Re: [PATCH v2] ceph: invalidate pages when doing DIO in encrypted inodes

Xiubo Li
2022-04-06T09:59:55Z

On 4/1/22 9:32 PM, Luís Henriques wrote:
> When doing DIO on an encrypted node, we need to invalidate the page cache in
> the range being written to, otherwise the cache will include invalid data.
>
> Signed-off-by: Luís Henriques <lhenriques@suse.de>
> ---
> fs/ceph/file.c | 11 ++++++++++-
> 1 file changed, 10 insertions(+), 1 deletion(-)
>
> Changes since v1:
> - Replaced truncate_inode_pages_range() by invalidate_inode_pages2_range
> - Call fscache_invalidate with FSCACHE_INVAL_DIO_WRITE if we're doing DIO
>
> Note: I'm not really sure this last change is required, it doesn't really
> affect generic/647 result, but seems to be the most correct.
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 5072570c2203..b2743c342305 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1605,7 +1605,7 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
> if (ret < 0)
> return ret;
>
> - ceph_fscache_invalidate(inode, false);
> + ceph_fscache_invalidate(inode, (iocb->ki_flags & IOCB_DIRECT));
> ret = invalidate_inode_pages2_range(inode->i_mapping,
> pos >> PAGE_SHIFT,
> (pos + count - 1) >> PAGE_SHIFT);

The above has already invalidated the pages, why doesn't it work ?

-- Xiubo

> @@ -1895,6 +1895,15 @@ 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)) {
> + ret = invalidate_inode_pages2_range(
> + inode->i_mapping,
> + write_pos >> PAGE_SHIFT,
> + (write_pos + write_len - 1) >> PAGE_SHIFT);
> + if (ret < 0)
> + dout("invalidate_inode_pages2_range returned %d\n", ret);
> + }
> +
> /* Set up the assertion */
> if (rmw) {
> /*
>