iov_iter: reduce code duplication
authorAl Viro <viro@zeniv.linux.org.uk>
Wed, 28 Nov 2018 03:32:59 +0000 (22:32 -0500)
committerAl Viro <viro@zeniv.linux.org.uk>
Wed, 28 Nov 2018 03:35:08 +0000 (22:35 -0500)
The same combination of csum_partial_copy_nocheck() with csum_add_block()
is used in a bunch of places.  Add a helper doing just that and use it.

Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
lib/iov_iter.c

index 54c2485..6219847 100644 (file)
@@ -560,13 +560,20 @@ static size_t copy_pipe_to_iter(const void *addr, size_t bytes,
        return bytes;
 }
 
+static __wsum csum_and_memcpy(void *to, const void *from, size_t len,
+                             __wsum sum, size_t off)
+{
+       __wsum next = csum_partial_copy_nocheck(from, to, len, 0);
+       return csum_block_add(sum, next, off);
+}
+
 static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,
                                __wsum *csum, struct iov_iter *i)
 {
        struct pipe_inode_info *pipe = i->pipe;
        size_t n, r;
        size_t off = 0;
-       __wsum sum = *csum, next;
+       __wsum sum = *csum;
        int idx;
 
        if (!sanity(i))
@@ -578,8 +585,7 @@ static size_t csum_and_copy_to_pipe_iter(const void *addr, size_t bytes,
        for ( ; n; idx = next_idx(idx, pipe), r = 0) {
                size_t chunk = min_t(size_t, n, PAGE_SIZE - r);
                char *p = kmap_atomic(pipe->bufs[idx].page);
-               next = csum_partial_copy_nocheck(addr, p + r, chunk, 0);
-               sum = csum_block_add(sum, next, off);
+               sum = csum_and_memcpy(p + r, addr, chunk, sum, off);
                kunmap_atomic(p);
                i->idx = idx;
                i->iov_offset = r + chunk;
@@ -1400,17 +1406,15 @@ size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
                err ? 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);
+               sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
+                                     p + v.bv_offset, v.bv_len,
+                                     sum, off);
                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);
+               sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
+                                     v.iov_base, v.iov_len,
+                                     sum, off);
                off += v.iov_len;
        })
        )
@@ -1444,17 +1448,15 @@ bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
                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);
+               sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
+                                     p + v.bv_offset, v.bv_len,
+                                     sum, off);
                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);
+               sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
+                                     v.iov_base, v.iov_len,
+                                     sum, off);
                off += v.iov_len;
        })
        )
@@ -1491,17 +1493,15 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, __wsum *csum,
                err ? v.iov_len : 0;
        }), ({
                char *p = kmap_atomic(v.bv_page);
-               next = csum_partial_copy_nocheck((from += v.bv_len) - v.bv_len,
-                                                p + v.bv_offset,
-                                                v.bv_len, 0);
+               sum = csum_and_memcpy(p + v.bv_offset,
+                                     (from += v.bv_len) - v.bv_len,
+                                     v.bv_len, sum, off);
                kunmap_atomic(p);
-               sum = csum_block_add(sum, next, off);
                off += v.bv_len;
        }),({
-               next = csum_partial_copy_nocheck((from += v.iov_len) - v.iov_len,
-                                                v.iov_base,
-                                                v.iov_len, 0);
-               sum = csum_block_add(sum, next, off);
+               sum = csum_and_memcpy(v.iov_base,
+                                    (from += v.iov_len) - v.iov_len,
+                                    v.iov_len, sum, off);
                off += v.iov_len;
        })
        )