ceph: protect access to d_parent
d_parent is protected by d_lock: use it when looking up a dentry's parent
directory inode. Also take a reference and drop it in the caller to avoid
a use-after-free.
Reported-by: Al Viro <viro@ZenIV.linux.org.uk>
Reviewed-by: Yehuda Sadeh <yehuda@hq.newdream.net>
Signed-off-by: Sage Weil <sage@newdream.net>
diff --git a/fs/ceph/dir.c b/fs/ceph/dir.c
index 883c954..ed296ec 100644
--- a/fs/ceph/dir.c
+++ b/fs/ceph/dir.c
@@ -71,6 +71,21 @@
return 0;
}
+struct inode *ceph_get_dentry_parent_inode(struct dentry *dentry)
+{
+ struct inode *inode = NULL;
+
+ if (!dentry)
+ return NULL;
+
+ spin_lock(&dentry->d_lock);
+ if (dentry->d_parent) {
+ inode = dentry->d_parent->d_inode;
+ ihold(inode);
+ }
+ spin_unlock(&dentry->d_lock);
+ return inode;
+}
/*