From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from out30-118.freemail.mail.aliyun.com (out30-118.freemail.mail.aliyun.com [115.124.30.118]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 685742D660E; Tue, 9 Sep 2025 09:58:30 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=115.124.30.118 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757411914; cv=none; b=I7NG0NaoofqC1Vzznh7yLAQKnvThLYmgiA/orKl+BDBDK9GU6/gvortWYx4YiTlCnCbcoIaqqr3tp+SM0PKmmkR3niPVyoKSsni6+ptzpRTtNJHK5p2qIjww9MUM6W8S0/p/xypaDSLwR4Xdlc5fsLpS2XOodrBJ2EYWLYe1brw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1757411914; c=relaxed/simple; bh=2ylkYUVqm1vukpYw/TZOVR4NyJJMS1WlgKwyBnvvaPo=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=spF7lwoCoxUvgGbKJUlKRsQTg28DzVMpCIwIEtvtkCIioRmhMygOFgFZ+wNXJRnMwcAqvEpljBhJuSbWsWij39ENPX7BLxnOFO3dotwhQQFtkOvdtMwzoMZebDVdQB6HtXhh40XAs8TCXKHUe+iFNNBeVEq6Z1vyOujh/9tAh6k= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com; spf=pass smtp.mailfrom=linux.alibaba.com; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b=nEQsWNY2; arc=none smtp.client-ip=115.124.30.118 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; spf=pass smtp.mailfrom=linux.alibaba.com Authentication-Results: smtp.subspace.kernel.org; dkim=pass (1024-bit key) header.d=linux.alibaba.com header.i=@linux.alibaba.com header.b="nEQsWNY2" DKIM-Signature:v=1; a=rsa-sha256; c=relaxed/relaxed; d=linux.alibaba.com; s=default; t=1757411903; h=Message-ID:Date:MIME-Version:Subject:To:From:Content-Type; bh=laCkHECgYhbQ7uAXupGXaMZIzy0vHoixB6ifh+oN2q0=; b=nEQsWNY2sTu/mF/NUXhMvna3UqyocoZKjicaVr6z2lnGTsxVRMtUhDIcV3Hw6Zxs0JnOMFBRnp8U5YTzix9M5ZKX+N942LYKMi3coUaxmu/veKrD6qfGabh4S1XECHsMAybi6ZZ97OgTjKptgJTVZxvKctmHADVur9yJkZPmG0Y= Received: from 30.221.128.137(mailfrom:joseph.qi@linux.alibaba.com fp:SMTPD_---0WndX6FR_1757411901 cluster:ay36) by smtp.aliyun-inc.com; Tue, 09 Sep 2025 17:58:22 +0800 Message-ID: <02814cfb-9a51-4e67-942c-4da0c57a75c4@linux.alibaba.com> Date: Tue, 9 Sep 2025 17:58:21 +0800 Precedence: bulk X-Mailing-List: linux-fsdevel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Subject: Re: [External] : [PATCH] ocfs2: retire ocfs2_drop_inode() and I_WILL_FREE usage To: Jan Kara Cc: Mateusz Guzik , Mark Tinguely , ocfs2-devel@lists.linux.dev, viro@zeniv.linux.org.uk, linux-kernel@vger.kernel.org, linux-fsdevel@vger.kernel.org, josef@toxicpanda.com, jlbec@evilplan.org, mark@fasheh.com, brauner@kernel.org, willy@infradead.org, david@fromorbit.com References: <766vdz3ecpm7hv4sp5r3uu4ezggm532ng7fdklb2nrupz6minz@qcws3ufabnjp> <20250904154245.644875-1-mjguzik@gmail.com> <8ddcaa59-0cf0-4b7c-a121-924105f7f5a6@linux.alibaba.com> From: Joseph Qi In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit On 2025/9/9 17:49, Jan Kara wrote: > On Tue 09-09-25 09:23:56, Joseph Qi wrote: >> On 2025/9/8 21:54, Jan Kara wrote: >>> On Mon 08-09-25 20:41:21, Joseph Qi wrote: >>>> >>>> >>>> On 2025/9/8 18:23, Jan Kara wrote: >>>>> On Mon 08-09-25 09:51:36, Joseph Qi wrote: >>>>>> On 2025/9/5 00:22, Mateusz Guzik wrote: >>>>>>> On Thu, Sep 4, 2025 at 6:15 PM Mark Tinguely wrote: >>>>>>>> >>>>>>>> On 9/4/25 10:42 AM, Mateusz Guzik wrote: >>>>>>>>> This postpones the