log_put.c
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上传日期:2022-05-23
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文件大小:33k
- /*-
- * 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_put.c,v 11.112 2002/09/10 02:39:26 bostic Exp $";
- #endif /* not lint */
- #ifndef NO_SYSTEM_INCLUDES
- #include <sys/types.h>
- #if TIME_WITH_SYS_TIME
- #include <sys/time.h>
- #include <time.h>
- #else
- #if HAVE_SYS_TIME_H
- #include <sys/time.h>
- #else
- #include <time.h>
- #endif
- #endif
- #include <stdio.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/rep.h"
- #include "dbinc/txn.h"
- static int __log_encrypt_record __P((DB_ENV *, DBT *, HDR *, u_int32_t));
- static int __log_fill __P((DB_LOG *, DB_LSN *, void *, u_int32_t));
- static int __log_flush_commit __P((DB_ENV *, const DB_LSN *, u_int32_t));
- static int __log_flush_int __P((DB_LOG *, const DB_LSN *, int));
- static int __log_newfh __P((DB_LOG *));
- static int __log_put_next __P((DB_ENV *,
- DB_LSN *, const DBT *, HDR *, DB_LSN *));
- static int __log_putr __P((DB_LOG *,
- DB_LSN *, const DBT *, u_int32_t, HDR *));
- static int __log_write __P((DB_LOG *, void *, u_int32_t));
- /*
- * __log_put --
- * Write a log record. This is the public interface, DB_ENV->log_put.
- *
- * PUBLIC: int __log_put __P((DB_ENV *, DB_LSN *, const DBT *, u_int32_t));
- */
- int
- __log_put(dbenv, lsnp, udbt, flags)
- DB_ENV *dbenv;
- DB_LSN *lsnp;
- const DBT *udbt;
- u_int32_t flags;
- {
- DB_CIPHER *db_cipher;
- DBT *dbt, t;
- DB_LOG *dblp;
- DB_LSN lsn, old_lsn;
- HDR hdr;
- LOG *lp;
- u_int32_t do_flush, op, writeonly;
- int lock_held, need_free, ret;
- u_int8_t *key;
- PANIC_CHECK(dbenv);
- ENV_REQUIRES_CONFIG(dbenv,
- dbenv->lg_handle, "DB_ENV->log_put", DB_INIT_LOG);
- /* Validate arguments. */
- op = DB_OPFLAGS_MASK & flags;
- if (op != 0 && op != DB_COMMIT)
- return (__db_ferr(dbenv, "DB_ENV->log_put", 0));
- /* Check for allowed bit-flags. */
- if (LF_ISSET(~(DB_OPFLAGS_MASK |
- DB_FLUSH | DB_NOCOPY | DB_PERMANENT | DB_WRNOSYNC)))
- return (__db_ferr(dbenv, "DB_ENV->log_put", 0));
- /* DB_WRNOSYNC and DB_FLUSH are mutually exclusive. */
- if (LF_ISSET(DB_WRNOSYNC) && LF_ISSET(DB_FLUSH))
- return (__db_ferr(dbenv, "DB_ENV->log_put", 1));
- /* Replication clients should never write log records. */
- if (F_ISSET(dbenv, DB_ENV_REP_CLIENT) ||
- F_ISSET(dbenv, DB_ENV_REP_LOGSONLY)) {
- __db_err(dbenv,
- "DB_ENV->log_put is illegal on replication clients");
- return (EINVAL);
- }
- dblp = dbenv->lg_handle;
- lp = dblp->reginfo.primary;
- db_cipher = dbenv->crypto_handle;
- dbt = &t;
- t = *udbt;
- lock_held = need_free = 0;
- do_flush = LF_ISSET(DB_FLUSH);
- writeonly = LF_ISSET(DB_WRNOSYNC);
- /*
- * If we are coming from the logging code, we use an internal
- * flag, DB_NOCOPY, because we know we can overwrite/encrypt
- * the log record in place. Otherwise, if a user called log_put
- * then we must copy it to new memory so that we know we can
- * write it.
- *
- * We also must copy it to new memory if we are a replication
- * master so that we retain an unencrypted copy of the log
- * record to send to clients.
- */
- if (!LF_ISSET(DB_NOCOPY) || F_ISSET(dbenv, DB_ENV_REP_MASTER)) {
- if (CRYPTO_ON(dbenv))
- t.size += db_cipher->adj_size(udbt->size);
- if ((ret = __os_calloc(dbenv, 1, t.size, &t.data)) != 0)
- goto err;
- need_free = 1;
- memcpy(t.data, udbt->data, udbt->size);
- }
- if ((ret = __log_encrypt_record(dbenv, dbt, &hdr, udbt->size)) != 0)
- goto err;
- if (CRYPTO_ON(dbenv))
- key = db_cipher->mac_key;
- else
- key = NULL;
- /* Otherwise, we actually have a record to put. Put it. */
- /* Before we grab the region lock, calculate the record's checksum. */
- __db_chksum(dbt->data, dbt->size, key, hdr.chksum);
- R_LOCK(dbenv, &dblp->reginfo);
- lock_held = 1;
- ZERO_LSN(old_lsn);
- if ((ret = __log_put_next(dbenv, &lsn, dbt, &hdr, &old_lsn)) != 0)
- goto err;
- if (F_ISSET(dbenv, DB_ENV_REP_MASTER)) {
- /*
- * Replication masters need to drop the lock to send
- * messages, but we want to drop and reacquire it a minimal
- * number of times.
