btree: avoid variable-length allocations
geo->keylen cannot be larger than 4. So we might as well make
fixed-size allocations.
Given the one remaining user, geo->keylen cannot even be larger than 1.
Logfs used to have 64bit and 128bit keys, tcm_qla2xxx only has 32bit
keys. But let's not break the code if we don't have to.
Signed-off-by: Joern Engel <joern@purestorage.com>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/lib/btree.c b/lib/btree.c
index f93a945..590facb 100644
--- a/lib/btree.c
+++ b/lib/btree.c
@@ -3,7 +3,7 @@
*
* As should be obvious for Linux kernel code, license is GPLv2
*
- * Copyright (c) 2007-2008 Joern Engel <joern@logfs.org>
+ * Copyright (c) 2007-2008 Joern Engel <joern@purestorage.com>
* Bits and pieces stolen from Peter Zijlstra's code, which is
* Copyright 2007, Red Hat Inc. Peter Zijlstra
* GPLv2
@@ -76,6 +76,8 @@ struct btree_geo btree_geo128 = {
};
EXPORT_SYMBOL_GPL(btree_geo128);
+#define MAX_KEYLEN (2 * LONG_PER_U64)
+
static struct kmem_cache *btree_cachep;
void *btree_alloc(gfp_t gfp_mask, void *pool_data)
@@ -313,7 +315,7 @@ void *btree_get_prev(struct btree_head *head, struct btree_geo *geo,
{
int i, height;
unsigned long *node, *oldnode;
- unsigned long *retry_key = NULL, key[geo->keylen];
+ unsigned long *retry_key = NULL, key[MAX_KEYLEN];
if (keyzero(geo, __key))
return NULL;
@@ -639,8 +641,8 @@ EXPORT_SYMBOL_GPL(btree_remove);
int btree_merge(struct btree_head *target, struct btree_head *victim,
struct btree_geo *geo, gfp_t gfp)
{
- unsigned long key[geo->keylen];
- unsigned long dup[geo->keylen];
+ unsigned long key[MAX_KEYLEN];
+ unsigned long dup[MAX_KEYLEN];
void *val;
int err;
