From: Christoph Hellwig <hch@lst.de>
To: Ira Weiny <ira.weiny@intel.com>
Cc: Christoph Hellwig <hch@lst.de>, 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: Fri, 3 Apr 2020 09:27:31 +0200 [thread overview]
Message-ID: <20200403072731.GA24176@lst.de> (raw)
In-Reply-To: <20200402205518.GF3952565@iweiny-DESK2.sc.intel.com>
On Thu, Apr 02, 2020 at 01:55:19PM -0700, Ira Weiny wrote:
> > 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.
I really, really dislike that idea. The whole point of not forcing
evictions is to make it clear - no this inode is "busy" you can't
do that. A reasonably smart application can try to evict itself.
But returning an error and doing a lazy change anyway is straight from
the playbook for arcane and confusing API designs.
next prev parent reply other threads:[~2020-04-03 7:27 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
2020-04-03 7:27 ` Christoph Hellwig [this message]
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
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