writeout to ocfs2_evict_inode(), which I'm told is >>>>>>>>> fine (tm). >>>>>>>>> >>>>>>>>> The intent is to retire the I_WILL_FREE flag. >>>>>>>>> >>>>>>>>> Signed-off-by: Mateusz Guzik >>>>>>>>> --- >>>>>>>>> >>>>>>>>> ACHTUNG: only compile-time tested. Need an ocfs2 person to ack it. >>>>>>>>> >>>>>>>>> btw grep shows comments referencing ocfs2_drop_inode() which are already >>>>>>>>> stale on the stock kernel, I opted to not touch them. >>>>>>>>> >>>>>>>>> This ties into an effort to remove the I_WILL_FREE flag, unblocking >>>>>>>>> other work. If accepted would be probably best taken through vfs >>>>>>>>> branches with said work, see https://urldefense.com/v3/__https://git.kernel.org/pub/scm/linux/kernel/git/vfs/vfs.git/log/?h=vfs-6.18.inode.refcount.preliminaries__;!!ACWV5N9M2RV99hQ!OLwk8DVo7uvC-Pd6XVTiUCgP6MUDMKBMEyuV27h_yPGXOjaq078-kMdC9ILFoYQh-4WX93yb0nMfBDFFY_0$ >>>>>>>>> >>>>>>>>> fs/ocfs2/inode.c | 23 ++--------------------- >>>>>>>>> fs/ocfs2/inode.h | 1 - >>>>>>>>> fs/ocfs2/ocfs2_trace.h | 2 -- >>>>>>>>> fs/ocfs2/super.c | 2 +- >>>>>>>>> 4 files changed, 3 insertions(+), 25 deletions(-) >>>>>>>>> >>>>>>>>> diff --git a/fs/ocfs2/inode.c b/fs/ocfs2/inode.c >>>>>>>>> index 6c4f78f473fb..5f4a2cbc505d 100644 >>>>>>>>> --- a/fs/ocfs2/inode.c >>>>>>>>> +++ b/fs/ocfs2/inode.c >>>>>>>>> @@ -1290,6 +1290,8 @@ static void ocfs2_clear_inode(struct inode *inode) >>>>>>>>> >>>>>>>>> void ocfs2_evict_inode(struct inode *inode) >>>>>>>>> { >>>>>>>>> + write_inode_now(inode, 1); >>>>>>>>> + >>>>>>>>> if (!inode->i_nlink || >>>>>>>>> (OCFS2_I(inode)->ip_flags & OCFS2_INODE_MAYBE_ORPHANED)) { >>>>>>>>> ocfs2_delete_inode(inode); >>>>>>>>> @@ -1299,27 +1301,6 @@ void ocfs2_evict_inode(struct inode *inode) >>>>>>>>> ocfs2_clear_inode(inode); >>>>>>>>> } >>>>>>>>> >>>>>>>>> -/* Called under inode_lock, with no more references on the >>>>>>>>> - * struct inode, so it's safe here to check the flags field >>>>>>>>> - * and to manipulate i_nlink without any other locks. */ >>>>>>>>> -int ocfs2_drop_inode(struct inode *inode) >>>>>>>>> -{ >>>>>>>>> - struct ocfs2_inode_info *oi = OCFS2_I(inode); >>>>>>>>> - >>>>>>>>> - trace_ocfs2_drop_inode((unsigned long long)oi->ip_blkno, >>>>>>>>> - inode->i_nlink, oi->ip_flags); >>>>>>>>> - >>>>>>>>> - assert_spin_locked(&inode->i_lock); >>>>>>>>> - inode->i_state |= I_WILL_FREE; >>>>>>>>> - spin_unlock(&inode->i_lock); >>>>>>>>> - write_inode_now(inode, 1); >>>>>>>>> - spin_lock(&inode->i_lock); >>>>>>>>> - WARN_ON(inode->i_state & I_NEW); >>>>>>>>> - inode->i_state &= ~I_WILL_FREE; >>>>>>>>> - >>>>>>>>> - return 1; >>>>>>>>> -} >>>>>>>>> - >>>>>>>>> /* >>>>>>>>> * This is called from our getattr. >>>>>>>>> */ >>>>>>>>> diff --git a/fs/ocfs2/inode.h b/fs/ocfs2/inode.h >>>>>>>>> index accf03d4765e..07bd838e7843 100644 >>>>>>>>> --- a/fs/ocfs2/inode.h >>>>>>>>> +++ b/fs/ocfs2/inode.h >>>>>>>>> @@ -116,7 +116,6 @@ static inline struct ocfs2_caching_info *INODE_CACHE(struct inode *inode) >>>>>>>>> } >>>>>>>>> >>>>>>>>> void ocfs2_evict_inode(struct inode *inode); >>>>>>>>> -int ocfs2_drop_inode(struct inode *inode); >>>>>>>>> >>>>>>>>> /* Flags for ocfs2_iget() */ >>>>>>>>> #define OCFS2_FI_FLAG_SYSFILE 0x1 >>>>>>>>> diff --git