linux-kernel - [PATCH v2 28/51] block: introduce bvec_for_each_sp

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-Id: <20170626121034.3051-29-ming.lei@redhat.com>
Date:   Mon, 26 Jun 2017 20:10:11 +0800
From:   Ming Lei <ming.lei@...hat.com>
To:     Jens Axboe <axboe@...com>, Christoph Hellwig <hch@...radead.org>,
        Huang Ying <ying.huang@...el.com>,
        Andrew Morton <akpm@...ux-foundation.org>,
        Alexander Viro <viro@...iv.linux.org.uk>
Cc:     linux-kernel@...r.kernel.org, linux-block@...r.kernel.org,
        linux-fsdevel@...r.kernel.org, linux-mm@...ck.org,
        Ming Lei <ming.lei@...hat.com>
Subject: [PATCH v2 28/51] block: introduce bvec_for_each_sp_bvec()

This helper can be used to iterate each singlepage bvec
from one multipage bvec.

Signed-off-by: Ming Lei <ming.lei@...hat.com>
---
 include/linux/bvec.h | 14 ++++++++++++++
 1 file changed, 14 insertions(+)

diff --git a/include/linux/bvec.h b/include/linux/bvec.h
index 5c51c58fe202..7addceea9828 100644
--- a/include/linux/bvec.h
+++ b/include/linux/bvec.h
@@ -192,4 +192,18 @@ static inline void bvec_iter_advance_mp(const struct bio_vec *bv,
 	.bi_bvec_done	= 0,						\
 }
 
+/*
+ * This helper iterates over the multipage bvec of @mp_bvec and
+ * returns each singlepage bvec via @sp_bvl.
+ */
+#define __bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, start)		\
+	for (iter = start,						\
+	     (iter).bi_size = (mp_bvec)->bv_len  - (iter).bi_bvec_done;	\
+	     (iter).bi_size &&						\
+		((sp_bvl = bvec_iter_bvec((mp_bvec), (iter))), 1);	\
+	     bvec_iter_advance((mp_bvec), &(iter), (sp_bvl).bv_len))
+
+#define bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter)			\
+	__bvec_for_each_sp_bvec(sp_bvl, mp_bvec, iter, BVEC_ITER_ALL_INIT)
+
 #endif /* __LINUX_BVEC_ITER_H */
-- 
2.9.4