9 files changed, 96 insertions, 167 deletions

diff --git a/fs/f2fs/crypto.c b/fs/f2fs/crypto.c
index c6d11229aee4..2c7819aebcc5 100644
--- a/fs/f2fs/crypto.c
+++ b/fs/f2fs/crypto.c
@@ -91,8 +91,6 @@ void f2fs_release_crypto_ctx(struct f2fs_crypto_ctx *ctx)
 	}
 	ctx->w.control_page = NULL;
 	if (ctx->flags & F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL) {
-		if (ctx->tfm)
-			crypto_free_tfm(ctx->tfm);
 		kmem_cache_free(f2fs_crypto_ctx_cachep, ctx);
 	} else {
 		spin_lock_irqsave(&f2fs_crypto_ctx_lock, flags);
@@ -113,7 +111,6 @@ void f2fs_release_crypto_ctx(struct f2fs_crypto_ctx *ctx)
 struct f2fs_crypto_ctx *f2fs_get_crypto_ctx(struct inode *inode)
 {
 	struct f2fs_crypto_ctx *ctx = NULL;
-	int res = 0;
 	unsigned long flags;
 	struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info;
 
@@ -138,56 +135,13 @@ struct f2fs_crypto_ctx *f2fs_get_crypto_ctx(struct inode *inode)
 	spin_unlock_irqrestore(&f2fs_crypto_ctx_lock, flags);
 	if (!ctx) {
 		ctx = kmem_cache_zalloc(f2fs_crypto_ctx_cachep, GFP_NOFS);
-		if (!ctx) {
-			res = -ENOMEM;
-			goto out;
-		}
+		if (!ctx)
+			return ERR_PTR(-ENOMEM);
 		ctx->flags |= F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
 	} else {
 		ctx->flags &= ~F2FS_CTX_REQUIRES_FREE_ENCRYPT_FL;
 	}
 	ctx->flags &= ~F2FS_WRITE_PATH_FL;
-
-	/*
-	 * Allocate a new Crypto API context if we don't already have
-	 * one or if it isn't the right mode.
-	 */
-	if (ctx->tfm && (ctx->mode != ci->ci_data_mode)) {
-		crypto_free_tfm(ctx->tfm);
-		ctx->tfm = NULL;
-		ctx->mode = F2FS_ENCRYPTION_MODE_INVALID;
-	}
-	if (!ctx->tfm) {
-		switch (ci->ci_data_mode) {
-		case F2FS_ENCRYPTION_MODE_AES_256_XTS:
-			ctx->tfm = crypto_ablkcipher_tfm(
-				crypto_alloc_ablkcipher("xts(aes)", 0, 0));
-			break;
-		case F2FS_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 = ci->ci_data_mode;
-	}
-	BUG_ON(ci->ci_size != f2fs_encryption_key_size(ci->ci_data_mode));
-
-out:
-	if (res) {
-		if (!IS_ERR_OR_NULL(ctx))
-			f2fs_release_crypto_ctx(ctx);
-		ctx = ERR_PTR(res);
-	}
 	return ctx;
 }
 
@@ -229,11 +183,8 @@ static void f2fs_crypto_destroy(void)
 {
 	struct f2fs_crypto_ctx *pos, *n;
 
-	list_for_each_entry_safe(pos, n, &f2fs_free_crypto_ctxs, free_list) {
-		if (pos->tfm)
-			crypto_free_tfm(pos->tfm);
+	list_for_each_entry_safe(pos, n, &f2fs_free_crypto_ctxs, free_list)
 		kmem_cache_free(f2fs_crypto_ctx_cachep, pos);
-	}
 	INIT_LIST_HEAD(&f2fs_free_crypto_ctxs);
 	if (f2fs_bounce_page_pool)
 		mempool_destroy(f2fs_bounce_page_pool);
@@ -383,32 +334,11 @@ static int f2fs_page_crypto(struct f2fs_crypto_ctx *ctx,
 	struct ablkcipher_request *req = NULL;
 	DECLARE_F2FS_COMPLETION_RESULT(ecr);
 	struct scatterlist dst, src;
-	struct f2fs_inode_info *fi = F2FS_I(inode);
-	struct crypto_ablkcipher *atfm = __crypto_ablkcipher_cast(ctx->tfm);
+	struct f2fs_crypt_info *ci = F2FS_I(inode)->i_crypt_info;
+	struct crypto_ablkcipher *tfm = ci->ci_ctfm;
 	int res = 0;
 
