Commit 8df3aaaf authored by Joern Engel's avatar Joern Engel Committed by Linus Torvalds
Browse files

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: default avatarJoern Engel <joern@purestorage.com>
Signed-off-by: default avatarLinus Torvalds <torvalds@linux-foundation.org>
parent fed8f509

lib/btree.c

+6 −4
Original line number Diff line number Diff line
@@ -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;

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