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Date: Tue, 11 Oct 2016 08:50:01 +0200
From: Jan Kara <jack@suse.cz>
To: Ross Zwisler <ross.zwisler@linux.intel.com>
Cc: linux-kernel@vger.kernel.org, "Theodore Ts'o" <tytso@mit.edu>,
        Alexander Viro <viro@zeniv.linux.org.uk>,
        Andreas Dilger <adilger.kernel@dilger.ca>,
        Andrew Morton <akpm@linux-foundation.org>,
        Christoph Hellwig <hch@lst.de>,
        Dan Williams <dan.j.williams@intel.com>,
        Dave Chinner <david@fromorbit.com>, Jan Kara <jack@suse.com>,
        Matthew Wilcox <mawilcox@microsoft.com>, linux-ext4@vger.kernel.org,
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        linux-nvdimm@ml01.01.org, linux-xfs@vger.kernel.org
Subject: Re: [PATCH v5 07/17] dax: remove the last BUG_ON() from fs/dax.c
Message-ID: <20161011065001.GB6952@quack2.suse.cz>
References: <1475874544-24842-1-git-send-email-ross.zwisler@linux.intel.com>
 <1475874544-24842-8-git-send-email-ross.zwisler@linux.intel.com>
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On Fri 07-10-16 15:08:54, Ross Zwisler wrote:
> Don't take down the kernel if we get an invalid 'from' and 'length'
> argument pair.  Just warn once and return an error.
> 
> Signed-off-by: Ross Zwisler <ross.zwisler@linux.intel.com>

Looks good. You can add:

Reviewed-by: Jan Kara <jack@suse.cz>

								Honza
> ---
>  fs/dax.c | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/fs/dax.c b/fs/dax.c
> index ac28cdf..98189ac 100644
> --- a/fs/dax.c
> +++ b/fs/dax.c
> @@ -1194,7 +1194,8 @@ int dax_zero_page_range(struct inode *inode, loff_t from, unsigned length,
>  	/* Block boundary? Nothing to do */
>  	if (!length)
>  		return 0;
> -	BUG_ON((offset + length) > PAGE_SIZE);
> +	if (WARN_ON_ONCE((offset + length) > PAGE_SIZE))
> +		return -EINVAL;
>  
>  	memset(&bh, 0, sizeof(bh));
>  	bh.b_bdev = inode->i_sb->s_bdev;
> -- 
> 2.7.4
> 
> 
-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR