From: Tejun Heo <tj@kernel.org>
To: Ian Kent <raven@themaw.net>
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
Minchan Kim <minchan@kernel.org>,
Eric Sandeen <sandeen@sandeen.net>,
Al Viro <viro@zeniv.linux.org.uk>,
Rick Lindsley <ricklind@linux.vnet.ibm.com>,
David Howells <dhowells@redhat.com>,
Miklos Szeredi <miklos@szeredi.hu>,
Carlos Maiolino <cmaiolino@redhat.com>,
linux-fsdevel <linux-fsdevel@vger.kernel.org>,
Kernel Mailing List <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH 1/2] kernfs: dont take i_lock on inode attr read
Date: Mon, 31 Oct 2022 12:30:58 -1000 [thread overview]
Message-ID: <Y2BMonmS0SdOn5yh@slm.duckdns.org> (raw)
In-Reply-To: <166606036215.13363.1288735296954908554.stgit@donald.themaw.net>
On Tue, Oct 18, 2022 at 10:32:42AM +0800, Ian Kent wrote:
> The kernfs write lock is held when the kernfs node inode attributes
> are updated. Therefore, when either kernfs_iop_getattr() or
> kernfs_iop_permission() are called the kernfs node inode attributes
> won't change.
>
> Consequently concurrent kernfs_refresh_inode() calls always copy the
> same values from the kernfs node.
>
> So there's no need to take the inode i_lock to get consistent values
> for generic_fillattr() and generic_permission(), the kernfs read lock
> is sufficient.
>
> Signed-off-by: Ian Kent <raven@themaw.net>
Acked-by: Tejun Heo <tj@kernel.org>
Thanks.
--
tejun
next prev parent reply other threads:[~2022-10-31 22:31 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2022-10-18 2:32 [PATCH 0/2] kernfs: remove i_lock usage that isn't needed Ian Kent
2022-10-18 2:32 ` [PATCH 1/2] kernfs: dont take i_lock on inode attr read Ian Kent
2022-10-24 8:50 ` Miklos Szeredi
2022-10-31 22:30 ` Tejun Heo [this message]
2022-12-21 13:34 ` Anders Roxell
2022-12-22 23:11 ` Ian Kent
2022-12-29 9:20 ` Arnd Bergmann
2022-12-29 13:07 ` Ian Kent
2023-01-23 3:11 ` Ian Kent
2023-07-18 19:00 ` Anders Roxell
2023-07-19 4:23 ` Ian Kent
2023-07-20 2:03 ` Ian Kent
2023-07-26 13:49 ` Miklos Szeredi
2023-07-27 0:38 ` Ian Kent
2023-07-27 4:30 ` Imran Khan
2023-07-27 5:35 ` Imran Khan
2023-07-28 0:00 ` Ian Kent
2023-07-28 0:16 ` Ian Kent
2023-07-28 1:06 ` Imran Khan
2023-07-28 1:29 ` Ian Kent
2022-10-18 2:32 ` [PATCH 2/2] kernfs: dont take i_lock on revalidate Ian Kent
2022-10-24 8:38 ` Miklos Szeredi
2022-10-31 22:31 ` Tejun Heo
2022-11-01 7:46 ` Amir Goldstein
2022-11-01 8:09 ` Ian Kent
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