- */
- R_UNLOCK(dbenv, &dblp->reginfo);
- lock_held = 0;
- /*
- * If we changed files and we're in a replicated
- * environment, we need to inform our clients now that
- * we've dropped the region lock.
- *
- * Note that a failed NEWFILE send is a dropped message
- * that our client can handle, so we can ignore it. It's
- * possible that the record we already put is a commit, so
- * we don't just want to return failure.
- */
- if (!IS_ZERO_LSN(old_lsn))
- (void)__rep_send_message(dbenv,
- DB_EID_BROADCAST, REP_NEWFILE, &old_lsn, NULL, 0);
- /*
- * Then send the log record itself on to our clients.
- *
- * If the send fails and we're a commit or checkpoint,
- * there's nothing we can do; the record's in the log.
- * Flush it, even if we're running with TXN_NOSYNC, on the
- * grounds that it should be in durable form somewhere.
- */
- /*
- * !!!
- * In the crypto case, we MUST send the udbt, not the
- * now-encrypted dbt. Clients have no way to decrypt
- * without the header.
- */
- if ((__rep_send_message(dbenv,
- DB_EID_BROADCAST, REP_LOG, &lsn, udbt, flags) != 0) &&
- LF_ISSET(DB_PERMANENT))
- do_flush |= DB_FLUSH;
- }
- /*
- * If needed, do a flush. Note that failures at this point
- * are only permissible if we know we haven't written a commit
- * record; __log_flush_commit is responsible for enforcing this.
- *
- * If a flush is not needed, see if WRITE_NOSYNC was set and we
- * need to write out the log buffer.
- */
- if (do_flush || writeonly) {
- if (!lock_held) {
- R_LOCK(dbenv, &dblp->reginfo);
- lock_held = 1;
- }
- if (do_flush)
- ret = __log_flush_commit(dbenv, &lsn, flags);
- else if (lp->b_off != 0)
- /*
- * writeonly: if there's anything in the current
- * log buffer, we need to write it out.
- */
- if ((ret = __log_write(dblp,
- dblp->bufp, (u_int32_t)lp->b_off)) == 0)
- lp->b_off = 0;
- }
- err: if (lock_held)
- R_UNLOCK(dbenv, &dblp->reginfo);
- if (need_free)
- __os_free(dbenv, dbt->data);
- if (ret == 0)
- *lsnp = lsn;
- return (ret);
- }
- /*
- * __log_txn_lsn --
- *
- * PUBLIC: void __log_txn_lsn
- * PUBLIC: __P((DB_ENV *, DB_LSN *, u_int32_t *, u_int32_t *));
- */
- void
- __log_txn_lsn(dbenv, lsnp, mbytesp, bytesp)
- DB_ENV *dbenv;
- DB_LSN *lsnp;
- u_int32_t *mbytesp, *bytesp;
- {
- DB_LOG *dblp;
- LOG *lp;
- dblp = dbenv->lg_handle;
- lp = dblp->reginfo.primary;
- R_LOCK(dbenv, &dblp->reginfo);
- /*
- * We are trying to get the LSN of the last entry in the log. We use
- * this in two places: 1) DB_ENV->txn_checkpiont uses it as a first
- * value when trying to compute an LSN such that all transactions begun
- * before it are complete. 2) DB_ENV->txn_begin uses it as the
- * begin_lsn.
- *
- * Typically, it's easy to get the last written LSN, you simply look
- * at the current log pointer and back up the number of bytes of the
- * last log record. However, if the last thing we did was write the
- * log header of a new log file, then, this doesn't work, so we return
- * the first log record that will be written in this new file.
- */
- *lsnp = lp->lsn;
- if (lp->lsn.offset > lp->len)
- lsnp->offset -= lp->len;
- /*
- * Since we're holding the log region lock, return the bytes put into
- * the log since the last checkpoint, transaction checkpoint needs it.
- *
- * We add the current buffer offset so as to count bytes that have not
- * yet been written, but are sitting in the log buffer.
- */
- if (mbytesp != NULL) {
- *mbytesp = lp->stat.st_wc_mbytes;
- *bytesp = (u_int32_t)(lp->stat.st_wc_bytes + lp->b_off);
- lp->stat.st_wc_mbytes = lp->stat.st_wc_bytes = 0;
- }
- R_UNLOCK(dbenv, &dblp->reginfo);
- }
- /*
- * __log_put_next --
- * Put the given record as the next in the log, wherever that may
- * turn out to be.
- */
- static int
- __log_put_next(dbenv, lsn, dbt, hdr, old_lsnp)
- DB_ENV *dbenv;
- DB_LSN *lsn;
- const DBT *dbt;
- HDR *hdr;
- DB_LSN *old_lsnp;
- {
- DB_LOG *dblp;
- DB_LSN old_lsn;
- LOG *lp;
- int newfile, ret;
- dblp = dbenv->lg_handle;
- lp = dblp->reginfo.primary;
- /*
- * Save a copy of lp->lsn before we might decide to switch log
- * files and change it. If we do switch log files, and we're
- * doing replication, we'll need to tell our clients about the
- * switch, and they need to receive a NEWFILE message
- * with this "would-be" LSN in order to know they're not
- * missing any log records.
