From 8836b78e945d6cabb0e21c04f89a40bd0478359f Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Wed, 2 Jul 2014 11:44:06 -0700
Subject: [PATCH] Fix subDB/ovpage copying

---
 libraries/liblmdb/mdb.c | 57 ++++++++++++++++++++++++++++++-----------
 1 file changed, 42 insertions(+), 15 deletions(-)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 5becba2..9d24aef 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -8018,7 +8018,6 @@ typedef struct mdb_copy {
 	pthread_mutex_t mc_mutex[2];
 	char *mc_wbuf[2];
 	char *mc_over[2];
-	void *mc_obuf[2];
 	void *mc_free;
 	MDB_env *mc_env;
 	MDB_txn *mc_txn;
@@ -8043,8 +8042,10 @@ mdb_env_copythr(void *arg)
 #define DO_WRITE(rc, fd, ptr, w2, len)	len = write(fd, ptr, w2); rc = (len >= 0)
 #endif
 
+	pthread_mutex_lock(&my->mc_mutex[toggle^1]);
 	for(;;) {
 		pthread_mutex_lock(&my->mc_mutex[toggle]);
+		pthread_mutex_unlock(&my->mc_mutex[toggle^1]);
 		if (!my->mc_wlen[toggle]) {
 			pthread_mutex_unlock(&my->mc_mutex[toggle]);
 			break;
@@ -8067,6 +8068,7 @@ again:
 				break;
 			}
 		}
+		my->mc_wlen[toggle] = wsize;
 		if (rc) {
 			my->mc_status = rc;
 			pthread_mutex_unlock(&my->mc_mutex[toggle]);
@@ -8079,7 +8081,6 @@ again:
 			my->mc_olen[toggle] = 0;
 			goto again;
 		}
-		pthread_mutex_unlock(&my->mc_mutex[toggle]);
 		toggle ^= 1;
 	}
 	return NULL;
@@ -8104,12 +8105,12 @@ mdb_env_cthr_toggle(mdb_copy *my)
 }
 
 static int
-mdb_env_cwalk(mdb_copy *my, pgno_t pg)
+mdb_env_cwalk(mdb_copy *my, pgno_t *pg, int flags)
 {
 	MDB_cursor mc;
 	MDB_txn *txn = my->mc_txn;
 	MDB_node *ni;
-	MDB_page *mo, *mp;
+	MDB_page *mo, *mp, *leaf;
 	char *buf, *ptr;
 	int rc, toggle;
 	unsigned int i;
@@ -8118,7 +8119,7 @@ mdb_env_cwalk(mdb_copy *my, pgno_t pg)
 	mc.mc_top = 0;
 	mc.mc_txn = txn;
 
-	rc = mdb_page_get(my->mc_txn, pg, &mc.mc_pg[0], NULL);
+	rc = mdb_page_get(my->mc_txn, *pg, &mc.mc_pg[0], NULL);
 	if (rc)
 		return rc;
 	rc = mdb_page_search_root(&mc, NULL, MDB_PS_FIRST);
@@ -8126,7 +8127,7 @@ mdb_env_cwalk(mdb_copy *my, pgno_t pg)
 		return rc;
 
 	/* Make cursor pages writable */
-	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_top);
+	buf = ptr = malloc(my->mc_env->me_psize * mc.mc_snum);
 	if (buf == NULL)
 		return ENOMEM;
 
@@ -8136,6 +8137,9 @@ mdb_env_cwalk(mdb_copy *my, pgno_t pg)
 		ptr += my->mc_env->me_psize;
 	}
 
+	/* This is writable space for a leaf page. Usually not needed. */
+	leaf = (MDB_page *)ptr;
+
 	toggle = my->mc_toggle;
 	while (mc.mc_snum > 0) {
 		unsigned n;
@@ -8143,12 +8147,21 @@ mdb_env_cwalk(mdb_copy *my, pgno_t pg)
 		n = NUMKEYS(mp);
 
 		if (IS_LEAF(mp)) {
-			if (!IS_LEAF2(mp)) {
+			if (!IS_LEAF2(mp) && !(flags & F_DUPDATA)) {
 				for (i=0; i<n; i++) {
 					ni = NODEPTR(mp, i);
 					if (ni->mn_flags & F_BIGDATA) {
 						MDB_page *omp;
 						pgno_t pg;
+
+						/* Need writable leaf */
+						if (mp != leaf) {
+							mc.mc_pg[mc.mc_top] = leaf;
+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
+							mp = leaf;
+							ni = NODEPTR(mp, i);
+						}
+
 						memcpy(&pg, NODEDATA(ni), sizeof(pg));
 						rc = mdb_page_get(txn, pg, &omp, NULL);
 						if (rc)
@@ -8164,20 +8177,33 @@ mdb_env_cwalk(mdb_copy *my, pgno_t pg)
 						mo->mp_pgno = my->mc_next_pgno;
 						my->mc_next_pgno += omp->mp_pages;
 						my->mc_wlen[toggle] += my->mc_env->me_psize;
-						my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
-						my->mc_obuf[toggle] = (char *)omp + my->mc_env->me_psize;
-						rc = mdb_env_cthr_toggle(my);
-						if (rc)
-							goto done;
-						toggle ^= 1;
+						if (omp->mp_pages > 1) {
+							my->mc_olen[toggle] = my->mc_env->me_psize * (omp->mp_pages - 1);
+							my->mc_over[toggle] = (char *)omp + my->mc_env->me_psize;
+							rc = mdb_env_cthr_toggle(my);
+							if (rc)
+								goto done;
+							toggle ^= 1;
+						}
+						memcpy(NODEDATA(ni), &mo->mp_pgno, sizeof(pgno_t));
 					} else if (ni->mn_flags & F_SUBDATA) {
 						MDB_db db;
+
+						/* Need writable leaf */
+						if (mp != leaf) {
+							mc.mc_pg[mc.mc_top] = leaf;
+							mdb_page_copy(leaf, mp, my->mc_env->me_psize);
+							mp = leaf;
+							ni = NODEPTR(mp, i);
+						}
+
 						memcpy(&db, NODEDATA(ni), sizeof(db));
 						my->mc_toggle = toggle;
-						rc = mdb_env_cwalk(my, db.md_root);
+						rc = mdb_env_cwalk(my, &db.md_root, ni->mn_flags & F_DUPDATA);
 						if (rc)
 							goto done;
 						toggle = my->mc_toggle;
+						memcpy(NODEDATA(ni), &db, sizeof(db));
 					}
 				}
 			}
@@ -8218,6 +8244,7 @@ again:
 		my->mc_wlen[toggle] += my->mc_env->me_psize;
 		mdb_cursor_pop(&mc);
 	}
+	*pg = mo->mp_pgno;
 done:
 	free(buf);
 	return rc;
@@ -8309,7 +8336,7 @@ mdb_env_copyfd2(MDB_env *env, HANDLE fd)
 	my.mc_wlen[0] = env->me_psize * 2;
 	my.mc_txn = txn;
 	pthread_create(&thr, NULL, mdb_env_copythr, &my);
-	rc = mdb_env_cwalk(&my, txn->mt_dbs[1].md_root);
+	rc = mdb_env_cwalk(&my, &txn->mt_dbs[1].md_root, 0);
 	if (rc == MDB_SUCCESS && my.mc_wlen[my.mc_toggle])
 		rc = mdb_env_cthr_toggle(&my);
 	my.mc_wlen[my.mc_toggle] = 0;