Initial revision

CVS patchset: 4644
CVS date: 2001/03/21 18:33:35

1 files changed, 662 insertions, 0 deletions

diff --git a/db/mp/mp_bh.c b/db/mp/mp_bh.c
new file mode 100644
index 000000000..e802b165b
--- /dev/null
+++ b/db/mp/mp_bh.c
@@ -0,0 +1,662 @@
+/*-
+ * See the file LICENSE for redistribution information.
+ *
+ * Copyright (c) 1996, 1997, 1998, 1999, 2000
+ *	Sleepycat Software.  All rights reserved.
+ */
+#include "db_config.h"
+
+#ifndef lint
+static const char revid[] = "$Id: mp_bh.c,v 11.25 2001/01/10 04:50:53 ubell Exp $";
+#endif /* not lint */
+
+#ifndef NO_SYSTEM_INCLUDES
+#include <sys/types.h>
+
+#include <string.h>
+#include <unistd.h>
+#endif
+
+#include "db_int.h"
+#include "db_shash.h"
+#include "mp.h"
+#include "log.h"
+#include "db_page.h"
+
+static int __memp_upgrade __P((DB_MPOOL *, DB_MPOOLFILE *, MPOOLFILE *));
+
+/*
+ * __memp_bhwrite --
+ *	Write the page associated with a given bucket header.
+ *
+ * PUBLIC: int __memp_bhwrite
+ * PUBLIC:     __P((DB_MPOOL *, MPOOLFILE *, BH *, int *, int *));
+ */
+int
+__memp_bhwrite(dbmp, mfp, bhp, restartp, wrotep)
+	DB_MPOOL *dbmp;
+	MPOOLFILE *mfp;
+	BH *bhp;
+	int *restartp, *wrotep;
+{
+	DB_MPOOLFILE *dbmfp;
+	DB_MPREG *mpreg;
+	int incremented, ret;
+
+	if (restartp != NULL)
+		*restartp = 0;
+	if (wrotep != NULL)
+		*wrotep = 0;
+	incremented = 0;
+
+	/*
+	 * If the file has been removed or is a closed temporary file, Jump
+	 * right ahead and pretend that we've found the file we want-- the
+	 * page-write function knows how to handle the fact that we don't have
+	 * (or need!) any real file descriptor information.
+	 */
+	if (F_ISSET(mfp, MP_DEADFILE)) {
+		dbmfp = NULL;
+		goto found;
+	}
+
+	/*
+	 * Walk the process' DB_MPOOLFILE list and find a file descriptor for
+	 * the file.  We also check that the descriptor is open for writing.
+	 * If we find a descriptor on the file that's not open for writing, we
+	 * try and upgrade it to make it writeable.  If that fails, we're done.
+	 */
+	MUTEX_THREAD_LOCK(dbmp->dbenv, dbmp->mutexp);
+	for (dbmfp = TAILQ_FIRST(&dbmp->dbmfq);
+	    dbmfp != NULL; dbmfp = TAILQ_NEXT(dbmfp, q))
+		if (dbmfp->mfp == mfp) {
+			if (F_ISSET(dbmfp, MP_READONLY) &&
+			    __memp_upgrade(dbmp, dbmfp, mfp)) {
+				MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+				return (0);
+			}
+
+			/*
+			 * Increment the reference count -- see the comment in
+			 * memp_fclose().
+			 */
+			++dbmfp->ref;
+			incremented = 1;
+			break;
+		}
+	MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+	if (dbmfp != NULL)
+		goto found;
+
+	/*
+	 * !!!
+	 * Don't try to attach to temporary files.  There are two problems in
+	 * trying to do that.  First, if we have different privileges than the
+	 * process that "owns" the temporary file, we might create the backing
+	 * disk file such that the owning process couldn't read/write its own
+	 * buffers, e.g., memp_trickle() running as root creating a file owned
+	 * as root, mode 600.  Second, if the temporary file has already been
+	 * created, we don't have any way of finding out what its real name is,
+	 * and, even if we did, it was already unlinked (so that it won't be
+	 * left if the process dies horribly).  This decision causes a problem,
+	 * however: if the temporary file consumes the entire buffer cache,
+	 * and the owner doesn't flush the buffers to disk, we could end up
+	 * with resource starvation, and the memp_trickle() thread couldn't do
+	 * anything about it.  That's a pretty unlikely scenario, though.
