From fb0eb5df09307603b21845af1d143cc910154593 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Fri, 14 Jul 2017 16:14:43 +0800
Subject: [PATCH] md: raid1/raid10: initialize bvec table via bio_add_page()
Git-commit: fb0eb5df09307603b21845af1d143cc910154593
Patch-mainline: v4.13-rc3
References: fate#322738,fate#322919,fate#322950,fate#323773

We will support multipage bvec soon, so initialize bvec
table using the standardy way instead of writing the
talbe directly. Otherwise it won't work any more once
multipage bvec is enabled.

Acked-by: Guoqing Jiang <gqjiang@suse.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Shaohua Li <shli@fb.com>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/raid1-10.c | 19 +++++++++++++++++++
 drivers/md/raid1.c    | 18 ++++--------------
 drivers/md/raid10.c   |  6 ++++--
 3 files changed, 27 insertions(+), 16 deletions(-)
 create mode 100644 drivers/md/raid1-10.c

diff --git a/drivers/md/raid1-10.c b/drivers/md/raid1-10.c
new file mode 100644
index 000000000000..3adb5b9dc4b4
--- /dev/null
+++ b/drivers/md/raid1-10.c
@@ -0,0 +1,19 @@
+/* generally called after bio_reset() for reseting bvec */
+static void md_bio_reset_resync_pages(struct bio *bio, struct resync_pages *rp,
+			       int size)
+{
+	int idx = 0;
+
+	/* initialize bvec table again */
+	do {
+		struct page *page = resync_fetch_page(rp, idx);
+		int len = min_t(int, size, PAGE_SIZE);
+
+		/*
+		 * won't fail because the vec table is big
+		 * enough to hold all these pages
+		 */
+		bio_add_page(bio, page, len, 0);
+		size -= len;
+	} while (idx++ < RESYNC_PAGES && size > 0);
+}
diff --git a/drivers/md/raid1.c b/drivers/md/raid1.c
index 0896c772a560..fe86ab18961b 100644
--- a/drivers/md/raid1.c
+++ b/drivers/md/raid1.c
@@ -81,6 +81,8 @@ static void lower_barrier(struct r1conf *conf, sector_t sector_nr);
 #define raid1_log(md, fmt, args...)				\
 	do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid1 " fmt, ##args); } while (0)
 
+#include "raid1-10.c"
+
 /*
  * 'strct resync_pages' stores actual pages used for doing the resync
  *  IO, and it is per-bio, so make .bi_private points to it.
@@ -2085,10 +2087,7 @@ static void process_checks(struct r1bio *r1_bio)
 	/* Fix variable parts of all bios */
 	vcnt = (r1_bio->sectors + PAGE_SIZE / 512 - 1) >> (PAGE_SHIFT - 9);
 	for (i = 0; i < conf->raid_disks * 2; i++) {
-		int j;
-		int size;
 		blk_status_t status;
-		struct bio_vec *bi;
 		struct bio *b = r1_bio->bios[i];
 		struct resync_pages *rp = get_resync_pages(b);
 		if (b->bi_end_io != end_sync_read)
@@ -2097,8 +2096,6 @@ static void process_checks(struct r1bio *r1_bio)
 		status = b->bi_status;
 		bio_reset(b);
 		b->bi_status = status;
-		b->bi_vcnt = vcnt;
-		b->bi_iter.bi_size = r1_bio->sectors << 9;
 		b->bi_iter.bi_sector = r1_bio->sector +
 			conf->mirrors[i].rdev->data_offset;
 		b->bi_bdev = conf->mirrors[i].rdev->bdev;
@@ -2106,15 +2103,8 @@ static void process_checks(struct r1bio *r1_bio)
 		rp->raid_bio = r1_bio;
 		b->bi_private = rp;
 
-		size = b->bi_iter.bi_size;
-		bio_for_each_segment_all(bi, b, j) {
-			bi->bv_offset = 0;
-			if (size > PAGE_SIZE)
-				bi->bv_len = PAGE_SIZE;
-			else
-				bi->bv_len = size;
-			size -= PAGE_SIZE;
-		}
+		/* initialize bvec table again */
+		md_bio_reset_resync_pages(b, rp, r1_bio->sectors << 9);
 	}
 	for (primary = 0; primary < conf->raid_disks * 2; primary++)
 		if (r1_bio->bios[primary]->bi_end_io == end_sync_read &&
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index fa8bcf04e791..9952721e1cde 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -110,6 +110,8 @@ static void end_reshape(struct r10conf *conf);
 #define raid10_log(md, fmt, args...)				\
 	do { if ((md)->queue) blk_add_trace_msg((md)->queue, "raid10 " fmt, ##args); } while (0)
 
+#include "raid1-10.c"
+
 /*
  * 'strct resync_pages' stores actual pages used for doing the resync
  *  IO, and it is per-bio, so make .bi_private points to it.
@@ -2086,8 +2088,8 @@ static void sync_request_write(struct mddev *mddev, struct r10bio *r10_bio)
 		rp = get_resync_pages(tbio);
 		bio_reset(tbio);
 
-		tbio->bi_vcnt = vcnt;
-		tbio->bi_iter.bi_size = fbio->bi_iter.bi_size;
+		md_bio_reset_resync_pages(tbio, rp, fbio->bi_iter.bi_size);
+
 		rp->raid_bio = r10_bio;
 		tbio->bi_private = rp;
 		tbio->bi_iter.bi_sector = r10_bio->devs[i].addr;
-- 
2.13.1