1 files changed, 26 insertions, 9 deletions

diff --git a/drivers/md/md.c b/drivers/md/md.c
index a986845ea0c..827824a9f3e 100644
--- a/drivers/md/md.c
+++ b/drivers/md/md.c
@@ -2001,9 +2001,11 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
         char *e;
         unsigned long long size = simple_strtoull(buf, &e, 10);
         unsigned long long oldsize = rdev->size;
+        mddev_t *my_mddev = rdev->mddev;
+
         if (e==buf || (*e && *e != '\n'))
                 return -EINVAL;
-        if (rdev->mddev->pers)
+        if (my_mddev->pers)
                 return -EBUSY;
         rdev->size = size;
         if (size > oldsize && rdev->mddev->external) {
@@ -2016,7 +2018,7 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                 int overlap = 0;
                 struct list_head *tmp, *tmp2;
 
-                mddev_unlock(rdev->mddev);
+                mddev_unlock(my_mddev);
                 for_each_mddev(mddev, tmp) {
                         mdk_rdev_t *rdev2;
 
@@ -2036,7 +2038,7 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                                 break;
                         }
                 }
-                mddev_lock(rdev->mddev);
+                mddev_lock(my_mddev);
                 if (overlap) {
                         /* Someone else could have slipped in a size
                          * change here, but doing so is just silly.
@@ -2048,8 +2050,8 @@ rdev_size_store(mdk_rdev_t *rdev, const char *buf, size_t len)
                         return -EBUSY;
                 }
         }
-        if (size < rdev->mddev->size || rdev->mddev->size == 0)
-                rdev->mddev->size = size;
+        if (size < my_mddev->size || my_mddev->size == 0)
+                my_mddev->size = size;
         return len;
 }
 
@@ -2070,10 +2072,21 @@ rdev_attr_show(struct kobject *kobj, struct attribute *attr, char *page)
 {
         struct rdev_sysfs_entry *entry = container_of(attr, struct rdev_sysfs_entry, attr);
         mdk_rdev_t *rdev = container_of(kobj, mdk_rdev_t, kobj);
+        mddev_t *mddev = rdev->mddev;
+        ssize_t rv;
 
         if (!entry->show)
                 return -EIO;
-        return entry->show(rdev, page);
+
+        rv = mddev ? mddev_lock(mddev) : -EBUSY;
+        if (!rv) {
+                if (rdev->mddev == NULL)
+                        rv = -EBUSY;
+                else
+                        rv = entry->show(rdev, page);
+                mddev_unlock(mddev);
+        }
+        return rv;
 }
 
 static ssize_t
@@ -2082,15 +2095,19 @@ 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;
+        ssize_t rv;
+        mddev_t *mddev = rdev->mddev;
 
         if (!entry->store)
                 return -EIO;
         if (!capable(CAP_SYS_ADMIN))
                 return -EACCES;
-        rv = mddev_lock(rdev->mddev);
+        rv = mddev ? mddev_lock(mddev): -EBUSY;
         if (!rv) {
-                rv = entry->store(rdev, page, length);
+                if (rdev->mddev == NULL)
+                        rv = -EBUSY;
+                else
+                        rv = entry->store(rdev, page, length);
                 mddev_unlock(rdev->mddev);
         }
         return rv;