From 2b960613e03dbc5b371378abfd051c8e75821171 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Wed, 3 Oct 2012 18:04:07 +0200
Subject: [PATCH 01/20] ITS#7377 Document caveats/troubeshooting.

---
 libraries/libmdb/mdb.h | 55 ++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 55 insertions(+)

diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index 925bf17d37..1272630787 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -38,6 +38,61 @@
  *	corrupt the database. Of course if your application code is known to
  *	be bug-free (...) then this is not an issue.
  *
+ *	Troubleshooting the lock file, plus semaphores on BSD systems:
+ *
+ *	- A broken lockfile can cause sync issues.
+ *	  Stale reader transactions left behind by an aborted program
+ *	  cause further writes to grow the database quickly, and
+ *	  stale locks can block further operation.
+ *
+ *	  Fix: Terminate all programs using the database, or make
+ *	  them close it.  Next database user will reset the lockfile.
+ *
+ *	- On BSD systems or others configured with MDB_USE_POSIX_SEM,
+ *	  startup can fail due to semaphores owned by another userid.
+ *
+ *	  Fix: Open and close the database as the user which owns the
+ *	  semaphores (likely last user) or as root, while no other
+ *	  process is using the database.
+ *
+ *	Restrictions/caveats (in addition to those listed for some functions):
+ *
+ *	- Only the database owner should normally use the database on
+ *	  BSD systems or when otherwise configured with MDB_USE_POSIX_SEM.
+ *	  Multiple users can cause startup to fail later, as noted above.
+ *
+ *	- A thread can only use one transaction at a time, plus any child
+ *	  transactions.  Each transaction belongs to one thread.  See below.
+ *
+ *	- Use an MDB_env* in the process which opened it, without fork()ing.
+ *
+ *	- Do not have open an MDB database twice in the same process at
+ *	  the same time.  Not even from a plain open() call - close()ing it
+ *	  breaks flock() advisory locking.
+ *
+ *	- Avoid long-lived transactions.  Read transactions prevent
+ *	  reuse of pages freed by newer write transactions, thus the
+ *	  database can grow quickly.  Write transactions prevent
+ *	  other write transactions, since writes are serialized.
+ *
+ *	...when several processes can use a database concurrently:
+ *
+ *	- Avoid suspending a process with active transactions.  These
+ *	  would then be "long-lived" as above.
+ *
+ *	- Avoid aborting a process with an active transaction.
+ *	  The transaction becomes "long-lived" as above until the lockfile
+ *	  is reset, since the process may not remove it from the lockfile.
+ *
+ *	- If you do that anyway, close the environment once in a while,
+ *	  so the lockfile can get reset.
+ *
+ *	- Do not use MDB databases on remote filesystems.  This breaks
+ *	  flock() on some OSes, even between two processes on the same host.
+ *
+ *	- Opening a database can fail if another process is opening or
+ *	  closing it at exactly the same time.
+ *
  *	@author	Howard Chu, Symas Corporation.
  *
  *	@copyright Copyright 2011-2012 Howard Chu, Symas Corp. All rights reserved.

From ab3fea51dc890feaca7075643efe9410949e5363 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Wed, 3 Oct 2012 18:06:29 +0200
Subject: [PATCH 02/20] ITS#7377 Catch ftruncate() error

---
 libraries/libmdb/mdb.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 42e33824b1..e92b5e7b1b 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -2629,7 +2629,8 @@ mdb_env_open2(MDB_env *env, unsigned int flags)
 	prot = PROT_READ;
 	if (flags & MDB_WRITEMAP) {
 		prot |= PROT_WRITE;
-		ftruncate(env->me_fd, env->me_mapsize);
+		if (ftruncate(env->me_fd, env->me_mapsize) < 0)
+			return ErrCode();
 	}
 	env->me_map = mmap(meta.mm_address, env->me_mapsize, prot, i,
 		env->me_fd, 0);

From 38fb8e6eb1c2db048fd2473bfcdd5eb16ec54517 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Wed, 3 Oct 2012 18:06:29 +0200
Subject: [PATCH 03/20] ITS#7377 Wrap fcntl F_SETLK in EINTR loop too.

This can happen even on local filesystems.
---
 libraries/libmdb/mdb.c | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index e92b5e7b1b..9e3e2ae9d7 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -2806,7 +2806,9 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
 	lock_info.l_whence = SEEK_SET;
 	lock_info.l_start = 0;
 	lock_info.l_len = 1;
-	if (!fcntl(env->me_lfd, F_SETLK, &lock_info)) {
+	while ((rc = fcntl(env->me_lfd, F_SETLK, &lock_info)) &&
+			(rc = ErrCode()) == EINTR) ;
+	if (!rc) {
 		*excl = 1;
 	} else
 # ifdef MDB_USE_POSIX_SEM

From a3f33dd20e71b9c94e94a0e1125fcee8d35fc70f Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Wed, 3 Oct 2012 18:08:56 +0200
Subject: [PATCH 04/20] Fix mdb_open() off-by-one error in maxdbs check

---
 libraries/libmdb/mdb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 9e3e2ae9d7..262919a24c 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -6548,7 +6548,7 @@ int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
 	}
 
 	/* If no free slot and max hit, fail */
-	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs - 1)
+	if (!unused && txn->mt_numdbs >= txn->mt_env->me_maxdbs)
 		return MDB_DBS_FULL;
 
 	/* Find the DB info */

From 756ce8e10ca52ff4516b56d42308116fac3c185d Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Wed, 3 Oct 2012 21:13:21 +0200
Subject: [PATCH 05/20] Tweak MDB restrictions

---
 libraries/libmdb/mdb.h | 6 ++++--
 1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index 1272630787..8ded7374c0 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -87,8 +87,10 @@
  *	- If you do that anyway, close the environment once in a while,
  *	  so the lockfile can get reset.
  *
- *	- Do not use MDB databases on remote filesystems.  This breaks
- *	  flock() on some OSes, even between two processes on the same host.
+ *	- Do not use MDB databases on remote filesystems, even between
+ *	  processes on the same host.  This breaks flock() on some OSes,
+ *	  possibly memory map sync, and certainly sync between programs
+ *	  on different hosts.
  *
  *	- Opening a database can fail if another process is opening or
  *	  closing it at exactly the same time.

From ebb6859ea5f4ca44ca528e49b17800f9992703e7 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Thu, 11 Oct 2012 12:21:40 -0700
Subject: [PATCH 06/20] Add mdb_copy for backing up a DB environment

---
 libraries/libmdb/Makefile   |  3 +-
 libraries/libmdb/mdb.c      | 96 +++++++++++++++++++++++++++++++++++++
 libraries/libmdb/mdb.h      | 12 +++++
 libraries/libmdb/mdb_copy.c | 43 +++++++++++++++++
 4 files changed, 153 insertions(+), 1 deletion(-)
 create mode 100644 libraries/libmdb/mdb_copy.c

diff --git a/libraries/libmdb/Makefile b/libraries/libmdb/Makefile
index 796be078d4..67a2007bb8 100644
--- a/libraries/libmdb/Makefile
+++ b/libraries/libmdb/Makefile
@@ -5,7 +5,7 @@ CFLAGS	= -pthread $(OPT) $(W) $(XCFLAGS)
 LDLIBS	=
 SOLIBS	=
 
-PROGS	= mdb_stat mtest mtest2 mtest3 mtest4 mtest5
+PROGS	= mdb_stat mdb_copy mtest mtest2 mtest3 mtest4 mtest5
 all:	libmdb.a libmdb.so $(PROGS)
 
 clean:
@@ -22,6 +22,7 @@ libmdb.so:	mdb.o midl.o
 	gcc -pthread -shared -o $@ mdb.o midl.o $(SOLIBS)
 
 mdb_stat: mdb_stat.o libmdb.a
+mdb_copy: mdb_copy.o libmdb.a
 mtest:    mtest.o    libmdb.a
 mtest2:	mtest2.o libmdb.a
 mtest3:	mtest3.o libmdb.a
diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 262919a24c..7d9ea5cd4a 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -32,6 +32,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
+#define _GNU_SOURCE
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/param.h>
@@ -3280,6 +3281,101 @@ mdb_env_close0(MDB_env *env, int excl)
 	env->me_lfd = INVALID_HANDLE_VALUE;	/* Mark env as reset */
 }
 
