mdbx: Merge branch 'devel' into master.

CHANGES

@@ -16,6 +16,14 @@ LMDB 0.9.17 Release Engineering
 	Fix ITS#7789 ensure mapsize >= pages in use
 	Fix ITS#7971 mdb_txn_renew0() new reader slots
 	Fix ITS#7969 use __sync_synchronize on non-x86
+	Fix ITS#8311 page_split from update_key
+	Fix ITS#8312 loose pages in nested txn
+	Fix ITS#8313 mdb_rebalance dummy cursor
+	Fix ITS#8315 dirty_room in nested txn
+	Fix ITS#8316 page_merge cursor tracking
+	Fix ITS#8319 mdb_load error messages
+	Fix ITS#8320 mdb_load plaintext input
+	Fix ITS#8321 cursor tracking
 	Added mdb_txn_id() (ITS#7994)
 	Added robust mutex support
 	Miscellaneous cleanup/simplification

mdb.c

@@ -889,7 +889,6 @@ struct MDB_cursor {
 #define C_EOF	0x02			/**< No more data */
 #define C_SUB	0x04			/**< Cursor is a sub-cursor */
 #define C_DEL	0x08			/**< last op was a cursor_del */
-#define C_SPLITTING	0x20		/**< Cursor is in page_split */
 #define C_UNTRACK	0x40		/**< Un-track cursor when closing */
 #define C_RECLAIMING	0x80		/**< FreeDB lookup is prohibited */
 /** @} */
@@ -1033,7 +1032,7 @@ enum {
 #define MDB_END_UPDATE	0x10	/**< update env state (DBIs) */
 #define MDB_END_FREE	0x20	/**< free txn unless it is #MDB_env.%me_txn0 */
 #define MDB_END_SLOT MDB_NOTLS	/**< release any reader slot if #MDB_NOTLS */
-static void mdb_txn_end(MDB_txn *txn, unsigned mode);
+static int mdb_txn_end(MDB_txn *txn, unsigned mode);
 
 static int  mdb_page_get(MDB_txn *txn, pgno_t pgno, MDB_page **mp, int *lvl);
 static int  mdb_page_search_root(MDB_cursor *mc,
@@ -1059,7 +1058,7 @@ static int  mdb_node_add(MDB_cursor *mc, indx_t indx,
 				MDB_val *key, MDB_val *data, pgno_t pgno, unsigned flags);
 static void mdb_node_del(MDB_cursor *mc, int ksize);
 static void mdb_node_shrink(MDB_page *mp, indx_t indx);
-static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst);
+static int	mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft);
 static int  mdb_node_read(MDB_txn *txn, MDB_node *leaf, MDB_val *data);
 static size_t	mdb_leaf_size(MDB_env *env, MDB_val *key, MDB_val *data);
 static size_t	mdb_branch_size(MDB_env *env, MDB_val *key);
@@ -1401,7 +1400,7 @@ mdb_cursor_chk(MDB_cursor *mc)
 	MDB_node *node;
 	MDB_page *mp;
 
-	if (!mc->mc_snum && !(mc->mc_flags & C_INITIALIZED)) return;
+	if (!mc->mc_snum || !(mc->mc_flags & C_INITIALIZED)) return;
 	for (i=0; i<mc->mc_top; i++) {
 		mp = mc->mc_pg[i];
 		node = NODEPTR(mp, mc->mc_ki[i]);
@@ -1521,6 +1520,8 @@ mdb_page_malloc(MDB_txn *txn, unsigned num)
 	}
 #endif
 	VALGRIND_MAKE_MEM_UNDEFINED(np, size);
+	np->mp_flags = 0;
+	np->mp_pages = num;
 	return np;
 }
 
@@ -2317,6 +2318,8 @@ done:
 
 	np->mp_pgno = pgno;
 	np->mp_ksize = 0;
+	np->mp_flags = 0;
+	np->mp_pages = num;
 	mdb_page_dirty(txn, np);
 	*mp = np;
 
@@ -2600,14 +2603,15 @@ mdb_cursor_shadow(MDB_txn *src, MDB_txn *dst)
 				*bk = *mc;
 				mc->mc_backup = bk;
 				mc->mc_db = &dst->mt_dbs[i];
-				/* Kill pointers into src - and dst to reduce abuse: The
+				/* Kill pointers into src to reduce abuse: The
-				 * user may not use mc until dst ends. Otherwise we'd...
+				 * user may not use mc until dst ends. But we need a valid
+				 * txn pointer here for cursor fixups to keep working.
 				 */
-				mc->mc_txn    = NULL;	/* ...set this to dst */
+				mc->mc_txn    = dst;
-				mc->mc_dbflag = NULL;	/* ...and &dst->mt_dbflags[i] */
+				mc->mc_dbflag = &dst->mt_dbflags[i];
 				if ((mx = mc->mc_xcursor) != NULL) {
 					*(MDB_xcursor *)(bk+1) = *mx;
-					mx->mx_cursor.mc_txn = NULL; /* ...and dst. */
+					mx->mx_cursor.mc_txn = dst;
 				}
 				mc->mc_next = dst->mt_cursors[i];
 				dst->mt_cursors[i] = mc;
@@ -2696,8 +2700,13 @@ mdb_txn_renew0(MDB_txn *txn)
 	uint16_t x;
 	int rc, new_notls = 0;
 