+	 *
+	 * Note that we should never get here when the temporary file
+	 * in question has already been closed in another process, in which
+	 * case it should be marked MP_DEADFILE.
+	 */
+	if (F_ISSET(mfp, MP_TEMP)) {
+		DB_ASSERT(!F_ISSET(mfp, MP_DEADFILE));
+		return (0);
+	}
+
+	/*
+	 * It's not a page from a file we've opened.  If the file requires
+	 * input/output processing, see if this process has ever registered
+	 * information as to how to write this type of file.  If not, there's
+	 * nothing we can do.
+	 */
+	if (mfp->ftype != 0) {
+		MUTEX_THREAD_LOCK(dbmp->dbenv, dbmp->mutexp);
+		for (mpreg = LIST_FIRST(&dbmp->dbregq);
+		    mpreg != NULL; mpreg = LIST_NEXT(mpreg, q))
+			if (mpreg->ftype == mfp->ftype)
+				break;
+		MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+		if (mpreg == NULL)
+			return (0);
+	}
+
+	/*
+	 * Try and open the file, attaching to the underlying shared area.
+	 * Ignore any error, assume it's a permissions problem.
+	 *
+	 * XXX
+	 * There's no negative cache, so we may repeatedly try and open files
+	 * that we have previously tried (and failed) to open.
+	 */
+	if (__memp_fopen(dbmp, mfp, R_ADDR(dbmp->reginfo, mfp->path_off),
+	    0, 0, mfp->stat.st_pagesize, 0, NULL, &dbmfp) != 0)
+		return (0);
+
+found:	ret = __memp_pgwrite(dbmp, dbmfp, bhp, restartp, wrotep);
+
+	if (incremented) {
+		MUTEX_THREAD_LOCK(dbmp->dbenv, dbmp->mutexp);
+		--dbmfp->ref;
+		MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+	}
+
+	return (ret);
+}
+
+/*
+ * __memp_pgread --
+ *	Read a page from a file.
+ *
+ * PUBLIC: int __memp_pgread __P((DB_MPOOLFILE *, BH *, int));
+ */
+int
+__memp_pgread(dbmfp, bhp, can_create)
+	DB_MPOOLFILE *dbmfp;
+	BH *bhp;
+	int can_create;
+{
+	DB_IO db_io;
+	DB_ENV *dbenv;
+	DB_MPOOL *dbmp;
+	MPOOLFILE *mfp;
+	size_t len, pagesize;
+	size_t nr;
+	int created, ret;
+
+	dbmp = dbmfp->dbmp;
+	dbenv = dbmp->dbenv;
+	mfp = dbmfp->mfp;
+	pagesize = mfp->stat.st_pagesize;
+
+	F_SET(bhp, BH_LOCKED | BH_TRASH);
+	MUTEX_LOCK(dbenv, &bhp->mutex, dbenv->lockfhp);
+	R_UNLOCK(dbenv, dbmp->reginfo);
+
+	/*
+	 * Temporary files may not yet have been created.  We don't create
+	 * them now, we create them when the pages have to be flushed.
+	 */
+	nr = 0;
+	if (F_ISSET(&dbmfp->fh, DB_FH_VALID)) {
+		/*
+		 * Ignore read errors if we have permission to create the page.
+		 * Assume that the page doesn't exist, and that we'll create it
+		 * when we write it out.
+		 *
+		 * XXX
+		 * Theoretically, we could overwrite a page of data if it were
+		 * possible for a file to be successfully opened for reading
+		 * and then for the read to fail.  Shouldn't ever happen, but
+		 * it might be worth checking to see if the offset is past the
+		 * known end-of-file.
+		 */
+		db_io.fhp = &dbmfp->fh;
+		db_io.mutexp = dbmfp->mutexp;
+		db_io.pagesize = db_io.bytes = pagesize;
+		db_io.pgno = bhp->pgno;
+		db_io.buf = bhp->buf;
+
+		ret = __os_io(dbenv, &db_io, DB_IO_READ, &nr);
+	} else
+		ret = 0;
+
+	created = 0;
+	if (nr < pagesize) {
+		if (can_create)
+			created = 1;
+		else {
+			/*
+			 * If we had a short read, ret may be 0.  This may not
+			 * be an error -- in particular DB recovery processing
+			 * may request pages that have never been written to
+			 * disk, in which case we won't find the page.  So, the
+			 * caller must know how to handle the error.
+			 */
+			if (ret == 0)
+				ret = EIO;
+			goto err;
+		}
+	}
+
+	/*
+	 * Clear any bytes we didn't read that need to be cleared.  If we're
+	 * running in diagnostic mode, smash any bytes on the page that are
+	 * unknown quantities for the caller.
+	 */
+	if (nr != pagesize) {
+		len = mfp->clear_len == 0 ? pagesize : mfp->clear_len;
+		if (nr < len)
+			memset(bhp->buf + nr, 0, len - nr);
+#ifdef DIAGNOSTIC
+		if (nr > len)
+			len = nr;
+		if (len < pagesize)
+			memset(bhp->buf + len, CLEAR_BYTE, pagesize - len);
+#endif
+	}
+
+	/* Call any pgin function. */
+	ret = mfp->ftype == 0 ? 0 : __memp_pg(dbmfp, bhp, 1);
+
+	/* Unlock the buffer and reacquire the region lock. */
+err:	MUTEX_UNLOCK(dbenv, &bhp->mutex);
+	R_LOCK(dbenv, dbmp->reginfo);
+
+	/*
+	 * If no errors occurred, the data is now valid, clear the BH_TRASH
+	 * flag; regardless, clear the lock bit and let other threads proceed.
+	 */
+	F_CLR(bhp, BH_LOCKED);
+	if (ret == 0) {
+		F_CLR(bhp, BH_TRASH);
+
+		/* Update the statistics. */
+		if (created)
+			++mfp->stat.st_page_create;
+		else
+			++mfp->stat.st_page_in;
+	}
+
+	return (ret);
+}
+
+/*
+ * __memp_pgwrite --
+ *	Write a page to a file.
+ *
+ * PUBLIC: int __memp_pgwrite
+ * PUBLIC:     __P((DB_MPOOL *, DB_MPOOLFILE *, BH *, int *, int *));
+ */
+int
+__memp_pgwrite(dbmp, dbmfp, bhp, restartp, wrotep)
+	DB_MPOOL *dbmp;
+	DB_MPOOLFILE *dbmfp;
+	BH *bhp;
+	int *restartp, *wrotep;
+{
+	DB_ENV *dbenv;
+	DB_IO db_io;
+	DB_LSN lsn;
+	MPOOL *c_mp, *mp;
+	MPOOLFILE *mfp;
+	size_t nw;
+	int callpgin, dosync, ret, syncfail;
+	const char *fail;
+
+	dbenv = dbmp->dbenv;
+	mp = dbmp->reginfo[0].primary;
+	mfp = dbmfp == NULL ? NULL : dbmfp->mfp;
+
+	if (restartp != NULL)
+		*restartp = 0;
+	if (wrotep != NULL)
+		*wrotep = 0;
+	callpgin = 0;
+
+	/*
+	 * Check the dirty bit -- this buffer may have been written since we
+	 * decided to write it.
+	 */
+	if (!F_ISSET(bhp, BH_DIRTY)) {
+		if (wrotep != NULL)
+			*wrotep = 1;
+		return (0);
+	}
+
+	MUTEX_LOCK(dbenv, &bhp->mutex, dbenv->lockfhp);
+
+	/*
+	 * If there were two writers, we may have just been waiting while the
+	 * other writer completed I/O on this buffer.  Check the dirty bit one
+	 * more time.
+	 */
+	if (!F_ISSET(bhp, BH_DIRTY)) {
+		MUTEX_UNLOCK(dbenv, &bhp->mutex);
+
+		if (wrotep != NULL)
+			*wrotep = 1;
+		return (0);
+	}
+
+	F_SET(bhp, BH_LOCKED);
+	R_UNLOCK(dbenv, dbmp->reginfo);
+
+	if (restartp != NULL)
+		*restartp = 1;
+
+	/*
+	 * It's possible that the underlying file doesn't exist, either
+	 * because of an outright removal or because it was a temporary
+	 * file that's been closed.
+	 *
+	 * !!!
