Merge branches 'release' and 'autoload' into release

[mv-sheeva.git] / fs / ecryptfs / crypto.c

diff --git a/fs/ecryptfs/crypto.c b/fs/ecryptfs/crypto.c
index 942edfaa71133a51ddb068d1be19cb5dfa107b4f..a066e109ad9c05a7cbc0670f92045a3475e9aac1 100644 (file)
--- a/fs/ecryptfs/crypto.c
+++ b/fs/ecryptfs/crypto.c
@@ -1128,7 +1128,7 @@ write_ecryptfs_flags(char *page_virt, struct ecryptfs_crypt_stat *crypt_stat,
 
 struct ecryptfs_cipher_code_str_map_elem {
        char cipher_str[16];
-       u16 cipher_code;
+       u8 cipher_code;
 };
 
 /* Add support for additional ciphers by adding elements here. The
@@ -1152,10 +1152,10 @@ ecryptfs_cipher_code_str_map[] = {
  *
  * Returns zero on no match, or the cipher code on match
  */
-u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
+u8 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
 {
        int i;
-       u16 code = 0;
+       u8 code = 0;
        struct ecryptfs_cipher_code_str_map_elem *map =
                ecryptfs_cipher_code_str_map;
 
@@ -1187,7 +1187,7 @@ u16 ecryptfs_code_for_cipher_string(struct ecryptfs_crypt_stat *crypt_stat)
  *
  * Returns zero on success
  */
-int ecryptfs_cipher_code_to_string(char *str, u16 cipher_code)
+int ecryptfs_cipher_code_to_string(char *str, u8 cipher_code)
 {
        int rc = 0;
        int i;
@@ -1779,7 +1779,7 @@ out:
 
 struct kmem_cache *ecryptfs_key_tfm_cache;
 static struct list_head key_tfm_list;
-static struct mutex key_tfm_list_mutex;
+struct mutex key_tfm_list_mutex;
 
 int ecryptfs_init_crypto(void)
 {
@@ -1788,6 +1788,11 @@ int ecryptfs_init_crypto(void)
        return 0;
 }
 
+/**
+ * ecryptfs_destroy_crypto - free all cached key_tfms on key_tfm_list
+ *
+ * Called only at module unload time
+ */
 int ecryptfs_destroy_crypto(void)
 {
        struct ecryptfs_key_tfm *key_tfm, *key_tfm_tmp;
@@ -1811,6 +1816,8 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
        struct ecryptfs_key_tfm *tmp_tfm;
        int rc = 0;
 
+       BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
        tmp_tfm = kmem_cache_alloc(ecryptfs_key_tfm_cache, GFP_KERNEL);
        if (key_tfm != NULL)
                (*key_tfm) = tmp_tfm;
@@ -1837,13 +1844,50 @@ ecryptfs_add_new_key_tfm(struct ecryptfs_key_tfm **key_tfm, char *cipher_name,
                        (*key_tfm) = NULL;
                goto out;
        }
-       mutex_lock(&key_tfm_list_mutex);
        list_add(&tmp_tfm->key_tfm_list, &key_tfm_list);
-       mutex_unlock(&key_tfm_list_mutex);
 out:
        return rc;
 }
 
+/**
+ * ecryptfs_tfm_exists - Search for existing tfm for cipher_name.
+ * @cipher_name: the name of the cipher to search for
+ * @key_tfm: set to corresponding tfm if found
+ *
+ * Searches for cached key_tfm matching @cipher_name
+ * Must be called with &key_tfm_list_mutex held
+ * Returns 1 if found, with @key_tfm set
+ * Returns 0 if not found, with @key_tfm set to NULL
+ */
+int ecryptfs_tfm_exists(char *cipher_name, struct ecryptfs_key_tfm **key_tfm)
+{
+       struct ecryptfs_key_tfm *tmp_key_tfm;
+
+       BUG_ON(!mutex_is_locked(&key_tfm_list_mutex));
+
+       list_for_each_entry(tmp_key_tfm, &key_tfm_list, key_tfm_list) {
+               if (strcmp(tmp_key_tfm->cipher_name, cipher_name) == 0) {
+                       if (key_tfm)
+                               (*key_tfm) = tmp_key_tfm;
+                       return 1;
+               }
+       }
+       if (key_tfm)
+               (*key_tfm) = NULL;
+       return 0;
+}
+
+/**
+ * ecryptfs_get_tfm_and_mutex_for_cipher_name
+ *
+ * @tfm: set to cached tfm found, or new tfm created
+ * @tfm_mutex: set to mutex for cached tfm found, or new tfm created
+ * @cipher_name: the name of the cipher to search for and/or add
+ *
+ * Sets pointers to @tfm & @tfm_mutex matching @cipher_name.
+ * Searches for cached item first, and creates new if not found.
+ * Returns 0 on success, non-zero if adding new cipher failed
+ */
 int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
                                               struct mutex **tfm_mutex,
                                               char *cipher_name)
@@ -1853,22 +1897,17 @@ int ecryptfs_get_tfm_and_mutex_for_cipher_name(struct crypto_blkcipher **tfm,
 
        (*tfm) = NULL;
        (*tfm_mutex) = NULL;
+
        mutex_lock(&key_tfm_list_mutex);
-       list_for_each_entry(key_tfm, &key_tfm_list, key_tfm_list) {
-               if (strcmp(key_tfm->cipher_name, cipher_name) == 0) {
-                       (*tfm) = key_tfm->key_tfm;
-                       (*tfm_mutex) = &key_tfm->key_tfm_mutex;
-                       mutex_unlock(&key_tfm_list_mutex);
+       if (!ecryptfs_tfm_exists(cipher_name, &key_tfm)) {
+               rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
+               if (rc) {
+                       printk(KERN_ERR "Error adding new key_tfm to list; "
+                                       "rc = [%d]\n", rc);
                        goto out;
                }
        }
        mutex_unlock(&key_tfm_list_mutex);
-       rc = ecryptfs_add_new_key_tfm(&key_tfm, cipher_name, 0);
-       if (rc) {
-               printk(KERN_ERR "Error adding new key_tfm to list; rc = [%d]\n",
-                      rc);
-               goto out;
-       }
        (*tfm) = key_tfm->key_tfm;
        (*tfm_mutex) = &key_tfm->key_tfm_mutex;
 out: