Merge tag 'iwlwifi-for-kalle-2015-06-12' of https://git.kernel.org/pub/scm/linux...
[linux-2.6-block.git] / fs / ext4 / crypto.c
index 8ff15273ab0cc00663dd12497c97209368ff5b8e..45731558138c8e00cb3126f077bb0e9be7714d6f 100644 (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.
@@ -68,18 +71,12 @@ void ext4_release_crypto_ctx(struct ext4_crypto_ctx *ctx)
 {
        unsigned long flags;
 
-       if (ctx->bounce_page) {
-               if (ctx->flags & EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL)
-                       __free_page(ctx->bounce_page);
-               else
-                       mempool_free(ctx->bounce_page, ext4_bounce_page_pool);
-               ctx->bounce_page = NULL;
-       }
-       ctx->control_page = NULL;
+       if (ctx->flags & EXT4_WRITE_PATH_FL && ctx->w.bounce_page)
+               mempool_free(ctx->w.bounce_page, ext4_bounce_page_pool);
+       ctx->w.bounce_page = NULL;
+       ctx->w.control_page = NULL;
        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 +84,6 @@ 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
@@ -118,10 +98,10 @@ struct ext4_crypto_ctx *ext4_get_crypto_ctx(struct inode *inode)
        struct ext4_crypto_ctx *ctx = NULL;
        int res = 0;
        unsigned long flags;
-       struct ext4_encryption_key *key = &EXT4_I(inode)->i_encryption_key;
+       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
 
-       if (!ext4_read_workqueue)
-               ext4_init_crypto();
+       if (ci == NULL)
+               return ERR_PTR(-ENOKEY);
 
        /*
         * We first try getting the ctx from a free list because in
@@ -140,50 +120,16 @@ 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;
        } else {
                ctx->flags &= ~EXT4_CTX_REQUIRES_FREE_ENCRYPT_FL;
        }
-
-       /* Allocate a new Crypto API context if we don't already have
-        * one or if it isn't the right mode. */
-       BUG_ON(key->mode == EXT4_ENCRYPTION_MODE_INVALID);
-       if (ctx->tfm && (ctx->mode != key->mode)) {
-               crypto_free_tfm(ctx->tfm);
-               ctx->tfm = NULL;
-               ctx->mode = EXT4_ENCRYPTION_MODE_INVALID;
-       }
-       if (!ctx->tfm) {
-               switch (key->mode) {
-               case EXT4_ENCRYPTION_MODE_AES_256_XTS:
-                       ctx->tfm = crypto_ablkcipher_tfm(
-                               crypto_alloc_ablkcipher("xts(aes)", 0, 0));
-                       break;
-               case EXT4_ENCRYPTION_MODE_AES_256_GCM:
-                       /* TODO(mhalcrow): AEAD w/ gcm(aes);
-                        * crypto_aead_setauthsize() */
-                       ctx->tfm = ERR_PTR(-ENOTSUPP);
-                       break;
-               default:
-                       BUG();
-               }
-               if (IS_ERR_OR_NULL(ctx->tfm)) {
-                       res = PTR_ERR(ctx->tfm);
-                       ctx->tfm = NULL;
-                       goto out;
-               }
-               ctx->mode = key->mode;
-       }
-       BUG_ON(key->size != ext4_encryption_key_size(key->mode));
-
-       /* There shouldn't be a bounce page attached to the crypto
-        * context at this point. */
-       BUG_ON(ctx->bounce_page);
+       ctx->flags &= ~EXT4_WRITE_PATH_FL;
 
 out:
        if (res) {
@@ -204,20 +150,8 @@ void ext4_exit_crypto(void)
 {
        struct ext4_crypto_ctx *pos, *n;
 
-       list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list) {
-               if (pos->bounce_page) {
-                       if (pos->flags &
-                           EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL) {
-                               __free_page(pos->bounce_page);
-                       } else {
-                               mempool_free(pos->bounce_page,
-                                            ext4_bounce_page_pool);
-                       }
-               }
-               if (pos->tfm)
-                       crypto_free_tfm(pos->tfm);
-               kfree(pos);
-       }
+       list_for_each_entry_safe(pos, n, &ext4_free_crypto_ctxs, free_list)
+               kmem_cache_free(ext4_crypto_ctx_cachep, pos);
        INIT_LIST_HEAD(&ext4_free_crypto_ctxs);
        if (ext4_bounce_page_pool)
                mempool_destroy(ext4_bounce_page_pool);
@@ -225,6 +159,12 @@ 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;
 }
 
 /**
@@ -237,23 +177,31 @@ 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);
@@ -317,32 +265,11 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
        struct ablkcipher_request *req = NULL;
        DECLARE_EXT4_COMPLETION_RESULT(ecr);
        struct scatterlist dst, src;
-       struct ext4_inode_info *ei = EXT4_I(inode);
-       struct crypto_ablkcipher *atfm = __crypto_ablkcipher_cast(ctx->tfm);
+       struct ext4_crypt_info *ci = EXT4_I(inode)->i_crypt_info;
+       struct crypto_ablkcipher *tfm = ci->ci_ctfm;
        int res = 0;
 
