diff options
| -rw-r--r-- | fs/crypto/crypto.c | 93 | ||||
| -rw-r--r-- | include/linux/fscrypto.h | 8 |
2 files changed, 56 insertions, 45 deletions
diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index f287f76cc906..8c104e712bb2 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -147,9 +147,9 @@ typedef enum { } fscrypt_direction_t; static int do_page_crypto(const struct inode *inode, - fscrypt_direction_t rw, pgoff_t index, + fscrypt_direction_t rw, u64 lblk_num, struct page *src_page, struct page *dest_page, - unsigned int src_len, unsigned int src_offset, + unsigned int len, unsigned int offs, gfp_t gfp_flags) { struct { @@ -163,6 +163,8 @@ static int do_page_crypto(const struct inode *inode, struct crypto_skcipher *tfm = ci->ci_ctfm; int res = 0; + BUG_ON(len == 0); + req = skcipher_request_alloc(tfm, gfp_flags); if (!req) { printk_ratelimited(KERN_ERR @@ -176,14 +178,14 @@ static int do_page_crypto(const struct inode *inode, page_crypt_complete, &ecr); BUILD_BUG_ON(sizeof(xts_tweak) != FS_XTS_TWEAK_SIZE); - xts_tweak.index = cpu_to_le64(index); + xts_tweak.index = cpu_to_le64(lblk_num); memset(xts_tweak.padding, 0, sizeof(xts_tweak.padding)); sg_init_table(&dst, 1); - sg_set_page(&dst, dest_page, src_len, src_offset); + sg_set_page(&dst, dest_page, len, offs); sg_init_table(&src, 1); - sg_set_page(&src, src_page, src_len, src_offset); - skcipher_request_set_crypt(req, &src, &dst, src_len, &xts_tweak); + sg_set_page(&src, src_page, len, offs); + skcipher_request_set_crypt(req, &src, &dst, len, &xts_tweak); if (rw == FS_DECRYPT) res = crypto_skcipher_decrypt(req); else @@ -214,44 +216,53 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags) /** * fscypt_encrypt_page() - Encrypts a page - * @inode: The inode for which the encryption should take place - * @plaintext_page: The page to encrypt. Must be locked. - * @plaintext_len: Length of plaintext within page - * @plaintext_offset: Offset of plaintext within page - * @index: Index for encryption. This is mainly the page index, but - * but might be different for multiple calls on same page. - * @gfp_flags: The gfp flag for memory allocation + * @inode: The inode for which the encryption should take place + * @page: The page to encrypt. Must be locked for bounce-page + * encryption. + * @len: Length of data to encrypt in @page and encrypted + * data in returned page. + * @offs: Offset of data within @page and returned + * page holding encrypted data. + * @lblk_num: Logical block number. This must be unique for multiple + * calls with same inode, except when overwriting + * previously written data. + * @gfp_flags: The gfp flag for memory allocation * - * Encrypts plaintext_page using the ctx encryption context. If - * the filesystem supports it, encryption is performed in-place, otherwise a - * new ciphertext_page is allocated and returned. + * Encrypts @page using the ctx encryption context. Performs encryption + * either in-place or into a newly allocated bounce page. + * Called on the page write path. * - * Called on the page write path. The caller must call + * Bounce page allocation is the default. + * In this case, the contents of @page are encrypted and stored in an + * allocated bounce page. @page has to be locked and the caller must call * fscrypt_restore_control_page() on the returned ciphertext page to * release the bounce buffer and the encryption context. * - * Return: An allocated page with the encrypted content on success. Else, an + * In-place encryption is used by setting the FS_CFLG_INPLACE_ENCRYPTION flag in + * fscrypt_operations. Here, the input-page is returned with its content + * encrypted. + * + * Return: A page with the encrypted content on success. Else, an * error value or NULL. */ struct