+int
+mdb_env_copy(MDB_env *env, const char *path)
+{
+	MDB_txn *txn = NULL;
+	int rc, len, oflags;
+	size_t wsize;
+	char *lpath, *ptr;
+	HANDLE newfd = INVALID_HANDLE_VALUE;
+
+	if (env->me_flags & MDB_NOSUBDIR) {
+		lpath = path;
+	} else {
+		len = strlen(path);
+		len += sizeof(DATANAME);
+		lpath = malloc(len);
+		if (!lpath)
+			return ENOMEM;
+		sprintf(lpath, "%s" DATANAME, path);
+	}
+
+	/* The destination path must exist, but the destination file must not.
+	 * We don't want the OS to cache the writes, since the source data is
+	 * already in the OS cache.
+	 */
+#ifdef _WIN32
+	newfd = CreateFile(lpath, GENERIC_WRITE, 0, NULL, CREATE_NEW,
+				FILE_FLAG_NO_BUFFERING|FILE_FLAG_WRITE_THROUGH, NULL);
+#else
+	newfd = open(lpath, O_WRONLY|O_CREAT|O_EXCL
+#ifdef O_DIRECT
+		|O_DIRECT
+#endif
+		, 0666);
+#endif
+	if (!(env->me_flags & MDB_NOSUBDIR))
+		free(lpath);
+	if (newfd == INVALID_HANDLE_VALUE) {
+		rc = ErrCode();
+		goto leave;
+	}
+
+#ifdef F_NOCACHE	/* __APPLE__ */
+	rc = fcntl(newfd, F_NOCACHE, 1);
+	if (rc) {
+		rc = ErrCode();
+		goto leave;
+	}
+#endif
+
+	/* Temporarily block writers until we snapshot the meta pages */
+	LOCK_MUTEX_W(env);
+
+	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
+	if (rc) {
+		UNLOCK_MUTEX_W(env);
+		goto leave;
+	}
+
+	wsize = env->me_psize * 2;
+#ifdef _WIN32
+	{
+		DWORD len;
+		rc = WriteFile(newfd, env->me_map, wsize, &len, NULL);
+		rc = (len == wsize) ? MDB_SUCCESS : ErrCode();
+	}
+#else
+	rc = write(newfd, env->me_map, wsize);
+	rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
+#endif
+	UNLOCK_MUTEX_W(env);
+
+	if (rc)
+		goto leave;
+
+	ptr = env->me_map + wsize;
+	wsize = txn->mt_next_pgno * env->me_psize - wsize;
+#ifdef _WIN32
+	{
+		DWORD len;
+		rc = WriteFile(newfd, ptr, wsize, &len, NULL);
+		rc = (len == wsize) ? MDB_SUCCESS : ErrCode();
+	}
+#else
+	rc = write(newfd, ptr, wsize);
+	rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
+#endif
+	mdb_txn_abort(txn);
+
+leave:
+	if (newfd != INVALID_HANDLE_VALUE)
+		close(newfd);
+
+	return rc;
+}
+
 void
 mdb_env_close(MDB_env *env)
 {
diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index 8ded7374c0..1735fbd375 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -450,6 +450,18 @@ int  mdb_env_create(MDB_env **env);
 	 */
 int  mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode);
 
+	/** @brief Copy an MDB environment to the specified path.
+	 *
+	 * This function may be used to make a backup of an existing environment.
+	 * @param[in] env An environment handle returned by #mdb_env_create(). It
+	 * must have already been opened successfully.
+	 * @param[in] path The directory in which the copy will reside. This
+	 * directory must already exist and be writable but must otherwise be
+	 * empty.
+	 * @return A non-zero error value on failure and 0 on success.
+	 */
+int  mdb_env_copy(MDB_env *env, const char *path);
+
 	/** @brief Return statistics about the MDB environment.
 	 *
 	 * @param[in] env An environment handle returned by #mdb_env_create()
diff --git a/libraries/libmdb/mdb_copy.c b/libraries/libmdb/mdb_copy.c
new file mode 100644
index 0000000000..c5eb6b500b
--- /dev/null
+++ b/libraries/libmdb/mdb_copy.c
@@ -0,0 +1,43 @@
+/* mdb_copy.c - memory-mapped database backup tool */
+/*
+ * Copyright 2012 Howard Chu, Symas Corp.
+ * All rights reserved.
+ *
+ * Redistribution and use in source and binary forms, with or without
+ * modification, are permitted only as authorized by the OpenLDAP
+ * Public License.
+ *
+ * A copy of this license is available in the file LICENSE in the
+ * top-level directory of the distribution or, alternatively, at
+ * <http://www.OpenLDAP.org/license.html>.
+ */
+#include <stdio.h>
+#include <stdlib.h>
+#include <time.h>
+#include "mdb.h"
+
+int main(int argc,char * argv[])
+{
+	int rc;
+	MDB_env *env;
+	char *envname = argv[1];
+
+	if (argc != 3) {
+		fprintf(stderr, "usage: %s srcpath dstpath\n", argv[0]);
+		exit(EXIT_FAILURE);
+	}
+
+	rc = mdb_env_create(&env);
+
+	rc = mdb_env_open(env, envname, MDB_RDONLY, 0);
+	if (rc) {
+		printf("mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
+	} else {
+		rc = mdb_env_copy(env, argv[2]);
+		if (rc)
+			printf("mdb_env_copy failed, error %d %s\n", rc, mdb_strerror(rc));
+	}
+	mdb_env_close(env);
+
+	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
+}

From f037dd2d19978256182a0f91f9a8178d37a8193f Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Thu, 11 Oct 2012 16:47:56 -0700
Subject: [PATCH 07/20] Silence warning in prev commit

---
 libraries/libmdb/mdb.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 7d9ea5cd4a..15432178c2 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -3291,7 +3291,7 @@ mdb_env_copy(MDB_env *env, const char *path)
 	HANDLE newfd = INVALID_HANDLE_VALUE;
 
 	if (env->me_flags & MDB_NOSUBDIR) {
-		lpath = path;
+		lpath = (char *)path;
 	} else {
 		len = strlen(path);
 		len += sizeof(DATANAME);

From e40713b631506dcab54402c26a826bd2d421dcb0 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Sat, 13 Oct 2012 04:05:00 -0700
Subject: [PATCH 08/20] Support read access on read-only media

---
 libraries/libmdb/mdb.c | 77 ++++++++++++++++++++++++++++--------------
 1 file changed, 52 insertions(+), 25 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 15432178c2..9bfe2f8d1f 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -913,6 +913,8 @@ struct MDB_env {
 	HANDLE		me_mfd;			/**< just for writing the meta pages */
 	/** Failed to update the meta page. Probably an I/O error. */
 #define	MDB_FATAL_ERROR	0x80000000U
+	/** Read-only Filesystem. Allow read access, no locking. */
+#define	MDB_ROFS	0x40000000U
 	uint32_t 	me_flags;		/**< @ref mdb_env */
 	unsigned int	me_psize;	/**< size of a page, from #GET_PAGESIZE */
 	unsigned int	me_maxreaders;	/**< size of the reader table */
@@ -1638,33 +1640,39 @@ mdb_txn_renew0(MDB_txn *txn)
 	txn->mt_dbxs = env->me_dbxs;	/* mostly static anyway */
 
 	if (txn->mt_flags & MDB_TXN_RDONLY) {
-		MDB_reader *r = pthread_getspecific(env->me_txkey);
-		if (!r) {
-			pid_t pid = env->me_pid;
-			pthread_t tid = pthread_self();
+		if (env->me_flags & MDB_ROFS) {
+			i = mdb_env_pick_meta(env);
+			txn->mt_txnid = env->me_metas[i]->mm_txnid;
+			txn->mt_u.reader = NULL;
+		} else {
+			MDB_reader *r = pthread_getspecific(env->me_txkey);
+			if (!r) {
+				pid_t pid = env->me_pid;
+				pthread_t tid = pthread_self();
 
