On Mon, Jun 22, 2020 at 10:24:53AM -0500, Goldwyn Rodrigues wrote:
> From: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
>
> The flag indicates that if the page invalidation fails, it should return
> back control to the filesystem so it may fallback to buffered mode.
>
> Signed-off-by: Goldwyn Rodrigues <rgoldwyn@xxxxxxxx>
Looks reasonable enough, I suppose...
Reviewed-by: Darrick J. Wong <darrick.wong@xxxxxxxxxx>
--D
> ---
> fs/iomap/direct-io.c | 8 +++++++-
> include/linux/iomap.h | 5 +++++
> 2 files changed, 12 insertions(+), 1 deletion(-)
>
> diff --git a/fs/iomap/direct-io.c b/fs/iomap/direct-io.c
> index 7ed857196a39..20c4370e6b1b 100644
> --- a/fs/iomap/direct-io.c
> +++ b/fs/iomap/direct-io.c
> @@ -484,8 +484,14 @@ iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> */
> ret = invalidate_inode_pages2_range(mapping,
> pos >> PAGE_SHIFT, end >> PAGE_SHIFT);
> - if (ret)
> + if (ret) {
> + if (dio_flags & IOMAP_DIOF_PGINVALID_FAIL) {
> + if (ret == -EBUSY)
> + ret = 0;
> + goto out_free_dio;
> + }
> dio_warn_stale_pagecache(iocb->ki_filp);
> + }
> ret = 0;
>
> if (iov_iter_rw(iter) == WRITE && !wait_for_completion &&
> diff --git a/include/linux/iomap.h b/include/linux/iomap.h
> index f6230446b08d..95024e28dec5 100644
> --- a/include/linux/iomap.h
> +++ b/include/linux/iomap.h
> @@ -261,6 +261,11 @@ struct iomap_dio_ops {
>
> /* Wait for completion of DIO */
> #define IOMAP_DIOF_WAIT_FOR_COMPLETION 0x1
> +/*
> + * Return zero if page invalidation fails, so caller filesystem may fallback
> + * to buffered I/O
> + */
> +#define IOMAP_DIOF_PGINVALID_FAIL 0x2
>
> ssize_t iomap_dio_rw(struct kiocb *iocb, struct iov_iter *iter,
> const struct iomap_ops *ops, const struct iomap_dio_ops *dops,
> --
> 2.25.0
>
