Re: [PATCH 06/13] cifs: clean up handle_mid_response

[Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>]

On Sun, 12 Dec 2010 17:52:26 -0600
Shirish Pargaonkar <shirishpargaonkar-Re5JQEeQqe8AvxtiuMwx3w@public.gmane.org> wrote:

> On Fri, Dec 10, 2010 at 9:44 AM, Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org> wrote:
> > Make it use a switch statement based on the value of the midStatus. If
> > the resp_buf is set, then MID_RESPONSE_RECEIVED is too.
> >
> > Signed-off-by: Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>
> > ---
> >  fs/cifs/transport.c |   36 ++++++++++++++++++------------------
> >  1 files changed, 18 insertions(+), 18 deletions(-)
> >
> > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> > index 0c0dadd..05ced17 100644
> > --- a/fs/cifs/transport.c
> > +++ b/fs/cifs/transport.c
> > @@ -356,33 +356,33 @@ handle_mid_result(struct mid_q_entry *mid, struct TCP_Server_Info *server)
> >  {
> >        int rc = 0;
> >
> > -       spin_lock(&GlobalMid_Lock);
> > +       cFYI(1, "%s: cmd=%d mid=%d state=%d", __func__, mid->command,
> > +               mid->mid, mid->midState);
> >
> > -       if (mid->resp_buf) {
> > +       spin_lock(&GlobalMid_Lock);
> > +       switch (mid->midState) {
> > +       case MID_RESPONSE_RECEIVED:
> >                spin_unlock(&GlobalMid_Lock);
> >                return rc;
> > -       }
> > -
> > -       cERROR(1, "No response to cmd %d mid %d", mid->command, mid->mid);
> > -       if (mid->midState == MID_REQUEST_SUBMITTED) {
> > -               if (server->tcpStatus == CifsExiting)
> > +       case MID_REQUEST_SUBMITTED:
> > +               /* socket is going down, reject all calls */
> > +               if (server->tcpStatus == CifsExiting) {
> > +                       cERROR(1, "%s: canceling mid=%d cmd=0x%x state=%d",
> > +                              __func__, mid->mid, mid->command, mid->midState);
> >                        rc = -EHOSTDOWN;
> > -               else
> > -                       mid->midState = MID_RETRY_NEEDED;
> > -       }
> > -
> > -       if (rc != -EHOSTDOWN) {
> > -               if (mid->midState == MID_RETRY_NEEDED) {
> > -                       rc = -EAGAIN;
> > -                       cFYI(1, "marking request for retry");
> > -               } else {
> > -                       rc = -EIO;
> > +                       break;
> >                }
> > +               mid->midState = MID_RETRY_NEEDED;
> 
> Would it be cleaner to set rc to -EAGAIN instead of setting state here
> to fall down and then setting rc as -EAGAIN?
> 

I'm not sure it'll be any more clear. It seems clear enough to me -- if
it's still SUBMITTED, then we want to treat it if it were
"RETRY_NEEDED".

Honestly, this really shouldn't happen. With this patchset, you should
never reach this function if the state is still 'SUBMITTED'. I left it
there for completeness sake and future-proofness.

> > +       case MID_RETRY_NEEDED:
> > +               rc = -EAGAIN;
> > +               break;
> > +       default:
> > +               cERROR(1, "%s: invalid mid state mid=%d state=%d", __func__,
> > +                       mid->mid, mid->midState);
> >        }
> >        spin_unlock(&GlobalMid_Lock);
> >
> >        DeleteMidQEntry(mid);
> > -       /* Update # of requests on wire to server */
> >        atomic_dec(&server->inFlight);
> >        wake_up(&server->request_q);
> >
> > --
> > 1.7.3.2
> >
> > --
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> >


-- 
Jeff Layton <jlayton-H+wXaHxf7aLQT0dZR+AlfA@public.gmane.org>