bio: convert bio_copy_kern to use bio_copy_user

bio_copy_kern and bio_copy_user are very similar. This converts
bio_copy_kern to use bio_copy_user.

Signed-off-by: FUJITA Tomonori <fujita.tomonori@lab.ntt.co.jp>
Cc: Jens Axboe <jens.axboe@oracle.com>
Signed-off-by: Jens Axboe <jens.axboe@oracle.com>

1 files changed, 4 insertions, 50 deletions

diff --git a/fs/bio.c b/fs/bio.c
index a2f072647cdf..9d68ddb89b71 100644
--- a/fs/bio.c
+++ b/fs/bio.c
@@ -995,48 +995,13 @@ static void bio_copy_kern_endio(struct bio *bio, int err)
 struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
                           gfp_t gfp_mask, int reading)
 {
-        unsigned long kaddr = (unsigned long)data;
-        unsigned long end = (kaddr + len + PAGE_SIZE - 1) >> PAGE_SHIFT;
-        unsigned long start = kaddr >> PAGE_SHIFT;
-        const int nr_pages = end - start;
         struct bio *bio;
         struct bio_vec *bvec;
-        struct bio_map_data *bmd;
-        int i, ret;
-        struct sg_iovec iov;
-
-        iov.iov_base = data;
-        iov.iov_len = len;
-
-        bmd = bio_alloc_map_data(nr_pages, 1, gfp_mask);
-        if (!bmd)
-                return ERR_PTR(-ENOMEM);
-
-        ret = -ENOMEM;
-        bio = bio_alloc(gfp_mask, nr_pages);
-        if (!bio)
-                goto out_bmd;
-
-        while (len) {
-                struct page *page;
-                unsigned int bytes = PAGE_SIZE;
-
-                if (bytes > len)
-                        bytes = len;
-
-                page = alloc_page(q->bounce_gfp | gfp_mask);
-                if (!page) {
-                        ret = -ENOMEM;
-                        goto cleanup;
-                }
-
-                if (bio_add_pc_page(q, bio, page, bytes, 0) < bytes) {
-                        ret = -EINVAL;
-                        goto cleanup;
-                }
+        int i;
 
-                len -= bytes;
-        }
+        bio = bio_copy_user(q, NULL, (unsigned long)data, len, 1, gfp_mask);
+        if (IS_ERR(bio))
+                return bio;
 
         if (!reading) {
                 void *p = data;
@@ -1049,20 +1014,9 @@ struct bio *bio_copy_kern(struct request_queue *q, void *data, unsigned int len,
                 }
         }
 
-        bio->bi_private = bmd;
         bio->bi_end_io = bio_copy_kern_endio;
 
-        bio_set_map_data(bmd, bio, &iov, 1, 1);
         return bio;
-cleanup:
-        bio_for_each_segment(bvec, bio, i)
-                __free_page(bvec->bv_page);
-
-        bio_put(bio);
-out_bmd:
-        bio_free_map_data(bmd);
-
-        return ERR_PTR(ret);
 }
 
 /*