diff options
Diffstat (limited to 'storage/bdb/db/db_dispatch.c')
| -rw-r--r-- | storage/bdb/db/db_dispatch.c | 1404 |
1 files changed, 1404 insertions, 0 deletions
diff --git a/storage/bdb/db/db_dispatch.c b/storage/bdb/db/db_dispatch.c new file mode 100644 index 00000000000..2cf29ec2f33 --- /dev/null +++ b/storage/bdb/db/db_dispatch.c @@ -0,0 +1,1404 @@ +/*- + * 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: db_dispatch.c,v 11.121 2002/09/07 17:36:31 ubell Exp $"; +#endif /* not lint */ + +#ifndef NO_SYSTEM_INCLUDES +#include <sys/types.h> + +#include <stddef.h> +#include <stdlib.h> +#include <string.h> +#endif + +#include "db_int.h" +#include "dbinc/db_page.h" +#include "dbinc/hash.h" +#include "dbinc/log.h" +#include "dbinc/fop.h" +#include "dbinc/rep.h" +#include "dbinc/txn.h" + +static int __db_limbo_fix __P((DB *, + DB_TXN *, DB_TXNLIST *, db_pgno_t *, DBMETA *)); +static int __db_limbo_bucket __P((DB_ENV *, DB_TXN *, DB_TXNLIST *)); +static int __db_limbo_move __P((DB_ENV *, DB_TXN *, DB_TXN *, DB_TXNLIST *)); +static int __db_lock_move __P((DB_ENV *, + u_int8_t *, db_pgno_t, db_lockmode_t, DB_TXN *, DB_TXN *)); +static int __db_default_getpgnos __P((DB_ENV *, DB_LSN *lsnp, void *)); +static int __db_txnlist_find_internal __P((DB_ENV *, void *, db_txnlist_type, + u_int32_t, u_int8_t [DB_FILE_ID_LEN], DB_TXNLIST **, int)); +static int __db_txnlist_pgnoadd __P((DB_ENV *, DB_TXNHEAD *, + int32_t, u_int8_t [DB_FILE_ID_LEN], char *, db_pgno_t)); + +/* + * __db_dispatch -- + * + * This is the transaction dispatch function used by the db access methods. + * It is designed to handle the record format used by all the access + * methods (the one automatically generated by the db_{h,log,read}.sh + * scripts in the tools directory). An application using a different + * recovery paradigm will supply a different dispatch function to txn_open. + * + * PUBLIC: int __db_dispatch __P((DB_ENV *, + * PUBLIC: int (**)__P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *)), + * PUBLIC: size_t, DBT *, DB_LSN *, db_recops, void *)); + */ +int +__db_dispatch(dbenv, dtab, dtabsize, db, lsnp, redo, info) + DB_ENV *dbenv; /* The environment. */ + int (**dtab)__P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *)); + size_t dtabsize; /* Size of the dtab. */ + DBT *db; /* The log record upon which to dispatch. */ + DB_LSN *lsnp; /* The lsn of the record being dispatched. */ + db_recops redo; /* Redo this op (or undo it). */ + void *info; +{ + DB_LSN prev_lsn; + u_int32_t rectype, txnid; + int make_call, ret; + + memcpy(&rectype, db->data, sizeof(rectype)); + memcpy(&txnid, (u_int8_t *)db->data + sizeof(rectype), sizeof(txnid)); + make_call = ret = 0; + + /* If we don't have a dispatch table, it's hard to dispatch. */ + DB_ASSERT(dtab != NULL); + + /* + * If we find a record that is in the user's number space and they + * have specified a recovery routine, let them handle it. If they + * didn't specify a recovery routine, then we expect that they've + * followed all our rules and registered new recovery functions. + */ + switch (redo) { + case DB_TXN_ABORT: + case DB_TXN_APPLY: + case DB_TXN_PRINT: + make_call = 1; + break; + case DB_TXN_OPENFILES: + /* + * We collect all the transactions that have + * "begin" records, those with no previous LSN, + * so that we do not abort partial transactions. + * These are known to be undone, otherwise the + * log would not have been freeable. + */ + memcpy(&prev_lsn, (u_int8_t *)db->data + + sizeof(rectype) + sizeof(txnid), sizeof(prev_lsn)); + if (txnid != 0 && prev_lsn.file == 0 && (ret = + __db_txnlist_add(dbenv, info, txnid, TXN_OK, NULL)) != 0) + return (ret); + + /* FALLTHROUGH */ + case DB_TXN_POPENFILES: + if (rectype == DB___dbreg_register || + rectype == DB___txn_ckp || rectype == DB___txn_recycle) + return (dtab[rectype](dbenv, db, lsnp, redo, info)); + break; + case DB_TXN_BACKWARD_ROLL: + /* + * Running full recovery in the backward pass. If we've + * seen this txnid before and added to it our commit list, + * then we do nothing during this pass, unless this is a child + * commit record, in which case we need to process it. If + * we've never seen it, then we call the appropriate recovery + * routine. + * + * We need to always undo DB___db_noop records, so that we + * properly handle any aborts before the file was closed. + */ + switch(rectype) { + case DB___txn_regop: + case DB___txn_recycle: + case DB___txn_ckp: + case DB___db_noop: + case DB___fop_file_remove: + case DB___txn_child: + make_call = 1; + break; + + case DB___dbreg_register: + if (txnid == 0) { + make_call = 1; + break; + } + /* FALLTHROUGH */ + default: + if (txnid != 0 && (ret = + __db_txnlist_find(dbenv, + info, txnid)) != TXN_COMMIT && ret != TXN_IGNORE) { + /* + * If not found then, this is an incomplete + * abort. + */ + if (ret == TXN_NOTFOUND) + return (__db_txnlist_add(dbenv, + info, txnid, TXN_IGNORE, lsnp)); + make_call = 1; + if (ret == TXN_OK && + (ret = __db_txnlist_update(dbenv, + info, txnid, + rectype == DB___txn_xa_regop ? + TXN_PREPARE : TXN_ABORT, NULL)) != 0) + return (ret); + } + } + break; + case DB_TXN_FORWARD_ROLL: + /* + * In the forward pass, if we haven't seen the transaction, + * do nothing, else recover it. + * + * We need to always redo DB___db_noop records, so that we + * properly handle any commits after the file was closed. + */ + switch(rectype) { + case DB___txn_recycle: + case DB___txn_ckp: + case DB___db_noop: + make_call = 1; + break; + + default: + if (txnid != 0 && (ret = __db_txnlist_find(dbenv, + info, txnid)) == TXN_COMMIT) + make_call = 1; + else if (ret != TXN_IGNORE && + (rectype == DB___ham_metagroup || + rectype == DB___ham_groupalloc || + rectype == DB___db_pg_alloc)) { + /* + * Because we cannot undo file extensions + * all allocation records must be reprocessed + * during rollforward in case the file was + * just created. It may not have been + * present during the backward pass. + */ + make_call = 1; + redo = DB_TXN_BACKWARD_ALLOC; + } else if (rectype == DB___dbreg_register) { + /* + * This may be a transaction dbreg_register. + * If it is, we only make the call on a COMMIT, + * which we checked above. If it's not, then we + * should always make the call, because we need + * the file open information. + */ + if (txnid == 0) + make_call = 1; + } + } + break; + case DB_TXN_GETPGNOS: + /* + * If this is one of DB's own log records, we simply + * dispatch. + */ + if (rectype < DB_user_BEGIN) { + make_call = 1; + break; + } + + /* + * If we're still here, this is a custom record in an + * application that's doing app-specific logging. Such a + * record doesn't have a getpgno function for the user + * dispatch function to call--the getpgnos functions return + * which pages replication needs to lock using the TXN_RECS + * structure, which is private and not something we want to + * document. + * + * Thus, we leave any necessary locking for the app's + * recovery function to do during the upcoming + * DB_TXN_APPLY. Fill in default getpgnos info (we need + * a stub entry for every log record that will get + * DB_TXN_APPLY'd) and return success. + */ + return (__db_default_getpgnos(dbenv, lsnp, info)); + default: + return (__db_unknown_flag(dbenv, "__db_dispatch", redo)); + } + /* + * The switch statement uses ret to receive the return value of + * __db_txnlist_find, which returns a large number of different + * statuses, none of which we will be returning. For safety, + * let's reset this here in case we ever do a "return(ret)" + * below in the future. + */ + ret = 0; + + if (make_call) { + if (rectype >= DB_user_BEGIN && dbenv->app_dispatch != NULL) + return (dbenv->app_dispatch(dbenv, db, lsnp, redo)); + else { + /* + * The size of the dtab table argument is the same as + * the standard table, use the standard table's size + * as our sanity check. + */ + if (rectype > dtabsize || dtab[rectype] == NULL) { + __db_err(dbenv, + "Illegal record type %lu in log", + (u_long)rectype); + return (EINVAL); + } + return (dtab[rectype](dbenv, db, lsnp, redo, info)); + } + } + + return (0); +} + +/* + * __db_add_recovery -- + * + * PUBLIC: int __db_add_recovery __P((DB_ENV *, + * PUBLIC: int (***)(DB_ENV *, DBT *, DB_LSN *, db_recops, void *), size_t *, + * PUBLIC: int (*)(DB_ENV *, DBT *, DB_LSN *, db_recops, void *), u_int32_t)); + */ +int +__db_add_recovery(dbenv, dtab, dtabsize, func, ndx) + DB_ENV *dbenv; + int (***dtab) __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *)); + size_t *dtabsize; + int (*func) __P((DB_ENV *, DBT *, DB_LSN *, db_recops, void *)); + u_int32_t ndx; +{ + size_t i, nsize; + int ret; + + /* Check if we have to grow the table. */ + if (ndx >= *dtabsize) { + nsize = ndx + 40; + if ((ret = + __os_realloc(dbenv, nsize * sizeof((*dtab)[0]), dtab)) != 0) + return (ret); + for (i = *dtabsize; i < nsize; ++i) + (*dtab)[i] = NULL; + *dtabsize = nsize; + } + + (*dtab)[ndx] = func; + return (0); +} + +/* + * __db_txnlist_init -- + * Initialize