All of lore.kernel.org
 help / color / mirror / Atom feed
From: Daejun Park <daejun7.park@samsung.com>
To: Andreas Dilger <adilger@dilger.ca>,
	Daejun Park <daejun7.park@samsung.com>,
	harshad shirwadkar <harshadshirwadkar@gmail.com>
Cc: "tytso@mit.edu" <tytso@mit.edu>,
	"linux-ext4@vger.kernel.org" <linux-ext4@vger.kernel.org>,
	"linux-kernel@vger.kernel.org" <linux-kernel@vger.kernel.org>
Subject: RE: Re: [PATCH] ext4: Remove expensive flush on fast commit
Date: Fri, 08 Jan 2021 11:37:07 +0900	[thread overview]
Message-ID: <20210108023707epcms2p32beb982610c9460e5fb08f927c52ad1d@epcms2p3> (raw)
In-Reply-To: <8A3C241B-9536-447B-B22D-F922D64731C7@dilger.ca>

> > In the fast commit, it adds REQ_FUA and REQ_PREFLUSH on each fast commit
> > block when barrier is enabled. However, in recovery phase, ext4 compares
> > CRC value in the tail. So it is sufficient adds REQ_FUA and REQ_PREFLUSH
> > on the block that has tail.
> 
> Does the tail block *always* contain a CRC, or is that dependent on
> EXT4_FEATURE_RO_COMPAT_METADATA_CSUM, JBD2_FEATURE_INCOMPAT_CSUM_V2,
> or JBD2_FEATURE_INCOMPAT_CSUM_V3 being enabled?

In the fast commit, the tail block always contain a CRC.
 
> If one of those features is *required* before the FAST_COMMIT feature
> can be used, then this patch looks OK.  Otherwise, the CSUM feature
> should be checked before the FUA is skipped for non-tail blocks.

So, I think it is OK without checking other CSUM feature.

Thanks,
Daejun

  parent reply	other threads:[~2021-01-08  2:38 UTC|newest]

Thread overview: 6+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <CGME20210106013242epcms2p5b6b4ed8ca86f29456fdf56aa580e74b4@epcms2p5>
2021-01-06  1:32 ` [PATCH] ext4: Remove expensive flush on fast commit Daejun Park
2021-01-06 21:58   ` harshad shirwadkar
2021-01-08  2:26     ` Andreas Dilger
     [not found]     ` <CGME20210106013242epcms2p5b6b4ed8ca86f29456fdf56aa580e74b4@epcms2p3>
2021-01-08  2:37       ` Daejun Park [this message]
2021-01-06 22:05   ` Darrick J. Wong
2021-01-14  3:44   ` Theodore Ts'o

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=20210108023707epcms2p32beb982610c9460e5fb08f927c52ad1d@epcms2p3 \
    --to=daejun7.park@samsung.com \
    --cc=adilger@dilger.ca \
    --cc=harshadshirwadkar@gmail.com \
    --cc=linux-ext4@vger.kernel.org \
    --cc=linux-kernel@vger.kernel.org \
    --cc=tytso@mit.edu \
    /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
Be sure your reply has a Subject: header at the top and a blank line before the message body. 
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.