From 98f0bc99055da5797fae0c35d3d18261d59df9ac Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sat, 23 Sep 2017 16:23:18 -0400 Subject: [PATCH] bio_map_user_iov(): move alignment check into the main loop Signed-off-by: Al Viro --- block/bio.c | 46 +++++++++++++++++++++++----------------------- 1 file changed, 23 insertions(+), 23 deletions(-) diff --git a/block/bio.c b/block/bio.c index fe40948d62af..d851f68727f1 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1344,11 +1344,6 @@ struct bio *bio_map_user_iov(struct request_queue *q, return ERR_PTR(-EINVAL); nr_pages += end - start; - /* - * buffer must be aligned to at least logical block size for now - */ - if (uaddr & queue_dma_alignment(q)) - return ERR_PTR(-EINVAL); } if (!nr_pages) @@ -1373,29 +1368,34 @@ struct bio *bio_map_user_iov(struct request_queue *q, npages = DIV_ROUND_UP(offs + bytes, PAGE_SIZE); - for (j = 0; j < npages; j++) { - unsigned int n = PAGE_SIZE - offs; - unsigned short prev_bi_vcnt = bio->bi_vcnt; + if (unlikely(offs & queue_dma_alignment(q))) { + ret = -EINVAL; + j = 0; + } else { + for (j = 0; j < npages; j++) { + struct page *page = pages[j]; + unsigned int n = PAGE_SIZE - offs; + unsigned short prev_bi_vcnt = bio->bi_vcnt; - if (n > bytes) - n = bytes; + if (n > bytes) + n = bytes; - if (!bio_add_pc_page(q, bio, pages[j], n, offs)) - break; + if (!bio_add_pc_page(q, bio, page, n, offs)) + break; - /* - * check if vector was merged with previous - * drop page reference if needed - */ - if (bio->bi_vcnt == prev_bi_vcnt) - put_page(pages[j]); + /* + * check if vector was merged with previous + * drop page reference if needed + */ + if (bio->bi_vcnt == prev_bi_vcnt) + put_page(page); - added += n; - bytes -= n; - offs = 0; + added += n; + bytes -= n; + offs = 0; + } + iov_iter_advance(&i, added); } - iov_iter_advance(&i, added); - /* * release the pages we didn't map into the bio, if any */