+	if (unlikely(env->me_pid != getpid())) {
+		env->me_flags |= MDB_FATAL_ERROR;
+		return MDB_PANIC;
+	}
+
 	if ((flags &= MDB_TXN_RDONLY) != 0) {
-		struct MDB_rthc* rthc = NULL;
+		struct MDB_rthc *rthc = NULL;
 		MDB_reader *r = NULL;
 		if (likely(env->me_flags & MDB_ENV_TXKEY)) {
 			mdb_assert(env, !(env->me_flags & MDB_NOTLS));
@@ -2885,6 +2894,11 @@ mdb_txn_begin(MDB_env *env, MDB_txn *parent, unsigned flags, MDB_txn **ret)
 	if (unlikely(env->me_signature != MDBX_ME_SIGNATURE))
 		return MDB_VERSION_MISMATCH;
 
+	if (unlikely(env->me_pid != getpid())) {
+		env->me_flags |= MDB_FATAL_ERROR;
+		return MDB_PANIC;
+	}
+
 	flags &= MDB_TXN_BEGIN_FLAGS;
 	flags |= env->me_flags & MDB_WRITEMAP;
 
@@ -3060,12 +3074,17 @@ mdbx_txn_straggler(MDB_txn *txn, int *percent)
  * @param[in] txn the transaction handle to end
  * @param[in] mode why and how to end the transaction
  */
-static void
+static int
 mdb_txn_end(MDB_txn *txn, unsigned mode)
 {
 	MDB_env	*env = txn->mt_env;
 	static const char *const names[] = MDB_END_NAMES;
 
+	if (unlikely(txn->mt_env->me_pid != getpid())) {
+		env->me_flags |= MDB_FATAL_ERROR;
+		return MDB_PANIC;
+	}
+
 	/* Export or close DBI handles opened in this txn */
 	mdb_dbis_update(txn, mode & MDB_END_UPDATE);
 
@@ -3135,6 +3154,8 @@ mdb_txn_end(MDB_txn *txn, unsigned mode)
 		txn->mt_signature = 0;
 		free(txn);
 	}
+
+	return MDB_SUCCESS;
 }
 
 int
@@ -3150,8 +3171,7 @@ mdb_txn_reset(MDB_txn *txn)
 	if (unlikely(!(txn->mt_flags & MDB_TXN_RDONLY)))
 		return EINVAL;
 
-	mdb_txn_end(txn, MDB_END_RESET);
+	return mdb_txn_end(txn, MDB_END_RESET);
-	return MDB_SUCCESS;
 }
 
 int
@@ -3166,8 +3186,7 @@ mdb_txn_abort(MDB_txn *txn)
 	if (txn->mt_child)
 		mdb_txn_abort(txn->mt_child);
 
-	mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
+	return mdb_txn_end(txn, MDB_END_ABORT|MDB_END_SLOT|MDB_END_FREE);
-	return MDB_SUCCESS;
 }
 
 static int
@@ -3645,6 +3664,11 @@ mdb_txn_commit(MDB_txn *txn)
 	if(unlikely(txn->mt_signature != MDBX_MT_SIGNATURE))
 		return MDB_VERSION_MISMATCH;
 
+	if (unlikely(txn->mt_env->me_pid != getpid())) {
+		txn->mt_env->me_flags |= MDB_FATAL_ERROR;
+		return MDB_PANIC;
+	}
+
 	/* mdb_txn_end() mode for a commit which writes nothing */
 	end_mode = MDB_END_EMPTY_COMMIT|MDB_END_UPDATE|MDB_END_SLOT|MDB_END_FREE;
 
@@ -3782,7 +3806,7 @@ mdb_txn_commit(MDB_txn *txn)
 		}
 
 		/* Append our loose page list to parent's */
-		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(lp))
+		for (lp = &parent->mt_loose_pgs; *lp; lp = &NEXT_LOOSE_PAGE(*lp))
 			;
 		*lp = txn->mt_loose_pgs;
 		parent->mt_loose_count += txn->mt_loose_count;
@@ -3860,8 +3884,7 @@ mdb_txn_commit(MDB_txn *txn)
 	end_mode = MDB_END_COMMITTED|MDB_END_UPDATE;
 
 done:
-	mdb_txn_end(txn, end_mode);
+	return mdb_txn_end(txn, end_mode);
-	return MDB_SUCCESS;
 
 fail:
 	mdb_txn_abort(txn);
@@ -4050,7 +4073,8 @@ mdb_env_sync0(MDB_env *env, unsigned flags, MDB_meta *pending)
 			if (unlikely(prev_mapsize != pending->mm_mapsize)) {
 				/* LY: It is no reason to use fdatasync() here, even in case
 				 * no such bug in a kernel. Because "no-bug" mean that a kernel
-				 * internally do nearly the same.
+				 * internally do nearly the same, e.g. fdatasync() == fsync()
+				 * when no-kernel-bug and file size was changed.
 				 *
 				 * So, this code is always safe and without appreciable
 				 * performance degradation.
@@ -4200,14 +4224,16 @@ mdb_env_map(MDB_env *env, void *addr)
 		return errno;
 	}
 
-	if (flags & MDB_NORDAHEAD) {
+	unsigned madvise_flags = MADV_DONTFORK;
+	if (flags & MDB_NORDAHEAD)
 		/* Turn off readahead. It's harmful when the DB is larger than RAM. */
-#ifdef MADV_RANDOM
+		madvise_flags |= MADV_RANDOM;
-		madvise(env->me_map, env->me_mapsize, MADV_RANDOM);
+	if (madvise(env->me_map, env->me_mapsize, madvise_flags))
-#elif defined(POSIX_MADV_RANDOM)
+		return errno;
-		posix_madvise(env->me_map, env->me_mapsize, POSIX_MADV_RANDOM);
+
-#endif /* MADV_RANDOM & POSIX_MADV_RANDOM */
+#ifdef MADV_DONTDUMP
-	}
+	madvise(env->me_map, env->me_mapsize, MADV_DONTDUMP);
+#endif
 
