From: Wu Fengguang <fengguang.wu@intel.com>
To: Rabin Vincent <rabin@rab.in>
Cc: Chanho Min <chanho0207@gmail.com>, Jens Axboe <axboe@kernel.dk>,
linux-kernel@vger.kernel.org
Subject: Re: [PATCH] mm/backing-dev.c: fix crash when USB/SCSI device is detached
Date: Mon, 16 Jan 2012 10:53:32 +0800 [thread overview]
Message-ID: <20120116025331.GA16516@localhost> (raw)
In-Reply-To: <20120115153838.GA4279@debian>
On Sun, Jan 15, 2012 at 09:11:07PM +0530, Rabin Vincent wrote:
> On Sun, Jan 15, 2012 at 08:58:53PM +0800, Wu Fengguang wrote:
> > On Sun, Jan 15, 2012 at 03:58:43PM +0530, Rabin Vincent wrote:
> > > diff --git a/mm/backing-dev.c b/mm/backing-dev.c
> > > index 71034f4..a39ad70 100644
> > > --- a/mm/backing-dev.c
> > > +++ b/mm/backing-dev.c
> > > @@ -318,7 +318,7 @@ static void wakeup_timer_fn(unsigned long data)
> > > if (bdi->wb.task) {
> > > trace_writeback_wake_thread(bdi);
> > > wake_up_process(bdi->wb.task);
> > > - } else {
> > > + } else if (bdi->dev) {
> > > /*
> > > * When bdi tasks are inactive for long time, they are killed.
> > > * In this case we have to wake-up the forker thread which
> > > @@ -584,6 +584,8 @@ EXPORT_SYMBOL(bdi_register_dev);
> > > */
> > > static void bdi_wb_shutdown(struct backing_dev_info *bdi)
> > > {
> > > + struct task_struct *task = NULL;
> >
> > NULL not necessary?
>
> Will fix.
>
> Also, I notice another problem here. bdi->dev should be made NULL before the
> device is unregistered, not after:
Yes, good catch!
> if (!bdi_cap_flush_forker(bdi))
> bdi_wb_shutdown(bdi);
> bdi_debug_unregister(bdi);
> device_unregister(bdi->dev);
> bdi->dev = NULL;
Thanks,
Fengguang
next prev parent reply other threads:[~2012-01-16 2:53 UTC|newest]
Thread overview: 21+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-01-05 8:49 [PATCH] mm/backing-dev.c: fix crash when USB/SCSI device is detached Chanho Min
2012-01-15 10:28 ` Rabin Vincent
2012-01-15 12:58 ` Wu Fengguang
2012-01-15 15:41 ` Rabin Vincent
2012-01-16 2:53 ` Wu Fengguang [this message]
2012-01-16 5:28 ` Chanho Min
2012-01-16 5:50 ` Wu Fengguang
2012-01-16 5:53 ` Wu Fengguang
2012-01-16 6:34 ` Chanho Min
2012-01-18 19:43 ` Rabin Vincent
2012-01-19 16:50 ` [PATCHv2] backing-dev: fix wakeup timer races with bdi_unregister() Rabin Vincent
2012-01-19 23:46 ` Namjae Jeon
2012-01-20 5:24 ` Rabin Vincent
2012-01-20 6:15 ` Namjae Jeon
2012-01-20 10:03 ` Rabin Vincent
2012-01-20 11:18 ` Namjae Jeon
2012-01-20 12:08 ` Rabin Vincent
2012-01-20 15:04 ` Namjae Jeon
2012-01-31 13:24 ` Wu Fengguang
[not found] <004401ccc932$444a0070$ccde0150$@min@lge.com>
2012-01-02 9:57 ` [PATCH] mm/backing-dev.c: fix crash when USB/SCSI device is detached Wu Fengguang
[not found] ` <002e01ccc9c7$1928c940$4b7a5bc0$@min@lge.com>
2012-01-03 4:49 ` Wu Fengguang
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