From: Dave Chinner <david@fromorbit.com>
To: Wang Shilong <wangshilong1991@gmail.com>
Cc: linux-ext4@vger.kernel.org, linux-fs@vger.kernel.org,
linux-xfs@vger.kernel.org, Wang Shilong <wshilong@ddn.com>,
Andreas Dilger <adilger@dilger.ca>, Li Xi <lixi@ddn.com>
Subject: Re: [RFC PATCH] ext4: add link file support for {GET,SET}XATTR ioctl
Date: Thu, 31 Jan 2019 14:41:06 +1100 [thread overview]
Message-ID: <20190131034106.GJ4205@dastard> (raw)
In-Reply-To: <1548899232-30311-1-git-send-email-wshilong1991@gmail.com>
On Thu, Jan 31, 2019 at 10:47:12AM +0900, Wang Shilong wrote:
> From: Wang Shilong <wshilong@ddn.com>
>
> Currently there is no way to change project ID of
> symlink file itself, this is important to implement
> Directory quota for an existed directory.
This seems like something open(O_PATH|O_NOFOLLOW) should allow.
from open(2):
If pathname is a symbolic link and the O_NOFOLLOW flag is
also specified, then the call returns a file descriptor
referring to the symbolic link. This file descriptor
can be used as the dirfd argument in calls to fchownat(2),
fstatat(2), linkat(2), and read¿ linkat(2) with an empty
pathname to have the calls operate on the symbolic link.
Changing the project id is the equivalent of fchownat().....
Cheers,
Dave.
--
Dave Chinner
david@fromorbit.com
next prev parent reply other threads:[~2019-01-31 3:41 UTC|newest]
Thread overview: 6+ messages / expand[flat|nested] mbox.gz Atom feed top
2019-01-31 1:47 [RFC PATCH] ext4: add link file support for {GET,SET}XATTR ioctl Wang Shilong
2019-01-31 3:41 ` Dave Chinner [this message]
2019-01-31 17:40 ` Darrick J. Wong
2019-01-31 20:43 ` Dave Chinner
2019-02-14 8:14 ` 答复: " Wang Shilong
2019-02-14 15:54 ` Darrick J. Wong
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