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ext4 crypto: use slab caches

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Use slab caches the ext4_crypto_ctx and ext4_crypt_info structures for
slighly better memory efficiency and debuggability.

Signed-off-by: Theodore Ts'o <tytso@mit.edu>
This commit is contained in:
Theodore Ts'o 2015-05-18 13:19:47 -04:00
parent f5aed2c2a8
commit 8ee0371470
3 changed files with 39 additions and 34 deletions
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60
fs/ext4/crypto.c
View file

@ -55,6 +55,9 @@ static mempool_t *ext4_bounce_page_pool;
static LIST_HEAD(ext4_free_crypto_ctxs);
static DEFINE_SPINLOCK(ext4_crypto_ctx_lock);
static struct kmem_cache *ext4_crypto_ctx_cachep;
struct kmem_cache *ext4_crypt_info_cachep;
/**
* ext4_release_crypto_ctx() - Releases an encryption context
* @ctx: The encryption context to release.
@ -79,7 +82,7 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
if (ctx->flags & EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL) {
if (ctx->tfm)
crypto_free_tfm(ctx->tfm);
kfree(ctx);
kmem_cache_free(ext4_crypto_ctx_cachep, ctx);
} else {
spin_lock_irqsave(&ext4_crypto_ctx_lock, flags);
list_add(&ctx->free_list, &ext4_free_crypto_ctxs);
@ -87,23 +90,6 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
}
}
/**
* ext4_alloc_and_init_crypto_ctx() - Allocates and inits an encryption context
* @mask: The allocation mask.
*
* Return: An allocated and initialized encryption context on success. An error
* value or NULL otherwise.
*/
static struct ext4_crypto_ctx *ext4_alloc_and_init_crypto_ctx(gfp_t mask)
{
struct ext4_crypto_ctx *ctx = kzalloc(sizeof(struct ext4_crypto_ctx),
mask);
if (!ctx)
return ERR_PTR(-ENOMEM);
return ctx;
}
/**
* ext4_get_crypto_ctx() - Gets an encryption context
* @inode: The inode for which we are doing the crypto
@ -121,8 +107,6 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
BUG_ON(ci == NULL);
if (!ext4_read_workqueue)
ext4_init_crypto();
/*
* We first try getting the ctx from a free list because in
@ -141,9 +125,9 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
list_del(&ctx->free_list);
spin_unlock_irqrestore(&ext4_crypto_ctx_lock, flags);
if (!ctx) {
ctx = ext4_alloc_and_init_crypto_ctx(GFP_NOFS);
if (IS_ERR(ctx)) {
res = PTR_ERR(ctx);
ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
if (!ctx) {
res = -ENOMEM;
goto out;
}
ctx->flags |= EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
@ -217,7 +201,7 @@ void ext4_exit_crypto(void)
}
if (pos->tfm)
crypto_free_tfm(pos->tfm);
kfree(pos);
kmem_cache_free(ext4_crypto_ctx_cachep, pos);
}
INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
if (ext4_bounce_page_pool)
@ -226,6 +210,12 @@ void ext4_exit_crypto(void)
if (ext4_read_workqueue)
destroy_workqueue(ext4_read_workqueue);
ext4_read_workqueue = NULL;
if (ext4_crypto_ctx_cachep)
kmem_cache_destroy(ext4_crypto_ctx_cachep);
ext4_crypto_ctx_cachep = NULL;
if (ext4_crypt_info_cachep)
kmem_cache_destroy(ext4_crypt_info_cachep);
ext4_crypt_info_cachep = NULL;
}
/**
@ -238,23 +228,31 @@ void ext4_exit_crypto(void)
*/
int ext4_init_crypto(void)
{
int i, res;
int i, res = -ENOMEM;
mutex_lock(&crypto_init);
if (ext4_read_workqueue)
goto already_initialized;
ext4_read_workqueue = alloc_workqueue("ext4_crypto", WQ_HIGHPRI, 0);
if (!ext4_read_workqueue) {
res = -ENOMEM;
if (!ext4_read_workqueue)
goto fail;
ext4_crypto_ctx_cachep = KMEM_CACHE(ext4_crypto_ctx,
SLAB_RECLAIM_ACCOUNT);
if (!ext4_crypto_ctx_cachep)
goto fail;
ext4_crypt_info_cachep = KMEM_CACHE(ext4_crypt_info,
SLAB_RECLAIM_ACCOUNT);
if (!ext4_crypt_info_cachep)
goto fail;
}
for (i = 0; i < num_prealloc_crypto_ctxs; i++) {
struct ext4_crypto_ctx *ctx;
ctx = ext4_alloc_and_init_crypto_ctx(GFP_KERNEL);
if (IS_ERR(ctx)) {
res = PTR_ERR(ctx);
ctx = kmem_cache_zalloc(ext4_crypto_ctx_cachep, GFP_NOFS);
if (!ctx) {
res = -ENOMEM;
goto fail;
}
list_add(&ctx->free_list, &ext4_free_crypto_ctxs);

12
fs/ext4/crypto_key.c
View file

@ -96,7 +96,7 @@ void ext4_free_encryption_info(struct inode *inode)
key_put(ci->ci_keyring_key);
crypto_free_ablkcipher(ci->ci_ctfm);
memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
kfree(ci);
kmem_cache_free(ext4_crypt_info_cachep, ci);
ei->i_crypt_info = NULL;
}
@ -113,6 +113,12 @@ int _ext4_get_encryption_info(struct inode *inode)
struct ext4_sb_info *sbi = EXT4_SB(inode->i_sb);
int res;
if (!ext4_read_workqueue) {
res = ext4_init_crypto();
if (res)
return res;
}
if (ei->i_crypt_info) {
if (!ei->i_crypt_info->ci_keyring_key ||
key_validate(ei->i_crypt_info->ci_keyring_key) == 0)
@ -134,7 +140,7 @@ int _ext4_get_encryption_info(struct inode *inode)
return -EINVAL;
res = 0;
crypt_info = kmalloc(sizeof(struct ext4_crypt_info), GFP_KERNEL);
crypt_info = kmem_cache_alloc(ext4_crypt_info_cachep, GFP_KERNEL);
if (!crypt_info)
return -ENOMEM;
@ -188,7 +194,7 @@ int _ext4_get_encryption_info(struct inode *inode)
if (res < 0) {
if (res == -ENOKEY)
res = 0;
kfree(crypt_info);
kmem_cache_free(ext4_crypt_info_cachep, crypt_info);
} else {
ei->i_crypt_info = crypt_info;
crypt_info->ci_keyring_key = keyring_key;

1
fs/ext4/ext4.h
View file

@ -2059,6 +2059,7 @@ int ext4_get_policy(struct inode *inode,
struct ext4_encryption_policy *policy);
/* crypto.c */
extern struct kmem_cache *ext4_crypt_info_cachep;
bool ext4_valid_contents_enc_mode(uint32_t mode);
uint32_t ext4_validate_encryption_key_size(uint32_t mode, uint32_t size);
extern struct workqueue_struct *ext4_read_workqueue;