linux-ext4 - Re: [PATCH v2] ext2: don't set *count in the case of failure in ext2_try_to

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] [day] [month] [year] [list]

Message-ID: <20191030101511.GA28525@quack2.suse.cz>
Date:   Wed, 30 Oct 2019 11:15:11 +0100
From:   Jan Kara <jack@...e.cz>
To:     Chengguang Xu <cgxu519@...ernel.net>
Cc:     jack@...e.com, linux-ext4@...r.kernel.org
Subject: Re: [PATCH v2] ext2: don't set *count in the case of failure in
 ext2_try_to_allocate()

On Sat 26-10-19 17:07:21, Chengguang Xu wrote:
> Currently we set *count to num(value 0) in the failure
> of block allocation in ext2_try_to_allocate(). Without
> reservation, we reuse *count(value 0) to retry block
> allocation and wrong *count will cause only allocating
> maximum 1 block even though having sufficent free blocks
> in that block group. Finally, it probably cause significant
> fragmentation.
> 
> Signed-off-by: Chengguang Xu <cgxu519@...ernel.net>

Thanks! Patch applied.

								Honza

> ---
> v1->v2:
> - Add detail explanation of effect to changelog.
> 
>  fs/ext2/balloc.c | 1 -
>  1 file changed, 1 deletion(-)
> 
> diff --git a/fs/ext2/balloc.c b/fs/ext2/balloc.c
> index e0cc55164505..29fc3a5054f8 100644
> --- a/fs/ext2/balloc.c
> +++ b/fs/ext2/balloc.c
> @@ -736,7 +736,6 @@ ext2_try_to_allocate(struct super_block *sb, int group,
>  	*count = num;
>  	return grp_goal - num;
>  fail_access:
> -	*count = num;
>  	return -1;
>  }
>  
> -- 
> 2.21.0
> 
> 
> 
-- 
Jan Kara <jack@...e.com>
SUSE Labs, CR