-			LOCK_MUTEX_R(env);
-			for (i=0; i<env->me_txns->mti_numreaders; i++)
-				if (env->me_txns->mti_readers[i].mr_pid == 0)
-					break;
-			if (i == env->me_maxreaders) {
+				LOCK_MUTEX_R(env);
+				for (i=0; i<env->me_txns->mti_numreaders; i++)
+					if (env->me_txns->mti_readers[i].mr_pid == 0)
+						break;
+				if (i == env->me_maxreaders) {
+					UNLOCK_MUTEX_R(env);
+					return MDB_READERS_FULL;
+				}
+				env->me_txns->mti_readers[i].mr_pid = pid;
+				env->me_txns->mti_readers[i].mr_tid = tid;
+				if (i >= env->me_txns->mti_numreaders)
+					env->me_txns->mti_numreaders = i+1;
+				/* Save numreaders for un-mutexed mdb_env_close() */
+				env->me_numreaders = env->me_txns->mti_numreaders;
 				UNLOCK_MUTEX_R(env);
-				return MDB_READERS_FULL;
+				r = &env->me_txns->mti_readers[i];
+				pthread_setspecific(env->me_txkey, r);
 			}
-			env->me_txns->mti_readers[i].mr_pid = pid;
-			env->me_txns->mti_readers[i].mr_tid = tid;
-			if (i >= env->me_txns->mti_numreaders)
-				env->me_txns->mti_numreaders = i+1;
-			/* Save numreaders for un-mutexed mdb_env_close() */
-			env->me_numreaders = env->me_txns->mti_numreaders;
-			UNLOCK_MUTEX_R(env);
-			r = &env->me_txns->mti_readers[i];
-			pthread_setspecific(env->me_txkey, r);
+			txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
+			txn->mt_u.reader = r;
 		}
-		txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
 		txn->mt_toggle = txn->mt_txnid & 1;
 		txn->mt_next_pgno = env->me_metas[txn->mt_toggle]->mm_last_pg+1;
-		txn->mt_u.reader = r;
 	} else {
 		LOCK_MUTEX_W(env);
 
@@ -1804,7 +1812,8 @@ mdb_txn_reset0(MDB_txn *txn)
 	MDB_env	*env = txn->mt_env;
 
 	if (F_ISSET(txn->mt_flags, MDB_TXN_RDONLY)) {
-		txn->mt_u.reader->mr_txnid = (txnid_t)-1;
+		if (!(env->me_flags & MDB_ROFS))
+			txn->mt_u.reader->mr_txnid = (txnid_t)-1;
 	} else {
 		MDB_oldpages *mop;
 		MDB_page *dp;
@@ -2580,7 +2589,7 @@ mdb_env_open2(MDB_env *env, unsigned int flags)
 	MDB_meta meta;
 	MDB_page *p;
 
-	env->me_flags = flags;
+	env->me_flags |= flags;
 
 	memset(&meta, 0, sizeof(meta));
 
@@ -2921,6 +2930,11 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 	if ((env->me_lfd = CreateFile(lpath, GENERIC_READ|GENERIC_WRITE,
 		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
 		FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
+		rc = ErrCode();
+		if (rc == ERROR_WRITE_PROTECT) {
+			env->me_flags |= MDB_ROFS;
+			return MDB_SUCCESS;
+		}
 		goto fail_errno;
 	}
 	/* Try to get exclusive lock. If we succeed, then
@@ -2933,15 +2947,27 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 #if !(O_CLOEXEC)
 	{
 		int fdflags;
-		if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1)
+		if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
+			rc = ErrCode();
+			if (rc == EROFS) {
+				env->me_flags |= MDB_ROFS;
+				return MDB_SUCCESS;
+			}
 			goto fail_errno;
+		}
 		/* Lose record locks when exec*() */
 		if ((fdflags = fcntl(env->me_lfd, F_GETFD) | FD_CLOEXEC) >= 0)
 			fcntl(env->me_lfd, F_SETFD, fdflags);
 	}
 #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */
-	if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1)
+	if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) {
+		rc = ErrCode();
+		if (rc == EROFS) {
+			env->me_flags |= MDB_ROFS;
+			return MDB_SUCCESS;
+		}
 		goto fail_errno;
+	}
 #endif
 
 	/* Try to get exclusive lock. If we succeed, then
@@ -3128,6 +3154,7 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
 		sprintf(dpath, "%s" DATANAME, path);
 	}
 
+	env->me_flags = 0;
 	rc = mdb_env_setup_locks(env, lpath, mode, &excl);
 	if (rc)
 		goto leave;

From 462d9dfd104397652a905e8f685289bd4ac8a6e1 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Mon, 15 Oct 2012 17:03:33 +0200
Subject: [PATCH 09/20] Fix last commit.

Add flag MDB_ENV_ACTIVE instead of using the state of me_lfd.
Require MDB_RDONLY for MDB_ROFS.  Swap reader/writer mutex lock.
---
 libraries/libmdb/mdb.c | 58 +++++++++++++++++++++++++++---------------
 1 file changed, 37 insertions(+), 21 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 9bfe2f8d1f..b39fbfbfcb 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -915,6 +915,8 @@ struct MDB_env {
 #define	MDB_FATAL_ERROR	0x80000000U
 	/** Read-only Filesystem. Allow read access, no locking. */
 #define	MDB_ROFS	0x40000000U
+	/** Some fields are initialized. */
+#define	MDB_ENV_ACTIVE	0x20000000U
 	uint32_t 	me_flags;		/**< @ref mdb_env */
 	unsigned int	me_psize;	/**< size of a page, from #GET_PAGESIZE */
 	unsigned int	me_maxreaders;	/**< size of the reader table */
@@ -2583,14 +2585,13 @@ mdb_env_get_maxreaders(MDB_env *env, unsigned int *readers)
 /** Further setup required for opening an MDB environment
  */
 static int
-mdb_env_open2(MDB_env *env, unsigned int flags)
+mdb_env_open2(MDB_env *env)
 {
+	unsigned int flags = env->me_flags;
 	int i, newenv = 0, prot;
 	MDB_meta meta;
 	MDB_page *p;
 
-	env->me_flags |= flags;
-
 	memset(&meta, 0, sizeof(meta));
 
 	if ((i = mdb_env_read_header(env, &meta)) != 0) {
@@ -2931,7 +2932,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		FILE_SHARE_READ|FILE_SHARE_WRITE, NULL, OPEN_ALWAYS,
 		FILE_ATTRIBUTE_NORMAL, NULL)) == INVALID_HANDLE_VALUE) {
 		rc = ErrCode();
-		if (rc == ERROR_WRITE_PROTECT) {
+		if (rc == ERROR_WRITE_PROTECT && (env->me_flags & MDB_RDONLY)) {
 			env->me_flags |= MDB_ROFS;
 			return MDB_SUCCESS;
 		}
@@ -2949,7 +2950,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		int fdflags;
 		if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT, mode)) == -1) {
 			rc = ErrCode();
-			if (rc == EROFS) {
+			if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
 				env->me_flags |= MDB_ROFS;
 				return MDB_SUCCESS;
 			}
@@ -2962,7 +2963,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 #else /* O_CLOEXEC on Linux: Open file and set FD_CLOEXEC atomically */
 	if ((env->me_lfd = open(lpath, O_RDWR|O_CREAT|O_CLOEXEC, mode)) == -1) {
 		rc = ErrCode();
-		if (rc == EROFS) {
+		if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
 			env->me_flags |= MDB_ROFS;
 			return MDB_SUCCESS;
 		}
@@ -3154,15 +3155,15 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
 		sprintf(dpath, "%s" DATANAME, path);
 	}
 
-	env->me_flags = 0;
+	/* silently ignore WRITEMAP if we're only getting read access */
+	if (F_ISSET(flags, MDB_RDONLY|MDB_WRITEMAP))
+		flags ^= MDB_WRITEMAP;
+	env->me_flags = flags |= MDB_ENV_ACTIVE;
+
 	rc = mdb_env_setup_locks(env, lpath, mode, &excl);
 	if (rc)
 		goto leave;
 
-	/* silently ignore WRITEMAP if we're only getting read access */
-	if (F_ISSET(flags, MDB_RDONLY) && F_ISSET(flags, MDB_WRITEMAP))
-		flags ^= MDB_WRITEMAP;
-
 #ifdef _WIN32
 	if (F_ISSET(flags, MDB_RDONLY)) {
 		oflags = GENERIC_READ;
@@ -3187,7 +3188,7 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
 		goto leave;
 	}
 
-	if ((rc = mdb_env_open2(env, flags)) == MDB_SUCCESS) {
+	if ((rc = mdb_env_open2(env)) == MDB_SUCCESS) {
 		if (flags & (MDB_RDONLY|MDB_NOSYNC|MDB_NOMETASYNC|MDB_WRITEMAP)) {
 			env->me_mfd = env->me_fd;
 		} else {
@@ -3242,7 +3243,7 @@ mdb_env_close0(MDB_env *env, int excl)
 {
 	int i;
 
