On Wed, Jan 15, 2020 at 02:46:53PM +0100, Christoph Hellwig wrote:
> Direct I/O reads can also be used with RWF_NOWAIT & co. Fix the inode
> locking in xfs_file_dio_aio_read to take IOCB_NOWAIT into account.
>
> Signed-off-by: Christoph Hellwig <hch@xxxxxx>
> ---
>
> Resending standalone to get a little more attention.
>
> fs/xfs/xfs_file.c | 7 ++++++-
> 1 file changed, 6 insertions(+), 1 deletion(-)
>
> diff --git a/fs/xfs/xfs_file.c b/fs/xfs/xfs_file.c
> index c93250108952..b8a4a3f29b36 100644
> --- a/fs/xfs/xfs_file.c
> +++ b/fs/xfs/xfs_file.c
> @@ -187,7 +187,12 @@ xfs_file_dio_aio_read(
>
> file_accessed(iocb->ki_filp);
>
> - xfs_ilock(ip, XFS_IOLOCK_SHARED);
> + if (iocb->ki_flags & IOCB_NOWAIT) {
> + if (!xfs_ilock_nowait(ip, XFS_IOLOCK_SHARED))
> + return -EAGAIN;
> + } else {
> + xfs_ilock(ip, XFS_IOLOCK_SHARED);
> + }
/me really wishes we had a better way to do this than to open-code this
idiom over and over and over again in every fs. Unfortunately I know of
no way to accomplish that without macros(!) so this will have to do:
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ret = iomap_dio_rw(iocb, to, &xfs_read_iomap_ops, NULL,
> is_sync_kiocb(iocb));
> xfs_iunlock(ip, XFS_IOLOCK_SHARED);
> --
> 2.24.1
>