+	 * Once we pass this point, we know that dbmfp and mfp aren't NULL,
+	 * and that we have a valid file reference.
+	 */
+	if (mfp == NULL || F_ISSET(mfp, MP_DEADFILE))
+		goto file_dead;
+
+	/*
+	 * Ensure the appropriate log records are on disk.  If the page is
+	 * being written as part of a sync operation, the flush has already
+	 * been done, unless it was written by the application *after* the
+	 * sync was scheduled.
+	 */
+	if (LOGGING_ON(dbenv) &&
+	    (!F_ISSET(bhp, BH_SYNC) || F_ISSET(bhp, BH_SYNC_LOGFLSH))) {
+		memcpy(&lsn, bhp->buf + mfp->lsn_off, sizeof(DB_LSN));
+		if ((ret = log_flush(dbenv, &lsn)) != 0)
+			goto err;
+	}
+	DB_ASSERT(!LOGGING_ON(dbenv) ||
+	   log_compare(&((LOG *)((DB_LOG *)
+	   dbenv->lg_handle)->reginfo.primary)->s_lsn, &LSN(bhp->buf)) > 0);
+
+	/*
+	 * Call any pgout function.  We set the callpgin flag so that we flag
+	 * that the contents of the buffer will need to be passed through pgin
+	 * before they are reused.
+	 */
+	if (mfp->ftype == 0)
+		ret = 0;
+	else {
+		callpgin = 1;
+		if ((ret = __memp_pg(dbmfp, bhp, 0)) != 0)
+			goto err;
+	}
+
+	/* Temporary files may not yet have been created. */
+	if (!F_ISSET(&dbmfp->fh, DB_FH_VALID)) {
+		MUTEX_THREAD_LOCK(dbenv, dbmp->mutexp);
+		if (!F_ISSET(&dbmfp->fh, DB_FH_VALID) &&
+		    ((ret = __db_appname(dbenv, DB_APP_TMP, NULL, NULL,
+		    DB_OSO_CREATE | DB_OSO_EXCL | DB_OSO_TEMP,
+		    &dbmfp->fh, NULL)) != 0 ||
+		    !F_ISSET(&dbmfp->fh, DB_FH_VALID))) {
+			MUTEX_THREAD_UNLOCK(dbenv, dbmp->mutexp);
+			__db_err(dbenv,
+			    "unable to create temporary backing file");
+			goto err;
+		}
+		MUTEX_THREAD_UNLOCK(dbenv, dbmp->mutexp);
+	}
+
+	/* Write the page. */
+	db_io.fhp = &dbmfp->fh;
+	db_io.mutexp = dbmfp->mutexp;
+	db_io.pagesize = db_io.bytes = mfp->stat.st_pagesize;
+	db_io.pgno = bhp->pgno;
+	db_io.buf = bhp->buf;
+	if ((ret = __os_io(dbenv, &db_io, DB_IO_WRITE, &nw)) != 0) {
+		ret = __db_panic(dbenv, ret);
+		fail = "write";
+		goto syserr;
+	}
+	if (nw != mfp->stat.st_pagesize) {
+		ret = EIO;
+		fail = "write";
+		goto syserr;
+	}
+
+file_dead:
+	/*
+	 * !!!
+	 * Once we pass this point, dbmfp and mfp may be NULL, we may not have
+	 * a valid file reference.
+	 *
+	 * Unlock the buffer and reacquire the region lock.
+	 */
+	MUTEX_UNLOCK(dbenv, &bhp->mutex);
+	R_LOCK(dbenv, dbmp->reginfo);
+
+	/*
+	 * Clean up the flags based on a successful write.
+	 *
+	 * If we rewrote the page, it will need processing by the pgin
+	 * routine before reuse.
+	 */
+	if (callpgin)
+		F_SET(bhp, BH_CALLPGIN);
+	F_CLR(bhp, BH_DIRTY | BH_LOCKED);
+
+	/*
+	 * If we write a buffer for which a checkpoint is waiting, update
+	 * the count of pending buffers (both in the mpool as a whole and
+	 * for this file).  If the count for this file goes to zero, set a
+	 * flag so we flush the writes.
