On Mon, May 16, 2022 at 12:13:10PM +0200, Damien Le Moal wrote:
> On 2022/05/13 18:13, Keith Busch wrote:
> > From: Keith Busch <kbusch@xxxxxxxxxx>
> >
> > If the iterator has an offset, filling a bio to the max bvecs may result
> > in a size that isn't aligned to the block size. Mask off bytes for the
> > bio being constructed.
> >
> > Signed-off-by: Keith Busch <kbusch@xxxxxxxxxx>
> > ---
> > block/bio.c | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/block/bio.c b/block/bio.c
> > index 4259125e16ab..b42a9e3ff068 100644
> > --- a/block/bio.c
> > +++ b/block/bio.c
> > @@ -1144,6 +1144,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
> > {
> > unsigned short nr_pages = bio->bi_max_vecs - bio->bi_vcnt;
> > unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt;
> > + struct request_queue *q = bdev_get_queue(bio->bi_bdev);
> > struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt;
> > struct page **pages = (struct page **)bv;
> > bool same_page = false;
> > @@ -1160,6 +1161,9 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter)
> > pages += entries_left * (PAGE_PTRS_PER_BVEC - 1);
> >
> > size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset);
> > + if (size > 0)
> > + size = size & ~(queue_logical_block_size(q) - 1);
>
> I think that __bio_iov_append_get_pages() needs the same change. And given that
> both __bio_iov_append_get_pages() and __bio_iov_iter_get_pages() start with
> iov_iter_get_pages(), should we do that and check the size in the single caller:
> bio_iov_iter_get_pages() ?
Right, __bio_iov_append_get_pages needs this too. I'll see if we can remove much
of the duplicated code among these two functions as a prep patch.
