[PATCH 14/28] ovl: Add helper ovl_inode_realdata()

[Miklos Szeredi]

From: Vivek Goyal <vgoyal@xxxxxxxxxx>

Add an helper to retrieve real data inode associated with overlay inode.
This helper will ignore all metacopy inodes and will return only the real
inode which has data.

Signed-off-by: Vivek Goyal <vgoyal@xxxxxxxxxx>
Reviewed-by: Amir Goldstein <amir73il@xxxxxxxxx>
Signed-off-by: Miklos Szeredi <mszeredi@xxxxxxxxxx>
---
 fs/overlayfs/overlayfs.h |  1 +
 fs/overlayfs/util.c      | 12 ++++++++++++
 2 files changed, 13 insertions(+)

diff --git a/fs/overlayfs/overlayfs.h b/fs/overlayfs/overlayfs.h
index 558a1b444286..dcd600201ec8 100644
--- a/fs/overlayfs/overlayfs.h
+++ b/fs/overlayfs/overlayfs.h
@@ -229,6 +229,7 @@ struct inode *ovl_inode_upper(struct inode *inode);
 struct inode *ovl_inode_lower(struct inode *inode);
 struct inode *ovl_inode_lowerdata(struct inode *inode);
 struct inode *ovl_inode_real(struct inode *inode);
+struct inode *ovl_inode_realdata(struct inode *inode);
 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode);
 void ovl_set_dir_cache(struct inode *inode, struct ovl_dir_cache *cache);
 void ovl_dentry_set_flag(unsigned long flag, struct dentry *dentry);
diff --git a/fs/overlayfs/util.c b/fs/overlayfs/util.c
index 63311c536216..73939e08d8bf 100644
--- a/fs/overlayfs/util.c
+++ b/fs/overlayfs/util.c
@@ -256,6 +256,18 @@ struct inode *ovl_inode_lowerdata(struct inode *inode)
 	return OVL_I(inode)->lowerdata ?: ovl_inode_lower(inode);
 }
 
+/* Return real inode which contains data. Does not return metacopy inode */
+struct inode *ovl_inode_realdata(struct inode *inode)
+{
+	struct inode *upperinode;
+
+	upperinode = ovl_inode_upper(inode);
+	if (upperinode && ovl_has_upperdata(inode))
+		return upperinode;
+
+	return ovl_inode_lowerdata(inode);
+}
+
 struct ovl_dir_cache *ovl_dir_cache(struct inode *inode)
 {
 	return OVL_I(inode)->cache;
-- 
2.14.3