From 594b9a89af8e7629e95a4cd844d188361be32790 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Wed, 27 Feb 2019 20:40:13 +0800
Subject: [PATCH] block: introduce mp_bvec_for_each_page() for iterating over
 page

mp_bvec_for_each_segment() is a bit big for the iteration, so introduce
a light-weight helper for iterating over pages, then 32bytes stack
space can be saved.

Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
---
 include/linux/bvec.h | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 4376f683c08ae..87e82e503a52f 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -188,4 +188,9 @@ static inline void mp_bvec_last_segment(const struct bio_vec *bvec,
 	}
 }
 
+#define mp_bvec_for_each_page(pg, bv, i)				\
+	for (i = (bv)->bv_offset / PAGE_SIZE;				\
+		(i <= (((bv)->bv_offset + (bv)->bv_len - 1) / PAGE_SIZE)) && \
+		(pg = bvec_nth_page((bv)->bv_page, i)); i += 1)
+
 #endif /* __LINUX_BVEC_ITER_H */
-- 
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