 	/* Can happen because the address argument to mmap() is just a
 	 * hint.  mmap() can pick another, e.g. if the range is in use.
@@ -4422,17 +4448,18 @@ static pthread_mutex_t mdb_rthc_lock = PTHREAD_MUTEX_INITIALIZER;
 /* LY: TODO: Yet another problem is here - segfault in case if a DSO will
  * be unloaded before a thread would been finished. */
 static void
-mdb_env_reader_dest(void *ptr)
+mdb_env_reader_destr(void *ptr)
 {
 	struct MDB_rthc* rthc = ptr;
 	MDB_reader *reader;
 
+	if (! rthc)
+		/* LY: paranoia */
+		return;
+
 	mdb_ensure(NULL, pthread_mutex_lock(&mdb_rthc_lock) == 0);
-	/* LY: Here may be a race with mdb_env_close(),
-	 * see https://github.com/ReOpen/ReOpenLDAP/issues/48
-	 */
 	reader = rthc->rc_reader;
-	if (reader) {
+	if (reader && reader->mr_pid == getpid()) {
 		mdb_ensure(NULL, reader->mr_rthc == rthc);
 		rthc->rc_reader = NULL;
 		reader->mr_rthc = NULL;
@@ -4605,7 +4632,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 		if (rc == EROFS && (env->me_flags & MDB_RDONLY)) {
 			return MDB_SUCCESS;
 		}
-		goto fail_errno;
+		return rc;
 	}
 
 	/* Lose record locks when exec*() */
@@ -4613,22 +4640,22 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 			fcntl(env->me_lfd, F_SETFD, fdflags);
 
 	if (!(env->me_flags & MDB_NOTLS)) {
-		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_dest);
+		rc = pthread_key_create(&env->me_txkey, mdb_env_reader_destr);
 		if (rc)
-			goto fail;
+			return rc;
 		env->me_flags |= MDB_ENV_TXKEY;
 	}
 
 	/* Try to get exclusive lock. If we succeed, then
 	 * nobody is using the lock region and we should initialize it.
 	 */
-	if ((rc = mdb_env_excl_lock(env, excl))) goto fail;
+	if ((rc = mdb_env_excl_lock(env, excl))) return rc;
 
 	size = lseek(env->me_lfd, 0, SEEK_END);
-	if (size == -1) goto fail_errno;
+	if (size == -1) return errno;
 	rsize = (env->me_maxreaders-1) * sizeof(MDB_reader) + sizeof(MDB_txninfo);
 	if (size < rsize && *excl > 0) {
-		if (ftruncate(env->me_lfd, rsize) != 0) goto fail_errno;
+		if (ftruncate(env->me_lfd, rsize) != 0) return errno;
 	} else {
 		rsize = size;
 		size = rsize - sizeof(MDB_txninfo);
@@ -4637,9 +4664,16 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 
 	m = mmap(NULL, rsize, PROT_READ|PROT_WRITE, MAP_SHARED, env->me_lfd, 0);
 	if (m == MAP_FAILED)
-		goto fail_errno;
+		return errno;
 	env->me_txns = m;
 
+	if (madvise(env->me_txns, rsize, MADV_DONTFORK | MADV_WILLNEED))
+		return errno;
+
+#ifdef MADV_DODUMP
+	madvise(env->me_txns, rsize, MADV_DODUMP);
+#endif
+
 	if (*excl > 0) {
 		pthread_mutexattr_t mattr;
 
@@ -4650,7 +4684,7 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 #endif /* MDB_USE_ROBUST */
 			|| (rc = pthread_mutex_init(&env->me_txns->mti_rmutex, &mattr))
 			|| (rc = pthread_mutex_init(&env->me_txns->mti_wmutex, &mattr)))
-			goto fail;
+			return rc;
 		pthread_mutexattr_destroy(&mattr);
 
 		env->me_txns->mti_magic = MDB_MAGIC;
@@ -4660,27 +4694,19 @@ mdb_env_setup_locks(MDB_env *env, char *lpath, int mode, int *excl)
 	} else {
 		if (env->me_txns->mti_magic != MDB_MAGIC) {
 			mdb_debug("lock region has invalid magic");
-			rc = MDB_INVALID;
+			return MDB_INVALID;
-			goto fail;
 		}
 		if (env->me_txns->mti_format != MDB_LOCK_FORMAT) {
 			mdb_debug("lock region has format+version 0x%x, expected 0x%x",
 				env->me_txns->mti_format, MDB_LOCK_FORMAT);
-			rc = MDB_VERSION_MISMATCH;
+			return MDB_VERSION_MISMATCH;
-			goto fail;
 		}
 		rc = errno;
-		if (rc && rc != EACCES && rc != EAGAIN) {
+		if (rc && rc != EACCES && rc != EAGAIN)
-			goto fail;
+			return rc;
-		}
 	}
 
