Re: [PATCH 2/2 v2] fs: Fix hang with BSD accounting on frozen filesystem

[Dave Chinner <david@fromorbit.com>]

On Thu, Nov 08, 2012 at 01:41:38PM +0100, Jan Kara wrote:
> When BSD process accounting is enabled and logs information to a filesystem
> which gets frozen, system easily becomes unusable because each attempt to
> account process information blocks. Thus e.g. every task gets blocked in exit.
> 
> It seems better to drop accounting information (which can already happen when
> filesystem is running out of space) instead of locking system up. So we
> open the accounting file with O_NONBLOCK.
> 
> Reported-and-tested-by: Nikola Ciprich <nikola.ciprich@linuxbox.cz>
> Signed-off-by: Jan Kara <jack@suse.cz>
> ---
>  kernel/acct.c |    3 ++-
>  1 files changed, 2 insertions(+), 1 deletions(-)
> 
> diff --git a/kernel/acct.c b/kernel/acct.c
> index 051e071..a061116 100644
> --- a/kernel/acct.c
> +++ b/kernel/acct.c
> @@ -201,7 +201,8 @@ static int acct_on(struct filename *pathname)
>  	struct bsd_acct_struct *acct = NULL;
>  
>  	/* Difference from BSD - they don't do O_APPEND */
> -	file = file_open_name(pathname, O_WRONLY|O_APPEND|O_LARGEFILE, 0);
> +	file = file_open_name(pathname,
> +			      O_WRONLY|O_APPEND|O_LARGEFILE|O_NONBLOCK, 0);
>  	if (IS_ERR(file))
>  		return PTR_ERR(file);

Looks good.

Reviewed-by: Dave Chinner <dchinner@redhat.com>

-- 
Dave Chinner
david@fromorbit.com