linux-ext4 - Re: ENOSPC error returned too late

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: <20080818133046.GA8184@mit.edu>
Date:	Mon, 18 Aug 2008 09:30:46 -0400
From:	Theodore Tso <tytso@....edu>
To:	"Aneesh Kumar K.V" <aneesh.kumar@...ux.vnet.ibm.com>
Cc:	linux-ext4@...r.kernel.org
Subject: Re: ENOSPC error returned too late

On Mon, Aug 18, 2008 at 04:21:40PM +0530, Aneesh Kumar K.V wrote:
> --- a/fs/ext4/balloc.c
> +++ b/fs/ext4/balloc.c
> @@ -1628,6 +1628,9 @@ ext4_fsblk_t ext4_has_free_blocks(struct ext4_sb_info *sbi,
>  		free_blocks =
>  			percpu_counter_sum_and_set(&sbi->s_freeblocks_counter);
>  #endif
> +	if (free_blocks <= root_blocks)
> +		/* we don't have free space */
> +		return 0;
>  	if (free_blocks - root_blocks < nblocks)
>  		return free_blocks - root_blocks;
>  	return nblocks;

Thanks, I'll try it out.  Given that ext4_fsblk_t is an unsigned long
(BTW, this is one of the reasons why the common coding style guide
dislikes typedefs; it hides this kind of errors), it's obviously a
good patch to add regardless of whether it solves are problem, since
if freeblocks < root_blocks, the following condition is going to do
the Wrong Thing.

Signed-off-by: "Theodore Ts'o" <tytso@....edu>

						- Ted

--
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