[PATCH RFC 03/24] vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink}

[Jeff Layton]

In order to add directory delegation support, we need to break
delegations on the parent whenever there is going to be a change in the
directory.

vfs_link, vfs_unlink, and vfs_rename all have existing delegation break
handling for the children in the rename. Add the necessary calls for
breaking delegations in the parent(s) as well.

Signed-off-by: Jeff Layton <jlayton@xxxxxxxxxx>
---
 fs/namei.c | 20 +++++++++++++++++---
 1 file changed, 17 insertions(+), 3 deletions(-)

diff --git a/fs/namei.c b/fs/namei.c
index 9342fa6a38c2..56d3ebed7bac 100644
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4332,6 +4332,9 @@ int vfs_unlink(struct mnt_idmap *idmap, struct inode *dir,
 	else {
 		error = security_inode_unlink(dir, dentry);
 		if (!error) {
+			error = try_break_deleg(dir, delegated_inode);
+			if (error)
+				goto out;
 			error = try_break_deleg(target, delegated_inode);
 			if (error)
 				goto out;
@@ -4603,9 +4606,12 @@ int vfs_link(struct dentry *old_dentry, struct mnt_idmap *idmap,
 	else if (max_links && inode->i_nlink >= max_links)
 		error = -EMLINK;
 	else {
-		error = try_break_deleg(inode, delegated_inode);
-		if (!error)
-			error = dir->i_op->link(old_dentry, dir, new_dentry);
+		error = try_break_deleg(dir, delegated_inode);
+		if (!error) {
+			error = try_break_deleg(inode, delegated_inode);
+			if (!error)
+				error = dir->i_op->link(old_dentry, dir, new_dentry);
+		}
 	}
 
 	if (!error && (inode->i_state & I_LINKABLE)) {
@@ -4870,6 +4876,14 @@ int vfs_rename(struct renamedata *rd)
 		    old_dir->i_nlink >= max_links)
 			goto out;
 	}
+	error = try_break_deleg(old_dir, delegated_inode);
+	if (error)
+		goto out;
+	if (new_dir != old_dir) {
+		error = try_break_deleg(new_dir, delegated_inode);
+		if (error)
+			goto out;
+	}
 	if (!is_dir) {
 		error = try_break_deleg(source, delegated_inode);
 		if (error)

-- 
2.44.0