- */
- old_lsn = lp->lsn;
- newfile = 0;
- /*
- * If this information won't fit in the file, or if we're a
- * replication client environment and have been told to do so,
- * swap files.
- */
- if (lp->lsn.offset == 0 ||
- lp->lsn.offset + hdr->size + dbt->size > lp->log_size) {
- if (hdr->size + sizeof(LOGP) + dbt->size > lp->log_size) {
- __db_err(dbenv,
- "DB_ENV->log_put: record larger than maximum file size");
- return (EINVAL);
- }
- if ((ret = __log_newfile(dblp, NULL)) != 0)
- return (ret);
- /*
- * Flag that we switched files, in case we're a master
- * and need to send this information to our clients.
- * We postpone doing the actual send until we can
- * safely release the log region lock and are doing so
- * anyway.
- */
- newfile = 1;
-
- if (dbenv->db_noticecall != NULL)
- dbenv->db_noticecall(dbenv, DB_NOTICE_LOGFILE_CHANGED);
- }
- /*
- * The offset into the log file at this point is the LSN where
- * we're about to put this record, and is the LSN the caller wants.
- */
- *lsn = lp->lsn;
- /* If we switched log files, let our caller know where. */
- if (newfile)
- *old_lsnp = old_lsn;
- /* Actually put the record. */
- return (__log_putr(dblp, lsn, dbt, lp->lsn.offset - lp->len, hdr));
- }
- /*
- * __log_flush_commit --
- * Flush a record for which the DB_FLUSH flag to log_put has been set.
- */
- static int
- __log_flush_commit(dbenv, lsnp, flags)
- DB_ENV *dbenv;
- const DB_LSN *lsnp;
- u_int32_t flags;
- {
- DB_LOG *dblp;
- DB_LSN flush_lsn;
- LOG *lp;
- int ret;
- u_int32_t op;
- dblp = dbenv->lg_handle;
- lp = dblp->reginfo.primary;
- flush_lsn = *lsnp;
- op = DB_OPFLAGS_MASK & flags;
- if ((ret = __log_flush_int(dblp, &flush_lsn, 1)) == 0)
- return (0);
- /*
- * If a flush supporting a transaction commit fails, we must abort the
- * transaction. (If we aren't doing a commit, return the failure; if
- * if the commit we care about made it to disk successfully, we just
- * ignore the failure, because there's no way to undo the commit.)
- */
- if (op != DB_COMMIT)
- return (ret);
- if (flush_lsn.file != lp->lsn.file || flush_lsn.offset < lp->w_off)
- return (0);
- /*
- * Else, make sure that the commit record does not get out after we
- * abort the transaction. Do this by overwriting the commit record
- * in the buffer. (Note that other commits in this buffer will wait
- * wait until a sucessful write happens, we do not wake them.) We
- * point at the right part of the buffer and write an abort record
- * over the commit. We must then try and flush the buffer again,
- * since the interesting part of the buffer may have actually made
- * it out to disk before there was a failure, we can't know for sure.
- */
- if (__txn_force_abort(dbenv,
- dblp->bufp + flush_lsn.offset - lp->w_off) == 0)
- (void)__log_flush_int(dblp, &flush_lsn, 0);
- return (ret);
- }
- /*
- * __log_newfile --
- * Initialize and switch to a new log file. (Note that this is
- * called both when no log yet exists and when we fill a log file.)
- *
- * PUBLIC: int __log_newfile __P((DB_LOG *, DB_LSN *));
- */
- int
- __log_newfile(dblp, lsnp)
- DB_LOG *dblp;
- DB_LSN *lsnp;
- {
- DB_CIPHER *db_cipher;
- DB_ENV *dbenv;
- DB_LSN lsn;
- DBT t;
- HDR hdr;
- LOG *lp;
- int need_free, ret;
- u_int32_t lastoff;
- size_t tsize;
- u_int8_t *tmp;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /* If we're not at the beginning of a file already, start a new one. */
- if (lp->lsn.offset != 0) {
- /*
- * Flush the log so this file is out and can be closed. We
- * cannot release the region lock here because we need to
- * protect the end of the file while we switch. In
- * particular, a thread with a smaller record than ours
- * could detect that there is space in the log. Even
- * blocking that event by declaring the file full would
- * require all threads to wait here so that the lsn.file
- * can be moved ahead after the flush completes. This
- * probably can be changed if we had an lsn for the
- * previous file and one for the curent, but it does not
- * seem like this would get much more throughput, if any.
- */
- if ((ret = __log_flush_int(dblp, NULL, 0)) != 0)
- return (ret);
- DB_ASSERT(lp->b_off == 0);
- /*
- * Save the last known offset from the previous file, we'll
- * need it to initialize the persistent header information.
- */
- lastoff = lp->lsn.offset;
- /* Point the current LSN to the new file. */
- ++lp->lsn.file;
- lp->lsn.offset = 0;
- /* Reset the file write offset. */
- lp->w_off = 0;
- } else
- lastoff = 0;
- /*
- * Insert persistent information as the first record in every file.
