Re: [PATCH 06/14] audit: Factor out chunk replacement code

On Tue 06-11-18 08:58:36, Paul Moore wrote: > On Thu, Oct 18, 2018 at 3:27 PM Richard Guy Briggs <rgb(a)redhat.com&gt; wrote: > > On 2018-10-17 12:14, Jan Kara wrote: > > > Chunk replacement code is very similar for the cases where we grow or > > > shrink chunk. Factor the code out into a common helper function. > > > > Noting just the switch from list_replace_init() to list_splice_init(). > > Yeah, I wasn't expecting to see that, maybe it will make sense as I > work through the rest of the patchset. > > Jan, can you explain the reason behind the change? I'm a little > nervous that this is simply hiding a problem (e.g. the list_empty() > check in splice). The reason is very simple: replace_chunk() gets called from tag_chunk() *after* we have possibly done: if (!tree->root) { tree->root = chunk; list_add(&tree->same_root, &chunk->trees); } So new->trees is possibly non-empty and we need to preserve its contents. That's why we need list_splice() and not plain list_replace().