From: Ming Lei <tom.leiming@gmail.com>
To: Shaohua Li <shli@kernel.org>, Jens Axboe <axboe@fb.com>,
linux-kernel@vger.kernel.org, linux-raid@vger.kernel.org,
linux-block@vger.kernel.org,
Christoph Hellwig <hch@infradead.org>
Cc: Ming Lei <tom.leiming@gmail.com>
Subject: [PATCH v1 02/14] block: introduce bio_remove_last_page()
Date: Fri, 24 Feb 2017 23:42:39 +0800 [thread overview]
Message-ID: <1487950971-1131-3-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1487950971-1131-1-git-send-email-tom.leiming@gmail.com>
MD need this helper to remove the last added page, so introduce
it.
Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
block/bio.c | 23 +++++++++++++++++++++++
include/linux/bio.h | 1 +
2 files changed, 24 insertions(+)
diff --git a/block/bio.c b/block/bio.c
index 5eec5e08417f..0ce7ffcd7939 100644
--- a/block/bio.c
+++ b/block/bio.c
@@ -837,6 +837,29 @@ int bio_add_pc_page(struct request_queue *q, struct bio *bio, struct page
EXPORT_SYMBOL(bio_add_pc_page);
/**
+ * bio_remove_last_page - remove the last added page
+ * @bio: destination bio
+ *
+ * Attempt to remove the last added page from the bio_vec maplist.
+ */
+void bio_remove_last_page(struct bio *bio)
+{
+ /*
+ * cloned bio must not modify vec list
+ */
+ if (WARN_ON_ONCE(bio_flagged(bio, BIO_CLONED)))
+ return;
+
+ if (bio->bi_vcnt > 0) {
+ struct bio_vec *bv = &bio->bi_io_vec[bio->bi_vcnt - 1];
+
+ bio->bi_iter.bi_size -= bv->bv_len;
+ bio->bi_vcnt--;
+ }
+}
+EXPORT_SYMBOL(bio_remove_last_page);
+
+/**
* bio_add_page - attempt to add page to bio
* @bio: destination bio
* @page: page to add
diff --git a/include/linux/bio.h b/include/linux/bio.h
index 3364b3ed90e7..32aeb493d1fe 100644
--- a/include/linux/bio.h
+++ b/include/linux/bio.h
@@ -443,6 +443,7 @@ extern void bio_init(struct bio *bio, struct bio_vec *table,
extern void bio_reset(struct bio *);
void bio_chain(struct bio *, struct bio *);
+extern void bio_remove_last_page(struct bio *bio);
extern int bio_add_page(struct bio *, struct page *, unsigned int,unsigned int);
extern int bio_add_pc_page(struct request_queue *, struct bio *, struct page *,
unsigned int, unsigned int);
--
2.7.4
next prev parent reply other threads:[~2017-02-24 15:42 UTC|newest]
Thread overview: 19+ messages / expand[flat|nested] mbox.gz Atom feed top
2017-02-24 15:42 [PATCH v1 00/14] md: cleanup on direct access to bvec table Ming Lei
2017-02-24 15:42 ` [PATCH v1 01/14] block: introduce bio_segments_all() Ming Lei
2017-02-25 18:22 ` Christoph Hellwig
2017-02-28 12:15 ` Ming Lei
2017-02-24 15:42 ` Ming Lei [this message]
2017-02-25 18:23 ` [PATCH v1 02/14] block: introduce bio_remove_last_page() Christoph Hellwig
2017-02-28 12:18 ` Ming Lei
2017-02-24 15:42 ` [PATCH v1 03/14] md: raid1/raid10: use bio_remove_last_page() Ming Lei
2017-02-24 15:42 ` [PATCH v1 04/14] md: move two macros into md.h Ming Lei
2017-02-24 15:42 ` [PATCH v1 05/14] md: prepare for managing resync I/O pages in clean way Ming Lei
2017-02-24 15:42 ` [PATCH v1 06/14] md: raid1: simplify r1buf_pool_free() Ming Lei
2017-02-24 15:42 ` [PATCH v1 07/14] md: raid1: don't use bio's vec table to manage resync pages Ming Lei
2017-02-24 15:42 ` [PATCH v1 08/14] md: raid1: retrieve page from pre-allocated resync page array Ming Lei
2017-02-24 15:42 ` [PATCH v1 09/14] md: raid1: use bio helper in process_checks() Ming Lei
2017-02-24 15:42 ` [PATCH v1 10/14] md: raid1: use bio_segments_all() Ming Lei
2017-02-24 15:42 ` [PATCH v1 11/14] md: raid10: refactor code of read reshape's .bi_end_io Ming Lei
2017-02-24 15:42 ` [PATCH v1 12/14] md: raid10: don't use bio's vec table to manage resync pages Ming Lei
2017-02-24 15:42 ` [PATCH v1 13/14] md: raid10: retrieve page from preallocated resync page array Ming Lei
2017-02-24 15:42 ` [PATCH v1 14/14] md: raid10: avoid direct access to bvec table in handle_reshape_read_error Ming Lei
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