md: lock address when changing attributes of component devices

Signed-off-by: Neil Brown <neilb@suse.de>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

1 files changed, 7 insertions, 1 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index 7c9a87b02e77..39757566f39b 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2075,12 +2075,18 @@ rdev_attr_store(struct kobject *kobj, struct attribute *attr,
 {
         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
         mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
+        int rv;
 
         if (!entry->store)
                 return -EIO;
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
-        return entry->store(rdev, page, length);
+        rv = mddev_lock(rdev->mddev);
+        if (!rv) {
+                rv = entry->store(rdev, page, length);
+                mddev_unlock(rdev->mddev);
+        }
+        return rv;
 }
 
 static void rdev_free(struct kobject *ko)