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

Al Viro
2024-03-17T00:00:37Z

On Fri, Mar 15, 2024 at 12:52:54PM -0400, Jeff Layton wrote:
> @@ -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);
> + }

A minor nit: that might be easier to follow as
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);

and let the compiler deal with optimizing it - any C compiler is going to be
able to figure out that one out. vfs_link() is a mix of those styles anyway -
we have
if (!error && (inode->i_state & I_LINKABLE)) {
spin_lock(&inode->i_lock);
inode->i_state &= ~I_LINKABLE;
spin_unlock(&inode->i_lock);
}
immediately afterwards; might as well make that consistent, especially since
you are getting more shallow nesting that way.