-	BUG_ON(!ctx->tfm);
-	BUG_ON(ctx->mode != fi->i_crypt_info->ci_data_mode);
-
-	if (ctx->mode != F2FS_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, fi->i_crypt_info->ci_raw,
-					fi->i_crypt_info->ci_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",
diff --git a/fs/f2fs/crypto_fname.c b/fs/f2fs/crypto_fname.c
index 016c4b63b53d..81852cca7bbe 100644
--- a/fs/f2fs/crypto_fname.c
+++ b/fs/f2fs/crypto_fname.c
@@ -249,52 +249,6 @@ static int digest_decode(const char *src, int len, char *dst)
 	return cp - dst;
 }
 
-int f2fs_setup_fname_crypto(struct inode *inode)
-{
-	struct f2fs_inode_info *fi = F2FS_I(inode);
-	struct f2fs_crypt_info *ci = fi->i_crypt_info;
-	struct crypto_ablkcipher *ctfm;
-	int res;
-
-	/* Check if the crypto policy is set on the inode */
-	res = f2fs_encrypted_inode(inode);
-	if (res == 0)
-		return 0;
-
-	res = f2fs_get_encryption_info(inode);
-	if (res < 0)
-		return res;
-	ci = fi->i_crypt_info;
-
-	if (!ci || ci->ci_ctfm)
-		return 0;
-
-	if (ci->ci_filename_mode != F2FS_ENCRYPTION_MODE_AES_256_CTS) {
-		printk_once(KERN_WARNING "f2fs: unsupported key mode %d\n",
-				ci->ci_filename_mode);
-		return -ENOKEY;
-	}
-
-	ctfm = crypto_alloc_ablkcipher("cts(cbc(aes))", 0, 0);
-	if (!ctfm || IS_ERR(ctfm)) {
-		res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
-		printk(KERN_DEBUG "%s: error (%d) allocating crypto tfm\n",
-				__func__, res);
-		return res;
-	}
-	crypto_ablkcipher_clear_flags(ctfm, ~0);
-	crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
-			     CRYPTO_TFM_REQ_WEAK_KEY);
-
-	res = crypto_ablkcipher_setkey(ctfm, ci->ci_raw, ci->ci_size);
-	if (res) {
-		crypto_free_ablkcipher(ctfm);
-		return -EIO;
-	}
-	ci->ci_ctfm = ctfm;
-	return 0;
-}
-
 /**
  * f2fs_fname_crypto_round_up() -
  *
@@ -427,7 +381,7 @@ int f2fs_fname_setup_filename(struct inode *dir, const struct qstr *iname,
 		fname->disk_name.len = iname->len;
 		return 0;
 	}
-	ret = f2fs_setup_fname_crypto(dir);
+	ret = f2fs_get_encryption_info(dir);
 	if (ret)
 		return ret;
 	ci = F2FS_I(dir)->i_crypt_info;
diff --git a/fs/f2fs/crypto_key.c b/fs/f2fs/crypto_key.c
index 8a10569a8b7c..95b8f936f00b 100644
--- a/fs/f2fs/crypto_key.c
+++ b/fs/f2fs/crypto_key.c
@@ -87,20 +87,31 @@ out:
 	return res;
 }
 
-void f2fs_free_encryption_info(struct inode *inode)
+static void f2fs_free_crypt_info(struct f2fs_crypt_info *ci)
 {
-	struct f2fs_inode_info *fi = F2FS_I(inode);
-	struct f2fs_crypt_info *ci = fi->i_crypt_info;
-
 	if (!ci)
 		return;
 
