1 files changed, 10 insertions, 0 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index eb38a2c645f..47e1c686cb0 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -65,6 +65,15 @@ struct writeback_control {
          * so we use a single control to update them
          */
         unsigned no_nrwrite_index_update:1;
+
+        /*
+         * For WB_SYNC_ALL, the sb must always be pinned. For WB_SYNC_NONE,
+         * the writeback code will pin the sb for the caller. However,
+         * for eg umount, the caller does WB_SYNC_NONE but already has
+         * the sb pinned. If the below is set, caller already has the
+         * sb pinned.
+         */
+        unsigned sb_pinned:1;
 };
 
 /*
@@ -73,6 +82,7 @@ struct writeback_control {
 struct bdi_writeback;
 int inode_wait(void *);
 void writeback_inodes_sb(struct super_block *);
+void writeback_inodes_sb_locked(struct super_block *);
 int writeback_inodes_sb_if_idle(struct super_block *);
 void sync_inodes_sb(struct super_block *);
 void writeback_inodes_wbc(struct writeback_control *wbc);