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

[Darrick J. Wong]

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
>