- * Note that the previous length is wrong for the very first record
- * of the log, but that's okay, we check for it during retrieval.
- */
- DB_ASSERT(lp->b_off == 0);
- memset(&t, 0, sizeof(t));
- memset(&hdr, 0, sizeof(HDR));
- need_free = 0;
- tsize = sizeof(LOGP);
- db_cipher = dbenv->crypto_handle;
- if (CRYPTO_ON(dbenv))
- tsize += db_cipher->adj_size(tsize);
- if ((ret = __os_calloc(dbenv, 1, tsize, &tmp)) != 0)
- return (ret);
- lp->persist.log_size = lp->log_size = lp->log_nsize;
- memcpy(tmp, &lp->persist, sizeof(LOGP));
- t.data = tmp;
- t.size = (u_int32_t)tsize;
- need_free = 1;
- if ((ret =
- __log_encrypt_record(dbenv, &t, &hdr, (u_int32_t)tsize)) != 0)
- goto err;
- __db_chksum(t.data, t.size,
- (CRYPTO_ON(dbenv)) ? db_cipher->mac_key : NULL, hdr.chksum);
- lsn = lp->lsn;
- if ((ret = __log_putr(dblp, &lsn,
- &t, lastoff == 0 ? 0 : lastoff - lp->len, &hdr)) != 0)
- goto err;
- /* Update the LSN information returned to the caller. */
- if (lsnp != NULL)
- *lsnp = lp->lsn;
- err:
- if (need_free)
- __os_free(dbenv, tmp);
- return (ret);
- }
- /*
- * __log_putr --
- * Actually put a record into the log.
- */
- static int
- __log_putr(dblp, lsn, dbt, prev, h)
- DB_LOG *dblp;
- DB_LSN *lsn;
- const DBT *dbt;
- u_int32_t prev;
- HDR *h;
- {
- DB_CIPHER *db_cipher;
- DB_ENV *dbenv;
- DB_LSN f_lsn;
- LOG *lp;
- HDR tmp, *hdr;
- int ret, t_ret;
- size_t b_off, nr;
- u_int32_t w_off;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /*
- * If we weren't given a header, use a local one.
- */
- db_cipher = dbenv->crypto_handle;
- if (h == NULL) {
- hdr = &tmp;
- memset(hdr, 0, sizeof(HDR));
- if (CRYPTO_ON(dbenv))
- hdr->size = HDR_CRYPTO_SZ;
- else
- hdr->size = HDR_NORMAL_SZ;
- } else
- hdr = h;
- /* Save our position in case we fail. */
- b_off = lp->b_off;
- w_off = lp->w_off;
- f_lsn = lp->f_lsn;
- /*
- * Initialize the header. If we just switched files, lsn.offset will
- * be 0, and what we really want is the offset of the previous record
- * in the previous file. Fortunately, prev holds the value we want.
- */
- hdr->prev = prev;
- hdr->len = (u_int32_t)hdr->size + dbt->size;
- /*
- * If we were passed in a nonzero checksum, our caller calculated
- * the checksum before acquiring the log mutex, as an optimization.
- *
- * If our caller calculated a real checksum of 0, we'll needlessly
- * recalculate it. C'est la vie; there's no out-of-bounds value
- * here.
- */
- if (hdr->chksum[0] == 0)
- __db_chksum(dbt->data, dbt->size,
- (CRYPTO_ON(dbenv)) ? db_cipher->mac_key : NULL,
- hdr->chksum);
- if ((ret = __log_fill(dblp, lsn, hdr, (u_int32_t)hdr->size)) != 0)
- goto err;
- if ((ret = __log_fill(dblp, lsn, dbt->data, dbt->size)) != 0)
- goto err;
- lp->len = (u_int32_t)(hdr->size + dbt->size);
- lp->lsn.offset += (u_int32_t)(hdr->size + dbt->size);
- return (0);
- err:
- /*
- * If we wrote more than one buffer before failing, get the
- * first one back. The extra buffers will fail the checksums
- * and be ignored.
- */
- if (w_off + lp->buffer_size < lp->w_off) {
- if ((t_ret =
- __os_seek(dbenv,
- &dblp->lfh, 0, 0, w_off, 0, DB_OS_SEEK_SET)) != 0 ||
- (t_ret = __os_read(dbenv, &dblp->lfh, dblp->bufp,
- b_off, &nr)) != 0)
- return (__db_panic(dbenv, t_ret));
- if (nr != b_off) {
- __db_err(dbenv, "Short read while restoring log");
- return (__db_panic(dbenv, EIO));
- }
- }
- /* Reset to where we started. */
- lp->w_off = w_off;
- lp->b_off = b_off;
- lp->f_lsn = f_lsn;
- return (ret);
- }
- /*
- * __log_flush --
- * Write all records less than or equal to the specified LSN.
- *
- * PUBLIC: int __log_flush __P((DB_ENV *, const DB_LSN *));
- */
- int
- __log_flush(dbenv, lsn)
- DB_ENV *dbenv;
- const DB_LSN *lsn;
- {
- DB_LOG *dblp;
- int ret;
- PANIC_CHECK(dbenv);
- ENV_REQUIRES_CONFIG(dbenv,
- dbenv->lg_handle, "DB_ENV->log_flush", DB_INIT_LOG);
- dblp = dbenv->lg_handle;
- R_LOCK(dbenv, &dblp->reginfo);
- ret = __log_flush_int(dblp, lsn, 1);
- R_UNLOCK(dbenv, &dblp->reginfo);
- return (ret);
- }
- /*
- * __log_flush_int --
- * Write all records less than or equal to the specified LSN; internal
- * version.
