On Thu, Dec 13, 2012 at 12:08:11AM -0800, Darrick J. Wong wrote: > diff --git a/mm/bounce.c b/mm/bounce.c > index 0420867..fa11935 100644 > --- a/mm/bounce.c > +++ b/mm/bounce.c > @@ -178,6 +178,38 @@ static void bounce_end_io_read_isa(struct bio *bio, int > err) > __bounce_end_io_read(bio, isa_page_pool, err); > } > > +#ifdef CONFIG_NEED_BOUNCE_POOL > +static int might_snapshot_stable_page_write(struct bio **bio_orig) > +{ > + return bio_data_dir(*bio_orig) == WRITE; > +} > + > +static int should_snapshot_stable_pages(struct page *page, int rw) > +{ > + struct backing_dev_info *bdi; > + struct address_space *mapping = page_mapping(page); > + > + if (!mapping) > + return 0; > + bdi = mapping->backing_dev_info; > + if (!bdi_cap_stable_pages_required(bdi)) > + return 0; > + > + return mapping->host->i_sb->s_flags & MS_SNAP_STABLE && > + rw == WRITE; > +} > +#else > +static int might_snapshot_stable_page_write(struct bio **bio_orig) > +{ > + return 0; > +} > + > +static int should_snapshot_static_pages(struct page *page, int rw) ^^^^^^ It should be _stable_.
Regards, - Zheng > +{ > + return 0; > +} > +#endif /* CONFIG_NEED_BOUNCE_POOL */ > + > static void __blk_queue_bounce(struct request_queue *q, struct bio > **bio_orig, > mempool_t *pool) > { > @@ -192,7 +224,8 @@ static void __blk_queue_bounce(struct request_queue *q, > struct bio **bio_orig, > /* > * is destination page below bounce pfn? > */ > - if (page_to_pfn(page) <= queue_bounce_pfn(q)) > + if (page_to_pfn(page) <= queue_bounce_pfn(q) && > + !should_snapshot_stable_pages(page, rw)) > continue; > > /* > @@ -284,7 +317,8 @@ void blk_queue_bounce(struct request_queue *q, struct bio > **bio_orig) > * don't waste time iterating over bio segments > */ > if (!(q->bounce_gfp & GFP_DMA)) { > - if (queue_bounce_pfn(q) >= blk_max_pfn) > + if (queue_bounce_pfn(q) >= blk_max_pfn && > + !might_snapshot_stable_page_write(bio_orig)) > return; > pool = page_pool; > } else { -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/