vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink}

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.

Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: NeilBrown <neil@brown.name>
Signed-off-by: Jeff Layton <jlayton@kernel.org>
Link: https://patch.msgid.link/20251111-dir-deleg-ro-v6-5-52f3feebb2f2@kernel.org
Signed-off-by: Christian Brauner <brauner@kernel.org>

diff --git a/fs/namei.c b/fs/namei.c
index bf42f146f847a5330fc581595c7256af28d9db90..5bcf3e93d350ffd290f72725c378d3dffeeae364 100644 (file)
--- a/fs/namei.c
+++ b/fs/namei.c
@@ -4667,6 +4667,9 @@ 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;
@@ -4936,7 +4939,9 @@ 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);
+               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);
        }
@@ -5203,6 +5208,14 @@ 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)