From d05f443554b3c7dc6d46e3ba9c3c4de468875d4f Mon Sep 17 00:00:00 2001 From: Sagi Grimberg Date: Mon, 3 Dec 2018 17:52:09 -0800 Subject: 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 Signed-off-by: Sagi Grimberg Signed-off-by: Christoph Hellwig --- lib/iov_iter.c | 16 ++++++++++++++++ 1 file changed, 16 insertions(+) (limited to 'lib') diff --git a/lib/iov_iter.c b/lib/iov_iter.c index 63a8999a234d..1928009f506e 100644 --- a/lib/iov_iter.c +++ b/lib/iov_iter.c @@ -6,6 +6,7 @@ #include #include #include +#include #define PIPE_PARANOIA /* for now */ @@ -1511,6 +1512,21 @@ size_t csum_and_copy_to_iter(const void *addr, size_t bytes, void *csump, } EXPORT_SYMBOL(csum_and_copy_to_iter); +size_t hash_and_copy_to_iter(const void *addr, size_t bytes, void *hashp, + struct iov_iter *i) +{ + struct ahash_request *hash = hashp; + struct scatterlist sg; + size_t copied; + + copied = copy_to_iter(addr, bytes, i); + sg_init_one(&sg, addr, copied); + ahash_request_set_crypt(hash, &sg, NULL, copied); + crypto_ahash_update(hash); + return copied; +} +EXPORT_SYMBOL(hash_and_copy_to_iter); + int iov_iter_npages(const struct iov_iter *i, int maxpages) { size_t size = i->count; -- cgit v1.2.3