From af440f52927e4b6941aa94e3cfc698adb0f22663 Mon Sep 17 00:00:00 2001 From: Eric Sandeen Date: Wed, 6 Feb 2008 01:38:37 -0800 Subject: ecryptfs: check for existing key_tfm at mount time Jeff Moyer pointed out that a mount; umount loop of ecryptfs, with the same cipher & other mount options, created a new ecryptfs_key_tfm_cache item each time, and the cache could grow quite large this way. Looking at this with mhalcrow, we saw that ecryptfs_parse_options() unconditionally called ecryptfs_add_new_key_tfm(), which is what was adding these items. Refactor ecryptfs_get_tfm_and_mutex_for_cipher_name() to create a new helper function, ecryptfs_tfm_exists(), which checks for the cipher on the cached key_tfm_list, and sets a pointer to it if it exists. This can then be called from ecryptfs_parse_options(), and new key_tfm's can be added only when a cached one is not found. With list locking changes suggested by akpm. Signed-off-by: Eric Sandeen Cc: Michael Halcrow Cc: Jeff Moyer Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds --- fs/ecryptfs/main.c | 10 +++++++--- 1 file changed, 7 insertions(+), 3 deletions(-) (limited to 'fs/ecryptfs/main.c') diff --git a/fs/ecryptfs/main.c b/fs/ecryptfs/main.c index dc620fc16595..778c420e4cac 100644 --- a/fs/ecryptfs/main.c +++ b/fs/ecryptfs/main.c @@ -410,9 +410,13 @@ static int ecryptfs_parse_options(struct super_block *sb, char *options) if (!cipher_key_bytes_set) { mount_crypt_stat->global_default_cipher_key_size = 0; } - rc = ecryptfs_add_new_key_tfm( - NULL, mount_crypt_stat->global_default_cipher_name, - mount_crypt_stat->global_default_cipher_key_size); + mutex_lock(&key_tfm_list_mutex); + if (!ecryptfs_tfm_exists(mount_crypt_stat->global_default_cipher_name, + NULL)) + rc = ecryptfs_add_new_key_tfm( + NULL, mount_crypt_stat->global_default_cipher_name, + mount_crypt_stat->global_default_cipher_key_size); + mutex_unlock(&key_tfm_list_mutex); if (rc) { printk(KERN_ERR "Error attempting to initialize cipher with " "name = [%s] and key size = [%td]; rc = [%d]\n", -- cgit v1.2.3