Re: [PATCH] block: Make blkdev_issue_discard() interruptible

[Lukas Czerner <lczerner@redhat.com>]

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On Wed, 15 Sep 2010, Mike Snitzer wrote:

> On Wed, Sep 15, 2010 at 10:32 AM, Lukas Czerner <lczerner@redhat.com> wrote:
> > Since the discard may take quite long time, especially with really big
> > extents (like the whole device for example), it would be nice to give to
> > users the opportunity to abort it. This is especially useful for mkfs,
> > when user can not know in advance how long it will take.
> >
> > In conjunction with mke2fs patch "Inform user about ongoing discard"
> > it gives the user all the comfort of being informed about discard and
> > being able to abort the operation.
> >
> > Signed-off-by: Lukas Czerner <lczerner@redhat.com>
> > ---
> >  block/blk-lib.c |    5 +++++
> >  1 files changed, 5 insertions(+), 0 deletions(-)
> >
> > diff --git a/block/blk-lib.c b/block/blk-lib.c
> > index d0216b9..4f54a1a 100644
> > --- a/block/blk-lib.c
> > +++ b/block/blk-lib.c
> > @@ -102,6 +102,11 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
> >                else if (!bio_flagged(bio, BIO_UPTODATE))
> >                        ret = -EIO;
> >                bio_put(bio);
> > +
> > +               if (signal_pending(current)) {
> > +                       ret = -ERESTARTSYS;
> > +                       break;
> > +               }
> >        }
> >        return ret;
> >  out_free_page:
> 
> Neil Brown recently suggested the use of fatal_signal_pending() rather
> than signal_epnding() in another thread:
> http://lkml.org/lkml/2010/9/12/232
> 
> I think Neil's suggestion applies here too?
> 
> Mike

Good to know, thanks a lot. I'll resend the patch shortly.

-Lukas