[PATCH v9 5/8] block: set FOLL_PCI_P2PDMA in __bio_iov_iter_get_pages()
From: Logan Gunthorpe <logang@deltatee.com>
Date: 2022-08-25 15:25:09
Also in:
linux-mm, linux-nvme, linux-pci, lkml
Subsystem:
block layer, the rest · Maintainers:
Jens Axboe, Linus Torvalds
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@deltatee.com> --- block/bio.c | 10 ++++++++-- 1 file changed, 8 insertions(+), 2 deletions(-)
diff --git a/block/bio.c b/block/bio.c
index 969607bc1f4d..ca09d79a0683 100644
--- a/block/bio.c
+++ b/block/bio.c@@ -1200,6 +1200,7 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) unsigned short entries_left = bio->bi_max_vecs - bio->bi_vcnt; struct bio_vec *bv = bio->bi_io_vec + bio->bi_vcnt; struct page **pages = (struct page **)bv; + unsigned int flags = 0; ssize_t size, left; unsigned len, i = 0; size_t offset, trim;
@@ -1213,6 +1214,10 @@ 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); + if (bio->bi_bdev && bio->bi_bdev->bd_disk && + blk_queue_pci_p2pdma(bio->bi_bdev->bd_disk->queue)) + flags |= FOLL_PCI_P2PDMA; + /* * Each segment in the iov is required to be a block size multiple. * However, we may not be able to get the entire segment if it spans
@@ -1220,8 +1225,9 @@ static int __bio_iov_iter_get_pages(struct bio *bio, struct iov_iter *iter) * result to ensure the bio's total size is correct. The remainder of * the iov data will be picked up in the next bio iteration. */ - size = iov_iter_get_pages2(iter, pages, UINT_MAX - bio->bi_iter.bi_size, - nr_pages, &offset); + size = iov_iter_get_pages_flags(iter, pages, + UINT_MAX - bio->bi_iter.bi_size, + nr_pages, &offset, flags); if (unlikely(size <= 0)) return size ? size : -EFAULT;
--
2.30.2