Re: [PATCH 9/9] aio: implement IOCB_CMD_FSYNC and IOCB_CMD_FDSYNC

From: Darrick J. Wong
Date: Wed Mar 21 2018 - 12:33:09 EST


On Wed, Mar 21, 2018 at 08:32:32AM +0100, Christoph Hellwig wrote:
> Simple workqueue offload for now, but prepared for adding a real aio_fsync
> method if the need arises. Based on an earlier patch from Dave Chinner.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>

Looks ok,
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>

--D

> ---
> fs/aio.c | 50 ++++++++++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 50 insertions(+)
>
> diff --git a/fs/aio.c b/fs/aio.c
> index da87cbf7c67a..79d3eb3d2dd9 100644
> --- a/fs/aio.c
> +++ b/fs/aio.c
> @@ -156,9 +156,16 @@ struct kioctx {
> unsigned id;
> };
>
> +struct fsync_iocb {
> + struct work_struct work;
> + struct file *file;
> + bool datasync;
> +};
> +
> struct aio_kiocb {
> union {
> struct kiocb rw;
> + struct fsync_iocb fsync;
> };
>
> struct kioctx *ki_ctx;
> @@ -1565,6 +1572,43 @@ static ssize_t aio_write(struct kiocb *req, struct iocb *iocb, bool vectored,
> return ret;
> }
>
> +static void aio_fsync_work(struct work_struct *work)
> +{
> + struct fsync_iocb *req = container_of(work, struct fsync_iocb, work);
> + int ret;
> +
> + ret = vfs_fsync(req->file, req->datasync);
> + fput(req->file);
> + aio_complete(container_of(req, struct aio_kiocb, fsync), ret, 0);
> +}
> +
> +static int aio_fsync(struct fsync_iocb *req, struct iocb *iocb, bool datasync)
> +{
> + int ret;
> +
> + if (iocb->aio_buf)
> + return -EINVAL;
> + if (iocb->aio_offset || iocb->aio_nbytes || iocb->aio_rw_flags)
> + return -EINVAL;
> +
> + req->file = fget(iocb->aio_fildes);
> + if (unlikely(!req->file))
> + return -EBADF;
> +
> + ret = -EINVAL;
> + if (!req->file->f_op->fsync)
> + goto out_fput;
> +
> + req->datasync = datasync;
> + INIT_WORK(&req->work, aio_fsync_work);
> + schedule_work(&req->work);
> + return -EIOCBQUEUED;
> +out_fput:
> + if (unlikely(ret && ret != -EIOCBQUEUED))
> + fput(req->file);
> + return ret;
> +}
> +
> static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> struct iocb *iocb, bool compat)
> {
> @@ -1628,6 +1672,12 @@ static int io_submit_one(struct kioctx *ctx, struct iocb __user *user_iocb,
> case IOCB_CMD_PWRITEV:
> ret = aio_write(&req->rw, iocb, true, compat);
> break;
> + case IOCB_CMD_FSYNC:
> + ret = aio_fsync(&req->fsync, iocb, false);
> + break;
> + case IOCB_CMD_FDSYNC:
> + ret = aio_fsync(&req->fsync, iocb, true);
> + break;
> default:
> pr_debug("invalid aio operation %d\n", iocb->aio_lio_opcode);
> ret = -EINVAL;
> --
> 2.14.2
>