From bd7b8290388dd58a8c0a3710b171e58ef952ca4d Mon Sep 17 00:00:00 2001 From: David Gstir Date: Tue, 6 Dec 2016 23:53:56 +0100 Subject: fscrypt: Cleanup page locking requirements for fscrypt_{decrypt,encrypt}_page() Rename the FS_CFLG_INPLACE_ENCRYPTION flag to FS_CFLG_OWN_PAGES which, when set, indicates that the fs uses pages under its own control as opposed to writeback pages which require locking and a bounce buffer for encryption. Signed-off-by: David Gstir Signed-off-by: Theodore Ts'o --- fs/crypto/crypto.c | 11 ++++++++--- 1 file changed, 8 insertions(+), 3 deletions(-) (limited to 'fs/crypto') diff --git a/fs/crypto/crypto.c b/fs/crypto/crypto.c index 8c104e712bb2..5ffc59436397 100644 --- a/fs/crypto/crypto.c +++ b/fs/crypto/crypto.c @@ -238,7 +238,7 @@ static struct page *alloc_bounce_page(struct fscrypt_ctx *ctx, gfp_t gfp_flags) * fscrypt_restore_control_page() on the returned ciphertext page to * release the bounce buffer and the encryption context. * - * In-place encryption is used by setting the FS_CFLG_INPLACE_ENCRYPTION flag in + * In-place encryption is used by setting the FS_CFLG_OWN_PAGES flag in * fscrypt_operations. Here, the input-page is returned with its content * encrypted. * @@ -258,7 +258,7 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, BUG_ON(len % FS_CRYPTO_BLOCK_SIZE != 0); - if (inode->i_sb->s_cop->flags & FS_CFLG_INPLACE_ENCRYPTION) { + if (inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES) { /* with inplace-encryption we just encrypt the page */ err = do_page_crypto(inode, FS_ENCRYPT, lblk_num, page, ciphertext_page, @@ -269,6 +269,8 @@ struct page *fscrypt_encrypt_page(const struct inode *inode, return ciphertext_page; } + BUG_ON(!PageLocked(page)); + ctx = fscrypt_get_ctx(inode, gfp_flags); if (IS_ERR(ctx)) return (struct page *)ctx; @@ -301,7 +303,7 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); * fscrypt_decrypt_page() - Decrypts a page in-place * @inode: The corresponding inode for the page to decrypt. * @page: The page to decrypt. Must be locked in case - * it is a writeback page. + * it is a writeback page (FS_CFLG_OWN_PAGES unset). * @len: Number of bytes in @page to be decrypted. * @offs: Start of data in @page. * @lblk_num: Logical block number. @@ -315,6 +317,9 @@ EXPORT_SYMBOL(fscrypt_encrypt_page); int fscrypt_decrypt_page(const struct inode *inode, struct page *page, unsigned int len, unsigned int offs, u64 lblk_num) { + if (!(inode->i_sb->s_cop->flags & FS_CFLG_OWN_PAGES)) + BUG_ON(!PageLocked(page)); + return do_page_crypto(inode, FS_DECRYPT, lblk_num, page, page, len, offs, GFP_NOFS); } -- cgit v1.2.3