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

Luís Henriques
2022-04-06T13:41:34Z

Xiubo Li <xiubli@redhat.com> writes:

> 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);
>> @@ -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);
>> + }
>
> Shouldn't we fail it if the 'invalidate_inode_pages2_range()' fails here ?

Yeah, I'm not really sure. I'm simply following the usual pattern where
an invalidate_inode_pages2_range() failure is logged and ignored. And
this is not ceph-specific, other filesystems seem to do the same thing.

Cheers,
--
Luís

>
> -- Xiubo
>
>> +
>> /* Set up the assertion */
>> if (rmw) {
>> /*
>>
>