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authorNeilBrown <neilb@suse.com>2016-06-02 16:19:52 +1000
committerShaohua Li <shli@fb.com>2016-06-13 11:54:21 -0700
commit40cf2123c57928c3ec0626c49bef97ebdbce008e (patch)
tree0583f446c659c85f627d447f978a017a67bacf83 /drivers/md/multipath.c
parent5fd133511d5f2a9167573d100e14fddd9c621581 (diff)
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md/multipath: add rcu protection to rdev access in multipath_status.
Signed-off-by: NeilBrown <neilb@suse.com> Signed-off-by: Shaohua Li <shli@fb.com>
Diffstat (limited to 'drivers/md/multipath.c')
-rw-r--r--drivers/md/multipath.c12
1 files changed, 7 insertions, 5 deletions
diff --git a/drivers/md/multipath.c b/drivers/md/multipath.c
index dd483bb2e111..69244de2036b 100644
--- a/drivers/md/multipath.c
+++ b/drivers/md/multipath.c
@@ -141,17 +141,19 @@ static void multipath_make_request(struct mddev *mddev, struct bio * bio)
return;
}
-static void multipath_status (struct seq_file *seq, struct mddev *mddev)
+static void multipath_status(struct seq_file *seq, struct mddev *mddev)
{
struct mpconf *conf = mddev->private;
int i;
seq_printf (seq, " [%d/%d] [", conf->raid_disks,
conf->raid_disks - mddev->degraded);
- for (i = 0; i < conf->raid_disks; i++)
- seq_printf (seq, "%s",
- conf->multipaths[i].rdev &&
- test_bit(In_sync, &conf->multipaths[i].rdev->flags) ? "U" : "_");
+ rcu_read_lock();
+ for (i = 0; i < conf->raid_disks; i++) {
+ struct md_rdev *rdev = rcu_dereference(conf->multipaths[i].rdev);
+ seq_printf (seq, "%s", rdev && test_bit(In_sync, &rdev->flags) ? "U" : "_");
+ }
+ rcu_read_unlock();
seq_printf (seq, "]");
}