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Date:   Tue, 3 Oct 2023 17:22:40 -0400
From:   Phillip Susi <phill@thesusis.net>
To:     Damien Le Moal <dlemoal@kernel.org>
Cc:     linux-ide@vger.kernel.org, linux-scsi@vger.kernel.org,
        "Martin K . Petersen" <martin.petersen@oracle.com>,
        John Garry <john.g.garry@oracle.com>,
        Rodrigo Vivi <rodrigo.vivi@intel.com>,
        Paul Ausbeck <paula@soe.ucsc.edu>,
        Kai-Heng Feng <kai.heng.feng@canonical.com>,
        Joe Breuer <linux-kernel@jmbreuer.net>,
        Geert Uytterhoeven <geert@linux-m68k.org>,
        Chia-Lin Kao <acelan.kao@canonical.com>
Subject: Re: [PATCH v8 00/23] Fix libata suspend/resume handling and code
 cleanup
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On Tue, Oct 03, 2023 at 09:44:50AM +0900, Damien Le Moal wrote:
> Hmmm... So this could be the fs suspend then, which issues a sync but the device
> is already suspended and was synced already. In that case, we should turn that
> sync into a nop to not wakeup the drive unnecessarily. The fix may be needed on
> scsi sd side rather than libata.

I did some tracing today on a test ext4 fs I created on a loopback device, and it
seems that the superblocks are written every time you sync, even if no files on the
filesystem have even been opened for read access.