On Fri, 2022-04-01 at 12:38 +0100, Luís Henriques wrote:
> When doing DIO on an encrypted node, we need to truncate the page cache in
> the range being written to, otherwise the cache will include invalid data.
>
> Signed-off-by: Luís Henriques <lhenriques@xxxxxxx>
> ---
> fs/ceph/file.c | 5 +++++
> 1 file changed, 5 insertions(+)
>
> This patch should fix generic/647 fstest when run with test_dummy_encryption.
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 5072570c2203..0f31c4d352a4 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1895,6 +1895,11 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
> req->r_inode = inode;
> req->r_mtime = mtime;
>
> + if (IS_ENCRYPTED(inode) && (iocb->ki_flags & IOCB_DIRECT))
> + truncate_inode_pages_range(
> + inode->i_mapping, write_pos,
> + PAGE_ALIGN(write_pos + write_len) - 1);
> +
> /* Set up the assertion */
> if (rmw) {
> /*
Truncating the pagecache like this could cause dirty data to be
discarded. I know we're planning to overwrite this range, but you are
having to invalidate more than the written range here. We could
potentially lose a write to that region.
Have you tried using something like invalidate_inode_pages2_range ?
That's more of what we'd want here, as it's a bit more cautious about
tossing out dirty pages. I see too that that is what
ceph_direct_read_write calls in the write case as well.
--
Jeff Layton <jlayton@xxxxxxxxxx>
