From 0e5b935d43f385ab23d2e38e7134b1abb0e7907e Mon Sep 17 00:00:00 2001 From: Al Viro Date: Sun, 24 Sep 2017 13:14:35 -0400 Subject: [PATCH] bio_alloc_map_data(): do bmd->iter setup right there just need to copy it iter instead of iter->nr_segs Signed-off-by: Al Viro --- block/bio.c | 20 ++++++++++++-------- 1 file changed, 12 insertions(+), 8 deletions(-) diff --git a/block/bio.c b/block/bio.c index e87f70cd528e..ad34cdb99ad2 100644 --- a/block/bio.c +++ b/block/bio.c @@ -1070,14 +1070,21 @@ struct bio_map_data { struct iovec iov[]; }; -static struct bio_map_data *bio_alloc_map_data(unsigned int iov_count, +static struct bio_map_data *bio_alloc_map_data(struct iov_iter *data, gfp_t gfp_mask) { - if (iov_count > UIO_MAXIOV) + struct bio_map_data *bmd; + if (data->nr_segs > UIO_MAXIOV) return NULL; - return kmalloc(sizeof(struct bio_map_data) + - sizeof(struct iovec) * iov_count, gfp_mask); + bmd = kmalloc(sizeof(struct bio_map_data) + + sizeof(struct iovec) * data->nr_segs, gfp_mask); + if (!bmd) + return NULL; + memcpy(bmd->iov, data->iov, sizeof(struct iovec) * data->nr_segs); + bmd->iter = *data; + bmd->iter.iov = bmd->iov; + return bmd; } /** @@ -1206,7 +1213,7 @@ struct bio *bio_copy_user_iov(struct request_queue *q, unsigned int len = iter->count; unsigned int offset = map_data ? offset_in_page(map_data->offset) : 0; - bmd = bio_alloc_map_data(iter->nr_segs, gfp_mask); + bmd = bio_alloc_map_data(iter, gfp_mask); if (!bmd) return ERR_PTR(-ENOMEM); @@ -1216,9 +1223,6 @@ struct bio *bio_copy_user_iov(struct request_queue *q, * shortlived one. */ bmd->is_our_pages = map_data ? 0 : 1; - memcpy(bmd->iov, iter->iov, sizeof(struct iovec) * iter->nr_segs); - bmd->iter = *iter; - bmd->iter.iov = bmd->iov; nr_pages = DIV_ROUND_UP(offset + len, PAGE_SIZE); if (nr_pages > BIO_MAX_PAGES) -- 2.25.1