From: Roman Mamedov <rm@romanrm.net>
To: Alexander Tomokhov <alexoundos@ya.ru>
Cc: "linux-btrfs@vger.kernel.org" <linux-btrfs@vger.kernel.org>
Subject: Re: Does data checksumming remain for files with No_COW file attribute?
Date: Sat, 24 Sep 2016 17:40:12 +0500 [thread overview]
Message-ID: <20160924174012.51d44caa@natsu> (raw)
In-Reply-To: <767591474719974@web21o.yandex.ru>
[-- Attachment #1: Type: text/plain, Size: 586 bytes --]
On Sat, 24 Sep 2016 15:26:14 +0300
Alexander Tomokhov <alexoundos@ya.ru> wrote:
> does setting No_COW on a file (chattr +C) imply disabling data checksumming on it?
Yes. IIRC the reasoning was that it's more difficult to track checksums of
data which is being overwritten in-place (as opposed to CoW).
> may it disable checksumming only for newly written extents and keep for reading existing ones?
You can't apply chattr +C to any files of non-zero length, so by definition
there won't be any pre-existing checksummed extents in that file.
--
With respect,
Roman
[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 181 bytes --]
next prev parent reply other threads:[~2016-09-24 12:40 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-09-24 12:26 Does data checksumming remain for files with No_COW file attribute? Alexander Tomokhov
2016-09-24 12:37 ` Hugo Mills
2016-09-24 23:25 ` Alexander Tomokhov
2016-09-24 23:50 ` Adam Borowski
2016-09-25 5:44 ` Duncan
2016-09-26 20:41 ` Adam Borowski
2016-09-24 12:40 ` Roman Mamedov [this message]
2016-09-24 12:43 ` Hugo Mills
2016-09-24 18:11 ` Christoph Anton Mitterer
2016-09-25 13:49 ` Goffredo Baroncelli
2016-09-25 19:53 ` Christoph Anton Mitterer
2016-09-26 11:11 ` Austin S. Hemmelgarn
2016-09-24 18:09 ` Christoph Anton Mitterer
2016-09-24 21:44 ` Adam Borowski
2016-09-24 22:52 ` Christoph Anton Mitterer
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=20160924174012.51d44caa@natsu \
--to=rm@romanrm.net \
--cc=alexoundos@ya.ru \
--cc=linux-btrfs@vger.kernel.org \
/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.