From: Li Nan <linan122@xxxxxxxxxx>
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@xxxxxxxxxx>
---
drivers/md/raid10.c | 30 +++++++++++++++++++++---------
1 file changed, 21 insertions(+), 9 deletions(-)
diff --git a/drivers/md/raid10.c b/drivers/md/raid10.c
index 3e6a09aaaba6..eaaf6307ddda 100644
--- a/drivers/md/raid10.c
+++ b/drivers/md/raid10.c
@@ -1346,6 +1346,26 @@ static void raid10_write_one_disk(struct mddev *mddev, struct r10bio *r10_bio,
}
}
+static void get_rdev_repl_from_mirror(struct raid10_info *mirror,
+ struct md_rdev **prdev,
+ 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;
+ *prdev = rdev;
+}
+
static void wait_blocked_dev(struct mddev *mddev, struct r10bio *r10_bio)
{
int i;
@@ -1489,15 +1509,7 @@ 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;
+ get_rdev_repl_from_mirror(&conf->mirrors[d], &rdev, &rrdev);
if (rdev && (test_bit(Faulty, &rdev->flags)))
rdev = NULL;
if (rrdev && (test_bit(Faulty, &rrdev->flags)))
--
2.39.2
