[PATCH 24/29] iov_iter: Split csum_and_copy_from_iter_full()

From: David Howells
Date: Sat Nov 21 2020 - 09:16:53 EST


Split csum_and_copy_from_iter_full() by type.

Signed-off-by: David Howells <dhowells@xxxxxxxxxx>
---

lib/iov_iter.c | 62 ++++++++++++++++++++++++++++++++++++++++++--------------
1 file changed, 47 insertions(+), 15 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 1f596cffddf9..8820a9e72815 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1841,20 +1841,16 @@ static size_t no_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
return 0;
}

-static bool xxx_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+static bool iovec_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(iov_iter_is_pipe(i) || iov_iter_is_discard(i))) {
- WARN_ON(1);
- return false;
- }
if (unlikely(i->count < bytes))
return false;
- iterate_all_kinds(i, bytes, v, ({
+ iterate_over_iovec(i, bytes, v, ({
next = csum_and_copy_from_user(v.iov_base,
(to += v.iov_len) - v.iov_len,
v.iov_len);
@@ -1863,25 +1859,61 @@ static bool xxx_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *c
sum = csum_block_add(sum, next, off);
off += v.iov_len;
0;
- }), ({
+ }));
+ *csum = sum;
+ iov_iter_advance(i, bytes);
+ return true;
+}
+
+static bool bvec_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum;
+ size_t off = 0;
+ sum = *csum;
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_over_bvec(i, bytes, v, ({
char *p = kmap_atomic(v.bv_page);
sum = csum_and_memcpy((to += v.bv_len) - v.bv_len,
p + v.bv_offset, v.bv_len,
sum, off);
kunmap_atomic(p);
off += v.bv_len;
- }),({
+ }));
+ *csum = sum;
+ iov_iter_advance(i, bytes);
+ return true;
+}
+
+static bool kvec_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum;
+ size_t off = 0;
+ sum = *csum;
+ if (unlikely(i->count < bytes))
+ return false;
+ iterate_over_kvec(i, bytes, v, ({
sum = csum_and_memcpy((to += v.iov_len) - v.iov_len,
v.iov_base, v.iov_len,
sum, off);
off += v.iov_len;
- })
- )
+ }));
*csum = sum;
iov_iter_advance(i, bytes);
return true;
}

+static bool no_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ WARN_ON(1);
+ return false;
+}
+
static size_t xxx_csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump,
struct iov_iter *i)
{
@@ -2226,7 +2258,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
.csum_and_copy_from_iter = iovec_csum_and_copy_from_iter,
- .csum_and_copy_from_iter_full = xxx_csum_and_copy_from_iter_full,
+ .csum_and_copy_from_iter_full = iovec_csum_and_copy_from_iter_full,

.zero = iovec_zero,
.alignment = iovec_alignment,
@@ -2260,7 +2292,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
.csum_and_copy_from_iter = kvec_csum_and_copy_from_iter,
- .csum_and_copy_from_iter_full = xxx_csum_and_copy_from_iter_full,
+ .csum_and_copy_from_iter_full = kvec_csum_and_copy_from_iter_full,

.zero = kvec_zero,
.alignment = kvec_alignment,
@@ -2294,7 +2326,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
.csum_and_copy_from_iter = bvec_csum_and_copy_from_iter,
- .csum_and_copy_from_iter_full = xxx_csum_and_copy_from_iter_full,
+ .csum_and_copy_from_iter_full = bvec_csum_and_copy_from_iter_full,

.zero = bvec_zero,
.alignment = bvec_alignment,
@@ -2328,7 +2360,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
.csum_and_copy_from_iter = no_csum_and_copy_from_iter,
- .csum_and_copy_from_iter_full = xxx_csum_and_copy_from_iter_full,
+ .csum_and_copy_from_iter_full = no_csum_and_copy_from_iter_full,

.zero = pipe_zero,
.alignment = pipe_alignment,
@@ -2362,7 +2394,7 @@ static const struct iov_iter_ops discard_iter_ops = {
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
.csum_and_copy_from_iter = no_csum_and_copy_from_iter,
- .csum_and_copy_from_iter_full = xxx_csum_and_copy_from_iter_full,
+ .csum_and_copy_from_iter_full = no_csum_and_copy_from_iter_full,

.zero = discard_zero,
.alignment = no_alignment,