From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-16.7 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,INCLUDES_CR_TRAILER,INCLUDES_PATCH, MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5C58BC4338F for ; Wed, 18 Aug 2021 16:06:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 42832610A1 for ; Wed, 18 Aug 2021 16:06:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229541AbhHRQH0 (ORCPT ); Wed, 18 Aug 2021 12:07:26 -0400 Received: from mail.kernel.org ([198.145.29.99]:38652 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229454AbhHRQHZ (ORCPT ); Wed, 18 Aug 2021 12:07:25 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 9DE98610A6; Wed, 18 Aug 2021 16:06:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1629302811; bh=GfJ8QyFgkWPNtzLynTbuRKM5P5pWtWZlGElDNc9hr5M=; h=Subject:From:To:Cc:Date:In-Reply-To:References:From; b=j8OAlx4ob9UlRjUldmKVjS4ggo8RdmCF25kSW8aUQe8V9JmecBE63k65s7D4aKt55 O3SsFNwpuuf3QLRr4suuKKZj86MKfKs1PSjkEcrLU4XbPnRd6h5TUXIRyvFZayD8NG m7nkRSnLeyBeoPvhvQtIaPxrbDy3EgPDToIGJlcq+w6Np7GJovcMl3AcKQ2Ym1+zjP 3VJqyeoyljUgXZg50hCiy02qUXItNtoX8OwHzg3+5HU2DzRADYw59cHmy9TYbeSj24 wm/deTCn0ZtO6OmkIltztgs/n2THC63v/GaDireyJKrmeUhApNlgu4hPbNHlC0r50h fGTW/GxP1zphA== Message-ID: <007becbddbb928e7cb52feb5ffafb4f254dd5ba0.camel@kernel.org> Subject: Re: [PATCH v4] ceph: correctly release memory from capsnap From: Jeff Layton To: xiubli@redhat.com Cc: idryomov@gmail.com, pdonnell@redhat.com, ceph-devel@vger.kernel.org Date: Wed, 18 Aug 2021 12:06:49 -0400 In-Reply-To: <20210818133842.15993-1-xiubli@redhat.com> References: <20210818133842.15993-1-xiubli@redhat.com> Content-Type: text/plain; charset="ISO-8859-15" User-Agent: Evolution 3.40.3 (3.40.3-1.fc34) MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: ceph-devel@vger.kernel.org On Wed, 2021-08-18 at 21:38 +0800, xiubli@redhat.com wrote: > From: Xiubo Li > > When force umounting, it will try to remove all the session caps. > If there has any capsnap is in the flushing list, the remove session > caps callback will try to release the capsnap->flush_cap memory to > "ceph_cap_flush_cachep" slab cache, while which is allocated from > kmalloc-256 slab cache. > > At the same time switch to list_del_init() because just in case the > force umount has removed it from the lists and the > handle_cap_flushsnap_ack() comes then the seconds list_del_init() > won't crash the kernel. > > URL: https://tracker.ceph.com/issues/52283 > Signed-off-by: Xiubo Li > --- > > Changed in V4: > - add a new is_capsnap field in ceph_cap_flush struct. > > > fs/ceph/caps.c | 19 ++++++++++++------- > fs/ceph/mds_client.c | 7 ++++--- > fs/ceph/snap.c | 1 + > fs/ceph/super.h | 3 ++- > 4 files changed, 19 insertions(+), 11 deletions(-) > > diff --git a/fs/ceph/caps.c b/fs/ceph/caps.c > index 4663ab830614..52c7026fd0d1 100644 > --- a/fs/ceph/caps.c > +++ b/fs/ceph/caps.c > @@ -1712,7 +1712,11 @@ int __ceph_mark_dirty_caps(struct ceph_inode_info *ci, int mask, > > struct ceph_cap_flush *ceph_alloc_cap_flush(void) > { > - return kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL); > + struct ceph_cap_flush *cf; > + > + cf = kmem_cache_alloc(ceph_cap_flush_cachep, GFP_KERNEL); > + cf->is_capsnap = false; > + return cf; > } > > void ceph_free_cap_flush(struct ceph_cap_flush *cf) > @@ -1747,7 +1751,7 @@ static bool __detach_cap_flush_from_mdsc(struct