Commit bd7b8290 authored by David Gstir's avatar David Gstir Committed by Theodore Ts'o
Browse files

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: default avatarDavid Gstir <david@sigma-star.at>
Signed-off-by: default avatarTheodore Ts'o <tytso@mit.edu>
parent 1400451f

fs/crypto/crypto.c

+8 −3
Original line number Diff line number Diff line
@@ -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);

}

fs/ext4/inode.c

+0 −1
Original line number Diff line number Diff line
@@ -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));

		}

fs/f2fs/data.c

+0 −1
Original line number Diff line number Diff line
@@ -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,

include/linux/fscrypto.h

+1 −1
Original line number Diff line number Diff line
@@ -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