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Date:   Thu, 1 Dec 2022 15:11:44 +0100
From:   Jan Kara <jack@suse.cz>
To:     "Ritesh Harjani (IBM)" <ritesh.list@gmail.com>
Cc:     Jan Kara <jack@suse.cz>, Ted Tso <tytso@mit.edu>,
        linux-ext4@vger.kernel.org, Christoph Hellwig <hch@infradead.org>
Subject: Re: [PATCH 9/9] ext4: Remove ordered data support from
 ext4_writepage()
Message-ID: <20221201141144.rgosvsixfkcyagbc@quack3>
References: <20221130162435.2324-1-jack@suse.cz>
 <20221130163608.29034-9-jack@suse.cz>
 <20221201112152.slnmx3u6jh7bhww5@riteshh-domain>
 <20221201133619.cov6ntr2fuceqhjs@riteshh-domain>
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On Thu 01-12-22 19:06:19, Ritesh Harjani (IBM) wrote:
> On 22/12/01 04:51PM, Ritesh Harjani (IBM) wrote:
> > On 22/11/30 05:36PM, Jan Kara wrote:
> > > -	ext4_io_submit_init(&io_submit, wbc);
> > > -	io_submit.io_end = ext4_init_io_end(inode, GFP_NOFS);
> > > -	if (!io_submit.io_end) {
> > > -		redirty_page_for_writepage(wbc, page);
> > > +	WARN_ON_ONCE(!ext4_should_journal_data(inode));
> 
> Oh and one more thing, this will give a WARN_ON_ONCE(), until we change the pageout()
> function from reclaim path to not call ->writepage() method.
> This until then might cause random fstest to fail for sometime if it observes a
> kernel warning message while the test was running.
> 
> [ 5081.820019] WARNING: CPU: 3 PID: 125 at fs/ext4/inode.c:1994 ext4_writepage+0x380/0xb80
> [ 5081.822884] Modules linked in:
> [ 5081.824487] CPU: 3 PID: 125 Comm: kswapd0 Not tainted 6.1.0-rc4-00054-g969d94a2d4d6 #101
> [ 5081.825559] Hardware name: IBM pSeries (emulated by qemu) POWER9 (raw) 0x4e1200 0xf000005 of:SLOF,git-6b6c16 pSeries
> [ 5081.826743] NIP:  c00000000077a2c0 LR: c00000000077a2b4 CTR: c000000000779f40
> [ 5081.827547] REGS: c0000000073d72d0 TRAP: 0700   Not tainted  (6.1.0-rc4-00054-g969d94a2d4d6)
> <...>
> [ 5081.862838] NIP [c00000000077a2c0] ext4_writepage+0x380/0xb80
> [ 5081.864963] LR [c00000000077a2b4] ext4_writepage+0x374/0xb80
> [ 5081.865995] Call Trace:
> [ 5081.866510]  ext4_writepage+0x190/0xb80 (unreliable)
> [ 5081.867438]  pageout+0x1b0/0x550
> [ 5081.868110]  shrink_folio_list+0xb48/0x1400
> [ 5081.868803]  shrink_inactive_list+0x2ec/0x6b0
> [ 5081.869504]  shrink_lruvec+0x6f0/0x7b0
> [ 5081.870160]  shrink_node+0x5e4/0x980
> [ 5081.870801]  balance_pgdat+0x4cc/0x910
> [ 5081.871453]  kswapd+0x6e4/0x820
> [ 5081.872062]  kthread+0x168/0x170
> [ 5081.872691]  ret_from_kernel_thread+0x5c/0x64

Hum, right. It didn't trigger for me :). I'll see how to fix this.

								Honza

-- 
Jan Kara <jack@suse.com>
SUSE Labs, CR