ceph_mds_client *mdsc, > prev->wake = true; > wake = false; > } > - list_del(&cf->g_list); > + list_del_init(&cf->g_list); > return wake; > } > > @@ -1762,7 +1766,7 @@ static bool __detach_cap_flush_from_ci(struct ceph_inode_info *ci, > prev->wake = true; > wake = false; > } > - list_del(&cf->i_list); > + list_del_init(&cf->i_list); > return wake; > } > > @@ -2400,7 +2404,7 @@ static void __kick_flushing_caps(struct ceph_mds_client *mdsc, > ci->i_ceph_flags &= ~CEPH_I_KICK_FLUSH; > > list_for_each_entry_reverse(cf, &ci->i_cap_flush_list, i_list) { > - if (!cf->caps) { > + if (cf->is_capsnap) { > last_snap_flush = cf->tid; > break; > } > @@ -2419,7 +2423,7 @@ static void __kick_flushing_caps(struct ceph_mds_client *mdsc, > > first_tid = cf->tid + 1; > > - if (cf->caps) { > + if (!cf->is_capsnap) { > struct cap_msg_args arg; > > dout("kick_flushing_caps %p cap %p tid %llu %s\n", > @@ -3568,7 +3572,7 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid, > cleaned = cf->caps; > > /* Is this a capsnap? */ > - if (cf->caps == 0) > + if (cf->is_capsnap) > continue; > > if (cf->tid <= flush_tid) { > @@ -3642,7 +3646,8 @@ static void handle_cap_flush_ack(struct inode *inode, u64 flush_tid, > cf = list_first_entry(&to_remove, > struct ceph_cap_flush, i_list); > list_del(&cf->i_list); > - ceph_free_cap_flush(cf); > + if (!cf->is_capsnap) > + ceph_free_cap_flush(cf); > } > > if (wake_ci) > diff --git a/fs/ceph/mds_client.c b/fs/ceph/mds_client.c > index dcb5f34a084b..b9e6a69cc058 100644 > --- a/fs/ceph/mds_client.c > +++ b/fs/ceph/mds_client.c > @@ -1656,7 +1656,7 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, > spin_lock(&mdsc->cap_dirty_lock); > > list_for_each_entry(cf, &to_remove, i_list) > - list_del(&cf->g_list); > + list_del_init(&cf->g_list); > > if (!list_empty(&ci->i_dirty_item)) { > pr_warn_ratelimited( > @@ -1710,8 +1710,9 @@ static int remove_session_caps_cb(struct inode *inode, struct ceph_cap *cap, > struct ceph_cap_flush *cf; > cf = list_first_entry(&to_remove, > struct ceph_cap_flush, i_list); > - list_del(&cf->i_list); > - ceph_free_cap_flush(cf); > + list_del_init(&cf->i_list); > + if (!cf->is_capsnap) > + ceph_free_cap_flush(cf); > } > > wake_up_all(&ci->i_cap_wq); > diff --git a/fs/ceph/snap.c b/fs/ceph/snap.c > index af502a8245f0..62fab59bbf96 100644 > --- a/fs/ceph/snap.c > +++ b/fs/ceph/snap.c > @@ -487,6 +487,7 @@ static void ceph_queue_cap_snap(struct ceph_inode_info *ci) > pr_err("ENOMEM allocating ceph_cap_snap on %p\n", inode); > return; > } > + capsnap->cap_flush.is_capsnap = true; > > spin_lock(&ci->i_ceph_lock); > used = __ceph_caps_used(ci); > diff --git a/fs/ceph/super.h b/fs/ceph/super.h > index 106ddfd1ce92..336350861791 100644 > --- a/fs/ceph/super.h > +++ b/fs/ceph/super.h > @@ -186,8 +186,9 @@ struct ceph_cap { > > struct ceph_cap_flush { > u64 tid; > - int caps; /* 0 means capsnap */ > + int caps; > bool wake; /* wake up flush waiters when finish ? */ > + bool is_capsnap; /* true means capsnap */ > struct list_head g_list; // global > struct list_head i_list; // per inode > struct ceph_inode_info *ci; Looks good, Xiubo. I'll merge into testing after a bit of local testing on my part. I'll plan to mark this one for stable too, but I'll need to look at the prerequisites as there may be merge conflicts with earlier kernels. -- Jeff Layton