linux-kernel - Re: [PATCH] Fix regression in O_DIRECT|O

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <20100415104224.GA27482@lst.de>
Date:	Thu, 15 Apr 2010 12:42:24 +0200
From:	Christoph Hellwig <hch@....de>
To:	Anton Blanchard <anton@...ba.org>
Cc:	Jan Kara <jack@...e.cz>, Christoph Hellwig <hch@....de>,
	Alexander Viro <viro@...iv.linux.org.uk>,
	Jens Axboe <jens.axboe@...cle.com>,
	Andrew Morton <akpm@...ux-foundation.org>,
	linux-kernel@...r.kernel.org
Subject: Re: [PATCH] Fix regression in O_DIRECT|O_SYNC writes to block devices

On Thu, Apr 15, 2010 at 02:40:39PM +1000, Anton Blanchard wrote:
>  int blkdev_fsync(struct file *filp, struct dentry *dentry, int datasync)
>  {
> -	struct block_device *bdev = I_BDEV(filp->f_mapping->host);
> +	struct inode *bd_inode = filp->f_mapping->host;
> +	struct block_device *bdev = I_BDEV(bd_inode);
>  	int error;
>  
> +	mutex_unlock(&bd_inode->i_mutex);
> +
>  	error = sync_blockdev(bdev);

Actually you can just drop this call entirely.  sync_blockdev is an
overcomplicated alias for filemap_write_and_wait on the  block device
inode, which is exactl what we did just before calling into ->fsync

It might be worth to still drop i_mutex for the cache flush, though.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/