Messages in this thread | | | Date | Thu, 21 Aug 2008 13:13:08 -0700 | From | Jeremy Fitzhardinge <> | Subject | Re: [PATCH] Xen: Fix warning when hot-unplugging virtual block devices |
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Alex Nixon wrote: > From: Alex Nixon <alex.nixon@citrix.com> > Date: Thu, 21 Aug 2008 12:30:54 +0100 > Subject: [PATCH] Xen: Fix warning when hot-unplugging virtual block devices > > WARNING: at kernel/softirq.c:136 local_bh_enable+0x3f/0x8a() > > del_gendisk needs IRQs enabled, as the code path eventually reaches local_bh_enable. > blk_stop_queue needs them disabled - so do so temporarily. > > It shouldn't matter if an interrupt comes in whilst blkif_io_lock is held, as it will block on the lock. Upon acquisition, it'll realise the device is down and exit cleanly. > > Signed-off-by: Alex Nixon <alex.nixon@citrix.com> > Acked-by: Jeremy Fitzhardinge <jeremy.fitzhardinge@citrix.com>
Send a clean copy to Jens with my ack.
J > --- > drivers/block/xen-blkfront.c | 6 ++++-- > 1 files changed, 4 insertions(+), 2 deletions(-) > > diff --git a/drivers/block/xen-blkfront.c b/drivers/block/xen-blkfront.c > index d5e7532..95cee2c 100644 > --- a/drivers/block/xen-blkfront.c > +++ b/drivers/block/xen-blkfront.c > @@ -899,16 +899,18 @@ static void blkfront_closing(struct xenbus_device *dev) > if (info->rq == NULL) > goto out; > > - spin_lock_irqsave(&blkif_io_lock, flags); > + spin_lock(&blkif_io_lock); > > del_gendisk(info->gd); > > + local_irq_save(flags); > /* No more blkif_request(). */ > blk_stop_queue(info->rq); > + local_irq_restore(flags); > > /* No more gnttab callback work. */ > gnttab_cancel_free_callback(&info->callback); > - spin_unlock_irqrestore(&blkif_io_lock, flags); > + spin_unlock(&blkif_io_lock); > > /* Flush gnttab callback work. Must be done with no locks held. */ > flush_scheduled_work(); >
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