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 <viro@zeniv.linux.org.uk>

diff --git a/block/bio.c b/block/bio.c
index e87f70c..ad34cdb 100644 (file)
--- 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)