Re: [PATCH] cifs: Fix the smb1 readv callback to correctly call netfs

[Pali Rohár]

On Tuesday 25 February 2025 22:25:00 David Howells wrote:
>     
> Fix cifs_readv_callback() to call netfs_read_subreq_terminated() rather
> than queuing the subrequest work item (which is unset).  Also call the
> I/O progress tracepoint.
> 
> Fixes: e2d46f2ec332 ("netfs: Change the read result collector to only use one work item")
> Reported-by: Jean-Christophe Guillain <jean-christophe@xxxxxxxxxxxx>
> Closes: https://bugzilla.kernel.org/show_bug.cgi?id=219793
> Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
> cc: Steve French <stfrench@xxxxxxxxxxxxx>
> cc: Pali Rohár <pali@xxxxxxxxxx>
> cc: Paulo Alcantara <pc@xxxxxxxxxxxxx>
> cc: Jeff Layton <jlayton@xxxxxxxxxx>
> cc: linux-cifs@xxxxxxxxxxxxxxx
> cc: netfs@xxxxxxxxxxxxxxx
> cc: linux-fsdevel@xxxxxxxxxxxxxxx

Thanks! With this change, I cannot reproduce crash anymore.

Tested-by: Pali Rohár <pali@xxxxxxxxxx>

Steve, could you please include this fix into some queue? This should be
merged into next -rc.

> ---
>  fs/smb/client/cifssmb.c |    3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/smb/client/cifssmb.c b/fs/smb/client/cifssmb.c
> index 6a3e287eabfa..bf9acea53ccb 100644
> --- a/fs/smb/client/cifssmb.c
> +++ b/fs/smb/client/cifssmb.c
> @@ -1338,7 +1338,8 @@ cifs_readv_callback(struct mid_q_entry *mid)
>  	rdata->credits.value = 0;
>  	rdata->subreq.error = rdata->result;
>  	rdata->subreq.transferred += rdata->got_bytes;
> -	queue_work(cifsiod_wq, &rdata->subreq.work);
> +	trace_netfs_sreq(&rdata->subreq, netfs_sreq_trace_io_progress);
> +	netfs_read_subreq_terminated(&rdata->subreq);
>  	release_mid(mid);
>  	add_credits(server, &credits, 0);
>  }
>