 	if (ci->ci_keyring_key)
 		key_put(ci->ci_keyring_key);
 	crypto_free_ablkcipher(ci->ci_ctfm);
-	memzero_explicit(&ci->ci_raw, sizeof(ci->ci_raw));
 	kmem_cache_free(f2fs_crypt_info_cachep, ci);
-	fi->i_crypt_info = NULL;
+}
+
+void f2fs_free_encryption_info(struct inode *inode, struct f2fs_crypt_info *ci)
+{
+	struct f2fs_inode_info *fi = F2FS_I(inode);
+	struct f2fs_crypt_info *prev;
+
+	if (ci == NULL)
+		ci = ACCESS_ONCE(fi->i_crypt_info);
+	if (ci == NULL)
+		return;
+	prev = cmpxchg(&fi->i_crypt_info, ci, NULL);
+	if (prev != ci)
+		return;
+
+	f2fs_free_crypt_info(ci);
 }
 
 int _f2fs_get_encryption_info(struct inode *inode)
@@ -113,17 +124,23 @@ int _f2fs_get_encryption_info(struct inode *inode)
 	struct f2fs_encryption_key *master_key;
 	struct f2fs_encryption_context ctx;
 	struct user_key_payload *ukp;
+	struct crypto_ablkcipher *ctfm;
+	const char *cipher_str;
+	char raw_key[F2FS_MAX_KEY_SIZE];
+	char mode;
 	int res;
 
 	res = f2fs_crypto_initialize();
 	if (res)
 		return res;
-
-	if (fi->i_crypt_info) {
-		if (!fi->i_crypt_info->ci_keyring_key ||
-			key_validate(fi->i_crypt_info->ci_keyring_key) == 0)
+retry:
+	crypt_info = ACCESS_ONCE(fi->i_crypt_info);
+	if (crypt_info) {
+		if (!crypt_info->ci_keyring_key ||
+				key_validate(crypt_info->ci_keyring_key) == 0)
 			return 0;
-		f2fs_free_encryption_info(inode);
+		f2fs_free_encryption_info(inode, crypt_info);
+		goto retry;
 	}
 
 	res = f2fs_getxattr(inode, F2FS_XATTR_INDEX_ENCRYPTION,
@@ -143,18 +160,30 @@ int _f2fs_get_encryption_info(struct inode *inode)
 	crypt_info->ci_data_mode = ctx.contents_encryption_mode;
 	crypt_info->ci_filename_mode = ctx.filenames_encryption_mode;
 	crypt_info->ci_ctfm = NULL;
+	crypt_info->ci_keyring_key = NULL;
 	memcpy(crypt_info->ci_master_key, ctx.master_key_descriptor,
 				sizeof(crypt_info->ci_master_key));
 	if (S_ISREG(inode->i_mode))
-		crypt_info->ci_size =
-			f2fs_encryption_key_size(crypt_info->ci_data_mode);
+		mode = crypt_info->ci_data_mode;
 	else if (S_ISDIR(inode->i_mode) || S_ISLNK(inode->i_mode))
-		crypt_info->ci_size =
-			f2fs_encryption_key_size(crypt_info->ci_filename_mode);
+		mode = crypt_info->ci_filename_mode;
 	else
 		BUG();
 
-	BUG_ON(!crypt_info->ci_size);
+	switch (mode) {
+	case F2FS_ENCRYPTION_MODE_AES_256_XTS:
+		cipher_str = "xts(aes)";
+		break;
+	case F2FS_ENCRYPTION_MODE_AES_256_CTS:
+		cipher_str = "cts(cbc(aes))";
+		break;
+	default:
+		printk_once(KERN_WARNING
+			    "f2fs: unsupported key mode %d (ino %u)\n",
+			    mode, (unsigned) inode->i_ino);
+		res = -ENOKEY;
+		goto out;
+	}
 
