[PATCH v2 10/16] maple_tree: convert mas_insert() to preallocate nodes

[Sidhartha Kumar <sidhartha.kumar@oracle.com>]

By setting the store type in mas_insert(), we no longer need to use
mas_wr_modify() to determine the correct store function to use. Instead,
set the store type and call mas_wr_store_entry(). Also, pass in the
requested gfp flags to mas_insert() so they can be passed to the call to
mas_wr_preallocate().

Signed-off-by: Sidhartha Kumar <sidhartha.kumar@oracle.com>
---
 lib/maple_tree.c | 33 ++++++++++++++++-----------------
 1 file changed, 16 insertions(+), 17 deletions(-)

diff --git a/lib/maple_tree.c b/lib/maple_tree.c
index 2c42e99c400c..c37bfac4f622 100644
--- a/lib/maple_tree.c
+++ b/lib/maple_tree.c
@@ -4442,11 +4442,12 @@ static inline void mas_wr_preallocate(struct ma_wr_state *wr_mas, void *entry, g
  * mas_insert() - Internal call to insert a value
  * @mas: The maple state
  * @entry: The entry to store
+ * @gfp: The GFP_FLAGS to use for allocations
  *
  * Return: %NULL or the contents that already exists at the requested index
  * otherwise.  The maple state needs to be checked for error conditions.
  */
-static inline void *mas_insert(struct ma_state *mas, void *entry)
+static inline void *mas_insert(struct ma_state *mas, void *entry, gfp_t gfp)
 {
 	MA_WR_STATE(wr_mas, mas, entry);
 
@@ -4468,26 +4469,24 @@ static inline void *mas_insert(struct ma_state *mas, void *entry)
 	if (wr_mas.content)
 		goto exists;
 
-	if (mas_is_none(mas) || mas_is_ptr(mas)) {
-		mas_store_root(mas, entry);
+	mas_wr_preallocate(&wr_mas, entry, gfp);
+	if (mas_is_err(mas))
 		return NULL;
-	}
 
 	/* spanning writes always overwrite something */
-	if (!mas_wr_walk(&wr_mas))
+	if (mas->store_type == wr_spanning_store)
 		goto exists;
 
 	/* At this point, we are at the leaf node that needs to be altered. */
-	wr_mas.offset_end = mas->offset;
-	wr_mas.end_piv = wr_mas.r_max;
-
-	if (wr_mas.content || (mas->last > wr_mas.r_max))
-		goto exists;
+	if (mas->store_type != wr_new_root && mas->store_type != wr_store_root) {
+		wr_mas.offset_end = mas->offset;
+		wr_mas.end_piv = wr_mas.r_max;
 
-	if (!entry)
-		return NULL;
+		if (wr_mas.content || (mas->last > wr_mas.r_max))
+			goto exists;
+	}
 
-	mas_wr_modify(&wr_mas);
+	mas_wr_store_entry(&wr_mas);
 	return wr_mas.content;
 
 exists:
@@ -4532,7 +4531,7 @@ int mas_alloc_cyclic(struct ma_state *mas, unsigned long *startp,
 		return ret;
 
 	do {
-		mas_insert(mas, entry);
+		mas_insert(mas, entry, gfp);
 	} while (mas_nomem(mas, gfp));
 	if (mas_is_err(mas))
 		return xa_err(mas->node);
@@ -6536,7 +6535,7 @@ int mtree_insert_range(struct maple_tree *mt, unsigned long first,
 
 	mtree_lock(mt);
 retry:
-	mas_insert(&ms, entry);
+	mas_insert(&ms, entry, gfp);
 	if (mas_nomem(&ms, gfp))
 		goto retry;
 
@@ -6585,7 +6584,7 @@ int mtree_alloc_range(struct maple_tree *mt, unsigned long *startp,
 	if (ret)
 		goto unlock;
 
-	mas_insert(&mas, entry);
+	mas_insert(&mas, entry, gfp);
 	/*
 	 * mas_nomem() may release the lock, causing the allocated area
 	 * to be unavailable, so try to allocate a free area again.
@@ -6667,7 +6666,7 @@ int mtree_alloc_rrange(struct maple_tree *mt, unsigned long *startp,
 	if (ret)
 		goto unlock;
 
-	mas_insert(&mas, entry);
+	mas_insert(&mas, entry, gfp);
 	/*
 	 * mas_nomem() may release the lock, causing the allocated area
 	 * to be unavailable, so try to allocate a free area again.
-- 
2.45.2