[PATCH 23/29] iov_iter: Split csum_and_copy_from_iter()

From: David Howells
Date: Sat Nov 21 2020 - 09:16:52 EST


Split csum_and_copy_from_iter() by type.

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

lib/iov_iter.c | 56 +++++++++++++++++++++++++++++++++++++++++---------------
1 file changed, 41 insertions(+), 15 deletions(-)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index a038bfbbbd53..1f596cffddf9 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -1777,18 +1777,14 @@ static ssize_t no_get_pages_alloc(struct iov_iter *i,
return -EFAULT;
}

-static size_t xxx_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+static size_t iovec_csum_and_copy_from_iter(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 0;
- }
- iterate_and_advance(i, bytes, v, ({
+ iterate_and_advance_iovec(i, bytes, v, ({
next = csum_and_copy_from_user(v.iov_base,
(to += v.iov_len) - v.iov_len,
v.iov_len);
@@ -1797,24 +1793,54 @@ static size_t xxx_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum
off += v.iov_len;
}
next ? 0 : v.iov_len;
- }), ({
+ }));
+ *csum = sum;
+ return bytes;
+}
+
+static size_t bvec_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum;
+ size_t off = 0;
+ sum = *csum;
+ iterate_and_advance_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;
+ return bytes;
+}
+
+static size_t kvec_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ char *to = addr;
+ __wsum sum;
+ size_t off = 0;
+ sum = *csum;
+ iterate_and_advance_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;
return bytes;
}

+static size_t no_csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum,
+ struct iov_iter *i)
+{
+ WARN_ON(1);
+ return 0;
+}
+
static bool xxx_csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum,
struct iov_iter *i)
{
@@ -2199,7 +2225,7 @@ static const struct iov_iter_ops iovec_iter_ops = {
.copy_mc_to_iter = iovec_copy_mc_to_iter,
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
- .csum_and_copy_from_iter = xxx_csum_and_copy_from_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,

.zero = iovec_zero,
@@ -2233,7 +2259,7 @@ static const struct iov_iter_ops kvec_iter_ops = {
.copy_mc_to_iter = kvec_copy_mc_to_iter,
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
- .csum_and_copy_from_iter = xxx_csum_and_copy_from_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,

.zero = kvec_zero,
@@ -2267,7 +2293,7 @@ static const struct iov_iter_ops bvec_iter_ops = {
.copy_mc_to_iter = bvec_copy_mc_to_iter,
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
- .csum_and_copy_from_iter = xxx_csum_and_copy_from_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,

.zero = bvec_zero,
@@ -2301,7 +2327,7 @@ static const struct iov_iter_ops pipe_iter_ops = {
.copy_mc_to_iter = pipe_copy_mc_to_iter,
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
- .csum_and_copy_from_iter = xxx_csum_and_copy_from_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,

.zero = pipe_zero,
@@ -2335,7 +2361,7 @@ static const struct iov_iter_ops discard_iter_ops = {
.copy_mc_to_iter = discard_copy_to_iter,
#endif
.csum_and_copy_to_iter = xxx_csum_and_copy_to_iter,
- .csum_and_copy_from_iter = xxx_csum_and_copy_from_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,

.zero = discard_zero,