 	memcpy(full_key_descriptor, F2FS_KEY_DESC_PREFIX,
 					F2FS_KEY_DESC_PREFIX_SIZE);
@@ -169,6 +198,7 @@ int _f2fs_get_encryption_info(struct inode *inode)
 		keyring_key = NULL;
 		goto out;
 	}
+	crypt_info->ci_keyring_key = keyring_key;
 	BUG_ON(keyring_key->type != &key_type_logon);
 	ukp = ((struct user_key_payload *)keyring_key->payload.data);
 	if (ukp->datalen != sizeof(struct f2fs_encryption_key)) {
@@ -180,19 +210,40 @@ int _f2fs_get_encryption_info(struct inode *inode)
 				F2FS_KEY_DERIVATION_NONCE_SIZE);
 	BUG_ON(master_key->size != F2FS_AES_256_XTS_KEY_SIZE);
 	res = f2fs_derive_key_aes(ctx.nonce, master_key->raw,
-					crypt_info->ci_raw);
-out:
-	if (res < 0) {
-		if (res == -ENOKEY)
-			res = 0;
-		kmem_cache_free(f2fs_crypt_info_cachep, crypt_info);
-	} else {
-		fi->i_crypt_info = crypt_info;
-		crypt_info->ci_keyring_key = keyring_key;
-		keyring_key = NULL;
+				  raw_key);
+	if (res)
+		goto out;
+
+	ctfm = crypto_alloc_ablkcipher(cipher_str, 0, 0);
+	if (!ctfm || IS_ERR(ctfm)) {
+		res = ctfm ? PTR_ERR(ctfm) : -ENOMEM;
+		printk(KERN_DEBUG
+		       "%s: error %d (inode %u) allocating crypto tfm\n",
+		       __func__, res, (unsigned) inode->i_ino);
+		goto out;
 	}
-	if (keyring_key)
-		key_put(keyring_key);
+	crypt_info->ci_ctfm = ctfm;
+	crypto_ablkcipher_clear_flags(ctfm, ~0);
+	crypto_tfm_set_flags(crypto_ablkcipher_tfm(ctfm),
+			     CRYPTO_TFM_REQ_WEAK_KEY);
+	res = crypto_ablkcipher_setkey(ctfm, raw_key,
+					f2fs_encryption_key_size(mode));
+	if (res)
+		goto out;
+
+	memzero_explicit(raw_key, sizeof(raw_key));
+	if (cmpxchg(&fi->i_crypt_info, NULL, crypt_info) != NULL) {
+		f2fs_free_crypt_info(crypt_info);
+		goto retry;
+	}
+	return 0;
+
+out:
+	if (res == -ENOKEY && !S_ISREG(inode->i_mode))
+		res = 0;
+
+	f2fs_free_crypt_info(crypt_info);
+	memzero_explicit(raw_key, sizeof(raw_key));
 	return res;
 }
 
diff --git a/fs/f2fs/dir.c b/fs/f2fs/dir.c
index 3e923763daca..a34ebd8312ab 100644
--- a/fs/f2fs/dir.c
+++ b/fs/f2fs/dir.c
@@ -825,11 +825,11 @@ static int f2fs_readdir(struct file *file, struct dir_context *ctx)
 	struct f2fs_str fstr = FSTR_INIT(NULL, 0);
 	int err = 0;
 
-	err = f2fs_setup_fname_crypto(inode);
-	if (err)
-		return err;
-
 	if (f2fs_encrypted_inode(inode)) {
+		err = f2fs_get_encryption_info(inode);
+		if (err)
+			return err;
+
 		err = f2fs_fname_crypto_alloc_buffer(inode, F2FS_NAME_LEN,
 								&fstr);
 		if (err < 0)
diff --git a/fs/f2fs/f2fs.h b/fs/f2fs/f2fs.h
index 7e93fcf2df78..70cdf7b81e80 100644
--- a/fs/f2fs/f2fs.h
+++ b/fs/f2fs/f2fs.h
@@ -2016,7 +2016,7 @@ int f2fs_decrypt_one(struct inode *, struct page *);
 void f2fs_end_io_crypto_work(struct f2fs_crypto_ctx *, struct bio *);
 
 /* crypto_key.c */
-void f2fs_free_encryption_info(struct inode *);
+void f2fs_free_encryption_info(struct inode *, struct f2fs_crypt_info *);
 int _f2fs_get_encryption_info(struct inode *inode);
 
 /* crypto_fname.c */
@@ -2051,7 +2051,6 @@ static inline int f2fs_get_encryption_info(struct inode *inode)
 	return 0;
 }
 