-	if (env->me_lfd == INVALID_HANDLE_VALUE) /* 1st field to get inited */
+	if (!(env->me_flags & MDB_ENV_ACTIVE))
 		return;
 
 	free(env->me_dbflags);
@@ -3303,9 +3304,11 @@ mdb_env_close0(MDB_env *env, int excl)
 #endif
 		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
 	}
-	close(env->me_lfd);
+	if (env->me_lfd != INVALID_HANDLE_VALUE) {
+		close(env->me_lfd);
+	}
 
-	env->me_lfd = INVALID_HANDLE_VALUE;	/* Mark env as reset */
+	env->me_flags &= ~MDB_ENV_ACTIVE;
 }
 
 int
@@ -3357,13 +3360,25 @@ mdb_env_copy(MDB_env *env, const char *path)
 	}
 #endif
 
-	/* Temporarily block writers until we snapshot the meta pages */
-	LOCK_MUTEX_W(env);
-
+	/* Do the lock/unlock of the reader mutex before starting the
+	 * write txn.  Otherwise other read txns could block writers.
+	 */
 	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc) {
-		UNLOCK_MUTEX_W(env);
+	if (rc)
 		goto leave;
+
+	if (!(env->me_flags & MDB_ROFS)) {
+		/* We must start the actual read txn after blocking writers */
+		mdb_txn_reset0(txn);
+
+		/* Temporarily block writers until we snapshot the meta pages */
+		LOCK_MUTEX_W(env);
+
+		rc = mdb_txn_renew0(txn);
+		if (rc) {
+			UNLOCK_MUTEX_W(env);
+			goto leave;
+		}
 	}
 
 	wsize = env->me_psize * 2;
@@ -3377,7 +3392,8 @@ mdb_env_copy(MDB_env *env, const char *path)
 	rc = write(newfd, env->me_map, wsize);
 	rc = (rc == (int)wsize) ? MDB_SUCCESS : ErrCode();
 #endif
-	UNLOCK_MUTEX_W(env);
+	if (! (env->me_flags & MDB_ROFS))
+		UNLOCK_MUTEX_W(env);
 
 	if (rc)
 		goto leave;

From 092f9a5c66425535f9d538d8fefd0049ad65f452 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Mon, 15 Oct 2012 17:03:46 +0200
Subject: [PATCH 10/20] More for mdb_env_copy().

Fix #define _GNU_SOURCE = 1 to match any command line -D_GNU_SOURCE.
.gitignore += mdb_copy.
---
 libraries/libmdb/.gitignore | 1 +
 libraries/libmdb/mdb.c      | 2 +-
 2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/libraries/libmdb/.gitignore b/libraries/libmdb/.gitignore
index 134c457f7d..0d493fe188 100644
--- a/libraries/libmdb/.gitignore
+++ b/libraries/libmdb/.gitignore
@@ -1,6 +1,7 @@
 mtest
 mtest[23456]
 testdb
+mdb_copy
 mdb_stat
 *.[ao]
 *.so
diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index b39fbfbfcb..07ecf99eba 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -32,7 +32,7 @@
  * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
  * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
  */
-#define _GNU_SOURCE
+#define _GNU_SOURCE 1
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <sys/param.h>

From e9d87866c49acdba4118259fb05de2dafb4d698f Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Mon, 15 Oct 2012 17:04:11 +0200
Subject: [PATCH 11/20] mdb_env_open(): Keep mdb_env_set_flags() flags.

---
 libraries/libmdb/mdb.c | 1 +
 libraries/libmdb/mdb.h | 3 ++-
 2 files changed, 3 insertions(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 07ecf99eba..cd2ad9a510 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -3155,6 +3155,7 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
 		sprintf(dpath, "%s" DATANAME, path);
 	}
 
+	flags |= env->me_flags;
 	/* silently ignore WRITEMAP if we're only getting read access */
 	if (F_ISSET(flags, MDB_RDONLY|MDB_WRITEMAP))
 		flags ^= MDB_WRITEMAP;
diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index 1735fbd375..d78868cb08 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -401,6 +401,7 @@ int  mdb_env_create(MDB_env **env);
 	 * @param[in] flags Special options for this environment. This parameter
 	 * must be set to 0 or by bitwise OR'ing together one or more of the
 	 * values described here.
+	 * Flags set by mdb_env_set_flags() are also used.
 	 * <ul>
 	 *	<li>#MDB_FIXEDMAP
 	 *      use a fixed address for the mmap region. This flag must be specified
@@ -501,7 +502,7 @@ void mdb_env_close(MDB_env *env);
 
 	/** @brief Set environment flags.
 	 *
-	 * This may be used to set some flags that weren't already set during
+	 * This may be used to set some flags in addition to those from
 	 * #mdb_env_open(), or to unset these flags.
 	 * @param[in] env An environment handle returned by #mdb_env_create()
 	 * @param[in] flags The flags to change, bitwise OR'ed together

From 88b7bb46394a53675b452b70e5a7a109626bdd3f Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Mon, 15 Oct 2012 17:04:43 +0200
Subject: [PATCH 12/20] Explicitly unlock the MDB lockfile on Windows.

---
 libraries/libmdb/mdb.c | 12 +++++++++++-
 1 file changed, 11 insertions(+), 1 deletion(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index cd2ad9a510..383616116e 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -2806,7 +2806,9 @@ mdb_env_excl_lock(MDB_env *env, int *excl)
 	} else {
 		OVERLAPPED ov;
 		memset(&ov, 0, sizeof(ov));
-		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+		if (LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+			*excl = 0;
+		} else {
 			rc = ErrCode();
 		}
 	}
@@ -3306,6 +3308,14 @@ mdb_env_close0(MDB_env *env, int excl)
 		munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
 	}
 	if (env->me_lfd != INVALID_HANDLE_VALUE) {
+#ifdef _WIN32
+		if (excl >= 0) {
+			/* Unlock the lockfile.  Windows would have unlocked it
+			 * after closing anyway, but not necessarily at once.
+			 */
+			UnlockFile(env->me_lfd, 0, 0, 1, 0);
+		}
+#endif
 		close(env->me_lfd);
 	}
 

From 94965307c831be615f5fbb771c348fd72217adc0 Mon Sep 17 00:00:00 2001
From: Hallvard Furuseth <hallvard@openldap.org>
Date: Mon, 15 Oct 2012 17:04:48 +0200
Subject: [PATCH 13/20] ITS#7377 Errorcheck Windows calls and thread keys.

---
 libraries/libmdb/mdb.c | 26 ++++++++++++++++++--------
 1 file changed, 18 insertions(+), 8 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 383616116e..2ac9278113 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -141,10 +141,11 @@
 #define pthread_mutex_t	HANDLE
 #define pthread_key_t	DWORD
 #define pthread_self()	GetCurrentThreadId()
-#define pthread_key_create(x,y)	(*(x) = TlsAlloc())
+#define pthread_key_create(x,y)	\
+	((*(x) = TlsAlloc()) == TLS_OUT_OF_INDEXES ? ErrCode() : 0)
 #define pthread_key_delete(x)	TlsFree(x)
 #define pthread_getspecific(x)	TlsGetValue(x)
-#define pthread_setspecific(x,y)	TlsSetValue(x,y)
+#define pthread_setspecific(x,y)	(TlsSetValue(x,y) ? 0 : ErrCode())
 #define pthread_mutex_unlock(x)	ReleaseMutex(x)
 #define pthread_mutex_lock(x)	WaitForSingleObject(x, INFINITE)
 #define LOCK_MUTEX_R(env)	pthread_mutex_lock((env)->me_rmutex)
@@ -1636,6 +1637,7 @@ mdb_txn_renew0(MDB_txn *txn)
 {
 	MDB_env *env = txn->mt_env;
 	unsigned int i;
+	int rc;
 
