From: Mark Fasheh <mfasheh@suse.de>
To: linux-fsdevel@vger.kernel.org
Cc: linux-btrfs@vger.kernel.org, linux-xfs@vger.kernel.org
Subject: [PATCH 0/2] vfs: better dedupe permission check
Date: Fri, 11 May 2018 12:26:49 -0700 [thread overview]
Message-ID: <20180511192651.21324-1-mfasheh@suse.de> (raw)
Hi,
The following patches fix a couple of issues with the permission
check we do in vfs_dedupe_file_range().
The first patch expands our check to allow dedupe of a readonly file
if the user owns it. Existing behavior is that we'll allow dedupe only
if:
- the user is an admin (root)
- the user has the file open for write
This makes it impossible for a user to dedupe their own file set
unless they do it as root, or ensure that all files have write
permission. There's a couple of duperemove bugs open for this:
https://github.com/markfasheh/duperemove/issues/129
https://github.com/markfasheh/duperemove/issues/86
The solution is simple - we allow dedupe of the target if the user
owns it. With that patch, a user can dedupe all of their files.
The 2nd patch fixes our return code for permission denied to be
EPERM. For some reason we're returning EINVAL - I think that's
probably my fault. At any rate, we need to be returning something
descriptive of the actual problem, otherwise callers see EINVAL and
can't really make a valid determination of what's gone wrong.
This has also popped up in duperemove, mostly in the form of cryptic
error messages. Because this is a code returned to userspace, I did
check the other users of extent-same that I could find. Both 'bees'
and 'rust-btrfs' do the same as duperemove and simply report the error
(as they should).
The patches are also available in git:
git pull https://github.com/markfasheh/linux dedupe-perms
Thanks,
--Mark
next reply other threads:[~2018-05-11 19:27 UTC|newest]
Thread overview: 17+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-05-11 19:26 Mark Fasheh [this message]
2018-05-11 19:26 ` [PATCH 1/2] vfs: allow dedupe of user owned read-only files Mark Fasheh
2018-05-11 23:58 ` Darrick J. Wong
2018-05-12 2:49 ` Adam Borowski
2018-05-13 18:16 ` Mark Fasheh
2018-05-13 20:50 ` Adam Borowski
2018-05-17 23:01 ` Mark Fasheh
2018-05-11 19:26 ` [PATCH 2/2] vfs: dedupe should return EPERM if permission is not granted Mark Fasheh
2018-05-12 0:06 ` Darrick J. Wong
2018-05-12 4:15 ` Amir Goldstein
2018-05-12 4:37 ` Duncan
2018-05-13 14:30 ` Adam Borowski
2018-05-13 18:21 ` Mark Fasheh
2018-05-13 18:26 ` Darrick J. Wong
2018-05-17 5:15 ` Zygo Blaxell
2018-05-17 23:03 ` Mark Fasheh
2018-05-14 14:58 ` David Sterba
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=20180511192651.21324-1-mfasheh@suse.de \
--to=mfasheh@suse.de \
--cc=linux-btrfs@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-xfs@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 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).