lkml.org 
[lkml]   [2022]   [Mar]   [17]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
From
SubjectRE: [PATCH v2] exfat: do not clear VolumeDirty in writeback
Date
Hi Yuezhang

> When call exfat_clear_volume_dirty(sb), all dirty buffers had synced by
> sync_blockdev(), so I think REQ_FUA/REQ_PREFLUSH is not needed.

I think Kohada-san's meaning is like below:

- sync_dirty_buffer(sbi->boot_bh);
+ __sync_dirty_buffer(sbi->boot_bh, REQ_SYNC | REQ_FUA | REQ_PREFLUSH);

I guess sync_blockdev() won't guarantee sync to non-volatile storage if disk contains cache.

Best Regards
Andy Wu

> -----Original Message-----
> From: Mo, Yuezhang <Yuezhang.Mo@sony.com>
> Sent: Wednesday, March 16, 2022 5:18 PM
> To: Namjae Jeon <linkinjeon@kernel.org>;
> Kohada.Tetsuhiro@dc.MitsubishiElectric.co.jp
> Cc: sj1557.seo@samsung.com; linux-fsdevel@vger.kernel.org;
> linux-kernel@vger.kernel.org; Wu, Andy <Andy.Wu@sony.com>; Aoyama,
> Wataru (SGC) <Wataru.Aoyama@sony.com>
> Subject: RE: [PATCH v2] exfat: do not clear VolumeDirty in writeback
>
> Hi Namjae, Kohada.Tetsuhiro,
>
> > >> - if (sync)
> > >> - sync_dirty_buffer(sbi->boot_bh);
> > >> + sync_dirty_buffer(sbi->boot_bh);
> > >> +
> > >
> > > Use __sync_dirty_buffer() with REQ_FUA/REQ_PREFLUSH instead to
> > > guarantee a strict write order (including devices).
> > Yuezhang, It seems to make sense. Can you check this ?
> >
>
> When call exfat_clear_volume_dirty(sb), all dirty buffers had synced by
> sync_blockdev(), so I think REQ_FUA/REQ_PREFLUSH is not needed.
>
> ```
> sync_blockdev(sb->s_bdev);
> if (exfat_clear_volume_dirty(sb)) ```
>
> exfat_clear_volume_dirty() is only called in sync or umount context.
> In sync or umount context, all requests will be issued with REQ_SYNC
> regardless of whether REQ_SYNC is set when submitting buffer.
>
> And since the request of set VolumeDirty is issued with REQ_SYNC. So for
> simplicity, call sync_dirty_buffer() unconditionally.
>
> Best Regards,
> Yuezhang Mo
>

\
 
 \ /
  Last update: 2022-03-17 06:48    [W:0.079 / U:0.108 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site