page *fscrypt_encrypt_page(const struct inode *inode, - struct page *plaintext_page, - unsigned int plaintext_len, - unsigned int plaintext_offset, - pgoff_t index, gfp_t gfp_flags) + struct page *page, + unsigned int len, + unsigned int offs, + u64 lblk_num, gfp_t gfp_flags) { struct fscrypt_ctx *ctx; - struct page *ciphertext_page = plaintext_page; + struct page *ciphertext_page = page; int err; - BUG_ON(plaintext_len % FS_CRYPTO_BLOCK_SIZE != 0); + BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0); if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) { /* with inplace-encryption we just encrypt the page */ - err = do_page_crypto(inode, FS_ENCRYPT, index, - plaintext_page, ciphertext_page, - plaintext_len, plaintext_offset, - gfp_flags); + err = do_page_crypto(inode, FS_ENCRYPT, lblk_num, + page, ciphertext_page, + len, offs, gfp_flags); if (err) return ERR_PTR(err); @@ -267,11 +278,10 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, if (IS_ERR(ciphertext_page)) goto errout; - ctx->w.control_page = plaintext_page; - err = do_page_crypto(inode, FS_ENCRYPT, index, - plaintext_page, ciphertext_page, - plaintext_len, plaintext_offset, - gfp_flags); + ctx->w.control_page = page; + err = do_page_crypto(inode, FS_ENCRYPT, lblk_num, + page, ciphertext_page, + len, offs, gfp_flags); if (err) { ciphertext_page = ERR_PTR(err); goto errout; @@ -289,11 +299,12 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); /** * fscrypt_decrypt_page() - Decrypts a page in-place - * @inode: Encrypted inode to decrypt. - * @page: The page to decrypt. Must be locked. - * @len: Number of bytes in @page to be decrypted. - * @offs: Start of data in @page. - * @index: Index for encryption. + * @inode: The corresponding inode for the page to decrypt. + * @page: The page to decrypt. Must be locked in case + * it is a writeback page. + * @len: Number of bytes in @page to be decrypted. + * @offs: Start of data in @page. + * @lblk_num: Logical block number. * * Decrypts page in-place using the ctx encryption context. * @@ -302,10 +313,10 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); * Return: Zero on success, non-zero otherwise. */ int fscrypt_decrypt_page(const struct inode *inode, struct page *page, - unsigned int len, unsigned int offs, pgoff_t index) + unsigned int len, unsigned int offs, u64 lblk_num) { - return do_page_crypto(inode, FS_DECRYPT, index, page, page, len, offs, - GFP_NOFS); + return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len, + offs, GFP_NOFS); } EXPORT_SYMBOL(fscrypt_decrypt_page); diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h index 42ef82d60790..2d9abfa22b94 100644 --- a/include/linux/fscrypto.h +++ b/include/linux/fscrypto.h @@ -173,9 +173,9 @@ extern struct fscrypt_ctx *fscrypt_get_ctx(const struct inode *, gfp_t); extern void fscrypt_release_ctx(struct fscrypt_ctx *); extern struct page *fscrypt_encrypt_page(const struct inode *, struct page *, unsigned int, unsigned int, - pgoff_t, gfp_t); + u64, gfp_t); extern int fscrypt_decrypt_page(const struct inode *, struct page *, unsigned int, - unsigned int, pgoff_t); + unsigned int, u64); extern void fscrypt_decrypt_bio_pages(struct fscrypt_ctx *, struct bio *); extern void fscrypt_pullback_bio_page(struct page **, bool); extern void fscrypt_restore_control_page(struct page *); @@ -221,14 +221,14 @@ static inline struct page *fscrypt_notsupp_encrypt_page(const struct inode *i, struct page *p, unsigned int len, unsigned int offs, - pgoff_t index, gfp_t f) + u64 lblk_num, gfp_t f) { return ERR_PTR(-EOPNOTSUPP); } static inline int fscrypt_notsupp_decrypt_page(const struct inode *i, struct page *p, unsigned int len, unsigned int offs, - pgoff_t index) + u64 lblk_num) { return -EOPNOTSUPP; } |