 	return MDB_SUCCESS;
-
-fail_errno:
-	rc = errno;
-fail:
-	return rc;
 }
 
 	/** The name of the lock file in the DB environment */
@@ -4903,20 +4929,25 @@ mdb_env_close0(MDB_env *env)
 	 * data owned by this process (me_close_readers and
 	 * our readers), and clear each reader atomically.
 	 */
-	mdb_ensure(env, pthread_mutex_lock(&mdb_rthc_lock) == 0);
+	if (pid == getpid()) {
-	for (i = env->me_close_readers; --i >= 0; ) {
+		mdb_ensure(env, pthread_mutex_lock(&mdb_rthc_lock) == 0);
-		MDB_reader *reader = &env->me_txns->mti_readers[i];
+		for (i = env->me_close_readers; --i >= 0; ) {
-
+			MDB_reader *reader = &env->me_txns->mti_readers[i];
-		if (reader->mr_pid == pid) {
+			if (reader->mr_pid == pid) {
-			mdb_ensure(env, reader->mr_rthc->rc_reader == reader);
+				struct MDB_rthc *rthc = reader->mr_rthc;
-			reader->mr_rthc->rc_reader = NULL;
+				if (rthc) {
-			reader->mr_rthc = NULL;
+					mdb_ensure(env, rthc->rc_reader == reader);
-			mdb_compiler_barrier();
+					rthc->rc_reader = NULL;
-			reader->mr_pid = 0;
+					reader->mr_rthc = NULL;
+					free(rthc);
+				}
+				reader->mr_pid = 0;
+			}
 		}
+		mdb_coherent_barrier();
+		mdb_ensure(env, pthread_mutex_unlock(&mdb_rthc_lock) == 0);
 	}
-	mdb_coherent_barrier();
+
-	mdb_ensure(env, pthread_mutex_unlock(&mdb_rthc_lock) == 0);
 	munmap((void *)env->me_txns, (env->me_maxreaders-1)*sizeof(MDB_reader)+sizeof(MDB_txninfo));
 	env->me_txns = NULL;
 
@@ -5533,6 +5564,7 @@ mdb_ovpage_free(MDB_cursor *mc, MDB_page *mp)
 				return MDB_CORRUPTED;
 			}
 		}
+		txn->mt_dirty_room++;
 		if (!(env->me_flags & MDB_WRITEMAP))
 			mdb_dpage_free(env, mp);
 release:
@@ -6502,16 +6534,18 @@ fix_parent:
 			 * update branch key if there is a parent page
 			 */
 			if (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
-				unsigned short top = mc->mc_top;
+				unsigned short dtop = 1;
 				mc->mc_top--;
 				/* slot 0 is always an empty key, find real slot */
-				while (mc->mc_top && !mc->mc_ki[mc->mc_top])
+				while (mc->mc_top && !mc->mc_ki[mc->mc_top]) {
 					mc->mc_top--;
+					dtop++;
+				}
 				if (mc->mc_ki[mc->mc_top])
 					rc2 = mdb_update_key(mc, key);
 				else
 					rc2 = MDB_SUCCESS;
-				mc->mc_top = top;
+				mc->mc_top += dtop;
 				if (rc2)
 					return rc2;
 			}
@@ -6687,6 +6721,7 @@ current:
 						return ENOMEM;
 					id2.mid = pg;
 					id2.mptr = np;
+					/* Note - this page is already counted in parent's dirty_room */
 					rc2 = mdb_mid2l_insert(mc->mc_txn->mt_u.dirty_list, &id2);
 					mdb_cassert(mc, rc2 == 0);
 					if (!(flags & MDB_RESERVE)) {
@@ -6800,6 +6835,7 @@ put_sub:
 				MDB_xcursor *mx = mc->mc_xcursor;
 				unsigned i = mc->mc_top;
 				MDB_page *mp = mc->mc_pg[i];
+				int nkeys = NUMKEYS(mp);
 
 				for (m2 = mc->mc_txn->mt_cursors[mc->mc_dbi]; m2; m2=m2->mc_next) {
 					if (m2 == mc || m2->mc_snum < mc->mc_snum) continue;
@@ -6807,9 +6843,9 @@ put_sub:
 					if (m2->mc_pg[i] == mp) {
 						if (m2->mc_ki[i] == mc->mc_ki[i]) {
 							mdb_xcursor_init2(m2, mx, new_dupdata);
-						} else if (!insert_key) {
+						} else if (!insert_key && m2->mc_ki[i] < nkeys) {
 							MDB_node *n2 = NODEPTR(mp, m2->mc_ki[i]);
-							if (!(n2->mn_flags & F_SUBDATA))
+							if ((n2->mn_flags & (F_SUBDATA|F_DUPDATA)) == F_DUPDATA)
 								m2->mc_xcursor->mx_cursor.mc_pg[0] = NODEDATA(n2);
 						}
 					}
@@ -7643,10 +7679,26 @@ mdb_update_key(MDB_cursor *mc, MDB_val *key)
 static void
 mdb_cursor_copy(const MDB_cursor *csrc, MDB_cursor *cdst);
 
