On Tue, May 27, 2025 at 8:34 AM Ming Lei <ming.lei@xxxxxxxxxx> wrote:
>
> file_start_write() and file_end_write() should be added around ->write_iter().
>
> Recently we switch to ->write_iter() from vfs_iter_write(), and the
> implied fs_start_write() and fs_end_write() are lost.
Still referring to "fs_start_write()" and "fs_end_write()" here
>
> Also we never add them for dio code path, so add them back for covering
> both.
>
> Cc: Jeff Moyer <jmoyer@xxxxxxxxxx>
> Fixes: f2fed441c69b ("loop: stop using vfs_iter_{read,write} for buffered I/O")
> Fixes: bc07c10a3603 ("block: loop: support DIO & AIO")
> Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
> ---
> V2:
> - fix commit log & patch title
>
> drivers/block/loop.c | 8 ++++++--
> 1 file changed, 6 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/block/loop.c b/drivers/block/loop.c
> index b8ba7de08753..7eca957dc656 100644
> --- a/drivers/block/loop.c
> +++ b/drivers/block/loop.c
> @@ -308,11 +308,14 @@ static void lo_complete_rq(struct request *rq)
> static void lo_rw_aio_do_completion(struct loop_cmd *cmd)
> {
> struct request *rq = blk_mq_rq_from_pdu(cmd);
> + struct loop_device *lo = rq->q->queuedata;
>
> if (!atomic_dec_and_test(&cmd->ref))
> return;
> kfree(cmd->bvec);
> cmd->bvec = NULL;
> + if (req_op(rq) == REQ_OP_WRITE)
> + file_end_write(lo->lo_backing_file);
> if (likely(!blk_should_fake_timeout(rq->q)))
> blk_mq_complete_request(rq);
> }
> @@ -387,9 +390,10 @@ static int lo_rw_aio(struct loop_device *lo, struct loop_cmd *cmd,
> cmd->iocb.ki_flags = 0;
> }
>
> - if (rw == ITER_SOURCE)
> + if (rw == ITER_SOURCE) {
> + file_start_write(lo->lo_backing_file);
> ret = file->f_op->write_iter(&cmd->iocb, &iter);
> - else
> + } else
> ret = file->f_op->read_iter(&cmd->iocb, &iter);
>
> lo_rw_aio_do_completion(cmd);
> --
> 2.47.0
>
