[PATCH v9 6/8] block: set FOLL_PCI_P2PDMA in bio_map_user_iov()

Logan Gunthorpe
2022-08-25T15:25:12Z

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 NVMe passthru requests to
use P2PDMA pages.

Signed-off-by: Logan Gunthorpe <logang@deltatee.com>
---
block/blk-map.c | 7 ++++++-
1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/block/blk-map.c b/block/blk-map.c
index 7196a6b64c80..1378f49ca5ca 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -236,6 +236,7 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
{
unsigned int max_sectors = queue_max_hw_sectors(rq->q);
unsigned int nr_vecs = iov_iter_npages(iter, BIO_MAX_VECS);
+ unsigned int flags = 0;
struct bio *bio;
int ret;
int j;
@@ -248,13 +249,17 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
return -ENOMEM;
bio_init(bio, NULL, bio->bi_inline_vecs, nr_vecs, req_op(rq));

+ if (blk_queue_pci_p2pdma(rq->q))
+ flags |= FOLL_PCI_P2PDMA;
+
while (iov_iter_count(iter)) {
struct page **pages;
ssize_t bytes;
size_t offs, added = 0;
int npages;

- bytes = iov_iter_get_pages_alloc2(iter, &pages, LONG_MAX, &offs);
+ bytes = iov_iter_get_pages_alloc_flags(iter, &pages, LONG_MAX,
+ &offs, flags);
if (unlikely(bytes <= 0)) {
ret = bytes ? bytes : -EFAULT;
goto out_unmap;
--
2.30.2