3 files changed, 28 insertions, 39 deletions

diff --git a/block/blk-map.c b/block/blk-map.c
index a54f0543b956..b9f88b7751fb 100644
--- a/block/blk-map.c
+++ b/block/blk-map.c
@@ -9,24 +9,6 @@
 
 #include "blk.h"
 
-static bool iovec_gap_to_prv(struct request_queue *q,
-                             struct iovec *prv, struct iovec *cur)
-{
-        unsigned long prev_end;
-
-        if (!queue_virt_boundary(q))
-                return false;
-
-        if (prv->iov_base == NULL && prv->iov_len == 0)
-                /* prv is not set - don't check */
-                return false;
-
-        prev_end = (unsigned long)(prv->iov_base + prv->iov_len);
-
-        return (((unsigned long)cur->iov_base & queue_virt_boundary(q)) ||
-                prev_end & queue_virt_boundary(q));
-}
-
 int blk_rq_append_bio(struct request_queue *q, struct request *rq,
                       struct bio *bio)
 {
@@ -125,31 +107,18 @@ int blk_rq_map_user_iov(struct request_queue *q, struct request *rq,
                         struct rq_map_data *map_data,
                         const struct iov_iter *iter, gfp_t gfp_mask)
 {
-        struct iovec iov, prv = {.iov_base = NULL, .iov_len = 0};
-        bool copy = (q->dma_pad_mask & iter->count) || map_data;
+        bool copy = false;
+        unsigned long align = q->dma_pad_mask | queue_dma_alignment(q);
         struct bio *bio = NULL;
         struct iov_iter i;
         int ret;
 
-        if (!iter || !iter->count)
-                return -EINVAL;
-
-        iov_for_each(iov, i, *iter) {
-                unsigned long uaddr = (unsigned long) iov.iov_base;
-
-                if (!iov.iov_len)
-                        return -EINVAL;
-
-                /*
-                 * Keep going so we check length of all segments
-                 */
-                if ((uaddr & queue_dma_alignment(q)) ||
-                    iovec_gap_to_prv(q, &prv, &iov))
-                        copy = true;
-
-                prv.iov_base = iov.iov_base;
-                prv.iov_len = iov.iov_len;
-        }
+        if (map_data)
+                copy = true;
+        else if (iov_iter_alignment(iter) & align)
+                copy = true;
+        else if (queue_virt_boundary(q))
+                copy = queue_virt_boundary(q) & iov_iter_gap_alignment(iter);
 
         i = *iter;
         do {
diff --git a/include/linux/uio.h b/include/linux/uio.h
index fd9bcfedad42..1b5d1cd796e2 100644
--- a/include/linux/uio.h
+++ b/include/linux/uio.h
@@ -87,6 +87,7 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i);
 size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i);
 size_t iov_iter_zero(size_t bytes, struct iov_iter *);
 unsigned long iov_iter_alignment(const struct iov_iter *i);
+unsigned long iov_iter_gap_alignment(const struct iov_iter *i);
 void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov,
                         unsigned long nr_segs, size_t count);
 void iov_iter_kvec(struct iov_iter *i, int direction, const struct kvec *kvec,
diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5fecddc32b1b..ca5316e0087b 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -569,6 +569,25 @@ unsigned long iov_iter_alignment(const struct iov_iter *i)
 }
 EXPORT_SYMBOL(iov_iter_alignment);
 
+unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
+{
+        unsigned long res = 0;
+        size_t size = i->count;
+        if (!size)
+                return 0;
+
+        iterate_all_kinds(i, size, v,
+                (res |= (!res ? 0 : (unsigned long)v.iov_base) |
+                        (size != v.iov_len ? size : 0), 0),
+                (res |= (!res ? 0 : (unsigned long)v.bv_offset) |
+                        (size != v.bv_len ? size : 0)),
+                (res |= (!res ? 0 : (unsigned long)v.iov_base) |
+                        (size != v.iov_len ? size : 0))
+                );
+                return res;
+}
+EXPORT_SYMBOL(iov_iter_gap_alignment);
+
 ssize_t iov_iter_get_pages(struct iov_iter *i,
                    struct page **pages, size_t maxsize, unsigned maxpages,
                    size_t *start)