block: set FOLL_PCI_P2PDMA in bio_map_user_iov()

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>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: John Hubbard <jhubbard@nvidia.com>
Reviewed-by: Chaitanya Kulkarni <kch@nvidia.com>
Link: https://lore.kernel.org/r/20221021174116.7200-8-logang@deltatee.com
Signed-off-by: Jens Axboe <axboe@kernel.dk>

diff --git a/block/blk-map.c b/block/blk-map.c
index 46688e7..19940c9 100644 (file)
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -267,6 +267,7 @@ 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 gup_flags = 0;
        struct bio *bio;
        int ret;
        int j;
@@ -278,6 +279,9 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
        if (bio == NULL)
                return -ENOMEM;
 
+       if (blk_queue_pci_p2pdma(rq->q))
+               gup_flags |= FOLL_PCI_P2PDMA;
+
        while (iov_iter_count(iter)) {
                struct page **pages, *stack_pages[UIO_FASTIOV];
                ssize_t bytes;
@@ -286,11 +290,11 @@ static int bio_map_user_iov(struct request *rq, struct iov_iter *iter,
 
                if (nr_vecs <= ARRAY_SIZE(stack_pages)) {
                        pages = stack_pages;
-                       bytes = iov_iter_get_pages2(iter, pages, LONG_MAX,
-                                                       nr_vecs, &offs);
+                       bytes = iov_iter_get_pages(iter, pages, LONG_MAX,
+                                                  nr_vecs, &offs, gup_flags);
                } else {
-                       bytes = iov_iter_get_pages_alloc2(iter, &pages,
-                                                       LONG_MAX, &offs);
+                       bytes = iov_iter_get_pages_alloc(iter, &pages,
+                                               LONG_MAX, &offs, gup_flags);
                }
                if (unlikely(bytes <= 0)) {
                        ret = bytes ? bytes : -EFAULT;