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From: Ming Lei <ming.lei@redhat.com>
To: Jens Axboe <axboe@kernel.dk>
Cc: linux-block@vger.kernel.org, Ming Lei <ming.lei@redhat.com>
Subject: [PATCH] block: fix mp_bvec_for_each_page
Date: Thu, 28 Feb 2019 20:29:27 +0800	[thread overview]
Message-ID: <20190228122927.3495-1-ming.lei@redhat.com> (raw)

mp_bvec_for_each_page() may miss the 1st page in case that the bvec
ends before last byte of the 1st PAGE.

So fix it by checking against the last page.

Fixes: 05d5585e42a399700 ("block: introduce mp_bvec_for_each_page() for iterating over page")
Signed-off-by: Ming Lei <ming.lei@redhat.com>
---
 include/linux/bvec.h | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 98a140fa4dac..85894d5000a1 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -197,7 +197,7 @@ 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) / 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 */
-- 
2.9.5


             reply	other threads:[~2019-02-28 12:29 UTC|newest]

Thread overview: 2+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-02-28 12:29 Ming Lei [this message]
2019-02-28 12:56 ` [PATCH] block: fix mp_bvec_for_each_page Jens Axboe

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