- */
- static int
- __log_flush_int(dblp, lsnp, release)
- DB_LOG *dblp;
- const DB_LSN *lsnp;
- int release;
- {
- DB_ENV *dbenv;
- DB_LSN flush_lsn, f_lsn;
- DB_MUTEX *flush_mutexp;
- LOG *lp;
- int current, do_flush, first, ret;
- size_t b_off;
- struct __db_commit *commit;
- u_int32_t ncommit, w_off;
- ret = 0;
- ncommit = 0;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- flush_mutexp = R_ADDR(&dblp->reginfo, lp->flush_mutex_off);
- /*
- * If no LSN specified, flush the entire log by setting the flush LSN
- * to the last LSN written in the log. Otherwise, check that the LSN
- * isn't a non-existent record for the log.
- */
- if (lsnp == NULL) {
- flush_lsn.file = lp->lsn.file;
- flush_lsn.offset = lp->lsn.offset - lp->len;
- } else if (lsnp->file > lp->lsn.file ||
- (lsnp->file == lp->lsn.file &&
- lsnp->offset > lp->lsn.offset - lp->len)) {
- __db_err(dbenv,
- "DB_ENV->log_flush: LSN past current end-of-log");
- return (EINVAL);
- } else {
- /*
- * See if we need to wait. s_lsn is not locked so some
- * care is needed. The sync point can only move forward.
- * If the file we want is in the past we are done.
- * If the file numbers are the same check the offset.
- * If this fails check the file numbers again since the
- * offset might have changed while we were looking.
- * This all assumes we can read an integer in one
- * state or the other, not in transition.
- */
- if (lp->s_lsn.file > lsnp->file)
- return (0);
- if (lp->s_lsn.file == lsnp->file &&
- lp->s_lsn.offset > lsnp->offset)
- return (0);
- if (lp->s_lsn.file > lsnp->file)
- return (0);
- flush_lsn = *lsnp;
- }
- /*
- * If a flush is in progress and we're allowed to do so, drop
- * the region lock and block waiting for the next flush.
- */
- if (release && lp->in_flush != 0) {
- if ((commit = SH_TAILQ_FIRST(
- &lp->free_commits, __db_commit)) == NULL) {
- if ((ret =
- __db_shalloc(dblp->reginfo.addr,
- sizeof(struct __db_commit),
- MUTEX_ALIGN, &commit)) != 0)
- goto flush;
- memset(commit, 0, sizeof(*commit));
- if ((ret = __db_mutex_setup(dbenv, &dblp->reginfo,
- &commit->mutex, MUTEX_SELF_BLOCK |
- MUTEX_NO_RLOCK)) != 0) {
- __db_shalloc_free(dblp->reginfo.addr, commit);
- return (ret);
- }
- MUTEX_LOCK(dbenv, &commit->mutex);
- } else
- SH_TAILQ_REMOVE(
- &lp->free_commits, commit, links, __db_commit);
- lp->ncommit++;
- /*
- * Flushes may be requested out of LSN order; be
- * sure we only move lp->t_lsn forward.
- */
- if (log_compare(&lp->t_lsn, &flush_lsn) < 0)
- lp->t_lsn = flush_lsn;
- commit->lsn = flush_lsn;
- SH_TAILQ_INSERT_HEAD(
- &lp->commits, commit, links, __db_commit);
- R_UNLOCK(dbenv, &dblp->reginfo);
- /* Wait here for the in-progress flush to finish. */
- MUTEX_LOCK(dbenv, &commit->mutex);
- R_LOCK(dbenv, &dblp->reginfo);
- lp->ncommit--;
- /*
- * Grab the flag before freeing the struct to see if
- * we need to flush the log to commit. If so,
- * use the maximal lsn for any committing thread.
- */
- do_flush = F_ISSET(commit, DB_COMMIT_FLUSH);
- F_CLR(commit, DB_COMMIT_FLUSH);
- SH_TAILQ_INSERT_HEAD(
- &lp->free_commits, commit, links, __db_commit);
- if (do_flush) {
- lp->in_flush--;
- flush_lsn = lp->t_lsn;
- } else
- return (0);
- }
- /*
- * Protect flushing with its own mutex so we can release
- * the region lock except during file switches.
- */
- flush: MUTEX_LOCK(dbenv, flush_mutexp);
- /*
- * If the LSN is less than or equal to the last-sync'd LSN, we're done.
- * Note, the last-sync LSN saved in s_lsn is the LSN of the first byte
- * after the byte we absolutely know was written to disk, so the test
- * is <, not <=.
- */
- if (flush_lsn.file < lp->s_lsn.file ||
- (flush_lsn.file == lp->s_lsn.file &&
- flush_lsn.offset < lp->s_lsn.offset)) {
- MUTEX_UNLOCK(dbenv, flush_mutexp);
- goto done;
- }
- /*
- * We may need to write the current buffer. We have to write the
- * current buffer if the flush LSN is greater than or equal to the
- * buffer's starting LSN.
