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

From: Jeff Layton <jlayton@kernel.org>
To: Al Viro <viro@zeniv.linux.org.uk>
Cc: Christian Brauner <brauner@kernel.org>, Jan Kara <jack@suse.cz>,
	Chuck Lever <chuck.lever@oracle.com>,
	Alexander Aring <alex.aring@gmail.com>,
	Trond Myklebust <trond.myklebust@hammerspace.com>,
	Anna Schumaker <anna@kernel.org>,
	Steve French <sfrench@samba.org>,
	Paulo Alcantara <pc@manguebit.com>,
	Ronnie Sahlberg <ronniesahlberg@gmail.com>,
	Shyam Prasad N <sprasad@microsoft.com>,
	Tom Talpey <tom@talpey.com>,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
	"Rafael J. Wysocki" <rafael@kernel.org>,
	David Howells <dhowells@redhat.com>,
	Tyler Hicks <code@tyhicks.com>,  Neil Brown <neilb@suse.de>,
	Olga Kornievskaia <kolga@netapp.com>,
	Dai Ngo <Dai.Ngo@oracle.com>, Miklos Szeredi <miklos@szeredi.hu>,
	Amir Goldstein <amir73il@gmail.com>,
	Namjae Jeon <linkinjeon@kernel.org>,
	Sergey Senozhatsky <senozhatsky@chromium.org>,
	 "David S. Miller" <davem@davemloft.net>,
	Eric Dumazet <edumazet@google.com>,
	Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>,
	linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org,
	 linux-nfs@vger.kernel.org, linux-cifs@vger.kernel.org,
	 samba-technical@lists.samba.org, netfs@lists.linux.dev,
	ecryptfs@vger.kernel.org,  linux-unionfs@vger.kernel.org,
	netdev@vger.kernel.org
Subject: Re: [PATCH RFC 03/24] vfs: add try_break_deleg calls for parents to vfs_{link,rename,unlink}
Date: Sun, 17 Mar 2024 10:09:51 -0400	[thread overview]
Message-ID: <a635d0fc7d43bc10ed486efcae627f278e0df328.camel@kernel.org> (raw)
In-Reply-To: <20240316235717.GI538574@ZenIV>

On Sat, 2024-03-16 at 23:57 +0000, Al Viro wrote:
> 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.

Sounds good. Fixed in my tree.

Thanks for the review so far!
-- 
Jeff Layton <jlayton@kernel.org>