Fixed the issue for me.
Tested-by: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
On Mon, Nov 23, 2015 at 1:09 PM, Jan Kara <jack@xxxxxxx> wrote:
> The following test program from Dmitry can cause softlockups or RCU
> stalls as it copies 1GB from tmpfs into eventfd and we don't have any
> scheduling point at that path in sendfile(2) implementation:
>
> int r1 = eventfd(0, 0);
> int r2 = memfd_create("", 0);
> unsigned long n = 1<<30;
> fallocate(r2, 0, 0, n);
> sendfile(r1, r2, 0, n);
>
> Add cond_resched() into __splice_from_pipe() to fix the problem.
>
> CC: Dmitry Vyukov <dvyukov@xxxxxxxxxx>
> CC: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Jan Kara <jack@xxxxxxx>
> ---
> fs/splice.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/fs/splice.c b/fs/splice.c
> index 22adbbe51e52..4cf700d50b40 100644
> --- a/fs/splice.c
> +++ b/fs/splice.c
> @@ -891,6 +891,7 @@ ssize_t __splice_from_pipe(struct pipe_inode_info *pipe, struct splice_desc *sd,
>
> splice_from_pipe_begin(sd);
> do {
> + cond_resched();
> ret = splice_from_pipe_next(pipe, sd);
> if (ret > 0)
> ret = splice_from_pipe_feed(pipe, sd, actor);
> --
> 2.1.4
>
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