Messages in this thread Patch in this message |  | | Date | Wed, 11 Sep 2002 12:58:07 +0200 | From | Jens Axboe <> | Subject | Re: 2.5 Problem Status Report |
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On Wed, Sep 11 2002, Oleg Drokin wrote: > Hello! > > On Wed, Sep 11, 2002 at 12:29:26PM +0200, Jens Axboe wrote: > > > > ok I see the bug. it's due to the imbalanced nature of ide_map_buffer() > > > vs ide_unmap_buffer(). i'll cook up a fix right away. > > Does this make it work? > > No. It fails exactly like without the patch.
Hmm, ok I'll try and reproduce it here then.
> > --- include/linux/ide.h~ 2002-09-11 12:27:14.000000000 +0200 > > +++ include/linux/ide.h 2002-09-11 12:27:29.000000000 +0200 > > @@ -597,9 +597,10 @@ > > return rq->buffer + task_rq_offset(rq); > > } > > > > -extern inline void ide_unmap_buffer(char *buffer, unsigned long *flags) > > +extern inline void ide_unmap_buffer(struct request *rq, char *buffer, unsigned long *flags) > > { > > - bio_kunmap_irq(buffer, flags); > > + if (rq->bio) > > + bio_kunmap_irq(buffer, flags); > > } > > > > /* > > Perhaps you forgot to make sure rq->bio is zeroed on unmapping/freeing?
rq->bio must not be zeroed or free'd or anything like that. ok I see what happens now. does this patch work for you? just back out the other patch first (well you don't have to, but might as well).
# This is a BitKeeper generated patch for the following project: # Project Name: Linux kernel tree # This patch format is intended for GNU patch command version 2.5 or higher. # This patch includes the following deltas: # ChangeSet 1.639 -> 1.640 # include/linux/bio.h 1.17 -> 1.18 # # The following is the BitKeeper ChangeSet Log # -------------------------------------------- # 02/09/11 axboe@burns.home.kernel.dk 1.640 # clean up with bio_kmap_irq() thing properly. remove the micro optimization # of _not_ calling kmap_atomic() if this isn't a highmem page. we could # keep that and do the inc_preempt_count() ourselves, but I'm not sure # it's worth it and this is cleaner. # -------------------------------------------- # diff -Nru a/include/linux/bio.h b/include/linux/bio.h --- a/include/linux/bio.h Wed Sep 11 12:57:45 2002 +++ b/include/linux/bio.h Wed Sep 11 12:57:45 2002 @@ -215,17 +215,11 @@ { unsigned long addr; - local_save_flags(*flags); - - /* - * could be low - */ - if (!PageHighMem(bio_page(bio))) - return bio_data(bio); - /* - * it's a highmem page + * might not be a highmem page, but the preempt/irq count + * balancing is a lot nicer this way */ + local_save_flags(*flags); local_irq_disable(); addr = (unsigned long) kmap_atomic(bio_page(bio), KM_BIO_SRC_IRQ); -- Jens Axboe
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