uids: merge multiple error paths in alloc_uid() into one
There are already 4 error paths in alloc_uid() that do incremental rollbacks.
I think it's time to merge them. This costs us 8 lines of code :)
Maybe it would be better to merge this patch with the previous one, but I
remember that some time ago I sent a similar patch (fixing the error path and
cleaning it), but I was told to make two patches in such cases.
Signed-off-by: Pavel Emelyanov <xemul@openvz.org>
Acked-by: Dhaval Giani <dhaval@linux.vnet.ibm.com>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
diff --git a/kernel/user.c b/kernel/user.c
index ab4fd706..bc1c48d 100644
--- a/kernel/user.c
+++ b/kernel/user.c
@@ -319,7 +319,7 @@
struct user_struct * alloc_uid(struct user_namespace *ns, uid_t uid)
{
struct hlist_head *hashent = uidhashentry(ns, uid);
- struct user_struct *up;
+ struct user_struct *up, *new;
/* Make uid_hash_find() + uids_user_create() + uid_hash_insert()
* atomic.
@@ -331,13 +331,9 @@
spin_unlock_irq(&uidhash_lock);
if (!up) {
- struct user_struct *new;
-
new = kmem_cache_alloc(uid_cachep, GFP_KERNEL);
- if (!new) {
- uids_mutex_unlock();
- return NULL;
- }
+ if (!new)
+ goto out_unlock;
new->uid = uid;
atomic_set(&new->__count, 1);
@@ -353,28 +349,14 @@
#endif
new->locked_shm = 0;
- if (alloc_uid_keyring(new, current) < 0) {
- kmem_cache_free(uid_cachep, new);
- uids_mutex_unlock();
- return NULL;
- }
+ if (alloc_uid_keyring(new, current) < 0)
+ goto out_free_user;
- if (sched_create_user(new) < 0) {
- key_put(new->uid_keyring);
- key_put(new->session_keyring);
- kmem_cache_free(uid_cachep, new);
- uids_mutex_unlock();
- return NULL;
- }
+ if (sched_create_user(new) < 0)
+ goto out_put_keys;
- if (uids_user_create(new)) {
- sched_destroy_user(new);
- key_put(new->uid_keyring);
- key_put(new->session_keyring);
- kmem_cache_free(uid_cachep, new);
- uids_mutex_unlock();
- return NULL;
- }
+ if (uids_user_create(new))
+ goto out_destoy_sched;
/*
* Before adding this, check whether we raced
@@ -402,6 +384,17 @@
uids_mutex_unlock();
return up;
+
+out_destoy_sched:
+ sched_destroy_user(new);
+out_put_keys:
+ key_put(new->uid_keyring);
+ key_put(new->session_keyring);
+out_free_user:
+ kmem_cache_free(uid_cachep, new);
+out_unlock:
+ uids_mutex_unlock();
+ return NULL;
}
void switch_uid(struct user_struct *new_user)