 	/* Setup db info */
 	txn->mt_numdbs = env->me_numdbs;
@@ -1668,7 +1670,10 @@ mdb_txn_renew0(MDB_txn *txn)
 				env->me_numreaders = env->me_txns->mti_numreaders;
 				UNLOCK_MUTEX_R(env);
 				r = &env->me_txns->mti_readers[i];
-				pthread_setspecific(env->me_txkey, r);
+				if ((rc = pthread_setspecific(env->me_txkey, r)) != 0) {
+					env->me_txns->mti_readers[i].mr_pid = 0;
+					return rc;
+				}
 			}
 			txn->mt_txnid = r->mr_txnid = env->me_txns->mti_txnid;
 			txn->mt_u.reader = r;
@@ -2771,9 +2776,12 @@ mdb_env_share_locks(MDB_env *env, int *excl)
 		 * then release the existing exclusive lock.
 		 */
 		memset(&ov, 0, sizeof(ov));
-		LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov);
-		UnlockFile(env->me_lfd, 0, 0, 1, 0);
-		*excl = 0;
+		if (!LockFileEx(env->me_lfd, 0, 0, 1, 0, &ov)) {
+			rc = ErrCode();
+		} else {
+			UnlockFile(env->me_lfd, 0, 0, 1, 0);
+			*excl = 0;
+		}
 	}
 #else
 	{
@@ -3029,7 +3037,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 			mdb_all_sa.lpSecurityDescriptor = &mdb_null_sd;
 			mdb_sec_inited = 1;
 		}
-		GetFileInformationByHandle(env->me_lfd, &stbuf);
+		if (!GetFileInformationByHandle(env->me_lfd, &stbuf)) goto fail_errno;
 		idbuf.volume = stbuf.dwVolumeSerialNumber;
 		idbuf.nhigh  = stbuf.nFileIndexHigh;
 		idbuf.nlow   = stbuf.nFileIndexLow;
@@ -3209,7 +3217,9 @@ mdb_env_open(MDB_env *env, const char *path, unsigned int flags, mode_t mode)
 			}
 		}
 		DPRINTF("opened dbenv %p", (void *) env);
-		pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
+		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
+		if (rc)
+			goto leave;
 		env->me_numdbs = 2;	/* this notes that me_txkey was set */
 #ifdef _WIN32
 		/* Windows TLS callbacks need help finding their TLS info. */

From 65d40eb5d2c7c28df05e2c1d9b21d90e2a82e0b5 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Tue, 16 Oct 2012 14:53:25 -0700
Subject: [PATCH 14/20] Make sure increases of mapsize are persisted

---
 libraries/libmdb/mdb.c | 24 ++++++++++++++++--------
 1 file changed, 16 insertions(+), 8 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 2ac9278113..9fd7db3c89 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -2417,7 +2417,7 @@ static int
 mdb_env_write_meta(MDB_txn *txn)
 {
 	MDB_env *env;
-	MDB_meta	meta, metab;
+	MDB_meta	meta, metab, *mp;
 	off_t off;
 	int rc, len, toggle;
 	char *ptr;
@@ -2433,9 +2433,12 @@ mdb_env_write_meta(MDB_txn *txn)
 		toggle, txn->mt_dbs[MAIN_DBI].md_root);
 
 	env = txn->mt_env;
+	mp = env->me_metas[toggle];
 
 	if (env->me_flags & MDB_WRITEMAP) {
-		MDB_meta *mp = env->me_metas[toggle];
+		/* Persist any increases of mapsize config */
+		if (env->me_mapsize > mp->mm_mapsize)
+			mp->mm_mapsize = env->me_mapsize;
 		mp->mm_dbs[0] = txn->mt_dbs[0];
 		mp->mm_dbs[1] = txn->mt_dbs[1];
 		mp->mm_last_pg = txn->mt_next_pgno - 1;
@@ -2456,7 +2459,13 @@ mdb_env_write_meta(MDB_txn *txn)
 	metab.mm_last_pg = env->me_metas[toggle]->mm_last_pg;
 
 	ptr = (char *)&meta;
-	off = offsetof(MDB_meta, mm_dbs[0].md_depth);
+	if (env->me_mapsize > mp->mm_mapsize) {
+		/* Persist any increases of mapsize config */
+		meta.mm_mapsize = env->me_mapsize;
+		off = offsetof(MDB_meta, mm_mapsize);
+	} else {
+		off = offsetof(MDB_meta, mm_dbs[0].md_depth);
+	}
 	len = sizeof(MDB_meta) - off;
 
 	ptr += off;
@@ -2604,11 +2613,11 @@ mdb_env_open2(MDB_env *env)
 			return i;
 		DPUTS("new mdbenv");
 		newenv = 1;
+		meta.mm_mapsize = env->me_mapsize > DEFAULT_MAPSIZE ? env->me_mapsize : DEFAULT_MAPSIZE;
 	}
 
-	if (!env->me_mapsize) {
-		env->me_mapsize = newenv ? DEFAULT_MAPSIZE : meta.mm_mapsize;
-	}
+	if (env->me_mapsize < meta.mm_mapsize)
+		env->me_mapsize = meta.mm_mapsize;
 
 #ifdef _WIN32
 	{
@@ -2657,7 +2666,6 @@ mdb_env_open2(MDB_env *env)
 #endif
 
 	if (newenv) {
-		meta.mm_mapsize = env->me_mapsize;
 		if (flags & MDB_FIXEDMAP)
 			meta.mm_address = env->me_map;
 		i = mdb_env_init_meta(env, &meta);
@@ -3336,7 +3344,7 @@ int
 mdb_env_copy(MDB_env *env, const char *path)
 {
 	MDB_txn *txn = NULL;
-	int rc, len, oflags;
+	int rc, len;
 	size_t wsize;
 	char *lpath, *ptr;
 	HANDLE newfd = INVALID_HANDLE_VALUE;

From 7f0771a3ed4ec42bd57f246919aba1dd755a207c Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Tue, 16 Oct 2012 15:28:20 -0700
Subject: [PATCH 15/20] Merge mdb_stata into mdb_stat

---
 libraries/libmdb/mdb_stat.c  | 112 +++++++++++++++++++++++++++++------
 libraries/libmdb/mdb_stata.c |  84 --------------------------
 2 files changed, 93 insertions(+), 103 deletions(-)
 delete mode 100644 libraries/libmdb/mdb_stata.c

diff --git a/libraries/libmdb/mdb_stat.c b/libraries/libmdb/mdb_stat.c
index 97bd8d4467..73891cfcdb 100644
--- a/libraries/libmdb/mdb_stat.c
+++ b/libraries/libmdb/mdb_stat.c
@@ -13,49 +13,123 @@
  */
 #include <stdio.h>
 #include <stdlib.h>
-#include <time.h>
+#include <string.h>
+#include <unistd.h>
 #include "mdb.h"
 
-int main(int argc,char * argv[])
+static void prstat(MDB_stat *ms)
 {
-	int rc;
+	printf("Page size: %u\n", ms->ms_psize);
+	printf("Tree depth: %u\n", ms->ms_depth);
+	printf("Branch pages: %zu\n", ms->ms_branch_pages);
+	printf("Leaf pages: %zu\n", ms->ms_leaf_pages);
+	printf("Overflow pages: %zu\n", ms->ms_overflow_pages);
+	printf("Entries: %zu\n", ms->ms_entries);
+}
+
+static void usage(char *prog)
+{
+	fprintf(stderr, "usage: %s dbpath [-a|-s subdb]\n", prog);
+	exit(EXIT_FAILURE);
+}
+
+int main(int argc, char *argv[])
+{
+	int i, rc;
 	MDB_env *env;
 	MDB_txn *txn;
 	MDB_dbi dbi;
 	MDB_stat mst;
-	char *envname = argv[1];
+	char *prog = argv[0];
+	char *envname;
 	char *subname = NULL;
+	int alldbs = 0;
 
-	rc = mdb_env_create(&env);
-
-	if (argc > 2) {
-		mdb_env_set_maxdbs(env, 4);
-		subname = argv[2];
+	if (argc < 2) {
+		usage(prog);
 	}
 
