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Subject: [PATCH 08/29] iov_iter: Split the iterate_all_kinds() macro
From:   David Howells <dhowells@redhat.com>
To:     Pavel Begunkov <asml.silence@gmail.com>,
        Matthew Wilcox <willy@infradead.org>,
        Jens Axboe <axboe@kernel.dk>,
        Alexander Viro <viro@zeniv.linux.org.uk>
Cc:     dhowells@redhat.com,
        Linus Torvalds <torvalds@linux-foundation.org>,
        linux-fsdevel@vger.kernel.org, linux-block@vger.kernel.org,
        linux-kernel@vger.kernel.org
Date:   Sat, 21 Nov 2020 14:14:25 +0000
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Precedence: bulk

Split the iterate_all_kinds() macro into iovec, bvec and kvec variants.
It doesn't handle pipes and the discard variant is a no-op and can be built
in directly.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 lib/iov_iter.c |   27 +++++++++++++++++++++++++++
 1 file changed, 27 insertions(+)

diff --git a/lib/iov_iter.c b/lib/iov_iter.c
index 5b18dfe0dcc7..934193627540 100644
--- a/lib/iov_iter.c
+++ b/lib/iov_iter.c
@@ -106,6 +106,33 @@ static inline bool page_copy_sane(struct page *page, size_t offset, size_t n);
 	}							\
 }
 
+#define iterate_over_iovec(i, n, v, CMD) {			\
+	if (likely(n)) {					\
+		size_t skip = i->iov_offset;			\
+		const struct iovec *iov;			\
+		struct iovec v;					\
+		iterate_iovec(i, n, v, iov, skip, (CMD))	\
+	}							\
+}
+
+#define iterate_over_bvec(i, n, v, CMD) {			\
+	if (likely(n)) {					\
+		size_t skip = i->iov_offset;			\
+		struct bio_vec v;				\
+		struct bvec_iter __bi;				\
+		iterate_bvec(i, n, v, __bi, skip, (CMD))	\
+	}							\
+}
+
+#define iterate_over_kvec(i, n, v, CMD) {			\
+	if (likely(n)) {					\
+		size_t skip = i->iov_offset;			\
+		const struct kvec *kvec;			\
+		struct kvec v;					\
+		iterate_kvec(i, n, v, kvec, skip, (CMD))	\
+	}							\
+}
+
 #define iterate_and_advance(i, n, v, I, B, K) {			\
 	if (unlikely(i->count < n))				\
 		n = i->count;					\