Re: [PATCH 03/11] mm: Protect operations adding pages to page cache with invalidate_lock

From: Matthew Wilcox <willy@infradead.org>
To: Jan Kara <jack@suse.cz>
Cc: linux-fsdevel@vger.kernel.org,
	Christoph Hellwig <hch@infradead.org>,
	Dave Chinner <david@fromorbit.com>,
	ceph-devel@vger.kernel.org, Chao Yu <yuchao0@huawei.com>,
	Damien Le Moal <damien.lemoal@wdc.com>,
	"Darrick J. Wong" <darrick.wong@oracle.com>,
	Jaegeuk Kim <jaegeuk@kernel.org>,
	Jeff Layton <jlayton@kernel.org>,
	Johannes Thumshirn <jth@kernel.org>,
	linux-cifs@vger.kernel.org, linux-ext4@vger.kernel.org,
	linux-f2fs-devel@lists.sourceforge.net, linux-mm@kvack.org,
	linux-xfs@vger.kernel.org, Miklos Szeredi <miklos@szeredi.hu>,
	Steve French <sfrench@samba.org>, Ted Tso <tytso@mit.edu>
Subject: Re: [PATCH 03/11] mm: Protect operations adding pages to page cache with invalidate_lock
Date: Wed, 12 May 2021 15:20:44 +0100	[thread overview]
Message-ID: <YJvkPEAdVhM9JsbN@casper.infradead.org> (raw)
In-Reply-To: <20210512134631.4053-3-jack@suse.cz>

On Wed, May 12, 2021 at 03:46:11PM +0200, Jan Kara wrote:

> diff --git a/mm/truncate.c b/mm/truncate.c
> index 57a618c4a0d6..93bde2741e0e 100644
> --- a/mm/truncate.c
> +++ b/mm/truncate.c
> @@ -415,7 +415,7 @@ EXPORT_SYMBOL(truncate_inode_pages_range);
>   * @mapping: mapping to truncate
>   * @lstart: offset from which to truncate
>   *
> - * Called under (and serialised by) inode->i_rwsem.
> + * Called under (and serialised by) inode->i_rwsem and inode->i_mapping_rwsem.

mapping->invalidate_lock, surely?  And could we ask lockdep to assert
this for us instead of just a comment?

>   *
>   * Note: When this function returns, there can be a page in the process of
>   * deletion (inside __delete_from_page_cache()) in the specified range.  Thus
> -- 
> 2.26.2
> 
> 