When a bio's queue supports PCI P2PDMA, set FOLL_PCI_P2PDMA for iov_iter_get_pages_flags(). This allows PCI P2PDMA pages to be passed from userspace and enables the O_DIRECT path in iomap based filesystems and direct to block devices. Signed-off-by: Logan Gunthorpe <logang@xxxxxxxxxxxx> --- block/bio.c | 8 +++++++- 1 file changed, 7 insertions(+), 1 deletion(-) diff --git a/block/bio.c b/block/bio.c index f4e2e30d7a24..f0a17c7f41c3 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1096,6 +1096,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; struct page **pages = (struct page **)bv; bool same_page = false; + unsigned int flags = 0; ssize_t size, left; unsigned len, i; size_t offset; @@ -1108,7 +1109,12 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) BUILD_BUG_ON(PAGE_PTRS_PER_BVEC < 2); pages += entries_left * (PAGE_PTRS_PER_BVEC - 1); - size = iov_iter_get_pages(iter, pages, LONG_MAX, nr_pages, &offset); + if (bio->bi_bdev && bio->bi_bdev->bd_disk && + blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue)) + flags |= FOLL_PCI_P2PDMA; + + size = iov_iter_get_pages_flags(iter, pages, LONG_MAX, nr_pages, + &offset, flags); if (unlikely(size <= 0)) return size ? size : -EFAULT; -- 2.30.2
