[Ocfs2-devel] [PATCH] the ac->ac_allow_chain_relink=0 won't disable group relink

[Andrew Morton]

On Thu, 21 Feb 2013 15:54:19 +0800
xiaowei.hu at oracle.com wrote:

> ocfs2_block_group_alloc_discontig() disables chain relink by setting
> ac->ac_allow_chain_relink = 0 because it grabs clusters from multiple
> cluster groups. It doesn't keep the credits for all chain relink,but
> ocfs2_claim_suballoc_bits overrides this in this call trace:
> ocfs2_block_group_claim_bits()->ocfs2_claim_clusters()->
> __ocfs2_claim_clusters()->ocfs2_claim_suballoc_bits()
> ocfs2_claim_suballoc_bits set ac->ac_allow_chain_relink = 1; then call
> ocfs2_search_chain() one time and disable it again, and then we run
> out of credits.
> 
> Fix is to allow relink by default and disable it in
> ocfs2_block_group_alloc_discontig.

What is the end-user impact of this bug?

Please always include this info in changelogs to help other to decide
which kernel version(s) need the patch, thanks.