Commit f38b24c9 authored by Firo Yang's avatar Firo Yang Committed by David S. Miller

fib_trie: coding style: Use pointer after check

As Alexander Duyck pointed out that:
struct tnode {
        ...
        struct key_vector kv[1];
}
The kv[1] member of struct tnode is an arry that refernced by
a null pointer will not crash the system, like this:
struct tnode *p = NULL;
struct key_vector *kv = p->kv;
As such p->kv doesn't actually dereference anything, it is simply a
means for getting the offset to the array from the pointer p.

This patch make the code more regular to avoid making people feel
odd when they look at the code.
Signed-off-by: default avatarFiro Yang <firogm@gmail.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent cbab1510
...@@ -325,13 +325,15 @@ static inline void empty_child_dec(struct key_vector *n) ...@@ -325,13 +325,15 @@ static inline void empty_child_dec(struct key_vector *n)
static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
{ {
struct tnode *kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL); struct key_vector *l;
struct key_vector *l = kv->kv; struct tnode *kv;
kv = kmem_cache_alloc(trie_leaf_kmem, GFP_KERNEL);
if (!kv) if (!kv)
return NULL; return NULL;
/* initialize key vector */ /* initialize key vector */
l = kv->kv;
l->key = key; l->key = key;
l->pos = 0; l->pos = 0;
l->bits = 0; l->bits = 0;
...@@ -346,24 +348,26 @@ static struct key_vector *leaf_new(t_key key, struct fib_alias *fa) ...@@ -346,24 +348,26 @@ static struct key_vector *leaf_new(t_key key, struct fib_alias *fa)
static struct key_vector *tnode_new(t_key key, int pos, int bits) static struct key_vector *tnode_new(t_key key, int pos, int bits)
{ {
struct tnode *tnode = tnode_alloc(bits);
unsigned int shift = pos + bits; unsigned int shift = pos + bits;
struct key_vector *tn = tnode->kv; struct key_vector *tn;
struct tnode *tnode;
/* verify bits and pos their msb bits clear and values are valid */ /* verify bits and pos their msb bits clear and values are valid */
BUG_ON(!bits || (shift > KEYLENGTH)); BUG_ON(!bits || (shift > KEYLENGTH));
pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0), tnode = tnode_alloc(bits);
sizeof(struct key_vector *) << bits);
if (!tnode) if (!tnode)
return NULL; return NULL;
pr_debug("AT %p s=%zu %zu\n", tnode, TNODE_SIZE(0),
sizeof(struct key_vector *) << bits);
if (bits == KEYLENGTH) if (bits == KEYLENGTH)
tnode->full_children = 1; tnode->full_children = 1;
else else
tnode->empty_children = 1ul << bits; tnode->empty_children = 1ul << bits;
tn = tnode->kv;
tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0; tn->key = (shift < KEYLENGTH) ? (key >> shift) << shift : 0;
tn->pos = pos; tn->pos = pos;
tn->bits = bits; tn->bits = bits;
...@@ -2054,11 +2058,12 @@ static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter) ...@@ -2054,11 +2058,12 @@ static struct key_vector *fib_trie_get_next(struct fib_trie_iter *iter)
static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter, static struct key_vector *fib_trie_get_first(struct fib_trie_iter *iter,
struct trie *t) struct trie *t)
{ {
struct key_vector *n, *pn = t->kv; struct key_vector *n, *pn;
if (!t) if (!t)
return NULL; return NULL;
pn = t->kv;
n = rcu_dereference(pn->tnode[0]); n = rcu_dereference(pn->tnode[0]);
if (!n) if (!n)
return NULL; return NULL;
......
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