transaction linked list. + * + * PUBLIC: int __db_txnlist_init __P((DB_ENV *, + * PUBLIC: u_int32_t, u_int32_t, DB_LSN *, void *)); + */ +int +__db_txnlist_init(dbenv, low_txn, hi_txn, trunc_lsn, retp) + DB_ENV *dbenv; + u_int32_t low_txn, hi_txn; + DB_LSN *trunc_lsn; + void *retp; +{ + DB_TXNHEAD *headp; + u_int32_t tmp; + int ret, size; + + /* + * Size a hash table. + * If low is zero then we are being called during rollback + * and we need only one slot. + * Hi maybe lower than low if we have recycled txnid's. + * The numbers here are guesses about txn density, we can afford + * to look at a few entries in each slot. + */ + if (low_txn == 0) + size = 1; + else { + if (hi_txn < low_txn) { + tmp = hi_txn; + hi_txn = low_txn; + low_txn = tmp; + } + tmp = hi_txn - low_txn; + /* See if we wrapped around. */ + if (tmp > (TXN_MAXIMUM - TXN_MINIMUM) / 2) + tmp = (low_txn - TXN_MINIMUM) + (TXN_MAXIMUM - hi_txn); + size = tmp / 5; + if (size < 100) + size = 100; + } + if ((ret = __os_malloc(dbenv, + sizeof(DB_TXNHEAD) + size * sizeof(headp->head), &headp)) != 0) + return (ret); + + memset(headp, 0, sizeof(DB_TXNHEAD) + size * sizeof(headp->head)); + headp->maxid = hi_txn; + headp->generation = 0; + headp->nslots = size; + headp->gen_alloc = 8; + if ((ret = __os_malloc(dbenv, headp->gen_alloc * + sizeof(headp->gen_array[0]), &headp->gen_array)) != 0) { + __os_free(dbenv, headp); + return (ret); + } + headp->gen_array[0].generation = 0; + headp->gen_array[0].txn_min = TXN_MINIMUM; + headp->gen_array[0].txn_max = TXN_MAXIMUM; + if (trunc_lsn != NULL) + headp->trunc_lsn = *trunc_lsn; + else + ZERO_LSN(headp->trunc_lsn); + ZERO_LSN(headp->maxlsn); + ZERO_LSN(headp->ckplsn); + + *(void **)retp = headp; + return (0); +} + +/* + * __db_txnlist_add -- + * Add an element to our transaction linked list. + * + * PUBLIC: int __db_txnlist_add __P((DB_ENV *, + * PUBLIC: void *, u_int32_t, int32_t, DB_LSN *)); + */ +int +__db_txnlist_add(dbenv, listp, txnid, status, lsn) + DB_ENV *dbenv; + void *listp; + u_int32_t txnid; + int32_t status; + DB_LSN *lsn; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *elp; + int ret; + + if ((ret = __os_malloc(dbenv, sizeof(DB_TXNLIST), &elp)) != 0) + return (ret); + + hp = (DB_TXNHEAD *)listp; + LIST_INSERT_HEAD(&hp->head[DB_TXNLIST_MASK(hp, txnid)], elp, links); + + elp->type = TXNLIST_TXNID; + elp->u.t.txnid = txnid; + elp->u.t.status = status; + elp->u.t.generation = hp->generation; + if (txnid > hp->maxid) + hp->maxid = txnid; + if (lsn != NULL && IS_ZERO_LSN(hp->maxlsn) && status == TXN_COMMIT) + hp->maxlsn = *lsn; + + DB_ASSERT(lsn == NULL || + status != TXN_COMMIT || log_compare(&hp->maxlsn, lsn) >= 0); + + return (0); +} + +/* + * __db_txnlist_remove -- + * Remove an element from our transaction linked list. + * + * PUBLIC: int __db_txnlist_remove __P((DB_ENV *, void *, u_int32_t)); + */ +int +__db_txnlist_remove(dbenv, listp, txnid) + DB_ENV *dbenv; + void *listp; + u_int32_t txnid; +{ + DB_TXNLIST *entry; + + return (__db_txnlist_find_internal(dbenv, + listp, TXNLIST_TXNID, txnid, + NULL, &entry, 1) == TXN_NOTFOUND ? TXN_NOTFOUND : TXN_OK); +} + +/* + * __db_txnlist_ckp -- + * Used to record the maximum checkpoint that will be retained + * after recovery. Typically this is simply the max checkpoint, but + * if we are doing client replication recovery or timestamp-based + * recovery, we are going to virtually truncate the log and we need + * to retain the last checkpoint before the truncation point. + * + * PUBLIC: void __db_txnlist_ckp __P((DB_ENV *, void *, DB_LSN *)); + */ +void +__db_txnlist_ckp(dbenv, listp, ckp_lsn) + DB_ENV *dbenv; + void *listp; + DB_LSN *ckp_lsn; +{ + DB_TXNHEAD *hp; + + COMPQUIET(dbenv, NULL); + + hp = (DB_TXNHEAD *)listp; + + if (IS_ZERO_LSN(hp->ckplsn) && !IS_ZERO_LSN(hp->maxlsn) && + log_compare(&hp->maxlsn, ckp_lsn) >= 0) + hp->ckplsn = *ckp_lsn; +} + +/* + * __db_txnlist_end -- + * Discard transaction linked list. Print out any error messages + * for deleted files. + * + * PUBLIC: void __db_txnlist_end __P((DB_ENV *, void *)); + */ +void +__db_txnlist_end(dbenv, listp) + DB_ENV *dbenv; + void *listp; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *p; + int i; + + if ((hp = (DB_TXNHEAD *)listp) == NULL) + return; + + for (i = 0; i < hp->nslots; i++) + while (hp != NULL && (p = LIST_FIRST(&hp->head[i])) != NULL) { + LIST_REMOVE(p, links); + switch (p->type) { + case TXNLIST_LSN: + __os_free(dbenv, p->u.l.lsn_array); + break; + default: + /* + * Possibly