Switch user_ns to use the new hashtable implementation. This reduces the amount
of
generic unrelated code in user_ns.
Signed-off-by: Sasha Levin <levinsasha...@gmail.com>
---
kernel/user.c | 53 ++++++++++++++++++-----------------------------------
1 files changed, 18 insertions(+), 35 deletions(-)
diff --git a/kernel/user.c b/kernel/user.c
index b815fef..555c71a 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -16,6 +16,7 @@
#include <linux/interrupt.h>
#include <linux/export.h>
#include <linux/user_namespace.h>
+#include <linux/hashtable.h>
/*
* userns count is 1 for root user, 1 for init_uts_ns,
@@ -50,15 +51,14 @@ EXPORT_SYMBOL_GPL(init_user_ns);
* UID task count cache, to get fast user lookup in "alloc_uid"
* when changing user ID's (ie setuid() and friends).
*/
-
-#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7)
-#define UIDHASH_SZ (1 << UIDHASH_BITS)
-#define UIDHASH_MASK (UIDHASH_SZ - 1)
-#define __uidhashfn(uid) (((uid >> UIDHASH_BITS) + uid) & UIDHASH_MASK)
-#define uidhashentry(uid) (uidhash_table + __uidhashfn((__kuid_val(uid))))
+#define UIDHASH_BITS (CONFIG_BASE_SMALL ? 3 : 7)
+#define UIDHASH_CMP(obj, key) ((obj)->uid == (key))
+#define uidhash_entry(key) (hash_get(&uidhash_table, key, \
+ struct user_struct, uidhash_node, \
+ UIDHASH_CMP))
static struct kmem_cache *uid_cachep;
-struct hlist_head uidhash_table[UIDHASH_SZ];
+DEFINE_STATIC_HASHTABLE(uidhash_table, UIDHASH_BITS);
/*
* The uidhash_lock is mostly taken from process context, but it is
@@ -84,29 +84,14 @@ struct user_struct root_user = {
/*
* These routines must be called with the uidhash spinlock held!
*/
-static void uid_hash_insert(struct user_struct *up, struct hlist_head *hashent)
+static void uid_hash_insert(struct user_struct *up)
{
- hlist_add_head(&up->uidhash_node, hashent);
+ hash_add(&uidhash_table, &up->uidhash_node, up->uid);
}
static void uid_hash_remove(struct user_struct *up)
{
- hlist_del_init(&up->uidhash_node);
-}
-
-static struct user_struct *uid_hash_find(kuid_t uid, struct hlist_head
*hashent)
-{
- struct user_struct *user;
- struct hlist_node *h;
-
- hlist_for_each_entry(user, h, hashent, uidhash_node) {
- if (uid_eq(user->uid, uid)) {
- atomic_inc(&user->__count);
- return user;
- }
- }
-
- return NULL;
+ hash_del(&up->uidhash_node);
}
/* IRQs are disabled and uidhash_lock is held upon function entry.
@@ -135,7 +120,9 @@ struct user_struct *find_user(kuid_t uid)
unsigned long flags;
spin_lock_irqsave(&uidhash_lock, flags);
- ret = uid_hash_find(uid, uidhashentry(uid));
+ ret = uidhash_entry(uid);
+ if (ret)
+ atomic_inc(&ret->__count);
spin_unlock_irqrestore(&uidhash_lock, flags);
return ret;
}
@@ -156,11 +143,10 @@ void free_uid(struct user_struct *up)
struct user_struct *alloc_uid(kuid_t uid)
{
- struct hlist_head *hashent = uidhashentry(uid);
struct user_struct *up, *new;
spin_lock_irq(&uidhash_lock);
- up = uid_hash_find(uid, hashent);
+ up = uidhash_entry(uid);
spin_unlock_irq(&uidhash_lock);
if (!up) {
@@ -176,13 +162,13 @@ struct user_struct *alloc_uid(kuid_t uid)
* on adding the same user already..
*/
spin_lock_irq(&uidhash_lock);
- up = uid_hash_find(uid, hashent);
+ up = uidhash_entry(uid);
if (up) {
key_put(new->uid_keyring);
key_put(new->session_keyring);
kmem_cache_free(uid_cachep, new);
} else {
- uid_hash_insert(new, hashent);
+ uid_hash_insert(new);
up = new;
}
spin_unlock_irq(&uidhash_lock);
@@ -196,17 +182,14 @@ out_unlock:
static int __init uid_cache_init(void)
{
- int n;
-
uid_cachep = kmem_cache_create("uid_cache", sizeof(struct user_struct),
0, SLAB_HWCACHE_ALIGN|SLAB_PANIC, NULL);
- for(n = 0; n < UIDHASH_SZ; ++n)
- INIT_HLIST_HEAD(uidhash_table + n);
+ hash_init(&uidhash_table, UIDHASH_BITS);
/* Insert the root user immediately (init already runs as root) */
spin_lock_irq(&uidhash_lock);
- uid_hash_insert(&root_user, uidhashentry(GLOBAL_ROOT_UID));
+ uid_hash_insert(&root_user);
spin_unlock_irq(&uidhash_lock);
return 0;
--
1.7.8.6
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