+/** Track a temporary cursor */
+#define CURSOR_TMP_TRACK(mc, mn, dummy, tracked) \
+	if (mc->mc_flags & C_SUB) { \
+		dummy.mc_flags =  C_INITIALIZED; \
+		dummy.mc_xcursor = (MDB_xcursor *)&mn; \
+		tracked = &dummy; \
+	} else { \
+		tracked = &mn; \
+	} \
+	tracked->mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi]; \
+	mc->mc_txn->mt_cursors[mc->mc_dbi] = tracked
+
+/** Stop tracking a temporary cursor */
+#define CURSOR_TMP_UNTRACK(mc, tracked) \
+	mc->mc_txn->mt_cursors[mc->mc_dbi] = tracked->mc_next
+
 /** Move a node from csrc to cdst.
  */
 static int
-mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
+mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst, int fromleft)
 {
 	MDB_node		*srcnode;
 	MDB_val		 key, data;
@@ -7748,13 +7800,15 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 
 		mps = csrc->mc_pg[csrc->mc_top];
 		/* If we're adding on the left, bump others up */
-		if (!cdst->mc_ki[csrc->mc_top]) {
+		if (fromleft) {
 			mpd = cdst->mc_pg[csrc->mc_top];
 			for (m2 = csrc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
 				if (csrc->mc_flags & C_SUB)
 					m3 = &m2->mc_xcursor->mx_cursor;
 				else
 					m3 = m2;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
 				if (m3 != cdst &&
 					m3->mc_pg[csrc->mc_top] == mpd &&
 					m3->mc_ki[csrc->mc_top] >= cdst->mc_ki[csrc->mc_top]) {
@@ -7777,6 +7831,8 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 				else
 					m3 = m2;
 				if (m3 == csrc) continue;
+				if (!(m3->mc_flags & C_INITIALIZED) || m3->mc_top < csrc->mc_top)
+					continue;
 				if (m3->mc_pg[csrc->mc_top] == mps) {
 					if (!m3->mc_ki[csrc->mc_top]) {
 						m3->mc_pg[csrc->mc_top] = cdst->mc_pg[cdst->mc_top];
@@ -7794,6 +7850,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 	 */
 	if (csrc->mc_ki[csrc->mc_top] == 0) {
 		if (csrc->mc_ki[csrc->mc_top-1] != 0) {
+			MDB_cursor dummy, *tracked;
 			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
 				key.mv_data = LEAF2KEY(csrc->mc_pg[csrc->mc_top], 0, key.mv_size);
 			} else {
@@ -7806,7 +7863,11 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 			mdb_cursor_copy(csrc, &mn);
 			mn.mc_snum--;
 			mn.mc_top--;
-			if (unlikely((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS))
+			/* We want mdb_rebalance to find mn when doing fixups */
+			CURSOR_TMP_TRACK(csrc, mn, dummy, tracked);
+			rc = mdb_update_key(&mn, &key);
+			CURSOR_TMP_UNTRACK(csrc, tracked);
+			if (unlikely(rc != MDB_SUCCESS))
 				return rc;
 		}
 		if (IS_BRANCH(csrc->mc_pg[csrc->mc_top])) {
@@ -7822,6 +7883,7 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 
 	if (cdst->mc_ki[cdst->mc_top] == 0) {
 		if (cdst->mc_ki[cdst->mc_top-1] != 0) {
+			MDB_cursor dummy, *tracked;
 			if (IS_LEAF2(csrc->mc_pg[csrc->mc_top])) {
 				key.mv_data = LEAF2KEY(cdst->mc_pg[cdst->mc_top], 0, key.mv_size);
 			} else {
@@ -7834,7 +7896,11 @@ mdb_node_move(MDB_cursor *csrc, MDB_cursor *cdst)
 			mdb_cursor_copy(cdst, &mn);
 			mn.mc_snum--;
 			mn.mc_top--;
-			if (unlikely((rc = mdb_update_key(&mn, &key)) != MDB_SUCCESS))
+			/* We want mdb_rebalance to find mn when doing fixups */
+			CURSOR_TMP_TRACK(cdst, mn, dummy, tracked);
+			rc = mdb_update_key(&mn, &key);
+			CURSOR_TMP_UNTRACK(cdst, tracked);
+			if (unlikely(rc != MDB_SUCCESS))
 				return rc;
 		}
 		if (IS_BRANCH(cdst->mc_pg[cdst->mc_top])) {
@@ -7974,6 +8040,9 @@ mdb_page_merge(MDB_cursor *csrc, MDB_cursor *cdst)
 				m3->mc_pg[top] = pdst;
 				m3->mc_ki[top] += nkeys;
 				m3->mc_ki[top-1] = cdst->mc_ki[top-1];
+			} else if (m3->mc_pg[top-1] == csrc->mc_pg[top-1] &&
+				m3->mc_ki[top-1] > csrc->mc_ki[top-1]) {
+				m3->mc_ki[top-1]--;
 			}
 		}
 	}
@@ -8023,7 +8092,7 @@ static int
 mdb_rebalance(MDB_cursor *mc)
 {
 	MDB_node	*node;
-	int rc;
+	int rc, fromleft;
 	unsigned ptop, minkeys, thresh;
 	MDB_cursor	mn;
 	indx_t oldki;
@@ -8074,7 +8143,8 @@ mdb_rebalance(MDB_cursor *mc)
 						m3 = &m2->mc_xcursor->mx_cursor;
 					else
 						m3 = m2;
-					if (m3->mc_snum < mc->mc_snum) continue;
+					if (!(m3->mc_flags & C_INITIALIZED) || (m3->mc_snum < mc->mc_snum))
+						continue;
 					if (m3->mc_pg[0] == mp) {
 						m3->mc_snum = 0;
 						m3->mc_top = 0;
@@ -8110,6 +8180,8 @@ mdb_rebalance(MDB_cursor *mc)
 					else
 						m3 = m2;
 					if (m3 == mc) continue;
+					if (!(m3->mc_flags & C_INITIALIZED))
+						continue;
 					if (m3->mc_pg[0] == mp) {
 						for (i=0; i<mc->mc_db->md_depth; i++) {
 							m3->mc_pg[i] = m3->mc_pg[i+1];
@@ -8153,6 +8225,7 @@ mdb_rebalance(MDB_cursor *mc)
 			return rc;
 		mn.mc_ki[mn.mc_top] = 0;
 		mc->mc_ki[mc->mc_top] = NUMKEYS(mc->mc_pg[mc->mc_top]);
+		fromleft = 0;
 	} else {
 		/* There is at least one neighbor to the left.
 		 */
@@ -8164,6 +8237,7 @@ mdb_rebalance(MDB_cursor *mc)
 			return rc;
 		mn.mc_ki[mn.mc_top] = NUMKEYS(mn.mc_pg[mn.mc_top]) - 1;
 		mc->mc_ki[mc->mc_top] = 0;
+		fromleft = 1;
 	}
 
