From: Paul Eggert <eggert@cs.ucla.edu>
To: Zygo Blaxell <ce3g8jdj@umail.furryterror.org>,
Tom Yan <tom.ty89@gmail.com>
Cc: 48833@debbugs.gnu.org, linux-btrfs@vger.kernel.org
Subject: Re: bug#48833: reflink copying does not check/set No_COW attribute and fail
Date: Sun, 6 Jun 2021 22:47:05 -0700 [thread overview]
Message-ID: <4354c814-9f9f-0c26-fb11-36567da6f530@cs.ucla.edu> (raw)
In-Reply-To: <20210606054242.GI11733@hungrycats.org>
On 6/5/21 10:42 PM, Zygo Blaxell wrote:
> If cp -a implements the inode attribute propagation (or inheritance), then
> only users of cp -a are impacted. They are more likely to be aware that
> they may be creating new files with reduced-integrity storage attributes.
True, although I think this aspect of attribute-copying will typically
come as a surprise even to "cp -a" users.
> If the file is empty, you can chattr +C or -C. If the file is not
> empty, chattr fails with an error.
Although coreutils 'cp -a' currently truncates any already-existing
output file (by opening it with O_TRUNC), it then calls copy_file_range
before calling fsetxattr on the destination. Presumably cp should do the
equivalent of chattr +C before doing the copy_file_range stuff. (Perhaps
you've already mentioned this point; if so, my apologies for the
duplication.)
next prev parent reply other threads:[~2021-06-07 5:53 UTC|newest]
Thread overview: 9+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-06-04 14:33 reflink copying does not check/set No_COW attribute and fail Tom Yan
2021-06-04 14:37 ` Tom Yan
2021-06-04 20:16 ` Zygo Blaxell
2021-06-05 5:56 ` Tom Yan
2021-06-05 10:35 ` Forza
2021-06-06 5:42 ` Zygo Blaxell
2021-06-07 5:47 ` Paul Eggert [this message]
2021-06-08 2:41 ` bug#48833: " Zygo Blaxell
2021-06-27 10:56 ` A L
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=4354c814-9f9f-0c26-fb11-36567da6f530@cs.ucla.edu \
--to=eggert@cs.ucla.edu \
--cc=48833@debbugs.gnu.org \
--cc=ce3g8jdj@umail.furryterror.org \
--cc=linux-btrfs@vger.kernel.org \
--cc=tom.ty89@gmail.com \
/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.