From: Linus Torvalds <torvalds@linux-foundation.org>
To: Eric Sandeen <sandeen@redhat.com>
Cc: Miklos Szeredi <mszeredi@redhat.com>,
Ira Weiny <ira.weiny@intel.com>,
David Howells <dhowells@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
linux-man <linux-man@vger.kernel.org>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
xfs <linux-xfs@vger.kernel.org>,
Ext4 Developers List <linux-ext4@vger.kernel.org>,
Xiaoli Feng <xifeng@redhat.com>
Subject: Re: [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to filesystems
Date: Tue, 1 Dec 2020 12:04:56 -0800 [thread overview]
Message-ID: <CAHk-=wgOu9vgUfOSsjO3hHHxGDn4BKhitC_8XCfgmGKiiSm_ag@mail.gmail.com> (raw)
In-Reply-To: <05a0f4fd-7f62-8fbc-378d-886ccd5b3f11@redhat.com>
On Tue, Dec 1, 2020 at 8:59 AM Eric Sandeen <sandeen@redhat.com> wrote:
>
> It's a bit odd to set STATX_ATTR_DAX into the statx attributes in the VFS;
> while the VFS can detect the current DAX state, it is the filesystem which
> actually sets S_DAX on the inode, and the filesystem is the place that
> knows whether DAX is something that the "filesystem actually supports" [1]
> so that the statx attributes_mask can be properly set.
>
> So, move STATX_ATTR_DAX attribute setting to the individual dax-capable
> filesystems, and update the attributes_mask there as well.
I'm not really understanding the logic behind this.
The whole IS_DAX(inode) thing exists in various places outside the
low-level filesystem, why shouldn't stat() do this?
If IS_DAX() is incorrect, then we have much bigger problems than some
stat results. We have core functions like generic_file_read_iter() etc
all making actual behavioral judgements on IS_DAX().
And if IS_DAX() is correct, then why shouldn't this just be done in
generic code? Why move it to every individual filesystem?
Linus
next prev parent reply other threads:[~2020-12-01 20:05 UTC|newest]
Thread overview: 27+ messages / expand[flat|nested] mbox.gz Atom feed top
2020-12-01 16:54 [PATCH 0/2] statx: Fix DAX attribute collision and handling Eric Sandeen
2020-12-01 16:57 ` [PATCH 1/2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT Eric Sandeen
2020-12-01 17:32 ` Darrick J. Wong
2020-12-01 17:44 ` Eric Sandeen
2020-12-01 18:31 ` Andreas Dilger
2020-12-01 18:36 ` Eric Sandeen
2020-12-02 2:16 ` Ira Weiny
2020-12-02 20:42 ` Linus Torvalds
2020-12-03 2:45 ` Ira Weiny
2020-12-03 18:04 ` Linus Torvalds
2020-12-01 16:59 ` [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to filesystems Eric Sandeen
2020-12-01 17:39 ` Darrick J. Wong
2020-12-01 17:53 ` Eric Sandeen
2020-12-01 20:52 ` Dave Chinner
2020-12-01 22:03 ` Eric Sandeen
2020-12-01 22:12 ` Linus Torvalds
2020-12-01 22:26 ` Eric Sandeen
2020-12-02 2:29 ` Ira Weiny
2020-12-02 8:03 ` Christoph Hellwig
2020-12-01 20:04 ` Linus Torvalds [this message]
2020-12-01 20:50 ` Eric Sandeen
2020-12-01 21:04 ` David Howells
2020-12-01 22:09 ` Linus Torvalds
2020-12-02 0:11 ` Eric Sandeen
2020-12-01 17:18 ` [PATCH 1/2] uapi: fix statx attribute value overlap for DAX & MOUNT_ROOT David Howells
2020-12-01 17:20 ` [PATCH 2/2] statx: move STATX_ATTR_DAX attribute handling to filesystems David Howells
2020-12-01 17:28 ` David Howells
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