Linux-Fsdevel Archive on lore.kernel.org
help / color / mirror / Atom feed
From: "Sungjong Seo" <sj1557.seo@samsung.com>
To: "'Tetsuhiro Kohada'" <kohada.t2@gmail.com>
Cc: <kohada.tetsuhiro@dc.mitsubishielectric.co.jp>,
	<mori.takahiro@ab.mitsubishielectric.co.jp>,
	<motai.hirotaka@aj.mitsubishielectric.co.jp>,
	"'Namjae Jeon'" <namjae.jeon@samsung.com>,
	<linux-fsdevel@vger.kernel.org>, <linux-kernel@vger.kernel.org>
Subject: RE: [PATCH] exfat: remove EXFAT_SB_DIRTY flag
Date: Fri, 12 Jun 2020 17:34:46 +0900	[thread overview]
Message-ID: <219a01d64094$5418d7a0$fc4a86e0$@samsung.com> (raw)
In-Reply-To: <20200612012834.13503-1-kohada.t2@gmail.com>

> remove EXFAT_SB_DIRTY flag and related codes.
> 
> This flag is set/reset in exfat_put_super()/exfat_sync_fs() to avoid
> sync_blockdev().
> However ...
> - exfat_put_super():
> Before calling this, the VFS has already called sync_filesystem(), so sync
> is never performed here.
> - exfat_sync_fs():
> After calling this, the VFS calls sync_blockdev(), so, it is meaningless
> to check EXFAT_SB_DIRTY or to bypass sync_blockdev() here.
> Not only that, but in some cases can't clear VOL_DIRTY.
> ex:
> VOL_DIRTY is set when rmdir starts, but when non-empty-dir is detected,
> return error without setting EXFAT_SB_DIRTY.
> If performe 'sync' in this state, VOL_DIRTY will not be cleared.
> 
> Remove the EXFAT_SB_DIRTY check to ensure synchronization.
> And, remove the code related to the flag.
> 
> Signed-off-by: Tetsuhiro Kohada <kohada.t2@gmail.com>
> ---
>  fs/exfat/balloc.c   |  4 ++--
>  fs/exfat/dir.c      | 16 ++++++++--------
>  fs/exfat/exfat_fs.h |  5 +----
>  fs/exfat/fatent.c   |  7 ++-----
>  fs/exfat/misc.c     |  3 +--
>  fs/exfat/namei.c    | 12 ++++++------
>  fs/exfat/super.c    | 11 +++--------
>  7 files changed, 23 insertions(+), 35 deletions(-)
> 
[snip]
> 
> @@ -62,11 +59,9 @@ static int exfat_sync_fs(struct super_block *sb, int
> wait)
> 
>  	/* If there are some dirty buffers in the bdev inode */
>  	mutex_lock(&sbi->s_lock);
> -	if (test_and_clear_bit(EXFAT_SB_DIRTY, &sbi->s_state)) {
> -		sync_blockdev(sb->s_bdev);
> -		if (exfat_set_vol_flags(sb, VOL_CLEAN))
> -			err = -EIO;
> -	}

I looked through most codes related to EXFAT_SB_DIRTY and VOL_DIRTY.
And your approach looks good because all of them seem to be protected by
s_lock.

BTW, as you know, sync_filesystem() calls sync_fs() with 'nowait' first,
and then calls it again with 'wait' twice. No need to sync with lock twice.
If so, isn't it okay to do nothing when wait is 0?

> +	sync_blockdev(sb->s_bdev);
> +	if (exfat_set_vol_flags(sb, VOL_CLEAN))
> +		err = -EIO;
>  	mutex_unlock(&sbi->s_lock);
>  	return err;
>  }
> --
> 2.25.1



  reply	other threads:[~2020-06-12  8:34 UTC|newest]

Thread overview: 7+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20200612012902epcas1p4194d6fa3b3f7c46a8becb9bb6ce23d56@epcas1p4.samsung.com>
2020-06-12  1:28 ` Tetsuhiro Kohada
2020-06-12  8:34   ` Sungjong Seo [this message]
2020-06-12 10:22     ` Tetsuhiro Kohada
2020-06-15  2:59       ` Sungjong Seo
2020-06-15  8:31         ` Kohada.Tetsuhiro
2020-06-12  8:48 Markus Elfring
2020-06-12 10:01 ` Greg KH

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to='219a01d64094$5418d7a0$fc4a86e0$@samsung.com' \
    --to=sj1557.seo@samsung.com \
    --cc=kohada.t2@gmail.com \
    --cc=kohada.tetsuhiro@dc.mitsubishielectric.co.jp \
    --cc=linux-fsdevel@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=mori.takahiro@ab.mitsubishielectric.co.jp \
    --cc=motai.hirotaka@aj.mitsubishielectric.co.jp \
    --cc=namjae.jeon@samsung.com \
    --subject='RE: [PATCH] exfat: remove EXFAT_SB_DIRTY flag' \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for NNTP newsgroup(s).