Re: [PATCH v1] NFSD: Fix crash in nfsd4_read_release()

[Jeff Layton <jlayton@kernel.org>]

On Tue, 2025-09-30 at 10:05 -0400, Chuck Lever wrote:
> From: Chuck Lever <chuck.lever@oracle.com>
> 
> When tracing is enabled, the trace_nfsd_read_done trace point
> crashes during the pynfs read.testNoFh test.
> 
> Fixes: 87c5942e8fae ("nfsd: Add I/O trace points in the NFSv4 read proc")
> Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
> ---
>  fs/nfsd/nfs4proc.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4proc.c b/fs/nfsd/nfs4proc.c
> index e466cf52d7d7..f9aeefc0da73 100644
> --- a/fs/nfsd/nfs4proc.c
> +++ b/fs/nfsd/nfs4proc.c
> @@ -988,10 +988,11 @@ nfsd4_read(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  static void
>  nfsd4_read_release(union nfsd4_op_u *u)
>  {
> -	if (u->read.rd_nf)
> +	if (u->read.rd_nf) {
> +		trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
> +				     u->read.rd_offset, u->read.rd_length);
>  		nfsd_file_put(u->read.rd_nf);
> -	trace_nfsd_read_done(u->read.rd_rqstp, u->read.rd_fhp,
> -			     u->read.rd_offset, u->read.rd_length);
> +	}
>  }
>  
>  static __be32

Not sending a filehandle is pretty rare so I guess we won't miss the
lack of a tracepoint in that case.

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