+	 */
+	dosync = 0;
+	if (F_ISSET(bhp, BH_SYNC)) {
+		F_CLR(bhp, BH_SYNC | BH_SYNC_LOGFLSH);
+
+		--mp->lsn_cnt;
+		if (mfp != NULL)
+			dosync = --mfp->lsn_cnt == 0 ? 1 : 0;
+	}
+
+	/* Update the page clean/dirty statistics. */
+	c_mp = BH_TO_CACHE(dbmp, bhp);
+	++c_mp->stat.st_page_clean;
+	--c_mp->stat.st_page_dirty;
+
+	/* Update I/O statistics. */
+	if (mfp != NULL)
+		++mfp->stat.st_page_out;
+
+	/*
+	 * Do the sync after everything else has been updated, so any incoming
+	 * checkpoint doesn't see inconsistent information.
+	 *
+	 * XXX:
+	 * Don't lock the region around the sync, fsync(2) has no atomicity
+	 * issues.
+	 *
+	 * XXX:
+	 * We ignore errors from the sync -- it makes no sense to return an
+	 * error to the calling process, so set a flag causing the checkpoint
+	 * to be retried later.  There is a possibility, of course, that a
+	 * subsequent checkpoint was started and that we're going to force it
+	 * to fail.  That should be unlikely, and fixing it would be difficult.
+	 */
+	if (dosync) {
+		R_UNLOCK(dbenv, dbmp->reginfo);
+		syncfail = __os_fsync(dbenv, &dbmfp->fh) != 0;
+		R_LOCK(dbenv, dbmp->reginfo);
+		if (syncfail)
+			F_SET(mp, MP_LSN_RETRY);
+	}
+
+	if (wrotep != NULL)
+		*wrotep = 1;
+
+	return (0);
+
+syserr:	__db_err(dbenv, "%s: %s failed for page %lu",
+	    __memp_fn(dbmfp), fail, (u_long)bhp->pgno);
+
+err:	/* Unlock the buffer and reacquire the region lock. */
+	MUTEX_UNLOCK(dbenv, &bhp->mutex);
+	R_LOCK(dbenv, dbmp->reginfo);
+
+	/*
+	 * Clean up the flags based on a failure.
+	 *
+	 * The page remains dirty but we remove our lock.  If we rewrote the
+	 * page, it will need processing by the pgin routine before reuse.
+	 */
+	if (callpgin)
+		F_SET(bhp, BH_CALLPGIN);
+	F_CLR(bhp, BH_LOCKED);
+
+	return (ret);
+}
+
+/*
+ * __memp_pg --
+ *	Call the pgin/pgout routine.
+ *
+ * PUBLIC: int __memp_pg __P((DB_MPOOLFILE *, BH *, int));
+ */
+int
+__memp_pg(dbmfp, bhp, is_pgin)
+	DB_MPOOLFILE *dbmfp;
+	BH *bhp;
+	int is_pgin;
+{
+	DBT dbt, *dbtp;
+	DB_MPOOL *dbmp;
+	DB_MPREG *mpreg;
+	MPOOLFILE *mfp;
+	int ftype, ret;
+
+	dbmp = dbmfp->dbmp;
+	mfp = dbmfp->mfp;
+
+	MUTEX_THREAD_LOCK(dbmp->dbenv, dbmp->mutexp);
+
+	ftype = mfp->ftype;
+	for (mpreg = LIST_FIRST(&dbmp->dbregq);
+	    mpreg != NULL; mpreg = LIST_NEXT(mpreg, q)) {
+		if (ftype != mpreg->ftype)
+			continue;
+		if (mfp->pgcookie_len == 0)
+			dbtp = NULL;
+		else {
+			dbt.size = mfp->pgcookie_len;
+			dbt.data = R_ADDR(dbmp->reginfo, mfp->pgcookie_off);
+			dbtp = &dbt;
+		}
+		MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+
+		if (is_pgin) {
+			if (mpreg->pgin != NULL &&
+			    (ret = mpreg->pgin(dbmp->dbenv,
+			    bhp->pgno, bhp->buf, dbtp)) != 0)
+				goto err;
+		} else
+			if (mpreg->pgout != NULL &&
+			    (ret = mpreg->pgout(dbmp->dbenv,
+			    bhp->pgno, bhp->buf, dbtp)) != 0)
+				goto err;
+		break;
+	}
+
+	if (mpreg == NULL)
+		MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+
+	return (0);
+
+err:	MUTEX_THREAD_UNLOCK(dbmp->dbenv, dbmp->mutexp);
+	__db_err(dbmp->dbenv, "%s: %s failed for page %lu",
+	    __memp_fn(dbmfp), is_pgin ? "pgin" : "pgout", (u_long)bhp->pgno);
+	return (ret);
+}
+
+/*
+ * __memp_bhfree --
+ *	Free a bucket header and its referenced data.
