[PATCH] SPDY: fixed handling of sc->length in ngx_http_spdy_state_read_data()

[Valentin V. Bartenev]

On Wednesday 26 March 2014 15:46:05 Xiaochen Wang wrote:
> hi,
> 
> On Wed, Mar 26, 2014 at 3:02 PM, Valentin V. Bartenev <vbart at nginx.com>wrote:
> 
> > On Wednesday 26 March 2014 12:30:11 Xiaochen Wang wrote:
> > > In our production, sometimes, the disk was full. In which case, the
> > > requests after the POST request were handled wrongly in one spdy
> > > connection.
> > >
> > > Because the input body (DATA frame) of POST request could not be written
> > > to disk, then ngx_http_spdy_state_read_data() tried to skip this DATA
> > > frame with wrong sc->length, which broke spdy stream.
> > >
> > >
> > > # HG changeset patch
> > > # User Xiaochen Wang <wangxiaochen0 at gmail.com>
> > > # Date 1395807655 -28800
> > > # Node ID c18a0115c6027ad0ad475061d2984d90544d8449
> > > # Parent  bd91f286ee0ade98e9c0f8f55bfef54a122adaf2
> > > SPDY: fixed handling of sc->length in ngx_http_spdy_state_read_data()
> > >
> > > diff -r bd91f286ee0a -r c18a0115c602 src/http/ngx_http_spdy.c
> > > --- a/src/http/ngx_http_spdy.c        Mon Mar 24 16:35:44 2014 -0700
> > > +++ b/src/http/ngx_http_spdy.c        Wed Mar 26 12:20:55 2014 +0800
> > > @@ -1519,7 +1519,6 @@
> > >          complete = 1;
> > >
> > >      } else {
> > > -        sc->length -= size;
> > >          complete = 0;
> > >      }
> > >
> > > @@ -1567,6 +1566,7 @@
> > >              buf->pos = pos;
> > >
> > >              pos += size;
> > > +            sc->length -= size;
> > >
> > >              buf->end = pos;
> > >              buf->last = pos;
> > > @@ -1585,6 +1585,7 @@
> > >          } else {
> > >              buf->last = ngx_cpymem(buf->last, pos, size);
> > >              pos += size;
> > > +            sc->length -= size;
> > >          }
> > >
> > >          r->request_length += size;
> > >
> >
> > Thank you for the report.  I'd prefer a slightly smaller patch:
> >
> Agree.

It has been committed:
http://hg.nginx.org/nginx/rev/d74889fbf06d

Thanks.

  wbr, Valentin V. Bartenev