a/fs/ocfs2/ocfs2_trace.h b/fs/ocfs2/ocfs2_trace.h >>>>>>>>> index 54ed1495de9a..4b32fb5658ad 100644 >>>>>>>>> --- a/fs/ocfs2/ocfs2_trace.h >>>>>>>>> +++ b/fs/ocfs2/ocfs2_trace.h >>>>>>>>> @@ -1569,8 +1569,6 @@ DEFINE_OCFS2_ULL_ULL_UINT_EVENT(ocfs2_delete_inode); >>>>>>>>> >>>>>>>>> DEFINE_OCFS2_ULL_UINT_EVENT(ocfs2_clear_inode); >>>>>>>>> >>>>>>>>> -DEFINE_OCFS2_ULL_UINT_UINT_EVENT(ocfs2_drop_inode); >>>>>>>>> - >>>>>>>>> TRACE_EVENT(ocfs2_inode_revalidate, >>>>>>>>> TP_PROTO(void *inode, unsigned long long ino, >>>>>>>>> unsigned int flags), >>>>>>>>> diff --git a/fs/ocfs2/super.c b/fs/ocfs2/super.c >>>>>>>>> index 53daa4482406..e4b0d25f4869 100644 >>>>>>>>> --- a/fs/ocfs2/super.c >>>>>>>>> +++ b/fs/ocfs2/super.c >>>>>>>>> @@ -129,7 +129,7 @@ static const struct super_operations ocfs2_sops = { >>>>>>>>> .statfs = ocfs2_statfs, >>>>>>>>> .alloc_inode = ocfs2_alloc_inode, >>>>>>>>> .free_inode = ocfs2_free_inode, >>>>>>>>> - .drop_inode = ocfs2_drop_inode, >>>>>>>>> + .drop_inode = generic_delete_inode, >>>>>>>>> .evict_inode = ocfs2_evict_inode, >>>>>>>>> .sync_fs = ocfs2_sync_fs, >>>>>>>>> .put_super = ocfs2_put_super, >>>>>>>> >>>>>>>> >>>>>>>> I agree, fileystems should not use I_FREEING/I_WILL_FREE. >>>>>>>> Doing the sync write_inode_now() should be fine in ocfs_evict_inode(). >>>>>>>> >>>>>>>> Question is ocfs_drop_inode. In commit 513e2dae9422: >>>>>>>> ocfs2: flush inode data to disk and free inode when i_count becomes zero >>>>>>>> the return of 1 drops immediate to fix a memory caching issue. >>>>>>>> Shouldn't .drop_inode() still return 1? >>>>>>> >>>>>>> generic_delete_inode is a stub doing just that. >>>>>>> >>>>>> In case of "drop = 0", it may return directly without calling evict(). >>>>>> This seems break the expectation of commit 513e2dae9422. >>>>> >>>>> generic_delete_inode() always returns 1 so evict() will be called. >>>>> ocfs2_drop_inode() always returns 1 as well after 513e2dae9422. So I'm not >>>>> sure which case of "drop = 0" do you see... >>>>> >>>> I don't see a real case, just in theory. >>>> As I described before, if we make sure write_inode_now() will be called >>>> in iput_final(), it would be fine. >>> >>> I'm sorry but I still don't quite understand what you are proposing. If >>> ->drop() returns 1, the filesystem wants to remove the inode from cache >>> (perhaps because it was deleted). Hence iput_final() doesn't bother with >>> writing out such inodes. This doesn't work well with ocfs2 wanting to >>> always drop inodes hence ocfs2 needs to write the inode itself in >>> ocfs2_evice_inode(). Perhaps you have some modification to iput_final() in >>> mind but I'm not sure how that would work so can you perhaps suggest a >>> patch if you think iput_final() should work differently? Thanks! >>> >> I'm just discussing if generic_delete_inode() will always returns 1. And >> if it is, I'm fine with this change. Sorry for the confusion. > > generic_delete_inode() is defined as: > > int generic_delete_inode(struct inode *inode) > { > return 1; > } > > So the return is pretty much guaranteed :). But I agree with Mateusz the > function name could be less confusing. > Oops, I've mixed it with generic_drop_inode()... Thanks, Joseph