X-Git-Url: http://plrg.eecs.uci.edu/git/?a=blobdiff_plain;f=fs%2Fattr.c;h=6530ced19697d49a9189fa289c9112187448fee3;hb=5dc806cc889ffa876e7a6cea2787acb3bc02240f;hp=66fa6251c398d7584042c7169967f54bfed4278e;hpb=2075186d012c815911494f34fc16aef7c8f3492b;p=firefly-linux-kernel-4.4.55.git

diff --git a/fs/attr.c b/fs/attr.c
index 66fa6251c398..6530ced19697 100644
--- a/fs/attr.c
+++ b/fs/attr.c
@@ -167,7 +167,27 @@ void setattr_copy(struct inode *inode, const struct iattr *attr)
 }
 EXPORT_SYMBOL(setattr_copy);
 
-int notify_change(struct dentry * dentry, struct iattr * attr)
+/**
+ * notify_change - modify attributes of a filesytem object
+ * @dentry:	object affected
+ * @iattr:	new attributes
+ * @delegated_inode: returns inode, if the inode is delegated
+ *
+ * The caller must hold the i_mutex on the affected object.
+ *
+ * If notify_change discovers a delegation in need of breaking,
+ * it will return -EWOULDBLOCK and return a reference to the inode in
+ * delegated_inode.  The caller should then break the delegation and
+ * retry.  Because breaking a delegation may take a long time, the
+ * caller should drop the i_mutex before doing so.
+ *
+ * Alternatively, a caller may pass NULL for delegated_inode.  This may
+ * be appropriate for callers that expect the underlying filesystem not
+ * to be NFS exported.  Also, passing NULL is fine for callers holding
+ * the file open for write, as there can be no conflicting delegation in
+ * that case.
+ */
+int notify_change(struct dentry * dentry, struct iattr * attr, struct inode **delegated_inode)
 {
 	struct inode *inode = dentry->d_inode;
 	umode_t mode = inode->i_mode;
@@ -236,6 +256,9 @@ int notify_change(struct dentry * dentry, struct iattr * attr)
 		return 0;
 
 	error = security_inode_setattr(dentry, attr);
+	if (error)
+		return error;
+	error = try_break_deleg(inode, delegated_inode);
 	if (error)
 		return error;