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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>, NeilBrown <neilb@suse.com>
Cc: Ming Lei <tom.leiming@gmail.com>
Subject: [PATCH 12/17] md: raid1: avoid direct access to bvec table in process_checks()
Date: Thu, 16 Feb 2017 19:45:42 +0800	[thread overview]
Message-ID: <1487245547-24384-13-git-send-email-tom.leiming@gmail.com> (raw)
In-Reply-To: <1487245547-24384-1-git-send-email-tom.leiming@gmail.com>

Given process_checks is only called in resync path, it should be
ok to allocate three stack variable(total 320byteds) to store
pages from bios.

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 drivers/md/raid1.c | 20 ++++++++++++++++----
 1 file changed, 16 insertions(+), 4 deletions(-)

diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 4400fbe7ce8c..54ec32be3277 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -2010,6 +2010,9 @@ static void process_checks(struct r1bio *r1_bio)
 	int primary;
 	int i;
 	int vcnt;
+	struct bio_vec *bi;
+	int page_len[RESYNC_PAGES];
+	struct page *pbio_pages[RESYNC_PAGES], *sbio_pages[RESYNC_PAGES];
 
 	/* Fix variable parts of all bios */
 	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
@@ -2017,7 +2020,6 @@ static void process_checks(struct r1bio *r1_bio)
 		int j;
 		int size;
 		int error;
-		struct bio_vec *bi;
 		struct bio *b = r1_bio->bios[i];
 		if (b->bi_end_io != end_sync_read)
 			continue;
@@ -2051,6 +2053,11 @@ static void process_checks(struct r1bio *r1_bio)
 			break;
 		}
 	r1_bio->read_disk = primary;
+
+	/* .bi_vcnt has been set for all read bios */
+	bio_for_each_segment_all(bi, r1_bio->bios[primary], i)
+		pbio_pages[i] = bi->bv_page;
+
 	for (i = 0; i < conf->raid_disks * 2; i++) {
 		int j;
 		struct bio *pbio = r1_bio->bios[primary];
@@ -2062,14 +2069,19 @@ static void process_checks(struct r1bio *r1_bio)
 		/* Now we can 'fixup' the error value */
 		sbio->bi_error = 0;
 
+		bio_for_each_segment_all(bi, sbio, j) {
+			sbio_pages[j] = bi->bv_page;
+			page_len[j] = bi->bv_len;
+		}
+
 		if (!error) {
 			for (j = vcnt; j-- ; ) {
 				struct page *p, *s;
-				p = pbio->bi_io_vec[j].bv_page;
-				s = sbio->bi_io_vec[j].bv_page;
+				p = pbio_pages[j];
+				s = sbio_pages[j];
 				if (memcmp(page_address(p),
 					   page_address(s),
-					   sbio->bi_io_vec[j].bv_len))
+					   page_len[j]))
 					break;
 			}
 		} else
-- 
2.7.4

  parent reply	other threads:[~2017-02-16 11:46 UTC|newest]

Thread overview: 31+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2017-02-16 11:45 [PATCH 00/17] md: cleanup on direct access to bvec table Ming Lei
2017-02-16 11:45 ` [PATCH 01/17] block: introduce bio_segments_all() Ming Lei
2017-02-16 11:45 ` [PATCH 02/17] block: introduce bio_remove_last_page() Ming Lei
2017-02-16 12:08   ` Johannes Thumshirn
2017-02-16 13:30     ` Ming Lei
2017-02-16 13:40       ` Johannes Thumshirn
2017-02-16 13:59         ` Ming Lei
2017-02-16 14:10           ` Johannes Thumshirn
2017-02-16 11:45 ` [PATCH 03/17] md: raid1/raid10: use bio_remove_last_page() Ming Lei
2017-02-16 11:45 ` [PATCH 04/17] md: introduce helpers for dealing with fetch/store preallocated pages in bio Ming Lei
2017-02-16 11:45 ` [PATCH 05/17] md: raid1/raid10: use the introduced helpers Ming Lei
2017-02-16 11:45 ` [PATCH 06/17] md: raid1/raid10: borrow .bi_error as pre-allocated page index Ming Lei
2017-02-16 11:45 ` [PATCH 07/17] md: raid1/raid10: don't use .bi_vcnt to check if all pages are added Ming Lei
2017-02-16 11:45 ` [PATCH 08/17] md: raid1: simplify r1buf_pool_free() Ming Lei
2017-02-16 11:45 ` [PATCH 09/17] md: raid1/raid10: use bio helper in *_pool_free Ming Lei
2017-02-16 11:45 ` [PATCH 10/17] md: raid1: remove direct access to bvec table in fix_sync_read_error Ming Lei
2017-02-16 11:45 ` [PATCH 11/17] md: raid1: use bio helper in process_checks() Ming Lei
2017-02-16 11:45 ` Ming Lei [this message]
2017-02-17  8:33   ` [PATCH 12/17] md: raid1: avoid direct access to bvec table " kbuild test robot
2017-02-16 11:45 ` [PATCH 13/17] md: raid1: use bio_segments_all() Ming Lei
2017-02-16 12:35   ` Johannes Thumshirn
2017-02-16 13:32     ` Ming Lei
2017-02-16 13:34       ` Johannes Thumshirn
2017-02-16 13:38         ` Ming Lei
2017-02-16 11:45 ` [PATCH 14/17] md: raid10: avoid direct access to bvec table in sync_request_write() Ming Lei
2017-02-16 11:45 ` [PATCH 15/17] md: raid10: avoid direct access to bvec table in fix_recovery_read_error Ming Lei
2017-02-16 11:45 ` [PATCH 16/17] md: raid10: avoid direct access to bvec table in reshape_request Ming Lei
2017-02-16 11:45 ` [PATCH 17/17] md: raid10: avoid direct access to bvec table in handle_reshape_read_error Ming Lei
2017-02-16 22:16 ` [PATCH 00/17] md: cleanup on direct access to bvec table Shaohua Li
2017-02-17  1:25   ` Ming Lei
2017-02-17  4:16     ` Shaohua Li

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