From: Christoph Hellwig <hch@infradead.org>
To: Amir Goldstein <amir73il@gmail.com>
Cc: Chi Zhiling <chizhiling@163.com>,
Dave Chinner <david@fromorbit.com>,
djwong@kernel.org, cem@kernel.org, linux-xfs@vger.kernel.org,
linux-kernel@vger.kernel.org, Chi Zhiling <chizhiling@kylinos.cn>,
John Garry <john.g.garry@oracle.com>
Subject: Re: [PATCH] xfs: Remove i_rwsem lock in buffered read
Date: Tue, 7 Jan 2025 09:12:22 -0800 [thread overview]
Message-ID: <Z31gdpNdwHYG2xY3@infradead.org> (raw)
In-Reply-To: <CAOQ4uxgUZuMXpe3DX1dO58=RJ3LLOO1Y0XJivqzB_4A32tF9vA@mail.gmail.com>
On Tue, Jan 07, 2025 at 01:13:17PM +0100, Amir Goldstein wrote:
> The issue with atomicity of buffered I/O is the xfs has traditionally
> provided atomicity of write vs. read (a.k.a no torn writes), which is
> not required by POSIX standard (because POSIX was not written with
> threads in mind) and is not respected by any other in-tree filesystem.
That is true for original Posix, but once Posix Threads joined the game
the behavior was and still is required. See "2.9.7 Thread Interactions
with Regular File Operations" here:
https://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
Now most Linux filesystems ignored that and got away with ignoring
the requirement, but it still exists.
next prev parent reply other threads:[~2025-01-07 17:12 UTC|newest]
Thread overview: 50+ messages / expand[flat|nested] mbox.gz Atom feed top
2024-12-26 6:16 [PATCH] xfs: Remove i_rwsem lock in buffered read Chi Zhiling
2024-12-26 21:50 ` Dave Chinner
2024-12-28 7:37 ` Chi Zhiling
2024-12-28 22:17 ` Dave Chinner
2024-12-30 2:42 ` Chi Zhiling
2025-01-07 12:13 ` Amir Goldstein
2025-01-07 17:12 ` Christoph Hellwig [this message]
2025-01-08 7:43 ` Chi Zhiling
2025-01-08 11:33 ` Amir Goldstein
2025-01-08 11:45 ` Amir Goldstein
2025-01-08 12:15 ` John Garry
2025-01-09 10:07 ` Amir Goldstein
2025-01-09 12:40 ` John Garry
2025-01-09 8:37 ` Chi Zhiling
2025-01-09 10:25 ` Amir Goldstein
2025-01-09 12:10 ` Chi Zhiling
2025-01-09 12:25 ` John Garry
2025-01-08 17:35 ` Darrick J. Wong
2025-01-09 23:28 ` Dave Chinner
2025-01-10 1:31 ` Chi Zhiling
2025-01-10 17:07 ` Amir Goldstein
2025-01-12 10:05 ` Chi Zhiling
2025-01-13 2:44 ` Darrick J. Wong
2025-01-13 5:59 ` Chi Zhiling
2025-01-13 13:40 ` Brian Foster
2025-01-13 16:19 ` Darrick J. Wong
2025-01-15 5:55 ` Christoph Hellwig
2025-01-15 21:41 ` Dave Chinner
2025-01-16 4:36 ` Christoph Hellwig
2025-01-17 22:20 ` Dave Chinner
2025-01-16 14:23 ` Brian Foster
2025-01-17 13:27 ` Amir Goldstein
2025-01-17 22:19 ` Dave Chinner
2025-01-18 13:03 ` Amir Goldstein
2025-01-20 5:11 ` Dave Chinner
2025-01-22 6:08 ` Christoph Hellwig
2025-01-22 23:35 ` Dave Chinner
2025-01-17 16:12 ` Chi Zhiling
2025-01-24 7:57 ` Chi Zhiling
2025-01-27 20:49 ` Dave Chinner
2025-01-28 5:15 ` Christoph Hellwig
2025-01-28 21:23 ` David Laight
2025-01-29 0:59 ` Dave Chinner
2025-01-29 5:20 ` Christoph Hellwig
2025-02-10 1:44 ` Chi Zhiling
2025-01-14 0:09 ` Dave Chinner
2025-01-25 8:43 ` Jinliang Zheng
2025-01-25 14:14 ` Amir Goldstein
2025-06-20 14:03 ` Jinliang Zheng
-- strict thread matches above, loose matches on Subject: below --
2019-03-25 0:10 [QUESTION] Long read latencies on mixed rw buffered IO Dave Chinner
2025-06-20 13:46 ` [PATCH] xfs: Remove i_rwsem lock in buffered read Jinliang Zheng
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