Date:   Thu, 18 Apr 2019 09:10:24 -0700
From:   Matthew Wilcox <willy@infradead.org>
To:     David Howells <dhowells@redhat.com>
Cc:     viro@zeniv.linux.org.uk, Jan Harkes <jaharkes@cs.cmu.edu>,
        coda@cs.cmu.edu, codalist@coda.cs.cmu.edu,
        linux-afs@lists.infradead.org, linux-ext4@vger.kernel.org,
        linux-ntfs-dev@lists.sourceforge.net,
        linux-fsdevel@vger.kernel.org, linux-kernel@vger.kernel.org
Subject: Re: [RFC PATCH 1/6] vfs, coda: Fix the lack of locking in FID
 replacement inode rehashing
Message-ID: <20190418161024.GG7751@bombadil.infradead.org>
References: <155559635133.21702.4737487773869377967.stgit@warthog.procyon.org.uk>
 <155559636704.21702.4538723150377303298.stgit@warthog.procyon.org.uk>
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
In-Reply-To: <155559636704.21702.4538723150377303298.stgit@warthog.procyon.org.uk>
User-Agent: Mutt/1.9.2 (2017-12-15)
Sender: linux-ext4-owner@vger.kernel.org
Precedence: bulk

On Thu, Apr 18, 2019 at 03:06:07PM +0100, David Howells wrote:
> Fix this by moving the core part of the code to fs/inode.c and providing it
> with a set() function akin to iget5().  We can then take the inode cache
> lock whilst performing the move.

> @@ -123,6 +132,8 @@ void coda_replace_fid(struct inode *inode, struct CodaFid *oldfid,
>  	
>  	BUG_ON(!coda_fideq(&cii->c_fid, oldfid));
>  
> +	rehash_inode(inode, hash, coda_reset_inode, newfid);
> +	
>  	/* replace fid and rehash inode */
>  	/* XXX we probably need to hold some lock here! */
>  	remove_inode_hash(inode);

Don't you also need to delete the remove_inode_hash() and
__insert_inode_hash() calls?