 	mdb_debug("found neighbor page %zu (%u keys, %.1f%% full)",
@@ -8175,32 +8249,22 @@ mdb_rebalance(MDB_cursor *mc)
 	 * (A branch page must never have less than 2 keys.)
 	 */
 	if (PAGEFILL(mc->mc_txn->mt_env, mn.mc_pg[mn.mc_top]) >= thresh && NUMKEYS(mn.mc_pg[mn.mc_top]) > minkeys) {
-		rc = mdb_node_move(&mn, mc);
+		rc = mdb_node_move(&mn, mc, fromleft);
-		if (!mc->mc_ki[mc->mc_top]) {
+		if (fromleft) {
 			/* if we inserted on left, bump position up */
 			oldki++;
 		}
 	} else {
-		if (mc->mc_ki[ptop] == 0) {
+		if (!fromleft) {
 			rc = mdb_page_merge(&mn, mc);
 		} else {
-			MDB_cursor dummy;
+			MDB_cursor dummy, *tracked;
 			oldki += NUMKEYS(mn.mc_pg[mn.mc_top]);
 			mn.mc_ki[mn.mc_top] += mc->mc_ki[mn.mc_top] + 1;
 			/* We want mdb_rebalance to find mn when doing fixups */
-			if (mc->mc_flags & C_SUB) {
+			CURSOR_TMP_TRACK(mc, mn, dummy, tracked);
-				dummy.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &dummy;
-				dummy.mc_xcursor = (MDB_xcursor *)&mn;
-			} else {
-				mn.mc_next = mc->mc_txn->mt_cursors[mc->mc_dbi];
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = &mn;
-			}
 			rc = mdb_page_merge(mc, &mn);
-			if (mc->mc_flags & C_SUB)
+			CURSOR_TMP_UNTRACK(mc, tracked);
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = dummy.mc_next;
-			else
-				mc->mc_txn->mt_cursors[mc->mc_dbi] = mn.mc_next;
 			mdb_cursor_copy(&mn, mc);
 		}
 		mc->mc_flags &= ~C_EOF;
@@ -8238,7 +8302,7 @@ mdb_cursor_del0(MDB_cursor *mc)
 					if (m3->mc_ki[mc->mc_top] > ki)
 						m3->mc_ki[mc->mc_top]--;
 					else if (mc->mc_db->md_flags & MDB_DUPSORT)
-						m3->mc_xcursor->mx_cursor.mc_flags |= C_EOF;
+						m3->mc_xcursor->mx_cursor.mc_flags &= ~C_INITIALIZED;
 				}
 			}
 		}
@@ -8391,12 +8455,19 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 	rp->mp_ksize = mp->mp_ksize;
 	mdb_debug("new right sibling: page %zu", rp->mp_pgno);
 
-	if (mc->mc_snum < 2) {
+	/* Usually when splitting the root page, the cursor
+	 * height is 1. But when called from mdb_update_key,
+	 * the cursor height may be greater because it walks
+	 * up the stack while finding the branch slot to update.
+	 */
+	if (mc->mc_top < 1) {
 		if ((rc = mdb_page_new(mc, P_BRANCH, 1, &pp)))
 			goto done;
 		/* shift current top to make room for new parent */
-		mc->mc_pg[1] = mc->mc_pg[0];
+		for (i=mc->mc_snum; i>0; i--) {
-		mc->mc_ki[1] = mc->mc_ki[0];
+			mc->mc_pg[i] = mc->mc_pg[i-1];
+			mc->mc_ki[i] = mc->mc_ki[i-1];
+		}
 		mc->mc_pg[0] = pp;
 		mc->mc_ki[0] = 0;
 		mc->mc_db->md_root = pp->mp_pgno;
@@ -8412,15 +8483,14 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			mc->mc_db->md_depth--;
 			goto done;
 		}
-		mc->mc_snum = 2;
+		mc->mc_snum++;
-		mc->mc_top = 1;
+		mc->mc_top++;
 		ptop = 0;
 	} else {
 		ptop = mc->mc_top-1;
 		mdb_debug("parent branch page is %zu", mc->mc_pg[ptop]->mp_pgno);
 	}
 
