Introduce a helper ovl_wait_wb_inodes() to wait until all
target upper inodes finish writeback.
Signed-off-by: Chengguang Xu <cgxu519@xxxxxxxxxxxx>
---
fs/overlayfs/super.c | 30 ++++++++++++++++++++++++++++++
1 file changed, 30 insertions(+)
diff --git a/fs/overlayfs/super.c b/fs/overlayfs/super.c
index e5607a908d82..9a535fc11221 100644
--- a/fs/overlayfs/super.c
+++ b/fs/overlayfs/super.c
@@ -255,6 +255,36 @@ static void ovl_put_super(struct super_block *sb)
ovl_free_fs(ofs);
}
+void ovl_wait_wb_inodes(struct ovl_fs *ofs)
+{
+ LIST_HEAD(tmp_list);
+ struct ovl_inode *oi;
+ struct inode *upper;
+
+ spin_lock(&ofs->syncfs_wait_list_lock);
+ list_splice_init(&ofs->syncfs_wait_list, &tmp_list);
+
+ while (!list_empty(&tmp_list)) {
+ oi = list_first_entry(&tmp_list, struct ovl_inode, wait_list);
+ list_del_init(&oi->wait_list);
+ ihold(&oi->vfs_inode);
+ spin_unlock(&ofs->syncfs_wait_list_lock);
+
+ upper = ovl_inode_upper(&oi->vfs_inode);
+ if (!mapping_tagged(upper->i_mapping, PAGECACHE_TAG_WRITEBACK)) {
+ iput(&oi->vfs_inode);
+ goto wait_next;
+ }
+
+ filemap_fdatawait_keep_errors(upper->i_mapping);
+ iput(&oi->vfs_inode);
+ cond_resched();
+wait_next:
+ spin_lock(&ofs->syncfs_wait_list_lock);
+ }
+ spin_unlock(&ofs->syncfs_wait_list_lock);
+}
+
/* Sync real dirty inodes in upper filesystem (if it exists) */
static int ovl_sync_fs(struct super_block *sb, int wait)
{
--
2.26.2