-	rc = mdb_env_open(env, envname, MDB_RDONLY, 0);
+	/* -a: print stat of main DB and all subDBs
+	 * -s: print stat of only the named subDB
+	 * (default) print stat of only the main DB
+	 */
+	while ((i = getopt(argc, argv, "as:")) != EOF) {
+		switch(i) {
+		case 'a':
+			alldbs++;
+			break;
+		case 's':
+			subname = optarg;
+			break;
+		default:
+			fprintf(stderr, "%s: unrecognized option -%c\n", prog, optopt);
+			usage(prog);
+		}
+	}
+
+	if (optind != argc - 1)
+		usage(prog);
+
+	envname = argv[optind];
+	rc = mdb_env_create(&env);
+
+	if (alldbs || subname) {
+		mdb_env_set_maxdbs(env, 4);
+	}
+
+	rc = mdb_env_open(env, envname, MDB_RDONLY, 0664);
 	if (rc) {
-		printf("mdb_env_open failed, error %d\n", rc);
+		printf("mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto env_close;
 	}
 	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
 	if (rc) {
-		printf("mdb_txn_begin failed, error %d\n", rc);
+		printf("mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto env_close;
 	}
 	rc = mdb_open(txn, subname, 0, &dbi);
 	if (rc) {
-		printf("mdb_open failed, error %d\n", rc);
+		printf("mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto txn_abort;
 	}
    
 	rc = mdb_stat(txn, dbi, &mst);
-	printf("Page size: %u\n", mst.ms_psize);
-	printf("Tree depth: %u\n", mst.ms_depth);
-	printf("Branch pages: %zu\n", mst.ms_branch_pages);
-	printf("Leaf pages: %zu\n", mst.ms_leaf_pages);
-	printf("Overflow pages: %zu\n", mst.ms_overflow_pages);
-	printf("Entries: %zu\n", mst.ms_entries);
+	if (rc) {
+		printf("mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
+		goto txn_abort;
+	}
+	prstat(&mst);
+
+	if (alldbs) {
+		MDB_cursor *cursor;
+		MDB_val key;
+
+		rc = mdb_cursor_open(txn, dbi, &cursor);
+		if (rc) {
+			printf("mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
+			goto txn_abort;
+		}
+		while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT)) == 0) {
+			char *str = malloc(key.mv_size+1);
+			MDB_dbi db2;
+			memcpy(str, key.mv_data, key.mv_size);
+			str[key.mv_size] = '\0';
+			rc = mdb_open(txn, str, 0, &db2);
+			if (rc == MDB_SUCCESS)
+				printf("\n%s\n", str);
+			free(str);
+			if (rc) continue;
+			rc = mdb_stat(txn, db2, &mst);
+			if (rc) {
+				printf("mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
+				goto txn_abort;
+			}
+			prstat(&mst);
+			mdb_close(env, db2);
+		}
+		mdb_cursor_close(cursor);
+	}
+
 	mdb_close(env, dbi);
 txn_abort:
 	mdb_txn_abort(txn);
diff --git a/libraries/libmdb/mdb_stata.c b/libraries/libmdb/mdb_stata.c
deleted file mode 100644
index 7cfebb4914..0000000000
--- a/libraries/libmdb/mdb_stata.c
+++ /dev/null
@@ -1,84 +0,0 @@
-/* mdb_stat.c - memory-mapped database status tool */
-/*
- * Copyright 2011 Howard Chu, Symas Corp.
- * All rights reserved.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted only as authorized by the OpenLDAP
- * Public License.
- *
- * A copy of this license is available in the file LICENSE in the
- * top-level directory of the distribution or, alternatively, at
- * <http://www.OpenLDAP.org/license.html>.
- */
-#include <stdio.h>
-#include <stdlib.h>
-#include <string.h>
-#include "mdb.h"
-
-int main(int argc,char * argv[])
-{
-	int rc;
-	MDB_env *env;
-	MDB_txn *txn;
-	MDB_dbi dbi;
-	MDB_stat mst;
-	MDB_cursor *cursor;
-	MDB_val key;
-	char *envname = argv[1];
-
-	rc = mdb_env_create(&env);
-
-	mdb_env_set_maxdbs(env, 4);
-
-	rc = mdb_env_open(env, envname, MDB_RDONLY, 0);
-	if (rc) {
-		printf("mdb_env_open failed, error %d\n", rc);
-		goto env_close;
-	}
-	rc = mdb_txn_begin(env, NULL, MDB_RDONLY, &txn);
-	if (rc) {
-		printf("mdb_txn_begin failed, error %d\n", rc);
-		goto env_close;
-	}
-	rc = mdb_open(txn, NULL, 0, &dbi);
-	if (rc) {
-		printf("mdb_open failed, error %d\n", rc);
-		goto txn_abort;
-	}
-   
-	rc = mdb_stat(txn, dbi, &mst);
-	printf("Page size: %u\n", mst.ms_psize);
-	printf("Tree depth: %u\n", mst.ms_depth);
-	printf("Branch pages: %zu\n", mst.ms_branch_pages);
-	printf("Leaf pages: %zu\n", mst.ms_leaf_pages);
-	printf("Overflow pages: %zu\n", mst.ms_overflow_pages);
-	printf("Entries: %zu\n", mst.ms_entries);
-
-	rc = mdb_cursor_open(txn, dbi, &cursor);
-	while ((rc = mdb_cursor_get(cursor, &key, NULL, MDB_NEXT)) == 0) {
-		char *str = malloc(key.mv_size+1);
-		MDB_dbi db2;
-		memcpy(str, key.mv_data, key.mv_size);
-		str[key.mv_size] = '\0';
-		printf("\n%s\n", str);
-		rc = mdb_open(txn, str, 0, &db2);
-		if (rc) break;
-		free(str);
-		rc = mdb_stat(txn, db2, &mst);
-		printf("Tree depth: %u\n", mst.ms_depth);
-		printf("Branch pages: %zu\n", mst.ms_branch_pages);
-		printf("Leaf pages: %zu\n", mst.ms_leaf_pages);
-		printf("Overflow pages: %zu\n", mst.ms_overflow_pages);
-		printf("Entries: %zu\n", mst.ms_entries);
-		mdb_close(env, db2);
-	}
-	mdb_cursor_close(cursor);
-	mdb_close(env, dbi);
-txn_abort:
-	mdb_txn_abort(txn);
-env_close:
-	mdb_env_close(env);
-
-	return rc ? EXIT_FAILURE : EXIT_SUCCESS;
-}

From 754cd88819cceafe503b7a5c428b52c6abbcb748 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Tue, 16 Oct 2012 16:22:21 -0700
Subject: [PATCH 16/20] Add mdb_env_info() to retrieve interesting env params

---
 libraries/libmdb/mdb.c      | 17 +++++++++++++++++
 libraries/libmdb/mdb.h      | 17 +++++++++++++++++
 libraries/libmdb/mdb_stat.c | 19 +++++++++++++++++--
 3 files changed, 51 insertions(+), 2 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 9fd7db3c89..f3c482d888 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -6651,6 +6651,23 @@ mdb_env_stat(MDB_env *env, MDB_stat *arg)
 	return mdb_stat0(env, &env->me_metas[toggle]->mm_dbs[MAIN_DBI], arg);
 }
 
+int
+mdb_env_info(MDB_env *env, MDB_envinfo *arg)
+{
+	int toggle;
+
+	if (env == NULL || arg == NULL)
+		return EINVAL;
+
+	toggle = mdb_env_pick_meta(env);
+	arg->me_mapsize = env->me_mapsize;
+	arg->me_maxreaders = env->me_maxreaders;
+	arg->me_numreaders = env->me_numreaders;
+	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
+	arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
+	return MDB_SUCCESS;
+}
+
 /** Set the default comparison functions for a database.
  * Called immediately after a database is opened to set the defaults.
  * The user can then override them with #mdb_set_compare() or
diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index d78868cb08..739fee7265 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -358,6 +358,15 @@ typedef struct MDB_stat {
 	size_t		ms_entries;			/**< Number of data items */
 } MDB_stat;
 
+/** @brief Information about the environment */
+typedef struct MDB_envinfo {
+	size_t	me_mapsize;				/**< Size of the data memory map */
+	size_t	me_last_txnid;			/**< ID of the last committed transaction */
+	size_t	me_last_pgno;			/**< ID of the last used page */
+	unsigned int me_maxreaders;		/**< maximum number of threads for the environment */
+	unsigned int me_numreaders;		/**< maximum number of threads used in the environment */
+} MDB_envinfo;
+
 	/** @brief Return the mdb library version information.
 	 *
 	 * @param[out] major if non-NULL, the library major version number is copied here
@@ -471,6 +480,14 @@ int  mdb_env_copy(MDB_env *env, const char *path);
 	 */
 int  mdb_env_stat(MDB_env *env, MDB_stat *stat);
 
+	/** @brief Return information about the MDB environment.
+	 *
+	 * @param[in] env An environment handle returned by #mdb_env_create()
+	 * @param[out] stat The address of an #MDB_envinfo structure
+	 * 	where the information will be copied
+	 */
+int  mdb_env_info(MDB_env *env, MDB_envinfo *stat);
+
 	/** @brief Flush the data buffers to disk.
 	 *
 	 * Data is always written to disk when #mdb_txn_commit() is called,
diff --git a/libraries/libmdb/mdb_stat.c b/libraries/libmdb/mdb_stat.c
index 73891cfcdb..8b196d1757 100644
--- a/libraries/libmdb/mdb_stat.c
+++ b/libraries/libmdb/mdb_stat.c
@@ -40,10 +40,11 @@ int main(int argc, char *argv[])
 	MDB_txn *txn;
 	MDB_dbi dbi;
 	MDB_stat mst;
+	MDB_envinfo mei;
 	char *prog = argv[0];
 	char *envname;
 	char *subname = NULL;
-	int alldbs = 0;
+	int alldbs = 0, envinfo = 0;
 
 	if (argc < 2) {
 		usage(prog);
@@ -51,13 +52,17 @@ int main(int argc, char *argv[])
 
