From mboxrd@z Thu Jan 1 00:00:00 1970 From: Vladimir Davydov Subject: Re: [PATCH v12 05/18] fs: do not use destroy_super() in alloc_super() fail path Date: Tue, 3 Dec 2013 17:48:52 +0400 Message-ID: <529DE144.8020005@parallels.com> References: <20131203090041.GB8803@dastard> <529DA2F5.1040602@parallels.com> <20131203133755.GJ10323@ZenIV.linux.org.uk> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20131203133755.GJ10323@ZenIV.linux.org.uk> Sender: linux-kernel-owner@vger.kernel.org List-ID: Content-Type: text/plain; charset="us-ascii" To: Al Viro Cc: Dave Chinner , hannes@cmpxchg.org, mhocko@suse.cz, dchinner@redhat.com, akpm@linux-foundation.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, cgroups@vger.kernel.org, devel@openvz.org, glommer@openvz.org On 12/03/2013 05:37 PM, Al Viro wrote: > On Tue, Dec 03, 2013 at 01:23:01PM +0400, Vladimir Davydov wrote: > >> Actually, I'm not going to modify the list_lru structure, because I >> think it's good as it is. I'd like to substitute it with a new >> structure, memcg_list_lru, only in those places where this functionality >> (per-memcg scanning) is really needed. This new structure would look >> like this: >> >> struct memcg_list_lru { >> struct list_lru global_lru; >> struct list_lru **memcg_lrus; >> struct list_head list; >> void *old_lrus; >> } >> >> Since old_lrus and memcg_lrus can be NULL under normal operation, in >> memcg_list_lru_destroy() I'd have to check either the list or the >> global_lru field, i.e. it would look like: >> >> if (!list.next) >> /* has not been initialized */ >> return; >> >> or > ... or just use hlist_head. list_head serves as a list node here (those structures are organized in a linked list) and I have to remove it from the list upon destruction so hlist_head is not relevant here. Thanks.