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authorLi Nan <linan122@huawei.com>2023-07-01 16:05:28 +0800
committerSong Liu <song@kernel.org>2023-07-27 00:13:30 -0700
commitb99f8fd2d91eb734f13098aa1cf337edaca454b7 (patch)
tree5f1ece777891e5a8c9348604422e460f7bf31f3b
parent7e85c41b9e1df9192c225afd7cfec8dcad137feb (diff)
md/raid10: factor out dereference_rdev_and_rrdev()
Factor out a helper to get 'rdev' and 'replacement' from config->mirrors. Just to make code cleaner and prepare to fix the bug of io loss while 'replacement' replace 'rdev'. There is no functional change. Signed-off-by: Li Nan <linan122@huawei.com> Link: https://lore.kernel.org/r/20230701080529.2684932-3-linan666@huaweicloud.com Signed-off-by: Song Liu <song@kernel.org>
-rw-r--r--drivers/md/raid10.c29
1 files changed, 20 insertions, 9 deletions
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 60963449d3f5..d21aeb9546d9 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1321,6 +1321,25 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
}
}
+static struct md_rdev *dereference_rdev_and_rrdev(struct raid10_info *mirror,
+ struct md_rdev **prrdev)
+{
+ struct md_rdev *rdev, *rrdev;
+
+ rrdev = rcu_dereference(mirror->replacement);
+ /*
+ * Read replacement first to prevent reading both rdev and
+ * replacement as NULL during replacement replace rdev.
+ */
+ smp_mb();
+ rdev = rcu_dereference(mirror->rdev);
+ if (rdev == rrdev)
+ rrdev = NULL;
+
+ *prrdev = rrdev;
+ return rdev;
+}
+
static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
{
int i;
@@ -1464,15 +1483,7 @@ static void raid10_write_request(struct mddev *mddev, struct bio *bio,
int d = r10_bio->devs[i].devnum;
struct md_rdev *rdev, *rrdev;
- rrdev = rcu_dereference(conf->mirrors[d].replacement);
- /*
- * Read replacement first to prevent reading both rdev and
- * replacement as NULL during replacement replace rdev.
- */
- smp_mb();
- rdev = rcu_dereference(conf->mirrors[d].rdev);
- if (rdev == rrdev)
- rrdev = NULL;
+ rdev = dereference_rdev_and_rrdev(&conf->mirrors[d], &rrdev);
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))