 	/* -a: print stat of main DB and all subDBs
 	 * -s: print stat of only the named subDB
+	 * -e: print env info
 	 * (default) print stat of only the main DB
 	 */
-	while ((i = getopt(argc, argv, "as:")) != EOF) {
+	while ((i = getopt(argc, argv, "aes:")) != EOF) {
 		switch(i) {
 		case 'a':
 			alldbs++;
 			break;
+		case 'e':
+			envinfo++;
+			break;
 		case 's':
 			subname = optarg;
 			break;
@@ -87,6 +92,16 @@ int main(int argc, char *argv[])
 		printf("mdb_txn_begin failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto env_close;
 	}
+
+	if (envinfo) {
+		rc = mdb_env_info(env, &mei);
+		printf("Map size: %zu \n", mei.me_mapsize);
+		printf("Last transaction ID: %zu\n", mei.me_last_txnid);
+		printf("Last page used: %zu\n", mei.me_last_pgno);
+		printf("Max readers: %u\n", mei.me_maxreaders);
+		printf("Number of readers used: %u\n", mei.me_numreaders);
+	}
+
 	rc = mdb_open(txn, subname, 0, &dbi);
 	if (rc) {
 		printf("mdb_open failed, error %d %s\n", rc, mdb_strerror(rc));

From 617769bce5bcac809791adb11301e40d27c31566 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Tue, 16 Oct 2012 16:52:13 -0700
Subject: [PATCH 17/20] Tweak output, add free page info

---
 libraries/libmdb/mdb.c      |  3 +-
 libraries/libmdb/mdb.h      |  3 +-
 libraries/libmdb/mdb_stat.c | 75 ++++++++++++++++++++++++++++---------
 3 files changed, 62 insertions(+), 19 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index f3c482d888..89bfd71f36 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -6660,11 +6660,12 @@ mdb_env_info(MDB_env *env, MDB_envinfo *arg)
 		return EINVAL;
 
 	toggle = mdb_env_pick_meta(env);
+	arg->me_mapaddr = (env->me_flags & MDB_FIXEDMAP) ? env->me_map : 0;
 	arg->me_mapsize = env->me_mapsize;
 	arg->me_maxreaders = env->me_maxreaders;
 	arg->me_numreaders = env->me_numreaders;
-	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
 	arg->me_last_pgno = env->me_metas[toggle]->mm_last_pg;
+	arg->me_last_txnid = env->me_metas[toggle]->mm_txnid;
 	return MDB_SUCCESS;
 }
 
diff --git a/libraries/libmdb/mdb.h b/libraries/libmdb/mdb.h
index 739fee7265..e3fc129829 100644
--- a/libraries/libmdb/mdb.h
+++ b/libraries/libmdb/mdb.h
@@ -360,9 +360,10 @@ typedef struct MDB_stat {
 
 /** @brief Information about the environment */
 typedef struct MDB_envinfo {
+	void	*me_mapaddr;			/**< Address of map, if fixed */
 	size_t	me_mapsize;				/**< Size of the data memory map */
-	size_t	me_last_txnid;			/**< ID of the last committed transaction */
 	size_t	me_last_pgno;			/**< ID of the last used page */
+	size_t	me_last_txnid;			/**< ID of the last committed transaction */
 	unsigned int me_maxreaders;		/**< maximum number of threads for the environment */
 	unsigned int me_numreaders;		/**< maximum number of threads used in the environment */
 } MDB_envinfo;
diff --git a/libraries/libmdb/mdb_stat.c b/libraries/libmdb/mdb_stat.c
index 8b196d1757..88ac801807 100644
--- a/libraries/libmdb/mdb_stat.c
+++ b/libraries/libmdb/mdb_stat.c
@@ -19,17 +19,19 @@
 
 static void prstat(MDB_stat *ms)
 {
-	printf("Page size: %u\n", ms->ms_psize);
-	printf("Tree depth: %u\n", ms->ms_depth);
-	printf("Branch pages: %zu\n", ms->ms_branch_pages);
-	printf("Leaf pages: %zu\n", ms->ms_leaf_pages);
-	printf("Overflow pages: %zu\n", ms->ms_overflow_pages);
-	printf("Entries: %zu\n", ms->ms_entries);
+#if 0
+	printf("  Page size: %u\n", ms->ms_psize);
+#endif
+	printf("  Tree depth: %u\n", ms->ms_depth);
+	printf("  Branch pages: %zu\n", ms->ms_branch_pages);
+	printf("  Leaf pages: %zu\n", ms->ms_leaf_pages);
+	printf("  Overflow pages: %zu\n", ms->ms_overflow_pages);
+	printf("  Entries: %zu\n", ms->ms_entries);
 }
 
 static void usage(char *prog)
 {
-	fprintf(stderr, "usage: %s dbpath [-a|-s subdb]\n", prog);
+	fprintf(stderr, "usage: %s dbpath [-e] [-f] [-n] [-a|-s subdb]\n", prog);
 	exit(EXIT_FAILURE);
 }
 
@@ -44,7 +46,7 @@ int main(int argc, char *argv[])
 	char *prog = argv[0];
 	char *envname;
 	char *subname = NULL;
-	int alldbs = 0, envinfo = 0;
+	int alldbs = 0, envinfo = 0, envflags = 0, freinfo = 0;
 
 	if (argc < 2) {
 		usage(prog);
@@ -53,9 +55,11 @@ int main(int argc, char *argv[])
 	/* -a: print stat of main DB and all subDBs
 	 * -s: print stat of only the named subDB
 	 * -e: print env info
+	 * -f: print freelist info
+	 * -n: use NOSUBDIR flag on env_open
 	 * (default) print stat of only the main DB
 	 */
-	while ((i = getopt(argc, argv, "aes:")) != EOF) {
+	while ((i = getopt(argc, argv, "aefns:")) != EOF) {
 		switch(i) {
 		case 'a':
 			alldbs++;
@@ -63,11 +67,16 @@ int main(int argc, char *argv[])
 		case 'e':
 			envinfo++;
 			break;
+		case 'f':
+			freinfo++;
+			break;
+		case 'n':
+			envflags |= MDB_NOSUBDIR;
+			break;
 		case 's':
 			subname = optarg;
 			break;
 		default:
-			fprintf(stderr, "%s: unrecognized option -%c\n", prog, optopt);
 			usage(prog);
 		}
 	}
@@ -82,7 +91,7 @@ int main(int argc, char *argv[])
 		mdb_env_set_maxdbs(env, 4);
 	}
 
-	rc = mdb_env_open(env, envname, MDB_RDONLY, 0664);
+	rc = mdb_env_open(env, envname, envflags | MDB_RDONLY, 0664);
 	if (rc) {
 		printf("mdb_env_open failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto env_close;
@@ -94,12 +103,43 @@ int main(int argc, char *argv[])
 	}
 
 	if (envinfo) {
+		rc = mdb_env_stat(env, &mst);
 		rc = mdb_env_info(env, &mei);
-		printf("Map size: %zu \n", mei.me_mapsize);
-		printf("Last transaction ID: %zu\n", mei.me_last_txnid);
-		printf("Last page used: %zu\n", mei.me_last_pgno);
-		printf("Max readers: %u\n", mei.me_maxreaders);
-		printf("Number of readers used: %u\n", mei.me_numreaders);
+		printf("Environment Info\n");
+		printf("  Map address: %p\n", mei.me_mapaddr);
+		printf("  Map size: %zu\n", mei.me_mapsize);
+		printf("  Page size: %u\n", mst.ms_psize);
+		printf("  Max pages: %zu\n", mei.me_mapsize / mst.ms_psize);
+		printf("  Number of pages used: %zu\n", mei.me_last_pgno+1);
+		printf("  Last transaction ID: %zu\n", mei.me_last_txnid);
+		printf("  Max readers: %u\n", mei.me_maxreaders);
+		printf("  Number of readers used: %u\n", mei.me_numreaders);
+	}
+
+	if (freinfo) {
+		MDB_cursor *cursor;
+		MDB_val data;
+		size_t pages = 0, *iptr;
+
+		printf("Freelist Status\n");
+		dbi = 0;
+		rc = mdb_cursor_open(txn, dbi, &cursor);
+		if (rc) {
+			printf("mdb_cursor_open failed, error %d %s\n", rc, mdb_strerror(rc));
+			goto txn_abort;
+		}
+		rc = mdb_stat(txn, dbi, &mst);
+		if (rc) {
+			printf("mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
+			goto txn_abort;
+		}
+		while ((rc = mdb_cursor_get(cursor, NULL, &data, MDB_NEXT)) == 0) {
+			iptr = data.mv_data;
+			pages += *iptr;
+		}
+		mdb_cursor_close(cursor);
+		prstat(&mst);
+		printf("  Free pages: %zu\n", pages);
 	}
 
