From 3630066843b7ca6b2cd12911d3e2fe3314cd4549 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Sat, 26 Jul 2014 18:16:02 -0700
Subject: [PATCH 1/2] Fix MIPS cache coherency on Linux

MIPS chips require manual control of on-chip caches. The cacheflush
syscall being used here only exists on MIPS Linux, other OSs will
require revisiting.
---
 libraries/liblmdb/mdb.c | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index 84477c4285..e1d774887b 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -70,6 +70,15 @@
 #include <fcntl.h>
 #endif
 
+#if defined(__mips) && defined(__linux)
+/* MIPS has cache coherency issues, requires explicit cache control */
+#include <asm/cachectl.h>
+extern int cacheflush(char *addr, int nbytes, int cache);
+#define CACHEFLUSH(addr, bytes, cache)	cacheflush(addr, bytes, cache)
+#else
+#define CACHEFLUSH(addr, bytes, cache)
+#endif
+
 #include <errno.h>
 #include <limits.h>
 #include <stddef.h>
@@ -3581,6 +3590,11 @@ done:
 	if (env->me_txns)
 		env->me_txns->mti_txnid = txn->mt_txnid;
 
+	/* MIPS has cache coherency issues, this is a no-op everywhere else */
+	if (!(env->me_flags & MDB_WRITEMAP)) {
+		CACHEFLUSH(env->me_map, txn->mt_next_pgno * env->me_psize, DCACHE);
+	}
+
 	return MDB_SUCCESS;
 }
 

From 8498c6cba2d78de420e626245a49db4705e5a6f6 Mon Sep 17 00:00:00 2001
From: Howard Chu <hyc@symas.com>
Date: Thu, 31 Jul 2014 09:59:52 -0700
Subject: [PATCH 2/2] ITS#7913 mdb_cursor_get(*_DUP) cleanup

FIRST_DUP/LAST_DUP should succeed even on non-duplicate values
PREV_DUP should reset cursor's EOF flag.
---
 libraries/liblmdb/mdb.c | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/libraries/liblmdb/mdb.c b/libraries/liblmdb/mdb.c
index e1d774887b..96f5772903 100644
--- a/libraries/liblmdb/mdb.c
+++ b/libraries/liblmdb/mdb.c
@@ -5355,8 +5355,10 @@ mdb_cursor_prev(MDB_cursor *mc, MDB_val *key, MDB_val *data, MDB_cursor_op op)
 			if (op == MDB_PREV || op == MDB_PREV_DUP) {
 				rc = mdb_cursor_prev(&mc->mc_xcursor->mx_cursor, data, NULL, MDB_PREV);
 				if (op != MDB_PREV || rc != MDB_NOTFOUND) {
-					if (rc == MDB_SUCCESS)
+					if (rc == MDB_SUCCESS) {
 						MDB_GET_KEY(leaf, key);
+						mc->mc_flags &= ~C_EOF;
+					}
 					return rc;
 				}
 			} else {
@@ -5833,6 +5835,15 @@ fetchm:
 			rc = MDB_INCOMPATIBLE;
 			break;
 		}
+		{
+			MDB_node *leaf = NODEPTR(mc->mc_pg[mc->mc_top], mc->mc_ki[mc->mc_top]);
+			if (!F_ISSET(leaf->mn_flags, F_DUPDATA)) {
+				MDB_GET_KEY(leaf, key);
+				if (data)
+					rc = mdb_node_read(mc->mc_txn, leaf, data);
+				break;
+			}
+		}
 		if (!(mc->mc_xcursor->mx_cursor.mc_flags & C_INITIALIZED)) {
 			rc = EINVAL;
 			break;