an incomplete DB_TXNLIST; just + * free it. + */ + break; + } + __os_free(dbenv, p); + } + + if (hp->gen_array != NULL) + __os_free(dbenv, hp->gen_array); + __os_free(dbenv, listp); +} + +/* + * __db_txnlist_find -- + * Checks to see if a txnid with the current generation is in the + * txnid list. This returns TXN_NOTFOUND if the item isn't in the + * list otherwise it returns (like __db_txnlist_find_internal) + * the status of the transaction. A txnid of 0 means the record + * was generated while not in a transaction. + * + * PUBLIC: int __db_txnlist_find __P((DB_ENV *, void *, u_int32_t)); + */ +int +__db_txnlist_find(dbenv, listp, txnid) + DB_ENV *dbenv; + void *listp; + u_int32_t txnid; +{ + DB_TXNLIST *entry; + + if (txnid == 0) + return (TXN_NOTFOUND); + return (__db_txnlist_find_internal(dbenv, listp, + TXNLIST_TXNID, txnid, NULL, &entry, 0)); +} + +/* + * __db_txnlist_update -- + * Change the status of an existing transaction entry. + * Returns TXN_NOTFOUND if no such entry exists. + * + * PUBLIC: int __db_txnlist_update __P((DB_ENV *, + * PUBLIC: void *, u_int32_t, u_int32_t, DB_LSN *)); + */ +int +__db_txnlist_update(dbenv, listp, txnid, status, lsn) + DB_ENV *dbenv; + void *listp; + u_int32_t txnid; + u_int32_t status; + DB_LSN *lsn; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *elp; + int ret; + + if (txnid == 0) + return (TXN_NOTFOUND); + hp = (DB_TXNHEAD *)listp; + ret = __db_txnlist_find_internal(dbenv, + listp, TXNLIST_TXNID, txnid, NULL, &elp, 0); + + if (ret == TXN_NOTFOUND) + return (ret); + elp->u.t.status = status; + + if (lsn != NULL && IS_ZERO_LSN(hp->maxlsn) && status == TXN_COMMIT) + hp->maxlsn = *lsn; + + return (ret); +} + +/* + * __db_txnlist_find_internal -- + * Find an entry on the transaction list. If the entry is not there or + * the list pointer is not initialized we return TXN_NOTFOUND. If the + * item is found, we return the status. Currently we always call this + * with an initialized list pointer but checking for NULL keeps it general. + */ +static int +__db_txnlist_find_internal(dbenv, listp, type, txnid, uid, txnlistp, delete) + DB_ENV *dbenv; + void *listp; + db_txnlist_type type; + u_int32_t txnid; + u_int8_t uid[DB_FILE_ID_LEN]; + DB_TXNLIST **txnlistp; + int delete; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *p; + int32_t generation; + u_int32_t hash; + struct __db_headlink *head; + int i, ret; + + if ((hp = (DB_TXNHEAD *)listp) == NULL) + return (TXN_NOTFOUND); + + switch (type) { + case TXNLIST_TXNID: + hash = txnid; + /* Find the most recent generation containing this ID */ + for (i = 0; i <= hp->generation; i++) + /* The range may wrap around the end. */ + if (hp->gen_array[i].txn_min < + hp->gen_array[i].txn_max ? + (txnid >= hp->gen_array[i].txn_min && + txnid <= hp->gen_array[i].txn_max) : + (txnid >= hp->gen_array[i].txn_min || + txnid <= hp->gen_array[i].txn_max)) + break; + DB_ASSERT(i <= hp->generation); + generation = hp->gen_array[i].generation; + break; + case TXNLIST_PGNO: + memcpy(&hash, uid, sizeof(hash)); + generation = 0; + break; + default: + DB_ASSERT(0); + return (EINVAL); + } + + head = &hp->head[DB_TXNLIST_MASK(hp, hash)]; + + for (p = LIST_FIRST(head); p != NULL; p = LIST_NEXT(p, links)) { + if (p->type != type) + continue; + switch (type) { + case TXNLIST_TXNID: + if (p->u.t.txnid != txnid || + generation != p->u.t.generation) + continue; + ret = p->u.t.status; + break; + + case TXNLIST_PGNO: + if (memcmp(uid, p->u.p.uid, DB_FILE_ID_LEN) != 0) + continue; + + ret = 0; + break; + default: + DB_ASSERT(0); + ret = EINVAL; + } + if (delete == 1) { + LIST_REMOVE(p, links); + __os_free(dbenv, p); + } else if (p != LIST_FIRST(head)) { + /* Move it to head of list. */ + LIST_REMOVE(p, links); + LIST_INSERT_HEAD(head, p, links); + } + *txnlistp = p; + return (ret); + } + + return (TXN_NOTFOUND); +} + +/* + * __db_txnlist_gen -- + * Change the current generation number. + * + * PUBLIC: int __db_txnlist_gen __P((DB_ENV *, + * PUBLIC: void *, int, u_int32_t, u_int32_t)); + */ +int +__db_txnlist_gen(dbenv, listp, incr, min, max) + DB_ENV *dbenv; + void *listp; + int incr; + u_int32_t min, max; +{ + DB_TXNHEAD *hp; + int ret; + + /* + * During recovery generation numbers keep track of "restart" + * checkpoints and recycle records. Restart checkpoints occur + * whenever we take a checkpoint and there are no outstanding + * transactions. When that happens, we can reset transaction IDs + * back to TXNID_MINIMUM. Currently we only do the reset + * at then end of recovery. Recycle records occrur when txnids + * are exhausted during runtime. A free range of ids is identified + * and logged. This code maintains a stack of ranges. A txnid + * is given the generation number of the first range it falls into + * in the stack. + */ + hp = (DB_TXNHEAD *)listp; + hp->generation += incr; + if (incr < 0) + memmove(hp->gen_array, &hp->gen_array[1], + (hp->generation + 1) * sizeof(hp->gen_array[0])); + else { + if (hp->generation >= hp->gen_alloc) { + hp->gen_alloc *= 2; + if ((ret = __os_realloc(dbenv, hp->gen_alloc * + sizeof(hp->gen_array[0]), &hp->gen_array)) != 0) + return (ret); + } + memmove(&hp->gen_array[1], &hp->gen_array[0], + hp->generation * sizeof(hp->gen_array[0])); + hp->gen_array[0].generation = hp->generation; + hp->gen_array[0].txn_min = min; + hp->gen_array[0].txn_max = max; + } + return (0); +} + +#define TXN_BUBBLE(AP, MAX) { \ + int __j; \ + DB_LSN __tmp; \ + \ + for (__j = 0; __j < MAX - 1; __j++) \ + if (log_compare(&AP[__j], &AP[__j + 1]) < 0) { \ + __tmp = AP[__j]; \ + AP[__j] = AP[__j + 1]; \ + AP[__j + 1] = __tmp; \ + } \ +} + +/* + * __db_txnlist_lsnadd -- + * Add to or re-sort the transaction list lsn entry. Note that since this + * is used during an abort, the __txn_undo code calls into the "recovery" + * subsystem explicitly, and there is only a single TXNLIST_LSN entry on + * the list. + * + * PUBLIC: int __db_txnlist_lsnadd __P((DB_ENV *, void *, DB_LSN *, u_int32_t)); + */ +int +__db_txnlist_lsnadd(dbenv, listp, lsnp, flags) + DB_ENV *dbenv; + void *listp; + DB_LSN *lsnp; + u_int32_t flags; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *elp; + int i, ret; + + hp = (DB_TXNHEAD *)listp; + + for (elp = LIST_FIRST(&hp->head[0]); + elp != NULL; elp = LIST_NEXT(elp, links)) + if (elp->type == TXNLIST_LSN) + break; + + if (elp == NULL) + return (DB_SURPRISE_KID); + + if (LF_ISSET(TXNLIST_NEW)) { + if (elp->u.l.ntxns >= elp->u.l.maxn) { + if ((ret = __os_realloc(dbenv, + 2 * elp->u.l.maxn * sizeof(DB_LSN), + &elp->u.l.lsn_array)) != 0) + return (ret); + elp->u.l.maxn *= 2; + } + elp->u.l.lsn_array[elp->u.l.ntxns++] = *lsnp; + } else + /* Simply replace the 0th element. */ + elp->u.l.lsn_array[0] = *lsnp; + + /* + * If we just added a new entry and there may be NULL entries, so we + * have to do a complete bubble sort, not just trickle a changed entry + * around. + */ + for (i = 0; i < (!LF_ISSET(TXNLIST_NEW) ? 1 : elp->u.l.ntxns); i++) + TXN_BUBBLE(elp->u.l.lsn_array, elp->u.l.ntxns); + + *lsnp = elp->u.l.lsn_array[0]; + + return (0); +} + +/* + * __db_txnlist_lsninit -- + * Initialize a transaction list with an lsn array entry. + * + * PUBLIC: int __db_txnlist_lsninit __P((DB_ENV *, DB_TXNHEAD *, DB_LSN *)); + */ +int +__db_txnlist_lsninit(dbenv, hp, lsnp) + DB_ENV *dbenv; + DB_TXNHEAD *hp; + DB_LSN *lsnp; +{ + DB_TXNLIST *elp; + int ret; + + elp = NULL; + + if ((ret = __os_malloc(dbenv, sizeof(DB_TXNLIST), &elp)) != 0) + goto err; + LIST_INSERT_HEAD(&hp->head[0], elp, links); + + if ((ret = __os_malloc(dbenv, + 12 * sizeof(DB_LSN), &elp->u.l.lsn_array)) != 0) + goto err; + elp->type = TXNLIST_LSN; + elp->u.l.maxn = 12; + elp->u.l.ntxns = 1; + elp->u.l.lsn_array[0] = *lsnp; + + return (0); + +err: __db_txnlist_end(dbenv, hp); + return (ret); +} + +/* + * __db_add_limbo -- add pages to the limbo list. + * Get the file information and call pgnoadd for each page. + * + * PUBLIC: int __db_add_limbo __P((DB_ENV *, + * PUBLIC: void *, int32_t, db_pgno_t, int32_t)); + */ +int +__db_add_limbo(dbenv, info, fileid, pgno, count) + DB_ENV *dbenv; + void *info; + int32_t fileid; + db_pgno_t pgno; + int32_t count; +{ + DB_LOG *dblp; + FNAME *fnp; + int ret; + + dblp = dbenv->lg_handle; + if ((ret = __dbreg_id_to_fname(dblp, fileid, 0, &fnp)) != 0) + return (ret); + + do { + if ((ret = + __db_txnlist_pgnoadd(dbenv, info, fileid, fnp->ufid, + R_ADDR(&dblp->reginfo, fnp->name_off), pgno)) != 0) + return (ret); + pgno++; + } while (--count != 0); + + return (0); +} + +/* + * __db_do_the_limbo -- move pages from limbo to free. + * + * Limbo processing is what ensures that we correctly handle and + * recover from page allocations. During recovery, for each database, + * we process each in-question allocation, link them into the free list + * and then write out the new meta-data page that contains the pointer + * to the new beginning of the free list. On an abort, we use our + * standard __db_free mechanism in a compensating transaction which logs + * the specific modifications to the free list. + * + * If we run out of log space during an abort, then we can't write the + * compensating transaction, so we abandon the idea of a compenating + * transaction, and go back to processing how we do during recovery. + * The reason that this is not the norm is that it's expensive: it requires + * that we flush any database with an in-question allocation. Thus if + * a compensating transaction fails, we never try to restart it. + * + * Since files may be open and closed within transactions (in particular, + * the master database for subdatabases), we must be prepared to open + * files during this process. If there is a compensating transaction, we + * can open the files in that transaction. If this was an abort and there + * is no compensating transaction, then we've got to perform these opens + * in the context of the aborting transaction so that we do not deadlock. + * During recovery, there's no locking, so this isn't an issue. + * + * What you want to keep in mind when reading this is that there are two + * algorithms going on here: ctxn == NULL, then we're either in recovery + * or our compensating transaction has failed and we're doing the + * "create list and write meta-data page" algorithm. Otherwise, we're in + * an abort and doing the "use compensating transaction" algorithm. + * + * PUBLIC: int __db_do_the_limbo __P((DB_ENV *, + * PUBLIC: DB_TXN *, DB_TXN *, DB_TXNHEAD *)); + */ +int +__db_do_the_limbo(dbenv, ptxn, txn, hp) + DB_ENV *dbenv; + DB_TXN *ptxn, *txn; + DB_TXNHEAD *hp; +{ + DB_TXNLIST *elp; + int h, ret; + + ret = 0; + /* + * The slots correspond to hash buckets. We've hashed the + * fileids into hash buckets and need to pick up all affected + * files. (There will only be a single slot for an abort.) + */ + for (h = 0; h < hp->nslots; h++) { + if ((elp = LIST_FIRST(&hp->head[h])) == NULL) + continue; + if (ptxn != NULL) { + if ((ret = + __db_limbo_move(dbenv, ptxn, txn, elp)) != 0) + goto err; + } else if ((ret = __db_limbo_bucket(dbenv, txn, elp)) != 0) + goto err; + } + +err: if (ret != 0) { + __db_err(dbenv, "Fatal error in abort of an allocation"); + ret = __db_panic(dbenv, ret); + } + + return (ret); +} + +/* Limbo support routines. */ + +/* + * __db_lock_move -- + * Move a lock from child to parent. + */ +static int +__db_lock_move(dbenv, fileid, pgno, mode, ptxn, txn) + DB_ENV *dbenv; + u_int8_t *fileid; + db_pgno_t pgno; + db_lockmode_t mode; + DB_TXN *ptxn, *txn; +{ + DBT lock_dbt; + DB_LOCK lock; + DB_LOCK_ILOCK lock_obj; + DB_LOCKREQ req; + int ret; + + lock_obj.pgno = pgno; + memcpy(lock_obj.fileid, fileid, DB_FILE_ID_LEN); + lock_obj.type = DB_PAGE_LOCK; + + memset(&lock_dbt, 0, sizeof(lock_dbt)); + lock_dbt.data = &lock_obj; + lock_dbt.size = sizeof(lock_obj); + + if ((ret = dbenv->lock_get(dbenv, + txn->txnid, 0, &lock_dbt, mode, &lock)) == 0) { + memset(&req, 0, sizeof(req)); + req.lock = lock; + req.op = DB_LOCK_TRADE; + + ret = dbenv->lock_vec(dbenv, ptxn->txnid, 0, &req, 1, NULL); + } + return (ret); +} + +/* + * __db_limbo_move + * Move just the metapage lock to the parent. + */ +static int +__db_limbo_move(dbenv, ptxn, txn, elp) + DB_ENV *dbenv; + DB_TXN *ptxn, *txn; + DB_TXNLIST *elp; +{ + int ret; + + for (; elp != NULL; elp = LIST_NEXT(elp, links)) { + if (elp->type != TXNLIST_PGNO || elp->u.p.locked == 1) + continue; + if ((ret = __db_lock_move(dbenv, elp->u.p.uid, + PGNO_BASE_MD, DB_LOCK_WRITE, ptxn, txn)) != 0) + return (ret); + elp->u.p.locked = 1; + } + + return (0); +} +/* + * __db_limbo_bucket + * Perform limbo processing for a single hash bucket in the txnlist. + * txn is the transaction aborting in the case of an abort and ctxn is the + * compensating transaction. + */ + +#define T_RESTORED(txn) ((txn) != NULL && F_ISSET(txn, TXN_RESTORED)) +static int +__db_limbo_bucket(dbenv, txn, elp) + DB_ENV *dbenv; + DB_TXN *txn; + DB_TXNLIST *elp; +{ + DB *dbp; + DB_MPOOLFILE *mpf; + DBMETA *meta; + DB_TXN *ctxn, *t; + db_pgno_t last_pgno, pgno; + int dbp_created, in_retry, ret, t_ret; + + ctxn = NULL; + in_retry = 0; + meta = NULL; + mpf = NULL; + ret = 0; + for (; elp != NULL; elp = LIST_NEXT(elp, links)) { + if (elp->type != TXNLIST_PGNO) + continue; +retry: dbp_created = 0; + + /* + * Pick the transaction in which to potentially + * log compensations. + */ + if (!in_retry && !IS_RECOVERING(dbenv) && !T_RESTORED(txn) + && (ret = __txn_compensate_begin(dbenv, &ctxn)) != 0) + return (ret); + + /* + * Either use the