Re: [PATCH v4 4/7] ext4: support direct I/O with fscrypt using blk-crypto

Jaegeuk Kim
2020-07-22T17:07:41Z

On 07/20, Satya Tangirala wrote:
> From: Eric Biggers <ebiggers@google.com>
>
> Wire up ext4 with fscrypt direct I/O support. direct I/O with fscrypt is
> only supported through blk-crypto (i.e. CONFIG_BLK_INLINE_ENCRYPTION must
> have been enabled, the 'inlinecrypt' mount option must have been specified,
> and either hardware inline encryption support must be present or
> CONFIG_BLK_INLINE_ENCYRPTION_FALLBACK must have been enabled). Further,
> direct I/O on encrypted files is only supported when I/O is aligned
> to the filesystem block size (which is *not* necessarily the same as the
> block device's block size).
>
> Signed-off-by: Eric Biggers <ebiggers@google.com>
> Co-developed-by: Satya Tangirala <satyat@google.com>
> Signed-off-by: Satya Tangirala <satyat@google.com>

Reviewed-by: Jaegeuk Kim <jaegeuk@kernel.org>

> ---
> fs/ext4/file.c | 10 ++++++----
> 1 file changed, 6 insertions(+), 4 deletions(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index 2a01e31a032c..d534f72675d9 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -36,9 +36,11 @@
> #include "acl.h"
> #include "truncate.h"
>
> -static bool ext4_dio_supported(struct inode *inode)
> +static bool ext4_dio_supported(struct kiocb *iocb, struct iov_iter *iter)
> {
> - if (IS_ENABLED(CONFIG_FS_ENCRYPTION) && IS_ENCRYPTED(inode))
> + struct inode *inode = file_inode(iocb->ki_filp);
> +
> + if (!fscrypt_dio_supported(iocb, iter))
> return false;
> if (fsverity_active(inode))
> return false;
> @@ -61,7 +63,7 @@ static ssize_t ext4_dio_read_iter(struct kiocb *iocb, struct iov_iter *to)
> inode_lock_shared(inode);
> }
>
> - if (!ext4_dio_supported(inode)) {
> + if (!ext4_dio_supported(iocb, to)) {
> inode_unlock_shared(inode);
> /*
> * Fallback to buffered I/O if the operation being performed on
> @@ -490,7 +492,7 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
> }
>
> /* Fallback to buffered I/O if the inode does not support direct I/O. */
> - if (!ext4_dio_supported(inode)) {
> + if (!ext4_dio_supported(iocb, from)) {
> if (ilock_shared)
> inode_unlock_shared(inode);
> else
> --
> 2.28.0.rc0.105.gf9edc3c819-goog