iov_iter: introduce hash_and_copy_to_iter helper

Allow consumers that want to use iov iterator helpers and also update
a predefined hash calculation online when copying data. This is useful
when copying incoming network buffers to a local iterator and calculate
a digest on the incoming stream. nvme-tcp host driver that will be
introduced in following patches is the first consumer via
skb_copy_and_hash_datagram_iter.

Acked-by: David S. Miller <davem@davemloft.net>
Signed-off-by: Sagi Grimberg <sagi@lightbitslabs.com>
Signed-off-by: Christoph Hellwig <hch@lst.de>
This commit is contained in:
Sagi Grimberg
2018-12-03 17:52:09 -08:00
committed by Christoph Hellwig
parent 950fcaecd5
commit d05f443554
2 changed files with 19 additions and 0 deletions

View File

@@ -11,6 +11,7 @@
#include <linux/kernel.h>
#include <linux/thread_info.h>
#include <crypto/hash.h>
#include <uapi/linux/uio.h>
struct page;
@@ -269,6 +270,8 @@ static inline void iov_iter_reexpand(struct iov_iter *i, size_t count)
size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, struct iov_iter *i);
size_t csum_and_copy_from_iter(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
bool csum_and_copy_from_iter_full(void *addr, size_t bytes, __wsum *csum, struct iov_iter *i);
size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp,
struct iov_iter *i);
int import_iovec(int type, const struct iovec __user * uvector,
unsigned nr_segs, unsigned fast_segs,