-	mc->mc_flags |= C_SPLITTING;
 	mdb_cursor_copy(mc, &mn);
 	mn.mc_pg[mn.mc_top] = rp;
 	mn.mc_ki[ptop] = mc->mc_ki[ptop]+1;
@@ -8471,8 +8541,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				rp->mp_lower += sizeof(indx_t);
 				rp->mp_upper -= ksize - sizeof(indx_t);
 				mc->mc_ki[mc->mc_top] = x;
-				mc->mc_pg[mc->mc_top] = rp;
-				mc->mc_ki[ptop]++;
 			}
 		} else {
 			int psize, nsize, k;
@@ -8565,21 +8633,20 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 	/* Copy separator key to the parent.
 	 */
 	if (SIZELEFT(mn.mc_pg[ptop]) < mdb_branch_size(env, &sepkey)) {
+		int snum = mc->mc_snum;
+		MDB_cursor dummy, *tracked;
 		mn.mc_snum--;
 		mn.mc_top--;
 		did_split = 1;
+		/* We want other splits to find mn when doing fixups */
+		CURSOR_TMP_TRACK(mc, mn, dummy, tracked);
 		rc = mdb_page_split(&mn, &sepkey, NULL, rp->mp_pgno, 0);
-		if (unlikely(rc))
+		CURSOR_TMP_UNTRACK(mc, tracked);
+		if (unlikely(rc != MDB_SUCCESS))
 			goto done;
 
 		/* root split? */
-		if (mn.mc_snum == mc->mc_snum) {
+		if (mc->mc_snum > snum) {
-			mc->mc_pg[mc->mc_snum] = mc->mc_pg[mc->mc_top];
-			mc->mc_ki[mc->mc_snum] = mc->mc_ki[mc->mc_top];
-			mc->mc_pg[mc->mc_top] = mc->mc_pg[ptop];
-			mc->mc_ki[mc->mc_top] = mc->mc_ki[ptop];
-			mc->mc_snum++;
-			mc->mc_top++;
 			ptop++;
 		}
 		/* Right page might now have changed parent.
@@ -8605,10 +8672,8 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		rc = mdb_node_add(&mn, mn.mc_ki[ptop], &sepkey, NULL, rp->mp_pgno, 0);
 		mn.mc_top++;
 	}
-	mc->mc_flags ^= C_SPLITTING;
+	if (unlikely(rc != MDB_SUCCESS))
-	if (unlikely(rc != MDB_SUCCESS)) {
 		goto done;
-	}
 	if (nflags & MDB_APPEND) {
 		mc->mc_pg[mc->mc_top] = rp;
 		mc->mc_ki[mc->mc_top] = 0;
@@ -8675,11 +8740,6 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 		/* reset back to original page */
 		if (newindx < split_indx) {
 			mc->mc_pg[mc->mc_top] = mp;
-			if (nflags & MDB_RESERVE) {
-				node = NODEPTR(mp, mc->mc_ki[mc->mc_top]);
-				if (!(node->mn_flags & F_BIGDATA))
-					newdata->mv_data = NODEDATA(node);
-			}
 		} else {
 			mc->mc_pg[mc->mc_top] = rp;
 			mc->mc_ki[ptop]++;
@@ -8693,13 +8753,32 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				}
 			}
 		}
+		if (nflags & MDB_RESERVE) {
+			node = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (!(node->mn_flags & F_BIGDATA))
+				newdata->mv_data = NODEDATA(node);
+		}
+	} else {
+		if (newindx >= split_indx) {
+			mc->mc_pg[mc->mc_top] = rp;
+			mc->mc_ki[ptop]++;
+			/* Make sure mc_ki is still valid.
+			 */
+			if (mn.mc_pg[ptop] != mc->mc_pg[ptop] &&
+				mc->mc_ki[ptop] >= NUMKEYS(mc->mc_pg[ptop])) {
+				for (i=0; i<=ptop; i++) {
+					mc->mc_pg[i] = mn.mc_pg[i];
+					mc->mc_ki[i] = mn.mc_ki[i];
+				}
+			}
+		}
 	}
 
 	{
 		/* Adjust other cursors pointing to mp */
 		MDB_cursor *m2, *m3;
 		MDB_dbi dbi = mc->mc_dbi;
-		int fixup = NUMKEYS(mp);
+		nkeys = NUMKEYS(mp);
 
 		for (m2 = mc->mc_txn->mt_cursors[dbi]; m2; m2=m2->mc_next) {
 			if (mc->mc_flags & C_SUB)
@@ -8710,16 +8789,17 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 				continue;
 			if (!(m2->mc_flags & m3->mc_flags & C_INITIALIZED))
 				continue;
-			if (m3->mc_flags & C_SPLITTING)
-				continue;
 			if (new_root) {
 				int k;
+				/* sub cursors may be on different DB */
+				if (m3->mc_pg[0] != mp)
+					continue;
 				/* root split */
 				for (k=new_root; k>=0; k--) {
 					m3->mc_ki[k+1] = m3->mc_ki[k];
 					m3->mc_pg[k+1] = m3->mc_pg[k];
 				}
-				if (m3->mc_ki[0] >= split_indx) {
+				if (m3->mc_ki[0] > nkeys) {
 					m3->mc_ki[0] = 1;
 				} else {
 					m3->mc_ki[0] = 0;
@@ -8731,10 +8811,13 @@ mdb_page_split(MDB_cursor *mc, MDB_val *newkey, MDB_val *newdata, pgno_t newpgno
 			if (m3->mc_top >= mc->mc_top && m3->mc_pg[mc->mc_top] == mp) {
 				if (m3->mc_ki[mc->mc_top] >= newindx && !(nflags & MDB_SPLIT_REPLACE))
 					m3->mc_ki[mc->mc_top]++;
-				if (m3->mc_ki[mc->mc_top] >= fixup) {
+				if (m3->mc_ki[mc->mc_top] >= nkeys) {
 					m3->mc_pg[mc->mc_top] = rp;
-					m3->mc_ki[mc->mc_top] -= fixup;
+					m3->mc_ki[mc->mc_top] -= nkeys;
-					m3->mc_ki[ptop] = mn.mc_ki[ptop];
+					for (i=0; i<mc->mc_top; i++) {
+						m3->mc_ki[i] = mn.mc_ki[i];
+						m3->mc_pg[i] = mn.mc_pg[i];
+					}
 				}
 			} else if (!did_split && m3->mc_top >= ptop && m3->mc_pg[ptop] == mc->mc_pg[ptop] &&
 				m3->mc_ki[ptop] >= mc->mc_ki[ptop]) {
@@ -9151,7 +9234,9 @@ mdb_env_copyfd0(MDB_env *env, HANDLE fd)
 		return rc;
 
