}
#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 (n) { \
+ 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; \
+ } \
+ 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,
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),
}
EXPORT_SYMBOL(iov_iter_alignment);
+unsigned long iov_iter_gap_alignment(const struct iov_iter *i)
+{
+ unsigned long res = 0;
+ size_t size = i->count;
+ if (!size)
+ return 0;
+
+ iterate_all_kinds(i, size, v,
+ (res |= (!res ? 0 : (unsigned long)v.iov_base) |
+ (size != v.iov_len ? size : 0), 0),
+ (res |= (!res ? 0 : (unsigned long)v.bv_offset) |
+ (size != v.bv_len ? size : 0)),
+ (res |= (!res ? 0 : (unsigned long)v.iov_base) |
+ (size != v.iov_len ? size : 0))
+ );
+ return res;
+}
+EXPORT_SYMBOL(iov_iter_gap_alignment);
+
ssize_t iov_iter_get_pages(struct iov_iter *i,
struct page **pages, size_t maxsize, unsigned maxpages,
size_t *start)
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;