[CRYPTO] api: Add crypto_alg reference counting

Up until now we've relied on module reference counting to ensure that the
crypto_alg structures don't disappear from under us.  This was good enough
as long as each crypto_alg came from exactly one module.

However, with parameterised crypto algorithms a crypto_alg object may need
two or more modules to operate.  This means that we need to count the
references to the crypto_alg object directly.

Signed-off-by: Herbert Xu <herbert@gondor.apana.org.au>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 3 insertions, 0 deletions

diff --git a/include/linux/crypto.h b/include/linux/crypto.h
index cb1e6631b132..7f57ff8ec975 100644
--- a/include/linux/crypto.h
+++ b/include/linux/crypto.h
@@ -17,6 +17,7 @@
 #ifndef _LINUX_CRYPTO_H
 #define _LINUX_CRYPTO_H
 
+#include <asm/atomic.h>
 #include <linux/module.h>
 #include <linux/kernel.h>
 #include <linux/types.h>
@@ -148,6 +149,7 @@ struct crypto_alg {
         unsigned int cra_alignmask;
 
         int cra_priority;
+        atomic_t cra_refcnt;
 
         char cra_name[CRYPTO_MAX_ALG_NAME];
         char cra_driver_name[CRYPTO_MAX_ALG_NAME];
@@ -160,6 +162,7 @@ struct crypto_alg {
 
         int (*cra_init)(struct crypto_tfm *tfm);
         void (*cra_exit)(struct crypto_tfm *tfm);
+        void (*cra_destroy)(struct crypto_alg *alg);
         
         struct module *cra_module;
 };