Re: [PATCH 01/10] fsnotify: rename fsnotify_{get,put}_sb_connectors()

From: Jan Kara <jack@suse.cz>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Jan Kara <jack@suse.cz>, Jens Axboe <axboe@kernel.dk>,
	Christian Brauner <brauner@kernel.org>,
	linux-fsdevel@vger.kernel.org
Subject: Re: [PATCH 01/10] fsnotify: rename fsnotify_{get,put}_sb_connectors()
Date: Wed, 27 Mar 2024 11:01:22 +0100	[thread overview]
Message-ID: <20240327100122.odg6bc4lgsrryt6w@quack3> (raw)
In-Reply-To: <20240317184154.1200192-2-amir73il@gmail.com>

On Sun 17-03-24 20:41:45, Amir Goldstein wrote:
> Instead of counting the number of connectors in an sb, we would like
> to count the number of watched objects per priority group.
> 
> As a start, create an accessor fsnotify_sb_watched_objects() to
> s_fsnotify_connectors and rename the fsnotify_{get,put}_sb_connectors()
> helpers to fsnotify_{get,put}_sb_watchers() to better describes the
> counter.
> 
> Increment the counter at the end of fsnotify_attach_connector_to_object()
> if connector was attached instead of decrementing it on race to connect.
> 
> This is fine, because fsnotify_delete_sb() cannot be running in parallel
> to fsnotify_attach_connector_to_object() which requires a reference to
> a filesystem object.
> 
> Signed-off-by: Amir Goldstein <amir73il@gmail.com>
...
> +static void fsnotify_put_inode_ref(struct inode *inode)
> +{
> +	iput(inode);
> +	fsnotify_put_sb_watched_objects(inode->i_sb);
> +}

This is a UAF issue. Will fix on commit. Otherwise the patch looks good.

								Honza
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR