Re: [PATCH 2/4] cifs, freezer: add wait_event_freezekillable andhave cifs use it

[Jeff Layton]

On Wed, 28 Sep 2011 23:28:02 -0500
Steve French <smfrench@xxxxxxxxx> wrote:

> The general idea of the patch seems like a good idea to
> me.  Assuming testing feedback was good from the problem
> reporters, what tree would you want it merged from?
> 

There's the rub -- this requires a number of changes in different
areas. What I really need at this point is a verdict on patch #1. If
that looks OK, then that should probably go in via the one of the
linux-pm trees. Then patch #2 can probably go in via your tree and 3
and 4 can go in via Trond's.

However, none of this should go in unless #1 is ok. Make sense?

> On Wed, Sep 28, 2011 at 6:52 AM, Jeff Layton <jlayton@xxxxxxxxxx> wrote:
> > CIFS currently uses wait_event_killable to put tasks to sleep while
> > they await replies from the server. That function though does not
> > allow the freezer to run. In many cases, the network interface may
> > be going down anyway, in which case the reply will never come. The
> > client then ends up blocking the computer from suspending.
> >
> > Fix this by adding a new wait_event_freezable variant --
> > wait_event_freezekillable. The idea is to combine the behavior of
> > wait_event_killable and wait_event_freezable -- put the task to
> > sleep and only allow it to be awoken by fatal signals, but also
> > allow the freezer to do its job.
> >
> > Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
> > ---
> > Âfs/cifs/transport.c   |  Â3 ++-
> > Âinclude/linux/freezer.h | Â 19 +++++++++++++++++--
> > Â2 files changed, 19 insertions(+), 3 deletions(-)
> >
> > diff --git a/fs/cifs/transport.c b/fs/cifs/transport.c
> > index 10ca6b2..791bc4f 100644
> > --- a/fs/cifs/transport.c
> > +++ b/fs/cifs/transport.c
> > @@ -26,6 +26,7 @@
> > Â#include <linux/wait.h>
> > Â#include <linux/net.h>
> > Â#include <linux/delay.h>
> > +#include <linux/freezer.h>
> > Â#include <asm/uaccess.h>
> > Â#include <asm/processor.h>
> > Â#include <linux/mempool.h>
> > @@ -324,7 +325,7 @@ wait_for_response(struct TCP_Server_Info *server, struct mid_q_entry *midQ)
> > Â{
> > Â Â Â Âint error;
> >
> > - Â Â Â error = wait_event_killable(server->response_q,
> > + Â Â Â error = wait_event_freezekillable(server->response_q,
> > Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â ÂmidQ->midState != MID_REQUEST_SUBMITTED);
> > Â Â Â Âif (error < 0)
> > Â Â Â Â Â Â Â Âreturn -ERESTARTSYS;
> > diff --git a/include/linux/freezer.h b/include/linux/freezer.h
> > index 1effc8b..3672f73 100644
> > --- a/include/linux/freezer.h
> > +++ b/include/linux/freezer.h
> > @@ -134,10 +134,25 @@ static inline void set_freezable_with_signal(void)
> > Â}
> >
> > Â/*
> > - * Freezer-friendly wrappers around wait_event_interruptible() and
> > - * wait_event_interruptible_timeout(), originally defined in <linux/wait.h>
> > + * Freezer-friendly wrappers around wait_event_interruptible(),
> > + * wait_event_killable() and wait_event_interruptible_timeout(), originally
> > + * defined in <linux/wait.h>
> > Â*/
> >
> > +#define wait_event_freezekillable(wq, condition) Â Â Â Â Â Â Â Â Â Â Â \
> > +({ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â \
> > + Â Â Â int __retval; Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â \
> > + Â Â Â do { Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â Â Â Â Â __retval = wait_event_killable(wq, Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â (condition) || freezing(current)); Â Â Â\
> > + Â Â Â Â Â Â Â if (__retval && !freezing(current)) Â Â Â Â Â Â Â Â Â Â \
> > + Â Â Â Â Â Â Â Â Â Â Â break; Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â Â Â Â Â else if (!(condition)) Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â Â Â Â Â Â Â Â Â __retval = -ERESTARTSYS; Â Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â } while (try_to_freeze()); Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â\
> > + Â Â Â __retval; Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â \
> > +})
> > +
> > Â#define wait_event_freezable(wq, condition) Â Â Â Â Â Â Â Â Â Â Â Â Â Â\
> > Â({ Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â \
> > Â Â Â Âint __retval; Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â Â \
> > --
> > 1.7.6.2
> >
> >
> 
> 
> 


-- 
Jeff Layton <jlayton@xxxxxxxxxx>
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