-int f2fs_setup_fname_crypto(struct inode *);
 void f2fs_fname_crypto_free_buffer(struct f2fs_str *);
 int f2fs_fname_setup_filename(struct inode *, const struct qstr *,
 				int lookup, struct f2fs_filename *);
@@ -2065,8 +2064,6 @@ static inline void f2fs_exit_crypto(void) { }
 
 static inline int f2fs_has_encryption_key(struct inode *i) { return 0; }
 static inline int f2fs_get_encryption_info(struct inode *i) { return 0; }
-
-static inline int f2fs_setup_fname_crypto(struct inode *i) { return 0; }
 static inline void f2fs_fname_crypto_free_buffer(struct f2fs_str *p) { }
 
 static inline int f2fs_fname_setup_filename(struct inode *dir,
diff --git a/fs/f2fs/f2fs_crypto.h b/fs/f2fs/f2fs_crypto.h
index e33cec9c3f36..be59d91928fd 100644
--- a/fs/f2fs/f2fs_crypto.h
+++ b/fs/f2fs/f2fs_crypto.h
@@ -75,13 +75,11 @@ struct f2fs_encryption_key {
 } __attribute__((__packed__));
 
 struct f2fs_crypt_info {
-	unsigned char	ci_size;
 	char		ci_data_mode;
 	char		ci_filename_mode;
 	char		ci_flags;
 	struct crypto_ablkcipher *ci_ctfm;
 	struct key	*ci_keyring_key;
-	char		ci_raw[F2FS_MAX_KEY_SIZE];
 	char		ci_master_key[F2FS_KEY_DESCRIPTOR_SIZE];
 };
 
@@ -90,7 +88,6 @@ struct f2fs_crypt_info {
 #define F2FS_WRITE_PATH_FL			      0x00000004
 
 struct f2fs_crypto_ctx {
-	struct crypto_tfm *tfm;         /* Crypto API context */
 	union {
 		struct {
 			struct page *bounce_page;       /* Ciphertext page */
@@ -103,7 +100,6 @@ struct f2fs_crypto_ctx {
 		struct list_head free_list;     /* Free list */
 	};
 	char flags;                      /* Flags */
-	char mode;                       /* Encryption mode for tfm */
 };
 
 struct f2fs_completion_result {
diff --git a/fs/f2fs/inode.c b/fs/f2fs/inode.c
index ea6ba3bc8472..2550868dc651 100644
--- a/fs/f2fs/inode.c
+++ b/fs/f2fs/inode.c
@@ -364,7 +364,7 @@ no_delete:
 out_clear:
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
 	if (F2FS_I(inode)->i_crypt_info)
-		f2fs_free_encryption_info(inode);
+		f2fs_free_encryption_info(inode, F2FS_I(inode)->i_crypt_info);
 #endif
 	clear_inode(inode);
 }
diff --git a/fs/f2fs/namei.c b/fs/f2fs/namei.c
index a316783de8c9..55d0d27dfdf2 100644
--- a/fs/f2fs/namei.c
+++ b/fs/f2fs/namei.c
@@ -364,7 +364,7 @@ static int f2fs_symlink(struct inode *dir, struct dentry *dentry,
 		if (err)
 			goto err_out;
 
-		err = f2fs_setup_fname_crypto(inode);
+		err = f2fs_get_encryption_info(inode);
 		if (err)
 			goto err_out;
 
@@ -929,7 +929,7 @@ static void *f2fs_encrypted_follow_link(struct dentry *dentry,
 	u32 max_size = inode->i_sb->s_blocksize;
 	int res;
 
-	res = f2fs_setup_fname_crypto(inode);
+	res = f2fs_get_encryption_info(inode);
 	if (res)
 		return ERR_PTR(res);
 
diff --git a/fs/f2fs/super.c b/fs/f2fs/super.c
index d4cd04dc3314..8b5f5fb8f5cb 100644
--- a/fs/f2fs/super.c
+++ b/fs/f2fs/super.c
@@ -449,7 +449,8 @@ static int f2fs_drop_inode(struct inode *inode)
 
 #ifdef CONFIG_F2FS_FS_ENCRYPTION
 			if (F2FS_I(inode)->i_crypt_info)
-				f2fs_free_encryption_info(inode);
+				f2fs_free_encryption_info(inode,
+					F2FS_I(inode)->i_crypt_info);
 #endif
 			spin_lock(&inode->i_lock);
 		}