[Ocfs2-devel] [PATCH] run out of jbd2 credits during discontig group alloc.

[Xiaowei <xiaowei.hu@oracle.com>]

Could someone review this patch please? it's verified one testing box , 
fixed the run out of credits crash.

Thanks,
Xiaowei


On 11/15/2012 09:20 AM, xiaowei.hu at oracle.com wrote:
> From: "Xiaowei.Hu" <xiaowei.hu@oracle.com>
>
> ocfs2_block_group_alloc_discontig doesn't keep credits for chain relink,
> and mean to disable chain relink setting ac->ac_allow_chain_relink = 0,
> but this value will be set to 1 in function ocfs2_claim_suballoc_bits,
> so need to make it's default allow relink, and disable it with one
> switch could be passed in.
>
> Signed-off-by: Xiaowei.Hu <xiaowei.hu@oracle.com>
> ---
>   fs/ocfs2/suballoc.c |    7 +++----
>   fs/ocfs2/suballoc.h |    2 +-
>   2 files changed, 4 insertions(+), 5 deletions(-)
>
> diff --git a/fs/ocfs2/suballoc.c b/fs/ocfs2/suballoc.c
> index 4b5e568..033bfc6 100644
> --- a/fs/ocfs2/suballoc.c
> +++ b/fs/ocfs2/suballoc.c
> @@ -642,7 +642,7 @@ ocfs2_block_group_alloc_discontig(handle_t *handle,
>   	 * cluster groups will be staying in cache for the duration of
>   	 * this operation.
>   	 */
> -	ac->ac_allow_chain_relink = 0;
> +	ac->ac_disable_chain_relink = 1;
>   
>   	/* Claim the first region */
>   	status = ocfs2_block_group_claim_bits(osb, handle, ac, min_bits,
> @@ -1823,7 +1823,7 @@ static int ocfs2_search_chain(struct ocfs2_alloc_context *ac,
>   	 * Do this *after* figuring out how many bits we're taking out
>   	 * of our target group.
>   	 */
> -	if (ac->ac_allow_chain_relink &&
> +	if (!ac->ac_disable_chain_relink &&
>   	    (prev_group_bh) &&
>   	    (ocfs2_block_group_reasonably_empty(bg, res->sr_bits))) {
>   		status = ocfs2_relink_block_group(handle, alloc_inode,
> @@ -1928,7 +1928,6 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
>   
>   	victim = ocfs2_find_victim_chain(cl);
>   	ac->ac_chain = victim;
> -	ac->ac_allow_chain_relink = 1;
>   
>   	status = ocfs2_search_chain(ac, handle, bits_wanted, min_bits,
>   				    res, &bits_left);
> @@ -1947,7 +1946,7 @@ static int ocfs2_claim_suballoc_bits(struct ocfs2_alloc_context *ac,
>   	 * searching each chain in order. Don't allow chain relinking
>   	 * because we only calculate enough journal credits for one
>   	 * relink per alloc. */
> -	ac->ac_allow_chain_relink = 0;
> +	ac->ac_disable_chain_relink = 1;
>   	for (i = 0; i < le16_to_cpu(cl->cl_next_free_rec); i ++) {
>   		if (i == victim)
>   			continue;
> diff --git a/fs/ocfs2/suballoc.h b/fs/ocfs2/suballoc.h
> index b8afabf..a36d0aa 100644
> --- a/fs/ocfs2/suballoc.h
> +++ b/fs/ocfs2/suballoc.h
> @@ -49,7 +49,7 @@ struct ocfs2_alloc_context {
>   
>   	/* these are used by the chain search */
>   	u16    ac_chain;
> -	int    ac_allow_chain_relink;
> +	int    ac_disable_chain_relink;
>   	group_search_t *ac_group_search;
>   
>   	u64    ac_last_group;