From: Amir Goldstein <amir73il@gmail.com>
Date: Mon, 27 Aug 2018 12:55:59 +0000 (+0300)
Subject: ovl: respect FIEMAP_FLAG_SYNC flag
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=80d34810815b1d708e3e59901a2afcdbd90c2a6f;p=openwrt%2Fstaging%2Fblogic.git

ovl: respect FIEMAP_FLAG_SYNC flag

Stacked overlayfs fiemap operation broke xfstests that test delayed
allocation (with "_test_generic_punch -d"), because ovl_fiemap()
failed to write dirty pages when requested.

Fixes: 9e142c4102db ("ovl: add ovl_fiemap()")
Signed-off-by: Amir Goldstein <amir73il@gmail.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
---

diff --git a/fs/overlayfs/inode.c b/fs/overlayfs/inode.c
index e0bb217c01e2..5014749fd4b4 100644
--- a/fs/overlayfs/inode.c
+++ b/fs/overlayfs/inode.c
@@ -467,6 +467,10 @@ static int ovl_fiemap(struct inode *inode, struct fiemap_extent_info *fieinfo,
 		return -EOPNOTSUPP;
 
 	old_cred = ovl_override_creds(inode->i_sb);
+
+	if (fieinfo->fi_flags & FIEMAP_FLAG_SYNC)
+		filemap_write_and_wait(realinode->i_mapping);
+
 	err = realinode->i_op->fiemap(realinode, fieinfo, start, len);
 	revert_creds(old_cred);