- */
- current = 0;
- if (lp->b_off != 0 && log_compare(&flush_lsn, &lp->f_lsn) >= 0) {
- if ((ret = __log_write(dblp,
- dblp->bufp, (u_int32_t)lp->b_off)) != 0) {
- MUTEX_UNLOCK(dbenv, flush_mutexp);
- goto done;
- }
- lp->b_off = 0;
- current = 1;
- }
- /*
- * It's possible that this thread may never have written to this log
- * file. Acquire a file descriptor if we don't already have one.
- * One last check -- if we're not writing anything from the current
- * buffer, don't bother. We have nothing to write and nothing to
- * sync.
- */
- if (!F_ISSET(&dblp->lfh, DB_FH_VALID) || dblp->lfname != lp->lsn.file)
- if (!current || (ret = __log_newfh(dblp)) != 0) {
- MUTEX_UNLOCK(dbenv, flush_mutexp);
- goto done;
- }
- /*
- * We are going to flush, release the region.
- * First get the current state of the buffer since
- * another write may come in, but we may not flush it.
- */
- b_off = lp->b_off;
- w_off = lp->w_off;
- f_lsn = lp->f_lsn;
- lp->in_flush++;
- if (release)
- R_UNLOCK(dbenv, &dblp->reginfo);
- /* Sync all writes to disk. */
- if ((ret = __os_fsync(dbenv, &dblp->lfh)) != 0) {
- MUTEX_UNLOCK(dbenv, flush_mutexp);
- if (release)
- R_LOCK(dbenv, &dblp->reginfo);
- ret = __db_panic(dbenv, ret);
- return (ret);
- }
- /*
- * Set the last-synced LSN.
- * This value must be set to the LSN past the last complete
- * record that has been flushed. This is at least the first
- * lsn, f_lsn. If the buffer is empty, b_off == 0, then
- * we can move up to write point since the first lsn is not
- * set for the new buffer.
- */
- lp->s_lsn = f_lsn;
- if (b_off == 0)
- lp->s_lsn.offset = w_off;
- MUTEX_UNLOCK(dbenv, flush_mutexp);
- if (release)
- R_LOCK(dbenv, &dblp->reginfo);
- lp->in_flush--;
- ++lp->stat.st_scount;
- /*
- * How many flush calls (usually commits) did this call actually sync?
- * At least one, if it got here.
- */
- ncommit = 1;
- done:
- if (lp->ncommit != 0) {
- first = 1;
- for (commit = SH_TAILQ_FIRST(&lp->commits, __db_commit);
- commit != NULL;
- commit = SH_TAILQ_NEXT(commit, links, __db_commit))
- if (log_compare(&lp->s_lsn, &commit->lsn) > 0) {
- MUTEX_UNLOCK(dbenv, &commit->mutex);
- SH_TAILQ_REMOVE(
- &lp->commits, commit, links, __db_commit);
- ncommit++;
- } else if (first == 1) {
- F_SET(commit, DB_COMMIT_FLUSH);
- MUTEX_UNLOCK(dbenv, &commit->mutex);
- SH_TAILQ_REMOVE(
- &lp->commits, commit, links, __db_commit);
- /*
- * This thread will wake and flush.
- * If another thread commits and flushes
- * first we will waste a trip trough the
- * mutex.
- */
- lp->in_flush++;
- first = 0;
- }
- }
- if (lp->stat.st_maxcommitperflush < ncommit)
- lp->stat.st_maxcommitperflush = ncommit;
- if (lp->stat.st_mincommitperflush > ncommit ||
- lp->stat.st_mincommitperflush == 0)
- lp->stat.st_mincommitperflush = ncommit;
- return (ret);
- }
- /*
- * __log_fill --
- * Write information into the log.
- */
- static int
- __log_fill(dblp, lsn, addr, len)
- DB_LOG *dblp;
- DB_LSN *lsn;
- void *addr;
- u_int32_t len;
- {
- LOG *lp;
- u_int32_t bsize, nrec;
- size_t nw, remain;
- int ret;
- lp = dblp->reginfo.primary;
- bsize = lp->buffer_size;
- while (len > 0) { /* Copy out the data. */
- /*
- * If we're beginning a new buffer, note the user LSN to which
- * the first byte of the buffer belongs. We have to know this
- * when flushing the buffer so that we know if the in-memory
- * buffer needs to be flushed.
- */
- if (lp->b_off == 0)
- lp->f_lsn = *lsn;
- /*
- * If we're on a buffer boundary and the data is big enough,
- * copy as many records as we can directly from the data.
- */
- if (lp->b_off == 0 && len >= bsize) {
- nrec = len / bsize;
- if ((ret = __log_write(dblp, addr, nrec * bsize)) != 0)
- return (ret);
- addr = (u_int8_t *)addr + nrec * bsize;
- len -= nrec * bsize;
- ++lp->stat.st_wcount_fill;
- continue;
- }
- /* Figure out how many bytes we can copy this time. */
- remain = bsize - lp->b_off;
- nw = remain > len ? len : remain;
- memcpy(dblp->bufp + lp->b_off, addr, nw);
- addr = (u_int8_t *)addr + nw;
- len -= (u_int32_t)nw;
- lp->b_off += nw;
- /* If we fill the buffer, flush it. */
- if (lp->b_off == bsize) {
- if ((ret = __log_write(dblp, dblp->bufp, bsize)) != 0)
- return (ret);
- lp->b_off = 0;
- ++lp->stat.st_wcount_fill;
- }
- }
- return (0);
- }
- /*
- * __log_write --
- * Write the log buffer to disk.
