2016-12-14 03:08:33

by Shaohua Li

Subject: [PATCH] block_dev: don't update file access position for sync direct IO

For sync direct IO, generic_file_direct_write/generic_file_read_iter
will update file access position. Don't duplicate the update in
.direct_IO. This cause my raid array can't assemble.

Cc: Christoph Hellwig <[email protected]>
Cc: Jens Axboe <[email protected]>
Signed-off-by: Shaohua Li <[email protected]>
---
fs/block_dev.c | 5 +----
1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/fs/block_dev.c b/fs/block_dev.c
index 95acbd2..1eb7dcf 100644
--- a/fs/block_dev.c
+++ b/fs/block_dev.c
@@ -264,7 +264,6 @@ __blkdev_direct_IO_simple(struct kiocb *iocb, struct iov_iter *iter,

if (unlikely(bio.bi_error))
return bio.bi_error;
- iocb->ki_pos += ret;
return ret;
}

@@ -411,10 +410,8 @@ __blkdev_direct_IO(struct kiocb *iocb, struct iov_iter *iter, int nr_pages)
__set_current_state(TASK_RUNNING);

ret = dio->bio.bi_error;
- if (likely(!ret)) {
+ if (likely(!ret))
ret = dio->size;
- iocb->ki_pos += ret;
- }

bio_put(&dio->bio);
return ret;
--
2.9.3

2016-12-14 04:08:50

by Jens Axboe

Subject: Re: [PATCH] block_dev: don't update file access position for sync direct IO

On 12/13/2016 08:07 PM, Shaohua Li wrote:
> For sync direct IO, generic_file_direct_write/generic_file_read_iter
> will update file access position. Don't duplicate the update in
> .direct_IO. This cause my raid array can't assemble.

That's not great... Thanks, added.

--
Jens Axboe

2016-12-14 10:29:52

by Christoph Hellwig

Subject: Re: [PATCH] block_dev: don't update file access position for sync direct IO

On Tue, Dec 13, 2016 at 09:08:18PM -0700, Jens Axboe wrote:
> That's not great... Thanks, added.

Ooops, yeah - we're still going through ->direct_IO for block devices.
I'll take a stab at removing that, as it's just a pointless indirect
call.