Fix several bugs in LSM:

* the logic for setting the "no eviction" flag on LSM chunks was reversed, causing unnecessary eviction once the cache became full;
* calling session.checkpoint while writing to an LSM tree could confuse the logic around switching to new chunks; and
* fix a possible NULL pointer indirection when switching chunks.

4 files changed, 22 insertions, 15 deletions

diff --git a/src/btree/bt_handle.c b/src/btree/bt_handle.c
index c41b002d995..0b13b4cee43 100644
--- a/src/btree/bt_handle.c
+++ b/src/btree/bt_handle.c
@@ -477,9 +477,9 @@ void
 __wt_btree_evictable(WT_SESSION_IMPL *session, int on)
 {
 	if (on)
-		F_SET(session->btree, WT_BTREE_NO_EVICTION);
-	else
 		F_CLR(session->btree, WT_BTREE_NO_EVICTION);
+	else
+		F_SET(session->btree, WT_BTREE_NO_EVICTION);
 }
 
 /*
diff --git a/src/include/btree.i b/src/include/btree.i
index 5ff4dcd2271..87dc15d1bb4 100644
--- a/src/include/btree.i
+++ b/src/include/btree.i
@@ -531,26 +531,30 @@ __wt_skip_choose_depth(void)
 /*
  * __wt_btree_size_overflow --
  *      Check if the size of an in-memory tree with a single leaf page is
- *      over a specified maximum.
+ *      over a specified maximum.  If called on anything other than a simple
+ *      tree with a single leaf page, returns true so the calling code will
+ *      switch to a new tree.
  */
 static inline int
 __wt_btree_size_overflow(WT_SESSION_IMPL *session, uint32_t maxsize)
 {
 	WT_BTREE *btree;
-	WT_PAGE *child;
+	WT_PAGE *child, *root;
 
-	/*
-	 * Only return true if:
-	 * - We have a valid btree
-	 * - The btree has only a single leaf page
-	 * - The single leaf page is in memory
-	 */
 	btree = session->btree;
-	if (btree == NULL || btree->root_page->entries != 1 ||
-	    btree->root_page->u.intl.t->page == NULL)
+	root = btree->root_page;
+
+	if (btree == NULL || root == NULL ||
+	    (child = root->u.intl.t->page) == NULL)
 		return (0);
 
-	child = btree->root_page->u.intl.t->page;
+	/* Make sure this is a simple tree, or LSM should switch. */
+	if (!F_ISSET(btree, WT_BTREE_NO_EVICTION) ||
+	    root->entries != 1 ||
+	    root->u.intl.t->state != WT_REF_MEM ||
+	    child->type != WT_PAGE_ROW_LEAF)
+		return (1);
+
 	return (child->memory_footprint > maxsize);
 }
 
diff --git a/src/lsm/lsm_cursor.c b/src/lsm/lsm_cursor.c
index 5b0574f56bb..bb886332f71 100644
--- a/src/lsm/lsm_cursor.c
+++ b/src/lsm/lsm_cursor.c
@@ -842,8 +842,11 @@ __clsm_put(
 		 * in switching: if something went wrong, we should keep
 		 * trying to switch.
 		 */
-		if (ret == 0)
+		if (ret == 0) {
+			WT_SET_BTREE_IN_SESSION(session,
+			    ((WT_CURSOR_BTREE *)primary)->btree);
 			__wt_btree_evictable(session, 1);
+		}
 
 		WT_TRET(__wt_rwunlock(session, lsm_tree->rwlock));
 	}
diff --git a/src/lsm/lsm_worker.c b/src/lsm/lsm_worker.c
index fa8ed1aa4bf..b85c8618965 100644
--- a/src/lsm/lsm_worker.c
+++ b/src/lsm/lsm_worker.c
@@ -341,9 +341,9 @@ __lsm_free_chunks(WT_SESSION_IMPL *session, WT_LSM_TREE *lsm_tree)
 		if ((chunk = lsm_tree->old_chunks[i]) == NULL)
 			continue;
 		if (!locked) {
-			locked = 1;
 			/* TODO: Do we need the lsm_tree lock for all drops? */
 			WT_ERR(__wt_writelock(session, lsm_tree->rwlock));
+			locked = 1;
 		}
 		if (F_ISSET(chunk, WT_LSM_CHUNK_BLOOM)) {
 			WT_WITH_SCHEMA_LOCK(session, ret = __wt_schema_drop(