- */
- static int
- __log_write(dblp, addr, len)
- DB_LOG *dblp;
- void *addr;
- u_int32_t len;
- {
- DB_ENV *dbenv;
- LOG *lp;
- size_t nw;
- int ret;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /*
- * If we haven't opened the log file yet or the current one
- * has changed, acquire a new log file.
- */
- if (!F_ISSET(&dblp->lfh, DB_FH_VALID) || dblp->lfname != lp->lsn.file)
- if ((ret = __log_newfh(dblp)) != 0)
- return (ret);
- /*
- * Seek to the offset in the file (someone may have written it
- * since we last did).
- */
- if ((ret =
- __os_seek(dbenv,
- &dblp->lfh, 0, 0, lp->w_off, 0, DB_OS_SEEK_SET)) != 0 ||
- (ret = __os_write(dbenv, &dblp->lfh, addr, len, &nw)) != 0)
- return (ret);
- /* Reset the buffer offset and update the seek offset. */
- lp->w_off += len;
- /* Update written statistics. */
- if ((lp->stat.st_w_bytes += len) >= MEGABYTE) {
- lp->stat.st_w_bytes -= MEGABYTE;
- ++lp->stat.st_w_mbytes;
- }
- if ((lp->stat.st_wc_bytes += len) >= MEGABYTE) {
- lp->stat.st_wc_bytes -= MEGABYTE;
- ++lp->stat.st_wc_mbytes;
- }
- ++lp->stat.st_wcount;
- return (0);
- }
- /*
- * __log_file --
- * Map a DB_LSN to a file name.
- *
- * PUBLIC: int __log_file __P((DB_ENV *, const DB_LSN *, char *, size_t));
- */
- int
- __log_file(dbenv, lsn, namep, len)
- DB_ENV *dbenv;
- const DB_LSN *lsn;
- char *namep;
- size_t len;
- {
- DB_LOG *dblp;
- int ret;
- char *name;
- PANIC_CHECK(dbenv);
- ENV_REQUIRES_CONFIG(dbenv,
- dbenv->lg_handle, "DB_ENV->log_file", DB_INIT_LOG);
- dblp = dbenv->lg_handle;
- R_LOCK(dbenv, &dblp->reginfo);
- ret = __log_name(dblp, lsn->file, &name, NULL, 0);
- R_UNLOCK(dbenv, &dblp->reginfo);
- if (ret != 0)
- return (ret);
- /* Check to make sure there's enough room and copy the name. */
- if (len < strlen(name) + 1) {
- *namep = ' ';
- __db_err(dbenv, "DB_ENV->log_file: name buffer is too short");
- return (EINVAL);
- }
- (void)strcpy(namep, name);
- __os_free(dbenv, name);
- return (0);
- }
- /*
- * __log_newfh --
- * Acquire a file handle for the current log file.
- */
- static int
- __log_newfh(dblp)
- DB_LOG *dblp;
- {
- DB_ENV *dbenv;
- LOG *lp;
- int ret;
- char *name;
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /* Close any previous file descriptor. */
- if (F_ISSET(&dblp->lfh, DB_FH_VALID))
- (void)__os_closehandle(dbenv, &dblp->lfh);
- /*
- * Get the path of the new file and open it.
- *
- * Adding DB_OSO_LOG to the flags may add additional platform-specific
- * optimizations. On WinNT, the logfile is preallocated, which may
- * have a time penalty at startup, but have better overall throughput.
- * We are not certain that this works reliably, so enable at your own
- * risk.
- *
- * XXX:
- * Initialize the log file size. This is a hack to push the log's
- * maximum size down into the Windows __os_open routine, because it
- * wants to pre-allocate it.
- */
- dblp->lfname = lp->lsn.file;
- dblp->lfh.log_size = lp->log_size;
- if ((ret = __log_name(dblp, dblp->lfname,
- &name, &dblp->lfh,
- DB_OSO_CREATE |/* DB_OSO_LOG |*/ DB_OSO_SEQ |
- (F_ISSET(dbenv, DB_ENV_DIRECT_LOG) ? DB_OSO_DIRECT : 0))) != 0)
- __db_err(dbenv,
- "DB_ENV->log_put: %s: %s", name, db_strerror(ret));
- __os_free(dbenv, name);
- return (ret);
- }
- /*
- * __log_name --
- * Return the log name for a particular file, and optionally open it.
- *
- * PUBLIC: int __log_name __P((DB_LOG *,
- * PUBLIC: u_int32_t, char **, DB_FH *, u_int32_t));
- */
- int
- __log_name(dblp, filenumber, namep, fhp, flags)
- DB_LOG *dblp;
- u_int32_t filenumber, flags;
- char **namep;
- DB_FH *fhp;
- {
- DB_ENV *dbenv;
- LOG *lp;
- int ret;
- char *oname;
- char old[sizeof(LFPREFIX) + 5 + 20], new[sizeof(LFPREFIX) + 10 + 20];
- dbenv = dblp->dbenv;
- lp = dblp->reginfo.primary;
- /*
- * !!!
