On Fri, 2018-11-30 at 17:15 -0500, Chuck Lever wrote:
> > On Nov 30, 2018, at 4:55 PM, Trond Myklebust <trondmy@xxxxxxxxx>
> > wrote:
> >
> > A call to gss_wrap_req_priv() will end up replacing the original
> > array
> > in rqstp->rq_snd_buf.pages with a new one containing the encrypted
> > data. In order to avoid having the rqstp->rq_snd_buf.bvec point to
> > the
> > wrong page data, we need to refresh that too.
>
> I would add a note here that this patch fixes a memory leak. And
> you might want to add a Fixes: tag.
>
It only applies to new code that went into 4.20, so it won't need any
stable backporting.
That said, I'm realising (slowly - apparently I'm asleep today) that
this is receive side code, so
a) The contents of rq_snd_buf are irrelevant.
b) We want to beware of changing it while there is a copy in
rq_private_buf.
IOW: a v4 is forthcoming.
> I'm trying it out now.
>
>
> > Signed-off-by: Trond Myklebust <trond.myklebust@xxxxxxxxxxxxxxx>
> > ---
> > include/linux/sunrpc/xdr.h | 1 -
> > net/sunrpc/xprt.c | 2 ++
> > net/sunrpc/xprtsock.c | 1 +
> > 3 files changed, 3 insertions(+), 1 deletion(-)
> >
> > diff --git a/include/linux/sunrpc/xdr.h
> > b/include/linux/sunrpc/xdr.h
> > index 43106ffa6788..2ec128060239 100644
> > --- a/include/linux/sunrpc/xdr.h
> > +++ b/include/linux/sunrpc/xdr.h
> > @@ -72,7 +72,6 @@ xdr_buf_init(struct xdr_buf *buf, void *start,
> > size_t len)
> > buf->head[0].iov_base = start;
> > buf->head[0].iov_len = len;
> > buf->tail[0].iov_len = 0;
> > - buf->bvec = NULL;
> > buf->pages = NULL;
> > buf->page_len = 0;
> > buf->flags = 0;
> > diff --git a/net/sunrpc/xprt.c b/net/sunrpc/xprt.c
> > index 86bea4520c4d..122c91c28e7c 100644
> > --- a/net/sunrpc/xprt.c
> > +++ b/net/sunrpc/xprt.c
> > @@ -1623,6 +1623,8 @@ xprt_request_init(struct rpc_task *task)
> > req->rq_snd_buf.buflen = 0;
> > req->rq_rcv_buf.len = 0;
> > req->rq_rcv_buf.buflen = 0;
> > + req->rq_snd_buf.bvec = NULL;
> > + req->rq_rcv_buf.bvec = NULL;
> > req->rq_release_snd_buf = NULL;
> > xprt_reset_majortimeo(req);
> > dprintk("RPC: %5u reserved req %p xid %08x\n", task->tk_pid,
> > diff --git a/net/sunrpc/xprtsock.c b/net/sunrpc/xprtsock.c
> > index ae77c71c1f64..615ef2397fc5 100644
> > --- a/net/sunrpc/xprtsock.c
> > +++ b/net/sunrpc/xprtsock.c
> > @@ -843,6 +843,7 @@ static int xs_nospace(struct rpc_rqst *req)
> > static void
> > xs_stream_prepare_request(struct rpc_rqst *req)
> > {
> > + xdr_free_bvec(&req->rq_rcv_buf);
> > req->rq_task->tk_status = xdr_alloc_bvec(&req->rq_rcv_buf,
> > GFP_NOIO);
> > }
> >
> > --
> > 2.19.2
> >
>
> --
> Chuck Lever
>
>
>
--
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@xxxxxxxxxxxxxxx