+ *
+ * PUBLIC: void __memp_bhfree __P((DB_MPOOL *, BH *, int));
+ */
+void
+__memp_bhfree(dbmp, bhp, free_mem)
+	DB_MPOOL *dbmp;
+	BH *bhp;
+	int free_mem;
+{
+	DB_HASHTAB *dbht;
+	MPOOL *c_mp, *mp;
+	MPOOLFILE *mfp;
+	int n_bucket, n_cache;
+
+	mp = dbmp->reginfo[0].primary;
+	c_mp = BH_TO_CACHE(dbmp, bhp);
+	n_cache = NCACHE(mp, bhp->pgno);
+	n_bucket = NBUCKET(c_mp, bhp->mf_offset, bhp->pgno);
+	dbht = R_ADDR(&dbmp->reginfo[n_cache], c_mp->htab);
+
+	/* Delete the buffer header from the hash bucket queue. */
+	SH_TAILQ_REMOVE(&dbht[n_bucket], bhp, hq, __bh);
+
+	/* Delete the buffer header from the LRU queue. */
+	SH_TAILQ_REMOVE(&c_mp->bhq, bhp, q, __bh);
+
+	/* Clear the mutex this buffer recorded */
+	__db_shlocks_clear(&bhp->mutex, &dbmp->reginfo[n_cache],
+	    (REGMAINT *)R_ADDR(&dbmp->reginfo[n_cache], mp->maint_off));
+	/*
+	 * Find the underlying MPOOLFILE and decrement its reference count.
+	 * If this is its last reference, remove it.
+	 */
+	mfp = R_ADDR(dbmp->reginfo, bhp->mf_offset);
+	if (--mfp->block_cnt == 0 && mfp->mpf_cnt == 0)
+		__memp_mf_discard(dbmp, mfp);
+
+	/*
+	 * If we're not reusing it immediately, free the buffer header
+	 * and data for real.
+	 */
+	if (free_mem) {
+		--c_mp->stat.st_page_clean;
+		__db_shalloc_free(dbmp->reginfo[n_cache].addr, bhp);
+	}
+}
+
+/*
+ * __memp_upgrade --
+ *	Upgrade a file descriptor from readonly to readwrite.
+ */
+static int
+__memp_upgrade(dbmp, dbmfp, mfp)
+	DB_MPOOL *dbmp;
+	DB_MPOOLFILE *dbmfp;
+	MPOOLFILE *mfp;
+{
+	DB_FH fh;
+	int ret;
+	char *rpath;
+
+	/*
+	 * !!!
+	 * We expect the handle to already be locked.
+	 */
+
+	/* Check to see if we've already upgraded. */
+	if (F_ISSET(dbmfp, MP_UPGRADE))
+		return (0);
+
+	/* Check to see if we've already failed. */
+	if (F_ISSET(dbmfp, MP_UPGRADE_FAIL))
+		return (1);
+
+	/*
+	 * Calculate the real name for this file and try to open it read/write.
+	 * We know we have a valid pathname for the file because it's the only
+	 * way we could have gotten a file descriptor of any kind.
+	 */
+	if ((ret = __db_appname(dbmp->dbenv, DB_APP_DATA,
+	    NULL, R_ADDR(dbmp->reginfo, mfp->path_off), 0, NULL, &rpath)) != 0)
+		return (ret);
+	if (__os_open(dbmp->dbenv, rpath, 0, 0, &fh) != 0) {
+		F_SET(dbmfp, MP_UPGRADE_FAIL);
+		ret = 1;
+	} else {
+		/* Swap the descriptors and set the upgrade flag. */
+		(void)__os_closehandle(&dbmfp->fh);
+		dbmfp->fh = fh;
+		F_SET(dbmfp, MP_UPGRADE);
+		ret = 0;
+	}
+	__os_freestr(rpath);
+	return (ret);
+}