- * The semantics of this routine are bizarre.
- *
- * The reason for all of this is that we need a place where we can
- * intercept requests for log files, and, if appropriate, check for
- * both the old-style and new-style log file names. The trick is
- * that all callers of this routine that are opening the log file
- * read-only want to use an old-style file name if they can't find
- * a match using a new-style name. The only down-side is that some
- * callers may check for the old-style when they really don't need
- * to, but that shouldn't mess up anything, and we only check for
- * the old-style name when we've already failed to find a new-style
- * one.
- *
- * Create a new-style file name, and if we're not going to open the
- * file, return regardless.
- */
- (void)snprintf(new, sizeof(new), LFNAME, filenumber);
- if ((ret = __db_appname(dbenv,
- DB_APP_LOG, new, 0, NULL, namep)) != 0 || fhp == NULL)
- return (ret);
- /* Open the new-style file -- if we succeed, we're done. */
- if ((ret = __os_open(dbenv, *namep, flags, lp->persist.mode, fhp)) == 0)
- return (0);
- /*
- * The open failed... if the DB_RDONLY flag isn't set, we're done,
- * the caller isn't interested in old-style files.
- */
- if (!LF_ISSET(DB_OSO_RDONLY)) {
- __db_err(dbenv,
- "%s: log file open failed: %s", *namep, db_strerror(ret));
- return (__db_panic(dbenv, ret));
- }
- /* Create an old-style file name. */
- (void)snprintf(old, sizeof(old), LFNAME_V1, filenumber);
- if ((ret = __db_appname(dbenv, DB_APP_LOG, old, 0, NULL, &oname)) != 0)
- goto err;
- /*
- * Open the old-style file -- if we succeed, we're done. Free the
- * space allocated for the new-style name and return the old-style
- * name to the caller.
- */
- if ((ret = __os_open(dbenv,
- oname, flags, lp->persist.mode, fhp)) == 0) {
- __os_free(dbenv, *namep);
- *namep = oname;
- return (0);
- }
- /*
- * Couldn't find either style of name -- return the new-style name
- * for the caller's error message. If it's an old-style name that's
- * actually missing we're going to confuse the user with the error
- * message, but that implies that not only were we looking for an
- * old-style name, but we expected it to exist and we weren't just
- * looking for any log file. That's not a likely error.
- */
- err: __os_free(dbenv, oname);
- return (ret);
- }
- /*
- * __log_rep_put --
- * Short-circuit way for replication clients to put records into the
- * log. Replication clients' logs need to be laid out exactly their masters'
- * are, so we let replication take responsibility for when the log gets
- * flushed, when log switches files, etc. This is just a thin PUBLIC wrapper
- * for __log_putr with a slightly prettier interface.
- *
- * Note that the log region mutex should be held when this is called.
- *
- * PUBLIC: int __log_rep_put __P((DB_ENV *, DB_LSN *, const DBT *));
- */
- int
- __log_rep_put(dbenv, lsnp, rec)
- DB_ENV *dbenv;
- DB_LSN *lsnp;
- const DBT *rec;
- {
- DB_CIPHER *db_cipher;
- DB_LOG *dblp;
- HDR hdr;
- DBT *dbt, t;
- LOG *lp;
- int need_free, ret;
- dblp = dbenv->lg_handle;
- lp = dblp->reginfo.primary;
- memset(&hdr, 0, sizeof(HDR));
- t = *rec;
- dbt = &t;
- need_free = 0;
- db_cipher = (DB_CIPHER *)dbenv->crypto_handle;
- if (CRYPTO_ON(dbenv))
- t.size += db_cipher->adj_size(rec->size);
- if ((ret = __os_calloc(dbenv, 1, t.size, &t.data)) != 0)
- goto err;
- need_free = 1;
- memcpy(t.data, rec->data, rec->size);
- if ((ret = __log_encrypt_record(dbenv, dbt, &hdr, rec->size)) != 0)
- goto err;
- __db_chksum(t.data, t.size,
- (CRYPTO_ON(dbenv)) ? db_cipher->mac_key : NULL, hdr.chksum);
- DB_ASSERT(log_compare(lsnp, &lp->lsn) == 0);
- ret = __log_putr(dblp, lsnp, dbt, lp->lsn.offset - lp->len, &hdr);
- err:
- if (need_free)
- __os_free(dbenv, t.data);
- return (ret);
- }
- static int
- __log_encrypt_record(dbenv, dbt, hdr, orig)
- DB_ENV *dbenv;
- DBT *dbt;
- HDR *hdr;
- u_int32_t orig;
- {
- DB_CIPHER *db_cipher;
- int ret;
- if (CRYPTO_ON(dbenv)) {
- db_cipher = (DB_CIPHER *)dbenv->crypto_handle;
- hdr->size = HDR_CRYPTO_SZ;
- hdr->orig_size = orig;
- if ((ret = db_cipher->encrypt(dbenv, db_cipher->data,
- hdr->iv, dbt->data, dbt->size)) != 0)
- return (ret);
- } else {
- hdr->size = HDR_NORMAL_SZ;
- }
- return (0);
- }