n = wanted; \
}
-#define iterate_bvec(i, n, __v, __p, skip, STEP) { \
- size_t wanted = n; \
- __p = i->bvec; \
- __v.bv_len = min_t(size_t, n, __p->bv_len - skip); \
- if (likely(__v.bv_len)) { \
- __v.bv_page = __p->bv_page; \
- __v.bv_offset = __p->bv_offset + skip; \
- (void)(STEP); \
- skip += __v.bv_len; \
- n -= __v.bv_len; \
- } \
- while (unlikely(n)) { \
- __p++; \
- __v.bv_len = min_t(size_t, n, __p->bv_len); \
- if (unlikely(!__v.bv_len)) \
+#define iterate_bvec(i, n, __v, __bi, skip, STEP) { \
+ struct bvec_iter __start; \
+ __start.bi_size = n; \
+ __start.bi_bvec_done = skip; \
+ __start.bi_idx = 0; \
+ for_each_bvec(__v, i->bvec, __bi, __start) { \
+ if (!__v.bv_len) \
continue; \
- __v.bv_page = __p->bv_page; \
- __v.bv_offset = __p->bv_offset; \
(void)(STEP); \
- skip = __v.bv_len; \
- n -= __v.bv_len; \
} \
- n = wanted; \
}
#define iterate_all_kinds(i, n, v, I, B, K) { \
size_t skip = i->iov_offset; \
if (unlikely(i->type & ITER_BVEC)) { \
- const struct bio_vec *bvec; \
struct bio_vec v; \
- iterate_bvec(i, n, v, bvec, skip, (B)) \
+ struct bvec_iter __bi; \
+ iterate_bvec(i, n, v, __bi, skip, (B)) \
} else if (unlikely(i->type & ITER_KVEC)) { \
const struct kvec *kvec; \
struct kvec v; \
}
#define iterate_and_advance(i, n, v, I, B, K) { \
- size_t skip = i->iov_offset; \
- if (unlikely(i->type & ITER_BVEC)) { \
- const struct bio_vec *bvec; \
- struct bio_vec v; \
- iterate_bvec(i, n, v, bvec, skip, (B)) \
- if (skip == bvec->bv_len) { \
- bvec++; \
- skip = 0; \
- } \
- i->nr_segs -= bvec - i->bvec; \
- i->bvec = bvec; \
- } else if (unlikely(i->type & ITER_KVEC)) { \
- const struct kvec *kvec; \
- struct kvec v; \
- iterate_kvec(i, n, v, kvec, skip, (K)) \
- if (skip == kvec->iov_len) { \
- kvec++; \
- skip = 0; \
- } \
- i->nr_segs -= kvec - i->kvec; \
- i->kvec = kvec; \
- } else { \
- const struct iovec *iov; \
- struct iovec v; \
- iterate_iovec(i, n, v, iov, skip, (I)) \
- if (skip == iov->iov_len) { \
- iov++; \
- skip = 0; \
+ if (unlikely(i->count < n)) \
+ n = i->count; \
+ if (i->count) { \
+ size_t skip = i->iov_offset; \
+ if (unlikely(i->type & ITER_BVEC)) { \
+ const struct bio_vec *bvec = i->bvec; \
+ struct bio_vec v; \
+ struct bvec_iter __bi; \
+ iterate_bvec(i, n, v, __bi, skip, (B)) \
+ i->bvec = __bvec_iter_bvec(i->bvec, __bi); \
+ i->nr_segs -= i->bvec - bvec; \
+ skip = __bi.bi_bvec_done; \
+ } else if (unlikely(i->type & ITER_KVEC)) { \
+ const struct kvec *kvec; \
+ struct kvec v; \
+ iterate_kvec(i, n, v, kvec, skip, (K)) \
+ if (skip == kvec->iov_len) { \
+ kvec++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= kvec - i->kvec; \
+ i->kvec = kvec; \
+ } else { \
+ const struct iovec *iov; \
+ struct iovec v; \
+ iterate_iovec(i, n, v, iov, skip, (I)) \
+ if (skip == iov->iov_len) { \
+ iov++; \
+ skip = 0; \
+ } \
+ i->nr_segs -= iov - i->iov; \
+ i->iov = iov; \
} \
- i->nr_segs -= iov - i->iov; \
- i->iov = iov; \
+ i->count -= n; \
+ i->iov_offset = skip; \
} \
- i->count -= n; \
- i->iov_offset = skip; \
}
static size_t copy_page_to_iter_iovec(struct page *page, size_t offset, size_t bytes,
buf = iov->iov_base + skip;
copy = min(bytes, iov->iov_len - skip);
- if (!fault_in_pages_writeable(buf, copy)) {
+ if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_writeable(buf, copy)) {
kaddr = kmap_atomic(page);
from = kaddr + offset;
copy = min(bytes, iov->iov_len - skip);
}
/* Too bad - revert to non-atomic kmap */
+
kaddr = kmap(page);
from = kaddr + offset;
left = __copy_to_user(buf, from, copy);
bytes -= copy;
}
kunmap(page);
+
done:
if (skip == iov->iov_len) {
iov++;
buf = iov->iov_base + skip;
copy = min(bytes, iov->iov_len - skip);
- if (!fault_in_pages_readable(buf, copy)) {
+ if (IS_ENABLED(CONFIG_HIGHMEM) && !fault_in_pages_readable(buf, copy)) {
kaddr = kmap_atomic(page);
to = kaddr + offset;
copy = min(bytes, iov->iov_len - skip);
}
/* Too bad - revert to non-atomic kmap */
+
kaddr = kmap(page);
to = kaddr + offset;
left = __copy_from_user(to, buf, copy);
bytes -= copy;
}
kunmap(page);
+
done:
if (skip == iov->iov_len) {
iov++;
size_t copy_to_iter(const void *addr, size_t bytes, struct iov_iter *i)
{
const char *from = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_to_user(v.iov_base, (from += v.iov_len) - v.iov_len,
v.iov_len),
size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_from_user((to += v.iov_len) - v.iov_len, v.iov_base,
v.iov_len),
size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i)
{
char *to = addr;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__copy_from_user_nocache((to += v.iov_len) - v.iov_len,
v.iov_base, v.iov_len),
size_t iov_iter_zero(size_t bytes, struct iov_iter *i)
{
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
iterate_and_advance(i, bytes, v,
__clear_user(v.iov_base, v.iov_len),
memzero_page(v.bv_page, v.bv_offset, v.bv_len),
char *to = addr;
__wsum sum, next;
size_t off = 0;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
sum = *csum;
iterate_and_advance(i, bytes, v, ({
int err = 0;
const char *from = addr;
__wsum sum, next;
size_t off = 0;
- if (unlikely(bytes > i->count))
- bytes = i->count;
-
- if (unlikely(!bytes))
- return 0;
-
sum = *csum;
iterate_and_advance(i, bytes, v, ({
int err = 0;