On Fri, Oct 25, 2024 at 09:15:53AM +0530, Ritesh Harjani (IBM) wrote:
> iomap will not return -ENOTBLK in case of dio atomic writes. But let's
> also add a WARN_ON_ONCE and return -EIO as a safety net.
>
> Signed-off-by: Ritesh Harjani (IBM) <ritesh.list@xxxxxxxxx>
> ---
> fs/ext4/file.c | 10 +++++++++-
> 1 file changed, 9 insertions(+), 1 deletion(-)
>
> diff --git a/fs/ext4/file.c b/fs/ext4/file.c
> index f9516121a036..af6ebd0ac0d6 100644
> --- a/fs/ext4/file.c
> +++ b/fs/ext4/file.c
> @@ -576,8 +576,16 @@ static ssize_t ext4_dio_write_iter(struct kiocb *iocb, struct iov_iter *from)
> iomap_ops = &ext4_iomap_overwrite_ops;
> ret = iomap_dio_rw(iocb, from, iomap_ops, &ext4_dio_write_ops,
> dio_flags, NULL, 0);
> - if (ret == -ENOTBLK)
> + if (ret == -ENOTBLK) {
> ret = 0;
> + /*
> + * iomap will never return -ENOTBLK if write fails for atomic
> + * write. But let's just add a safety net.
> + */
> + if (WARN_ON_ONCE(iocb->ki_flags & IOCB_ATOMIC))
> + ret = -EIO;
> + }
Why can't the iomap code return EIO in this case for IOCB_ATOMIC?
That way we don't have to put this logic into every filesystem.
When/if we start supporting atomic writes for buffered IO, then it's
worth pushing this out to filesystems, but right now it doesn't seem
necessary...
-Dave.
--
Dave Chinner
david@xxxxxxxxxxxxx
