KEYS: big_key: Use key preparsing

Make use of key preparsing in the big key type so that quota size determination
can take place prior to keyring locking when a key is being added.

Signed-off-by: David Howells <dhowells@redhat.com>
Acked-by: Steve Dickson <steved@redhat.com>

diff --git a/include/keys/big_key-type.h b/include/keys/big_key-type.h
index d69bc8a..e0970a5 100644 (file)
--- a/include/keys/big_key-type.h
+++ b/include/keys/big_key-type.h
@@ -16,7 +16,8 @@
 
 extern struct key_type key_type_big_key;
 
-extern int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep);
+extern int big_key_preparse(struct key_preparsed_payload *prep);
+extern void big_key_free_preparse(struct key_preparsed_payload *prep);
 extern void big_key_revoke(struct key *key);
 extern void big_key_destroy(struct key *key);
 extern void big_key_describe(const struct key *big_key, struct seq_file *m);

diff --git a/security/keys/big_key.c b/security/keys/big_key.c
index 8137b27..c2f91a0 100644 (file)
--- a/security/keys/big_key.c
+++ b/security/keys/big_key.c
@@ -34,7 +34,9 @@ MODULE_LICENSE("GPL");
 struct key_type key_type_big_key = {
        .name                   = "big_key",
        .def_lookup_type        = KEYRING_SEARCH_LOOKUP_DIRECT,
-       .instantiate            = big_key_instantiate,
+       .preparse               = big_key_preparse,
+       .free_preparse          = big_key_free_preparse,
+       .instantiate            = generic_key_instantiate,
        .match                  = user_match,
        .revoke                 = big_key_revoke,
        .destroy                = big_key_destroy,
@@ -43,11 +45,11 @@ struct key_type key_type_big_key = {
 };
 
 /*
- * Instantiate a big key
+ * Preparse a big key
  */
-int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
+int big_key_preparse(struct key_preparsed_payload *prep)
 {
-       struct path *path = (struct path *)&key->payload.data2;
+       struct path *path = (struct path *)&prep->payload;
        struct file *file;
        ssize_t written;
        size_t datalen = prep->datalen;
@@ -58,11 +60,9 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
                goto error;
 
        /* Set an arbitrary quota */
-       ret = key_payload_reserve(key, 16);
-       if (ret < 0)
-               goto error;
+       prep->quotalen = 16;
 
-       key->type_data.x[1] = datalen;
+       prep->type_data[1] = (void *)(unsigned long)datalen;
 
        if (datalen > BIG_KEY_FILE_THRESHOLD) {
                /* Create a shmem file to store the data in.  This will permit the data
@@ -73,7 +73,7 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
                file = shmem_kernel_file_setup("", datalen, 0);
                if (IS_ERR(file)) {
                        ret = PTR_ERR(file);
-                       goto err_quota;
+                       goto error;
                }
 
                written = kernel_write(file, prep->data, prep->datalen, 0);
@@ -93,24 +93,33 @@ int big_key_instantiate(struct key *key, struct key_preparsed_payload *prep)
        } else {
                /* Just store the data in a buffer */
                void *data = kmalloc(datalen, GFP_KERNEL);
-               if (!data) {
-                       ret = -ENOMEM;
-                       goto err_quota;
-               }
+               if (!data)
+                       return -ENOMEM;
 
-               key->payload.data = memcpy(data, prep->data, prep->datalen);
+               prep->payload[0] = memcpy(data, prep->data, prep->datalen);
        }
        return 0;
 
 err_fput:
        fput(file);
-err_quota:
-       key_payload_reserve(key, 0);
 error:
        return ret;
 }
 
 /*
+ * Clear preparsement.
+ */
+void big_key_free_preparse(struct key_preparsed_payload *prep)
+{
+       if (prep->datalen > BIG_KEY_FILE_THRESHOLD) {
+               struct path *path = (struct path *)&prep->payload;
+               path_put(path);
+       } else {
+               kfree(prep->payload[0]);
+       }
+}
+
+/*
  * dispose of the links from a revoked keyring
  * - called with the key sem write-locked
  */