 	/* We must start the actual read txn after blocking writers */
-	mdb_txn_end(txn, MDB_END_RESET_TMP);
+	rc = mdb_txn_end(txn, MDB_END_RESET_TMP);
+	if (rc)
+		return rc;
 
 	/* Temporarily block writers until we snapshot the meta pages */
 	wmutex = MDB_MUTEX(env, w);
@@ -9996,6 +10081,11 @@ mdb_reader_check0(MDB_env *env, int rlocked, int *dead)
 	pid_t *pids, pid;
 	int rc = MDB_SUCCESS, count = 0;
 
+	if (unlikely(env->me_pid != getpid())) {
+		env->me_flags |= MDB_FATAL_ERROR;
+		return MDB_PANIC;
+	}
+
 	rdrs = env->me_txns->mti_numreaders;
 	pids = malloc((rdrs+1) * sizeof(pid_t));
 	if (!pids)

mdb_chk.c

@@ -122,27 +122,42 @@ error(const char* msg, ...) {
 	}
 }
 
+static void pagemap_cleanup(void) {
+	int i;
+
+	for( i = 1; i < MAX_DBI; ++i ) {
+		if (walk.dbi_names[i]) {
+			free((void *) walk.dbi_names[i]);
+			walk.dbi_names[i] = NULL;
+		}
+	}
+
+	free(walk.pagemap);
+	walk.pagemap = NULL;
+}
+
 static int pagemap_lookup_dbi(const char* dbi) {
 	static int last;
+	int i;
 
 	if (last > 0 && strcmp(walk.dbi_names[last], dbi) == 0)
 		return last;
 
-	for(last = 1; walk.dbi_names[last] && last < MAX_DBI; ++last)
+	for(i = 1; walk.dbi_names[i] && last < MAX_DBI; ++i)
-		if (strcmp(walk.dbi_names[last], dbi) == 0)
+		if (strcmp(walk.dbi_names[i], dbi) == 0)
-			return last;
+			return last = i;
 
-	if (last == MAX_DBI)
+	if (i == MAX_DBI)
-		return last = -1;
+		return -1;
 
-	walk.dbi_names[last] = strdup(dbi);
+	walk.dbi_names[i] = strdup(dbi);
 
 	if (verbose > 1) {
 		print(" - found '%s' area\n", dbi);
 		fflush(NULL);
 	}
 
-	return last;
+	return last = i;
 }
 
 static void problem_add(const char* object, size_t entry_number, const char* msg, const char *extra, ...) {
@@ -581,6 +596,8 @@ int main(int argc, char *argv[])
 	struct timespec timestamp_start, timestamp_finish;
 	double elapsed;
 
+	atexit(pagemap_cleanup);
+
 	if (clock_gettime(CLOCK_MONOTONIC, &timestamp_start)) {
 		rc = errno;
 		error("clock_gettime failed, error %d %s\n", rc, mdbx_strerror(rc));
@@ -897,7 +914,6 @@ bailout:
 		mdbx_txn_abort(locktxn);
 	if (env)
 		mdbx_env_close(env);
-	free(walk.pagemap);
 	fflush(NULL);
 	if (rc) {
 		if (rc < 0)

mdb_load.c

@@ -332,7 +332,7 @@ int main(int argc, char *argv[])
 			putflags = MDB_NOOVERWRITE|MDB_NODUPDATA;
 			break;
 		case 'T':
-			mode |= NOHDR;
+			mode |= NOHDR | PRINT;
 			break;
 		default:
 			usage();
@@ -399,20 +399,22 @@ int main(int argc, char *argv[])
 
 		while(1) {
 			rc = readline(&key, &kbuf);
-			if (rc == EOF)
+			if (rc)  /* rc == EOF */
 				break;
-			if (rc)
-				goto txn_abort;
 
 			rc = readline(&data, &dbuf);
-			if (rc)
+			if (rc) {
+				fprintf(stderr, "%s: line %" Z "d: failed to read key value\n", prog, lineno);
 				goto txn_abort;
+			}
 
 			rc = mdb_cursor_put(mc, &key, &data, putflags);
 			if (rc == MDB_KEYEXIST && putflags)
 				continue;
-			if (rc)
+			if (rc) {
+				fprintf(stderr, "mdb_cursor_put failed, error %d %s\n", rc, mdb_strerror(rc));
 				goto txn_abort;
+			}
 			batch++;
 			if (batch == 100) {
 				rc = mdb_txn_commit(txn);

mtest6.c

@@ -159,6 +159,7 @@ int main(int argc,char * argv[])
 	mdb_dbi_close(env, dbi);
 #endif
 	mdb_env_close(env);
+	free(sval);
 
 	return 0;
 }