2022-04-07 20:07:55

by Jeff Layton

[permalink] [raw]
Subject: Re: [PATCH v3] ceph: invalidate pages when doing direct/sync writes

On Thu, 2022-04-07 at 15:38 +0100, Lu?s Henriques wrote:
> When doing a direct/sync write, we need to invalidate the page cache in
> the range being written to. If we don't do this, the cache will include
> invalid data as we just did a write that avoided the page cache.
>
> Signed-off-by: Lu?s Henriques <[email protected]>
> ---
> fs/ceph/file.c | 9 +++++++++
> 1 file changed, 9 insertions(+)
>
> Ok, here's a new attempt. After discussion in this thread and on IRC, I
> think this is the right fix. generic/647 now passes with and without
> encryption. Thanks!
>
> Changes since v2:
> - Invalidation needs to be done after a write
>
> 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
>
> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
> index 5072570c2203..63e67eb60310 100644
> --- a/fs/ceph/file.c
> +++ b/fs/ceph/file.c
> @@ -1938,6 +1938,15 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
> break;
> }
> ceph_clear_error_write(ci);
> + ret = invalidate_inode_pages2_range(
> + inode->i_mapping,
> + pos >> PAGE_SHIFT,
> + (pos + len - 1) >> PAGE_SHIFT);
> + if (ret < 0) {
> + dout("invalidate_inode_pages2_range returned %d\n",
> + ret);
> + ret = 0;
> + }
> pos += len;
> written += len;
> dout("sync_write written %d\n", written);

Looks good. I suspect we can also remove the
invalidate_indode_pages2_range call earlier in this function too. I may
roll that into this patch.

I'll give this an xfstests run with fscrypt enabled and see how it does.

Thanks!
--
Jeff Layton <[email protected]>


2022-04-07 20:19:08

by Luis Henriques

[permalink] [raw]
Subject: Re: [PATCH v3] ceph: invalidate pages when doing direct/sync writes

Jeff Layton <[email protected]> writes:

> On Thu, 2022-04-07 at 15:38 +0100, Luís Henriques wrote:
>> When doing a direct/sync write, we need to invalidate the page cache in
>> the range being written to. If we don't do this, the cache will include
>> invalid data as we just did a write that avoided the page cache.
>>
>> Signed-off-by: Luís Henriques <[email protected]>
>> ---
>> fs/ceph/file.c | 9 +++++++++
>> 1 file changed, 9 insertions(+)
>>
>> Ok, here's a new attempt. After discussion in this thread and on IRC, I
>> think this is the right fix. generic/647 now passes with and without
>> encryption. Thanks!
>>
>> Changes since v2:
>> - Invalidation needs to be done after a write
>>
>> 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
>>
>> diff --git a/fs/ceph/file.c b/fs/ceph/file.c
>> index 5072570c2203..63e67eb60310 100644
>> --- a/fs/ceph/file.c
>> +++ b/fs/ceph/file.c
>> @@ -1938,6 +1938,15 @@ ceph_sync_write(struct kiocb *iocb, struct iov_iter *from, loff_t pos,
>> break;
>> }
>> ceph_clear_error_write(ci);
>> + ret = invalidate_inode_pages2_range(
>> + inode->i_mapping,
>> + pos >> PAGE_SHIFT,
>> + (pos + len - 1) >> PAGE_SHIFT);
>> + if (ret < 0) {
>> + dout("invalidate_inode_pages2_range returned %d\n",
>> + ret);
>> + ret = 0;
>> + }
>> pos += len;
>> written += len;
>> dout("sync_write written %d\n", written);
>
> Looks good. I suspect we can also remove the
> invalidate_indode_pages2_range call earlier in this function too. I may
> roll that into this patch.

Right, that occurred to me as well but I wasn't really sure that would be
safe.

> I'll give this an xfstests run with fscrypt enabled and see how it does.

I'll do the same here, I just run a few tests on a vstart cluster. But
I'll definitely give it some more testing.

Cheers,
--
Luís