1 files changed, 96 insertions, 2 deletions

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 691a52b634fe..228892dabba6 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -569,6 +569,31 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
 }
 EXPORT_SYMBOL(copy_from_iter);
 
+bool copy_from_iter_full(void *addr, size_t bytes, struct iov_iter *i)
+{
+        char *to = addr;
+        if (unlikely(i->type & ITER_PIPE)) {
+                WARN_ON(1);
+                return false;
+        }
+        if (unlikely(i->count < bytes))                         \
+                return false;
+
+        iterate_all_kinds(i, bytes, v, ({
+                if (__copy_from_user((to += v.iov_len) - v.iov_len,
+                                      v.iov_base, v.iov_len))
+                        return false;
+                0;}),
+                memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+                                 v.bv_offset, v.bv_len),
+                memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+        )
+
+        iov_iter_advance(i, bytes);
+        return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full);
+
 size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 {
         char *to = addr;
@@ -588,6 +613,30 @@ size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
 }
 EXPORT_SYMBOL(copy_from_iter_nocache);
 
+bool copy_from_iter_full_nocache(void *addr, size_t bytes, struct iov_iter *i)
+{
+        char *to = addr;
+        if (unlikely(i->type & ITER_PIPE)) {
+                WARN_ON(1);
+                return false;
+        }
+        if (unlikely(i->count < bytes))                         \
+                return false;
+        iterate_all_kinds(i, bytes, v, ({
+                if (__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
+                                             v.iov_base, v.iov_len))
+                        return false;
+                0;}),
+                memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page,
+                                 v.bv_offset, v.bv_len),
+                memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len)
+        )
+
+        iov_iter_advance(i, bytes);
+        return true;
+}
+EXPORT_SYMBOL(copy_from_iter_full_nocache);
+
 size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes,
                          struct iov_iter *i)
 {
@@ -1009,7 +1058,7 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
         }
         iterate_and_advance(i, bytes, v, ({
                 int err = 0;
-                next = csum_and_copy_from_user(v.iov_base, 
+                next = csum_and_copy_from_user(v.iov_base,
                                                (to += v.iov_len) - v.iov_len,
                                                v.iov_len, 0, &err);
                 if (!err) {
@@ -1038,6 +1087,51 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
 }
 EXPORT_SYMBOL(csum_and_copy_from_iter);
 
+bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+                               struct iov_iter *i)
+{
+        char *to = addr;
+        __wsum sum, next;
+        size_t off = 0;
+        sum = *csum;
+        if (unlikely(i->type & ITER_PIPE)) {
+                WARN_ON(1);
+                return false;
+        }
+        if (unlikely(i->count < bytes))
+                return false;
+        iterate_all_kinds(i, bytes, v, ({
+                int err = 0;
+                next = csum_and_copy_from_user(v.iov_base,
+                                               (to += v.iov_len) - v.iov_len,
+                                               v.iov_len, 0, &err);
+                if (err)
+                        return false;
+                sum = csum_block_add(sum, next, off);
+                off += v.iov_len;
+                0;
+        }), ({
+                char *p = kmap_atomic(v.bv_page);
+                next = csum_partial_copy_nocheck(p + v.bv_offset,
+                                                 (to += v.bv_len) - v.bv_len,
+                                                 v.bv_len, 0);
+                kunmap_atomic(p);
+                sum = csum_block_add(sum, next, off);
+                off += v.bv_len;
+        }),({
+                next = csum_partial_copy_nocheck(v.iov_base,
+                                                 (to += v.iov_len) - v.iov_len,
+                                                 v.iov_len, 0);
+                sum = csum_block_add(sum, next, off);
+                off += v.iov_len;
+        })
+        )
+        *csum = sum;
+        iov_iter_advance(i, bytes);
+        return true;
+}
+EXPORT_SYMBOL(csum_and_copy_from_iter_full);
+
 size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
                              struct iov_iter *i)
 {
@@ -1052,7 +1146,7 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
         iterate_and_advance(i, bytes, v, ({
                 int err = 0;
                 next = csum_and_copy_to_user((from += v.iov_len) - v.iov_len,
-                                             v.iov_base, 
+                                             v.iov_base,
                                              v.iov_len, 0, &err);
                 if (!err) {
                         sum = csum_block_add(sum, next, off);