnlist_init(dbenv, 0, 0, NULL, &txnlist)) != 0) return (ret); else if (ptxn != NULL) ptxn->txn_list = txnlist; if (F_ISSET(txnp, TXN_CHILDCOMMIT) && (ret = __db_txnlist_lsninit(dbenv, txnlist, &txnp->last_lsn)) != 0) return (ret); if ((ret = dbenv->log_cursor(dbenv, &logc, 0)) != 0) goto err; while (ret == 0 && !IS_ZERO_LSN(key_lsn)) { /* * The dispatch routine returns the lsn of the record * before the current one in the key_lsn argument. */ if ((ret = logc->get(logc, &key_lsn, &rdbt, DB_SET)) == 0) { ret = __db_dispatch(dbenv, dbenv->recover_dtab, dbenv->recover_dtab_size, &rdbt, &key_lsn, DB_TXN_ABORT, txnlist); if (F_ISSET(txnp, TXN_CHILDCOMMIT)) (void)__db_txnlist_lsnadd(dbenv, txnlist, &key_lsn, 0); } if (ret == DB_SURPRISE_KID) { if ((ret = __db_txnlist_lsninit( dbenv, txnlist, &key_lsn)) == 0) F_SET(txnp, TXN_CHILDCOMMIT); } else if (ret != 0) { __db_err(txnp->mgrp->dbenv, "DB_TXN->abort: Log undo failed for LSN: %lu %lu: %s", (u_long)key_lsn.file, (u_long)key_lsn.offset, db_strerror(ret)); goto err; } } ret = __db_do_the_limbo(dbenv, ptxn, txnp, txnlist); err: if (logc != NULL && (t_ret = logc->close(logc, 0)) != 0 && ret == 0) ret = t_ret; if (ptxn == NULL && txnlist != NULL) __db_txnlist_end(dbenv, txnlist); return (ret); } /* * Transaction checkpoint. * If either kbytes or minutes is non-zero, then we only take the checkpoint * more than "minutes" minutes have passed since the last checkpoint or if * more than "kbytes" of log data have been written since the last checkpoint. * When taking a checkpoint, find the oldest active transaction and figure out * its first LSN. This is the lowest LSN we can checkpoint, since any record * written after since that point may be involved in a transaction and may * therefore need to be undone in the case of an abort. * * PUBLIC: int __txn_checkpoint * PUBLIC: __P((DB_ENV *, u_int32_t, u_int32_t, u_int32_t)); */ int __txn_checkpoint(dbenv, kbytes, minutes, flags) DB_ENV *dbenv; u_int32_t kbytes, minutes, flags; { DB_LSN ckp_lsn, last_ckp; DB_TXNMGR *mgr; DB_TXNREGION *region; TXN_DETAIL *txnp; time_t last_ckp_time, now; u_int32_t bytes, mbytes; int ret; PANIC_CHECK(dbenv); ENV_REQUIRES_CONFIG(dbenv, dbenv->tx_handle, "txn_checkpoint", DB_INIT_TXN); /* * On a replication client, all transactions are read-only; therefore, * a checkpoint is a null-op. * * We permit txn_checkpoint, instead of just rendering it illegal, * so that an application can just let a checkpoint thread continue * to operate as it gets promoted or demoted between being a * master and a client. */ if (F_ISSET(dbenv, DB_ENV_REP_CLIENT)) return (0); mgr = dbenv->tx_handle; region = mgr->reginfo.primary; /* * The checkpoint LSN is an LSN such that all transactions begun before * it are complete. Our first guess (corrected below based on the list * of active transactions) is the last-written LSN. */ __log_txn_lsn(dbenv, &ckp_lsn, &mbytes, &bytes); if (!LF_ISSET(DB_FORCE)) { /* Don't checkpoint a quiescent database. */ if (bytes == 0 && mbytes == 0) return (0); if (kbytes != 0 && mbytes * 1024 + bytes / 1024 >= (u_int32_t)kbytes) goto do_ckp; if (minutes != 0) { (void)time(&now); R_LOCK(dbenv, &mgr->reginfo); last_ckp_time = region->time_ckp; R_UNLOCK(dbenv, &mgr->reginfo); if (now - last_ckp_time >= (time_t)(minutes * 60)) goto do_ckp; } /* * If we checked time and data and didn't go to checkpoint, * we're done. */ if (minutes != 0 || kbytes != 0) return (0); } do_ckp: /* Look through the active transactions for the lowest begin LSN. */ R_LOCK(dbenv, &mgr->reginfo); for (txnp = SH_TAILQ_FIRST(®ion->active_txn, __txn_detail); txnp != NULL; txnp = SH_TAILQ_NEXT(txnp, links, __txn_detail)) if (!IS_ZERO_LSN(txnp->begin_lsn) && log_compare(&txnp->begin_lsn, &ckp_lsn) < 0) ckp_lsn = txnp->begin_lsn; R_UNLOCK(dbenv, &mgr->reginfo); if (MPOOL_ON(dbenv) && (ret = dbenv->memp_sync(dbenv, NULL)) != 0) { __db_err(dbenv, "txn_checkpoint: failed to flush the buffer cache %s", db_strerror(ret)); return (ret); } /* * Because we can't be a replication client here, and because * recovery (somewhat unusually) calls txn_checkpoint and expects * it to write a log message, LOGGING_ON is the correct macro here. */ if (LOGGING_ON(dbenv)) { R_LOCK(dbenv, &mgr->reginfo); last_ckp = region->last_ckp; R_UNLOCK(dbenv, &mgr->reginfo); /* * Put out records for the open files before we log * the checkpoint. The records are certain to be at * or after ckp_lsn, but before the checkpoint record * itself, so they're sure to be included if we start * recovery from the ckp_lsn contained in this * checkpoint. */ if ((ret = __dbreg_open_files(dbenv)) != 0 || (ret = __txn_ckp_log(dbenv, NULL, &ckp_lsn, DB_PERMANENT | DB_FLUSH, &ckp_lsn, &last_ckp, (int32_t)time(NULL))) != 0) { __db_err(dbenv, "txn_checkpoint: log failed at LSN [%ld %ld] %s", (long)ckp_lsn.file, (long)ckp_lsn.offset, db_strerror(ret)); return (ret); } __txn_updateckp(dbenv, &ckp_lsn); } return (0); } /* * __txn_getckp -- * Get the LSN of the last transaction checkpoint. * * PUBLIC: int __txn_getckp __P((DB_ENV *, DB_LSN *)); */ int __txn_getckp(dbenv, lsnp) DB_ENV *dbenv; DB_LSN *lsnp; { DB_LSN lsn; DB_TXNMGR *mgr; DB_TXNREGION *region; mgr = dbenv->tx_handle; region = mgr->reginfo.primary; R_LOCK(dbenv, &mgr->reginfo); lsn = region->last_ckp; R_UNLOCK(dbenv, &mgr->reginfo); if (IS_ZERO_LSN(lsn)) return (DB_NOTFOUND); *lsnp = lsn; return (0); } /* * __txn_activekids -- * Return if this transaction has any active children. * * PUBLIC: int __txn_activekids __P((DB_ENV *, u_int32_t, DB_TXN *)); */ int __txn_activekids(dbenv, rectype, txnp) DB_ENV *dbenv; u_int32_t rectype; DB_TXN *txnp; { /* * On a child commit, we know that there are children (i.e., the * commiting child at the least. In that case, skip this check. */ if (F_ISSET(txnp, TXN_COMPENSATE) || rectype == DB___txn_child) return (0); if (TAILQ_FIRST(&txnp->kids) != NULL) { __db_err(dbenv, "Child transaction is active"); return (EPERM); } return (0); } /* * __txn_force_abort -- * Force an abort record into the log if the commit record * failed to get to disk. * * PUBLIC: int __txn_force_abort __P((DB_ENV *, u_int8_t *)); */ int __txn_force_abort(dbenv, buffer) DB_ENV *dbenv; u_int8_t *buffer; { DB_CIPHER *db_cipher; HDR *hdr; u_int32_t offset, opcode, rec_len, rec_type, sum_len; u_int8_t *bp, *key, chksum[DB_MAC_KEY]; size_t hdrsize; int ret; db_cipher = dbenv->crypto_handle; /* * This routine depends on the layout of HDR and the __txn_regop * record in txn.src. We are passed the beginning of the commit * record in the log buffer and overwrite the commit with an abort * and recalculate the checksum. We may be passed a txn_xa_regop * that is, an XA prepare), there's no need to overwrite that one. */ hdr = (HDR *)buffer; memcpy(&rec_type, hdr, sizeof(rec_type)); if (rec_type == DB___txn_xa_regop) return (0); offset = sizeof(u_int32_t) + sizeof(u_int32_t) + sizeof(DB_LSN); rec_len = offset + sizeof(u_int32_t) + sizeof(int32_t); if (CRYPTO_ON(dbenv)) { key = db_cipher->mac_key; hdrsize = HDR_CRYPTO_SZ; sum_len = DB_MAC_KEY; if ((ret = db_cipher->decrypt(dbenv, db_cipher->data, &hdr->iv[0], buffer + hdrsize, rec_len)) != 0) return (__db_panic(dbenv, ret)); } else { key = NULL; hdrsize = HDR_NORMAL_SZ; sum_len = sizeof(u_int32_t); } bp = buffer + hdrsize + offset; opcode = TXN_ABORT; memcpy(bp, &opcode, sizeof(opcode)); if (CRYPTO_ON(dbenv) && (ret = db_cipher->encrypt(dbenv, db_cipher->data, &hdr->iv[0], buffer + hdrsize, rec_len)) != 0) return (__db_panic(dbenv, ret)); __db_chksum(buffer + hdrsize, rec_len, key, chksum); memcpy(buffer + SSZ(HDR, chksum), &chksum, sum_len); return (0); } /* * __txn_preclose * Before we can close an environment, we need to check if we * were in the midst of taking care of restored transactions. If * so, then we need to close the files that we opened. * * PUBLIC: int __txn_preclose __P((DB_ENV *)); */ int __txn_preclose(dbenv) DB_ENV *dbenv; { DB_TXNMGR *mgr; DB_TXNREGION *region; int do_closefiles, ret; mgr = (DB_TXNMGR *)dbenv->tx_handle; region = mgr->reginfo.primary; do_closefiles = 0; R_LOCK(dbenv, &mgr->reginfo); if (region != NULL && region->stat.st_nrestores <= mgr->n_discards && mgr->n_discards != 0) do_closefiles = 1; R_UNLOCK(dbenv, &mgr->reginfo); if (do_closefiles) { /* * Set the DBLOG_RECOVER flag while closing these * files so they do not create additional log records * that will confuse future recoveries. */ F_SET((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); ret = __dbreg_close_files(dbenv); F_CLR((DB_LOG *)dbenv->lg_handle, DBLOG_RECOVER); } else ret = 0; return (ret); } /* * __txn_reset -- * Reset the last txnid to its minimum value, and log the reset. * * PUBLIC: int __txn_reset __P((DB_ENV *)); */ int __txn_reset(dbenv) DB_ENV *dbenv; { DB_LSN scrap; DB_TXNREGION *region; region = ((DB_TXNMGR *)dbenv->tx_handle)->reginfo.primary; region->last_txnid = TXN_MINIMUM; DB_ASSERT(LOGGING_ON(dbenv)); return (__txn_recycle_log(dbenv, NULL, &scrap, 0, TXN_MINIMUM, TXN_MAXIMUM)); } /* * __txn_updateckp -- * Update the last_ckp field in the transaction region. This happens * at the end of a normal checkpoint and also when a replication client * receives a checkpoint record. * * PUBLIC: void __txn_updateckp __P((DB_ENV *, DB_LSN *)); */ void __txn_updateckp(dbenv, lsnp) DB_ENV *dbenv; DB_LSN *lsnp; { DB_TXNMGR *mgr; DB_TXNREGION *region; mgr = dbenv->tx_handle; region = mgr->reginfo.primary; /* * We want to make sure last_ckp only moves forward; since * we drop locks above and in log_put, it's possible * for two calls to __txn_ckp_log to finish in a different * order from how they were called. */ R_LOCK(dbenv, &mgr->reginfo); if (log_compare(®ion->last_ckp, lsnp) < 0) { region->last_ckp = *lsnp; (void)time(®ion->time_ckp); } R_UNLOCK(dbenv, &mgr->reginfo); }