From: Ira Weiny <ira.weiny@intel.com>
To: Christoph Hellwig <hch@lst.de>
Cc: Jan Kara <jack@suse.cz>,
"Darrick J. Wong" <darrick.wong@oracle.com>,
Dave Chinner <david@fromorbit.com>,
"Theodore Y. Ts'o" <tytso@mit.edu>,
Dan Williams <dan.j.williams@intel.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Alexander Viro <viro@zeniv.linux.org.uk>,
linux-ext4 <linux-ext4@vger.kernel.org>,
linux-xfs <linux-xfs@vger.kernel.org>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Andrew Morton <akpm@linux-foundation.org>,
Linus Torvalds <torvalds@linux-foundation.org>
Subject: Re: [PATCH V5 00/12] Enable per-file/per-directory DAX operations V5
Date: Thu, 2 Apr 2020 13:55:19 -0700 [thread overview]
Message-ID: <20200402205518.GF3952565@iweiny-DESK2.sc.intel.com> (raw)
In-Reply-To: <20200402085327.GA19109@lst.de>
On Thu, Apr 02, 2020 at 10:53:27AM +0200, Christoph Hellwig wrote:
> On Wed, Apr 01, 2020 at 12:25:11PM +0200, Jan Kara wrote:
> > > - Applications must call statx to discover the current S_DAX state.
> > >
> > > - There exists an advisory file inode flag FS_XFLAG_DAX that can be
> > > changed on files that have no blocks allocated to them. Changing
> > > this flag does not necessarily change the S_DAX state immediately
> > > but programs can query the S_DAX state via statx.
> >
> > I generally like the proposal but I think the fact that toggling
> > FS_XFLAG_DAX will not have immediate effect on S_DAX will cause quite some
> > confusion and ultimately bug reports. I'm thinking whether we could somehow
> > improve this... For example an ioctl that would try to make set inode flags
> > effective by evicting the inode (and returning EBUSY if the eviction is
> > impossible for some reason)?
>
> I'd just return an error for that case, don't play silly games like
> evicting the inode.
I think I agree with Christoph here. But I want to clarify. I was heading in
a direction of failing the ioctl completely. But we could have the flag change
with an appropriate error which could let the user know the change has been
delayed.
But I don't immediately see what error code is appropriate for such an
indication. Candidates I can envision:
EAGAIN
ERESTART
EUSERS
EINPROGRESS
None are perfect but I'm leaning toward EINPROGRESS.
Ira
next prev parent reply other threads:[~2020-04-02 20:55 UTC|newest]
Thread overview: 45+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-02-27 5:24 [PATCH V5 00/12] Enable per-file/per-directory DAX operations V5 ira.weiny
2020-02-27 5:24 ` [PATCH V5 01/12] fs/xfs: Remove unnecessary initialization of i_rwsem ira.weiny
2020-02-27 17:25 ` Ira Weiny
2020-02-27 5:24 ` [PATCH V5 02/12] fs: Remove unneeded IS_DAX() check ira.weiny
2020-02-27 5:24 ` [PATCH V5 03/12] fs/stat: Define DAX statx attribute ira.weiny
2020-02-27 5:24 ` [PATCH V5 04/12] fs/xfs: Isolate the physical DAX flag from enabled ira.weiny
2020-02-27 5:24 ` [PATCH V5 05/12] fs/xfs: Create function xfs_inode_enable_dax() ira.weiny
2020-03-01 22:37 ` Dave Chinner
2020-02-27 5:24 ` [PATCH V5 06/12] fs: Add locking for a dynamic address space operations state ira.weiny
2020-03-02 1:26 ` Dave Chinner
2020-03-02 1:36 ` Dave Chinner
2020-02-27 5:24 ` [PATCH V5 07/12] fs: Prevent DAX state change if file is mmap'ed ira.weiny
2020-02-27 5:24 ` [PATCH V5 08/12] fs/xfs: Hold off aops users while changing DAX state ira.weiny
2020-02-27 5:24 ` [PATCH V5 09/12] fs/xfs: Clean up locking in dax invalidate ira.weiny
2020-02-27 5:24 ` [PATCH V5 10/12] fs/xfs: Allow toggle of effective DAX flag ira.weiny
2020-02-27 5:24 ` [PATCH V5 11/12] fs/xfs: Remove xfs_diflags_to_linux() ira.weiny
2020-02-27 5:24 ` [PATCH V5 12/12] Documentation/dax: Update Usage section ira.weiny
2020-03-05 15:51 ` [PATCH V5 00/12] Enable per-file/per-directory DAX operations V5 Christoph Hellwig
2020-03-09 17:04 ` Ira Weiny
2020-03-11 3:36 ` Darrick J. Wong
2020-03-11 6:29 ` Christoph Hellwig
2020-03-11 17:07 ` Dan Williams
2020-03-16 9:52 ` Jan Kara
2020-03-16 9:55 ` Christoph Hellwig
2020-04-01 4:00 ` Darrick J. Wong
2020-04-01 10:25 ` Jan Kara
2020-04-02 8:53 ` Christoph Hellwig
2020-04-02 20:55 ` Ira Weiny [this message]
2020-04-03 7:27 ` Christoph Hellwig
2020-04-03 15:48 ` Ira Weiny
2020-04-03 17:03 ` Jan Kara
2020-04-03 18:18 ` Ira Weiny
2020-04-03 18:21 ` Ira Weiny
2020-04-03 18:37 ` Darrick J. Wong
2020-04-05 6:19 ` Ira Weiny
2020-04-06 10:00 ` Jan Kara
2020-04-03 18:29 ` Darrick J. Wong
2020-04-03 16:05 ` Darrick J. Wong
2020-04-03 4:39 ` Ira Weiny
2020-03-11 6:39 ` Dave Chinner
2020-03-11 6:44 ` Christoph Hellwig
2020-03-11 17:07 ` Dan Williams
2020-03-12 0:49 ` Dave Chinner
2020-03-12 3:00 ` Darrick J. Wong
2020-03-12 7:27 ` Christoph Hellwig
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=20200402205518.GF3952565@iweiny-DESK2.sc.intel.com \
--to=ira.weiny@intel.com \
--cc=akpm@linux-foundation.org \
--cc=dan.j.williams@intel.com \
--cc=darrick.wong@oracle.com \
--cc=david@fromorbit.com \
--cc=hch@lst.de \
--cc=jack@suse.cz \
--cc=linux-ext4@vger.kernel.org \
--cc=linux-fsdevel@vger.kernel.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-xfs@vger.kernel.org \
--cc=torvalds@linux-foundation.org \
--cc=tytso@mit.edu \
--cc=viro@zeniv.linux.org.uk \
/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.