linux-ext4 - Re: [PATCH] ext3: truncate block allocated on a failed ext3_write

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: <m33akoi5kb.fsf@dmon-lap.sw.ru>
Date:	Fri, 29 Aug 2008 12:33:24 +0400
From:	Dmitri Monakhov <dmonakhov@...nvz.org>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Cc:	cmm@...ibm.com, tytso@....edu, sandeen@...hat.com,
	linux-ext4@...r.kernel.org
Subject: Re: [PATCH] ext3: truncate block allocated on a failed ext3_write_begin

"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com> writes:

> For blocksize < pagesize we need to remove blocks that
> got allocte in block_wirte_begin if we fail with ENOSPC
> for later blocks. block_write_begin internally does
> this if it allocated page locally. This make sure
> we don't have blocks outisde inode.i_size during
> ENOSPC
BTW why this check was moved from generic_XXX_write to fs speciffic code?
>
> Signed-off-by: Aneesh Kumar K.V <aneesh.kumar@...ux.vnet.ibm.com>
> ---
>  fs/ext3/inode.c |    7 +++++++
>  1 files changed, 7 insertions(+), 0 deletions(-)
>
> diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c
> index ebfec4d..f8424ad 100644
> --- a/fs/ext3/inode.c
> +++ b/fs/ext3/inode.c
> @@ -1186,6 +1186,13 @@ static int ext3_write_begin(struct file *file, struct address_space *mapping,
>  		ext3_journal_stop(handle);
>  		unlock_page(page);
>  		page_cache_release(page);
> +		/*
> +		 * block_write_begin may have instantiated a few blocks
> +		 * outside i_size.  Trim these off again. Don't need
> +		 * i_size_read because we hold i_mutex.
> +		 */
> +		if (pos + len > inode->i_size)
> +			vmtruncate(inode, inode->i_size);
>  	}
>  	if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries))
>  		goto retry;
> -- 
> 1.6.0.1.90.g27a6e
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
> the body of a message to majordomo@...r.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
--
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html