diff options
| -rw-r--r-- | include/linux/uio.h | 1 | ||||
| -rw-r--r-- | mm/iov_iter.c | 21 |
2 files changed, 22 insertions, 0 deletions
diff --git a/include/linux/uio.h b/include/linux/uio.h index c567655b9595..bd8569a14c4a 100644 --- a/include/linux/uio.h +++ b/include/linux/uio.h @@ -83,6 +83,7 @@ size_t copy_page_from_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i); size_t copy_to_iter(void *addr, size_t bytes, struct iov_iter *i); size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i); +size_t copy_from_iter_nocache(void *addr, size_t bytes, struct iov_iter *i); size_t iov_iter_zero(size_t bytes, struct iov_iter *); unsigned long iov_iter_alignment(const struct iov_iter *i); void iov_iter_init(struct iov_iter *i, int direction, const struct iovec *iov, diff --git a/mm/iov_iter.c b/mm/iov_iter.c index 88c052e63a1d..a1599ca4ab0e 100644 --- a/mm/iov_iter.c +++ b/mm/iov_iter.c @@ -399,6 +399,27 @@ size_t copy_from_iter(void *addr, size_t bytes, struct iov_iter *i) } EXPORT_SYMBOL(copy_from_iter); +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), + memcpy_from_page((to += v.bv_len) - v.bv_len, v.bv_page, + v.bv_offset, v.bv_len), + memcpy((to += v.iov_len) - v.iov_len, v.iov_base, v.iov_len) + ) + + return bytes; +} +EXPORT_SYMBOL(copy_from_iter_nocache); + size_t copy_page_to_iter(struct page *page, size_t offset, size_t bytes, struct iov_iter *i) { |