Re: [PATCH] ext4: Prevent creation of files larger than RLIMIT_FSIZE using fallocate

["Amit K. Arora" <aarora@linux.vnet.ibm.com>]

On Tue, May 04, 2010 at 11:15:04AM +0530, Nikanth Karthikesan wrote:
> I assumed that Amit would send a patch with s-o-b, if not, please take
> this patch.
Have added my sign-off below. Thanks!

--
Regards,
Amit Arora
> Thanks
> Nikanth
> 
> Prevent creation of files larger than RLIMIT_FSIZE using fallocate.
> 
> Currently using posix_fallocate one can bypass an RLIMIT_FSIZE limit
> and create a file larger than the limit. Add a check for that.
> 
> 
> Signed-off-by: Nikanth Karthikesan <knikanth@suse.de>
Signed-off-by: Amit Arora <aarora@in.ibm.com>
 
> ---
> 
> diff --git a/fs/ext4/extents.c b/fs/ext4/extents.c
> index 236b834..39b8123 100644
> --- a/fs/ext4/extents.c
> +++ b/fs/ext4/extents.c
> @@ -3672,6 +3672,11 @@ long ext4_fallocate(struct inode *inode, int mode, loff_t offset, loff_t len)
>  	 */
>  	credits = ext4_chunk_trans_blocks(inode, max_blocks);
>  	mutex_lock(&inode->i_mutex);
> +	ret = inode_newsize_ok(inode, (len + offset));
> +	if (ret) {
> +		mutex_unlock(&inode->i_mutex);
> +		return ret;
> +	}
>  retry:
>  	while (ret >= 0 && ret < max_blocks) {
>  		block = block + ret;