From: Theodore Ts'o Subject: Re: [PATCH 1/1 linux-next] ext4: atomically read inode size Date: Mon, 23 Jan 2017 13:26:11 -0500 Message-ID: <20170123182611.xvgouds4ug7cgps5@thunk.org> References: <20170123175609.6032-1-fabf@skynet.be> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: linux-ext4@vger.kernel.org, linux-kernel@vger.kernel.org To: Fabian Frederick Return-path: Content-Disposition: inline In-Reply-To: <20170123175609.6032-1-fabf@skynet.be> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org On Mon, Jan 23, 2017 at 06:56:09PM +0100, Fabian Frederick wrote: > See i_size_read() comments in include/linux/fs.h > > Signed-off-by: Fabian Frederick > --- > fs/ext4/super.c | 3 ++- > 1 file changed, 2 insertions(+), 1 deletion(-) > > diff --git a/fs/ext4/super.c b/fs/ext4/super.c > index 9d15a62..3746f77 100644 > --- a/fs/ext4/super.c > +++ b/fs/ext4/super.c > @@ -3798,7 +3798,8 @@ static int ext4_fill_super(struct super_block *sb, void *data, int silent) > goto cantfind_ext4; > > /* check blocks count against device size */ > - blocks_count = sb->s_bdev->bd_inode->i_size >> sb->s_blocksize_bits; > + blocks_count = i_size_read(sb->s_bdev->bd_inode) >> > + sb->s_blocksize_bits; > if (blocks_count && ext4_blocks_count(es) > blocks_count) { > ext4_msg(sb, KERN_WARNING, "bad geometry: block count %llu " > "exceeds size of device (%llu blocks)", Um, this is at mount time, and we're talking about the i_size of the block device --- which typically isn't moving around a huge amount. - Ted