compensating transaction or + * the one passed in, which will be null if recovering. + */ + t = ctxn == NULL ? txn : ctxn; + + /* First try to get a dbp by fileid. */ + ret = __dbreg_id_to_db(dbenv, t, &dbp, elp->u.p.fileid, 0); + + /* + * File is being destroyed. No need to worry about + * dealing with recovery of allocations. + */ + if (ret == DB_DELETED || + (ret == 0 && F_ISSET(dbp, DB_AM_DISCARD))) + goto next; + + if (ret != 0) { + if ((ret = db_create(&dbp, dbenv, 0)) != 0) + goto err; + + /* + * This tells the system not to lock, which is always + * OK, whether this is an abort or recovery. + */ + F_SET(dbp, DB_AM_COMPENSATE); + dbp_created = 1; + + /* It is ok if the file is nolonger there. */ + dbp->type = DB_UNKNOWN; + ret = __db_dbopen(dbp, t, elp->u.p.fname, NULL, + DB_ODDFILESIZE, __db_omode("rw----"), PGNO_BASE_MD); + if (ret == ENOENT) + goto next; + } + + /* + * Verify that we are opening the same file that we were + * referring to when we wrote this log record. + */ + if (memcmp(elp->u.p.uid, dbp->fileid, DB_FILE_ID_LEN) != 0) + goto next; + + mpf = dbp->mpf; + last_pgno = PGNO_INVALID; + + if (ctxn == NULL) { + pgno = PGNO_BASE_MD; + if ((ret = + mpf->get(mpf, &pgno, 0, (PAGE **)&meta)) != 0) + goto err; + last_pgno = meta->free; + } + + ret = __db_limbo_fix(dbp, ctxn, elp, &last_pgno, meta); + /* + * If we were doing compensating transactions, then we are + * going to hope this error was due to running out of space. + * We'll change modes (into the sync the file mode) and keep + * trying. If we weren't doing compensating transactions, + * then this is a real error and we're sunk. + */ + if (ret != 0) { + if (ret == DB_RUNRECOVERY || ctxn == NULL) + goto err; + in_retry = 1; + goto retry; + } + + if (ctxn != NULL) { + ret = ctxn->commit(ctxn, DB_TXN_NOSYNC); + ctxn = NULL; + if (ret != 0) + goto retry; + goto next; + } + + /* + * This is where we handle the case where we're explicitly + * putting together a free list. We need to decide whether + * we have to write the meta-data page, and if we do, then + * we need to sync it as well. + */ + if (last_pgno == meta->free) { + /* No change to page; just put the page back. */ + if ((ret = mpf->put(mpf, meta, 0)) != 0) + goto err; + meta = NULL; + } else { + /* + * These changes are unlogged so we cannot have the + * metapage pointing at pages that are not on disk. + * Therefore, we flush the new free list, then update + * the metapage. We have to put the meta-data page + * first so that it isn't pinned when we try to sync. + */ + if (!IS_RECOVERING(dbenv) && !T_RESTORED(txn)) + __db_err(dbenv, "Flushing free list to disk"); + if ((ret = mpf->put(mpf, meta, 0)) != 0) + goto err; + meta = NULL; + dbp->sync(dbp, 0); + pgno = PGNO_BASE_MD; + if ((ret = + mpf->get(mpf, &pgno, 0, (PAGE **)&meta)) != 0) + goto err; + meta->free = last_pgno; + if ((ret = mpf->put(mpf, meta, DB_MPOOL_DIRTY)) != 0) + goto err; + meta = NULL; + } + +next: + /* + * If we get here, either we have processed the list + * or the db file has been deleted or could no be opened. + */ + if (ctxn != NULL && + (t_ret = ctxn->abort(ctxn)) != 0 && ret == 0) + ret = t_ret; + + if (dbp_created && + (t_ret = __db_close_i(dbp, txn, 0)) != 0 && ret == 0) + ret = t_ret; + dbp = NULL; + __os_free(dbenv, elp->u.p.fname); + __os_free(dbenv, elp->u.p.pgno_array); + if (ret == ENOENT) + ret = 0; + else if (ret != 0) + goto err; + } + +err: if (meta != NULL) + (void)mpf->put(mpf, meta, 0); + return (ret); +} + +/* + * __db_limbo_fix -- + * Process a single limbo entry which describes all the page allocations + * for a single file. + */ +static int +__db_limbo_fix(dbp, ctxn, elp, lastp, meta) + DB *dbp; + DB_TXN *ctxn; + DB_TXNLIST *elp; + db_pgno_t *lastp; + DBMETA *meta; +{ + DBC *dbc; + DB_MPOOLFILE *mpf; + PAGE *freep, *pagep; + db_pgno_t next, pgno; + int i, put_page, ret, t_ret; + + /* + * Loop through the entries for this txnlist element and + * either link them into the free list or write a compensating + * record for each. + */ + put_page = 0; + ret = 0; + mpf = dbp->mpf; + dbc = NULL; + + for (i = 0; i < elp->u.p.nentries; i++) { + pgno = elp->u.p.pgno_array[i]; + + if ((ret = mpf->get(mpf, &pgno, DB_MPOOL_CREATE, &pagep)) != 0) + goto err; + put_page = 1; + + if (IS_ZERO_LSN(LSN(pagep))) { + if (ctxn == NULL) { + /* + * If this is a fatal recovery which + * spans a previous crash this page may + * be on the free list already. + */ + for (next = *lastp; next != 0; ) { + if (next == pgno) + break; + if ((ret = mpf->get(mpf, + &next, 0, &freep)) != 0) + goto err; + next = NEXT_PGNO(freep); + if ((ret = + mpf->put(mpf, freep, 0)) != 0) + goto err; + } + + if (next != pgno) { + P_INIT(pagep, dbp->pgsize, pgno, + PGNO_INVALID, *lastp, 0, P_INVALID); + LSN(pagep) = LSN(meta); + *lastp = pgno; + } + } else { + P_INIT(pagep, dbp->pgsize, pgno, + PGNO_INVALID, *lastp, 0, P_INVALID); + if (dbc == NULL && (ret = + dbp->cursor(dbp, ctxn, &dbc, 0)) != 0) + goto err; + /* + * If the dbp is compensating (because we + * opened it), the dbc will automatically be + * marked compensating, but in case we didn't + * do the open, we have to mark it explicitly. + */ + F_SET(dbc, DBC_COMPENSATE); + ret = __db_free(dbc, pagep); + put_page = 0; + /* + * On any error, we hope that the error was + * caused due to running out of space, and we + * switch modes, doing the processing where we + * sync out files instead of doing compensating + * transactions. If this was a real error and + * not out of space, we assume that some other + * call will fail real soon. + */ + if (ret != 0) { + /* Assume that this is out of space. */ + (void)dbc->c_close(dbc); + dbc = NULL; + goto err; + } + } + } + + if (put_page == 1) { + ret = mpf->put(mpf, pagep, DB_MPOOL_DIRTY); + put_page = 0; + } + if (ret != 0) + goto err; + } + +err: if (put_page && + (t_ret = mpf->put(mpf, pagep, DB_MPOOL_DIRTY)) != 0 && ret == 0) + ret = t_ret; + if (dbc != NULL && (t_ret = dbc->c_close(dbc)) != 0 && ret == 0) + ret = t_ret; + return (ret); +} + +#define DB_TXNLIST_MAX_PGNO 8 /* A nice even number. */ + +/* + * __db_txnlist_pgnoadd -- + * Find the txnlist entry for a file and add this pgno, or add the list + * entry for the file and then add the pgno. + */ +static int +__db_txnlist_pgnoadd(dbenv, hp, fileid, uid, fname, pgno) + DB_ENV *dbenv; + DB_TXNHEAD *hp; + int32_t fileid; + u_int8_t uid[DB_FILE_ID_LEN]; + char *fname; + db_pgno_t pgno; +{ + DB_TXNLIST *elp; + u_int32_t hash; + int len, ret; + + elp = NULL; + + if (__db_txnlist_find_internal(dbenv, hp, + TXNLIST_PGNO, 0, uid, &elp, 0) != 0) { + if ((ret = + __os_malloc(dbenv, sizeof(DB_TXNLIST), &elp)) != 0) + goto err; + memcpy(&hash, uid, sizeof(hash)); + LIST_INSERT_HEAD( + &hp->head[DB_TXNLIST_MASK(hp, hash)], elp, links); + elp->u.p.fileid = fileid; + memcpy(elp->u.p.uid, uid, DB_FILE_ID_LEN); + + len = (int)strlen(fname) + 1; + if ((ret = __os_malloc(dbenv, len, &elp->u.p.fname)) != 0) + goto err; + memcpy(elp->u.p.fname, fname, len); + + elp->u.p.maxentry = 0; + elp->u.p.locked = 0; + elp->type = TXNLIST_PGNO; + if ((ret = __os_malloc(dbenv, + 8 * sizeof(db_pgno_t), &elp->u.p.pgno_array)) != 0) + goto err; + elp->u.p.maxentry = DB_TXNLIST_MAX_PGNO; + elp->u.p.nentries = 0; + } else if (elp->u.p.nentries == elp->u.p.maxentry) { + elp->u.p.maxentry <<= 1; + if ((ret = __os_realloc(dbenv, elp->u.p.maxentry * + sizeof(db_pgno_t), &elp->u.p.pgno_array)) != 0) + goto err; + } + + elp->u.p.pgno_array[elp->u.p.nentries++] = pgno; + + return (0); + +err: __db_txnlist_end(dbenv, hp); + return (ret); +} + +/* + * __db_default_getpgnos -- + * Fill in default getpgnos information for an application-specific + * log record. + */ +static int +__db_default_getpgnos(dbenv, lsnp, summary) + DB_ENV *dbenv; + DB_LSN *lsnp; + void *summary; +{ + TXN_RECS *t; + int ret; + + t = (TXN_RECS *)summary; + + if ((ret = __rep_check_alloc(dbenv, t, 1)) != 0) + return (ret); + + t->array[t->npages].flags = LSN_PAGE_NOLOCK; + t->array[t->npages].lsn = *lsnp; + t->array[t->npages].fid = DB_LOGFILEID_INVALID; + memset(&t->array[t->npages].pgdesc, 0, + sizeof(t->array[t->npages].pgdesc)); + + t->npages++; + + return (0); +} + +#ifdef DEBUG +/* + * __db_txnlist_print -- + * Print out the transaction list. + * + * PUBLIC: void __db_txnlist_print __P((void *)); + */ +void +__db_txnlist_print(listp) + void *listp; +{ + DB_TXNHEAD *hp; + DB_TXNLIST *p; + int i; + char *stats[] = { "ok", "commit", "prepare", "abort", "notfound", + "ignore", "expected", "unexpected" }; + + hp = (DB_TXNHEAD *)listp; + + printf("Maxid: %lu Generation: %lu\n", + (u_long)hp->maxid, (u_long)hp->generation); + for (i = 0; i < hp->nslots; i++) + for (p = LIST_FIRST(&hp->head[i]); p != NULL; p = LIST_NEXT(p, links)) { + switch (p->type) { + case TXNLIST_TXNID: + printf("TXNID: %lx(%lu): %s\n", + (u_long)p->u.t.txnid, (u_long)p->u.t.generation, + stats[p->u.t.status]); + break; + default: + printf("Unrecognized type: %d\n", p->type); + break; + } + } +} +#endif |