[PATCH 03/38] kref: remove kref_set

From: Greg Kroah-Hartman
Date: Fri May 21 2010 - 13:00:16 EST


From: NeilBrown <neilb@xxxxxxx>

Of the three uses of kref_set in the kernel:

One really should be kref_put as the code is letting go of a
reference,
Two really should be kref_init because the kref is being
initialised.

This suggests that making kref_set available encourages bad code.
So fix the three uses and remove kref_set completely.

Signed-off-by: NeilBrown <neilb@xxxxxxx>
Acked-by: Mimi Zohar <zohar@xxxxxxxxxx>
Acked-by: Serge Hallyn <serue@xxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxx>
---
include/linux/kref.h | 1 -
kernel/user_namespace.c | 4 ++--
lib/kref.c | 15 ++-------------
security/integrity/ima/ima_iint.c | 4 ++--
4 files changed, 6 insertions(+), 18 deletions(-)

diff --git a/include/linux/kref.h b/include/linux/kref.h
index baf4b9e..6cc38fc 100644
--- a/include/linux/kref.h
+++ b/include/linux/kref.h
@@ -21,7 +21,6 @@ struct kref {
atomic_t refcount;
};

-void kref_set(struct kref *kref, int num);
void kref_init(struct kref *kref);
void kref_get(struct kref *kref);
int kref_put(struct kref *kref, void (*release) (struct kref *kref));
diff --git a/kernel/user_namespace.c b/kernel/user_namespace.c
index 076c7c8..b2d70d3 100644
--- a/kernel/user_namespace.c
+++ b/kernel/user_namespace.c
@@ -54,8 +54,8 @@ int create_user_ns(struct cred *new)
#endif
/* tgcred will be cleared in our caller bc CLONE_THREAD won't be set */

- /* alloc_uid() incremented the userns refcount. Just set it to 1 */
- kref_set(&ns->kref, 1);
+ /* root_user holds a reference to ns, our reference can be dropped */
+ put_user_ns(ns);

return 0;
}
diff --git a/lib/kref.c b/lib/kref.c
index 6d19f69..d3d227a 100644
--- a/lib/kref.c
+++ b/lib/kref.c
@@ -16,23 +16,13 @@
#include <linux/slab.h>

/**
- * kref_set - initialize object and set refcount to requested number.
- * @kref: object in question.
- * @num: initial reference counter
- */
-void kref_set(struct kref *kref, int num)
-{
- atomic_set(&kref->refcount, num);
- smp_mb();
-}
-
-/**
* kref_init - initialize object.
* @kref: object in question.
*/
void kref_init(struct kref *kref)
{
- kref_set(kref, 1);
+ atomic_set(&kref->refcount, 1);
+ smp_mb();
}

/**
@@ -72,7 +62,6 @@ int kref_put(struct kref *kref, void (*release)(struct kref *kref))
return 0;
}

-EXPORT_SYMBOL(kref_set);
EXPORT_SYMBOL(kref_init);
EXPORT_SYMBOL(kref_get);
EXPORT_SYMBOL(kref_put);
diff --git a/security/integrity/ima/ima_iint.c b/security/integrity/ima/ima_iint.c
index 2dc2d65..7625b85 100644
--- a/security/integrity/ima/ima_iint.c
+++ b/security/integrity/ima/ima_iint.c
@@ -94,7 +94,7 @@ void iint_free(struct kref *kref)
iint->opencount);
iint->opencount = 0;
}
- kref_set(&iint->refcount, 1);
+ kref_init(&iint->refcount);
kmem_cache_free(iint_cache, iint);
}

@@ -133,7 +133,7 @@ static void init_once(void *foo)
iint->readcount = 0;
iint->writecount = 0;
iint->opencount = 0;
- kref_set(&iint->refcount, 1);
+ kref_init(&iint->refcount);
}

static int __init ima_iintcache_init(void)
--
1.7.0.3

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