[PATCH 17/26] netfs: Fix writethrough-mode error handling

[Jeff Layton]

On Thu, 2024-03-28 at 16:34 +0000, David Howells wrote:
> Fix the error return in netfs_perform_write() acting in writethrough-mode
> to return any cached error in the case that netfs_end_writethrough()
> returns 0.
> 
> Signed-off-by: David Howells <dhowells at redhat.com>
> cc: Jeff Layton <jlayton at kernel.org>
> cc: netfs at lists.linux.dev
> cc: linux-fsdevel at vger.kernel.org
> ---
>  fs/netfs/buffered_write.c | 10 ++++++----
>  1 file changed, 6 insertions(+), 4 deletions(-)
> 
> diff --git a/fs/netfs/buffered_write.c b/fs/netfs/buffered_write.c
> index 8e4a3fb287e3..db4ad158948b 100644
> --- a/fs/netfs/buffered_write.c
> +++ b/fs/netfs/buffered_write.c
> @@ -188,7 +188,7 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
>  	enum netfs_how_to_modify howto;
>  	enum netfs_folio_trace trace;
>  	unsigned int bdp_flags = (iocb->ki_flags & IOCB_SYNC) ? 0: BDP_ASYNC;
> -	ssize_t written = 0, ret;
> +	ssize_t written = 0, ret, ret2;
>  	loff_t i_size, pos = iocb->ki_pos, from, to;
>  	size_t max_chunk = PAGE_SIZE << MAX_PAGECACHE_ORDER;
>  	bool maybe_trouble = false;
> @@ -409,10 +409,12 @@ ssize_t netfs_perform_write(struct kiocb *iocb, struct iov_iter *iter,
>  
>  out:
>  	if (unlikely(wreq)) {
> -		ret = netfs_end_writethrough(wreq, iocb);
> +		ret2 = netfs_end_writethrough(wreq, iocb);
>  		wbc_detach_inode(&wbc);
> -		if (ret == -EIOCBQUEUED)
> -			return ret;
> +		if (ret2 == -EIOCBQUEUED)
> +			return ret2;
> +		if (ret == 0)
> +			ret = ret2;
>  	}
>  
>  	iocb->ki_pos += written;
> 

Should this be merged independently? It looks like a bug that's present
now.

Reviewed-by: Jeff Layton <jlayton at kernel.org>