-       BUG_ON(!ctx->tfm);
-       BUG_ON(ctx->mode != ei->i_encryption_key.mode);
-
-       if (ctx->mode != EXT4_ENCRYPTION_MODE_AES_256_XTS) {
-               printk_ratelimited(KERN_ERR
-                                  "%s: unsupported crypto algorithm: %d\n",
-                                  __func__, ctx->mode);
-               return -ENOTSUPP;
-       }
-
-       crypto_ablkcipher_clear_flags(atfm, ~0);
-       crypto_tfm_set_flags(ctx->tfm, CRYPTO_TFM_REQ_WEAK_KEY);
-
-       res = crypto_ablkcipher_setkey(atfm, ei->i_encryption_key.raw,
-                                      ei->i_encryption_key.size);
-       if (res) {
-               printk_ratelimited(KERN_ERR
-                                  "%s: crypto_ablkcipher_setkey() failed\n",
-                                  __func__);
-               return res;
-       }
-       req = ablkcipher_request_alloc(atfm, GFP_NOFS);
+       req = ablkcipher_request_alloc(tfm, GFP_NOFS);
        if (!req) {
                printk_ratelimited(KERN_ERR
                                   "%s: crypto_request_alloc() failed\n",
@@ -384,6 +311,15 @@ static int ext4_page_crypto(struct ext4_crypto_ctx *ctx,
        return 0;
 }
 
+static struct page *alloc_bounce_page(struct ext4_crypto_ctx *ctx)
+{
+       ctx->w.bounce_page = mempool_alloc(ext4_bounce_page_pool, GFP_NOWAIT);
+       if (ctx->w.bounce_page == NULL)
+               return ERR_PTR(-ENOMEM);
+       ctx->flags |= EXT4_WRITE_PATH_FL;
+       return ctx->w.bounce_page;
+}
+
 /**
  * ext4_encrypt() - Encrypts a page
  * @inode:          The inode for which the encryption should take place
@@ -413,27 +349,17 @@ struct page *ext4_encrypt(struct inode *inode,
                return (struct page *) ctx;
 
        /* The encryption operation will require a bounce page. */
-       ciphertext_page = alloc_page(GFP_NOFS);
-       if (!ciphertext_page) {
-               /* This is a potential bottleneck, but at least we'll have
-                * forward progress. */
-               ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-                                                GFP_NOFS);
-               if (WARN_ON_ONCE(!ciphertext_page)) {
-                       ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-                                                        GFP_NOFS | __GFP_WAIT);
-               }
-               ctx->flags &= ~EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-       } else {
-               ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-       }
-       ctx->bounce_page = ciphertext_page;
-       ctx->control_page = plaintext_page;
+       ciphertext_page = alloc_bounce_page(ctx);
+       if (IS_ERR(ciphertext_page))
+               goto errout;
+       ctx->w.control_page = plaintext_page;
        err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, plaintext_page->index,
                               plaintext_page, ciphertext_page);
        if (err) {
+               ciphertext_page = ERR_PTR(err);
+       errout:
                ext4_release_crypto_ctx(ctx);
-               return ERR_PTR(err);
+               return ciphertext_page;
        }
        SetPagePrivate(ciphertext_page);
        set_page_private(ciphertext_page, (unsigned long)ctx);
@@ -470,8 +396,8 @@ int ext4_decrypt_one(struct inode *inode, struct page *page)
 
        struct ext4_crypto_ctx *ctx = ext4_get_crypto_ctx(inode);
 
-       if (!ctx)
-               return -ENOMEM;
+       if (IS_ERR(ctx))
+               return PTR_ERR(ctx);
        ret = ext4_decrypt(ctx, page);
        ext4_release_crypto_ctx(ctx);
        return ret;
@@ -493,21 +419,11 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
        if (IS_ERR(ctx))
                return PTR_ERR(ctx);
 
-       ciphertext_page = alloc_page(GFP_NOFS);
-       if (!ciphertext_page) {
-               /* This is a potential bottleneck, but at least we'll have
-                * forward progress. */
-               ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-                                                GFP_NOFS);
-               if (WARN_ON_ONCE(!ciphertext_page)) {
-                       ciphertext_page = mempool_alloc(ext4_bounce_page_pool,
-                                                        GFP_NOFS | __GFP_WAIT);
-               }
-               ctx->flags &= ~EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
-       } else {
-               ctx->flags |= EXT4_BOUNCE_PAGE_REQUIRES_FREE_ENCRYPT_FL;
+       ciphertext_page = alloc_bounce_page(ctx);
+       if (IS_ERR(ciphertext_page)) {
+               err = PTR_ERR(ciphertext_page);
+               goto errout;
        }
-       ctx->bounce_page = ciphertext_page;
 
        while (len--) {
                err = ext4_page_crypto(ctx, inode, EXT4_ENCRYPT, lblk,
@@ -529,6 +445,7 @@ int ext4_encrypted_zeroout(struct inode *inode, struct ext4_extent *ex)
                        goto errout;
                }
                err = submit_bio_wait(WRITE, bio);
+               bio_put(bio);
                if (err)
                        goto errout;
        }