From bd7b8290388dd58a8c0a3710b171e58ef952ca4d Mon Sep 17 00:00:00 2001 From: David Gstir Date: Tue, 6 Dec 2016 23:53:56 +0100 Subject: [PATCH] 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 ++++++++--- fs/ext4/inode.c | 1 - fs/f2fs/data.c | 1 - include/linux/fscrypto.h | 2 +- 4 files changed, 9 insertions(+), 6 deletions(-) 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); } diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index 1485ac273bfb..fb2b514f675b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -3744,7 +3744,6 @@ static int __ext4_block_zero_page_range(handle_t *handle, /* We expect the key to be set. */ BUG_ON(!fscrypt_has_encryption_key(inode)); BUG_ON(blocksize != PAGE_SIZE); - BUG_ON(!PageLocked(page)); WARN_ON_ONCE(fscrypt_decrypt_page(page->mapping->host, page, PAGE_SIZE, 0, page->index)); } diff --git a/fs/f2fs/data.c b/fs/f2fs/data.c index 435590c4b341..9f0ba90b92e4 100644 --- a/fs/f2fs/data.c +++ b/fs/f2fs/data.c @@ -1194,7 +1194,6 @@ int do_write_data_page(struct f2fs_io_info *fio) f2fs_wait_on_encrypted_page_writeback(F2FS_I_SB(inode), fio->old_blkaddr); retry_encrypt: - BUG_ON(!PageLocked(fio->page)); fio->encrypted_page = fscrypt_encrypt_page(inode, fio->page, PAGE_SIZE, 0, fio->page->index, diff --git a/include/linux/fscrypto.h b/include/linux/fscrypto.h index 2d9abfa22b94..188b4fa59cbf 100644 --- a/include/linux/fscrypto.h +++ b/include/linux/fscrypto.h @@ -80,7 +80,7 @@ struct fscrypt_name { /* * fscrypt superblock flags */ -#define FS_CFLG_INPLACE_ENCRYPTION (1U << 1) +#define FS_CFLG_OWN_PAGES (1U << 1) /* * crypto opertions for filesystems