 	rc = mdb_open(txn, subname, 0, &dbi);
@@ -113,6 +153,7 @@ int main(int argc, char *argv[])
 		printf("mdb_stat failed, error %d %s\n", rc, mdb_strerror(rc));
 		goto txn_abort;
 	}
+	printf("Status of %s\n", subname ? subname : "Main DB");
 	prstat(&mst);
 
 	if (alldbs) {
@@ -131,7 +172,7 @@ int main(int argc, char *argv[])
 			str[key.mv_size] = '\0';
 			rc = mdb_open(txn, str, 0, &db2);
 			if (rc == MDB_SUCCESS)
-				printf("\n%s\n", str);
+				printf("Status of %s\n", str);
 			free(str);
 			if (rc) continue;
 			rc = mdb_stat(txn, db2, &mst);

From 5c1ee7f7ba9580d5ff29e74cbb02eee335c33d94 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Mon, 22 Oct 2012 15:58:46 -0700
Subject: [PATCH 18/20] Fix MDB_PREV

Could return 1 garbage record before actual data, if starting from EOF
---
 libraries/libmdb/mdb.c | 19 +++++++++++++------
 1 file changed, 13 insertions(+), 6 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 89bfd71f36..994a5d95f3 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -3982,8 +3982,12 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right)
 		       : (mc->mc_ki[mc->mc_top] == 0)) {
 		DPRINTF("no more keys left, moving to %s sibling",
 		    move_right ? "right" : "left");
-		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS)
+		if ((rc = mdb_cursor_sibling(mc, move_right)) != MDB_SUCCESS) {
+			/* undo cursor_pop before returning */
+			mc->mc_top++;
+			mc->mc_snum++;
 			return rc;
+		}
 	} else {
 		if (move_right)
 			mc->mc_ki[mc->mc_top]++;
@@ -4393,8 +4397,8 @@ mdb_cursor_last(MDB_cursor *mc, MDB_val *key, MDB_val *data)
 	}
 	assert(IS_LEAF(mc->mc_pg[mc->mc_top]));
 
-	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
 	mc->mc_flags |= C_INITIALIZED|C_EOF;
+	mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]) - 1;
 	}
 	leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
 
@@ -4525,9 +4529,10 @@ fetchm:
 	case MDB_PREV_NODUP:
 		if (!(mc->mc_flags & C_INITIALIZED) || (mc->mc_flags & C_EOF)) {
 			rc = mdb_cursor_last(mc, key, data);
-			mc->mc_flags &= ~C_EOF;
-		} else
-			rc = mdb_cursor_prev(mc, key, data, op);
+			mc->mc_flags |= C_INITIALIZED;
+			mc->mc_ki[mc->mc_top]++;
+		}
+		rc = mdb_cursor_prev(mc, key, data, op);
 		break;
 	case MDB_FIRST:
 		rc = mdb_cursor_first(mc, key, data);
@@ -4575,7 +4580,9 @@ mdb_cursor_touch(MDB_cursor *mc)
 
 	if (mc->mc_dbi > MAIN_DBI && !(*mc->mc_dbflag & DB_DIRTY)) {
 		MDB_cursor mc2;
-		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI, NULL);
+		MDB_xcursor mcx;
+		mdb_cursor_init(&mc2, mc->mc_txn, MAIN_DBI,
+			mc->mc_txn->mt_dbs[MAIN_DBI].md_flags & MDB_DUPSORT ? &mcx : NULL);
 		rc = mdb_page_search(&mc2, &mc->mc_dbx->md_name, MDB_PS_MODIFY);
 		if (rc)
 			 return rc;

From 5f2ddb5532df92c765f2f36a7606ed6ef28d23db Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Mon, 22 Oct 2012 16:13:06 -0700
Subject: [PATCH 19/20] Minor cleanup

---
 libraries/libmdb/mdb.c | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index 994a5d95f3..e4d543eb22 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -1949,15 +1949,15 @@ mdb_txn_commit(MDB_txn *txn)
 		return EINVAL;
 	}
 
-	/* Merge (and close) our cursors with parent's */
-	mdb_cursor_merge(txn);
-
 	if (txn->mt_parent) {
 		MDB_db *ip, *jp;
 		MDB_dbi i;
 		unsigned x, y;
 		MDB_ID2L dst, src;
 
+		/* Merge (and close) our cursors with parent's */
+		mdb_cursor_merge(txn);
+
 		/* Update parent's DB table */
 		ip = &txn->mt_parent->mt_dbs[2];
 		jp = &txn->mt_dbs[2];
@@ -2140,7 +2140,7 @@ again:
 	while (env->me_pgfree) {
 		MDB_oldpages *mop = env->me_pgfree;
 		env->me_pgfree = mop->mo_next;
-		free(mop);;
+		free(mop);
 	}
 
 	/* Check for growth of freelist again */
@@ -4000,7 +4000,7 @@ mdb_cursor_sibling(MDB_cursor *mc, int move_right)
 
 	indx = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
 	if ((rc = mdb_page_get(mc->mc_txn, NODEPGNO(indx), &mp)))
-		return rc;;
+		return rc;
 
 	mdb_cursor_push(mc, mp);
 

From 66f2b7b2ec4318557be079ad4764becf4e36ec73 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Mon, 22 Oct 2012 17:03:15 -0700
Subject: [PATCH 20/20] Make sure mdb_open flags are committed on main DB

If no data was modified in the txn, mdb_open flag changes were dropped.
---
 libraries/libmdb/mdb.c | 12 +++++++++---
 1 file changed, 9 insertions(+), 3 deletions(-)

diff --git a/libraries/libmdb/mdb.c b/libraries/libmdb/mdb.c
index e4d543eb22..7d89ec3fbc 100644
--- a/libraries/libmdb/mdb.c
+++ b/libraries/libmdb/mdb.c
@@ -826,6 +826,7 @@ struct MDB_txn {
  */
 #define MDB_TXN_RDONLY		0x01		/**< read-only transaction */
 #define MDB_TXN_ERROR		0x02		/**< an error has occurred */
+#define MDB_TXN_DIRTY		0x04		/**< must write, even if dirty list is empty */
 /** @} */
 	unsigned int	mt_flags;		/**< @ref mdb_txn */
 	/** Tracks which of the two meta pages was used at the start
@@ -2005,7 +2006,7 @@ mdb_txn_commit(MDB_txn *txn)
 		return EINVAL;
 	}
 
-	if (!txn->mt_u.dirty_list[0].mid)
+	if (!txn->mt_u.dirty_list[0].mid && !(txn->mt_flags & MDB_TXN_DIRTY))
 		goto done;
 
 	DPRINTF("committing txn %zu %p on mdbenv %p, root page %zu",
@@ -6715,8 +6716,13 @@ int mdb_open(MDB_txn *txn, const char *name, unsigned int flags, MDB_dbi *dbi)
 	/* main DB? */
 	if (!name) {
 		*dbi = MAIN_DBI;
-		if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY))
-			txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
+		if (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY)) {
+			/* make sure flag changes get committed */
+			if ((txn->mt_dbs[MAIN_DBI].md_flags | flags) != txn->mt_dbs[MAIN_DBI].md_flags) {
+				txn->mt_dbs[MAIN_DBI].md_flags |= (flags & (MDB_DUPSORT|MDB_REVERSEKEY|MDB_INTEGERKEY));
+				txn->mt_flags |= MDB_TXN_DIRTY;
+			}
+		}
 		mdb_default_cmp(txn, MAIN_DBI);
 		return MDB_SUCCESS;
 	}